Megakaryocyte c-Mpl expression in chronic myeloproliferative disorders and the myelodysplastic syndrome: immunoperoxidase staining patterns and clinical correlates

The objectives of this study were to expand on recent observations that have suggested decreased thrombopoietin receptor (c-Mpl) expression in megakaryocytes of patients with polycythemia vera (PV) and agnogenic myeloid metaplasia (AMM). We applied an immunoperoxidase method with anti-c-Mpl antibody to 55 bone marrow sections from previously untreated patients with chronic myeloproliferative disorder (CMPD) or myelodysplastic syndrome (MDS). These included 8 patients with PV, 15 with AMM, 9 with essential thrombocythemia, 5 with chronic myelocytic leukemia, 9 with the 5q-syndrome and 9 with MDS with fibrosis. The findings were compared with those in four patients with reactive erythrocytosis (RE), six with immune thrombocytopenic purpura (ITP) and five normal controls. Staining intensity (SI) was moderate to strong both in normal controls and in patients with RE or ITP. In contrast, SI was weak in variable proportions of the megakaryocytes in every one of the aforementioned clonal myeloid disorders. The staining pattern (SP) was relatively uniform in MDS and heterogeneous in CMPD. Neither SI nor SP was significantly correlated with certain clinical or laboratory parameters. We concluded that altered megakaryocyte c-Mpl expression may be a nonspecific phenomenon in various subtypes of both CMPD and MDS. However, the characteristic staining patterns may complement the morphological distinction between clonal and reactive myeloproliferation.

Bacterial endobionts in the big non-mycorrhizal roots of Scots pine (Pinus sylvestris L.)

Subsurface bacterial growth occurred in an N-free medium inoculated with interior tissues of big non-mycorrhizal roots (7 to 8 mm diameter) of 15-20 years-old Scots pine (Pinus sylvestris L.) growing on sand dunes at the Baltic Sea of Poland. The bacteria were not N2 fixers as determined by the acetylene reduction method. Light microscopic and scanning electron microscopic observations revealed massive bacterial clusters residing in the cortical cells underlying epidermis and parenchyma. The bacteria produced yellow-green pigments on King's medium, which fluoresced under ultraviolet (UV) irradiation at 366 nm wavelength, and could be a siderophore-producing Pseudomonas.

Combination treatment of murine tumors by adenovirus-mediated local B7/IL12 immunotherapy and radiotherapy

Failure of local tumor control still poses a problem for radiotherapy and translates into reduced survival. Combining radiation with chemotherapy or other newer modalities has shown promising results. Immunological approaches to tumor therapy have found renewed interest due to improved insight into mechanisms involved in the immune response to tumors. In this paper, we studied tumor growth delay after various combination regimens of locally injected adenovirus constitutively expressing IL12 and B7.1 (AdIL12/B7.1) and fractionated radiotherapy in two nonimmunogenic murine tumor models, 4T1 and B16.F10. Effects of radiation and virus infection on surface antigen expression in these tumor lines were assessed. Mechanisms of action of AdIL12/B7.1 were studied by conducting additional experiments with and without depletion of NK-cells and/or T-cells, and by cytotoxic T-lymphocyte assays, and immunohistochemical evaluation of tumor blood vessels. Both B7.1 and IL12 were effectively expressed in both irradiated and unirradiated 4T1 and B16.F10 tumor cells but did not add significantly to radiation-induced cell killing in vitro. However, local tumor infection by AdIL12/B7.1 after irradiation significantly increases the effectiveness of radiotherapy when applied after completion of radiotherapy. The mechanism appears to be complicated, involving a host of factors that included the ability of IL12 to activate T-cells and NK-cells and to inhibit angiogenesis and the ability of radiation to induce apoptosis or necrosis among tumor cells. These data support the combination of radiotherapy with adenovirus-mediated immunotherapy and suggest that the concept of adding genetic immunotherapy after radiotherapy in a combined regimen merits further study.

Heat shock protein 70 inhibits apoptosis downstream of cytochrome c release and upstream of caspase-3 activation

Heat shock protein 70 (HSP70) has been shown to act as an inhibitor of apoptosis. We have also observed an inhibitory effect of HSP70 on apoptotic cell death both in preheated U937 and stably transfected HSP70-overexpressing U937 (U937/HSP70) cells. However, the molecular mechanism whereby HSP70 prevents apoptosis still remains to be solved. To address this issue, we investigated the effect of HSP70 on apoptotic processes in an in vitro system. Caspase-3 cleavage and DNA fragmentation were detected in cytosolic fractions from normal cells upon addition of dATP, but not from preheated U937 or U937/hsp70 cells. Moreover, the addition of purified recombinant HSP70 to normal cytosolic fractions prevented caspase-3 cleavage and DNA fragmentation, suggesting that HSP70 prevents apoptosis upstream of caspase-3 processing. Because cytochrome c was still released from mitochondria into the cytosol by lethal heat shock despite prevention of caspase-3 activation and cell death in both preheated U937 and U937/hsp70 cells, it was evident that HSP70 acts downstream of cytochrome c release. Results obtained in vitro with purified deletion mutants of HSP70 showed that the carboxyl one-third region (from amino acids 438 to 641) including the peptide-binding domain and the carboxyl-terminal EEVD sequence was essential to prevent caspase-3 processing. From these results, we conclude that HSP70 acts as a strong suppressor of apoptosis acting downstream of cytochrome c release and upstream of caspase-3 activation.

Longest held occupation in a lifetime and risk of disability in activities of daily living

OBJECTIVES

To examine the association between the longest held occupation in a lifetime and risk of disability in activities of daily living (ADL) among elderly people (65 years and older) in northern Taiwan.

METHODS

A case-control design was used nested within two cohorts of a total of 2198 elderly people who had been followed up either between 1993 and 1997 or between 1996 and 1997. Cases were 360 elderly people with ADL disability within the study period. For each case, two sex matched controls were randomly sampled from the pool of elderly people free from ADL disability. Occupational data were collected through interviews conducted in 1997. Performed job contents were classified into occupational categories and occupation based social classes. Unconditional logistic regression techniques were used to estimate relative risk and 95% confidence intervals (95% CIs) of ADL disability.

RESULTS

Compared with people who were former legislators, government administrators, or business executives and managers, workers in agriculture, animal husbandry, forestry, or fishing (odds ratio (OR) 1.9, 95% CI 1.1 to 3.5) and workers in craft and related trades (OR 1.9, 95% CI 1.1 to 3.4) had significantly increased risks of subsequent ADL disability. Differential risks of ADL disability were found across social classes, with a significant dose-response trend in which unskilled blue collar workers had an 1.8 times higher risk of ADL disability than higher social classes of white collar workers.

CONCLUSIONS

After adjustment for education, there was still an inverse relation between risk of ADL disability and social class. Although total control for all the known risk factors for ADL disability among elderly people was impossible, the results tend to suggest a potential for an effect of longest held occupation in a lifetime on risk of ADL disability.

Immunohistochemical staining for megakaryocyte c-mpl may complement morphologic distinction between polycythemia vera and secondary erythrocytosis

Recent studies have shown decreased megakaryocyte expression of the thrombopoietin receptor (c-mpl) in patients with polycythemia vera (PV) but not in those with reactive erythrocytosis. We examined the diagnostic utility of this observation in 22 patients with PV, 7 patients with secondary erythrocytosis (SE), and 10 normal controls. Commercial antibodies against c-mpl were used with standard immunoperoxidase methods. Megakaryocyte c-mpl staining intensity was uniformly moderate-to-strong in the healthy controls and in all the patients with SE. In contrast, staining intensity in 9 patients with PV (41%) was uniformly weak. Furthermore, in 12 of the remaining 13 patients with PV, the c-mpl staining pattern in each case was heterogeneous and was associated with weak staining intensity in more than 20% of the megakaryocyte population. These preliminary data suggest that c-mpl immunostains may complement bone marrow histopathology in distinguishing PV from nonclonal causes of erythrocytosis. (Blood. 2000;96:771-772)

Image analysis and flow cytometric DNA studies of benign and malignant body cavity fluids: reappraisal of the role of current methods in the differential diagnosis of reactive versus malignant conditions

Cytologic examination of body fluids is commonly performed in the clinical laboratory. Determination of the presence of malignancy may sometimes be difficult. In this study, we prospectively studied 60 body fluids with a panel of antibodies, including MOC-31, epithelial membrane antigen, carcinoembryonic antigen, B72.3, keratin, desmin, and CA-125. DNA and S-phase studies were performed both by flow cytometry and image analysis. Thirty-seven fluids were classified as benign and 23 were classified as malignant. The sensitivity of the antibodies for identification of carcinoma in descending order of percentage detection rate were MOC-31 (95%), epithelial membrane antigen (93%), B72.3 (84%), and carcinoembryonic antigen (80%). Desmin stained mesothelial cells in all cases. CA-125 gave similar results but was less specific. Flow cytometry detected 14 of 20 malignant fluids and image analysis 17 of 23 by identifying an aneuploid population. Benign reactive mesothelial cells were not aneuploid. Tetraploidy due to reactive mesothelial cells was found in 9 of 37 body fluids. Their S-phase fraction was low (average, 3.2%). Tetraploidy in malignant cells was distinguished from the reactive mesothelial cells by high S-phase (average, 25.95). S-phase had some use as a discriminating factor, because no benign reactive cases had more than 17%. However, 7 of 23 malignant cases had a value below 17%. DNA analysis by image was more sensitive and specific than flow. Either may be used when immunocytochemistry is nondiagnostic or cannot be performed.

Heat-induced gene expression as a novel targeted cancer gene therapy strategy

One of the main advantages of gene therapy over traditional therapy is the potential to target the expression of therapeutic genes in desired cells or tissues. To achieve targeted gene expression, we experimented with a new approach based on the long-established phenomenon of the heat shock response. By using the green fluorescence protein as a reporter gene, it was demonstrated that expression of a heterologous gene with a heat shock protein 70 promoter could be elevated to 500-1000-fold over background by moderate hyperthermia (39 degrees C to 43 degrees C) in tissue cultured cells. The heat-induced green fluorescence protein expression was first detectable at 3 h after heating and reached a maximum at 18-24 h. The expression dropped back to baseline within 72 h. In addition, when cells were infected with adenovirus vectors containing the heat-inducible interleukin 12 or tumor necrosis factor alpha genes and then heated (42 degrees C, 30 min), expression was at least 13,600- or 6.8 x 10(5)-fold over background, respectively. Intralesion injection of the interleukin-12-carrying adenovirus vector in a mouse melanoma tumor model caused significant tumor growth delay only with hyperthermia treatment. Our results therefore support heat-induced gene expression as a feasible approach for targeted cancer gene therapy.

Preincisional dextromethorphan treatment for postoperative pain management after upper abdominal surgery

Previous studies showed that ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, provides a preemptive analgesic effect and preemptive analgesia improves postoperative pain management. The aim of this study was to examine whether premedication with dextromethorphan (DM) improves postoperative pain management after upper abdominal surgery. Sixty (American Society of Anesthesiologists class 1 and 2 of either gender) patients scheduled for upper abdominal surgery were included in the study. Patients were randomly assigned to one of four groups: control, DM-10, DM-20, and DM-40. In the control group, chlorpheniramine maleate (CPM, 20 mg) was injected immediately before induction of anesthesia intramuscularly (IM). In the DM-10, DM-20, and DM-40 groups, patients were premedicated with DM 10 mg, 20 mg, and 40 mg IM, respectively. After operation, patient-controlled analgesia (PCA) with morphine was given for pain relief. The time to the first PCA trigger, morphine consumption, pain scores, and analgesic-related side effects were recorded at 1, 2, 4, 24, 48, and 72 hours after surgery. The time to first PCA trigger for the control group was 17.8 +/- 1.4 minutes, for group DM-10 20.2 +/- 1.6 minutes, for group DM-20 32.4 +/- 1.9 minutes, and for DM-40 77.9 +/- 6.5 minutes. The morphine delivered and PCA triggering frequency were 5.5 +/- 0.5/11.3 +/- 0.8 times for the controls, 5.5 +/- 0.4/ 14.1 +/- 1.3 times for DM-10, 3.1 +/- 0.3/6.3 +/- 1.2 times for DM-20, and 0.2 +/- 0.1/0.3 +/- 0.2 times for DM-40 during the first hour after operation. For the first day, the figures are 19.9 +/- 1.2/23.9 +/- 1.4 for the controls, 15.6 +/- 1.2/17.3 +/- 2.4 for DM-10, 12.6 +/- 0.7/15.9 +/- 1.6 for DM-20, and 5.0 +/- 0.21/5.6 +/- 0.9 for DM-40. On the first day, the cough pain scores were 6.67 +/- 0.23, 6.53 +/- 0.16, 6.67 +/- 0.23, and 5.73 +/- 0.18 for the controls, DM-10, DM-20, and DM-40 groups, respectively. All data showed dose-dependent better pain relief in DM-premedicated patients. We conclude that DM premedication offers preemptive analgesia and reduces postoperative pain and morphine requirement.

von Willebrand factor is the most reliable immunohistochemical marker for megakaryocytes of myelodysplastic syndrome and chronic myeloproliferative disorders

To find the best immunohistochemical marker for megakaryocytes in normal marrow, myelodysplastic syndrome (MDS), and chronic myeloproliferative disorders (CMPD), 57 marrow biopsy specimens were studied semiquantitatively with immunohistochemical methods using a panel of 7 antibodies. The staining intensity was graded 0 to 3 for scoring 100 consecutive megakaryocytes in each stained section. The final score for each stain was the sum of these 100 megakaryocytes individually multiplied by their corresponding grade. In normal marrow (11 cases), the average scores for antivon Willebrand factor (vWF) and Ulex europaeus agglutinin-1 (UEA-1) were 177.1 and 195.1, respectively. The scores for the other 5 markers, including anti-platelet-derived growth factor-BB, 2 anti-transforming growth factor-beta 3, anti-CD61, and anti-CD79a ranged from 96.1 to 124.1. In MDS (27 cases), the scores were 200.8 (vWF), 152.6 (UEA-1), and 28.7 to 98.5 (others). In CMPD (19 cases), the scores were 220.5 (vWF), 179.2 (UAE-1), and 64.8 to 101.2 (others). These results show that vWF and UEA-1 are good immunohistochemical markers for megakaryocytes in normal marrow, and vWF is the best marker in MDS and CMPD. For routine practice, vWF is the most reliable marker for identifying atypical megakaryocytes, especially in the cases of 5q-syndrome and agnogenic myeloid metaplasia.

The agreement between self-reporting and clinical diagnosis for selected medical conditions among the elderly in Taiwan

A cross-sectional survey was conducted to consider whether there is agreement between self-report and clinical diagnosis in the prevalence of selected common chronic diseases among elderly Taiwanese. Between July 1992 and June 1993, both face-to-face interview and clinical evaluation were applied to a sample of 228 Taiwanese aged 65 y and older to estimate the prevalence of heart diseases, hypertension and diabetes. The results showed that a self-reported history of diabetes had the highest sensitivity (66. 7%) and specificity (95.2%). The self-report of heart diseases was the least sensitive (20.5%), while self-reports of hypertension was the least specific (82.8%). Multivariate analyses showed that age, education and number of self-reported diseases suffered from, appeared to influence the accuracy of the self reported data. Our data suggest a notable lack of agreement abetween self-report and clinical diagnosis for medical conditions, even for those with clear and unambiguous diagnostic criteria. The elderly in Taiwan tended to under report (with a consistently higher false negative rate than false positive rate) the existence of the three selected medical conditions. This was especially so for heart diseases. Our findings suggest that, if the level of disease prevalence in the population needs to be known for health planning estimates for hypertension and diabetes would not necessarily be a problem. However, the prevalence for heart disease would be seriously under-estimated. We also argue that information obtained by self-report should be validated before use, especially in the case of assessment of the prevalence of medical conditions in the elderly.

Initial stages of tumor cell-induced angiogenesis: evaluation via skin window chambers in rodent models

BACKGROUND

There is a paucity of information about events that follow immediately after tumor cells are triggered to initiate the process of angiogenesis (the formation of new blood vessels). Such information is relevant to the issue of when micrometastases vascularize and has implications for the accessibility of micrometastases to various treatments. In this study, we attempted to monitor events at the initiation of angiogenesis at the earliest possible stage of tumor growth in vivo.

METHODS

Two different rodent mammary tumor cell lines, R3230Ac from the Fischer 344 rat and 4T1 from the BALB/c mouse, were stably transfected with a gene that encodes an enhanced version of green fluorescence protein (GFP). GFP-labeled R3230Ac or 4T1 cells (about 20-50 cells) were implanted into dorsal skinfold window chambers of Fischer 344 rats or BALB/c mice, respectively. Tumor angiogenesis was then monitored serially and noninvasively for up to 4 weeks.

RESULTS

Clear evidence of modification of the host vasculature was observed when tumor mass reached approximately 60-80 cells, and functional new blood vessels were seen when tumor mass reached roughly 100-300 cells. Individual tumor cells exhibited a chemotaxis-like growth pattern toward the pre-existing host vasculature. When ex-flk1 (a soluble, truncated vascular endothelial cell growth factor receptor protein known to be antiangiogenic) was injected with the tumor cells, the initial angiogenic and tumor growth activities were inhibited considerably, indicating that angiogenesis inhibitors may halt tumor growth even before the onset of angiogenesis.

CONCLUSION

Angiogenesis induced by tumor cells after implantation in the host begins at a very early stage, i.e., when the tumor mass contains roughly 100-300 cells. Identification of chemotactic signals that initiate tumor cell migration toward the existing vasculature may provide valuable targets for preventing tumor progression and/or metastases.

Mechanism of inhibition of platelet aggregation by HCL-31D

The antiplatelet effect of the pyridazinone analogue, 4, 5-dihydro-6-[4-[2-hydroxy-3-(3,4 dimethoxybenzylamino)propoxy]naphth-1-yl]-3(2H)-pyridazinone (HCL-31D), was investigated in vitro with rabbit platelets. HCL-31D dose-dependently inhibited the platelet aggregation and ATP release induced by collagen (10 microg/ml), arachidonic acid (100 microM) or thrombin (0.1 U/ml) with an IC(50) of about 0.95-5.41 microM. HCL-31D (0.5-5 microM) increased the platelet cyclic AMP level in a dose-dependent manner. Furthermore, HCL-31D potentiated cyclic AMP formation caused by prostaglandin E(1) but not that caused by 3-isobutyl-1-methylxanthine (IBMX). HCL-31D also attenuated phosphoinositide breakdown and intracellular Ca(2+) elevation induced by collagen, arachidonic acid or thrombin. HCL-31D inhibited the formation of thromboxane B(2) induced by collagen or thrombin but not by arachidonic acid. In addition, HCL-31D did not affect platelet cylooxygenase and thromboxane synthase activity. These data indicate that HCL-31D is an inhibitor of phosphodiesterase and that its antiplatelet effect is mainly mediated by elevation of cyclic AMP levels.

[AFLP analysis of photoperiod-sensitive genic male sterile(PGMS) rice mutant lines]

The reaction conditions for rice AFLP assay were optimized. The relative efficiencies for polymorphism detection of RFLP, RAPD and AFLP were compared through the analysis between a pair of PGMS allelic mutant lines(NK58S and NK58F). Results indicated that the efficiency for polymorphism detection in rice is in the order of AFLP > RAPD > RFLP, and also indicated that AFLP is a powerful DNA molecular marker technique for polymorphism detection, especially in the cases of extremely low polymorphism, such as isogeneic lines and allelic mutant lines. The advantages and disadvantages of these three molecular marker systems were discussed. Using AFLP in conjunction with bulked segregating analysis, 5106 AFLP loci were screened and 9 of them showed polymorphism between NK58S and NK58F, 4 of the polymorphic AFLP products were cloned, Southern bloting analysis showed that two of them were single copy sequences while the other two were low copy sequences in rice genome.

[Experimental study on repair of peripheral nerve defect by basic fibroblast growth factor combined with autogenous vein graft conduit]

OBJECTIVE

To explore the effect of basic fibroblast growth factor (bFGF) combined with autogenous vein graft conduit on peripheral nerve regeneration.

METHODS

Fifty four New Zealand rabbits were divided into three groups. The main trunk of sciatic nerve of rabbit in one side was severed and bridged by autogenous vein. 0.2 ml bFGF solution (4,000 U/ml) was intravenously injected to the vein graft conduit as group A, the same amount of saline solution as group B, and no solution injection as group C. Microscopic examination, axon video analysis and nerve conduct velocity were performed at the 10th, 30th, and 100th day after operation.

RESULTS

The nerve fibers were grown into vein graft conduit in all groups at 30th after operation, they were more and regular in group A than that of group B and C, and the axon regeneration rate in group A was more than that of group B and C.

CONCLUSION

bFGF combined with autogenous vein graft conduit can markedly promote nerve regeneration.

Immunophenotypic analysis of peripheral blood and bone marrow in the staging of B-cell malignant lymphoma

This study evaluated the contributing roles of flow cytometric immunophenotyping of blood and bone marrow and immunohistochemical paraffin section staining of bone marrow biopsies in the staging of B-cell malignant lymphoma. Flow immunophenotyping was performed on a marrow specimen in 175 cases; a corresponding blood specimen was also immunophenotyped in 135 of these cases. Morphologic marrow involvement by lymphoma was found in 59 cases; flow immunophenotyping identified 54 cases with a monoclonal B-cell process: morphology-positive/flow-positive (n = 49), morphology-positive/flow-negative (n = 10), morphology-negative/flow-positive (n = 5), and morphology-negative/flow-negative (n = 111). The 10 morphology-positive/flow-negative cases included 5 follicular and 5 large-cell lymphomas with minimal marrow involvement. All 5 morphology-negative/flow-positive cases were from patients with large-cell lymphomas and bulky clinical disease. Because the blood contained the same B-cell clone in 2 of 2 morphology-negative/flow-positive cases studied, blood contamination of marrow may account for these findings. Blood flow cytometric immunophenotyping studies were positive in 32 cases; 30 had marrow involvement by morphology and were from patients with follicular, mantle cell, lymphoplasmacytic, small lymphocytic, or marginal zone lymphomas. From our results, we conclude that (1) bone marrow flow cytometric immunophenotyping is not a cost-effective replacement for good morphologic evaluation in lymphoma staging and that (2) a positive peripheral blood flow cytometric immunophenotyping study when performed in low-grade lymphomas correlates with marrow involvement.

Antiplatelet effect of amlodipine: a possible mechanism through a nitric oxide-mediated process

The effect of amlodipine, a novel calcium channel blocker of the dihydropyridine type, on rabbit platelet aggregation, and the possible antiaggregatory mechanisms of amlodipine, especially on the nitric oxide (NO) guanosine 3',5'-cyclic monophosphate (cyclic GMP)-mediated pathway, were investigated. Other effects of amlodipine on thromboxane B2 (TXB2) formation in platelets also were examined. Amlodipine concentration-dependently inhibited rabbit platelet aggregation induced by collagen (10 microg/mL) or thrombin (0.1 U/mL) with an IC50 range of 32-69 microM. Along with this inhibition, our results also demonstrated that in the presence of L-arginine (100 IM), amlodipine (50 microM) increased nitric oxide synthetase (NOS) activity (from the resting activity of 2.05+/-0.36 to 7.11+/-0.95 pmol/mg protein/min) and NO release (by 80%), accompanied by an elevation of the cyclic GMP level (from the resting platelet level of 1.27+/-0.12 to 6.21+/-0.55 pmol/10(9) platelets) induced by collagen (10 microg/mL). However, the antiaggregatory effect of amlodipine (50 microM) could be attenuated significantly by oxyhemoglobin (5 microM), a NO scavenger, or N(G)-nitro-L-arginine methyl ester (100 microM), a specific NOS inhibitor. In addition, the TXB2 production in platelets induced by collagen or thrombin was concentration-dependently inhibited by amlodipine. Therefore, we propose that the antiaggregatory mechanisms of amlodipine might be mediated, in part, by a NO-cyclic GMP process accompanied by the inhibition of TXB2 formation in platelets.

Inhibitory mechanisms of dantrolene on platelet aggregation

The antiplatelet effect of dantrolene and possible inhibitory mechanisms were studied in rabbit platelets. Preincubation of rabbit washed platelets with dantrolene (50-300 microM) inhibited the platelet aggregation and adenosine triphosphate release induced by arachidonic acid (100 microM), collagen (10 microg/mL), or thrombin (0.1 U/mL) in a dose-dependent manner. The thromboxane B2 formation caused by collagen or thrombin was inhibited by dantrolene, while formation of thromboxane B2 and prostaglandin D2 induced by arachidonic acid were not inhibited. In addition, the formation of phosphoinositide breakdown and the rise of intracellular calcium level induced by collagen or thrombin were also inhibited in a dose-dependent manner by dantrolene in the presence of indomethacin (2 microM). However, the platelets cyclic AMP level was not affected by dantrolene. In conclusion, the present study demonstrates that dantrolene inhibits platelet activation mainly due to suppression of phosphoinositide breakdown.

Epicardial ST depression in acute myocardial infarction

The presence of electrocardiographic ST depression in acute infarction remains controversial and poorly explained. A combined animal and modeling study was performed to evaluate the source of ST changes in acute infarction. In anaesthetized sheep, small infarcts showed uniform ST elevation over the infarction whereas larger infarcts showed marked ST depression over the normal myocardium in addition to the ST elevation. These findings were replicated by bidomain models of the heart. A hollow sphere was used to model a gradually increasing infarct, and this showed that there was a decrease in the ratio of ST elevation to ST depression as the infarct was increased. The current flowing out of the heart must be identical to the current flowing back into the heart. This means that any infarction will produce ST depression as well as ST elevation, the ratio between the two being related to the size of the infarction. Small infarction is associated with a small region of ST elevation and minor ST depression of the remaining myocardium, and as the infarct region increases, the amplitude of the epicardial ST elevation falls and the amplitude of the ST depression increases. Infarction size is proportional to both the height of the ST depression on the epicardium and the strength of the epicardial ST segment dipole.

Effects of cognitive impairment and loss of physical capacities on survival of the elderly

This study investigates the effects of cognitive impairment and loss of physical capacity on the survival rates of the elderly in Taiwan. Data used for this research were obtained from a longitudinal study in northern Taiwan, where 1,434 elderly respondents were randomly selected and were interviewed in 1993 and 1996. Respondents were categorized into four groups: those with physical disability, those with cognitive impairment, those with neither condition and those with both conditions. The survival rates of these four groups were analyzed and compared. The effects of cognitive impairment and physical disability were assessed separately and jointly. Within the study period, we found that elderly persons with both conditions had the lowest survival rate (0.54, 95% confidence interval (CI) 0.35-0. 73), while those with neither condition had the most favorable survival rate (0.92, 95% CI 0.90-0.93). Results from the Cox proportional hazard model showed that physical disability had a significantly adverse effect on the risk of mortality (relative risk 2.5, 95% CI 1.5-4.2), while cognitive impairment did not. Our results are consistent with previous findings which have shown that the decline in physical function affects mortality more than the decline in cognitive function.

Glucose intolerance and other cardiovascular risk factors in chinese women with a history of gestational diabetes mellitus

Women with a history of gestational diabetes (GDM) are at increased risk of developing diabetes compared with other women. There are few data on associations between GDM and cardiovascular risk factors. Between 1988 and 1995, 801 Chinese women with a history of GDM were recruited for a 75g oral glucose tolerance test (OGTT) and assessment of various cardiovascular risk factors, namely obesity, hypertension and dyslipidaemia, 6 weeks after delivery at the Diabetes Centre of the Prince of Wales Hospital. Another 431 women with no past history of diabetes or GDM recruited in a diabetes prevalence study were used as control subjects. After adjustment for age, body mass index and smoking, the prevalence of glucose intolerance remained higher in women with a history of GDM when compared to normal controls. The relative risks of obesity, hypertension, dyslipidaemia, diabetes and impaired glucose tolerance in women with a history of GDM comparing to normal subjects were, respectively, 2.4, 7.5, 2.4, 8.1 and 5.0. After excluding those with abnormal glucose tolerance, subjects with a history of GDM still had more adverse cardiovascular risk factors, including higher blood pressure, glycaemic and lipid parameters, than control subjects (after adjustment for age, body mass index and smoking). In conclusion, compared with normal subjects, Chinese women with a history of GDM had an 8-fold increased risk of having diabetes based on their OGTTs performed 6 weeks postdelivery. These women also have increased rates of other cardiovascular risk factors including obesity, high blood pressure and dyslipidaemia.

Phase II study of 2-chlorodeoxyadenosine in combination with chlorambucil in previously untreated B-cell chronic lymphocytic leukemia

The objective was to determine the safety and efficacy of adding a maximally tolerated dose of 2-chlorodeoxyadenosine (2-CdA) to standard chlorambucil (CLB) therapy in previously untreated B-cell chronic lymphocytic leukemia (CLL). Thirty patients with CLL (median age, 64 years) received two courses of 2-CdA given intravenously (2 mg/m2 daily for 7 days) added to biweekly administration of CLB at 30 mg/m2 given orally. The diagnosis of CLL, treatment indications, and response criteria were according to the National Cancer Institute established guidelines. Sixteen patients (53%) had advanced-stage disease, and four (13%) had trisomy 12 abnormality. The overall remission rate was 80%, including 20% complete remission (CR), 30% nodular partial remission (nPR), and 30% partial remission (PR). Minimal residual disease was detected phenotypically in two of five patients with CR and in eight of nine with nPR. Overall, CR, nPR, and PR rates were not influenced significantly by the presence of cytogenetic abnormalities or advanced clinical stage. With a median follow-up of 33 months, 58% of patients who had a response had relapse. Median time to progression in all 30 patients was 30 months, and time to progression and progression-free survival were not significantly different for the different response groups, clinical stages, or cytogenetic groups. Severe neutropenia and thrombocytopenia occurred in 33% and 7% of patients, respectively. Only two patients had documented bacterial infections, and four had herpetic infections. Concurrent combination chemotherapy with abbreviated doses of 2-CdA and standard-dose CLB is feasible and safe in previously untreated CLL. Antitumor activity may be superior to that of CLB alone given in conventional doses. Whether a different schedule of combining these two agents would result in improved outcome is being investigated.

An evaluation of radio frequency exposure from therapeutic diathermy equipment

To assess the physiotherapist's exposure to radio frequency electromagnetic fields (RF) leaking from short wave diathermy equipment, we conducted on-site measurements of stray electric and magnetic fields (27.12 MHz) close to continuous wave (CW) short wave equipment. The results show that the operator's knees may have the highest exposure level for both electric field (E-field) and magnetic field (H-field) in the normal operating position, i.e., behind the device console. The whole-body E-field exposure normally does not exceed the 1992 IEEE recommended limit during a normal treatment session. On the other hand, the operator's whole-body exposure to H-field was barely below the recommended limit. Our data suggest little chance of immediate harmful effects of RF leakage from the diathermy. Nonetheless, physiotherapists should still be advised to remain at a distance of at least 20 cm from the electrodes and cables to avoid possible overexposure.

Bone marrow effects of anagrelide therapy in patients with myelofibrosis with myeloid metaplasia

In a prospective study investigating the therapeutic role of anagrelide in myelofibrosis with myeloid metaplasia, 20 patients received anagrelide in daily oral doses of 0.5-3 mg. 17 patients were evaluable and received anagrelide for a median of 2 years (range 0.5-4 years). No patient had a clinically appreciable benefit. Bone marrow (BM) examinations at baseline and after 6 and 12 months of treatment were available for 17, 17 and 12 patients, respectively. In all evaluable cases, BM megakaryocyte number increased after 6 months of anagrelide treatment. Also, Ulex europaeus agglutinin-1 staining of megakaryocytes revealed a left-shifted maturation pattern in most patients with a platelet response to anagrelide. However, megakaryocyte staining intensity for transforming (TGF-beta) and platelet-derived (PDGF) growth factors was not affected consistently by treatment. No patient had a >/=2 grade change in either BM fibrosis or osteosclerosis. These in-vivo data support our previous in-vitro observations that anagrelide interferes with megakaryocyte maturation rather than proliferation. Lack of a positive treatment effect is consistent with the finding that anagrelide did not significantly alter megakaryocyte expression of TGF-beta and PDGF.

Treatment of unfavorable myelodysplastic syndrome with all-trans-retinoic acid and subcutaneous Ara C

Thirty patients with high-risk myelodysplastic syndrome, defined as > 5% bone marrow blasts, were treated with a combination of oral all-trans-retinoic acid (45 mg/m2 daily) and subcutaneous AraC (10 mg/m2) on days 1-14 of each 28-35 day cycle repeated for 2-6 cycles. Complete remission lasting 9, 12, and 15 months was achieved in three patients. Partial and minor response did not translate into meaningful clinical improvement, like complete responders. Overall incidence of leukemia transformation and survival of this cohort of patients was no different from the expected outcome for a group of patients with similar characteristics.

Incidence of and predictors for chronic disability in activities of daily living among older people in Taiwan

OBJECTIVES

To estimate the incidence of chronic activities of daily living (ADL) disability and to analyze the sociodemographic, health status, adverse lifestyle, and leisure-time physical activity predictors for chronic ADL disability.

DESIGN

We recruited a cohort of community-dwelling older people in Taipei, Taiwan, who were not ADL disabled in August 1993, and we followed them until August 1996.

SETTINGS AND PARTICIPANTS

The study subjects were 1321 community-dwelling people aged 65 years or older who were ADL intact at the initial interview in August 1993. The study sample was a subset of a probability sample (n = 1583) randomly selected from household registrations in the four districts of the Taipei metropolitan area.

MEASUREMENTS

Baseline information regarding various factors potentially associated with the development of chronic ADL disability was assessed and collected at the beginning of the study. Study participants were assessed annually for ADL function by a structured home interview using a six-item scale. Participants who were unable to perform independently at least one of the six items--eating, bathing, dressing, toileting, transfers, and walking inside the house--for more than 3 months were considered chronically ADL disabled. Cox proportional hazard regression models were utilized to examine the independent effect of the potential predictors on risk of chronic ADL disability.

RESULTS

During the 3-year study period, 145 (11.0%) participants developed chronic ADL disability, 58 (4.4%) participants were lost to follow-up, and 83 (6.3%) participants died. Multiple hazard regression analysis showed that individuals aged 70 to 79 years or older than age 80 had increased risk of ADL disability (relative risk: 2.05 (95% confidence interval (CI), 1.35-3.11) and 3.89 (95%CI, 2.33-6.50), respectively) compared with those participants younger than age 70. Risk of chronic ADL disability was inversely associated with routine exercise (RR = 0.52; 95% CI, 0.39-0.68).

CONCLUSIONS

Age is the most significant predictor of chronic ADL disability. Lack of routine exercise is also a significant predictor of ADL disability in older adults.

Characterization of risk factors for vascular dementia: the Honolulu-Asia Aging Study

BACKGROUND

The Honolulu Heart Program (HHP) is a prospective study of heart disease and stroke that has accumulated risk factor data on a cohort of 8,006 Japanese American men since the study began in 1965. A recent examination of the cohort identified all patients with vascular dementia (VaD) using the criteria of the California Alzheimer's Disease Diagnostic and Treatment Center.

OBJECTIVE

To characterize patients with VaD by stroke subtype and to investigate risk factors for VaD in a cohort of Japanese American men, aged 71 to 93, living in Hawaii and participating in the HHP.

METHODS

Sixty-eight men with VaD were compared with 3,335 men without dementia or stroke (NSND). Men with VaD were also compared with 106 men with stroke who were not demented (SND). Candidate risk factors were measured prospectively.

RESULTS

Of the 68 men with VaD there were 34 (50%) whose VaD was attributed to small vessel infarcts, 16 (23%) whose VaD was related to large vessel infarcts, and 11 (16%) with both large and small vessel infarcts. The remainder could not be classified. In a multivariate logistic regression model for VaD compared with NSND containing variables found to be associated with VaD in a univariate analysis, age (odds ratio [OR] 1.19, 95% confidence interval [CI] 1.13 to 1.27), coronary heart disease (OR 2.50, 95% CI 1.35 to 4.62), and 1-hour postprandial glucose (OR 1.41, 95% CI 1.06 to 1.88) remained significantly predictive of VaD, whereas preference for a Western diet (OR 0.54, 95% CI 0.30 to 0.98) as opposed to an Oriental or mixed diet and use of supplementary vitamin E (OR 0.32, 95% CI 0.12 to 0.82) were protective. A similar model for the comparison of men with VaD and SND revealed age (OR 1.24, 95% CI 1.14 to 1.35) was predictive of VaD, whereas preference for a Western diet (OR 0.43, 95% CI 0.22 to 0.86) was protective.

CONCLUSIONS

The most common stroke subtype associated with VaD was lacunar stroke. Age and traditional vascular risk factors are important contributors to the development of VaD in late life. The antioxidant vitamin E and presently unknown factors related to a Western diet as opposed to an Oriental diet may be protective against developing VaD.

Rubella immune status among healthcare workers in the Department of Obstetrics and Gynaecology of a regional hospital in Hong Kong: the need for a vaccination policy

Rubella infection in early pregnancy is associated with severe consequences in the developing fetus. In Hong Kong, 8-11% of women of child-bearing age are still susceptible to rubella infection. Therefore, rubella immune status of healthcare workers who may have contact with pregnant women is of particular concern. Rubella immunity of healthcare workers in a Department of Obstetrics and Gynaecology was analysed. In the one and a half years of study, 134 healthcare workers voluntarily submitted blood samples for immunity determination and 16.4% of them were susceptible to rubella infection. A substantial proportion of healthcare workers of childbearing age (14%) was negative for rubella antibody. Susceptible healthcare workers have a risk of acquiring and subsequently transmitting the potentially teratogenic rubella infection to their patients. There is a need to review the rubella immunization policy for healthcare workers in Hong Kong.

A registry-based case-control study of risk factors for the development of multiple non-fatal injuries on the job

Using compensation records of Taiwan, we conducted a case-control study nested within a cohort of 77,846 active workers who experienced at least one incidence of non-fatal work-related injury between 1994 and 1996 in order to explore factors associated with risk of sustaining multiple non-fatal injuries in the workplace. Cases (n = 2,616) were workers with more than three incidences of non-fatal injury during the study period and controls (n = 3,974) were randomly sampled from workers who experienced only one incidence of non-fatal injury during the same period. Compared with construction workers, workers employed in mining and quarrying (OR = 2.7), manufacturing (OR = 1.2), commerce (OR = 1.6), transport, storage and communication (OR = 1.3) and social, personal and community service (OR = 1.4) were all at significantly elevated risk of multiple non-fatal injuries. Both age and wage showed a significant dose-response effect on the risk of developing multiple non-fatal injuries. The preliminary analysis suggests that workers in certain industries are at significantly elevated risks of multiple work-related non-fatal injuries, in particular those in the mining and quarry industries. Additionally, further preventive measures should be aimed at protecting older workers from such injuries and further studies would help provide more specific interpretations on the positive association between higher wage earning and risk of multiple non-fatal injuries.

Shape interactions in macaque inferior temporal neurons

Missal et al. observed that the responses of inferior temporal (IT) neurons to a shape were reduced markedly when this shape partially overlapped a larger second shape, suggesting that shape interactions determine IT responses. In the present study, we compared the responses of IT neurons with combinations of two shapes which did or did not overlap and studied the effect of the relative and absolute positions of the two shapes. In a first test, a preferred shape (figure) was presented at the fixation point while a second, nonpreferred, shape was displayed either in the background of the figure (overlap) or at one of four peripheral positions (nonoverlap). Controls consisted of presentations of either shape in isolation at each of the five positions. The stimuli were presented during a fixation task. The responses to these combinations of two shapes were, on average, reduced compared with those elicited by the preferred shape presented in isolation. This suppression occurred whether or not the two shapes overlapped, but the degree of suppression in the overlap and nonoverlap conditions did not correlate. These interactions were stronger when the interacting stimulus was located in the contralateral compared with the ipsilateral hemifield. The position of the interacting stimulus within a hemifield significantly affected the suppression associated with combined shapes in some neurons. The strength of the interactions of the two nonoverlapping shapes depended on the shape of the interacting stimulus in half of the neurons. In a second test, the preferred shape and interacting stimulus could appear either at the fixation point or at one eccentric position. Here we found that the suppression was, on average, strongest when the interacting stimulus, rather than the preferred shape, was presented at the fixation position. Also, in 40% of the neurons, the response reduction was similar in overlap and nonoverlap conditions if effects of stimulus position were taken into account. In both tests, we also measured the responses to combinations of a nonpreferred shape and the interacting stimulus and showed that the response to a combination of two nonpreferred shapes was, in general, smaller than the response to a combination of the preferred and nonpreferred shape. Overall the results indicate that stimulus interactions in the receptive fields of IT neurons can be position and shape selective; this can contribute to the coding for the relationships between object parts.

Preincisional dextromethorphan treatment decreases postoperative pain and opioid requirement after laparoscopic cholecystectomy

In the present study, we examined whether preincisional treatment with dextromethorphan (DM) provides preemptive analgesia. Ninety patients scheduled for laparoscopic cholecystectomy were included. Patients receiving chlorpheniramine maleate (CPM) 20 mg via an IM injection 30 min before skin incision were designated as the control group. Patients in Group A received DM 40 mg (containing CPM 20 mg) IM after removal of the gallbladder, whereas in Group B, DM 40 mg (containing CPM 20 mg) was administered IM 30 min before skin incision. Meperidine (1 mg/kg IM) was given for postoperative pain relief as required. Times to first meperidine injection, total meperidine consumption, worst pain score, bed rest time, and side effects were recorded for 48 h after surgery. Times to first meperidine injection were 9.3+/-15.9, 17.4+/-3.4, and 28.6+/-3.9 h for the control group and Groups A and B, respectively. The total meperidine consumption was 90.7+/-11.9, 77.5+/-12.7, and 20.0+/-4.4 mg for the control group and Groups A and B, respectively. The worst visual analog pain scores were 6.0+/-0.2, 6.0+/-0.2, and 4.0+/-0.4 for the control group and Groups A and B, respectively. The bed rest times were 21.0+/-0.5, 20.0+/-0.5, and 19.0+/-0.4 h for the control group and Groups A and B, respectively. The number of patients who required meperidine injection was 26, 22, and 12 for the control group and Groups A and B, respectively. We conclude that DM is more effective in producing postoperative analgesia when it is administered preincision rather than after the gallbladder removal treatment, which suggests a preemptive analgesic effect.

IMPLICATIONS

Preincisional dextromethorphan (40 mg IM) treatment offers a preemptive analgesic effect, thus improving the postoperative pain management.

A review of the healthy worker effect in occupational epidemiology

This review article aims to anatomize sources of the healthy worker effect (HWE) and to summarize advantages and limitations of several approaches frequently proposed to eliminate the HWE. Although the HWE is frequently addressed in the context of selection bias, our review suggests that the selection of occupational cohorts with advantageous health status would preferably be addressed as a source of confounding biases. The authors also conclude that the exclusion of unhealthy workers at employment and the study of active workers are the two main sources of HWE, and that the use of the general population as a comparison group in occupational epidemiology should be avoided if possible. The authors encourage investigators to make distinctions between the underlying factors related to the use of the general population as the comparison group in occupational epidemiology.

Successful pregnancy in a woman with secondary biliary cirrhosis with portal hypertension from recurrent pyogenic cholangitis. A case report

BACKGROUND

Pregnancy in women with secondary biliary cirrhosis due to recurrent pyogenic cholangitis is extremely rare. Little information is available on the effect of pregnancy on the disease and vice versa.

CASE

A patient who had secondary biliary cirrhosis due to recurrent pyogenic cholangitis complicated by splenomegaly and portal hypertension had a successful pregnancy. Although she had a history of esophageal variceal bleeding before this pregnancy, there was no such bleeding during pregnancy. She had an uneventful antenatal course except that her liver enzyme level fluctuated slightly. The serum bilirubin level increased during the third trimester of pregnancy but returned to the prepregnant level after delivery.

CONCLUSION

Termination of pregnancy may not be the only option for management. The management protocol for patients with primary biliary cirrhosis complicating pregnancy, which includes regular fetal surveillance and monitoring of maternal liver function, should be considered for pregnant women with secondary biliary cirrhosis.

Prognostic relevance of monosomy at the 13q14 locus detected by fluorescence in situ hybridization in B-cell chronic lymphocytic leukemia

Deletion of the chromosome band 13q14, which contains the putative deleted in B-cell malignancy (DBM) gene, and trisomy 12 have been demonstrated by fluorescence in situ hybridization (FISH) techniques in malignant B-cells from patients with B cell chronic lymphocytic leukemia (B-CLL). However, the prognostic relevance of 13q14 abnormalities as detected by FISH is unknown. We prospectively studied malignant blood cells from 54 consecutive, untreated B-CLL patients using FISH probes to the RB1 locus and DBM (markers D13S25 and D13S319) for band 13q14, as well as probes to chromosome 12. The cells from all cases were CD5+ CD20+, expressed clonally restricted surface immunoglobulin light chain, and had typical features for B-CLL on careful blood smear morphologic evaluation. Patients were followed for a mean of 3.9 years and treatment-free survival (TFS) was used in the prognostic factor analysis. Twenty-four (44%) patients were observed to have monosomy of the RB1 locus and 26 (48%) monosomy of D13S25 and D13S319. The 26 patients who had a deletion at at least one of these loci had a 48.4 month (mo) median TFS vs 31.1 mo for those without evidence of deletion at any 13q14 locus (p = 0.07). The seven patients found to have trisomy 12 had a median TFS of 6.9 mo vs 39.3 mo for those diploid for chromosome 12 (p < 0.01). When these seven patients with trisomy 12 were excluded from the analysis, patients who had a deletion at 13q14 tended to have a longer median TFS (50.1 vs 36.2 mos), but this was not statistically significant (p = 0.2). This study confirms the prevalence of 13q14 deletions in B-CLL and suggests that patients with this abnormality have a better TFS than those with trisomy 12.

Whipple's arthritis: direct detection of Tropheryma whippelii in synovial fluid and tissue

We describe 2 patients presenting with polyarthritis in whom the synovial fluid (1 patient) or synovial tissue (1 patient) was positive for Tropheryma whippelii, the Whipple's disease-associated bacillus, when examined by polymerase chain reaction (PCR) and DNA sequencing. Histopathologic findings were consistent with articular Whipple's disease in the synovial fluid of 1 patient and the synovial tissue of the other. In both patients, bowel mucosal specimens were negative for Whipple's disease features by histologic and PCR methods. One patient was positive for T whippelii in the peripheral blood. Control synovial fluid specimens from 40 patients with other arthritides, including Lyme arthritis, were negative. Sequencing of a 284-basepair region of the 16S ribosomal RNA gene confirmed that the sequence is closely related to the known T whippelii sequence. Both patients responded to treatment with antibiotics.

Autoantibodies to GM1b and GalNAc-GD1a: relationship to Campylobacter jejuni infection and acute motor axonal neuropathy in China

IgG antibodies to the minor gangliosides GM1b and GalNAc-GD1a frequently are present in sera of Japanese patients with Guillain-Barré syndrome. The relationship between these autoantibodies and Campylobacter jejuni infection, the type of disease (acute motor axonal neuropathy [AMAN], or acute inflammatory demyelinating polyneuropathy [AIDP]) has yet to be established. Sera samples were obtained from 55 Chinese patients with clinically defined Guillain-Barré syndrome. An electrophysiology study showed nine AIDP, 28 had AMAN, and 18 unclassified. C. jejuni serology was positively correlated with anti-GM1b and anti-GalNAc-GD1a IgG antibodies (respective P values, 0.007 and 0.02). The frequencies of positive anti-GM1b and anti-GalNAc-GD1a serology were greater in AMAN (32 and 21%) than in AIDP (11 and 0%), but the differences were not significant. Infection by C. jejuni may induce IgG anti-GM1b antibody in some patients and IgG anti-GalNAc-GD1a antibody in others. A larger population of patients must be studied to show whether there is a definite correlation.

Shift in speed selectivity of visual cortical neurons: a neural basis of perceived motion contrast

The perceived speed of motion in one part of the visual field is influenced by the speed of motion in its surrounding fields. Little is known about the cellular mechanisms causing this phenomenon. Recordings from mammalian visual cortex revealed that speed preference of the cortical cells could be changed by displaying a contrast speed in the field surrounding the cell's classical receptive field. The neuron's selectivity shifted to prefer faster speed if the contextual surround motion was set at a relatively lower speed, and vice versa. These specific center-surround interactions may underlie the perceptual enhancement of speed contrast between adjacent fields.

Bis(7)-tacrine, a novel dimeric AChE inhibitor, is a potent GABA(A) receptor antagonist

Heptylene-linked bis-(9-amino-1,2,3,4-tetrahydroacridine) (bis(7)-tacrine) is a potential palliative therapeutic agent for Alzheimer's disease (AD), on the basis of its superior acetylcholinesterase (AChE) inhibition and memory-enhancing potency relative to tacrine. In this study we report that bis(7)-tacrine exhibits a potentially complementary central nervous system action, antagonism of GABA(A) receptor function. Bis(7)-tacrine displaced [3H]muscimol from rat brain membranes with an apparent Ki of 6.0 microM; tacrine and physostigmine were shown to be 18 and 170 times less potent, respectively. In whole-cell patch-clamp recordings, bis(7)-tacrine inhibited GABA-induced inward current with an IC50 of 5.6 microM, and shifted the GABA concentration-response curve to the right in a parallel manner. These results suggest that bis(7)-tacrine is a competitive antagonist of the GABA(A) receptor.

Risk assessment of active smoking: smoking-attributable mortality and years of potential life lost in Taiwan, 1980 and 1992

Anti-smoking programs have been advocated by the government and other private organizations for decades in Taiwan, especially in the past ten years. We conducted an analysis to assess the effectiveness of anti-smoking programs by examining the changes in active smoking attributable mortality (ASAM) and active smoking attributable years of potential life lost (ASAYPLL) between 1980 and 1992. This analysis also evaluated the present health impact due to active smoking. Total estimated ASAM was 12,765 for 1980 and 14,764 for 1992, representing 34.9% and 31.8% of all deaths from smoking-related causes for each year, respectively. Our results suggested a progress of anti-smoking efforts contributed by the government and other private anti-smoking organizations. By comparing the figures between 1980 and 1992, a reduction in all dimensions has been observed. The overall smoking prevalence rate decreased from 31.7% to 29.5% and the ASAM rate declined from 121.8/10(5) to 91.5/10(5). Additionally, the ASAYPLL rate declined from 513.4/10(5) to 406.9/10(5). Furthermore, the ratio of ASAM from cardiovascular diseases (CVD) to all ASAM decreased from 56.3% in 1980 to 46.7% in 1992, while the ratio of ASAM from cancer to all ASAM increased from 22.9% in 1980 to 34.9% in 1992. Our analysis also found that active smoking seemed to be a more important risk factor for smoking-related causes of death in people aged 41-65 than in people of other age group. Although the anti-smoking programs seemed effective over the past 13 years, active smoking still contributed to an estimated number of 14,764 deaths and 63,743 economically productive years lost in 1992. More efforts should be devoted to further reduce the high smoking prevalence in men and particularly to hamper the increasing smoking trend in adolescents and young women. This remains a challenge for the government of Taiwan.

Chronic lymphocytic leukaemia with symptomatic diffuse central nervous system infiltration responding to therapy with systemic fludarabine

B-cell chronic lymphocytic leukaemia is an indolent disease characterized by the insidious accumulation of small mature-appearing lymphocytes in the peripheral blood, bone marrow and lymphoid tissues. Direct symptomatic invasion of the central nervous system is exceedingly rare and, to our knowledge, only three cases histologically confirmed as true chronic lymphocytic leukaemia have been reported in the literature. We describe the first case of early Rai stage B-cell chronic lymphocytic leukaemia presenting with symptomatic infiltration of the brain and spinal cord which could be demonstrated radiographically by magnetic resonance imaging. The diagnosis was confirmed by examination of peripheral blood, cerebrospinal fluid, brain and bone marrow biopsies, both morphologically and immunophenotypically by means of flow cytometric analysis. The patient demonstrated a complete response to therapy with standard-dose systemic fludarabine and remains in complete remission 6 months after completion of therapy.

The bakkenolides from the root of Petasites formosanus and their cytotoxicity

Thirty-two new bakkenolides, bakkenolides-Db (1)--Dh(7), -Fa(8), -Fb(9), -I(10)--M(14), -Na(15), -Nb(16), -O(17)--T(22), -Ua (23), -Ub(24), -V(25)--X(27), -Ya(28), -Yb(29), -Za(30), -Zb(31) and -III(32), from the roots of Petasites formosanus together with thirty known compounds were isolated. The structures were characterized by spectral analysis. The locations, C-1 and/or C-9 of bakkenolide skeleton, of the substituents, such as acetoxy, isobutyroyloxy and isovaleroyloxy groups, can be determined by the chemical shifts of their signals and the H-1 and/H-9 in the 1H-NMR spectra. The cytotoxicity was also discussed.

Four aristolochic acid esters of rearranged ent-elemane sesquiterpenes from aristolochia heterophylla

Four aristolochic acid esters of ent-elemane type sesquiterpene having a new carbon skeleton, aristophyllides A (1), B (2), C (3), and D (4), were isolated from the stems and roots of Aristolochia heterophylla. The esters were characterized by NMR and MS methods and included is a study of absolute configurations using the CD exciton chirality method.

Anti-GD1a antibody is associated with axonal but not demyelinating forms of Guillain-Barré syndrome

Immunopathological studies suggest that the target of immune attack is different in the subtypes of Guillain-Barré syndrome (GBS). In acute motor axonal neuropathy (AMAN), the attack appears directed against the axolemma and nodes of Ranvier. In acute inflammatory demyelinating polyneuropathy (AIDP), the attack appears directed against a component of the Schwann cell. However, the nature of the antigenic targets is still not clear. We prospectively studied 138 Chinese GBS patients and found that IgG anti-GD1a antibodies were closely associated with AMAN but not AIDP. With a cutoff titer of greater than 1:100, 60% of AMAN versus 4% of AIDP patients had IgG anti-GD1a antibodies; with a cutoff titer of greater than 1:1,000, 24% of AMAN patients and none of the AIDP patients had IgG anti-GD1a antibodies. In contrast, low levels of IgG anti-GM1 antibodies (> 1:100) were detected in both the AMAN and the AIDP forms (57% vs 35%, NS). High titers of IgG anti-GM1 (>1:1,000) were more common in the AMAN form (24% vs 8%, NS). Serological evidence of recent Campylobacter infection was detected in 81% of AMAN and 50% of AIDP patients, and anti-ganglioside antibodies were common in both Campylobacter-infected and noninfected patients. Our results suggest that IgG anti-GD1a antibodies may be involved in the pathogenesis of AMAN.

Epstein-Barr virus infection in Richter's transformation

Chronic lymphocytic leukemia (CLL) may convert to a diffuse large cell lymphoma (Richter's syndrome) over time. In occasional cases of Richter's transformation, Epstein-Barr virus (EBV) has been identified in the lymphoma cells. To evaluate the association of EBV infection with Richter's syndrome, the biopsy specimens and clinical records of 25 patients who were seen at the Mayo Clinic between 1984-1996 were retrospectively evaluated for the presence of EBV by immunoperoxidase staining for expression of EBV latent membrane protein (LMP), as well as the expression of EBV RNA and DNA in the cells by in situ hybridization. Four of the 25 patients showed evidence of EBV in the diffuse large cell lymphoma cells-three patients with a B-cell phenotype were positive for LMP, EBV DNA, and RNA; and one patient with a T-cell phenotype had positive EBV RNA in the large cell lymphoma cells. The Richter's syndrome was treated with combination chemotherapy in 15 patients, three received radiotherapy, three were followed without further therapy after a splenectomy, two died before treatment could be started, and one patient had insufficient follow-up. One patient with evidence of EBV in large cell lymphoma cells was treated with acyclovir as initial therapy. The median survival of EBV-positive patients was three months compared with nine months for EBV-negative patients, but this difference was not statistically significant (P = 0.385). Evidence for EBV infection related to Richter's transformation was present in 16% of the patients in this study and may be associated with a poorer outcome. Primary therapy with acyclovir in one patient did not seem to be beneficial and other therapeutic modalities in patients with EBV-positive Richter's transformation need to be explored.

Synergistic anticancer effects of tetrandrine combined with doxorubicin or vincristine in vitro

AIM

To study the interaction between tetrandrine (Tet) and doxorubicin (Dox) or vincristine (Vin) against human breast cancer cell lines MCF-7 and MCF-7/Dox or human nasopharyngeal cancer cell lines KB and KBV200 in vitro.

METHODS

Anticancer activities of a drug alone and a drug combination of Tet and Dox or Vin were determined by tetrazolium (MTT) method. The interaction between Tet and Dox or Vin was evaluated by both a value of a sum of fractional inhibitory concentration (SFIC) and an isobologram method.

RESULTS

The SFIC values of the three-different-ratio combinations between Tet and Dox ranged from 0.14 to 0.38 for MCF-7, and 0.10 to 0.29 for MCF-7/Dox; those of Tet-Vin combinations ranged from 0.21 to 0.37 for KB, and 0.32 to 0.63 for KBV200. All the SFIC values of the combination between Tet and Dox or Vin were less than 1.0 when the 3 ratios of the 2 drugs in combination were used, and the shapes of isobolic curves obtained from the combination were concave.

CONCLUSION

The interaction between Tet and Dox or Vin against the human cancer cells was markedly synergistic.

Fast Fourier transform analysis of ventricular fibrillation intervals to predict ventricular refractoriness and its spatial dispersion

A technique of fast Fourier transform analysis has been used to derive mean ventricular fibrillation (VF) intervals, and to confirm that these VF intervals predict ventricular refractory periods. Twenty episodes of VF were induced by a rapid ventricular pacing in 12 sheep. VF activations in a 10-second period were simultaneously acquired from 64 epicardial sites with an electrode sock. The VF electrograms were analyzed by a fast Fourier transform analysis. The dominant peak frequency of the VF spectrum in each epicardial site was converted into milliseconds and served as a mean VF interval. The dominant peak frequency of VF electrograms ranged from 8.1 to 11.5 Hz, and the corresponding mean VF intervals were 87 to 124 ms. In five sheep, the mean VF intervals and the effective refractory periods were determined by the extrastimulus technique obtained from 29 epicardial sites. There was a very good correlation between the two parameters when the effective refractory periods were determined at a basic cycle length of 300 ms (r = 0.89, P < 0.001) and 400 ms (r = 0.87, P < 0.001), respectively. VF was induced twice in eight sheep. The maximum difference in the mean VF intervals between the two VF episodes in the same sheep was 3 ms (P > 0.05). In conclusion, mean VF intervals determined by the fast Fourier transform analysis have a good reproducibility and a good correlation with ventricular refractory periods measured by the classic extrastimulus technique. The mean VF intervals could serve as an index of ventricular refractoriness.