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Biomedical subjects

S Thomas

Publications and source records attributed to S Thomas.

At least 397 records · Page 22Linked to original sources
PubMed1996

Sequence of the Saccharomyces cerevisiae YTP1 gene encoding a deduced novel type-III integral membrane protein with domains of sequence similarity to mitochondrial electron-transport enzymes.

The nucleotide sequence is reported for the Saccharomyces cerevisiae YTP1 (yeast putative transmembrane (TM) protein) gene, encoding a novel deduced protein of 459 amino acids (aa) in length (51 643 Da). The Ytp1 protein appears by computer analysis (hydropathy plots in conjunction with the combined predictions of several Internet on-line programs that deduce protein structure from primary sequence data) to be a type-III integral TM protein containing 10 or 11 TM-spanning domains. Blocks of aa sequence similarity, predominantly to mitochondrial electron transport proteins, are consistent with the notion that Ytp1 is an integral TM protein and may reflect some aspect of its functional role. The C terminus of Ytp1 is both hydrophilic and highly negatively charged, with 11 of the last 33 aa corresponding to Glu or Asp. Although Northern blot analysis indicates that this gene is expressed, a disruption of YTP1 shows that it is not essential. YTP1 is located between SIN4 (TSF3) and KEX2 (SRB1) at position 205 (kb) on the chromosome XIV physical map.

Amino Acid Sequence↗
PubMed1996

Effects of diminished and conflicting sensory information on balance in patients with cerebellar deficits.

We studied the effects of altered sensory information on standing balance in 25 patients with cortical cerebellar atrophy (CCA), nine patients with olivoponto-cerebellar atrophy (OPCA), and 10 normal subjects. The total sway path and its components, the anteroposterior (AP) sway path and the lateral sway path, were measured under six conditions: (1) standing on a fixed platform with the eyes open and visual surroundings fixed, (2) standing on a fixed platform with the eyes closed, (3) standing on a fixed platform with the eyes open and visual surroundings AP sway referenced, (4) standing on an AP sway-referenced platform with the eyes open and visual surroundings fixed, (5) standing on an AP sway-referenced platform with the eyes closed, and (6) standing on an AP sway-referenced platform with the eyes open and visual surroundings AP sway referenced. Patients swayed more than normal subjects during normal stance (condition 1), when the visual information was absent (condition 2) or distorted (condition 3), and when the proprioceptive information from the ankles was distorted (condition 4). Patients swayed much more than normal, and most fell, when two sensory modalities were affected under condition 5 (proprioceptive information distorted and visual information absent) and condition 6 (both proprioceptive information and visual information distorted). When the patients' sway was normalized to that of the first condition, however, only their lateral sway was greater than the sway in normal subjects. Unlike in normal subjects, the patients' lateral sway varied with the AP sway to approximately the same degree in each condition for conditions 1-5. Clinical ratings of gait and balance were highly correlated with the sway measures. Quantitative testing of standing balance with altered sensory information has better sensitivity than normal stance testing.

Adult↗
PubMed1996

Intraoperative autologous blood donation preserves red cell mass but does not decrease postoperative bleeding.

BACKGROUND: Postoperative bleeding and transfusion remain a source of morbidity and cost after open heart operations. The benefit of the acute removal and reinfusion of fresh autologous blood around the time of cardiopulmonary bypass-a technique known as intraoperative autologous donation (IAD)-has not been universally accepted. We sought to more clearly evaluate the effects of IAD on allogeneic transfusion and postoperative bleeding by removing, preserving, and reinfusing a calculated maximum volume of fresh autologous whole blood. METHODS: Ninety patients undergoing coronary artery bypass grafting or valvular operations were prospectively randomized to either have (IAD group) or not have (control group) calculated maximum volume IAD performed. Treatment was otherwise identical. Transfusion guidelines were uniformly applied to all patients. RESULTS: An average volume of 1,540 +/- 302 mL of fresh autologous blood was removed and reinfused in the IAD group. Postoperative hematocrits were significantly greater at 12 and 24 hours postoperatively in the IAD group versus the control group despite a significant decrease in both the percentage of patients in whom allogeneic red blood cells were transfused (17% versus 52%; p < 0.01) and the number of red blood cell units transfused per patient per group (0.28 +/- 0.66 and 1.14 +/- 1.19 units; p < 0.01). Conversely, chest tube output, incidence of excessive postoperative bleeding, postoperative prothrombin time, and platelet and coagulation factor transfusion requirement did not differ between groups. CONCLUSIONS: These results indicate that intraoperative autologous donation serves to preserve red blood cell mass. Its routine use in eligible patients is therefore justified. However, the removal and reinfusion of an individually calculated maximum volume of fresh autologous blood had no effect on postoperative bleeding or platelet and coagulation factor transfusion requirement. This lack of hemostatic effect belies the beliefs of many about the primary action of IAD, helps to delineate the optimal way in which to perform IAD, and carries implications regarding the use of allogeneic platelet and coagulation factors for the treatment of early postoperative bleeding.

Adult↗
PubMed1996

Carrier herbal medicine: traditional and contemporary plant use.

The Carrier, an Athapaskan-speaking people of northcentral British Columbia, occupy the sub-boreal spruce forests of the central interior. This report, which is based on field study, documents some traditional and contemporary knowledge of the medicinal use of plants by the Carrier people. Important medicinal plants include: Abies lasiocarpa, Alnus incana, Arctostaphylos uva-ursi, Artemisia frigida, Fragaria virginiana, Juniperus communis, Picea glauca, Pinus contorta, Populus tremuloides, Rubus idaeus and Shepherdia canadensis.

British Columbia↗
PubMed1996

The significance of increased 111indium platelet accumulation at post-angioplasty sites.

We assessed prospectively the significance of 111indium labelled platelet accumulation following angioplasty procedures in 12 patients (9 femoral angioplasties (2 laser, 1 atherectomy) and 3 iliac stents). Autologous 111indium labelled platelets were re-injected immediately after angioplasty. Radioactivity was measured over treated and reference sites, by single probe and gamma camera, and expressed as a radioactivity ratio (RR). All patients had duplex ultrasound assessment and occlusions were confirmed by arteriography. RR was always raised after angioplasty. Three patients who had acute occlusions showed markedly raised average RRs (significant at 99% ANOVA). RR was not raised after laser assisted angioplasty, however, our numbers were small. 111Indium platelet radioactivity did not predict subsequent occlusion after angioplasty but effectively detected existing acute post-angioplasty occlusions.

Angiography↗
PubMed1996

The EXT2 multiple exostoses gene defines a family of putative tumour suppressor genes.

Hereditary multiple exostoses (EXT) is an autosomal dominant condition characterized by short stature and the development of bony protuberances at the ends of all the long bones. Three genetic locl have been identified by genetic linkage analysis at chromosomes 8q24.1, 11p11-13 and 19p. The EXT1 gene on chromosome 8 was recently identified and characterized. Here, we report the isolation and characterization of the EXT2 gene. This gene shows striking sequence similarity to the EXT1 gene, and we have identified a four base deletion segregating with the phenotype. Both EXT1 and EXT2 show significant homology with one additional expressed sequence tag, defining a new multigene family of proteins with potential tumour suppressor activity.

Amino Acid Sequence↗
PubMed1996

Retroperitoneal surgery: its wider role in the management of malignant teratoma.

OBJECTIVE: To review the results of the use of laparotomy to excise retroperitoneal metastases in patients with malignant teratoma of the testis. PATIENTS AND METHODS: The results of surgery for retroperitoneal teratoma metastases in 37 patients during the 5-year period from 1988 to 1993 were reviewed. Information on sexual dysfunction was obtained using a postal questionnaire. RESULTS: Patients were divided into three groups: the first comprised 28 patients who underwent elective surgery (excision of residual disease) after platinum and bleomycin-based chemotherapy. The second group comprised four patients who underwent interventional surgery to excise disease not responding to treatment, after which they completed chemotherapy. The third group comprised five patients who underwent surgery for relapsed disease; two had suffered an early and three a late relapse. Overall, 34 patients are alive, four are considered to have residual disease and two have recently undergone re-operation. CONCLUSIONS: In addition to removing residual disease after primary chemotherapy, surgery has a wider role in the management of metastatic teratoma. Carefully timed interventional surgery for disease not responding to chemotherapy can be lifesaving. Surgery for early relapse should be preceded by chemotherapy but surgery alone is appropriate where relapse occurs several years after primary treatment, although raised levels of tumour markers or extensive recurrence might be an indication for preliminary chemotherapy.

Adolescent↗
PubMed1996

Uraemic pruritus and exposure to di(2-ethylhexyl) phthalate (DEHP) in haemodialysis patients.

Uraemic pruritus is a frequent and disabling symptom in patients on dialysis. The pathogenesis of uraemic pruritus is nevertheless still obscure. We investigated whether di(2-ethylhexyl)phthalate (DEHP), the most commonly used plasticizer in polyvinylchloride (PVC) haemodialysis tubings, is a possible pathogenetic factor in uraemic pruritus. Serum concentrations of DEHP and its major derivatives mono-(2-ethylhexyl)phthalate (MEHP), 2-ethylhexanol (2-EH) and phthalic acid (PA) were determined in uraemic patients before and after a haemodialysis session and compared with the occurrence and intensity of pruritus in these patients. Twenty-one patients on regular haemodialysis for at least 6 months were examined. The severity of uraemic pruritus was assessed using a standard questionnaire (pruritus score). The quantitative analysis of DEHP and its derivatives was carried out by GC/selected ion monitoring mass spectrometry. Fourteen out of 21 patients (66%) complained about uraemic pruritus to a variable degree. The post-dialysis serum concentrations of DEHP, MEHP and 2-EH were significantly higher than the corresponding pre-dialysis values, whereas the post-dialysis concentrations of PA (0.122 +/- 0.078 microgram/microliter) were significantly lower than pre-dialysis levels (0.194 +/- 0.101 microgram/microliter, P = 0.00068). Neither pre- nor post-dialysis serum concentrations of DEHP, MEHP, PA or 2-EH were correlated with the severity of uraemic pruritus. Additionally, serum concentrations of DEHP and its metabolites did not differ significantly in patients with and without pruritus. These findings suggest that patients on haemodialysis are regularly exposed to considerable amounts of DEHP and metabolites. Phthalic acid, one of the presumed end products of DEHP metabolism, might be eliminated at least in part by haemodialysis. The exposition to DEHP and metabolites during haemodialysis, as assessed by measuring serum concentrations, bears no immediate relation to the occurrence or intensity of uraemic pruritus.

Adult↗
PubMed1996

Critical care nurse satisfaction with levels of involvement in clinical decisions.

This research reports the results of a survey of 230 Australian critical care nurses. The respondents were asked to rate how frequently they were involved in 10 common critical care decisions and their levels of satisfaction with their involvement for each decision task. It was found that level of task satisfaction was positively correlated with level of task involvement, thus supporting the hypothesis that nurse task decision autonomy is associated with nurse task satisfaction. The paper argues for the importance of differentiation between task satisfaction and work satisfaction in research of these issues.

Adult↗
PubMed1996

Natriuretic peptides and cyclic guanosine 3',5'-monophosphate in asymptomatic and symptomatic left ventricular dysfunction.

BACKGROUND: Screening for patients with asymptomatic left ventricular dysfunction is of considerable importance because they may benefit from early treatment with angiotensin converting enzyme inhibitors. It has been suggested that atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and cyclic guanosine 3',5'-monophosphate (cGMP) might be useful markers for screening. OBJECTIVE: To compare directly the power of the three immunoreactive forms of ANP (CT-ANP, beta-ANP, NT-ANP) and BNP and cGMP to detect asymptomatic left ventricular dysfunction. METHODS AND RESULTS: Radionuclide ventriculography was used to study left ventricular ejection fraction in 37 patients with asymptomatic left ventricular dysfunction, 32 patients with mild to moderate congestive heart failure, and 38 controls. CT-ANP, NT-ANP, beta-ANP, BNP, and cGMP were measured at rest and 3 minutes after exercise. Plasma BNP was the most sensitive marker for patients with asymptomatic left ventricular dysfunction but it reached only a sensitivity of 58% and a specificity of 76% at rest and a sensitivity of 65% and a specificity of 84% after exercise. Combined measurements of all natriuretic peptides and cGMP did not improve the power to detect asymptomatic left ventricular function above that of a single BNP measurement. CONCLUSIONS: Although natriuretic peptides and cGMP measured at rest and three minutes after ergometry may be useful for monitoring left ventricular dysfunction they are unlikely to be suitable for more general routine screening for completely asymptomatic left ventricular dysfunction.

Adult↗
PubMed1996

Low-dose intradermal versus intramuscular hepatitis B vaccination in patients with end-stage renal failure. A preliminary study.

Patients with end-stage renal disease (ESRD) are at high risk of hepatitis B infection. Only 50-60% of the patients respond adequately to the routinely performed intramuscular (i.m.) hepatitis B vaccination. We examined whether low dose intradermal (i.d.) application of the vaccine is equivalent to regular i.m. administration. Thirty-two patients with ESRD of different etiologies were investigated at the onset of dialysis treatment [11 patients on continuous ambulatory peritoneal dialysis (CAPD) and 21 patients on hemodialysis (HD)]. Patients were vaccinated at month 0, 1, 3 and 6 with either 40 micrograms HBs Ag (2 ml Engerix B, 14 patients) i.m. or with 10 micrograms HBsAg (0.5 ml Engerix B, 18 patients) i.d. The i.m. vaccination was applied in the deltoid muscle, while for i.d. vaccination the vaccine was injected into the skin of the deltoid region. Six weeks after the last vaccination anti-HBs titers were measured. 61% (11 patients) of the patients vaccinated i.d. and 64% (9 patients) of the patients vaccinated i.m. developed protective titers. Neither the height of the titers nor the proportion of patients responding to the vaccination differed significantly between the two vaccination schedules. No difference regarding the height of titers achieved or the rate of seroconversion could be found when CAPD and HD patients were analyzed separately. Only minor side effects have been observed. According to these preliminary data i.d. hepatitis B vaccination in patients with ESRD may be equivalent to i.m. administration of the vaccine. Given equivalency i.d. vaccination may be a cost-saving alternative to i.m. vaccination (only a quarter of the dose of i.m. administered vaccine is needed) with a good practicability (vaccination can be performed during HD) and a low rate of side effects.

Female↗
PubMed1996

Inhibition of tissue factor and cytokine release.

The effect of inhibitors of cytokine release and plasma coagulation on lipopolysaccharide (LPS)-induced tissue factor and interleukin-6 (IL-6) was investigated. Dexamethasone, an inhibitor of cytokine production, inhibited LPS-induced tissue factor and IL-6 release by mononuclear cells (MNC), but enhanced IL-1beta-evoked tissue factor activity. Clinical antithrombin (AT) concentrates inhibited, in a dose-dependent manner, tissue factor and IL-6 production by MNC and human umbilical vein endothelial cells (HUVEC). The three AT preparations tested, when compared using the same antithrombin unit, had different potencies. Activated protein C (APC) augmented LPS stimulation of HUVEC and further increased the production of tissue factor and IL-6. The same effect was not observed with MNC; LPS-induced tissue factor and IL-6 release were unaffected by APC. Truncated tissue factor pathway inhibitor (TFPI1-161) inhibited LPS-induced MNC tissue factor and IL-6 production, but was unable to prevent LPS stimulatory activity on HUVEC. These data suggest a complex interaction between the coagulation pathway and the cytokine network.

Blood Coagulation↗
PubMed1996

MMPI differences among adolescent inpatients, rapists, sodomists, and sexual abusers.

This study examined Minnesota Multiphasic Personality Inventory (MMPI) responding among 61 adolescent sex offenders accused of Sexual Abuse (n = 22), Rape (n = 19), and Sodomy (n = 18) and 15 adolescents without a history of sexual offending admitted to an inpatient psychiatric unit. Results indicated significant differences between sex offenders and inpatients as well as among sex offender groups on both single-scale elevations and 2-point code types. Contrary to previous research, adolescents in the sex offender groups demonstrated significantly more psychopathology than those in the inpatient sample. Subjects in the Sodomy group achieved the highest clinical scale elevations and were more likely to have scales associated with significant psychopathology as one of their 2-point pairs. In general, increased psychopathology was associated with increased sexual deviancy. That is, subjects in the sexual offender groups evidenced more psychopathology than inpatients and the more deviant Sodomy and Rape groups evidenced more psychological disturbance on the MMPI than Sexual Abuser subjects. Results indicate that the MMPI can be useful in providing both quantitative and qualitative distinctions among adolescent sex offenders.

Adolescent↗
PubMed1996

High-compression bandages.

This report describes the results of a programme of tests carried out on a new high-compression bandage, with two application aids designed to produce specific pressures on normal-size and oedematous limbs. The product was tested to examine its performance in relation to the specified criteria of a Type 3c compression bandage and other pre-defined features. The results show that, with the use of both application aids, the bandage can provide the target pressure of 40 mmHg +/- 10% on ankles ranging from 21-26 cm and 27-33 cm in circumference. Ankles with circumferences between 26 and 27 cm will fall marginally outside the design criteria (40 +/- 6 mmHg).

Bandages↗
PubMed1996

Using larvae in modern wound management.

Initial clinical experience in the UK with maggot therapy for the treatment of necrotic or infected wounds has proved very encouraging. Sterile larvae have been reared in the Surgical Materials Testing Laboratory for this purpose. This paper reports the use of larvae in six patients and discusses some of the advantages and disadvantages of this form of therapy.

Adult↗