RESUMEN

Light microscopy has limited value in predicting where the primary site of a metastatic adenocarcinoma might be located. In our series, electron microscopy was useful in determining the primary site in approximately 85% of patients with a metastatic adenocarcinoma of unknown origin. This study is based on the ultrastructural examination of more than 100 such cases. In the remaining 15% of the cases, electron microscopy usually provided assistance in reducing the differential diagnosis to a minimum, usually to two possible primary sites. The majority of the metastatic adenocarcinomas showed rather specific ultrastructural features to suggest the site of origin. This application of electron microscopy has never been fully explored and has considerable clinical importance and economic impact in health care systems. An extensive work-up to determine the primary site, with its inconvenience to patient and family, as well as delay in adequate treatment, can be avoided with early diagnosis of the primary site.

Asunto(s)

RESUMEN

We have reported a rare, well documented case of poststreptococcal glomerulonephritis followed by rapidly progressive glomerulonephritis after weeks of stable renal function. The patient was successfully treated with steroids, azathioprine, and plasmapheresis. Progression of stable proliferative poststreptococcal glomerulonephritis to rapidly progressive glomerulonephritis appears to be uncommon.

Asunto(s)

RESUMEN

The effects of pulmonary artery infusion of delta-9-tetrahydrocannabinol (delta 9-THC), 0.5 mg/kg, have been studied in four pregnant sheep. Cardiac output (CO) decreased from a baseline of 4.49 +/- 0.91 l/min (mean +/- s.e.m.) to 4.19 +/- 0.87 at 3 min, 3.69 +/- 0.76 at 5 min, and 3.35 +/- 0.77 at 15 min post infusion and returned to baseline by 1 h post infusion. Maternal blood pressure (MBP) decreased from 114 +/- 9 to a nadir of 69 +/- 8 mmHg at 15 min post infusion. Uterine artery blood flow (UTABF) increased from 256 +/- 88 to 317 +/- 132 ml/min at 3 min post infusion, but this was not statistically significant. Maternal acidosis, hypercapnia, and hypoxemia also developed during the first 15 min post infusion. Although fetal blood pressure (FBP) decreased throughout the 1st h post infusion, statistically significant changes in FBP or fetal heart rate (FHR) were not observed. Umbilical artery blood flow (UMABF) increased from 188 +/- 58 to 211 +/- 68 1/min at 5 min post infusion and declined thereafter. This change was also statistically significant. As in the ewe the fetus developed acidosis and hypoxemia, but hypercapnia, although present, was not statistically significant. A single animal was studied following i.v. infusion of delta 9-THC (1 mg/kg). More pronounced effects, including a decrease in UTABF and UMABF, were noted. The sheep were maintained under pentobarbital anesthesia for the duration of the study.

Asunto(s)

RESUMEN

A retrospective study was conducted to evaluate ultrastructural aspects of hormone production by renal cell carcinomas. Fifteen renal cell carcinomas examined ultrastructurally were retrieved from the files. Six cases revealing abundant and diffusely distributed secretory granules in the neoplastic cells were found and correlated with clinical manifestations and laboratory findings. Five of these patients were hypercalcemic; the sixth patient was asymptomatic, and no abnormalities were detected in routine laboratory workup. Two additional cases showed focal aggregates of electron dense neurosecretory granules. These last 2 patients had no biochemical abnormalities and were entirely asymptomatic. The size and ultrastructural morphology of the cytoplasmic granules identified in the renal neoplasms were compared with the usual granular morphology associated with the specific hormones involved. Immunohistochemistry was used to confirm the parathormone hormone content of the granules in 7 of the 8 cases presented. The other case revealed granules with ultrastructural characteristics of prostaglandin granules.

Asunto(s)

RESUMEN

Vibratory angioedema is a rare form of physical angioedema. A Mexican-American boy presented with vibration-related prolonged angioedema of the hands at age 16. After the use of a controlled vibratory stimulus, 10 volunteers and seven members of the family (three generations) developed expected transient erythema and whealing reaction of the skin at the site of contact. However, with the same vibrating stimulus the patient developed large erythematous swelling that lasted for 12 hr. Vibratory challenge study revealed a rapid rise and fall in plasma histamine. No increase in levels of plasma histamine were detected from the nonstimulated arm. Prausnitz-Küstner testing was negative. Light and electron microscopic study of the mast cell revealed degranulation and extensive fragmentation of the granules from the stimulated site. No degranulation was seen in the contralateral unstimulated site. A state of tolerance to vibration was induced by graded increased exposure to vibratory stimulus and the patient's clinical problem was eliminated.

Asunto(s)

RESUMEN

The clinical and pathological features of three siblings from nonconsanguineous parents are described. Two of the children died at 6 1/2 and 7 months of age of a central nervous system disorder characterized by severe behavioral retardation, hypotonia, and pyramidal tract signs. The third child, now 8 years old, has global mental retardation, inability to talk, marked tremors, and gait disturbances. All children exhibited inability to concentrate or acidify the urine, with growth delay partially corrected in the living child by alkali therapy. Computed tomographic scans revealed hyperdense lesions in the thalamus of one of the siblings and more striking hyperdensity of the basal ganglia in the eldest child. Findings at postmortem examination in two children, and by renal and sural nerve biopsy in the third, include swollen axons in the internal capsule and peripheral nerves, and neurons with iron-staining deposits, gliosis, and macrophages containing lipofuscin pigments in the brain. The renal findings include material positive for periodic acid-Schiff and hyperdense granular deposits in renal tubules.

Asunto(s)

RESUMEN

The authors noted an unusual finding in the fallopian tubes of a 31-year-old woman who had received external and internal whole pelvis radiotherapy for squamous cell carcinoma of the cervix. Aggregates of macrophages containing pigment, identified in a subepithelial location, were reminiscent of melanosis coli, which is caused by abuse of anthracene-containing laxatives. Electron microscopic examination of the pigment revealed cytoplasmic material with the appearance of lipofuscin, identical to the pigment described in cases of colonic melanosis. After a careful study of possible etiologic agents, it was concluded that the pigment most likely resulted from cellular damage caused by radiotherapy. The authors are not aware of any other reported case of this entity, which will be called pigmentosis tubae.

Asunto(s)

RESUMEN

The entity known as "leiomyomatous hamartoma," a term that has been used in reference to metastatic smooth muscle neoplasms of uterine origin (MSMNUO), is uncommon. Several articles have dealt with clinical and light microscopic aspects of this lesion. Four reports on the ultrastructure of this type of neoplasm have been published, but they have been primarily concerned with its smooth muscle component. Much controversy exists as to whether the glandular elements are part of the neoplastic process or preexisting pulmonary elements. This ultrastructural study confirms that the gland-like spaces represent entrapped alveoli and terminal respiratory bronchioles.

Asunto(s)

Asunto(s)

RESUMEN

Nonossifying fibromas appear to be histiocytic lesions. On the basis of light and electron microscopic studies, as well as behavior, they are identical to benign fibrohistiocytomas found in soft tissues. The fibroblastic appearance of some of these lesions by light and electron microscopy, especially in older lesions, reflects the ability of histiocytes to behave as facultative fibroblasts. Final data of the cell of origin for these lesions must await more definitive studies by other methods, perhaps using immunologic, immunoperoxidase and/or surface markers techniques.

Asunto(s)

RESUMEN

Two soft tissue neoplasms considered to represent malignant fibrous histiocytomas by light microscopy showed typical findings indicative of Schwann cell origin when examined by electron microscopy. These findings included the presence of cells exhibiting long interdigitating cytoplasmic processes, which frequently contained collections of microtubules and were surrounded by thin, frequently interrupted, basal lamina material. In addition, pinocytotic activity at the cell surfaces and immature junctions joining apposing cellular membranes were identified. No evidence of fibroblastic, fibrohistiocytic, or myofibroblastic differentiation was identified ultrastructurally in the neoplastic cells. Our findings stress the need for ultrastructural examination to adequately classify soft tissue sarcomas. The 2 cases presented illustrate that there are some schwannomas that may be inaccurately classified as malignant fibrous histiocytomas if only light microscopy is used. It seems that only by ultrastructural means is it possible to accurately classify these peculiar neoplasms.

Asunto(s)

RESUMEN

A case of intraoral condyloma acuminatum with clinical, light microscopic, and ultrastructural features is presented. The presence of intranuclear virus particles is demonstrated by electron microscopy. To the best of our knowledge, the presence of viruses has not previously been reported in the oral lessions of this disease.

Asunto(s)

RESUMEN

Two hundred forty previously healthy military personnel with nonstreptococcal upper respiratory infections were prospectively studied to define the incidence and clinicopathologic characteristics of possible virus-associated glomerulonephritis. Nine patients without preceding streptococcal infection had erythrocyte casts on urinalysis and glomerulonephritis on biopsy. Of these nine, four had a reduction in total hemolytic complement and five had serologic evidence of infection with adenovirus, influenza A, or influenza B. Initial renal biopsy showed either focal or diffuse mesangial proliferation in all nine, with mesangial C3 deposits in six specimens. Repeat biopsy in three showed histologic improvement or loss of immunofluorescent staining, or both. Sequential creatinine clearances were reduced to 74 to 90 mL/min.1.73 m2 in five patients for the duration of follow-up. We conclude that nonstreptococcal upper respiratory infection is frequently associated with glomerulonephritis and that abnormal glomerular structure and decreased creatinine clearances may persist for at least 2 to 8 months.

Asunto(s)

RESUMEN

Marked uptake of 99mTc-diphosphonate was noted in an extraadrenal neuroblastoma. Calcification was not demonstrable on radiographic or light microscopic examination, nor was crystalline material identified on electron microscopic examination; capillaries in the lesion appeared to be intact. Similar uptake of phosphate radiopharmaceuticals by a variety of lesions has been reported, and possible mechanisms for this phenomenon are discussed.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

The cell wall of the freshwater diatom Navicula pelliculosa (Bréb.) Hilse is composed of the silica shell and an organic skin which surrounds it. Isolated skins can be prepared by first removing the contents of the cell by mechanical shaking, followed by a posttreatment of these isolated cell walls with HF vapor to remove the silica shell. T h e skins can also be seen in sections, particularly well after the silica shell has been removed B y H. F; vapor. The origin and morphological composition of the shin in N. pelliculosa are not yet completely ascertaincd. As parts of the cell wn11, both the silica shell and the skin are extracellularly located. The growth of the silica shell, however, occurs intracellularly inside a vesicle delimited by a triple-layered membrane, the silicalemma. This membrane or secondary excreted organic material or both in various proportions may compose the skin.