Flowcytometric evidence of platelet activation in patients on aspirin following myocardial infarction

BACKGROUND

Following a myocardial infarction, patients are usually started on long term antiplatelet therapy with aspirin in a dose of 80-150 mg/day. However, there are no quick and easy methods to assess the efficacy of the antiplatelet activity of aspirin.

METHODS

We studied 60 consecutive patients (men, < 40 years of age) 8-10 weeks after they had had acute myocardial infarction. These patients were receiving 100 mg aspirin daily orally with or without b-blockers. We measured P-selectin expression and fibrinogen binding by flowcytometry at least 3 times over a period of 2 years in all the patients. We also studied 100 age- and sex-matched controls.

RESULTS

Of the 60 patients, 30 (50%) showed both increased P-selectin and fibrinogen binding by platelets, suggesting platelet activation. Fourteen other patients had increased fibrinogen binding but normal P-selectin expression. Sixteen patients and all the controls had normal results of both tests.

CONCLUSION

Our data show evidence of platelet activation in at least 50% of patients receiving 100 mg of aspirin daily. Flowcytometry for P-selectin expression and fibrinogen binding to platelets can be used to monitor antiplatelet therapy with aspirin following acute myocardial infarction.

Molecular diversity of HLA-Cw alleles in the Maratha community of Mumbai, Maharashtra, western India

Recent advances suggest a significant role for the HLA-C locus as a target of alloreactions after bone marrow transplantation. The biological importance of products of the HLA-C locus, both as transplant antigens and as ligands for natural killer (NK) cells, is well established. A total of 10 different serologically defined HLA-Cw antigen specificities (Cw1-Cw10) are encoded by the C locus; however, there are now 151 different alleles that can be identified by molecular methods. Serological definition of Cw alleles therefore includes 20-50% blanks, which cannot be detected by the available antisera. We used the molecular method of polymerase chain reaction (PCR)-based sequence-specific amplification and probe hybridization to define Cw alleles in 91 individuals from the Maratha community, and compared the data with data for 92 serologically typed Maratha individuals from India. We identified Cw*12, Cw*14, Cw*15, Cw*16 and Cw*18, along with the serologically identified Cw*01, Cw*02, Cw*03, Cw*04, Cw*06 and Cw*07 alleles. The HLA-Cw blank allele frequency in the Maratha was reduced from 0.5706 to 0.00. Furthermore, by using a molecular technique, it was possible to identify novel allele subtypes, such as Cw*0104, Cw*0203 and Cw*0707, and a high frequency of Cw* 1801 in the Maratha community compared with other Indian and world populations. Our results will have clinical implications in related and unrelated HLA-matched bone marrow transplantation in India.

Co-existence of Bernard Soulier syndrome and factor XI deficiency in a family: a unified pathology?

Bernard Soulier syndrome (BSS) is an autosomal recessive disorder of platelet function. Factor XI deficiency leads to a variable bleeding tendency and the defect is also inherited in an autosomal recessive manner. In this paper we describe a case of BSS with severe deficiency of factor XI. The patient had both BSS and factor XI deficiency. The sister and both the parents were heterozygous for BSS and had factor XI deficiency. The brother is normal for both BSS and factor XI levels. Apart from the patient, no other family members had any history of bleeding in spite of having a deficiency of factor XI, which suggests that low level of factor XI in this family was not responsible for bleeding. Curiously, although the index patient inherited both Bernard Soulier syndrome and factor XI deficiency (FXI: C = 1.3%), he had mild bleeding symptoms restricted only to ecchymoses and petechiae. Detailed review of the pedigree showed that all the members who inherited the BSS phenotype, also inherited abnormal factor XI gene. Karyotype of the affected members of the family using standard Giemsa banding technique showed a normal picture. Considering the fact that the genes causing both BSS and factor XI are both on widely different chromosomes, their coinheritance in four members of the family without any unusual translocation suggest a unified pathology probably on the basis of a common transcription factor defect or a common post translational processing defect. This is the first case of coinheritance of BSS and factor XI deficiency reported in the English literature.

Immunogenetic association in patients with antineutrophil cytoplasmic antibodies (ANCA) from Mumbai, Maharashtra, India

Considerable genetic evidence exit for ANCA-associated vasculitis and pathogenesis. HLA A and B alleles identified serologically from 84 ANCA-positive patients were compared with 101 controls. Further subtyping were done in the 27 "pauci-immune" vasculitis patients using the polymerase chain reaction based PCR-SSOP technique and compared with controls (67). The results revealed that HLA A1 (OR=4.00; p value 2.72E-05), B17 (OR=3.38; p value 0.0008) and HLA B40 (OR=2.74; p value 0.001) were significantly increased among ANCA-positive patients when compared with the controls. Further, the molecular subtypes A*0101 (OR=5.04; p value 0.0005), B*5801 (OR=4.47; p value 0.0002) and haplotype A*0101-B*5801 (OR=4.47; p value 0.0001) were significantly increased among the autoimmune patients. The study revealed that HLA A1, B17 and B40 alleles are associated in production of antineutrophil autoantibodies and A*0101-B*5801 haplotype is significantly associated with autoimmune diseases and they may be invariably involved in disease pathogenesis in India.

Intracranial haemorrhage in severe haemophilia: prevalence and outcome in a developing country

Intracranial haemorrhage (ICH) is a common cause of morbidity and mortality in haemophilic patients all over the world. From 1995 to 2004, we have investigated 37 patients with 43 episodes of ICH at our Comprehensive Haemophilia Care Center from a total of 600 registered patients. Diagnosis of ICH in the patients was confirmed by clinical, haematological and computed tomographic imaging data. Three patients died despite replacement therapy while one child who had a ventriculo-atrial shunt for acute hydrocephalus also died before further intervention. One of the four patients who died also had severe aplastic anaemia for 6 years in addition to severe haemophilia. Detailed history obtained from 143 families with haemophilia attending the Genetic Diagnosis Clinic at our Center showed a positive history of cerebral bleed in 39 episodes in 37 patients. Sixteen families gave a history of death in the family of haemophilic patients due to ICH, while in the remaining 21 families, the patients had survived the episode after treatment elsewhere. However, the ICH was not confirmed by image data in these cases. The treatment protocols were also not available in these cases. Conservative factor replacement therapy 100% correction for 3 days followed by 50-60% correction for 7 days) coupled with the epsilon amino caproic acid, the antifibrinolytic agent at least for 30 days led to a mortality (10.8%) similar to that of the western countries and almost no morbidity. Surgery was not required in any of these patients except in one elderly patient with HIV infection on antiretroviral therapy.

Chemical constituents of Piper betle Linn. (Piperaceae) roots

Column chromatography of the alcoholic extract of Piper betle roots furnished aristololactam A-II and a new phenyl propene, characterized as 4-allyl resorcinol, while the petroleum-ether extract yielded a diketosteroid, viz. stigmast-4-en-3,6-dione. All these compounds were characterized by spectroscopic means. Isolation of these compounds from this source is being reported here for the first time.

Breast biopsy utilization: a population-based study

BACKGROUND

Breast biopsy, to determine the nature of a clinical or radiographic breast abnormality, was presumed to have increased in frequency with the widespread use of screening mammography. However, scant data exist regarding the utilization of breast biopsies in the community population.

METHODS

Through the resources of the Rochester Epidemiology Project, the medical records of women 18 years and older who had a breast biopsy from January 1, 1988, through December 31, 1999, were reviewed for the type of biopsy, presentation at biopsy, and tissue pathological findings. The overall and age-specific utilization rates of breast biopsies were assessed, as were changes in the breast biopsy technique after the introduction of image-guided core-needle biopsy in 1992.

RESULTS

The overall annual utilization rate of breast biopsies was 62.6 per 10 000 women per year and remained stable throughout the study. Excisional breast biopsies showed a decreasing trend and core-needle biopsies increased during the study duration. The age-adjusted incidence of benign results of breast biopsies for the study duration was 38.9 per 10 000 women. The benign-malignant ratio remained constant despite changes in the biopsy procedure.

CONCLUSIONS

This population-based study provides much-needed data regarding the frequency of breast biopsies and benign results of breast biopsies in a community population. The utilization rate of breast biopsies remained fairly constant throughout the study period despite the introduction of the image-guided, core-needle biopsy procedure in 1992. A multidisciplinary breast practice, along with established guidelines for breast biopsy, can ensure appropriate use of new technology and thereby improve patient care.

Benign breast disease and the risk of breast cancer

BACKGROUND

Benign breast disease is an important risk factor for breast cancer. We studied a large group of women with benign breast disease to obtain reliable estimates of this risk.

METHODS

We identified all women who received a diagnosis of benign breast disease at the Mayo Clinic between 1967 and 1991. Breast-cancer events were obtained from medical records and questionnaires. To estimate relative risks, we compared the number of observed breast cancers with the number expected on the basis of the rates of breast cancer in the Iowa Surveillance, Epidemiology, and End Results registry.

RESULTS

We followed 9087 women for a median of 15 years. The histologic findings were nonproliferative lesions in 67 percent of women, proliferative lesions without atypia in 30 percent, and atypical hyperplasia in 4 percent. To date, 707 breast cancers have developed. The relative risk of breast cancer for the cohort was 1.56 (95 percent confidence interval, 1.45 to 1.68), and this increased risk persisted for at least 25 years after biopsy. The relative risk associated with atypia was 4.24 (95 percent confidence interval, 3.26 to 5.41), as compared with a relative risk of 1.88 (95 percent confidence interval, 1.66 to 2.12) for proliferative changes without atypia and of 1.27 (95 percent confidence interval, 1.15 to 1.41) for nonproliferative lesions. The strength of the family history of breast cancer, available for 4808 women, was a risk factor that was independent of histologic findings. No increased risk was found among women with no family history and nonproliferative findings. In the first 10 years after the initial biopsy, an excess of cancers occurred in the same breast, especially in women with atypia.

CONCLUSIONS

Risk factors for breast cancer after the diagnosis of benign breast disease include the histologic classification of a benign breast lesion and a family history of breast cancer.

A possible mechanism of zero-crossing detection using the concept of the extended classical receptive field of retinal ganglion cells

The extended classical receptive field (ECRF) of retinal ganglion cells has been modelled as a combination of three zero-mean Gaussians at three different scales that has been shown to be equivalent to a Biharmonic or Bi-Laplacian of Gaussian filter. It has also been shown that the ECRF can be approximated by a combination of Laplacian of Gaussian (LoG) and the Dirac-delta function. Zero-crossings detected with this operator are more informative than those detected by the traditional filters like LoG or Difference of Gaussians (DoG) that had been devised using the classical receptive field of the ganglion cells. We have also explained that such an additional information processing is not in contradiction with the recent experimental findings on the physiology of retinal ganglion cells.

ANCA: serology in Wegener's granulomatosis

BACKGROUND AND OBJECTIVES

Wegener's granulomatosis (WG) is being increasingly diagnosed in India, which exists in two forms, the 'limited Wegener's granulomatosis' (LWG) having upper respiratory tract (URT) and lower respiratory tract (LRT) involvement and the 'classical Wegener's granulomatosis' (CWG), with the triad of URT, LRT involvement along with kidney involvement. Cytoplasmic ANCA (C-ANCA) or anti-Proteinase3 (anti-PR3), which is highly diagnostic for WG, rarely perinuclear ANCA (P-ANCA) may exist.

AIMS

To detect anti-neutrophil cytoplasmic antibodies (ANCA) and correlate it with serological, hematological parameters, and the Birmingham Vasculitis Activity Score (BVAS).

SETTINGS AND DESIGN

Twenty-three clinically and histopathologically proven WG (16 CWG, 7 LWG) were studied.

MATERIAL AND METHODS

C-ANCA and P-ANCA patterns were identified by immunofluorescence and specificities were confirmed by 'alpha granule' enzyme linked immunosorbent assay (ELISA), anti-PR3, anti-MPO (myeloperoxidase) and anti-Lactoferrin (anti-LF) by ELISA.

RESULTS

LRT involvement was seen in 91.3%, URT in 78.3%, and renal manifestations in 69.6% cases. The BVAS in CWG was significantly higher than BVAS in the LWG. Decreased hemoglobin, increased WBC counts, ESR, CRP and Creatinine were seen in CWG as compared to LWG. The C-ANCA was present in 65.2% patients and P-ANCA in 13% cases. Anti-PR3 was seen in 69.6% patients and anti-LF in 17.4% cases. Severity of disease and ANCA was higher in CWG than in LWG.

CONCLUSIONS

Vasculitis syndromes are known to overlap and many go undetected; therefore ANCA testing, along with the clinical and histopathological observations may be helpful in early detection and management of WG cases.

Evaluation of markers of endothelial damage in cases of young myocardial infarction

The pathogenesis of arterial thrombotic disease involves multiple genetic and environmental factors related to atherosclerosis and thrombosis. The endothelium is a monolayer of polygonal cells that extend continuously over the luminal surface of the entire vasculature. Injury to the endothelium leads to dysfunction. The causes of injury include lipids, immune complexes, microorganisms, smoking, hypertension, aging, diabetes mellitus and trauma. Studies have been done to evaluate the role of different adhesion molecules on the endothelial membrane in the pathogenesis of atherosclerosis. These molecules are intercellular adhesion molecule type-1 (ICAM-1), vascular cell adhesion molecule type-1 (VCAM-1), platelet/endothelial cell adhesion molecule-1 (PECAM-1), soluble P-selectin (sP-selectin) and soluble E-selectin (sE-selectin). One-hundred and twenty patients of myocardial infarction (age below 40 years) were recruited from the out-patients department of Department of Cardiology, KEM Hospital, Mumbai. All the patients were recruited 8-10 weeks after stabilization after MI. We estimated the levels of sP-selectin, sE-selectin, sPECAM-1 and serum homocysteine. Healthy age and sex-matched controls and family controls were also recruited in the present study. The levels of sP-selectin, sE-selectin and sPECAM-1 did not differ significantly in cases as compared to controls (p>0.05). Hyperhomocysteinemia was significantly associated with MI in comparison with controls (p<0.001) with an odds ratio of 6.26 (95% confidence limits 3.11-12.76). Folic acid was able to correct hyperhomocysteinemia in a large majority of the cases. Although the levels of sP-selectin, sE-selectin and sPECAM-1 decreased after folic acid therapy, it was only sE-selectin which was significantly reduced (p<0.05). Thus, folic acid had a dual effect in that it reduced hyperhomocysteinemia and sE-selectin which showed a significant reduction on folate supplementation for 15 days.

Frequency distribution of human platelet antigens in the Indian population

This study was undertaken with an aim of establishing the frequency distribution of various human platelet antigens (HPA) in Indian populations by means of DNA-based technology. A total of 1164 people belonging to various population groups were studied for the frequency distribution of HPA. DNA extraction was performed from peripheral venous blood samples. Polymerase chain reaction allele-specific amplification technique was used for HPA genotyping. The HPA bands were visualized by using ethidium bromide-stained agarose gel, after electrophoresis. The homozygosity of the HPA-1b/1b genotype was found to be significantly higher (P < 0.05) in the Parsi population group and Vatalia Prajapati population group, compared to Maharashtrians. Frequency distribution of HPA-1b in our populations was found to be slightly lower than that reported in some western populations. This study has established a DNA technique to diagnose cases of NAITP definitively and to treat these cases during the neonatal period, and also gives the frequency distribution of HPA in some of the Indian population.

Translating evidence-based information into effective risk communication: Current challenges and opportunities

Recent medical advances and the easy availability of evidence-based information at the point of care are believed to provide physicians with improved tools for risk communication. However, evidence indicates that physicians still display marked variability in ordering tests. Factors that determine a physician's test-ordering tendencies vary by specialization, practice, geographical location, defensive practice, and tolerance of uncertainty and are also modified by patient requests. Understanding of statistical terms on the part of both physicians and patients remains limited. Physicians may display limited ability to assess pretest and posttest probabilities, especially in low- and intermediate-risk patients, even after attending short courses in epidemiology, or may find the process impractical. Presentation of diagnostic-test results in a natural-frequency format might improve understanding. Both physicians and patients have difficulty grasping the term "number needed to treat" compared with "relative risk reduction" when comparing therapeutic options. Other patient-related factors that limit understanding include low literacy, individual risk tolerance, and framing patterns of the problem (potential gains vs losses). Despite numerous available modalities (quantitative and qualitative) of risk communication, consensus over the advantage of any single modality in translating evidence into risk communication is limited. It is essential that physicians remain patient-centered, generate trust, and build a partnership with the patient to achieve consensus for medical decision-making. Future studies are indicated to assess the effectiveness of novel risk-communication modalities based on patients' and physicians' characteristics and identify appropriate modality of translating evidence (quantitative or qualitative information).

Mutations in GPIIIa molecule as a cause for Glanzmann thrombasthenia in Indian patients

BACKGROUND

Glanzmann thrombasthenia (GT) results from a quantitative or qualitative defect of GPIIb-IIIa complex, the fibrinogen receptor on platelets, which plays a very important role in platelet aggregation. In this report we describe the molecular studies on 22 patients with Glanzmann Thrombasthenia at our institute.

OBJECTIVES

The main objective was to identify the mutations present in our GT population in order to establish a strategy for genetic counseling and antenatal diagnosis.

METHODS

Twenty-two patients with GT were included in the present study. Complete blood count (CBC), platelet aggregation, flow cytometry, Western blot, single strand conformation polymorphism (SSCP) and denaturing gradient gel electrophoresis (DGGE) were performed in all the patients. The patients showing an abnormal migration pattern in SSCP or DGGE were sequenced further on an automated sequencer.

RESULTS

Of the 22 patients studied, mutations were detected in 12 individuals. Of these, 11 were novel mutations and one mutation Y115C was reported earlier. Flow cytometric analysis showed the absence of receptors in type I GT, highly reduced levels in type II GT and normal levels in type III GT. The DGGE analysis and SSCP analysis of the patients showed different migration patterns. Sequencing was performed in all patients showing an abnormal migration pattern. Of the 22 cases studied mutations could be detected in 12 cases of GT. We could detect six patients with point mutations, four patients with insertions and five patients with deletion mutations. Exon 4 has been found to be the most common site for mutations in our patients.

CONCLUSION

This study has shown a wide array of mutations present in our GT patients which would be extremely useful in genetic counseling and prenatal diagnosis, essential in preventing these disorders in succeeding generations.

Maternal origin of extra marker chromosome 1Q31.1-qter and 13pter-q12.12 in a child with dysmorhic features

Maternal origin of extra marker chromosome Iq31.l-qter and 13pter-q12.12 in a child with dysmorphic features: We describe a twenty-days-old female child with dysmorphic features and chromosomal analysis with GTG-banding revealed an extra marker chromosome. Fluorescence in situ hybridization (FISH) study of extra marker chromosome confirmed to be maternal der(13) chromosome, contained 1q31.1-qter and 13pter-q11 chromosomal material and resulted from a maternal balanced translocation t(1;13)(q31.1; q12.12). The child had the majority of trisomy 1q clinical features: dysmorphic features, micropthalmia, high arched palate, long philthrum, micrognathia, hypertelorism, low set ears, short sternum, overlapping fingers, valgus of wrists, right knee and ankle joints were in flexion contractures. This is the first case of trisomy 1q with an extra marker chromosome which also contained chromosome 13pter-q12.12 material.