Alterations in red blood cell parameters, plasma amino acids, total cholesterol and fatty acids in Standardbred horses undergoing fitness training

Maintenance of metabolic homeostasis is vital to optimise the supply of nutrients to support exercise and facilitate recovery and repair processes in horses. This study assessed the effects of exercise on resting plasma homeostasis in horses upon initiation of a training program to attain fitness in preparation for competitive harness racing. Four Standardbred horses (three males and one female) that had not been in work for at least 6 months were assessed prior to the commencement of the training program and then progressively on a weekly basis for 8 weeks. Resting plasma samples were collected in the early morning prior to exercise training and feeding. Samples were analysed for amino acid composition, cholesterol, palmitic acid and stearic acid on a weekly basis, and red blood cell counts and haemoglobin were analysed at weeks 0, 4 and 8. The red cell counts and levels of haemoglobin increased progressively over the training period (P<0.05). Specific amino acids in the plasma displayed temporal variations during the training period. Glycine was the most abundant amino acid in resting horse plasma and together with serine was reduced throughout the first half of the training period, eventually returning to initial levels at weeks 7 and 8 (P<0.05). A number of amino acids were noted to increase in concentration throughout the 8 week training period including ornithine, histidine and hydroxyproline (P<0.05). Cholesterol fell to substantially lower levels after 8 weeks of exercise (P<0.05). Palmitic acid showed three ‘peaks’ of elevated concentrations in plasma (P<0.05) following the initiation of exercise and then again at the transitions into harder fast work sessions. Stearic acid was relatively constant throughout the exercise period. Adjustments in the plasma composition of these key metabolites were consistent with supporting the increased metabolic demands associated with the higher levels of exercise training.

Long term effects of gestational hypertension and pre-eclampsia on kidney function: Record linkage study

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We examine risk of chronic kidney disease (CKD) after pregnancy hypertension.

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We found increased risk of chronic kidney disease after gestational hypertension.

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Risk of chronic kidney disease was further increased after preeclampsia.

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Women with pregnancy hypertension develop CKD earlier than normotensive women.

Objective

To assess the long term effects of hypertensive disorders of pregnancy on renal function.

Design

Cohort study where exposure was gestational hypertension or preeclampsia in the first pregnancy. Normotensive women formed the comparison group.

Setting

Aberdeen, Scotland.

Participants

All women with date of birth on or before 30th June 1969 and at least their first singleton delivery recorded in the Aberdeen Maternity and Neonatal Databank.

Methods

Participants were linked to the Renal Biochemistry Register, Scottish Morbidity Records, Scottish Renal Registry and National Register for deaths.

Main outcome measures

Occurrence of chronic kidney disease (CKD) as identified from renal function tests in later life, hospital admissions or death from kidney disease or recorded as receiving renal replacement therapy.

Results

CKD was diagnosed in 7.5% and 5.2% of women who previously had GH and PE respectively compared to 3.9% in normotensive women. The unadjusted odds ratio (95% confidence interval) of having CKD in PE was 2.04 (1.53, 2.71) and that for GH was 1.37 (1.15, 1.65), while the adjusted odds ratio (95% confidence interval) of CKD was 1.93 (1.44, 2.57) and 1.36 (1.13, 1.63) in women with PE and GH respectively. Kaplan–Meier curves of survival time to development of chronic kidney disease revealed that women with preeclampsia were susceptible to kidney function impairment earliest, followed by those with gestational hypertension.

Conclusions

There was an increased subsequent risk of CKD associated with hypertensive disorders of pregnancy. Women with GH and PE were also found to have CKD earlier than normotensive women.

Emergency department screening for risk for post-traumatic stress disorder among injured children

OBJECTIVE

To discuss the successes and challenges associated with the implementation of a post-traumatic stress disorder (PTSD) screening tool in two pediatric emergency departments (ED).

METHODS

The STEPP screening tool has been developed previously on an inpatient population of motor vehicle trauma patients. It was applied here to the general ED population at two different pediatric trauma centers. Nurse screeners were trained and a convenience sample of patients with unintentional injuries who met study criteria were screened in the ED. Feedback from nurse screeners was obtained.

RESULTS

The process of implementing a screening tool to identify patients and their families significantly at risk for PTSD symptomatology presented some barriers, but overall acceptability of the process was high for both the emergency department staff and the patient. Recommendations for others considering implementation of screening programs in the ED are offered.

CONCLUSIONS

Future research using screening protocols in the ED should, in their design, attempt to capitalize on the successes identified in the current protocol and circumvent barriers also encountered.

Associations between noise sensitivity and sleep, subjectively evaluated sleep quality, annoyance, and performance after exposure to nocturnal traffic noise

In order to determine the influence of noise sensitivity on sleep, subjective sleep quality, annoyance, and performance after nocturnal exposure to traffic noise, 12 women and 12 men (age range, 19-28 years) were observed during four consecutive nights over a three weeks period. After a habituation night, the participants were exposed with weekly permuted changes to air, rail and road traffic noise. Of the four nights, one was a quiet night (32 dBA), while three were noisy nights with exposure to equivalent noise levels of 39, 44, and 50 dBA in a permuted order. The traffic noise caused alterations of most of the physiological parameters, subjective evaluation of sleep, annoyance, and performance. Correlations were found between noise sensitivity and subjective sleep quality in terms of worsened restoration, decreased calmness, difficulty to fall asleep, and body movements. The results suggest that alterations of subjective evaluation of sleep were determined by physical parameters of the noise but modified by individual factors like noise sensitivity.

IP3 type 1 receptors in the heart: Their predominance in atrial walls with ganglion cells

Previously we have shown that inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) are abundantly expressed in the atria of rat hearts. Since arrangement of atria is very heterogeneous, in this work we focused on the precise localization of IP3 receptors in the left atrium, where the gene expression of the type 1 IP3R was the highest. The mRNA levels of the IP3 type 1 receptors in the left atrium, left ventricle and myocytes were determined using real-time polymerase chain reaction and Taqman probe. For precise localization, immunohistochemistry with the antibody against type 1 IP3Rs was performed. The mRNA of type 1 IP3 receptor was more than three times higher in the left atrium than in the left ventricle, as determined by real-time PCR. Expression of the type 1 IP3 receptor mRNA was higher in the atria, especially in parts containing cardiac ganglion cells. The atrial auricles, which are particularly free of ganglion cells, and the ventricles (wall of the right and left ventricle and ventricular septum) contained four to five times less IP3 receptors than atrial samples with ganglia. IP3R type 1 immunoreactivity detected by a confocal microscope attributed the most condensed signal on ganglionic cells, although light immunoreactivity was also seen in cardiomyocytes. These results show that type 1IP3 receptors predominate in intrinsic neuronal ganglia of cardiac atria.

Demography of a yellow-footed rock-wallaby Petrogale xanthopus colony in the threatened New South Wales sub-population

The remnant New South Wales (NSW) yellow-footed rock-wallaby (Petrogale xanthopus) population underwent a substantial decline between 1985 and 1992 and remained at dangerously low levels until 1995. To determine the processes underlying this decline, a population study was conducted at one colony, between winter 1995 and winter 1998. The colony was observed to remain relatively constant in size, consisting of between 12 or 13 individuals throughout the study. Reproductive rates were found to be relatively high. Both reproduction and pouch young survival were comparable with those reported for other P. xanthopus colonies, while adult survival rates were higher than those noted in other studies. Because population size remained constant during the study and adult survivorship was consistently high, this suggested that juvenile recruitment into the colony was low. Such low levels of recruitment may have had a substantive role in the slow decline of the entire NSW P. xanthopus population. The results of this study suggest that any management actions undertaken in the NSW P. xanthopus population should focus on increasing juvenile survival rates. Further research is required to determine whether juvenile survival is constrained by predation or competition with other herbivores.

Role of astrocytic S100β in behavioral hypersensitivity in rodent models of neuropathic pain

S100beta is a calcium-binding peptide produced mainly by astrocytes that exerts paracrine and autocrine effects on neurons and glia. We have previously shown that S100beta is markedly elevated at the mRNA level in the spinal cord following peripheral inflammation, intraplantar administration of complete Freund's adjuvant in the rat. The purpose of the present study was to further investigate the role of astrocytic S100beta in mediating behavioral hypersensitivity in rodent models of persistent pain. First, we assessed the lumbar spinal cord expression of S100beta at the mRNA and protein level using real-time RT-PCR, Western blot and immunohistochemistry analysis following L5 spinal nerve transection in rats, a rodent model of neuropathic pain. Second, we assessed behavioral hypersensitivity (mechanical allodynia) in wild type and genetically modified mice lacking or overexpressing S100beta following L5 spinal nerve transection. Third, we assessed the expression level of S100beta protein in the CD1 wild type mice after nerve injury. We report that lumbar spinal S100beta mRNA steadily increased from days 4-28 after nerve injury. S100beta protein in the lumbar spinal cord was significantly increased in both rats and mice at day 14 following nerve injury as compared with sham control groups. S100beta genetically deficient mice displayed significantly increased tactile thresholds (reduced response to non-noxious stimuli) after nerve injury as compared with the wild type group. S100beta overexpressing mice displayed significantly decreased tactile threshold responses (enhanced response to non-noxious stimuli). Together, these results from both series of experiments using a peripheral nerve injury model in two different species implicate the involvement of glial-derived S100beta in the pathophysiology of neuropathic pain.

S100A6 is a negative regulator of the induction of cardiac genes by trophic stimuli in cultured rat myocytes

S100A6 (calcyclin), a member of the S100 family of EF-hand Ca2+ binding proteins, has been implicated in the regulation of cell growth and proliferation. We have previously shown that S100B, another member of the S100 family, is induced postinfarction and limits the hypertrophic response of surviving cardiac myocytes. We presently report that S100A6 expression is also increased in the periinfarct zone of rat heart postinfarction and in cultured neonatal rat myocytes by treatment with several trophic agents, including platelet-derived growth factor (PDGF), the alpha1-adrenergic agonist phenylephrine (PE), and angiotensin II (AII). Cotransfection of S100A6 in cultured neonatal rat cardiac myocytes inhibits induction of the cardiac fetal gene promoters skeletal alpha-actin (skACT) and beta-myosin heavy chain (beta-MHC) by PDGF, PE, AII, and the prostaglandin F2alpha (PGF2alpha), induction of the S100B promoter by PE, and induction of the alpha-MHC promoter by triiodothyronine (T3). By contrast, S100B cotransfection selectively inhibited only PE induction of skACT and beta-MHC promoters. Fluorescence microscopy demonstrated overlapping intracellular distribution of S100B and S100A6 in transfected myocytes and in postinfarct myocardium but heterodimerization of the two proteins could not be detected by co-immunoprecipitation. We conclude that S100A6 may function as a global negative modulator of differentiated cardiac gene expression comparable to its putative role in cell cycle progression of dividing cells.

Spatial and temporal expression of S100B in cells of oligodendrocyte lineage

The analysis of oligodendrocyte (OL) lineage development has been facilitated by the immunocytochemical characterization of OL-specific antigens and definition of the phenotypes sequentially acquired by differentiating OLs. The purpose of the present study was to address an enduring discrepancy between several reported cases of S100B immunodetection in CNS myelin and myelinating OLs on the one hand, and the systematic use of the S100B protein as an alleged astrocytic marker in studies of the mammalian CNS on the other. To resolve this discrepancy, we have compared the developmental distribution of EGFP+ cells in the CNS of s100b-enhanced green fluorescent protein (EGFP) (Vives et al., 2003) and cnp-EGFP (Yuan et al., 2002) mice, and examined the degree of overlap between EGFP expression and that of stage-specific markers of OL differentiation during the embryonic and postnatal phases of development. We demonstrate that the S100B protein is expressed in postnatal and adult populations of NG2+ progenitors of mouse brain, as well as in immature and mature myelinating OLs present in the brain and spinal cord of embryonic and adult mice, respectively. Comparison between EGFP and endogenous S100B expression in the s100b-EGFP and cnp-EGFP mice indicates that S100B protein expression is upregulated in immature and mature OLs. These results argue against the current view that S100B expression is restricted to the astrocytic lineage in the CNS, and indicate that the use of S100B in combination with other molecular markers will help discriminate oligodendrocytes from astrocytes.

The breeding season diet of wedge-tailed eagles (Aquila audax) in western New South Wales and the influence of Rabbit Calicivirus Disease

A total of 2071 individual prey items were identified from 34 active and 55 inactive wedge-tailed eagle nests following the 1995, 1996 and 1997 breeding seasons. Overall, the eagle's diet was comparable to that reported in other studies within semi-arid regions, with rabbits, reptiles and macropods accounting for 47.8, 22.6 and 13.7% of prey items, respectively. In spring 1996 rabbit calicivirus moved into the study area, resulting in a 44-78% reduction in rabbit abundance (Sharp et al. 2001). An index was developed to enable the time since death for individual prey items to be approximated and a historical perspective of the eagle's diet to be constructed. Rabbits constituted 56-69% of dietary items collected during the pre-rabbit calicivirus disease (RCD) samples, but declined to 31% and 16% in the two post-RCD samples. A reciprocal trend was observed for the proportion of reptiles in the diet, which increased from 8-21% of pre-RCD dietary items to 49-54% after the advent of RCD. Similarly, the proportion of avian prey items was observed to increase in the post-RCD samples. These data suggested that prey switching may have occurred following the RCD epizootic. However, a lack of data on the relative abundances of reptiles and birds prevented an understanding of the eagle's functional responses to be developed and definitive conclusions to be drawn. Nevertheless, the eagles were observed to modify their diet to the change in rabbit densities by consuming larger quantities of native prey species.

Changes in interhemispheric transfer rate and the development of bimanual coordination during childhood

In this study, we investigated the effect of the development of interhemispheric communication on age-related change in bimanual coordination. Interhemispheric communication was assessed by comparing the latency of a manual response to a visual stimulus when the hemisphere perceiving the stimulus and the hemisphere controlling the manual response were the same (uncrossed condition) to the latency when they were different (crossed condition). In the first experiment (5- to 10-year-old children) we used a two-choice response-time task, and in the second experiment (3- to 7-year-old children) we used a simple response-time task. In both studies, bimanual coordination was tested on a line-drawing task, and we compared performance on mirror and parallel movements. The crossed-uncrossed difference decreased with age in both experiments. When estimated on the simple response-time task, the crossed-uncrossed difference was related to the difference in performance between mirror and parallel movements on the bimanual task. Thus, improved interhemispheric communication contributes to progress in bimanual coordination, especially that which requires resisting the attraction of mirror movements in order to rotate both hands with parallel movements.

Defining a test for HER-2/neu evaluation in breast cancer in the diagnostic setting

In breast cancer amplification of the HER-2/neu oncogene and over-expression of the protein product is associated with poor prognosis, predicts response to some chemotherapeutic regimens and is the target for Herceptin treatment. To date there are several methods to assess the amplification/over-expression of HER-2/neu with each having advantages and disadvantages. We have studied amplification and over-expression of HER-2/neu in 250 consecutive cases of breast cancer (220 invasive and 30 in situ carcinomas) presenting to the Department of Pathology at Women's College Campus of Sunnybrook and Women's College Health Sciences Center. Thirty percent of the invasive carcinomas were node positive. HER-2/neu protein over-expression was assessed by immunohistochemistry (IH) using antibody CB11 and amplification of the gene by differential PCR. The percentage of tumor cells showing CB11 staining was determined and the most significant cut off point for positivity was > or =10% moderate or strong complete membranous staining. The gene was considered amplified if the density score of the product was > or =2. There was 94% concordance between the two methods (P value.0001). Both methods were positive in 16% of cases and negative in 78% of cases. Discrepant cases were examined by FISH which confirmed the IH results in 9/11 invasive carcinomas. These results show that there is excellent concordance between IH and PCR. However, immunohistochemistry is easier to perform and cheaper than PCR and could be used in routine assessment of HER-2/neu in breast cancer patients.

Loss of androgen receptor associated protein 70 (ARA70) expression in a subset of HER2-positive breast cancers

Co-transfection studies indicate that HER2 (erbB-2) overexpression results in the phosphorylation and enhanced transcriptional activity of the androgen receptor (AR). This amplification of AR action is further enhanced by the expression of ARA70, a putative co-activator with a predilection for the AR. Because androgens inhibit the growth of breast cancer cells whereas HER2 overexpression stimulates the growth of these cells, it seems possible that loss of expression of AR or ARA70 in some HER2 overexpressing tumors might confer a growth advantage to these cells. We examined ARA70 and AR expression in 20 HER2-positive (overexpressing) and 21 HER2-negative cases of breast invasive ductal carcinoma (IDC) to determine the relationship between loss of ARA70 and/or AR with HER2 overexpression. Strong ARA70 immunostaining was observed in all normal and breast epithelial cells in fibrocystic change and in in situ carcinoma present in the patient samples. Of the 41 cases of IDC, focal or complete loss of ARA70 protein expression was observed in 46% of the cases, with 60% of HER2-positive versus 33% of HER2-negative cases showing loss. Loss of AR expression was observed in 60% of HER2-positive versus 43% of HER2-negative cases. Remarkably, only 20% of HER2-positive tumors expressed both AR and ARA70, while 43% of HER2-negative tumors expressed both of these elements of the AR signaling pathway. This trend is consistent with a possible clinical relevance of the potential crosstalk between the HER2 and AR signaling pathways. Western blot analysis for ARA70 expression performed on frozen breast biopsies of normal or malignant breast tissue from four patients revealed a 70 kDa immunoreactive band in all four normal tissue samples, with an additional 35 kDa band in two of the breast cancer samples and in human breast cancer MCF-7 cells. This may reflect aberrant splicing in some breast cancers, leading to the emergence of the 35 kDa isoform.

Analysis of the prostate cancer-susceptibility locus HPC20 in 172 families affected by prostate cancer

A recent study of hereditary prostate cancer has provided evidence for a prostate cancer-susceptibility locus, HPC20, which maps to 20q13. To assess further the potential contribution of this locus to prostate cancer susceptibility, we studied 172 unrelated families affected by prostate cancer, using 17 polymorphic markers across a 98.5-cM segment of chromosome 20 that contains the candidate region. Parametric analysis, allowing for heterogeneity, resulted in an overall HLOD score of 0.09 (P=.39) at D20S171, under the assumption of linkage in 6% of families. Mode-of-inheritance-free analysis of the entire data set resulted in a maximal Zlr score of 0.76 (LOD 0.13; P=.22) at the same location. The strongest evidence for linkage was seen in the subset of 16 black families (LOD 0.86; Zlr=1.99; P=.023) between markers D20S893 and D20S120, near the putative location of HPC20. Although some positive results were observed, our linkage study does not provide statistically significant support for the existence of a prostate cancer-susceptibility locus HPC20 at 20q13.

Enhanced calcium transients in glial cells in neonatal cerebellar cultures derived from S100B null mice

S100B is the major low-affinity Ca(2+)-binding protein in astrocytes. In order to study the role of S100B in the maintenance of Ca(2+) homeostasis, we generated S100B null mice by a targeted inactivation of the S100B gene. Absence of S100B expression was demonstrated by Northern and Western blotting for S100B mRNA and protein, respectively, and immunoperoxidase staining of sections of various brain regions. S100B null mice were viable, fertile, and exhibited no overt behavioral abnormalities up to 12 months of age. On the basis of light microscopy and immunohistochemical staining, there were no discernable alterations in the distribution and morphology of astrocytes or neurons in sections of adult brains of these mice. Astrocytes in cerebellar cultures derived from 6-day-old S100B null mice exhibited enhanced Ca(2+) transients in response to treatment with KCl or caffeine. On the other hand, granule neurons, in the same cultures, exhibited normal Ca(2+) transients in response to treatment with KCl, caffeine, or N-methyl-d-aspartate. These results demonstrate a specific decrease in Ca(2+)-handling capacity in astrocytes derived from S100B null mice and suggest that S100B plays a role in the maintenance of Ca(2+) homeostasis in astrocytes.

Toward neuroanatomical models of analogy: a positron emission tomography study of analogical mapping

Several brain regions associated with analogical mapping were identified using (15)O-positron emission tomography with 12 normal, high intelligence adults. Each trial presented during scanning consisted of a source picture of colored geometric shapes, a brief delay, and a target picture of colored geometric shapes. Analogous pictures did not share similar geometric shapes but did share the same system of abstract visuospatial relations. Participants judged whether each source-target pairing was analogous (analogy condition) or identical (literal condition). The results of the analogy-literal comparison showed activation in the dorsomedial frontal cortex and in the left hemisphere; the inferior, middle, and medial frontal cortices; the parietal cortex; and the superior occipital cortex. Based on these results as well as evidence from relevant cognitive neuroscience studies of reasoning and of executive working memory, we hypothesize that analogical mapping is mediated by the left prefrontal and inferior parietal cortices.

RT-PCR amplification of CK19 mRNA in the blood of breast cancer patients: correlation with established prognostic parameters

We optimized the assay for detection of cytokeratin 19 (CK19) mRNA by the reverse transcriptase-polymerase chain reaction (RT-PCR) in blood as an index of circulating tumor cells in breast cancer patients. The limit of detection of < 1 MCF7 tumor cells per 10(6) peripheral blood leukocytes (PBL) was achieved in mixing experiments. We did not detect CK19 mRNA in control bloods (0/30) or in the blood of patients with benign breast disease (0/15). In blood samples from 109 patients with invasive breast cancer, CK19 mRNA was detected in 7/23 patients with node-negative disease, in 21/58 with node-positive disease, and in 20/28 with distant metastases. There was a significant association (P < 0.01) of CK19 positivity with distant metastatic versus both node-negative and node-positive disease, but not with any other histopathological parameter examined. In a small number of patients with distant metastases, increased intensity of the CK19 RT-PCR signal was associated with a reduced survival.

Detection of calcium ionophore induced membrane changes in dog sperm as a simple method to predict the cryopreservability of dog semen

The sensitivity of dog sperm cells for extracellular Ca(2+)/Ca(2+)-ionophore challenge was compared to the detrimental effects of an optimized freeze/thawing protocol. Three sperm-rich fractions of ejaculates from 9 dogs were obtained, and one aliquot of each ejaculate was washed in a modified Tyrode's medium (HBT containing 0.1 mM Ca(2+)), without (control sample) and with 2.5 microM Ca(2+)-ionophore (induced sample) and incubated for 60 min at 38 degrees C in humidified atmosphere. Another aliquot from the same semen fractions was diluted, washed in a Tris buffer, and packed into 0.5-ml straws with a Tris buffer containing 7.5 vol % glycerol. The samples were stored for 1 week in liquid nitrogen after a computer-driven three-step freeze protocol and subsequently thawed for 50 sec in a 37 degrees C water bath and reconstituted into HBT. The acrosome integrity was determined using fluorescein-conjugated peanut agglutinin (PNA-FITC) as an acrosomal marker, while the vitality of the sperm cells was simultaneously assessed with the membrane impermeable DNA supravital stain ethidium homodimer 1 (EthD-1) using fluorescence microscopy and flow cytometry. The motility of frozen/thawed sperm samples was evaluated by microscopic as well as computerized motility analyses. Remarkably, the percentage sperm cells that underwent acrosome reactions induced by Ca(2+)-ionophore correlated very positively (r = 0.93) with the amount of acrosome damage observed in cryopreserved sperm samples. Furthermore, the degree of cellular damage induced by Ca(2+)-ionophore treatment correlated very negatively (r = -0.99) with the relative amount of sperm cells that remained motile after cryopreservation. Such clear correlations between Ca(2+)-ionophore induced acrosome reaction and motility parameters for frozen/thawed dog sperm cells were not found, suggesting that the generation of acrosome leakage and sperm immotility are two independent detrimental processes occurring during cryopreservation. From these results it can be concluded that Ca(2+)-ionophore treatment followed by simultaneous determination PNA-FITC and EthD-1 staining can be used to predict the cryopreservability of ejaculates from individual dogs used as donors.

Effect of sperm diluents on the acrosome reaction in canine sperm

In this study we investigated the influence of sperm diluting media and temperature on the incidence of the acrosome reaction in dog sperm. Ejaculates were collected from 5 dogs, diluted with six different media and then incubated at 37 degrees C and 20 degrees C. Fluorescein isothiocynate conjugated peanut agglutinin (FITC-PNA) and ethidium homodimer as a vital stain were used in combination to determine the acrosomal status of viable spermatozoa, the technique was validated using electron microscopy. The outer acrosomal membrane of dog spermatozoa was shown to be the specific binding site for FITC-PNA. After 6 h of incubation, ejaculates diluted in media with a high Ca2+ concentration showed a significantly higher percentage (means +/- SD) of acrosome reacted spermatozoa [64 +/- 7 and 58 +/- 9 in sperm capacitation medium with (SP-TALP-1) and without BSA (SP-TALP-2), respectively] than those diluted in media with a low Ca2+ concentration [36 +/- 5, 39 +/- 4, 18 +/- 2 and 20 +/- 4 in Canine Capacitation Medium (CCM), Egg Yolk Tris dog semen extender (EXT-1), Modified Egg Yolk Tris extender (EXT-2) and Modified CCM (MCCM), respectively]. The increase in the percentage of acrosome reaction (AR) was slower at 20 degrees C than at 37 degrees C. In addition, the percentage of viable acrosome reacted spermatozoa increased significantly from 19 +/- 5 and 22 +/- 3 in non-bound sperm to 27 +/- 4 and 30 +/- 6 in zona pellucida bound sperm (diluted in EXT-2 and MCCM, respectively). We conclude that the composition of the spermatozoa diluent has a marked effect on the incidence of the acrosome reaction. Therefore, both the media used to dilute dog sperm and the temperature at which the spermatozoa are handled are important factors to consider when processing spermatozoa for artificial insemination, IVF procedures or preservation.

Characterization and distribution of an oncofetal antigen (M2A antigen) expressed on testicular germ cell tumours

M2A antigen is an oncofetal antigen associated with germ cell neoplasia, present in testis on fetal gonocytes and re-expressed on carcinoma in situ (CIS) and germ cell tumours. We developed a panel of monoclonal antibodies (mAb), M2A (IgG2a), D1-26 (IgG2b) and D2-40 (IgG1), to this antigen in order to characterize its structure and study its distribution among germ cell tumours. M2A antigen was purified by sequential lectin and antibody affinity chromatography and characterized as a monomeric M, 40 000 surface sialoglycoprotein, extensively glycosylated with O-linked carbohydrate structures, but devoid of N-linked sugars. Terminal sialic acid residues were required for reactivity with mAb M2A and D1-26, but not D2-40. Sections of 69 testicular germ cell tumours, fixed in formalin and embedded in paraffin, were stained with mAb D2-40 to examine the distribution of M2A antigen. Uniform membrane staining was observed in seminomas, and focal staining in 69% of embryonal carcinomas, 29% of teratomas and 25% of yolk sac tumours. CIS in the vicinity of all germ cell tumours also displayed uniform membrane staining. The characterization of M2A antigen, and the development of mAb which react with it in conventionally preserved archival specimens, provide important initiatives to study the origin and progression of germ cell neoplasia.

Inhibition of intimal thickening after balloon angioplasty in porcine coronary arteries by targeting regulators of the cell cycle

BACKGROUND

Although percutaneous transluminal coronary angioplasty (PTCA) is a highly effective procedure to reduce the severity of stenotic coronary atherosclerotic disease, its long-term success is significantly limited by the high rate of restenosis. Several cellular and molecular mechanisms have been implicated in the development of restenosis post-PTCA, including vascular smooth muscle cell (VSMC) activation, migration, and proliferation. Recently, our group demonstrated that rapamycin, an immunosuppressant agent with antiproliferative properties, inhibits both rat and human VSMC proliferation and migration in vitro. In the present study, we investigated (1) whether rapamycin administration could reduce neointimal thickening in a porcine model of restenosis post-PTCA and (2) the mechanism by which rapamycin inhibits VSMCs in vivo.

METHODS AND RESULTS

PTCA was performed on a porcine model at a balloon/vessel ratio of 1.7+/-0.2. Coronary arteries were analyzed for neointimal formation 4 weeks after PTCA. Intramuscular administration of rapamycin started 3 days before PTCA at a dose of 0.5 mg/kg and continued for 14 days at a dose of 0.25 mg/kg. Cyclin-dependent kinase inhibitor (CDKI) p27(kip1) protein levels and pRb phosphorylation within the vessel wall were determined by immunoblot analysis. PTCA in the control group was associated with the development of significant luminal stenosis 4 weeks after the coronary intervention. Luminal narrowing was a consequence of significant neointimal formation in the injured areas. Rapamycin administration was associated with a significant inhibition in coronary stenosis (63+/-3.4% versus 36+/-4.5%; P<0.001), resulting in a concomitant increase in luminal area (1.74+/-0.1 mm2 versus 3. 3+/-0.4 mm2; P<0.001) after PTCA. Inhibition of proliferation was associated with markedly increased concentrations of the p27(kip1) levels and inhibition of pRb phosphorylation within the vessel wall.

CONCLUSIONS

Rapamycin administration significantly reduced the arterial proliferative response after PTCA in the pig by increasing the level of the CDKI p27(kip1) and inhibition of the pRb phosphorylation within the vessel wall. Therefore, pharmacological interventions that elevate CDKI in the vessel wall and target cyclin-dependent kinase activity may have a therapeutic role in the treatment of restenosis after angioplasty in humans.

Demonstration of heterodimer formation between S100B and S100A6 in the yeast two-hybrid system and human melanoma

S100B (S100beta) and S100A6 (calcyclin) are two 10-kDa Ca2+- and Zn2+-binding proteins coexpressed in melanoma and cell-cycle regulated. These proteins are members of the S100 subfamily and are thought to exert their function through interaction with intracellular target proteins. In order to search for potential target proteins interacting with S100B, we used a yeast two-hybrid strategy with human S100B as bait to screen a human brain cDNA library. The fusion proteins interacting with the S100B bait were identified as S100B, S100A1, and S100A6. This indicates the potential of S100B to form homodimers and heterodimers with other members of the S100 subfamily. By Northern and Western blotting, S100B and S100A6 were shown to be expressed at high levels in a panel of human melanoma cell lines. S100B and S100A6 were coimmunoprecipitated from melanoma cell lysates in the presence of 100 microM Zn2+. Confocal microscopy demonstrated that both proteins were distributed throughout the cytoplasm and concentrated in the nucleus. The demonstration of an association and colocalization of S100B and S100A6 in melanoma supports the possibility that an S100B/S100A6 heterodimer plays a functional role in these cells.

Reversion of the differentiated phenotype and maturation block in Sertoli cells in pathological human testis

To study the relationship between abnormal Sertoli cell differentiation and spermatogenic impairment, we examined the expression of Sertoli cell markers normally lost at puberty, cytokeratin 18 (CK18), anti-Müllerian hormone (AMH) and M2A antigen, in three children (aged 1-2 years), 50 adults (aged 19-45 years) with obstructive or non-obstructive azoospermia or oligozoospermia, and six patients (aged 1-18 years) with 5 alpha-reductase deficiency. There was CK18 and/or AMH expression, but never M2A antigen expression, associated with spermatogonial arrest or Sertoli cell-only (SCO) syndrome in infertile men. Loss of M2A antigen suggests the transition of Sertoli cells to an adult phenotype, while CK18 and/or AMH expression may be a manifestation of de-differentiation of Sertoli cells. In 5 alpha-reductase deficiency, there was a sequential loss of CK18, M2A antigen and AMH around puberty, associated with partial spermatogenesis. The persistence of immature Sertoli cells expressing M2A antigen was associated with prepubertal seminiferous cords and SCO syndrome. Therefore, 5 alpha-reductase deficiency may prevent the maturation of Sertoli cells, resulting in impairment of spermatogenesis, and loss of M2A antigen expression coincides with a critical step in the Sertoli cell maturation. High follicle stimulating hormone concentrations due to failure of normal Sertoli cell differentiation indicate a normal development pattern of the hypothalamic-pituitary-gonadal axis.

Inhibition of norepinephrine-induced cardiac hypertrophy in s100beta transgenic mice

We have recently reported that the Ca2+-binding protein S100beta was induced in rat heart after infarction and forced expression of S100beta in neonatal rat cardiac myocyte cultures inhibited alpha1-adrenergic induction of beta myosin heavy chain (MHC) and skeletal alpha-actin (skACT). We now extend this work by showing that S100beta is induced in hearts of human subjects after myocardial infarction. Furthermore, to determine whether overexpression of S100beta was sufficient to inhibit in vivo hypertrophy, transgenic mice containing multiple copies of the human gene under the control of its own promoter, and CD1 control mice were treated with norepinephrine (NE) (1.5 mg/kg) or vehicle, intraperitoneally twice daily for 15 d. In CD1, NE produced an increase in left ventricular/body weight ratio, ventricular wall thickness, induction of skACT, atrial natriuretic factor, betaMHC, and downregulation of alphaMHC. In transgenic mice, NE induced S100beta transgene mRNA and protein, but provoked neither hypertrophy nor regulated cardiac-specific gene expression. NE induced hypertrophy in cultured CD1 but not S100beta transgenic myocytes, confirming that the effects of S100beta on cardiac mass reflected myocyte-specific responses. These transgenic studies complement in vitro data and support the hypothesis that S100beta acts as an intrinsic negative regulator of the myocardial hypertrophic response.

Induction of S100b in myocardium: an intrinsic inhibitor of cardiac hypertrophy

Cardiac hypertrophy induced by pressure overload and following myocardial infarction entails regulation of myocardial gene expression, recapitulating an embryonic phenotype, including activation of fetal beta-myosin heavy chain and skeletal alpha-actin. Progressive hypertrophy and alterations in gene expression may contribute to myocardial failure. Although signaling pathways that contribute to hypertrophy development have been identified, intrinsic cardiac regulators that limit hypertrophic response have not been determined. The beta subunit of S100 protein is induced in the myocardium of human subjects and an experimental rat model following myocardial infarction. Forced S100 beta expression in neonatal rat cardiac myocyte cultures and high level expression of S100 beta in transgenic mice hearts inhibit cardiac hypertrophy and the associated phenotype by modulating protein kinase C-dependent pathways. S100 beta expression is probably a component of the myocyte response to trophic stimulation that serves as a negative feedback mechanism to limit cellular growth and the associated alterations in gene expression.

S100beta inhibits alpha1-adrenergic induction of the hypertrophic phenotype in cardiac myocytes

In an experimental rat model of myocardial infarction, surviving cardiac myocytes undergo hypertrophy in response to trophic effectors. This response involves gene reprogramming manifested by the re-expression of fetal genes, such as the previously reported isoform switch from adult alpha- to embryonic beta-myosin heavy chain. We now report the transient re-expression of a second fetal gene, skeletal alpha-actin in rat myocardium at 7 days post-infarction, and its subsequent down-regulation coincident with the delayed induction of S100beta, a protein normally expressed in brain. In cultured neonatal rat cardiac myocytes, co-transfection with an S100beta-expression vector inhibits a pathway associated with hypertrophy, namely, alpha1-adrenergic induction of beta-myosin heavy chain and skeletal alpha-actin promoters mediated by beta-protein kinase C. The induction of beta-myosin heavy chain by hypoxia was similarly blocked by forced expression of S100beta. Our results suggest that S100beta may be an intrinsic negative regulator of the hypertrophic response of surviving cardiac myocytes post-infarction. Such negative regulators may be important in limiting the adverse consequences of unchecked hypertrophy leading to ventricular remodeling and dysfunction.

Hepatocyte nuclear factor 3beta is involved in pancreatic beta-cell-specific transcription of the pdx-1 gene

The mammalian homeobox gene pdx-1 is expressed in pluripotent precursor cells in the dorsal and ventral pancreatic bud and duodenal endoderm, which will produce the pancreas and the rostral duodenum. In the adult, pdr-1 is expressed principally within insulin-secreting pancreatic islet beta cells and cells of the duodenal epithelium. Our objective in this study was to localize sequences within the mouse pdx-1 gene mediating selective expression within the islet. Studies of transgenic mice in which a genomic fragment of the mouse pdx-1 gene from kb -4.5 to +8.2 was used to drive a beta-galactosidase reporter showed that the control sequences sufficient for appropriate developmental and adult specific expression were contained within this region. Three nuclease-hypersensitive sites, located between bp -2560 and -1880 (site 1), bp -1330 and -800 (site 2), and bp -260 and +180 (site 3), were identified within the 5'-flanking region of the endogenous pdx-1 gene. Pancreatic beta-cell-specific expression was shown to be controlled by sequences within site 1 from an analysis of the expression pattern of various pdr-1-herpes simplex virus thymidine kinase promoter expression constructs in transfected beta-cell and non-beta-cell lines. Furthermore, we also established that this region was important in vivo by demonstrating that expression from a site 1-driven beta-galactosidase reporter construct was directed to islet beta-cells in transgenic mice. The activity of the site 1-driven constructs was reduced substantially in beta-cell lines by mutating a hepatocyte nuclear factor 3 (HNF3)-like site located between nucleotides -2007 and -1996. Gel shift analysis indicated that HNF3beta present in islet beta cells binds to this element. Immunohistochemical studies revealed that HNF3beta was present within the nuclei of almost all islet beta cells and subsets of pancreatic acinar cells. Together, these results suggest that HNF3beta, a key regulator of endodermal cell lineage development, plays an essential role in the cell-type-specific transcription of the pdx-1 gene in the pancreas.

Transcriptional regulation of the human S100 beta gene

S100 beta is a calcium-binding protein produced and secreted by glial cells in the central and peripheral nervous systems. S100 beta promotes neuronal differentiation and survival but may be detrimental to cells if overexpressed. The selective overproduction of S100 beta has been implicated in the progression of the neuropathological changes in Alzheimer's disease. In addition, at high concentrations, S100 beta stimulates toxic intracellular pathways in cultured cells. To begin to define the regulation of S100 beta expression, we characterized the human S100 beta promoter and mapped its upstream regulatory elements by using a luciferase reporter system. The functional S100 beta promoter was localized to a region -168/ +697 containing 168 bp upstream of the transcription initiation site of the gene. This minimal promoter was active in a variety of cell types, including those of glial, neuronal, and non-neural origin. The human S100 beta promoter activity is regulated by both positive and negative regulatory elements located upstream in the 5' flanking DNA regions. The regions -788/ -391 and -1012/ -788 contain strong positive, cell type-specific regulatory elements. Negative regulatory elements were mapped to the more distal -4437/ -1012 and -1012/ -788 regions of the gene. The -4437/ -1012 negative element suppressed promoter activity in all cell types examined, except C6 glioma cells. These data demonstrate that the expression of the human S100 beta gene is under complex transcriptional regulation that allows for precise control of the S100 beta level in the nervous system.

High-throughput DNA sequencing on a capillary array electrophoresis system

A capillary array electrophoresis apparatus capable of running and analyzing 48 DNA sequencing samples simultaneously has been constructed. The instrument uses a replaceable sieving buffer and incorporates a convenient method for introducing the buffer into the capillaries. Data from laser-induced fluorescence are collected as four separate images, one for each optical channel. The integrated data analysis software employs an open architecture that allows use of any DNA base-calling algorithm. DNA sequencing runs are completed in approx. 1 hr (approximately 500 bases), and instrument turnaround time between runs is less than 15 min. Overall, the instrument throughput is on the order of 720 templates/day, or 360,000 bases/day.

Acrosome-intact boar spermatozoa initiate binding to the homologous zona pellucida in vitro

The acrosome reaction is a prerequisite for zona pellucida penetration by mammalian spermatozoa. In some species, the sperm undergo the acrosome reaction before binding to the zona pellucida, and in other species only acrosome-intact sperm can initiate binding to the zona. In the present investigation, we addressed the question whether acrosome-intact or acrosome-reacted boar sperm initiate binding to the pig zona pellucida by studying the acrosomal status of sperm bound to zonae pellucidae. Our approach was to vary the percentage of acrosome-intact sperm in suspension by long preincubation before incubation with hemizonae for 1 min. We hypothesized that if only acrosome-intact sperm are able to initiate binding to the zona pellucida, the majority of the sperm on the zona surface would be acrosome-intact regardless of the percentage of acrosome-reacted sperm in suspension. Fluorescein isothiocyanate-conjugated peanut agglutinin (Arachis hypogaea; FITC-PNA) in combination with optical sectioning by confocal laser-scanning microscopy was used to study the acrosomal status of sperm bound to the hemizona. Electron microscope studies showed that the FITC-PNA binding site is mainly limited to the outer acrosomal membrane of boar sperm, thus validating the use of FITC-PNA as an accurate probe for studying boar sperm acrosome reaction. Over 90% of the sperm bound to a hemizona were acrosome-intact irrespective of whether the majority of sperm in the suspension were acrosome-intact, acrosome-reacting, or acrosome-reacted. There was a significant difference (Kruskal-Wallis test, p < 0.05) in the mean +/- SEM number of sperm bound to the outer side, inner side, and edge of a hemizona (48 +/- 8, 14 +/- 3, and 7 +/- 2; n = 58; respectively). The acrosomal status of sperm bound to the various surfaces of hemizonae was similar. Taking the respective zona pellucida surface area into consideration, it was calculated that an average of 1.9 +/- 0.3, 1.0 +/- 0.2, and 1.5 +/- 0.3 spermatozoa were bound per 1000 microm2 of outer side, inner side, and edge of a hemizona, respectively (mean +/- SEM, n = 38). These observations indicate that acrosome-intact boar spermatozoa initiate binding to the pig zona pellucida. A gradient of sperm binding sites also exists, decreasing from the outside to the inside of the zona pellucida.

Induction of acrosome reaction in dog sperm by calcium ionophore

The sensitivity of the plasma membrane to calcium ionophore (A23187) challenge was studied in dog sperm using fluorescein lectin staining for the assessment of acrosomal status and viability. Second fraction ejaculates from 5 dogs were washed, resuspended in Ca(2+)-free (EDTA-treated), 50, 100, 500, 1000 and 2000 microM/l Ca(2+)-containing Sp-TALP medium and induced with 50, 250, 500, 1000, 2500 and 5000 nM/l calcium ionophore. Samples were collected from each aliquot after 30 and 60 min of induction to assess the percentage of acrosome reacted sperm cells (AR rate), viability and motility by fluorescein isothiocyanate conjugated peanut agglutinin (FITC-PNA) and ethidium-homodimer combined staining. On each slide, 200 sperm cells were assessed under epifluorescence microscope (x 1250) in a blind manner. The response to ionophore challenge (AR rate, viability, motility) varied with Ca2+ and ionophore concentration in the suspension. A significantly higher AR rate was detected in samples containing 100, 500, 1000 and 2000 microM/L Ca2+ (> 40%) than in that containing 50 microM/L. Acrosome reaction could not be successfully induced in the EDTA-treated sample and in any of the aliquots in which 50, 250 and 500 nM/L ionophore concentrations were used for induction. Motility decreased drastically in all of the treated samples and stopped in that sample where as significant AR rate could be detected. Viability remained high (> 75%) during the incubation and did not differ significantly in the treated and the control groups.

Detection and enrichment of carcinoma-in-situ cells in semen by an immunomagnetic method using monoclonal antibody M2A

Carcinoma-in-situ (CIS) is a precursor of germ cell cancers in the testis. Early detection and treatment of CIS can prevent the development of invasive cancer. We have developed an immunomagnetic approach for enrichment of CIS cells from semen. Immunomagnetic beads were coated with monoclonal antibody (mAb) M2A, which is specific for seminoma and CIS. In preliminary mixing experiments, cultured human HEY cells, which express the M2A surface antigen, were added to semen samples and recovered selectively by incubation with M2A-coated immunomagnetic beads followed by magnetic activated cell sorting (MACS). Application of this procedure to ejaculates from five subjects with CIS and 22 control subjects with no evidence of testicular neoplasia resulted in the preferential recovery of a population of large round cells from a 0.5 ml semen sample obtained from CIS subjects (median 1 x 10(4), range 2 x 10(3) to 2 x 10(4)) relative to controls (median 2 x 10(2); range 0 to 10(3)), with no overlap between the two groups (p < 0.001). These results suggest that a subpopulation of large round cells recovered from the semen of CIS patients by incubation with M2A-coated immunomagnetic beads and MACS are CIS cells. Immunomagnetic enrichment of CIS cells in semen will facilitate the definitive identification of exfoliated CIS cells in ejaculates and could be an important first step in a non-invasive screening procedure for testicular CIS.

Use of peanut agglutinin to assess the acrosomal status and the zona pellucida-induced acrosome reaction in stallion spermatozoa

Peanut agglutinin (PNA) was used to assess the sperm acrosomal status and the acrosome reaction during gamete interaction in the equine species. PNA exclusively binds to the outer acrosomal membrane of stallion spermatozoa, as was established by transmission electron microscopy. Fluorescein isothiocyanate-PNA (FITC-PNA) labeling was used to monitor sperm acrosomal changes during a prolonged incubation period of 24 hours and during a 2-hours incubation in the presence of 5 microM calcium ionophore A23187. In addition, after a 4-hours preincubation in SP-TALP medium, sperm samples were incubated with matching hemizonae for 1 minute (onset binding) followed by a 60-minute incubation (1-hour binding) of the sperm-hemizona complexes in sperm-free medium to assess the acrosomal status of the bound spermatozoa. For acrosome assessment, spermatozoa and washed sperm-hemizona complexes were air dried onto microscope slides, fixed, permeabilized in ethanol, stained with FITC-PNA, and counterstained with the DNA dye ethidium homodimer. Both zona-bound and non-bound spermatozoa showed similar staining patterns. Acrosome-intact spermatozoa displayed intensively green fluorescence over the acrosomal cap, whereas reacting spermatozoa showed a patchy disrupted image of fluorescence. Sperm cells that completed the acrosome reaction were principally stained on the equatorial segment or not stained at all. During prolonged incubation and during the calcium ionophore treatment, the proportion of spermatozoa with an acrosomal modification (reacting) and a complete breakdown of the acrosome (reacted) increased noticeably. Significant induction of the acrosome reaction was observed within 60 minutes of sperm-zona contact (P < 0.001). In conclusion, a rapid and reliable assessment of the acrosomal status and the incidence of the acrosome reaction of stallion spermatozoa at the zona surface were demonstrated in this study.

Fertility, reproductive outcomes, and health of offspring, of patients treated for Hodgkin's disease: an investigation including chromosome examinations

Reproductive outcomes and health of offspring were investigated in 340 patients with Hodgkin's disease first treated at Mount Vernon Hospital, Middlesex, England, at ages under 40 (females) or 45 (males) during 1970-91. Information on offspring was obtained from case-notes and postal questionnaires to the patients. Eleven men and 16 women who had conceived any children after treatment were then interviewed. There was no excess of stillbirths, low birthweight or cogenital malformations, and no cancers have occurred in the 49 offspring after treatment. There was a significant excess of twins, compared with national expectations, in offspring of female patients (RR = 8.52, P = 0.025). Aggregation of series from the literature also showed an excess of twins. Chromosomes from cultures of peripheral lymphocytes from 45 children born to 25 patients (11 men and 14 women) after treatment were examined for numerical abnormalities and for structural abnormalities at the 550 or greater band level of resolution. All were normal except in one child with Down's syndrome (47, XY, +21), for whom we found the origin of the trisomy was from the parent without Hodgkin's disease. The chromosome constitution was also abnormal in one miscarriage (69, XXY; originating from the parent without Hodgkin's disease) and one termination (45, X; for with the parental origin could not be determined) after treatment. The study adds to previous questionnaire data and for the first time provides data also from chromosome analysis, that offspring of patients treated in adulthood for Hodgkin's disease are not at greatly raised risk of genotoxic or other adverse outcomes as a consequence of their parent's treatment. The numbers of offspring assessed in the literature remains small, however, and surveillance of larger numbers of subjects is needed to enable reliable treatment-specific analyses.