Search PubMed⌕ Search

Biomedical subjects

R Saxena

Publications and source records attributed to R Saxena.

At least 55 records · Page 3Linked to original sources
PubMed2004

Clinical, haematological and histomorphological profile of adult myelodysplastic syndrome. Study of 96 cases in a single institute.

Myelodysplastic syndromes (MDS) are clonal haematopoietic stem cell disorders characterised by ineffective and dyspoietic haematopoiesis. The natural history of these disorders is variable and ranges from a chronic to a rapid course towards leukaemic progression. Certain shortcomings have been encountered in the French-American-British (FAB) classification over the years, and therefore there is a need for an alternative method of classification. In 1999, the WHO published a revised classification of MDS. In the present study, we have analysed the clinical, haematological and histomorphological features in 96 cases of primary MDS seen in the department of haematology at the All India Institute of Medical Sciences (AIIMS) over a 6-yr period (1996-2001). Both FAB and WHO classifications have been incorporated and the Bournemouth scoring system applied in each case at presentation. The Bournemouth scoring system, in the absence of a cytogenetic study, offers a good prognostication and long-term survival estimate.

Adolescent↗
PubMed2004

Hemophilia A: role of FVIIIC/vWF Ag in assisting linkage analysis for carrier detection.

Carrier detection for hemophilia A was carried out in 52 females from 30 families presenting to the Haematology Department AIIMS, using linkage analysis and factor VIIIC (FVIIIC)-von Willebrand factor (vWF) antigen assay. The allelic frequency for the marker Bcl 1 and Xba 1 was 0.58 and 0.54, respectively, for the positive alleles and 0.42 and 0.46, respectively, for the negative alleles. The heterozygosity frequency of Bcl I and Xba 1 was 0.65 and 0.55, respectively. Of the 52 females, 30 were mothers of hemophilic patients and 22 were sisters of hemophilic patients. Of the 30 mothers, positive family history was present in 14. In these patients, the defective X chromosome was tracked in 10, and in four the defective X chromosome could not be tracked because the mothers were homozygous for the marker used. Of the 16 mothers without a family history of disease, three were observed to be carriers based on linkage analysis and reduced factor VIII levels in mother/sister. Possible defective X chromosome was tracked in 11 mothers and five were noninformative because they did not show heterozygosity for the markers used. Using linkage analysis, nine of the 22 sisters were found to be definite carriers, 10 noncarriers, and three were noninformative. It is thus concluded that using Bcl 1 and Xba 1 linkage analysis, carrier status can be definitely ascertained in 50% females and this level of information can be increased to 61.5% by measuring FVIIIC/vWF antigen levels in them.

Chromosome Mapping↗
PubMed2003

Pro CR global: an effective screening test for thrombophilia.

In the present study, the Pro C(R) Global test was evaluated as a screening test for estimation of the activity of the main plasma components of the anticoagulant protein C (PC) / protein S (PS) pathway; 300 patients with a history of thrombosis were investigated for Pro C(R) Global. It was positive in 74 patients. Tests for estimation of PC, PS, activated protein C resistance (APCR), and lupus anticoagulant (LAC) were performed in all the patients with abnormal Pro C(R) Global and in 10 patients with normal Pro C(R) Global. In all, 66 of the 74 patients had a defect in PC/PS/APCR or LAC; 18 patients had both PC and PS deficiency, 25 had PS deficiency alone, 10 had PC deficiency alone, one had APCR alone, eight had PS, PC deficiency with APCR, and four had PS deficiency with APCR. In the 10 patients who tested negative with the Pro C(R) Global test, PC, APCR, and LAC were negative in all. However, PS deficiency was seen in two of them. The sensitivity and specificity of Pro C(R) Global, calculated with respect to positivity of PC, PS, LAC, or APCR as the gold standard, were 97% and 50%, respectively. The diagnostic accuracy of the assay was 88.1%. It is thus recommended that Pro C(R) Global can be used effectively as a screening test to detect abnormality in the PC/PS/APCR/LAC pathway.

Case-Control Studies↗
PubMed2003

Neonatal thrombosis.

Neonatal thrombosis is a serious event that can cause mortality or result in severe morbidity and disability. The most important risk factor for the development of thrombosis during the neonatal period is the presence of an indwelling central line and consequently the vessels involved tend to be those most frequently used for catheterization. Other documented risk factors for the development of neonatal thrombosis include asphyxia, septicemia, dehydration, maternal diabetes and cardiac disease. Main laboratory findings for the diagnosis of hypercoagulable states, include shortened aPTT, decreased levels of inhibitors (AT III, Protein C and Protein S), increased resistance to activated protein C, defective fibrinolysis (basal and after stimuli), increased levels of clotting factors (fibrinogen, factor VII, factor VIII, etc.), increased and/or hyperactive platelets, increased whole blood and/or plasma viscosity, Antiphospholipid antibodies and presence of prothrombotic molecular defects like FV Leiden, P20210 and MTHFR. Approximately 4% and 2% respectively of Caucasians are heterozygous for these gene defects. Their causative role in neonatal thrombosis is unknown but they may have a contributory role in the pathogenesis of thrombosis in neonates.

Disseminated Intravascular Coagulation↗
PubMed2003

Molecular analysis of Huntington's disease and linked polymorphisms in the Indian population.

OBJECTIVES: To understand the population variation and haplotypes of Huntington's disease (HD) in India we have analysed CAG repeats at the HD locus together with closely linked polymorphisms in both HD patients and normal controls. MATERIALS AND METHODS: The CAG repeat and linked polymorphisms were analysed in 30 Indian HD families together with 250 ethnically matched controls using fluorescent polymerase chain reaction (PCR) based size estimation. RESULTS: CAG repeats at the HD locus in the normal population showed a mean size of 17.99 +/- 2.66 repeats (range nine to 33 repeats). The HD mutation in our families did not show any significant association with either the (CCG)7 or (CCG)10 allele while haplotype analysis suggested the over-representation of the 7-2-I (CCG-D4s127-Delta 2642 loci) haplotype in a subset of families. CONCLUSION: The distribution of CAG repeats in the normal population suggests a higher prevalence of HD, closer to that seen in Western Europe. Haplotype analysis suggests the presence of a founder mutation in a subset of families and provides evidence for multiple and geographically distinct origins for the HD mutation in India.

Female↗
PubMed2003

Subclassification of HbS syndrome: is it necessary?

Sickle beta-thalassaemia (S beta-thalassaemia) is a condition, which results from coinheritance of a sickle cell gene and a beta-thalassaemia gene. The clinical phenotype depends on the type of beta-thalassaemia gene (beta+ or beta(o)). There are several similarities in clinical and haematological features, which sometimes pose a difficulty in correct diagnosis. A definitive diagnosis is required in order to initiate early supportive treatment in patients with homozygous sickle cell disease (SS disease) and to define the later clinical course. Forty-seven cases of haemoglobin sickle syndrome (HbS syndrome) were studied. The clinico-haematological features and high-performance liquid chromatography (HPLC) results from 17 patients with S beta-thalassaemia were compared with those of SS disease (10 patients). Splenomegaly was more commonly found in patients with S beta-thalassaemia. Among the haematological features, red blood cell counts and HbA2 levels were significantly higher in patients with S beta-thalassaemia, while red cell indices, such as MCV, MCH were significantly lower than those seen SS disease. MCHC, PCV total haemoglobin (Hb), HbS, A and HbF were similar in the two groups.

Adolescent↗
PubMed2003

Inherited bleeding disorders in Indian women with menorrhagia.

In order to define the prevalence of haemostatic defects in women presenting with menorrhagia in our region, the coagulation data on women bleeders investigated in the Department of Haematology, AIIMS, were analysed. A total of 337 of the 2200 menorrhagic women investigated were characterized to have an inherited bleeding disorder; 221 of these 337 women presented with menorrhagia alone while 116 also had other associated bleeding manifestations as prolonged bleeding from injury site, ecchymotic patches in the skin, epistaxis, haematomas, haemarthroses and major bleeds like intracerebral bleeding. The tests performed included bleeding time (BT), platelet count, prothrombin time (PT), prothrombin consumption index (PCI), activated partial thromboplastin time (APTT), PF3 release with adenosine diphosphate (ADP) at 0 and 20 min, total PF3 assay and platelet Aggregation studies with collagen, ADP, adrenaline, arachidonic acid and ristocetin. Coagulation factor assays, von Willebrand antigen estimation, ristocetin cofactor assay and electron microscopy were performed wherever necessary. Inherited platelet dysfunction was seen in 283 (83.9%) of the patients. Amongst these, isolated PF3 availability defect was seen in 163 (48.4%) cases. Glanzman's thrombasthenia was seen in 30 (8.9%) patients, Storage pool disease in eight (2.4%) patients, arachidonic acid pathway defect in five (1.5%) patients and Bernard-Soulier Syndrome in six (1.8%) patients. In 71 (21.1%) patients, the platelet function defect could not be classified into any specific subtypes. Inherited defects of coagulation were observed in 54 (16%) of the cases. Amongst these, von Willebrand disease (vWD) was the most frequent being seen in 40 (11.9%) of the cases. Factor XIII deficiency was seen in one (0.3%), factor X deficiency in four (1.2%), factor VII deficiency in one (0.3%) and factor XII deficiency in one (0.3%) of the patients. It is concluded that although hereditary platelet function defects constitute a large majority of women bleeders in India but among the coagulation defects, vWD is the commonest as reported from the caucasian population. It is thus suggested that in women presenting with menorrhagia, screening tests for haemostasis especially for vWD and inherited platelet function defects must be performed.

Adolescent↗
PubMed2003

Small cells in hepatoblastoma lack "oval" cell phenotype.

Hepatoblastoma, a childhood tumor of the liver, is composed of epithelial and mesenchymal elements in varying proportions and at various stages of differentiation. The epithelial element recapitulates the stages of hepatocyte development from the primitive blastema through embryonal hepatocytes to fetal hepatocytes. The blastemal or undifferentiated cells have been postulated to represent neoplastic hepatocyte progenitor cells. In this study, we examine the immunophenotype of the various epithelial cells of hepatoblastoma with special emphasis on the small undifferentiated cell component and compare it with that of adult hepatocytes and hepatic stem (oval) cells. Putative stem cells in the liver can express all of the following markers: alpha-feto protein, CK19 (OV-6), chromogranin A, Bcl-2, HepPar-1, and alpha1 microglobulin. The latter, like alpha-feto protein, is a plasma protein synthesized by hepatocytes. Both alpha1 microglobulin and HepPar-1 are expressed in fetal liver cells as early as 7 weeks of intrauterine life. They are also expressed in hepatocellular carcinoma and in hepatocytic cell lines derived from normal fetal or adult liver. Formalin-fixed, paraffin-embedded archival tissues from 10 predominantly epithelial hepatoblastomas were immunostained with antibodies directed against CD 34, alpha1 microglobulin, Bcl-2, HepPar 1, and CK19 using the avidin-biotin-peroxidase method. The undifferentiated small cell component did not express any of the markers studied, namely, Bcl-2, HepPar-1, alpha(1) microglobulin, CD34, or CK19. Hepatocyte-like cells were alpha1 microglobulin- and HepPar-1-positive, with the intensity of staining correlating with the degree of hepatocytic differentiation. Bcl-2 expression was restricted to areas of ductular differentiation. CK19 was detected in foci that showed duct formation. The small cells of hepatoblastoma did not express HepPar-1, Bcl-2, CK19, alpha1 microglobulin, or CD34, markers that characterize the immunophenotype of hepatic stem cells ("oval" cells). Thus, this observation raises the following questions: (1) is "hepatoblastoma" a misnomer? (2) is the expression of tumor antigens dysregulated in hepatoblastoma? (3) does the liver have two different types of progenitor cells, oval cells and blastemal cells, with differing immunophenotypes? and (4) do the blastemal cells, rather than oval cells, represent the more primitive progenitor cells of the liver?

Cell Differentiation↗
PubMed2003

Correlation between confocal scanning laser ophthalmoscopy and scanning laser polarimetry in open angle glaucoma.

PURPOSE: To correlate the findings of confocal scanning laser ophthalmoscopy and scanning laser polarimetry in diagnosed cases of glaucoma with established visual field defects. METHODS: A total of 53 diagnosed cases of primary open angle glaucoma that had at least two recorded of IOP more than 21 mm Hg on Goldmann applanation tonometry, open angles on gonioscopy and glaucomatous visual field defects on automated perimetry, were examined by confocal scanning laser ophthalmoscopy (HRT-II) and scanning laser polarimetry (GDx-NFA), in random order. RESULTS: The number on GDx advanced analysis had a significant (p < 0.05) correlation with the rim area (r = -0.279; p = 0.043), cup area (r = 0.311; p = 0.023) and the vertical cup: disc ratio (r = 0.376; p = 0.006). The correlation between HRT-II stereometric parameters and GDx advanced analysis parameters was significant (p < 0.05) for more parameters targeting the inferior pole of the disc than the superior pole. Numerically, the worst values of GDx parameters were associated with a worse result on Moorfields regression analysis, but there was poor agreement between the diagnostic labels like within or outside normal limits as obtained on GDx and HRT-II. CONCLUSIONS: Nerve fiber loss as detected on GDx correlates well with topographic optic nerve head changes as measured with the HRT-II. However, automated diagnosis on the two machines showed poor agreement.

Female↗
PubMed2003

Ultrasound biomicroscopy in lens "coloboma".

PURPOSE: To study the morphology of the Lens "Coloboma" using the technique of ultrasound biomicroscopy. METHODS: We used the Paradigm 40 Ultrasound biomicroscope to study the morphology of the lens "Coloboma". RESULTS: Ultrasound biomicroscopy of the lens "Coloboma" revealed a greatly increased sphericity of the lens and the deficiency of zonules in the "colobomatous" area. CONCLUSIONS: Ultrasound biomicroscopy has helped in elucidating the pathology of the lens "Coloboma".

Coloboma↗
PubMed2003

Peak pressures: crossover study of timolol and latanoprost.

PURPOSE: To compare the diurnal efficacy and action on peak intraocular pressures (IOP) of 0.005% latanoprost and 0.5% timolol as primary therapy in 60 eyes having dark brown irides with primary open angle glaucoma (POAG). METHODS: A prospective, comparative, observer-masked, crossover, interventional trial including the mean of both eyes of 30 patients with POAG who were randomly started on either latanoprost once daily or timolol twice daily. Three months after treatment with one drug, the second drug was substituted. A masked observer carried out diurnal assessments of IOP before the start of therapy and at 3 and 7 months. The fourth month was the washout period for the first drug. RESULTS: The average baseline IOP was 23.36 +/- 2.14 mm Hg, which was reduced by 8.8 +/- 2.2 mmHg with latanoprost (p < 0.01) and by 6.75 +/- 1.9 mm Hg with timolol (p = 0.01). The reduction was greater for latanoprost (p < 0.005). The average peak IOP at baseline was 27.6 +/- 2.22 mmHg. The effective fall in IOP at the time of new peaks in subsequent diurnal recordings of IOP compared to the baseline diurnal curve was 8.9 mm Hg with latanoprost (p < 0.005) and 5.77 mm Hg with timolol (p < 0.01). This difference in IOP reduction between the two drugs was statistically significant (p < 0.01). Latanoprost had a lower efficacy in peak IOP reduction in eyes with evening peak of IOP than in those with morning peak (p < 0.005). The efficacy of timolol was lower overall compared to latanoprost, but was similar in all circadian rhythms. The shift in timing of IOP peak was greater with latanoprost compared to timolol (4.34 hours vs -0.72 hours, p < .01). A total of 90% of patients on latanoprost and 33.3% on timolol achieved a reduction of > 30% in baseline mean IOP. The average of the trough IOP recorded in each of the individual baseline IOP curves was 19.05 +/- 2.05 mm Hg. CONCLUSIONS: Greater mean and peak IOP reduction was achieved with latanoprost compared to timolol. Dampening of the circadian rhythm was better with latanoprost. Latanoprost appears to be more effective than timolol at all points in time with greater efficacy in eyes with morning peaks compared to evening peaks.

Administration, Topical↗
PubMed2003

HPLC--how necessary is it for haemoglobinopathy diagnosis in India?

Cation exchange high performance liquid chromatography (HPLC) is emerging as the method of choice for the initial screening of thalassemias and haemoglobinopathies and quantification of Haemoglobins (Hbs) like HbA, HbA2 and HbF. Since it is expensive, the present study was conducted to evaluate the need for HPLC in Indian laboratories and identify situations where it would be imperative. Eighty three patients suspected to have thalassemia and haemoglobinopathies were analysed. Both HPLC and alkaline gel electrophoresis detected 14 cases of HbE syndrome and 14 cases of HbS syndrome. However of the 14 cases diagnosed as HbD syndrome by alkaline electrophoresis, eight cases were diagnosed as Hb Q India, 1 case as HbD Iran and 5 cases of HbD Punjab on HPLC. Thirty-one cases were detected to have beta heterozygous thalassemia based on the high HbA2 levels (>3.9%) and eight cases were diagnosed as beta homozygous thalassemia by both HPLC and gel electrophoresis. One of them had an unknown Hb migrating in F-A region. Her mother also had same unknown Hb variant. In view of electrophoretic migration and retention time (RT) on HPLC, possibility of HbG-San Jose was considered. HPLC being an automated instrument is highly sensitive and specific, has high resolution and helps in quantification of various haemoglobins. However in a developing country like India where economical factors play a major role in planning for management of patients, the role of HPLC is limited.

Chromatography, High Pressure Liquid↗
PubMed2003

D-dimer test: diagnostic role in clinical and sub-clinical DIC.

D-dimer test is used as a diagnosis test for acute disseminated intravascular coagulation (DIC). This study was undertaken to find out its sensitivity and specificity in the diagnosis of acute DIC and its role in diagnosis of sub-clinical DIC, as there is limited data available on the subject. Of the 29 patients of clinically acute DIC, all had positive D-dimer test, and markedly prolonged PT, APTT and TT were seen in 24 (83%) of these patients. D-dimer test was found to be highly specific but less sensitive for the diagnosis of acute DIC. Of the 29 patients predisposed to sub-clinical DIC. D-dimer was positive is 26 (90%) patients and PT, APTT and TT were mildly prolonged in 11 patients. It is suggested that D-dimer positivity for the diagnoses of sub-clinical DIC need to be considered with caution and to be supplemented by other coagulation test including serial follow up with d-dimer and coagulation tests.

Disseminated Intravascular Coagulation↗
PubMed2002

Venous invasion may predict lymph node metastasis in early rectal cancer.

AIM: The aim of this study was to evaluate the role of histopathological and demographic characteristics in predicting lymph node metastasis in patients with adenocarcinoma of the rectum confined to the mucosal and submucosal layers. METHODS: Fifty-nine patients with early rectal cancer underwent resection of the rectum including lymph nodes and five showed lymph node metastasis (8.6%). Pathology slides of these patients were reviewed by a single pathologist. Demographic and clinical characteristics of these 59 patients were correlated with the existence of nodal metastasis. Formal tests of comparability were carried out by using Fisher's exact test. Logistic regression models were fitted to data to examine possible relationships with 12 covariates measured from each patient and to obtain corresponding odds ratios (as well as a 95% confidence interval for the odds ratios). These covariates included age at surgery, gender, morphology, histology, degree of differentiation, Haggitt's classification for polyps according to the level of invasion, lymphatic and venous invasion, desmoplastic reaction, degree of lymphocytic invasion, presence of lymphoid follicles and presence of infiltrating or pushing margins. RESULTS: A significantly higher rate of lymph node metastasis occurs in the presence of venous invasion (P < 0.01). Venous invasion was present in three of five (60%) patients with lymph node metastasis and only four of 54 (7%) patients without lymph node metastasis. Other variables did not achieve statistical significance. CONCLUSIONS: Only the presence of venous invasion was found to be highly significant. The odds ratio of lymph node metastasis increased 18-fold for a patient who had venous invasion compared with a patient who did not. This suggests that the presence of venous invasion in early rectal cancer may provide valuable information to determine which patients would benefit from radical surgery, or adjuvant radiation therapy after sphincter-sparing surgery owing to an increased risk of lymph node metastasis.

Adenocarcinoma↗