Discordance in HIV-1 viral loads and antiretroviral drug concentrations comparing semen and blood plasma

Objectives

For individuals not on antiretroviral therapy, the risk of heterosexual transmission of HIV appears negligible when blood plasma (BP) viral loads are <1500 HIV‐1 RNA copies/mL. It is not clear whether this observation can be extrapolated to individuals on highly active antiretroviral therapy (HAART). Because of differential tissue penetration, antiretroviral drug concentrations may be sufficient to maintain an undetectable viral load in the BP yet not achieve adequate levels to suppress HIV in the genital tract. Therefore, we wanted to correlate HIV viral loads and drug concentrations in semen plasma (SP) and BP.

Methods

Thirty‐three men were included. All were on combination antiretroviral therapy with an undetectable BP viral load for at least 1 year. Blood and semen samples were collected within 2 h of each other and tested for HIV RNA by the NucliSens QT (bioMerieux, St Laurent, QC, Canada) method; drug concentrations were determined by liquid chromatography tandem mass spectrometry.

Results

Two of the 33 patients (6.1%) with BP viral loads below detection had time‐matched HIV viral loads in SP ≥700 copies/mL. Both patients were on efavirenz, the SP concentrations of which were ≤10% of the levels in BP and well below the minimal therapeutic drug monitoring target concentration required to suppress HIV.

Conclusions

Because, at least in part, of poor drug penetration into the genital tract, an undetectable HIV viral load in the BP does not guarantee an undetectable viral load in semen. In view of this, caution should be taken in concluding that patients on HAART with suppressed viraemia are sexually non‐infectious.     

Sperm chromatin integrity in young men with no experiences of infertility and men from idiopathic infertility couples

Damage to the genetic component of spermatozoa seems to play the main role in a majority of cases where current approaches fail to reveal the specific cause of male infertility. In this study, we compared semen quality in men assigned to two defined groups: men from couples with unexplained infertility – idiopathic infertility (A) and young men with no experiences of infertility (B). All samples were examined by standard ejaculate analysis and sperm chromatin structure assay (SCSA). Sperm chromatin damage was significantly higher in men from group A than in those from group B. Similar results were obtained by comparison of men from group A (all men were normozoospermic) with normozoospermic men from group B. According to these results, we can suppose that chromatin disorders may be the causal factor of subfertility or infertility in some of these men. No evidence for a strong association between chromatin disorders and standard parameters of ejaculates was found. We failed to confirm a relationship between smoking and sperm quality in men from any of the investigated groups. SCSA is a method that facilitates the identification of infertile men who otherwise show normal semen variables.     

Reassessment of the accuracy of traditional sperm characteristics and adenosine triphosphate (ATP) in estimating the fertilizing potential of human semen in vivo

Receiver operating characteristic curves and accuracy parameters were computed for traditional sperm characteristics (concentration, motility, morphology) and the number of peroxidase negative cells, and the concentration of adenosine triphosphate (ATP) in semen from populations of fertile and infertile men, and men who achieved a pregnancy after varicocele treatment. The percentage and concentration per millilitre of spermatozoa with rapid linear progressive motility, and the ATP concentration, provided the best discrimination between fertile and treated fertile from infertile men. The misclassification rate was higher for sperm morphology, total progressive motility and viability, whereas sperm concentration and the total sperm count per ejaculate had the worst discriminating power. The number of peroxidase negative cells per 100 spermatozoa was highly specific in identifying men who achieved pregnancy after varicocele treatment. The lower limit of normality of sperm characteristics was remarkably different between fertile men and men achieving pregnancy after treatment or during infertility work-up.     

The influence of pentoxifylline on motility and viability of spermatozoa from normozoospermic semen samples

In order to evaluate the effects of pentoxifylline on sperm motility and longevity, a controlled in-vitro study was conducted on normozoospermic donor semen samples using the Cellsoft automated system for sperm motility analysis. After incubation and selection, pentoxifylline was found to improve the recovery of spermatozoa and to increase their velocity. In the subgroup of progressively motile spermatozoa, curvilinear velocity was also enhanced. It is concluded that pentoxifylline has an effect on the vigour, but not on the pattern, of sperm motion. Pentoxifylline did not improve the motility characteristics of senescent spermatozoa in normozoospermic sperm samples. Sperm survival, as shown by supra-vital staining, and motility longevity both decreased with time after pentoxifylline treatment.     

广东省SARS流行株M基因序列分析

目的：测定广东省不同流行时期13份SARS病毒(SARS CoV)标本的M基因序列，通过分析该基因序列的变异情况，初步了解广东省SARS病毒在流行过程中是否发生了变异。方法：提取病毒RNA，用M基因特异引物进行RT-PCR，将产物纯化后直接测定核苷酸序列。结果：13份标本M基因核苷酸序列同源性很高，为99．7％～100％，M基因核苷酸序列只在2个位点(80和203位)发生变异，1株80位点的变化引起编码的氨基酸从苯丙氨酸(F)变为半胱氨酸(C)，3株203位变化为无义突变。结论：M基因核苷酸序列变异不大，初期和后期M基因核苷酸序列与流行高峰期的毒株相差1个碱基，但氨基酸序列相同；从香港感染病人分离的1株病毒M基因与广东本地感染分离株存在1个氨基酸的差异。     

10个钨矿职工死因分析

对中南地区10个钨矿1972—1974年入矿(工龄至少1年)的在册职工28453人进行了队列研究。队列成员追访至1989年,死亡2870人,比全国居民死亡率计算的期望值略高(SMR=1.15,95％CI=1.11—1.19);主要是非恶性呼吸道疾病,特别是尘肺(SMR=66.79,95％CI=59.65—73.68)以及与呼吸道疾病相关的肺心病明显超高(SMR=8.19,95％CI=7.42—9.02),比全国居民死亡率高5倍。癌症死亡数在全死因中虽占第一位,但仅鼻咽癌轻度超高(SMR=1.73,95％CI=1.23—2.37),而肺癌死亡率明显偏低(SMR=0.53)。研究结果不支持矽肺与肺癌病因学相关的假说。     

输精管结扎干扰前列腺增生过程的机制探讨——精浆睾酮双氢睾酮的放射免疫测定

本文应用放射免疫测定的方法检测了13例输精管结扎后(平均15.3年,平均年龄50岁)的男性精浆双氢睾酮和睾酮的浓度,另取同年龄组男性13例作为对照。结果表明,精浆睾酮在结扎组(374.54p/ml)和正常对照组(315.64Pg/ml)中没有明显差异,而结扎组精浆中双氢睾酮(46.21pg/ml)却明显低子对照组(184.27pg/ml(p<0.01)。作者认为,输精管结扎对精浆DHT有长期影响,这可能是其对前列腺增生过程产生抑制作用的原因之一。     

Improvement in quality of cryopreserved human spermatozoa by swim-up before freezing

Selecting a population of spermatozoa by the swim-up technique yields, after freezing and thawing, a population of cells that contains proportionally more spermatozoa which are morphologically normal, fewer spermatozoa with damaged tail membranes, and a greater percentage of progressively motile spermatozoa with greater velocities and amplitudes of head displacement than those obtained after freezing and thawing the same semen samples in the normal way. This pattern was found for the semen from 10 patients and five volunteers. However, the cells selected by swim-up were as susceptible to the stresses caused by freezing and thawing as unselected spermatozoa in the original semen sample, and the improvement came from the better quality of the initial sample.     

A longitudinal study of semen quality in pesticide spraying danish farmers

It was hypothesized that occupational exposure to pesticides during a spraying season causes changes in semen quality that might be detected in a longitudinal study. We analyzed the within-person changes in semen quality and reproductive hormones across a spraying season in groups of farmers using and not using pesticides. A total of 248 men collected two semen samples (participation rate: 32%). The median sperm concentration declined significantly from the first to the second sample in both groups, but there was no statistical difference in the decline between the two groups, unadjusted or adjusted. Only minor changes were found in sperm morphology, vitality, motility, sperm chromatin denaturation (SCSA), and reproductive hormones, and the differences in changes between the two groups were nonsignificant, or, in the opposite direction to the expected. There was no relation between the changes in sperm parameters in relation to pesticide exposure variables. In conclusion, use of pesticides by Danish farmers is not a likely cause of short-term effects on semen quality and reproductive hormones.     

用速率法测定尿NAG活性及其临床应用

本文报道用５５０型全自动生化分析仪，以速率法测定尿ＮＡＧ活性及本室尿ＮＡＧ活性的正常参考范围；并对可能影响尿ＮＡＧ活性的尿ＰＨ，尿素浓度等进行了干扰试验及分析。