Restricting dairy cow access time to pasture in early lactation: the effects on milk production, grazing behaviour and dry matter intake.

One of the main aims of pasture-based systems of dairy production is to increase the proportion of grazed grass in the diet. This is most easily achieved by increasing the number of grazing days. However, periods of inclement weather conditions can reduce the number of days at pasture. The two objectives of this experiment were: (i) to investigate the effect of restricting pasture access time on animal production, grazing behaviour and dry matter intake (DMI) of spring calving dairy cows in early lactation; and (ii) to establish whether silage supplementation is required when cows return indoors after short grazing periods. In all, 52 Holstein-Friesian spring calving dairy cows were assigned to a four-treatment study from 25 February to 26 March 2008. The four treatments were: full-time access to pasture (22H; control); 4.5-h- pasture access after both milkings (2 × 4.5H); 3-h pasture access after both milkings (2 × 3H); 3-h pasture access after both milkings with silage supplementation by night (2 × 3SH). All treatments were offered 14.4 kg DM/cow per day herbage from swards, with a mean pre-grazing yield of 1739 kg DM/ha above 4 cm, - and were supplemented with 3 kg DM/cow per day of concentrate. The 2 × 3SH treatment was offered an additional 4 kg DM/cow of grass silage by night. Restricting pasture access time (2 × 3H, 2 × 3SH and 2 × 4.5H) had no effect on milk (28.3 kg/cow per day) and solids-corrected milk (27.2 kg/cow per day) yield when compared with the treatment grazing full time. Supplementing animals with grass silage did not increase milk production when compared with all other treatments. Milk protein concentration tended to be lower (P = 0.08; 32.2 g/kg) for the 2 × 3SH animals when compared with the 22H animals (33.7 g/kg). The grass DMI of the 2 × 3SH treatment was significantly lower (-2.3 kg DM/cow per day) than all other treatments (11.9 kg DM/cow per day), yet the total DMI of these animals was highest (16.6 kg DM/cow per day). The 22H cows grazed for 481 min/cow per day, which is significantly longer than all other treatments. The 2 × 3H animals grazed for 98% of the time, whereas the 2 × 3SH grazed for 79% of their time at pasture. Restricting pasture access time did not affect end body weight or body condition score. The results of this study indicate that restricting pasture access time of dairy cows in early lactation does not affect milk production performance. Furthermore, supplementing cows with grass silage does not increase milk production but reduces grazing efficiency.

MR imaging volumetry of subcortical structures and cerebellar hemispheres in temporal lobe epilepsy.

BACKGROUND AND PURPOSE: There is mounting evidence of extratemporal volume changes associated with medically refractory temporal lobe epilepsy (TLE). This MR imaging study aimed to characterize volume changes in subcortical structures and cerebellar hemispheres with respect to lateralization of the seizure focus, onset and duration of epilepsy, and frequency of generalized tonic-clonic seizures (GTCS). METHODS: Amygdalar, hippocampal, thalamic, caudate head, and cerebellar volume measurements were obtained in the preoperative MR images of 40 patients with TLE (20 right, 20 left), who underwent temporal lobe resection with good outcome, and in 20 right-handed control participants. All 3D MR images were spatially aligned and normalized before measurements were obtained. Standardized volumes and right-to-left volume ratios (VRs) were compared between control participants and right and left TLE groups. Multiple regression analyses were performed to study the effects of epilepsy onset and duration and GTCS frequency on ipsilateral-to-contralateral VRs with respect to the resected seizure focus. RESULTS: Thalamic volumes were smaller bilaterally in patients with TLE. Hippocampal volumes were smaller ipsilateral to the seizure focus, but there was no significant volume loss involving the amygdala, caudate, or cerebellum. Hippocampal and amygdalar right-to-left VRs differed significantly between right and left TLE groups and controls, whereas thalamic right-to-left VRs differed only between the TLE groups. Thalamic ipsilateral-to-contralateral VRs were correlated positively with epilepsy onset and negatively with epilepsy duration. Caudate ipsilateral-to-contralateral VRs were positively, whereas amygdalar and cerebellar VRs were negatively, correlated with GTCS frequency. CONCLUSIONS: Unilateral amygdalar and bilateral thalamic volume loss, in the absence of caudate head atrophy, is likely to reflect seizure-induced injury due to TLE. Correlations of VRs affecting the amygdala, caudate, and cerebellum with GTCS frequency may also reflect injury or a prediposition for secondary generalization. Potential effects of complex partial seizures, febrile seizures, or antiepileptic medications on subcortical structures need to be evaluated in future studies.

Socio-demographic and clinical characteristics of Jamaican adolescents with HIV/AIDS

BACKGROUND: Clinical symptomatology and socio-demographic factors have not been characterized in Jamaican adolescents with HIV/AIDS. METHODS: We studied these factors in 25 HIV-positive Jamaican adolescents, 10-19 years of age, who were seen at the Centre for HIV/AIDS Research, Education, and Services (CHARES) between the years 1996 and 2002. Data were collected between June 2003 and August 2003 from CHARES social work files and The University Hospital of the West Indies (UHWI) medical records. Microsoft Excel was used to compile descriptive statistics for the data. RESULTS: The mean age of HIV diagnosis was 15.6 (+/-3.09) years, and the mean age of enrollment at CHARES was 16.3 (+/- 2.9) years. Consensual sexual intercourse was the most prominent mode of transmission (56), followed by vertical transmission (16), unknown (16), forced sexual intercourse (8), and blood transfusion (4). The predominant clinical presentations among these adolescent patients were generalized dermatitis (77.2) and lymphadenopathy (50). Of the patients for whom clinical status could be determined, 70 were [quot ]Severely Symptomatic [quot]. Of these patients only 14 were recommended for antiretroviral treatment. CONCLUSIONS: These findings reinforce the need to globally incorporate the goal of the 2002 Joint United Nations Programme on HIV/AIDS (UNAIDS) [quot]to provide reproductive health services, including low-cost or free condoms, voluntary counselling and testing, diagnosis and treatment of sexually transmitted diseases and infections for adolescents in order to effectively prevent HIV infection [quot] (1)

Did a rising tide lift all boats? The NIH budget and pediatric research portfolio.

This paper examines National Institutes of Health (NIH) pediatric research spending in absolute terms and relative to the doubling of the NIH overall budget between fiscal years 1998 and 2003. Pediatric spending increased by an average annual rate of 12.8 percent during the doubling period (almost on par with the NIH average annual growth rate of 14.7 percent). However, the proportion of the total NIH budget devoted to the pediatric portfolio declined from 12.3 to 11.3 percent. We offer recommendations for implementing existing commitments to strengthen the pediatric research portfolio and to protect the gains of the doubling period.

Socio-demographic and clinical characteristics of Jamaican adolescents with HIV/AIDS.

BACKGROUND: Clinical symptomatology and socio-demographic factors have not been characterized in Jamaican adolescents with HIV/AIDS. METHODS: We studied these factors in 25 HIV-positive Jamaican adolescents, 10-19 years of age, who were seen at the Centre for HIV/AIDS Research, Education, and Services (CHARES) between the years 1996 and 2002. Data were collected between June 2003 and August 2003 from CHARES social work files and The University Hospital of the West Indies (UHWI) medical records. Microsoft Excel was used to compile descriptive statistics for the data. RESULTS: The mean age of HIV diagnosis was 15.6 (+/-3.09) years, and the mean age of enrollment at CHARES was 16.3 (+/- 2.9) years. Consensual sexual intercourse was the most prominent mode of transmission (56%), followed by vertical transmission (16%), unknown (16%), forced sexual intercourse (8%), and blood transfusion (4%). The predominant clinical presentations among these adolescent patients were generalized dermatitis (77.2%) and lymphadenopathy (50%). Of the patients for whom clinical status could be determined, 70% were "Severely Symptomatic ". Of these patients only 14% were recommended for antiretroviral treatment. CONCLUSIONS: These findings reinforce the need to globally incorporate the goal of the 2002 Joint United Nations Programme on HIV/AIDS (UNAIDS) "to provide reproductive health services, including low-cost or free condoms, voluntary counselling and testing, diagnosis and treatment of sexually transmitted diseases and infections for adolescents in order to effectively prevent HIV infection " (1).

Personality, job level, job stressors, and their interaction as predictors of coping behavior.

Hypotheses concerning the relationships among job stressors, job level, personality, and coping responses were investigated in a sample of 305 electrical contracting employees. Coping behaviors were measured with questionnaire items based on interviews conducted with a sample of the subjects. Neuroticism (N) and Extraversion (E) were the personality variables most strongly related to coping behavior. Overall, more coping variance was explained by personality than by job stressors; however, when the effects of job level and job stressors were combined, they explained more variance in complaining/quitting and seeking social support than did the personality variables. Both work situation and personality seem to be important variables in the choice of coping behaviors. There was no evidence of interactions among personality, stressors, and job level in explaining coping behavior.

An assessment of neurotoxicity of aroclors 1016, 1242, 1254, and 1260 administered in diet to Sprague-Dawley rats for one year.

As part of a comparative chronic toxicity/oncogenicity study of different Aroclors (1016, 1242, 1254, and 1260), neurotoxicity was assessed in male and female Sprague-Dawley rats using functional observational battery (FOB) and motor activity tests, and histopathologic evaluation of selected nervous system tissues. Doses varied by Aroclor and ranged from 25 to 200 ppm in the diet. Animals were evaluated prior to initiation of dosing and at 13, 26, 39, and 52 weeks of exposure. Clinical signs, body weights, and feed consumption were evaluated weekly. Data analysis of FOB and motor activity results revealed several instances where Aroclor-treated groups were different from control. However, these were considered incidental, as they lacked any consistent dose- or time-related pattern that would suggest Aroclor-induced neurotoxicity. The nonremarkable findings during each of the four assessments were supported by the absence of any treatment-related clinical signs or mortality. Decreased body weight gain was evident in the male 100 ppm Aroclor 1254 dose group and in all female Aroclor 1254 dose groups late in the study (when a linear relationship was assumed between body weight and time), correlating with decreased feed consumption. Although a variety of incidental, spontaneous, degenerative changes were found in nervous tissue evaluated histopathologically, these changes were seen with similar incidence and severity in treated and control groups. No lesions were found that could be attributed to Aroclor-related neurotoxicity. In summary, 52 weeks of exposure to Aroclors 1016, 1242, 1254, or 1260 mixed in the diet did not yield any functional or morphologic changes indicative of PCB-induced neurotoxicity.

Comparative carcinogenicity in Sprague-Dawley rats of the polychlorinated biphenyl mixtures Aroclors 1016, 1242, 1254, and 1260.

A comprehensive chronic toxicity and carcinogenicity study was conducted on a series of Aroclors (1016, 1242, 1254, and 1260). Each Aroclor was assessed at multiple dietary concentrations, ranging from 25 to 200 ppm, for 24 months in male and female Sprague-Dawley rats. Liver toxicity was indicated by elevated serum enzyme activity (AST, ALT, and GGT), elevated serum cholesterol concentration, decreases in hematologic parameters (RBC, Hb, and Hct), hepatocellular hypertrophy, an increased incidence of altered hepatocellular foci, and an increased incidence of hepatocellular neoplasms (primarily adenomas). Liver toxicity was distinctly more severe in females than in males. The incidence of hepatocellular neoplasms was highly sex-dependent (females >> males), differed between Aroclor mixtures and, for females, increased with dose and followed the general incidence pattern of Aroclor 1254 > Aroclor 1260 approximately Aroclor 1242 > Aroclor 1016. A significant response (p < 0.05) in males was seen only for the high dose of Aroclor 1260. A small increase in the incidence of thyroid gland follicular cell adenomas was noted in males for Aroclors 1242, 1254, and 1260, with the incidence being uniform across dose groups and Aroclor mixtures. For females, increased survival relative to controls was observed for all Aroclor treatment groups. A significantly decreased trend in the incidence of mammary gland neoplasms compared to control was also noted for females receiving Aroclors 1242, 1254, and 1260.

Subchronic toxicity (90-day) study with para-nonylphenol in rats.

As a component to the risk assessment process for para-nonylphenol (NP; CASRN 84852-15-3), a 90-day study was conducted in rats following U.S. EPA TSCA guidelines and Good Laboratory Practice regulations. NP was administered to four groups of rats at dietary concentrations of 0, 200, 650, or 2000 ppm which corresponded to approximate dietary intakes of 0, 15, 50, or 150 mg/kg/day, respectively. There were 25 rats/sex/group in the control and high-dose groups and 15 rats/sex/group in the low- and middose groups. Ten of the 25 rats/sex in the control and high-dose groups were designated as recovery animals and were maintained on control diets for 4 weeks after completion of the 90-day exposure period to assess the reversibility of any effects which might be observed. To evaluate for the possible weak estrogen-like activity that has been reported for NP in a number of screening assays, estrous cyclicity was monitored using vaginal cytology during Week 8 of the study, and sperm count, motility, and morphology were evaluated at termination. In-life effects from NP exposure were limited to small decreases in body weight and food consumption in the 2000-ppm dose group. Postmortem measurements at Week 14 indicated a dose-related kidney weight increase in males and a decrease in renal hyaline globules/droplets in males from the high-dose group. The kidney weights showed complete recovery following the 4-week postdosing recovery period. Due to the small magnitude of the changes (i.e., all weights were within or near laboratory historical control values) and the lack of correlating clinical or histopathological changes, the kidney weight alterations were not considered toxicologically significant. The biological significance of reduced hyaline in the kidneys of male rats from the high-dose group is uncertain. Renal tubular hyaline is associated with the rat-specific protein, alpha-2u-globulin, and, therefore, this finding was not considered toxicologically relevant to humans. No other effects attributable to NP were observed. No changes were observed for estrous cycling, sperm evaluations, or effects on endocrine organs. NP, therefore, did not manifest any estrogen-like activity as measured in these parameters at dietary concentrations as high as 2000 ppm, the maximum dose administered in this study. Based on the minor findings for the 2000-ppm dose group, the NOAEL (no-observed-adverse-effect level) for NP in this study is considered to be 650 ppm in the diet, corresponding to an approximate intake of 50 mg/kg/day.

Evaluation and treatment of seizures in patients with systemic lupus erythematosus.

Seizures associated with systemic lupus erythematosus (SLE) occur in 9 to 58% of patients in reported series, often early in the disease course. Approximately half of seizures reported in SLE patients are associated with infection and with metabolic or iatrogenic complications. However, in clinical practice, this number might be much larger, as relatively few prospective studies are available. The seizure type in nearly 75% of SLE patients is generalized tonic-clonic. These often begin with and recur, even without anticonvulsant treatment, only during an SLE disease flare. In contrast, seizures in SLE patients with a focal onset often recur without anticonvulsant treatment, irrespective of SLE disease activity. This review offers a practical diagnostic and management approach to the SLE patient with new or recurrent seizures and takes into consideration the effects of immunosuppressive therapy and multi-organ failure. This approach is based on a synthesis of the literature regarding seizures and epilepsy in SLE patients and on the authors' personal experience.

Induction, via immunization with a monoclonal antiidiotypic antibody, of viral envelope specific Ab3 antisera that neutralize retrovirus infectivity.

We have developed five mouse monoclonal antiidiotypic antibodies to the 35/56 (Ab1) rat monoclonal that neutralizes retroviral infectivity by binding to the gp70f epitope of murine leukemia retrovirus. The anti-Id nature of these five Ab2s was evidenced by their inability to react with a panel of six other rat IgG2a kappa monoclonals isotype-matched to the 35/56 anti-gp70f mAb1, including two to the distinct epitopes "g" and "h" of gp70, or to normal rat IgG2a. On the basis of several competition assays four mAb2 were clearly either directed to the paratope of anti-gp70f mAb1 (.1C7, .1B, and .E) or not (.A, representing a noninternal image Ab2 alpha anti-Id). The P3E8 mAb2 was difficult to classify. Based on relative efficiency in these assays, .1C7 was chosen for further study, and upon injection was able to induce Ab3 responses in C57BL/6, BALB/c, and CBA mice. The fact that the Ab3 activity was detected in a competitive ELISA in which the hyperimmune antisera blocked the binding of Ab1 to Ab2, plus the ability to raise Ab3 neutralizing antibodies in three different mouse strains were consistent with .1C7 as an internal image Ab2 beta anti-Id. These results thus indicate the potential for internal-image monoclonal antiidiotypic antibody-based vaccines for retroviral diseases.

Subchronic oral and intravenous (i.v.) safety evaluation and pharmacokinetics in rats and dogs of ipazilide fumarate (Win 54, 177-4), an antiarrhythmic agent.

Ipazilide fumarate (Win 54, 177-4) is a chemically novel antiarrhythmic agent that prolongs ventricular refractoriness and possesses antiectopic activity. Subchronic (29 days) nonclinical safety evaluation of ipazilide was conducted following oral and iv administration in Sprague-Dawley rats (20-320 mg/kg oral and 1.25-10 mg/kg iv) and 14 and 28 days in beagle dogs (3-30 mg/kg oral and 2.5-20 mg/kg iv). The pharmacokinetic parameters of ipazilide indicate that ipazilide is absorbed (tmax less than or equal to 1 hr) in fasted rats and dogs following single and repeated oral administrations. The apparent elimination half-life in the two species is approximately 1 hr (except in rats at a dosage of 320 mg/kg), suggesting rapid clearance. Increases in liver weights (rats 320 mg/kg) accompanied by the observation of centrilobular hypertrophy of hepatocytes were considered an expression of an adaptive metabolic response of the liver to ipazilide and may be associated with the induction of microsomal enzymes. Duodenal villous atrophy and epithelial hyperplasia (rats, 80 and 320 mg/kg) were interpreted to represent an irritant response to the drug. Local irritation was also observed at the injection site in rats and dogs. Dogs tolerated the oral and the iv administration of ipazilide at dosages of up to 30 and 20 mg/kg, respectively. Despite emesis (oral dogs), which was reduced in frequency following repeated treatment over several weeks, plasma levels in treated dogs (i.e., Cmax 4-5 micrograms/ml) were approximately twice that required to convert spontaneous arrhythmias in the conscious dog model 24 hr after myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Standing up to the big squeeze.

Consumer confidence is at its lowest ebb since 1980. Economic growth is at a standstill & unemployment & inflation are both rising. Here's a front-line report from more than three dozen operators who are fending off the recession's dual pressures of slow sales & rising costs. They are using discount pricing, partnering with vendors, setting pay for performance standards & a variety of other recession-beating practices.

The nomological validity of the Type A personality among employed adults.

The nomological validity of the Type A behavior pattern was explored. The Structured Interview (SI) and a battery of personality trait, physical health, and strain measures were administered to an occupationally diverse sample of 568 workers. Ss were also monitored for physiological reactivity and recovery (blood pressure, heart rate, skin temperature, and electrodermal response) to the SI and a subsequent Stroop Color-Word Conflict Task. A confirmatory factor analysis demonstrated that SI scores can be factored into three distinct dimensions. There was considerable overlap in the patterns of personality traits that characterized the Type A components, but only a Hostility dimension was significantly related to physiological reactivity and recovery. The results have implications for distinguishing coronary-proneness from the more traditional Type A conceptualization.

Subarachnoid administration of iohexol in cynomolgus monkeys.

A non-ionic diagnostic medium, iohexol, was administered by subarachnoid injection to groups of six cynomolgus monkeys and compared with the vehicle, physiologically normal saline, and/or saline of equal osmolality to determine its potential for increasing total protein and leucocyte levels in cerebrospinal fluid. Also investigated was the effect of repeated spinal taps not subsequently followed by the intrathecal injection of test or control articles. In the monkey, unlike man, low-level leucocyte counts were consistently observed following initial withdrawal of spinal fluid. Elevated leucocyte and total protein levels were observed in the present investigations one day to a week after intrathecal injection of radiopaque, vehicle or saline solution. Total protein returned to normal levels earlier than did leucocyte counts. However, repeated needle puncture alone was found to be sufficient to cause an elevation of leucocytes 3 to 4 times the baseline level, while inflammatory effects were observed histologically only when autopsy was performed soon after the final spinal tap.

Steady growth cone currents revealed by a novel circularly vibrating probe: a possible mechanism underlying neurite growth.

The rate and direction of neurite growth have been shown in a number of studies to be determined by the distribution of adhesive sites on the growth cone. Recent evidence showing that the application of extrinsic electric fields can redistribute membrane molecules and alter both the rate and direction of neurite growth have raised the question whether endogenous electric fields might be produced by steady currents in growth cones. To investigate this question, we have devised a novel circularly vibrating microprobe capable of measuring current densities in the range of 5 nA/cm2 (near the theorectical limit of sensitivity), with a spatial resolution of 2 micron. The design of this device and the development of a novel algorithm for computing current vectors on-line is described. Using this probe we have found that cultured goldfish retinal ganglion cell growth cones generate steady inward currents at their tips. The measured currents, in the range of 10-100 nA/cm2, appear to flow into the filopodia at their tips and back outward near the junctures of the filopodia and the growth cone. The currents appear to be produced only during active growth. Ion substitution experiments support the conclusion that the majority of this current is carried by Ca2+ ions, which we postulate flow through a population of activated voltage-sensitive Ca2+ channels located on the filopodial tips. Calculation of the transmembrane current density (4 X 10(-6) nA/cm2) leads to an estimate of channel density (10 channels/micron2) in close agreement with the measured density of Ca2+ channels in other systems. The assumption that calcium channel proteins are conveyed to nerve terminals by active transport, whereas sodium channel proteins are conveyed passively by a slower somatofugal diffusion process [Strichartz et al, 1984], would explain why developing neurons tend to display Ca2+-sensitive electrogenesis at their growing tips, and Na+-sensitive action potentials later in development. In order to gain some insight into the possible role of these steady growth currents, we estimated the membrane depolarization and axial voltage gradient they produce. It is likely that the currents produce sufficient membrane depolarization (approximately equal to 4 mV) to cause autogenous activation of ion channel permeabilities. Similarly, the axial voltage gradient (approximately equal to 4 mV/cm) would be expected to move intracytoplasmic vesicles by electrophoresis at a rate (20-40 microns/hr) very close to that at which the filopodia are observed to grow.(ABSTRACT TRUNCATED AT 400 WORDS)