Acinetobacter baumannii: An overview of emerging multidrug-resistant pathogen

The emergence of infections caused by Acinetobacter baumannii, a multidrug-resistant bacterium, has been a concern worldwide. This bacterium is an important hospitalacquired pathogen that causes several diseases including ventilator-associated pneumonia, bloodstream infections, and meningitis. This study aimed to determine antibioticresistant mechanisms in the pathogenesis of A. baumannii and the alternative treatment strategies against it. The combined actions of outer membrane protein A, formation of a biofilm on biotic and abiotic surfaces, phospholipases C and D, metal homeostatic system, lipopolysaccharides, and verotoxins are relevant for virulence and pathogenesis. A. baumannii resists the broad-spectrum antibiotics by its mechanisms of resistance, such as β-lactamases, efflux pump, aminoglycoside modifying enzymes, permeability changes, and alternation of targets. In an attempt to overcome the resistance mechanisms, plant-derived compounds and a combination of the antibiotics and the plant phytocompounds have been focused. Nanoparticles synthesised with the plant extract have been studied extensively. Furthermore, we projected modern methods, including multi-omics analysis, to study insight into mechanisms of actions of antibiotics. The information suggested that the potential antibiotic mechanisms of A. baumannii could lead to an alternative treatment against A. baumannii infections.

Electrodeposited Thin-Film Micro-Thermoelectric Coolers with Extreme Heat Flux Handling and Microsecond Time Response

Thin-film thermoelectric coolers are emerging as a viable option for the on-chip temperature management of electronic and photonic integrated circuits. In this work, we demonstrate the record heat flux handling capability of electrodeposited Bi₂Te₃ films of 720(±60) W cm^-2 at room temperature, achieved by careful control of the contact interfaces to reduce contact resistance. The characteristic parameters of a single leg thin-film devices were measured in situ, giving a Seebeck coefficient of S = -121(±6) μV K^-1, thermal conductivity of κ = 0.85(±0.08) W m^-1 K^-1, electrical conductivity of σ = 5.2(±0.32) × 10⁴ S m^-1, and electrical contact resistivity of ∼10^-11 Ω m². These thermoelectric parameters lead to a material ZT = 0.26(±0.04), which, for our device structure, allowed a net cooling of ΔT_max = 4.4(±0.12) K. A response time of τ = 20 μs was measured experimentally. This work shows that with the correct treatment of contact interfaces, electrodeposited thin-film thermoelectrics can compete with more complicated and expensive technologies such as metal organic chemical vapor deposition (MOCVD) multilayers.

Results of trabecular metal augments in Paprosky IIIA and IIIB defects

Aims

The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky IIIA and IIIB defects.

Patients and Methods

A retrospective study was conducted at four centres between August 2008 and January 2015. Patients treated with TM augments and TM shell for a Paprosky grade IIIA or IIIB defect, in the absence of pelvic discontinuity, and who underwent revision hip arthroplasty with the use of TM augments were included in the study. A total of 41 patients with minimum follow-up of two years were included and evaluated using intention-to-treat analysis.

Results

There were 36 (87.8%) patients with a Paprosky IIIA defect and five (12.2%) patients with a Paprosky IIIB defect. The mean age was 56.7 years (28 to 94). There were 21 (51.2%) women and 20 (48.8%) men. The mean follow-up was 39.4 months (12 to 96). One (2%) patient died after eight years. No failures were noted in the series. The mean survivorship was 100% at the time of latest follow-up.

Conclusion

The results of this multicentre study showed encouraging short- and mid-term results for the use of TM augments in the management of Paprosky grade IIIA and IIIB defects. Cite this article: Bone Joint J 2018;100-B:903–8.

Histopathological analysis of hysterectomy specimens: one year study

Backgound: The uterus is prone to develop several non-neoplastic and neoplastic conditions during the life time of a woman. The aim of this study is to study the histopathological features of varied uterine lesions, their profile and distribution of different lesions in relation of age.Materials and Methods: This is a histopathological database analysis of hysterectomy specimen of one year 2011/12 in Patan Hospital. The variables studied were age and histopathological diagnosis. SPSS version 16 was used as an analytical tool.Results: A total of 3576 histopathology samples were received in this period. There were 1173 gynaecology samples during this period out of which 22% (261 cases) were that of hysterectomy. Histopathology diagnosis showed Leiomyoma in 48.6% (127 cases), Adenomyosis was seen in 10.3% (27 cases), Endometrioid Adenocarcinoma was seen in 1.14% (3 cases).Conclusion: A large number of hysterectomy specimens had no significant findings. However, adenomyosis, leiomyomya and adenocarcinoma are also found which may be the cause of abnormal uterine bleeding. 

Histological changes and neural elements in the posterior cruciate ligament in osteoarthritic knees

PURPOSE

To evaluate histological changes and neural elements in 100 posterior cruciate ligaments (PCLs) in patients with osteoarthritis.

METHODS

100 PCLs were obtained from a consecutive series of 46 women and 16 men aged 49 to 91 (mean, 67) years who underwent primary PCL-retaining total knee replacement for osteoarthritis. Histology was examined using conventional light microscopy. The PCLs were graded histologically in terms of parallel orientation of collagen fibres, mucoid degeneration, inflammation, and haemosiderin deposition. Histological changes were graded as normal, mild degeneration, moderate degeneration, and severe degeneration. The neural elements were assessed using immunohistochemical staining for S100 protein and neurofilaments. The histopathologist was blinded to the age, gender, and clinical and radiological grades of osteoarthritis.

RESULTS

One specimen was excluded from analysis owing to inadequate tissue. In the remaining 99 specimens, histology was normal in 72, mildly degenerative in 4, moderately degenerative in 4, and severely degenerative in 15. 76 specimens were positive for S100 protein or neurofilament or both by immunohistochemical staining, indicating the presence of neural elements.

CONCLUSION

Most knees with osteoarthritis present with viable PCLs. Retaining the PCL in total knee replacement is a good option for better kinematics, stability, and proprioception.

Thermodynamics of Micellization and Conductance Behavior of Uranyl Soap Solutions

The conductance results showed that uranyl soaps behave as weak electrolyte in dilute solution of N,N-dimethylformamide (DMF) at various temperatures below the critical micelle concentration, indicating that Debye–Hückel–Onsager's equation is not applicable to these soaps solutions. The value of critical micelle concentration decreases with increasing chain length of the soap and increasing temperature. The results were used to evaluate various thermodynamic parameters for both dissociation and association processes and may be satisfactorily explained in the light of phase separation model. The results show that the dissociation process of these soaps was found to be endothermic while micellization is exothermic in nature.

Role of the M3 muscarinic acetylcholine receptor in beta-cell function and glucose homeostasis

The release of insufficient amounts of insulin in the presence of elevated blood glucose levels is one of the key features of type 2 diabetes. Various lines of evidence indicate that acetylcholine (ACh), the major neurotransmitter of the parasympathetic nervous system, can enhance glucose-stimulated insulin secretion from pancreatic beta-cells. Studies with isolated islets prepared from whole body M(3) muscarinic ACh receptor knockout mice showed that cholinergic amplification of glucose-dependent insulin secretion is exclusively mediated by the M(3) muscarinic receptor subtype. To investigate the physiological relevance of this muscarinic pathway, we used Cre/loxP technology to generate mutant mice that lack M(3) receptors only in pancreatic beta-cells. These mutant mice displayed impaired glucose tolerance and significantly reduced insulin secretion. In contrast, transgenic mice overexpressing M(3) receptors in pancreatic beta-cells showed a pronounced increase in glucose tolerance and insulin secretion and were resistant to diet-induced glucose intolerance and hyperglycaemia. These findings indicate that beta-cell M(3) muscarinic receptors are essential for maintaining proper insulin secretion and glucose homeostasis. Moreover, our data suggest that enhancing signalling through beta-cell M(3) muscarinic receptors may represent a new avenue in the treatment of glucose intolerance and type 2 diabetes.

Use of hydrogen peroxide to assess the sperm susceptibility to oxidative stress in subjects presenting a normal semen profile

Human sperm susceptibility to oxidative stress is vital as it affects various characteristics of sperm function. In the present study, we report a simple, sensitive and quick method of assessing the capacity of the sperms to withstand increased oxidative stress. The basis for the test was derived from the fact that human sperms suspended in Ham's F-10 medium tend to lose the forward progressive motility when co-incubated with H(2)O(2) (600 microm). Replacement of the medium with seminal plasma (1: 1) was able to reduce the loss of sperm motility (40%). Retention of sperm motility in semen (0-30%) following 10 min of H(2)O(2) (600 microm) exposure was taken as the criteria for delineating the quality of sperm as poor, moderate, good and excellent types. The protocol was tested in 87 subjects presenting a normal semen profile. On the basis of this test, 44% of the semen samples were classified as poor and the rest as moderate, good or excellent. Lipid peroxidation was found higher in the sperms from the 'poor' category. Activities of superoxide dismutase and catalase were also significantly elevated in the seminal plasma of these subjects as compared with combined categories of good or excellent. The test described here can be used routinely in laboratory investigations to assess sperm susceptibility to oxidative stress in subjects presenting a normal semen profile.

Comparative assessment of DNA fingerprinting techniques (RAPD, ISSR and AFLP) for genetic analysis of cashew (Anacardium occidentale L.) accessions of India

Nineteen cashew accessions were analysed with 50 random primers, 12 ISSR primers and 6 AFLP primer pairs to compare the efficiency and utility of these techniques for detecting variation in cashew germplasm. Each marker system could discriminate between all of the accessions, albeit with varied efficiency of polymorphism detection. AFLP exhibited maximum discrimination efficiency with a genotype index of 1. The utility of each molecular marker technique, expressed as marker index, was estimated as a function of average band informativeness and effective multiplex ratio. Marker index was calculated to be more than 10 times higher in AFLP than in RAPD and ISSR. Similarity matrices were determined based on the data generated by molecular and morphometric analyses, and compared for congruency. AFLP displayed no correspondence with RAPD and ISSR. Correlation between ISSR and RAPD similarity matrices was low but significant (r = 0.63; p < 0.005). The similarity matrix based on morphometric markers exhibited no correlation with any of the molecular markers. AFLP, with its superior marker utility, was concluded to be the marker of choice for cashew genetic analysis.

Role of brain insulin receptor in control of body weight and reproduction

Insulin receptors (IRs) and insulin signaling proteins are widely distributed throughout the central nervous system (CNS). To study the physiological role of insulin signaling in the brain, we created mice with a neuron-specific disruption of the IR gene (NIRKO mice). Inactivation of the IR had no impact on brain development or neuronal survival. However, female NIRKO mice showed increased food intake, and both male and female mice developed diet-sensitive obesity with increases in body fat and plasma leptin levels, mild insulin resistance, elevated plasma insulin levels, and hypertriglyceridemia. NIRKO mice also exhibited impaired spermatogenesis and ovarian follicle maturation because of hypothalamic dysregulation of luteinizing hormone. Thus, IR signaling in the CNS plays an important role in regulation of energy disposal, fuel metabolism, and reproduction.

Poncet's disease

Tuberculous rheumatism is not generally accepted as a specific disease entity in Great Britain or the U.S.A. We are reporting a adult male whom we believe suffered from this disease, to open the controversy surrounding its existence with a review of the literature.