Biomedical subjects
Publications and source records attributed to R L Reid.
The anatomy of the radial nerve, functional loss from nerve damage at various levels, timing of tendon transfers, choices of tendon motors for transfer, and operative and postoperative management have been discussed. My preference of transfers for complete radial nerve palsy is: (table: see text).
Explore the source record for details and available documents.
The stability of GnRH stored in solution under different conditions was assessed employing both immunoassay and bioassay techniques. No appreciable loss of activity was encountered after 4 weeks of storage at either 4 degrees C or room temperature.
Explore the source record for details and available documents.
Thirty reference Leptospira strains and twelve leptospire-like cultures were examined for aminopeptidase activity using twenty-two aminoacyl-beta-naphthylamide substrates. Aminopeptidase activity was demonstrated in extracts of each of the cultures and their substrate specificity profiles compared using several computer analysis procedures. The specificity profiles were consistent for each of the strains examined. Leptospira were readily differentiated from non Leptospira strains. This was supported by DNA base ratios calculated for the strains. Of the non Leptospira strains, seven appeared similar to the "L. illini" cultured included. Two of these strains, which included the strain "L. parva" sp. nov., formed a subgroup of this "L. illini" group. Substrate specificity profiles for the L. interrogans and L. biflexa strains examined were also different from each other.
To gain insights into the neuroendocrine basis for the initiation of folliculogenesis, the hormonal dynamics during the period from the late luteal to the early follicular phase of the menstrual cycle (the luteal-follicular transition) were examined. Blood samples were obtained at 2-h intervals for 5 consecutive days in seven women and at 15-min intervals for 8 h on each of 4 consecutive days in five women. The results indicate that the luteolytic process, as reflected by an exponential decline of both serum estradiol and progesterone levels, began at least 64 h before the onset of menses. During estradiol and progesterone withdrawal, there was a selective increase in mean serum FSH levels (P less than 0.001) beginning 24 h before and reaching a peak 24 h after the onset of menses. The frequency of LH pulses increased slightly but not significantly during this period, with a significant rise in mean serum LH levels on the day of menses. Thus, an acute rise in FSH concentrations the day before and in LH concentrations the day after the onset of menses occurs during luteal-follicular transition. The dissociation of FSH and LH secretion observed suggests that additional neuroendocrine events other than changes in pulsatile GnRH secretion may be operative during this period. These findings indicate that the initiation of folliculogenesis for the ensuing cycle occurs during the late luteal phase by a process of selective augmentation in FSH secretion independent of hypothalamic GnRH secretion. This event may ultimately prove to be a manifestation of the action of recently characterized ovarian peptides on FSH secretion.
Defined mixtures of two grass (orchardgrass, perennial ryegrass) and two legume (alfalfa, red clover) hays, harvested in two cuttings in 2 yr, were fed in digestibility, intake and mineral balance trials to wether lambs. Each mixture was fed in ad libitum amounts to six crossbred wether lambs weighing 35 to 45 kg. The effect of increasing proportion of legume in mixtures on dry matter digestibility (DMD), neutral detergent fiber digestibility (DNDF) and digestible dry matter intake (DDMI) differed with species combination. For all combinations, a quadratic regression (P less than .05) for DMD and DNDF indicated a small, negative associative effect for mixtures of grasses and legumes compared with pure species. Dry matter intake (DMI) showed a quadratic increase with level of legume inclusion, indicating a positive associative effect. The observed increase of DMI was approximately 6 to 7% over predicted values with 25 or 50% legume in the mixture. Intake of NDF also showed a quadratic response to level of legume, but lambs tended to eat to a fairly constant intake of 42 to 43 g NDF/kg wt.75. Mineral utilization (apparent absorption, retention) differed (P less than .05) with cutting but not species combination, and generally improved with increasing legume content in the mixture. With the exception of calcium retention (negative quadratic effect), there was little evidence for significant associative effects between grasses and legumes in mineral utilization.
Zinc concentrations in alfalfa hay were varied using a N-Zn liquid fertilizer as a foliar applicant (.34 or .68 kg Zn/ha) or as a soil fertilizer (4.07 kg Zn/ha). Mean concentrations of Zn across five cuttings of alfalfa in 2 yr were 18, 27, 41 and 21 mg Zn/kg DM for control, low foliar, high foliar and soil treatments, respectively. Each treatment was fed in ad libitum amounts to eight crossbred wether lambs (20 to 35 kg) in 6-wk growth and intake trials, followed by 2-wk digestibility and balance trials with individual lambs. For one cutting, hays were also fed in an 81-d trial to four ram lambs (30 to 35 kg) and live weight gain and testicular development were measured. Average daily gain (ADG) and intake over 6 wk differed (P less than .01) with cutting but not with Zn treatment. Average daily gain and testes weight of ram lambs also were not affected by treatment. In the metabolism trials, Zn treatment did not alter (P greater than .05) intake or dry matter digestibility (DMD) of alfalfa, but did influence digestibility of neutral detergent fiber (NDF). Digestible NDF (%) was higher (P less than .05) for high foliar than for low foliar treatments. Apparent absorption and retention of Zn was significantly greater for control than for Zn-treated alfalfas and did not differ with cutting. Mean serum Zn concentrations for control, low and high foliar, and soil treatments were .79, .81, .78 and .75 micrograms Zn/ml, respectively, for all cuttings, with no differences due to treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Ruminal solubility of N, K, P, Ca, Mg and S were measured for three forages at six growth stages. The three forages were Kentucky 31 tall fescue (TF), Kenhy fescue (KN) and a red clover-tall fescue mixture (RC). Disappearance parameters were measured by means of the dacron bag technique using cannulated steers. Exposures were for 48 h; maximum extent of disappearance for all elements occurred before this time. High proportions (greater than 60%) of P, K and Mg were released from all three forages during the first 3 h of incubation, with small losses thereafter. Amounts of N and S released during the first 3 h ranged between 40 to 75%. Ca had the lowest initial disappearance. Forages differed (P less than .05) in extent of mineral disappearance after 3- and 48-h incubations and in rate of disappearance (Kd) of the potentially available, slowly solubilizing, fraction of N, Ca and S. Across growth stages, TF had generally the lowest extent and rate of disappearance. With increasing maturity, Kd for Mg, Ca and S decreased (P less than .05). For each element, Kd was not correlated with herbage concentration or initial (3 h) disappearance. Partial correlations between disappearance of N, K, Ca, Mg and S after the 48-h incubation and herbage concentration were significant. Solubilization values corrected for rate of passage (ERS) showed significant differences among forages for K, Ca and S. Average ERS values for S and K were highest for KN; RC herbage had higher ERS values for Ca. Increases in forage maturity lowered (P less than .001) ERS for all elements. The results indicate that for all growth stages, ruminal solubility and potential availability of N and minerals from the three forages was high. The rate of release differed among elements and may have affected efficiency of microbial fermentation. Although ruminal solubility of minerals from TF was generally lower than from the other two forages, the difference was not sufficient to explain fully the lower apparent availability observed in previous studies.
Thyroid disorders are often ubiquitous and insidious in their presentation. They have been implicated in a broad spectrum of reproductive disorders ranging from abnormal sexual development to menstrual irregularities and infertility. If pregnancy occurs in a patient with thyroid disease, the physician must ensure that therapeutic measures instituted to restore the health of the mother do not adversely affect the developing fetus. This review examines the role of thyroid disease in disorders confronting the obstetrician/gynecologist and provides a theoretical framework upon which to base practical management decisions.
Because the majority of women with PMS complain of sweats and chills resembling menopausal flushes, we attempted to document the physiologic changes during these episodes. A 26-year-old nulliparous woman with PMS described the occurrence of hot flush-like episodes coincident with PMS symptoms. The patient completed prospective self-rating scales for two consecutive cycles to establish the pattern and severity of PMS. On day 26 of the first cycle when PMS symptom scores were elevated, continuous monitoring of skin resistance and finger temperature and frequent blood sampling for LH were performed for 8 hours. The patient experienced five flush episodes, each of which was associated with a drop in skin resistance of up to 4000 ohms and was coincident with an LH pulse. Three of the flushes were associated with a rise in finger temperature of up to 10 degrees C. These physiologic changes are identical to those seen during menopausal flushes and suggest that PMS may be associated with neuroendocrine events typical of E withdrawal.
Premenstrual syndrome has emerged as an important reproductive health care issue amid heated debate about whether such a condition, in fact, exists. Polarization of opinion on this issue has been the result of imprecision in the definition of premenstrual syndrome, leading to inappropriate generalization of the disruptive physical, emotional, or behavioral changes of premenstrual syndrome to the entire female population. A shortage of reliable scientific information on premenstrual syndrome has led to inconsistent, and often ineffective, medical intervention by a sometimes skeptical medical profession. Examination of individual biases and the external factors that have influenced our thinking on this issue may allow us to more clearly define our role as a specialty in the ongoing investigations and management of menstrual cycle-related illnesses.
Rigorous criteria were used to select women with severe premenstrual syndrome for inclusion in an 8-month double-blind placebo-controlled clinical trial of progesterone vaginal suppositories. Following a control month without treatment, progesterone (200 mg in polyethylene glycol base) or placebo was self administered twice daily by vaginal suppository for a minimum of 12 days before the onset of menstruation for 3 months. Crossover to the opposite medication for a further 3 months was followed by a final control cycle without treatment in month 8. Physician contact was minimized throughout the study to avoid any possible positive effects of psychological support which may have confounded past investigations. Detailed self-report questionnaires were completed every 3 days for the duration of the study. Although the attrition rate was high, 20 women completed the trial and their records are analyzed here. The results of this trial indicate that the response to vaginal progesterone in these dosages is, at best, marginal and not significantly different from response with placebo use.
To resolve existing controversies about the impact of the menstrual cycle on oral glucose tolerance, we examined the glucose, insulin, and glucagon responses to an oral glucose challenge at different phases of the menstrual cycle in five normal women (NW) and six women with premenstrual syndrome and alleged premenstrual hypoglycemic attacks (PMHA). Responses to oral glucose did not differ significantly between follicular and luteal phase studies in either group, nor were significant differences found between the responses of NW and women reporting PMHA. In parallel studies, the possible glucoregulatory effects of endogenous opiates were assessed. Concomitant infusion of naloxone altered neither the basal concentrations of glucose, insulin, and glucagon nor the responses of these measures to the glucose challenge. We conclude that NW and women with premenstrual syndrome and alleged PMHA have no menstrual cycle-related changes in glucose, insulin, or glucagon responses to an oral glucose load. The fact that four of six PMHA subjects had symptoms typical of hypoglycemia at glucose nadirs above 50 mg/dl suggests that an explanation other than hypoglycemia must be sought for such symptomatic episodes. Endogenous opiate peptides appear to exert no glucoregulatory effects at naloxone-sensitive receptor sites.
Explore the source record for details and available documents.
Substantial evidence now exists to indicate that the endogenous hypothalamic opioidergic mechanism(s) represents one of the important controlling systems for release of gonadotropin-releasing hormone. Modulations of frequency and amplitude of the secretory activity of gonadotropin-releasing hormone appears to be mediated through an inhibitory action of endogenous opioids, and the functional coupling of the opioidergic and gonadotropin-releasing hormone systems is an ovarian steroid-dependent event. There is also evidence to implicate suprahypothalamic mechanism(s) that enhance endogenous opioid inhibition of secretion of gonadotropin-releasing hormone. Although exogenous opioid peptides and their synthetic analogs consistently induce the secretion of prolactin, blockade of opioid receptors in humans by naloxone failed to elicit a decrement in the levels of prolactin under a variety of conditions. On the contrary, naloxone induced a remarkable increment in the secretion of prolactin via an increased frequency of pulsatile release which is synchronized with pulses of luteinizing hormone. These observations suggest that a common neuroendocrine mechanism is involved in the opioidergic control of the secretion of both luteinizing hormone and prolactin in women.
Pituitary apoplexy, a rare but life-threatening condition, may be highly variable in its clinical appearance and therefore should be considered in any patient with abrupt neurologic deterioration. We reviewed the literature on acute massive pituitary infarction to create an awareness of predisposing factors, the pathophysiologic mechanisms responsible for its heterogeneous manifestations, and possible options for investigation and management. These concepts are reinforced by examining the course and outcome of a rare case of pituitary apoplexy manifesting a full range of neurologic and endocrine abnormalities.