Potential Microbial Consortium for Plant Growth Promotion of Sunflower (Helianthus annuus L.)

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Bioinoculants are formulations of beneficial microorganisms used to promote plant growth. Their mode of...     

Role of prostaglandin E in the biphasic fever response to endotoxin

Biphasic fevers were induced in sheep with intravascular infusions or injections of 4-10 μg (80-200 ng/kg) of endotoxin, whereas monophasic fevers were obtained with doses of 1-2/μg (20-40 ng/kg). A marked increase in arterial blood pressure invariably accompanied the onset of fever; the latency of responses to the higher and lower doses of endotoxins averaged 26 min and 42 min, respectively. Prostaglandin (PG) assays of plasma from the carotid artery and jugular vein during fever episodes revealed a surge of PGE and PGF coincident with the pressor response and the first phase of fever, but PG were not detected in plasma samples taken throughout the second phase of fever. PG measurements of arterial and venous plasma collected at a distal site (hind limb) showed a similar surge of PGE and PGF in association with the early fever response, indicating that intravascular PG synthesis and release represents a generalized systemic response to circulating endotoxin. Carotid arterial infusions of PGE(2) produced immediate monophasic fevers and pressor responses, whereas PGD(2) infusions produced an immediate pressor effect but no fever. Infusions of PGF(2α) or prostacyclin, however, evoked neither fever nor pressor effects. Intracarotid infusions of leukocyte pyrogen (LP) caused monophasic fevers with latent periods of 15-20 min but pressor responses were not seen and neither PGE nor PGF were detected in plasma samples from the carotid artery or jugular vein before or during fever. Indomethacin, a potent inhibitor of arachidonic acid metabolism, blocked fever responses to endotoxin and to LP. These findings implicate PGE as the mediator of the early phase of endotoxin fever and imply a role for another pyrogenic metabolite ofarachidonic acid in the mediation of the second phase of fever, i.e., the phase associated with circulating LP. It is possible that both pyrogenic metabolites are generated within the vascular compartment, reaching thermoregulatory centers of the brain by transfer across the blood-brain interface.     

CAUSTIC SODA BURNS TO THE EXTREMITIES: DIFFICULTIES IN MANAGEMENT

SUMMARY Alkali burns to the extremities are unusual, but they are also a cause of significant morbidity, often because of their late presentation. Their management centres around water lavage, burn debridement and split-skin grafting; there is controversy over the timing of surgery. Three unusual cases of caustic soda burn in adults, and the difficulties encountered in their management, are described, and the literature is reviewed.     

Surgical Approach for Polycystic Ovarian Syndrome in Management of Infertility

Background

In patients with Polycystic Ovarian Syndrome (PCOS), resolution of infertility is an important goal of treatment. Wedge resection of the ovaries described as a means to achieve this was practiced in the middle of twentieth century. With the advent of endoscopic surgery, surgical approach for the same condition has been modified. Multi point biopsy, multiple needle puncture, electofulguration and laser fulguration are being tried in the context of PCOS. This project was taken up to evaluate the scope of electo fulguration in clomiphene resistant PCOS.

Methods

Forty patients who did not show sonographic evidence of ovulation with clomiphene citrate (CC) 100mg OD for 05 days in two cycles were subjected to laparoscopy. The patients who did not show any pelvic factor for infertility were alternately assigned to electro - fulguration treatment of ovaries or no fulguration during laparoscopy. These were designated as ‘Lap EC’ & ‘Only CC’ group respectively. For ‘Only CC’ group’ stimulation with CC was continued for four cycles with a higher dose 150 mg OD for 05 days. Lap EC group were subjected to CC 100mg OD for 5 days for two cycles in case of non achievement of ovulation in the first two drug free cycles following EC. Folliculometry, HCG administration and Intra Uterine Insemination (IUI) was performed for both groups.

Results

Total percentage of ovulatory cycles were 51.8% in EC group compared to 5.26% in the CC group. Overall pregnancy rate of 30% was achieved in the Lap EC group as compared to only 10% in the CC group (p<0.05).

Conclusion

Laparoscopic electrofulguration of ovaries increases the chances of ovulation and conception. This being a cheaper one time procedure as compared to other expensive ovulation inducing agents, should be the preferred mode and the primary procedure wherever polycystic ovaries are encountered while evaluating a case of infertility by laparoscopy.Key Words: Infertility, PCOS, Electrofulguration     

Comparative study of patients with chronic hepatitis C virus infection due to genotypes 1 and 3 referred for treatment in southeast Brazil

Background

The progression of liver disease in patients with chronic hepatitis C virus (HCV) infection is influenced by host and viral factors. Distinct clinical outcomes in patients infected with different HCV genotypes have been described in the literatute. However, the association between specific HCV genotype and clinical outcome remains unclear. We set out to study the natural history of HCV genotype 1 and 3 infections in Campinas, São Paulo state, Brazil, focusing on epidemiological, clinical, biochemical, and histological characteristics.

Methods

Patients with HCV infection referred for treatment between January 2003 and December 2006 were included in this study. We collected epidemiological, clinical, and laboratorial data using standard forms.

Results

A total of 283 patients were included; genotype 1 was idenfied in 163 (57.6%) patients, genotype 3 in 112 (39.6%), genotype 2 in 7 (2.5%), and genotype 4 in 1 (0.35%). Patients with genotype 2 and 4 were excluded from analysis. Multivariate analysis showed that intravenous energetic drug, positive cryoglobulin, and cirrhosis were independently and significantly associated with HCV genotype 3 (p < 0.05).

Conclusion

Genotype 3 currently seems to be associated with intravenous energetic drug, high frequency of cryoglobulinemia, and advanced liver disease in our region. Understanding the distribution of the different HCV genotypes can elucidate transmission of HCV and support optimal prevention strategies.

     

Risks for methicillin‐resistant Staphylococcus aureus colonization or infection among patients with HIV infection*

Background

Risks for methicillin‐resistant Staphylococcus aureus (MRSA) among those with HIV infection have been found to vary, and the epidemiology of USA‐300 community‐acquired (CA) MRSA has not been adequately described.

Methods

We conducted a retrospective review of HIV‐infected out‐patients from January 2002 to December 2007 and employed multivariate logistic regression (MLR) to identify risks for MRSA colonization or infection. Pulsed‐field gel electrophoresis (PFGE) was used to identify USA‐300 strains. Results Seventy‐two (8%) of 900 HIV‐infected patients were colonized or infected with MRSA. MLR identified antibiotic exposure within the past year [odds ratio (OR) 3.4; 95% confidence interval (CI) 1.5–7.7] and nadir CD4 count <200 cells/μL (OR 2.5; 95% CI 1.2–5.3) as risks for MRSA colonization or infection. Receipt of antiretroviral therapy (ART) within the past year was associated with decreased risk (OR 0.16; 95% CI 0.07–0.4). Eighty‐nine percent of available strains were USA‐300. MLR identified skin or soft tissue infection (SSTI) as the only predictor for infection with USA‐300 (OR 5.9; 95% CI 1.4–24.3). Conclusion Significant risks for MRSA among HIV‐infected patients were CD4 count nadir <200 cells/μL and antibiotic exposure. Only the presence of an SSTI was associated with having USA‐300, and thus the use of patient characteristics to predict those with USA‐300 was limited. In addition, ART within the previous year significantly reduced the risk of MRSA colonization or infection.

     

Delineation of an immunodominant and human T-cell lymphotropic virus (HTLV)-specific epitope within the HTLV-I transmembrane glycoprotein

Antibody reactivity to the transmembrane region of human T-cell lymphotropic virus type I (HTLV-I) envelope, gp21, is observed in virtually all individuals infected with HTLV-I or HTLV-II. Recombinant proteins encoding selected portions of gp21 are described and used to define two immunogenic regions. The first epitope (designated GD21-I) contains amino acids 361 to 404 of the HTLV-I envelope and reacted with all of 54 sera from HTLV-I- and HTLV-II-infected individuals. The second epitope (designated BA21) expresses amino acids 397 to 430 of the HTLV-I envelope and was recognized by 33 of 54 HTLV antisera. To determine the specificity of GD21-I and BA21, sera from 17 HTLV- negative individuals with nonspecific reactivity to p21E were tested. None of these sera reacted with GD21-I, but 16 of 17 sera reacted with BA21. With virtually complete reactivity to sera from HTLV-infected individuals and no reactivity to sera from p21E-reactive uninfected individuals, GD21-I will be useful in immunoassays for the detection of HTLV infection.     

Refined mapping of genomic rearrangements involving the short arm of chromosome 9 in acute lymphoblastic leukemias and other hematologic malignancies

Deletions of chromosomal band 9p21 have been detected in various tumor types as well as in more than 20% of acute lymphoblastic leukemia (ALL). These deletions frequently include the entire interferon (IFN) gene cluster as well as the methylthioadenosine phosphorylase (MTAP) gene. Recently, the CDKN2 gene (p16INK4A, MTS I, CDK41) was proposed as a candidate tumor-suppressor gene on 9p21 because it is frequently deleted in cell lines derived from multiple tumor types. To determine if CDKN2 or another closely related gene on 9p is the target of 9p deletions in ALL and other hematologic malignancies, we analyzed 20 primary patient samples (13 ALL, 2 acute myeloid leukemias [AML], and 5 non-Hodgkin's lymphomas [NHL]) with 9p rearrangements using Southern blot analysis, fluorescence in situ hybridization (FISH), and single- strand conformation polymorphism (SSCP) for alterations of CDKN2. Homozygous deletions of the CDKN2/CDKN2B (p15) region were detected in 10 cases (50%; 6 ALL, 2 AML, and 2 NHL). In 1 additional case, the intensity of the Southern blot band was significantly reduced, suggesting a CDKN2 deletion in a subpopulation of the malignant cells. No CDKN2 or CDKN2B rearrangements were seen. The IFN gene cluster was homozygously deleted in 2 of 15 (13%) analyzed cases, whereas the MTAP gene was deleted in 6 of 15 cases (40%). In addition, hemizygous deletions of the CDKN2 region were identified in 6 ALL cases using interphase FISH. No point mutation of the coding region of CDKN2 was detected by SSCP in these cases. We conclude that CDKN2 is the most frequently homozygously deleted marker on 9p. The absence of point mutations in the coding region of CDKN2 in cases with hemizygous 9p deletions and the frequent codeletion of MTAP, CDKN2B, and other yet unidentified neighboring genes suggest that the simultaneous deletion of these genes may be necessary for the selective growth advantage of malignant cells.     

Point mutations in the conserved box 1 region inactivate the human granulocyte colony-stimulating factor receptor for growth signal transduction and tyrosine phosphorylation of p75c-rel

The human granulocyte colony-stimulating factor receptor (hG-CSFR) belongs to the cytokine receptor superfamily. As with other members of this family, the cytoplasmic domain of hG-CSFR lacks intrinsic tyrosine kinase activity. To identify critical regions mediating growth signal transduction by hG-CSFR, deletions or site-directed amino acid substitutions were introduced into the cytoplasmic domain of hG-CSFR, and the mutant cDNAs were transfected into the murine interleukin-3 (IL- 3)-dependent Ba/F3 and FDCP cell lines. Truncation of the carboxy- terminal end of the receptor to the membrane-proximal 53 amino acids of the cytoplasmic domain, which retained the conserved Box 1 and Box 2 sequence motifs, decreased the ability of hG-CSFR to transduce G-CSF- mediated growth signals without an associated loss in receptor binding affinity. Substitution of proline by alanine at amino acid positions 639 and 641 within Box 1 completely abolished the G-CSF-mediated growth signal. Rapid induction of tyrosine phosphorylation of several cellular proteins, including a 75-kD protein (p75) identified as c-rel, was an early event associated with transduction of proliferative signals by hG- CSFR in Ba/F3 transfectants. Mutant receptors containing Pro-to-Ala substitutions that inactivated the receptor for mitogenic activity also inactivated the receptor for tyrosine-specific phosphorylation of p75. These results show that the conserved Box 1 sequence motif (amino acids 634 to 641) is critical for mitogenesis and activation of cellular tyrosine kinases by hG-CSFR.     

Toxicity induced by nanoparticles

Nanoparticle research is currently an area of intense scientific interest due to a wide variety of potential applications. Human beings have been exposed to airborne nanosized particles throughout their evolutionary stages, and such exposures have increased dramatically over the last century. Nanoparticle can modify the physicochemical properties of the material as well as create the opportunity for increased uptake and interaction with biological tissues through inhalation, ingestion, and injection. This combination of effects can generate adverse biological effects in living cells. Nanoparticles have proved toxic to human once in the blood stream, nanoparticles, spleen, bone marrow and nervous system can be transported around the body and be taken up by organs tissue and cell cultures, resulting in increased oxidative stress, inflammatory cytokine production and cell death. Unlike larger particles, nanoparticles may be taken up by cell mitochondria and the cell nucleus studies demonstrate the potential for nanoparticles to cause DNA mutation and induce major structural damage to mitochondria, even resulting in cell death. Size is therefore a key factor in determining the potential toxicity of a particle. How these nanoparticles behave inside the body is still a major question that needs to be resolved. There is a responsibility to test and optimize these new nanomaterials early during the development process to eliminate or ameliorate identified toxic characteristics.