High fat diet affects reproductive functions in female diet-induced obese and dietary resistant rats.

The incidence of ovulatory disorders is common in obese animal models. The mechanism behind this effect is unclear. We hypothesised that a high-fat (HF) diet induces alterations in neuroendocrine mechanisms resulting in anovulation in diet-induced obese (DIO) animals. Adult female DIO and diet-resistant (DR) rats were fed either chow or a HF diet (45% calories from fat) for 6 weeks. Oestrous cyclicity and body weight were monitored regularly. At the end of treatment, rats were implanted with a jugular catheter to monitor luteinising hormone (LH) levels on the day of pro-oestrous. Rats were sacrificed on the next pro-oestrous, and their brains and ovaries were collected. Plasma from trunk blood was analysed for oestradiol and leptin concentrations. Ovaries were fixed and sectioned for histological analysis. Brains were removed, frozen and sectioned, and norepinephrine (NE) concentrations in discrete hypothalamic areas were measured using high-performance liquid chromatography with electrochemical detection. A HF diet exposure affected oestrous cyclicity in both DIO and DR rats, with the effect being more pronounced in DIO animals. HF diet exposure increased leptin levels in both DIO and DR rats. Oestradiol levels were low in the DIO-HF group. NE levels in the hypothalamus were unaffected by HF diet or genotype. A normal LH surge was observed in DR-Chow rats and LH levels were low in the remaining groups. These results lead to the conclusion that DIO rats have an inherently reduced reproductive capacity and exposure to a HF diet decreases it further. A reduction in oestradiol and LH surge levels could contribute to this effect; however, the underlying mechanisms need to be investigated further.

Reproductive and developmental toxicities of zinc supplemented rats.

Reproductive and developmental toxicities of zinc supplementation in F(0) rats and F(1) progeny were examined. Rats were treated by gavaging with zinc chloride (ZnCl(2)) at 0.0, 7.5, 15 and 30 mg/kg-d. ZnCl(2) treatment was associated with deficient energy imbalances, reduced number of live pups/litter, decreased live birth index, increased mortality and increased fetal resorption. Changes in serum clinical chemistry and hematologic parameters were sex-related. In F(0) females, ZnCl(2) was associated with increased liver/body weight ratios, reduced creatinine and reduced alkaline phosphatase concentrations. In F(0) males, ZnCl(2) significantly increased relative liver weight and elevated γ-GGT. In addition, at birth, F(1) males exhibited, a significant (p<0.05) increase in anogenital distance, whereas ZnCl(2) hastened the time of eye opening and incisor eruption in males and females. These results indicate that excess ZnCl(2) supplementation before and during pregnancy and during lactation could pose some health risk concerns to pregnant mothers and their offspring.

Immunohistochemical detection of CD34, E-cadherin, claudin-1, glucose transporter 1, laminin, and protein gene product 9.5 in 28 canine and 8 feline meningiomas.

The variation in histologic pattern of meningiomas can make their diagnosis challenging. The immunohistochemical profile of 28 canine and 8 feline meningiomas was examined. Tumor types included anaplastic (6 dogs), angiomatoid (1 cat), fibroblastic (3 dogs, 1 cat), meningothelial (1 dog), microcystic (2 dogs), myxoid (3 dogs), psammomatous (4 cats), and transitional (13 dogs, 2 cats). The authors compared the expression of novel markers (CD34, E-cadherin, claudin-1, glucose transporter 1 [GLUT-1], laminin, and protein gene product [PGP] 9.5) with published markers (cytokeratins, glial fibrillary acidic protein [GFAP], progesterone receptor, S100, and vimentin). Neoplastic cells were immunohistochemically positive for vimentin in 100% of the meningiomas; CD34, 94%; GLUT-1, 86%; E-cadherin, 81%; S100, 75%; laminin, 72%; claudin-1, 60%; PGP 9.5, 55%; progesterone receptor, 44%; pancytokeratins, 39%; cytokeratins 8/18, 17%, and GFAP in 9%. Ki67 index did not correlate well with mitotic index. Based on these results and those in the human literature, immunohistochemistry for vimentin, CD34, and E-cadherin is proposed to support a diagnosis of meningioma. Immunohistochemistry for claudin-1, albeit of only moderate to low sensitivity in canine and feline meningiomas, may help to distinguish meningioma from some mesenchymal neoplasms involving the brain and associated structures, such as schwannomas, which in humans express claudin-1 poorly or not at all. Further studies with CD34, E-cadherin, and claudin-1 in canine and feline tumors that may mimic meningiomas are needed to determine the adequacy of this approach.

Cholesterol content of menstrual discharge. Influence of contraceptives.

PIP: An investigation was undertaken to study the cholesterol content of menstrual discharge and to establish its relationship to the cyclic acti vities of the endometrium. The effects that an oral contraceptive and IUD might have on cholesterol concentration in menstrual discharge and blood serum were also investigated. A total of 38 subjects were used. 9 were taking the oral contraceptive, Ortho-Novum; 4 were fitted with an IUD; and the remaining 25 were used as controls. Blood and menstrual discharges were collected and tested. Blood serum levels for all groups were constant during the menstrual cycle. It was found that the concentrations of cholesterol in the menstrual discharge samples of each group were significantly lower than the corresponding values in blood serum. The cholesterol levels in the menstrual discharge of the control and IUD groups were in the same narrow range and did not vary with the day of the cycle. The values for the oral contraceptives users also did not vary significantly with the day of the cycle, but they were signific antly lower than for levels obtained for the other 2 groups. The total excretion rate of cholesterol was highest for the IUD group, while the oral contraceptive users showed a significantly lowered rate of excretion than either the control or IUD group. The high excretion pattern shown by the IUD group is a reflection of these women's heavier flow.^ieng