Platelet serotonin transporter in coeliac disease

Abstract We investigated a peripheral serotonergic marker, i.e. platelet tritiated imipramine (³H-IMI) binding sites, which are part of the 5-HT transporter complex similar to that present in the brain, in 20 patients affected by coeliac disease (CD), as compared with 20 healthy controls. Platelet membranes and ³H-IMI binding were carried out according to a standardized protocol. The results showed that coeliac patients had significantly lower H-IMI binding sites than controls. This finding would suggest the presence of a dysfunction at the level of the 5-HT transporter that might underline the psychic disturbances frequently observed in coeliac patients.     

前庭神经切断术中内镜技术的应用

目的　探讨经乙状窦后径路行前庭神经切断术 (vestibularneurotomy ,VNT)控制梅尼埃病眩晕症状中 ,辅助应用内镜微创技术的方法及其减轻术中脑组织压迫和减少术后并发症发生率的价值和意义。方法　临床观察乙状窦后径路常规VNT( 12例 )与辅助应用内镜技术VNT( 9例 )的 2组手术患者手术前后症状控制效果、面神经功能及其听觉和前庭生理功能变化结果。结果　常规VNT组患者术后有 2例发生脑水肿 ,需行脱水、降压等处理 ;平均听阈上升>15dB者 2例 ;平衡功能代偿所需时间平均为 ( 2 9.0 0± 9.60 )天。辅助应用内镜的VNT组术后平均听阈上升 >15dB者 2例 ;平衡功能代偿所需时间平均为 ( 2 8.5 6± 7.91)天。 2组术后均未出现面瘫等并发症 ;术后 2年内再发作眩晕 ,常规手术组有 2例 (分别发作 1次和 4次 ) ,内镜手术组有 1例 (发作 2次 )。结论　经乙状窦后径路行VNT是目前普遍采用的一种较为方便、安全的控制或消除梅尼埃病患者眩晕症状手术方法 ,同时能保存听觉功能和面神经完整性 ;手术中辅助应用内镜技术 ,使该手术操作成为微创和安全 ,可有效地减轻对脑组织的压迫和减少术后脑水肿发生 ,未出任何由此而导致的并发症     

Ligation of CD69 induces apoptosis and cell death in human eosinophils cultured with granulocyte-macrophage colony-stimulating factor

Peripheral blood (PB) eosinophils rapidly undergo apoptosis and cell death in vitro unless cultured in the presence of cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF) in which their survival is prolonged for up to 10 days. CD69 is a type II membrane antigen expressed by cytokine-activated, but not freshly isolated, PB human eosinophils. We have examined the effect of ligation of CD69 by specific monoclonal antibody (MoAb) on the viability of human eosinophils cultured with recombinant human (rh)GM-CSF. Eosinophils were purified by immunomagnetic selection and cultured with GM-CSF (10(-10) mol/L). Eighteen hours after the start of culture, a panel of CD69 MoAb or controls (anti-CR3 or isotype-matched control MoAb) were added. Viability was assessed by trypan blue exclusion and apoptosis by morphologic assessment, DNA laddering, and flow cytometric analysis of eosinophil red autofluorescence. Up to 50% of the eosinophils had undergone apoptosis 48 hours after addition of anti- CD69 MoAb compared with less than 10% apoptosis for CR3 or the isotype matched control. The majority of apoptotic eosinophils excluded trypan blue at 48 hours post CD69 ligation. More apoptotic eosinophils were observed at later time-points and this was associated with loss of viability. At 120 hours post-addition of the anti-CD69 MoAb MLR3, 24% +/- 10.6% eosinophils were viable compared with 84% +/- 3.4% for the CR3 control (P < .001). A F(ab)2 fragment of CD69 MoAb P8, also induced apoptosis in GM-CSF cultured eosinophils. A more rapid induction of eosinophil apoptosis was obtained with CD69 MoAb immobilized via their Fc portions on protein-A coated plastic 96 well plates. Ligation of CD69 or CR3 resulted in the release of comparable quantities of eosinophil peroxidase at 48 hours post-ligation. These levels of EPO were consistent with the viability of these cells at 48 hours as assessed by exclusion of trypan blue. Finally, a neutralizing MoAb to TGF beta 1 had no effect on CD69-dependent apoptosis induction nor were there detectable quantities of TGF beta 1 in supernatants from GM-CSF-- cultured eosinophils ligated with CD69 or control MoAb. These results suggest that eosinophils cultured with GM-CSF can be induced to undergo apoptosis as a result of cell signalling mediated by perturbation of CD69. This may represent an important physiologic mechanism for eosinophil removal in vivo.     

A randomized controlled trial of pentoxifylline for the prevention of regimen-related toxicities in patients undergoing allogeneic marrow transplantation

This study evaluated the effect of pentoxifylline (PTX) on the incidence of regimen-related toxicity in patients receiving allogeneic marrow transplants from related donors. All patients received a regimen of methotrexate and cyclosporine as prophylaxis against acute graft- versus-host disease (GVHD). Patients were randomized to receive PTX or a placebo for 70 days and the outcome was examined in a blinded fashion. Forty-four patients were evaluate in each study arm. PTX had no significant effect on engraftment, the incidence of GVHD, venocclusive disease of the liver, infection, the need for oxygen, posttransplant survival, or the duration of hospitalization. Patients receiving PTX were significantly more likely to develop major elevations of serum creatinine levels. PTX was poorly tolerated and induced significantly more vomiting than the placebo. PTX as administered in this randomized study was associated with significant toxicity and offered no benefit in reducing transplant-related morbidity or mortality.     

Perturbation of red blood cell membrane rigidity by extracellular ligands

It is known that binding of extracellular antibodies against the major sialoglycoprotein, glycophorin A, reduced the deformability of the red blood cell membrane. This has been taken to result from new or altered interactions between the glycophorin A and the membrane skeleton. We have shown by means of the micropipette aspiration technique that antibodies against the preponderant transmembrane protein, band 3, induce similar effects. A definite but much smaller reduction in elasticity of the membrane is engendered by univalent Fab fragments of the anti-band 3 antibodies. By examining cells genetically devoid of glycophorin A or containing a variant of this constituent, truncated at the inner membrane surface, we have shown that the anti-band 3 antibodies do not act through the band 3-associated glycophorin A. We examined the effect of anti-glycophorin A antibodies on homozygous Wr(a+b-) cells, in which an amino acid replacement in band 3 annihilates the Wright b (Wrb) epitope (comprising sequence elements of glycophorin A and band 3) and thus, by implication disrupts or perturbs the band 3-glycophorin A interaction; these cells show a much smaller response to an anti-glycophorin A antibody than do normal controls. We infer that in this case anti-glycophorin A antibodies exert their rigidifying effect through the associated band 3. Another anti- glycophorin A antibody, directed against an epitope remote from the membrane surface, however, increases the rigidity of both Wr(a+b-) and normal cells. This implies that not all antibodies act in the same manner in modifying the membrane mechanical properties. The effect exerted by anti-band 3 antibodies appears not to be transmitted through the band 3-ankyrin-spectrin pathway because the rigidifying effect of the intact antibody persists at alkaline pH, at which there is evidence that the ankyrin-band 3 link is largely dissociated. The large difference between the effects of saturating concentrations of the divalent and univalent anti-band 3 antibodies implies the existence of an overriding effect on rigidity, resulting from the bifunctionality of the intact antigen. Freeze-fracture electron microscopy shows that the anti-band 3 promotes the formation of small clusters of intra-membrane proteins. Extracellular ligands may in general act by promoting strong or transient interactions between integral membrane proteins, thereby impeding local distortion of the membrane skeletal network in response to shear.     

Mechanical properties of oxygenated red blood cells in sickle cell (HbSS) disease

Little data exist for the mechanical properties of individual irreversible or reversible sickle cells (ISC and RSC, respectively), nor is the process of ISC formation well understood. For oxygenated ISC and density-fractionated RSC, we have used micropipette techniques to measure cell surface area (SA) and volume (V), membrane shear elastic modulus (mu), time constant for viscoelastic shape recovery (tc), and hence to calculate membrane surface viscosity (eta = mu X tc). Volume loss associated with increasing cell density was accompanied by a proportionately smaller surface area decrease; SA/V ratio thus increased for denser cells, with ISC having the highest values. Membrane area loss by fragmentation must thus be accompanied by an accelerated decrease in cell volume. ISC had relatively rigid membranes (mu 130% above normal controls) and tc close to normal values, so that their effective membrane viscosity was more than double control. RSC had viscoelastic properties close to control, but showed wider variation between sickle cell donors and within samples. Measurements on density-separated RSC showed that, on average, mu was nearly constant, but that tc was longer for the densest cells, with their eta approaching ISC levels. A small subpopulation of RSC were found that had mu close to ISC values. Hypotonically swollen ISC (with internal hemoglobin concentration decreased to normal levels) retained their increased membrane stiffness but had markedly decreased tc, so that their eta approached normal values. The results show that elevated hemoglobin concentration influences the viscoelastic behavior of ISC and RSC, but that an irreversible change in membrane elasticity also occurs for ISC. These data suggest that ISC formation occurs via a two- stage process: (1) accelerated volume loss leading to increased cytoplasmic and effective membrane viscosity; (2) a sharp rise in membrane rigidity, presumably linked to membrane structural alteration.     

Demographic characteristics, unreported risk behaviors, and the prevalence and incidence of viral infections: a comparison of apheresis and whole-blood donors. The Retrovirus Epidemiology Donor Study

BACKGROUND: The demographics, deferrable risk behaviors, and the prevalence and incidence of viral infections of apheresis (PH) and whole-blood (WB) donors were compared, to characterize these two populations and to evaluate the relative safety of PH and WB donors in terms of transfusion-transmitted viral infections. STUDY DESIGN AND METHODS: A comparison was made of 36,119 PH donors (> or = 1 PH donation) and 1.38 million WB donors (> or = 1 WB donation) in terms of demographics and the prevalence (/100,000 donors) and incidence (/100,000 person-years) of viral infections, by using data collected at five United States blood collection centers between 1991 and 1994. Deferrable risk behaviors were defined as those risk behaviors that would have resulted in donor deferral, had they been reported. The prevalence of deferrable risk behaviors was estimated by using data collected through an anonymous mail survey. RESULTS: PH donors were older and more likely than repeat (2+ donations) WB donors to be female, white, and United States-born and to have a higher degree of education (p < or = 0.001). The prevalence of any viral infection was 50 percent higher in WB donors than in PH donors (p = 0.04), whereas the incidence of HIV, human T-lymphotropic virus, and hepatitis B surface antigen was nonsignificantly higher in WB donors. The prevalence of deferrable risk behaviors did not differ in the two groups. CONCLUSION: Further studies will be needed to evaluate whether the difference in the prevalence of viral infections observed in this study can be explained by demographic characteristics and patterns of donation frequency.     

Choledochal cyst with large stone cast and portal hypertension

BACKGROUND:Choledochal cysts in adults are more commonly associated with complications such as cystolithiasis,recurrent cholangitis,portal hypertension and malignancy,than in the pediatric age group.METHOD:We report a case of adult choledochal cyst with long-term complication of large stone cast and portal hypertension due to secondary biliary cirrhosis.RESULTS:A 50-year-old patient presented with obstructive jaundice and hepatosplenomegaly.On investigation,she was diagnosed as having a choledochal cyst wit...     

Platelet sulphotransferase activity, plasma sulphate levels and sulphation capacity in patients with migraine and tension headache

Activity of both the M- and P-forms of sulphotransferase (ST) was measured in platelets from patients with migraine, tension headache and controls. Mean PST values were 0.065±0.023 and 0.057±0.052 mnol/mg protein/min for migraine patients with and without aura. The corresponding values for tension headache and controls were 0.122±0.059 and 0.127:0.093 nmol/mg protein/min respectively (p<0.05). Mean MST values were not different for any of the groups, and MST and PST activities measured in two patients during a migraine attack were not significantly altered from baseline levels. Mean plasma inorganic sulphate concentrations and paracetamol metabolitcs were not significantly different in any of the groups studied. The results suggest that PST activity may be a factor in the aetiology of migraine.     

Homozygosity mapping at Alstrom syndrome to chromosome 2p

Alstrom syndrome is a rare autosomal recessive disorder characterized by pigmentary retinal degeneration, sensorineural hearing loss, childhood obesity, non-insulin-dependent diabetes mellitus, hyperlipidemia and chronic nephropathy. Features occasionally observed include acanthosis nigricans, hypogonadism, hypothyroidism, alopecia, short stature and cardiomyopathy. We report here the results of a linkage study in a large French Acadian kindred, as a first step in identifying the molecular basis of Alstrom syndrome. Evidence of a founder effect made if feasible to use a homozygosity mapping strategy to identify the chromosomal location of the Alstrom gene. In a genome- wide screen, haplotype sharing for a region on chromosome 2 was observed in all affected individuals. Two point linkage analysis resulted in a maximum lod score of 3.84 (theta = 0.00) for marker D2S292. By testing additional markers, the disease gene was localized to a 14.9 cM region on chromosome 2p.