Vasectomy increases the severity of diet-induced atherosclerosis in Macaca fascicularis

Pathological Investigations of Intracranial Atherosclerosis Using Multiple Hypercholesterolemic Rabbit Models

BACKGROUND

Intracranial atherosclerosis (ICAS) is one of the most common causes of ischemic stroke, but there are few animal models that can recapitulate its pathological features. In this study, we examined ICAS pathological features and anatomic distributions using three types of hyperlipidemic rabbit models. We also investigated the effect of different lipoprotein profiles and hypertension on ICAS.

MATERIALS AND METHODS

We examined Watanabe heritable hyperlipidemic (WHHL) rabbits, apoE knockout (KO) rabbits and wild-type rabbits (WT) fed a cholesterol diet, in addition to WT rabbits fed a standard diet as a control. The whole brain was dissected and embedded in paraffin. Serial sections were stained with either hematoxylin/eosin or elastica van Gieson, or immunohistochemically stained with monoclonal antibodies against macrophages and smooth muscle cells. We investigated (1) the presence of cerebral atherosclerosis; (2) the lesion locations in the cerebral arteries; (3) the degree of lumen stenosis; (4) pathological features and cellular components of the lesions in these rabbits; and (5) whether hypertension affects ICAS.

RESULTS

ICAS was detected in apoE and WHHL rabbits, but not in WT rabbits. Compared with apoE KO rabbits, WHHL rabbits had greater ICAS. The lesions of cerebral atherosclerosis were mainly distributed at the bifurcations of the posterior cerebral artery, basilar artery and vertebral artery, and they were basically characterized by smooth muscle cells and extracellular matrix with few macrophages. The extent of the ICAS in WHHL rabbits was significantly increased by hypertension.

CONCLUSIONS

ICAS was detected in WHHL and apoE KO rabbits, and occurred in specific locations in the cerebral arteries. Hypertension promotes the development of ICAS in the setting of hypercholesterolemia.

Vasectomy and prostate cancer risk: a historical synopsis of undulating false causality

The potential influence of vasectomy being a risk factor for the development of prostate cancer is not a new concept, with more than 30 publications addressing the topic. Given the global frequency of vasectomy and the prevalence of prostate cancer, this subject justifiably deserves scrutiny. Several articles have claimed that vasectomy puts men at risk for future development of prostate cancer. We explore articles that have shown the contrary (no link), explore the studies’ strengths and weaknesses, describe possible prostate cancer pathophysiologic mechanisms, and apply Bradford Hill criteria to help discern correlation with causation. The risk and interest of association of prostate cancer with vasectomy has waxed and waned over the last three decades. Based on our review, vasectomy remains a safe form of sterilization and does not increase prostate cancer risk.

Putative health risks associated with vasectomy

Vasectomy is widely regarded as a safe method of contraception, but over the years there have been many reports suggesting putative health risks associated with the procedure. Concerns over the possible association of vasectomy with a number of medical conditions, including cardiovascular disease, testicular cancer, prostate cancer, psychologic distress, and a variety of immune complex-mediated disease processes have been reported. Most recently, a manuscript from the neurology literature has described an association between vasectomy and primary progressive aphasia, a rare variety of frontotemporal dementia. This article reviews the literature surrounding each of these purported health concerns. Because the ultimate findings have important ramifications for both informed consent of vasectomy patients and for public health, the reported health risks in question should be critically evaluated.

High fat and high fructose diet induced intracranial atherosclerosis and enhanced vasoconstrictor responses in non-human primate

The present study examined the effect of high fat and high fructose (HFF) diet on the development of atherosclerosis and vascular contractile responses in the cerebral artery and thoracic aorta in non-human primates. Female cynomolgus monkeys (age: 3 to 4 years) were divided into normal control diet (N=5) and HFF diet groups (N=5). Twenty-eight weeks after feeding the HFF diet, total cholesterol and low-density lipoprotein-cholesterol in serum were significantly increased in the HFF diet group compared to the control group. The ultrastructural analyses of the basilar artery and aorta demonstrated the infiltration of lipid-laden foam cells and the appearance of lipid droplet-filled smooth muscle cells in the monkeys fed with the HFF diet. In terms of vascular reactivity, there was significantly greater vasoconstriction of the aorta and basilar artery in response to 5-hydroxytryptamine in the HFF diet group compared to the normal diet-fed group. In addition, KCl-induced vasoconstriction of the basilar arteries was also significantly enhanced in the HFF diet group compared to the normal diet-fed monkeys. In all, our present study has demonstrated that changes in the vascular responsiveness of the cerebral artery and its cellular architecture may manifest into cerebrovascular complications consistent with a pathological state normally observed with the onset and progression of atherosclerosis.

Cancer and cardiovascular disease after vasectomy: an epidemiological database study

OBJECTIVE

To determine whether vasectomy is associated with an increased long-term risk of cancer or cardiovascular disease.

DESIGN

Analysis of database of linked statistical records of hospital admissions and deaths.

SETTING

Health region in southern England.

PATIENT(S)

Men aged 20-59 years who were admitted to a hospital for vasectomy.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Rates of cancer and cardiovascular disease compared with the corresponding rates in a reference cohort, expressed as a rate ratio.

RESULT(S)

We found no elevation of risk, after vasectomy, of prostate cancer (rate ratio 0.74, 95% confidence interval [CI] 0.45-1.14) or other cancers. The rate ratio for coronary heart disease overall after vasectomy was 0.95 (95% CI 0.88-1.02); and the rate ratio > or =20 years after vasectomy was 0.98 (95% CI 0.80-1.19).

CONCLUSION(S)

Our findings add to the evidence that vasectomy is not associated with an increase in the long-term risk of these diseases.

Canadian Contraception Consensus

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

High titres of serum antinuclear antibodies, mostly directed against nucleolar antigens, are associated with the presence of coronary atherosclerosis

BACKGROUND

Inappropriate inflammation is a key mechanism in the development of atherosclerosis. Antibodies against components of the atherosclerotic lesion, in particular, oxidised low density lipoprotein, have been described.

OBJECTIVE

To determine whether a systemic autoimmune response, characterised by the presence of high titres of antinuclear antibodies, is associated with the presence of coronary atherosclerosis.

METHODS

Serum was prepared from 40 subjects (aged 53-76) with at least 50% stenoses of three main coronary arteries (TVD subjects), and 30 subjects (aged 48-74) with no evidence of coronary atherosclerosis (NCA subjects) determined by coronary angiography.

RESULTS

Antinuclear antibodies (ANA), characterised by immunofluorescent detection of human antibodies bound to HEp-2000 cells, were detected at a titre of at least 1/40 in 28 (70%) of the TVD subjects, but only five (17%) of the NCA patients (odds ratio 11.67 (95% confidence interval (CI) 3.91 to 17.82; p<0.001)). Most ANA positive TVD subjects had a pattern typical of antibodies directed against nucleolar antigens. The antigen has not yet been identified, but several common extractable antigens were excluded. The presence of ANA was not associated with incidence of prior myocardial infarction among the TVD group.

CONCLUSION

The presence of ANA, commonly associated with autoimmune diseases, is substantially more prevalent among subjects with severe coronary atherosclerosis than those with normal coronary arteries. This association merits further assessment as a potentially useful indicator of increased risk of coronary heart disease.

Vasectomy

Vasectomy is regarded as the safest method now available for male fertility control. Almost 100 million men worldwide have relied on vasectomy for family planning. This review discusses all currently relevant operative techniques, including no-scalpel vasectomy, complications, possible long-term effects on the testis and epididymis, and diseases for which associations with vasectomy have been suggested, such as arteriosclerosis, autoimmune diseases and cancer of the prostate and testis. Other topics of discussion include the timing of post-operative semen analysis, patient noncompliance concerning post-operative controls, persistent cryptozoospermia and transient reappearance of spermatozoa after vasectomy, vasectomy failure and legal aspects.

Vasectomy and subsequent cardiovascular disease in US physicians

Due to previous animal research suggesting accelerated atherosclerosis following vasectomy, we examined whether vasectomy increases the risk of subsequent cardiovascular disease (CVD), including myocardial infarction (MI), angina pectoris, coronary revascularization, and stroke, in the US Physicians' Health Study. Of 22,071 US male physicians participating in the study, aged 40 to 84 years at entry and free from cardiovascular disease and cancer, 21,028 reported on the 60-month questionnaire whether they had undergone vasectomy prior to randomization. Of the 4546 physicians with vasectomy, 1159 had undergone the procedure at least 15 years before entry. During 258,892 person-years of follow-up, we documented 773 cases of MI (719 nonfatal and 54 fatal), 1907 cases of angina pectoris or coronary revascularization, and 604 confirmed cases of ischemic or hemorrhagic stroke (566 nonfatal and 38 fatal). When compared to men without prior vasectomy, the multivariate relative risk (RR) of total MI adjusted for age and other coronary risk factors was 0.94 (95% confidence interval [CI], 0.77-1.14) among men with vasectomy. Risk estimates for fatal and nonfatal events did not appreciably differ from each other. For angina or coronary revascularization or both, the multivariate relative risk was 0.99 (0.88-1.12) and for total stroke the RR was 0.95 (0.75-1.21). For men who had undergone vasectomy 15 or more years previously, the multivariate relative risks were 0.98 (0.73-1.32) for total MI, 1.17 (0.87-1.57) for total stroke, and 1.12 (0.94-1.35) for angina/revascularization. These results provide reassuring evidence that vasectomy does not materially increase the risk of subsequent cardiovascular disease, even 15 or more years following the procedure.

A change in practice: current urologic practice in response to reports concerning vasectomy and prostate cancer

OBJECTIVE

To examine the practice patterns of urologists performing vasectomy in response to studies reporting an increased risk of prostate cancer in vasectomized men.

DESIGN

A mailed survey.

SETTING

A university medical institution.

PARTICIPANTS

One thousand five hundred randomly selected United States urologists under the age of 65 years.

MAIN OUTCOME MEASURE

Urologists reported practice patterns of vasectomy in response to studies showing possible link between vasectomy and prostate cancer.

RESULTS

A response rate of 51% (759/1,500) was obtained. Although > 90% state that these studies have had little or no effect upon their practice of vasectomy, 27% screen vasectomized men earlier for prostate cancer, and 20% would be reluctant to recommend a vasectomy to a man with a strong family history of prostate cancer.

CONCLUSIONS

Over one fourth of urologists who screen for prostate cancer have altered their screening patterns even though they responded that the studies have not affected their practice patterns.

Sterilization

Sterilization is accepted as a permanent method of contraception by many couples in the world. Female sterilization is more widely used than male sterilization, but the latter is used by many couples in developed countries. The most widely used methods for female sterilization are simple tubal ligation, electrocautery of the fallopian tubes, and occlusion of the tubes by Hulka or Filshie clips or Falope rings. These procedures may be carried out either by minilaparotomy or by laparoscopy, under local anaesthesia. Sterilization may be performed immediately following pregnancy, or as an interval operation. The effectiveness of female sterilization is high, with failure rates of about 1-2 per 1000 procedures. Immediate complications are few and minor, while there appear to be no serious, long-term adverse effects. It is possible that there is a protective effect against ovarian cancer. Potential new technologies for female sterilization include the use of chemicals, such as quinacrine, for transcervical tubal occlusion, and hysteroscopic methods. Male sterilization is more simple and can readily be performed under local anaesthesia. A new technique originating in China, the no-scalpel technique, has made the procedure even more simple and produces fewer complications such as haematoma. It is possible that the direct injection of plug-forming material into the vas may render the procedure more reversible. Concerns about possible adverse effects of vasectomy on cardiovascular diseases and testicular cancer largely have been dispelled, but a possible weak association between vasectomy and prostatic cancer continues to be studied.

Vasectomy and vasectomy reversal

Vasectomy remains the safest method of birth control and there is much to commend it in the setting of a stable family relationship. However, some aspects of this operation have been wrongly presented in an attempt to widen its popularity and increase public acceptance. A simple procedure it may be but it is not totally free of complications; sometimes the operation has to be repeated and rarely it may reverse spontaneously even after the most stringent precautions. The family planning officer who counsels a prospective candidate and the surgeon who undertakes the procedure must ensure that these facts are understood by the patient with crystal clarity and that this fact is duly recorded on a signed and witnessed permission slip. Any organization which includes vasectomy in its programme of family planning should include advice and referral for vasectomy reversal in exactly the same way that the pill may be stopped or a coil can be removed. Fertility can be successfully restored by vasovasostomy in 50% of men who wish to have their vasectomies reversed, which often is due to a change in circumstances beyond their direct control.

Vasectomy, serum assays, and coronary heart disease symptoms and risk factors

We compared three serum assays (two antisperm antibody assays and one assay for circulating immune complexes) and a number of CHD-related variables in 69 vasectomized (V) and 126 non-vasectomized (NV) participants in the Portland Center for the Multiple Risk Factor Intervention Trial. Significant differences between the V and NV men were found in sperm agglutination (SA) and sperm immobilization (SI) titers, as well as in several CHD risk factors, symptoms, and treatments; men in the V group had higher titers for SA and SI, smoked more, and had lower diastolic and systolic blood pressure than men in the NV group. Differences between V and NV in SA and SI activity remained even after we controlled for any effects that CHD risk factors, symptoms, and treatments may have had on the serum assays. Antibody development tended to decrease with age-at-vasectomy and increase with time-post-vasectomy. In the case of SA the antibodies clearly increased with time-post-vasectomy.

Conducting a hospital-based case-control study of the relationship between vasectomy and cardiovascular disease in Korea--an experience in an Asian setting

An increasing number of case-control studies are being performed in the developing world. This paper describes the difficulties and advantages the author has experienced in conducting a hospital-based case-control study in the Republic of Korea testing the hypothesis of whether vasectomy is associated with subsequent cardiovascular disease. This experience should provide a useful reference for researchers planning studies using a similar approach in an Asian setting.

A long-term study of mortality in men who have undergone vasectomy

BACKGROUND

Vasectomy is a reliable and widely accepted method of contraception, but there is some uncertainty and few data about a possible long-term adverse effect on health.

METHODS

We examined the relation between vasectomy and mortality rates from cardiovascular disease, cancer, and all causes in a retrospective cohort of husbands of members of the Nurses' Health Study. In 1989 we obtained data by questionnaire on 14,607 men who had undergone vasectomy as of 1976 and 14,607 men who had not.

RESULTS

Among the men who were free of cancer at the start of the study, 1052 died: 446 of cardiovascular disease, 341 of cancer, and 265 of other causes. Vasectomy was associated with reductions in mortality from all causes (age-adjusted relative risk, 0.85; 95 percent confidence interval, 0.76 to 0.96) and mortality from cardiovascular disease (relative risk, 0.76; 95 percent confidence interval, 0.63 to 0.92). Vasectomy was unrelated to mortality from all forms of cancer (relative risk, 1.01; 95 percent confidence interval, 0.82 to 1.25). Among men who had a vasectomy at least 20 years earlier, the procedure had no relation to mortality from all causes (relative risk, 1.11; 95 percent confidence interval, 0.92 to 1.33) or that from cardiovascular disease (relative risk, 0.85; 95 percent confidence interval, 0.63 to 1.16). However, mortality from cancer was increased in men who had a vasectomy at least 20 years earlier (relative risk, 1.44; 95 percent confidence interval, 1.07 to 1.92). The excess risk of cancer in these men was due primarily to lung cancer. None of the observed associations were confounded by smoking habits, body-mass index, alcohol consumption, or educational level.

CONCLUSIONS

Vasectomy is not associated with an increase in overall mortality or mortality from cardiovascular disease. Our study also found no increase in overall mortality from cancer after vasectomy, but there was an apparent increase in the risk of cancer 20 or more years after vasectomy that requires further study.

Incidence of disease after vasectomy: a record linkage retrospective cohort study

OBJECTIVE

To determine whether vasectomy is associated with an increased risk of several diseases, and in particular testicular cancer, after operation.

DESIGN

Retrospective cohort study using linked medical record abstracts.

SETTING

Six health districts in Oxford region.

SUBJECTS

13,246 men aged 25-49 years who had undergone vasectomy between 1970 and 1986, and 22,196 comparison subjects who had been admitted during the same period for one of three specified elective operations, appendicitis, or injuries.

MAIN OUTCOME MEASURES

Hospital admission and death after vasectomy or comparison event.

RESULTS

The mean durations of follow up were 6.6 years for men with a vasectomy and 7.5 years for men with a comparison condition. The relative risk of cancer of the testis in the vasectomy cohort (4 cases) compared with that in the other cohorts (17 cases) was 0.46 (95% confidence interval 0.1 to 1.4), that of cancer of the prostate (1 v 5 cases) 0.44 (0.1 to 4.0), and that of myocardial infarction (97 v 226 cases) 1.00 (0.8 to 1.3). There was no evidence of an increase associated with vasectomy in the incidence of a range of other diseases.

CONCLUSIONS

Vasectomy was not associated with an increased risk of testicular cancer or the other diseases studied. With respect to prostatic cancer, while we found no cause for concern, longer periods of observation on large numbers of men are required.

Does vasectomy have long-term effects on somatic and psychological health status?

All the major international articles on the somatic and psychological consequences of vasectomy published over the last 10 years have been reviewed and analysed. Although some experiments on animals have revealed harmful effects, none of the large-scale epidemiological studies has pointed to any increase in health risks (cardiovascular, hypertensive, psychiatric) in vasectomized men. The contradictions which arise between the clinical and large-scale epidemiological studies may be the result of methodological or experimental conditions. As our knowledge stands at present it can therefore be considered that vasectomy has no major effects on the physical or mental health of men.

Early testicular changes after vasectomy and vasovasostomy in Lewis rats

The testes of Lewis rats were studied at intervals from 2 weeks to 3 months after bilateral vasectomy, vasectomy followed 1 month later by vasovasostomy, or sham operations. Aims were to determine the nature of early alterations after vasectomy, and to determine whether vasovasostomy after 1 month would result in reversal of vasectomy-induced changes. Approximately one-fourth of the testes in the vasectomy and vasovasostomy groups displayed histological changes, which consisted mainly of depletion of germ cells. The extent of the depletion varied greatly in different seminiferous tubules. In testes altered in this way, no abnormal infiltrations of lymphocytes, macrophages, or other cells were observed in the seminiferous epithelium or in the interstitium. The rete testis and straight tubules were normal in testes with altered seminiferous epithelium. A few testes in the vasectomy and vasovasostomy groups had necrotic centers. The results suggest that depletion of germ cells occurred as a result of shedding from the seminiferous epithelium into the lumen of the tubules. A cellular immune response, such as occurs in experimental allergic orchitis in other species, did not appear to be responsible for the observed loss of germ cells. This suggests a possible role for humoral antibody in this model, since there is an association between testicular changes and serum antisperm antibodies at longer intervals after vasectomy. Testicular alterations were not reversed by performance of a vasovasostomy 1 month after vasectomy.

Atherosclerosis research in cynomolgus monkeys (Macaca fascicularis)

This is a review of the utilization of cynomolgus monkeys (Macaca fascicularis) in atherosclerosis research. Naturally occurring and experimentally induced atherosclerosis progression and regression studies are described. This species has been utilized as an animal model to study the effects of immunologic injury, aging, exercise, and drug intervention on atherosclerotic lesions. Cynomolgus macaque atherosclerosis induced by feeding cholesterol is a good model of human atherosclerosis because of similar gender-related differences in susceptibility to coronary artery atherosclerosis, a relatively high incidence of myocardial infarction, and characterized psychosocial factors that influence the development of atherosclerosis.

Atherosclerosis of cynomolgus monkeys hyper- and hyporesponsive to dietary cholesterol. Lack of effect of vasectomy

A moderately atherogenic diet was fed to young adult cynomolgus macaque males that were observed to be either hypo- or hyperresponsive to dietary cholesterol and who were randomized into groups to be either vasectomized or sham-vasectomized. The extent of atherosclerosis was found to be considerably greater at all arterial sites studied for the monkeys that were hyperresponsive to dietary cholesterol. The differences in atherosclerosis development among the hyperresponder monkeys occurred primarily in the proximal portions of the coronary arteries, the proximal and distal portions of the common carotid arteries, and only in the most proximal portions of the femoral arteries. There were no significant effects of vasectomy or sham vasectomy on atherosclerosis extent in either the hyper- or the hyporesponding groups, although there was a suggestion of somewhat larger lesions in the left circumflex coronary artery of hyperresponder monkeys that were vasectomized and somewhat smaller atherosclerotic lesions in the left common carotid arteries of vasectomized monkeys. The data presented here do not support our first report of worsened atherosclerosis among cynomolgus monkeys fed diets high in cholesterol. The findings of the current study are consistent with recent epidemiological studies of vasectomized and nonvasectomized human males.

Vasectomy and urolithiasis

The relation between vasectomy and renal disease was examined in the data collection phase of a study of vasectomy and coronary artery disease. The date of onset and type of urological disease was obtained for 11,205 men enrolled in the US Coronary Artery Surgery Study. Urolithiasis was the most common reported urological disease. The relative risk for calculi in men who had had a vasectomy ranged from 2.6 for patients 30-35 years old to 1.3 for those aged 55-65. The age-adjusted relative risk was 1.67 (p less than 0.001).

Effect of vasectomy on humoral and cell-mediated immunity in monkeys with experimentally induced atherosclerosis

The development of humoral and cell-mediated immune responses and circulating immune complexes following vasectomy were studied in rhesus monkeys fed a high cholesterol (atherogenic) diet. Four groups of monkeys were studied: (i) sham-vasectomized males fed a normal stock diet, (ii) sham-vasectomized males fed an atherogenic diet, (iii) vasectomized males fed a normal stock diet, and (iv) vasectomized males fed an atherogenic diet. Monkeys were observed for a period of 1.5 years. Sperm agglutinins and immobilizins in serum were detected in 100 and 60%, respectively, of vasectomized monkeys fed stock diet. In contrast, 60% of vasectomized monkeys fed an atherogenic diet showed agglutinins in their sera and only 20% exhibited immobilizins. The sensitization of lymphocytes by seminal plasma antigens was of a lower order in vasectomized monkeys fed an atherogenic diet as compared to those maintained on a stock diet. Circulating immune complexes (CIC) were present in both the groups of vasectomized monkeys but the level was higher in animals fed an atherogenic diet. The aortic atherosclerosis score was increased significantly in vasectomized monkeys fed an atherogenic diet, whereas the coronary atherosclerosis score was increased both in vasectomized males and in animals fed an atherogenic diet.

Longitudinal and secular trends in lipoprotein cholesterol measurements in a general population sample. The Framingham Offspring Study

Two fasting lipoprotein cholesterol measurements have been made on Framingham Offspring Study participants, first in 1971-75 and again in 1979-83. Longitudinal analysis (n = 2433, age 20-49 at first exam) using multivariate regression found aging, weight gain, vasectomy, menopause, and increased smoking are associated with worsening lipoprotein profiles, while increased alcohol consumption is associated with increased high density lipoprotein cholesterol (HDL-C). Average increases in low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein cholesterol (VLDL-C) in women accelerate with age; in men the increases are similar or perhaps decelerate with age. Secular trends were measured using age-adjusted mean values for individuals aged 25-54. Averages of total cholesterol, LDL-C (men only), systolic and diastolic blood pressure, body mass index, number of cigarettes per day, and alcohol consumption were lower at the second examination. Two secular trends in women indicate a possible worsening of population lipoprotein profiles: mean VLDL-C was higher and mean HDL-C lower at the second exam.

New perspectives on cardiovascular risk factors

Atherogenic traits, living habits, signs of preclinical disease, and susceptibility all contribute to cardiovascular disease. High low-density lipoprotein is positively related to coronary heart disease, and high high-density lipoprotein is inversely related. Systolic or diastolic hypertension at any age in either sex contributes powerfully. The impact of diabetes is greater for women and varies with the number of accompanying risk factors. High-normal fibrinogen values further escalate risk of these atherogenic factors. An atherogenic life-style is typified by a diet excessive in fat, calories, and salt; sedentary habits; unrestrained weight gain; and cigarette smoking. Moderate alcohol use may be beneficial. Use of oral contraceptives beyond age 35 years and in conjunction with cigarette smoking predisposes one to thromboembolism. Type A behavior carries an increased risk, and men married to more highly educated women and to women in white-collar jobs are more vulnerable. Signs of preclinical ischemia include silent myocardial infarction, left ventricular hypertrophy on ECG, blocked intraventricular conduction, and repolarization abnormalities. Measures of innate susceptibility include a family history of early cardiovascular disease. Quantitative combination of risk factors provides optimal prediction, including persons with multiple marginal abnormalities. Preventive management should also be multifactorial and requires a commitment to behavior modification and alteration in life-style.

Vasectomy and vasovasostomy have no effect on seminal plasma zinc concentrations

Mean zinc concentrations were determined for human seminal plasma obtained from 110 nonvasectomized men (139 micrograms. per ml.), 43 recently vasectomized men (144 micrograms. per ml.), 25 long-term vasectomized men (139 micrograms. per ml.) and 25 men who had undergone vasovasostomy (129 micrograms. per ml.). The results indicate that there is no significant short-term or long-term effect of these surgical procedures on prostatic secretory function as measured by seminal plasma zinc concentration.

Antisperm antibodies and circulating immune complexes of vasectomized men with and without coronary events

We compared antisperm antibody and circulating immune complex (CIC) levels in serum samples from 101 vasectomized and 101 normal age-matched nonvasectomized men; 31 of each group had histories of coronary heart disease (CHD). Vasectomy and CHD status were treated as categorical independent variables in the two-way analysis of variance. Elevations of both systolic and diastolic blood pressures were significantly associated with age and body mass index but not vasectomy. Antisperm antibodies (immobilizing and agglutinating) were significantly associated with vasectomy (P less than or equal to .001); the incidences were similar in men with and without CHD. The CICs were significantly associated with vasectomy in a Staphylococcus aureus (FcSa) CIC assay (P less than or equal to .001) and a Raji cell CIC assay (P less than or equal to .05). A third CIC assay, the Clq binding assay, did not reveal a difference between any subgroups. Generally, CICs occurred more frequently in the CHD group by the FcSa assay and particularly the Raji cell assay (P less than or equal to .001). In summary, vasectomized men had a higher incidence and higher levels of circulating antisperm autoantibodies and CICs than did age-matched controls.

Coronary atheroma in the cynomolgus monkey: predictive value of serum and cutaneous lipoprotein measurement

Hyperlipaemia was induced by a high fat diet in 11 cynomolgus monkeys. Morphological study of coronary arteries was carried out in 5 coronary samples from these 11 monkeys. The degree of arterial involvement was compared with the serum and cutaneous lipoprotein levels. These experimental data confirm that cutaneous apoprotein B measurement is the best marker for evaluation of coronary atheroma.

Diet and vasectomy: effects on atherogenesis in cynomolgus macaques

We report here the effect of a moderately atherogenic diet on the progression of atherosclerosis among cynomolgus macaques that were either vasectomized or sham vasectomized. Both groups were compared to sham vasectomized monkeys fed a control Monkey Chow diet. As expected, slight hyperlipoproteinemia induced by the moderately atherogenic diet increased endothelial cell replication rates and resulted in the development of intimal lesions among sham vasectomized monkeys. Unexpectedly, vasectomy resulted in reduced leukocyte adherence to arterial surfaces, reduced endothelial cell replication rates in response to the moderately atherogenic diet, and at most arterial sites, smaller intimal lesions were produced. These data suggest that with slight hyperlipoproteinemia vasectomy may result in a small protective effect against atherosclerosis, while other studies have shown that marked hyperlipoproteinemia in cynomolgus macaques along with vasectomy results in exacerbation of atherogenesis.

Nonhuman primate models of atherosclerosis: potential for the study of diabetes mellitus and hyperinsulinemia

Nonhuman primates have been used for many years to investigate the pathogenesis and progression of atherosclerosis. The use of these animal models has resulted in a better understanding of the risk factors associated with atherosclerosis. Nonhuman primates that have consumed an atherogenic diet for several years develop lesions that are comparable to those found in human beings. Diabetes, both spontaneous and chemically induced, has been described in a number of nonhuman primate species. These diabetic models may be used to understand the accelerated progression and vascular complications of atherosclerosis in diabetic human beings.

A late post-vasectomy syndrome

A group of 20 surgical specimens in 18 patients with a previously unappreciated syndrome of unremitting epididymal pain and induration 5 to 7 years after vasectomy was collected during a 2-year interval. These symptoms uniformly were unresponsive to conservative measures, including empiric antibiotics. Total unilateral or bilateral epididymectomy and partial vasectomy led to complete relief of symptoms, usually within 24 hours. Pathological examination of the specimens revealed features consistent with sequelae of long-standing obstruction. Recognition of this late post-vasectomy syndrome, which represents a major complication of vasectomy, might be expected to increase as cohorts of vasectomized individuals age.

Serum lipid levels before and after vasectomy in men

The blood lipid profile was determined in sixty-two men, 24 to 62 years old, before and two, six and twelve months after surgical occlusion of the vas deferens. No statistically significant differences were found in mean body weight, blood pressure, serum levels of non-esterified fatty acids, total lipids, triglycerides, total cholesterol and alpha, beta and prebeta fractions of the lipoproteins, which were measured before and after surgery. When the serum levels of the alpha and beta fractions were considered in the same subject, it was observed that 12 months after vasectomy a similar percentage of cases showed a predominance of either one of them. Hence, no modifications on the lipid profile of these subjects were found that could indicate an increased risk of arteriosclerotic disease.

Increased atherosclerosis in rabbits immunized with endothelial cells

Rabbits maintained on normal ration or cholesterol-supplemented diet were immunized with homogenates of endothelial cells grown in cultures that were derived from either bovine or human aorta. Minimal aortic lesions were found in all groups of rabbits fed regular diet; microscopically, differences were seen that manifested as medial lesions in controls and intimal lesions in animals immunized with endothelial cells. Aortic atherosclerosis was significantly increased in the immunized, cholesterol-fed animals over that in controls. This difference was more pronounced in the abdominal aorta where the area with lesions in immunized rabbits was 4-7 times that of controls; atherosclerosis of the thoracic aorta was 2.5-5 times greater in the immunized animals (P less than 0.001 for both segments). Increased atherosclerosis was observed despite a significant reduction in plasma cholesterol in the immunized rabbits (770 +/- 119 mg/dl) compared to controls (1595 +/- 225 mg/dl) (P less than 0.001). Immunization with endothelial cells elicited strong cell-mediated and humoral responses as determined by dermal delayed hypersensitivity and solid-phase immunoradiometric tests, respectively. Cross-reactivity in both assays was found against human and bovine cells. Enhancement of atherosclerosis appears to depend not on induction of immune complexes but on specific antibodies and cell-mediated reactions.

Effect of vasectomy on high density lipoproteins

Primate research has associated vasectomy with accelerated rates of atherogenesis. We have evaluated the effect of vasectomy on serum lipoprotein profiles in healthy men. There was a decrease in high density lipoprotein levels, which was greatest in men with a family history of atherosclerotic disease. With the great number of variables known to affect high density lipoprotein levels further studies are needed to determine if this change can be attributed to the vasectomy.

Prevention of antisperm autoantibody response in vasectomised Swiss white mice by infusion of heterologous antisperm serum

Antisperm autoimmunisation may cause infertility in men following spermatic cord torsion, testicular biopsy and vasectomy with attempted reversal. The demonstration in addition of antisperm autoantibody-associated systemic disease in animals is cause for concern, although there is to date little evidence for these effects in man. We have investigated the use of heterologous antisperm antiserum to block the autoimmunising effect of vasectomy in Swiss white mice. Antisperm autoantibodies were detected by microimmunofluorescence at 1/8 dilution in all eight control mice tested 1 month after vasectomy, and in none of the five mice who had received high-titre or low-titre immune serum (P less than 0.001). However, the high-titre serum was toxic in the amounts used.