Endothelial lipopigment as an indicator of α-tocopherol deficiency in two equine neurodegenerative diseases

Two spontaneous neurodegenerative diseases of the horse, equine motor neuron disease (EMND) and equine degenerative myeloencephalopathy (EDM), have been associated with -tocopherol deficiency, and both were characterized by prominent accumulations of endothelial lipopigment in the small vessels of the spinal cord. These endothelial pigment deposits appear to be reversible. In EMND horses pasture-supplemented for 9 months or more after the progression of weakness and wasting had arrested, there was very little endothelial lipopigment. The origin and the potential effects of these endothelial lipopigment accumulations are discussed.     

Association of apolipoprotein ɛ4 allele and neuropathologic findings in patients with dementia

Apolipoprotein E (APOE) is a lipoprotein expressed in liver and brain as one of three isoforms (APOE 2, APOE 3 and APOE 4). Recent findings suggest that the presence of APOE 4 is associated with an increased risk for both familial Alzheimer's disease and late-onset Alzheimer's disease. We extended these observations by determining the frequency of APOE alleles in patients with pathologically confirmed Alzheimer's Disease (AD), Parkinson's disease (PD), diffuse Lewy Body disease (DLBD), AD with concomitant PD pathology, demented PD patients without or with concomitant AD pathology and in schizophrenics with a progressive dementia (SCHIZ+DEM). The APOE genotype was determined by restriction digestion of polymerase chain reaction-amplified DNA isolated from frozen brain samples. The frequency of the APOE 4 allele was highest among sporadic AD and DLBD patients (0.30 and 0.38, respectively) and lowest in the SCHIZ+DEM and non-demented PD patients (0.06 and 0.1, respectively). Thus, the APOE 4 allele is over-represented selectively in patients with dementias associated with plaques and tangles and/or cortical Lewy bodies, but not in demented schizophrenics or non-demented PD patients.     

CGRP inhibition of electromechanical coupling in the guinea-pig isolated renal pelvis

We aimed at studying the mechanism(s) of the inhibitory effect exerted by calcitonin gene-related peptide (CGRP) on the spontaneous activity of the guinea-pig isolated renal pelvis. In organ bath experiments, CGRP (1–100 nM) produced a concentration-dependent (EC₅₀ 8 nM) partial inhibition (Emax about 35% inhibition of motility index) of spontaneous contractions. The potassium (K) channel opener, cromakalim (3–10 M) promptly suppressed the spontaneous contractions in a glibenclamide- (10 M) sensitive manner. Glibenclamide (10 M) did not affect the inhibitory action of CGRP. The calcium (Ca) channel agonist, Bay K 8644 (1 M), markedly enhanced the spontaneous activity of the renal pelvis and reduced the inhibitory effect of CGRP. The protein kinase A inhibitors Rp-cAMPS (300 M), H8 (100 M) and H89 (10 M), and the blockers of intracellular Ca handling bysarcoplasmic reticulum, ryanodine (100 M) and thapsigargin (1 M) did not affect the response to CGRP. The response to CGRP was likewise unaffected by the nitric oxide synthase inhibitor, L-nitroarginine (30 M) and by the protein kinase G inhibitor, KT5823 (3 M). Furthermore, the inhibitory action of CGRP was not modified by lowering the extracellular concentration of K (from 5.9 to 1.2 mM) nor by increasing (from 2.5 to 3.75 mM) or decreasing (from 2.5 to 0.25 mM) the extracellular Ca concentration. Replacement of 80% glucose with 2-deoxyglucose (2-DOG) reduced the amplitude of spontaneous contractions, both in the absence and presence of 10 M glibenclamide. In the presence of 2-DOG, the inhibitory action of CGRP was enhanced at a similar extent, either in the absence or presence of glibenclamide. In sucrose gap, the effect of CGRP (0.1 M for 5 min) was separately analyzed in the proximal (close to the kidney) and distal (close to the ureter) regions of the renal pelvis. Both preparations discharged spontaneous (pacemaker) action potentials having different shape, duration and frequency. CGRP had no effect on pacemaker potentials in the proximal renal pelvis while producing about 30% reduction of the frequency of pacemaker potentials and motility index in the distal renal pelvis. Cromakalim (3 M) abolished pacemaker potentials in both regions of the renal pelvis.In conjunction with the results of previous studies in the guinea-pig ureter, the present findings document the existence of remarkable regional differences in the effector mechanisms initiated by CGRP receptor occupancy in the guinea-pig pyeloureteral tract. CGRP appears to be inherently unable to activate glibenclamide-sensitive K channels in the guinea-pig renal pelvis, a mechanism which is central for its ability to suppress latent pacemakers in the ureter. Within the renal pelvis, the sensitivity to the inhibitory effect of CGRP appears in the more distal region, from which an ureter-like action potential is recorded.     

Heterogeneity of Na+/K+-ATPase from rectal gland of Squalus acanthias is not due to α isoform diversity

 Purified Na⁺/K⁺-ATPase (EC 3.6.1.37) isolated from the rectal gland of Squalus acanthias was characterized in ouabain-binding studies and with respect to isoform(s) of the α peptide. To avoid enzyme inactivation [³H]ouabain equilibrium binding was carried out at 20°C. The heterogeneity of Na⁺/K⁺-ATPase isolated from shark rectal gland was similar in [³H]ouabain binding as previously seen in hydrolytic studies. The binding isotherms were compatible with the existence of a high-affinity (K _dis 0.69 nM) and a low-affinity (K _dis 42 nM) component of 1.46 and 0.79 nmol^.(mg protein)^–1, respectively. In Western blots the α peptide of the enzyme hybridized with an isoform-specific polyclonal antibody raised to an α₃-specific region of the large intracellular domain of rat Na⁺/K⁺-ATPase, but not with the supposed α₃-specific monoclonal antibody MA3-915 with its epitope near the N-terminus. Semi-quantitative analysis of the reaction of the α₃-specific polyclonal antibody with the α peptide from the shark enzyme compared to the reaction with α peptide from rat brain enzyme indicated that this region is not exactly the same in the two species. The α peptide of shark enzyme was not recognized by α₁- or α₂-specific polyclonal antibodies, or by the α₁-specific monoclonal antibodies 3B and F6. The large intracellular domain of Na⁺/K⁺-ATPase from shark rectal gland thus seems to be α₃-like and no α isoform heterogeneity seems able to account for the heterogeneity seen in ouabain binding. Received: 7 August 1998 / Accepted: 6 November 1998     

Apolipoprotein E phenotypes in healthy normal controls and demented subjects with Alzheimer's disease and vascular dementia in Mie Prefecture of Japan

In order to clarify the association between apolipoprotein E4 (ApoE4) and the pathogenesis of Alzheimer's disease (AD), we analyzed the distribution of the apolipoprotein E (ApoE) phenotypes and the frequency of the apo E alleles epsilon2, epsilon3, and epsilon4 in Japanese healthy controls (n = 1090, an average age of 51.2+/-12.6 years) and demented patients (n=103, mean age of 73.6+/-9.2 years). Demented subjects were divided into three subgroups: early-onset AD group (EOAD; n=25, mean age 63.0+/-6.2 years), late-onset AD group (LOAD; n=33, mean age 79.3+/-5.1 years), and vascular dementia group (VD; n=45, mean age 75.3+/-8.0 years). The apolipoprotein E phenotype was determined by isoelectric focusing and immunoblotting. There were no significant differences in the distribution of the apo E phenotypes by gender or age, and the estimated frequencies of epsilon2, epsilon3 and epsilon4 were 0.05, 0.86 and 0.09, respectively, in the normal controls. There was a significant difference in the distribution of the apo E phenotypes between LOAD and elderly controls aged more than 65 years (P<0.0001). The distribution of the apo E phenotypes in EOAD was the same as that in LOAD. The frequency of the epsilon4 allele was significantly higher in LOAD (0.35, P<0.0001) and EOAD (0.28, P<0.0001) than that in the control subjects (0.07), but not in VD (0.12, P=0.1630). The present findings suggest that ApoE4 is related with both EOAD and LOAD, but not with VD, and support the hypothesis that it is a genetic risk factor of AD.     

膀胱癌上皮细胞粘附分子蛋白表达的意义

目的 探讨上皮细胞粘附分子（Ｅ－ＣＤ）表达情况对判断膀胱癌恶性程度、复发及预后的意义。方法 采用免疫组织化学方法对５４例膀胱癌标本中Ｅ－ＣＤ的表达情况进行研究。结果Ｅ－Ｃ原表达情况与膀胱癌的病理分级、分期均有密切关系。（ｘ＾２＝６．６５,Ｐ〈０．０５,Ｘ＾２＝７．１５,Ｐ〈０．０１）。Ｅ－ＣＤ的的民光癌的近期昨发及不良预后有关。（Ｘ＾２＝４．８８,Ｐ〈０．０５;Ｌｏｎｇ－Ｒａｎｋ ｔｅｓｔ;ｘ＾２     

An action research investigation into the feasibility of experienced registered sick children's nurses (RSCNs) becoming children's emergency nurse practitioners (ENPs)

• ? Emergency nurse practitioners (ENPs) formally developed in accident and emergency (A & E) departments as a direct response to waiting times for the walking wounded, the need to reduce junior doctors hours and changes in nursing practice.
• ? ENPs existed informally for many years in minor injuries units and specialist ophthalmic departments.
• ? This study aimed to examine whether or not the role of ENP could be applied to the specialist service of a paediatric casualty department.
• ? The results showed that 3% of patients could be seen and treated to conclusion by a children's ENP, and some patients could have their care accelerated by a children's ENP.
• ? The introduction of children's ENPs would have an impact on waiting times, junior doctors work-load and the quality of patient care.