Analysis of cellular response to isocyanate using N‐succinimidyl N‐methylcarbamate exposure in cultured mammalian cells

Isocyanates (R? N?C?O), one of the highly reactive industrial intermediates, possess the capability to modulate the bio‐molecules by forming toxic metabolites and adducts which may cause adverse health effects. Some of their toxic degradations have previously been unknown and overlooked; of which, molecular repercussions underlying their genetic hazards upon occupational/accidental exposures still remain as an intricate issue and are hitherto unknown. To assess the genotoxic potential of methyl isocyanate in cultured mammalian cells after in vitro exposure, we performed a study in three different normal cell lines MM55.K (mouse kidney epithelial), B/CMBA.Ov (mouse ovarian epithelial), and NIH/3T3 (primary mouse embryonic fibroblast). Cellular DNA damage response was studied for qualitative phosphorylation states of ATM, γH2AX proteins and quantitative state of p53 phosphorylation; DNA cell cycle analysis and measure of cellular apoptotic index before and after treatment were also investigated. Our results demonstrate that methyl isocyanate by negatively regulating the DNA damage response pathway, might promote cell cycle arrest, and apoptosis in cultured mammalian cells suggestive of causing genetic alterations. We anticipate that these data along with other studies reported in the literature would help to design better approaches in risk assessment of occupational and accidental exposure to isocyanates. We also predict that increasing knowledge on DNA damage‐triggered signaling leading to cell death could provide new strategies for investigating the effects of DNA repair disorders and decreased repair capacity on the toxicity and carcinogenic properties of environmental toxins. Environ. Mol. Mutagen., 2009. © 2009 Wiley‐Liss, Inc.     

Dysgerminoma of the ovary: A retrospective study

A retrospective analysis of 22 patients with ovarian dysgerminoma who were treated between 1980 and 1987 was carried out. The median age at presentation was 24.5 years. A total of 15 patients were in stage I, one patient was in stage II and six patients were in stage III. Bilateral ovarian involvement was present in four patients. Conservative surgery was carried out in nine patients and 11 patients underwent radical surgery. Two patients had biopsy only. Fourteen patients received adjuvant radiotherapy and three patients received salvage radiation for recurrent disease. The 10-year actuarial survival rate was 81.8%. All 15 patients in stage I were alive and disease-free at a median follow-up of 125 months. Four patients (one in stage II and three in stage III) died of progressive or recurrent abdominopelvic disease. Pelvic recurrence occurred after conservative surgery in two patients in stage IA who had a tumour size greater than 10 cm, but they were salvaged with radical surgery, chemotherapy and radiotherapy. There were seven patients aged 20 years or less. All were alive and disease-free at a median follow-up of 127 months.     

Exchange transfusion in neutropenic septicemic neonates: effect on granulocyte functions

Depletion neutropenia caused by overwhelming bacterial infection is associated with fatal outcome and is an objective indicator of the severity of sepsis. Studies on controlled evaluation of exchange transfusion in the management of severe neonatal sepsis have not considered neutropenia as an inclusion critcrion, and randomized, controlled trials on evaluation of ncutrophil functions after exchange transfusion are scarce. This prompted us to carry out the present study. Septicemic neonates were enrolled if they had neutropenia and were randomized to undergo exchange transfusion (study group, n = 20) or not (controls, n= 10). Granulocyte functions were assessed using the nitro blue tetrazolium (NBT) reduction test and the staphylococcicidal index. Blood was drawn for granulocyte function tests once from controls and donors, and before, immediately after and 6 h after exchange transfusion in the study group. Mortality was 35% in the study group and 70% in controls. Gram-negative organisms accounted for 80%, in the study group and 90% in controls. Mean total leukocyte count and neutrophil count increased significantly immediately after exchange transfusion and 6 h later. Absolute band count decreased significantly immediately after exchange transfusion and incrcased 6 h later. NBT reduction in septicemic neonates in the study group, as wclras in controls. was significantly decreascd as compared to donor cells. NBT reduction improved significantly immediately after exchange transfusion and 6 h later. The valucs of the perccntage of viable staphylococci recovered from neutrophils also improved significantly immediately after exchange transfusion and 6 h later. We conclude that exchange transfusion with fresh whole blood in severe neonatal septicemia with neutropenia improves survival, increases the neutrophil count and cnhances neutrophil function.     

Local Anaesthesia for Fiberoptic Intubation : A Comparison of Three Techniques

Background

The successful conduct of fiberoptic aided intubation is dependent upon effective local anaesthesia. The aim of the study was to compare three different methods of anaesthetizing the airway.

Methods

60 adult patients (American Society of Anaesthesiologists status I-III and Mallampati class III & IV), scheduled for elective surgery, received sedation followed by spraying of the nares and posterior pharyngeal wall with 4% lignocaine. Thereafter the patients received 4 ml of 4% lignocaine either by transtracheal injection (n=20, group A), via intubating fiberscope (Pentax F1-10P2) using ‘spray as you go’ technique (n=20, group B) or by nebulizer (Devilbiss 5610W) 20 min before intubation, (n=20, group C). Patients were asked to score the procedure using visual analog scale (VAS) and severity scores. Episodes of coughing, choking, stridor, extra / total local anaesthetic used and intubation times were recorded. Patients were monitored continuously for vital parameters.

Results

Group B patients showed better VAS scores with shorter intubation times and had a lower incidence of coughing and choking. The endoscopists’ VAS scores also showed a preference for group B.

Conclusion

In conclusion the ‘spray as you go’ technique was safe, provided effective local anaesthesia and was preferred by both patients and endoscopists.Key Words: Awake intubation, Difficult airway, Fiberoptic intubation     

Efficacy and Toxicity Profile of Methotrexate Chloroquine Combination in Treatment of Active Rheumatoid Arthritis

Background

The present study was conducted to study the efficacy and toxicity profile of methotrexate chloroquine combination in treatment of active rheumatoid arthritis.

Methods

24 patients of rheumatoid arthritis confirming to revised American Rheumatism Association (ARA) criteria were studied prospectively for twenty months. Clinical evaluation was made every 3 months. Clinical disease variables measured at each visit were number of joints with swelling, number of joints with tenderness and pain, duration of morning stiffness and physician and patient assessment of disease activity. Blood counts, liver function tests and other adverse effects due to drugs were monitored every 2 months.

Results

10 patients demonstrated more than 50% improvement. 4 patients withdrew from study, 2 because of excessive nausea and vomiting and 2 because of noncompliance. Other side effects noted were hyperpigmentation, photosensitivity, skin rashes, raised transaminases and stomatitis.

Conclusion

Methotrexate chloroquine combination has good efficacy and toxicity profile. Gastrointestinal side effects are most common and usually responsible for the discontinuation of the drugs.Key Words: Rheumatoid arthritis, Methotrexate, Chloroquine, Efficacy, Toxicity     

Lymphadenectomy prior to rat hind limb allotransplantation prevents graft-versus-host disease in chimeric hosts

In previous rat studies, the use of mixed allogeneic chimerism (MAC) to induce host tolerance to hind limb allografts has resulted in severe graft-versus-host disease (GVHD). The purpose of this study was to determine if immunocompetent cells in bone marrow (BM) and/or lymph nodes (LNs) of transplanted limbs were responsible for inducing GVHD in mixed chimeric hosts. [ACIWistar Furth] chimeric rats received ACI hind limbs that were non-irradiated, irradiated (1050 cGy) or lymphadenectomized. Rejection, GVHD and donor chimerism was assessed. Chimeric hosts rejected none of their limbs. However, hosts of non-irradiated hind limbs succumbed to GVHD 22.4±0.8 days after transplantation. In contrast, chimeras that received irradiated or lymphadenectomized ACI hind limbs showed no clinical or histological signs of GVHD at 5 months. We conclude that mixed chimeric hosts are susceptible to GVHD due to the immunocompetent cell load provided by the LNs, not the BM, of hind limb allografts.Abbreviations BM Bone marrow - CPM Counts per minute - CTA Composite tissue allograft - FACS Fluorescence activated cell sorter - FITC Fluorescent iso-thiocyanate - GVH Graft-versus-host - GVHD Graft-versus-host disease - HVG Host-versus-graft - LN Lymph node - MAC Mixed allogeneic chimerism - MHC Major histocompatibility complex - MLR Mixed lymphocyte reaction - MoAb Monoclonal antibody - PBL Peripheral blood lymphocytes - SEM Standard error of mean - TBI Total body irradiation - TCD T-cell depletion/T-cell depleted - TCR T-cell receptor     

Routine Cyclosporine concentration - C2 level Monitoring. Is it helpful during the early post Transplant Period?

Background

Pre dose or trough blood cyclosporine (CSA) concentration is routinely monitored and the result is used to alter patient''s drug dosing. Patients with identical pre dose blood CSA may have very different systemic exposure to the drug. Recently CSA 2 hour post dose level [C2] has been reported to correlate better with drug exposure. We undertook this study to evaluate the influence of trough and C2, CSA concentration monitoring on short-term renal allograft outcomes.

Methods

25 patients of renal transplant receiving a triple drug regimen of CSA micro emulsion (Panacea Biotec) 8mg/kg, azathioprine 1mg/kg and prednisolone 0.5mg/kg were analyzed prospectively for graft outcomes. CSA levels were monitored in whole blood by radioimmunoassay using monoclonal antibodies, at 72 hours after the transplant.

Results

The mean age of patients was 37.08 + 9.1 years. There were 20 males and 5 females. The mean age of donors was 40.2 + 8.2 years. There were 11 related donors with at least a haplomatch, 4 spousal and 10 unrelated donors with a nil antigen match. The mean pre dose CSA concentration was 289.22 + 171.9ng/ml; range (98.8 + 783.41ng/ml). The CSA concentration at 2 hours after the CSA administration was 838 + 310.87ng/ml (range, 169 + 1268ng/ml). 3 (12%) patients had acute rejection. In these patients the mean pre dose CSA concentration was 328.67ng/ml and the mean C2, CSA concentration was 1006.26ng/ml. CSA induced hemolytic uraemic syndrome was diagnosed in one patient. The trough and C2, CSA concentration levels were 174 and 870.83ng/ml respectively in this patient.

Conclusion

In our study CSA levels, trough and peak showed significant inter patient variability. The trough and C2 concentration levels did not correlate with the episodes of acute rejection. We conclude that in a triple drug regimen with fixed dosing schedules routine trough CSA level monitoring is not helpful in the acute post renal transplant period.Key Words: Cyclosporine levels, Cyclosporine trough levels, C2 levels