Non-invasive Assessment of Coronary Flow Velocity Reserve: A New Method Using Transthoracic Doppler Echocardiography

Coronary flow reserve (CFR) has been used toassess coronary microcirculation and epicardial coro-nary stenoses[1— 3 ] . CFR is defined as the ratio ofcoronary flow under maximal coronary vasodilatationto coronary flow under resting conditions[4 ] .Whenthe cross- sectional area of epicardial coronary arteriesis constant,coronary flow velocity (CFV) ratios areequal to volume flow ratios.The most common method used clinically formeasuring CFVR is intracoronary Doppler flow(ICD) analysis re…     

Primary hyperparathyroidism. Pathogenesis--diagnosis--therapy]

A report is given on 33 patients with primary hyperparathyroidism who underwent surgical treatment in our institution in the period from 1980 to 1989. In 57 per cent of the cases a hypercalcaemic syndrome was present. The primary hyperparathyroidism manifested itself in 75 per cent at the kidneys in the form of nephrolithiasis. One third of the patients showed a renal manifestation form exclusively. Remarkable is the relatively high number of exclusively gastrointestinal manifestations (11 per cent). In all patients the diagnosis was established on the coincidence of hypercalcaemia and increased parathormone in the serum. Preoperative localization diagnostics by means of parathyroid sonography, computed tomography and scintigraphy yielded unsatisfactory results. A satisfactory accuracy with regard to the lateral localization of the hyperfunctioning parathyroid tissue can presently be achieved only by selective catheterization of the cervical vein with determination of the parathormone. 35 patients clinically suspected of having primary hyperparathyroidism were subjected to a total of 44 operative interventions, i.e., apart from 35 primary operations, 7 secondary and 2 tertiary interventions. Of the 35 primary operations, 10 (28.6 per cent) were without success. This was due to 2 misdiagnoses and 8 cases with insufficient intraoperative exploration and premature discontinuation of the operation. In 67 per cent of the cases, there was a predominance of the solitary parathyroid adenoma, which was chiefly located at the dorsal lower thyroid poles. In order to reduce the number of unsuccessful primary interventions, a surgically-tactical approach is recommended.     

Molecular cloning, characterization, and overexpression of ERG7, the Saccharomyces cerevisiae gene encoding lanosterol synthase.

We report the cloning, characterization, and overexpression of Saccharomyces cerevisiae ERG7, which encodes lanosterol synthase [(S)-2,3-epoxysqualene mutase (cyclizing, lanosterol forming), EC 5.4.99.7], the enzyme responsible for the complex cyclization/rearrangement step in sterol biosynthesis. Oligonucleotide primers were designed corresponding to protein sequences conserved between Candida albicans ERG7 and the related Arabidopsis thaliana cycloartenol synthase [(S)-2,3-epoxysqualene mutase (cyclizing, cycloartenol forming), EC 5.4.99.8]. A PCR product was amplified from yeast genomic DNA using these primers and was used to probe yeast libraries by hybridization. Partial-length clones homologous to the two known epoxysqualene mutases were isolated, but a full-length sequence was found neither in cDNA nor genomic libraries, whether in phage or plasmids. Two overlapping clones were assembled to make a functional reconstruction of the gene, which contains a 2196-bp open reading frame capable of encoding an 83-kDa protein. The reconstruction complemented the erg7 mutation when driven from either its native promoter or the strong ADH1 promoter.     

Auditory brainstem evoked potentials in leprosy

An electrophysiological study of conduction in the auditory nerve and brainstem auditory pathways using the brainstem auditory evoked potential was undertaken in a group of 47 leprosy patients. There were no statistically significant differences between mean conduction times (interpeak latencies) in the leprosy and the control groups. Abnormal interpeak latencies were encountered in 3 leprosy patients, 1 of whom had a positive serological test for syphilis. In the remaining 2 patients, caudal pathway dysfunction (I-III interpeak latency abnormality) was indicated but specific auditory nerve involvement (an abnormally prolonged I-II interpeak latency) was not demonstrated. An explanation for these findings, other than the patients' disease, was not apparent.     

The effects of anticholinergics on the photopalpebral reflex, memory and mood

This study investigated central anticholinergic drug effects on: (1) the Randt Memory Test, a relatively new instrument which measures the acquisition and recall of verbal and pictorial information; (2) the averaged photopalpebral reflex (PPR), an electrophysiological parameter, the validity of which needs to be further investigated in pharmacological research and; (3) mood as measured by a 16-item visual analogue scale. Atropine (1 mg and 2 mg), pirenzepine (20 mg) and a placebo were administered intramuscularly in a double-blind cross-over trial in eight healthy volunteers. There were no inter-treatment differences on the Randt Memory Test. This finding is seemingly in contrast to those reported by some authors using other memory tests. In contrast to the reported effects of some benzodiazepines, the anticholinergics used in the present study did not prolong the latencies of the PPR, but reduced the amplitudes. Visual analogue scales indicated central effects for both pirenzepine and atropine. This implies pirenzepine's penetration of the blood-brain barrier and a physiological function for central muscarinic-1-receptors. The significant anticholinergic effects were exclusive to the "alertness" factor.