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Biomedical subjects

K Thomas

Publications and source records attributed to K Thomas.

At least 253 records · Page 14Linked to original sources
PubMed1988

Correlation of transconjunctival PO2 with cerebral oxygen delivery during cardiopulmonary resuscitation in dogs.

The relationship between transconjunctival PO2 (PcjO2) and cerebral oxygen delivery (DO2) was examined in dogs during sinus rhythm and CPR with an inflatable vest. Microsphere-determined cerebral blood flow (CBF), DO2, and PcjO2 readings were normal during sinus rhythm. During CPR, with carotid pressure of 82 +/- 11/25 +/- 5 (SEM) mm Hg, cerebral perfusion and DO2 fell by 53% and 57%, respectively, while PcjO2 fell by 87%. After epinephrine administration, carotid pressure increased to 128 +/- 13/48 +/- 9 mm Hg, and CBF and DO2 rose to 130% and 115% of pre-arrest levels, respectively, but PcjO2 readings remained at 11% of control values. Thus, PcjO2 failed to reflect accurately either CBF or DO2 during CPR. In the presence of epinephrine, PcjO2 does not seem to provide an accurate index of the effectiveness of CPR.

Animals↗
PubMed1988

A prosthesis to camouflage indented scars.

Traditional silicone prostheses have been found to be inflexible, heavy, and of poor color match when used on the limbs. Ten patients distressed by contour deformities on their limbs after the wide excision of malignancies or following trauma were fitted with a light-weight prosthesis whose special features include a flexible foam backing, an outer tinted skin, and finely feathered edges that draw the eye away from the margins of the defect. The prosthesis sticks dependably to the skin and is particularly effective when worn under stockings or tights. When reviewed, all patients were continuing to use the device. It is a useful alternative to surgical reconstruction in such patients.

Adult↗
PubMed1988

Short-term utilization of a gonadotropin-releasing hormone agonist (buserelin) for induction of ovulation in an in vitro fertilization program.

Benefits of the short-term utilization of a gonadotropin-releasing hormone (GnRH) agonist (Buserelin, Hoechst, AG, Frankfurt am Mein, FRG) for induction of ovulation in an in vitro fertilization program (IVF) program were assessed. Eighteen patients underwent consecutively an induction of ovulation by clomiphene citrate (CC) and human menopausal gonadotropin (hMG), then by hMG alone, and finally by Buserelin and hMG. The switchover from CC and hMG to hMG alone significantly increased the number of aspirated follicles and the oocyte recovery rate. The addition of Buserelin prevented the outcome of spontaneous luteinizing hormone (LH) surges. It reduced the preovulatory luteinization and increased the number of recovered oocytes as well as the number of embryos available for transfer. A 33% clinical pregnancy rate per ovum pick-up was achieved with the Buserelin-hMG treatment.

Buserelin↗
PubMed1988

Evolution of NMRI mice ovaries and corpora lutea during pregnancy: morphologic and morphometric study.

During pregnancy in mice, three groups of corpora lutea (CL) originating from 4 successive ovulatory cycles could be distinguished taking into account their size, cellular structure and stain affinity. Type I CL originated at the onset of pregnancy, type II CL originated during the 2 previous estrous cycles and type III CL were produced during a cycle preceding the two others. CL volume of type I increased 10-fold between day 0 and day 18.5, a 2.5-fold increase in volume occurred in type II CL between day 0 and day 3, although they derived from cycles preceding pregnancy. The volume of type III remained unchanged. This fact suggested that types I and II CL probably play a functional role in the ongoing pregnancy. After day 10 of pregnancy a high correlation coefficient (r = 0.933) is observed between type I CL and the number of embryos in the corresponding uterine horn.

Animals↗
PubMed1988

[The beneficial effects of short-term administration of a LHRH agonist (buserelin) in in vitro fertilization].

We have assessed the beneficial effects of administering a short course of an agonist of LHRH (Buserelin) in vitro fertilisation. 274 cycles were treated with CC-HMG, 159 were treated with HMG alone and 253 by Buserelin-HMG. These were compared retrospectively. The use of a short course of Buserelin lowered significantly the rate of failed treated cycles (7% instead of 19% when it was used with CC-HMG and 27% when used with HMG). This made it possible to administer hCG in all cases in the programme (100% as against 69% and 89% respectively for CC-HMG and HMG without Buserelin), and increase significantly the number of oocytes that could be recovered and the number of embryos available for transfer. The overall number of pregnancies per cycle treated is significantly raised when Buserelin is used with HMG (20.4% as against 13.5% for CC-HMG and HMG). The number of pregnancies that progressed, on the other hand, was similar when the cycle was stimulated with HMG alone (10.6%) or with Buserelin-HMG (10.6%).

Buserelin↗
PubMed1987

Simultaneous cloacogenic carcinoma in dizygotic twins.

Dizygotic twins developed cloacogenic carcinoma of the anus almost simultaneously. The patients, although separated from the time they were 20-years-old, had very similar life styles. There are several reports in the medical literature of synchronous tumors in mono and dizygotic twins. It is recommended that if a cancer diagnosis is made in one twin, the other undergo workup to exclude the presence of a tumor with similar histology. The establishment of state or national twin registries would provide valuable information regarding the role of genetic and environmental factors in the development of not only cancer but also of various nonmalignant disorders.

Anus Neoplasms↗
PubMed1987

Na+-K+ pump in chronic renal failure.

This review summarizes the evidence for the defect in Na+-K+ pump in chronic renal failure, considers the role of various factors in causing this defect, and discusses the clinical implications thereof. Intracellular Na is elevated in erythrocytes, leukocytes, and muscle cells from some patients with chronic renal failure (CRF). Recent evidence suggests that this elevation of cell Na may be, in large part, a consequence of decreased number of Na+-K+ pump units per cell. Maintenance dialysis over a period of weeks ameliorates the defect in intracellular Na+, and this improvement is contemporaneous with an increase in the number of Na+-K+ pump sites per cell. In erythrocytes with normal cell Na+, acute hemodialysis increases the rate of Na+ and K+ transport. Many factors such as the presence of retained toxic metabolite or circulating inhibitor in the uremic plasma, or biochemical changes produced by acute hemodialysis, may explain this finding. In cells with high cell Na+, the pump-mediated K+ transport is normalized at the expense of a raised cell Na+. The decreased muscle membrane potential in uremic subjects has been attributed to a decreased activity of Na+-K+ pump. Enzymatic Na+-K+-ATPase activity of the uremic erythrocyte, leukocyte, sarcolemma, and intestines is also decreased. We discuss the role of hormonal abnormalities and circulating inhibitors, which may cause an acute inhibition of the pump and of other factors such as K+ depletion, which may cause more chronic alterations. The implications of alteration of Na+ and K+ pump transport and raised cell Na+ on other non-pump-mediated transport pathways are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Transport↗
PubMed1987

Growth stimulation of rat calvaria osteoblastic cells by acidic fibroblast growth factor.

Purified acidic fibroblast growth factor (aFGF) from bovine brain stimulates the proliferation of calvaria-derived osteoblastic cells. Maximum stimulation, relative to corresponding controls, was seen at 0.2% serum (2- to 3-fold), and no stimulation was seen in the absence of serum or under serum replete conditions. The effect was dose-dependent with an ED50 of around 750 pg/ml (47 pM). aFGF (5 ng/ml) sustained the growth of calvaria cells in culture during multiple passages (72 days) at 0.2% serum. In DNA synthesis assays aFGF produced 2- to 4-fold stimulation; insulin-like growth factor I had a slight effect on DNA synthesis on its own, but enhanced the effect of aFGF 2-fold. In cells fully stimulated by epidermal growth factor (5-fold), aFGF had no further effect. Stimulation of DNA synthesis peaked at 5 ng/ml, while higher concentrations were inhibitory. Recombinant aFGF (bovine sequence) also stimulated cell proliferation (1.5-fold), and its potency was augmented by heparin (50 micrograms/ml), about 2-fold. Using simultaneous histochemical staining for alkaline phosphatase activity and [3H]thymidine nuclear uptake we found that aFGF stimulates DNA synthesis to the same extent in alkaline phosphatase-rich (osteoblastic) and alkaline phosphatase-poor (nonosteoblastic) cells. However, after cell division there is a significant decrease in PTH-responsive adenylate cyclase (2- to 3-fold) and in alkaline phosphatase levels (4- to 8-fold). These findings indicate that aFGF is mitogenic to rat calvaria osteoblastic cells, its action requires additional factors, and its growth stimulation is associated with a reduction in phenotypic expression.

Adenylyl Cyclases↗
PubMed1987

[Experiences with the use of sulprostone (Nalador) for the termination of pregnancy in the 1st trimester in primigravidae].

Sulprostone in different doses and application forms (25, 50 or 100 micrograms extra-amnionic; 500 micrograms or 3 times 500 micrograms every 4 hours intramuscularly) was given to perform termination of pregnancy between 7th and 12th week. The dose of 500 micrograms three times given was most effectiveness, but there were the most side effects, too. The dose of 500 micrograms Sulproston was accompanied by less side effects and the therapeutic success was sufficient. The extra-amnionic application was effective also in all used dosages.

Abortifacient Agents↗
PubMed1987

Audit of work at a medical centre for the homeless over one year.

An audit of one years' work at a voluntary health care service for the homeless involving doctors, a chiropodist, nurses and social workers was carried out. It was found that although certain health problems are more common among the homeless than in the general population, the range resembles that in any general practice. However, registration with general practitioners was much less common among the homeless than in the general population, and a high proportion of referrals to hospital did not lead to appropriate treatment. The value of a special primary health care service for the homeless is discussed.

Adult↗
PubMed1987

Splenic abscess.

Explore the source record for details and available documents.

Abscess↗
PubMed1986

Hypogammaglobulinemia and hemophagocytic syndrome associated with lymphoproliferative disorders.

Four patients with lymphohistiocytic disorders had or subsequently experienced severe hypogammaglobulinemia and pancytopenia due to hemophagocytosis. The percentages of B- and T-lymphocytes and the ratios of helper (OKT4) cells to suppressor (OKT8) cells in the peripheral blood were variably altered. Mitogenic response to pokeweed mitogen and phytohemagglutinin was depressed but could be restored to near normal by the in vitro addition of indomethacin or interleukin-2. The half-life of intravenously administered immunoglobulin was markedly shortened. The data indicate that hyperactive monocytes/histiocytes are capable of simultaneously ingesting apparently normal blood cells and immunoglobulin, leading to pancytopenia and hypogammaglobulinemia. The monocytes with suppressor activity (which could be abrogated with indomethacin or interleukin-2) appeared to additionally contribute to the hypogammaglobulinemia, possibly by interfering with the terminal differentiation of the B-lymphocytes. Hemophagocytosis occurs frequently in histiocytic and occasionally in lymphoproliferative disorders or viral diseases. More frequent and serial determination of serum immunoglobulin levels in such situations may lead to the discovery of additional cases.

Adult↗