Search PubMed⌕ Search

Biomedical subjects

K Reemtsma

Publications and source records attributed to K Reemtsma.

At least 163 records · Page 9Linked to original sources
PubMed1978

Quantitation of HLA-D differences.

The predictability of MLC non-reactivity by HTC typing was tested in a single checkerboard experiment which involved 39 unrelated individuals belonging to 12 different groups of HLA-D identical phenotypes. The strength of one-way MLC reactions in all possible responder-stimulator combinations (39 X 39) was quantitated by the Linear Clustering Analysis Program. Individuals who, by HTC typing, were identical for two HLA-D antigens gave 51% negative, 36% intermediate and 13% strong positive MLC responses. Identity for only one HLA-D antigen resulted in 3% negative, 40% intermediate and 57% strong MLC reactions. When no HLA-D antigen was shared, 88% of the reactions were strongly positive. HLA-D antigens behaved as equipotent stimulators in MLC between half-identical pairs. The only exception consisted of the higher frequency of weak responses displayed by the Dw5 positive individuals against stimulators differing by LD107. The same pattern was observed when LD107 homozygous cells were used as stimulators, suggesting that determinants of this specificity might be partially included in Dw5.

Epitopes↗
PubMed1978

Tissue culture preservation and intramuscular transplantation of pancreatic islets.

Pancreatic tissue from neonatal rats was cultured for 6 days and then transplanted into isologous animals made diabetic with streptozotocin. The cultured pancreatic tissue was implanted either into the peritoneal cavity or into muscle pockets and showed survival by functional and morphological studies for longer than 40 weeks. Pancreatic tissue from a patient subjected to subtotal pancreatectomy for chronic pancreatitis was maintained in culture for 7 days, with evidence for insulin release into medium, sterility, and histological viability of islets. Autotransplantation of this tissue into muscle pockets of the forearm was tolerated well. Glucose tolerance improved following transplantation, but evidence for function of the graft (insulin, C-peptide) remains inconclusive, 4 months after transplantation.

Animals↗
PubMed1978

[Counterpulsation by means of a new device with a pulsatile blood flow in open heart operations (author's transl)].

A new counterpulsation method in operations on an open heart is described. Clinical experience in the use of the new device in 124 patients, which also makes it possible to produce a pulsatile flow of blood in the system of extracorporeal circulation, testifies to its effectiveness. The authors claim that the positive changes in cardiac output, diastolic and systolic pressure, and coronary circulation are among the factors which cause an improvement in the final result of the operation in patients with severe valvular diseases and ischemic heart disease.

Adult↗
PubMed1977

A pulsatile assist device (PAD) for use during cardiopulmonary bypass.

A pulsatile assist device (PAD) has been developed to convert roller pump flow to pulsatile flow in a simple fashion. The device can also be used as an arterial counterpulsator before and after cardiopulmonary bypass. The PAD has been used in 125 adult patients undergoing open-heart operations for coronary artery or valvular heart disease or the combination. Ninety-two patients were in New York Heart Association Functional Class III or IV or had ejection fractions of less than 0.3. The PAD functioned as a hemodynamically effective arterial counterpulsator before and after perfusion. All patients were successfully weaned from bypass with the PAD. There has been 1 intraoperative death and 2 late deaths. Only 1 patient had a perioperative myocardial infarction, and this person was successfully treated with intraaortic balloon pumping. We believe the PAD is a simple and reliable device for intraoperative counterpulsation and for the creation of pulsatile cardiopulmonary bypass. More important, use of the PAD may decrease both the incidence of perioperative myocardial infarction and the need for postoperative intraaortic balloon pumping.

Adult↗
PubMed1977

An improved method of myocardial protection with pulsation during cardiopulmonary bypass.

A new valveless pulsatile assist device (PAD) has been developed that converts roller pump flow into synchronized pulsatile flow. The PAD can also be used as an arterial counter-pulsator (ACtP) before and after cardiopulmonary bypass (CPB). The PAD was employed in 100 adult patients undergoing open heart surgery for coronary artery and/or valvular heart disease. Seventy-three of these patients were NYHA class III or IV, had ejection fractions of less than 0.3, or an LVEDP greater than or equal to 18 mm Hg. Sixty-one patients underwent coronary artery bypass alone, 17 valve replacement alone, three ventricular aneurysm alone, 12 combined coronaries and valves, and seven combined coronaries and ventricular aneurysms. The device functioned as a hemodynamically effective ACtP before and after CPB. During CPB, pulse pressures of 40-50 mm Hg were readily obtained. Urinary outputs during CPB were increased on the PAD when compared to a control group (9.18 +/- 0.68 cc/min vs 3.90 +/- 0.34 cc/min). In addition, during CPB, coronary graft blood flow (CBF) increased an average of 21.4 +/- 6.1% with the PAD, and after CPB, CBF increased an average of 25.0 +/- 5.9%. Free plasma hemoglobins after CPB were not elevated. Only one patient had a perioperative myocardial infarction, and this patient was successfully treated with intra-aortic balloon pumping. It is suggested from these data that use of the PAD may decrease both the incidence of perioperative myocardial infarction and the need for postoperative intra-aortic balloon pumping.

Assisted Circulation↗
PubMed1977

Tissue culture isolation and preservation of human cadaveric pancreatic islets.

Six specimens of human cadaveric pancreas were collagenase-dispersed and placed in tissue culture. Media were changed at 2 day intervals and assayed for insulin and amylase. Experiments were terminated after 8 days, and phase-contrast and light microscopy were performed on cultured tissue. Insulin content in media remained high for 6 days in five cases and for 8 days in four experiments; this correlated directly with morphologic viability of cultured tissue. Media amylase fell to zero after 4 days in four cases and after 6 days in two cases. These data support the concept that tissue culture may be an efficient method for (1) islet cell purification, since acinar tissue and amylase activity disappear, and (2) islet preservation.

Adult↗
PubMed1977

The HLA system and the genetics of juvenile diabetes mellitus.

Eighteen families with a total of 68 children were completely typed for HLA-A, B, C, D and Bf. With only one exception, all affected children within each family with 2 or more diabetic siblings, shared both HLA-D alleles indicating that J.D.M. is a recessive trait. Since half of the siblings who are HLA-D identical to the first affected child developed J.D.M. (as is the case of monozygotic twins), the gene(s) in question is most likely the sole genetic requirement for this disease and has a penetrance of 50%. No evidence of association between J.D.M. and B8, Dw3 or Bw15 was observed by analyzing the segregation of J.D.M. and of each of the above HLA antigens in informative families. A total of 9 out of 68 children bore a recombinant HLA haplotype. This increased rate of crossing-over in J.D.M. seems to require a single J.D.M. gene since the parents (9) in whom recombinations occurred were non-diabetic. No association was seen between the presence of the disease and the existence of a recombinant hoplotype.

Adult↗
PubMed1977

Increased cardiac output by downstream pumping with a reversed unidirectional intra-aortic balloon.

Downstream and upstream pumping with unidirectional intra-aortic balloons was compared in 8 open-chest normal mongrel dogs anesthetized with pentobarbital. Downstream pumping effect a 32 per cent increase in cardiac index, a 24 per cent decrease in systemic resistance, and a 2 per cent decrease in heart rate. Upstream pumping did not significantly affect these parameters. Mean aorta pressure proximal and distal to the balloon was not altered significantly by pumping in either direction. This unique observation of increased cardiac output may have important implications for the treatment of low output cardiac failure. Preliminary studies including baroreceptor denervation suggest that a reflex mechanism may be involved.

Animals↗
PubMed1976

The HLA system in the families of patients with juvenile diabetes mellitus.

The HLA and Bf genotypes were determined in 10 families with one or more children with JDM. A statistically significant association was found between HLA-D-identity and the chance to present JDM within a sibship. No such association was detectable with the SD antigens. A highly significant increase in the frequency of intra-HLA recombination was also found in these families.

Diabetes Mellitus, Type 1↗