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Biomedical subjects

M J Henry

Publications and source records attributed to M J Henry.

At least 19 recordsLinked to original sources
PubMed2002

Fracture thresholds revisited. Geelong Osteoporosis Study.

Osteoporosis, in the absence of fracture, is defined as a deficit in bone mineral density (BMD) of 2.5 SD or more below the young adult reference mean in postmenopausal Caucasian populations. BMD is a measure of fracture risk but not the sole predictor. We have assessed a combination of easily accessible measures of age, height, weight, and BMD to improve fracture risk assessment. Women with low trauma fractures and a control group were recruited from south-eastern Australia. Discriminant analysis derived multivariate equations that assessed fracture risk. Age was not in the best models at the spine and forearm sites. Weight and height contributed to the relationship for the forearm sites only. At the proximal femur, the BMD level that separates fracture cases from nonfracture cases, increases with age. These separation levels of BMD were higher than the WHO's level of osteoporosis (T-score < -2.5 SD) at ages older than 62 years. This increasing BMD threshold with age suggests that other age-related risk factors assume increasing importance among the elderly.

Adult↗
PubMed2001

Vitamin D status of women in the Geelong Osteoporosis Study: association with diet and casual exposure to sunlight.

OBJECTIVE: To assess vitamin D intake and casual exposure to sunshine in relation to serum 25-hydroxyvitamin D (25OHD) levels. DESIGN: Cross-sectional study of a population-based, random sample of women aged 20-92 years, assessed between 1994 and 1997. SETTING AND PARTICIPANTS: 861 women from the Barwon Statistical Division (population, 218000), which includes the city of Geelong (latitude 38 degrees south) in Victoria. MAIN OUTCOME MEASURES: Vitamin D intake; serum 25OHD level; season of assessment; exposure to sunshine. RESULTS: Median intake of vitamin D was 1.2 microg/day (range, 0.0-11.4 microg/day). Vitamin D supplements, taken by 7.9% of participants, increased intake by 8.1% to 1.3 microg/day (range, 0.0-101.2 microg/day) (P< 0.001). A dose-response relationship in serum 25OHD levels was observed for sunbathing frequency before and after adjusting for age (P< 0.05). During winter (May-October), serum 25OHD levels were dependent on vitamin D intake (partial r2= 0.01; P<0.05) and were lower than during summer (November-April) (age-adjusted mean, 59nmol/L [95% Cl, 57-62] v 81 nmol/L [95% CI, 78-84]; P<0.05). No association was detected between serum 25OHD and vitamin D intake during summer. The prevalences of low concentrations of serum 25OHD were, for <28nmol/L, 7.2% and 11.3% overall and in winter, respectively; and, for <50 nmol/L, 30.0% and 43.2% overall and in winter, respectively. CONCLUSIONS: At latitude 38 degrees south, the contribution of vitamin D from dietary sources appears to be insignificant during summer. However, during winter vitamin D status is influenced by dietary intake. Australia has no recommended dietary intake (RDI) for vitamin D, in the belief that adequate vitamin D can be obtained from solar irradiation alone. Our results suggest that an RDI may be needed.

Adult↗
PubMed2001

Serum leptin levels are associated with bone mass in nonobese women.

Both serum leptin and bone mineral density are positively correlated with body fat, generating the hypothesis that leptin may be a systemic and/or local regulator of bone mass. We investigated 214 healthy, nonobese Australian women aged 20-91 yr. Bone mineral content, projected bone area, and body fat mass were measured by dual energy x-ray absorptiometry and fasting serum leptin levels by RIA. Associations between bone mineral content (adjusted for age, body weight, body fat mass, and bone area) and the natural logarithm of serum leptin concentrations were analyzed by multiple regression techniques. There was a significant positive association at the lateral spine, two proximal femur sites (Ward's triangle and trochanter), and whole body (partial r(2) = 0.019 to 0.036; all P < 0.05). Similar trends were observed at the femoral neck and posterior-anterior-spine. With bone mineral density the dependent variable (adjusted for age, body weight, and body fat mass), the association with the natural logarithm of leptin remained significant at the lateral spine (partial r(2) = 0.030; P = 0.011), was of borderline significance at the proximal femur sites (partial r(2) = 0.012 to 0.017; P = 0.058 to 0.120), and was not significant at the other sites. Our results demonstrate an association between serum leptin levels and bone mass consistent with the hypothesis that circulating leptin may play a role in regulating bone mass.

Adult↗
PubMed2001

Assessment of fracture risk: value of random population-based samples--the Geelong Osteoporosis Study.

Fracture risk is determined by bone mineral density (BMD). The T-score, a measure of fracture risk, is the position of an individual's BMD in relation to a reference range. The aim of this study was to determine the magnitude of change in the T-score when different sampling techniques were used to produce the reference range. Reference ranges were derived from three samples, drawn from the same region: (1) an age-stratified population-based random sample, (2) unselected volunteers, and (3) a selected healthy subset of the population-based sample with no diseases or drugs known to affect bone. T-scores were calculated using the three reference ranges for a cohort of women who had sustained a fracture and as a group had a low mean BMD (ages 35-72 yr; n = 484). For most comparisons, the T-scores for the fracture cohort were more negative using the population reference range. The difference in T-scores reached 1.0 SD. The proportion of the fracture cohort classified as having osteoporosis at the spine was 26, 14, and 23% when the population, volunteer, and healthy reference ranges were applied, respectively. The use of inappropriate reference ranges results in substantial changes to T-scores and may lead to inappropriate management.

Absorptiometry, Photon↗
PubMed2000

Oral contraceptives and bone mineral density: A population-based study.

OBJECTIVE: We sought to test the hypothesis that exposure to oral contraceptives protects the skeleton. STUDY DESIGN: Multiple regression techniques were used to analyze data for a random sample of 710 Australian women (age range, 20-69 years). Bone mineral density was measured at the lumbar spine, proximal femur, whole body, and distal forearm. Oral contraceptive exposure was assessed by a questionnaire. RESULTS: Women exposed to oral contraceptives had a 3.3% greater mean bone mineral density adjusted for body mass index and age at the lumbar spine (partial r (2) = 0.009; P =.014). Adjusted mean vertebral bone mineral density was 3.3% greater for premenopausal women (partial r (2) = 0.008; P <.05), but the effect did not reach significance among postmenopausal women. Higher bone mineral density was associated with increased duration of exposure, with a mean increase of 3.2% associated with the first 5 years and a further 0.2% with >/=5 years of exposure. No association was detected at other sites. CONCLUSION: Exposure to oral contraceptives may be associated with higher lumbar spine bone mineral density.

Absorptiometry, Photon↗
PubMed2000

Calcium intakes among Australian women: Geelong Osteoporosis Study.

BACKGROUND: Dietary calcium deficiency may be a risk factor for osteoporosis. AIMS: To estimate habitual calcium intakes and prevalence of calcium supplementation among free-living Australian women and validate a calcium-specific food-frequency questionnaire. METHODS: Calcium intakes for 1045 randomly selected women (20-92 years) were estimated by questionnaire which was tested against estimates from four day weighed records kept by 32 randomly selected women. RESULTS: The mean difference between calcium estimates was not statistically significantly different from zero (mean difference=121 mg; standard deviation of differences=357 mg; p>0.05). There was moderate agreement (weighted kappa=0.4) between methods in ranking subjects into tertiles of calcium intake. Mean dietary calcium intakes were 615 mg/day for 20-54 years, 646 mg/day for 55-92 years and 782 mg/day for lactating women. Seventy-six per cent of women aged 20-54 years, 87% of older and 82% of lactating women had intakes below the recommended dietary intake (RDI). There was no association detected between calcium intake and age. Dairy foods provided 79.0% of dietary calcium intake. Calcium supplements were used by 6.6% and multivitamins by a further 4.3% of women. Supplementation was independent of dietary calcium intake and more likely used by postmenopausal women. CONCLUSIONS: Our results suggest that 76% of women consume less than the RDI even when supplemental calcium is included. Furthermore, 14% have less than the minimal requirement of 300 mg/day and would, therefore, be in negative calcium balance and at risk of bone loss. Despite advertising campaigns promoting better nutrition and increased awareness of osteoporosis, many women are failing to achieve an adequate calcium intake.

Adult↗
PubMed2000

A polymorphism in the tumor necrosis factor-alpha gene promoter region may predispose to a poor prognosis in COPD.

STUDY OBJECTIVES: To determine whether the adenine (A)-guanine (G) substitution polymorphism at position - 308 on the tumor necrosis factor-alpha gene confers susceptibility to COPD or to the development of a more severe form of disease. DESIGN: A cross-sectional study was undertaken to compare the frequency of the A allele in a group of 106 patients with COPD with that in a control population (n = 99). Patients were followed up prospectively for a period of 2 years. PARTICIPANTS AND SETTING: Participants included 106 COPD patients recruited from a respiratory outpatient clinic and 99 control subjects recruited from patients admitted for cardiac catheterization. MEASUREMENTS AND RESULTS: DNA was extracted from venous blood, and each subject was genotyped for the polymorphism by polymerase chain reaction amplification and restriction digestion using Nco1. There was no increased frequency of the A allele in patients compared to control subjects. AA homozygous patients had less reversible airflow obstruction (p<0.05) and a significantly greater mortality (both all-cause and respiratory deaths) on follow-up (p<0.001), despite a shorter cigarette smoking history. CONCLUSIONS: This study suggests that homozygosity for this A allele predisposes to more severe airflow obstruction and a worse prognosis in COPD.

Aged↗
PubMed2000

Prevalence of osteoporosis in Australian women: Geelong Osteoporosis Study.

To evaluate the prevalence of osteoporosis at various sites among Australian women, cross-sectional bone mineral density (BMD) data for adult females was obtained from an age-stratified population-based sample (n = 1494; 20-94 yr) drawn at random from the Barwon Statistical Division, a population characteristic of Australia. Age- and weight- (and for three sites, height) matched reference ranges for BMD at the lumbar spine, proximal femur, forearm, and total body were developed using regression techniques. The cutoff BMD level for osteoporosis at the PA spine was 0. 917g/cm(2) and 0.713 g/cm(2) at the femoral neck according to the World Health Organization (WHO) guidelines. The upper cutoff level for osteopenia was 1.128 g/cm(2) at the PA spine and 0.913g/cm(2) for the femoral neck. The proportion of Australian women categorized as having osteoporosis at the PA spine, femoral neck, or midforearm ranged from 0.9% among those aged 40-44 yr to 87.0% for those older than 79 yr. This study provides reference data representative of the Australian female population. A large proportion of elderly Australian women has osteoporosis according to the WHO guidelines.

Absorptiometry, Photon↗
PubMed1999

Femoral neck dimensions are unlikely to be associated with age at menarche.

Hip axis length (HAL) has been reported as an independent risk factor for hip fracture. Later puberty may increase bone size because of delayed epiphyseal fusion. We sought to identify associations between bone size at the proximal femur with age at menarche and other indices of growth such as stature. Femoral neck dimensions were measured from dual-energy X-ray absorptiometry scans of the proximal femur in a random sample of 203 premenopausal Caucasian women (age 20-30 years). There were no associations between age at menarche and HAL, femoral axis length (FAL) or femoral neck width (FNW). Age at menarche was associated with height (r = 0.2, p = 0.02). Variations in HAL, FAL and FNW do not appear to be related to age at menarche.

Absorptiometry, Photon↗
PubMed1999

Identification of incident fractures: the Geelong Osteoporosis Study.

BACKGROUND: Complete fracture ascertainment is critical for fracture cost estimates and planning for future health care facilities. Virtually complete ascertainment is possible for hip fractures because they nearly always require hospitalisation. AIMS: To validate the use of radiological reports as a resource for ascertaining fracture cases, using hip fracture as a model. METHODS: Hip fracture rates obtained from radiological reports were compared with rates obtained from hospital discharge summaries of medical records using International Classification of Diseases-9 (ICD-9) codes 820.0-820.9 and 733.1 over a three-year period. RESULTS: Hip fracture cases numbered 589 using radiological reports and 585 using medical records. Discharge summaries failed to identify 15 cases ascertained through radiology reports whereas 11 cases ascertained through medical records were not identified from X-ray reports. The age-specific incidence rates for radiological ascertainment were within the 95% confidence limits of the rates derived from medical records. CONCLUSIONS: Among a population of patients generally admitted to hospital for treatment of their fracture, we were able to identify more cases from radiological reports than from medical records. Incidence rates for hip fracture were comparable using the two methods. Radiological reports provide a valuable resource for identifying incident fractures. This method of case ascertainment would be suitable for identifying both major and minor fractures in regions with self-contained health services where access to all radiological reports is possible.

Adolescent↗
PubMed1999

Comparison of weigh-suckle-weigh and machine milking for measuring ewe milk production.

Thirteen crossbred ewes were used to compare weigh-suckle-weigh (WSW) and machine milking (MM) methods for determining milk production of ewes that were rearing single or twin lambs. At parturition, ewes were 13 mo of age and produced six single lambs and seven pairs of twin lambs. Milk production estimates were initiated on d 6 of lactation and a 3-d rotation of the two techniques was implemented. On d 6, milk production was measured using WSW; on d 7, MM was used. No measurement was made on d 8. The 3-d rotation was repeated 20 times throughout a 63-d lactation, resulting in 20 point estimates of milk production for each method of measurement for each ewe. The WSW procedure consisted of a 3-h period in which lambs were withheld from suckling their dams. This was followed by a suckling period, a second 3-h withholding period, and a second suckling period. Differences in pre- and postsuckling lamb weights of the second suckling period were defined as milk consumption and, indirectly, 3-h milk production. The MM procedure included an administration of 10 IU of oxytocin (i.v.), followed by evacuation of the udder with a machine using commercially available sheep milking equipment, and the milk was discarded. Lambs were withheld from suckling the ewes for a 3-h period, followed by a repetition of the oxytocin and machine milking procedures. Milk from the second milking was weighed. Milk production estimates determined using the WSW and MM techniques were similar (P = .42). Average 3-h milk production was 340 and 351 g for WSW and MM, respectively. Machine milking provides a reliable tool in evaluating the milk-producing ability of ewes that are rearing single or twin lambs.

Analysis of Variance↗
PubMed1998

The effects of carbohydrate restriction in patients with diet-controlled gestational diabetes.

OBJECTIVE: To determine the effect of carbohydrate restriction on perinatal outcome in patients with diet-controlled gestational diabetes mellitus (GDM). METHODS: Women with diet-controlled GDM were divided non-randomly into two groups based on their dietary carbohydrate content: those with low dietary carbohydrate content (below 42%) and those with high dietary carbohydrate content (exceeding 45%). Subjects kept dietary accounts and were followed with daily fasting and postprandial glucose assessments. Subjects also were tested daily for urinary ketones. Glycosylated hemoglobin, mean fasting and postprandial glucose values, incidence of macrosomia and large for gestational age (LGA) infants, cesarean deliveries for cephalopelvic disproportion and macrosomia, and need for insulin therapy were compared between the groups. RESULTS: The two groups were identical in terms of demographic characteristics. Significant reductions in the postprandial glucose values were seen among subjects in the low-carbohydrate group (P < .04). Fewer subjects in the low-carbohydrate group required the addition of insulin for glucose control (P < .047; relative risk [RR] 0.14; 95% confidence interval [CI] 0.02, 1.00). The incidence of LGA infants was significantly lower in the low-carbohydrate group (P < .035; RR 0.22; 95% CI 0.05, 0.91). Subjects in the low carbohydrate group also had a lower rate of cesarean deliveries for cephalopelvic disproportion and macrosomia (P < .037; RR 0.15; 95% CI 0.04, 0.94). CONCLUSION: Carbohydrate restriction in patients with diet-controlled GDM results in improved glycemic control, less need for insulin therapy, a decrease in the incidence LGA infants, and a decrease in cesarean deliveries for cephalopelvic disproportion and macrosomia.

Adult↗
PubMed1997

Design of the cyclops flap for chest-wall reconstruction.

The cyclops flap is a little-known but not forgotten alternative in chest-wall reconstruction for women. Female patients having a large, pendulous breast with a contralateral adjacent defect may be reconstructed by this technique. The flap derives its name from the repositioning of the remaining nipple to the center of the chest. The design of the flap is described. By knowing the width and length of the defect, the surgeon can design incisions on the remaining breast tissue that will allow the flap to advance easily, reliably filling the defect. The flap is an axial-pattern flap nourished by the lateral thoracic artery and the variable external mammary artery. This arterial inflow will serve the medial portion of the flap. The operation is straightforward and predictable. In using this design scheme three times in the last two years, there have been no complications. There is little discomfort after surgery. Occasionally, patients will benefit from this reconstructive option.

Aged↗
PubMed1993

Linkage analysis and physical mapping near the gene for X-linked agammaglobulinemia at Xq22.

The gene for X-linked agammaglobulinemia (XLA) has been mapped to Xq22. No recombinations have been reported between the gene and the probe p212 at DXS178; however, this probe is informative in only 30-40% of women and the reported flanking markers, DXS3 and DXS94, are 10-15 cM apart. To identify additional probes that might be useful in genetic counseling, we examined 11 polymorphisms that have been mapped to the Xq21.3-q22 region in 13 families with XLA. In addition, pulsed-field gel electrophoresis and yeast artificial chromosomes (YACs) were used to further characterize the segment of DNA within which the gene for XLA must lie. The results demonstrated that DXS366 and DXS442, which share a 430-kb pulsed-field fragment, could replace DXS3 as proximal flanking markers. Probes at DXS178 and DXS265 identified the same 145-kb pulsed-field fragment, and both loci were contained within a 200-kb YAC identified with the probe p212. A highly polymorphic CA repeat (DXS178CA) was isolated from one end of this YAC and used in linkage analysis. Probes at DXS101 and DXS328 shared several pulsed-field fragments, the smallest of which was 250 kb. No recombinations were seen between XLA and the DXS178-DXS265-DXS178CA complex, DXS101, DXS328, DXS87, or the gene for proteolipid protein (PLP). Key crossovers, when combined with the linkage data from families with Alport syndrome, suggested the following order of loci: cen-DXS3-DXS366-DXS442-(PLP, DXS101, DXS328, DXS178-DXS265-DXS178CA complex, XLA)-(DXS87, DXS94)-DXS327-(DXS350, DXS362)-tel.(ABSTRACT TRUNCATED AT 250 WORDS)

Agammaglobulinemia↗
PubMed1991

Cytologic assessment of tumor cell kinetics: applications of monoclonal antibody Ki-67 to fine-needle aspiration smears.

Rates of tumor-cell proliferation often provide prognostic information about a given neoplasm. Previously available methods for accessing cell kinetics are time consuming and expensive, and often require special equipment or radioactive reagents. Monoclonal antibody Ki-67 binds a nuclear antigen expressed in proliferating but not in resting cells. We studied Ki-67 immunostaining of fine-needle aspiration smears from 40 benign and malignant masses. Labeling indices ranged from 0 (thyroid follicular adenoma) to 75 percent (pulmonary oat-cell carcinoma). Frozen section immunostaining (11 cases) and flow cytometric assessment of cell proliferation (8 cases) were in good agreement with Ki-67 labeling indices on smear material. We suggest that this method provides a rapid, inexpensive, and dependable means of assessing tumor-cell kinetics in cytologic preparations.

Antibodies, Monoclonal↗