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BACKGROUND: Boxer elbow and handball goalkeeper elbow are causes of impingement characterized by osteophytes formation at the olecranon and coronoid tip as well as their corresponding fossae. Herein, we present another distinct pathology in these patients: the formation of an exostosis at the posterolateral aspect of the elbow. METHODS: Between April 2016 and May 2020, 12 athletes with boxer elbow and handball goalkeeper elbow (mean age of 22 years) suffering from elbow pain were enrolled in the present study. Plain radiography, magnetic resonance imaging (MRI), and computer tomography (CT) scans were used to evaluate the bone conformation of the posterolateral aspect of the elbow. Assessment and staging of the ossification was performed by two independent fellowship-trained elbow surgeons. RESULTS: Bone marrow edema of the posterior aspect of the elbow at the origin of the anconeus muscle was initially detected in MRI scans. With the progression of the condition, imaging revealed an ossification posterior to the capitellum with bony bridges. In the advanced stage of the disease, the exostoses was unstable as the ossification had no adherence to the posterior capitellum during surgical excision. Plain radiographs are limited in their ability to detect the condition, whereas MRI and CT scans allow to identify a signal enhancement at the posterolateral aspect of the elbow. CONCLUSION: In patients without history of elbow trauma, bony irregularities of the posterior aspect of the capitellum may indicate ossification of the posterolateral aspect of the elbow, most likely caused by repetitive hyperextensions.
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Articulación del Codo , Artropatías , Humanos , Adulto Joven , Adulto , Osteogénesis , Codo , Articulación del Codo/diagnóstico por imagen , Articulación del Codo/cirugía , RadiografíaRESUMEN
OBJECTIVE: Neutralizing a posteromedial rotatory instability (PMRI) caused by coronoid deficiency by restoration of the humeroulnar joint surface with an autologous iliac crest bone graft. INDICATIONS: Surgery is indicated in patients with chronic deficiency of the anteromedial facet of the coronoid with subsequent PMRI. CONTRAINDICATIONS: Coronoid reconstruction is not recommended in patients with advanced osteoarthritis of the elbow caused by subluxation of the humeroulnar joint. General contraindications like acute infection, pregnancy and lack of operability should also be taken into account. SURGICAL TECHNIQUE: First, a medial approach is established and the base of the coronoid is prepared. Afterwards an autologous iliac crest bone graft is placed onto the defect and secured by screws or a plate. In addition, a reconstruction of the anterior bundle of the medial collateral ligament with an autologous tendon graft is performed. POSTOPERATIVE MANAGEMENT: An elbow orthesis is worn for 6 weeks after surgery to avoid valgus or varus stress. There is no restriction in range of motion. A continuous passive motion elbow chair supports the patient in regaining elbow mobility. RESULTS: Between 2015 and 2017, we treated 10 patients suffering from chronic coronoid defects with coronoid reconstruction. Eight of the patients were available for follow-up 86 weeks after surgery. The mean age was 41.4 years. In all patients, elbow range of motion and patient-related outcome measures were improved after surgery. Plain radiographs illustrated correct centering of the elbow joint. One patient had to undergo elbow arthroplasty and was excluded. Coronoid reconstruction with an autologous iliac crest bone graft restored humeroulnar joint congruency and improved satisfaction in patients suffering from chronic coronoid deficiency.
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Articulación del Codo , Inestabilidad de la Articulación , Humanos , Adulto , Articulación del Codo/diagnóstico por imagen , Articulación del Codo/cirugía , Ilion , Inestabilidad de la Articulación/cirugía , Resultado del TratamientoRESUMEN
BACKGROUND: The Mayo Elbow Performance Score (MEPS) is a rating system consisting of four dimensions to evaluate elbow performance. It is a common tool for assessment of elbow impairments worldwide. We determined the validity and reliability of its German version (MEPS-G) after cross-cultural adaptation. METHODS: Six investigators examined 57 patients with elbow pathologies. The MEPS-G was compared to validated elbow scores such as the German versions of DASH, the Oxford Elbow Score, pain level and subjective elbow performance on a VAS. Inter-rater reliability (IRR) and validity of the score and its dimensions were also reviewed. Verification was performed using the intraclass correlation coefficient (ICC), the prevalence and bias with adjusted Kappa (PABAK) and the Spearman correlation. RESULTS: The IRR of the MEPS-G score was moderate (ICC (2.1) = 0.65). The IRR of the four individual dimensions was moderate to high (KPABAK = 0.55 -0.81). Validity for the sum score (r = 0.52-0.65) and the dimensions pain (r = 0.53-0.62), range of motion (r = 0.7) and stability (r = - 0.61) was verified. The function subscale reached insufficient validity (r = 0.15-0.39). CONCLUSION: The MEPS-G is not sufficiently valid, which is consistent with its English version. The patient-based dimensions were a weakness, demonstrating high risk of bias. There is no general recommendation for the utilization of the MEPS-G as outcome measurement for patients with elbow pathologies.
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Comparación Transcultural , Codo , Humanos , Dolor , Reproducibilidad de los Resultados , Encuestas y CuestionariosAsunto(s)
Lesiones de Codo , Articulación del Codo , Luxaciones Articulares , Inestabilidad de la Articulación , Codo , Articulación del Codo/cirugía , Traumatismos del Antebrazo/diagnóstico , Humanos , Luxaciones Articulares/diagnóstico , Luxaciones Articulares/cirugía , Inestabilidad de la Articulación/diagnóstico , Inestabilidad de la Articulación/cirugía , Rango del Movimiento ArticularRESUMEN
BACKGROUND AND OBJECTIVE: Posttraumatic or postoperative movement restrictions in elbow joints can often occur (including capsular contracture) and can generate everyday limitations. In persistent elbow stiffness, arthroscopic arthrolysis with removal of the dorsal and ventral capsule portions can be carried out. The purpose of this study was to assess the efficacy of arthroscopic capsulectomy by means of an in vitro anatomical study. METHODS: A standardized elbow arthroscopy with ventral and dorsal capsulectomy was performed and image-documented in five fresh-frozen elbow specimens. Subsequently, open dissection of the elbow joint was performed to analyze the amount of residual capsule by means of photodocumentation of the specimens. RESULTS: Regardless of the surgeon and surgical experience, anterior and posterior remnants of the capsule remained in all specimens. Dorsal capsule strands around the standard arthroscopy portals were noticed particularly more often in the area of the high dorsolateral camera portal. An incomplete capsulectomy was seen on the ulnar side at the level of the posterior medial ligament (PML) in the immediate vicinity of the ulnar nerve. Ventrally, a capsulectomy was performed from the radial side and also the ulnar side until the brachialis muscle and additionally a complete capsulectomy as far as the anterior medial ligament (AML) and radial collateral ligament (RCL) was achieved. The capsule was completely resected in a proximal direction. Distally, irrelevant capsular remnants were found in the region of the annular ligament and distal of the tip of the coronoid process. CONCLUSION: Arthroscopic arthrolysis can be performed with a high degree of radicality. The radicality must be self-critically taken into account in one's own action. The radicality of the portal change may even be higher ventrally than with an isolated column procedure. On the other hand, it must be critically considered that posteriorly, the PML cannot be adequately addressed by means of arthroscopy due to the risk of ulnar nerve injury. Portal changes might help to enable a more complete visualization of the joint capsule and may avoid leaving possibly relevant remnants of the capsule. If a release of the PML is required, this may have to be carried out in combination with an ulnar nerve release in a mini-open technique.
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Artroscopía , Articulación del Codo , Ligamentos , Músculo Esquelético , Nervio CubitalRESUMEN
BACKGROUND: Arthroscopic and open debridement arthroplasty for elbow arthrosis produce excellent results. Resection of the tip of the olecranon and coronoid, as well as debridement of the associated fossae, is frequently described as sufficient for restoring range of motion and reducing pain. OBJECTIVES: The purpose of this study was to demonstrate that medial and lateral osteophytes of the olecranon and the coronoid usually mark the first bony contact and may, therefore, restrict range of motion. MATERIAL AND METHODS: 11 fresh-frozen elbows were dissected. The fossae were coated with Optosil P Plus (C-silicone), and maximal flexion and extension was simulated. The distribution of Csilicone impressions was documented. 6/7 donors were male. The mean age at the time of death was 82 . RESULTS: Out of 11 elbows, 4 exhibited arthritic changes. All arthritic elbows showed marginal osteophytes of the olecranon without characteristic dipping of the olecranon into its fossa. In 1/4 cases, additional osteophytes at the side of the coronoid were detected (in comparison to 1/7 in healthy elbows). CONCLUSION: The distribution of osteophytes in elbow arthrosis may be underestimated. Many clinicians describe a resection of the tip of the olecranon and the coronoid and debridement of the related fossa as sufficient. Our study supports the theory that marginal osteophytes, especially of the olecranon, should be resected during debridement arthroplasty, since the distribution of bony contact differs in arthritic and healthy elbows.
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Articulación del Codo , Osteoartritis , Artroplastia , Cadáver , Humanos , Masculino , Rango del Movimiento ArticularRESUMEN
BACKGROUND: An inadequate clinical outcome after conservatively treated radial head fractures is not uncommon. We analyzed the subjective limitations, objective complaints, and surgical procedures for radial head fractures initially treated conservatively. PATIENTS AND METHOD: Between 2007 and 2016, 70 patients (42 men, 28 women) who suffered from fracture sequelae after conservatively treated radial head fractures were examined. Demographic (age, 41.8 years, range, 16-75 years) and clinical data (pain, range of motion, instability) were retrospectively evaluated. RESULTS: The average time to surgery after trauma was 50 months (range, 5-360 months). In 38 cases, radial head fractures were initially treated with immobilization for 3.4 weeks (range, 1-8 weeks). Physiotherapeutic treatment was performed in 39 cases. In only half of the cases was retrospective Mason classification possible: 20 type I, 8 type II, 5 type III, and 2 type IV. Of the 70 patients, 53 had posttraumatic elbow stiffness; 34 had isolated lateral and four patients isolated medial ligament instability. There were eight cases with a combination of lateral and medial ligament instability and 27 cases of elbow stiffness combined with instability. An average of 1.2 (range, 1-4) surgical procedures per patient were performed. In all, 64 patients underwent elbow arthroscopy with arthrolysis and additional treatment depending on other injuries. The range of motion improved on average from preoperative flexion/extension of 131-15-0° to postoperative flexion/extension of 135-5-0° (gain in flexion: 4.2° and extension: 10.6°). CONCLUSION: Conservative treatment of radial head fractures does not always yield good results. Reasons for a poor outcome include chronic instability, cartilage damage, stiffness, or a combination thereof. Improved outcomes can be achieved via arthroscopic arthrolysis.
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BACKGROUND: Radiocapitellar arthritis or defects most often result from trauma. Most of the patients are young and have high functional demands with high load capacities. Therefore, endoprosthetic options should be postponed for as long as possible. If conservative treatment cannot relieve symptoms sufficiently, radial head preservation, resection or replacement options are at the surgeon's disposal. In early stages of radiocapitellar arthritis, radial head preservation options can be taken into account. The chances ofgood results decrease with increasing cartilage damage. TREATMENT OPTIONS: In addition to radial head preservation options this article discusses radial head resection with and without anconeus interposition and radial head as well as radiocapitellar replacement. Clinical data are rare. The advantages and disadvantages of each option must be discussed with the patient and the decision should be made individually on the basis of patient specific factors. The aim must be to postpone endoprosthetic options - especially total elbow arthroplasty - for as long as possible, while assuring a functional range of motion with an acceptable pain level.
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Artroplastia de Reemplazo de Codo/métodos , Artroplastia/métodos , Cartílago Articular/lesiones , Articulación del Codo/cirugía , Músculo Esquelético/cirugía , Osteoartritis/cirugía , Radio (Anatomía)/cirugía , Artroscopía , Cartílago Articular/diagnóstico por imagen , Cartílago Articular/cirugía , Articulación del Codo/diagnóstico por imagen , Cuerpos Libres Articulares/diagnóstico por imagen , Cuerpos Libres Articulares/cirugía , Osteoartritis/diagnóstico por imagen , Osteofito/diagnóstico por imagen , Osteofito/cirugía , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Diseño de Prótesis , Falla de Prótesis , Radio (Anatomía)/diagnóstico por imagen , Fracturas del Radio/diagnóstico por imagen , Fracturas del Radio/cirugía , Rango del Movimiento Articular/fisiología , Reoperación , Tomografía Computarizada por Rayos X , Lesiones de CodoRESUMEN
BACKGROUND: In the young patient, treatment of post-traumatic elbow arthritis remains difficult. Total elbow arthroplasty must be delayed for as long as possible. Therapy starts with nonoperative treatment. If this fails, operative options can be discussed. TREATMENT AIM: The aim of surgery is to provide a functional range of motion with acceptable pain without obstructing future treatment options. THERAPY: Patients with pain at terminal extension and/or flexion may benefit from arthroscopic or open debridement. Patients with advanced osteoarthritis and pain throughout the complete range of motion, who are too young for total elbow arthroplasty, are offered interposition arthroplasty or arthrodesis. Arthrodesis of the elbow leads to significant restrictions in daily life due to the complete loss of extension/flexion. Therefore, arthrodesis is only offered as treatment in exceptional circumstances. Interposition arthroplasty is a reasonable option for the young patient without significant bony defects, which may provide a stable, functional flexion arc with an acceptable pain level. Interposition arthroplasty preserves the revision options of re-interposition arthroplasty as well as the withdrawal to total elbow arthroplasty. Partial and total elbow arthroplasty are treatment options of elbow arthritis but are not subjects of this article.
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Artritis/diagnóstico , Artritis/terapia , Artrodesis/métodos , Desbridamiento/métodos , Lesiones de Codo , Fracturas Óseas/terapia , Inestabilidad de la Articulación/terapia , Artritis/complicaciones , Artroplastia de Reemplazo de Codo , Terapia Combinada/métodos , Articulación del Codo/cirugía , Medicina Basada en la Evidencia , Fracturas Óseas/diagnóstico , Humanos , Inmovilización/métodos , Inestabilidad de la Articulación/diagnóstico , Inestabilidad de la Articulación/etiología , Resultado del TratamientoRESUMEN
BACKGROUND: Mason I fractures of the radial head are judged to be simple injuries that can generally be treated nonoperatively. According to the current literature mainly good and excellent results can be expected. We present a case series of patients presenting to us due to complications of Mason I fractures. PATIENTS AND METHODS: We reviewed all cases of patients that were treated because of complaints following Mason I radial head fractures. In all, 16 patients (10 men and 6 women) were identified. Mean age was 37 years (range 16-59 years). Mean time between trauma and surgery was 25 months (range 1-108 months). RESULTS: Ten patients developed painful osteoarthritis with elbow stiffness and loose bodies, 4 patients suffered a posterolateral rotatory instability that had to be treated with ligament reconstruction, 1 patient presented with a combined medial and lateral instability, and 1 patient with a symptomatic hypertophic plica posterolateralis. Diagnotics and therapeutic concepts of these complications will be presented. CONCLUSION: In light of the complications, Mason I fractures must be reevaluated. They remain the domain of conservative treatment but close follow-up is recommended to recognize possible complications early in order to prevent stiffness, chronic instabilities, and osteoarthritis.
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Lesiones de Codo , Articulación del Codo/cirugía , Osteoartritis/etiología , Osteoartritis/terapia , Fracturas del Radio/diagnóstico , Fracturas del Radio/terapia , Terapia Combinada , Femenino , Humanos , Inmovilización/métodos , Masculino , Osteoartritis/diagnóstico , Modalidades de Fisioterapia , Fracturas del Radio/complicaciones , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
OBJECTIVE: Re-establishment of radial stability within the elbow joint in cases of arthroscopically or clinically confirmed posterolateral rotatory instability. INDICATIONS: Posttraumatic or chronic degenerative posterolateral rotatory instability at least grade I-II according to O'Driscoll. CONTRAINDICATIONS: Elbow stiffness or elbow arthritis and lateral epicondylitis, if a posterolateral rotatory instability has been excluded as the reason for the symptoms. SURGICAL TECHNIQUE: Reconstruction or augmentation of the insufficient lateral ulnar collateral ligament (LUCL) with an autologous triceps tendon graft. A stripe of the triceps tendon is fixed at the epicondylus humeri radialis and at the base of the annular ligament at the proximal radial ulna with tenodesis screws or buttons, then the extensor origins, which were detached before are fixated as well. POSTOPERATIVE MANAGEMENT: Postoperative treatment with an elbow orthesis for 6 weeks, in the first 4 weeks limitation of complete extension and flexion, full weight bearing after 3 months. RESULTS: Retrospective analysis of 47 LUCL reconstructions from 2008-2010 with good results concerning pain reduction and acceptance, improvement of the Mayo Elbow Performance Score from 49 to 82, low complication rate with one elbow stiffness, one temporary ulnar nerve lesion, and one recurrent instability.
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Tornillos Óseos , Articulación del Codo/cirugía , Inestabilidad de la Articulación/cirugía , Ligamentos Articulares/cirugía , Procedimientos de Cirugía Plástica/instrumentación , Procedimientos de Cirugía Plástica/métodos , Tendones/trasplante , Adulto , Anciano , Articulación del Codo/diagnóstico por imagen , Femenino , Humanos , Inestabilidad de la Articulación/diagnóstico , Ligamentos Articulares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Radiografía , Rango del Movimiento Articular , Procedimientos de Cirugía Plástica/rehabilitación , Rotación , Tendones/diagnóstico por imagen , Resultado del TratamientoRESUMEN
INTRODUCTION: The chronic lateral epicondylitis (EHR) as a common pathology of the elbow is often associated with posterolateral rotatory instability of the elbow (PLRI). After evaluation of intra-articular pathology by prior diagnostic arthroscopy, we aimed to build patient groups regarding the stability of the elbow joint. In patients with a stable elbow joint, open surgery with a debridement to the origin of the common extensor tendon and transosseous refixation was performed. Patients with relevant posterolateral rotatory instability, however, underwent an additional LUCL complex stabilisation using triceps tendon graft besides debridement as mentioned above. The purpose of this study was to evaluate and compare the clinical functional outcome between these groups. MATERIAL AND METHODS: 101 patients were included in our study. Arthroscopies were first performed on all patients to identify intra-articular pathological changes. In 26 patients with stable elbows, open surgery with debridement to the origin of the common extensor tendon and transosseous refixation was performed. For the other 75 patients who were found presenting a relevant posterolateral rotatory instability, a stabilisation of the LUCL in addition to the open procedure mentioned above was performed. Examinations and questionnaires were used for retrospective evaluation at follow-up. RESULTS: Both groups of patients revealed significant improvement in pain relief and elbow function. We observed no significant difference between the two methods concerning clinical and functional outcome. CONCLUSION: We recommend diagnostic arthroscopy with assessment of stability prior to the open performance to offer a more reliable evidence for surgical technique selection and therefore to achieve a better clinical outcome.
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Artroscopía/estadística & datos numéricos , Desbridamiento/estadística & datos numéricos , Satisfacción del Paciente/estadística & datos numéricos , Procedimientos de Cirugía Plástica/estadística & datos numéricos , Transferencia Tendinosa/estadística & datos numéricos , Codo de Tenista/epidemiología , Codo de Tenista/cirugía , Adulto , Anciano , Terapia Combinada/estadística & datos numéricos , Femenino , Alemania/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Recuperación de la Función , Estudios Retrospectivos , Factores de Riesgo , Codo de Tenista/diagnóstico , Resultado del Tratamiento , Adulto JovenRESUMEN
INTRODUCTION: Acute elbow instability usually develops after injuries involving the bony or ligamentous stabilizers of the joint. It occurs frequently after dislocation and/or fracture-dislocation, but isolated valgus or varus overloading can also lead to ligament ruptures with subsequent instability. Chronic instability can result from incompletely healed acute injuries or from recurring microtrauma, for example after repetitive strain from participating in certain sports. CONCLUSION: Stable conditions of the joint are essential for early functional post-traumatic or postoperative treatment of the elbow, as permanent mobility deficits may result otherwise. The following article gives an overview of the current understanding of these injuries and concepts in treatment.
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OBJECTIVE: To review investigations on the early detection of HIV infection in infants to determine adherence to traditional methods of study design and analysis for evaluating new laboratory tests. DATA SOURCES: A National Library of Medicine (MEDLINE) search was conducted to identify such investigations through 1993. Cited references in identified manuscripts were also considered. The search was restricted to investigations of human subjects and those published in the English language. STUDY SELECTION: Final inclusion criteria included (1) report of the age and human immunodeficiency virus (HIV) infection status of the subjects at the time of the diagnostic testing, and (2) presentation of data allowing confirmation of presented analyses and additional analyses. DATA EXTRACTION: Criteria for judging the investigations included (1) whether the criteria used to determine the positive and negative test results were defined; (2) whether the necessary sample size for the study was calculated; (3) whether the patients studied were representative of the patients to whom the test would be applied; (4) whether a gold standard evaluation was performed; (5) whether the outcomes included in the analyses were independent; (6) whether the test characteristics were properly analyzed; and, (7) whether confidence intervals were presented. DATA SYNTHESIS: An informative presentation of a diagnostic test should include as a minimum the seven criteria listed above. Only 21 of 36 (58%) of the studies incorporated at least three of the criteria. CONCLUSIONS: There is a wide variation in the manner in which investigations of diagnostic tests are conducted and the results reported. Increased awareness and use of standard study designs and analyses will allow the application of metanalyses. Such analyses will help guide the direction taken for finding and establishing early diagnostic procedures for HIV infection at birth or during infancy.
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Serodiagnóstico del SIDA/métodos , Serodiagnóstico del SIDA/normas , Infecciones por VIH/diagnóstico , Proyectos de Investigación/normas , Factores de Edad , Sesgo , Intervalos de Confianza , Infecciones por VIH/clasificación , Infecciones por VIH/inmunología , Humanos , Lactante , Recién Nacido , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Brodifacoum is a readily available, second-generation anticoagulant rodenticide (superwarfarin) that causes extended depletion of vitamin K1-dependent clotting factors. Brodifacoum ingestions are being reported with increasing frequency. For the first time, we compare plasma brodifacoum concentration to prothrombin levels over time in a case of brodifacoum poisoning. Brodifacoum was eliminated according to a two-compartment model, with an initial half-life of 0.75 days and a terminal half-life of 24.2 days. On admission, the brodifacoum level was 731 micrograms/L and the patient suffered severe urinary tract hemorrhage, requiring transfusion of blood products. Persistently increased prothrombin times necessitated treatment with phytonadione up to 80 mg/d for 4 months, until the brodifacoum level reached 10 micrograms/L. These data may help project the duration of phytonadione treatment required in future cases of brodifacoum poisoning. Superwarfarin exposure must be suspected in an otherwise unexplained vitamin K1-deficient coagulopathy.
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4-Hidroxicumarinas/envenenamiento , Rodenticidas/envenenamiento , 4-Hidroxicumarinas/sangre , 4-Hidroxicumarinas/farmacocinética , Adulto , Transfusión Sanguínea , Semivida , Humanos , Masculino , Intoxicación/terapia , Tiempo de Protrombina , Rodenticidas/sangre , Rodenticidas/farmacocinética , Vitamina K 1/uso terapéuticoRESUMEN
We investigated the use of diethyldithiocarbamate (DTC, or Imuthiolr, Merieux Institute) as a therapeutic agent in patients with Acquired Immune Deficiency Syndrome (AIDS) and AIDS-Related Complex (ARC). Patients were prospectively stratified and randomized to receive DTC 200 mg/m2 intravenously weekly for 16 weeks or no therapy, followed by crossover to the opposite arm for an equal period. Forty-four patients were entered and forty were evaluable. There was a statistically significant decrease in symptoms in the DTC treated patients compared to the controls (p = .002). There was a significant improvement in lymphadenopathy in the treated patients compared to the controls (p = .005). One patient showed disappearance of splenomegaly, one clearing of antifungal agent-resistant perianal moniliasis, and one clearing of hairy leukoplakia. No significant differences in progression were noted. No changes were seen in any of the immunological parameters measured. There was no significant toxicity. Because of the changes in symptoms and in lymphadenopathy, we suggest that further study of DTC, both alone and in combination with other agents, may be indicated.
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Complejo Relacionado con el SIDA/tratamiento farmacológico , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Ditiocarba/uso terapéutico , Distribución de Chi-Cuadrado , Ensayos Clínicos como Asunto , Ditiocarba/administración & dosificación , Ditiocarba/efectos adversos , Humanos , Inyecciones Intravenosas , Tablas de Vida , Proyectos Piloto , Distribución Aleatoria , Tasa de SupervivenciaRESUMEN
We tested the hypothesis that beta-adrenergic receptor stimulation is involved with the increase in regional cerebral blood flow (rCBF) during hypoglycemia. Rats were surgically prepared with the use of halothane-nitrous oxide anesthesia. A plaster restraining cast was placed around the hindquarters, and anesthesia was discontinued. Hypoglycemia was produced by an intravenous injection of insulin (15 U/kg); normoglycemic control rats were given saline. Propranolol (1.5 mg/kg) was administered to some control and some hypoglycemic rats to block the beta-adrenergic receptors. Regional CBF was measured using 4-[N-methyl-14C]iodoantipyrine. Plasma glucose in the normoglycemic and hypoglycemic groups was approximately 6 and 1.4 mumol/ml, respectively. Regional CBF increased during hypoglycemia in rats that were not treated with propranolol. The increase varied from approximately 60 to 200% depending on the brain region. During hypoglycemia, propranolol abolished the increase in rCBF in the hypothalamus, cerebellum, and pyramidal tract. In other regions the increase in rCBF was only 33-65% of the increase in hypoglycemic rats that were not treated with propranolol. We conclude that beta-receptor stimulation plays a major role in the increase in rCBF during hypoglycemia.
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Circulación Cerebrovascular , Hipoglucemia/fisiopatología , Receptores Adrenérgicos beta/fisiología , Animales , Antipirina/metabolismo , Glucemia/análisis , Cerebelo/irrigación sanguínea , Hipotálamo/irrigación sanguínea , Insulina/farmacología , Masculino , Propranolol/farmacología , Tractos Piramidales/irrigación sanguínea , RatasRESUMEN
The effects of hypoglycemia on regional cerebral blood flow (rCBF) were studied in awake restrained rats. The rats were divided into three groups consisting of a normoglycemic control group that received only saline, a hypoglycemic group A, which was given insulin 30 min before flow was measured, and a hypoglycemic group B, which was given insulin 90 and 30 min before flow was measured. Regional CBF was measured using 14C-iodoantipyrine. Mean plasma glucose was 8.76 mumol/ml in the control group, 2.63 mumol/ml in hypoglycemic group A, and 1.51 mumol/ml in hypoglycemic group B. Plasma epinephrine and norepinephrine concentrations increased to approximately 375% and 160%, respectively, of control values in hypoglycemic groups A and B. In the hypoglycemic group A, rCBF significantly increased in three brain regions. In the hypoglycemic group B, rCBF increased significantly in all brain regions measured, with the exception of the neural lobe, in which it decreased. The increase in rCBF ranged from 38% in the hypothalamus to 138% in the thalamus. Neural lobe blood flow significantly decreased by 31%. The neural lobe was the only brain region studied that is not protected by a blood-brain barrier. It may be sensitive to changes in the concentration of vasoactive agents in blood, such as epinephrine and norepinephrine.
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Circulación Cerebrovascular , Hipoglucemia/fisiopatología , Neurohipófisis/irrigación sanguínea , Animales , Presión Sanguínea , Barrera Hematoencefálica , Dióxido de Carbono/sangre , Insulina/farmacología , Masculino , Ratas , Flujo Sanguíneo RegionalRESUMEN
Release of surfactant from pulmonary type II epithelial cells was stimulated by the beta-adrenergic agonist terbutaline and the diterpene forskolin. Cytosolic cyclic adenosine monophosphate (cAMP) concentrations increased significantly following exposure to terbutaline or forskolin and reached maximal levels within 5 min after treatment. Terbutaline and forskolin had a synergistic effect on cytosolic cAMP levels when added simultaneously. cAMP-dependent protein kinase activity was identified in cytosolic preparations of type II pneumocytes by phosphorylation of the peptide substrate Kemptide (Leu-Arg-Arg-Ala-Ser-Leu-Gly) and binding of 3H-cAMP to the regulatory components of cAMP-dependent protein kinase. Type I and type II regulatory subunits of the cANP-dependent kinase were present in approximately equal concentrations in type II cell cytosol. Activation ratio of cAMP-dependent protein kinase in cultured type II cells increased significantly in the presence of terbutaline, forskolin, or terbutaline plus forskolin. Activation ratios increased from 0.45 +/- 0.03 for control cells to 0.96 +/- 0.06 for cells exposed to terbutaline (10 microM) plus forskolin (5 microM) for 20 min. Release of 3H-phosphatidylcholine was also stimulated by terbutaline and forskolin. Effects of terbutaline and forskolin on surfactant release were approximately additive. Our results demonstrated increased cytosolic cAMP levels, increased cAMP-dependent protein kinase activation ratios, and subsequent augmented surfactant release from isolated type II pneumocytes in response to terbutaline and forskolin. These data support a role for activation of cAMP-dependent protein kinase as a mediator of surfactant release and document the utility of forskolin for study of cAMP-mediated effects in isolated type II cells.
Asunto(s)
Pulmón/citología , Proteínas Quinasas/metabolismo , Surfactantes Pulmonares/metabolismo , Animales , Colforsina/farmacología , AMP Cíclico/biosíntesis , Dimetilsulfóxido/farmacología , Activación Enzimática , Pulmón/enzimología , Oligopéptidos/metabolismo , Ratas , Ratas Endogámicas , Terbutalina/farmacología , Factores de TiempoRESUMEN
Muscarinic cholinergic receptors were identified and partially characterized in crude membrane fractions of rat lung and trachea from day 17 of gestation to adulthood using (-)-[3H]quinuclidinyl benzilate (QNB). (-)-[3H]QNB binding to rat lung membrane was characteristic of muscarinic cholinergic receptor sites. Binding capacity of muscarinic receptors sites was relatively low in rat lung compared to that in other tissues. The number of (-)-[3H]QNB-binding sites (binding capacity) decreased progressively and significantly from 79 +/- 8 fmol X mg-1 protein on days 17-18 of gestation to 21 +/- 3 fmol X mg-1 mean +/- SEM on days 21-22 of gestation, p less than 0.01. Binding capacity did not vary thereafter from birth to adulthood. Affinity of (-)-[3H]QNB binding for lung membranes did not change with age (KD approximately 70 pM). (-)-[3H] QNB-binding sites were significantly higher in membrane preparations of trachea or tracheal-bronchial tissue than in lung parenchyma from both the adult and newborn rats. (-)-[3H]QNB binding was undetectable in crude membrane preparations of cultured purified type II epithelial cells isolated from the adult rat lung. Muscarinic cholinergic receptor sites are present in rat lung as early as day 17 of gestation. Since preparations of proximal portions of the lung are relatively enriched in (-)-[3H]QNB binding compared to more peripheral portions of the lung, ontogenic decreases in (-)-[3H]QNB binding may result from the higher contribution of tracheal-bronchial tissue compared to alveolar tissue in the preparations of early fetal lung, rather than to a specific regulation of muscarinic receptor sites.