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Biomedical subjects

A Byrne

Publications and source records attributed to A Byrne.

At least 19 recordsLinked to original sources
PubMed1992

Prepregnancy counselling: experience from 1,075 cases.

OBJECTIVE: To assess the activity of a prepregnancy counselling clinic in terms of investigations, counselling, treatment and subsequent pregnancy outcome. DESIGN: Review of 1,075 couples attending over a nine year period. SETTING: University Hospital offering a tertiary referral service for fetal medicine. SUBJECTS: Couples referred to the clinic from a variety of sources. MAIN OUTCOME MEASURES: Categories of referral, value of diagnostic tests, and subsequent pregnancy outcome. RESULTS: The main categories of referral were: previous miscarriage (44.4%); previous fetal abnormality (19.6%); chronic maternal disease (22.3%); and others (13.7%). Routine investigations produced a low yield of abnormality (1%), in contrast to investigations selected for specific reasons (12%). Subsequent pregnancy outcome, which was unaltered in either the previous miscarriage or fetal abnormality groups, did improve in the chronic maternal disease group. CONCLUSIONS: This study does not prove the value of prepregnancy counselling. However, it does illustrate the importance of making an accurate assessment of previous problems and current health as a means of determining both maternal and fetal risks in a subsequent pregnancy, a process which seems to lead to an improved outcome within selected groups. The importance of continuity of care in all couples, especially when there has been a previous adverse pregnancy outcome is emphasized.

Abortion, Spontaneous↗
PubMed1991

IS406 and IS407, two gene-activating insertion sequences for Pseudomonas cepacia.

We have determined the nucleotide sequences of IS406 (1368 bp) and IS407 (1236 bp), two insertion sequence (IS) elements isolated from Pseudomonas cepacia 249 on the basis of their abilities to activate the expression of the lac genes of Tn951. IS406 and IS407 when inserted into the lac promoter/operator region of Tn951 generated, respectively, duplications of 8 and 4 bp of target DNA. IS406 had 41-bp terminal inverted repeat (IR) sequences with eleven mismatches. IR-L (left) contained a 12-bp motif present at the ends of Tn2501. In other respects, IS406 was distinct from previously described bacterial IS elements listed in the GenBank and EMBL databases. IS407 had 49-bp terminal IRs with 18 mismatches. IR-R (right) contained an outwardly directed sigma 70-like promoter. IS407 was closely related to IS476 and ISR1 from Xanthomonas and Rhizobium sp., respectively.

Amino Acid Sequence↗
PubMed1991

Psychiatric and neurological effects of chronic solvent abuse.

This study is a review of the psychiatric and neurological effects of solvent inhalation on a group of 22 patients with chronic histories of solvent abuse, primarily toluene-based solvents. The findings suggest that the chronic inhalation of toluene-based adhesives can produce a paranoid psychosis which may persist. Other findings were a high incidence of temporal lobe epilepsy and decrease in IQ. We suggest that the psychiatric and neurological sequelae of chronic solvent abuse are serious and potentially irreversible. Toluene is felt to be a major factor in the morbidity associated with chronic solvent abuse, and attention is drawn to the necessity for educational programs in this area. The burden caused by the resulting psychiatric problems resulting from solvent abuse may have implications for health care budgets.

Adolescent↗
PubMed1989

Etomidate infusions for the control of refractory status epilepticus.

Etomidate was used in eight patients to control status epilepticus which had been refractory to previous anticonvulsant therapy. Cortical activity was measured using a Cerebral Function Analysing Monitor and etomidate administered to achieve a 5 microV mean amplitude, avoiding burst suppression if possible with obliteration of any paroxysmal increase in amplitude. Neuromuscular blockade facilitated endotracheal intubation and mechanical ventilation, and corticosteroid replacement was provided. Rapid control of seizure activity, with cardiovascular stability, was obtained in all cases. Initially the mean infusion rate of etomidate required to achieve adequate suppression of cortical activity was 25 micrograms kg-1 min-1, but several patients exhibited tachyphylaxis. Weaning from the infusion presented difficulties in four patients due to recurring seizures. Adrenocortical function returned to normal within 96 hrs of stopping the infusion. At six month follow up, two patients had died, and two patients had significant reduction in cerebral function compared with their pre-morbid state.

Adult↗
PubMed1989

Opioidergic control of gonadotropin secretion in the female rabbit: divergent effects of morphine on secretion of follicle-stimulating hormone and luteinizing hormone.

The nature of secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was followed in female rabbits on a daily basis from age 36 to 60 days by sequential 5-min blood sampling over 1- to 2-h periods each day. Both LH and FSH were found to be secreted in a pulsatile manner. The mean LH pulse amplitude over the 25 days was 0.95 +/- 0.32 ng/mL and for FSH it was 10.15 +/- 1.11 ng/mL. Mean plasma LH levels were significantly increased from 1.46 +/- 0.08 ng/mL in 36 to 42-day-old rabbits to 1.89 +/- 0.12 ng/mL in 43 to 50-day-old rabbits and remained elevated from 50 to 60 days. FSH levels during the same periods also rose significantly from 14.93 +/- 0.79 to 19.57 +/- 2.05 ng/mL. To examine the influence of endogenous opioid peptides on the release of LH and FSH in 36 to 60-day-old female rabbits, morphine sulfate at 0.2, 0.5, 2.0, and 5.0 mg/kg was administered subcutaneously after 30 min baseline sampling, and blood was taken for another 60-120 min. Morphine at all doses and at all ages inhibited the amplitude and frequency of LH pulses but had no effect on FSH secretion. To determine whether the effects of morphine on LH secretion could be reversed with naloxone, females aged 82-114 days were used. Naloxone administered 1 h after morphine reversed the inhibitory effects of morphine, whereas the simultaneous administration of naloxone with morphine had variable effects but seemed to delay the LH increase.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1989

Pimozide in pathological jealousy.

A 39-year-old man had his pathological jealousy successfully treated with pimozide. It is suggested that pimozide might be considered the drug of choice in all the monodelusional disorders.

Adult↗
PubMed1988

Gastric exocrine "failure" in critically ill patients: incidence and associated features.

Following the observation that many critically ill patients cannot maintain their gastric juice pH below 4 without treatment a study was performed to measure the gastric juice pH in such patients and relate it to other clinical data. The case notes of 64 patients who had been admitted to the intensive care unit and taken part in two trials of ranitidine treatment were reviewed. During those trials gastric juice was aspirated hourly and the pH and volume measured. In this study the values recorded during a six hour untreated control phase were used. Data on age, diagnosis, treatment, outcome, episodes of hypoxia, episodes of hypotension, and use of inotropic drugs were also reviewed. Full data were available for 61 patients: 27 had a mean baseline pH of greater than 5 during the control phase and 34 a mean baseline pH of less than 5. Significantly more of those with a high pH suffered hypotension (21/27 v 13/34) and received inotropic drugs (16/27 v 8/34). These findings suggest that hypotension in critically ill patients adversely affects gastric exocrine function; prophylaxis with drugs that can improve gastric mucosal blood flow may be more effective than with antacids.

Adolescent↗
PubMed1988

Hidradenitis suppurativa. Glucose tolerance, clinical, microbiologic, and immunologic features and HLA frequencies in 27 patients.

Glucose tolerance, lymphocyte populations, and HLA types were studied in 27 patients with untreated hidradenitis suppurativa; 18 of these patients had a negative history for acne vulgaris. Six patients (22%) had an increased incidence of impaired glucose tolerance. We failed to confirm a previous report of high incidence of flat glucose tolerance curves. The frequency of HLA-A and HLA-B antigen loci and the median values of peripheral blood T lymphocytes were similar to the control population. However, seven patients with moderate or severe clinical disease had a marked reduction in T lymphocytes and these patients had an increased frequency of the HLA antigens, A1 and B8. These results suggest that T lymphocytes may play a role in the pathogenesis of hidradenitis suppurativa and that HLA-A1 and HLA-B8 may predispose the patient to more severe disease, but further research is necessary to clarify this.

Adolescent↗
PubMed1988

Opioidergic control of luteinizing hormone secretion in the female rabbit: influence of age on the response to naloxone.

To examine the role of opioid neurons on luteinizing hormone (LH) secretion in the female rabbit, we determined LH release at timed intervals after naloxone administration to rabbits aged 25-150 days. The LH response to naloxone (10 mg/kg) was not significantly elevated until day 43 when LH rose 76-113% above basal levels at 40-80 min. In 56-day-old females the corresponding increase was 160% at 15 min and in 65- to 67-day-olds it was 154%. From 70 to 80 days of age the LH response was blunted and no significant elevations could be elicited. By contrast, naloxone-induced LH increases were again evident when rabbits were older than 100 days. At all ages no significant change in FSH concentrations was observed. In the adult females, naloxone at 2.5, 5, and 10 mg/kg caused increases in LH secretion which occasionally were high enough to induce ovulation as exemplified by elevated serum progesterone 4 days later. These data suggest that opioid peptides may be involved in the prepubertal rise in LH and in the normal inhibition of adult secretion in the female rabbit.

Aging↗