Multidrug resistant Vibrio cholerae O1 El Tor carrying classical ctxB allele involved in a cholera outbreak in South Western India

Cholera is a fatal diarrheal disease characterized with enormous fluid loss through stools. A total of 41 Vibrio cholerae isolates collected from a recent cholera outbreak in Solapur, South Western India were found to belong to serogroup O1, biotype El Tor and serotype Ogawa. Molecular analysis revealed the prevalence of different toxigenic and pathogenic genes in the isolates. All the isolates harboured rstR(El)(Tor) allele indicating the presence of CTXΦ(El)(Tor). However, cholera toxin (ctxB) gene sequencing and a ctxB allele specific PCR of the isolates confirmed the presence of ctxB of classical biotype. The antibiogram profile revealed the resistance for several antibiotics including nalidixic acid, polymyxin B, streptomycin, sulfamethoxazole, trimethoprim, rifampicin and vibriostatic agent 2,4-diamino-6,7-diisopropylpteridine (O/129). All the isolates were PCR positive for class 1 integron and SXT elements also. Fingerprinting analysis revealed the clonal relationship among the outbreak isolates. The results suggested the involvement of multidrug resistant V. cholerae El Tor biotype isolates having ctxB gene of classical biotype in the cholera outbreak.

Mcleod syndrome: Report of an Indian family with phenotypic heterogeneity

The present report deals with the clinical phenomenology of three members (brothers) of one family with McLeod syndrome (MLS). In two, the clinical pictures were of choreiform disorders with amyotrophy, which were found to be neurogenic in origin by detailed electrophysiological study. The index case had peripheral acanthocytosis; immunohematological and molecular genetic studies confirmed diagnosis of MLS. However, one brother only had a slowly progressive motor neuron disease like picture but no abnormal movement disorder. He had peripheral acanthocytes as well. The inheritance seems to be X-linked recessive in nature. The affected family members exhibited much phenotypic heterogeneity. This appears to be the first report of MLS from India.

Unilateral paravertebral block: an alternative to conventional spinal anaesthesia for inguinal hernia repair

BACKGROUND

Inguinal herniorrhaphy can be successfully performed using general, regional or local anaesthesia. Paravertebral block (PVB) has been used for unilateral procedures such as thoracotomy, breast surgery, chest wall trauma, hernia repair or renal surgery.

METHODS

We compared unilateral lumbar PVB with conventional spinal anaesthesia (SA) in 60 consenting ASA I and II males aged 18-65 years, scheduled for unilateral inguinal hernia repair. Patients were randomly assigned into two groups, P (n=30) or S (n=30) to receive either PVB or SA, respectively. Two patients (7%) in group P had to be converted to general anaesthesia due to block failure. During surgery, patients of both groups received intravenous infusion of propofol titrated to light sedation.

RESULTS

The time to first post-operative analgesic requirement (primary outcome measure) as 342 +/- 73 min in group P and 222 +/- 22 min in group S (P<0.0001). Time to ambulation was 234 +/- 111 min in group P and 361 +/- 32 min in group S (P<0.0001). Urinary retention requiring catheterization were found in zero (0%) patients in group P compared with five (16%) in group S (P=0.024).

CONCLUSION

It can be concluded that unilateral PVB is more efficacious than conventional SA in terms of prolonging post-operative analgesia and reducing morbidities in patients undergoing elective unilateral inguinal hernia repair.

Hyperpolarized MR imaging: neurologic applications of hyperpolarized metabolism

Hyperpolarization is the general term for a method of enhancing the spin-polarization difference of populations of nuclei in a magnetic field. No less than 5 distinct techniques (dynamic nuclear polarization [DNP]; parahydrogen-induced polarization-parahydrogen and synthesis allow dramatically enhanced nuclear alignment [PHIP-PASADENA]; xenon/helium polarization transfer; Brute Force; (1)H hyperpolarized water) are currently under exhaustive investigation as means of amplifying the intrinsically (a few parts per million) weak signal intensity used in conventional MR neuroimaging and spectroscopy. HD-MR imaging in vivo is a metabolic imaging tool causing much of the interest in HD-MR imaging. The most successful to date has been DNP, in which carbon-13 ((13)C) pyruvic acid has shown many. PHIP-PASADENA with (13)C succinate has shown HD-MR metabolism in vivo in tumor-bearing mice of several types, entering the Krebs-tricarboxylic acid cycle for ultrafast detection with (13)C MR imaging, MR spectroscopy, and chemical shift imaging. We will discuss 5 promising preclinical studies: (13)C succinate PHIP in brain tumor; (13)C ethylpyruvate DNP and (13)C acetate; DNP in rodent brain; (13)C succinate PHIP versus gadolinium imaging of stroke; and (1)H hyperpolarized imaging. Recent developments in clinical (13)C neurospectroscopy encourage us to overcome the remaining barriers to clinical HD-MR imaging.

Airway management of two patients with penetrating neck trauma

SUMMARY

Direct trauma to the airway is a rare injury which can lead to disastrous consequences due to compounding effect of bleeding, aspiration of blood, airway obstruction and severe sympathetic stimulation. Here we are presenting two cases of open tracheal injury in two adult males following assault with sharp weapon. Two different techniques of securing the airways were employed depending upon the severity and urgency of the situation. In the first case, orotracheal intubation helped the surgeon to repair airway around the endotracheal tube whereas in the second patient this stenting effect was absent as he was intubated through the distal cut-end of trachea in the face of airway emergency.

Optical polarization modulation and gain anisotropy in an electrically injected spin laser

The effects of spin-induced gain anisotropy on output polarization and threshold current reduction of electrically pumped spin-polarized lasers have been studied. Analytical forms of these parameters are derived by considering diffusive transport from the spin injector to the active region. The calculated values of the parameter are in excellent agreement with values obtained from measurements made at 200 K on an InAs/GaAs quantum dot spin-polarized vertical cavity surface-emitting laser. Electrical modulation of the output polarization of the laser is demonstrated with a peak modulation index of 0.6.

Electrically driven spin dynamics of paramagnetic impurities

The spin dynamics of dilute paramagnetic impurities embedded in a semiconductor GaAs channel of a conventional lateral spin valve has been investigated. It is observed that the electron spin of paramagnetic Mn atoms can be polarized electrically when driven by a spin valve in the antiparallel configuration. The transient current through the MnAs/GaAs/MnAs spin valve bears the signature of the underlying spin dynamics driven by the exchange interaction between the conduction band electrons in GaAs and the localized Mn electron spins. The time constant for this interaction is observed to be dependent on temperature and is estimated to be 80 ns at 15 K.

Predisposition to HPV16/18-related cervical cancer because of proline homozygosity at codon 72 of p53 among Indian women is influenced by HLA-B*07 and homozygosity of HLA-DQB1*03

This study was undertaken to examine whether predisposition to human papillomavirus (HPV)16/18-related cervical cancer (CaCx) because of p53 proline homozygosity (Pro72Pro) among Indian women was mediated singly or jointly with immunogenetic risk factors such as HLA-B*07 or homozygosity of HLA-DQB1*03. Molecular detection of all three genetic factors was performed by polymerase chain reaction-restriction fragment length polymorphism using DNA from (i) 114 CaCx samples (78 HPV16/18 positive) and (ii) 195 cytologically normal cervical scrapes (116 HPV-negative and 79 HPV16/18-positive samples). Multiple logistic regression analyses were performed to examine independent effects of the three factors and to determine age-adjusted odds ratio (OR) [95% confidence interval (CI)] and P-values. HLA-B*07 was observed to be significantly associated with HPV16/18 infection in asymptomatic controls (OR(age-adjusted) = 4.73; 95% CI: 1.55-14.45; P = 0.006) and CaCx (OR(age-adjusted) = 6.14; 95% CI: 2.15-17.53; P < 0.001) in this enhanced sample set of CaCx cases. There was a lack of association between HLA-B*07 and HLA-DQB1*03 in our study samples. The association of p53Pro72Pro with CaCx was non-significant in the absence of HLA-B*07 in HPV16/18-positive women. In this group, prevalence of p53Pro72Pro and HLA-B*07 together was significantly higher (7.0%) among CaCx cases (OR(age-adjusted) = 14.05; 95% CI: 1.11-177.30; P = 0.04), compared with controls (1.3%) lacking both factors. HLA-DQB1*03 homozygosity (OR(age-adjusted) = 4.75; 95% CI: 1.17-19.30; P = 0.03) or p53Pro72Pro (OR(age-adjusted) = 5.84; 95% CI: 1.18-28.99; P = 0.03) was found to be significantly associated with CaCx, each in the absence of the other in this group but not when present jointly in contrast to those lacking both factors (P = 0.214). Thus, modulation of p53Pro72Pro-mediated susceptibility to CaCx by immunogenetic factors could possibly be mediated through cross talk between HPV16/18-induced immune evasion and cell transformation.

Angiosarcoma of pericardium: a report of two cases

Angiosarcomas are uncommon malignant neoplasms characterized by rapidly proliferating extensively infiltrating anaplastic cells derived from blood vessels and lining irregular, blood-filled spaces. The cells manifest many of the functional and morphological properties of normal endothelium. They are collectively one of the rarest forms of soft tissue neoplasms. Here we present two cases of pericardial angiosarcoma, one of them showing widespread dissemination, which caused considerable diagnostic dilemma and the diagnosis could only be established very late in their course of disease.

Multiwavelength ultralow-threshold lasing in quantum dot photonic crystal microcavities

We demonstrate multiwavelength lasing of resonant modes in linear (L3) microcavities in a triangular-lattice 2D photonic crystal (PC) slab. The broad spontaneous emission spectrum from coupled quantum dots, modified by the PC microcavity, is studied as a function of the intensity of incident optical excitation. We observe lasing with an ultralow-threshold power of approximately 600 nW and an output efficiency of approximately 3% at threshold. Two other resonant modes exhibit weaker turnon characteristics and thresholds of approximately 2.5 and 200 microW, respectively.

Electrical spin injection and threshold reduction in a semiconductor laser

A spin-polarized vertical-cavity surface-emitting laser is demonstrated with electrical spin injection from an Fe/Al0.1Ga0.9As Schottky tunnel barrier. Laser operation with a spin-polarized current results in a maximum threshold current reduction of 11% and degree of circular polarization of 23% at 50 K. A cavity spin polarization of 16.8% is estimated from spin-dependent rate equation analysis of the observed threshold reduction.

A comparative profile of the prevalence and age distribution of human papillomavirus type 16/18 infections among three states of India with focus on northeast India

Human papillomavirus (HPV) DNA in cervical scrape samples of married women from Manipur (n= 692) and Sikkim (n= 415) in northeast India was determined and compared with that of women from West Bengal (n= 1112) in eastern India by polymerase chain reaction. HPV prevalence was lower in Manipur (7.4%) than in Sikkim (12.5%), which was closely followed by West Bengal (12.9%). HPV18 was predominant in Manipur (2.03%) and strikingly lower (0.2%) in Sikkim and West Bengal (0.9%), while the reverse was true for HPV16. The proportion of HPV16/18 infections in Manipur (3.3%, 22/672) and Sikkim (3.89%, 14/359) were comparable and significantly lower compared to that in West Bengal (7.8%, 79/1007) among women having normal cervical cytology. Such prevalence was similar among all age groups in Manipur: increased with age for women in Sikkim and dropped with age for those in West Bengal similar to that reported previously. At age < or =30 years, HPV16/18 prevalence in Manipur (3.3%) and Sikkim (2.5%) was comparable but was significantly lower (P < 0.05) in contrast to that in West Bengal (8.8%). Among abnormal cytologic lesions, HPV16/18 infections were significantly higher than in normals (P= 0.000) both in Sikkim (14.3%) and West Bengal (20.9%) and absent in Manipur. Such prevalence was noted among women in Sikkim aged >30 years and equally among those in West Bengal aged < or =30 or >30 years. Thus, women from northeast India, particularly from Manipur, appear less susceptible to HPV16/18 infection and related cervical lesions compared to those from West Bengal, where such proneness was prominently evident at age < or =30 years.