Concurrent use of simvastatin and estrogen--progestin therapy compared with each therapy alone for hypercholesterolemia in postmenopausal women

OBJECTIVE

Substantial improvements in lipoprotein-lipid profiles have previously been shown with both simvastatin and combined estrogen-progestin therapy in postmenopausal hypercholesterolemic women. Since little is known about the impact of the concomitant use of these therapies, the effects of concurrent hormone therapy and simvastatin in hypercholesterolemic postmenopausal women have been evaluated.

METHODS

Twenty-three postmenopausal women with fasting serum total cholesterol levels greater than 250 mg/dl received, in a randomized cross-over design, simvastatin (10 mg daily) for 8 weeks or postmenopausal hormone therapy (up to 1.25 mg of conjugated equine estrogens plus 5 mg of medroxyprogesterone acetate daily) for 8 weeks, with an 8-week wash-out interval between the two treatment periods. In a third, non-randomized treatment period after a second wash-out interval, each woman received a combination of simvastatin and postmenopausal hormone therapy in the same dosage regimens as above. Fasting blood was sampled monthly from baseline to measure total cholesterol, high- and low-density lipoprotein (HDL and LDL) cholesterol, triglycerides and lipoprotein(a).

RESULTS

For total cholesterol, the mean decreases with hormone therapy, simvastatin and combination therapy were 12% (95% confidence interval 6-17%), 26% (20-31%) and 28% (24-31%), respectively, and for LDL cholesterol 21% (14-27%), 37% (30-44%) and 46% (41-51%), respectively. Simvastatin was more effective than hormone therapy (p < 0.001), while the effect of the combined therapy was even greater (total cholesterol, p = 0.012; LDL cholesterol, p < 0.001). The level of HDL cholesterol increased similarly with each treatment: 4% (-3-11%), 6% (2-10%) and 7% (2-13%), respectively. Triglyceride levels increased with hormone therapy and decreased with simvastatin (p < 0.001), while there was little change with the combination (effect of combined therapy vs. simvastatin, p = 0.002; vs. hormone therapy, p < 0.001). Both hormone therapy and combined therapy reduced lipoprotein(a) similarly (-23% and -14%, respectively, p = 0.078). Simvastatin had no effect on lipoprotein(a) levels.

CONCLUSION

For postmenopausal women with hypercholesterolemia, use of a statin in combination with continuous combined oral estrogen and progestin therapy can result in a more cardioprotective lipoprotein-lipid profile than that achieved with either therapy used alone.

Combined inhibin and CA125 assays in the detection of ovarian cancer

BACKGROUND

The reproductive hormone inhibin has been used as a diagnostic marker of ovarian mucinous and granulosa cell cancers. The aims of this study were to develop a new inhibin immunofluorometric assay (alphaC IFMA) to replace an inhibin RIA as a diagnostic marker of these ovarian cancers and to assess whether the alphaC IFMA in combination with CA125, which detects serous cancers, leads to an improved biochemical diagnosis of all ovarian cancers.

METHODS

Serum inhibin concentrations were determined in healthy postmenopausal women (n = 165) and women with ovarian cancers (n = 154), using an inhibin RIA and an alphaC IFMA, which detects inhibin forms containing the alphaC subunit as well as the free alphaC subunit.

RESULTS

The alphaC IFMA gave a similar or better discrimination of mucinous (90% vs 71%) and granulosa cell (100% vs 100%) cancers compared with the inhibin RIA. Combination of CA125 and alphaC IFMA values by canonical variate analysis or by multiROC analysis showed that the percentage of all ovarian cancers detected was significantly increased compared with either CA125 or alphaC IFMA alone.

CONCLUSIONS

The alphaC IFMA shows a similar or better specificity compared with the RIA, but with increased sensitivity. In combination with CA125, the alphaC IFMA provides an effective dual test for the detection of the majority (90%) of ovarian cancers.

Estrogen and progestin compared with simvastatin for hypercholesterolemia in postmenopausal women

BACKGROUND

Postmenopausal estrogen therapy has favorable effects on serum lipoproteins in women with normal serum lipid levels, but the effect of combined estrogen and progestin therapy on lipoproteins in women with hypercholesterolemia has not been determined, nor has it been directly compared with the effect of conventional lipid-lowering therapy.

METHODS

In a randomized crossover trial, we studied 58 postmenopausal women with fasting serum total cholesterol levels greater than 250 mg per deciliter. Each woman received simvastatin (10 mg daily) for eight weeks and postmenopausal hormone therapy (up to 1.25 mg of conjugated equine estrogens daily, along with 5 mg of medroxyprogesterone acetate daily) for eight weeks, with an eight-week washout period between the two treatment phases.

RESULTS

At base line, the mean (+/-SD) cholesterol values were as follows: total cholesterol, 305+/-39 mg per deciliter; high-density lipoprotein (HDL) cholesterol, 62+/-19 mg per deciliter; and low-density lipoprotein (LDL) cholesterol, 217+/-39 mg per deciliter. For total cholesterol, the mean decrease with hormone therapy was 14 percent (95 percent confidence interval, 11 to 16 percent) and the mean decrease with simvastatin was 26 percent (95 percent confidence interval, 23 to 29 percent). For LDL cholesterol, the mean decrease was 24 percent (95 percent confidence interval, 20 to 28 percent) with hormone therapy and 36 percent (95 percent confidence interval, 32 to 40 percent) with simvastatin. The effect of simvastatin was significantly greater than that of hormone therapy (P<0.001). HDL cholesterol increased similarly with hormone therapy (mean increase, 7 percent; 95 percent confidence interval, 2 to 12 percent) and simvastatin (mean increase, 7 percent; 95 percent confidence interval, 4 to 10 percent). Triglyceride levels increased with hormone therapy (mean increase, 29 percent; 95 percent confidence interval, 15 to 42 percent) but decreased with simvastatin (mean decrease, 14 percent; 95 percent confidence interval, 8 to 20 percent). Lp(a) lipoprotein decreased with hormone therapy (mean decrease, 27 percent; 95 percent confidence interval, 20 to 34 percent), but not with simvastatin.

CONCLUSIONS

In postmenopausal women with hypercholesterolemia, therapy with estrogen plus progestin has beneficial effects on lipoprotein levels. Hormone therapy may be an effective alternative to treatment with simvastatin, especially in women with normal triglyceride levels.

Do infants of depressed mothers cry more than other infants?

OBJECTIVE

This study compared the crying behaviour of infants of depressed and non-depressed mothers at 3 and 6 months of age.

METHODOLOGY

Twenty-nine depressed and 44 non-depressed mothers, their infants and partners participated in this study. Mothers were asked to complete 24-hour diaries of the amount their infants cried for 1 week.

RESULTS

The diurnal variations in crying patterns of infants of depressed and non-depressed mothers were not significantly different. However, infants of depressed mothers were found to cry significantly more in total per day than infants of non-depressed mothers at 3 months of age, but not at 6 months. The results could not be explained by differences in infant temperament.

CONCLUSION

Maternal depression may be a contributory factor to infant crying at 3 months of age.

The effect of the Myo device on the gingival health in orthodontic patients

The purpose of the present investigation was to determine the effectiveness of the Myo in reducing plaque and gingivitis development in orthodontic patients using a single-blind, cross-over design. Thirty subjects were randomly assigned to experimental and control groups. All subjects continued their customary oral hygiene procedures. In addition, the experimental group was instructed to chew on the Myo for four minutes, twice each day. Plaque Index and Gingivitis Index were assessed each time the subjects attended their scheduled orthodontic appointment. The patients failed to demonstrate any significant reduction in plaque and gingivitis development when the Myo was introduced as an additional oral hygiene measure. Some soft tissue injuries were found.

Serum inhibin during lactation: relation to the gonadotrophins and gonadal steroids

OBJECTIVE

The aims of the study were to describe the changes in serum immunoreactive inhibin (INH) during normal lactation and to examine the relations between INH, oestradiol (E2) and follicle stimulating hormone (FSH), particularly during the first weeks post partum.

DESIGN

Blood samples were obtained from normally lactating women for hormone measurements at daily intervals until discharge from hospital, and subsequently at weekly intervals until the resumption of menses, or one year post partum.

SUBJECTS

Eighteen breast feeding women aged 27-36 years volunteered for the study.

MEASUREMENTS

INH, FSH, luteinizing hormone (LH), prolactin (PRL), E2, and progesterone (P4) were measured by standard radioimmunoassays. Non-linear modelling was used to quantify the hormone patterns observed.

RESULTS

Hormone levels were compared with those found in the follicular phase of the normal menstrual cycle. Levels of INH fell rapidly in the first week post partum and remained at the lower end of the follicular phase range for the period of study, rising only just prior to resumption of menses. E2 fell more slowly, into the follicular phase range, reaching the lower end of that range only at about approximately 100 days post partum. FSH levels were suppressed initially below the follicular phase range, commencing to rise 4.7-24 days post partum, reaching a plateau high in the follicular phase range 17.5-53 days post partum, and subsequently showing a slow decline. Human chorionic gonadotrophin (hCG), initially measured because of its cross-reactivity in the LH assay, fell rapidly post partum and LH remained in the low follicular phase range for several weeks. PRL fell slowly throughout and was still elevated at 150 days post partum, while P4 fell very rapidly and was less than 1 nmol/l until just prior to first menses.

CONCLUSIONS

Inhibin levels fall rapidly post partum and remain low until close to the time of resumption of follicular activity and menses. The post partum rise in serum FSH appears to be much more closely related to falling oestradiol levels than to the very early and rapid fall in inhibin. Oestradiol thus appears to be the predominant negative feedback factor influencing FSH secretion during the post partum period. The low inhibin levels may allow FSH to rise to levels high in the follicular phase range under the predominant negative feedback control of oestradiol. Inhibin levels do not appear to be a suitable marker of returning fertility.

Determinants of forearm mineral density and its correlation with fracture history in women

In order to evaluate the role of single photon absorptiometry (SPA) in the prediction of osteoporotic fracture risk, 1935 women, referred for measurement of forearm mineral density (FMD) at the distal radial site, were studied by questionnaire in a cross-sectional design. There was no significant decline in FMD until the age of 47, after which there was a linear decline with age of about 1.2% per year. There was no relationship between age and FMD, or forearm mineral content (FMC), in premenopausal women. There was a fall in FMD with the number of years since menopause, after correcting for the effects of age, of approximately 0.5% per year. Body weight was positively correlated with FMC in postmenopausal women. The duration of exposure to hormone replacement therapy (HRT) was positively correlated with FMD, and the magnitude of this effect was reduced the longer the delay between the onset of the menopause and the commencement of HRT. There was no significant association of FMD with calcium intake, weight-bearing exercise, tobacco or alcohol consumption, or family history of osteoporosis. FMD was significantly lower in postmenopausal women who reported fractures after the age of 25, after correcting for age and years postmenopause. In conclusion, a low FMD is predictive of a past history of fractures and may therefore be capable of predicting future fracture risk.

Follicle-stimulating hormone induces dose-dependant stimulation of immunoreactive inhibin secretion during the follicular phase of the human menstrual cycle

To determine whether FSH is a physiological regulator of the serum immunoreactive inhibin (INH) concentration during the follicular phase of the normal menstrual cycle, purified FSH (Metrodin) was administered in doses of 100 IU (n = 6), 150 IU (n = 5), and 200 IU (n = 5) to normal, regularly cycling volunteers between days 3-7 of the menstrual cycle. A control group (n = 5) received normal saline. There was a linear dose-related increase in serum INH (and in serum FSH) in response to the three doses of FSH, with 200 IU leading to a 107% increase in INH and a 68% increase in FSH. Serum estradiol rose in response to the two higher doses of FSH. There was a significant correlation between the actual increases in INH and estradiol (r = 0.53; P < 0.01). It was concluded that FSH stimulates INH in the follicular phase of the normal menstrual cycle, consistent with a physiological role for FSH in the regulation of granulosa cell production of inhibin.

Age and follicular phase estradiol are better predictors of pregnancy outcome than luteinizing hormone in menotropin ovulation induction for anovulatory polycystic ovarian syndrome

OBJECTIVE

To examine the relationship of baseline and preovulatory serum E2, P, and LH levels and age with pregnancy outcome in polycystic ovarian syndrome (PCOS) patients undergoing hMG ovulation induction.

DESIGN

Retrospective analysis of all available data over 2 years.

SETTING

Tertiary referral ovulation induction clinic.

SUBJECTS

Forty-four anovulatory PCOS patients with 25 ovulatory nonconception and 50 conception cycles after hMG ovulation induction.

MAIN OUTCOME MEASURES

Ovulation (midluteal serum P > 25 nmol/L [7.86 ng/mL]); pregnancy (serum beta-hCG > 30 mIU/mL 16 days after ovulating injection); pregnancy outcome: pregnancy termination < 20 weeks' or > or = 20 weeks' amenorrhea.

RESULTS

Of the endocrine parameters considered, none was significantly different in nonconceptive and conceptive ovulatory cycles. Miscarriage was associated with low basal serum E2: median value for pregnancies ending < 20 weeks, 105 pmol/L (28.6 pg/mL) and for > or = 20 weeks 150 pmol/L (40.9 pg/mL). It was also significantly associated with age. For patients > 29.5 years of age, (29.5 years, population mean age) a baseline E2 < or = 140 pmol/L (38.2 pg/mL) had sensitivity 92%, specificity 54%, positive predictive value 65%, and negative predictive value 87% for the prediction of miscarriage. The nature of the previous cycle, the day of the cycle on which therapy commenced, and a past history of miscarriage were not related either to pregnancy outcome or to basal serum E2.

Continuation of long term treatment with hydroxychloroquine in systemic lupus erythematosus and rheumatoid arthritis

BACKGROUND

Hydroxychloroquine is used for the treatment of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Long term studies have shown a high rate of termination of hydroxychloroquine treatment in patients with RA. Although it has been shown that discontinuation of treatment with hydroxychloroquine is associated with exacerbation of SLE, long term maintenance rates of treatment with hydroxychloroquine in patients with SLE have not been investigated.

METHODS

Hydroxychloroquine use in patients with RA and SLE in a group of patients in a single community rheumatology practice was studied. Information was drawn from a computer drug use database containing details of the beginning and end of treatment. Data were analysed using life table methods.

RESULTS

Four hundred and three treatment episodes (366 patients with RA, 37 patients with SLE) were observed over eight years. In patients with RA, the cumulative probability of discontinuing treatment was 37% at 12 months and 54% at 24 months. In contrast, hydroxychloroquine treatment of patients with SLE continued over significantly longer periods of time (p < 0.001); the discontinuation probabilities at 12 and 24 months were 8 and 24% respectively. Treatment terminations were predominantly for inefficacy; terminations for toxicity were limited to the first 19 months of treatment. No ocular toxicity was observed.

CONCLUSIONS

Treatment of patients with RA in a community rheumatology practice with hydroxychloroquine has a low probability of long term continuation, mostly because of inadequate control of disease manifestations rather than toxicity. In patients with SLE, treatment with hydroxychloroquine has a significantly higher probability of long term continuation.

Components of blood pressure variability in the elderly and effects on sample size calculations for clinical trials

This study investigated components of blood pressure variability in the elderly using both ambulatory blood pressure monitoring (ABPM) and casual clinic blood pressure measurement. These were then used to determine sample size requirements for clinical trials of different design scenarios in the elderly. Twenty-six elderly subjects not receiving antihypertensive medication were recruited from general practices and seen on four occasions at weekly intervals. On each occasion of blood pressure was measured in the clinic using a standard mercury sphygmomanometer and then for 24 h using a noninvasive ambulatory monitoring device. The between subject and between subject/within occasion components of blood pressure variability were determined by analysis of variance and used to calculate to sample size requirements for parallel and crossover trials respectively. The between subject variance of mean blood pressure was 1/3 greater with clinic readings, except within a subgroup of subjects who had isolated systolic hypertension (ISH). Increasing the number of readings or occasions on which measurement was performed in a parallel group trial only reduced the variability substantially when the number of subjects involved was small. With crossover designs, the between subject component of variance is eliminated resulting in substantial reduction in sample size. Whereas 60 subjects with ISH would be required to detect a 10 mm Hg difference in systolic blood pressure between two treatments in a parallel design using casual readings, only 18 are required with a crossover trial. If ABPM is used the number of subjects required are 54 and 14, respectively. Reducing variability with ABPM involves a trade-off between the increased number of readings available with the technique against the highly uniform and standardized conditions used to determine clinic blood pressures. ABPM appears most useful as a strategy for reducing sample size in parallel group trials involving small numbers of subjects measured on one occasion.

Survival prospects of extremely preterm infants: a 10-year experience in a single perinatal center

During a 10-year period, 1977 to 1986, 233 (53%) of 442 inborn live births between 23 and 28 weeks' gestation survived; their 1-year survival rate was 7% at 23 weeks, 30% at 24 weeks, 31% at 25 weeks, 55% at 26 weeks, 67% at 27 weeks, and 71% at 28 weeks. No significant change in survival rate was observed over the years. Twelve percent of pregnancies and 20% of infants were multiple gestations. Singleton births had significantly higher survival rates compared with multiple births (58% versus 41%). The obstetric intervention rate, as measured by the frequency of cesarean section, increased significantly over the years: from 15% in 1977-1978 to 33% in 1985-1986. The neonatal intervention rate, as measured by the frequency of live births offered neonatal intensive care, remained unchanged. Ten percent were not treated: 4% had major malformations and 6% were considered "nonviable." Active perinatal management, which assumed fetal-neonatal viability, accounted for better survival rates compared with centers with a more passive management policy. Information on survival based on gestational cohorts plays an important role in helping obstetricians, neonatologists, and parents make appropriate management decisions.

Life table analysis of 879 treatment episodes with slow acting antirheumatic drugs in community rheumatology practice

In 596 patients with RA managed over a decade in a community practice setting, 879 slow acting antirheumatic drug (SAARD) treatment episodes were analyzed using 5-year life tables. The probability of continuation of therapy was 50% by 9-24 months for all drugs except for methotrexate (MTX), which was 62% by 5 years [corrected]. MTX treatments were of significantly longer duration than those of all other SAARD (p less than 0.001); terminations for both inefficacy (p less than 0.001) and toxicity (NS) were less likely. These findings concur with recent evidence suggesting that MTX is a superior SAARD in this setting.

Inhibin and age in men

OBJECTIVE

Normal elderly men are reported to have decreased testicular function despite elevated gonadotrophin levels. We wished therefore to determine if changes in testicular function occur over the age range 19-60 years.

DESIGN

Single fasting blood samples were obtained between 0800 and 0900 h.

PATIENTS

Working men in a large industrial company between the ages of 19 and 60 years participated in the study.

MEASUREMENTS

FSH, serum immunoreactive inhibin and total testosterone were measured, the latter two as measurements of Sertoli and Leydig cell function respectively.

RESULTS

The mean baseline serum immunoreactive inhibin level was significantly lower in men from the older age groups, 31-40 years (479 U/l), 41-50 years (439 U/l) and 51-60 years (415 U/l) than in men from the youngest age group, 21-30 years (613 U/l) while serum FSH was higher in men from the older age groups, 41-50 years (3.7 IU/l) and 51-60 years (6.1 IU/l) than in men from the youngest age group, 21-30 years (2.6 IU/l). There appears to be a change in both FSH and inhibin production, consistent with a primary decline in testicular function. There was no significant difference in testosterone levels between the older age group, age 51-60 years and the younger age group, age 21-30 years. However, testosterone levels were significantly lower in the 41-50 year age group, when compared with the 21-30 year, this significance levelling out at about age 45 years.

CONCLUSION

The data are consistent with the hypothesis that immunoreactive inhibin reflects inhibin bioactivity, and that inhibin plays a role in the feedback control of FSH secretion in men.

Ovarian sensitization to gonadotrophins by human growth hormone. Persistence of the effect beyond the treated cycle

OBJECTIVE

To document the persistence of a sensitizing effect of human growth hormone on the ovarian responsiveness to human menopausal gonadotrophin in anovulatory patients resistant to standard gonadotrophin doses.

DESIGN

We performed an open study of three patients given 4, 12 or 24 IU recombinant growth hormone on alternate days for 5-7 doses, concomitantly with gonadotrophin, and assessed gonadotrophin dose requirements before, during and after the cycle of growth hormone therapy.

PATIENTS

We studied two with isolated gonadotrophin deficiency and primary amenorrhoea and one with a pituitary tumour and hyperprolactinaemia which normalized with bromocriptine but in whom there was persisting secondary amenorrhoea.

MEASUREMENTS

We measured body mass index, FSH, LH, prolactin, growth hormone, insulin-like growth factor I (IGF-I), oestradiol and inhibin at baseline and growth hormone, IGF-I, oestradiol and inhibin during treatment. In addition we noted the numbers of ampoules (75 IU) and the last pre-hCG dose of gonadotrophin used before, during and after growth hormone therapy.

RESULTS

Baseline growth hormone levels were low but IGF-I levels were normal. IGF-I increased by 20% in the subject given 4 IU growth hormone, and by 50-100% in the other two. Pretreatment daily gonadotrophin dosage of 8-11 ampoules pre-hCG was reduced to 3-6 ampoules during growth hormone and 3-4 post growth hormone. This effect persisted for 4 cycles over 7 months in one subject.

CONCLUSION

Growth hormone causes persisting ovarian sensitization to gonadotrophin and may produce a substantial lowering of gonadotrophin requirement for ovulation induction in patients with large dosage needs.

Duration of hospitalization in extremely preterm infants

This study reports the age at hospital discharge of 233 survivors and age at death of 209 infants who were born at 23-28 weeks gestation over a 10 year period, 1977-86. The mean duration of hospitalization of survivors was 95 days and was inversely related to maturity at birth; those born at 23-25 weeks remained in hospital on average 1-2 weeks beyond term while those born at 26-28 weeks went home on average at term or 1 week before term. The mean age at death was 12 days: 53% within 1 day, 23% between 2 and 7 days, 15% between 8 and 28 days and 9% between 28 days and 1 year. The proportions of death in the post-neonatal period for infants born at 23-24 weeks, 25-26 weeks and 27-28 weeks were 2, 9 and 16% respectively. There was no significant trend in prolonged hospitalization of survivors or postponement of neonatal deaths to the post-neonatal period over the 1977-86 period. Nevertheless, both neonatal and post-neonatal mortality should continually be monitored in this extremely preterm group.

Doxycycline tolerance study. Incidence of nausea after doxycycline administration to healthy volunteers: a comparison of 2 formulations (Doryx' vs Vibramycin')

In a randomised, double-blind, 3-way cross-over trial, the incidence of nausea associated with 2 doxycycline 100 mg formulations (Doryx' and Vibramycin') were compared. The original study cohort comprised 103 healthy male volunteers, with 97 subjects completing the trial. Subjects were randomly allocated to 1 of 3 treatment sequences and received a single dose of Doryx', Vibramycin' or placebo, with a 7-day washout prior to cross-over. At half-hourly intervals, from 0 to 2 h post-dose, subjects completed questionnaires to indicate if they felt nauseous. Data were analysed according to a log-linear method for the analysis of cross-over trials with categorical responses. Seventeen, 29 and 11 subjects experienced nausea with Doryx', Vibramycin' and placebo, respectively. A significantly greater number of volunteers indicated a positive response with Vibramycin' vs Doryx' and vs placebo; the positive response frequency was not significantly different for the Doryx' vs the placebo regimen. Treatment sequence had no significant effect on response, although a marked first-dose effect was noted; the first (vs the second and vs the third) regimen was 1.5-2 times more likely to induce a positive response.

Serum gonadotropin, sex steroid, and immunoreactive inhibin levels in the first two years of life

To characterize the changes in serum immunoreactive inhibin (INH) in the first 2 yr of life, blood samples were obtained from 46 boys (age range, 61-659 days) and 37 girls (76-666 days) undergoing minor surgery for nonendocrine related conditions. Serum levels were compared with those of simultaneously measured FSH, LH, and either testosterone (T) or estradiol (E2). In the boys, the levels of all 4 hormones fell progressively with age up to about 300 days, with a minor fall only in the second year. FSH (0.7-1.4 IU/L) was initially at the lower adult male limit, while LH (3.2-5.0 IU/L) was at the midrange. T levels (2.2-3.3 nmol/L) were in the adult female range, while INH (200-820 U/L) was in the midrange for men. In the youngest girls, FSH levels (12-26 IU/L) were frequently above the upper limit of normal for the adult follicular phase, but fell to approximately 2.0 IU/L after 300 days. LH levels (0.5-3.5 IU/L) were at the lower adult normal limit and changed little with age, while E2 levels in the youngest girls (280-550 pmol/L) were in the midfollicular range, but were generally less than 10 pM at more than 200 days. INH levels (175-260 U/L) were in the low adult range initially, but the majority were undetectable over 200 days. In the boys, significant negative correlations were observed for all 4 hormones with age, while FSH, LH, and T were positively correlated with INH. In the girls, there were weaker negative correlations of the 4 hormones with age, but no significant correlations between the gonadotropins and INH. E2 was strongly correlated with INH. Thus, the previously described early postnatal activation of the hypothalamo-pituitary-gonadal axis involves INH as well as the se steroids and gonadotropins. FSH levels in young girls were strikingly high, and INH levels were much higher in boys than girls. The low INH levels in girls may contribute to the elevated FSH seen during the period of neonatal gonadal activation.

Effect of restricted feeding on the relationship between hypophysial portal concentrations of growth hormone (GH)-releasing factor and somatostatin, and jugular concentrations of GH in ovariectomized ewes

These studies characterized the secretion of GH-releasing factor (GRF) and somatostatin (SRIF) into the hypophysial portal circulation in ewes after long term restricted feeding. In addition, we examined the temporal relationship between the concentrations of these two hypothalamic peptides in portal blood and the concentration of GH in jugular blood. Six sheep were fed 1000 g hay/day (normal feeding) and 6 sheep were fed 400-600 g hay/day (restricted feeding). This resulted in a wt loss of 35% in restricted animals compared with 6% in control animals after 20 weeks. Fluctuations in portal levels of GRF indicated a pulsatile pattern of secretion with approximately 60% of pulses coincident with, or immediately preceding, a GH pulse. Similarly, 65% of GH pulses were associated with GRF pulses. Restricted feeding increased (P less than 0.01) mean ( +/- SEM) plasma GH levels (9.8 +/- 1.4 vs. 2.9 +/- 0.6 ng/ml) and mean GH pulse amplitude (7.9 +/- 1.8 vs. 2.8 +/- 0.3 ng/ml) but did not affect mean GH pulse frequency (6.0 +/- 1.1 vs. 5.7 +/- 1.1 pulses/8 h). The level of feeding had no effect on mean portal concentration of GRF (restricted: 5.5 +/- 0.8, normal: 6.6 +/- 1.4 pg/ml), GRF pulse amplitude (14.7 +/- 2.3 vs. 13.5 +/- 0.7 pg/ml), or GRF pulse frequency (5.3 +/- 1.1 vs. 6.7 +/- 0.9 pulses/8 h). Portal concentrations of SRIF in sheep on a restricted diet were half (P less than 0.01) those of sheep fed a normal diet (10.2 +/- 2.3 vs. 19.6 +/- 1.6 pg/ml). Pulses of SRIF were not significantly associated with changes in GH or GRF concentrations. These data indicate a functional role for hypothalamic GRF in initiating GH pulses. Furthermore, the increase in GH secretion in underfed sheep was most probably due to a decrease in the release of SRIF into hypophysial portal blood. Restricted feeding had no affect on GRF secretion, but because of the reduced exposure of the pituitary gland to SRIF, it is possible that responsiveness to GRF is enhanced.

Passive immunisation of children with bovine colostrum containing antibodies to human rotavirus

The efficacy of a 10-day course of bovine colostrum with high antibody titre against the four known human rotavirus serotypes in protecting children against rotavirus infection was examined in patients admitted to hospital. Children aged 3 to 15 months were blocked in pairs according to ward accommodation (ie, isolation or open area). Each block contained 1 treated and 1 control child. The allocation to treatment or control (an artificial infant formula) was randomised. 9 of 65 control children but none of 55 treated children acquired rotavirus infection during the treatment period (p less than 0.001). The importance of protecting against rotavirus infection was highlighted by the fact that parents of symptomatic rotavirus-positive children sought medical attention seven times more often than did parents of symptomatic rotavirus-negative children (p less than 0.05).

Passive immunisation of children with bovine colostrum containing antibodies to human rotavirus

The efficacy of a 10-day course of bovine colostrum with high antibody titre against the four known human rotavirus serotypes in protecting children against rotavirus infection was examined in patients admitted to hospital. Children aged 3 to 15 months were blocked in pairs according to ward accommodation (ie, isolation or open area). Each block contained 1 treated and 1 control child. The allocation to treatment or control (an artificial infant formula) was randomised. 9 of 65 control children but none of 55 treated children acquired rotavirus infection during the treatment period (p less than 0.001). The importance of protecting against rotavirus infection was highlighted by the fact that parents of symptomatic rotavirus-positive children sought medical attention seven times more often than did parents of symptomatic rotavirus-negative children (p less than 0.05).

Salinity and climatic effects on the yields of citrus

A multiple linear regression analysis of salinity and climate against yield of Valencia and Washington Navel Oranges was performed for the period 1945-79 on data from irrigated orchards in Sunraysia, Berri, Waikerie and Mypolonga. Principal component analysis was utilized to reduce the number of climatic variables introduced into the multiple regression analysis. High temperatures and high evaporation during flowering and fruit set (November and December) were associated with reduced yields in Sunraysia, Berri and Waikerie, possibly by increasing flower and fruit drop, and by reducing fruit set. At Mypolonga, the coolest location studied, high temperatures were associated with increased yields. Salinity was negatively associated with yield at Mypolonga, Waikerie and Berri, the locations of highest salinity. No effects were observed at Sunraysia. It was not possible to deduce a critical level of salinity in irrigation water that is associated with yield loss or the magnitude of yield loss from the statistical analyses. However, we did observe that salinity during the irrigation season prior to harvest was associated with decreased yields, while only at Mypolonga was salinity in the year of harvest a significant variable in the analyses.

An energy response curve for a commercial white Leghorn laying-strain cross

Individually-caged White Leghorn hens, 235-d-old, were given daily metabolisable energy (ME) intakes ranging from 707 to 1321 kJ for 8 two-week periods. Energy was the first limiting nutrient, in those cases where the differences in egg output between treatments were sufficiently large. Body weight, egg number and egg weight all responded (P less than 0.001) to energy intake, and as judged by regression analyses, these responses had stabilised by the fifth period. For a near-maximum egg output of 48 g/bird d, the difference between the ME requirement of the average bird and of the flock, estimated from linear and curvilinear models respectively, was 20.5%. The ME requirement (Y, kJ/bird d) of the average bird for egg production (E, g/bird d) and maintenance of metabolic body size (kg W0.75) corrected to an ambient temperature of 22 degrees C is given by the equation, Y = 440W0.75 + 8.96 E.

Estimation of the Density of Feral Goats in Part of Arid South Australia by means of the Peterson Estimate

The density of feral goats in about 234 km2 of arid rangeland used for sheep grazing in South Australia was estimated by means of a mark-resight technique. Marking and subsequent resighting were done at watering points. The Petersen estimate was 4.4 goats per square kilometre; adjustment to allow for nonrandom behaviour raised this estimate to 5.0 km-1. Maximum allowable sheep density is 12 km-2. The goat density we observed imposes an added burden on the vegetation. The densities of red and western grey kangaroos, when added together, approximate that of the goats. Rabbits are virtually absent. The long-term effects of the total grazing pressure on the vegetation cannot be predicted in detail but will probably be deleterious.

The pattern of endemic parvovirus infection in four pig herds

Serological surveys were conducted on the gilts and adult sows in 4 herds endemically infected with porcine parvovirus. The study assessed the influence of the type of management of breeders on the spread of virus infection and the influence of endemic parvovirus infection on reproductive parameters of the herd. The practice of holding gilts and sows in groups did not reliably promote infection or maintain a 100% level of active immunity amongst adult sows in 2 of 3 group husbandry herds. In the 4 herds, the prevalence of adult sows (greater than 12 months) with active immune haemagglutination inhibition titres (greater than or equal to 256) ranged between 44% and 100%, while between 0% and 100% of gilts (6 to 12 months of age) had active immune titres. Fully susceptible gilts older than 9 months of age held in groups, failed to become infected by 12 months of age on farms endemically infected with PPV. In 2 herds a continued low infection rate of gilts resulted in increasing the potential of breeding animals becoming susceptible to parvovirus infection as infected sows were replaced by noninfected gilts. In both herds, epidemics of parvovirus infection followed, which were characterised by an increase in reproductive failure. Parvovirus infection during the first 70 days of pregnancy reduced the average number of piglets born alive per litter by 1.6 piglets (p less than 0.05). This was due to the combined effect of more piglets being born dead per litter and an overall reduction in litter size.