Search PubMed⌕ Search

Biomedical subjects

H Montgomery

Publications and source records attributed to H Montgomery.

At least 37 records · Page 2Linked to original sources
PubMed2001

Explaining own and others' behavior in a controversial issue: animal experimentation.

The authors investigated how 2 groups with different attitudes toward animal experimentation-researchers who conducted animal experiments and members of animal welfare organizations who protested against animal experiments--made attributions for the behavior of the opposing group. The 2 groups showed an actor--observer effect, mentioning more internal causes for the opponents' behavior and more external causes for their own behavior. Both groups were able to take the other's perspective, resulting in a reversed actor-observer effect. The less involved participants followed the pattern of ratings of the group whose attitudes corresponded to their own. In particular, the participants with a negative attitude toward animal experimentation rated researchers' behavior as more internally caused than did those with a positive attitude. The results illustrated how the participants formed and defended attitudes in a social context.

Adult↗
PubMed2001

Angiotensin-I converting enzyme genotype-dependent benefit from hormone replacement therapy in isometric muscle strength and bone mineral density.

Low bone mineral density (BMD) and muscle weakness are major risk factors for postmenopausal osteoporotic fracture. Hormone replacement therapy (HRT) reverses the menopausal decline in maximum voluntary force of the adductor pollicis and reduces serum angiotensin-I converting enzyme (ACE) levels. The insertion (I) allele of the ACE gene polymorphism is associated with lower ACE activity and improved muscle efficiency in response to physical training. Therefore, we examined whether the presence of the I allele in postmenopausal women would affect the muscle response to HRT. Those taking HRT showed a significant gain in normalized muscle maximum voluntary force slope, the rate of which was strongly influenced by ACE genotype (16.0 +/- 1.53%, 14.3 +/- 2.67%, and 7.76 +/- 4.13%, mean +/- SEM for II, ID, and DD genotype, respectively; P = 0.017 for gene effect, P = 0.004 for I allele effect). There was also a significant ACE gene effect in the response of BMD to HRT in Ward's triangle (P = 0.03) and a significant I allele effect in the spine (P = 0.03), but not in the neck of femur or total hip. These data suggests that low ACE activity associated with the I allele confers an improved muscle and BMD response in postmenopausal women treated with HRT.

Bone Density↗
PubMed2000

Transmission of Mycobacterium bovis from experimentally infected ferrets to non-infected ferrets (Mustela furo).

AIMS: To demonstrate the transmission of Mycobacterium bovis infection from experimentally infected ferrets (Mustela furo) to non-infected ferrets in a laboratory setting, using three different isotypes of M. bovis, and to observe ferret behaviour that might be implicated in disease transmission. METHODS: Three female ferrets, each experimentally infected with a unique strain of M. bovis, were housed together with six female and two male non-infected ferrets in an isolation facility. Transmission of infection was monitored clinically, serologically (using an ELISA test), bacteriologically, histologically, and by isotype analysis of M. bovis isolates using spoligotyping to determine whether or not transmission of each strain occurred. Ferret behaviour was observed using a time-lapse video recorder. RESULTS: Transmission of M. bovis infection was confirmed in two male and four female ferrets. Isotype analysis showed that of the experimentally infected females, one did not infect any other ferret, another transmitted M. bovis to one ferret before it died prematurely 49 days post-infection, and the third, which was cannibalised, appears to have transmitted M. bovis to both males and three females. However, two of these latter three females had died before the event of cannibalism took place. One female was infected with two strains. Several behavioural interactions were observed that could have resulted in M. bovis transmission, including den sharing, sniffing of orifices and faeces, cannibalism and aggressive breeding behaviour. CONCLUSIONS: Horizontal transmission of M. bovis infection was demonstrated in ferrets under experimental housing conditions. Routes of transmission may involve cannibalism and factors such as den sharing, playing, fighting, mating, and sniffing of faeces.

Journal Article↗
PubMed2000

Gene-environment interactions and the response to exercise.

Many of the symptoms of heart failure (breathlessness and fatigue) are not primarily due to reduced cardiac output, but relate to an impairment of peripheral muscle performance and metabolic efficiency. With regular training it is possible to increase skeletal muscle performance through improvements in muscle efficiency. Recent data suggest that such improvements may be modulated by local tissue renin-angiotensin systems and, in particular, by the local activity of angiotensin-converting enzyme (ACE). These findings might explain the remarkable benefits of ACE inhibition in the treatment of heart failure.

Exercise↗
PubMed2000

Angiotensin-converting enzyme genotype affects the response of human skeletal muscle to functional overload.

The response to strength training varies widely between individuals and is considerably influenced by genetic variables, which until now, have remained unidentified. The deletion (D), rather than the insertion (I), variant of the human angiotensin-converting enzyme (ACE) genotype is an important factor in the hypertrophic response of cardiac muscle to exercise and could also be involved in skeletal muscle hypertrophy - an important factor in the response to functional overload. Subjects were 33 healthy male volunteers with no experience of strength training. We examined the effect of ACE genotype upon changes in strength of quadriceps muscles in response to 9 weeks of specific strength training (isometric or dynamic). There was a significant interaction between ACE genotype and isometric training with greater strength gains shown by subjects with the D allele (mean +/- S.E.M.: II, 9.0+/-1.7 %; ID, 17.6 +/-2.2 %; DD, 14.9+/-1.3 %, ANOVA, P 0.05). A consistent genotype and training interaction (ID DD II) was observed across all of the strength measures, and both types of training. ACE genotype is the first genetic factor to be identified in the response of skeletal muscle to strength training. The association of the ACE I/D polymorphism with the responses of cardiac and skeletal muscle to functional overload indicates that they may share a common mechanism. These findings suggest a novel mechanism, involving the renin-angiotensin system, in the response of skeletal muscle to functional overload and may have implications for the management of conditions such as muscle wasting disorders, prolonged bed rest, ageing and rehabilitation, where muscle weakness may limit function.

Adolescent↗
PubMed1999

Angiotensin-converting-enzyme gene insertion/deletion polymorphism and response to physical training.

BACKGROUND: The function of local renin-angiotensin systems in skeletal muscle and adipose tissue remains largely unknown. A polymorphism of the human angiotensin converting enzyme (ACE) gene has been identified in which the insertion (I) rather than deletion (D) allele is associated with lower ACE activity in body tissues and increased response to some aspects of physical training. We studied the association between the ACE gene insertion or deletion polymorphism and changes in body composition related to an intensive exercise programme, to investigate the metabolic effects of local human renin-angiotensin systems. METHODS: We used three independent methods (bioimpedance, multiple skinfold-thickness assessment of whole-body composition, magnetic resonance imaging of the mid-thigh) to study changes in body composition in young male army recruits over 10 weeks of intensive physical training. FINDINGS: Participants with the II genotype had a greater anabolic response than those with one or more D alleles for fat mass (0.55 vs -0.20 kg, p=0.04 by bioimpedance) and non-fat mass (1.31 vs -0.15 kg, p=0.01 by bioimpedance). Changes in body morphology with training measured by the other methods were also dependent on genotype. INTERPRETATION: II genotype, as a marker of low ACE activity in body tissues, may conserve a positive energy balance during rigorous training, which suggests enhanced metabolic efficiency. This finding may explain some of the survival and functional benefits of therapy with ACE inhibitors.

Adipose Tissue↗
PubMed1999

Urinary incontinence and depression.

PURPOSE: Serotonergic neuronal systems have been implicated in anxiety and depression. Because descending serotonin pathways from the brain stem inhibit bladder contractions, we postulated that depression associated with altered serotonin function may predispose to urge incontinence. We demonstrate an association between depression and idiopathic urge incontinence. MATERIALS AND METHODS: A total of 115 consecutive incontinent patients presenting to an incontinence clinic were compared to 80 continent controls. Patients were queried for a history of depression and completed a Beck Depression Inventory (BDI). Cases were classified by history and video urodynamics as genuine stress (36), urge (44) or mixed (35) incontinence. RESULTS: A BDI of greater than 12 and/or a history of depression was noted in 30% of incontinent patients and 17% of controls (odds ratio 2.3, 95% confidence interval 1.0 to 5.0, p = 0.044). An abnormal BDI or history of depression was revealed in 60% of patients with idiopathic urge incontinence (p<0.001). Patients with stress or urge incontinence due to neuropathology or obstruction had no greater odds of having depression than continent controls. CONCLUSIONS: These data suggest a strong association between depression and idiopathic urinary incontinence. This link may be due to altered serotonin function and may help explain the efficacy of serotonergic based antidepressants in the treatment of urge incontinence.

Depression↗
PubMed1999

Human angiotensin I-converting enzyme gene and endurance performance.

Human physical performance is strongly influenced by genetic factors. A variation in the structure of the human angiotensin I-converting enzyme (ACE) gene has been reported in which the insertion (I) variant is associated with lower ACE levels than the deletion (D) gene. We have previously reported that the I variant was associated with improved endurance performance in high-altitude mountaineers and British Army recruits. We now examine this genotype distribution in 91 British Olympic-standard runners (79 Caucasians). DNA was extracted from the buccal cells contained in 10 ml of saline mouthwash donated by the subjects, and the I and D variants of the ACE gene were identified by PCR amplification of the polymorphic region. There was an increasing frequency of the I allele with distance run [0.35, 0.53, and 0.62 for </=200 m (n = 20), 400-3,000 m (n = 37), and >/=5,000 m (n = 34), respectively; P = 0.009 for linear trend]. Among 404 Olympic-standard athletes from 19 other mixed sporting disciplines (in which endurance performance was not necessarily a key factor), the I allele did not differ significantly from that found in control subjects: 0.50 vs. 0.49 (P = 0.526). These results support a positive association of the I allele with elite endurance performance.

Alleles↗
PubMed1999

High intensity training and the heart.

Absence may make the heart grow fonder, but exercise makes the heart grow stronger. This review discusses the cardiac impact of high intensity training, and discusses the possible mechanisms underlying the risk and benefit of such training.

Adult↗
PubMed1998

Daily patterns of secretion of neurohypophysial hormones in man: effect of age.

The neurohypophysial hormone vasopressin contributes to control of urine output and, while urine flow shows a clear daily rhythm, there has been debate as to whether this is true of neurohypophysial hormones. A study was performed on fifteen adult males, with a mean age of 25 years, over a 24 h period, nine blood samples being taken at regular intervals for the determination of neurohypophysial hormones and indices of fluid balance. Samples were taken via an indwelling cannula so that sleep was undisturbed. A daily variation in the plasma concentrations of oxytocin and vasopressin was demonstrated with concentrations reaching a nadir in the late afternoon. Concentrations of both hormones peaked at 02.00 h. Vasopressin concentrations were inversely correlated with packed cell volume, indicating that the altered hormone release was affecting fluid retention. Consistent with this was the observation that the relationship of plasma osmolality to vasopressin depended on the time of day. To determine the effect of ageing, a similar study was performed on nine healthy elderly subjects with a mean age of 70 years. The nocturnal peak of vasopressin was markedly attenuated, while oxytocin release was similar to that in the younger group. These observations confirm the existence of a daily rhythm in the plasma concentrations of neurohypophysial hormones and indicate that the amplitude of the vasopressin change decreases with age.

Adult↗
PubMed1996

Importance and attainment of life values among disabled and non-disabled people.

How do disabled persons evaluate their life situation? To address this issue, importance and attainment ratings of 82 different life values as well as mood ratings were collected from 325 chronically ill and/or disabled persons and 504 non-disabled persons. Both groups largely agreed on what is important in life. The disabled persons, however, gave lower importance ratings on functions related to health and mobility. The attainment and mood ratings were in general slightly lower for the disabled persons. The attainment ratings for health and mobility were markedly lower. The concordance between rated importance and attainment across different life values was positive in both groups. This measure was also positively related to mood in both samples. It was suggested that disabled persons adjust to their life situation by de-emphasizing the importance of the physical functions affected by the disability and through habituation.

Affect↗