Coeliac haemodynamic effects of endothelin-1, endothelin-3, proendothelin-1 [1-38] and proendothelin-3 [1-41] in conscious rats.

1. Conscious, chronically-instrumented, Long Evans rats were given bolus doses of endothelin-1, endothelin-3 (both at 0.01 and 0.1 nmol kg-1), proendothelin-1 [1-38] and proendothelin-3 [1-41] (both 0.1 and 1 nmol kg-1) in order to compare their effects on coeliac haemodynamics, because it has been reported that, in conscious dogs, endothelin-1 has paradoxical, prolonged hyperaemic vasodilator effects in this vascular bed. Measurements were made also of mesenteric and hindquarters haemodynamics for comparison. In a separate experiment, endothelin-1 (0.1 nmol kg-1) was given before and 20 min after the onset of an infusion of mecamylamine (50 mumol kg h-1) to ensure that the responses measured were not confounded by rapid reflex changes in autonomic activity. 2. None of the peptides caused any increases in coeliac flow or any sustained rises in coeliac vascular conductance, although such changes were clear-cut in the hindquarters vascular bed following the higher dose of endothelin-1 and endothelin-3. In animals treated with mecamylamine the regional haemodynamic effects of the higher dose endothelin-1 were not different from those in animals with intact baroreflexes. 3. Although the lower dose of both endothelin-1 and endothelin-3 caused less marked coeliac, than mesenteric vasoconstriction, this difference was not apparent with the higher dose of the peptides, or with proendothelin-1 [1-38]. However, proendothelin-3 [1-41] had less marked coeliac and hindquarters vasoconstrictor effects than proendothelin-1 [1-38], in spite of both peptides causing similar changes in mesenteric haemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of the antimigraine compound zolmitriptan ('Zomig') on psychomotor performance alone and in combination with diazepam in healthy volunteers

Zolmitriptan (Zomig^TM) is a 5HT_1B/1D agonist which has the ability to cross the intact blood-brain barrier to access central as well as peripheral receptors. Because of the potential for central nervous system side effects, this randomized, double-blind, placebo-controlled, 6-period crossover study evaluated the effects of 2.5 and 5 mg doses of zolmitriptan on psychomotor performance and investigated any pharmacodynamic or pharmacokinetic interaction with diazepam. Twelve healthy volunteers received the following "treatments" as single doses: zolmitriptan 2.5 mg, zolmitriptan 5 mg, diazepam 10 mg, zolmitriptan 2.5 mg+diazepam 10 mg, zolmitriptan 5 mg+diazepam 10 mg and placebo. Pre-dose and at 1, 4, 8, and 24 h post-dose, the following validated battery of psychomotor tests was performed: Bond-Lader visual analogue scales (calmness, contentedness, and alertness factors), critical flicker fusion test, choice reaction time (recognition, motor, and total reaction times), finger-tapping test, number cancellation test and digit symbol substitution test. Plasma concentrations of zolmitriptan, its active metabolite, and diazepam and its active metabolites were measured at the same timepoints. Zolmitriptan 2.5 and 5 mg had no effect on psychomotor function when given alone. In contrast, diazepam 10 mg had profound effects, consistent with its sedative properties, but there was no synergism on concomitant administration of either dose of zolmitriptan. Plasma concentrations of zolmitriptan, diazepam, and their respective active metabolites were similar when the two drugs were given alone or in combination.     

Surgical management of upper lid entropion.

One hundred and eighty-three surgical procedures were conducted on 107 patients over seven years. 91% of the cases of upper lid entropion were corrected satisfactorily with only one operation. It is postulated that this level of success is achieved by grading the degree of surgical intervention according to the clinical established on systematic examination of upper lid entropion.     

Inhibition of the haemodynamic effects of angiotensin II in conscious rats by AT2-receptor antagonists given after the AT1-receptor antagonist, EXP 3174.

1. Conscious, Long Evans rats (n = 10), chronically instrumented for the measurement of regional haemodynamics, were studied on 3 consecutive experimental days to assess responses to angiotensin II (AII) (125 pmol kg-1, i.v.) and noradrenaline (1 nmol kg-1, i.v.) in the absence and presence of the AT2-receptor antagonist, PD 123319 (10 mg kg-1, i.v.) (day 1), the AT1-receptor antagonist, EXP 3174 (1 mg kg-1, i.v.) (day 2), and PD 123319 (10 mg kg-1, i.v.) given 24 h after EXP 3174 (day 3). 2. In naive rats (day 1), PD 123319 did not antagonize the haemodynamic effects of AII or noradrenaline. EXP 3174 (day 2) caused a marked, prolonged blockade of the haemodynamic effects of AII but not those of noradrenaline. Twenty four h after administration of EXP 3174 (day 3) there was still significant attenuation of the haemodynamic effects of AII. However, administration of PD 123319 at this time caused a further inhibition (lasting 1 h) of the effects of AII but not those of noradrenaline. 3. An identical 3 day protocol was used in a separate group of rats (n = 6) in which the AT2-receptor antagonist, PD 123177, was given instead of PD 123319, and the results were essentially the same, i.e., PD 123177 significantly attenuated the haemodynamic effects of AII but only when given 24 h after EXP 3174.(ABSTRACT TRUNCATED AT 250 WORDS)     

Echinomycin (NSC 526417) in recurrent and metastatic nonsquamous cell carcinoma of the cervix. A phase II trial of the Gynecologic Oncology Group.

Eighteen evaluable patients with recurrent or metastatic nonsquamous carcinoma of the uterine cervix were treated with 1,500 micrograms/m2 of echinomycin every 4 weeks. Seven patients had received prior chemotherapy. There was one complete response (5.6%), 95% confidence interval for response of 0-27%. The major toxicity was nausea and vomiting, which was moderate to severe in eight patients. Myelosuppression was minimal. Echinomycin in this dose and schedule displays minimal activity in patients with advanced nonsquamous carcinoma of the cervix.     

A survey of New Zealanders with tinnitus.

A sample of 338 New Zealanders regularly experiencing tinnitus completed questionnaires posted to associations for people with tinnitus or hearing impairment. Nearly half the sample was sometimes depressed by tinnitus; those reporting depression and those reporting more severe problems as a consequence of their tinnitus saw more health-care professionals and used more coping strategies. Most respondents did not remember exactly when they first noticed their tinnitus; those that did reported a range of events that might have precipitated it. Respondents who sought medical help generally rated professionals as sympathetic, but few had been offered effective treatment. Comparison of the tinnitus sample with a sample of university students and staff indicated that though the respondents of the university sample often had some experience of tinnitus they reported sensations rather different from those of the tinnitus sample.     

Characterization of three species of nucleocapsids of equine herpesvirus type-1 (EHV-1).

Three distinct species of nucleocapsids of equine herpesvirus type-1 (EHV-1) were isolated from infected L-M cell nuclei. The particles were classified on the basis of their densities in Renografin gradients as Light (L; ? = 1.237 g/cc), Intermediate (I; ? = 1.244 g/cc), and Heavy (H; ? = 1.258 g/cc). Analysis of the three nucleocapsid species, radioactively labeled with an ³H-labeled or ¹⁴C-labeled amino acid mixture, by discontinuous SDS-polyacrylamide-gel electrophoresis revealed significant and reproducible differences in their structural protein compositions. H nucleocapsids were comprised of six major proteins (I, II, III, IV, IVa, and V) with respective molecular weights of 148,000, 59,000, 46,000, 37,000, 30,000, and 18,000; these proteins comprised 63.7, 9.3, 6.0, 10.8, 5.3, and 4.1%, respectively, of total protein. These six proteins were also present in I nucleocapsids, however nucleocapsid protein IVa (MW, 30,000) was present only as a minor component and comprised less than 1% of total protein. L nucleocapsids were comprised of only four of these major structural proteins, as proteins III (MW, 46,000) and IVa (MW, 30,000) were absent. In addition, several minor proteins, each comprising less than 1% of total nucleocapsid protein, were present in each nucleocapsid species.Electrophoretic analysis of nucleocapsids labeled with [³H]arginine indicated that proteins extremely rich in arginine are not present in these three species. Phosphoproteins both of enveloped virions and of nucleocapsids were identified by electrophoretic analysis of particles radioactively labeled with inorganic phosphate (H₃³²PO₄). Twelve virion structural proteins were phosphorylated in vivo; five of these, including the major virion phosphoprotein VP 10 (MW, 127,000), were envelope specific proteins. Four of these 12 viral proteins were also phosphorylated in nucleocapsids, however the pattern of phosphorylation of nucleocapsid proteins varied among the three species. The two major phosphoproteins of nucleocapsids were proteins III and IVa which are absent in L nucleocapsids; protein V is phosphorylated only in H nucleocapsids.Analysis of the DNA content of the three nucleocapsid species indicated that preparations of H nucleocapsids contain more DNA than do those of the I and L species. Electron microscopic analysis of the nucleocapsids supported these results, as L and I nucleocapsids lack a dense inner nucleoid structure characteristic of the H species.     

PCR analysis of pulsed-field gel electrophoresis-purified plastid DNA,a sensitive tool to judge the hetero-/homoplastomic status of plastid transformants

The genetic transformation of plastids of higher plants has developed into a powerful approach for both basic research and biotechnology. Due to the high copy number of the plastid genome per plastid and per cell, repeated cycles of shoot regeneration under conditions selective for the modified plastid chromosome are required to obtain transformants entirely lacking wild-type plastid genomes. The presence of promiscuous plastid DNA in nuclear and/or mitochondrial genomes that generally contaminate even gradient-purified plastid fractions reduces the applicability of the highly sensitive PCR approach to monitor the absence of residual wild-type plastid chromosomes in transformed lines. It is therefore difficult, or even impossible, to assess reliably the hetero- or homoplastomic state of plastid transformants in this manner. By analysing wild-type and transplastomic mutants of tobacco, we demonstrate that separation of plastid chromosomes isolated from gradient-purified plastid fractions by pulsed-field gel electrophoresis can overcome the problem of (co)amplification of interfering promiscuous plastid DNA. PCR analyses with primers specific for plastid, mitochondrial and nuclear genes reveal an impressive purity of such plastid DNA fractions at a detection limit of less than one wild-type plastid chromosome copy per ten transplastomic cells.     

Elongation of very long-chain fatty acids is enhanced in X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (X-ALD) is a progressive neurodegenerative disorder characterized by the accumulation of saturated and mono-unsaturated very long-chain fatty acids (VLCFA) and reduced peroxisomal VLCFA beta-oxidation activity. In this study, we investigated the role of VLCFA biosynthesis in X-ALD fibroblasts. Our data demonstrate that elongation of both saturated and mono-unsaturated VLCFAs is enhanced in fibroblasts from patients with peroxisomal beta-oxidation defects including X-ALD, and peroxisome biogenesis disorders. These data indicate that enhanced VLCFA elongation is a general phenomenon associated with an impairment in peroxisomal beta-oxidation, and not specific for X-ALD alone. Analysis of plasma samples from patients with X-ALD and different peroxisomal beta-oxidation deficiencies revealed increased concentrations of VLCFAs up to 32 carbons. We infer that enhanced elongation does not result from impaired peroxisomal beta-oxidation alone, but is due to the additional effect of unchecked chain elongation. We demonstrate that elongated VLCFAs are incorporated into complex lipids. The role of chain elongation was also studied retrospectively in samples from patients with X-ALD previously treated with "Lorenzo's oil." We found that the decrease in plasma C26:0 previously found is offset by the increase of mono-unsaturated VLCFAs, not measured previously during the trial. We conclude that evaluation of treatment protocols for disorders of peroxisomal beta-oxidation making use of plasma samples should include the measurement of saturated and unsaturated VLCFAs of chain lengths above 26 carbon atoms. We also conclude that chain elongation offers an interesting target to be studied as a possible mode of treatment for X-ALD and other peroxisomal beta-oxidation disorders.     

Analysis of very long-chain fatty acids using electrospray ionization mass spectrometry

Elevated levels of very long-chain fatty acids (VLCFA) in plasma and tissues are the biochemical hallmark for patients with X-linked adrenoleukodystrophy (X-ALD). Current methods for the determination of VLCFA levels are laborious and time-consuming. We describe a rapid and easy method using electrospray ionization mass spectrometry (ESI-MS) with deuterated internal standards. VLCFA are hydrolyzed, extracted, and quantified in less than 4h. This includes 2h of hydrolysis and 4min of quantification. We validated the method by analyzing 60 plasma samples from controls and patients with X-ALD or Zellweger syndrome using both the ESI-MS protocol and an established method for VLCFA analysis using gas chromatography (GC). The C26:0 concentrations determined with ESI-MS in plasma and fibroblasts of X-ALD patients are in good agreement with those reported previously for GC and GC-MS. Besides saturated straight chain VLCFA, we also determined the concentrations of the mono-unsaturated VLCFA C24:1 and C26:1 and established that while C24:1 levels are not elevated, C26:1 levels are elevated in both plasma and fibroblasts from X-ALD patients.