Mutagenicity of selected functionalized benz(c)acridines and a benz(a)phenazine in the Salmonella typhimurium/microsome assay

Five functionalized benz(c)acridines - 5,6-dimethylbenz(c)acridine; 5,6,7-trimethylbenz(c)acridine; 7-chloro-5,6-dimethylbenz(c)acridine; 7-amino-5,6-dimethylbenz(c)acridine; 7-oxo-5,6-dimethylbenz(c)-acridine and 5,6-dimethylbenz(a)phenazine - were tested for mutagenic activity in the Ames Salmonella typhimurium assay. Compounds were initially screened by spot tests with 5 tester strains and both plate incorporation and pre-incubation assays were performed when the results of the tests were positive or weakly positive. All assays were done with and without S9 activation. 7-Amino-5, 6-dimethylbenz(c)acridine and 7-chloro-5, 6-dimethylbenz(c)acridine were found to be moderately mutagenic with the 3 frameshift strains TA1537, TA98, and TA97.     

Transfusion Transmitted Infections in Armed Forces: Prevalence and Trends

Background

This study presents data on the prevalence rate of infectious markers among voluntary and replacement donors in the blood transfusion service in Armed Forces from 2000 to 2004.

Methods

39,646 units of blood were collected from donors during the period from 2000 to 2004. All the samples were screened for hepatitis B surface antigen (HBsAg), human immunodeficiency virus (HIV) 1&2, hepatitis C virus (HCV), and by venereal disease research laboratory test (VDRL).

Results

24,527 (61.9%) were voluntary donations and 15,119 (38.1%) replacement donations. Prevalence of HBsAg had decreased, amongst voluntary donors from 1.67% to 0.77% but the positivity rate has not showed significant change. Seropositivity of HIV had decreased both in voluntary and replacement donors to 0.22% and 0.86% respectively. The seropositivity for anti-HCV showed steady decrease amongst voluntary donors from 0.46% to 0.20% in 2004, but in replacement donors, there was an increase in reactivity rate from 0.43% to 0.65%.

Conclusion

The increased seropositivity for HCV, HIV and HBsAg could be decreased by introduction of nucleic acid amplification testing (NAT) in minipools for HCV and HIV and introduction of anti-HBcAg (IgM) for hepatitis B virus (HBV) infection. But this may not be possible in near future in developing countries due to financial constraints. At present implementation of strict donor criteria and with use of sensitive laboratory screening tests it is possible to reduce the incidence of transfusion transmitted infections (TTI) in Indian scenario.Key Words: Transfusion transmitted infections, Human immunodeficiency virus, Hepatitis C virus, Hepatitis B virus     

Evaluation of Suspected Monoclonal Gammopathies: Experience in a Tertiary Care Hospital

Background

Monoclonal gammopathies occurs in patients with malignant diseases of plasma cells and lymphocytes and in few benign conditions. The objective of this study was to assess the precision, accuracy and confirmation of monoclonal gammopathies on serum protein electrophoresis (SPE) and the clinical relevance of detection and characterization of M component.

Methods

All samples received for serum electrophoresis in the last 3 years were analysed for data on M band positivity and correlating it with clinical profile of the patients. Immunofixation (IFE), Immunoelectrophoresis (IEP) and IgG, IgM estimation were carried out in few cases. The follow up of cases was done by serial monitoring of SPE and β₂ microglobulin levels.

Results

1155 samples were received during the 3 years period. 282 (24.4%) samples were positive for M component on SPE. Of these, 239 (84.8%) patients had M spike in λ region and 43 patients had M spike in β region. The mean load of the M protein band in the λ region was 37.8% and in β region was 35.8%. IgG with κ chain was seen in 40%, IgG with λ chain was seen in 50%, 5% patients each had IgM with κ and IgA with λ light chain. 246 samples (96.5%) had high levels of β₂ microglobulin. Of the 116 cases of multiple myeloma, IgG levels was more commonly raised (5%) as compared to IgA (6.9%) and IgM (5.2%).

Conclusion

It is recommended that SPE should be performed in patients having unexplained weakness, anaemia, back pain, osteoporosis, osteolytic lesions, fractures, renal insufficiency or recurrent infections.Key Words: Serum protein, Electrophoresis, M band, Multiple myeloma     

Cervical Disc Replacement for Spondylotic Myeloradiculopathy

Background

Cervical disc replacement is a newer concept and rapidly developing surgical treatment. A prospective study was conducted to determine, if accurately implanted Bryan''s cervical disc prostheses can provide relief from objective neurological symptoms and signs, stability and normal range of motion in cases of cervical disc prolapse with myeloradiculopathy.

Material and Method

Twenty patients underwent Bryan cervical disc replacement from Jan 2002 to Dec 2003. Young patients between age groups 21 to 50 years with degenerative cervical disc prolapse at C3-C7 with myeloradiculopathy were included in this study. Patients with significant facet joint arthropathy, unstable spine, trauma, tumour, osteoporosis and active infection were excluded from this study. Nurick''s grading was used for quantifying the neurological deficit. Patients were operated by anterior cervical approach using a specially designed Bryan''s cervical discectomy system. Neurological and radiological outcome was assessed post operatively and at 2,6,12 and 24 months follow up. Outcome analysis was carried out using modified Odom''s criteria. The radiographic results were assessed by taking antero posterior (AP) and lateral radiographs of cervical spine to find range of motion and device position.

Results

The patients were in the age group of 31 to 50 years. There were 14 (70%) male and 6 (30%) female in this study. Neck pain and brachialgia were the presenting symptoms in all cases, 12 (60%) had radiculopathy and 8 (40%) had myelopathy. Single level disc prolapse was present as per Magnetic Resonance Imaging (MRI) in four (20%) at C4-C5, 12 (60%) at C5-C6 and 4 (20%) at C6-C7. Bryan''s disc size 15 was used in 8 (40%) and size 17 was used in 12(60%) patients. During post-operative, 02, 06, 12, and 24 months follow up, the clinical outcome was excellent in 16 (80%) and good in 4 (20%) as per modified Odom''s criteria. There was demonstrated improvement in flexion, extension and rotation clinically and radiologically during follow up. There was no migration or displacement of device.

Conclusion

Cervical disc replacement for cervical disc prolapse with myeloradiculopathy represents an exciting new technology. Patients treated with the Bryan cervical disc prosthesis for single level cervical disc prolapse showed good to excellent improvement in neurological deficit. Clinically and radiologically maintenance of motion was found during follow up. More patients with longer follow up and post operative MRI to find out the protection to adjacent discs from abnormal stress will be required before this prosthesis is accepted as a treatment option.Key Words: Spondylotic myeloradiculopathy, Cervical disc replacement     

Inhibition of depurinating estrogen-DNA adduct formation by natural compounds

Specific metabolites of estrogens, catechol estrogen-3,4-quinones, if produced in relatively large amounts, can become chemical carcinogens by reacting with DNA to form predominantly depurinating DNA adducts. Estradiol (E2)-3,4-quinone (Q) reacts with DNA to form predominantly the depurinating DNA adducts, 4-hydroxyestradiol (OHE2)-1-N3Ade and 4-OHE 2-1-N7Gua. The depurinating adducts induce mutations by error-prone repair. We have conducted a study in which selected natural chemopreventing agents, N-acetylcysteine (NAcCys), melatonin, reduced lipoic acid, and resveratrol, have been tested for their ability to prevent the reaction of E(2)-3,4-Q with DNA. When DNA was incubated with E(2)-3,4-Q or lactoperoxidase-activated 4-OHE2 in the presence of an antioxidant, the formation of the N3Ade and N7Gua adducts was reduced. E(2)-3,4-Q or lactoperoxidase-oxidized 4-OHE 2 (87 microM final concentration) was incubated with calf-thymus DNA and one of the antioxidants at different ratios (1:0, 1:0.3, 1:1, and 1:3 with respect to E(2)-3,4-Q or 4-OHE2) at 37 degrees C. After 10 h, the DNA was precipitated, and the supernatant was analyzed by using ultraperformance liquid chromatography/tandem mass spectrometry (LC/MS/MS). As anticipated, resveratrol and melatonin did not affect the formation of the depurinating adducts when E(2)-3,4-Q was reacted with DNA in their presence. On the other hand, NAcCys and lipoic acid (reduced form) showed a significant inhibition of the formation of the depurinating adducts by E(2)-3,4-Q. With reaction of lactoperoxidase-activated 4-OHE2 with DNA, resveratrol achieved the highest level of inhibition, NAcCys and reduced lipoic acid produced moderate inhibition, and melatonin had the least inhibition. These results demonstrate that all four selected compounds can inhibit the formation of depurinating estrogen-DNA adducts and set the stage for studies of their ability to inhibit adduct formation and malignant transformation in mammary epithelial cells. This approach is highly useful for identifying agents to prevent the initiation of human cancers, especially breast and prostate cancer.     

Subcutaneous and intranasal immunization with type III secreted proteins can prevent colonization and shedding of Escherichia coli O157:H7 in mice

Type III secreted proteins from Escherichia coli O157:H7 are involved in the attachment of the organism to mammalian cells and have been shown to be effective vaccine components capable of reducing colonization of cattle by the organism. In the current study, we used a streptomycin-treated mouse model to evaluate the efficacy of subcutaneous vs intranasal administration of the vaccine. Following immunization, mice were infected with E. coli O157:H7 and feces were monitored for shedding. Immune responses against EspA and Tir were also monitored. Subcutaneous immunization of mice with type III secreted proteins induced significant EspA- and Tir-specific serum IgG antibodies but did not significantly induce any antigen-specific IgA in feces, whereas intranasal immunization elicited significant EspA- and Tir-specific serum IgG antibodies with some animals developing antigen-specific IgA in feces. Only mice that were immunized intranasally with formulations containing mucosal adjuvants, either cholera toxin or CpG-containing oligonucleotides, showed decreased E. coli O157:H7 shedding following experimental infection. Mice immunized subcutaneously with type III secreted proteins did not shed E. coli in feces. These results demonstrate the potential for the use of type III secreted proteins in mucosal vaccine formulations to prevent colonization and shedding of E. coli O157:H7.     

The long-term effectiveness of generic adult fixed-dose combination antiretroviral therapy for HIV-infected Ugandan children

Background

Access to pediatric antiretroviral formulations is increasing in resource-limited countries, however adult FDCs are still commonly used by antiretroviral therapy (ART) programs.

Objective

To describe long-term effectiveness of using adult FDC of d4T+3TC+NVP (Triomune) in children for HIV treatment.

Methods

Clinical, immunologic, and virologic outcomes of HIV-infected ART-naïve children aged six months to 12 years, were evaluated up to 96 weeks post-ART initiation.

Results

From March 2004 to June 2006, 104 children were followed with a median age of 5.4 years, median CD4 cell percent and HIV-1 RNA were 11.0% (IQR 6.7–13.9) and 348,846copies/mL (IQR 160,941–681,313) respectively at baseline. Using Kaplan-Meir estimates, 75% of children had undetectable viral loads (<400copies/mL) at 96weeks of ART. Children with a baseline CD4 cell percent >15% were 3 times more likely to achieve viral load <400copies/mL than those with baseline CD4 cell percent <5% after adjusting for baseline age {aHR = 3.03 (1.10–8.32), p=0.03}; no difference was found among those with CD4 cell percent >5–14.9% and <5%.

Conclusion

Treatment with generic adult FDC for HIV-infected Ugandan children led to sustained clinical, immunologic and virologic response during 96 weeks of ART. Early initiation of ART is key to achieving virological success.     

The Knee Osteoarthritis Grading System for Arthroplasty

Background

The aim of this study is to validate the Knee Osteoarthritis Grading System (KOGS) of progressive osteoarthritic degeneration for the tri-compartmental knee. This system defines the site and severity of osteoarthritis to determine a specific knee arthroplasty.