Estrogen receptor genotype modulates myocardial perfusion in young men

Most of the effects of estrogens are mediated by estrogen receptors. Vascular endothelial cells and smooth muscle cells express estrogen receptor (ESR1) in both genders. A long genotype group of a common thymine-adenine (TA) dinucleotide repeat polymorphism in the regulatory region of this gene has previously been related to coronary artery disease. The present study examined whether coronary blood flow is affected by this genotype. A total of 49 healthy men were genotyped by PCR and divided into three groups according to median number of the ESR1 promoter TA repeat (=19), i.e., in the short allele genotype group both alleles were of fewer than 19 repeats whereas in the long allele group both alleles were 19 repeats or more. The intermediate group comprised men who had one short and one long allele. Myocardial blood flow was measured by positron emission tomography using [¹⁵O]water, performed at rest and during adenosine stimulation. Men with long alleles had lower adenosine-stimulated coronary flow than those with short alleles and those with one short and one long allelle. Our results suggest that adenosine-stimulated myocardial perfusion is lower in subjects with ESR1 long alleles than the other TA repeat genotypes.     

Human mtDNA sublimons resemble rearranged mitochondrial genoms found in pathological states

Sublimons, originally identified in plant mitochondria, are defined as rearranged mtDNA molecules present at very low levels. We have analysed the primary structures of sublimons found in human cells and tissues and estimated their abundance. Each tissue of a given individual contains a wide range of different sublimons and the most abundant species differ between tissues in a substantially systematic manner. Sublimons are undetectable in rho(0) cells, indicating that they are bona fide derivatives of mtDNA. They are most prominent in post-mitotic tissue subject to oxidative stress. Rearrangement break-points, often defined by short direct repeats, are scattered, but hotspot regions are clearly identifiable, notably near the end of the D-loop. The region between the replication origins is therefore frequently eliminated. One other hotspot region is located adjacent to a known site of protein binding, suggesting that recombination may be facilitated by protein-protein interactions. For a given primary rearrangement, both deleted and partially duplicated species can be detected. Although each sublimon is typically present at a low level, at most a few copies per cell, sublimon abundance in a given tissue can vary over three orders of magnitude between healthy individuals. Collectively, therefore, they can represent a non-negligible fraction of total mtDNA. Their structures are very similar to those of the rearranged molecules found in pathological states, such as adPEO and MNGIE; therefore, we propose that, as in plants, human mtDNA sublimons represent a pool of variant molecules that can become amplified under pathological conditions, thus contributing to cellular dysfunction.     

Post-mortem cast angiography in the diagnostics of graft complications in patients with fatal outcome following coronary artery bypass grafting (CABG)

The advantages and limitations of a novel post-mortem angiographic method using solidifying silicone rubber and lead oxide as a contrast medium in detecting coronary artery graft complications on a routine basis were evaluated in a series of 223 consecutive patients with fatal outcome within 30 days following coronary artery bypass grafting (CABG). Of these patients, 166 (74.4%) were male and 57 (25.6%) female (mean age 61.9 ± 9). Coronary grafts totalled 660 (3.0 per patient) with 517 aortic and 838 coronary anastomoses. At autopsy, the rubber cast model of the grafts and coronary arterial tree was exposed by a bend scalpel and sites of possible complications were examined. Post-mortem angiographs were re-evaluated and compared with preoperative angiographs and dissection findings. By combining the findings of angiography and heart dissection, 122 (54.7%) of the 223 patients were found to have some type of complication of the graft or the anastomosis. The diagnostic sensitivity and specificity of postmortem angiography was 100% in assessing narrowing or twisting of the graft as well as narrowing of the aortal anastomosis, whereas these findings were revealed with difficulty by autopsy dissection only. In cases with correct x-ray projection, narrowing and occlusion of the proximal aortal and distal coronary anastomosis were also reliably revealed by angiography. In contrast, graft thrombosis was clearly overdiagnosed by angiography, leading to a lower specificity (84%) but high sensitivity (100%) in detecting this complication. Post-mortem angiography also failed to detect dissection of the wall of the graft or anastomosis. Technical problems with this angiographic method were due to too low perfusion pressure, too rapid polymerizing of the silicone rubber, leakage of contrast medium into the ventricles, or faulty x-ray projections. These results suggest that our post-mortem angiographic technique, yielding a permanent rubber- cast model of the graft and anastomosis site, improves the accuracy of diagnostics of postoperative CABG complications and eases postoperative autopsy dissection, which can now be directed to confirm suspected complications. Received: 27 October 1997 / Received in revised form: 2 July 1998     

Death following ingestion of MDMA (ecstasy) and moclobemide

Four deaths following the ingestion of moclobemide and MDMA ('ecstasy') are described. The probable cause of death in each case was serotonin syndrome as a result of an interaction between the two drugs. As none of the victims had been prescribed moclobemide it seems that each had taken the drug to enhance the effects of MDMA, with fatal consequences. Warnings are needed against misinformed attempts to potentiate the pharmacological effects of illicit drugs.     

The GPIIIa (beta3 integrin) PlA polymorphism in the early development of coronary atherosclerosis

The GPIIIa (beta3 integrin) is an integral part of two glycoprotein receptors - the GP(IIb/IIIa) fibrinogen receptors in platelets and the GP(V/IIIa) vitronectin receptors in endothelium and vascular smooth muscle cells (vSMC). The PlA polymorphism of the gene for GPIIIa (beta3 integrin) has been suggested to play an important role in the progression of coronary artery disease (CAD) and in coronary thrombosis. Whether the action of the PlA polymorphism is due to differences in platelet aggregability or function of the vSMC and endothelial GPIIIa is not known. The association of the PlA polymorphism with the early, non-complicated atherosclerosis and CAD was studied in the Helsinki Sudden Death Study (HSDS) comprising two independent, autopsy series of altogether 700 middle-aged Caucasian Finnish men (33-70 year) suffering sudden out-of-hospital death. The burden of complicated lesions was greater in men with the A2 allele (heterozygotes or homozygotes for A2) (P=0.01) compared with PlA1/A1 homozygotes in the entire series. To further estimate the role of platelet-independent GPIIIa receptors, we excluded all cases with coronary thrombosis and thrombus-overlaid complicated lesions. In this subset of men, fibrous coronary lesions were more frequent (OR 2.9; P<0.01) in the coronary arteries of PlA1/A1 homozygotes compared with men with the PlA2 allele. Moreover, men with the PlA1/A1 genotype also had more stenotic coronary arteries (P<0.05) compared with men with the A2 allele at this early, non-complicated stage of atherosclerosis. The findings of this study suggest that Pl(A1/A1) homozygotes may be prone to early atherosclerosis and more rapid progression of stable CAD whereas carriers of the PlA2 allele are more prone to thrombotic complications. We hypothesize that the PlA polymorphism may account for the early atherosclerosis by affecting the function of endothelial and vSMC GP(V/IIIa) receptors, whereas the PlA polymorphism on platelet GP(IIb/IIIa) receptors may play a major role in coronary thrombosis.     

Concentrations of metronidazole and tinidazole in female reproductive organs after a single intravenous infusion and after repeated oral administration

Summary Concentrations of metronidazole and tinidazole in serum and gynecological organs were analyzed after a single 500 mg intravenous infusion and after three days of treatment with 400 mg t.i.d. of metronidazole or 500 mg b.i.d. of tinidazole. The studies were performed in 67 patients subjected to hysterectomy and/or oophorectomy because of myomatosis uteri, carcinoma uteri or endometriosis. At the time of organ removal (about 30 min after infusion), metronidazole and tinidazole levels in serum were 14.5 ± 0.45 mg/l and 12.3 ± 0.38 mg/l, respectively. Concentrations of both drugs in the uterus and Fallopian tube were about the same as the simultaneous serum levels and concentrations in the ovaries about 55% thereof. At steady-state, the concentrations of tinidazole in serum (23.5 ± 1.0 mg/l) were remarkably higher than those of metronidazole (13.5 ± 0.84 mg/l) about three hours after the last oral dose. Drug concentrations in organs of the female reproductive tract were 70 to 100% those of the simultaneous serum levels.

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Konzentrationen von Metronidazol und Tinidazol in weiblichen Genitalorganen nach intravenöser Einzelinfusion und wiederholter oraler Gabe

Zusammenfassung Die Konzentrationen von Metronidazol und Tinidazol in Serum und Genitalorganen wurden nach einer intravenösen Einzelinfusion von 500 mg sowie nach dreitägiger oraler Behandlung mit 400 mg Metronidazol dreimal täglich oder 500 mg Tinidazol, zweimal täglich, bestimmt. Die Untersuchungen wurden bei 67 Patientinnen durchgeführt, bei denen eine Hysterektomie und/oder Oophorektomie wegen Myomatosis uteri, Uteruskarzinom oder Endometriose vorgenommen wurde. Zum Zeitpunkt der Organentnahme (etwa 30 min nach Infusion) betrugen die Metronidazol-und Tinidazolspiegel im Serum 14,5 ± 0,45 mg/l bzw. 12,3 ± 0,38 mg/l. Die Konzentrationen der beiden Medikamente im Uterus und in der Tube entsprachen den gleichzeitig bestimmten Serumspiegeln; die Konzentrationen in den Ovarien lagen bei etwa 55% der Serumspiegel. Im Steady state, etwa drei Stunden nach der letzten oralen Dosis, waren die Serumkonzentrationen von Tinidazol mit 23,5 ± 1,0 mg/l erheblich höher als die Metronidazolserumspiegel (13,5 ± 0,84 mg/l). Die Konzentrationen der Medikamente in den weiblichen Genitalorganen lagen bei 70 bis 100% der simultanen Serumspiegel.

     

Analysis of pancreas tissue in a child positive for islet cell antibodies

AIMS/HYPOTHESIS: Type 1 diabetes is caused by an immune-mediated process, reflected by the appearance of autoantibodies against pancreatic islets in the peripheral circulation. Detection of multiple autoantibodies predicts the development of diabetes, while positivity for a single autoantibody is a poor prognostic marker. The present study assesses whether positivity for a single autoantibody correlates with pathological changes in the pancreas. METHODS: We studied post mortem pancreatic tissue of a child who repeatedly tested positive for islet cell antibodies (ICA) in serial measurements. Paraffin sections were stained with antibodies specific for insulin, glucagon, somatostatin, interferon alpha, CD3, CD68, cyclooxygenase-2 (COX-2), beta-2-microglobulin, coxsackie B and adenovirus receptor (CAR), natural killer and dendritic cells. Apoptosis was detected using Fas-specific antibody and TUNEL assay. Enterovirus was searched for using immunohistochemistry and in situ hybridisation, as well as enterovirus-specific RT-PCR from serum samples. RESULTS: The structure of the pancreas did not differ from normal. The number of beta cells was not reduced and no signs of insulitis were observed. Beta-2-microglobulin and CAR were strongly produced in the islets, but not in the exocrine pancreas. Enterovirus protein was detected selectively in the islets by two enterovirus-specific antibodies, but viral RNA was not found. CONCLUSIONS/INTERPRETATION: These observations suggest that positivity for ICA alone, even when lasting for more than 1 year, is not associated with inflammatory changes in the islets. However, it is most likely that the pancreatic islets were infected by an enterovirus in this child.     

Laminin isoforms in fetal and adult human adrenal cortex

Laminin has been proposed to influence the function of human adrenal cortex. We have studied the distribution of laminin (Ln) chains using immunofluorescence in human fetal and adult adrenal cortex. In the fetal gland Ln alpha2- and alpha5-chains were weakly expressed in the definitive zone, whereas Ln alpha4-, beta1-, and gamma1-chains occurred around vessels. In the adult gland, Ln alpha2-, alpha5-, and gamma1-chains were found in epithelial basement membranes (BM) in all cortical zones, Ln alpha4-chain in vessels, Ln beta1-chain in outer zone, and Ln beta2-chain in the two inner zones of the cortex, respectively. Among the integrins in adult gland, integrin alpha(3)-subunit was confined to basal surfaces of cortical cells, alpha(6) to vessels, alpha(1) to the stroma, and alpha(2) diffusely to epithelial cells. Lutheran glycoprotein and dystroglycan occurred in the fetal gland diffusely in the definitive zone and throughout the epithelium in the adult. The isoform composition of BM of the adult adrenal gland is distinct, with Ln-2 and -10 in BM of the outer zone and Ln-4 and -11 in BM of the two inner zones. The results suggest that integrin alpha(3)beta(1) and Lutheran are candidate receptors for Ln-10 and -11, whereas dystroglycan probably binds Ln-2 and -4.