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Biomedical subjects

J Glover

Publications and source records attributed to J Glover.

At least 55 records · Page 3Linked to original sources
PubMed1989

The effect of intravenous nutrition on muscle mass and exercise capacity in perioperative patients.

This study was undertaken to compare the efficacy of four different types of perioperative intravenous nutritional support. Fifty-five patients undergoing routine major surgery were studied. They were prospectively assigned to one of four study groups. Group 1 received formal total parenteral nutrition (90 g amino acids, 3,000 calories as glucose, per day); Group 2, 100 g glucose per day; Group 3, 90 g amino acids per day; and Group 4, peripheral parenteral nutrition (90 g amino acids plus 1,600 calories, 60 percent as fat per day). Group 1 was maintained on therapy for 3 weeks and the other groups for 8 days. Nitrogen balance, maintenance of body cell mass, serum albumin levels, and maintenance of exercise capacity were measured. Patients receiving peripheral parenteral nutrition maintained their nutritional parameters, as did those receiving total parenteral nutrition. These infusions were both markedly superior to those receiving glucose alone or those receiving amino acids alone. Nitrogen balance was not correlated with maintenance of function, but maintenance of body cell mass was correlated with maintenance of exercise capacity (r = 0.66, p less than or equal to 0.01). We conclude that perioperative peripheral parenteral nutrition, in contradistinction to hypocaloric infusions of glucose or amino acids, is capable of maintaining postoperative muscle mass and function close to preoperative levels after major surgery, and in situations of relatively mild surgical stress, approaches the efficacy of total parenteral nutrition in this regard. A significant correlation exists between changes in body cell mass determined from isotope dilution and changes in the exercise capacity of large muscle masses.

Adult↗
PubMed1988

The transport of plasma thyroxine in white storks (Ciconia ciconia) and the association of high levels of plasma transthyretin (thyroxine-binding prealbumin) with moult.

Antisera raised against domestic fowl transthyretin (thyroxine-binding prealbumin) and quail albumin were used to identify thyroxine-binding proteins in the plasma of White storks (Ciconia ciconia) and to measure seasonal changes in these proteins. Three plasma proteins were shown to bind thyroxine (T4). They were albumin, transthyretin and a protein with an electrophoretic mobility on non-denaturing polyacrylamide gel electrophoresis intermediate between albumin and transthyretin. There was no thyroxine-binding globulin. The plasma concentrations of transthyretin and albumin were measured in male and female storks exposed to the photoperiodic and climatic conditions experienced during an annual cycle at 46 degrees N, 11 degrees E. The storks were in four age groups, fledglings and 1-, 2- and 3-year-old birds. A strong correlation (P less than 0.001) was found between daylength and the concentration of transthyretin during the period from February to August in the 1-, 2- and 3-year-old male and female storks, with peak values of 150-210 mg/l in May, June and July coinciding with the annual moult. Between September and January the concentration of plasma transthyretin was low, ranging between 80 and 100 mg/l. The concentration of plasma albumin was not correlated with seasonal changes in daylength and did not change during moult. It is suggested that seasonally high concentrations of plasma transthyretin may have a physiological role in moult.

Animals↗
PubMed1987

Leukocyte depletion enhances cultured endothelial retention on vascular prostheses.

Approximately 90% of endothelial cells that are seeded or cultured onto vascular prostheses are lost from the flow surface within 24 hours of implantation. To determine the contribution of leukocytes to endothelial cell loss, 111In-labeled, cultured canine jugular venous endothelial cells were grown to confluence on fibronectin-coated polyester elastomer tubes measuring 4 mm inner diameter and 30 mm in length. Autogenous cell-lined tubes were implanted as bilateral carotid replacement grafts in six dogs made leukopenic by cyclophosphamide. Similar unilateral grafts were placed in 12 control dogs. Grafts were removed and perfusion-fixed from six control animals after 2 hours of in vivo arterial perfusion and from the other six animals after 6 hours of perfusion. One graft was removed and perfusion-fixed from each leukopenic animal after 2 hours of implantation and the other after 6 hours. Attachment of endothelial cells to the grafts was measured by indium-labeling technique. Retention of endothelium on grafts removed after 2 hours was measured by planimetric counting with scanning electron microscopy and on those removed after 6 hours by radioisotope quantification. Endothelial cell retention after 2 hours was 37.6% +/- 27.0% in control dogs and 97.0% +/- 3.4% in leukopenic animals (p less than 0.0007). After 6 hours retention was 35.9% +/- 23.2% in control animals and 86.5% +/- 6.0% in leukopenic animals (p less than 0.0009). Leukocyte surface activity was present in less than 1% of the leukopenic dogs compared with 8.5% of the other in vivo midgrafts after 2 hours. These results suggest that leukocytes play a significant role in the loss of seeded endothelium from vascular prostheses.

Animals↗
PubMed1987

Improvements in the determination of the turnover rate of plasma thyroxine in avian species: application to the Japanese quail.

The disappearance of the thyroid hormone thyroxine (T4) from plasma in fully grown male Japanese quail can be described as a first order process with a rate constant of 0.178 +/- 0.013/h (mean +/- S.E.M., n = 8), which represents a half-life of 3.90 h. A small amount of [125I]T4 in relation to total circulating T4 was injected i.v. into Japanese quail and plasma samples were taken at appropriate time-intervals for the determination of residual plasma radioactivity. The rate of disappearance of [125I]T4 was subsequently equated to the turnover rate of the endogenous hormone. Previous methods were modified to overcome problems arising from possible disturbance of plasma T4 metabolism, recirculation of radiolabelled iodide, and to purify the [125I]T4 from the plasma samples. By using labelled T4 of very high specific activity, the amount of [125I]T4 administered was kept much smaller than has been used in previous studies on Japanese quail, thus limiting any interference with plasma T4 dynamics. To minimize any disturbance of plasma T4 metabolism, only four blood samples were taken, at three-hourly intervals after the injection of [125I]T4. The rapid turnover of T4 produced a large amount of labelled inorganic iodide, the re-entry of which into the plasma T4 pool was inhibited by s.c. administration of sodium thiocyanate 1 h before injection of [125I]T4. Assay of the true [125I]T4 turnover was significantly improved over that used in previous studies by purifying the [125I]T4 from the plasma samples chromatographically. The samples were applied to small Sephadex G-25 columns with sodium hydroxide (0.1 mol/l) as the eluant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Methodological considerations of epidemiological diagnoses in respiratory diseases.

Since epidemiological research depends extensively on questionnaire responses, a comparison of such responses with a standardized medical evaluation was conducted. It was found that standardized questionnaires do well in comparison for certain kinds of information on chronic conditions. However, clinical evaluations will elicit more information, specifically of a milder nature. It was concluded that standardized epidemiological questionnaires are satisfactory for survey of chronic conditions.

Adolescent↗
PubMed1985

Endothelium develops on seeded human arterial prosthesis: a brief clinical note.

Despite a considerable and growing body of evidence that endothelial cell seeding accelerates the healing of arterial prostheses in laboratory animals, there has been no histologic evidence thus far to indicate that a similar process occurs in human beings. A case is reported of histologically confirmed, extensive endothelial healing on a polytetrafluoroethylene femoropopliteal bypass graft 90 days after it was seeded and implanted.

Arterial Occlusive Diseases↗
PubMed1984

Patency in canine inferior vena cava grafting: effects of graft material, size, and endothelial seeding.

We studied 117 inferior vena cava (IVC) replacements in dogs to determine the effects of graft material, graft size, endothelial seeding, and cultured endothelial linings on graft patency. As a control, the IVC was removed and reimplanted in 11 dogs. Dacron (n = 7) and expanded polytetrafluoroethylene (e-PTFE) grafts (n = 12) were seeded immediately with the use of enzymatically derived autogenous jugular vein endothelium. Cultured linings were prepared for e-PTFE grafts (n = 9) by inoculating the graft with jugular endothelium and nurturing the lining in tissue culture for 14 to 30 days before implantation. Unseeded grafts (n = 27) were prepared according to the manufacturer's recommendations. These six methods of preparation were tested in grafts measuring 6 mm I.D. and 60 mm in length. Other sizes were tested with a Latin square study design. After 30 to 60 days the grafts were perfusion fixed and studied with light and transmission electron microscopy. Patency was determined by contrast cavography after 7 and 30 days. Patency in the IVC reimplantation was 100% compared with 28.0% of the e-PTFE (p = 0.001) and none of the Dacron grafts that measured 6 mm I.D. and 60 mm long. e-PTFE and Dacron graft patency also differed significantly (p = 0.035). Seeded and culture-lined e-PTFE grafts in that same size were patent in 31.6% compared with 16.7% of unseeded e-PTFE. With grafts measuring 80 mm long, three of the five e-PTFE grafts were patent between 3 and 7 days. All progressed to occlusion by 30 days and compared poorly with all other graft sizes tested (2.6% progression to occlusion [p = 3 X 10(-8)]). Recanalization was not seen in 10 occluded grafts that were followed for 60 days. The histologic features of seeded grafts differed remarkably from grafts previously studied in the arterial circulation and from culture-lined and unseeded venous prostheses in that 60% had prominent large, random, endothelium-lined channels within the inner capsule. Larger graft diameters (p = 0.009) and the omission of an endothelial surface treatment (p = 0.004) were associated with anastomotic subendothelial fibrous hyperplasia. We conclude that graft material is the major determinant of patency in IVC replacements, that an extensive endothelial surface promotes patency, but that simply seeding e-PTFE or Dacron grafts with 10(5) endothelial cells does not provide sufficient endothelium to alter early patency.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Percutaneous transhepatic drainage for malignant biliary obstruction.

Percutaneous transhepatic drainage ( PTHD ) is an adjunct in the management of malignant biliary obstruction. It can be used for two purposes: as a palliative measure alone or as part of the preoperative preparation. This study assesses the efficacy of this technique. The charts of all patients undergoing PTHD were reviewed, and the data were collated according to the intent of catheterization. In the palliative group (18 patients), bilirubin levels fell from 20 +/- 1.8 to 10 +/- 1.9 mg/dl. PTHD complications developed in 14 (78%), the 1-month mortality was 56 per cent (10/18), and all of the patients have died (mean, 2.3 months). In the preoperative group (17 patients), bilirubin levels fell from 17 +/- 1.4 to 6 +/- 0.6 mg/dl, PTHD complications developed in three (18%), and postoperative complications occurred in five (30%). All patients in the preoperative group survived operation, 11 of 16 dying a mean of 4.5 months postoperatively. The five surviving patients have lived 2 to 25 months. The authors conclude that PTHD significantly lowers the serum bilirubin in both preoperative and palliative groups. In the preoperative group, its use is associated with low morbidity and may improve the patient's preoperative condition. In the palliative group, PTHD is associated with an appreciable morbidity that tempers the enthusiasm for its routine use in this circumstance.

Aged↗
PubMed1984

Seeding human arterial prostheses with mechanically derived endothelium. The detrimental effect of smoking.

Endothelial healing of Dacron arterial prostheses can be hastened in dogs by seeding autogenous venous endothelium onto the prostheses in a single-staged operation. To determine whether this technique enhances the patency of human grafts, we studied the results of 186 operations on 161 patients performed between February 23, 1978, and December 1, 1982. Alternately allocating patients to treatment with seeded and unseeded Dacron knitted prostheses, we performed axillary-femoral and axillary-femoral-femoral bypasses in 11 patients (six seeded and five unseeded) and femoral-femoral bypasses in 28 (13 seeded and 15 unseeded). By a randomized block method of treatment allocation, femoral-popliteal grafts were installed in 147 limbs (112 vein, 18 seeded, and 17 unseeded). Patency was analyzed by the life-table method. Overall, femoral-femoral and femoral-popliteal bypasses demonstrated no difference between the seeded and unseeded grafts. Patency was somewhat better in seeded than unseeded axillary-femoral bypasses. Nevertheless, nonsmokers with seeded femoral-popliteal Dacron grafts enjoyed a significantly better graft patency than those with unseeded grafts (p = 0.035), whereas a substantial deterioration of seeded Dacron grafts was observed in those patients who smoked (p = 0.008 at 6 months). Vein grafts performed better than either seeded or unseeded Dacron prostheses (p = 0.016). Serum beta-thromboglobulin (BTG) levels varied widely and did not differ among any of the treatment groups. We concluded that endothelial seeding improved the patency of human arterial prostheses but that results were worse if the patient was a smoker. BTG was not a useful measure of the platelet activation induced by an arterial prosthesis.

Blood Coagulation Disorders↗
PubMed1984

Endothelial seeding of Dacron and polytetrafluoroethylene grafts: the cellular events of healing.

To detect cellular differences in the healing of polytetrafluoroethylene (e-PTFE) and Dacron grafts up to 7 months after implantation, we studied 108 aortic graft interpositions in dogs. Each prosthesis was alternately prepared by endothelial seeding or by an unseeded control method. The grafts were perfusion fixed and studied with light, scanning, and transmission electron microscopy at intervals from before to 221 days after implantation. Seeding resulted in the development of an extensive endothelial flow surface in two out of three of the e-PTFE and none out of four of the Dacron grafts by 10 days after implantation (p = 0.053). After 30 days a microfibrillar subendothelial matrix ranging from 5 to 11 mu formed in all but three grafts with endothelial coverage. The inner capsule of mature Dacron grafts was significantly thicker (169 +/- 143 mu) than in e-PTFE grafts (22 +/- 32 mu; p = 0.002). Seeded and unseeded Dacron grafts had predominantly fibroblasts in the outer capsule of the graft by 10 days. Surface endothelium, vasa vasorum, fibroblasts, and myointimal cells appeared in the inner capsule between 10 and 30 days after implantation. In Dacron grafts, fibroblasts and myointimal cells predominated in the inner capsule at 30 days, with smooth muscle cells not being definitely identifiable until after 150 days. Neither fibroblasts nor myointimal cells were common (present but sparse in one of four e-PTFE grafts) at 30 days, and transmural vasa vasorum were never seen. The seeded endothelial cells migrated rapidly from the sites of initial adhesion near the e-PTFE onto the flow surface. Only one of four of the unseeded e-PTFE grafts had surface endothelium after 30 days, and only moderate coverage developed during 180 days. We conclude that endothelial healing is more rapid in seeded e-PTFE grafts than in seeded Dacron grafts and occurs by a different mechanism.

Animals↗
PubMed1984

Does geographical location influence inflow requirements of the Bain breathing system?

A review of publications from various countries, using the Bain system with a fresh gas flow of 70 ml kg-1 min-1 and controlled ventilation, show a range of mean PaCO2 values between 36 and 43 mmHg. It was suggested that these differences could be related to the geographic location of the patient population studied. Anaesthetists from seven institutions in West Germany, England, Sweden, the United States, Australia and Canada collaborated in a preliminary study designed to find out whether these differences could be reduplicated. In 142 patients under a standard anaesthesia with controlled ventilation, PaCO2 values were determined 30 min after the fresh gas flows had been set. For 70 ml kg-1 min-1 the mean PaCO2 values ranged from 33 to 40 mmHg; for 100 ml kg-1 min-1 from 28 to 35 mmHg. Compared to the mean PaCO2 values from Canada, the results from Australia and the USA were not different and all at the lower end of this range; Sweden, West Germany and England reported significantly higher PaCO2 values. In the absence of any other obvious explanation, we suggest that patients in England and Northern Europe could have a higher CO2 output under anaesthesia than North American or Australian patients.

Adult↗
PubMed1983

Blood pressure readings in rural Black South African children--a pointer to future adult hypertension?

The blood pressures of 394 rural Black South African children were recorded and compared with existing records on the blood pressures of Black and White American children. It was found that the blood pressures of these rural Blacks were not significantly different from those of the American Negroes, but that they were higher than those of the White children. If blood pressure readings in the children of a population are a good predictor of future hypertension among the adults of that population, then the rural South African Black population will increasingly suffer from hypertensive disease.

Adolescent↗