Monoclonal Antibodies to Trypanosoma cruzi Inhibit Motility and Nucleic Acid Synthesis of Culture Forms

Monoclonal antibodies were raised against the surface of epimastigotes and metacylic trypomastigotes of Trypanosoma cruzi, as shown by electron microscopy, agglutination, and immunofluorescence. The antibodies were stage specific but not strain specific. A deleterious effect of the antibodies on T. cruzi culture forms was shown by the drastic reduction of parasite motility and incorporation of nucleic acid precursors. Some fraction of the parasite population, however, was viable and replicated and infected mouse macrophages in culture. The antibodies were found to also mediate complement-induced lysis of culture forms of T. cruzi.     

No germline TP53 mutations detected in familial and bilateral testicular cancer

Mutations in the TP53 gene are considered to be among the most common genetic alterations in human cancers. Both somatic and germline mutations have been found. Using potymerase chain reaction (PCR), constant denaturant gel electrophoresis (CDGE), and denaturing gradient gel electrophoresis (DGGE), we have examined 32 patients with bilateral and familial germ cell tumors (GCT) and two patients with sporadic GCT for germline mutations within the conserved regions of the gene. In addition, 15 tumors were screened for somatic mutations and analyzed for loss of heterozygocity (LOH) at the TP53 locus. Twelve tumors were analyzed for expression of TP53 via immunohistochemistry. Neither germline nor somatic TP53 mutations were deteeted. LOH was observed in one of five informative cases. No tumors showed increased expression of TP53 protein. These results indicate that alterations in the TP53 gene are not important for the predisposition to and development of GCT. © 1993 Wiley-Liss, Inc.     

Agouti-related peptide-expressing neurons are mandatory for feeding

Multiple hormones controlling energy homeostasis regulate the expression of neuropeptide Y (NPY) and agouti-related peptide (AgRP) in the arcuate nucleus of the hypothalamus. Nevertheless, inactivation of the genes encoding NPY and/or AgRP has no impact on food intake in mice. Here we demonstrate that induced selective ablation of AgRP-expressing neurons in adult mice results in acute reduction of feeding, demonstrating direct evidence for a critical role of these neurons in the regulation of energy homeostasis.     

Parenting stress and parental bonding

Attachment experiences are thought to be important because of their implications for later development. The authors' aim with the questionnaire-based study was to investigate the differences between recalled parental bonding regarding 4 types of maternal and paternal bonding with respect to experienced parenting stress caused by child characteristics, parent attributes, and life events under the consideration of the child's gender and age. The authors gathered parental bonding behavior data with the German version of the Parental Bonding Instrument (PBI). The authors assessed parenting stress with their German version of the "Parenting Stress Index (PSI)." They found significant differences among 120 mothers grouped in the 4 maternal and the 4 paternal bonding types regarding parenting stress caused by child, maternal bonding: F(5, 113) = 4.13, p = .002, paternal bonding: F(5, 111) = 8.50, p < or = .0001, and parent characteristics, maternal bonding: F(5, 113) = 3.33, p = .008, paternal bonding: F(5, 111) = 7.80, p < or = .0001. The lowest level of parenting stress was experienced by mothers who themselves recalled the "optimal parental bonding type" with respect to the child and parental domain. The authors did not find any significant differences between the 4 maternal, F(5, 113) = 1.25, p = .29, and the 4 paternal, F(5, 111) = 1.87, p = .106, bonding types with respect to the life stress. According to the authors' findings, the representation of attachment relationships seems to have a special impact on the adult's capacity to cope with challenges and stress, either directly or indirectly as an internal working model of attachment. For the clinical practice, these findings seem to recommend the combination of both the PSI and PBI regarding the diagnostic of stressful mother-child system to plan an optimal intervention program.     

Review of Technology: Planning for the Development of Telesonography

Teleradiology allows contemporaneous interpretation of imaging exams performed at some distance from the interpreting radiologist. The transmitted images are usually static. However, there is benefit to real-time review of full-motion ultrasound (US) exams as they are performed. Telesonography is transmission of full-motion sonographic data to a remote site. We hypothesize that US exams, read after having been compressed utilizing Motion Picture Experts Group version 4 (MPEG-4) compression scheme, transmitted over the Internet as streaming multimedia, decompressed, and displayed, are equivalent in diagnostic accuracy to reading the examinations locally. MPEG-4 uses variable compression on each image frame to achieve a constant output bit rate. With less compression, the bit rate rises, and the only way the encoder can contain bit rate within the set bandwidth is by lowering frame rate or reducing image quality. We review the relevant technologies and industry standard components that will enable low-cost telesonography.     

Cloning and genomic characterization of Felis domesticus papillomavirus type 1

A novel papillomavirus was cloned from hyperkeratotic cutaneous lesions of a Persian domestic cat. The Felis domesticus papillomavirus (FdPV-1) genome counts 8300 bp and has a typical genome structure with an early region (E1, E2, E4, E6, E7), a late region (L1, L2), and a noncoding upstream regulatory region (URR or NCR1) between the end of L1 and the beginning of E6. The FdPV-1 also shows an unusual second noncoding region (NCR2) of 1.3 kb, situated between the end of E2 and the beginning of L2. This NCR2 is uniquely related to a similar region in the canine oral papillomavirus (COPV). Phylogenetic analysis places FdPV-1 together with COPV, the cottontail rabbit papillomavirus, human papillomavirus type 1 (HPV-1), and HPV-63 in the group of the benign cutaneous papillomaviruses. The position of FdPV-1 in the phylogenetic tree allows us to hypothesize that already in an early phase of the papillomavirus molecular evolution, a split occurred into viruses with a dual tropism primarily for cutaneous epithelia but also secondarily for mucosal surfaces, and viruses with a specific monotropism for mucosal surfaces. The close relationship between FdPV-1 and COPV, and between their Canidae and Felidae hosts, supports the hypothesis that papillomaviruses have speciated and coevolved together with their hosts throughout vertebrate evolution. A papillomavirus mutation rate of 0.73 to 0.96 x 10(-8) nucleotide substitutions per base per year was calculated.     

Fine-needle aspiration of pancreatic extramedullary plasmacytoma: Possible confusion with islet cell tumor

We report two cases of extramedullary plasmacytoma (EMP) of the pancreas, diagnosed by fine-needle aspiration (FNA). Plasmacytoma of the pancreas is a rare neoplasm with only 12 cases recorded in the literature. Because of its scarcity and the cytomorphologic similarity between plasma cells and endocrine cells, EMP of the pancreas may be confused with neuroendocrine (islet cell) tumors of the pancreas. Immunohistochemical staining for light chain and/or neuroendocrine markers will prevent diagnostic error when interpreting plasmacytoid neoplasms of any site susceptible to endocrine tumors, including the pancreas. © 1994 Wiley-Liss, Inc.     

Human herpesvirus 8 infection among various population groups in southern Israel

OBJECTIVE: To compare the prevalence of antibodies to human herpesvirus 8 (HHV-8) or Kaposi sarcoma-associated herpesvirus among Israeli and Ethiopian subjects. METHODS: Serum samples were obtained from 98 Israeli Jewish students aged 18-30 years, 100 HIV-1-seronegative Ethiopian immigrants to Israel of the same age, and 100 HIV-1-seronegative Ethiopian children 1-12 years old upon their arrival in southern Israel. Plasma samples were obtained from 3 hospitalized patients with multicentric Castleman disease (MCD) as positive controls. All serum samples were tested for antibodies to both latent and lytic antigens. Antibodies to the lytic antigens and the latency-associated nuclear antigen (LANA) of HHV-8 were detected by enzyme linked immunosorbent assay and by immunofluorescence assay. HHV-8 DNA from serum or plasma samples was detected by polymerase chain reaction analysis. RESULTS: Antibodies to HHV-8 LANA were detected in 2.9% of the Israeli subjects aged 18-30 years and in 26% of the Ethiopian subjects from both age groups tested. Antibodies to the lytic antigens were detected in all 3 MCD patients, in 4% of the Ethiopian children, and in 2% of the 18- to 30-year-old Ethiopians. No antibodies to the lytic antigens were detected in the Israeli students. HHV-8 DNA was detected in all 3 MCD patients and in 2 of 4 of the Ethiopian children positive for the lytic antigens. CONCLUSIONS: HHV-8 is highly prevalent in Ethiopian immigrants to Israel as compared with Israeli students. Antibodies to HHV-8 in Ethiopia are acquired before puberty. The results of this study indicate the association of HHV-8 with MCD, as has been documented by many other researchers.