The clinical year dilemma: Examining the stressors and alternatives of pre-radiology training

Since its reinstatement in 1997, the effectiveness of the clinical year prior to radiology residency has been a contentious topic concerning its role in cultivating skilled radiologists. This review evaluates the limitations of the one-year internship and explores alternative approaches. Utilizing databases such as PubMed, Google Scholar, and Scopus, this study identified pertinent articles that aligned with the inclusion criteria for post-graduate year 1 (PGY-1) training before radiology residency. Through a qualitative analysis of the literature, the review identifies prevalent themes concerning the drawbacks of the preliminary clinical year and potential alternative strategies. Many current trainees express skepticism about the value of the clinical year, noting a disconnect between its generalist nature and the specialized demands of subsequent radiology training. Interns felt uncertain about radiology exam indications and found radiology departments to be unapproachable, reflecting the need for alternative educational strategies to improve the preparedness and confidence of radiology interns as they transition from academic environments to clinical practice. The preparatory clinical year prior to entering radiology residency presents a mix of utility, along with alternative approaches to structuring this year. These alternatives include incorporating it into the undergraduate medical curriculum, restructuring or designing radiology-focused clinical years, and reevaluating the overall effectiveness of the clinical year in training.

Metabolic-associated fatty liver disease and hepatocellular carcinoma: a prospective study of characteristics and response to therapy

BACKGROUND AND AIM

The rising incidence of hepatocellular carcinoma (HCC) in Australia is related to increasing rates of metabolic-associated fatty liver disease (MAFLD). This study aimed to prospectively characterize the metabolic profile, lifestyle, biometric features, and response to treatment of HCC patients in an Australian population.

METHOD

Multicenter prospective cohort analysis of newly diagnosed HCC patients at six multidisciplinary team meetings over a 2-year period.

RESULTS

Three hundred and thirteen (313) newly diagnosed HCC patients with MAFLD (n = 77), MAFLD plus other liver disease (n = 57) (the "mixed" group), and non-MAFLD (n = 179) were included in the study. Alcohol-associated liver disease (ALD) (43%) and MAFLD (43%) were the most common underlying liver diseases. MAFLD-HCC patients were older (73 years vs 67 years vs 63 years), more likely to be female (40% vs 14% vs 20%), less likely to have cirrhosis (69% vs 88% vs 85%), showed higher ECOG, and were less likely to be identified by screening (29% vs 53% vs 45%). Metabolic syndrome was more prevalent in the MAFLD and mixed groups. The severity of underlying liver disease and HCC characteristics were the same across groups. While the MAFLD population self-reported more sedentary lifestyles, reported dietary patterns were no different across the groups. Dyslipidemia was associated with tumor size, and those taking statins had a lower recurrence rate.

CONCLUSION

Equal to ALD, MAFLD is now the most common underlying liver disease seen in HCC patients in Australia. Future HCC prevention screening and treatment strategies need to take this important group of patients into consideration.

Troponin I Elevation after Elective Percutaneous Coronary Interventions: Prevalence and Risk Factors

Percutaneous coronary intervention (PCI) is one of the most important modalities of treatment for coronary artery disease (CAD). Minor extents of injury to the myocardium have been observed even after successful PCI. This peri-procedural injury might therefore reduce some of the beneficial effects of coronary revascularization. The objective of this hospital based comparative observational study was to determine the prevalence of post procedural Cardiac troponin I (cTnI) elevation after elective PCI and also to find out the relation with risk factors such as age, sex, body mass index (BMI), smoking, anemia, diabetes mellitus, hypertension, dyslipidemia, family history, left ventricular dysfunction, renal insufficiency, type of stent, number of stent and length of stent. This was a hospital based comparative observational study carried out in the Department of Cardiology, Chattogram Medical College Hospital (CMCH), Chattogram, Bangladesh from July 2018 to June 2019. A total of 50 patients who underwent elective PCI were included as sampled by purposive sampling method. Serum cTnI was measured by FIA8000 quantitative immunoassay analyzer with an analytical measurement before and at 24 hours of PCI. Value >1.0ng/ml was considered elevated. Univariate and multivariate analysis were applied to assess predictors for the occurrence of post-procedural elevation of cTnI. The mean±SD age of the study population was 54.96±9.1 years (range 35-74 years) and 34(68.0%) patients were male. Regarding cardiovascular risk factors, 17(34.0%) patients had diabetes mellitus, 27(54.0%) had dyslipidemia, 30(60.0%) had hypertension, 32(64.0%) were current or ex-smokers and 20(40.0%) had a family history of CAD. Eighteen patients (36.0%) had post-procedural cTnI elevation but only 8(16.0%) had significant (>1.0ng/ml) elevation. Change of cTnI before and at 24 hours of PCI was not significant (p=0.057). Cardiac Troponin I increase was related to age, pre-procedural serum creatinine and multi-vessel stenting. Minor elevation of cTnI was common following elective PCI and associated with few risk factors such as elderly patient (more than 50 years), raised serum creatinine and multi-vessel stenting. So, early detection of these risk factors, as well as effective intervention may help to prevent injury to cardiac tissue hence stop elevation of cardiac TnI following elective PCI.

Comparison of Risk Factors and Angiographic Profile between Younger and Older Patients with Acute Myocardial Infarction

Acute myocardial infarction (AMI) in younger adults (≤40 years) is being increasingly encountered in recent years among the South Asian population. Data regarding the presentation, risk factors and angiographic findings on this important subset of patients is lacking in our country. The aim of this study was to compare the risk factors and pattern of Coronary artery involvement in younger patients presenting with AMI with that of the older age group. This was a cross-sectional observational study conducted during the period from October 2018 to June 2019. Seventy consecutive AMI patients age ≤40 years and another 70 consecutive AMI patients age >40 years undergoing Coronary Angiogram (CAG) were included in the study. After taking informed written consent; demographic, anthropometric, risk factors, CAG findings were recorded in a pre-designed case record form. The severity of Coronary Artery Disease (CAD) was calculated by using Gensini score. The mean age of the younger and older patient groups was 36.89±4.4 years and 57.00±8.4 years respectively. Among the risk factors, smoking (67.1% versus 45.7%, p=0.017), positive family history CAD (38.6% versus 22.9%, p=0.040) and obesity (34.3% versus 20.0%, p= 0.05) were more common in younger group. Whereas, Hypertension (41.4% versus 72.9%, p=0.010) and DM (28.6% versus 50.0%, p=0.024) were more common in older patients. Younger patients mainly presented with STEMI (60.0% versus 48.6%) and predominantly had single vessel disease (42.9%), whereas older patients readily presented with NSTEMI (51.4%) and had a higher incidence of double vessel disease (32.9%) and triple vessel disease (30.0%). The Median Gensini score was significantly higher among the older patients than in the younger age group. Patients in younger age group showed a different pattern of risk factors and coronary artery involvement in comparison to the older age group. Thus, offering younger individuals to make them aware of these risk factors and their early detection, as well as an effective intervention may help to prevent AMI in younger people.

Governing roles for Trib3 pseudokinase during stress erythropoiesis

In response to anemia, the heightened production of erythropoietin (EPO) can sharply promote erythroid progenitor cell (EPC) formation. Specific mediators of such EPO- accelerated erythropoiesis, however, are not well understood. Presently, we first report that the expression of Trib3 in adult bone marrow EPCs in vivo is nominal at steady state, but strongly activated on EPO challenge. In a knockout mouse model, Trib3 disruption modestly increased steady-state erythrocyte numbers and decreased mean corpuscular volume. Following 5-fluorouracil myeloablation, however, rebound red blood cell production and hemoglobin levels were substantially (and selectively) compromised in Trib3^-/- mice versus Trib3^+/+ congenic controls. Erythrocytes from 5-fluorouracil-treated Trib3^-/- mice additionally were more prone to lysis and exhibited elevated peroxide-induced reactive oxygen species. Ex vivo, the development of CD71^posTer119^pos erythroblasts from Trib3^-/- bone marrow progenitors was attenuated, and this was associated with heightened EPO-dependent Erk1/2 activation and moderately increased Akt activation. For developmentally staged EPCs, gene profiling provided further initial insight into candidate mediators of EPO-induced Trib3 gene expression, including Cebp-beta, Atf4, Egr-1, and Nab1. Overall, Trib3 is indicated to act as a novel EPC-intrinsic governor of stress erythropoiesis.

Factors associated with poor adherence to antiviral treatment for hepatitis B

Antiviral therapy for hepatitis B is effective and reduces the risk of progression to cirrhosis and liver cancer but is often required for an indefinite duration. Treatment adherence is important to prevent the development of resistance and optimize outcomes. Pharmacy adherence measures can be used to assess treatment adherence, with the medication possession ratio being less susceptible to bias than physician- or self-reported adherence. The aim of this study was to measure adherence in public hospital outpatients over a 3-year period and to examine factors associated with nonadherence. A retrospective study of pharmacy records of patients dispensed antiviral therapy for hepatitis B from four major hospitals in Melbourne between 2010 and 2013. Hospital record numbers were linked with and de-identified demographic information including age, sex, Indigenous status, country of birth, interpreter requirement, spoken language and postcode of residence. The medication possession ratio was the outcome measure with poor adherence defined <.90. Univariate logistic regression and multivariate logistic regression were performed to examine associations with nonadherence. Records of 1026 patients were included in the analysis. Twenty per cent of all participants met the definition of poor adherence. Significant factors affecting adherence included age <35 years (P=.002), hospital site and treatment by multiple doctors within shorter time periods. This is the largest study examining detailed factors associated with adherence to hepatitis B treatment. Understanding poor adherence in clinical settings, and the factors associated with lower adherence, is important to inform efforts towards promoting treatment adherence for hepatitis B.

Nano-curcumin influences blue light photodynamic therapy for restraining glioblastoma stem cells growth

Nano-curcumin based blue light photodynamic therapy has therapeutic potential in the arsenal of glioblastoma cancer stem cells recurrence.

Paraduodenal pancreatitis

Paraduodenal pancreatitis is a distinct clinicopathological entity involving the duodenum and the pancreatic tissue in the vicinity of the minor papilla. Most afflicted patients are young alcoholic males who present clinically with upper abdominal pain, weight loss, nausea, and vomiting. Pancreatic tissue elements in the duodenal wall and impedance to exocrine pancreatic secretions at the minor papilla are key factors in the pathogenesis of this condition. On imaging, the condition may manifest as a solid fibrotic mass around the minor papilla or as cysts in the duodenum and the pancreaticoduodenal groove. Duodenal stenosis, biliary strictures, chronic calcifying pancreatitis, and pancreatic ductal dilatation are also often observed.

Generation of substrate-free III-V nanodisks from user-defined multilayer nanopillar arrays for integration on Si

High material quality InP-based multilayer nanopillar (NP) arrays are fabricated using a combination of self-assembly of silica particles for mask generation and dry etching. In particular, the NP arrays are made from user-defined epitaxial multilayer stacks with specific materials and layer thicknesses. An additional degree of flexibility in the structures is obtained by changing the lateral diameters of the NP multilayer stacks. Pre-defined NP arrays made from InGaAsP/InP and InGaAs/InP NPs are then used to generate substrate-free nanodisks of a chosen material from the stack by selective etching. A soft-stamping method is demonstrated to transfer the generated nanodisks with arbitrary densities onto Si. The transferred nanodisks retain their smooth surface morphologies and their designed geometrical dimensions. Both InP and InGaAsP nanodisks display excellent photoluminescence properties, with line-widths comparable to unprocessed reference epitaxial layers of similar composition. The multilayer NP arrays are potentially attractive for broad-band absorption in third-generation solar cells. The high optical quality, substrate-free InP and InGaAsP nanodisks on Si offer a new path to explore alternative ways to integrate III-V on Si by bonding nanodisks to Si. The method also has the advantage of re-usable III-V substrates for subsequent layer growth.

Erythropoietin-directed erythropoiesis depends on serpin inhibition of erythroblast lysosomal cathepsins

Serpina3g/Spi2A inhibits cathepsins B/L to enhance erythropoietin induced red blood cell formation.

Erythropoietin (EPO) and its cell surface receptor (EPOR) are essential for red blood cell production and exert important cytoprotective effects on select vascular, immune, and cancer cells. To discover novel EPO action modes, we profiled the transcriptome of primary erythroid progenitors. We report Serpina3g/Spi2A as a major new EPO/EPOR target for the survival of erythroid progenitors. In knockout mice, loss of Spi2A worsened anemia caused by hemolysis, radiation, or transplantation. EPO-induced erythropoiesis also was compromised. In particular, maturing erythroblasts required Spi2A for cytoprotection, with iron and reactive oxygen species as cytotoxic agents. Spi2A defects were ameliorated by cathepsin-B/L inhibition, and by genetic co-deletion of lysosomal cathepsin B. Pharmacological inhibition of cathepsin B/L enhanced EPO-induced red cell formation in normal mice. Overall, we define an unexpected EPO action mode via an EPOR–Spi2A serpin–cathepsin axis in maturing erythroblasts, with lysosomal cathepsins as novel therapeutic targets.

Stable enhancement of near-band-edge emission of ZnO nanowires by hydrogen incorporation

We report on the photoluminescence properties of ZnO nanowires treated with a mild Ar plasma. The nanowires exhibited stable and strong enhancement of the near-band-edge emission and quenching of the deep level emission. The low temperature PL revealed a strong hydrogen donor-bound-exciton line in the plasma-treated samples indicating unintentional incorporation of hydrogen during the plasma treatment. To confirm the results, hydrogen was implanted into the ZnO nanowires with a low ion energy of 600 eV and different fluences. The observed result can be related to the passivation of deep centers by hydrogen. The absolute photoluminescence intensity measured by an integrating sphere showed stable and strong UV emission from the treated samples even after several weeks.

A newborn with hereditary haemorrhagic telangiectasia and an unusually severe phenotype

Hereditary haemorrhagic telangiectasia (HHT), associated with arteriovenous malformations, is a genetic disease of the vascular system with a frequency of approx. 1:10,000. Genetic diagnosis serves to identify individuals at risk of developing the disease and is a useful tool for genetic counselling purposes.

QUESTIONS UNDER STUDY

Here we report on a child presenting severe arteriovenous malformations leading to heart failure. Her mother and grandmother present fewer symptoms of hereditary haemorrhagic telangiectasia. In this study we identify the cause of HHT in the family.

METHODS

Clinical examination, PCR, DNA sequencing, quantitative PCR, Southern blot, xray, ultrasound, cardiac catheterisation and angiocardiography.

RESULTS

Initially the sequence variant in c.392C>T in the endoglin gene was detected in the grandmother, but not in other affected family members. Further analyses revealed a deletion of exon 1 of endoglin, segregating with the phenotype.

CONCLUSIONS

This report points out the need for careful evaluation of molecular genetic findings, particularly in diseases with highly variable phenotype.

DYRK3 dual-specificity kinase attenuates erythropoiesis during anemia

During anemia erythropoiesis is bolstered by several factors including KIT ligand, oncostatin-M, glucocorticoids, and erythropoietin. Less is understood concerning factors that limit this process. Experiments performed using dual-specificity tyrosine-regulated kinase-3 (DYRK3) knock-out and transgenic mice reveal that erythropoiesis is attenuated selectively during anemia. DYRK3 is restricted to erythroid progenitor cells and testes. DYRK3-/- mice exhibited essentially normal hematological profiles at steady state and reproduced normally. In response to hemolytic anemia, however, reticulocyte production increased severalfold due to DYRK3 deficiency. During 5-fluorouracil-induced anemia, both reticulocyte and red cell formation in DYRK3-/- mice were elevated. In short term transplant experiments, DYRK3-/- progenitors also supported enhanced erythroblast formation, and erythropoietic advantages due to DYRK3-deficiency also were observed in 5-fluorouracil-treated mice expressing a compromised erythropoietin receptor EPOR-HM allele. As analyzed ex vivo, DYRK3-/- erythroblasts exhibited enhanced CD71posTer119pos cell formation and 3HdT incorporation. Transgenic pA2gata1-DYRK3 mice, in contrast, produced fewer reticulocytes during hemolytic anemia, and pA2gata1-DYRK3 progenitors were compromised in late pro-erythroblast formation ex vivo. Finally, as studied in erythroid K562 cells, DYRK3 proved to effectively inhibit NFAT (nuclear factor of activated T cells) transcriptional response pathways and to co-immunoprecipitate with NFATc3. Findings indicate that DYRK3 attenuates (and possibly apportions) red cell production selectively during anemia.

Interferon and ribavirin therapy does not select for resistance mutations in hepatitis C virus polymerase

Ribavirin has a minor and transient effect on hepatitis C virus (HCV) replication and has been suggested to select a novel mutation, F415Y, in the RNA-dependent RNA polymerase of subtype 1a viruses. Twenty-nine patients with chronic hepatitis C (subtyped by INNO LiPA as 1a, 17; 1b, 11; 1a/1b, 1) who were nonresponders to interferon-based therapies were identified retrospectively and screened at Baseline, week 24 of treatment, and 24 weeks post-treatment. Selection of resistance mutations, including at amino acid position 415 of the polymerase, was investigated. Using clonal sequencing and pyrosequencing of the NS5B gene, we screened for the F415Y resistance mutation among patients who received combination therapy with ribavirin and interferon α. Of the 15 subtype 1a patients treated with interferon plus ribavirin, only one had the F415Y change at week 24, and an F/Y mixture was still present 24 weeks after therapy. Four additional patients in this group had the F415Y change 24 weeks post-therapy. The NS5B genes were sequenced in order to identify amino acid changes associated with ribavirin therapy, but no evidence was found that ribavirin selects for particular amino acids in the RNA-dependent RNA polymerase. Ribavirin, a weak inhibitor of HCV replication, does not select for resistance mutations in the sequence of the HCV RNA polymerase.

A newborn with hereditary haemorrhagic telangiectasia and an unusually severe phenotype

Hereditary haemorrhagic telangiectasia (HHT), associated with arteriovenous malformations, is a genetic disease of the vascular system with a frequency of approx. 1:10,000. Genetic diagnosis serves to identify individuals at risk of developing the disease and is a useful tool for genetic counselling purposes.

QUESTIONS UNDER STUDY

Here we report on a child presenting severe arteriovenous malformations leading to heart failure. Her mother and grandmother present fewer symptoms of hereditary haemorrhagic telangiectasia. In this study we identify the cause of HHT in the family.

METHODS

Clinical examination, PCR, DNA sequencing, quantitative PCR, Southern blot, xray, ultrasound, cardiac catheterisation and angiocardiography.

RESULTS

Initially the sequence variant in c.392C>T in the endoglin gene was detected in the grandmother, but not in other affected family members. Further analyses revealed a deletion of exon 1 of endoglin, segregating with the phenotype.

CONCLUSIONS

This report points out the need for careful evaluation of molecular genetic findings, particularly in diseases with highly variable phenotype.

Mice deficient for RNA-binding protein brunol1 show reduction of spermatogenesis but are fertile

RNA-binding proteins are involved in post-transcriptional processes like mRNA stabilization, alternative splicing, and transport. Brunol1 is a novel mouse gene related to elav/Bruno family of genes encoding for RNA-binding proteins. We report here the expression and functional analysis of murine Brunol1. Expression analysis of Brunol1 during embryogenesis by RT-PCR showed that Brunol1 expression starts at 9.5 dpc and continues to the later stages of embryonic development. In adult mice, the Brunol1 expression is restricted to brain and testis. We also analyzed the Brunol1 expression in testes of different mutants with spermatogenesis defects: W/W(V), Tfm/y, Leyl(-/-), olt/olt, and qk/qk. Brunol1 transcript was detectable in Leyl(-/-), olt/olt, and qk/qk mutant but not in W/W(V) and Tfm/y mutants. We also showed by transfection of a fusion protein of green fluorescent protein and Brunol1 protein into NIH3T3 cells, that Brunol1 is localized in cytoplasm and nucleus. In order to elucidate the function of the Brunol1 protein in spermatogenesis, we disrupted the Brunol1 locus in mouse by homologous recombination, which resulted in a complete loss of the Brunol1 transcript. Male and female Brunol1(+/-) and Brunol1(-/-) mice from genetic backgrounds C57BL/6J x 129/Sv hybrid and 129X1/SvJ when inbred exhibited normal phenotype and are fertile, although the number and motility of sperms are significantly reduced. An intensive phenotypic analysis showed no gross abnormalities in testis morphology. Collectively our results demonstrate that Brunol1 might be nonessential protein for mouse embryonic development and spermatogenesis.

Expression, localization and tau exon 10 splicing activity of the brain RNA-binding protein TNRC4

Elucidating the mechanisms of alternative splicing in the brain is a prerequisite to the understanding of the pathogenesis of major neurological diseases linked to impairment of pre-mRNA alternative splicing. The gene trinucleotide repeat-containing 4 (TNRC4) is predicted to encode a member of the CELF (CUG-BP- and ETR-3-like factors) family of RNA-binding proteins containing a 15-18-residue polyglutamine sequence. The TNRC4 transcript is selectively expressed in the brain. Using an anti-peptide antibody against the predicted sequence, we establish the presence of TNRC4 as a approximately 50 kDa protein in the brain. Full-length TNRC4 displays nuclear and cytoplasmic localizations in transfected cells, whereas a C-terminally truncated mutant is essentially confined to the cytoplasm. TNRC4 is not recruited into inclusions formed by polyglutamine-expanded ataxin-1 or huntingtin. TNRC4 activates tau exon 10 (E10) inclusion at high efficiency in transfected cells. TNRC4 contains two consecutive N-terminal RNA recognition motifs (RRMs) separated from the C-terminal RRM. Deletion and point mutant analysis show that the activity of TNRC4 on tau E10 splicing is mainly mediated by the RNA-binding activity of the second RRM and involves an intronic element of the tau pre-mRNA. The polyglutamine sequence has no effect on the activity of TNRC4 on tau E10 splicing. This study represents the first characterization of TNRC4 and provides further insight into the mechanisms of brain-specific alternative splicing and their possible pathological implications.

Premature translation of transition protein 2 mRNA causes sperm abnormalities and male infertility

During mammalian spermiogenesis somatic histones are replaced at first by transition proteins, which are in turn replaced by the protamines, forming the sperm nucleoprotamines. It is believed that transition protein 2 (Tnp2) is necessary for maintaining the normal processing of protamines and, consequently, the completion of chromatin condensation. The transition protein mRNAs are stored in translationally inert messenger ribonucleoprotein particles for up to 7 days until translational activation in elongated spermatids. Substantial evidence suggests an involvement of 3'untranslated region (UTR) in the translational regulation of the Tnp2 mRNAs. In order to determine the role of Tnp2 3'UTR in translational regulation and to study whether the translational repression of Tnp2 mRNA is necessary for normal spermatid differentiation in mice, we generated transgenic mice that carry a Tnp2-hGH transgene. In this transgene, 3'UTR of Tnp2 gene was replaced by 3' 3'UTR of human growth hormone gene. In these transgenic animals, transcription and translation of Tnp2 occur simultaneously in round spermatids which is an evidence for involvement of Tnp2 3'UTR in its translation repression. Premature translation of Tnp2 mRNA caused abnormal head morphogenesis, reduced sperm motility and male infertility. These results show clearly that a strict temporal and stage-specific Tnp2 translation is necessary for the correct differentiation of round spermatids into mature spermatozoa and for male fertility.

Asthenoteratozoospermia in mice lacking testis expressed gene 18 (Tex18)

Testis expressed gene 18 (Tex18) is a small gene with one exon of 240 bp, which is specifically expressed in male germ cells. The gene encodes for a protein of 80 amino acids with unknown domain. To investigate the function of (Tex18) gene, we generated mice with targeted disruption of the (Tex18) gene by homologous recombination. Homozygous mutant males on a mixed genetic background (C57BL/6J x 129/Sv) are fertile, while they are subfertile on the 129/Sv background, although mating is normal. We showed that Tex18(-/-) males are subfertile because of abnormal sperm morphology and reduced motility, which is called asthenoteratozoospermia, suggesting that (Tex18) affects sperm characteristics. Maturation of spermatids is unsynchronized and partially impaired in seminiferous tubules of Tex18(-/-) mice. Electron microscopical examination demonstrated abnormal structures of sperm head. In vivo experiments with sperm of Tex18(-/-) 129/Sv mice revealed that the migration of spermatozoa from the uterus into the oviduct is reduced. This result is supported by the observation that sperm motility, as determined by the computer-assisted semen analysis system, is significantly affected, compared to wild-type spermatozoa. Generation of transgenic mice containing Tex18-EGFP fusion construct revealed a high transcriptional activity of (Tex18) during spermiogenesis, a process with morphological changes of haploid germ cells and development to mature spermatozoa. These results indicate that (Tex18) is expressed predominantly during spermatid differentiation and subfertility of the male Tex18(-/-) mice on the 129/Sv background is due to the differentiation arrest, abnormal sperm morphology and reduced sperm motility.

Putative human male germ cells from bone marrow stem cells

Germ cells must develop along distinct male or female paths to produce the spermatozoa or oocyte required for sexual reproduction. Male germline stem cells maintain spermatogenesis in the postnatal human testis. Here we show that a small population of bone marrow cells is able to transdifferentiate to male germ cell-like cells. We show expression of early germ cell markers (Oct4, Fragilis, Stella and Vasa) and male germ cell specific markers (Dazl, TSPY, Piwil2 and Stra8) in these cells. Our preliminary findings provide direct evidence that human bone marrow cells can differentiate to putative male germ cells and identify bone marrow as a potential source of male germ cells that could sustain sperm production.

The neuroleptic malignant syndrome: A report of 14 cases from North India

Neuroleptic malignant syndrome (NMS) is a rare, life-threatening but potentially treatable condition. This study was performed to investigate the clinical spectrum, antecedent events and outcome of NMS patients admitted in the Neurology department of a large teaching hospital of North India. Fourteen cases of NMS were taken after a thorough search during a three-year period (May 2000 to April 2003). The Incidence of NMS was 1.40/ 1000 patients treated with neuroleptics and mortality rate was 14.28%. Amongst the neuroleptics Haloperidol (parenteral) was implicated as a most common drug for NMS in 57% of patients. An association with coexisting precipitating illness was clearly recorded in 71.4% patients. All the recorded patients of NMS received 500-700 mg CPZ equivalent/day of neuroleptics. NMS as an indiosyncratic phenomenon was noticed in 28% patients. 85.7% responded to dopaminergic drugs along with supportive treatment and showed partial or complete recovery within 7-14 days. In those with partial recovery residual deficits included Parkinsonian features, depression and diaphoresis in a small percentage of patients.

In vitro-differentiated embryonic stem cells give rise to male gametes that can generate offspring mice

Male gametes originate from a small population of spermatogonial stem cells (SSCs). These cells are believed to divide infinitely and to support spermatogenesis throughout life in the male. Here, we developed a strategy for the establishment of SSC lines from embryonic stem (ES) cells. These cells are able to undergo meiosis, are able to generate haploid male gametes in vitro, and are functional, as shown by fertilization after intracytoplasmic injection into mouse oocytes. Resulting two-cell embryos were transferred into oviducts, and live mice were born. Six of seven animals developed to adult mice. This is a clear indication that male gametes derived in vitro from ES cells by this strategy are able to induce normal fertilization and development. Our approach provides an accessible in vitro model system for studies of mammalian gametogenesis, as well as for the development of new strategies for the generation of transgenic mice and treatment of infertility.

Co-existence of dual intracranial pathology clinical relevance of proton MRS

The co-existence of neuro-cysticercosis (NCC) and intracranial neoplasm in an individual is a rare entity. Atypical presentation of cerebral cysticercosis may mimic glioma, metastasis, cerebral abscess or vice versa. The dual existence of these two lesions have led to several postulates which may have clinical impact in due course of time i.e. NCC as an oncogenetic factor for glioma or similarity of antigen found in glioma and NCC etc. An adequate management of such cases poses a challenge to both imageologists as well as clinicians. Thus, a proper diagnostic evaluation is essential for successful management of such cases. MR spectroscopy (MRS), although still a clinical research tool, may be extremely useful for exclusion or confirmation of neoplastic lesions in such a clinical scenario. The findings of MRS in collaboration with imaging parameters may increase the diagnostic yield of a MR investigation. The authors encountered five cases of dual intracranial pathologies i.e. neurocysticercosis and glioma. MR spectroscopy was useful to arrive at a definitive diagnosis in such a situation.

Detection of moving objects in video using a robust motion similarity measure

This correspondence deals with the segmentation of a video clip into independently moving visual objects. This is an important step in structuring video data for storage in digital libraries. The method follows a bottom-up approach. The major contribution is a new well-founded measure for motion similarity leading to a robust method for merging regions. The improvements with respect to existing methods have been confirmed by experimental results.

Acquired tracheo-oesophageal fistula (a case report)

A case of acquired tracheo-oesophageal fistula in a 16-year-old boy, caused by a bullet wound, is presented. The fistula was located just below the cricoid cartilage and was successfully treated by excision of the fistula followed by interposition of the sternomastoid muscle.