Immunomodulation by biphalin,dimeric synthetic opioid peptide,and its analog

The opioid pentapeptides called enkephalins were originally described as the endogenous ligands for the opioid receptors. Although their precise physiological significance still remains elusive, the enkephalins have been reported to exhibit analgesic, antidepressant, antianxiety and anticonvulsant activities. In addition, enkephalins have also been shown to act as immunomodulator. The first generation of dimeric peptides was derived from enkephalins. Biphalin [(Tyr-D-Ala-Gly-Phe-NH)2] is a bivalent opioid analog containing two tyrosine residues. We have evaluated the immunomodulatory properties of biphalin and its analogs in various in vitro tests. We report that biphalin and one of its analogs [Tyr-D-Ala-Gly-Phe-NH.NH-Phe(p-Cl)-H] stimulate human T cell proliferation, natural killer (NK) cell cytotoxicity in vitro and interleukin-2 (IL-2) production. Biphalin and its analog also released chemokine like factor in the culture supernatant that was responsible for increased chemotaxis of monocytes. Furthermore, these peptides inhibited tumor necrosis factor (TNF-alpha) production in lipopolysaccharide (LPS) stimulated peripheral blood mononuclear cells (PBMC) and nitric oxide (NO) production in mouse macrophage cells, RAW 264.7. Our observations suggest immunomodulatory property of biphalin and its analog.     

Outbreak of Pichia anomala infection in the pediatric service of a tertiary-care center in Northern India

An outbreak of nosocomial fungemia due to the unusual yeast, Pichia anomala occurred in the pediatric wards of our hospital over a period of 23 months (April 1996 to February 1998). A total of 379 neonates and children (4.2% admissions) were infected. The probable index case was admitted to the pediatric emergency ward, with subsequent transmission to the premature nursery, pediatric intensive care units, and other children wards. Carriage on the hands of health care personnel was likely to be responsible for dissemination of the fungus. The outbreak could only be controlled after a health education campaign to improve hand-washing practices was instituted and after nystatin-fluconazole prophylaxis to all premature neonates and high-risk infants was introduced. In a case-control study, we identified a lower gestational age, a very low birth weight (<1,500 g), and a longer duration of hospital stay as significant risk factors associated with P. anomala fungemia in premature neonates. We conducted a culture prevalence survey of 50 consecutive premature neonates and found that 28% were colonized with P. anomala at a skin or mucosal site on the date of delivery and that 20% of these neonates subsequently developed P. anomala fungemia. We performed multilocus enzyme electrophoresis on 40 P. anomala outbreak isolates (including patient and health care workers' hand isolates), and the results suggested that these isolates were identical. Our study highlights the importance of P. anomala as an emerging nosocomial fungal pathogen.     

Aspiration vs nonaspiration technique of cytodiagnosis--a critical evaluation in 160 cases

The two sampling techniques were studied in 160 randomly selected cases of superficial swellings in various sites of the body. They were sampled by fine needle aspiration (FNA) and by non-aspiration (NA) (a needle without application of aspiration pressure). Cell samples were cytologically assessed and critically evaluated using five objective parameters. Contamination with blood was more in lymphnode, thyroid and liver lesions in aspiration smears than NA smears and values were statistically significant. Similarly when compared for the degree of cellular trauma and cellular degeneration statistically significant better results were obtained by nonaspiration technique for lymphnode lesions. Regarding amount of cellular material obtained by FNA, statistical significant better results were found for breast lesions only. Statistically significant better maintenance of architecture was observed only for thyroid lesions by NA technique. Better average scores were observed by NA technique for lymphnode and thyroid only. Categorizing all the smears obtained by FNA & NA on the basis of their scores according to predetermined criteria, greater number of diagnostically adequate specimens were obtained by FNA than by NA but the number of diagnostically superior specimens obtained by NA technique was found to be more than that by FNA. The difference was found to be statistically significant. However the number of inadequate smears was also more by NA technique than by FNA technique.     

Antilymphoproliferative activity of ethanolic extract of Boerhaavia diffusa roots

Extracts of plants have been widely evaluated for possible antiproliferative and anticarcinogenic properties. The antiproliferative activity of ethanolic extract of Boerhaavia diffusa, a plant used in traditional medicine, was evaluated in several cells. It inhibited T cell mitogen phytohemagglutinin and concanavalin A-stimulated proliferation of human peripheral blood mononuclear cells (PBMC). It also inhibited purified protein derivative antigen-stimulated PBMC proliferation and human mixed lymphocyte culture. In addition, B. diffusa extract inhibited the growth of several cell lines of mouse and human origin, such as mouse macrophage cells (RAW 264.7), human macrophage cells (U937), human monocytic cells (THP-1), mouse fibroblast cells (L929), human embryonic kidney cells (HEK293), mouse liver cells (BNLCL.2), African green monkey kidney cells (COS-1), mouse lymphoma cells (EL-4), human erythroleukemic cells (K562), and human T cells (Jurkat). The present study has demonstrated the antiproliferative potential of ethanolic extract of B. diffusa in vitro.     

Studies on pathogenesis of fowl pox: virological study

One-month-old WLH chickens were inoculated with a field isolate of fowl pox virus (FPV) by intradermal (i.d.) and intratracheal (i.t.) routes. In intradermally infected chickens, the virus in titrable amounts was first detected in the skin at the inoculation site on day 2 and in lungs on day 4 followed by viraemia on the day 5 post-infection (p.i.). Subsequently the virus was recovered from liver, spleen, kidney and brain, but not from the heart. The chickens infected by i.t. route showed an almost similar outcome with minor differences as the virus was first demonstrated in the lungs on day 2 p.i., viraemia occurred on day 4 p.i. Initiation of pocks at the inoculation site in i.d. infected birds was observed on days 3 to 4 p.i., generalized cutaneous pock lesions appeared from 7 to 8 days p.i.     

Loss of heterozygosity in normal breast epithelial tissue and benign breast lesions in BRCA1/2 carriers with breast cancer

Loss of heterozygosity (LOH) of the wild-type BRCA1/2 allele is a reproducible event in breast tumors of BRCA1/2 mutation carriers, but it is unknown if this allelic loss occurs only in association with recognizable histopathologic abnormalities. We evaluated the early genomic changes that occur in the mammary glands of patients with increased predisposition to breast cancer due to germline mutations in the BRCA1/2 genes. We tested the hypothesis that these genomic changes may be detected, not only in histologically abnormal and malignant breast tissues, but also in morphologically normal tissues and in areas with pathologically benign changes. Samples were obtained from five breast cancer patients: four BRCA1 carriers and one BRCA2 carrier. In each case, nontumor tissue areas surrounding the tumor or from other locations of the breast were isolated using laser capture microdissection. We evaluated 29 areas showing normal terminal ductal lobular units (TDLUs) or histopathologically benign changes (in particular, sclerosing adenosis), using a panel of polymorphic dinucleotide microsatellite markers for the BRCA1 gene and other chromosome 17 loci, for the BRCA2 gene and other chromosome 13 loci, and for the FHIT gene on 3p14.2. Overall, we analyzed a total of 105 samples of nontumor tissues; LOH was detected in 59 of the 105 (56%). In the normal TDLUs, 15 of 30 samples (50%) showed LOH; in the tissues with benign proliferative changes, such as sclerosing adenosis, 44 of 75 samples showed LOH (59%). Our results suggest that there is a field effect of early genetic events preceding morphologic changes in the mammary glands of BRCA mutation carriers.     

A Vero cell-attenuated Goatpox virus provides protection against virulent virus challenge

An Indian isolate of Goatpox virus (GTPV) was adapted and propagated in Vero cells for development of an attenuated virus. The virus was initially passaged in primary lamb testes cells and subsequently in Vero cells. At the 55th passage, the virus showed evidence of attenuation when tested for safety in seronegative goats. At this stage, the virus was found to be completely non-pathogenic. The virus was passaged further and the 60th passage was used for testing its immunogenicity in goats. The latter were inoculated with 10, 100 and 1000 TCID50 of the attenuated virus by intradermal (i.d.) route and challenged after 28 days with virulent GTPV. The attenuated virus produced no adverse reaction even at the highest dose and conferred complete protection even at the lowest dose against challenge with a high dose (2 x 10(6) of 50% skin-reactive dose SRD50) of virulent virus. Increased levels of virus-specific serum antibodies could be demonstrated by both indirect enzyme-linked immunosorbent assay (ELISA) and virus neutralization (VN) test in all the immunized goats. No horizontal transmission of the virus from the immunized to in-contact animals took place. Our results suggest that this attenuated virus could be a safe, immunogenic and potent candidate for developing a vaccine against goatpox.     

Glial cell and fibroblast cytotoxicity study on 4026-cyclotene photosensitive benzocyclobutene (BCB) polymer films

Photosensitive benzocyclobutene (photo-BCB) is a class of polymers with the trade name Cyclotene. The photoimagable property of Cyclotene makes it suitable for the manufacture of microelectronic devices. The motivation behind this study is that we see an exciting application of photo-BCB as substrates in implantable microelectronic biomedical devices due to several desirable properties distinctive from other polymer materials. To our knowledge, however, photo-BCB has never been tested for biomedical implant applications, as evidenced by the lack reported data on its biocompatibility. This study takes the first step towards assessing photo-BCB biocompatibility by evaluating the cytotoxicity and cell adhesion behavior of Cyclotene 4026 coatings exposed to monolayers of glial and fibroblast cells in vitro. It can be concluded from these studies that photo-BCB films deposited on silicon wafers using microfabrication processes did not adversely affect 3T3 fibroblast and T98-G glial cell function in vitro. We also successfully rendered photo-BCB films non-adhesive (no significant fibroblast or glial cell adhesion) with surface immobilized dextran using methods developed for other biomaterials and applications. Future work will further develop prototype photo-BCB microelectrode devices for chronic neural implant applications.     

Alteration in plasma glucose levels in Japanese encephalitis patients

A unique factor, human T cell hypoglycaemic factor (hTCHF), has been shown to produce hypoglycaemia during the convalescent stage in the plasma of patients with Japanese encephalitis virus (JEV) infection. The present study was undertaken to investigate the ability of T cells from fresh peripheral blood mononuclear cells (PBMC) of such patients to produce hTCHF. The PBMC, as well as the individual subpopulations, were cultured for 24 h and the culture supernatants (CS) were assayed for hypoglycaemic activity. The activity was observed in the CD8+ T cells. The hypoglycaemia in JE-confirmed patients coincided with the gradual rise in circulating glucagon level, with no significant alterations in insulin, growth hormone and cortisol levels. The hTCHF was purified by ion exchange chromatography and the purified protein was observed as a approximately 25 kDa band on SDS-PAGE. Secretory hTCHF in the sera of patients and T cell CS was present in 88% of convalescent serum samples. We conclude that during the convalescent stage of JEV infection, a unique factor, hTCHF, is secreted by activated CD8+ T cells from patients and that this is responsible for the development of hypoglycaemia.