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Biomedical subjects

L Watson

Publications and source records attributed to L Watson.

At least 73 records · Page 4Linked to original sources
PubMed1995

Breast and ovarian cancer incidence after infertility and in vitro fertilisation.

Concern has been expressed that exposure to fertility drugs might be associated with a risk of ovarian cancer. We have examined the incidence of breast and ovarian cancer in a cohort of 10,358 women referred for in-vitro fertilisation (IVF) treatment in Victoria, Australia, between 1978 and 1992. The "exposed" group (n = 5564) had had ovarian stimulation to induce multiple folliculogenesis and the "unexposed" group (n = 4794) had been referred for IVF but were untreated or had had "natural cycle" treatment without ovarian stimulation. Duration of follow-up ranged from 1 to 15 years. Cases of cancer were determined by record linkage with data from population-based cancer registries. 34 cases of invasive breast cancer and 6 of invasive ovarian cancer were observed. A comparison with the expected numbers, derived by applying age-standardised general population rates to the cohort gave standardised incidence ratios (SIR) for breast cancer of 0.89 (95% CI 0.55-1.46) in the exposed group and 0.98 (0.62-1.56) in the unexposed group, and for ovarian cancer SIRs were 1.70 (0.55-5.27) and 1.62 (0.52-5.02), respectively. Rates of all cancers were not significantly different from general population rates. The relative risk (RR) of cancer, adjusted for age and infertility type, was, in the treated group compared with the untreated group, 1.11 (95% CI 0.56-2.20) for breast cancer and 1.45 (0.28-7.55) for ovarian cancer. The risk of body of uterus cancer was increased in the exposed and unexposed groups combined (SIR 2.84 [1.18-6.81]). Women with unexplained infertility, independent of IVF exposure, had significantly increased risks of ovarian cancer (RR = 19.19 [2.23-165.0]) and body of uterus cancer (RR = 6.34 [1.06-38.0]) compared with women with known causes of infertility. This relatively short-term follow-up suggests that ovarian stimulation with IVF is not associated with an increased risk of breast cancer. Although there was no significantly increased risk of ovarian cancer after ovarian stimulation with IVF the small number of cases limits the conclusions that can be drawn. Longer-term follow-up of large cohorts of women who have been in IVF programmes will be necessary.

Adult↗
PubMed1995

Comparison of women who do and do not have amniocentesis or chorionic villus sampling.

Even in areas where prenatal diagnostic testing is offered at no cost to women over a certain age, uptake of testing is not complete. We have studied the factors that affect uptake in Victoria, Australia. In 1988-92, 43% of 37-39-year-old women and 29% of those 40 years and over had no diagnostic testing despite their eligibility for a free test. We compared the characteristics of untested women (n = 3074) with those of tested women (2462 amniocentesis, 1575 chorionic villus sampling) by use of record-linkage between the Victorian birth register and fetal diagnosis data collection. The indication for testing was maternal age alone. Women who had had 3 or more previous births were less likely than those of lower parity to undergo testing (odds ratio 0.54 [95% CI 0.46-0.63], p < 0.001), whereas those who had had a previous termination of pregnancy were more likely to be tested than those who had not (1.52 [1.26-1.83], p < 0.001). Women born in non-English-speaking countries and women who lived in rural areas were less likely to be tested. Women who gave birth in private hospitals were more likely to be tested than those who gave birth in any public hospital or at home. These data help to distinguish between issues of choice and access to diagnostic testing. Factors that hinder testing of rural women and of those from non-English-speaking backgrounds should be addressed.

Abortion, Induced↗
PubMed1995

Static lung compliance in chronic heart failure: relation with dyspnoea and exercise capacity.

BACKGROUND: The pathogenesis of dyspnoea in patients with chronic heart failure is poorly understood. Static lung compliance is reduced in chronic heart failure. The relation between static lung compliance and exercise capacity and dyspnoea in chronic heart failure has been investigated. METHODS: Static lung compliance was calculated from expiratory pressure-volume curves in 18 patients with chronic heart failure (three women, mean age 62 years). Catheter mounted pressure transducers were used to measure changes in oesophageal pressure. Changes in lung volume were determined by integrating flow at the mouth, measured by a pneumotachograph. New York Heart Association (NYHA) class for dyspnoea was determined by a single observer. Patients underwent treadmill exercise to symptom limited maximum using staged and fixed rate protocols. Borg ratings for dyspnoea at submaximal exercise were measured. RESULTS: Static lung compliance, whether expressed as % total lung capacity (TLC)/cm H2O or % predicted TLC/cm H2O, was unrelated to NYHA class. Similarly, there was no relation between static lung compliance and exercise capacity with either protocol or with Borg ratings for dyspnoea at submaximal exercise, with the exception of that measured after 11 minutes of the staged protocol. CONCLUSIONS: Static lung compliance at rest has no relation with treadmill exercise capacity in chronic heart failure, and its relation with measures of dyspnoea is variable. No role for lung elasticity in determining the symptomatology of chronic heart failure was found.

Cardiac Output↗
PubMed1995

Respiratory muscle strength in chronic heart failure.

BACKGROUND: Several studies have suggested that the respiratory muscles are weak in patients with heart failure, but the aetiology and clinical relevance of this weakness are unclear. In order to see if respiratory muscle weakness in this context is part of a more generalised myopathic process, respiratory and limb muscle strength were compared in patients with heart failure. The relation between respiratory muscle strength, breathlessness on exercise, and exercise capacity was also examined. METHODS: Twenty patients (three women) with New York Heart Association (NYHA) class II-IV heart failure of mean age 63 years were studied. Respiratory muscle strength was assessed using maximum inspiratory and expiratory mouth pressures (MIP and MEP) and transdiaphragmatic pressure during sniffs (sniff PDI). These parameters were compared with cardiac output (indirect Fick) and with limb muscle strength as assessed by grip strength. The patients also performed two exercise tests during which they rated their breathlessness on a Borg scale. RESULTS: Mean (SD) cardiac index was 2.2 (0.4) l/min/m2. MIP and MEP were 66 (27) and 99 (29) cm H2O respectively. Sniff PDI was 103 (21) cm H2O and was positively correlated with grip strength and cardiac output (Spearman rank correlation coefficients 0.527 and 0.451, respectively). None of the indices of respiratory muscle strength were related to exercise time or breathlessness during exercise. CONCLUSIONS: The respiratory muscles are weak in patients with heart failure. This weakness reflects a more generalised myopathic process, possibly related to reduced cardiac output. However, respiratory muscle weakness does not appear to be an important factor in the aetiology of breathlessness on exercise.

Aged↗
PubMed1995

Circulating ICAM-1 is increased in septic shock.

Adhesion molecules play a critical role in the interaction of circulating neutrophils with vascular endothelium during inflammation. Increased quantities of soluble, circulating intercellular adhesion molecule-1 (cICAM-1) are present in various inflammatory conditions. The purpose of this investigation was to measure cICAM-1 levels in septic adults, as well as to examine the relationship between this potential marker of endothelial-cell activation and the consequences of sepsis (i.e., multiple organ failure and death). Using a sandwich-type enzyme-linked immunosorbent assay (ELISA), we measured cICAM-1 in blood samples obtained within 12 h of admission to an intensive care unit (ICU) for sepsis and other conditions. We found cICAM-1 levels to be increased in 25 septic patients (1,259 +/- 159 ng/ml, mean +/- SEM) as compared with 12 healthy volunteers (355 +/- 41 ng/ml, p < 0.0001) and four ICU patients without systemic inflammatory response syndrome (SIRS) (585 +/- 76 ng/ml, p < 0.001). Twenty-five patients with SIRS but no evidence of causative infection also had elevated levels of cICAM-1 (937 +/- 144 ng/ml, p = 0.12 versus sepsis). Serial measurements over the first week of sepsis demonstrated persistent elevation in most patients. Day 1 cICAM-1 levels were higher (p = 0.017, ANOVA) in 16 patients with septic shock than in seven with severe sepsis and two with sepsis but without hypotension or hypoperfusion. There was a positive correlation (r = 0.50, p = 0.009) between Day-1 cICAM-1 measurements and severity of shock as determined by the presence of hypotension and vasopressor use.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Octreotide reduces alcohol-induced hypotension and orthostatic symptoms in primary autonomic failure.

Symptomatic postural hypotension is a major problem in patients with primary idiopathic autonomic failure, and ingestion of small quantities of alcohol may worsen the degree of postural hypotension. The proposed mechanisms include mesenteric vasodilation and release of vasodilatory gut peptides. We measured systemic, mesenteric, other regional vascular and biochemical responses to alcohol ingestion before and after pre-treatment with the somatostatin analogue Octreotide (which inhibits the release of a wide range of gut peptides normally released in response to food ingestion) in six patients with primary autonomic failure. Octreotide effectively prevented alcohol-induced hypotension and vasodilatation of the mesenteric vascular bed, with improvement of signs and symptoms of hypotension post-alcohol. This suggests that the mechanism of alcohol-induced symptomatic hypotension in autonomic failure is at least partly mediated by release of vasodilatatory gut peptides with resultant mesenteric vasodilatation.

Aged↗
PubMed1995

Transition to parenthood. What about fathers?

Family physicians are in a strategic position to help couples adjust to the many changes that occur during the transition to parenthood. We review some of the issues for fathers at this time and suggest strategies for family physicians for including fathers and assisting couples to adjust to the changes in the interest of promoting healthy families.

Adaptation, Psychological↗
PubMed1994

The influence of continuous ambulatory peritoneal dialysis connection technique on peritonitis rate and technique survival.

Peritonitis is still the most common complication of continuous ambulatory peritoneal dialysis (CAPD). Several measures have been used to prevent peritonitis, including prophylactic antibiotics and a variety of connection techniques. This study was designed to evaluate the effects of different connection techniques, age at the start of CAPD, sex, and diabetic status on peritonitis rate and technique survival. Three hundred twenty-seven patients treated with CAPD and followed for 8,804.4 patient-months at the Vancouver General Hospital between February 13, 1978, and August 31, 1992, were reviewed. The mean age of the patients was 57.1 +/- 16.3 years. The overall peritonitis rate was 16.6 patient-months per episode. The overall technique survival was 79.6%, 60.2%, and 41.8%, at 1, 2, and 3 years, respectively. Patients using "standard" spike technique (group A, n = 87), Luer lock connector (group B, n = 77), and Luer lock with iodine instillation at the dialysis bag connection site (group C, n = 120) had peritonitis rates of 10.4, 14.7, and 33.3 patient-months per episode, respectively. The relative risk (RR) of peritonitis was 3.5 for group A (95% confidence interval, 2.1 to 4.5) and 2.6 for group B (95% confidence interval, 1.7 to 3.9) compared with group C. Patient age at the start of CAPD, sex, and diabetic status had no effect on the RR of peritonitis. None of the variables studied, except patient age, affected technique survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1994

Lymphocyte responses to DR1/4 restricted peptides in rheumatoid arthritis.

OBJECTIVE: To determine whether analog and unrelated DR1/4 binding peptides alter DR1/4 restricted responses of peripheral blood lymphocytes (PBL) from patients with rheumatoid arthritis (RA). METHODS: PBL from 25 patients with RA and 12 healthy controls were cultured with DR1/4 restricted peptides of the influenza haemagglutinin, amino acids 307-319 (HA) and matrix proteins, amino acids 17-29 (IM). Responses were determined by 3H-thymidine uptake proliferation assays and limiting dilution analysis. Competitor peptides were analogs HA-R312 and HA-K313 differing from HA by one amino acid at the 312 or 313 position respectively or unrelated peptides which bind to DR1/4. RESULTS: The responses of eight patients with RA to the two stimulatory influenza peptides did not differ significantly from controls and this was confirmed by the frequency estimate of T cells in PBL which responded to HA (mean frequency: 1 in 9.0 x 10(4), n = 5, in DR1/4+ RA patients, 1 in 7.6 x 10(4), n = 5, in DR1/4+ healthy controls). DR1/4 binding analogs of the HA peptide inhibited HA specific peptide responses of PBL from patients with RA and controls. Inhibition was also detected with unrelated peptides which bind to DR1/4 but to which the individual did not respond. CONCLUSION: Similar responses to two DR1/4 restricted peptides were observed in patients with RA and controls. Both antigen analog- and unrelated peptide-major histocompatibility complexes (MHC) can result in the inhibition of antigen specific responses in multi-clonal human lymphocyte populations. However, an analog peptide may be stimulatory in some individuals. These results provide some initial data for the development of a rational approach to MHC-specific immunomodulation in rheumatoid arthritis.

Adult↗
PubMed1994

Behavioral management of specific pathogen-free rhesus macaques: group formation, reproduction, and parental competence.

Breeding colonies of specific pathogen-free (SPF) rhesus macaques were established to eradicate the transmission of Herpesvirus simiae and several retroviruses in this species. Strategies to attain this goal included the combination of large numbers of monkeys into groups, the establishment of small unimale groups, and a program using animals that were temporarily socially restricted. All methods required the establishment of new social groups from unfamiliar animals. In using these methods, we encountered important behavioral questions related to the group formation process, as well as reproductive and parental competence. Age and prior social experience were important determinants of social and parental success. New multimale-multifemale SPF group formations were successful initially and involved the least aggression during the first breeding season when young females and older males were used. Formation of unimale groups was successful, even when males and females were of similar ages. Breeding competence did not seem to be affected by any of the SPF colony management procedures, but animals with restricted early social experience exhibited impaired parental competence when compared with animals with more social experience. Males were more sensitive to the effects of early social restriction than females. A variety of behavioral obstacles will be encountered when attempting to establish an SPF breeding colony by forming groups by use of these methods. Skilled behavioral management is necessary to surmount these obstacles and to achieve satisfactory social integration, reproduction, and parenting.

Aging↗
PubMed1993

Twins, triplets, and cerebral palsy in births in Western Australia in the 1980s.

OBJECTIVES: To examine the rate of cerebral palsy in twins and triplets in births from 1980 to 1989 in Western Australia and to identify factors associated with increase in risk. DESIGN: Pluralities for all births in Western Australia were identified through the standardised midwives' notification system, and cases of cerebral palsy were identified from the Western Australian cerebral palsy register. MAIN OUTCOME MEASURES: Multiple births, cerebral palsy, excluding postneonatal cause. RESULTS: The prevalence of cerebral palsy in triplets, of 28 per 1000 survivors to 1 year (95% confidence interval 11 to 63) exceeded that in twins (7.3; 5.2 to 10) and singletons (1.6; 1.4 to 1.8). Although twins and triples were more likely than singletons to be low in birth weight, their risks of cerebral palsy if low in birth weight were similar. In contrast, in normal birthweight categories twins had a higher rate of cerebral palsy (4.2; 2.2 to 7.7) than singletons (1.1; 1.0 to 1.3). The prevalence of cerebral palsy was similar in twins of unlike sex pairs, all of whom are dizygotic, and in like sex pairs. A twin pair in which one member died in utero was at higher risk of cerebral palsy: 96 per 1000 twin pairs (36 to 218) compared with 12 (8.2 to 17) for twin pregnancies in which both survived. There was a similar but non-significant trend for death of one triplet to be associated with increased risk of cerebral palsy in the survivors of the set. CONCLUSION: Triplet pregnancies produced a child with cerebral palsy 47 times more often than singleton pregnancies did and twin pregnancies eight times more often. Eighty six per cent of cerebral palsy in multiple births was in twins. As multiple births are increasing mainly because of personal and medical decisions the increased risk of cerebral palsy in multiple births is of concern.

Birth Order↗
PubMed1993

The effect of captopril on the superior mesenteric artery and portal venous blood flow in normal man.

1. Measurements of superior mesenteric artery and portal venous blood flow were made non-invasively along with systemic and other regional (cardiac index, forearm and cutaneous blood flow) vascular responses to acute ingestion of the ACE inhibitor captopril (50 mg) or placebo (50 mg vitamin C), in 12 healthy subjects while supine and during head-up tilt. 2. After captopril, superior mesenteric artery and portal blood flow rose markedly with a reduction in superior mesenteric artery vascular resistance. Supine blood pressure was unchanged but cardiac index and forearm blood flow rose; during head-up tilt, blood pressure fell in some subjects. 3. There was a rise in levels of plasma renin activity and a fall in levels of plasma angiotensin II after captopril. After placebo, there were no significant changes in splanchnic blood flow, systemic or other regional responses and in biochemical measurements, while supine. 4. Our studies indicate that captopril is a potent dilator of the splanchnic vascular bed and suggest that this action may contribute to its therapeutic effects. The studies indicate a role for angiotensin II in the control of this large vascular bed although other agents (bradykinin, prostacyclin) may contribute.

Adult↗
PubMed1993

Spastic quadriplegia in Western Australia: a genetic epidemiological study. I: Case population and perinatal risk factors.

In a case-control study of all cerebral palsy cases with moderate and severe spastic quadriplegia born between 1976 and 1985, males comprised three-quarters of the cases and tended to have more severe motor impairment than females. The majority of cases had multiple and severe disabilities, and 27 per cent had died by the time of data collection. There was an excess of low-birthweight and preterm births compared with all live births in WA. An intrapartum cause was considered possible in 18 of the 74 children; however, half of these had evidence of compromise before labour.

Australia↗
PubMed1993

Normal range for transdiaphragmatic pressures during sniffs with catheter mounted transducers.

BACKGROUND: Transdiaphragmatic pressure (sniff PDI) during maximal sniffs is a useful clinical test of inspiratory muscle function. Although a normal range has been established for sniff PDI using air filled balloons, no comparable data are available for catheter mounted pressure transducers. METHODS: Using a single catheter with two pressure transducers 15 cm apart, oesophageal and gastric pressures were recorded in 50 normal volunteers (25 women), five of each sex from each decade between the third and seventh decades of life. Each subject performed 10 maximal sniffs at functional residual capacity. RESULTS: Mean (SD) sniff PDI was 149 (32) cm H2O in men and 127 (22) cm H2O in women. The lower limits of normal for sniff PDI (mean -1.96 x SD) after logarithmic transformation of the data were 95 and 78 cm H2O in men and women respectively. CONCLUSIONS: With this technique transdiaphragmatic pressure can be measured using a single catheter which can easily be cleaned and reused. The values for sniff PDI are similar to those recorded previously with air filled balloons, suggesting that the method of recording pressure does not significantly affect the values obtained.

Adult↗
PubMed1993

Facial reconstruction of a 3500-year-old Egyptian mummy using axial computed tomography.

Rebuilding faces from skulls presented for forensic identification or of historical importance has been carried out for many years using standardized methods. However, the reproduction of the face of a 3500-year-old mummy still enclosed in its cartonnage proved to be an unusual challenge. The face had to be rebuilt without opening the cartonnage to ensure preservation of the remains. Consequently, the method devised involved using the latest medical imaging technology to determine the shape of the skull.

Adult↗