The freeze-fracture technique was used to study the fine structure of native collagen from rat tendon and lung. The collagen filaments were organized into a spiraled lamellar substructure within each fibril. Small particles, representing the broken ends of the collagen filaments, were found in nearly straight rows when the lamellae were broken tranversely. Filamentous connections were shown which span the interfibrillar matrix and unite all of the fibrils into a reticular network. The fibrils were coated with material that was greatly hydrated in vivo. Sublimation occurred more rapidly from some portions of the coating substance than from others, resulting in a banding pattern with a 610 A repeat distance.

Animals↗

PubMedDate not supplied

The incorporation and localization of aldehydes (highly reactive cigarette smoke components) into cellular fractions of cultured human lung cells.

WI 38 human fetal lung fibroblasts were incubated with tracer amounts of 14C-labeled formaldehyde and acetaldehyde which are highly reactive components of cigarette smoke. A pulse of 10 min with formaldehyde followed by a 60-min and 24-hr chase showed migration of 14C label into the nucleus. Fractionation of the nucleus revealed that the RNA fraction had the highest absolute and specific activity while the DNA and protein fractions contained considerably lower activities. All of the counts from formaldehyde were found in the adenine and guanine components of RNA. The DNA counts were distributed among adenine, guanine, and thymine. Incubation with 14C acetaldehyde showed a majority of the counts localized in the membrane plus nuclear lipid fraction. A small proportion of counts was found in the protein portion of the cells.

Acetaldehyde↗

PubMedDate not supplied

A program for surveillance of hospital-acquired infections in a general hospital: a two-year experience.

A program for surveillance of nosocomial infections was developed and carried out in six departments of Chaim Sheba Medical Center, Tel Hashomer, Israel. A team of nurse-epidemiologist made regular visits to the wards and the microbiology laboratory and recorded all episodes of nosocomial infections, which had been defined by a team of specialist from various hospitals and institutions in Israel. Monthly computerized reports were used to follow the pattern of hospital-acquired infections and the patterns of antibiotic sensitivity of the causative organisms. During a two-year period, 15,207 patients were admitted to the hospital and 1,851 episodes of nosocomial infection were reported-a rate of 12.2% for such infection. Postoperative wound infections were the most common infections in surgical services, accounting for between one-third and one-half of the total number of the infections among patients in these units. More than 50% of the infections in the intensive coronary care unit were located at iv sites. In the services for premature and newborn babies the most common infections were conjunctivitis and bacteriuria, the clinical significance of which is not clear. Between one-half and three-fourth of the nosocomial infections were caused by gram-negative organisms. Surgical wound infections were more common after extensive and lengthy operations. The risk of such infections usually increased with age of the patient and was higher after emergency surgery.

Age Factors↗

PubMedDate not supplied

Immunologic study of artificial skin used in the treatment of thermal injuries.

Artificial skin (Integra) has been developed as an effective treatment of full-thickness burns. The material consists of a bovine collagen and chondroitin-6-sulfate dermal matrix with a silicone rubber "epidermal" layer. After burn wound excision, the artificial skin is implanted. Only the temporary silicone rubber epidermal membrane is removed. The dermal collagen matrix is incorporated by the host. Serial serum samples were obtained from patients who had grafts of Integra artificial skin for the determination of the humoral immune response to Integra. Integra artificial skin presents few if any humoral immunologic problems to patients. Increased antibody activity to bovine skin collagen, bovine skin collagen with chondroitin sulfate, and human skin collagen was not considered immunologically significant.

Adult↗

PubMedDate not supplied

Complicated infective endocarditis: surgical treatment.

The destructive intracardiac complications of infective endocarditis present a continuing problem even though the mortality from the disease is decreasing. Osler in 1885 correctly described it as a malignant process. Tissue necrosis secondary to infection can cause destruction of valve leaflets and abscess formation in the valve annulus; the process may extend into adjacent parts of the heart and may even perforate into the pericardial cavity. For surgery to succeed it is necessary to excise all necrotic tissue, to replace the valve, and repair annular or other defects and suture the prosthesis to healthy tissue. The technical considerations in achieving a successful surgical result are illustrated and discussed in relation to a patient suffering from severe aortic valve regurgitation and a ventricular septal defect due to active infective endocarditis.

Aortic Valve↗

PubMedDate not supplied

The nature of refractile inclusions in leukocytes of synovial effusions.

Explore the source record for details and available documents.

Amyloidosis↗

PubMedDate not supplied

Aging of the population of a city and its implications for hospital-based services: the example of Tel Aviv-Yaffo.

The Tel Aviv (Israel) Medical Center serves an area with 270,000 residents, more than 20 percent of whom are over 65 years of age. This high proportion of elderly patients and increasing costs of hospitalization have prompted the center to develop alternative health care services that have made it possible for a number of aged patients to remain at home and ambulatory. Two such alternatives to hospitalization--the center's Day Care Clinic and Home Care Clinic--are described and estimates of savings in hospitalization costs are presented.

Adolescent↗