How to use natural history collections to resurrect information on historical parasite abundances.

Many of the most contentious questions that concern the ecology of helminths could be resolved with data on helminth abundance over the past few decades or centuries, but unfortunately these data are rare. A new sub-discipline - the historical ecology of parasitism - is resurrecting long-term data on the abundance of parasites, an advancement facilitated by the use of biological natural history collections. Because the world's museums hold billions of suitable specimens collected over more than a century, these potential parasitological datasets are broad in scope and finely resolved in taxonomic, temporal and spatial dimensions. Here, we set out best practices for the extraction of parasitological information from natural history collections, including how to conceive of a project, how to select specimens, how to engage curators and receive permission for proposed projects, standard operating protocols for dissections and how to manage data. Our hope is that other helminthologists will use this paper as a reference to expand their own research programmes along the dimension of time.

Young's modulus and hardness of human trabecular bone with bisphosphonate treatment durations up to 20 years.

Bone modulus from patients with osteoporosis treated with bisphosphonates for 1 to 20 years was analyzed. Modulus increases during the first 6 years of treatment and remains unchanged thereafter. INTRODUCTION: Bisphosphonates are widely used for treating osteoporosis, but the relationship between treatment duration and bone quality is unclear. Since material properties partially determine bone quality, the present study quantified the relationship between human bone modulus and hardness with bisphosphonate treatment duration. METHODS: Iliac crest bone samples from a consecutive case series of 86 osteoporotic Caucasian women continuously treated with oral bisphosphonates for 1.1-20 years were histologically evaluated to assess bone turnover and then tested using nanoindentation. Young's modulus and hardness were measured and related to bisphosphonate treatment duration by statistical modeling. RESULTS: All bone samples had low bone turnover. Statistical models showed that with increasing bisphosphonate treatment duration, modulus and hardness increased, peaked, and plateaued. These models used quadratic terms to model modulus increases from 1 to 6 years of bisphosphonate treatment and linear terms to model modulus plateaus from 6 to 20 years of treatment. The treatment duration at which the quadratic-linear transition (join point) occurred also depended upon trabecular location. Hardness increased and peaked at 12.4 years of treatment; it remained constant for the next 7.6 years of treatment and was insensitive to trabecular location. CONCLUSIONS: Bone modulus increases with bisphosphonate treatment durations up to 6 years, no additional modulus increases occurred after 6 years of treatment. Although hardness increased, peaked at 12.4 years and remained constant for the next 7.6 years of BP treatment, the clinical relevance of hardness remains unclear.

Observational study of clinical outcomes for testosterone treatment of pubertal delay in Duchenne muscular dystrophy.

BACKGROUND: Adolescents with DMD treated with chronic high dose GC therapy typically have profound pubertal delay. Testosterone, the main circulating androgen in men, promotes virilisation and growth with associated accrual of fat-free muscle mass and bone mineral content. Testosterone therapy is routinely used to mimic the normal stages of pubertal development in patients with hypogonadotrophic hypogonadism, androgen deficiency secondary to testicular disease and in constitutional delay of growth and puberty (CDGP). Improved life expectancy in DMD has meant that more adolescents are eligible for testosterone supplementation but there is little objective data regarding the impact of this treatment on muscle structure and function, bone integrity and overall well-being. METHODS: This is a single centre observational clinical trial (NCT02571205) that aims to follow the progress of 15 adolescents with Duchenne muscular dystrophy and delayed puberty as they are managed with incremental testosterone therapy to induce puberty. Subjects will all be treated with a steadily increasing dose of testosterone administered by injection every 4 weeks and data will be collected to help us determine the effectiveness and tolerability of the described treatment regimen. We will use the data to explore the effects of testosterone on pubertal development, growth, muscle strength and function, bone mineral density, body composition with a detailed record of any adverse events. We will also carry out interviews to explore the boys' views on the tolerability of the regimen. The study will last for 27 months in total for each participant. DISCUSSION: Our experience has indicated that testosterone treatment in adolescents with DMD is liked and well tolerated but we have not collected objective data on a specific treatment regimen and there is no current consensus. Testosterone supplementation is not part of the standard of care of pubertal delay in DMD but inclusion in future protocols may be appropriate depending on the results of this trial. TRIAL REGISTRATION: EudraCT Number: 2015-003195-68. Research Registry & References: Clinical trials.gov- NCT02571205 (registered 8/10/15).

Muscle hypertrophy as the presenting sign in a patient with a complete FHL1 deletion.

Four and a half LIM protein 1 (FHL1/SLIM1) has recently been identified as the causative gene mutated in four distinct diseases affecting skeletal muscle that have overlapping features, including reducing body myopathy, X-linked myopathy, X-linked dominant scapuloperoneal myopathy and Emery-Dreifuss muscular dystrophy. FHL1 localises to the sarcomere and the sarcolemma and is believed to participate in muscle growth and differentiation as well as in sarcomere assembly. We describe in this case report a boy with a deletion of the entire FHL1 gene who is now 15 years of age and presented with muscle hypertrophy, reduced subcutaneous fat, rigid spine and short stature. This case is the first, to our knowledge, with a complete loss of the FHL1 protein and MAP7D3 in combination. It supports the theory that dominant negative effects (accumulation of cytotoxic-mutated FHL1 protein) worsen the pathogenesis. It extends the phenotype of FHL1-related myopathies and should prompt future testing in undiagnosed patients who present with unexplained muscle hypertrophy, contractures and rigid spine, particularly if male.

A comparison of timed artificial insemination and automated activity monitoring with hormone intervention in 3 commercial dairy herds.

The objective of this study was to compare the reproductive performance of cows inseminated based on automated activity monitoring with hormone intervention (AAM) to cows from the same herds inseminated using only an intensive timed artificial insemination (TAI) program. Cows (n=523) from 3 commercial dairy herds participated in this study. To be considered eligible for participation, cows must have been classified with a body condition score of at least 2.50, but no more than 3.50, passed a reproductive tract examination, and experienced no incidences of clinical, recorded metabolic diseases in the current lactation. Within each herd, cows were balanced for parity and predicted milk yield, then randomly assigned to 1 of 2 treatments: TAI or AAM. Cows assigned to the TAI group were subjected to an ovulation synchronization protocol consisting of presynchronization, Ovsynch, and Resynch for up to 3 inseminations. Cows assigned to the AAM treatment were fitted with a leg-mounted accelerometer (AfiAct Pedometer Plus, Afimilk, Kibbutz Afikim, Israel) at least 10 d before the end of the herd voluntary waiting period (VWP). Cows in the AAM treatment were inseminated at times indicated by the automated alert system for up to 90 d after the VWP. If an open cow experienced no AAM alert for a 39±7-d period (beginning at the end of the VWP), hormone intervention in the form of a single injection of either PGF2α or GnRH (no TAI) was permitted as directed by the herd veterinarian. Subsequent to hormone intervention, cows were inseminated when alerted in estrus by the AAM system. Pregnancy was diagnosed by ultrasound 33 to 46 d after insemination. Pregnancy loss was determined via a second ultrasound after 60 d pregnant. Timed artificial insemination cows experienced a median 11.0 d shorter time to first service. Automated activity-monitored cows experienced a median 17.5-d shorter service interval. No treatment difference in probability of pregnancy to first AI, probability of pregnancy to repeat AI, pregnancy loss, time to pregnancy, or proportion of pregnant cows at 90 d past the VWP existed. Based on these results, inseminating cows using AAM with hormone intervention can achieve a level of reproductive performance comparable to TAI. Considering the strict cow selection criteria used in this study, interpretation of results for on-farm implementation should be performed cautiously; the results cannot be directly extrapolated to whole herds of cows.

Changes in vitamin D and matrix metalloproteinase-9 in submariners during a submerged patrol.

OBJECTIVES: To quantify changes in vitamin D and matrix metalloproteinase-9 (MMP9) in submariners over a single long patrol and compare the data to a group of non-deploying servicemen from their base port. METHODS: A prospective time-series analysis was performed. Blood samples were taken from 49 submariners deploying on patrol and 43 shore-side controls from the base port (naval officers from base or non-deploying submariners), following a winter ashore at latitude 56° north. Samples were drawn immediately before the submarine sailed, in January, and again in the final week of patrol 85 days later. Paired pre-patrol and late samples from each individual were assayed together and changes in vitamin D and MMP9 were assessed. RESULTS: Mean pre-patrol vitamin D concentrations were 58 and 49 nmol/L for the controls and submariners, respectively. Mean vitamin D concentrations increased in controls as expected (mean increase 12.6 nmol/L), but not in the submariners (mean decrease 1.6 nmol/L). MMP9 levels were significantly higher in submariners pre-patrol, and increased significantly during the patrol. There was a significant inverse correlation between MMP9 and vitamin D levels (r=-0.41, p=0.01). CONCLUSIONS: This is the first study to quantify vitamin D and MMP levels in submariners. Circulating vitamin D concentrations on board were insufficient to prevent a rise in MMP. This has potential for adverse health effects and requires further study.

Effect of a tea tree oil and organic acid footbath solution on digital dermatitis in dairy cows.

Copper sulfate is the industry gold standard footbath ingredient for controlling dairy cow digital dermatitis. However, when used footbath solutions are deposited on soil, high levels of copper in the soil may result, which can have toxic and negative effects on plant growth. An alternative to copper sulfate is Provita Hoofsure Endurance (Provita Eurotech Ltd., Omagh, UK), which is a biodegradable solution containing organic acids, tea tree oil, and wetting agents. The objective of this study was to quantify changes in digital dermatitis frequency when using Provita Hoofsure Endurance and copper sulfate in a split footbath in 3 commercial dairy herds. This study was conducted from January 5, 2012, to March 19, 2012, in 3 commercial Kentucky dairies with 120, 170, and 200 milking Holstein cows. None of the herds was using a footbath for digital dermatitis control before the study. Footbath solutions were delivered using a split footbath. During the study, a 3% Hoofsure Endurance solution for the left hooves and a 5% copper sulfate solution for the right hooves was used. Digital dermatitis was scored every 3wk using the M0 to M4 system, where M0=a claw free of signs of digital dermatitis; M1=a lesion <2cm that is not painful; M2=the ulcerative stage, with lesion diameter of >2cm, and painful to the touch; M3=the healing stage and covered by a scab; and M4=the chronic stage and characterized by dyskeratosis or proliferation of the surface that is generally not painful. McNemar's test statistic suggested that a statistically significant difference existed in the proportions of M1 and M2 lesions between the beginning and end of the study for both treatments. This indicates that each solution was effective in decreasing the proportion of M1 or M2 lesions from baseline to the last time point. A chi-square test calculated using PROC FREQUENCY of SAS (SAS Institute Inc., Cary, NC) indicated that no statistically significant relationship existed between the treatments among changes in digital dermatitis frequency from the baseline to the end of the study. Performance of the 2 footbath solutions was comparable throughout the study. No significant differences were observed between the copper sulfate and Provita Hoofsure Endurance.

The relationship between compost bedded pack performance, management, and bacterial counts.

The objective of this study was to assess the relationships among temperature, moisture, carbon-to-nitrogen (C:N) ratio, space per cow, and bacterial counts from bedding material collected from compost bedded pack (CBP) barns. A field survey of 42 routinely aerated CBP barns was conducted in Kentucky between October 2010 and March 2011. Two bedding material samples of 1,064.7 cm(3) each were collected during a single site visit from 9 evenly distributed locations throughout each barn and thoroughly mixed to create a composite sample representative of the entire CBP. Bacterial counts were determined for coliforms, Escherichia coli, streptococci, staphylococci, and Bacillus spp. University of Kentucky Regulatory Services (Lexington) laboratory personnel performed nutrient analyses to determine moisture, carbon, and nitrogen contents. Surface and 10.2-cm pack depth temperatures were collected for each of the 9 evenly distributed locations and the mean calculated to produce a composite temperature. Space per cow was calculated as the total CBP area divided by number of cows housed on the CBP. The GLM procedure of SAS (SAS Institute Inc., Cary, NC) generated models to describe factors affecting bacterial counts. Bacterial counts were 6.3 ± 0.6, 6.0 ± 0.6, 7.2 ± 0.7, 7.9 ± 0.5, and 7.6 ± 0.5 log 10 cfu/g of dry matter for coliform, Escherichia coli, streptococci, staphylococci, and Bacillus spp., respectively. Composite temperature, CBP moisture, C:N ratio, and space per cow had no effect on coliform counts. Escherichia coli reached a peak concentration when the C:N ratio was between 30:1 and 35:1. Staphylococci counts increased as ambient temperature increased. Streptococci counts decreased with increased space per cow and composite temperature and increased with increasing ambient temperature and moisture. Streptococci counts peaked at a C:N ratio ranging from 16:1 to 18:1. Bacillus spp. counts were reduced with increasing moisture, C:N ratio, and ambient temperature. Mastitis-causing bacteria thrive in similar conditions to that of composting bacteria and microbes, making elimination of these at higher temperatures (55 to 65°C) difficult in an active composting environment. Producers must use recommended milking procedures and other preventative practices to maintain low somatic cell count in herds with a CBP barn.

Changes in teat-end hyperkeratosis after installation of an individual quarter pulsation milking system.

The objective of this study was to examine changes in teat-end hyperkeratosis (HK) in a herd transitioning from a standard pulsation milking system to an individual quarter pulsation milking system. The Milpro P4C (Milkline, Gariga di Podenzano, Italy) system stops milking individual quarters using an individual quarter pulsation milking system with 4 independent pulsation channels per cluster instead of 2. Teat-end HK was evaluated immediately after cluster removal using a scoring system where N signifies no ring; S signifies a smooth, raised ring; R signifies a rough ring; and VR signifies a very rough ring. Scorings were classified for 69 cows (48 Holstein, 12 crossbred, and 9 Jersey) on 5 dates relative to installation of the Milpro P4C system on April 28, 2011, as follows: April 7 (PRE1); April 21 (PRE2), May 12 (POST1), May 26 (POST2), and June 9 (POST3). Hyperkeratosis classifications were converted to numerical scores as follows: N=1, S=2, R=3, and VR=4. The MIXED procedure of SAS (SAS Institute Inc., Cary, NC) was used to evaluate fixed effects of age, breed, parity, teat position, and all interactions on teat-end HK score with variables repeated by scoring with cow within breed as subject. The effects of teat position and scoring × breed on teat-end HK score were significant. Holstein HK scores improved from PRE2 to POST3 (1.64 ± 0.09 and 1.42 ± 0.10, respectively), POST1 to POST3 (1.59 ± 0.10 and 1.41 ± 0.10, respectively), and POST2 to POST3 (1.53 ± 0.10 and 1.42 ± 0.10, respectively). Crossbred HK scores did not differ among scorings. Jersey HK scores worsened from POST1 to POST3 (1.32±0.21 and 1.63 ± 0.22, respectively). For all cows included in the final analysis, right front and left front HK scores were higher than right rear and left rear HK scores (1.58 ± 0.09, 1.62 ± 0.09, 1.37 ± 0.09, and 1.36 ± 0.09, respectively). However, a significant decrease in teat-end HK scores for Holsteins did occur from PRE1 to PRE2 (1.75 ± 0.10 and 1.63 ± 0.10, respectively) and may represent biological variation in teat-end HK over time unrelated to installation of the individual quarter pulsation system. Individual quarter pulsation milking systems may prevent overmilking and reduce HK in Holstein cows. Further research is warranted to understand the breed differences observed in this study.

Influence of breed, milk production, season, and ambient temperature on dairy cow reticulorumen temperature.

Automatic monitoring of core body temperature in dairy cattle could be useful for identification of illness, heat stress, general physiological stress, and estrus. The SmartBolus (TenXSys Inc., Eagle, ID) system used a reticulorumen bolus to automatically record and transmit dairy cow temperatures. The objective of this research was to characterize the influence of milk yield (MY), time of day, breed, ambient temperature (AT), and season on reticulorumen temperatures (RT) in lactating dairy cows. Continuous RT and AT were collected by SmartBolus transponders every 15 min (96 records per d) from 93 cows (65 Holstein, 18 crossbred, and 10 Jersey) for 615 d. Mean (±SD) daily RT, AT, and MY were 40.14±0.32°C, 12.20±10.61°C, and 33.85±8.67 kg, respectively. The maximum and minimum RT were recorded at 2330 and 1000 h, respectively. Ambient temperature increased RT. Summer RT was significantly greater than spring, fall, or winter RT. The effect of MY on RT varied by breed, season, and AT. Crossbred RT was significantly lower than Holstein RT after adjusting for MY. Crossbred RT responded less to increasing AT than did Holstein RT, potentially indicating improved heat tolerance among these crossbred dairy cows. Reticulorumen temperature increased more dramatically for cows with greater milk yield as AT increased, demonstrating that high-producing cows are more susceptible to heat stress than low-producing cows. These results could be useful in interpretation of automatic temperature system data, heat stress management, and genetic selection of heat-tolerant cows.

The impact of testosterone therapy on quality of life in adolescents with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy in childhood. It is associated with progressive muscle function decline and premature death. Long-term oral glucocorticoid use slows muscle weakness but is associated with several side effects including delayed puberty. This study assessed the impact of a 2-year incremental intramuscular testosterone regimen on quality of life (QoL) in a cohort of 15 adolescents with DMD. The Pediatric Quality of Life Inventory (PedsQL) Neuromuscular module was used to assess QoL and was completed by parent-child dyads. Semi-structured interviews were carried out to understand patient views on testosterone therapy. QoL scores increased in 10 of the 15 participants during treatment, with a mean total PedsQL score of 74.6 pre-treatment v 80.2 post treatment (p = 0.04). This was supported by comments in the semi-structured interviews. Parent-reported PedsQL scores were lower than their child's post treatment (p = 0.007). Testosterone therapy for pubertal induction was associated with an improvement in QoL and the observed physical changes during puberty played an important role. Low self-esteem was also a prevailing theme. This data supports the inclusion of testosterone therapy for pubertal induction as a Standard of Care.

Profile of human macrophage transcripts: insights into macrophage biology and identification of novel chemokines.

High throughput partial sequencing of randomly selected cDNA clones has proven to be a powerful tool for examining the relative abundance of mRNAs and for the identification of novel gene products. Because of the important role played by macrophages in immune and inflammatory responses, we sequenced over 3000 randomly selected cDNA clones from a human macrophage library. These sequences represent a molecular inventory of mRNAs from macrophages and provide a catalog of highly expressed transcripts. Two of the most abundant clones encode recently identified CC chemokines. Macrophage-derived chemokine (MDC) plays a complex role in immunoregulation and is a potent chemoattractant for dendritic cells, T cells, and natural killer cells. The chemokine receptor CCR4 binds MDC with high affinity and also responds by calcium flux and chemotaxis. CCR4 has been shown to be expressed by Th2 type T cells. Recent studies also implicate MDC as a major component of the host defense against human immunodeficiency virus.

Oat bran increases serum acetate of hypercholesterolemic men.

Mechanisms for the hypocholesterolemic effects of oat bran remain unclear. Soluble fibers such as oat bran are fermented in the colon to short-chain fatty acids (SCFAs), which may enter the portal vein and attenuate hepatic cholesterol synthesis. To compare effects of oat bran and wheat bran on serum SCFA concentrations, 20 hypercholesterolemic men entered a metabolic ward and received control diets for 1 wk followed by oat-bran or wheat-bran diets for 3 wk. Oat bran decreased serum cholesterol 12.8% (P less than 0.001) whereas wheat bran had no effect. Peripheral serum SCFA concentrations were measured seven times over 14 h at the end of each diet. Serum acetate values from 1200 to 2200 were significantly higher in subjects fed oat-bran vs wheat-bran diets. Peak and incremental peak acetate values were also significantly higher than control values in subjects fed oat bran but not in subjects fed wheat bran. SCFA responses may contribute to the hypocholesterolemic effects of oat bran.

Long-term weight-loss maintenance: a meta-analysis of US studies.

BACKGROUND: Current perception is that participants of a structured weight-loss program regain all of their weight loss within 5 y. OBJECTIVE: The objective was to examine the long-term weight-loss maintenance of individuals completing a structured weight-loss program. DESIGN: Studies were required to 1) have been conducted in the United States, 2) have included participants in a structured weight-loss program, 3) have provided follow-up data with variance estimates for > or =2 y. Primary outcome variables were weight-loss maintenance in kilograms, weight-loss maintenance as a percentage of initial weight loss, and weight loss as a percentage of initial body weight (reduced weight). RESULTS: Twenty-nine studies met the inclusion criteria. Successful very-low-energy diets (VLEDs) were associated with significantly greater weight-loss maintenance than were successful hypoenergetic balanced diets (HBDs) at all years of follow-up. The percentage of individuals at 4 or 5 y of follow-up for VLEDs and HBDs were 55.4% and 79.7%, respectively. The results for VLEDs and HBDs, respectively, were as follows: weight-loss maintenance, 7.1 kg (95% CI: 6.1, 8.1 kg) and 2.0 (1.5, 2.5) kg; percentage weight-loss maintenance, 29% (25%, 33%) and 17% (13%, 22%); and reduced weight, 6.6% (5.7%, 7.5%) and 2.1% (1.6%, 2.7%). Weight-loss maintenance did not differ significantly between women and men. Six studies reported that groups who exercised more had significantly greater weight-loss maintenance than did those who exercised less. CONCLUSIONS: Five years after completing structured weight-loss programs, the average individual maintained a weight loss of >3 kg and a reduced weight of >3% of initial body weight. After VLEDs or weight loss of > or =20 kg, individuals maintained significantly more weight loss than after HBDs or weight losses of <10 kg.

Prospective, randomized, controlled comparison of the effects of low-fat and low-fat plus high-fiber diets on serum lipid concentrations.

Previous studies examining the hypocholesterolemic effects of high-soluble-fiber diets have not been designed to control for dietary fat intake. Serum cholesterol reductions may therefore be accounted for by differences in consumption of fat. Moderately hypercholesterolemic, nonobese, Caucasian men and women, 30-50 y old were randomly assigned to low-fat, low-fat plus high-fiber, or usual-diet groups and followed for 12 mo. At 12 mo the high-fiber group consumed significantly more soluble fiber than both the low-fat and usual-diet groups (P = 0.0063 and P = 0.0001); the high-fiber group did not differ from the low-fat group in quantity of dietary fat consumed. The high-fiber group experienced a greater average reduction (13%) in serum cholesterol than did the low-fat (9%) and usual-diet (7%) groups. After adjustment for relevant covariates, the reduction in the high-fiber group was significantly greater than that in the low-fat group (P = 0.0482). Supplementation with soluble fiber reduces serum cholesterol beyond the reduction observed with low-fat diet alone.

Metabolic effects of high-carbohydrate, high-fiber diets for insulin-dependent diabetic individuals.

The metabolic effects of high-carbohydrate (70%), high-fiber (70 g) (HCHF) and low-carbohydrate (39%), low-fiber (10 g) (LCLF) diets were examined for 10 subjects with insulin-dependent diabetes mellitus (IDDM). After a 1-wk control period subjects on a metabolic ward were randomly allocated to HCHF or LCLF diets for 4 wk. After a 6-wk washout period subjects re-entered the metabolic ward for 4 wk on the alternate diet. Artificial-pancreas studies were performed on each diet for measurement of insulin requirements. Compared with the LCLF diet, the HCHF diet reduced basal insulin requirements (P less than 0.025), increased carbohydrate disposed of per unit insulin (P less than 0.0008), and lowered total (P less than 0.0004) and high-density-lipoprotein cholesterol (P less than 0.0013). Glycemic control and other lipid fractions did not differ significantly. These results suggest that in IDDM patients, HCHF diets enhance peripheral glucose disposal, decrease basal insulin requirements, and lower total cholesterol without altering glycemic control or triglycerides.

Aging and endothelial barrier function in culture: effects of chronic exposure to fatty acid hydroperoxides and vitamin E.

As the endothelium ages it may become more susceptible to damage by atherogenic plasma components such as toxic lipid oxidation products. Vitamin E (vit E) might prove to be anti-atherogenic by reducing oxidative injury. This study investigated the effects of age and chronic exposure to fatty acid hydroperoxides (OFA) and/or vit E on endothelial barrier function (EBF) and cell growth characteristics. Chronic exposure to 5 microM OFA for 40 passages resulted in an age-related decrease in EBF, while supplementation of OFA-treated cultures with 25 microM vit E protected against the OFA-mediated decrease in EBF, independent of cell age. Vit E treatment alone had no significant effect on EBF relative to control cultures. No changes in growth characteristics, i.e., total DNA or protein per culture, were noted, regardless of treatment, although total DNA per culture decreased with increasing culture passage. These results suggest that chronic oxidative stress decreases EBF, predisposing the artery to infiltration by blood components and subsequent atherogenesis and that vit E delays cumulative changes in EBF related to chronic OFA exposure.

Vasoactive intestinal peptide effects on GH3 pituitary tumor cells: high affinity binding, affinity labeling, and adenylate cyclase stimulation. Comparison with peptide histidine isoleucine and growth hormone-releasing factor.

The vasoactive intestinal polypeptide (VIP) receptor was characterized on the GH3 rat pituitary tumor cell line using competitive binding studies with peptides having sequence homology with VIP. Further studies investigated receptor coupling to the adenylate cyclase complex by measurement of cAMP levels. Finally, the molecular weight of the receptor was estimated by affinity labeling techniques. Studies using 125I-VIP and unlabeled competing peptides revealed a single class of high affinity binding sites with a dissociation constant (KD) of 17 +/- 2 nM (mean +/- S.E.M.) for VIP, 275 +/- 46 nM for peptide histidine isoleucine (PHI), and 1380 +/- 800 nM for human pancreatic growth hormone releasing factor (GHRF). VIP and PHI each stimulated intracellular cAMP accumulation in a dose-dependent manner; both peptides demonstrated synergism with forskolin. In contrast, GHRF neither stimulated accumulation of cAMP nor demonstrated synergism with forskolin. VIP plus PHI (1 microM each) caused no significant increase in cAMP over either VIP or PHI alone, implying that the two peptides act through the same receptor. Covalent crosslinking of 125I-VIP to its binding site using either disuccinimidyl suberate (DSS) or ethylene glycol bis(succinimidyl succinate) (EGS) was followed by SDS-PAGE and autoradiography. The result is consistent with an Mr 47 000 VIP-binding subunit comprising or being associated with the VIP receptor of GH3 pituitary tumor cells.

Two-dimensional polyacrylamide gel electrophoresis of hymenoptera venom and venom sac extracts.

Hymenoptera venom and venom sac extracts were studied by two-dimensional polyacrylamide gel electrophoresis using non-equilibrium pH gradient electrophoresis in the first dimension and sodium sulfate electrophoresis in the second dimension. Pure Apis mellifera (honeybee) venom collected by electrical stimulation was resolved into five major and more than 20 minor components. Polistes (paper wasp), Vespula (yellow jacket), Dolichovespula (aerial hornet) and Vespa (old world hornet) venom sac extracts contained more than 40 components each. These results illustrate the complexity of the mixtures in current use for immunotherapy for stinging insect hypersensitivity. The degrees of similarity observed between the various aspects of Polistes and Vespula studied correlate with the phylogenetic classification of these species.

A role for inhibin in the control of follicle-stimulating hormone secretion in male rats.

We examined the relationship of testosterone (T) and porcine follicular fluid (pFF) in the negative feedback control of FSH and LH secretion in adult male rats. Either at the time of castration (acute) or at least 30 days after castration (chronic), we implanted T-filled Silastic capsules, which were 2 mm, 10 mm, or 30 mm long; empty capsules (30 mm) served as controls. Seven days later, we injected either 0.15 ml of pFF or saline (i.v.), decapitated the rats 6 hours later, and collected trunk blood for subsequent serum analysis of FSH, LH, and T by RIA. In the acute groups, T implants suppressed the postcastration rises in plasma FSH and LH levels in a dose-dependent manner, with only the largest implant, 30 mm, able to return them to intact levels. PFF injection significantly suppressed FSH levels in intact and acute rats but had no effect on serum LH. In chronic rats, T therapy for 7 days suppressed plasma LH levels in a dose-dependent relationship, yet did not do so to plasma FSH levels. FSH levels were significantly higher in rats with the 30 mm T implants than in intact rats, but were significantly suppressed as compared to chronic controls. PFF significantly suppressed serum FSH levels in all chronic groups with the chronic controls showing the greatest amount of suppression. We conclude that the role for inhibin in the normal control of FSH secretion is that of a secondary modulator which is superimposed on, yet independent of, the steroid feedback mechanism. At any given moment this modulation is dependent upon the secretory activity of the FSH gonadotrope.