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Biomedical subjects

F Smith

Publications and source records attributed to F Smith.

At least 91 records · Page 5Linked to original sources
PubMed1993

Selective T-cell-receptor gene usage in allorecognition and graft-versus-host disease.

Immune recognition of foreign HLA molecules is initiated by T cell recognition mediated by alloreactive T cell receptor (TCR) molecules. We analyzed the diversity of TCR expression in the clinical setting of allorecognition in a patient with acute graft-versus-host disease following bone marrow transplantation. Nearly 200 TCR transcripts from peripheral blood lymphocytes were cloned and sequenced at two time points during GVHD. HLA genes in the transplant donor and the recipient were mismatched for a very specific HLA-DR subtype: HLA-DRB1 genes in the donor (DR4/Dw4) and the recipient (DR4/Dw14) encode HLA molecules that differ at only two amino acids, providing a very restricted target for allorecognition. We also studied TCR genes from five T cell clones derived in vitro from mixed lymphocyte cultures between Dw4-positive responder and Dw14-positive stimulator cells. Comparisons of the derived TCR sequences implicate nonrandom patterns of TCR selection both in vivo and in vitro.

Acute Disease↗
PubMed1993

Study of left and right ventricular function in Romano-Ward syndrome.

OBJECTIVE: To examine left and right ventricular contraction in Romano-Ward syndrome: does abnormal myocardium affect the predisposition to arrhythmia? DESIGN: Tomographic radionuclide ventriculography was performed after the red blood cells were labelled conventionally with stannous pyrophosphate and technetium-99m. SETTING: Department of Nuclear Medicine, Aberdeen Royal Infirmary. PATIENTS: Eight subjects from two families known to have Romano-Ward syndrome, four of whom (two from each family) had had symptoms. RESULTS: The five subjects from family 1 had normal left ventricular contraction; two had subtle abnormalities of right ventricular phase. in family 2 all three subjects had abnormal left ventricular contraction (reduced amplitude in three, abnormal phase in two). All had subtle abnormalities of right ventricular phase. CONCLUSION: Abnormal right or left ventricular myocardium may be partly or wholly responsible for the repolarisation changes seen on the electrocardiogram of these families or may act as an ectopic focus to start ventricular tachycardias in a susceptible heart.

Adult↗
PubMed1993

Evaluation of ferric oxalate as an agent for use during surgery to prevent post-operative root hypersensitivity.

The aim of this study was to evaluate the effectiveness of a 6% ferric oxalate solution applied during periodontal surgery to prevent post-operative tooth hypersensitivity. Twenty-five adult patients with similar bilateral periodontal defects participated in this study. Data were collected at baseline (1 week prior to surgery) and 1, 2, 4, and 6 weeks following surgery. Sensitivity level was determined using the visual analog scale (VAS) with the following stimuli: 1) mechanical stimulation with a No. 23 dental explorer; 2) water at 50 degrees C; 3) ice; and 4) electric pulp tester (EPT). Teeth were randomly assigned to either test (6% ferric oxalate in 0.9% saline) or control (0.9% saline) groups. Solutions were applied to the exposed root surfaces for 1 minute during surgery. Data were analyzed by repeated measures ANOVA, paired t-test, and Pearson's correlation test. Results from this study demonstrated statistically significant reduction in the responses to thermal stimuli, especially cold, between groups treated with ferric oxalate as compared to those treated with saline. For the cold test the difference increased with time from baseline to 6 weeks. Statistically significant (P < 0.05) differences in sensitivity to heat between groups were also observed, but only at 2 and 4 weeks following surgery. There were no differences at any time period between the test and control groups when tactile or EPT techniques were used. In addition, there was no correlation between sensitivity and other clinical parameters. It was concluded from this study that 6% ferric oxalate was effective in reducing post-surgical cold sensitivity when applied during periodontal surgical procedures.

Adult↗
PubMed1993

Helicobacter pylori prevalence in acquired immunodeficiency syndrome.

Helicobacter pylori is consistently reported with high prevalence in HIV-negative patients with chronic gastritis and active ulcer disease. This study is an evaluation of the prevalence of H. pylori in AIDS patients, and the association with chronic gastritis, erosions, and ulcer disease. Seventy-three AIDS patients referred for the evaluation of gastrointestinal symptoms underwent upper endoscopy and antral gastric biopsy. Histologic gastritis was diagnosed and degree of activity graded on hematoxylin-eosin stain. H. pylori organisms were identified by acridine orange stain. A single pathologist evaluated the biopsy specimens. H. pylori was found in 15% (11 of 73) of AIDS patients. Histologic chronic active gastritis was evident in 94.5% (69 of 73) of the study group. H. pylori was identified in 15.9% (11 of 69) of biopsy specimens with histologic chronic active gastritis. The organism was more common in biopsy specimens with a higher grade of activity in the chronic gastritis. Endoscopic erosions or ulcers were noted in 11 patients (seven gastric, four duodenal). H. pylori was present in 18% (2 of 11) of AIDS patients with erosions or ulcers. The prevalence of H. pylori in AIDS patients with histologic chronic active gastritis is much lower than the prevalence previously reported for HIV-negative patients with similar pathology. The low prevalence observed does not implicate H. pylori as the causal agent in most chronic active gastritis in the AIDS population. Impaired acid secretion may reduce colonization of gastric mucosa and explain the low rate of H. pylori observed.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Pleural liposarcoma presenting with respiratory distress and suspected diaphragmatic hernia.

A young woman with a history of diaphragmatic hernia presented to the hospital in respiratory distress and in premature labor. Her admission chest roentgenogram showed opacification of the left hemithorax, and her arterial blood gas analysis revealed hypoxemia. Emergency cesarean section and exploratory left thoracotomy were carried out; a large tumor occupied the left side of the chest, and pneumonectomy was performed. No diaphragmatic hernia was present. A pathologic diagnosis of primary liposarcoma was made.

Adult↗
PubMed1992

Relationship between determinants of oxygen delivery and respiratory abnormalities in preterm infants with anemia.

To study the relationship between anemia and breathing abnormalities in preterm infants, we measured oxygen supply and demand in two groups of anemic infants less than or equal to 32 weeks of gestational age. Six-second apnea density was less than 1% in one group and greater than or equal to 5% in the other. There were no differences in hemoglobin concentration, available oxygen, oxygen consumption, or Doppler-determined cardiac output between the two groups of infants. Furthermore, in anemic preterm infants with apnea density greater than or equal to 5%, reductions in 6-second apnea density were similar after erythrocyte transfusion (mean +/- SEM: from 8.6% +/- 1.1% to 4.7% +/- 0.7%) or after an isovolemic infusion of 5% albumin (from 9.0% +/- 1.4% to 4.7% +/- 0.7%). These results show no relationship between measures of oxygen delivery and respiratory irregularities, and indicate that volume expansion may play a role in ameliorating the pneumocardiogram abnormalities.

Anemia↗
PubMed1992

Focal ventricular thinning caused by indomethacin in the late phase of coxsackievirus B4 murine myocarditis.

Indomethacin has been shown to increase virus titers and to worsen cardiac injury in the acute phase of coxsackievirus B4 murine myocarditis. The authors evaluated the effects of indomethacin on the histopathologic changes in a later phase of this disease after virus clearance. Two-day old CD1 mice were infected with coxsackievirus B4. Ten days later, surviving animals were randomized to receive indomethacin or saline intraperitoneally for 10 days. They were then euthanatized, and their hearts were examined for the presence of inflammation, necrosis, scarring, and focal thinning. Mortality was slightly higher among treated animals (7/15 versus 2/12, p = 0.3). The index of inflammation (0.6 +/- 0.5 versus 0.7 +/- 0.5) necrosis and scarring (0.4 +/- 0.5 versus 0.3 +/- 0.5) among treated and control animals, respectively, was not significantly different, but the size of involved myocardium (149742 +/- 201982 versus 35300 +/- 45413 microns2) was remarkably larger (p less than 0.05), and focal ventricular thinning (5/12 versus 0/10, p = 0.03) was encountered among indomethacin recipients exclusively. These findings indicate that indomethacin treatment in the late phase of coxsackievirus B4 myocarditis enhances myocardial damage and increases the incidence of focal ventricular thinning.

Animals↗
PubMed1992

[Behavior characteristics of 10-year-old ex-neonatal intensive care patients].

Subject of study was the analysis of behavioral characteristics of 51 10-year-old ex-NICU patients at home and at school. Parental assessment of child behavior proved not to differ from the normative data. Teachers however reported more problematic behaviors, particularly with regard to the introverted behavior in boys. On the basis of these findings one can conclude that the prognosis for this patient group is better than expected. A plea is made for future research to focus on factors that will facilitate a more favorable behavior development.

Achievement↗
PubMed1991

The influence of skin structure on permeability: an intersite and interspecies comparison with hydrophilic penetrants.

For reasons that are unclear, skin from various body sites has different permeability properties. We have used hydrophilic penetrants (water, ethanol, mannitol, and paraquat) to study the in vitro permeability of skin from marmoset (eight body sites), man, and rat. Skin structure (stratum corneum thickness and number of cell layers; epidermal and dermal thickness; number and area of hair follicle openings per mm2) was compared with permeability. There was no apparent relationship between skin structure and permeability to the most rapid penetrants, water and ethanol. Follicle area opening was the structural feature that varied most between species and between body sites. Different marmoset body sites showed a threefold range in follicle area but this did not appear to influence the absorption rates of the test penetrants. However, among the species there was an 80-times range in follicle area, which correlated with the observed differences in rate of mannitol and paraquat absorption. Thus, permeability could be related to inter-species differences in skin structure, but only with the relatively slowly absorbed test penetrants, mannitol and paraquat.

Animals↗
PubMed1991

Personality as a vulnerability factor to depression.

One hundred and forty non-depressed primiparous women in a stable relationship completed two personality measures (the EPI and the IPSM) antenatally, and were then assessed for depression at several times post-natally. The risk of depression at six months was increased up to tenfold by high interpersonal sensitivity and threefold by high neuroticism. When previously depressed women were excluded from analyses, high interpersonal sensitivity and, to a lesser extent, high neuroticism were still associated with an increased risk of being depressed. Interpersonal sensitivity, as measured, is suggested as a refined personality risk factor to both the onset and recurrence of depression.

Depressive Disorder↗
PubMed1991

Low protein/high calorie dietary regimen in the management of chronic renal failure. A preliminary study of Nigerian patients.

The progression of renal failure was evaluated in seven patients with established chronic renal failure (mean serum creatinine 4.17 mg%), while on a supervised dietary regimen consisting of low protein of high biological value (20-30 g/day), and a high calorie content (3000 kcal/day) for a period of between 18 and 28 months. Five other patients with a comparable degree of chronic renal failure whose protein intake was unrestricted (evaluated to vary between 40 and 60 g per day) served as controls. In the study group, serum creatinine levels stabilized or improved in five, while a moderate rise was observed in two. In contrast, a considerable and significant rise in serum creatinine values was observed in all the controls. Two significantly different slopes (P less than 0.01) were also obtained from the linear regression analysis of the reciprocal of serum creatinine values against time, for the two groups. Our preliminary observation of a beneficial effect of this regimen in our patients is particularly relevant to the developing countries because of the high prevalence of chronic renal failure against the background of grossly inadequate facilities for maintenance dialysis or renal transplantation.

Creatinine↗
PubMed1990

Charles Darwin

Explore the source record for details and available documents.

History, Modern 1601-↗
PubMed1990

Enhancement of coxsackievirus B4 virulence by indomethacin.

The safety of nonsteroidal anti-inflammatory agents in viral infections was assessed in a mouse model of coxsackievirus B4 neonatal myocarditis. Two-day-old mice were infected intraperitoneally with 10(4) TCID50 coxsackievirus B4 and then randomized to receive indomethacin or saline for 7 days. A number of them were killed on designated days. Mortality, viral titers, antibody, and interferon levels plus histopathologic changes in the heart were compared. Among treated animals, mortality was greater (22/45 vs 7/27; p = 0.07) and viral titers were higher on days 4 and 7 (p = 0.038 and 0.028, respectively). Interferon levels were lower on days 4 and 7 (p = 0.028 and 0.008, respectively), and histopathologic changes were more extensive on days 7 and 21 (p = 0.008 and 0.028, respectively). These findings show that indomethacin decreased interferon production, increased coxsackievirus4 titers, and enhanced the virulence of coxsackievirus B4. These results raise significant concerns about the safety of indiscriminate use of nonsteroidal anti-inflammatory agents during severe viral infections.

Animals↗