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Biomedical subjects

J Black

Publications and source records attributed to J Black.

At least 343 records · Page 19Linked to original sources
PubMed1981

Nutritional support in an inpatient rehabilitation unit.

Twenty-four patients with protein-calorie malnutrition were treated with intensive dietary support to improve nutritional status. Sixteen patients were able to ingest a mean of 1,945kcal and 77gm protein per 24 hours. Eight patients were unable to consume sufficient protein (11 gm) and kcal (311 gm) per 24 hours; these patients were treated with enteral tube feeding. Patients supported on tube feeding increased serum albumin levels by 0.5gm/100ml and were eventually able to consume 2,170kcal and 87gm of protein per 24-hour period after tube feeding was discontinued. Treatment of patients with protein-calorie malnutrition may require a multiple-modality nutritional support system in a rehabilitation unit.

Humans↗
PubMed1981

A multicenter study of the treatment of non-union with constant direct current.

A clinical study was initiated at the University of Pennsylvania in 1970 to evaluate the use of constant direct current in treating acquired non-union. In 1977 the study was expanded to include twelve participating investigators throughout the United States. The results indicate that, given proper electrical parameters and proper cast immobilization, a rate of bone union comparable to that seen with bone-graft surgery was achieved. Experience dictated that four cathodes, each delivering twenty microamperes of constant direct current for twelve weeks, were required to heal a non-union of a long bone. Of 178 non-union in 175 patients treated with adequate electricity in the University of Pennsylvania series, 149 (83.7 per cent) achieved solid bone union. Patients with a history of osteomyelitis had a healing rate of 74.4 per cent. The presence of previously inserted metallic fixation devices did not affect the end-result healing rate. Of eighty non-unions in seventy-nine patients treated with electricity in the participating investigators' series, fifty-eight (72.5 per cent) achieved solid bone union. Review of the non-unions treated unsuccessfully with constant direct current suggested that inadequate electricity, the presence of synovial pseudarthrosis or infection, and dislodgment of the electrodes are causes for failure with the procedure. Complications of the electrical treatment were minor and there was no deep infection resulting from this procedure in patients without previous osteomyelitis. We concluded that the practicing orthopaedic surgeon utilizing constant direct current to treat non-union should, by adhering to proper fracture management and by following the biophysical principles described herein, be able to achieve a rate of union comparable to that of bone-graft surgery, with a lower associated risk.

Adolescent↗
PubMed1981

Nutritional assessment in a rehabilitation unit.

Forty-nine consecutive patient admissions to a rehabilitation unit were evaluated by a nutritional assessment team. Measured parameters included serum albumin, height, weight, 24-hour protein and calorie intake, and response to 4 antigens (purified protein derivative, streptokinase/streptodornase, trichophyton, candida) administered by intradermal injections. Patients were classified normal (albumin greater than or equal to 3.5 gm%, positive skin tests, normal weight), Kwashiorkor (albumin less than 3.5gm%, anergic skin tests, no weight loss), marasmus (albumin greater than or equal to 3.5gm%, anergic skin tests, weight loss greater than 101lb (4.54kg) or obesity (greater than 130% ideal body weight). Protein-calories malnutrition (marasmus or kwashiorkor) was found in 34 (67%) of the patients. Only 15 patients (33%) satisfied criteria for normal nutritional status at the time of admission. Four subjects satisfied the criteria for both obesity and kwashiorkor. Because of the increased morbidity and mortality associated with protein-calorie malnutrition, all patients admitted to a rehabilitation unit should have a nutritional assessment. If the assessment demonstrates malnutrition, a program of metabolic support should be initiated to increase protein levels and restore immune competence.

Adolescent↗
PubMed1980

Haversian osteons: longitudinal variation of internal structure.

Previous studies have suggested that one general type of osteon exists, rather than the three types previously classified as light, intermediate, and dark. A method is presented that permits rapid, quantitative measurement of the percent transmission of osteons seen in thin section between crossed polarizers. In studies of osteon segments from human cortical bone, cut either 200 or 5 micrometers in length, a continuous variation of transmission is seen, both for the populations as a whole and for serial sections. These variations cannot be ascribed to angulation between the direction of observation and the axis of the osteonal segment. No correlation can be observed between the angle of the segment axis and the percent transmission. It is suggested that the collagen fiber orientation in osteonal segments must be considered to be continuous, as judged by scattering of polarized light.

Collagen↗
PubMed1980

Materials design analysis of the prosthetic anterior cruciate ligament.

Repair or replacement of the damaged anterior cruciate ligament (ACL) is a significant clinical problem. A design utilizing ultrahigh-molecular-weight polyethylene (UHMWPE) was developed and marketed by an orthopaedic device manufacturer. Mechanical failure rates of greater than 10%/year postoperatively raised the issue of the adequacy of UHMWPE in that design. A study has been made to estimate the forces in the human anterior cruciate ligament for young, middle age, and older patients and to thus derive the minimum materials requirements for a now withdrawn prosthetic anterior cruciate ligament (PACL) design. It is concluded that UHMWPE does not possess adequate yield, creep, or fatigue properties to meet the design. Furthermore, consideration of the varying requirements on the PACL, due to differences in age and activity levels of patients, suggest that a band-type design offers a better possibility of achieving adequate materials performance in the ACL prosthetic replacement.

Adult↗
PubMed1980

The biomechanical responses to tension in a peripheral nerve.

The biomechanical adjustments rat sciatic nerves make to tension were studied 7 weeks after experimental nerve repair. Nerve tissue adjusts to tension by increasing its compliance if stretched within its physiological limits. Anatomical changes observed in the nerve tissue 7 weeks after stretching apparently accounts for the nerves extensibility, a biomechanical adjustment that helps preserve nerve continuity during the joint extension phase of extremity rehabilitation.

Adaptation, Physiological↗
PubMed1980

Developments in the biology of neuroblastoma: implications for diagnosis and treatment.

There has been little improvement in the prognosis for neuroblastoma in childhood over recent years. The authors review recent investigations into the biology of the tumour and discuss their implications for diagnosis and therapy. Immunological studies suggest a heterogeneity in cell-surface antigens on different human neuroblastoma lines/fresh tumours. The reagents being developed against these antigens will play a rôle in the diagnosis of metastatic spread, and may be useful in autologous bone-marrow transplantation programmes. The occasional in vivo differentiation of the tumour is reviewed, with particular reference to in vitro studies on the differentiation of human and murine neuroblastoma cell-lines. This work may have implications for therapy if ways can be found to cause in vivo differentiation of the tumour into a benign ganglioneuroma.

Animals↗
PubMed1979

Articular cartilage preservation and storage. II. Mechanical indentation testing of viable, stored articular cartilage.

Mature rabbit articular cartilage in the form of distal femoral condyles, composite osteoarticular structures, were incubated in the presence of alpha-tocopherol (200 micrograms/ml) over a period of time. Indentation testing and 35S uptake indicate preservation of sustained load carrying capacity and viability, respectively, in the presence of alpha-tocopherol for up to 30 days in organ culture. Condylar cartilage stored in the absence of alpha-tocopherol as well as frozen cartilage demonstrated progressive inability to resist sustained loading over time. Nonoptimal synthetic function apparently occurred in these latter two groups when compared to alpha-tocopherol stored material.

Animals↗
PubMed1979

Serum cholecystokinin, basal acid secretion, and infantile pyloric stenosis.

The fasting serum cholecystokinin-like activity was measured in 21 infants with pyloric stenosis and in 13 normal controls. No significant difference was found between the two groups. The basal acid secretion was measured by continuously aspirating the previously emptied stomach for one hour. The basal gastric volume and the total and the free acidity were all greater in the pyloric group.

Cholecystokinin↗