Calcium release at fertilization in starfish eggs is mediated by phospholipase Cgamma.

Although inositol trisphosphate (IP3) functions in releasing Ca2+ in eggs at fertilization, it is not known how fertilization activates the phospholipase C that produces IP3. To distinguish between a role for PLCgamma, which is activated when its two src homology-2 (SH2) domains bind to an activated tyrosine kinase, and PLCbeta, which is activated by a G protein, we injected starfish eggs with a PLCgamma SH2 domain fusion protein that inhibits activation of PLCgamma. In these eggs, Ca2+ release at fertilization was delayed, or with a high concentration of protein and a low concentration of sperm, completely inhibited. The PLCgammaSH2 protein is a specific inhibitor of PLCgamma in the egg, since it did not inhibit PLCbeta activation of Ca2+ release initiated by the serotonin 2c receptor, or activation of Ca2+ release by IP3 injection. Furthermore, injection of a PLCgamma SH2 domain protein mutated at its phosphotyrosine binding site, or the SH2 domains of another protein (the phosphatase SHP2), did not inhibit Ca2+ release at fertilization. These results indicate that during fertilization of starfish eggs, activation of phospholipase Cgamma by an SH2 domain-mediated process stimulates the production of IP3 that causes intracellular Ca2+ release.

Vesical dysfunction in multiple sclerosis.

Sixty-four patients with multiple sclerosis and associated symptoms of neurogenic bladder dysfunction underwent urodynamic evaluation. The most common symptoms were urgency, incontinence, and frequency which did not correlate with urodynamic findings. Cystometrography demonstrated hyperreflexic bladders in 78 per cent and areflexic bladders in 20 per cent of patients. In those patients with hyperreflexia, voiding cystourethrography revealed poorly sustained uninhibited contractions associated with ineffective bladder emptying in 50 per cent, well-sustained contractions in 38 per cent, and detrusor-sphincter dyssynergia in 12 per cent. Therapy consisted of intermittent catheterization, pharmacologic manipulation, or transurethral resection of the external sphincter, according to urodynamic evaluation.

Effect of methylprednisolone on CSF IgG parameters, myelin basic protein and anti-myelin basic protein in multiple sclerosis exacerbations.

Clinical exacerbations of multiple sclerosis (MS) are characterized by elevated levels of cerebrospinal fluid (CSF) myelin basic protein (MBP). The purposes of this study were to determine whether anti-MBP antibodies are present in increased titer in CSF of MS patients with exacerbations, and whether they can be suppressed by the administration of immunosuppressive dosages of methylprednisolone (MP). A solid phase radio-immunoassay (RIA) was used to detect free and total anti-MBP antibodies before and after acid hydrolysis of CSF. In MS exacerbations, the majority of elevated anti-MBP is in the free form. With the exception of subacute sclerosing panencephalitis (SSPE) and some cases of post infectious encephalomyelitis, anti-MBP antibodies are not present in either MS patients in remission or in non-MS controls. Anti-MBP levels remained elevated over a 10 day period when patients are managed by bed rest only or when treated with intravenous (IV) ACTH. IV administration of MP in "high" (160 mg/day) or "mega" (2 g/day) dosages produces a highly significant reduction of both MBP (p less than 0.01) and anti-MBP (p less than 0.001) levels. Total intrathecal IgG synthesis is also significantly suppressed by IV-MP but not by ACTH.

A double-blind controlled pilot study of plasma exchange versus sham apheresis in chronic progressive multiple sclerosis.

Twenty patients with chronically progressive multiple sclerosis (MS) were randomised in a double-blind controlled study to assess the efficacy of plasma exchange therapy. All patients were immunosuppressed with prednisone and azathioprine and underwent either plasma exchange or sham apheresis. The 10 patients in each group were similar in age, sex, duration of disease and degree of disability. Clinical and laboratory responses were assessed immediately following the course of exchange or sham therapy, and 3 to 6 months later, by individuals blinded to the type of therapy administered. Although modest improvement was suggested on clinical examination in 7 of 10 patients exchanged and 3 of the 10 sham treated group, this was transient and was not accompanied by any change in disability status scores. No differences in abnormal laboratory investigations were demonstrable between the two patient groups following therapy. We conclude that plasma exchange therapy using this protocol is unlikely to be of clinical benefit as an adjunct in the management of chronically progressive M.S.

Variability of ovarian structures and plasma progesterone profiles in dairy cows with ovarian cysts.

Weekly reproductive health examinations were performed on 46 multiparous Holstein cows from 14 to 100 d post partum. Sixteen cows developed 19 nonsimultaneous ovarian cysts, with a mean day of first detection at 34.3 +/- 4.5 d post partum and a mean duration of 31.0 +/- 4.3 d after first detection. Coccygeal blood was collected three times weekly, and plasma progesterone concentrations were determined by radioimmunoassay. Cysts were diagnosed by palpation per rectum or by ultrasonography and classified as follicular or luteal cysts; the cows were not treated. Cows with a mean plasma progesterone concentration of < 1 ng/ml from the first day of detection (Day 1) of a cyst until Day 10 were classified as having a follicular cyst, and those with a mean plasma progesterone concentration of >or= 1 ng/ml from Day 1 to Day 10 were classified as having a luteal cyst. According to this classification, 58% of the cysts were follicular and 42% were luteal. There was an overall 47% agreement between classification by palpation and by ultrasonography on Day 1 with progesterone concentration during Days 1 to 10 after detection of the cyst. Detailed graphs of progesterone concentrations and area of largest follicles or cysts and corpora lutea demonstrate the variability of ovarian structures and progesterone profiles in cystic cows. Detection of a cyst at any one time accompanied by simultaneous measurement of progesterone can lead to different diagnoses of cyst type depending on the method of classification, the presence and age of luteinized tissue in the cyst and undetected corpora lutea.

Effects of dietary fat on metabolic disorders and reproductive performance of dairy cattle.

Improved reproductive performance and reduced incidence of metabolic disorders have been postulated to be benefits of feeding supplemental fat to dairy cows. Increased plasma nonesterified fatty acid concentrations during fat supplementation may result from incomplete tissue uptake of fatty acids after lipoprotein lipase hydrolysis of very-low-density lipoprotein triglyceride; however, evidence suggests that net adipose tissue triglyceride hydrolysis may be increased during fat supplementation. Plasma 3-OH-butyrate concentrations remain relatively constant during fat supplementation but may have a tendency to be reduced if fat is supplemented to cows having relatively high basal plasma 3-OH-butyrate concentrations. Because plasma ketone levels usually increase when nonesterified fatty acid concentrations are elevated, it is hypothesized that potential antiketogenic effects of added fat are due to a glucose sparing effect. Supplemental fat does not seem to reduce hepatic lipid infiltration near the time of calving. Potential mechanisms by which supplemental fat may improve reproductive performance include stimulation of prostaglandin F2 a synthesis and secretion and enhanced utilization of blood cholesterol for progesterone synthesis. Days postpartum until first ovulation and luteal function of dairy cattle have been related to energy balance during the first 3 wk postpartum. Energy balance data for early lactation cows fed supplemental fat are not plentiful; however, slight but statistically nonsignificant increases have been observed when feeding fat. Cows fed supplemental fat that experience improved energy balance may begin to cycle sooner because of enhanced follicular growth and development. Applied studies examining the effects of supplemental fat on reproductive performance have provided inconsistent results.

A review of lipoprotein cholesterol metabolism: importance to ovarian function.

Cholesterol utilized for steroid synthesis by ovarian tissue may be derived from de novo synthesis or cellular uptake of lipoprotein cholesterol. The majority of blood cholesterol is transported by either low (LDL) or high (HDL) density lipoproteins, depending on the animal species. Prior to vascularization, only HDL are in follicular fluid and contribute sterol to granulosa cells because other lipoproteins are unable to transverse the basement membrane due to their molecular masses. Following vascularization, both LDL and HDL bathe luteal cells. Most species preferentially use LDL cholesterol as a precursor for ovarian steroid synthesis. The LDL uptake by ovarian tissue occurs by receptor-mediated endocytosis. The receptor recognizes apolipoprotein B of LDL and apolipoprotein E found on some, but not all, HDL. Within a species, a positive relationship may exist between HDL apolipoprotein E content and importance of HDL cholesterol as a precursor for steroidogenesis. A "HDL pathway" exists for uptake of sterol from HDL void of apolipoprotein E. The HDL receptor exhibits broad binding specificity. Unlike LDL, the HDL particle is not internalized, and cholesterol preferentially is taken up relative to other HDL constituents. In most species, lipoproteins, rather than de novo synthesis from acetate, contribute the majority of cholesterol used for steroid production. Trophic hormones increase lipoprotein binding, internalization, degradation and conversion of lipoprotein-derived sterol to steroids, effects that are mediate through cyclic adenosine monophosphate. Knowledge recently acquired regarding lipoprotein sterol utilization by the ovary may be useful in developing nutritional, pharmacological or endocrine manipulations that may positively affect cholesterol clearance by the ovary, steroidogenesis and reproductive performance.

Progesterone production by cultured luteal cells in the presence of bovine low- and high-density lipoproteins purified by heparin affinity chromatography.

The objectives of this study were to separate plasma lipoprotein particles based on the presence (low-density lipoproteins; LDL) or absence of apolipoprotein B (high-density lipoproteins; HDL) and to compare the abilities of bovine LDL and HDL to stimulate progesterone production by bovine luteal cells in culture. Plasma lipoproteins were isolated by ultracentrifugation and separated into LDL and HDL by heparin affinity chromatography. Luteal cultures were treated with LDL or HDL cholesterol for 48 h on d 3 of the culture (d 0 = day of dissociation). Progesterone production by luteal cells increased in a dose-dependent manner with increasing concentrations of either LDL or HDL cholesterol. There were no differences in the ability of LDL or HDL cholesterol to stimulate luteal cells to produce progesterone. Because LDL and HDL were equally potent, and experiment was designed to investigate the ability of modified LDL or reconstituted particles without apolipoproteins to stimulate progesterone production. Stimulation of luteal cell progesterone production by lysine-modified LDL was 70% of unmodified LDL. Progesterone production in the presence of phosphatidylcholine liposomes or BSA containing cholesterol was 50 and 108% of that obtained with HDL or LDL. Evidence indicated that apolipoprotein-free particles that contained free cholesterol but not cholesterol esters stimulated luteal cells to produce progesterone.

Inventing the future of physicians and information technology: methods and results of the 1997 Lafayette Parish Medical Society Information Systems and Information Technology Project.

This paper challenges physicians to consider how to best invent a future in which they can personally leverage emerging information and communication technologies to maximize their effectiveness and efficiency as care givers. One Louisiana State Medical Society component medical society has already posed this challenge to its members. The paper describes the 1997 Lafayette Parish Medical Society Physicians' Information Systems and Information Project, conducted on behalf of the society by faculty of the Healthcare Administration MBA Program at the University of Southwestern Louisiana. Specific recommendations for application of health care information technologies by physicians and by health care institutions, based on findings and conclusions of the project, are highlighted.

A statewide survey of pharmacokinetic service provision in Georgia.

A survey of pharmacokinetic service (PKS) provision and characteristics of the service was conducted in Georgia's 223 hospitals. The survey's questionnaire, returned by 133 (59.6%) institutions, showed that 23.3% currently had a PKS and that 47% of those without a PKS had plans to establish one in the future. Services were primarily provided by pharmacists (93%) who were certified to provide the consultations in only 40% of the institutions and the PKS was run through either the pharmacy (93%) or pathology laboratory. All services used calculators and/or computers with a variety of software programs to assist in pharmacokinetic evaluations. Patients were charged for the service in 38% of the institutions.

Depression, social factors, and farmworker health care utilization.

PURPOSE: Farmworkers frequently live in rural areas and experience high rates of depressive symptoms. This study examines the association between elevated depressive symptoms and health care utilization among Latino farmworkers. METHODS: Data were obtained from 2,905 Latino farmworkers interviewed for the National Agricultural Workers Survey. Elevated depressive symptoms were measured using the Center for Epidemiologic Studies Depression short-form. A dichotomous health care utilization variable was constructed from self-reported use of health care services in the United States. A categorical measure of provider type was constructed for those reporting use of health care. RESULTS: Over 50% of farmworkers reported at least 1 health care visit in the United States during the past 2 years; most visits occurred in a private practice. The odds of reporting health care utilization in the United States were 45% higher among farmworkers with elevated depressive symptoms. Type of provider was not associated with depressive symptoms. Women were more likely to seek health care; education and family relationships were associated with health care utilization. CONCLUSIONS: Latino farmworkers who live and work in rural areas seek care from private practices or migrant/Community Health Clinics. Farmworkers with elevated depressive symptoms are more likely to access health care. Rural health care providers need to be prepared to recognize, screen, and treat mental health problems among Latino farmworkers. Outreach focused on protecting farmworker mental health may be useful in reducing health care utilization while improving farmworker quality of life.

Mental health research with Latino farmworkers: a systematic evaluation of the short CES-D.

Mental health research among Latino farmworkers is hampered by the absence of measurement evaluation that ensures farmworkers understand and can consistently and appropriately respond to questions about mental health. Cross-sectional data were obtained from 409 farmworkers via interviewer-administered survey questionnaires. Mental health was operationalized with the short-form Center for Epidemiologic Studies, Depression (CES-D) scale. The structured interviewer-administered survey questionnaires included measures to capture personal and work-related factors that could affect farmworkers' ability to understand and respond to mental health questions probed by the CES-D. Good variability in item response was observed across the 10 short-form CES-D items. There was no evidence of differential response across sub-groups of farmworkers for six of the 10 items. Responses to four of the 10 items differed by educational attainment, country of origin, and language preference. Overall, the internal consistency of the 10 items exceeded standard conventions, and observed differences in depressive symptoms were as expected. Researchers in farmworker mental health must remain attentive to the strength and validity of available measures for migrants, different ethnic groups and different socioeconomic backgrounds. Nevertheless, the overall pattern suggests that the CES-D is a viable tool for advancing farmworker mental health research.

Agricultural injury.

BACKGROUND: Agriculture is one of the most hazardous industries in the US. METHODS: We reviewed MEDLINE and NIOSHTIC to identify English-language studies addressing occupational injury among agricultural populations, focusing on North America. Additional references were identified from the reference lists of identified studies and from contacts with experts in the field. RESULTS: U.S. data indicate up to approximately 780 deaths and 140,000 cases of nonfatal disabling injuries in 1998. Risk of agricultural injuries is approximately 5-10/100 persons per year, but is higher in certain risk groups, such as males and cattle workers. Falls, machinery, and animals are among the most common causes. Unique features of the agricultural workplace and exposed population combine to increase risk and hinder accurate measurement. These features include a wide range of activities, hazards, and dispersed work places in agriculture; a seasonal hired work force that often has brief tenure, poor English skills, and a distrust of officialdom; and a history of exemption regarding occupational health and safety regulations. CONCLUSIONS: Research in agricultural injury should include epidemiologic study of risk factors and evaluation of interventions. Although only limited data are available documenting efficacy of specific preventive approaches, prevention should focus on engineering controls, regulatory approaches, and education.

Changes Occur in the Central Nervous System of the Nudibranch Berghia verrucicornis (Mollusca, Opisthobranchia) During Metamorphosis.

The structure of the larval and juvenile central nervous system (CNS) in Berghia verrucicornis, an aeolid nudibranch, was examined using 1-{mu}m serial sections. The CNS consists of paired optic, cerebral, pleural (also known as sub- and supra-intestinal ganglia), pedal, and buccal ganglia, and a single visceral ganglion. A pleurovisceral loop is present. The organization of the CNS changes as the nudibranch undergoes metamorphosis. In general, there is a condensation of the CNS. The cerebral and pleural ganglia fuse to form the prominent cerebropleural ganglia. The single visceral ganglion fuses with the pleural portion of the left cerebropleural ganglion. The buccal ganglia enlarge and fully organize into a cortex of nerve cell bodies and medulla of nerve fibers. Rhinophoral ganglia develop anterior to each cerebropleural ganglion and a pair of nervous processes extend from each: one to the developing rhinophore and the other anteroventral toward the mouth and associated structures. These metamorphic changes are similar to those seen in other commonly studied opisthobranch species, suggesting that Berghia verrucicornis is an appropriate model for the developmental examination of structure and function in molluscan nervous systems.

Proteases stimulate fertilization-like responses in starfish eggs.

Application of proteases to eggs of the starfish, Asterina miniata, caused several responses like those seen at fertilization. Cortical granule exocytosis and fertilization envelope elevation occurred within about 1 min after exposure to trypsin, chymotrypsin, or pronase; protease inhibitors prevented these responses. Kallikrein caused cortical granule exocytosis and fertilization envelope elevation, but this response required more time (congruent to 30 min). Exocytosis was also seen in response to a recombinant trypsin, but not to a point-mutated trypsin without proteolytic activity. The extent of exocytosis was similar to that seen at fertilization, as measured by the fluorescent dye FM 1-43. In addition to causing exocytosis, application of trypsin, chymotrypsin, or pronase caused an increase in intracellular free calcium, detected by calcium green dextran, and stimulation of DNA synthesis, detected by incorporation of bromodeoxyuridine. Exocytosis also occurred when trypsin or chymotrypsin was applied in artificial sea water in which the free calcium was reduced to a low level (40-70 nM) such that Ca influx would be reduce by > 10,000-fold; this indicated that the proteases did not act by damaging the eggs and causing external calcium to leak into the cytoplasm. These findings show that there is an extracellularly exposed protein that when proteolyzed can induce fertilization-like responses; this protein may be a receptor that transduces a signal from the sperm to initiate egg activation at fertilization.

Laboratory Culture of the Aeolid Nudibranch Berghia verrucicornis (Mollusca, Opisthobranchia): Some Aspects of Its Development and Life History.

Adult Berghia verrucicornis individuals lay white, spiral egg masses containing zygotes. Egg masses are easily cultured in aerated, Millipore-filtered, seasoned aquarium water. Development proceeds quickly, with the bilobed velum apparent by the end of the second day, and the larval shell appearing at the beginning of the third day after oviposition. Hatching occurs 11 to 12 days after oviposition (23.9 +/- 1.3°C). If egg masses are incubated without aeration, poecilogonous development is observed; both larvae and juveniles hatch from the same undisturbed egg mass. The larvae metamorphose soon after hatching, losing the velum and larval shell. A habitat-specific inducer is not required for metamorphosis; but a factor associated with the sea anemone Aiptasia pallida appears to enhance a larva's tendency to metamorphose. Juveniles begin feeding on A. pallida three to four days after metamorphosis. Reproductive maturity is achieved as early as 47 days after oviposition. Because B. verrucicornis can be cultured, along with its prey A. pallida, at inland facilities, this nudibranch species may be a useful model for laboratory-oriented life history and neurobiological investigations.

Effect of supplemental fish meal on the lactation and reproductive performance of dairy cows.

The influence of high protein diets (21% CP, DM basis), containing varied percentages of RUP, on lactation performance and fertility was evaluated. Sixty-two Holstein cows (65% multiparous) were blocked by age and randomly assigned to a 2 x 2 x 2 factorial design from d 12 to 125 postpartum. Factor 1 was 0 or 3.5% fish meal diet, factor 2 was location (Calan door versus free stall), and factor 3 was parity (first versus second or later). The soybean meal diet consisted of alfalfa hay, corn silage, barley, and soybean meal. The fish meal diet contained 3.5% fish meal (ruminant grade menhaden) that replaced a portion of the soybean meal. Cows fed the fish meal diet (40% RUP) had DMI, BW, and body condition similar to those of cows offered the soybean meal diet (34% RUP). Cows receiving the fish meal supplement tended to have higher milk protein production throughout the trial, higher milk production during the first 6 wk, and significantly lower ruminal ammonia concentrations than cows receiving the soybean meal diet. Differences in reproductive performance were not significant except for a diet by housing location interaction for conception rates from first AI.