Infection with an extended-spectrum beta-lactamase-producing strain of Serratia marcescens following tongue reconstruction

We report a case of postsurgical wound infection of polymicrobial etiology caused by Serratia marcescens and Pseudomonas aeruginosa following the use of a radial forearm free flap for oncological tongue reconstruction. S. marcescens was a producer of SHV-12 extended-spectrum beta-lactamase (ESBL). This is the first report from India of this ESBL. S. marcescens and P. aeruginosa were resistant to the empirical perioperative antibiotics administered. Delay in the recognition of the type of infection and in the institution of appropriate therapy resulted in total loss of the free flap.     

Genetic variability of begomoviruses associated with cotton leaf curl disease originating from India

Summary. Cotton leaf curl disease (CLCuD) causing viruses belong to the Begomovirus genus of the family Geminiviridae. Most begomoviruses are bipartite with two molecules of circular single stranded DNA (A and B) encapsidated in icosahedral geminate particles. However, the begomoviruses associated with CLCuD have DNA- instead of DNA-B. In this communication we report the complete genomic sequence of DNA-A component of two CLCuD-causing begomoviruses, cotton leaf curl Kokhran virus-Dabawali (CLCuKV-Dab), tomato leaf curl Bangalore virus-Cotton [Fatehabad] (ToLCBV-Cotton [Fat]) and partial sequences of two other isolates cotton leaf curl Rajasthan virus-Bangalore (CLCuRV-Ban) and cotton leaf curl Kokhran virus-Ganganagar (CLCuKV-Gang). A phylogenetic analysis of these isolates along with other related begomoviruses showed that ToLCBV-Cotton [Fat] isolate was closest to the tomato leaf curl Bangalore virus-5 (ToLCBV-Ban5) where as CLCuKV-Dab isolate was close to the cotton leaf curl Kokhran virus-Faisalabad1 (CLCuKV-Fai1), cotton leaf curl Kokhran virus-72b (CLCuKV-72b) and cotton leaf curl Kokhran virus-806b (CLCuKV-806b) isolates from Pakistan. The phylogenetic analysis further showed that the ToLCBV-Cotton [Fat] and CLCuKV-Dab isolates along with CLCuKV-Fai1, CLCuKV-72b and CLCuKV-806b are closer to the ToLCBV, tomato leaf curl Gujarat virus (ToLCGV), tomato leaf curl Gujarat virus-Varanasi (ToLCGV-Var) and tomato leaf curl Sri Lanka virus (ToLCSLV) isolates, where as cotton leaf curl Alabad virus-804a (CLCuAV-804a), cotton leaf curl Multhan virus (CLCuMV) cluster with the isolates from cotton leaf curl Rajasthan virus (CLCuRV) and okra yellow vein mosaic virus (OYVMV). These results demonstrate the extensive variability observed in this group of viruses. The AC4 ORF is the least conserved among these viruses. In order to further asses the variability in the CLCuD-causing begomoviruses, the region showing minimum similarity in the DNA-A sequence was first determined by a comparison of segments of different lengths of the aligned sequences. The results indicated that region 2411–424 (771nt) was the least conserved. A phylogenetic tree constructed using the sequences of all the CLCuD causing begomoviruses, corresponding to the least conserved region showed that they form two distinct clusters.     

Effects of interferon in malaria infection

Earlier, we reported that prophylactic treatment with human interferon gamma (rHuIFN-gamma) protected monkeys against Plasmodium cynomolgi B malaria infection. We have tested the efficacy of rHuIFN-gamma on relapsing stage of experimental P. cynomolgi B malaria infection in rhesus monkeys. No effect of rHuIFN-gamma was seen against experimental relapsing stage compared with controls; however, it appears that chloroquine (CHL) may have interfered with the antimalarial effect of IFN, since treatment with CHL inhibits the antiviral activity of mouse alpha/beta IFN and polyinosinic-polycytidylic acid (poly I:C) against Semliki forest virus (SFV) in mice. These results may have clinical implications especially with the use of IFN against virus infection, cancer and in parasitic infections in malaria endemic areas where CHL is one of the most widely used antimalarial drugs. Our result also shows that CHL treatment enhances the virus replication in mice and suggest a possible connection between AIDS and malaria infection, since the spread of AIDS has been rapid in parts of tropical Africa that have a high incidence of malaria, and chloroquine has been frequently used in the chemotherapy of malaria.     

Positron emission tomographic measurement of blood-to-brain and blood-to-tumour transport of 82Rb. I: Error analysis and computer simulations

Unidirectional blood-to-brain and blood-to-tumour transport rate constants (K1) for 82Rb (half-life 76 s) and plasma water volume per unit mass of brain/tumour tissue (Vp) can be estimated in vivo using dynamic positron emission tomography (PET). The accuracy of these estimates depends upon the accuracy of PET measurements of regional brain/tumour radioactivity and scintillation well detector measurements of whole-blood radioactivity, which, in turn, depend upon the time course of arterial blood radioactivity. A two-compartmental model has been employed to derive estimates for K1, k2 (efflux rate constant) and Vp from 82Rb/PET data. Errors in these parameter estimates have been studied (1) qualitatively using sensitivity function analysis and (2) quantitatively using computer simulations. The effect of adding a third irreversible compartment and its unidirectional rate constant, k3, has also been investigated. The advantages and disadvantages of bolus injection vs continuous infusion protocols are discussed. Precision in estimated parameters from actual patient data is compared to that obtained from computer simulations in part II of this paper.     

In vivo measurement of brain tumor pH using [11C]DMO and positron emission tomography

In vivo measurements of regional brain tissue/tumor pH (rpH) have been accomplished in 9 patients with primary or metastatic brain tumors using [11C]dimethyloxazolidinedione [( 11C]DMO) and positron emission tomography. Tumor rpH values ranged from 6.88 to 7.26, whereas gray matter and white matter rpH values ranged from 6.74 to 7.09 and from 6.77 to 7.03, respectively. Our results, which are consistent with reported [14C]DMO autoradiographic measurements of brain and tumor pH, suggest that the pH microenvironment of brain tumors is not more "acidic" than that of normal gray or white matter.     

Incidence of Clostridium difficile infection: a prospective study in an Indian hospital

Clostridium difficile is the commonest cause of hospital-acquired diarrhoea. A prospective study comprising of 156 patients and 54 healthy controls was undertaken to assess C. difficile associated diarrhoea (CDAD) incidence in an Indian hospital. Methods used included C. difficile culture and enzyme linked immunosorbent assay (ELISA) for Toxin A. Attempts were made to type isolates by antibiogram and SDS-PAGE. Of the 210 stool samples tested, 12 gave positive results in at least one assay. Of these, 11 were positive by the ELISA method, eight by culture, and seven by both methods. Neither the organisms nor the toxin was found in healthy controls or neonates. The average disease incidence of CDAD estimated by using both methods was 15%. Two antibiotypes of the isolates were obtained and of the isolates characterized by SDS-PAGE, two had identical patterns. This study shows that CDAD is an emerging problem in Indian hospitals. Monitoring should enable the development and implementation of policies and procedures that minimize the risk of this nosocomial pathogen.     

Immunostimulant Activity of Picroliv, the Iridoid Glycoside Fraction of Picrorhiza kurroa, and its Protective Action against Leishmania donovani Infection in Hamsters1

Picroliv, a standardised fraction from root and rhizome of Picrorhiza kurroa, consisting of iridoid glycosides and shown to be responsible for its hepatoprotective activity, was studied for immunostimulant activity. Oral administration of Picroliv (10 mg/kg x 7 days) in mice prior to immunization with sheep red blood cells (SRBC) resulted in a significant increase in haemagglutinating antibody (HA) titre, plaque forming cells (PFC), and delayed hypersensitivity (DTH) response to SRBC. Picroliv enhanced the non-specific immune response characterized by an increase in macrophage migration index (MMI), [14C]-glucosamine uptake, phagocytosis of [14C]-leucine labelled Escherichia coli, chemiluminescence of peritoneal macrophages, and higher uptake of [3H]-thymidine in the lymphocytes of treated mice. It also induced a high degree of protection in golden hamsters against challenge infection with Leishmania donovani promastigotes.     

Absolute quantitation in neurological PET: do we need it?

This article addresses the question posed in the title by examining the effects of parameters traditionally associated with improved absolute quantitation, on the analysis of 12 acquired immune deficiency syndrome dementia complex (ADC) patients compared to a normal control group. Results are discussed within the framework of the subprofile scaling model (SSM) for analyzing patterns of regional covariation. It is demonstrated that the ability to extract measures of group discrimination and disease progression are unaffected by (1) limited improvements in image resolution, (2) the use of transmission scan smoothing, (3) the application of a scatter deconvolution correction, and (4) converting region-of-interest measurements of counts per voxel to measurements of regional CMRglc. This "robustness" of the SSM approach is partly due to the extraction of disease-related subject weights, independent of any subject's global scaling effects. It is argued that other analysis techniques that initially reduce intersubject variation (e.g., using regional ratios or normalizing by global metabolic rates before applying traditional multivariate procedures) lack analytic features that may be important to identify multidimensional, disease-related image patterns. Based on the ADC patient data, it is concluded that measures of group discrimination and disease progression will not necessarily benefit from the organization of parameters traditionally associated with improved absolute quantitation.     

Evidence for central histaminergic mechanism in foot shock aggression

The role of central histaminergic system in foot shock induced aggression was studied in mice. Histamine administered by intracerebral (IC) injection (25–200 g) produced a significant increase in fighting episodes in a dose dependent manner. It was observed that mepyramine (H₁ blocker) given intraperitoneally (IP) significantly increased and metiamide (H₂ blocker) given IC decreased significantly the fighting response. To determine the nature of receptors involved in histamine induced facilitation of aggressive behaviour, histamine was administered IC in mice pretreated with mepyramine or metiamide. Mepyramine pretreatment further increased the facilitatory effect of histamine while metiamide blocked the enhancement of aggressiveness by histamine. Combined pretreatment with metiamide and mepyramine decreased significantly the fighting counts which remained unaffected after histamine. Haloperidol did not block the enhancement of aggression by histamine or mepyramine. However, atropine pretreatment partially inhibited the histamine induced increase in the fighting counts. Results of pretreatment with metiamide and atropine were similar to those obtained with pretreatment of metiamide and mepyramine. Metiamide alone or in combination with atropine failed to affect the facilitatory effect of amphetamine on the foot-shockaggression. It is concluded that central histamine H₂ receptors have a facilitatory role and H₁ receptors an inhibitory role on aggressive behaviour in mice induced by foot-shock. Since histamine per se had a facilitatory effect on foot-shock induced aggression, the central H₂ receptors seem to dominate over the H₁ receptors.