A flow cytometric assay for global estimation of tyrosine phosphorylation associated with capacitation of spermatozoa from two marsupial species, the tammar wallaby (Macropus eugenii) and the brushtail possum (Trichosurus vulpecula).

The phosphorylation of tyrosine residues in cellular proteins is a major signal transduction event during sperm capacitation. In this study protein phosphorylation was monitored using a fluorescein isothiocyanate (FITC)-labeled antiphosphotyrosine monoclonal antibody and a flow cytometric procedure optimized for sperm. Using this technique, the correlation between tyrosine phosphorylation and sperm capacitation was examined in two marsupial species, the brushtail possum and the tammar wallaby and compared with that of ram spermatozoa. The levels of tyrosine phosphorylation in sperm from all three species were increased by the addition of cyclic AMP (cAMP) and vandate, a phosphotyrosine phosphatase inhibitor and were decreased by the addition of the phosphotyrosine kinase inhibitor, staurosporine. Oviductal conditioned media (CM) induced a progressive increase in tyrosine phosphorylation in both marsupial species and also induced morphological transition from a streamlined to a 'T'-shape configuration in brushtail possum spermatozoa but not in tammar wallaby spermatozoa. Transition to the 'T'-shape orientation associated with capacitation in marsupial spermatozoa was observed by 2 h of incubation in both species when tyrosine phosphorylation was increased by higher levels of cAMP i.e. 5 mM dibutyryl cAMP plus 3 mM pentoxyphylline. Thus the tyrosine phosphorylation trigger with CM may differ in these two marsupial species. Ram sperm tyrosine phosphorylation could be increased by addition of lower levels of cAMP (1 mM). These results support the finding that tyrosine phosphorylation is associated with sperm capacitation in marsupials. Similar results were obtained by using SDS PAGE/Western blot analysis of tyrosine phosphorylation in the brushtail possum spermatozoa. The specificity, efficiency and sensitivity of the procedure described here make it applicable for routine assessment of capacitation in large numbers of samples and in other species.

Ionic calcium levels in oviduct explant-conditioned media from an Australian marsupial, the brushtail possum (Trichosurus vulpecula) and its relevance to in vitro fertilization.

Gametes from the brushtail possum (Trichosurus vulpecula), an Australian marsupial, require exposure to oviductal cells and/or their secretions before sperm binding and penetration of the zona pellucida can occur. Sperm-egg fusion, the next critical step in fertilization has not previously been reported in vitro. Here we describe the refinement of an oviduct epithelial cell (OEC) explant culture system using two different media to obtain in vitro sperm-egg fusion in the brushtail possum for the first time. Conditioned media from OEC explant cultures were supplemented with either 1% fetal calf serum (FCS) or 1 mg/ml polyvinyl alcohol and used for co-culture of epididymal sperm and superovulated eggs. Under these conditions zona penetration rates varied from 0 to 46% and sperm-egg fusion from 0 to 20%. Analysis of explant conditioned media indicated that qualitative and quantitative differences between batches could account, at least partially, for the large variability in zona penetration rates. Conditioned media that contained approximately 1 mM of ionic calcium were most effective for achieving sperm capacitation, zona binding, and penetration and sperm-egg fusion. The reorientation of the sperm head to T-shape, an indicator of capacitation in the brushtail possum, was closely linked with the concentration of calcium present in vitro.

Role of physiological lung exclusion in difficult lung resections for massive hemoptysis and other problems.

OBJECTIVES: Pulmonary tuberculosis and bronchiectasis are the major causes of massive hemoptysis in developing countries. Lung resection remains the surgical treatment of choice. This may not always be possible and may even be hazardous in some patients due to fibrosis and dense vascular adhesions between the lung and the chest wall. This leads to marked blood loss and control of hilar vessels becomes dangerous. METHODS: A series of 20 cases is described here. Nineteen presented with massive hemoptysis where control of bleeding was obtained by physiological lung exclusion. One patient had traumatic left main bronchus transection not suitable for repair or resection. Physiological lung exclusion was performed by surgical interruption of the bronchus and pulmonary artery of the involved lobe or lung, keeping pulmonary veins intact. RESULTS: Hemoptysis could be controlled in all these patients without any significant morbidity. There was no mortality. There was no postoperative empyema and recurrence of hemoptysis on long-term follow-up. No patient required anatomical lung resection later on. CONCLUSIONS: Physiological lung exclusion is a safe and effective method for control of massive hemoptysis in cases where lung resection is technically hazardous or difficult. This should be kept as an alternative or adjunct to anatomical lung resection.

Bioinformatic assessment of mass spectrometric chemical derivatisation techniques for proteome database searching.

Identification of proteins from the mass spectra of peptide fragments generated by proteolytic cleavage using database searching has become one of the most powerful techniques in proteome science, capable of rapid and efficient protein identification. Using computer simulation, we have studied how the application of chemical derivatisation techniques may improve the efficiency of protein identification from mass spectrometric data. These approaches enhance ion yield and lead to the promotion of specific ions and fragments, yielding additional database search information. The impact of three alternative techniques has been assessed by searching representative proteome databases for both single proteins and simple protein mixtures. For example, by reliably promoting fragmentation of singly-charged peptide ions at aspartic acid residues after homoarginine derivatisation, 82% of yeast proteins can be unambiguously identified from a single typical peptide-mass datum, with a measured mass accuracy of 50 ppm, by using the associated secondary ion data. The extra search information also provides a means to confidently identify proteins in protein mixtures where only limited data are available. Furthermore, the inclusion of limited sequence information for the peptides can compensate and exceed the search efficiency available via high accuracy searches of around 5 ppm, suggesting that this is a potentially useful approach for simple protein mixtures routinely obtained from two-dimensional gels.

Anterior cervical interbody fusion with rhBMP-2 and tantalum in a goat model.

BACKGROUND CONTEXT: Tricortical autogenous iliac crest has long served as the gold standard for arthrodesis after cervical discectomy. The added morbidity resulting from bone graft harvest may be eliminated by the use of a biocompatible synthetic bone graft substitute with osteoconductive abilities, and when used with an osteoinductive agent, such as recombinant bone morphogenic protein (rhBMP)-2, it may facilitate arthrodesis similar to autograft. PURPOSE: To determine by radiographic and histologic analysis whether tantalum with and without rhBMP-2 can facilitate bony ingrowth and arthrodesis in an animal model. STUDY DESIGN/SETTING: Single-level anterior cervical discectomy and fusion was performed using a tantalum bone graft substitute with and without rhBMP-2 in a previously established goat model for anterior cervical fusion. METHODS: Eight goats underwent single-level anterior cervical discectomy and stabilization with a porous tantalum implant. There were four goats in each experimental group. Group A underwent anterior cervical stabilization with tantalum alone, whereas in Group B rhBMP-2 was added to the tantalum implant. The goats were sacrificed at 12 weeks, and their cervical spines were removed for histologic and radiological analysis. RESULTS: Only one of four goats in Group A had any bony ingrowth into the tantalum. Three of four goats in Group B demonstrated bony ingrowth. The average extent of bony ingrowth at the perimeter of the tantalum in Group A was 2.5% compared with 12.5% in Group B. Similarly, the volume of bony ingrowth within the tantalum was 2.5% in Group A and 10% in Group B. The difference was not statistically significant. CONCLUSIONS: The data in this pilot study suggest that tantalum may function as a synthetic osteoconductive bone graft substitute. The addition of rhBMP-2 may facilitate osteoinduction within a synthetic osteoconductive implant. The sample size in this study was too small for statistical significance. The present animal model as used in this study was inadequate for cervical arthrodesis where rigid implant fixation is desired.

Sperm binding and penetration of the zona pellucida in vitro but not sperm-egg fusion in an Australian marsupial, the brushtail possum (Trichosurus vulpecula).

Sperm capacitation and in vitro fertilisation (IVF) have been achieved in most eutherian mammals and American marsupials under relatively simple culture conditions. In contrast sperm capacitation in Australian marsupials has not been achieved in vitro and attempts at IVF have previously been characterised by a complete lack of sperm-zona pellucida (ZP) binding. Recently, co-culture of sperm with oviduct epithelial cell monolayers or with oviductal explant conditioned media has been shown to prolong the viability and motility of brushtail possum spermatozoa, as well as to induce capacitation-associated changes such as transformation of sperm to the T-shape orientation. In this study we report that these in vitro produced T-shaped sperm, and in vivo derived T-shaped sperm flushed from the oviduct of artificially inseminated possums as a control, are able to bind to and penetrate the ZP of approximately 25% of eggs recovered from PMSG/LH-superovulated possums in vitro. Development of ZP receptivity and penetrability towards sperm was also identified as a major factor affecting the outcome of IVF. Neither in vivo nor in vitro derived T-shaped sperm were able to bind to or penetrate the ZP if eggs were obtained from animals that were treated with pLH less than 76 h after PMSG. Thus this study provides preliminary evidence for the necessity of sperm-oviduct epithelial cell interactions for capacitation in Australian species and lends further support to the suggestion that the T-shape head orientation is indicative of sperm capacitation. Despite the occurrence of sperm-ZP binding and penetration, sperm-egg membrane fusion and egg activation were not observed. Although the factor(s) responsible for the lack of sperm-egg membrane fusion in the possum have not been identified it is possible that egg capacity for membrane fusion develops independently of zona receptivity and is defective in these eggs, or alternatively that membrane fusion requires strictly defined ionic conditions which are not provided by the IVF media used in this study.

Laparoscopic anterior lumbar fusion.

PURPOSE: To assess the feasibility and complications of the laparoscopic approach to anterior lumbar fusion and to evaluate the ability of metoclopramide in conjunction with preoperative bowel preparation and early oral feeding to decrease postoperative ileus and reduce the length of hospital stay. PATIENTS AND METHODS: Laparoscopic anterior lumbar fusion was performed on 30 patients with persistent back pain between September 1997 and March 1999. All patients received metoclopramide 10 mg intravenously preoperatively and every 6 hours postoperatively, then 10 mg orally every 8 hours for 7 days. An experienced laparoscopic surgeon exposed the disc space, and lumbar fusion was performed by a neurosurgeon or an orthopedic surgeon. RESULTS: One procedure in an obese patient was converted to open surgery. The average operating time for the remaining patients was 2 hours 23 minutes. The average estimated blood loss was 75 mL. The only intraoperative complication was a trocar injury to the bladder. The average hospital stay was 2.3 days. CONCLUSION: In properly selected patients, laparoscopic anterior lumbar fusion with metoclopramide, preoperative bowel preparation, and early oral feeding results in a short hospital stay and yields better cosmetic results than traditional surgery.

Induction of thumbtack sperm during coculture with oviduct epithelial cell monolayers in a marsupial, the brushtail possum (Trichosurus vulpecula).

A reorientation of the sperm head so that it is perpendicular to the sperm tail (i.e., T-shape or thumbtack) is considered an indicator of sperm capacitation in the Australian marsupial the brushtail possum (Trichosurus vulpecula). This study describes a method of oviduct epithelial cell monolayer and sperm coculture in the brushtail possum to obtain a high percentage of thumbtack sperm. The oviduct epithelial cell (OEC) monolayers were prepared in vitro from the isthmal and ampullary segments of eCG- and LH-primed brushtail possum oviducts. Coculture experiments demonstrated that cauda epididymidal sperm from the brushtail possum attached equally to the OEC monolayers derived from the isthmal and ampullary segments of the oviduct. After 2 h of coculture, a large number of sperm attached to OEC monolayers (ampulla, 60.1+/-4.7% and isthmus, 63.1+/-5.7%) as well as to controls (tracheal epithelial cell monolayer, 46.2+/-3.7%; Matrigel, 57.4+/-7.7%; plastic, 29.2+/-3.2%). After 6 h, fewer sperm were attached to tracheal epithelial cell monolayers (1.2+/-0.2%; P<0.01) and Matrigel (10.2+/-2.5%; P<0.01), compared to those attached to ampullary and isthmal OEC monolayers (37.9+/-7.2% and 44.6+/-2.2%, respectively), and none were attached to the plastic surface. Fewer sperm were released from the ampullary and isthmal OEC monolayers compared to those from controls (P<0.05). At 6 h of coculture with ampullary and isthmal OEC, the percentage motility of both attached and unattached spermatozoa was maintained at 40-50%, which was higher (P<0.05) than in controls. Progressive motility of unattached sperm was maintained at about 2 (on an arbitrary scale of 1-5) and was not different among treatments until 6 h. More than 60-70% sperm were viable at 6 h of coculture in all the treatments. Coculture of brushtail possum epididymal sperm with OEC monolayers transformed 60% of motile streamlined spermatozoa to thumbtack orientation at 2 h compared to approximately 25% in controls. No acrosomal modifications were induced in spermatozoa in any of the treatments. This study has demonstrated a role of the oviduct in transforming a large number of sperm from a streamlined to thumbtack orientation, which may have relevance in sperm capacitation and fertilization in this species.

An alleged poisoning with methanol and formaldehyde.

It was alleged that a defendant added an unspecified amount of undyed formalin solution, containing formaldehyde and methanol, to the victim's bottle of ice and drinking water. The medical report indicated that except for a slight elevation of total creatine kinase, all other chemistry profiles were within normal ranges. The elevation of creatine kinase suggested muscle injury and inflammation; however, the significance of this elevation was not clear. Toxicological evaluations were made by conducting risk assessments. Based upon the medical report and risk assessments, the following conclusions were made: The calculated exposure doses of methanol and formaldehyde were too low to cause appreciable adverse effects; however, formaldehyde may have irritated the gastrointestinal tract causing smooth muscle and mucosal inflammation. The doses of methanol and formaldehyde were too low to cause death. The exposure scenario (a single oral exposure to formaldehyde) would not likely increase the cancer risk in the victim. The risk assessments provided resulted in a reduction in charge from attempted murder to felony.

Secretory proteins from the female reproductive tract of the brushtail possum (Trichosurus vulpecula): binding to sperm and effects on sperm survival in vitro.

Previous studies have demonstrated that co-culture of brushtail possum epididymal spermatozoa with oviduct epithelial cell monolayers prolongs sperm survival and results in the re-orientation of the sperm head and tail to the T-shape (thumbtack) configuration. Transformation of sperm to thumbtack orientation is believed to be associated with marsupial sperm capacitation. Here we report that incubation in oviduct-conditioned media also significantly prolongs sperm survival and results in the transformation of sperm to the thumbtack orientation. The major objective of the current study was to examine the proteins present in the conditioned media, to determine whether any of these proteins specifically bound to sperm and the relationship between these proteins and sperm survival and thumbtack orientation. Co-culturing brushtail possum sperm with biotin-labeled proteins in conditioned media (CM) from ampulla, isthmus and uterine explants demonstrated strong binding of two proteins of molecular mass 230 and 61 kD and weak binding of nine proteins of molecular mass 200, 180, 120, 140, 55, 52, 48, 34, 30 kD to sperm within 30 min. The binding of the 61-kD protein from the conditioned media appeared specific as increasing concentrations of non-labeled oviduct proteins, but not serum proteins, inhibited the binding of labeled proteins. The binding of oviduct and uterine proteins in the conditioned media significantly prolonged sperm survival and percentage motility and also transformed a large number of sperm to a thumbtack orientation. The implication of binding of these proteins is discussed in the context of sperm survival and capacitation in this species.

Localisation of low molecular weight sperm antigens during capacitation and acrosome reaction.

FITC-labelled sperm-specific antibodies against hamster spermatozoa were utilized as probes in acrosome reaction assays. An indirect immunofluorescence test demonstrated the localisation of two sperm proteins of 19 kDa and 23 kDa on the anterior acrosomal cap region of washed cauda epididymal sperm. These proteins were not detected in reacted acrosome or on immature or immotile sperm. Antisperm agglutinating antibodies specific to these two low molecular weight sperm antigens could be useful probes for evaluating the acrosomal status of mammalian spermatozoa.

Sperm-oviduct epithelial cell monolayer co-culture: an in vitro model of sperm-female tract interactions in a marsupial, the tammar wallaby (Macropus eugenii).

Oviduct epithelial cell (OEC) monolayers were prepared from the isthmic and ampullary parts of the oviducts of FSH-primed tammar wallabies. Co-culture experiments found that 50-60% of wallaby spermatozoa attached immediately to OEC monolayers, tracheal cell monolayer controls, and the surface of culture dishes with and without Matrigel coating. Spermatozoa were considered to be attached if they remained on the culture surface after rapidly pipetting the co-culture medium five times. The percentages of attached and unattached spermatozoa were calculated from the number of spermatozoa recovered in the agitated supernatant. After 2 h co-culture the percentage of attached spermatozoa rose to 60-80%. After 6 h co-culture the number of spermatozoa attached to OEC monolayers derived from the oviductal isthmus remained high and only a small percentage were recovered in the agitated supernatant (unattached spermatozoa 3.85 +/- 0.76%, P = 0.67). However, after 6 h co-culture of spermatozoa with OEC monolayers derived from the ampulla and with the controls the percentage of attached spermatozoa declined significantly (unattached spermatozoa: ampullary monolayer 23.08 +/- 4.80%, P < 0.01; tracheal monolayer 23.23 +/- 5.18%, P < 0.01; Matrigel 27.23 +/- 7.76%, P < 0.01; plastic surface 28.19 +/- 5.30%, P < 0.01). After 6 h co-culture with ampullary and isthmic OEC monolayers, the percentage motility of both attached and unattached spermatozoa was maintained at 64.00 +/- 1.90% and 56.66 +/- 3.18% and 62.00 +/- 3.11% and 52.00 +/- 2.43%, respectively, and was then maintained at > or = 35% after 24 h incubation. In the controls, that is, tracheal monolayer and Matrigel, the motility of attached spermatozoa declined rapidly to 48.66 +/- 2.15% and 33.63 +/- 8.66%, respectively, at 6 h, and all spermatozoa were immotile after 24 h incubation. However, the motility of unattached spermatozoa in the controls (tracheal monolayer and Matrigel) was maintained at 57.33 +/- 3.00% and 34.54 +/- 9.27%, respectively, until 6 h and then declined rapidly, and all spermatozoa were immotile after 24 h incubation. Co-culture of wallaby spermatozoa with OEC monolayers also induced acrosomal modifications that were followed by acrosomal loss. At 6 h incubation 38.92 +/- 3.98% of spermatozoa on ampullary OEC monolayers and 36.50 +/- 3.81% spermatozoa on isthmic OEC monolayers had shed their acrosome. Acrosomal loss during co-culture with both isthmic and ampullary OEC monolayers was significantly (P < 0.01) greater than that observed on tracheal epithelial monolayer (24.42 +/- 1.90%, P < 0.01), Matrigel (20.70 +/- 2.71%, P < 0.01) and plastic (15.54 +/- 2.49%, P < 0.01). Co-culturing spermatozoa with OEC monolayers also induced a transformation from streamlined orientation of sperm head and tail to T-shaped (thumbtack) orientation in a small number (10-15%) of motile spermatozoa after 6 h incubation (data not shown). The significance of these results in relation to the role of the oviduct in sperm capacitation is discussed.

Spinal instrumentation in the management of degenerative disorders of the lumbar spine.

The use of spinal instrumentation as an adjunct to fusion for the treatment of degenerative disorders of the lumbar spine is controversial. Instrumented lumbar fusions, in specific instances, may improve patient outcomes. For patients undergoing single level primary lumbar arthrodesis, the available data do not conclusively support the efficacy of spinal instrumentation. However, in the setting of previous failed lumbar surgery, iatrogenic or degenerative lumbar spondylolisthesis, spinal instrumentation may be useful as an adjunct to fusion. Possible advantages associated with the use of instrumentation include: correction of deformity in frontal and sagittal planes; decreased pseudarthrosis rates; prevention of progression of spondylolisthesis, and provision of spinal stability in the absence of intact posterior elements. Complications associated with the use of instrumentation include: increased cost; increased operative times; increased infection rate; increased reoperation rate; and a steep learning curve. Therefore, when instrumentation is to be used, the benefits must outweigh the risks. These risks can be minimized by the judicious use of instrumentation by experienced surgeons, for specific indications as supported by the literature.

Effect of sperm-agglutinating antibodies on sperm capacitation and acrosome reaction.

OBJECTIVE: To study the effect of polyclonal/monospecific antisera on sperm agglutination versus capacitation as well as acrosome reaction. MATERIALS AND METHODS: Swim-up spermatozoa from cauda epididymides of fertile male hamsters were incubated under liquid paraffin with polyclonal/monospecific antisera obtained from immunized BALB/C mice, as well as with normal serum from control BALB/C mice, at various dilutions. RESULTS: The anti-sperm antibodies caused a significant (P < .05) sperm agglutination of various types of dilutions below 1:1000. Both capacitation and true acrosome reaction were inhibited significantly in the spermatozoa incubated with polyclonal/monospecific antisera. Capacitation in the spermatozoa with normal serum started earlier, i.e., at 2 hours of incubation compared to 3 hours of incubation in controls. CONCLUSION: The data differentiate the sperm agglutinating activity from anticapacitation and antiacrosome reaction activity of antisperm antisera at 1:1000 dilution.

Potential health risks related to carcinogens in the atmospheric environment in India.

In India, rapid urbanization and industrialization have contributed positively toward meeting the materialistic needs of the citizens, but have also resulted in contamination of the atmospheric environment. This paper deals with the assessment of potential health risks posed by carcinogenic substances, namely cadmium, chromium, and nickel, present in certain atmospheric environments in India. Average air concentrations of these carcinogenic metals have been assessed for different states and regions of India (C. R. Krishnamurti and P. Vishwanathan, Toxic Metals in the Indian Environment, Tata/McGraw-Hill, New Delhi, 1991). Based on these assessments, both individual and societal risks have been estimated in different states of the country, and comparisons were made. Reported concentration, release sources, potential health risks including cancer risk estimates, and ambient air interim guidelines are discussed. The reported environmental releases and cancer risk from cadmium are minimal. There is a potential for increased respiratory cancer risk from exposure to chromium and nickel in some northern Indian states. These metals are irritants to nasal passages and the respiratory tract. Chromium is also corrosive to mucus membranes. They have the potential to cause chronic respiratory problems. Since it appears that these metals may cause some adverse health effects in humans, exposure to these ambient air pollutants should be minimized by managing the release of these contaminants to the environment. There is a need for the development and strict enforcement of national and state regulatory standards.

Potential public health risks related to mercury/amalgam discharge from dental offices.

Mercury is a toxic and bioaccumulative metal. It exists in elemental, inorganic and organic forms. The use of mercury by the dental profession represents approximately 6 percent of the total annual domestic consumption and is estimated to contribute significantly to the discharge of mercury (14 percent in one study) to waste-water streams. Publicly owned treatment works (POTW) must obtain and comply with a National Pollutant Discharge Elimination System waste-water discharge permit. When minimal mercury discharge limits into surface waters are exceeded, an upstream search for contributors of mercury to the waste stream may result. Given the present sociopolitical environment, mercury discharge from dental offices will increasingly receive scrutiny. Strategies to minimize discharge of mercury/amalgam waste include engineering controls such as changes in the discharge process, changes in the composition of commercial products, and changes in control equipment. Governmental strategies include an outright ban, the setting of discharge standards, and educational efforts. Study of these strategies with evaluation of effectiveness is needed.

Induction of buffalo (Bubalus bubalis ) sperm capacitation and acrosome reaction in the excised reproductive tract of hamsters.

A study was conducted on the induction of buffalo sperm capacitation and acrosome reaction in the excised reproductive tract of hamsters at the estrogen- and progesterone-dominated stages of estrus. The percentages of the maximum capacitation and acrosome reaction were significatly (P < 0.01) higher for spermatozoa incubated in the uterus with oviducts of estrogen dominated hamsters compared with those incubated in BWW medium in a test tube (64.6%, 60.2%; 16.2%, 14.7%). Buffalo spermatozoa incubated in the uterus and oviducts of progesterone-dominated hamsters showed significantly (P < 0.01) lower capacitation and acrosome reaction rates than those incubated in the uterus and oviducts of estrogen-dominated hamsters (34.8%, 34.3%: 64.6%, 60.2%). The percentage of capacitation and acrosome reaction in spermatozoa were significantly (P < 0.01) more when incubated in the uterus plus oviducts than without the oviduct irrespective of whether the reproduct tract of hamster was estrogen- or progesterone-dominated. The time for the onset of maximum capacitation and acrosome reaction was reduced from 12 to 10 h when the spermatozoa were incubated in the hamster reproductive tract rather than in BWW medium in test tubes. The significance of the results in relation to hormonal regulation of sperm capaciation and acrosome reaction are also discussed.

Need to revise the national drinking water regulation for copper.

Copper is an essential micronutrient and a potential toxic metal. The USEPA current maximum contaminant level goal (MCLG, a nonenforceable aspirational health goal) and the required treatment technique action level, both set at 1.3 mg/liter of copper are not adequately protective for infants and children under 10 years of age. Infants and children up to 10 years of age have increased susceptibility to copper toxicity. The two main reasons for the high sensitivity in this population subgroup are the presence of a normally high concentration of copper in the liver during early life and the lack of a fully developed homeostatic mechanism of copper in children under 10 years of age. This sensitive group of infants and children represents approximately 17% of the total U.S. population. The adverse health effects caused by drinking water contaminated with copper are abdominal pain, nausea, vomiting, diarrhea, headache, and dizziness. The proposed drinking water guideline of 0.3 mg/liter for copper was derived by the application of the risk assessment procedures approved by the USEPA. Drinking water containing 0.3 mg/liter of copper will provide approximately 26% of the nutritional requirement of copper. This proposed drinking water guideline (0.3 mg/liter) for copper will adequately protect health of infants, children, and adults.

Effect of luteinizing hormone and estradiol on in vitro maturation of follicular oocytes in goat (Capra hircus).

In vitro maturation of goat follicular oocytes in TALP medium supplemented with variable concentrations of luteinizing hormone (LH) [5-20 micrograms/ml] and estradiol [1 microgram/ml] was studied. Incubation of viable oocytes was carried out at 38.5 degrees C under liquid paraffin in 5% carbon dioxide/air mixture for 24 h. At 0 h all the oocytes were in germinal vesicle (GV) stage, each with a good cumulus. The cumulus expansion increased linearly with increasing concentrations of LH and a fixed concentration of estradiol [1 microgram/ml] at 24 h of incubation. Germinal vesicle breakdown (GVBD) was observed in 28% of the oocytes at 5 micrograms/ml concentration of LH and the same increased to 87% at 10 micrograms/ml of LH with 13% oocytes at metaphase II. At 20 micrograms/ml of LH, 45% of the oocytes were at metaphase II and the rest were at metaphase I. LH and estradiol seem to be important for acquisition of maturation competence in goat follicular oocytes.