Longitudinal brain MRI study in a mouse model of Rett Syndrome and the effects of choline.

Rett Syndrome (RTT), the second most common cause of mental retardation in girls, is associated with mutations of an X-linked gene encoding the transcriptional repressor protein MeCP2. Mecp2(1lox) mutant mice express no functional MeCP2 protein and exhibit behavioral abnormalities similar to those seen in RTT patients. Here we monitor the development of both whole brain and regional volumes between 21 and 42 days of age in this model of RTT using MRI. We see decreases in whole brain volumes in both male and female mutant mice. Cerebellar and ventricular volumes are also decreased in RTT males. Previous work has suggested that perinatal choline supplementation alleviates some of the behavioral deficits in both male and female Mecp2(1lox) mutant mice. Here we show that perinatal choline supplementation also positively affects whole brain volume in heterozygous females, and cerebellar volume in male RTT mice.

Anatomical and ontogenetic factors producing variation in HVc neuron number in zebra finches.

The volume of nucleus HVc of the avian song system varies greatly both among and within songbird species, and is positively correlated to song complexity in many species. Moreover, the number of neurons in HVc predicts the ability of individual zebra finches to imitate song accurately. To better understand this brain/behavior relationship, we used the retrograde tracer Fast Blue to assess how specific HVc neuronal subpopulations contribute to variation in overall HVc neuron number in adult male zebra finches. We also investigated whether sibling order predicts the number of HVc neurons and/or yolk levels of testosterone, a hormone that might regulate the development of HVc. We report that total HVc neuron number is consistently and independently predicted by the size of each of its two projection populations, suggesting that the proportional makeup of HVc is tightly regulated at least in male zebra finches. Also, while we failed to detect a significant effect of sibling order on either the number of neurons in HVc or yolk testosterone concentration, we found that clutch of origin made a large contribution to variation in both early hormone levels and HVc neuron number.

Individual variation in neuron number predicts differences in the propensity for avian vocal imitation.

Avian song learning involves memorizing and reproducing song material produced by conspecifics. In several species song repertoire size correlates with the overall volume of two song-related brain regions, the HVc (acronym used as the proper name) and the robust nucleus of the archistriatum (RA). We raised male zebra finches with two adult tutors and found that individual differences in HVc volume and neuron number correlated positively with differences in the number of tutor syllables accurately copied. These results were replicated in a second study. The relationship between RA volume and song learning was similar, but less robust. Importantly, total repertoire size (number of song syllables) did not correlate significantly with anatomical measures of either the HVc or RA. Because previous work suggests that the volume and neuron number of these regions are not regulated by song learning, it is possible that naturally occurring variation in neuron number constrains how much song material can be copied or reproduced.

Preoperative discrimination between ovarian carcinoma, non-ovarian gynecological malignancy and benign adnexal masses using serum levels of CA125 and the polymorphic epithelial mucin antigens CASA, OSA and MSA.

Serum levels of the tumor associated antigens CA125, CASA, OSA and MSA were determined preoperatively in a non-consecutive series of patients with: invasive epithelial ovarian cancer (OC, n = 87), ovarian tumors of low malignant potential (LMP, n = 9), benign adnexal masses (BAM, n = 48) and other peritoneal and pelvic malignancies (n = 48). In addition, serum levels of CASA, OSA, and MSA were determined in 3477 asymptomatic well women. Ninety-eight percent of the asymptomatic women had CASA levels < 6.0 U ml-1, OSA levels < 5.5 U ml-1 and MSA levels < 80.0 U ml-1. Serum CA125 levels were> 35 U ml-1 in 89% of OC, in 44% of LMP, and in 23% of BAM. Serum CASA levels were> 6.0 U ml-1 in 58% of OC, in 0% of LMP, and in 0% of BAM. Serum OSA levels were> 5.5 U ml-1 in 61% of OC in 0% of LMP and in 4% of BAM. Serum MSA levels were> 80.0 U ml-1 in 56% of OC, in 11% of LMP, and in 10% of BAM. When cut-off levels were set to exclude all patients with BAM, the best discrimination from OC using a single assay was achieved using CASA (58%). However, a combination of CASA and CA125 gave positive levels in 69% of OC at levels which precluded BAM. All markers were also elevated in some colon cancers, cervical cancers, uterine cancers and other peritoneal malignancies. A combination of CA125 and CASA levels, obtained preoperatively may assist the general gynecologist in avoiding potentially difficult oncologic surgery.

Arsanilic acid toxicity in rabbits.

Rations from several rabbitries experiencing increased mortality, weight loss and diminished reproduction were analyzed for arsanilic acid. Levels of less than 56 ppm of arsanilic acid were found. A 30 day trial was conducted where arsanilic acid was given in doses of 1.6-16.2 mg/day in water to weanling and adult rabbits. The higher doses induced diarrhea, terminal convulsions and death. Weight loss or reduced weight gains occurred in six of seven treated groups. No significant gross or microscopic lesions were observed. Chemical analysis demonstrated the presence of increased total hepatic arsenic levels in treated compared to control rabbits.

Transmission of enteritis in the Syrian hamster.

Twenty-six of 39 Syrian hamsters obtained by this laboratory from a pet supplier had enteritis and showed signs of "wet tail." An enteritis was reproduced in healthy hamsters by oral inoculation of homogenized ilea and jejuna from the diseased hamsters. The most characteristic pathologicfeatures were a variably enlarged distal jejunum and ileum and granulomatous lesions in the ileal subserosal wall. Histologic findings included a greatly hyperplastic jejunal and ileal mucosa that frequently contained submucosal accumulations of inflammatory cells. Often mucosal glands extended into these areas. The gross and histologic lesions produced were identical to those described in proliferative ileitis. Bacterial cultures from infected tissues consistently grew a slow lactose-fermenting Escherichia coli. Although diarrhea could be produced by oral inoculation of the organism, the typical morphologic lesions were not produced.

Visceral lesions in racoons naturally infected with Heterobilharzia americana.

Three free-ranging raccoons caught in southeastern Florida were found to be infected by Heterobilharzia americana. The livers were firm with rough surfaces and stellate patterns of periportal fibrosis. The portal tracts had excessive mature fibrous connective tissue and occasional ovum and necrotic fluke granulomas. There were also ovum granulomas with concomitant lesions in small and large intestine, pancreas, and lung. Numerous other parasites were seen.