Antibiotic prophylaxis is unnecessary in clean surgery

A significant number of paediatric surgical patients undergone clean surgical procedures. Most of the paediatric surgeon use perioperative prophylactic antibiotic in this clean procedure because of undue fear of infection in their mind. The objective of this study is to evaluate whether the use of perioperative prophylactic antibiotics have an effect to prevent post operative wound infection in clean operation in paediatric surgical patients. This study was conducted in the paediatric surgery department of Bangabandhu Sheikh Mujib Medical University and some private clinics of Dhaka city from January 2009 to December 2009. Two hundred patients who were undergone clean elective surgical procedure on day case basis were included in this study. They were divided into two equal groups (Group A and Group B). The patients of Group A were given intransverse Cephradine 30 minutes before incision and then oral Cephradine was advised postoperatively for 7 days. The patients of Group B were not given any perioperative antibiotic. All the patients of both groups were advised to come on 3rd, 6th and 10th postoperative day for examination of wound. In Group A (With chemo prophylaxis), five patients (5%) developed postoperative wound infection and in Group B (without chemo prophylaxis), three patients (3%) developed postoperative wound infection. Thus the rate of postoperative wound infection is slightly more in patients with chemo prophylaxis but it was not statistically significant by chi-square test. Based on the result of this study, it may be concluded that the antibiotic prophylaxis is not necessary in clean surgery in paediatric age group.

Femoroacetabular impingement and comparison of radiological indexes: a study on 50 cases

To study the asphericity of femoral head in femoroacetabular impingement using radiological indices such as alpha angle and triangular index, and to compare the alpha angle and triangular index measured in the radiograph and MRI. The study was conducted prospectively from January 2008 to June 2009 on 50 consecutive patients of suspected cam-type FAI hip, reporting to orthopedics outpatients department of Postgraduate Institute of Medical Education and Research. Radiograph of the affected hip was taken, and then alpha angle and triangular index are measured and compared. The mean alpha angle in anteroposterior view was measured as 75° ± 10°, and the mean in lateral view was 740 ± 80. In MRI the mean alpha angle was 79° ± 9°. The mean triangular index in radiograph was 2.9 ± 1.2. In MRI the mean triangular index was 2.6 ± 0.8. Frog-leg lateral view is sufficient for the diagnosis of the cam-type femoroacetabular impingement. But MRI is required in cases, where surgical intervention is planned to rule out other pathological condition and for decision making.

A 10 year old boy with rectal carcinoma

A 10 year old boy with mucinous carcinoma of rectum is a rare case at this age. Here the patient presented with constipation, mucus in stool & abdominal pain since one month. He got consultation from several physicians & went through sonology of whole abdomen several times. There he was missed diagnosed as a case of pyloric stenosis. We came to a probable diagnosis by doing simple digital rectal examination which seemed to be a hard rectal swelling. The diagnosis was established by colonoscopy followed by biopsy. Carcinoma rectum must be considered as a differential diagnosis if patient presents with altered bowel habit, per rectal bleeding, abdominal pain in conjunction with weight loss.

Composition and temperature-induced structural changes in lead-tellurite glasses on different length scales

Processes occurring at macroscopic and microscopic length scales across the glass transition (T(g)) in lead-tellurite glass (PbO)(x)(TeO(2))(1-x) (x = 0.1-0.3) are investigated using Brillouin and Raman spectroscopy, respectively. For all the samples, the temperature dependence of the longitudinal acoustic (LA) mode is found to exhibit a universal scaling below T(g) and a rapid softening above T(g). The lower value of elastic modulus at a higher concentration of network modifier PbO, estimated from Brillouin data, arises due to loss of network rigidity. From quantitative analysis of the reduced Raman spectra, several modes are found to exhibit anomalous changes across T(g). Instead of the expected anharmonic behaviour, several modes exhibit hardening, suggesting stiffening of the stretching force constants with temperature, the effect being more pronounced in glasses with higher x. In addition, incorporation of PbO in the glass is also found to narrow down the bond-length distribution, as evident from the sharpening of the Raman bands. The stiffening of the force constants of molecular units at a microscopic length scale and the decrease of elastic constant attributed to loss of network rigidity on a macroscopic length scale appear to be opposite. These different behaviours at two length scales are understood on the basis of a microscopic model involving TeO(n) and PbO units in the structure.

An improved plant regeneration and Agrobacterium - mediated transformation of red pepper (Capsicum annuum L.)

Capsicum annuum (red pepper) is an important spice cum vegetable crop in tropical and subtropical countries. Here, we report an effective and reproducible auxin free regeneration method for six different red pepper cultivars (ACA-10, Kashi Anmol, LCA-235, PBC-535, Pusa Jwala and Supper) using hypocotyl explants and an efficient Agrobacterium-mediated transformation protocol. The explants (hypocotyls, cotyledonary leaves and leaf discs) collected from axenic seedlings of six red pepper cultivars were cultured on either hormone free MS medium or MS medium supplemented with BAP alone or in combination with IAA. Inclusion of IAA in the regeneration medium resulted in callus formation at the cut ends of explants, formation of rosette leaves and ill defined shoot buds. Regeneration of shoot buds could be achieved from hypocotyls grown in MS medium supplemented with different concentrations of BAP unlike other explants which failed to respond. Incorporation of GA3 in shoot elongation medium at 0.5 mg/l concentration enhanced the elongation in two cultivars, LCA-235 and Supper, while other cultivars showed no significant response. Chilli cultivar, Pusa Jwala was transformed with βC1 ORF of satellite DNA β molecule associated with Chilli leaf curl Joydebpur virus through Agrobacterium tumefaciens. Transgene integration in putative transformants was confirmed by PCR and Southern hybridization analysis.

Diagnostic accuracy of dynamic contrast-enhanced MR imaging using a phase-derived vascular input function in the preoperative grading of gliomas

BACKGROUND AND PURPOSE

The accuracy of tumor plasma volume and K(trans) estimates obtained with DCE MR imaging may have inaccuracies introduced by a poor estimation of the VIF. In this study, we evaluated the diagnostic accuracy of a novel technique by using a phase-derived VIF and "bookend" T1 measurements in the preoperative grading of patients with suspected gliomas.

MATERIALS AND METHODS

This prospective study included 46 patients with a new pathologically confirmed diagnosis of glioma. Both magnitude and phase images were acquired during DCE MR imaging for estimates of K(trans)_φ and V(p_)φ (calculated from a phase-derived VIF and bookend T1 measurements) as well as K(trans)_SI and V(p_)SI (calculated from a magnitude-derived VIF without T1 measurements).

RESULTS

Median K(trans)_φ values were 0.0041 minutes(-1) (95 CI, 0.00062-0.033), 0.031 minutes(-1) (0.011-0.150), and 0.088 minutes(-1) (0.069-0.110) for grade II, III, and IV gliomas, respectively (P ≤ .05 for each). Median V(p_)φ values were 0.64 mL/100 g (0.06-1.40), 0.98 mL/100 g (0.34-2.20), and 2.16 mL/100 g (1.8-3.1) with P = .15 between grade II and III gliomas and P = .015 between grade III and IV gliomas. In differentiating low-grade from high-grade gliomas, AUCs for K(trans)_φ, V(p_φ), K(trans)_SI, and V(p_)SI were 0.87 (0.73-1), 0.84 (0.69-0.98), 0.81 (0.59-1), and 0.84 (0.66-0.91). The differences between the AUCs were not statistically significant.

CONCLUSIONS

K(trans)_φ and V(p_)φ are parameters that can help in differentiating low-grade from high-grade gliomas.

Biaxial nematic order induced by smectic fluctuations

We report on a series of measurements on the microscopic structure and the magneto-optical properties of a calamitic liquid crystalline compound in its nematic phase. Structural studies show the existence of short-range, tilted smectic order consistent with pretransitional effects above an underlying smectic phase. Concomitantly, magneto-optical results exhibit the existence of an optic axis not collinear with the uniaxial director. This apparent biaxial nature is discussed within the context of coupling between the tensor nematic and the smectic order parameters.

Biology and interactions of two distinct monopartite begomoviruses and betasatellites associated with radish leaf curl disease in India

BACKGROUND

Emerging whitefly transmitted begomoviruses are major pathogens of vegetable and fibre crops throughout the world, particularly in tropical and sub-tropical regions. Mutation, pseudorecombination and recombination are driving forces for the emergence and evolution of new crop-infecting begomoviruses. Leaf curl disease of field grown radish plants was noticed in Varanasi and Pataudi region of northern India. We have identified and characterized two distinct monopartite begomoviruses and associated beta satellite DNA causing leaf curl disease of radish (Raphanus sativus) in India.

RESULTS

We demonstrate that RaLCD is caused by a complex of two Old World begomoviruses and their associated betasatellites. Radish leaf curl virus-Varanasi is identified as a new recombinant species, Radish leaf curl virus (RaLCV) sharing maximum nucleotide identity of 87.7% with Tomato leaf curl Bangladesh virus-[Bangladesh:2] (Accession number AF188481) while the virus causing radish leaf curl disease-Pataudi is an isolate of Croton yellow vein mosaic virus-[India] (CYVMV-IN) (Accession number AJ507777) sharing 95.8% nucleotide identity. Further, RDP analysis revealed that the RaLCV has a hybrid genome, a putative recombinant between Euphorbia leaf curl virus and Papaya leaf curl virus. Cloned DNA of either RaLCV or CYVMV induced mild leaf curl symptoms in radish plants. However, when these clones (RaLCV or CYVMV) were individually co-inoculated with their associated cloned DNA betasatellite, symptom severity and viral DNA levels were increased in radish plants and induced typical RaLCD symptoms. To further extend these studies, we carried out an investigation of the interaction of these radish-infecting begomoviruses and their associated satellite, with two tomato infecting begomoviruses (Tomato leaf curl Gujarat virus and Tomato leaf curl New Delhi virus). Both of the tomato-infecting begomoviruses showed a contrasting and differential interaction with DNA satellites, not only in the capacity to interact with these molecules but also in the modulation of symptom phenotypes by the satellites.

CONCLUSION

This is the first report and experimental demonstration of Koch's postulate for begomoviruses associated with radish leaf curl disease. Further observations also provide direct evidence of lateral movement of weed infecting begomovirus in the cultivated crops and the present study also suggests that the exchange of betasatellites with other begomoviruses would create a new disease complex posing a serious threat to crop production.

Accuracy of brain imaging in the diagnosis of idiopathic intracranial hypertension

AIM

To investigate the accuracy of individual and combinations of signs on brain magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) in the diagnosis of idiopathic intracranial hypertension (IIH).

MATERIALS AND METHODS

This study was approved by the institutional research ethics board without informed consent. Forty-three patients and 43 control subjects were retrospectively identified. Each patient and control had undergone brain MRI and MRV. Images were anonymized and reviewed by three neuroradiologists, blinded to clinical data, for the presence or absence of findings associated with IIH. The severity of stenosis in each transverse sinus was graded and summed to generate a combined stenosis score (CSS). The sensitivity, specificity, and likelihood ratios (LR) were calculated for individual and combinations of signs.

RESULTS

Partially empty sella (specificity 95.3%, p < 0.0001), flattening of the posterior globes (specificity 100%, p < 0.0001), and CSS <4 (specificity 100%, p < 0.0001) were highly specific for IIH. The presence of one sign, or any combination, significantly increased the odds of a diagnosis of IIH (LR+ 18.5 to 46, p < 0.0001). Their absence, however, did not rule out IIH.

CONCLUSIONS

Brain MRI with venography significantly increased the diagnostic certainty for IIH if there was no evidence of a mass, hydrocephalus, or sinus thrombosis and one of the following signs was present: flattening of the posterior globes, partially empty sella, CSS <4. However, absence of these signs did not exclude a diagnosis of IIH.

Mathematical modeling of drug release profiles for modified hydrophobic HPMC based gels

Hydroxypropyl methylcellulose (HPMC) is now available in modified hydrophobic forms (Sangelose). In this paper, the effect of viscosity grade and HPMC concentration on in vitro release kinetics of a topically applied drug were studied using gel formulations of a nonsteroidal anti-inflammatory drug (NSAID), diclofenac potassium (DP), with different viscosity grades of the polymer (60L, 60 M, 90 M for hydrophobic HPMC and 50 cPs for conventional hydrophilic HPMC) in different proportions. It was found that hydrophobic HPMC-based gels having a higher viscosity and lower polymer concentration release a notably higher amount of drug compared with hydrophilic HPMC-based gels containing a higher concentration of polymer but with lower viscosity. For gels, the suitability of different common empirical (zero-order, first-order, and Higuchi), and semi-empirical (Ritger-Peppas and Peppas-Sahlin) models, and some new statistical (logistic, log-logistic, Weibull, Gumbel, and generalized extreme value distribution) models to describe the drug release profile were tested through non-linear least-square curve fitting. A general purpose mathematical analysis tool MATLAB was used. Further, instead of the widely used transformed linear fit method, direct fitting was used in the paper to avoid any form of truncation and transformation errors. The results revealed that the log-logistic distribution, amongst all the models investigated, was the best fit for hydrophobic formulations. For hydrophilic ones, the semi-empirical models and Weibull distribution worked best, although log-logistic also showed a close fit. The shape parameter for the log-logistic and Weibull distribution conveys vital information about the rate of release and helps improve understanding of drug release profiles.

Angiogenin functionally interacts with p53 and regulates p53-mediated apoptosis and cell survival

Angiogenin, a 14-kDa multi-functional pro-angiogenic growth factor, is up-regulated in several types of cancers. Anti-angiogenin monoclonal antibodies used as antagonists inhibited the establishment, progression, and metastasis of human cancer cells in athymic mice (Olson et al. 1994). Silencing angiogenin and inhibition of angiogenin’s nuclear translocation blocked cell survival and induced cell death in B-lymphoma and endothelial cells latently infected with Kaposi sarcoma associated herpesvirus (KSHV) (Sadagopan et al. 2009) suggesting that actively proliferating cancer cells could be inducing angiogenin for inhibiting apoptotic pathways. However, the mechanism of cell survival and apoptosis regulation by angiogenin and their functional significance in cancer is not known. We demonstrate that angiogenin interacts with p53 and colocalizes in the nucleus. Silencing endogenous angiogenin induced p53 promoter activation and p53 target gene (p53, p21 and Bax) expression, down-regulated anti-apoptotic Bcl-2 gene expression and increased p53 mediated cell death. In contrast, angiogenin expression blocked pro-apoptotic Bax and p21 expression, induced Bcl-2 and blocked cell death. Angiogenin also co-immunoprecipitated with p53 regulator protein Mdm2. Angiogenin expression resulted in the inhibition of p53 phosphorylation, increased p53-Mdm2 interaction, and consequently increased ubiquitination of p53. Taken together these studies demonstrate that angiogenin promotes the inhibition of p53 function to mediate anti-apoptosis and cell survival. Our results reveal for the first time a novel p53 interacting function of angiogenin in anti-apoptosis and survival of cancer cells and suggest that targeting angiogenin could be an effective therapy for several cancers.

Kaposi's Sarcoma Associated Herpesvirus Entry into Target Cells

Herpesvirus infection of target cells is a complex process involving multiple host cell surface molecules (receptors) and multiple viral envelope glycoproteins. Kaposi's sarcoma associated herpesvirus (KSHV or HHV-8) infects a variety of in vivo target cells such as endothelial cells, B cells, monocytes, epithelial cells, and keratinocytes. KSHV also infects a diversity of in vitro target cells and establishes in vitro latency in many of these cell types. KSHV interactions with the host cell surface molecules and its mode of entry in the various target cells are critical for the understanding of KSHV pathogenesis. KSHV is the first herpesvirus shown to interact with adherent target cell integrins and this interaction initiates the host cell pre-existing signal pathways that are utilized for successful infection. This chapter discusses the various aspects of the early stage of KSHV infection of target cells, receptors used and issues that need to be clarified, and future directions. The various signaling events triggered by KSHV infection and the potential role of signaling events in the different stages of infection are summarized providing the framework and starting point for further detailed studies essential to fully comprehend the pathogenesis of KSHV.

Self-referenced rectangular path cyclic interferometer with polarization phase shifting

A polarization phase shifting interferometer using a cyclic path configuration for measurement of phase nonuniformities in transparent samples is presented. A cube beam splitter masked by two linear polarizers is used to split the source wavefront into two counter propagating linearly polarized beams that pass through the sample. At the output of the interferometer, the two orthogonally polarized beams are rendered circularly polarized in the opposite sense through the use of a quarter wave plate. Finally, phase shifting is achieved by rotating a linear polarizer before the recording plane. In a rectangular path interferometer, although the two counter propagating wavefronts are laterally folded with respect to each other in the interferometer arms, the beams finally emerge mutually unfolded at the output of the interferometer. This phenomenon is utilized to create a reference if the sample is introduced in one lateral half of the beam in any one of the interferometer arms. The polarization phase shifting technique is used to generate four phase-shifted interferograms, which are utilized to evaluate the phase profile of the phase sample. Experimental results presented validate the proposed technique.