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Biomedical subjects

M Jones

Publications and source records attributed to M Jones.

At least 865 records · Page 48Linked to original sources
PubMed1980

Optimal preparation techniques for human saphenous vein grafts.

Endothelial damage during preparation of saphenous vein grafts is an important cause of early and late graft failure. To determine optimal preparation techniques for human saphenous veins (SVs), we made a scanning electron microscopic comparison of the effects of handling techniques, immersion media, and distention pressures on human SV morphology. Segments of SVs from 30 patients were divided into seven groups of five veins each. The effects of both blood and saline solution immersion at 4 degrees and 28 degrees C, 100 and 300 mm Hg distention pressures, and trauma from surgical instrumentation were examined. All groups of veins were fixed by perfusion with glutaraldehyde at 100 mm Hg to simulate arterial pressure and were examined with a scanning electron microscope. SVs immersed in warm saline solution showed massive endothelial cell loss, whereas SVs immersed in warm blood showed only moderate endothelial damage. Cold blood and saline immersion fully preserved endothelium; however, cold saline immersion produced mural edema. Distention to 300 mm Hg with saline solution produced severe endothelial damage and edema, an effect lessened by blood distention. Vascular clamping destroyed endothelium and fractured the intima and media. Marked luminal stenoses were caused by four of seven side branch ties that appeared normal externally. We conclude that human SVs are preserved best by a "no touch" harvesting technique in which manipulation is minimized, side branch ties are placed away from the SV wall, veins are immersed in cold blood, and distention above 100 mm Hg is avoided.

Blood↗
PubMed1979

State mental hospitals and the future.

There seems to be a general acceptance of the idea that at some future date mental hospitals will disappear to be replaced by community mental health services of various kinds. The author points out that remarkably little interest is focused on the possibility of a new model of residential care to replace the outmoded hospital. Some form of residential mental health care will probably always be needed, and should be complementary to the developing nonresidential services. A strategy for revitalizing mental hospitals is outlined.

Communication↗
PubMed1979

Sensitivity differences displayed by Drosophila melanogaster larvae of different ages to the toxic effects of growth on media containing aflatoxin B1.

Using Drosophila melanogaster, the relative sensitivities of various larval stages to the toxic effects of growth on media supplemented with either 0.44 or 0.88 ppm aflatoxin B1 (AFB1) were determined. Two strains of fruit flies were tested: strain A-11 which is relatively resistant to AFB1 induced toxicity, and strain A-9 which is quite sensitive. Eggs, mid-first, mid-second and early-, mid- and late-third instar larvae were transferred onto AFB1 media and allowed to complete larval and pupal development and eclose as adults. At the 0.44 ppm concentration, strain A-11 showed no effect, while only first instar larvae of strain A-9 showed significant mortality rates for first instar larvae, but the A-9 larvae die at higher rates than the A-11 larvae. In addition, second and third instar larvae of strain A-9 show significant mortality rates when grown at 0.88 ppm AFB1, while these stages are not affected in strain A-11.

Aflatoxins↗
PubMed1979

Pressure passive cerebral blood flow and breakdown of the blood-brain barrier in experimental fetal asphyxia.

Cerebral blood flow (CBF) was studied in non-exteriorized near-term sheep fetuses using the radioactive microsphere technique. By partially occluding the umbilical vessels for a period of 1--1 1/2 hours a progressive and severe asphyxia with a final arterial pH of 6.90 was achieved. Varying the mean arterial blood pressure in the fetuses by blood withdrawal or infusion in this state, CBF was measured at different perfusion pressures (mean arterial blood pressure (MABP) minus central venous pressure (CVP)). A passive flow/pressure relationship--loss of autoregulation--was found, with hyperemia reaching CBF values up to 6 times normal at normal MABP of about 60 to 70 mmHg, and severe ischemia reaching CBF values close to zero in large cortical areas at MABP of 30 mmHg. CVP remained essentially unchanged at 10--15 mmHg. The severe and prolonged asphyxia rendered the blood-brain barrier leaky to the albumin tracer Evans blue. In four other fetuses umbilical cord clamping was omitted. However, only in one of these cases was acidosis completely avoided, and CBF autoregulation maintained. The three other fetuses were acidotic at the end of the surgical procedure and had impaired autoregulation.

Animals↗
PubMed1979

Therapeutic communities, old and new.

The author attempts to clarify two largely different uses of term, Therapeutic Community (TC). By "old" TC he describes a movement which originated in psychiatry in the United Kingdom at the end of World War II. This was an attempt to establish a democratic system in hospitals where the domination of the doctors was replaced by open communication of content and feeling, information sharing, shared decision making, and problem solving shared as far as possible with all patients and staff. Daily meetings of all patients and staff formed the nucleus of this process. In recent years developments in the areas of systems theory, learning theory, and organization development have contributed to a better understanding of social organization and change. The "new" TCs derive from the more recent developments in the treatment of substance abuse. Central to this movement is Synanon and its many modification which use the clients' peer group to solve their own problems, largely eliminating mental health professionals. Linked with these "new" TCs is the development of Asklepieion units in prisons, which use Synanon "games" along with transactional analysis. An attempt is made to distinguish the methodologies used in TCs, "old" and "new".

Alcoholics Anonymous↗
PubMed1979

Biochemical quantitation of the chemotactic factor inactivator activity in human serum.

CFI of whole human serum was measured by a new assay that utilizes chemotactic factor-induced release of a lysosomal enzyme (N-acetyl glucosaminidase) from cytochalasin B-exposed neutrophils as an index of chemotactic activity. The effectiveness of serum as an inactivator of chemotactic factor-induced enzyme release closely correlated with the serum CFI as determined by assay of neutrophil chemotaxis in Boyden chambers. In comparison to serum from healthy persons, there was elevated CFI in the serum from patients with sarcoidosis and Hodgkin's disease by both assay systems. The results indicate that measurement of serum inhibition of chemotactic factor-induced lysosomal enzyme release from neutrophils provides a rapid, reliable, and reproducible assay of serum CFI. (J Lab Clin Med 93:17, 1979.)

Chemotaxis, Leukocyte↗