Subclavian artery injury caused by a screw in a clavicular compression plate

A 22-year-old man presented with left-arm ischaemia, 22 months after placement of a clavicular compression plate for a fractured left clavicle. Digital subtraction angiography revealed a distal subclavian artery injury which, during surgery, was found to be caused by a screw in the compression plate. Ligation of the subclavian artery followed by carotid-axillary bypass resulted in a symptom-free left arm.     

Colonic ischemia reveals thromboangiitis obliterans (Buerger's disease)

Two years before the appearance of distal peripheral manifestations of thromboangiitis obliterans (Buerger's disease), a young man had acute peritonitis attributable to an ischemic perforation of the sigmoid colon. Only the histological examination of excised tissue was able to differentially diagnose this entity unambiguously.     

Myocardial infarction following electric shock

A 17 year old man presented with a five-month history of swelling of the distal phalanx and a small ulcer on the pulp of the right fifth finger. Despite biopsy the diagnosis was missed until more than six months after onset, when the lesion was excised and histological examination showed a dermal leiomyosarcoma.     

Effect upon longitudinal growth of femur by intramedullary nailing in rats

In an experimental study using rats it was found that intramedullary nailing through the distal femoral growth plate resulted in a significant retardation of longitudinal growth. Drilling only and pin removal after 7 weeks also gave significant inhibition of growth after 14 weeks, while drilling only with immediate removal of the pin gave no growth disturbance during the first 7 weeks. The investigation indicates that damage to the central portion of the epiphyseal growth plate in rats leads to inhibition of longitudinal growth.     

Determinants of spatial polarity in the growth plate

Growth of long bones occurs at the growth plate, a layer of cartilage that separates the epiphysis from the metaphysis. Growth plate exhibits spatial polarity. Proliferative chondrocytes undergo terminal differentiation when they approach the metaphyseal, but not the epiphyseal, border of the growth plate. The adjacent bone also exhibits spatial polarity. Metaphyseal, but not epiphyseal, blood vessels and bone cells invade the adjacent growth plate, remodeling it into bone. As a result, the metaphysis, but not the epiphysis, elongates over time. To determine whether cartilage polarity determines bone polarity and/or whether bone polarity determines cartilage polarity, rabbit distal ulnar growth plates were excised, inverted, and reimplanted in their original beds. Thus, cartilage polarity was inverted relative to bone polarity. Histological examination showed that the inverted cartilage polarity was maintained over time. In contrast, the polarity of the adjacent bone reversed after surgery, to match that of the cartilage. Blood vessel and bone cell invasion ceased in the metaphysis and arose in the epiphysis. Longitudinal bone growth (measured with weekly radiographs) occurred at the epiphyseal, not at the metaphyseal, surface of the growth plate. We conclude that the polarity of growth plate cartilage is determined by intrinsic factors. The cartilage polarity then determines the polarity of the adjacent bone and, consequently, the functional polarity of longitudinal bone growth.     

Rotational displacement of the lower tibial epiphysis due to trauma

A rare form of injury to the distal tibial growth plate is described. Only two patients with such an injury have been reported previously. The injury, rotational displacement of the distal tibial epiphysis with posterior displacement of the fibula but without fracture, can be reduced easily and appears to have no lasting ill-effects.     

Biliary stricture due to mucosal hyperplasia of the common bile duct: a case report

A 71-year-old man with a tumorous lesion of the common bile duct is presented. Although histological examination of tumor biopsy specimens taken at the time of duodenoscopy or percutaneous transhepatic choledochoscopy showed mucosal hyperplasia, cancer could not be ruled out; therefore, the patient underwent pancreatoduodenectomy. However, histology showed nodular mucosal hyperplasia and an ectopic pancreas adjacent to the papilla of Vater, which was suspected to have contributed to the development of the lesion by stimulating the mucosa of the papilla and the distal common bile duct.     

Immunohistochemical localization of transforming growth factor-alpha and epidermal growth factor-receptor in the mesonephros and metanephros of the chicken

Transforming growth factor-alpha (TGF-alpha) is a polypeptide related to epidermal growth factor (EGF). Both bind to EGF-receptor (EGF-R) to carry out their function in a variety of tissues and cell lines. Several studies have shown their presence in mammalian kidney, however, nothing has to date been stated concerning their existence in avian kidney. Expression of TGF-alpha and EGF-R is reported here for the first time during the development of the chicken kidney. Using immunohistochemical techniques, we identified a TGF-alpha (but not EGF) in mesonephric distal tubule cells from day 8 to day 20 of embryonic development and in metanephric distal tubule cells from day 14 of embryonic development to the adult. The histochemical characteristics of these cells and their histological localization suggest that they may be the "principal cells" of the distal tubules. Similarly, EGF-R was found in mesonephric proximal tubule cells from day 7 to day 18 of embryonic development and in metanephric proximal tubule cells from day 13 of embryonic development up to adult stages. The coexistence of both TGF-alpha and EGF-R from the onset of development of mesonephros and metanephros supports their possible role in mechanisms of proliferation and differentiation of the cells of these organs.     

A PCR-RFLP method for the detection and species identification of human microsporidia

Amputation in a growing child should be performed through a joint and not above or below a joint, as is commonly the case in an adult. We describe a technique for performing a through-knee amputation in a situation in which a soft-tissue sarcoma involved a leg, reaching up to the knee joint. Soft-tissue dissection was performed above the knee, leaving a safe zone from the tumor. The distal femur was dissected free of all attachments to the tibia and leg, leaving it intact but protruding from the soft-tissue sleeve of the thigh. To be able to close the stump over the protruding distal femur, the femur was shortened in the metaphysodiaphyseal area. Follow-up over 3 years shows a good through-knee stump, tumor free, and a normal distal growth plate.     

The internal thoracic artery of poor quality: was cardiac massage a cause of ITA stenosis?

The case of stenotic left internal thoracic artery (LITA), with a very rare and interesting histological findings is reported. The patient, a 65-year-old man, fell into shock, due to acute myocardial infarction and received cardiopulmonary resuscitation at home immediately. Three months later, patient underwent coronary artery bypass grafting. The LITA was dissected from the chest wall with a tissue pedicle by usual manner. However, it was abandoned to use for grafting, because of extremely poor blood flow even after balloon dilatation was noticed. Histological study revealed a significant granulation of LITA media, led to severe stenosis of LITA lumen on it's portion. On other side, either proximal and distal portion of LITA remained intact. It seems that this unusual histological change of LITA media developed after LITA over stretching due to cardiac massage during cardiopulmonary resuscitation. If patient, scheduled for coronary bypass surgery, has in a personal history the presence of cardiac massage, traffic accident, some contact sport or any other chest trauma, it is recommended to perform LITA angiography preoperatively, if an intention to use the LITA for coronary artery bypass grafting exists.     

In utero and lactational exposure of the male rat to 2,3,7,8-tetrachlorodibenzo-p-dioxin impairs prostate development. 2. Effects on growth and cytodifferentiation

In the male Holtzman rat, in utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure decreases prostate weight without inhibiting testicular androgen production or decreasing circulating androgen concentrations. Therefore, the present study sought to characterize effects of TCDD exposure on prostate development, from very early outgrowth from the urogenital sinus (Gestation Day [GD] 20) until rapid growth and differentiation are essentially complete (Postnatal Day [PND] 32). Pregnant Holtzman rats were administered a single dose of TCDD (1.0 microgram/kg po) or vehicle on GD 15 and offspring were exposed via placental transfer (GD 20 euthanasia) or placental and subsequent lactational transfer until euthanasia (if before PND 21) or weaning. Results show that the prostatic epithelial budding process was impaired by in utero TCDD exposure, as evidence by significant decreases in the number of buds emerging from dorsal, lateral, and ventral aspects of the GD 20 urogenital sinus. Ventral prostate cell proliferation index was significantly decreased on PND 1 but was similar to or higher than control at later times, whereas apoptosis was an extremely rare event in ventral prostates from both control and TCDD-exposed animals. Delays were noted in the differentiation of pericordal smooth muscle cells and luminal epithelial cells. In addition, ventral prostates from approximately 40% of TCDD-exposed animals examined on PNDs 21 and 32 exhibited alterations in the histological arrangement of cell types that could not be explained by a developmental delay. Compared to controls, these ventral prostates exhibited a disorganized, hyperplastic epithelium containing fewer luminal epithelial cells and an increased density or continuous layer of basal epithelial cells, as well as thicker periductal smooth muscle sheaths. In addition, in ventral prostates from TCDD-exposed animals, the intensity of androgen receptor staining was relatively low in the central and distal epithelium, and the number of androgen receptor-positive cells was relatively high in the periductal stroma. These data suggest that in utero and lactational TCDD exposure interferes with prostate development by decreasing very early epithelial growth, delaying cytodifferentiation, and, in the most severely affected animals, producing alterations in epithelial and stromal cell histological arrangement and the spatial distribution of androgen receptor expression that may be of permanent consequence.     

Characterization of deletion mutations in the carboxy-terminal peptide-binding domain of the Kar2 protein in Saccharomyces cerevisiae

Hsp70 is structurally composed of three domains, an amino-terminal ATPase domain, a proximal 18 kDa peptide-binding domain and a distal 10 kDa carboxy-terminal (C-terminal) domain. To dissect the functional significance of the distal 10 kDa domain, and the boundary region between the proximal and distal C-terminal domains of Kar2p in vivo in Saccharomyces cerevisiae, we constructed a series of plasmids which were truncated or had internal deletion mutations in this region. We found that all these mutations are recessive, and that the distal 10 kDa C-terminal domain, including the HDEL ER-retention sequence, is not essential for cell growth, although the major role of this 10 kDa C-terminal domain is due to the function of the HDEL ER-retention signal. We also found that the Kar2p region (Thr492-Thr512), corresponding to the beta 8-sheet in the peptide-binding domain, which constitutes the bottom plate of the binding pocket in E. coli DnaK, is essential for cell viability, and that the following Kar2p region (Glu513-Lys542), corresponding to alpha-helices A and B of E. coli DnaK, which was proposed to compose the lid of the binding pocket, is critical but not essential for yeast cell growth. This was further supported by the fact that the latter deletion showed a fully reversible ts phenotype in its growth and only a slight inhibitory effect on the secretion of alpha-amylase at non-permissive temperature.     

Clinical diagnostic valuation cine magnetic resonance coronary angiography

OBJECTIVES: This biomechanical cadaver study was performed to compare the fixation stability of a standard lateral condylar buttress plate with a similar condylar buttress plate with the distal screws locked to the plate. Then the study was repeated with six additional matched femoral pairs to compare the locked plate with a standard 95-degree blade plate. DESIGN: Six matched pairs of mildly osteopenic femurs were selected, and each side was assigned randomly to fixation with either a standard lateral condylar buttress plate or a modified lateral condylar buttress plate with locked distal screws. The experiment was repeated with six additional matched pairs of femurs instrumented with either a modified lateral condylar buttress plate with locked distal screws or a standard 95-degree blade plate. INTERVENTION: The femurs were instrumented, and a gap osteotomy was created at the distal femoral metaphysis. The instrumented femurs were then mechanically tested in axial compression and bending/torsional loading to determine fixation stability; then they were loaded at 1,000 newtons for 10(5) cycles and retested for stability. MAIN OUTCOME MEASUREMENT: The displacement across the osteotomy gap at 100-newton and 1,000-newton axial loads was measured directly for each specimen before and after cycling. In addition, resistance to displacement in bending/torsional loading (newtons/centimeter) was determined from load/displacement curves, before and after cycling. RESULTS: The locked buttress plate provided significantly greater fixation stability than the standard plate both before and after cycling in axial loading. The locked buttress plate also proved significantly more stable in axial loading than the blade plate both before and after cycling. CONCLUSION: A condylar buttress plate with locked screws is a valid concept for improving fixation stability.     

Physeal and periphyseal injuries of the hand. Patterns of injury and results of treatment

To the authors' knowledge, this is the largest study assembled of finger fractures in children. Distribution of fractures according to location within the hand (see Fig. 1), location within the phalanges themselves, and the percent of epiphyseal fractures as well as the age distribution of the patients are all similar to what has previously been presented in smaller studies. Previously unreported synchronous and double epiphyseal injuries were identified. For the most part, thanks to the remodeling capacity and rapid healing of children's bone, treatment is short and complications are few. Nevertheless, as in other locations, there is a limited capacity to remodel angular deformity and no capacity to remodel rotational deformity. The clinical information in our study conflicts somewhat with previously described anatomic information about the insertion of ligaments with respect to the growth plate. Bogumill and Hankin and Janda have suggested that the ligaments insert primarily on the epiphysis in the proximal phalanx, and on the epiphysis and metaphysis in the middle and distal phalanges. Taken by itself, this information would suggest that a Salter-Harris III mechanism would be relatively more common at the MP joint, and the Salter-Harris II and IV mechanism (where the proximal fragment includes bone both proximal and distal to the growth plate at the point where the ligament is attached) would be relatively more common at the more distal levels. In fact, the opposite was true. The Salter-Harris II mechanism made up an overwhelming majority of the percentage of injuries of the MP joint, whereas the Salter-Harris III mechanism predominated at the PIP joint and was relatively common at the DIP joint as well. This would seem to suggest that either the contribution of ligament insertion distal to the growth plate of the PIP and DIP joints is not functionally important or that other factors are involved in the injury mechanism at both levels and play a role in producing these injuries. Further study will be required, possibly involving experimental fracture production to help elucidate this issue. Finally, it is critical to recognize and properly treat the four major categories of injury that constitute a small percentage of the total but a large percentage of the complications. The condylar and subcondylar fractures must be identified by obtaining a true lateral film by whatever means necessary. If undisplaced, they need to be adequately immobilized, possibly including the entire arm of a small child, and if displaced, they almost always require internal fixation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Role of the Y5 neuropeptide Y receptor in feeding and obesity

Removal of a plate from the distal femur creates a risk of fracture through the screw holes. This is a particular concern when a total knee arthroplasty is present because supracondylar fracture may occur with minimal trauma. A patient who presents after prior plating of a distal femur fracture with osteoporosis, retained hardware associated with pain, and gonarthrosis severe enough to warrant total knee arthroplasty is often difficult to manage. Prophylactic intramedullary rodding is a well-accepted method of treating pathologic stress risers in the femur. An intramedullary rod can be inserted into the femur at the time of total knee arthroplasty. This method permits simultaneous plate removal and total knee arthroplasty while protecting the femur from postoperative fracture.     

MR imaging of deferoxamine-induced bone dysplasia in an 8-year-old female with thalassemia major

Bone changes in thalassemic patients receiving deferoxamine therapy for iron chelation include metaphyseal and growth plate irregularities. We present a case of an 8-year-old female with thalassemia major, who had magnetic resonance imaging after plain radiographs had shown metaphyseal changes in the distal femur. The signal characteristics of these abnormalities were consistent with hyaline cartilage; the surrounding marrow showed no evidence of iron overload.     

Effects of fibroblast growth factor-2 on longitudinal bone growth

In vivo, fibroblast growth factor-2 (FGF-2) inhibits longitudinal bone growth. Similarly, activating FGF receptor 3 mutations impair growth in achondroplasia and thanatophoric dysplasia. To investigate the underlying mechanisms, we chose a fetal rat metatarsal organ culture system that would maintain growth plate histological architecture. Addition of FGF-2 to the serum-free medium inhibited longitudinal growth. We next assessed each major component of longitudinal growth: proliferation, cellular hypertrophy, and cartilage matrix synthesis. Surprisingly, FGF-2 stimulated proliferation, as assessed by [3H]thymidine incorporation. However, autoradiographic studies demonstrated that this increased proliferation occurred only in the perichondrium, whereas decreased labeling was seen in the proliferative and epiphyseal chondrocytes. FGF-2 also caused a marked decrease in the number of hypertrophic chondrocytes. To assess cartilage matrix synthesis, we measured 35SO4 incorporation into newly synthesized glycosaminoglycans. Low concentrations (10 ng/ml) of FGF-2 stimulated cartilage matrix production, but high concentrations (1000 ng/ml) inhibited matrix production. We conclude that FGF-2 inhibits longitudinal bone growth by three mechanisms: decreased growth plate chondrocyte proliferation, decreased cellular hypertrophy, and, at high concentrations, decreased cartilage matrix production. These effects may explain the impaired growth seen in patients with achondroplasia and related skeletal dysplasias.     

Bladder substitutes, bile acids and the risk of colorectal cancer: an experimental study

There is a large body of evidence relating the causation of colon cancer to bile acids. Using an animal model, we attempted to address the question, i.e., the incidences of carcinogenesis in the colon as consequences of resection of different bowel segments, predominantly employed in the construction of various forms of intestinal bladder substitutes. 60 male Wistar rats were operated. Group 1 served as control, in group 2, 20 cm of terminal ileum was resected, and rats in group 3 underwent resection of the distal 10 cm of the ileum and 7 cm of the proximal colon. All rats were killed 6 months after surgery and the colon was removed. After examination under 40-fold magnification, in the absence of tumors, 3 biopsies were performed at predetermined positions and underwent histological processing. Even if no tumor was found it would be incorrect to conclude that these results would have an appeasing relevance. The complex and highly different fecal bile acid profiles of the rat compared to man makes it impossible in this context to draw analogies between the rat model and human colonic carcinogenesis. Furthermore, 6 months of observation in the rat might be too short for 'spontaneous' colonic carcinogenesis. Nevertheless, there exists evidence from epidemiological studies to implicate bile acids as an etiological factor in the development and growth of colorectal cancer. Therefore, the importance of colorectal cancer in urologic surgery patients must be kept in perspective. In this direction, further studies are required besides the application of known appropriate preventive measures.     

Significance of a false-positive trisomy 18 multiple-marker screening test

We report our results in 24 children with malignant primary bone tumours of the distal femur treated with a Stanmore extendible endoprosthesis (SEER). This consists of a femoral component that can be lengthened, a constrained knee and an uncemented sliding tibial component which crosses the proximal tibial physeal plate perpendicularly. The average age of the patients at diagnosis was ten years and the mean follow-up was 4.7 years (2.5 to 7.9). The mean growth of the affected tibia was 76% (18 to 136) and of the fibula 83% (15 to 750) of the growth of the unaffected limb. Measurement of growth arrest lines showed that the mean growth of the proximal tibial physis on the affected side was 69% (43 to 100) of that of the normal side. The great variability in the growth of the physis cannot yet be explained.     

Central motor conduction evaluation in glycogenosis type III

We report a 20-year-old man affected by glycogenosis type III with distal muscle weakness, more severe in distal leg muscles. The electromyogram showed myopathic features. Nerve conduction studies and central motor conduction after magnetic stimulation of the brain were normal. Our results suggest that there is no involvement of central motor pathways in this disease.