Risk Factors Associated With Clostridium difficile-Associated Diarrhea

Introduction: Recent years have been alarming due to the sudden, dramatic rise in the incidence of Clostridium difficile infection (CDI). Identifying and addressing the risk factors associated with CDI will help in reducing the incidence of infection and associated complications.

Methods: This case-control study was conducted in a tertiary care hospital in Pakistan from June 2020 to March 2021, in which 200 patients diagnosed with Clostridium difficile-associated diarrhea (CDAD) were enrolled in the study. CDAD was diagnosed based on clinical symptoms and stool enzyme immunoassay. Another 200 participants without a diagnosis of CDAD were enrolled from the outpatient department as a control group. Participants were enrolled after seeking informed consent.

Results: In patients older than 65, risk of CDI was higher compared to participants lower than 65 years old (15.5% vs. 8.0%; p value: 0.02). Hospitalization (25.5% vs. 6.0%; p value < 0.0001), the use of proton pump inhibitors in last 30 days (23.0% vs. 10.5%; p value: 0.001) , and use of antibiotics in the last 30 days (36.0% vs. 10.5%; p value < 0.0001) were significantly higher in participants with CDI.

Conclusion: Hospitalization, the usage of proton pump inhibitors, and antibiotics in the last 30 days were significantly associated with CDI. A higher incidence of CDI was associated with risk factors like increased body mass index, diabetes, chronic kidney disease, and malignancy.

Frequency of Subclinical Hypothyroidism in Women With Polycystic Ovary Syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by hyperandrogenism and chronic anovulation. It may also influence thyroid hormones. Increasing evidence suggests that PCOS is linked with an increased prevalence of thyroid diseases such as nodular goiter, autoimmune thyroiditis, and subclinical hypothyroidism (SCH). Due to very limited global and regional data related to the prevalence of SCH in women with PCOS, we will determine the association between the two.

METHODS

This case-control study was conducted in the endocrinology ward of a tertiary care hospital in Pakistan from March 2020 to April 2021. We enrolled 200 females between the ages of 18 and 30 years, with documented evidence of PCOS in the study. Further 200 females without PCOS were enrolled as the case group. After demographics were noted, blood was drawn from their cubital vein via phlebotomy and sent to the laboratory to assess for thyroid-stimulating hormone, free thyroxine, and free triiodothyronine.

RESULTS

SCH was found to be more prevalent in participant with PCOS compared to participants without PCOS (43.5% vs. 20.5%; p-value: <0.00001). Increased weight (65.12 ± 5.62 kg vs. 60.02 ± 4.41 kg; p-value: <0.0001) and BMI (25.12 ± 2.51 kg/m² vs. 22.51 ± 2.01 kg/m²; p-value: <0.0001) was significantly more in participants with PCOS compared to participants without PCOS.

CONCLUSION

Based on our findings, this study demonstrated the strong association of SCH in women with PCOS as compared to their normal counterparts. Therefore, the clinical implication is to maintain a high index of suspicion for signs and symptoms of SCH, and awareness is needed for such women to enhance the reproductive and clinical pregnancy outcomes.

Impact of Coronavirus Diseases on Liver Enzymes

Introduction Coronavirus disease 2019 (COVID-19) affects various organs including lungs, brain, and eyes. Very limited data is available related to the effect of COVID-19 on liver. This study is conducted to determine the impact of COVID-10 on liver by measuring the frequency of participants with deranged liver enzymes in patients diagnosed with COVID-19. Methods This cross-sectional study was conducted in a COVID-19 unit of a tertiary care hospital in Pakistan from February 2021 to June 2021. A total of 900 patients admitted with COVID-19 were enrolled in the study after seeking informed consent. After enrollment, taking history and vitals, 5 mL blood was drawn via phlebotomy and sent to the laboratory to test for C-reactive protein, lactate dehydrogenase, and liver enzymes. Results Overall 141 (28.2%) participants had a minimum of one deranged liver enzyme. The most commonly deranged liver enzyme found was alanine transaminase (ALT), both in males (19.9%) and females (21.3%), followed by aspartate transaminase (male: 18.3% and female: 20.3%). Serum total bilirubin was deranged in both males (8.4%) and females (8.3%). There was no significant difference in the gender-wise prevalence of deranged liver enzymes.  Conclusion Liver enzymes are frequently deranged in patients admitted with COVID-19. Liver enzymes should be regularly monitored during the course of management of COVID-19, as various medications used in the treatment of COVID-19 may further deteriorate liver enzymes and may cause long-term damage.

CEACAM7 Is an Effective Target for CAR T-cell Therapy of Pancreatic Ductal Adenocarcinoma

PURPOSE

To investigate whether CEACAM7 represents a novel therapeutic target for treating pancreatic ductal adenocarcinoma (PDAC) and to generate CEACAM7-targeting CAR T cells to test this hypothesis.

EXPERIMENTAL DESIGN

We identified CEACAM7 (CGM2), a member of the CEA family of proteins with expression restricted to the colon and pancreas, as a potential CAR T-cell target for PDAC. We probed a panel of PDAC tumor sections as well as patient-derived PDAC cell cultures for CEACAM7 expression. We generated CAR-targeting CEACAM7, and assessed antitumor efficacy of CEACAM7 CAR T cells using in vitro and in vivo models.

RESULTS

We show here that CEACAM7 is expressed in a large subset of PDAC tumors, with low to undetectable expression in all normal tissues tested. CEACAM7 is also expressed in primary PDAC cultures isolated from patient-derived tumors, with high expression within the cancer stem cell-enriched subset. CAR T cells targeting CEACAM7 are capable of targeting antigen-expressing tumor cells, and mediate remission in patient-derived xenograft tumors.

CONCLUSIONS

We identify CEACAM7 as a potential therapeutic target in PDAC and describe the development of CEACAM7-targeted CAR T cells with efficacy against PDAC.

Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: an abridged Cochrane network meta-analysis

Postoperative nausea and vomiting is a common adverse effect of anaesthesia. Although dozens of different anti-emetics are available for clinical practice, there is currently no comparative ranking of efficacy and safety of these drugs to inform clinical practice. We performed a systematic review with network meta-analyses to compare, and rank in terms of efficacy and safety, single anti-emetic drugs and their combinations, including 5-hydroxytryptamine₃ , dopamine-2 and neurokinin-1 receptor antagonists; corticosteroids; antihistamines; and anticholinergics used to prevent postoperative nausea and vomiting in adults after general anaesthesia. We systematically searched for placebo-controlled and head-to-head randomised controlled trials up to November 2017 (updated in April 2020). We assessed how trustworthy the evidence was using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and Confidence In Network Meta-Analysis (CINeMA) approaches for vomiting within 24 h postoperatively, serious adverse events, any adverse event and drug class-specific side-effects. We included 585 trials (97,516 participants, 83% women) testing 44 single drugs and 51 drug combinations. The studies' overall risk of bias was assessed as low in only 27% of the studies. In 282 trials, 29 out of 36 drug combinations and 10 out of 28 single drugs lowered the risk of vomiting at least 20% compared with placebo. In the ranking of treatments, combinations of drugs were generally more effective than single drugs. Single neurokinin-1 receptor antagonists were as effective as other drug combinations. Out of the 10 effective single drugs, certainty of evidence was high for aprepitant, with risk ratio (95%CI) 0.26 (0.18-0.38); ramosetron, 0.44 (0.32-0.59); granisetron, 0.45 (0.38-0.54); dexamethasone, 0.51 (0.44-0.57); and ondansetron, 0.55 (0.51-0.60). It was moderate for fosaprepitant, 0.06 (0.02-0.21) and droperidol, 0.61 (0.54-0.69). Granisetron and amisulpride are likely to have little or no increase in any adverse event compared with placebo, while dimenhydrinate and scopolamine may increase the number of patients with any adverse event compared with placebo. So far, there is no convincing evidence that other single drugs effect the incidence of serious, or any, adverse events when compared with placebo. Among drug class specific side-effects, evidence for single drugs is mostly not convincing. There is convincing evidence regarding the prophylactic effect of at least seven single drugs for postoperative vomiting such that future studies investigating these drugs will probably not change the estimated beneficial effect. However, there is still considerable lack of evidence regarding safety aspects that does warrant investigation.

Switchable CAR-T cells mediate remission in metastatic pancreatic ductal adenocarcinoma

OBJECTIVE

Pancreatic ductal adenocarcinoma (PDAC) is a disease of unmet medical need. While immunotherapy with chimeric antigen receptor T (CAR-T) cells has shown much promise in haematological malignancies, their efficacy for solid tumours is challenged by the lack of tumour-specific antigens required to avoid on-target, off-tumour effects. Switchable CAR-T cells whereby activity of the CAR-T cell is controlled by dosage of a tumour antigen-specific recombinant Fab-based 'switch' to afford a fully tunable response may overcome this translational barrier.

DESIGN

In this present study, we have used conventional and switchable CAR-T cells to target the antigen HER2, which is upregulated on tumour cells, but also present at low levels on normal human tissue. We used patient-derived xenograft models derived from patients with stage IV PDAC that mimic the most aggressive features of PDAC, including severe liver and lung metastases.

RESULTS

Switchable CAR-T cells followed by administration of the switch directed against human epidermal growth factor receptor 2 (HER2)-induced complete remission in difficult-to-treat, patient-derived advanced pancreatic tumour models. Switchable HER2 CAR-T cells were as effective as conventional HER2 CAR-T cells in vivo testing a range of different CAR-T cell doses.

CONCLUSION

These results suggest that a switchable CAR-T system is efficacious against aggressive and disseminated tumours derived from patients with advanced PDAC while affording the potential safety of a control switch.

The miR-25-93-106b cluster regulates tumor metastasis and immune evasion via modulation of CXCL12 and PD-L1

The stromal microenvironment controls response to injury and inflammation, and is also an important determinant of cancer cell behavior. However, our understanding of its modulation by miRNA (miR) and their respective targets is still sparse. Here, we identified the miR-25-93-106b cluster and two new target genes as critical drivers for metastasis and immune evasion of cancer cells. Using miR-25-93-106b knockout mice or antagomiRs, we demonstrated regulation of the production of the chemoattractant CXCL12 controlling bone marrow metastasis. Moreover, we identified the immune checkpoint PD-L1 (CD274) as a novel miR-93/106b target playing a central role in diminishing tumor immunity. Eventually, upregulation of miR-93 and miR-106b via miR-mimics or treatment with an epigenetic reader domain (BET) inhibitor resulted in diminished expression of CXCL12 and PD-L1. These data suggest a potential new therapeutic rationale for use of BET inhibitors for dual targeting of cancers with strong immunosuppressive and metastatic phenotypes.

Hypoxia Inducible Factor 1: A Urinary Biomarker of Kidney Disease

Identifying noninvasive biomarkers of kidney disease is valuable for diagnostic and therapeutic purposes. Hypoxia inducible factor 1 (HIF-1) expression is known to be elevated in the kidneys in several renal disease pathologies. We hypothesized that the urinary HIF-1a mRNA level may be a suitable biomarker for expression of this protein in chronic kidney disease (CKD). We compared HIF-1a mRNA levels from urine pellets of CKD and healthy subjects. To ensure that urinary HIF-1a mRNA is of kidney origin, we examined colocalization of HIF-1a mRNA with two kidney specific markers in urine cells. We found that HIF-1a mRNA is readily quantifiable in urine pellets and its expression was significantly higher in CKD patients compared with healthy adults. We also showed that the urinary HIF-1a mRNA comes primarily from cells of renal origin. Our data suggest that urinary HIF-1a mRNA is a potential biomarker in CKD and can be noninvasively assessed in patients.

Atopic Dermatitis or Hyper IgE Syndrome?

Eczema and skin infections are commonly encountered in children in the outpatient department. However, presence of both recurrent dermatitis and skin infections should alarm one to consider Hyper IgE syndrome (HIES) as a differential. Here we present a case of HIES in a two and a half year old female child with history of recurrent dermatitis and skin infections in the form of cold abscesses. Laboratory investigations showed markedly elevated IgE levels and high absolute eosinophils counts. Patient was treated with trimethoprim-sulfamethoxazole and supportive care. The current report highlights the fact that HIES can present in early childhood with just skin manifestations and without any significant pulmonary manifestations.J Nepal Paediatr Soc 2015;35(1):59-61

MiR-93 Controls Adiposity via Inhibition of Sirt7 and Tbx3

Conquering obesity has become a major socioeconomic challenge. Here, we show that reduced expression of the miR-25-93-106b cluster, or miR-93 alone, increases fat mass and, subsequently, insulin resistance. Mechanistically, we discovered an intricate interplay between enhanced adipocyte precursor turnover and increased adipogenesis. First, miR-93 controls Tbx3, thereby limiting self-renewal in early adipocyte precursors. Second, miR-93 inhibits the metabolic target Sirt7, which we identified as a major driver of in vivo adipogenesis via induction of differentiation and maturation of early adipocyte precursors. Using mouse parabiosis, obesity in mir-25-93-106b(-/-) mice could be rescued by restoring levels of circulating miRNA and subsequent inhibition of Tbx3 and Sirt7. Downregulation of miR-93 also occurred in obese ob/ob mice, and this phenocopy of mir-25-93-106b(-/-) was partially reversible with injection of miR-93 mimics. Our data establish miR-93 as a negative regulator of adipogenesis and a potential therapeutic option for obesity and the metabolic syndrome.

Concise Review: Stem Cells in Pancreatic Cancer: From Concept to Translation

Pancreatic cancer stem cells (CSCs) have been first described in 2007 and since then have emerged as an intriguing entity of cancer cells with distinct functional features including self-renewal and exclusive in vivo tumorigenicity. The heterogeneous pancreatic CSC pool has been implicated in tumor propagation as well as metastatic spread. Clinically, the most important feature of CSCs is their strong resistance to standard chemotherapy, which results in fast disease relapse, even with today's more advanced chemotherapeutic regimens. Therefore, novel therapeutic strategies to most efficiently target pancreatic CSCs are being developed and their careful clinical translation should provide new avenues to eradicate this deadly disease.

Long-term safety and efficacy of factor IX gene therapy in hemophilia B

BACKGROUND

In patients with severe hemophilia B, gene therapy that is mediated by a novel self-complementary adeno-associated virus serotype 8 (AAV8) vector has been shown to raise factor IX levels for periods of up to 16 months. We wanted to determine the durability of transgene expression, the vector dose-response relationship, and the level of persistent or late toxicity.

METHODS

We evaluated the stability of transgene expression and long-term safety in 10 patients with severe hemophilia B: 6 patients who had been enrolled in an initial phase 1 dose-escalation trial, with 2 patients each receiving a low, intermediate, or high dose, and 4 additional patients who received the high dose (2×10(12) vector genomes per kilogram of body weight). The patients subsequently underwent extensive clinical and laboratory monitoring.

RESULTS

A single intravenous infusion of vector in all 10 patients with severe hemophilia B resulted in a dose-dependent increase in circulating factor IX to a level that was 1 to 6% of the normal value over a median period of 3.2 years, with observation ongoing. In the high-dose group, a consistent increase in the factor IX level to a mean (±SD) of 5.1±1.7% was observed in all 6 patients, which resulted in a reduction of more than 90% in both bleeding episodes and the use of prophylactic factor IX concentrate. A transient increase in the mean alanine aminotransferase level to 86 IU per liter (range, 36 to 202) occurred between week 7 and week 10 in 4 of the 6 patients in the high-dose group but resolved over a median of 5 days (range, 2 to 35) after prednisolone treatment.

CONCLUSIONS

In 10 patients with severe hemophilia B, the infusion of a single dose of AAV8 vector resulted in long-term therapeutic factor IX expression associated with clinical improvement. With a follow-up period of up to 3 years, no late toxic effects from the therapy were reported. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT00979238.).

Prevalence and risk factors for allergic bronchopulmonary aspergillosis in Indian children with cystic fibrosis

OBJECTIVES

Allergic bronchopulmonary aspergillosis (ABPA) is a common complication in patients with cystic fibrosis. This cross-sectional study was planned to determine the prevalence and risk factors for ABPA in Indian children with cystic fibrosis.

METHODS

Clinical evaluation, spirometry, chest radiograph, sputum, total IgE, specific IgE for Aspergillus fumigatus, IgG precipitins and skin prick tests were done in 33 CF patients.

RESULTS

Prevalence of allergic bronchopulmonary aspergillosis was 18.2% (95% CI 6.9% - 35.4%): allergic bronchopulmonary aspergillosis was higher in patients with low cystic fibrosis score, age >12 years, atopy, and eosinophilia.

CONCLUSION

Prevalence of ABPA is higher in Indian children with cystic fibrosis.

Right attitude, right decision and timely planning in surgical pedodontics -scoop out or expose it

Radicular cysts are the most common odontogenic cystic lesions of inflammatory origin and are usually asymptomatic and are left unnoticed, until detected by routine radiography. It is managed either by surgical enucleation or marsupialization. Conventional nonsurgical endodontic treatment has a high degree of clinical success, but in certain cases surgical intervention becomes necessary. This is the case report of a patient presenting with unilateral radicular cyst. The lesion is managed by marsupialization using a novel and safe method of separating the soft tissue mass of the periapical lesion which was in proximity to vital and vulnerable anatomical tissue, emphasizing the need of application of treatment in the best interest of patients. The treatment of choice is dependent on the size and localization of the lesion, the bone integrity of the lesions wall and its proximity to vital structure. This case report of radicular cysts emphasis on the advantages and disadvantages of the leading criteria that should be taken into consideration when assessing the treatment modalities for radicular cyst.

KEYWORDS

Odontogenic cysts, Radicular cyst, Marsupialization, Enucleation. How to cite this article: Kethineni B, Peddi R, Puppala R, Sunitha B, Chowdary U K, Raj D. Right Attitude, Right Decision and Timely Planning in Surgical Pedodontics -Scoop Out or Expose It. J Int Oral Health 2013; 5(2):50-54.

Self-complementary adeno-associated viral vectors for gene therapy of hemophilia B: progress and challenges

Therapies currently used for hemophilia involve injection of protein concentrates that are expensive, invasive and associated with side effects such as development of neutralizing antibodies (inhibitors) that diminish therapeutic efficacy. Gene transfer is an attractive alternative to circumvent these issues. However, until now, clinical trials using gene therapy to treat hemophilia have failed to demonstrate sustained efficacy, although a vector based on a self-complementary adeno-associated virus has recently shown promise. This article will briefly outline a novel gene-transfer approach using self-complementary adeno-associated viral vectors using hemophilia B as a target disorder. This approach is currently being evaluated in the clinic. We will provide an overview of the development of self-complementary adeno-associated virus vectors as well as preclinical and clinical data with this vector system.

Correlation of percent of core biopsies positive for prostate cancer and biochemical outcome following I-125 prostate brachytherapy or external beam radiation

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Background: The percentage of positive cores (PPC) on biopsy for prostate cancer has been identified as a predictor of outcome following definitive local treatment. We aim to identify whether this observation holds true for a modern cohort of patients (pts) treated at Cleveland Clinic with permanent prostate brachytherapy (PB) or external beam radiation therapy (EBRT).

Methods: We retrospectively reviewed pathology reports of pts treated with either PB or EBRT from our IRB-approved prospective prostate cancer registry. No pts underwent both PB and EBRT. The number of biopsy cores sampled, number of cores positive for prostate cancer, and maximum length of any core positive for prostate cancer were collected. Cox proportional hazards regression was used to analyze biochemical relapse free survival (bRFS) using the nadir + 2 ng/ml definition.

Results: We identified 1253 PB and 879 EBRT pts with complete pathology and clinical information. Among PB pts, 46% were low risk, 40% intermediate risk, and 14% high risk, while 78% had <50% PPC, and 22% had >=50% PPC. The 5-year bRFS for PB was 92.0% for <50% PPC, vs. 83.1% for >=50% PPC (HR 2.1, p=0.0005). For PB pts, significant predictors of bRFS on univariate analysis included: PPC, clinical T stage, PSA, biopsy Gleason score, androgen deprivation, and frequency of PSA testing. On multivariate analysis, only PPC, biopsy Gleason score, and PSA frequency remained significant predictors following PB. Among EBRT pts, 11% were low risk, 36% intermediate risk, and 53% high risk, while 55% had <50% PPC, and 45% had >=50% PPC. The 5-year bRFS for EBRT was 85.6% for <50% PPC, vs. 77.1% for >=50% PPC (HR 1.8, p<0.0001). For EBRT pts, significant predictors of bRFS on univariate analysis included: PPC, clinical T stage, PSA, biopsy Gleason score, androgen deprivation, EBRT dose, and frequency of PSA testing. On multivariate analysis, only PPC, biopsy Gleason score, and PSA frequency remained significant predictors following EBRT.

Conclusions: Following PB or EBRT, the percent of positive cores for prostate cancer was a significant predictor of bRFS on multivariate analysis, more so than conventional predictors such as T stage and PSA.

No significant financial relationships to disclose.

Long-term safety and efficacy following systemic administration of a self-complementary AAV vector encoding human FIX pseudotyped with serotype 5 and 8 capsid proteins

Adeno-associated virus vectors (AAV) show promise for liver-targeted gene therapy. In this study, we examined the long-term consequences of a single intravenous administration of a self-complementary AAV vector (scAAV2/ 8-LP1-hFIXco) encoding a codon optimized human factor IX (hFIX) gene in 24 nonhuman primates (NHPs). A dose-response relationship between vector titer and transgene expression was observed. Peak hFIX expression following the highest dose of vector (2 × 10(12) pcr-vector genomes (vg)/kg) was 21 ± 3 µg/ml (~420% of normal). Fluorescent in-situ hybridization demonstrated scAAV provirus in almost 100% of hepatocytes at that dose. No perturbations of clinical or laboratory parameters were noted and vector genomes were cleared from bodily fluids by 10 days. Macaques transduced with 2 × 10(11) pcr-vg/kg were followed for the longest period (~5 years), during which time expression of hFIX remained >10% of normal level, despite a gradual decline in transgene copy number and the proportion of transduced hepatocytes. All macaques developed serotype-specific antibodies but no capsid-specific cytotoxic T lymphocytes were detected. The liver was preferentially transduced with 300-fold more proviral copies than extrahepatic tissues. Long-term biochemical, ultrasound imaging, and histologic follow-up of this large cohort of NHP revealed no toxicity. These data support further evaluation of this vector in hemophilia B patients.

Long term results of the Corin C-Fit uncemented total hip arthroplasty in young patients

INTRODUCTION

We conducted a prospective study to evaluate the long-term results after Corin C-Fit uncemented total hip arthroplasty in young patients with hydroxyapatite or porous coated components.

MATERIALS AND METHODS

We prospectively followed 36 patients (38 hips) who had Corin C-Fit uncemented total hip arthroplasties by eight experienced consultant surgeons at two centres. The acetabular and femoral components were hydroxyapatite or porous coated.

RESULTS

The overall 10-year survival rate for the Corin C-Fit arthroplasty was 43%. The 10-year survivorship for the femoral implant was 56% and for the acetabular component 59%.

CONCLUSION

The evidence presented in this study suggests that the Corin C-Fit uncemented total hip arthroplasty has one of the highest mid- and long-term failure rates for both femoral and acetabular components in the literature. We believe this implant should not be used and patients who have had this form of total hip arthroplasty should be kept under regular review.

Copeland surface replacement of the shoulder. Results of an hydroxyapatite-coated cementless implant in patients over 80 years of age

We describe the results of Copeland surface replacement shoulder arthroplasty using the mark III prosthesis in patients over 80 years of age. End-stage arthritis of the shoulder is a source of significant pain and debilitating functional loss in the elderly. An arthroplasty offers good relief of pain and may allow the patient to maintain independence. The risk-benefit ratio of shoulder replacement may be felt to be too high in an elderly age group, but there is no published evidence to support this theory. We have assessed whether the procedure was as reliable and safe as previously seen in a younger cohort of patients. Between 1993 and 2003, 213 Copeland surface replacement arthroplasty procedures were performed in our unit, of which 29 (13.6%) were undertaken in patients over the age of 80. This group of patients was followed up for a mean of 4.5 years (2.1 to 9.3). Their mean age was 84.3 years (81 to 93), the mean operating time was 40 minutes (30 to 45) and the mean in-patient stay was five days (2 to 21). There were no peri-operative deaths or significant complications. The mean Constant score adjusted for age and gender, improved from 15.1% to 77%. Copeland surface replacement shoulder arthroplasty may be performed with minimal morbidity and rapid rehabilitation in the elderly.

Survivin repression by p53, Rb and E2F2 in normal human melanocytes

The inhibitor of apoptosis protein survivin is a dual mediator of apoptosis resistance and cell cycle progression and is highly expressed in cancer. We have shown previously that survivin is up-regulated in melanoma compared with normal melanocytes, is required for melanoma cell viability, and that melanocyte expression of survivin predisposes mice to ultraviolet-induced melanoma and metastasis. The mechanism of survivin up-regulation in the course of melanocyte transformation and its repression in normal melanocytes, however, has not been clearly defined. We show here that p53 and retinoblastoma (Rb), at basal levels and in the absence of any activating stimuli, are both required to repress survivin transcription in normal human melanocytes. Survivin repression in melanocytes does not involve alterations in protein stability or promoter methylation. p53 and Rb (via E2Fs) regulate survivin expression by direct binding to the survivin promoter; p53 also affects survivin expression by activating p21. We demonstrate a novel role for E2F2 in the negative regulation of survivin expression. In addition, we identify a novel E2F-binding site in the survivin promoter and show that mutation of either the p53- or E2F-binding sites is sufficient to increase promoter activity. These studies suggest that compromise of either p53 or Rb pathways during melanocyte transformation leads to up-regulation of survivin expression in melanoma.

Methicillin-resistant Staphylococcus aureus infection following arthroscopy of the knee joint

Arthroscopic surgery of the knee is considered to be a safe procedure. We had a microbiologically confirmed infection of methicillin-resistant Staphylococcus aureus (MRSA). Although various rare infective cases are reported following arthroscopy of the knee joint, to the best of our knowledge there is no previous report of MRSA infection following arthroscopy of the knee joint.

Tacrolimus immunosuppression in high-risk corneal grafts

BACKGROUND

Unlike the immune privilege enjoyed by low-risk corneal grafts, high-risk corneal grafts experience rejection rates comparable to liver and kidney transplants. Systemic immunosuppression reduces the risk of rejection in high-risk corneal grafts.

METHODS

Systemic tacrolimus, a specific T cell inhibitor, was used at a mean daily dose of 2.5 mg to immunosuppress 43 patients undergoing high-risk corneal transplantation. Immunosuppression was continued for a period of 18-24 months after the high-risk corneal graft.

RESULTS

During a mean follow-up period of 33.7 months, clarity of the graft was maintained in 65% of patients. Eight patients experienced rejection episodes while on tacrolimus, and this led to graft failure in five patients.

CONCLUSION

Tacrolimus is relatively safe and effective in reducing rejection and prolonging graft survival in patients with high-risk keratoplasty compared with other series where similar immunosuppression was not used.

Proteolytic cleavage of Livin (ML-IAP) in apoptotic melanoma cells potentially mediated by a non-canonical caspase

BACKGROUND

Several inhibitor of apoptosis proteins (IAPs) are cleaved during apoptosis. Studies of the melanoma-associated IAP (ML-IAP) Livin, using recombinant molecules, have implicated both caspases 3/7 and the serine protease Omi/HtrA2 in its proteolytic cleavage.

OBJECTIVE

To characterize the apoptotic cleavage of Livin in melanocytic cells, and evaluate the role of known proteases.

METHODS

We assessed the capacity of a variety of stimuli to induce Livin cleavage in human melanoma cell lines and normal human melanocytes. The role of caspases and Omi was examined using caspase inhibitors and RNAi, respectively. A potential caspase substrate was further examined by site-directed mutagenesis. Deletion mapping was used to identify the cleavage site.

RESULTS

Livin cleavage was observed in multiple human melanoma cell lines in response to a variety of apoptotic stimuli (UVB, 4-TBP, cisplatin, TNF, Bax), and not affected by the addition of various protease inhibitors or RNAi-mediated silencing of Omi/HtrA2. Livin cleavage induced by 4-TBP, but not UVB or cisplatin, was blocked by the pan-caspase inhibitor zVAD-fmk. Mutation of Asp52 to Glu in Livin did not affect cleavage, while either mutation of Asp52 to Ala, deletion of Asp52, or deletion of the adjacent region (residues 53-61) abrogated cleavage.

CONCLUSION

Livin cleavage, induced by multiple apoptotic stimuli in melanoma cells, likely occurs in an Omi-independent fashion at residue 52 within its potential caspase substrate (DHVD52). However, relative insensitivity of the apoptotic cleavage to zVAD-fmk, or Asp52 to Glu mutation, suggests the involvement of a non-canonical caspase.

Induction of melanoma cell apoptosis and inhibition of tumor growth using a cell-permeable Survivin antagonist

The inhibitor of apoptosis gene family member Survivin is highly expressed in most tumors, and appears to be a promising target for cancer therapy. Although a variety of Survivin antagonists have been shown to induce apoptosis in malignant cells, the potential utility of these agents is limited by inefficient delivery and cell impermeability. We generated recombinant fusion proteins containing the TAT protein transduction domain and either wild-type Survivin (TAT-Surv-WT) or a dominant-negative mutant (TAT-Surv-T34A). The TAT-Surv proteins were purified by sequential affinity and ion-exchange chromatography, and at 30 nM concentration demonstrated rapid entry into cells at 30 min. Whereas TAT-Surv-WT had minimal effect on YUSAC2 or WM793 melanoma cells, TAT-Surv-T34A induced cell detachment, DNA fragmentation, caspase-3 activation and mitochondrial release of apoptosis-inducing factor at low microM concentrations. Intraperitoneal (i.p.) injection of mice bearing subcutaneous YUSAC2 xenografts with TAT-Surv-T34A (10 mg/kg) was associated with rapid tumor accumulation at 1 h, and increased tumor cell apoptosis and aberrant nuclei formation in situ. Repeated i.p. injection of TAT-Surv-T34A resulted in a 40-50% reduction in growth and mass of established tumors, compared to those similarly injected with saline buffer or TAT-Surv-WT. These studies demonstrate the feasibility of systemic tumor treatment using a cell-permeable Survivin antagonist.

Keratinocyte apoptosis in epidermal development and disease

Keratinocyte (KC) apoptosis plays a critical role in regulating epidermal development and restraining carcinogenesis. Apoptosis balances proliferation to maintain epidermal thickness, contributes to stratum corneum formation and may eliminate pre-malignant cells. Apart from the normal developmental program, KC apoptosis can be triggered by UV light and other stimuli. Dysfunctional apoptosis occurs in some skin diseases, such as psoriasis and skin cancer. Here we review the current state of knowledge of KC apoptosis, with particular focus on apoptotic signaling pathways and molecular mechanisms of apoptosis control, and discuss new insights into the complex role of apoptosis in skin carcinogenesis that are emerging from mouse models.

The efficacy of sirolimus in the treatment of patients with refractory uveitis

AIMS

To determine the efficacy of sirolimus in the treatment of patients with severe non-infectious uveitis.

METHODS

Eight patients with severe non-infectious uveitis were recruited to an open study. Inclusion criteria were limited to patients whose disease was not controlled with at least two or more separate steroid sparing immunosuppressants (either because of unacceptable side effects or ineffectiveness of the drug) or who required regular doses of corticosteroids either as high dose systemic or orbital floor injections in order to control their disease. Intraocular inflammation, visual acuity, symptoms, corticosteroid burden, drug toxicity, and side effects were monitored.

RESULTS

Sirolimus therapy was effective in five of the eight patients, all of whom had their dose of corticosteroids reduced or discontinued. Treatment in three patients was considered a failure as it caused intolerable side effects and/or failed to control the uveitis. Side effects were common and were typically gastrointestinal or cutaneous in nature. The severity of symptoms was dose dependent in most cases and occurred at trough blood levels above 25 ng/ml.

CONCLUSION

Sirolimus is an effective and potent immunosuppressive treatment in the majority of patients with non-infectious uveitis and can reduce the need for long term supplementary corticosteroid therapy. Further studies are required to establish the long term efficacy and safety of sirolimus alone or in combination with other steroid sparing immunosuppressants.

Respiratory effects in human functional magnetic resonance imaging due to bulk susceptibility changes

Functional magnetic resonance imaging relies on detecting small changes in the signal in the presence of noise from various sources. It has been shown that periodic variations in the signal at the respiratory frequency occur in the brain and various techniques have been proposed to remove them. However, the precise mechanism by which respiration affects the fMRI signal has not yet been proven. Here, we explore the nature of respiratory signal variations and the artefacts they produce in brain images. Our results demonstrate conclusively that bulk susceptibility variations in the lungs during respiration cause variations in the static magnetic field within the brain tissue. These variations in field strength and homogeneity lead to a shift of the image and a shading of image intensity in the phase encoding direction. These artefacts, if left uncorrected, may lead to the production of spurious activations and/or decreased statistical significance of true activations in fMRI. In addition, these results suggest that respiration effects may not necessarily be well characterized as simple additive noise and that an alternative model based on the physical origins of susceptibility variations may be more appropriate.

Radiation dose to voluntary kidney donors during renal angiography procedures

The radiation dose to voluntary kidney donors undergoing renal angiography performed using digital subtraction angiography (DSA) was estimated. The effective dose was calculated from values of dose-area product measured using a Diamentor dose-area product meter. The duration of the fluoroscopic screening and the number of image acquisitions during each examination varied depending upon the number of arteries supplying the kidneys and other parameters. The effective dose varied from 2.3 mSv to 30.5 mSv. The clinical aspects involved during the study were also taken into consideration in the analysis of the data.

Treatment of unstable distal radial fractures by intrafocal, intramedullary K-wires

Displaced distal radial fractures with extensive dorsal comminution and plastic cancellous deformation are unstable and frequently cause treatment problems since there is no single, reliable method of treatment, notably in osteoporotic bone. We present a method of holding unstable distal radial fractures with blunt ended K-wires via intrafocal and intramedullary insertion, so modifying the Kapandji technique. Wires were placed dorsally, radially and when necessary from the volar direction depending on fracture configuration. Over a 7-year period (1992-1999) we treated 102 patients with unstable distal radial fractures in this way. Of these, 80 were followed up for 6-42 weeks according to clinical need and scored radiologically and functionally using modified Lidstrom scoring system. Results showed that 92 and 95% of these patients achieved good or excellent results in these scoring systems, respectively. We present this as a useful and reliable method of treating these common fractures, particularly in osteoporotic bone.

Regulatory responses to an oral D-glutamate load: formation of D-pyrrolidone carboxylic acid in humans

Previously published studies have shown D-glutamate to be the most potent natural inhibitor of glutathione synthesis known, yet how D-glutamate is handled in humans is unknown. Therefore, we administered an oral D-glutamate load to four healthy volunteers and monitored the plasma D-glutamate concentration and excretion over a 3-h postload period. Compared with time controls, the plasma D-glutamate concentration increased 10-fold in the 1st h and then reached a plateau over the remaining time course. In contrast, plasma D-pyrrolidone carboxylic acid increased progressively throughout the 3-h time course to a level 10-fold higher than the D-glutamate plasma concentration. Excretion of D-glutamate progressively increased despite a constant filtered D-glutamate load rising from only 5 to 95% of the filtered amount. Excretion of D-pyrrolidone carboxylic acid increased with the rise in filtered load without significant reabsorption. The amount of D-pyrrolidone carboxylic acid excreted over the 3-h time course was 10 times the amount excreted as D-glutamate and accounted for almost 20% of the administered D-glutamate. These findings indicate that plasma D-glutamate concentration is tightly regulated through two mechanisms: 1) the transport into cells and metabolic conversion to D-pyrrolidone carboxylic acid and excretion, and 2) the enhancement of D-glutamate clearance by the kidneys.

A model for susceptibility artefacts from respiration in functional echo-planar magnetic resonance imaging

Respiration causes variations in the signals acquired during magnetic resonance imaging (MRI) and therefore is a significant source of noise in functional brain imaging. A primary component of respiratory noise may arise from variations of bulk susceptibility or air volume in the chest. Here we investigate the nature of the image artefacts that can be caused by such changes. We develop a simple model which attempts to mimic the effects of variations in susceptibility and volume during respiration. Theoretical calculations, computer simulations and imaging experiments with this model show that small variations in susceptibility within the thorax from alterations in the paramagnetism of cavity gas may lead to a shift of the image on the order of 0.1 pixels as well as a shading of the intensity by +/-1%. These effects are observed to be predominant in the phase-encoding direction. They may lead to the production of spurious activations in functional MRI and are likely to be of more importance at higher field strengths.

Salt-induced changes in lipid composition and ethanol tolerance in Saccharomyces cerevisiae

The effect of salt stress on lipid composition and its relationship with ethanol tolerance in Saccharomyces cerevisiae was studied. Amounts of phospholipids as well as that of sterols decreased, whereas that of protein and glycolipids increased with increasing salt concentration. Relative proportion of amino phospholipids (phosphatidylethanolamine and phosphatidylserine) decreased, whereas that of phosphatidylcholine showed a reverse trend. Cells grown under increasing salt concentration were more resistant to ethanol-induced leakage of UV-absorbing substances, an index of ethanol endurance. Results showed an overlap between osmotolerance and ethanol tolerance in this strain.

Late-onset adrenal hyperplasia in north Indian hirsute women

The occurrence of late-onset congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency was studied in 60 consecutive hirsute women by means of adrenocorticotrophin (ACTH)-stimulated serum 17-hydroxyprogesterone (17-OHP) levels. Five (8.3%) women had an exaggerated response (ACTH-stimulated 17-OHP 3,160 +/- 560 ng/dl). All of them had regular periods and 3 were virilized. The other 2 were indistinguishable from those with idiopathic hirsutism or polycystic ovarian disease.