Telepathology for routine light microscopic and frozen section diagnosis

Telepathology (TP) uses telecommunication linkages to electronically capture, store, retrieve, and transmit images to distant sites. We assessed the feasibility of a dynamic real-time TP system for light microscopic (LM) diagnosis of anatomic pathology specimens, including frozen sections. Six pathologists, in 2 separate periods, read a set of 160 retrospectively retrieved slides (80 of which were frozen sections) by TP and LM. Reading times were recorded. Diagnoses were compared with the reference diagnosis (established by a group of 5 independent pathologists) and graded on a scale of 0 to 2 (2, correct; 1, incorrect but no clinical impact; 0, incorrect with clinical impact). Overall, LM was more accurate than TP compared with the reference diagnosis (score, 1.68 vs 1.54). There was no difference in accuracy between frozen section and paraffin-embedded tissue. Intraobserver agreement ranged from 82.5% to 88.2%. The average reading time was 6.0 minutes for TP and 1.4 minutes for LM. During the study, reading time decreased for TP but not for LM. These results show that despite marginally lower accuracy and longer reading times, TP isfeasible for routine light microscopic diagnosis, including frozen sections.     

Value of whole-cell antigen extracts for serologic detection of Helicobacter pylori.

Whole-cell protein extracts of Helicobacter pylori strains were evaluated by enzyme-linked immunosorbent assay to detect immunoglobulin G antibody against H. pylori in 113 patients with upper gastrointestinal complaints. These antigen preparations were of value for detecting infection by H. pylori in patients with high antibody titers (> or = 12,800), whereas for patients with lower titers, the results were inconclusive.     

ASSOCIATION OF MHC CLASS I WITH SPONDYLOARTHROPATHIES IN KUWAIT

This study is the first to assess the prevalence of HLA B27 in Kuwaiti patients with ankylosing spondylitis (AS) or related spondyloarthropathies compared to healthy controls. Positive HLA B27 was found in nine (25.7%) of 35 patients, but only in 22 (4%) of 544 controls (P = 0.000). A significant difference in Cw2 and Cw6 between patients and controls was also found (P < 0.01 and 0.000, respectively), suggesting a linkage disequilibrium between B27 and Cw2 (P < 0.000) in the Kuwaiti population. These findings suggest that B27-positive Kuwaitis are at high risk of developing AS and spondyloarthropathies, especially if they carry Cw2 and Cw6. The importance of HLA Cw loci is becoming increasingly apparent in disease association studies.     

Apoptosis in the ovary: molecular mechanisms

Cell death was first described in rabbit ovaries (Graaffian follicles), the phenomenon being called 'chromatolysis' rather than apoptosis. In humans, the ovarian endowment of primordial follicles is established during fetal life. Apoptotic cell death depletes this endowment by at least two-thirds before birth, executed with the help of several players and pathways conserved from worms to humans. To date, apoptosis has been reported to be involved in oogenesis, folliculogenesis, oocyte loss/selection and atresia. Several pro-survival and pro-apoptotic molecules are involved in ovarian apoptosis with the delicate balance between them being the determinant for the final destiny of the follicular cells. This review critically analyses the current knowledge about the biological roles of these molecules and their relevance to the dynamics of follicle development. It also presents the existing literature and assesses the gaps in our knowledge.     

Bone marrow transplantation for diamond-blackfan anemia.

Patients with Diamond-Blackfan anemia (DBA) who are unresponsive to or intolerant of corticosteroids, experience treatment failure with other treatments, develop additional cytopenias or clonal disease, or opt for curative therapy are often treated with allogeneic bone marrow transplantation. We studied the transplantation outcomes of 61 DBA patients whose data were reported to the International Bone Marrow Transplant Registry between 1984 and 2000. The median age was 7 years (range, 1-32 years). Among 55 patients with available transfusion information, 35 (64%) had received > or =20 units of blood before transplantation. Most patients (67%) received their bone marrow grafts from an HLA-matched related donor. The median time to neutrophil recovery was 17 days (range, 10-119 days) and to platelet recovery was 23 days (range, 9-119 days). Five patients did not achieve neutrophil engraftment. The 100-day mortality was 18% (95% confidence interval, 10%-29%). Grade II to IV acute graft-versus-host disease occurred in 28% (range, 17%-39%) and chronic graft-versus-host disease in 26% (range, 15%-39%). The 3-year probability of overall survival was 64% (range, 50%-74%). In univariate analysis, a Karnofsky score > or =90 and transplantation from an HLA-identical sibling donor were associated with better survival. These data suggest that allogeneic bone marrow transplantation is effective for the treatment of DBA. Transplantation before deterioration of the performance status and from an HLA-identical sibling donor may improve survival.     

Complete subtyping of the HLA-A locus by sequence-specific amplification followed by direct sequencing or single-strand conformation polymorphism analysis

Abstract: A variety of reasons related to the HLA class I system has complicated the application of molecular approaches to HLA class I typing. Here we present a PCR-based HLA-A typing strategy considering the sequence variations of the two most polymorphic exons which allows complete subtyping of the HLA-A locus. The method is based on a sequence-specific amplification identifying the serologically defined HLA-A specificities. The PCR products generated by these group-specific primers bear the sequence information necessary for a postamplification specificity step. The primer pairs are located within one exon, either exon 2 or exon 3, which avoids amplification of polymorphic intron sequences allowing subsequent single-strand conformation polymorphism analysis and facilitating direct sequencing. Using this method we investigated 48 cell lines and 153 clinical samples. 23 PCR reactions are performed per individual for the assignment of the serological specificities A1-A80. The reproducibility was 100% in all cell lines and 85 clinical samples typed on two separate occasions. With the exception of 13 out of 231 possible serological combinations all homozygous and heterozygous combinations of A1-A80 can be distinguished by specific amplification patterns. Comparing the PCR based typing results with those of serology in 12% a discrepancy was found. Solid-phase sequencing or SSCP analysis of the group-specific PCR fragments allowed complete subtyping of the HLA-A locus. This strategy can identify all 48 HLA-A alleles based on the sequence variations of the 2nd and 3rd exon. 1128 homozygous and heterozygous allele combinations are possible for the HLA-A locus. Only 4 out of these 1128 allele combinations remained unresolved.     

Changes in lipid profile variables in response to submaximal and maximal exercise in trained cyclists

This study examined the effect of prolonged submaximal exercise followed by a self-paced maximal performance test on cholesterol (T-Chol), triglycerides (TG), and high-density lipoprotein cholesterol (HDLC). Nine trained male athletes cycled at 70% of maximal oxygen consumption for 60 min, followed by a selfpaced maximal ride for 10 min. Venous blood samples were obtained at rest, at 30 and 60 min during submaximal exercise, and immediately after the performance test. Lactic acid, haematocrit (Hct), haemoglobin (Hb), T-Chol and TG were measured in the blood, while plasma was assayed for HDL-C. Plasma volume changes in response to exercise were calculated from Hct and Hb values and all lipid measurements were corrected accordingly. In order to ascertain the repeatability of lipid responses to exercise, all subjects were re-tested under identical testing conditions and experimental protocols. When data obtained during the two exercise trials were analysed by two-way ANOVA no significant differences (P > 0.05) between tests were observed. Consequently the data obtained during the two testing trials were pooled and analysed by one-way ANOVA. Blood lactic acid increased non-significantly (P > 0.05) during the prolonged submaximal test, but rose markedly (P < 0.05) following the performance ride. Lipid variables ascertained at rest were within the normal range for healthy subjects. ANOVA showed that blood T-Chol and TG were unchanged (P > 0.05), whereas HDL-C rose significantly (P < 0.05) in response to exercise. Post hoc analyses indicated that the latter change was due to a significant rise in HDL-C after the performance ride. It is concluded that apparent favourable changes in lipid profile variables occur in response to prolonged submaximal exercise followed by maximal effort, and these changes showed a good level of agreement over the two testing occasions.     

The amyloid proteins of Alzheimer's disease as potential targets for drug therapy

Two amyloid proteins accumulate in Alzheimer's disease. These proteins, beta amyloid protein and paired helical filament protein, are present in the hallmark lesions of Alzheimer's disease, neuritic plaques and neurofibrillary tangles. Although the amino acid sequences of these two proteins are likely to be different, they nevertheless share certain physical characteristics which define each as belonging to a common class of proteins, amyloid proteins. Since these proteins are probably important in the pathology of Alzheimer's disease, drugs that prevent their accumulation should have therapeutic utility. Based on the amyloidoses associated with other diseases, three mechanisms for amyloid formation have emerged. These mechanisms form a framework for studying Alzheimer amyloids and designing interventions. One mechanism involves posttranslational events which render a normal protein amyloidogenic. Proteolysis, phosphorylation, glycosylation, and transglutamination may be relevant posttranslational events in Alzheimer's disease. If more conclusive evidence can be generated suggesting that these events are involved in the abnormal formation of amyloid in Alzheimer's disease, then these events will become viable targets for drug therapy. Another mechanism for amyloid formation results from expression of an abnormal gene which, in the case of familial Alzheimer's disease, may be an important etiological component. A third mechanism involves the accumulation of a normal protein to a threshold concentration that spontaneously forms amyloid. An effective therapeutic approach for these last two mechanisms could likely include pharmacological manipulation of gene expression.     

Chromosomal aberrations and micronucleus frequency in nurses occupationally exposed to cytotoxic drugs

In this study, we evaluated the effect of low level occupationalexposure of nurses in a medical oncology unit in Cairo, Egypt,to anticancer drugs. Twenty nurses who constantly handled thesedrugs and 20 controls, matched according to age and sex, wereexamined. Metaphase chromosomes were studied. Percentages ofmetaphases with chromosomal aberrations were significantly higher(P < 0.001) in the exposed group (6.1 ± 2.7) versusthe controls (2.6 ± 1.6). The detected chromosomal aberrationswere in the form of chromatid gaps, chromatid breaks and acentricfragments. Micronucleated peripheral blood lymphocytes werealso analyzed in cytochalasin B treated binucleated lymphocytes.There was significant increase in cells with micronuclei (P< 0.001) in nurses (10.05 ± 4.71) in comparison tothe matched control (5.42 ± 2.22) (P < 0.001). Nursesexposed to the cytotoxic drugs for     

Concomitant airway expression of granulocyte-macrophage colony-stimulating factor and decorin, a natural inhibitor of transforming growth factor-beta, breaks established inhalation tolerance

We previously showed that granulocyte-macrophage colony-stimulating factor (GM-CSF) breaks tolerance induction. The objective of this study was to determine whether GM-CSF breaks established inhalation tolerance. To induce tolerance, BALB/c mice were exposed to aerosolized ovalbumin (OVA) for 10 consecutive days. A control group was exposed to saline. Subsequently, tolerant and control animals were exposed to OVA in a GM-CSF-enriched airway microenvironment. Tolerant animals, unlike control animals, did not develop airway and peripheral blood eosinophilia, had diminished levels of OVA-specific IgE, and reduced airway hyper-responsiveness. While tolerant animals did not express IL-4, IL-5 and IL-13, levels of the regulatory cytokines IL-10, IFN-gamma and transfoming growth factor (TGF)-beta were similar between tolerant and non-tolerant animals. Lung CD4+ T cells were activated according to CD69, CD25 and T1/ST2 expression, but systemic responses characterized by splenocyte proliferation and Th2 effector function were dramatically reduced. Concurrent expression of GM-CSF and decorin, a natural inhibitor of TGF-beta, reversed eosinophilic unresponsiveness. Our study suggests that the breakdown of tolerance and, by extension, the emergence of eosinophilic inflammation, requires two signals: one that triggers sensitization and one that interferes with negative regulation. Moreover, our study shows that dysregulated expression of an extracellular matrix protein may break established tolerance and lead to eosinophilic airway inflammation.