Biomedical subjects

M Mancini

Publications and source records attributed to M Mancini.

At least 55 records · Page 3Linked to original sources

PubMed2001

Mechanisms of pulmonary gas exchange improvement during a protective ventilatory strategy in acute respiratory distress syndrome.

To investigate the mechanisms underlying improvement of arterial oxygenation during a protective ventilatory strategy (PVS) in early acute respiratory distress syndrome (ARDS), we studied eight patients during volume-controlled mechanical ventilation, keeping respiratory rate and fraction of inspired oxygen (FI(O(2))) (0.82 +/- 0.20) unchanged: (1) at baseline (tidal volume [VT] 10 to 12 ml x kg(-1); positive end-expiratory pressure [PEEP] 8 to 10 cm H(2)O); (2) during PVS (PEEP 2 cm H(2)O above the low inflexion point (P(FLEX)) and VT of 5 to 7 ml x kg(-1)); and (3) post-PVS, back to baseline conditions. Inert gas measurements were done after 30 min in each ventilatory modality. During PVS, Pa(O(2)) increased significantly from 93 +/- 27 to 166 +/- 77 mm Hg (p < 0.008) and Pa(CO(2)) rose from 39 +/- 7 to 57 +/- 11 mm Hg (p < 0.0002) because of the decrease in minute ventilation (V E) (-3.6 L x min(-1)) (p < 0.005). Both heart rate (HR, +13 min(-1)) (p < 0.002) and cardiac output (Q, +1.2 L x min(-1)) (p < 0.05) increased. Static respiratory system linear compliance increased from 36 +/- 14 to 44 +/- 16 ml. cm H(2)O(-1) (p < 0.0002). PVS provoked recruitment of previously collapsed alveoli and redistribution of pulmonary blood flow from nonventilated alveoli to normal lung. Despite the increase in Q, intrapulmonary shunt fell from 39 +/- 15% to 31 +/- 11% (p < 0.04). We conclude that the decrease in intrapulmonary shunt owing to alveolar recruitment remains the pivotal mechanism to explain improvement of arterial oxygenation during this PVS.

Adult↗

PubMed2001

Oscillatory resistance measured during noninvasive proportional assist ventilation.

Setting proportional assist ventilation (PAV) requires the measurement of patient resistance and elastance. To avoid patient sedation/paralysis or the use of an esophageal balloon, noninvasive PAV is indirectly set by the "runaway" method or in accordance with patient comfort. The aim of this study was to ascertain whether the forced oscillation technique (FOT) applied by the ventilator during noninvasive PAV is useful in assessing patient respiratory resistance. Nasal PAV was applied to 14 patients with severe chronic obstructive pulmonary disease. During PAV a modified ventilator applied a 5-Hz pressure oscillation to noninvasively assess FOT resistance (Rrs). Lung resistance (RL) was measured in seven of the patients by using an esophageal balloon. Moreover, measurements were also performed in five of the patients when PAV was applied through the mouth. Rrs was close to RL both during nasal (Rrs = 8.9 +/- 3.1, RL = 9.0 +/- 2.6; cm H(2)O x s/L; n = 7, p > 0.05) and mouth (Rrs = 5.6 +/- 2.1, RL = 5.8 +/- 1.4; cm H(2)O x s/L; n = 5, p > 0.05) breathing. Rrs was slightly greater than the maximum value of flow assistance applied during the setting of PAV (FAmax): 11.1 +/- 5.4 and 9.5 +/- 2.9 cm H(2)O x s/L, respectively (n = 14, p > 0.05), both variables being significantly correlated (r = 0.72, p < 0.05). FOT applied by the PAV ventilator allowed the assessment of patient resistance. These results suggest that FOT could be useful in setting PAV flow assistance and in automatically and continuously updating this setting in accordance with patient resistance.

Aged↗

PubMed2001

Chimaeric Lym-1 monoclonal antibody-mediated cytolysis by neutrophils from G-CSF-treated patients: stimulation by GM-CSF and role of Fc gamma -receptors.

Chimaeric Lym-1 (chLym-1) is a monoclonal antibody generated by fusing the variable region genes of murine Lym-1 to human gamma1 and kappa constant regions. Owing to its selectivity and avidity for human malignant B cells, it is an attractive candidate for developing immune-interventions in B-lymphomas. In the attempt to identify rational bases for optimizing potential chLym-1 related therapeutic approaches, we studied the ability of this ch-mAb to trigger neutrophil-mediated Raji cell cytolysis in cooperation with two neutrophil-related cytokines, G-CSF and GM-CSF. ChLym-1 triggered low levels of cytolysis by normal neutrophils but induced consistent cytolysis in neutrophils from individuals treated with G-CSF. When exposed to GM-CSF, neutrophils from subjects treated with G-CSF became potent effectors, also leading to 75% lysis. By using mAbs specific for distinct FcgammaRs, normal neutrophils were inhibited by mAb IV.3, suggesting the intervention of FcgammaRII, constitutively expressed on the cells. On the other hand, neutrophils from patients treated with G-CSF were inhibited by mAb IV.3 plus mAb 197, a finding consistent with a cooperative intervention of FCgammaRII and G-CSF-induced FcgammaRI. The anti-FcgammaRIII mAb 3G8 promoted significant enhancement of the neutrophil cytolytic efficiency. Therefore, neutrophil FcgammaRIII behaves as a down-regulator of the cytolytic potential. The present findings suggest new attempts to develop mAb-based and G-CSF/GM-CSF combined immune-interventions in B lymphomas.

Antibodies, Monoclonal↗

PubMed2001

Histone deacetylase-targeted treatment restores retinoic acid signaling and differentiation in acute myeloid leukemia.

Histone deacetylase (HDAC)-dependent transcriptional repression of the retinoic acid (RA)-signaling pathway underlies the differentiation block of acute promyelocytic leukemia. RA treatment relieves transcriptional repression and triggers differentiation of acute promyelocytic leukemia blasts, leading to disease remission. We report that transcriptional repression of RA signaling is a common mechanism in acute myeloid leukemias (AMLs). HDAC inhibitors restored RA-dependent transcriptional activation and triggered terminal differentiation of primary blasts from 23 AML patients. Accordingly, we show that AML1/ETO, the commonest AML-associated fusion protein, is an HDAC-dependent repressor of RA signaling. These findings relate alteration of the RA pathway to myeloid leukemogenesis and underscore the potential of transcriptional/differentiation therapy in AML.

Acetylation↗

PubMed2001

Detection of BCR/ABL rearrangements in adult acute lymphoblastic leukemia using a highly sensitive interphase fluorescence in situ hybridization method (D-FISH).

INTRODUCTION: One hundred-and-six adult cases of acute lymphoblastic leukemia were prospectively investigated using a highly sensitive interphase fluorescence in situ hybridization assay which utilizes DNA probes that detect a double BCR/ABL fusion signal (D-FISH) in cells carrying the t(9;22) to evaluate the reliability and specificity of this method for the detection of the Ph translocation. The results were compared with those obtained in the same cases by conventional cytogenetics and by reverse-transcription polymerase chain reaction. MATERIALS AND METHODS: The study was performed using DNA probes that span the common breakpoints of the t(9;22) translocation and that detect a double BCR/ABL fusion in cells carrying this karyotypic anomaly, one on the abnormal chromosome 9 and one on the Ph chromosome. RESULTS: Interphase D-FISH detected a high number of rearranged cases (22/106) compared to conventional cytogenetics (15/106) and RT-PCR (21/106). CONCLUSION: Interphase D-FISH emerges as a reliable, fast and relatively inexpensive tool for the detection of BCR/ABL rearrangements in adult ALL patients at diagnosis. It has a sensitivity clearly higher than conventional karyotyping and it may prove also superior to that of RT-PCR in cases with unusual BCR/ABL breakpoints. Our results suggest that D-FISH might be considered as the initial test for the diagnosis of Ph+ adult ALL.

Adolescent↗

PubMed2001

Past history of nephrolithiasis and incidence of hypertension in men: a reappraisal based on the results of the Olivetti Prospective Heart Study.

BACKGROUND: We have previously reported that in the Olivetti Prospective Heart Study cohort the incidence of nephrolithiasis was higher in hypertensive participants than in normotensive ones. As the time sequence and the mechanisms underlying the association between nephrolithiasis and hypertension remain controversial, we further tested the hypothesis that in a cohort of normotensive males a history of nephrolithiasis predicts the development of future hypertension. METHODS: The analysis was conducted in 381 male workers at Olivetti who were normotensive at the baseline examination and who were re-examined 8 years later. RESULTS: A past history of nephrolithiasis is associated with an increased risk of hypertension of 1.96 (95% CI=1.25-3.07) relative to subjects with a negative history, after adjusting for age. CONCLUSION: In this 8-year follow-up study, a history of nephrolithiasis resulted in an increased risk of developing hypertension in the future. As the reverse was also true, as previously reported, a clear-cut time sequence, as well as the mechanisms linking these two conditions, remain to be identified.

Adult↗

PubMed2001

Impact of the Gubbio population study on community control of blood pressure and hypertension. Gubbio Study Research Group.

BACKGROUND: Awareness and treatment of hypertension have markedly increased in the last 30 years in most parts of the world, but a satisfactory control of blood pressure is still infrequent OBJECTIVES: To describe trends in community control of hypertension and blood pressure levels in the small town of Gubbio, Italy. METHODS: Large samples of the populations (aged 30-79 years) were examined 6 years apart for measurement of blood pressure, other cardiovascular risk factors and knowledge, attitude and practice towards control of hypertension. Data were available from a total of 1125 men and 1445 women with two examinations and 1566 men and 1658 women with at least one examination. Two different definitions of hypertension were used (old definition: systolic blood pressure (SBP) > or = 160 mmHg or diastolic blood pressure (DBP) > or = 95 mmHg or use of antihypertensive drugs; recent definition: SBP > or = 140 mmHg or DBP > or =90 mmHg or use of anti-hypertensive drugs). RESULTS: Awareness, treatment and control of hypertension increased from one survey to the other, whatever definition of hypertension was used. Control rose from 41 to 63% (old definition) and from 12 to 24% (recent definition). In a 6-year period, the average population SBP declined 2-8 mmHg and DBP declined 2-3 mmHg depending on type of analysis, against an expected rise of 9 mmHg for SBP and 2 mmHg for DBP. These trends are partly explained by a marked decline in alcohol consumption and by more common and intensive anti-hypertensive treatment, while change in body mass index, which showed a slight but systematic increase, cannot be considered as a contributor to this trend. CONCLUSIONS: An epidemiological study has motivated a population group and its medical profession towards a better control of hypertension.

Adult↗

PubMed2001

CpG oligodeoxynucleotides with hepatitis B surface antigen (HBsAg) for vaccination in HBsAg-transgenic mice.

DNA motifs containing unmethylated CpG dinucleotides within the context of certain flanking sequences enhance both innate and antigen-specific immune responses, due in part to the enhanced production of Th1-type cytokines. Here we explored the ability of CpG-containing oligodeoxynucleotides combined with recombinant hepatitis B surface antigen (HBsAg) to induce Th1 responses in mice that are transgenic for this antigen and that represent a model for asymptomatic hepatitis B virus chronic carriers. This was compared to hepatitis B virus-specific DNA-mediated immunization, which we have previously shown to induce the clearance of the transgene expression product and the down-regulation of hepatitis B virus mRNA in this transgenic mouse lineage. In control nontransgenic C57BL/6 mice, three immunizations with HBsAg and CpG triggered the production of anti-HBs antibodies and of HBs-specific T cells that secrete gamma interferon but do not display any HBsAg-specific cytotoxic activity. In the HBsAg-transgenic mice, immunization with HBsAg and CpG oligodeoxynucleotides, but not with CpG alone, induced the clearance of HBsAg circulating in the sera, with a concomitant appearance of specific antibodies, and was able to regulate the hepatitis B virus mRNA constitutively expressed in the liver. Finally, adoptive transfer experiments with CD8(+) T cells primed in C57BL/6 mice with HBsAg and CpG oligodeoxynucleotide-based immunization show that these cells were able to partially control transgene expression in the liver and to clear the HBsAg from the sera of recipient transgenic mice without an antibody requirement. CpG oligodeoxynucleotides motifs combined with HBsAg could therefore represent a potential therapeutic approach with which to treat chronically infected patients.

Adjuvants, Immunologic↗

PubMed2001

Site-specific atherosclerotic plaques in the carotid arteries of middle-aged women from southern Italy: associations with traditional risk factors and oxidation markers.

BACKGROUND AND PURPOSE: Studies on cardiovascular disease have preferentially involved men because of the lower frequency of the disease in preelderly women. The aim of this analysis was to examine, with the use of a standardized ultrasound protocol, a cohort of women to differentiate early atherosclerotic lesions in different carotid segments in relation to traditional (lipoprotein abnormalities, high blood pressure, cigarette smoking) and nontraditional (oxidation markers) cardiovascular risk factors. METHODS: More than 5000 clinically healthy, middle-aged women (n=5062; age range, 30 to 69 years) living in the area of Naples in southern Italy participated in the Progetto Atena, a population-based study on the etiology of cardiovascular disease and cancer in the female population. A subsample of 310 participants underwent high-resolution B-mode ultrasound to assess intima-media thickness of common carotid artery and carotid bifurcation. RESULTS: Early atherosclerotic plaques (intima-media thickness >1.2 mm) were detected within the common carotid arteries in 37 women, in the carotid bifurcations in 77 women, and in both sites in 91 women. After age adjustment, common carotid plaques were found to be associated with higher systolic blood pressure (143 versus 138 mm Hg; P<0.05) and higher body mass index (29 versus 27 kg/m(2); P<0.01), while lesions at the carotid bifurcations were associated with higher LDL cholesterol (4.3 versus 3.8 mmol/L; P<0.01) and with smoking habit. Multivariate odds ratios for the presence of common carotid plaques were related to antibodies against oxidized LDL (odds ratio, 2.72; 95% CI, 1.46 to 5.07), and those for plaques at the bifurcation were related to lipid peroxides (odds ratio, 1.90; 95% CI, 1.04 to 3.47), and both relationships were independent of age, LDL cholesterol concentrations, body mass index, smoking habit, and systolic blood pressure. CONCLUSIONS: In a cohort of clinically healthy, middle-aged women, we found a site-specific association of traditional risk factors and oxidation markers with early atherosclerotic lesions in arterial segments differing in geometry, shear stress, extracellular matrix composition, and cell type populations.

Adult↗

PubMed2001

L-arginine improves post-ischemic vasodilation in coronary heart disease patients taking vasodilating drugs.

BACKGROUND: The hypothesis that intravenous L-arginine infusion improves the vasodilatory response to ischemia in the resistance vessels of human lower limbs in relatively young coronary heart disease patients taking vasodilating drugs was tested. METHODS: Twenty patients with onset of symptoms of coronary artery disease before age 50, operated for aortocoronary bypass and taking vasodilating drugs, were compared with 20 control subjects of comparable age and gender; neither group included heavy smokers (>10 cigarettes/day). Blood flow in the lower limbs was measured noninvasively with strain-gauge plethysmography, both at rest and during a reactive hyperemia test. Intravenous infusion of L-arginine was performed in nine coronary heart disease patients and in nine control subjects. RESULTS: Resting blood flow to the lower limbs was 2.3 mL/min/100 mL in control subjects vs 3.4 mL/min/100 mL in patients (difference not statistically significant). Peak blood flow measured after a 3-minute arterial occlusion was 24.0 mL/min/100 mL in control subjects vs 20.3 mL/min/100 mL in coronary heart disease patients (P<0.05). Peripheral minimal vascular resistances were 4.28 and 5.46 peripheral resistances units (p.r.u.) in control subjects and patients, respectively (P<0.05). Intravenous infusion of L-arginine was followed by increased resting blood flow in cases and controls (P=0.009), with a parallel reduction in peripheral resting vascular resistances (P=0.009). Coronary heart disease patients showed increased peak blood flow (P=0.04) and reduced minimal vascular resistances (P=0.02), whereas no statistically significant changes in these parameters were detectable in control subjects. Intravenous glucose infusion, leading to increased serum insulin concentration, did not modify any hemodynamic parameter. CONCLUSIONS: Hemodynamic responses in the skeletal muscle are impaired during a reactive hyperemia test in relatively young coronary heart disease patients taking vasodilating drugs. Intravenous L-arginine infusion corrects the impaired vasodilatory response of the lower limbs to an acute increase in flow following a cuff thigh occlusion.

Adult↗

PubMed2001

Serum uric acid for short-term prediction of cardiovascular disease incidence in the Gubbio population Study.

OBJECTIVE: The Gubbio Study is an Italian population study measuring risk factors for and incidence of major cardiovascular diseases. This analysis investigates the association of serum uric acid with the incidence of coronary and cardiovascular events. METHODS: A population sample of 2469 men and women aged 35-74 years, free from major cardiovascular diseases and in whom serum uric acid was measured in 1983 along with other standard risk factors, were followed up for 6 years and the incidence of coronary heart disease (CHD) and all cardiovascular atherosclerotic (CVD) events, both fatal and non-fatal, was computed. Proportional hazards models were used for the prediction of these events. RESULTS: In six years 61 CHD hard criteria, 109 CHD any criterion and 149 CVD events were recorded. Age-adjusted rates per 1000 of the 3 event categories were computed in sex-specific quintiles (Q) of serum uric acid with 428 +/- 76 (Q5) and 198 +/- 42 (Q1) micromol/l, respectively. Although higher rates were seen in Q5 as compared to Q1 for all three first event categories considered (relative risks 6.2, 3.6 and 3.7, respectively), a statistically significant trend was seen only for CVD all criteria (t = 3.63, p < 0.036). These trends were borderline significant for CHD any criterion (t = 2.92, p < 0.06) and not significant for CHD hard criteria (t = 2.23, p < 0.11). In multivariate models, adjusted for 8 other risk factors, serum uric acid showed a statistically significant contribution to predict CVD incidence [relative risk (RR) for 92 micromol/l difference of 1.24 with 95% confidence intervals (CI) 1.05-1.45], whereas the statistical contribution to predict CHD any criterion (RR = 1.19 with CI 0.98-1.45) and CHD hard criteria (RR = 1.20 with CI 0.93-1.55) was not significant. Diuretic treatment and blood urea, as further confounders, were positively and significantly related to event incidence (RR ranging from 1.21 to 2.00) but serum uric acid maintained its independent and statistically significant role in the prediction of CVD events (RR = 1.18 with CI 1.00-1.39). Presence of specific treatments to lower serum uric acid levels (in 1.13% of the population), tested as final confounders, was not statistically contributory. CONCLUSIONS: Increased serum uric acid levels are independently and significantly associated with risk of CVD events in the 6-year follow-up of the Gubbio Study. Longer follow-up is needed before the contributory role of serum uric acid can be properly assessed to explain CHD incidence.

Adult↗

PubMed2001

Spontaneous remission in adult patients with de novo myelodysplastic syndrome: a possible event.

BACKGROUND AND OBJECTIVES: Spontaneous remission (SR) in de novo myelodysplastic syndromes (MDS) is a rare event, which has been so far described only in children with monosomy 7. The phenomenon is extremely heterogeneous, perhaps depending on different pathogeneses of the disease. DESIGN AND METHODS: We retrospectively evaluated the outcome of 564 consecutive adult patients with primary MDS diagnosed at our Institution in a 12-year period. SR was defined as an unexpected improvement lasting more than 1 year without concomitant treatments other than vitamins or low-dose steroids (in patients with platelets < 50 x 10(9)/L). RESULTS: Nine cases of SR were observed in 3 males and 6 females (median age 38.7 years). At diagnosis, all patients had Hb levels < 10 g/dL and 8/9 required packed red cell transfusions. The median time from diagnosis to SR was 18 months (range 4-46) and all patients had normalization of peripheral blood parameters: in 2 out of 3 patients with karyotypic abnormalities at onset, a cytogenetic remission was documented. The median duration of SR was 56 months; 5 patients are still in SR and 4 patients have relapsed (1 as MDS and 3 as acute myeloid leukemia). INTERPRETATION AND CONCLUSIONS: SR is a rare (less than 2% in our experience) but possible event also in adult MDS patients. It should be kept in mind in the evaluation of experimental treatments for MDS in which very low rates of complete responses are expected.

Adult↗

PubMed2001

Benefits of sustained moderate weight loss in obesity.

Over the last few years, weight loss has been recognised as a key factor in the control and prevention of coronary heart disease, hypertension, type 2 diabetes, hyperlipidaemia, cardiorespiratory failure and other chronic degenerative diseases. It has been shown that even a modest loss of 5% of initial body weight can reduce, eliminate or prevent these disorders in a large proportion of overweight patients. The early benefits of weight loss can be explained by the direct effects of a low calorie diet, but the long-term effects can only partially be attributed to diet, physical exercise or behavioural modifications. Long-term studies have shown that a sustained moderate weight loss of 10% improves glycemic control as a result of reduced insulin resistance, the better control or prevention of hypertension, increased HDL-and decreased LDL-cholesterol and VLDL triglycerides, improved diastolic function and the propagation of a cardiac stimulus that reduces the risk of ventricular arrhythmias. The health benefits of modest weight loss are particularly evident and useful when excess body fat is a major health hazard, as in the case of class III obesity (BMI > 40 kg/m2), which is often characterised by prevalent visceral fat accumulation. Baseline serum glucose, cholesterol, triglyceride, uric acid and blood pressure levels are usually higher in the upper body than is the case in peripheral obesity, and tend to decrease more in response to moderate weight loss. A therapeutic programme aimed at obtaining a gradual and moderate weight loss avoids the complications due to the rapid weight loss associated with inappropriate, unbalanced diets or even more harmful treatments. These complications include cholelithiasis and the subsequent risk of cholecystitis, lean body mass loss and a stable decrease in energy expenditure with a high probability of regaining weight (weight cycling syndrome). In conclusion, a large number of obese patients may be sensitive to a modest weight loss even without the achievement of ideal body weight. Sustained moderate weight loss by itself is definitely beneficial in obesity (especially "malignant" and "morbid" obesity), but also in diabetes, hypertension, hyperlipidaemia, cardiorespiratory diseases and other chronic degenerative diseases associated with any degree of excess body fat.

Cholelithiasis↗

PubMed2000

Tamoxifen but not 4-hydroxytamoxifen initiates apoptosis in p53(-) normal human mammary epithelial cells by inducing mitochondrial depolarization.

Despite the widespread clinical use of tamoxifen as a breast cancer prevention agent, the molecular mechanism of tamoxifen chemoprevention is poorly understood. Abnormal expression of p53 is felt to be an early event in mammary carcinogenesis. We developed an in vitro model of early breast cancer prevention to investigate how tamoxifen and 4-hydroxytamoxifen may act in normal human mammary epithelial cells (HMECs) that have acutely lost p53 function. p53 function was suppressed by retrovirally mediated expression of the human papillomavirus type 16 E6 protein. Tamoxifen, but not 4-hydroxytamoxifen, rapidly induced apoptosis in p53(-) HMEC-E6 cells as evidenced by characteristic morphologic changes, annexin V binding, and DNA fragmentation. We observed that a decrease in mitochondrial membrane potential, mitochondrial condensation, and caspase activation preceded the morphologic appearance of apoptosis in tamoxifen-treated early passage p53(-) HMEC-E6 cells. p53(-) HMEC-E6 cells rapidly developed resistance to tamoxifen-mediated apoptosis within 10 passages in vitro. Resistance to tamoxifen in late passage p53(-) HMEC-E6 cells correlated with an increase in mitochondrial mass and a lack of mitochondrial depolarization and caspase activation following tamoxifen treatment. We hypothesize that an early event in the induction of apoptosis by tamoxifen involves mitochondrial depolarization and caspase activation, and this may be important for effective chemoprevention.

Anticarcinogenic Agents↗

PubMed2000

Flow cytometric detection of HLA-specific antibodies as a predictor of heart allograft rejection.

BACKGROUND: Historically, panel reactive antibody (PRA) analysis to detect HLA antibodies has been performed using cell-based complement-dependent cytotoxicity (CDC) techniques. Recently, a flow cytometric procedure (FlowPRA) was introduced as an alternative approach to detect HLA antibodies. The flow methodology, using a solid phase matrix to which soluble HLA class I or class II antigens are attached is significantly more sensitive than CDC assays. However, the clinical relevance of antibodies detected exclusively by FlowPRAhas not been established. In this study of cardiac allograft recipients, FlowPRA was performed on pretransplant sera with no detectable PRA activity as assessed by CDC assays. FlowPRA antibody activity was then correlated with clinical outcome. METHODS: PRA analysis by anti-human globulin enhanced (AHG) CDC and FlowPRA was performed on sera corresponding to final cross-match specimens from 219 cardiac allograft recipients. In addition, sera collected 3-6 months posttransplant from 91 patients were evaluated. The presence or absence of antibodies was correlated with episodes of rejection and patient survival. A rejection episode was considered to have occurred based on treatment with antirejection medication and/or histology. RESULTS: By CDC, 12 patients (5.5%) had pretransplant PRA >10%. In contrast, 72 patients (32.9%) had pretransplant anti-HLA antibodies detectable by FlowPRA (34 patients with only class I antibodies; 7 patients with only class II antibodies; 31 patients with both class I and class II antibodies). A highly significant association (P<0.001) was observed between pretransplant HLA antibodies detected by FlowPRA and episodes of rejection that occurred during the first posttransplant year. Fifteen patients died within the first year posttransplant. Of nine retrospective flow cytometric cross-matches that were performed, two were in recipients who had no pretransplant antibodies detectable by FlowPRA. Both of these cross-matches were negative. In contrast, five of seven cross-matches were positive among recipients who had FlowPRA detectable pretransplant antibodies. Posttransplant serum specimens from 91 patients were also assessed for antibodies by FlowPRA. Among this group, 58 patients had FlowPRA antibodies and there was a trend (although not statistically significant) for a biopsy documented episode of rejection to have occurred among patients with these antibodies. CONCLUSIONS: Collectively, our data suggest that pre- and posttransplant HLA antibodies detectable by FlowPRA and not AHG-CDC identify cardiac allograft recipients at risk for rejection. Furthermore, a positive donor reactive flow cytometric cross-match is significantly associated with graft loss. Thus, we believe that detection and identification of HLA-specific antibodies can be used to stratify patients into high and low risk categories. An important observation of this study is that in the majority of donor:recipient pairs, pretransplant HLA antibodies were not directed against donor antigens. We speculate that these non-donor-directed antibodies are surrogate markers that correspond to previous T cell activation. Thus, the rejection episodes that occur in these patients are in response to donor-derived MHC peptides that share cryptic determinants with the HLA antigens that initially sensitized the patient.

Antibodies↗

PubMed2000

A new morphologic classification system for acute promyelocytic leukemia distinguishes cases with underlying PLZF/RARA gene rearrangements.

Acute promyelocytic leukemia (APL) is typified by the t(15;17) translocation, which leads to the formation of the PML/RARA fusion gene and predicts a beneficial response to retinoids. However, approximately 10% of all APL cases lack the classic t(15;17). This group includes (1) cases with cryptic PML/RARA gene rearrangements and t(5;17) that leads to the NPM/RARA fusion gene, which are retinoid-responsive, and (2) cases with t(11;17)(q23;q21) that are associated with the PLZF/RARA fusion gene, which are retinoid-resistant. A key issue is how to rapidly distinguish subtypes of APL that demand distinct treatment approaches. To address this issue, a European workshop was held in Monza, Italy, during June 1997, and a morphologic, immunophenotypic, cytogenetic, and molecular review was undertaken in 60 cases of APL lacking t(15;17). This process led to the development of a novel morphologic classification system that takes into account the major nuclear and cytoplasmic features of APL. There were no major differences observed in morphology or immunophenotype between cases with the classic t(15;17) and those with the cryptic PML/RARA gene rearrangements. Auer rods were absent in the t(5;17) case expressing NPM/RARA. Interestingly, this classification system distinguished 9 cases with t(11;17)(q23;q21) and, in addition, successfully identified 2 cases lacking t(11;17), which were subsequently shown to have underlying PLZF/RARA fusions. The PLZF/RARA cases were characterized by a predominance of blasts with regular nuclei, an increased number of Pelger-like cells, and by expression of CD56 in 4 of 6 cases tested. Use of this classification system, combined with an analysis for CD56 expression, should allow early recognition of APL cases requiring tailored molecular investigations. (Blood. 2000;96:1287-1296)

DNA-Binding Proteins↗

PubMed2000

Rostral ventrolateral medulla opioid receptor activation modulates glutamate release and attenuates the exercise pressor reflex.

We previously reported that the administration of [D-Ala(2)]methionine enkephalinamide (DAME), an opioid receptor agonist, into the rostral (RVLM) but not into the caudal ventrolateral medulla (CVLM), attenuated increases in mean arterial pressure (MAP) and heart rate (HR) during static muscle contraction that had been blocked by prior microdialysis of the opioid receptor antagonist, naloxone [Am. J. Physiol. 274 (1998) H139-H146]. In this study, we determine whether this RVLM-mediated opioidergic-modulation of cardiovascular responses is associated with localized changes in extracellular concentrations of glutamate, an excitatory amino acid, using microdialysis techniques in anesthetized rats. Muscle contraction increased MAP and HR by 37+/-5 mmHg and 23+/-3 bpm, respectively. Extracellular glutamate concentrations, determined using HPLC-ECD, increased from 0.8+/-0.2 to 6.6+/-1.2 ng/5 microliter in the bilateral RVLM areas. Microdialysis of DAME (100 microM) for 30 min attenuated the contraction-evoked increases in MAP, HR, and glutamate levels (20+/-4 mmHg, 10+/-2 bpm, and 1.8+/-0.2 ng/5 microliter, respectively). After microdialysis of naloxone (100 microM) for 30 min into the RVLM, muscle contraction blocked the attenuations (35+/-5 mmHg, 26+/-4 bpm, and 5.8+/-1.0 ng/5 microliter, respectively). Developed muscle tensions were similar throughout the protocol (676+/-38, 678+/-37 and 687+/-37 g, respectively). These results suggest that an opioidergic receptor-mediated mechanism within the RVLM attenuates cardiovascular responses during static exercise via modulating extracellular concentrations of glutamate in the RVLM.

Animals↗

PubMed2000

Caspase-2 is localized at the Golgi complex and cleaves golgin-160 during apoptosis.

Caspases are an extended family of cysteine proteases that play critical roles in apoptosis. Animals deficient in caspases-2 or -3, which share very similar tetrapeptide cleavage specificities, exhibit very different phenotypes, suggesting that the unique features of individual caspases may account for distinct regulation and specialized functions. Recent studies demonstrate that unique apoptotic stimuli are transduced by distinct proteolytic pathways, with multiple components of the proteolytic machinery clustering at distinct subcellular sites. We demonstrate here that, in addition to its nuclear distribution, caspase-2 is localized to the Golgi complex, where it cleaves golgin-160 at a unique site not susceptible to cleavage by other caspases with very similar tetrapeptide specificities. Early cleavage at this site precedes cleavage at distal sites by other caspases. Prevention of cleavage at the unique caspase-2 site delays disintegration of the Golgi complex after delivery of a pro-apoptotic signal. We propose that the Golgi complex, like mitochondria, senses and integrates unique local conditions, and transduces pro-apoptotic signals through local caspases, which regulate local effectors.

Apoptosis↗