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Biomedical subjects

K Purvis

Publications and source records attributed to K Purvis.

At least 19 recordsLinked to original sources
PubMed2001

Understanding of literal truth, ironic criticism, and deceptive praise following childhood head injury.

Children with closed head injury (CHI) have semantic-pragmatic language problems that include difficulty in understanding and producing both literal and nonliteral statements. For example, they are relatively insensitive to some of the social messages in nonstandard communication as well as to words that code distinctions among mental states. This suggests that they may have difficulty with comprehension tasks involving first- and second-order intentionality, such as those involved in understanding irony and deception. We studied how 6- to 15-year-old children, typically developing or with CHI, interpret scenarios involving literal truth, ironic criticism, and deceptive praise. Children with severe CHI had overall poorer mastery of the task. Even mild CHI impaired the ability to understand the intentionality underlying deceptive praise. CHI, especially biologically significant CHI, appears to place children at risk for failure to understand language as externalized thought.

Child↗
PubMed1999

Intracavernosal therapy for erectile failure--impact of treatment and reasons for drop-out and dissatisfaction.

OBJECTIVES: To examine the impact of intracavernosal therapy on libido, ejaculatory control, quality of life and treatment dependency in men with erectile failure. Furthermore to assess the drop-out rate and reasons for dissatisfaction with the technique. SUBJECTS AND METHODS: Questionnaires were sent to 1116 subjects with erectile failure who had previously elected to use intracavernosal therapy in the period 1995-1997. RESULTS: The response rate was 72.5%. The majority of erections lasted 30-60 min, 10-20% of the erections were considered unsatisfactory for intercourse and 15% of subjects reported erections lasting longer than 5 h on at least 10% of the occasions. Bleeding at the injection site occurred in 60% on at least 10% of the occasions and various degrees of deformation of the penis shaft were reported by 10%. The latter was related to the age of the subject and not the type of medication employed. Forty percent experienced at least partially improved control over ejaculation and almost 50% experienced some degree of increase in libido. One quarter retained penile rigidity after ejaculation but this was age-dependent. In those satisfied with intracavernosal treatment, 80% admitted that it had improved the quality of their lives. Sixty percent did not feel that their dependency on intracavernosal treatment had lessened during the treatment period. Approximately 40% of subjects admitted to dropping out of the programme, the majority within the first six months. The age of the subject did not influence the decision and the type of medication or the mode of injection had only a minor impact on drop-out rate. Of those currently using IC therapy, 87% were either fully or partly satisfied with this form of treatment. The corresponding figure for those discontinuing treatment was 58%. Dissatisfaction was higher in the younger age groups and could not be clearly related to the mode of injection. The major reasons for drop out or dissatisfaction were inadequate penile rigidity, the expense of the treatment, penile discomfort and the lack of spontaneity it necessitated. Penile discomfort was more associated with younger age groups, whilst an inadequate response to medication was more often experienced by men over 60 y. Deformation of the penile shaft was observed in 5% of those dissatisfied with IC therapy and was four times more often reported by those over 70 compared to subjects younger than 40 y. In 6% of cases, a return of spontaneous erections was given as reason for drop-out. This was more often associated with younger subjects. In 16% of the subjects, the partner had expressed dissatisfaction with the technique primarily because of inadequate rigidity, lack of spontaneity or the complicated nature of the treatment. CONCLUSIONS: Intracavernosal treatment for erection failure is associated with side-effects such as penile fibrosis and bleeding at the injection site but has advantages including increased libido, an increase in the quality of life and ejaculatory control. Only a small proportion of men reduce their dependency on the technique with time. The therapy has a relatively high attrition rate. In many cases, the reasons for subject and partner dissatisfaction are potentially correctable e.g. by altering the medication used, by the use of injector devices or by obtaining financial support for IC medication from medical welfare.

Adult↗
PubMed1999

Utility of the sperm chromatin structure assay as a diagnostic and prognostic tool in the human fertility clinic.

The sperm chromatin structure assay (SCSA) was used to measure over 500 human semen samples from two independent studies: Study I, 402 samples from 165 presumably fertile couples wishing to achieve pregnancy over 12 menstrual cycles; Study II, samples from 115 patients seeking fertility counselling. The SCSA measures susceptibility to DNA denaturation in situ in spermatozoa exposed to acid for 30 s, followed by acridine orange staining. SCSA data from the male partners of 73 couples (group 1) achieving pregnancy during months 1-3 of Study I were used as the standard of 'sperm chromatin compatible with high fertility' and were significantly different from those of 40 couples (group 3) achieving pregnancy in months 4-12 (P < 0.01) and those of male partners of 31 couples (group 4) not achieving pregnancy (P < 0.001). Group 2 contained couples who had a miscarriage. SCSA values for Study II were almost twice that of the Study I fertility standards. Within-couple repeatability tended to be less for group 3 than for groups 1, 2 or 4. Based on logistic regression, spermatozoa with denatured DNA (cells outside the main population, COMP alpha t) were the best predictor for whether a couple would not achieve pregnancy. Some 84% of males in group 1 had COMP alpha t < 15%, while no couples achieved pregnancy in group 1 with > or = 30% COMP alpha t, a threshold level considered not compatible with good fertility. Using selected cut-off values for chromatin integrity, the SCSA data predicted seven of 18 miscarriages (39%).

Chromatin↗
PubMed1998

Selenium in human male reproductive organs.

The objective of the study was to obtain information on the concentration and distribution of selenium throughout the human male reproductive tract. Material was removed at autopsy from 41 men who had died suddenly and unexpectedly. Semen samples were also provided from 184 men attending an andrology clinic for fertility investigation and from 32 healthy volunteers. Significant positive correlations in the selenium concentration were demonstrated between the different reproductive organs, the testis having the highest concentrations. No correlation was found between the concentration of selenium in the genital organs and liver, kidney or blood, suggesting that its uptake and/or biochemical activity in the reproductive organs may be controlled by similar mechanisms not shared by the other organs. No significant age-dependent changes could be detected in tissue selenium concentrations. In a group of men under fertility investigation, a significant positive correlation was obtained between seminal plasma concentrations of selenium and concentrations of spermatozoa in the same ejaculate. A significant positive correlation between concentrations of zinc and selenium in the same ejaculates indicated that selenium may arise largely from the prostate gland.

Adolescent↗
PubMed1996

Determinants of satisfactory rigidity after intracavernosal injection with prostaglandin E1 in men with erectile failure.

The study examines the erectile response of intracavernosal injection with increasing doses of prostaglandin E1 (PGE) and papaverine/phentolamine (PP) in 516 men with erectile failure. The response was correlated to age, the duration of erectile failure, the quality of spontaneous erections, tobacco consumption and medicine use. In addition, the erectile response was related to penile brachial index (PBI) the free testosterone index and various hormonal parameters. Over 60% of the subjects obtained satisfactory rigidity of at least 30 min duration with 7-15 micrograms PGE. A further 15% (PGE non-responders at the doses tested) obtained rigidity with PP. The average dose necessary to achieve rigidity was 8.8 micrograms for PGE and 0.94 ml (papaverine: 15 mg/ml; phentolamine 0.5 mg/ml) for PP. The average duration of rigidity was 2.2 h and 2.3 h for PGE and PP, respectively. Tobacco consumption, the duration of erectile failure and the age of the subject did not influence the response to intracavernosal injection. Moreover the PBI, the free testosterone index or libido of the subject, did not appear to be generally important for obtaining satisfactory rigidity. In contrast, chronic medication, especially antihypertensive drugs, was associated with significantly higher numbers of poor responders, a shorter duration of erection in the responders and higher doses of PGE necessary to achieve a satisfactory response. The combination of increasing age and antihypertensive medication was predictive for a poor intracavernosal response. In general, a reduced incidence of morning erections was predictive of a weaker response to PGE. The proportion of men with a PBI lower than 0.75 increased with age. These subjects more often took chronic medication, had a lower frequency of morning erections and exhibited a significantly weaker reaction to PGE than subjects with higher PBI. In summary, a large number of men with erectile failure can obtain satisfactory rigidity with intracavernosal injection. In men taking antihypertensive medication, especially in higher age groups, the dose of the intracavernosal medication had to be increased. A reduced sensitivity to intracavernosal medication could be predicted from a lower PBI and a reduced frequency of spontaneous erections.

Adrenergic alpha-Antagonists↗
PubMed1994

[Male infertility. Significance of life and occupation].

A retrospective study was carried out which focused on the impact of lifestyle and exposure to different external factors on sperm quality. A questionnaire was sent to 312 men who had previously attended our laboratory for semen analysis. Their answers were correlated to sperm quality. Men exposed to a relatively high degree of X-rays were found to have significantly reduced sperm count. A previous symptomatic genital infection did not significantly influence the sperm quality, but an earlier sexually transmitted disease in the female partner was associated with a reduced rate of pregnancy. Frequency of ejaculation was significantly positively correlated to sperm motility and inversely related to both semen volume and proportion of sperm with abnormal morphology. Information on exposure to the remaining factors was not related to reduced sperm quality or fertility.

Adult↗
PubMed1994

Seminal plasma lead, cadmium and zinc in relation to tobacco consumption.

The total quantity of zinc in the ejaculates of smokers was significantly lower than in non-smokers. This was not related to a significant increase in the quantities of seminal cadmium or lead, or to a decrease in sperm quality in the smoking group. It appears that tobacco consumption may have to exceed 20 cigarettes/day before a noticeable increase in seminal cadmium can be recorded. It is suggested that this reduction in zinc secretion may jeopardize the content of chromatin zinc, and thereby the stability of the sperm chromatin. This may then contribute to reproductive failure or have consequences for fetal development.

Adult↗
PubMed1993

Factors affecting sperm yield during swim-up.

PURPOSE: The migration of sperm (expressed as the percentage of the total motile cells in the ejaculate aliquot) from seminal plasma into overlying medium (swim-up) was increased with time, temperature, and increasing the surface area of contact between the two phases by increasing the angle of tube inclination. RESULTS: The proportion of sperm migrating into the medium was relatively constant with varying sperm count. Stimulation of the progressive motility of spermatozoa in vitro using a motility enhancing drug (2-deoxyadenosine) increased sperm migration initially but no more than the maximum reached by controls after extended incubation. CONCLUSION: Sperm yield from normozoospermic men and men with borderline asthenoteratozoospermia represented approximately 40 and 15% of the total motile cells in the ejaculate aliquots, respectively. In general, in both groups spermatozoa in the swim-up fraction exhibited superior motility, vitality, and morphology compared to the original ejaculates. Tail abnormalities were reduced more than head abnormalities and subjects with borderline sperm qualities exhibited less dramatic improvements in quality than the normozoospermic individuals.

Cell Separation↗
PubMed1993

Characteristics of women under fertility investigation with IgA/IgG seropositivity for Chlamydia trachomatis.

Chlamydial serology was performed in a group of 100 consecutive women and their partners under fertility investigation. Over one-quarter of the women had evidence of an ongoing, asymptomatic chlamydial infection. A significantly higher incidence of IgA-positivity was associated with women with evidence of tubal pathology, verified by hysterosalpingography and/or laparoscopy and with previous users of intrauterine devices. The male partners of IgA-positive women had a significantly higher incidence of IgA-positivity than the other men. However, this was not associated with an increase in sperm pathology relative to the controls. The study indicates that chlamydial serology should be integrated into the routine screening of women under fertility investigation regardless of previous history and that IgA serology provides more information about tubal pathology than IgG serology.

Antibodies, Bacterial↗
PubMed1993

Use of particle filters for increased practicability in sperm processing: application to the indirect immunobead test.

The use of sterile particle filters is described for the washing and incubation of living sperm before the indirect IBT. The filters greatly simplify the technique, shorten its duration, and remove all centrifugation steps that have potentially detrimental effects on the sperm. The same filters have a variety of applications and can be used whenever sperm have to be washed or incubated before biochemical tests including acrosome binding studies and flow cytometry.

Agglutination Tests↗
PubMed1993

Sperm quality assessed by flow cytometry and accessory sex gland function in spinal cord injured men after repeated vibration-induced ejaculation.

Semen was obtained by vibration-induced ejaculation from 5 spinal injured men once a week for 5 consecutive weeks under standardised conditions. The site of the spinal lesions varied from C5 to Th10. Although in all subjects except one, the total sperm count in the first ejaculate was within normal limits, conventional criteria indicated a high degree of asthenoteratozoospermia in all cases. In subsequent ejaculates there was no major general improvement in motility, vitality or morphology. However, 2 individuals exhibited a marked increase in the proportion of motile sperm in the ejaculate over the next 3 weeks. Flow cytometry of the same sperm samples indicated a high degree of abnormal chromatin condensation and reduced binding of a fluorescent acrosomal marker in the first ejaculates. No improvement in these parameters could be detected with time. Assessment of accessory sex gland function using specific secretory markers indicated that compared to the normal population, the vesicular contribution was markedly reduced in 3 subjects and prostatic contribution in the 2 remaining subjects in the first and subsequent ejaculations. Ejaculate volumes were consistently low in all subjects during the observation period. In contrast, total epididymal secretion was comparable to normal ejaculates. Prostatic contributions to the ejaculate increased significantly over the first 4 weeks. In conclusion, regular vibration-induced ejaculation at weekly intervals could not improve sperm quality in paraplegic men to an acceptable degree for assisted fertilisation to be recommended. Although certain aspects of sperm quality, as judged by conventional criteria, were improved in some cases, flow cytometry revealed persistent chromatin and acrosomal abnormalities.

Adult↗
PubMed1993

Infection in the male reproductive tract. Impact, diagnosis and treatment in relation to male infertility.

The following are the conclusions that can be derived from a review of the literature regarding the role of infection in the aetiology of male infertility. (i) Temporary inflammatory episodes in the male reproductive tract which are self-limiting are probably common. (ii) Caution should be exercised in the use of leukospermia or bacteriospermia as parameters for glandular infection. (iii) There is a need for alternative techniques for detecting non-symptomatic deep pelvic infections in the male; one technique of great promise is rectal ultrasound. (iv) Rectal ultrasound indicates that a large number of men with poor sperm quality have a non-symptomatic, chronic prostatovesiculitis. (v) Increasing evidence implicates Chlamydia trachomatis as being a major cause of chronic non-bacterial prostatitis. (vi) An important aspect of chlamydial infections in men may be that the male accessory sex glands may function as reservoirs for the organism, increasing the probability of infection in the female. (vii) Ureaplasma urealyticum may also play an important aetiological role in male infertility but its significance is confounded by its acknowledged function as a commensal in the reproductive tract. (viii) One of the manifestations of male reproductive tract infection is the induction of sperm autoantibodies. (ix) There is a need for more systematic controlled studies of the effects of antibiotic treatment on sperm quality with different preparations for extended periods using patient groups in which a glandular infection has been verified, e.g. by rectal ultrasonography.

Bacterial Infections↗
PubMed1993

Segmental distribution of alpha-glucosidase, ornithine decarboxylase and polyamines in the human epididymis.

Regional differences in the total activities of the epididymal secretory parameter, alpha-glucosidase, were demonstrated in the 20,000 g supernatants of human epididymal homogenates. A comparison of the enzymic activities in the supernatants and the washings from 12 one centimetre segments of human epididymides indicated an activity peak in segments 3-4 which appeared to be largely intracellular and which presumably reflects the acidic isoenzyme. A second peak in the caudal region, the segmental localization of which was more variable and differed in post-mortem and operation specimens, appeared to be primarily intraluminal. The activities of ornithine decarboxylase (ODC), the rate-limiting enzyme in the polyamine pathway, also exhibited regional differences with higher activities in relatively short segments in both caput and caudal portions. Corresponding alterations were also found in the tissue concentrations of the enzyme products, spermidine and spermine. The increased intracellular activities of ODC and alpha-glucosidase in the distal caput segments presumably reflect the transition of epithelium from the efferent to the epididymal ducts.

Adult↗
PubMed1993

Concentrations of lead, cadmium and zinc in the tissues of reproductive organs of men.

The concentrations of lead in blood and the concentrations of lead, cadmium and zinc in tissues were determined in various reproductive organs, liver and kidney removed at necropsy from 41 men who had died suddenly. None of the reproductive organs specifically accumulated lead and no significant correlation could be demonstrated between blood and organ concentrations or between concentrations and age, occupation or urban/rural background of the subject. Unlike lead, the tissue concentrations of cadmium increased with increasing age in all of the reproductive organs examined. Of these, the epididymides and seminal vesicles contained the highest concentrations. Whereas prostatic zinc also exhibited a significant age-dependent increase, the concentrations in the testes declined with age. The age-dependent increase in testicular cadmium did not become apparent until after the fourth decade, when any potentially deleterious impact on male fertility has less relevance. It is concluded that measurable amounts of lead and cadmium are present in all of the human reproductive organs but their organ and age distribution do not offer strong support for their involvement in the aetiology of male infertility or in the genesis of glandular neoplasms.

Adolescent↗
PubMed1992

The value of anamnestic information regarding previous genital infection in male fertility investigation.

The study was designed to assess the value of information from male subjects under fertility investigation, regarding previous genital infection, in clarifying the causes of depressed sperm quality. Information was gathered using a questionnaire which was sent to 312 men who had previously attended our laboratory for semen analysis. A previous sexual transmitted disease (STD) in the male partner did not significantly influence the sperm quality or the pregnancy rate. However, a previous STD in the female was generally associated with a lower pregnancy rate. Previous episodes with urethral discharge, dysuria, pain with ejaculation or suprapubic discomfort had little relevance for the subsequent sperm quality. The results indicate that, in general, information provided by men under fertility investigation, regarding previous genital infections or symptoms, is only of limited value in elucidating the cause of impaired sperm quality.

Adult↗
PubMed1992

Lifestyles of men in barren couples and their relationships to sperm quality.

This study is based on a questionnaire which focused on the possible association between lifestyle factors and male fertility in a group of 252 men attending our laboratory in connection with a fertility investigation. Their answers were correlated to sperm quality. No association could be documented between sperm quality and smoking habits, coffee drinking, a moderate alcohol intake, exposure to heat (sauna, hot baths, type of underwear, sedentary activities) or physical activities in their leisure time. In contrast, the reported average ejaculation frequency was significantly positively correlated to the motility of the sperm (% progressive) but inversely related to the proportion of sperm with abnormal morphology and semen volume. This indicates that the lifestyle of the subject has little, if any, impact on semen quality, at least within the limits recorded in the present study.

Alcohol Drinking↗