Diet and carcinogen alter the fecal microbial populations of rats

An analysis of viable bacterial populations enumerated on carbohydrate selective media was used to simulate the colonic environment in vitro and determine if differential media could detect significant microbial shifts due to dietary fiber source, dietary fat source, and carcinogen. Male Sprague-Dawley rats were provided with either pectin or cellulose as a fiber source, either corn or fish oil as a source of fatty acids, and injected with either azoxymethane (AOM), a gastrointestinal carcinogen, or saline in a 2 x 2 x 2 factorial design. At 6 and 10 mo of age, fresh feces were collected, homogenized in anaerobic buffer and anaerobically plated onto differential media. Diets containing pectin supported more anaerobes at 6 mo of age (P < 0.01) than diets containing cellulose. Rats injected with AOM and consuming either pectin or corn oil supported more anaerobes at 10 mo of age (P < 0.05) than rats injected with saline and consuming the same diets. Rats consuming cellulose and receiving AOM but not expressing tumors possessed larger anaerobic populations at 10 mo of age (P < 0.05) than rats consuming cellulose, injected with AOM and expressing tumors. These effects show that gastrointestinal bacterial populations, as measured by carbohydrate specific media, respond to dietary changes such as dietary fiber source, and thus may play a key role in the etiology of colon cancer.     

Reduced susceptibility to collagen-induced arthritis in mice deficient in intercellular adhesion molecule-1

Intercellular adhesion molecule-1 (ICAM-1) plays an important role in the firm adhesion of leukocytes to venular endothelium and facilitates leukocyte extravasation from the vasculature into inflamed tissue. In addition, ICAM-1 is an important costimulatory molecule during Ag presentation to lymphocytes. Using mice deficient in ICAM-1, we have investigated the role of this molecule in the development of collagen-induced arthritis. After immunization with type II collagen, 71% of wild-type mice developed arthritis compared with 50% of ICAM-1 heterozygote mutants and 18% of ICAM-1 homozygous mutants. In those ICAM-1 mutants that developed arthritis, the mean day of onset, the mean number of involved paws, and the severity of paw inflammation were not significantly different from those in wild-type mice. The reduced incidence of arthritis in the ICAM-1 homozygous mutant mice was not due to lack of immunity to type II collagen, since these mice developed similar levels of anti-type II collagen IgG compared with wild-type mice and had a positive delayed-type hypersensitivity reaction to type II collagen. The reduction of arthritis in heterozygous as well as homozygous deficient mice indicates that expression of ICAM-1 can be a pivotal variable in the pathogenesis of collagen-induced arthritis in mice. The results suggest that naturally occurring genetic variation in the expression of ICAM-1 or related inflammatory cell adhesion molecules might influence susceptibility to the complex disease of rheumatoid arthritis in humans and support the concept that pharmacologic approaches to chronic reduction in the expression or the function of ICAM-1 may be of therapeutic value.     

The gastrocnemius muscle flap in the correction of severe flexion contracture of the knee

Extreme flexion contracture of the knees due to extra-articular contracture of the knee joints is a frequent deformity in catastrophic neurological lesions such as multiple sclerosis, meningomyelocoele, paraplegia, quadriplegia, and cerebral spastic paralysis. Such gross knee contractures together with the coexisting hip flexion contractures create a severe nursing problem. Adequate perineal hygiene and positioning are very difficult to achieve and thus pressure sores frequently develop in these bed-ridden patients in spite of devoted nursing care. The orthopaedic surgeon can help alleviate the plight of these unfortunate victims: first the hip joint contractures are released by the classical methods and then, at the same session, the knee contractures: a simple one stage procedure is described. Primary cover of the large popliteal skin defect is achieved by a gastrocnemius versatile muscle flap, which is itself covered by a free split skin graft. An illustrative case is described.     

Replacement of the retrohepatic vena cava in segmental liver transplantation

Reduced grafts represent an important technical development in paediatric liver transplantation. The use of a left lateral segment graft has required preservation of the native inferior vena cava to "piggy-back" the graft onto it. We report four children who underwent left lateral segment transplantation with caval replacement using the donor iliac vein because the native retrohepatic inferior vena cava was small, friable or difficult to preserve. There were no caval or hepatic vein complications post-transplant and the donor iliac vein proved to be a satisfactory interpositional graft. The technique offers the advantages of a wider retrohepatic cava avoiding venous outflow or caval obstruction, provides good tissue to suture and is well suited for the triangulation technique of the left hepatic vein.     

The impact of condom availability [correction of distribution] in Seattle schools on sexual behavior and condom use

OBJECTIVES: Ten Seattle high schools made condoms available through vending machines, baskets in school clinics, or both. This study measured the number of condoms that students obtained and subsequent changes in sexual behavior and condom use. METHODS: Schoolwide surveys were administered in spring 1993 and in spring 1995, before and during the condom availability program. These data were compared with data from nationally representative surveys administered at the same time. RESULTS: Seattle students obtained an average of 4.6 condoms per year, the vast majority from baskets and very few from vending machines. Relative to the national samples, the percentage of Seattle students who had ever had sex remained stable after the program began; current sexual activity decreased significantly; and the percentage of sexually experienced students who used a condom the last time they had sex decreased significantly, particularly in the 5 schools with baskets of condoms in clinics. CONCLUSIONS: Making condoms available in Seattle schools enabled students to obtain relatively large numbers of condoms but did not lead to increases in either sexual activity or condom use.     

Tripeptidyl-peptidase I is apparently the CLN2 protein absent in classical late-infantile neuronal ceroid lipofuscinosis

We report that fragments of amino acid sequence recently described for tripeptidyl-peptidase I (TPP I) show that it is the rat homologue of the human CLN2 gene product that is deficient in classical late-infantile neuronal ceroid lipofuscinosis. This is unexpected, since the CLN2 protein has been thought to be a carboxyl-dependent endopeptidase, but TPP I is an exopeptidase possibly of serine-type.