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Spiders are equipped with a large number of innervated cuticular specializations, which respond to various sensory stimuli. The physiological function of mechanosensory organs has been analysed in great detail in some model spider species (e.g. Cupiennius salei); however, much less is known about the distribution and function of chemosensory organs. Furthermore, our knowledge on how the sense organ pattern develops on the spider appendages is limited. Here we analyse the development of the pattern and distribution of six different external mechano- and chemosensory organs in all postembryonic stages and in adult male and female spiders of the species Parasteatoda tepidariorum. We show that except for small mechanosensory setae, external sense organs appear in fixed positions on the pedipalps and first walking legs, arranged in longitudinal rows along the proximal-distal axis or in invariable positions relative to morphological landmarks (joints, distal tarsal tip). A comparison to other Entelegynae spiders shows that these features are conserved. We hope that this study lays the foundation for future molecular analysis to address the question how this conserved pattern is generated.

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A series of 18 microsurgical toe transfers for congenitally adactylous hands was done from 1983 to 1994. The functional results achieved depended on the approach and technical features applied to hand reconstruction in congenital amputations. Function was improved significantly by using 3-jointed second toes, including the metatarsophalangeal joint, and by performing meticulous intrinsic repair. The use of donor arteries changed during the 11-year study period toward the goal of perfect revascularization with a minimized ischemic time. Abundant nerve supply was found to be important for achieving near normal growth of the transferred digit. The results showed improvement in the use of the defective extremities. The ability to pinch was restored successfully in 14 of 17 congenitally defective extremities. Growth measurements were obtained from 11 transfers at followup, which ranged from 1.5 to 6 years (mean, 4 years). Linear growth was observed at the phalangeal epiphyses, whereas the metatarsal head epiphyses showed clear disturbances in at least 2 patients.

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Eight juvenile cattle with symptoms of hyena disease are described. This represents the first occurrence of the condition in the Republic of Poland. The growth of the affected animals was retarded, with a marked difference in longitudinal growth of the femoral, humeral, tibial and metatarsal bones. The animals showed altered nickel, manganese and inorganic phosphate concentrations, which may be related to the disease. The genetic studies did not reveal any aetiological factors.

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The thickness of the physeal cartilage (growth plate) was measured and the rate of longitudinal bone growth estimated in the femur, tibiotarsus and tarsometatarsus of different groups of domestic fowl. Birds were either a laying strain or broiler strain fed ad libitum, or a broiler strain on restricted feed. They were killed at different ages from hatching to 10 weeks and the mean thickness of the physeal cartilage and the mean estimated rate of longitudinal bone growth was calculated in the proximal bone extremities. Mean physeal thickness varied from 0.185 to 0.825 mm and longitudinal growth rates between 1.85 and 8.4 mm per week. When growth rates were plotted against physeal thickness the resulting scatter diagram suggested a positive linear relationship between the two. This study provides a range of baseline values for the assessment of proximal physeal thickness in other groups of fowl.

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A group of Leghorn and a group of broiler chicks were reared from day old. At two weeks old a metallic marker was placed unilaterally in the mid-diaphysis of the femur, tibiotarsus and tarsometatarsus of every chick. After the operation the limbs were radiographed. After a period of growth the birds were killed and the radiographs repeated. Measurements from the radiographs enabled the calculation of the rate of growth at the bone extremities. There were metaphyseal defects indicative of dyschondroplasia present in some of the broiler bone extremities, these bones were considered as a separate group. When the Leghorn and normal broilers were compared there was a significant reduction in the proportion of growth in the proximal tibiotarsus of the broilers. The dyschondroplastic bone extremities in broilers demonstrated a reduction in the proportional growth rate compared with normal extremities.

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The right sciatic nerve of 50 one-month-old male rats was cut under general anaesthesia. Groups of animals were sacrificed at intervals of up to 12 weeks after operation and the length of the femora, tibiae and first and fifth metatarsals were measured with a caliper accurate to 0.05 mm. From the first week, both metatarsals were between 3% and 5% shorter on the denervated side, but there was no further increase of the discrepancy. The femora were less than 1% longer in the denervated limb at the second and eighth week. No difference was found between the lengths of the tibiae. The various factors which could possibly be responsible for these findings are discussed.

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Osteosclerosis is an osteopetrotic mutation in the mouse characterized by reduced bone resorption, numerous small osteoclasts lacking elaborate ruffled borders, and resistance to cure by bone marrow transplants from normal littermates. The failure of osteosclerotic mice to be cured by bone marrow transplants could be due to the production of bone that is not resorbable by normal osteoclasts. We tested this hypothesis using a modification of the metatarsal organ culture system of Burger et al. (1982), in which metatarsals are cultured with various tissues that act as sources of osteoclast precursors. Metatarsals from neonatal mutants were isolated, and live bone rudiments were cultured with small cubes of liver or spleen from normal littermates for 7 days. Controls included normal and mutant metatarsals cultured alone or with spleen or liver from littermates of the same or different genotype. Mutant metatarsals cultured alone or with mutant tissue had small osteoclasts, no marrow spaces, and no evidence of bone resorption. Mutant metatarsals cultured with normal liver or spleen had larger osteoclasts, evidence of resorption of bone but not cartilage, and no marrow spaces because the calcified cartilage cores of metaphyseal trabeculae persisted. Normal metatarsals cultured with normal liver had large osteoclasts, bone resorption, and marrow spaces. By transmission EM, mutant trabeculae contained a layer of amorphous material between the central core of calcified cartilage and the surrounding bone matrix. This material was not present in normal metatarsals.(ABSTRACT TRUNCATED AT 250 WORDS)

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The influence of intermittent compressive force (ICF) and of continuous compressive force (CCF) on calcification of growth plate cartilage was investigated, using organ cultures of fetal mouse cartilaginous long bone rudiments. Sixteen-day-old metatarsal rudiments, still consisting of uncalcified cartilage, were isolated and cultured for 5 days. Initial calcification of hypertrophic cartilage occurred under control conditions (atmospheric pressure), and under the influence of ICF or CCF by intermittently or continuously compressing the gas phase above the culture medium. Calcification was monitored by means of 45Ca and 32P incorporation into calcium-phosphate mineral and by morphometric methods. Both ICF and CCF increased cartilage calcification, but ICF was about twice as effective as CCF. Killed rudiments did not calcify during the culture period, nor did ICF or CCF increase the incorporation of label. The effects of ICF and CCF on calcification could not be mimicked by increasing the PO2 and PCO2 levels in the gas phase. The length of the central zone of calcified cartilage was significantly increased by ICF and CCF. We conclude that hypertrophic chondrocytes respond directly to ICF and CCF by an increased deposition of calcium-phosphate mineral in the matrix. Discontinuous mechanical stimulation evokes a higher cellular response than does continuous stimulation.

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The effects of ionizing irradiation on the differentiation and activity of the osteoclast were investigated. Embryonic mouse metatarsal bones of different ages (14, 15, 16, 17 days) in which no osteoclasts had as yet been formed were irradiated with various x-ray doses and cultured until a marrow cavity became visible in the nonirradiated paired control bones. Bone growth and calcification were followed microscopically during culture. Irradiation caused a dose-dependent stunting of the longitudinal growth. Calcification was inhibited by high radiation doses (10 to 20 Gray (Gy), whereas a dose of 2.5 Gy stimulated the process in the early stages of long bone development. Histologic examination revealed complete inhibition of osteoclast formation in the 14- and 15-day-old bones after irradiation with 2.5 Gy or more. The number of osteoclasts in cultured older bones (16 days) was significantly reduced by irradiation, but osteoclast formation could not be completely prevented even by high dosages. Irradiation of explanted bone rudiments which were in a stage 1 day prior to the appearance of osteoclasts in vivo (17 days) did not significantly influence the formation of osteoclasts. Autoradiographic experiments using young bones showed that differentiation of osteoclast precursors into multinucleated osteoclasts is preceded by one or more divisions of the precursors in the periosteum. Furthermore, it was established from continuous 3H-thymidine-labeling experiments that in older bones (16 days) a part of the osteoclast nuclei originated from postmitotic osteoclast precursors. Irradiation mainly inhibited the appearance of labeled osteoclast nuclei in these bones. The results indicate that the osteoclast precursor, already present in the periosteum at an early stage of embryonic development, first proliferates and then differentiates into a mononuclear postmitotic preosteoclast. The proliferation is probably highly radiosensitive. Subsequently, the preosteoclasts fuse into multinucleated osteoclasts and invade the calcified hypertrophic cartilage zone. The resorbing activity of the osteoclast is less radiosensitive but can be inhibited by 5.0 Gy or more, as was established by morphometric and biochemical methods.

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Unsatisfactory results of the conservative treatment of club foot deformity in 220 patients (346 feet) were analyzed. Data of roentgenograms in 86 patients enabled the authors to make a conclusion that an early cause of recurrent club foot is the delayed formation of nuclei of ossification of the navicular and I sphenoid bones, the later cause of the recurrent deformity is early synostosis of the epiphysis of the metatarsal bone. The importance of dispensary observation ad prophylactic measures after the treatment of congenital club foot is emphasized.

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Long-bone growth at the distal ends of the radial bones, the distal ends of the 3rd metacarpal bones, the distal ends of the 3rd metatarsal bones, and the proximal ends of the proximal phalangeal bones (of thoracic and pelvic limbs) was quantitatively analyzed in 9 Thoroughbred-Quarter Horse foals from birth to 2 years of age. Metal growth markers were surgically implanted in the bones of the animals at 2 to 4 days of age. Radiographs of the bones were made on the day of surgical manipulation, the next day, and then once a week for 8 months, and once a month thereafter for an additional 18 months. On each radiograph, the intervals between the growth markers were measured and plotted, and these accumulated growth data were subjected to statistical analyses. Growth curves, cumulative growth, and relative growth rates were determined. The ages of radiographic growth plate closure also were determined. Total bone growth observed in these foals was proportionately greater than that observed in a similar study of Shetland-Welsh ponies, probably indicating a breed difference. The most rapid growth rate at the 5 anatomic sites in the foals occurred from birth to 10 weeks of age; however, in the distal part of the radius, there was a continuous, though declining growth rate until 60 weeks of age, whereas in the distal ends of the 3rd metacarpal and metatarsal bones and the proximal end of the proximal phalanges growth ceased abruptly and nearly plateaued after 10 weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)

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Groups of 25-day-old mice were kept at 33 degrees, 21 degrees and 8 degrees for up to 195 days. Measurements and observations on length, width, gross and microscopic structure using radiological and histological techniques were made on central and peripheral bones. Tail bones of animals kept at 33 degrees grew longer and faster than those in the cold but also closed their epiphyses earlier. The diaphyses of "hot" vertebrae were cylindrical but "cold" and "control" vertebrae were of narrower diameter in their mid-diaphyses compared to their distal ends producing a "waisted" appearance. The "cold" vertebrae in addition showed thickened cortical bone and more woven bone in the marrow cavity. These changes were interpreted as indicating a disproportionate sensitivity of external apposition of cortical bone to cold. The internal remodelling of bone as the vertebrae grew was only affected by the coldest conditions and accounted for the thickened cortex and denser woven bone in the marrow cavity.

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An exciting new development in the field of bone physiology has been the discovery of electrical potentials in stressed bone and the relation of this knowledge to Wolff's law. The application of these discoveries for the treatment of nonunions by exogenous bioelectric potentials via direct current and pulsed electromagnetic fields has been a major development in orthopedic surgery. To date, the literature reports the use of this new treatment modality in the large long bones of the extremities. The authors have utilized these techniques to repair nonunions of the metatarsals and, in the process, have adapted some of the principles for the small bones of the foot.

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This study presents a common finding in the first metatarsal bone of a distal epiphyseal cartilage which is considered as a physis. This growth center is omitted in the classic anatomical descriptions of the bone. Analyses of the growth of this physis relates to the metatarsal formula of the adult foot. It may result in a first metatarsal "index-plus," where the first metatarsal is longer than the second, depending upon the duration of the activity of the physis. The presence of this physis may be related, in some cases, to: 1) Hallux rigidus. The conformation of index-plus anatomically predisposes the development of such degeneration. 2) Kohler's metatarsal disease. Disturbance in the arterial vascularity of the epiphyseal-metaphyseal type may, in theory, cause osteonecrosis of the first metatarsal head, although no cases have been reported in the literature. 3) Osteochondritis dissecans. Our finding that disorders of epiphyseal ossification may lead to the development of osteochondritis dissecans.

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Late effects of single whole-body doses of 400--500 and 750--900 rads on skeletal growth in 32 rhesus monkeys were studied. Findings indicated growth inhibition strongly related to dose and age at irradiation. Doses of 750--900 rads before the age of 40 months resulted in significantly greater growth inhibition (11%) than doses given during or shortly after adolescence (p less than 0.005). Doses of less than 750 rads were not significant. In view of the close similarity between monkeys and man, irradiation of children at doses greater than 750 rads may carry a strong risk of subsequent growth retardation.

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