A sensitive and selective HPLC/ESI-MS/MS assay for the simultaneous quantification of 16-dehydropregnenolone and its major metabolites in rabbit plasma☆

A sensitive, selective and rapid liquid chromatographic/electrospray ionization tandem mass spectrometric assay was developed and validated for the simultaneous quantification of 16-dehydropregnenolone (DHP) and its five metabolites 4,16-pregnadien-3, 20-dione (M(1)), 5-pregnene-3beta-ol-20-one (M(2)), 5-pregnene-3beta, 20-diol (M(3)), 5-pregnene-3beta-ol-16, 17-epoxi-20-one (M(4)) and 5,16-pregnadien-3beta, 11-diol-20-one (M(5)) in rabbit plasma using dexamethasone as internal standard (IS). The analytes were chromatographed on Spheri-5 RP-18 column (5 microm, 100 mm x 4.6 mm i.d.) coupled with guard column using acetonitrile:ammonium acetate buffer (90:10, v/v) as mobile phase at a flow rate of 0.65 ml/min. The quantitation of the analytes was carried out using API 4000 LC-MS-MS system in the multiple reaction monitoring (MRM) mode. The method was validated in terms of linearity, specificity, sensitivity, recovery, accuracy, precision (intra- and inter-assay variation), freeze-thaw, long-term, auto injector and dry residue stability. Linearity in plasma was observed over a concentration range of 1.56-400 ng/ml with a limit of detection (LOD) of 0.78 ng/ml for all analytes except M(3) and M(5) where linearity was over the 3.13-400 ng/ml with LOD of 1.56 ng/ml. The absolute recoveries from plasma were consistent and reproducible over the linearity range for all analytes. The intra- and inter-day accuracy and precision method were within the acceptable limits and the analytes were stable after three freeze-thaw cycles and their dry residues were stable at -60 degrees C for 15 days. The method was successfully applied to determine concentrations of DHP and its putative metabolites in plasma during a pilot pharmacokinetic study in rabbits.

Pre-clinical assessment of DRF 4367, a novel COX-2 inhibitor: evaluation of pharmacokinetics, absolute oral bioavailability and metabolism in mice and comparative inter-species in vitro metabolism

The aim of this study was to characterize the pharmacokinetics and determine the absolute bioavailability and metabolism of DRF 4367, a novel COX-2 inhibitor, in mice. In addition, the in vitro metabolism of DRF 4367 was studied in mouse, rat, dog, monkey and human liver microsomes. Following oral administration, maximum concentrations of DRF 4367 were achieved after about 1 h. Upon intravenous (IV) administration, the concentration of DRF 4367 declined in a bi-exponential fashion with a terminal elimination half-life of 4.0 h. The elimination half-life was unchanged with route of administration. The volume of distribution and systemic clearance of DRF 4367 in mice were 0.80 l h(-1) kg(-1) and 0.14 l kg(-1), respectively, after IV administration. The absolute oral bioavailability of DRF 4367 was 44%. In all species of liver microsomes examined, the primary route of metabolism for DRF 4367 was demethylation of benzyl methoxy to form a hydroxy metabolite (M1). The formation of this metabolite was mediated by CYP2D6 and CYP2C19 enzymes. M1 was not found to possess COX-2 inhibitory activity. Chemical-inhibition studies showed that quinidine (selective for CYP2D6) and ticlopidine (selective for CYP2C19) inhibited the formation of the hydroxy metabolite of DRF 4367, whereas potent inhibitors selective for other forms of CYP did not inhibit this oxidative reaction. Upon oral or IV administration of DRF 4367 to mice, unchanged DRF 4367, M1, the O-glucuronide conjugate of M1 (M1-G) and the O-sulfate conjugate of M1 (M1-S) were identified in bile.

Serum ferritin in renal cell carcinoma: effect of tumor size, volume grade, and stage

AIM

To study the levels of serum ferritin in patients of renal cell carcinoma (RCC).

PATIENTS AND METHODS

Serum ferritin levels were measured preoperatively in 32 patients with radiological evidence of RCC using an enzyme immunoassay. The largest diameter of the primary tumor was measured in the pathological specimens in patients undergoing radical nephrectomy while in patients with non-operable tumor maximum tumor dimension was taken from CT scan. Pathological staging was done according TNM-1997.

RESULTS

Mean serum ferritin value in patients of RCC was 283.23+/-77.38 ng/ml while in controls the mean value was 79.98+/-32.96 ng/ml (P CONCLUSIONS: Serum ferritin levels are elevated in patients with RCC although its actual source is unclear. Further studies are needed to establish the role of ferritin in RCC.

Leishmania donovani: Effect of therapy on expression of CD2 antigen and secretion of macrophage migration inhibition factor by T-cells in patients with visceral leishmaniasis

Visceral leishmaniasis (VL) commonly known as Kala-azar in India is one of the several clinically important infections, where Th1 sub-population of CD4+ T-cells, despite a pre-requisite, fails to express macrophage migration inhibition factor (MIF) and interferon-gamma which both activate the macrophage and coordinate the immune response to intra-cellular Leishmania sp. Expression of CD2 receptors before and after antileishmanial therapy on CD4+ T-cells of VL patients and their corresponding effect on MIF were examined. Before treatment the number of T-cells expressing CD2 was low which incorporated insignificant MIF response. The immunological reconstitution was, however, observed after treatment as manifested through upregulation of CD2+ T-cells with pronounced MIF generation response. The study, therefore, identifies a possible role of CD2 antigen in immunity to VL.

Experimental studies on immunosuppressive effects of peste des petits ruminants (PPR) virus in goats

Effect of virulent and attenuated peste des petits ruminants (PPR) virus on the immune response to nonspecific antigen (ovalbumin) was investigated. Clinical and serological responses were monitored in goats administered with ovalbumin concurrently with either PPR vaccine or virulent virus. Study showed that PPR virulent virus causes marked immunosuppression as evidenced by leukopenia, lymphopenia, and reduced early antibody response to both specific and nonspecific antigen. These observations were predominant particularly during acute phase of disease (4-10 days post-infection). On the other hand, the vaccine virus induced only a transient lymphopenia without significantly affecting the immune response to nonspecific antigen or to itself during this period. Further, the antibody levels to ovalbumin in the group administered with virulent PPRV increased significantly between days 28 and 35 post-infection in comparison to the titers in other two groups given with either ovalbumin alone or in combination with vaccine.

Analysis of RAG expression by peripheral blood CD5+ and CD5- B cells of patients with childhood systemic lupus erythematosus

BACKGROUND

The assembly of immunoglobulin genes during B cell development in the bone marrow is dependent on the expression of recombination activating genes (RAG) 1 and 2. Recently, RAG expression in peripheral blood IgD+ B cells outside the bone marrow has been demonstrated and is associated with the development of autoimmune diseases.

OBJECTIVE

To investigate RAG expression in the CD5+ or CD5- IgD+ B cell compartment in childhood systemic lupus erythematosus (SLE).

METHODS

Using a combination of flow cytometric cell sorting and reverse transcriptase polymerase chain reaction analysis of cDNA libraries generated from individual cells, the expression of RAG, VpreB, and CD154 mRNA by individual peripheral blood B cells of three paediatric SLE patients was examined in detail.

RESULTS

While only one patient had a significantly increased frequency of RAG+ B cells in the CD5- B cell population, all patients showed higher frequencies of RAG+ B cells in the CD5+IgD+ B cell population. The frequency of RAG+ IgD+CD5+/- B cells was reduced during intravenous cyclophosphamide treatment. In healthy age matched children, RAG expressing IgD+ B cells were hardly detectable. Coexpression of RAG and VpreB or CD154 mRNA could only be found in SLE B cells.

CONCLUSIONS

RAG expression in peripheral blood B cells of SLE patients is particularly increased in the IgD+CD5+ B cell population. CD5+ and CD5- B cells in SLE have the potential to undergo receptor revision leading to the generation of high affinity pathogenic autoantibodies.

Biochemical and molecular markers in renal cell carcinoma: an update and future prospects

Cancer is a big problem in the developed world as well as in developing countries. Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90-95% of neoplasms arising from the kidney. RCC is more common in men than in women (2:1), and it most often occurs in patients between the ages of 50-70 years. In all cancers the cancerous cells release particular kind of proteins (called tumour markers) and blood tests are used to detect the presence of these markers. These tumour markers nowadays are an area of interest for oncologists who search for a possible solution in the detection and treatment of RCC. Different kinds of biochemical and molecular markers such as ferritin, MN/CA9, apoptotic index, p53, IL-2, gamma-enolase, CD44, CD95, chromosome instability and loss of heterozygosity have been tested in RCC, but so far no marker fulfils one or the other criteria to be considered as an ideal marker for RCC. This review gives basic and updated information about the different kinds of biomarkers studied in RCC and about the role implementation of genomics and proteomics in RCC.

Pituitary adenomas in childhood

Pituitary adenomas are common tumors composed of adenohypophysial cells. Although they usually arise in the sella turcica, they may occasionally be ectopic. Pituitary adenomas are rarely diagnosed in childhood and adolescence, but their mass effect and endocrine abnormalities can compromise both quality and length of life. Many signs or symptoms of pituitary adenoma, complained of in adulthood, not became evident during adolescence, suggesting true prevalence of this tumor in teenagers is higher than expected. Pititury adenoma occuring during adolescence are associated with features or therapeutic needs sometimes different from those occuring in adulthood. At the onset of disease, delay in growth was rarely observed in teenagers with pituitary adenomas. Many girls complain of oligoamenorrhoea and galactorrhoea, while headache and delay in pubertal development are the most commons features in boys. Hypopituitarism is occasionally encountered in adolescence. Early diagnosis and appropriate choice of therapy are necessary to avoid permanent endocrine complications of disease and its treatment.

Prevalence of GAD65 antibodies in lean subjects with type 2 diabetes

While type 2 diabetic subjects in developed countries are predominantly obese or overweight, those in India are often nonobese or lean. The reasons for leanness in these subjects has not been well understood. We assessed the prevalence of pancreatic islet autoimmunity in 83 lean adult subjects (BMI < 18.5 kg/m(2)) with type 2 diabetes by measuring antibodies to glutamic acid decarboxylase-65 (GAD Abs). Positivity to GAD Ab was present in 21 (25.3%) subjects. In addition, subjects with GAD Ab positivity were younger and had lower beta cell function (homeostasis model assessment, HOMA) as compared to the GAD Ab-negative group. This suggests that the antibody-positive group could have a slowly progressive form of type 1 diabetes.

Differential expression of chemokines in synovial cells exposed to different Borrelia burgdorferi isolates

OBJECTIVE

Lyme borreliosis is characterized by strong inflammatory reactions probably due to the presence of Borrelia burgdorferi in the joint. It has been suggested that Borrelia induces the immunological mechanisms that either can amplify the inflammatory response or can suppress it. To reveal the underlying mechanisms of chemoattraction and activation of responding leukocytes, we investigated the induction of chemokines in human synoviocytes exposed to two different B. burgdorferi sensu stricto isolates (strain Geho and B31).

METHODS

Synoviocytes were exposed in vitro up to 5 days. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was used to assess the relative chemokine mRNA expression of RANTES/CCL5, SDF-1alpha/CXCL12 alpha, SDF-1beta/CXCL12 beta, MCP-1/CCL2, MCP-2/CCL8, IL-8/CXCL8 and MIP-1alpha/CCL3, and enzyme-linked immunosorbant assay (ELISA) was used to assess the protein expression of RANTES, SDF-1, MCP-1, and MIP-1alpha in the culture supernatant.

RESULTS

MCP-1 gene expression was not changed by strain B31 but MCP-1 gene expression along with protein concentration was suppressed by strain Geho. Both strains induced RANTES mRNA and protein concentration. SDF-1 gene expression was suppressed, whereas protein concentrations were unchanged by both strains. IL-8 gene expression was unchanged by using strain Geho but significantly upregulated by strain B31. Both strains induced MCP-2 mRNA expression. MIP-1alpha mRNA expression was induced, but chemokine concentration was suppressed by both strains.

CONCLUSION

This study suggests that the orchestra of chemokines plays an important role in the immunopathogenesis of early Lyme arthritis.

Mutation C677T in the methylenetetrahydrofolate reductase gene is associated with male infertility in an Indian population1

A mutation (C677T) in the gene, MTHFR, is known to increase susceptibility to various multifactorial disorders. In order to assess this single nucleotide polymorphism (SNP) as risk factor for idiopathic male infertility, a case-control study was done on an Indian population. DNA from 151 cases of non-obstruction, idiopathic oligo-/azoospermia and 200 fertile males (controls) was polymerase chain reaction amplified using site-specific primers, and analysed for the mutation following HinfI-digestion. Our results show a significantly increased frequency of CT heterozygotes among infertile patients (p value <0.04). More importantly, while there were no T homozygotes in the control population, six of 151 infertile cases were T homozygous. Considering that T allele occurs in very low frequency in the control population, 677T is clearly a risk factor for infertility in the Indian population. We contend that the same could also be true for African and Southeast Asian populations where the frequency of 677T is very low. The lack of similar association in western populations could be because of the overall dietary enrichment of folates, which could nullify or minimize the effect of this polymorphism.

Beneficial effects of probiotics and prebiotics on human health

The primary role of a diet is not only to provide enough nutrients to fulfill metabolic requirements of the body but also to modulate various functions of the body. Probiotics, prebiotics and synbiotics are either beneficial microorganisms or substrates that facilitate the growth of these microorganisms which can be suitably harnessed by the food manufacturers and holds considerable promise for health care industry. Regardless of sufficient health benefits of these, there is a need to carry a multidisciplinary approach on safety evaluation as the conventional toxicological approach has various limitations. This article gives an overview of probiotics and prebiotics, their health effects, mode of action, growth and survival in GIT, quality assurance criteria and safety including future prospects.

A high throughput approach for simultaneous estimation of multiple synthetic trioxane derivatives using sample pooling for pharmacokinetic studies

The present study describes the application of concept of sample pooling to increase the throughput of pharmacokinetic screening at drug discovery and development stage. An HPLC-UV method for the simultaneous estimation of three synthetic antimalarial compounds 99/357, 99/408 and 99/411 has been developed and validated in rat serum with internal standard for pharmacokinetic profiling. Drug compounds in serum were extracted by two-step liquid-liquid extraction with 2% isopropyl alcohol in n-hexane and quantitated using a validated gradient HPLC-UV method, which was made feasible for all compounds using gradient elution scheme. The method was validated in terms of HPLC reproducibility, linearity, specificity, recovery, accuracy and precision, freeze thaw stability and long-term storage stability. Excellent linear relationships (r>0.99) were obtained for calibration as well as analytical standards over a concentration range of 25-1000 ng/ml for three analytes. Recoveries were fond to be >85% for 99/408 and 99/357 and >70% for 99/411. The method developed for three analytes was found to be accurate and precise as bias and percent relative standard deviation (% R.S.D.) values were within limits (<20%). By employing sample pooling approach, plasma level - time profile following single intravenous dose of all three compounds were obtained in a fraction of the time required by conventional single compound dosing and analysis.

Urethrovasocutaneous Fistula in a Case of Anterior Urethral Stricture

The occurrence of an urethrovasocutaneous fistula is an extremely rare event. We report the first case of such a fistula in a patient with anterior urethral stricture. The patient had epididymo-orchitis preceding the occurrence of the fistula. Increased intravesical and intraurethral pressure during voiding and the patulous ejaculatory ducts were the predisposing factors in this case. The patient was managed successfully by visual internal urethrotomy, bilateral vasectomy and excision of the fistula.

The burden of diabetes and impaired glucose tolerance in India using the WHO 1999 criteria: prevalence of diabetes in India study (PODIS)

This random multistage cross-sectional population survey was undertaken to determine the prevalence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) in subjects aged 25 years and above in India. The study was carried out in 77 centers (40 urban and 37 rural). 18363 (9008 males and 9355 females) subjects were studied. 10617 (5379 males and 5238 females) were from urban areas and 7746 (3629 males and 4117 females) from rural areas. Blood samples were taken after a fast of 10-12 h and 2 h after 75 g of oral glucose. Subjects were categorized as having IGT or DM using the World Health Organisation (WHO) (1999) criteria. The standardized prevalence rate for DM in the total Indian, urban and rural populations was 4.3, 5.9 and 2.7%, respectively. The corresponding IGT rates in the three populations was 5.2, 6.3 and 3.7%, respectively. The urban prevalence of DM and IGT was significantly greater than in the rural population (P < 0.001 in both instances). The prevalence of DM was significantly, more than that of IGT (P < 0.001) within both the rural and urban populations. Type 2 diabetes is a major health problem is India.

Differential expression of matrix metalloproteinases and cyclooxygenases in synovial cells exposed to Borrelia burgdorferi

OBJECTIVE AND DESIGN

Lyme arthritis is characterized by strong inflammatory reactions probably due to the presence of Borrelia burgdorferi in the joint. It has been suggested that Borrelia adopts different molecular mechanisms that either can amplify the host's inflammatory response or can suppress it. In the present study we analyzed the induction of matrix metalloproteinases (MMPs) and cyclooxygenases (COXs) in human synoviocytes exposed to different B. burgdorferi sensu stricto isolates (Geho and B31).

MATERIALS AND METHODS

Synoviocytes were exposed in vitro for 12 h up to 5 days. Semiquantitative reverse transcription polymerase chain reaction was used to assess the mRNA expression of MMP-1 to 13, COX-1 and COX-2. Prostaglandin E2 (PGE2) production was assessed by ELISA.

RESULTS

MMP-1 was unchanged in synovial cells exposed to strain Geho, whereas it was downregulated by strain B31. MMP-13 was downregulated by both strains. COX-2 was upregulated by strain B31, which resulted in increased PGE2 concentration in the supernatant. In contrast, COX-1 was slightly upregulated and COX-2 tended to be downregulated by Geho resulting in a decreased PGE2 concentration.

CONCLUSIONS

The differential expression of MMPs and COXs suggests that different B. burgdorferi strains influence different molecular mechanisms leading to chronic inflammation. This might be reflected in the clinical variability among Lyme arthritis patients.

Comparing the ADA 1997 and the WHO 1999 criteria: Prevalence of Diabetes in India Study

This random multistage cross-sectional population survey was undertaken to determine the prevalence of type 2 diabetes mellitus (DM) in subjects aged 25 years and above in India. The study was carried out in 77 centres (42 urban and 35 rural) to reflect the size and heterogeneity of the Indian population. 18,363 (9008 male and 9355 female) subjects were studied. 10,617 (5379 males and 5238 females) were from urban areas and 7746 (3629 males and 4117 females) from rural areas. Blood samples were taken after a fast of 10-12 and 2 h after 75 g of oral glucose. Subjects were categorized as having impaired fasting glycemia (IFG) or DM using the 1997 ADA or having impaired glucose tolerance (IGT) or DM using the 1999 WHO criteria. The age- and gender-standardized prevalence rate for DM using the ADA criteria was 3.6% whilst that using the WHO criteria was 4.3% (P < 0.001). The respective standardized prevalence of DM, using the two criteria was, 4.7 and 5.6%, respectively (P < 0.001) in the urban Indian population and 2.0 and 2.7% (P < 0.02) in the rural Indian population. Using the WHO criteria, 581 subjects were newly diagnosed whilst the ADA criteria newly diagnosed 437 subjects. The respective numbers for the urban population were 425 and 323, and for the rural population were 146 and 114, respectively. The ADA criteria could diagnose 75.2, 76.0 and 73.0% of the subjects who had DM as per the WHO criteria. Of 739 Indian subjects who had IFG, 106 (14.3%) were diagnosed as having DM by the WHO criteria whilst 505 (68.3%) had values compatible with a diagnosis of IGT. Of the 536 urban subjects with IFG, 74 (13.8%) had DM and 350 (65.3%) had IGT using the WHO criteria. Of the 302 rural subjects with IFG, 32 (15.8%) had DM and 155 (76.3%) had IGT using the WHO criteria. 505 (49.9%) of 1012 Indian subjects with IGT as per the WHO criteria had IFG. 350 (47.7%) of 733 urban subjects and 155 (55.5%) of 279 rural subjects with IGT had values compatible with IFG as per the ADA criteria. Type 2 diabetes is a major health problem is India. The use of the ADA criteria would underestimate the prevalence of DM by not diagnosing subjects showing a poor response to a glucose challenge. This along with the discrepancies between subjects showing IGF or IGT could be a challenge to any prevention program.

Toxicological effect and biochemical alterations induced by different fractions of Euphorbia royleana latex in freshwater harmful vector snail Lymnaea acuminata

Laboratory evaluation was made to assess the molluscicidal activity of different fractions of Euphorbia royleana (Family- Euphorbiaceae) latex obtained through sephadex gel column against freshwater snail Lymnaea (Radix) acuminata Lamarack. This snail is the vector of liver fluke, Fasciola hepatica Linnaeus and Fasciola gigantica Cobbold, which causes endemic fascioliasis in cattle and livestock. The toxic effect of the different fractions was time dependent and fifth fraction obtained through benzene: ethyl acetate (5:5) had maximum molluscicidal activity against Lymnaea acuminata. There was a significant negative correlation between LC values and exposure periods thus increase in exposure time, the LC50 value of V fraction of Euphorbia royleana latex was decreased from 14.28 mg/l (24 hr) to 9.28 mg/l (96 hr) against Lymnaea acuminata. After exposure to sub-lethal concentrations of this fraction there were significant time and dose dependent alterations observed in pyruvate, lactate levels, ALAT, AAT, AChE and cytochrome oxidase enzyme activities in different body tissues of Lymnaea acuminata. It is proposed that the fifth fraction of E. royleana latex can be used as a molluscicide for controlling the harmful snail population from aquatic ecosystem without any harm due to their reversible toxic action.

Polyglandular autoimmune endocrinopathy in type 2 diabetes

Polyglandular autoimmunity (PGA) type 2 presenting in childhood is extremely rare. We report a case of type 2 PGA who had hypothyroidism, followed by diabetic ketoacidosis and was later diagnosed to have adrenal insufficiency also.

The burden of diabetes and impaired fasting glucose in India using the ADA 1997 criteria: prevalence of diabetes in India study (PODIS)

This random multistage cross sectional population survey was undertaken to determine the prevalence of diabetes mellitus (DM) and impaired fasting glycemia/glucose (IFG) in subjects aged 25 years and above in India. The study was carried out in 108 centers (49 urban and 59 rural) to reflect the size and heterogeneity of the Indian population. 41,270 (20,534 males and 20,736 females) subjects were studied. 21,516 (10,865 males and 10,651 females) were from urban areas and 19,754 (9669 males and 10,085 females) from rural areas. Blood samples were taken after a fast of 10-12h and the subjects were categorized as having IFG or DM using the 1997 American Diabetes Association criteria. The age and gender standardized prevalence rate for DM and IFG in the total Indian population was 3.3 and 3.6% respectively (P < 0.001). The standardized prevalence of DM and IFG in urban areas was significantly higher than that for the rural population (urban DM prevalence 4.6% versus rural DM prevalence 1.9%, P < 0.001; urban IFG prevalence 4.8% versus rural IFG prevalence 2.5%, P < 0.001). There was no statistically significant difference in the prevalence between DM (4.6%) and IFG (4.8%) in the urban population. The rural prevalence of IFG (2.5%) was significantly (P <0.001) more than the rural prevalence of DM (1.9%). Type 2 diabetes is a major health problem is India.