Increased salt retention and hypertension from non-steroidal agents in the elderly

We studied blood pressure and natriuretic responses to acute salt loading, and the effect of non-steroidal anti-inflammatory agents on these responses, in five healthy normotensive women aged 65 to 71 years. Five women aged 25 to 31 years acted as controls. Intravenous saline loading, with and without prior ingestion of ibuprofen, was 15 ml/kg/h for 3 h. Baseline blood pressures were higher in the elderly. Saline infusion without ibuprofen raised systolic blood pressure (SBP) by about 25 mmHg in the older group only. Ibuprofen increased baseline SBP in the elderly (129 +/- 6 vs. 116 +/- 5 mmHg, p < 0.05). Saline loading after ibuprofen again raised blood pressure by about 25 mmHg in the elderly only. The elderly group showed markedly increased sodium excretion during saline loading, but this was reduced by ibuprofen. Ibuprofen had no effect on SBP or sodium excretion in controls. Ageing appears to increase susceptibility to salt retention and hypertension from non-steroidal anti-inflammatory agents.      

Imaging of thoracic aortic dissection

Acute thoracic aortic dissection has a high mortality if untreated, so the diagnosis must be rapidly made if mortality is to be lowered significantly. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause for death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 of 12 patients studied and correctly classified the type in only five. Aortography was performed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were performed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention.     

A double mutant [N543H+2393del9] allele in the LDL receptor gene in familial hypercholesterolemia: effect on plasma cholesterol levels and cardiovascular disease

Familial hypercholesterolemia is a genetic disorder caused by mutations in the LDL receptor gene. During a survey of mutations of LDL receptor gene in Spanish FH patients we found two mutations in the same allele: a missense N543H mutation in exon 11 and a 9bp inframe deletion (2393del9) located in exon 17. This double mutant allele was founded in 10 out of 458 unrelated patients: one homozygous FH [N543H+2393del9] + [N543H+2393del9], one compound heterozygote [N543H+2393del9] + [W-18X+E256K] and 8 heterozygotes. Flow cytometric analysis showed a defective LDL binding (20% of normal value) and internalization (23%) in lymphocytes from the homozygous patient; furthermore, studies of mitogen-stimulated lymphocytes demonstrated that the ability of LDL to support cell proliferation was impaired. Unexpectedly, not all carriers of the double mutant allele develop hypercholesterolemia and, furthermore, cholesterol-lowering treatment of the homozygous patient resulted in a 58% LDL cholesterol reduction. In conclusion, the phenotypic expression in the homozygous and heterozygous patients presented here, as well as the LDL-receptor residual activity, allowed the classification of this mutation as mild extending the group of mild mutations found at homozygosity.     

Distribution of mutations in the PEX gene in families with X-linked hypophosphataemic rickets (HYP)

Mutations in the PEX gene at Xp22.1 (phosphate-regulating gene with homologies to endopeptidases, on the X-chromosome), are responsible for X-linked hypophosphataemic rickets (HYP). Homology of PEX to the M13 family of Zn2+ metallopeptidases which include neprilysin (NEP) as prototype, has raised important questions regarding PEX function at the molecular level. The aim of this study was to analyse 99 HYP families for PEX gene mutations, and to correlate predicted changes in the protein structure with Zn2+ metallopeptidase gene function. Primers flanking 22 characterised exons were used to amplify DNA by PCR, and SSCP was then used to screen for mutations. Deletions, insertions, nonsense mutations, stop codons and splice mutations occurred in 83% of families screened for in all 22 exons, and 51% of a separate set of families screened in 17 PEX gene exons. Missense mutations in four regions of the gene were informative regarding function, with one mutation in the Zn2+-binding site predicted to alter substrate enzyme interaction and catalysis. Computer analysis of the remaining mutations predicted changes in secondary structure, N-glycosylation, protein phosphorylation and catalytic site molecular structure. The wide range of mutations that align with regions required for protease activity in NEP suggests that PEX also functions as a protease, and may act by processing factor(s) involved in bone mineral metabolism.      

Pilot study with 120 mg Andriol treatment for couples with a low fertilization rate during in-vitro fertilization.

Treatment with 120 mg/day of Andriol (testosterone undecanoate; Organon, The Netherlands) was given to 11 men whose semen had either failed to fertilize, or had resulted in a less than 33% fertilization rate in a first in-vitro fertilization (IVF) trial. Repeat IVF at the end of a 3 month treatment period resulted in a highly significant increase in the number of oocytes fertilized from 4/95 (4.2%) before to 23/87 (26.4%, P less than 0.001) after Andriol treatment. One couple attained spontaneous conception during the second month of Andriol intake and three pregnancies occurred among the remaining 10 cases undergoing repeat IVF, for a total ongoing pregnancy rate of 36.4%. Sperm concentration but not motility increased in the native semen after Andriol intake, but there were no significant changes in sperm characteristics after preparation. The improvement in pregnancy rate contrasts favourably with the results obtained by repeat IVF of untreated historical controls. The result obtained in the present pilot study should encourage the performance of a larger, placebo-controlled investigation protocol.     

Evaluation of {beta}-endorphin and interleukin-6 in seminal plasma of patients with certain andrological diseases

Human semen contains large amounts of opioid peptides and cytokines.We have measured the concentrations of interleukin (IL)-6 in140 semen samples and of -endorphinin 77 semen samples. Themedian concentration of endorphinin seminal plasma from normozoospermicmen(n = 23) was 154.7 pg/ml (10th—90th percentiles, 42.0—774.6),and there was no significant difference in the -endorphin concentrationamong normozoospermic, oligozoospermic (n= 28), asthenozoospermic(n= 15), azoospermic(n= 4) and post-vasectomy (n= 7) samples.There was no correlation between -endorphin concentration andsperm characteristics, nor with blood hormones. Endorphinconcentration was lower in cases with immunelogical infertility,as revealed by a positive direct mixedantiglobulin reactiontest (n = 12) ( > 0.01), than inmatched controls. The medianconcentration of IL-6 insamples with normal sperm concentration,motility andmorphology with or without white blood cells (n=39) was 26.1 pg/ml (10th–90th percentiles, 7.3–172.3),and there was no significant difference in the IL-6 concentrationamong normozoospermic, oligozoospermic (n= 46),asthenozoospermic(n= 32), azoospermic (n= 13) and post-vasectomy (n= 10) samples.The IL-6 concentration was significantly higher in cases ofvaricocele (n= 22)without white blood cells in semen (P <0.001) than in matched controls without varicocele (n= 23).In addition, the IL-6 concentration was elevated (P < 0.0001)in cases with accessory sex gland inflammation (n= 40). IL-6concentration was positively correlated with white blood cellsin semen (n= 60, r = 0.59, P < 0.0001), but there was nocorrelation with -endorphin concentration. The IL-6 concentrationchosen to differentiate between cases with and without accessorygland inflammation was 45.3 pg/ml, with a specificity of 80.6%and a sensitivity of 92.5%. It is concluded that -endorphinin seminal plasma playsan immune suppressive role, and thatincreased IL-6 concentration may be related to testicular dysfunctionincases with varicocele. Furthermore, IL-6 is an accurate markerof accessory sex gland inflammation.     

Male contraception: hormonal, mechanical and other

Methods of male contraception that have been developed so farhave mainly focused on the inhibition of spermatogenesis throughsuppression of the hypothalamo- pituitary secretion of gonodotrophins,and simultaneous supplementation with androgens. These methodsinclude the use of combinations of progestogens or luteinizinghormone-releasing hormone antagonists and testosterone derivatives,or high dose testosterone. Though effective contraception canbe obtained, side-effects and/or the high cost of treatmentlimit the widespread use of these approaches. Inhibition ofsperm maturation in the epididymis, or direct interference withspermatogenic cells or the cells of Sertoli by e.g. gossypolhave been abandoned because of toxic side-effects. Voluntarysterilization by vasectomy is the most commonly used methodof male contraception, but its surgical nature, problematicreversibility and suspected link with subsequent prostate cancerrender the method far from ideal. Non-surgical vas occlusionmay overcome some of these problems, but data on long-term side-effectsand reversibility are lacking. New contraceptive developmentsshould focus on interfering with highly specific aspects ofspermatogenesis such as unique enzymatic processes and intercellularcommunication through cytokines, or application of antibodiesagainst antigens of the epididymis or the spermatozoa. Onlythrough better understanding of normal and pathological spermatogenesiswill it be possible to develop an acceptable male contraceptive.     

Erythropoietin production in a primary culture of human renal carcinoma cells maintained in nude mice

The present studies report erythropoietin (Ep) production in primary cultures of a human renal carcinoma from a patient with erythrocytosis that has been serially transplanted to BALB/c nude mice. The levels of erythropoietin in the culture media were estimated using the exhypoxic polycythemic mouse assay (EHPCMA), fetal mouse liver erythroid colony- forming technique (FMLC), and a radioimmunoassay (RIA). The spent culture media of the exponentially growing cells contained less than 10 mU/ml of Ep measured by RIA. However, after the cells became confluent, Ep levels (RIA) in the spent media showed a marked increase to approximately 300 mU/ml. Ep levels estimated using the FMLC and EHPCMA were approximately 2/3 and 1/10, respectively, of those measured by RIA. Rabbit antiserum to highly purified human urinary Ep (70,400 U/mg protein) was utilized for immunocytochemical (peroxidase-antiperoxidase method) localization of Ep in the cultured cells. Very few of the cells in exponential growth exhibited Ep-like immunoreactivity, whereas intense Ep-like immunoreactivity was observed in the cytoplasm of the cells maintained in culture for a prolonged period after reaching confluency. The most intense staining was observed in some of the cells forming domes. The domes developed after the cells reached confluency, and their numbers increased with increasing time in confluent culture, in parallel with the increase in Ep levels in the spent media. This primary cell culture system of a renal cell carcinoma maintained in nude mice, which produces immunologically and biologically active Ep, may provide a useful model for studies of the mechanism of Ep production.