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Biomedical subjects

A Gardner

Publications and source records attributed to A Gardner.

At least 109 records · Page 6Linked to original sources
PubMed1979

Seeding endothelium onto canine arterial prostheses. The effects of graft design.

To identify prosthetic characteristics that support the proliferation of an endothelial lining, 14 different graft designs were studied in dogs. The grafts were prepared by the use of a technique of endothelial seeding that we described previously. They were studied two and four weeks after their implantation. Weft-knit Dacron grafts (water porosity from 1,400 to 1,650 mL/min/sq cm) were the most successful. A velour index (velour stitch frequency times velour loop height) was computed. When the internal velour index (IVI) was greater than 60,000 loop-mu/sq cm, the percentage of clot-free surface was 17.2 +/- 14.5%, compared with 62.0 +/- 26.9% when the IVI less than 60,000 loop-mu/sq cm. Endothelium could be detected on 61.5% of the grafts when the IVI less than 60,00 loop-mu/sq cm, compared with 0% when the IVI greater than 60,000 loop-mu/sq cm. The cells that formed the outer capsule were better organized and more adherent to the graft when an external velour was present, but external velour did not affect the inner lining. We conclude that weft-knit Dacron grafts with water porosities from 1,400 to 1,650 mL/min/sq cm and with limited internal velour (IVI less than 60,000 loop-mu/sq cm) are suitable substrates for single-staged endothelial-cell seeding.

Animals↗
PubMed1979

Seeding arterial prostheses with vascular endothelium. The nature of the lining.

Arterial prostheses seeded with autogenous vascular endothelium demonstrate a well-organized, cellular, inner lining. To determine the nature of the lining cells, six animals underwent replacement of the infrarenal aorta with Dacron prostheses. During the preparation of three such grafts, endothelium was scraped from the saphenous vein with a steel wool pledget, suspended in chilled Sack's solution, and mixed with blood used to preclot the graft. This suspension was omitted from the three control grafts. After six weeks, the grafts were removed, rinsed and examined. Fluorescent Factor VIII related antigen (F VIII-RA) strongly stained the lining cells. Silver nitrate Haütchen and electron microscopy preparations revealed a lining pattern characteristic of vascular endothelium. Endothelial cell-specific Weibel-Palade bodies were identified in the lining cell cytoplasm. Masson's trichrome staining revealed a relatively collagen-poor connective tissue within the seeded fabric. Transmission electron microscopy disclosed vascular smooth muscle cells between the seeded graft fabric and the lining cells. Vasa vasorum, arising from the outer capsule, penetrated the fabric to supply the inner capsules of the seeded grafts. It is concluded that the cells lining seeded canine arterial prostheses are true vascular endothelium supported by vascular smooth muscle cells, that the lining contains minimal connective tissue, and that vasa vasorum develop. Unseeded control grafts lacked these features.

Animals↗
PubMed1979

Radiologic heart volume and subsequent mortality.

In the London Civil Service Health Survey, both p.a. and lateral 100 mm chest films were taken on 12,630 men aged 40 and above. Radiologic heart volume was calculated on a 10 per cent sample and to the sample were added the films of all other subjects from the cohort who had died within 5 years of the survey, or more than 5 years afterwards. Radiologic heart volume could be calculated on 1,390 subjects of whom 233 had died within 5 years, and 47 after 5 years had elapsed. For deaths within the first 5 years there was a stepwise increase in mortality with increasing quintile of heart volume. Radiologic heart volume predicts death from cardiovascular disease both within 5 years of estimation and for deaths occurring more than 5 years after examination.

Adult↗
PubMed1977

Malarial antibodies in tropical splenomegaly syndrome in Papua New Guinea.

Levels of species and class-specific malarial antibody were studied in 249 New Guineans with tropical splenomegaly syndrome (TSS) and in 87 control subjects living in the same area. Titres of IgG and IgM antibody to Plasmodium falciparum, P. vivax and P. malariae were estimated by indirect immunofluorescence. Both Ig and IgM antibody levels were higher in subjects with TSS than in controls; IgM titres were highest in those with the greatest splenic enlargement. Responses to all three species were comparable. It is concluded that there is no evidence from this study to incriminate any one species of malaria parasite in the production of tropical splenomegaly syndrome.

Adolescent↗
PubMed1977

Multistage scoring system for identifying infants at risk of unexpected death.

Obstetric and perinatal records have been assembled on 250 infant deaths and an equal number of live controls including 55 deaths associated with congenital anomalies. The information was used to construct a scoring system to identify high-risk infants at birth. Parents of 115 of the cases and their controls were also interviewed and all hospital, general practitioner, and health service records abstracted. Cases and controls were compared item by item in respect of all information available up to the age of one month and a scoring system constructed for use at one month. The 'at birth' and combined scoring systems are presented. The chance of death by age attained is presented for various risk groups. In a small prospective test, the multistage scoring system was nearly 50% more effective than the birth score alone.

ABO Blood-Group System↗
PubMed1977

Mourning, mummification and living with the dead.

Six cases are reported in which the bereaved kept the decreased's body for periods ranging from one week to ten years. Some relevant anthropological and psychoanalytical observations are discussed. This phenomenon does not appear to have been reported in the literature of Western psychiatry.

Aged↗
PubMed1977

Induction of morphological transformation in mouse C3H/10T1/2 clone 8 cells and chromosomal damage in hamster A(T1)C1-3 cells by cancer chemotherapeutic agents.

Various cancer chemotherapeutic agents including alkylating agents, antimetabolites, and antibiotics or natural products were studied for their ability to produce morphological transformation in the C3H/10T1/2 clone 8 mouse cell line and chromosomal damage in the A(T1)C1-3 hamster cell line following a 24-hr exposure of each agent at different concentrations. Those drugs that were known to be carcinogenic in vivo also produced morphological transformation and chromosomal damage, whereas those agents that have not been shown to be carcinogenic in vivo produced neither transformation nor chromosomal lesions. The concentrations used for these studies were in general similar to those actually reached in the plasma of patients treated with these same drugs for malignant, as well as certain nonmalignant, conditions.

Antineoplastic Agents↗
PubMed1976

In vitro correlates of transformation in C3H/10T1/2 clone 8 mouse cells.

Various potential in vitro correlates of malignancy were studied in four chemically transformed C3H/10T1/2 Clone 8 mouse cell lines and were compared with controls cells. The degree of tumorigenicity was best predicted by the relative plating efficiencies of the morphologically transformed cells in soft agar. All transformed cells also showed an increase in extracellular fibrinolytic activity which may be an additional marker for transformation. Intracellular fibrinolytic activity and loss of 125I-labeled cell surface protein (M.W. 250,000) were not correlated with morphological transformation or tumorigenicity in these cells.

Agar↗
PubMedDate not supplied

Effects of home versus supervised exercise for patients with intermittent claudication.

PURPOSE: This study was performed to test the efficacy of a supervised, hospital-based exercise program compared with a home-based exercise program involving minimal supervision, for both walking ability and quality of life measures in patients with exercise-limiting intermittent leg claudication. METHODS: Twenty-one patients were assigned randomly to 12 weeks of supervised exercise or to a home-based exercise group. After 12 weeks the participants in the supervised group transitioned to a home-based program. Both groups were then reevaluated at the end of 24 weeks. The initial claudication distance (ICD) and absolute claudication distance (ACD) on progressive treadmill exercise was measured at baseline, 12 weeks, and 24 weeks. Additionally, self-reported quality of life status was evaluated using the MOS SF-36 questionnaire. RESULTS: Each group improved (P < 0.01) ACD from baseline to 12 weeks, which was sustained at the 24-week follow-up. Both groups experienced similar long-term improvements (P < 0.05) in ACD (521.5 +/- 253.4 meters to 741.9 +/- 365.6 meters for the supervised group, 532.2 +/- 263.5 meters to 715.0 +/- 394.4 meters in the home group, P not significant, between groups). The supervised group experienced a greater improvement (P < 0.01) in the ICD after 12 weeks than the home group but not at 24 weeks. The on-site group also experienced significant improvements in ICD after 24 weeks (P < 0.05). Neither group manifested an improvement in self-reported physical function or mental health as assessed by the MOS SF-36. CONCLUSION: A structured exercise program was more effective in improving the ICD over a 24-week period than a less formal, home-based program. However, if patients are screened properly and receive adequate instruction, a home-based program can be a safe, low-cost alternative providing similar long-term (24 weeks) exercise benefits in ACD.

Aged↗