Effect of maternal and infant covariates on sibship correlation in birth weight

Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight.     

The Framingham Disability Study: physical disability among community-dwelling survivors of stroke

The relationship between stroke and physical disability was examined in a cohort of adult, Framingham, Massachusetts, residents who, between 1948 and 1951, were assembled for a longitudinal examination of cardiovascular disease. Multivariate analyses examined the amount of residual disability attributable to stroke among 2540 community-dwelling survivors, 27 years after their initial examination, after controlling for age, cardiovascular risk factors, other cardiovascular diseases, and eight general health conditions related to physical disability. Among men living in the community, a history of stroke explained 12% of the variance in physical disability. Suffering a stroke, however, was not as strongly related to physical disability among women living in the community, accounting for only 3% of the variance. Results suggest that although older men and women die from the same major causes, they may not be disabled by the same conditions.     

Dietary intake of healthy subjects before and one year after dietary advice

This study was conducted to follow up healthy subjects from a previous study (Warwick & Williams, 1987) in which favourable dietary changes were achieved during 1 week immediately after dietary advice but were accompanied by reduced energy intakes and weight loss. Twenty-one subjects (8m, 13f; 57 per cent of the original group) participated in the follow-up study. Dietary intakes were measured using 7-d weighed records on three occasions: before, immediately after and 1 year after receiving dietary advice. Intakes 1 year after dietary advice continued to show some of the favourable changes observed immediately after the advice but were not accompanied by reduced energy intakes and weight loss. Intakes before, immediately after, and 1 year after dietary advice respectively were: energy, 9.0, 7.8 and 8.9 MJ/d (2150, 1860 and 2120 kcal/d); fat, 36.9, 32.9 and 31.5 per cent of total energy; carbohydrate, 44.2, 47.9 and 49.6 per cent of total energy; dietary fibre, 32, 36 and 36 g/d; sodium, 116, 97 and 110 mmol/d; and Na:K ratio, 1.4, 1.2 and 1.2 mmol. Nutrient densities for fibre and most micronutrients tended to be higher 1 year after dietary advice than before, but were highest immediately after the advice. Nutrient densities for sodium and total sugars did not vary between the 3 study weeks. It was concluded that our healthy subjects adapted their intakes to maintain energy balance while retaining favourable dietary changes for at least 1 year after dietary advice.     

Eledoisin and lacrimal secretion in the rabbit

Eledoisin has been tried as a possible treatment for dry eye based on the hypothesis that it pharmacologically stimulates tear secretion when topically applied to the eye. To determine if topically applied eledoisin pharmacologically stimulates orbital lacrimal secretion, the orbital lacrimal gland excretory duct of normal rabbits was cannulated, and eledoisin was applied topically with and without prior administration of proparacaine. To determine if topically applied eledoisin stimulated accessory lacrimal gland secretion, isotonic buffer with and without eledoisin was tested in a rabbit model with only accessory lacrimal tissue remaining after the administration of proparacaine. Topically applied eledoisin did not pharmacologically stimulate lacrimal secretion but rather increased lacrimal gland secretion only in non-anesthetized eyes through a sensory reflex mechanism that is blocked by proparacaine.     

Role of intracortical mechanisms in the late part of the silent period to transcranial stimulation of the human motor cortex

Transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES) of the human motor cortex produce a silent period (SP) following motor evoked potentials (MEPs). The early part of the SP can be explained by decreased alpha motor neuron excitability, whereas the late part is presumably due to suprasegmental mechanisms. In order to determine the level of the suprasegmental contribution to the generation of SPs, we recorded excitatory and inhibitory responses to TMS, TES, and percutaneous electrical brainstem stimulation (PBS) in the voluntarily activated first dorsal interosseous muscle of the hand. Stimulus intensities were set so that PBS and TES induced MEPs with areas equal to or larger than those of MEPs obtained with TMS. This procedure revealed that SPs were 49% and 83% shorter with TES and PBS, respectively, than with TMS. As TMS is more effective than TES or PBS in activating cortical interneurons, these findings support the idea that a significant component of the SP arises from intracortical mechanisms.     

Dorsal fracture of the hamate: distinctive radiographic appearance

Six patients who injured their wrists had radiographs documenting a dorsal, 5- to 10-mm oblong fragment of bone immediately proximal to the base of the fourth and/or fifth metacarpal bones. The fragment was seen on the pronation oblique and/or lateral projections, but not on the posteroanterior projection. The radiographic appearance of the fragment was remarkably similar in all cases. In the one patient in which it was performed, pluridirectional tomography demonstrated that the fragment originated from the dorsal surface of the hamate. Five of the six patients also had associated posterior dislocation of the fourth and/or fifth metacarpals. We conclude that this fragment represents a coronal fracture through the body of the hamate resulting from posterior dislocation or subluxation of the fourth and/or fifth metacarpal.     

The binding of blood-borne estrogens in normal vegetarian and omnivorous women and the risk of breast cancer

Serial blood samples were taken at two-hour intervals over a 24-hour period from 25 premenopausal vegetarians (12 vegans and 13 ovolactovegetarians) and from 21 omnivorous controls. All members of the former group had been on a vegetarian diet for a minimum of three years. The mean proportion of estradiol unbound to blood proteins was similar in both vegetarians (1.26%) and meat eaters (1.16%). However, the amount bound to albumin was significantly raised in vegetarians (50.1% vs. 43.1%, p less than 0.009), whereas that bound to sex hormone-binding globulin (SHBG) was correspondingly lower (48.7% vs. 55.8%, p = 0.01). Mean levels of SHBG were similar in vegetarians (59.9 nmole/l) and omnivores (62.0 nmole/l), as was the total amount of free fatty acid (0.42 mmole/l for both). Within the vegetarian group, no differences were detected between vegans and ovolactovegetarians.     

Assessment of sodium and potassium intakes

The sodium, potassium and creatinine contents of three non-consecutive 24-h urine samples collected by 34 selected adult individuals (10 m; 24 f) living in Cork City were determined. The pooled mean 24-h excretion of sodium and potassium in collections adjudged to be complete were 152 mmol and 78 mmol, respectively. There was no significant difference between group average weekday and weekend-day excretion of Na or K, for either males or females. This suggests that weekend 24-h urinary collections, which most subjects find more convenient, are suitable for studies of sodium and potassium intakes of groups. The ratios of intra- to inter-individual variation for 24-h urinary sodium were 1.4 and 2.1 for males and females, respectively. The corresponding ratios for 24-h urinary potassium were 6.6 for males and 4.9 for females. These ratios indicated that there were large individual day-to-day variations in urinary sodium and potassium excretion in this group. It was estimated that a sample size of 35-60 individuals would be required to estimate group mean sodium and potassium intakes by means of single 24-h urine collections.