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Biomedical subjects

A G Thomas

Publications and source records attributed to A G Thomas.

At least 55 records · Page 3Linked to original sources
PubMed1997

The effect of pregnancy on cyclosporine levels in renal allograft patients.

OBJECTIVE: To assess the effects of pregnancy on cyclosporine levels in six renal allograft patients. METHODS: Maternal demographic, laboratory, clinical, and perinatal outcome data were recorded in six pregnant women with previous renal allografts receiving cyclosporine immunosuppression. The cyclosporine and serum creatinine levels were measured before pregnancy, during each trimester, and postpartum. RESULTS: The mean (standard deviation [SD]) maternal age was 29.1 (3.8) years. Parity ranged from 0 to 3. Mean serum creatinine levels tended to be lower during pregnancy than before or after, as did the mean cyclosporine levels. After adjusting for dose, five of six patients had declines in cyclosporine level during pregnancy. The mean (SD) gestational age at delivery was 37.5 (2.8) weeks with a mean (SD) birth weight of 2837 (538) g. CONCLUSION: Pregnancy in patients with renal allografts can lead to a substantial decline in cyclosporine levels.

Adult↗
PubMed1997

Caregivers' perceptions following gastrostomy in severely disabled children with feeding problems.

Feeding difficulties are common in neurologically impaired children, often leading to great distress and frustration in the child and family. A gastrostomy may be advocated if oral intake is inadequate causing poor weight gain or when there is significant aspiration during feeding, or if feeding is very distressing. To find out if caregivers were happy with the outcome of gastrostomy (with fundoplication, when indicated), a 35-item questionnaire was developed and sent to 38 of them. Twenty-nine replies were received and appeared to be representative of the whole group. Coughing, choking, and vomiting improved in most cases. Weight gain improved in all in whom it had been a problem. In the majority, it became easier to give the children their medications although control of epilepsy was unchanged overall. Time spent feeding the child was reduced and many caregivers had more time to devote to other children and themselves. Only one parent regretted the operation. In children with severe disability and feeding problems, a gastrostomy (with fundoplication if there is significant reflux) can reduce symptoms of vomiting, coughing, and choking, help growth and improve quality of life in the child, when patients are properly selected.

Adolescent↗
PubMed1997

Vaginal douching and adverse health effects: a meta-analysis.

OBJECTIVES: The meta-analysis described here reviewed the current literature on adverse health effects of vaginal douching. METHODS: Papers published in English from 1965 through 1995 were potentially eligible. RESULTS: One third of White women and two thirds of Black women of reproductive age reported douching regularly. Analyses indicated that vaginal douching increases the overall risk of pelvic inflammatory disease by 73% and the risk of ectopic pregnancy by 76%. Frequent douching was shown to be highly associated with pelvic inflammatory disease and modestly associated with cervical cancer. CONCLUSIONS: Current literature suggests that frequent douching increases the risk of pelvic inflammatory disease, ectopic pregnancy, and, possibly, cervical cancer.

Female↗
PubMed1996

Protective effects of extracellular acidosis and blockade of sodium/hydrogen ion exchange during recovery from metabolic inhibition in neuronal tissue culture.

Acidosis is a universal response of tissue to ischemia. In the brain, severe acidosis has been linked to worsening of cerebral infarction. However, milder acidosis can have protective effects. As part of our investigations of the therapeutic window in our neuronal tissue culture model of ischemia, we investigated the effects of acidosis during recovery from brief simulated ischemia. Ischemic conditions were simulated in dissociated cortical cultures by metabolic inhibition with potassium cyanide to block oxidative metabolism and 2-deoxyglucose to block glycolysis. Lowering the extracellular pH (pH0) to 6.2 during metabolic inhibition had no effect on injury, as measured by lactate dehydrogenase release from cultures after 24 h of recovery. Lowering the pH0 during the first hour of recovery, in contrast, had profound protective effects. When the duration of metabolic inhibition was lengthened to 30 min, most of the protective effects of the NMDA receptor antagonist MK-801 were lost. However, the protective effects of acidosis were unchanged. This suggested that the protective effects of extracellular acidosis could be due to more than blockade of NMDA receptors. Intracellular acidosis might be responsible. To test this, recovery of intracellular pH (pH1) was slowed by incubation with blockers of Na+/H+ exchangers at normal pH0. The two compounds tested, dimethylamiloride and harmaline, had protective effects when present during recovery from metabolic inhibition. Measurements of pH1 confirmed that the blockers slowed recovery from intracellular acidosis; more rapid pH1 recovery was correlated with injury. The protective effects of acidosis could be reversed by brief incubation with the protonophore monensin, which rapidly normalized pH1. These results are the first demonstration of the protective effects of blocking Na+/H+ exchange in a model of cerebral ischemia. The protective effects of acidosis appear to arise either from suppressing pH-sensitive mechanisms of injury or from blocking sodium entry due to Na+/H+ exchange.

Acidosis↗
PubMed1996

Quality of life in children with Crohn's disease.

In a 10-week randomised cross-sectional study we used an 88-item questionnaire to assess the quality of life in 16 children (ages 8-17 years) with Crohn's disease and their families. The questionnaire covered six domains of health-related quality of life, including disease and its treatment, social, emotional, family, education, and future aspects. Crohn's disease affected education, with absenteeism in 12 and distraction during school work in six. Three children had had a home tutor, and five stated their need for one. Engaging in sports was a problem for eight children, mainly because of a lack of energy in five and the presence of a stoma in three children. Three children had missed every PE lesson in 1 year. Five children cited the social problem of being unable to stay over at friends' houses. Bullying concerned parents more than the children. Holiday difficulties included long distance traveling or lack of toilet facilities during school trips. Elemental diet was the preferred treatment, although the majority complained about the taste. Surgery was the most effective method of symptom control, though the resulting stoma was upsetting and restricted sports activities. Children on steroids had more depressive symptoms. Using the Rutter A Questionnaire, five children were designated "neurotic." Parents' views of the severity of symptoms significantly correlated with their children's views regarding rectal bleeding, poor growth, lack of energy, and poor appetite (p < 0.01). The main parental concerns were the side effects of medications and issues concerning their children's future, including schooling, job prospects, and marriage. The parents of 11 children cited problems with children's behaviour. The parents of seven cited disruption of work, and those of six named taking holidays. Crohn's disease in children, in addition to being a symptomatically disabling condition, has a great impact on the health-related quality of life of both sufferers and their parents. The questionnaire was a useful instrument, and with some adjustment it can be used again in large group studies.

Adolescent↗
PubMed1996

Inflammatory bowel disease in infancy: an increasing problem?

Seven children with intractable diarrhoea of infancy seen between 1990 and 1993 developed endoscopically established inflammatory bowel disease unrelated to bacterial infection and not responsive to whole protein exclusion. Mouth ulcers were present in two patients, endoscopic upper-gastrointestinal-tract inflammation in two, villous atrophy in six, and chronic nonspecific colitis in all seven. There was considerable clinical and histological heterogeneity. All patients required parenteral nutrition. Steroid therapy was completely successful in only one child, while two underwent colectomy, and two died. Previously described cases other than those due to infection or milk intolerance have been rare and sporadic. The prevalence of inflammatory bowel disease in infancy is unknown but appears to be increasing.

Biopsy↗
PubMed1995

Resonant photoemission from complex cuprates and nickelates.

Synchrotron-excited resonant-photoemission measurements at rare-earth 4d --> 4f and transition-metal 3p --> 3d thresholds have been carried out using a variety of complex cuprates and nickelates on stations 6.1 (grazing-incidence monochromator) and 6.2 (toroidal-grating monochromator) at the SRS CLRC Daresbury Laboratory. The systems studied are Nd(2)Ni(1 - x)Cu(x)O(4), La(2 - x)Sr(x)Ni(1- y)Fe(y)O(4 + delta) and Bi(2)Sr(2)Ca(1 - x)Y(x)Cu(2)O(8 + delta). A combination of EDC and constant-initial-state data is used to examine the 4f and 3d contributions to the valence-band density of states and their binding-energy positions relative to the Fermi energy. This allows the study of the valence states of the transition-metal ions and their modulation on doping. For La(2 - x)Sr(x)Ni(1 - y)Fe(y)O(4 + delta), this approach is used to infer a valence state of >/= 3.0 for Fe. In the case of Bi(2)Sr(2)Ca(1 - x)Y(x)Cu(2)O(8 + delta), the effect of Cu valence modulation on the 3p resonance is observed as x is varied. This is discussed in the light of controversy surrounding shifts in core-level photoemission with doping for this system.

Journal Article↗
PubMed1995

Manchester procedure vs. vaginal hysterectomy for uterine prolapse. A comparison.

The Manchester procedure (MP) was compared with vaginal hysterectomy (VH) to determine whether any differences regarding patient demographics or operative or postoperative outcome could be found between the two techniques. A retrospective chart analysis was done comparing data from 88 consecutive MP to 105 randomly selected VH patients. All the operations were performed for uterine prolapse at Mount Sinai Hospital between 1984 and 1988. MP patients, when compared to VH patients, were more likely to be older and postmenopausal at the time of surgery and to have a private physician. MP patients were less likely to have significant medical illnesses than were VH patients. Statistically significant differences between MP and VH were found for operative time (100 vs 130 minutes, respectively) and blood loss (200 vs. 300 mL, respectively) (P < .001). This difference was not dependent on the performance of anterior or posterior repair. MP was associated with shorter operative time and less blood loss when compared to VH. This, coupled with apparently similar operative outcomes, suggests the use of MP as an alternative to VH in the absence of uterine pathology in appropriate candidates with uterine prolapse. Prospective, controlled, long-term studies comparing the operative results of these two procedures are needed.

Adult↗
PubMed1994

Laparoscopic Pomeroy tubal ligation in a residency training program.

STUDY OBJECTIVE: To evaluate the efficacy of the laparoscopic Pomeroy method of tubal ligation as a teaching tool during the initial acquisition of advanced laparoscopic skills by 14 residents in a 28-person, 4-year program. DESIGN: A prospective, nonrandomized study. SETTING: A metropolitan teaching hospital. PATIENTS: Fifty-seven women who desired permanent sterilization, and 56 controls who underwent laparoscopic sterilization by standard coagulation. One refused entry and had standard sterilization by bipolar coagulation. In two women, both with several previous laparotomies, visualization of the pelvic organs was incomplete and the procedure was abandoned at the discretion of the surgeon. One had a minilaparotomy Pomeroy tubal ligation and the other was sterilized by standard two-puncture laparoscopic coagulation. One patient was excluded due to an incomplete data profile. INTERVENTIONS: Laparoscopic sterilizations using the Pomeroy technique and standard coagulation were performed by gynecology residents with an attending physician present. First-year residents performed 36 (68%) of the 53 procedures. MEASUREMENTS AND MAIN RESULTS: Operative times to teach this technique to house officers rotating on the gynecologic service were recorded by postgraduate year and stratified by the number of cases performed by each operator. The average operative times for residents in postgraduate years 1 through 4 were 18.6, 15.4, 21.7, and 14.8 minutes, respectively. These diminished with experience. A statistically longer time of 7.1 minutes was required to teach residents the Pomeroy technique compared with standard bipolar coagulation (p<0.0003). CONCLUSION: Laparoscopic Pomeroy tubal ligation as a method to begin educating residents in advanced operative video-laparoscopy appears to have great potential.

Female↗
PubMed1994

Selenium and glutathione peroxidase status in paediatric health and gastrointestinal disease.

To examine the effect of paediatric GI disease on selenium concentration in plasma and glutathione peroxidase activity in plasma and red cells, results in children with Crohn's disease (n = 39), cystic fibrosis (n = 14), intractable diarrhoea (n = 13), and biliary atresia (n = 10) were compared with those from 86 healthy children undergoing routine operations. In Crohn's disease, plasma selenium concentrations were rarely low, but glutathione peroxidase activity was increased in the plasma and reduced in the red cells. Selenium concentration and glutathione peroxidase activity increased with steroid treatment but decreased with a selenium-deficient elemental diet. Plasma selenium concentration was normal in children with cystic fibrosis but very low in severely malnourished children with biliary atresia and intractable diarrhoea. Selenium concentration and glutathione peroxidase activity should be monitored in children with severe malnutrition or requiring prolonged nutritional support. Supplementation is recommended in cases of severe selenium depletion.

Adolescent↗
PubMed1994

The effect of placenta previa on blood loss in second-trimester pregnancy termination.

OBJECTIVE: To determine whether placenta previa increases bleeding during second-trimester pregnancy termination. METHODS: The records of 131 consecutive women undergoing elective pregnancy termination at 13-24 weeks' gestation were reviewed and divided into those with and without placenta previa based on an ultrasound examination before the procedure. These two groups were then compared for differences in maternal characteristics, estimated blood loss, operative time, infection, and hospital admission. RESULTS: Twenty-three of 131 women (17.6%) had placenta previa. Sixty-seven percent of the previa patients smoked, versus 37% in the control group, a statistically significant difference. A statistical difference was noted with respect to placenta previa in intraoperative blood loss (P < .05), but not operative time, time to discharge, infection, hemorrhage, or other complications. CONCLUSION: Second-trimester pregnancy terminations in the presence of placenta previa are associated with a higher estimated blood loss, but no apparent increase in abortion-related infection, postoperative transfusion requirements, hysterectomy, or other complications.

Abortion, Therapeutic↗