The staphylococcal scalded skin syndrome. An experimental histochemical and electron microscopic study

Histochemical and electron microscopic studies were carried out on the newborn mouse model of the staphylococcal scalded skin syndrome to investigate the mechanism of action of the staphylococcal epidermolytic toxin that causes it. Histochemical studies showed that an intra-epidermal split develops below the subcorneal zone which is rich in catabolic enzymes (the so-called esterase-acid phosphatase-rich band). However, histochemical alterations in the enzyme pattern could not be demonstrated. The earliest change revealed by electron microscopy was a widening of the intercellular space, with the formation of microvilli at the level between the stratum spinosum and stratum granulosum where the split later occurs. A clearing of the peripheral cytoplasm along the cell membranes was also revealed. In pre-split areas, adhesion between cell membranes of adjacent cells seems to be lost; desmosomes continue to hold the cells together but the split develops when these are broken by mechanical pressure. Later, damaged cell membranes may be seen. Extracellular keratinosomes remain unchanged. Although these findings do not agree with the already divergent results of other studies, they help support the findings of all groups that cases of the Lyell syndrome produced by staphylococci do not occur through necrolysis; it is therefore inappropriate to continue applying the term 'toxic epidermal necrolysis' to such cases.     

Experimental studies of mechanically-induced articular cartilage defects following implantation of allogeneic embryonal chondrocytes in a collagen-fibrin gel in chickens

Full thickness defects (diameter 1,7 mm; depth 2,5 mm) were created mechanically in articular cartilage and subchondral bone of the condyles of tibiotarsal joints of 9-month old chickens. This full-thickness defects were repaired with cultured allogenic embryonic chick epiphyseal chondrocytes from the tibiae and femura of 10-days-old chicken embryos. The cells were embedded in a collagen-fibrinogen-matrix. Controls were similarly operated, but received either no treatment or implants the delivery substance only. Healing of the defects was observed macroscopically, histologically, histochemically and histomorphometrically after 3, 12 and 24 weeks. This graft was successfully transplanted in mechanically induced defects in 80%. The resulting hyaline cartilage was structurally reorganized according to the host pattern and under the influence of environmental conditions. The articular zone preserved it's cartilaginous phenotype, whereas the subchondral regions were transformed into bone. 12 weeks after the operation the defects in the experimental group were completely filled. In all instances in this group, there was an initial extreme increase of mitotic rate and cell number. After 24 weeks normal and subnormal values were founded. The defects in the control groups healed with fibrocartilage. Our results showed, that only the defects in the experimental group were completely filled with reparative hyaline cartilage tissue. In the present study the mixture of cultured allogenic embryonic chondrocytes and a collagen-fibrinogen-matrix was used successfully as a transplant for repairing defects in articular cartilage of chickens. Thus allogenic transplantation of cultured embryonal chondrocytes appears to be one of the most promising methods for the restoration of articular cartilage.     

Protein topology of presenilin 1

Mutations in a gene encoding a multitransmembrane protein, termed presenilin 1 (PS1), are causative in the majority of early-onset cases of AD. To determine the topology of PS1, we utilized two strategies: first, we tested whether putative transmembranes are sufficient to export a protease-sensitive substrate across a lipid bilayer; and second, we examined the binding of antibodies to specific PS1 epitopes in cultured cells selectively permeabilized with the pore-forming toxin, streptolysin-O. We document that the "loop," N-terminal, and C-terminal domains of PS1 are oriented toward the cytoplasm.     

Drugs and homicide by women

In this paper we use data derived from interviews with 215 female homicide offenders incarcerated or on parole in New York to examine their drug use prior to and at the time of the homicide, their victims' drug use, and their perceptions as to the drug-relatedness of the homicides. We found that about 7 out of 10 respondents had been regular users of some drug at some point in their lives prior to their incarceration, while over half had been addicted to a substance. Over one-third of the respondents who were present at the scene were high on a drug at the time, while about half of the victims of these homicides used drugs before the homicide. Almost two-thirds of the homicides committed by respondents who were present at the scene were perceived to be drug-related. Alcohol, crack, and powdered cocaine were the drugs most likely to be related to these homicides. The implications of our findings are discussed.     

Evaluation of drug concentration in tissues after percutaneous administration of non-steroidal antirheumatics]

Forty-two cases of medulloblastoma of posterior fossa in children are presented in this paper. Of the children, 28 were males and 14 females; their age ranged from 1.5 to 12 (mean 7.3) years. The foci found were in vermis (36) and cerebellar hemispheres (6). All of these children presented symptoms and signs of obviously increased intracranial pressure, and 31(77%) of them had the signs of cerebellar functional deficits. CT scan showed severe obstructive hydrocephalus in 39 cases. 42 children with posterior fossa medulloblastoma underwent surgical resection. Three died of postoperative prespiratory and circulatory failure, 39 made good recovery and received craniospinal radiotherapy and adjunct chemotherapy. Up to now, none died. Surgical intervention and operative procedures were emphasized particularly. Radiotherapy and chemotherapy were discussed also.     

High brachial artery bifurcation: a report of 2 cases

High division of the brachial artery was observed in two cadavers, during routine dissection of upper extremities. In the first case, the brachial artery of the right upper extremity was divided into its two terminal branches immediately after passing between the lateral and medial roots of the median nerve and just below the origin of the profunda brachii artery. The lateral branch was the radial artery, located in the space normally occupied by the brachial artery and the medial one was the ulnar artery. In the second case, the brachial artery was divided into its two terminal branches just below the origin of the profunda brachii artery. Accurate knowledge of the relationships and course of these major arterial conduits and particularly of their variational patterns, is of considerable practical importance in the conduct of reperative surgery in the arm, forearm and hand.