Prothrombotic Genotypes Are not Associated with Pre-eclampsia and Gestational Hypertension: Results from a Large Population-based Study and Systematic Review

DNA samples collected as part of a large population-based casecontrol study were genotyped to examine the associations of five prothrombotic gene polymorphisms with pre-eclampsia (PE) and gestational hypertension (GH). The polymorphisms studied were: G1691A in Factor V (Factor V Leiden; FVL), prothrombin G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T, plasminogen activator inhibitor-1 4G/5G and the platelet collagen receptor α2β1 C807T. A group of 404 women who developed PE were retrospectively compared with 303 women with GH and 164 control women. The frequency of genotypes did not differ significantly between cases of PE or GH and controls for any of the five polymorphisms studied. We conclude that these prothrombotic genotypes are not associated with the development of PE or GH in our population. The systematic review supports our conclusion, for all but cases of severe disease, which appear to be associated with FVL and, to a lesser extent, MTHFR C677T. There is little value in antenatal screening for prothrombotic polymorphisms to predict the development of pre-eclampsia or gestational hypertension.

Human interleukin-27: wide individual variation in plasma levels and complex inter-relationships with interleukin-17A

Although it is widely believed that interleukin (IL)-27 is anti-inflammatory, its role in controlling human immune responses is not fully established. In particular, its interactions with T helper type 17 (Th)17 cytokines are unclear. Our aims were to establish the relationships between IL-27 and proinflammatory cytokines, including IL-17A, in human sera and cultures of peripheral blood mononuclear cells. Plasma IL-27 levels in 879 healthy humans from 163 families varied widely, but with relatively low heritability (19%). Despite IL-27 including a subunit encoded by Epstein-Barr virus-induced gene 3 (EBI3), there was no correlation of levels with serological evidence of infection with the virus. Although IL-27 has been reported to inhibit IL-17A production, we demonstrated a strong positive correlation in sera, but lower correlations of IL-27 with other proinflammatory cytokines. We verified that IL-27 inhibited IL-17A production by human peripheral blood T cells in vitro, but not that it stimulated IL-10 secretion. Importantly, addition of IL-17A decreased IL-27 production by stimulated T cells but had the opposite effect on resting T cells. Together, these data suggest a model whereby IL-27 and IL-17A exerts complex reciprocal effects to boost inflammatory responses, but restrain resting cells to prevent inappropriate activation.

Polymorphisms in the Interleukin-10 and Interferon Gamma Genes in Hodgkin Lymphoma

Genetic factors are known to be important in the development of Hodgkin lymphoma (HL). Interleukin-10 (IL-10) secretion by both malignant and reactive cells is thought to be important in the pathogenesis of HL especially Epstein-Barr virus (EBV) positive cases. Polymorphisms of the IL-10 gene have been reported to be associated with susceptibility to EBV infection. The cytotoxic response to EBV is determined by a Th1 biased immune response which is characterised by interferon gamma (IFNgamma) secretion. We therefore investigated polymorphisms in the IL-10 (-1082 G/A and -592 C/A) and IFNgamma (intron 1 CA repeat) genes as predisposing factors in the development 147 cases of HL. A difference of borderline statistical significance was demonstrated for the IFNgamma gene polymorphism but significance was lost when analysis was restricted to the common genotypes. No significant differences in the distributions of genotypes were found for the IL-10 gene polymorphisms. IL-10 and IFNgamma levels were also measured on 26 patients with HL. No statistically significant differences were detected when the results were analysed by genotype. We found little evidence IL-10 and IFNgamma genotypes predispose to the development of HL or influence the inflammatory host response.

Novel genetic variants linked to coronary artery disease by genome-wide association are not associated with carotid artery intima-media thickness or intermediate risk phenotypes

Background

It is uncertain whether the novel single nucleotide polymorphisms (SNPs) that have recently been associated with coronary artery disease (CAD) in genome-wide studies also influence carotid atheroma and stroke risk. The mechanisms of their association with CAD are unknown; relationships to other cardiovascular phenotypes may give mechanistic clues. Carotid artery intima-media thickness (CIMT) is a subclinical marker of atherosclerosis associated with stroke. We investigated association of reported CAD risk variants with CIMT, and with other intermediate phenotypes that may implicate causative pathways.

Methods

We studied 1425 members of 248 British Caucasian families ascertained through a hypertensive proband. We genotyped CAD risk SNPs on chromosomes 9 (rs1333049, rs7044859, rs496892, rs7865618), 6 (rs6922269) and 2 (rs2943634) using TaqMan. Merlin software was used for family-based association testing.

Results

No significant association was found between genotype at any SNP and CIMT in 846 individuals with acceptable measurements. Nor were SNPs significantly associated with blood pressure, obesity, cholesterol, CRP, interleukin-6, TNF-α, or leptin.

Conclusions

These novel CAD variants are not associated with CIMT and do not appear to mediate the risk of atherothrombosis through known risk factors.

ABO(H) blood groups and vascular disease: a systematic review and meta-analysis

BACKGROUND

Associations between vascular disease and ABO(H) blood groups have a long history, but no consensus exists regarding its magnitude and significance, or whether it relates to all disorders equally. An accurate calculation of risk would allow direct assessment of whether the effects of non-O status on thrombosis risk are of the magnitude predicted by its effect on von Willebrand factor/FVIII levels.

METHODS AND RESULTS

We conducted a systematic review and meta-analysis of studies reporting associations with non-O blood groups. This gave pooled odds ratios of 1.25 [95% confidence interval (CI) 1.14-1.36] for myocardial infarction (MI), 1.03 (95% CI 0.89-1.19) for angina, 1.45 (95% CI 1.35-1.56) for peripheral vascular disease, 1.14 (95% CI 1.01-1.27) for cerebral ischemia of arterial origin, and 1.79 (95% CI 1.56 to 2.05) for venous thromboembolism (VTE). However, restriction to prospective MI studies only did not confirm the association (OR 1.01; 95% CI 0.84-1.23), although these studies may have failed to capture early-onset disease. For VTE, using a combined group of OO/A(2)A(2)/A(2)O as index, the combination of A(1)A(1)/A(1)B/BB gave an OR of 2.44 (95% CI 1.79-3.33) and A(1)O/ BO/A(2)B an OR of 2.11 (95% CI 1.66-2.68).

CONCLUSIONS

This study confirms the historical impression of linkage between some vascular disorders and non-O blood group status. Although the odds ratios are similar to those predicted by the effect of ABO(H) on von Willebrand factor levels, further work is required to assess risk prospectively and to refine the effect of reducing O(H) antigen expression on thrombosis. However, as non-O and particularly A(1)A(1), A(1)B, BB constitute a significant proportion of the population attributable fraction of VTE, there may be a role for more widespread adoption of ABO(H) typing in testing strategies.

Immunomodulation against leukemias and lymphomas: a realistic future treatment?

Immunotherapy offers the potential for cure of malignancy without the side effects too commonly seen with conventional chemotherapy. The efficacy of allogenic transplantation and monoclonal antibodies in hematological malignancies illustrate this principle and are now part of routine care. Newer cell based and molecular approaches aimed at stimulating cytotoxic activity against host derived tumor associated antigens are able to 'boost' anti-tumor immunity as judged by immunological assays in vitro. Although clinically meaningful responses were originally less evident, more promising results are now being reported. Our growing understanding of tumor immunology provide rationales for further improvements in the field.

Platelet and coagulation activation markers in myeloproliferative diseases: relationships with JAK2 V6I7 F status, clonality, and antiphospholipid antibodies

BACKGROUND AND OBJECTIVES

Patients with myeloproliferative disease (MPD) have an increased risk of thrombosis. We studied markers of platelet and coagulation activation in a large cohort of patients with MPD (n = 118) and related this to Janus Kinase 2 (JAK2) V617 F mutation status, a marker of clonality, and the presence of antiphospholipid antibodies (APA), all of which have been associated with thrombosis in MPD.

METHODS

D-dimer, thrombin-antithrombin complexes (TAT), prothrombin fragments 1 + 2 (F(1+2)), soluble E-selectin (sE-selectin), and soluble P-selectin (sP-selectin) levels were compared between patients and hypertensive controls (n = 127). Assays for lupus anticoagulant (LA), anticardiolipin antibodies (ACA), antibeta2 glycoprotein 1 antibodies (anti-beta(2)GP1), and antiprothrombin antibodies (alpha-Pro) were also performed. The JAK2 V617F mutation status was determined in the cohort using amplification refractory mutation system (ARMS) polymerase chain reaction. Disease clonality was determined in 54 patients using the HUMARA assay.

RESULTS

sP-selectin was significantly increased in patients with MPD (P

CONCLUSIONS

The JAK2 V617F mutation is associated with platelet activation, as measured by elevated sP-selectin levels, in MPD. In contrast to previous reports, we found no excess of APA in patients with MPD.

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Key Words Collapse

MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Antibodies, Antiphospholipid/chemistry
• Blood Coagulation
• Blood Platelets/cytology
• Blood Platelets/metabolism
• Cohort Studies
• Female
• Humans
• Janus Kinase 2/genetics
• Male
• Middle Aged
• Myeloproliferative Disorders/genetics
• Myeloproliferative Disorders/metabolism
• Thrombosis/genetics

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Grants Collapse

Affiliation(s)

B Robertson Haematology Department, Aberdeen Royal Infirmary, Aberdeen, UK.
C Urquhart
I Ford
J Townend
H G Watson
M A Vickers
M Greaves

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Pyoderma gangrenosum as a cause of splenomegaly and association with a T-cell clone

The spectrum of clinical presentation of haematological disease is wide. We highlight two features of this principle: a rare cause of a 'haematological' presentation and a possible haematological cause of a disease not normally considered as such. A case of systemic pyoderma gangrenosum presented with splenomegaly in the absence of a rash. A clonal gamma- and beta-T-cell receptor rearrangement was demonstrated. Such clones may be a general phenomenon involved in the pathogenesis of this condition.

The procoagulant potential of environmental particles (PM10)

BACKGROUND AND AIMS

Epidemiology studies have shown that cardiovascular (CV) disease is primarily responsible for the mortality associated with increased pulmonary environmental particle (PM10) exposure. The mechanisms involved in PM10 mediated CV effects are unknown although changes in plasma viscosity and in the homoeostasis of blood coagulation have been implicated. It was hypothesised that PM10 exposure would result in an inflammatory response and enhance the activation of the extrinsic coagulation mechanisms in pulmonary and vascular cells in culture.

METHODS

Primary human monocyte derived macrophages and human umbilical cord vein endothelial, human alveolar type II epithelial (A549), and human bronchial epithelial (16HBE) cells were tested for their inflammatory and procoagulant response to PM10 exposure. IL-8, tissue factor (TF), and tissue plasminogen activator (tPA) gene expression and protein release, and coagulation enhancing ability of culture media were determined 6 and 24 hours following exposure.

RESULTS

The culture media from macrophages and 16HBE bronchial epithelial cells, but not A549 cells, exposed to PM10 had an enhanced ability to cause clotting. Furthermore, H2O2 also increased the clotting activity. Apoptosis was significantly increased in macrophages exposed to PM10 and LPS as shown by annexin V binding. TF gene expression was enhanced in macrophages exposed to PM10, and HUVEC tissue factor and tPA gene and protein expression were inhibited.

CONCLUSIONS

These data indicate that PM10 has the ability to alter macrophage, epithelial, and endothelial cell function to favour blood coagulation via activation of the extrinsic pathway and inhibition of fibrinolysis pathways.

Phosphodiesterase type 5 inhibitors for the treatment of erectile dysfunction in patients with diabetes mellitus

Sildenafil, a phosphodiesterase 5 (PDE5) inhibitor, has become a first-line therapy for diabetic patients with erectile dysfunction (ED). The efficacy in this subgroup, based on the Global Efficacy Question, is 56% vs 84% in a selected group of non-diabetic men with ED. Two novel PDE5 inhibitors, tadalafil (Lilly ICOS) and vardenafil (Bayer), have recently completed efficacy and safety clinical trials in 'general' and diabetic study populations and are now candidates for US FDA approval. A summary analysis of the phase three clinical trials of sildenafil, tadalafil and vardenafil in both study populations is presented to provide a foundation on which the evaluation of the role of the individual PDE5 inhibitors for the treatment of patients with ED and DM can be built.

Prothrombotic genotypes are not associated with pre-eclampsia and gestational hypertension: results from a large population-based study and systematic review

DNA samples collected as part of a large population-based case-control study were genotyped to examine the associations of five prothrombotic gene polymorphisms with pre-eclampsia (PE) and gestational hypertension (GH). The polymorphisms studied were: G1691A in Factor V (Factor V Leiden; FVL), prothrombin G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T, plasminogen activator inhibitor-1 4G/5G and the platelet collagen receptor alpha2beta1 C807T. A group of 404 women who developed PE were retrospectively compared with 303 women with GH and 164 control women. The frequency of genotypes did not differ significantly between cases of PE or GH and controls for any of the five polymorphisms studied. We conclude that these prothrombotic genotypes are not associated with the development of PE or GH in our population. The systematic review supports our conclusion, for all but cases of severe disease. which appear to be associated with FVL and, to a lesser extent, MTHFR C677T. There is little value in antenatal screening for prothrombotic polymorphisms to predict the development of pre-eclampsia or gestational hypertension.

Estimation of mutation rate at human glycophorin A locus in hematopoietic stem cell progenitors

Surveys of human mutant cells exhibit a few individuals with relatively high "outlying" values, which might be explained by rare mutations occurring during development. To estimate how commonly this occurs, mutant red cell frequencies at the glycophorin A locus in 135 neonates and 109 children and adolescents from three research centers are compared with simulations in which mutations arise from successive cycles of binary fission. The simulations predict the data most accurately when the mutation rate in stem cell precursors is about 2-4 x 10(-7) per division cycle, which is similar to previous estimates from adult stem cell divisions. If these mutation rates are accurate, and the number of stem cell divisions during adult life is as low as previously estimated, it is predicted that up to one-sixth of mutant stem cells over a lifetime arose in early life. However, these mutant stem cells would be difficult to detect in surveys because their distribution within the general population is so skewed.

In vivo platelet activation in atherothrombotic stroke is not determined by polymorphisms of human platelet glycoprotein IIIa or Ib

Platelet membrane glycoprotein polymorphisms are candidate risk factors for thrombosis, but epidemiological data are conflicting. Thus, demonstration of a genotype-dependent alteration in function is desirable to resolve these inconsistencies. We investigated in vivo platelet activation in acute thrombosis and related this to platelet genotype. Frequencies of the 1b and 2b alleles of the HPA 1a/1b and HPA 2a/2b platelet glycoprotein polymorphisms were determined in 150 (52 men/98 women, mean age 58.3 years) patients with atherothrombotic stroke, and the influence of genotype on markers of platelet activation was assessed. Platelet P-selectin (CD62P) expression and fibrinogen binding was measured using whole blood flow cytometry within 24 h of stroke and 3 months later in 77 patients who provided a repeat blood sample. Results were compared with matched controls. Neither the 1b allele [allele frequency 0.11 vs. 0.13, odds ratio (OR) confidence interval (CI) 0.8 (0.5-1.3)] nor the 2b allele [0.09 vs. 0.07, OR (CI) 1.4 (0.8-2.4)] was significantly over-represented in patients. Increased numbers of activated platelets were found following stroke (acute mean P-selectin expression 0.64% vs. control 0.35%, P < 0.001; acute mean fibrinogen binding 1.6% vs. control 0.9%, P < 0.001). Activation persisted in the convalescent phase (P < 0.001 and P = 0.005 vs. controls for P-selectin and fibrinogen respectively). Expression of P-selectin and fibrinogen was not influenced by either the HPA 1a/1b genotype (P > 0.95 for each marker, Scheffe's test) or the 2a/2b genotype (P > 0.95 for each). Although persisting platelet activation is seen in atherothrombotic stroke, it is independent of HPA 1a/1b and 2a/2b genotypes. These data suggest an underlying prothrombotic state, but do not support the polymorphisms studied as risk factors for thrombotic stroke in this population.

Monosomy for the most telomeric, gene-rich region of the short arm of human chromosome 16 causes minimal phenotypic effects

We have examined the phenotypic effects of 21 independent deletions from the fully sequenced and annotated 356 kb telomeric region of the short arm of chromosome 16 (16p13.3). Fifteen genes contained within this region have been highly conserved throughout evolution and encode proteins involved in important housekeeping functions, synthesis of haemoglobin, signalling pathways and critical developmental pathways. Although a priori many of these genes would be considered candidates for critical haploinsufficient genes, none of the deletions within the 356 kb interval cause any discernible phenotype other than alpha thalassaemia whether inherited via the maternal or paternal line. These findings contrast with previous observations on patients with larger (> 1 Mb) deletions from the 16p telomere and therefore address the mechanisms by which monosomy gives rise to human genetic disease.

Assessment of mechanism of acquired skewed X inactivation by analysis of twins

Skewed X-chromosome inactivation in peripheral blood granulocytes becomes more frequent with increasing age, affecting up to half of those over 75 years old. To investigate the mechanisms underlying this phenomenon, X-inactivation profiles in 33 monozygotic and 22 dizygotic elderly twin pairs were studied. Differential methylation-sensitive restriction enzyme cutting at a hypervariable locus in the human androgen receptor gene (HUMARA) was studied on purified granulocytes using T cells as controls. A large genetic effect on skewed granulocytic X inactivation was shown (P <.05); heritability was estimated to be 0.68. A minor part (SD.0151 relative allele frequency [ie, larger/smaller] units) of the observed variance is due to experimental error. A further contributor to acquired skewing is stochastic asymmetric stem cell division, which was modeled and shown as unlikely to account for a substantial part of variance. Two monozygotic twin pairs had X-inactivation ratios skewed markedly in opposite directions, evidence for a further stochastic mechanism, suggestive of a single overrepresented clone. In conclusion, all 3 suggested mechanisms contribute to acquired X inactivation but the dominant mechanism is genetic selection. The observed proportion of putatively clonal hematopoiesis is similar to the lifetime incidence of hematopoietic stem cell malignancy consistent with the concept that clonal hematopoiesis precedes stem cell malignancy.

Plasma homocysteine concentrations in the acute and convalescent periods of atherothrombotic stroke

BACKGROUND AND PURPOSE

Homocysteine is a proposed causal risk factor for atherosclerosis, but this remains controversial. We measured fasting plasma homocysteine concentrations immediately after atherothrombotic stroke and in the convalescent period to investigate this controversy.

METHODS

One hundred six patients (59 men and 47 women, mean age 57.2 [25 to 70] and 56.5 [26 to 69] years, respectively) were recruited within 24 hours of admission, and 82 patients were resampled at least 3 months later. Fasting total plasma homocysteine (tHcy) concentrations were measured by high-performance liquid chromatography.

RESULTS

Median tHcy in the acute phase of stroke was not significantly higher than in matched control subjects (men 9.2 [range 4.4 to 22.8] versus 8.7 [4.9 to 20] micromol/L, P:=0.09, Mann-Whitney U: test; women 8.1 [4.8 to 32.3] versus 7.6 [3.3 to 14.4] micromol/L, P:=0.58). Median plasma concentrations increased significantly in the convalescent period (from 8.5 [4.8 to 19.2] to 10.1 [4.3 to 31.5] micromol/L, P:<0.001, Wilcoxon signed rank test) and were then significantly higher than in control subjects in both men and women (P:=0.03 and 0.05, respectively, Mann-Whitney U: test). This did not appear to be explained by alteration in the known covariates red-cell folate, serum B(12), or creatinine concentrations.

CONCLUSIONS

Homocysteine concentrations are not elevated after recent atherothrombotic stroke but rise in the convalescent period. These data do not support the hypothesis that raised plasma homocysteine concentrations predate atherothrombotic stroke. Instead, they offer an explanation for the discrepancies between prospective and retrospective studies and suggest that elevated tHcy levels may be caused by the disease process itself.

Tissue angiotensin II as a modulator of erectile function. I. Angiotensin peptide content, secretion and effects in the corpus cavernosum

PURPOSE

Although Angiotensin II (Ang II) is a major modulator of regional blood flow in the extracavernosal segments of the vascular bed, its role in erectile function is unknown. The corpus cavernosum penis is a modified vascular tissue that contains endothelial and smooth muscle cells. In other segments of the vascular bed, these cell types produce Ang II. Therefore, we explored the presence and function of an Ang II producing paracrine system in the corpus cavernosum.

METHODS

The angiotensin content of the human corpus cavernosum was measured by radioimmunoassay. The distribution pattern of Ang II containing cells within the corpus cavernosum was assessed by an immunohistochemical technique, and the rate of its secretion was determined by superfusion. The effects of Ang II and its antagonist, losartan, on intracavernosal pressure were determined under in vivo conditions, in anesthetized dogs.

RESULTS

Human corpus cavernosum contained 1178 +/- 223 (SEM) fmol Ang II, 528 +/- 171 fmol Ang I, 475 +/- 67 fmol des-asp-Ang I, and 1897 +/- 371 fmol des-asp-Ang II/gm. tissue (n = 4). Ang II was found mainly in endothelial cells lining blood vessels and smooth muscle bundles within the corpus cavernosum. Superfused cavernosal tissue secreted immuno-reactive Ang II (Ang II(ir)) at a rate of 57 +/- 36.5 fmol Ang II(ir)/gm. tissue/minute (n = 10). The amount of Ang II released per gram of tissue in an hour was 3-fold greater than the Ang II content/gm. tissue, suggesting a local production of Ang II. Papaverine and prostaglandin E1 suppressed Ang II secretion significantly (p <0.001, p = 0.013). The responsiveness to inhibition was a function of the initial rate of Ang II secretion. Tissue samples with a high rate of secretion were less responsive to the inhibitors than tissue that secreted small amounts of Ang II (n = 6). In anesthetized dogs, intra-cavernosal injection of Ang II terminated spontaneous erections, while losartan increased the intracavernosal pressure in a dose dependent manner up to the mean arterial pressure (n = 4).

CONCLUSIONS

The corpus cavernosum produces and secretes physiologically relevant amounts of Ang II. The rate of Ang II secretion can be modulated by pharmacologic agents that regulate cytosolic calcium levels and are used clinically to treat erectile dysfunction. Intracavernosal injection of Ang II causes contraction of cavernosal smooth muscle and terminates spontaneous erection in anesthetized dog, while administration of an Ang II receptor antagonist results in smooth muscle relaxation and thus erection.

Has the efficacy of penile arterial by-pass surgery in the treatment of arteriogenic erectile dysfunction been determined?

The evaluation of the efficacy of penile arterial by-pass surgery (PABG) must be based on data obtained in clinical trials which have utilized a traditionally acceptable scientific design. A review of the studies which have presented the PABG surgical outcomes analysis revealed that patient selection and patient assignment have not been randomized. Demographic and individual variables, which could potentially influence outcomes, have not been eliminated by use of a marched pair design. Treatment options, including an option which allows assessment of effect of surgery per se, have not been presented in any of the studies. A majority of the studies have not blinded the researcher who analyzed the results. Commonly, follow-up evaluations have been limited and have not used converging sources of evidence. Practical suggestions are offered to improve future clinical trials so that the question of the efficacy of PABG surgery can be scientifically answered.

Detection of leakage in inflatable genitourinary devices

OBJECTIVES

Improved manufacturing techniques and stronger materials have significantly reduced but not eliminated the incidence of hydraulic leakage in the inflatable genitourinary devices. This study was designed to test the efficacy of pressure dissipation and volume loss as potential tests for the detection of site-specific hydraulic leakage in the inflatable penile prosthesis (IPP) and the artificial sphincter (AS) and compare their efficacy with the current standard--the ohmmeter technique.

METHODS

Five IPPs and ASs were dismantled to achieve five reservoirs and cuff-pump assemblies. Each component was inspected visually and then tested for volume, pressure, and electrical resistance over 5 minutes. Next a needle puncture was deliberately made in these components, and the experiment was repeated. The in vivo pseudocapsule was simulated by an elastic covering, made from antiembolic hose.

RESULTS

The techniques of pressure, volume, and ohmmeter testing were not able to detect current leakage in all the components, with the pseudocapsule in place.

CONCLUSIONS

None of the currently available tests qualify for the label of "gold standard" in accurately detecting hydraulic leakage. We currently recommend testing the device's integrity by visual inspection in vivo, starting with the reservoirs. If a leakage is detected, the reservoir alone is replaced. If no leakage is found, we recommend that the entire unit be removed and replaced. If the malfunctioning device is more than 2 years old, we suggest that it be entirely replaced.

Assessment and modeling of the physical components of human corporovenous function

To understand and quantify specific causes of venoocclusive dysfunction, an analog model of penile hemodynamics, including a mechanism of flow limitation by subtunical veins, was developed and a detailed analytic study was conducted in patients with erectile dysfunction. Computer simulations for steady-state and transient intracavernosal conditions were carried out to study graded changes in cavernosal smooth muscle tone, subtunical venular resistance, and cavernosal and tunical compliances. The model predicted a steady-state cavernosal pressure (Pca)-infusion flow relationship with two phases: an initial phase characterized by a gradual slope up to a critical flow and a second phase characterized by a much steeper slope after limitation of subtunical venular flow. Model predictions were compared with clinical data obtained during incremental saline cavernosometry (SaC) and pharmacocavernosometry (PhC) in 13 patients with erectile dysfunction with use of a computer-controlled infusion system that automatically changed from constant-flow to constant-pressure feedback control when Pca reached the threshold of 80 mmHg. Steady-state pressure-flow and pressure-circumference relationships of the penis were analyzed and interpreted in terms of specific components of the electrical analog model. These clinical studies demonstrated that patients with a functional venoocclusive mechanism (i.e., those able to achieve 100 mmHg Pca with infusion flow rates < 60 ml/min during PhC) had a steeper initial slope of the pressure-flow relationship during SaC and a greater increase in penile circumference and Pca after intracavernosal injection of papaverine-phentolamine than those with an impaired venoocclusive mechanism. From the electrical analog model, initial steepness of the pressure-flow relationship (slope) during SaC mainly represented subtunical venular resistance, whereas maintenance of flow during PhC depended on overall function of the different components, i.e., subtunical venular resistance, cavernosal and subtunical compliances, and full relaxation of cavernosal smooth muscle. We conclude that the proposed analog model can be used to interpret and characterize clinical penile hemodynamic data and may provide guidelines for more successful management of patients with erectile dysfunction.

Conservation of position and sequence of a novel, widely expressed gene containing the major human alpha-globin regulatory element

We have determined the cDNA and genomic structure of a gene (-14 gene) that lies adjacent to the human alpha-globin cluster. Although it is expressed in a wide range of cell lines and tissues, a previously described erythroid-specific regulatory element that controls expression of the alpha-globin genes lies within intron 5 of this gene. Analysis of the -14 gene promoter shows that it is GC rich and associated with a constitutively expressed DNase 1 hypersensitive site; unlike the alpha-globin promoter, it does not contain a TATA or CCAAT box. These and other differences in promoter structure may explain why the erythroid regulatory element interacts specifically with the alpha-globin promoters and not the -14 gene promoter, which lies between the alpha promoters and their regulatory element. Interspecies comparisons demonstrate that the sequence and location of the -14 gene adjacent to the alpha cluster have been maintained since the bird/mammal divergence, 270 million years ago.

Correlation of American Urological Association symptom index with obstructive and nonobstructive prostatism

The precise role of the American Urological Association (AUA) symptom index in the management of benign prostatic hyperplasia (BPH) is not well established. The AUA symptom index has been recommended only for quantifying the symptoms of BPH but not for its diagnosis. However, to our knowledge the ability to discriminate obstructive from nonobstructive BPH using the AUA symptom index has never been investigated. To establish the relationship between the AUA symptom index and prostatic obstruction 125 men (mean age 67.7 +/- 8.4 years) with voiding dysfunction presumably related to BPH were analyzed. Patients were given the AUA symptom questionnaire, following which video urodynamic studies were done, including micturitional urethral pressure profilometry for specifically diagnosing outlet obstruction. The patients were divided into 2 groups: group 1-78 with primary BPH dysfunction and group 2-47 with prostatism of ambiguous etiology. The mean AUA symptom index in group 1 (15.5 +/- 7.1) was not statistically different from that in group 2 (14.8 +/- 7.9). In both groups the mean AUA symptom index in the patients with obstruction (15.3 +/- 7.2 for group 1 and 13.9 +/- 7.9 for group 2) was not statistically different from that in the nonobstructed group (17.0 +/- 5.4 and 16.1 +/- 7.9, respectively). Of the severely symptomatic patients 22% did not have obstruction whereas all mildly symptomatic patients did. No significant correlations were found between the severity of obstruction and the AUA symptom index in either group. These observations indicate that the AUA symptom index cannot discriminate obstructed from nonobstructed BPH cases, not all severely symptomatic BPH patients will have outlet obstruction, a significant proportion of mildly symptomatic BPH patients can have outlet obstruction and voiding dysfunctions in elderly men, regardless of the etiology, produce similar symptoms.

Prostate cancer screening: role of the digital rectal examination and prostate-specific antigen

BACKGROUND

This study was designed to determine the efficacy of digital rectal examination (DRE) and serum prostate-specific antigen (PSA) for early detection of prostate cancer in men > or = 50 years of age.

METHODS

A prospective single-center clinical trial was conducted to screen 644 asymptomatic men, who were elicited by newspaper and radio advertisements, with DRE and PSA. Quadrant biopsy examinations of the prostate were performed if PSA > 4 ng/ml or if DRE was suspicious.

RESULTS

Thirty-seven percent of the men (n = 241) had an abnormality of DRE or elevated PSA. Of the 163 patients who underwent transrectal ultrasound and quadrant biopsies of the prostate, 77% had normal biopsies, 14 (8%) had prostatic intraepithelial neoplasia, and 24 (15%) had carcinoma of the prostate. PSAs ranged from 0.3 to 65.5 ng/ml, with a mean of 2.35 and a median of 1.6. Ninety-five patients had a PSA > 4 ng/ml, of whom 17 had a PSA > 10 ng/ml. Sensitivity of PSA was 75% and specificity 87%; for DRE the sensitivity was 75% and the specificity 69%. Clinical stage of patients who underwent radical prostatectomy was B1 in 15 and B2 in five. Fifteen of 20 patients (75%) had organ-confined disease; the other five had specimen-confined disease. No patient was found to have nodal involvement.

CONCLUSION

The combination of PSA and DRE seems to improve the stage of diagnosis of patients with prostate cancer. Larger, randomized studies will be necessary to evaluate the effect of screening on overall survival.

Diagnosis and treatment of psychogenic erectile dysfunction in a urological setting: outcomes of 18 consecutive patients

The diagnostic criteria and treatment outcomes of 18 consecutive patients with psychogenic erectile dysfunction were examined. Average patient age was 38 years, and all patients had either awakening penile or masturbatory rigidity. Each patient was studied with home monitoring (ART-1000) on 2 consecutive nights. The average number of maximum erectile episodes, the event during which the maximum rigidity was maintained for at least 5 minutes, was 1.6. The maximum sleep erectile episodes averaged 11.2 minutes during which penile rigidity averaged 572 gm. The main predictor for remission of erectile dysfunction in this study was whether the dysfunction was primary or secondary. Of 14 patients with secondary psychogenic erectile dysfunction, that is history of being able to achieve and maintain penile rigidity sufficient for at least 5 minutes of vaginal intercourse, 10 (71%) experienced remission. Three patients noticed spontaneous remission during the initial evaluation and another 3 experienced remission within 3 months of completion of the evaluation and reassurance that they had normal erectile capacity. Two patients had remission while considering penile vascular surgery and in 2 normal erectile function returned during injection therapy. Only 2 of 3 patients referred for sex therapy actually received it (Freudian theory), and neither noticed improvement in erectile function. One patient received yohimbine without benefit. None of the patients elected treatment with the vacuum constriction device. All 4 patients with primary psychogenic erectile dysfunction, that is never able to achieve and/or maintain penile rigidity sufficient to achieve vaginal intercourse, failed to respond to physician reassurance and time. Of 2 patients who received sex therapy (1 Freudian and 1 behavioral) without improvement in erectile function 1 has entered the pharmacological erection program and has achieved vaginal penetration, and the other is considering the pharmacological erection program. The remaining 2 patients have deferred all therapy. Based on this experience, we currently reassure patients with secondary psychogenic erectile dysfunction that they have erectile capacity for sustained vaginal intercourse and schedule a followup visit in 3 months. Additional individualized therapy (pharmacological erection program, vacuum constriction device, sensate focus/psychodynamic specific therapy or penile prosthesis) is offered as needed and requested. Patients with primary psychogenic erectile dysfunction are initially offered the pharmacological erection program or the vacuum constriction device and sex sensate focus/psychodynamic specific therapy. The penile prosthesis is considered for treatment failures.

Structure of the human 3-methyladenine DNA glycosylase gene and localization close to the 16p telomere

We recently reported the presence of four genes lying between the human alpha-globin gene cluster and the telomere of the short arm of chromosome 16 (16p). We now report that one of these genes encodes 3-methyladenine DNA glycosylase, an enzyme important in the repair of DNA after damage by alkylating agents. The gene comprises five exons, representation of which differs in independently isolated cDNA clones. Although the gene is widely expressed, the abundance of its mRNA is considerably higher in a colon adenocarcinoma cell line (HT29) than in other cell lines that were tested. The major positive erythroid-specific regulatory element controlling alpha-globin gene expression lies equidistant between the promoters of the alpha-globin genes and the 3-methyladenine DNA glycosylase gene. Interestingly, in contrast to the alpha-globin genes, expression of the 3-methyladenine DNA glycosylase gene is not influenced by the regulatory element in the human erythroleukemia cell line K562.

Correlation of duplex sonography with arteriography in patients with erectile dysfunction

OBJECTIVE

Our objective was to assess the accuracy of using measurements of peak systolic velocity in the cavernosal artery for the diagnosis of arteriogenic impotence.

MATERIALS AND METHODS

Twenty consecutive men with erectile dysfunction had duplex sonography after intracavernosal injection of papaverine to induce an erection. Peak systolic velocities in the right and left cavernosal arteries were measured by using Doppler sonography. Right and left selective penile arteriography was performed with low-osmolality contrast media after intracavernosal injection of papverine and intraarterial tolazoline. On the basis of the angiographic findings, penile arterial function was classified as normal, moderately insufficient, or severely insufficient. Doppler measurements of peak systolic velocity were correlated with arteriographic results.

RESULTS

All 11 cavernosal arteries with peak velocities less than 25 cm/sec were associated with arterial disease, nine severe and two moderate. Thirteen of 17 carvernosal arteries with peak systolic velocities 25-34 cm/sec were associated with arterial disease, five severe and eight moderate. Only one of the 12 cavernosal arteries with peak velocity at or greater than 35 cm/sec was associated with arterial disease.

CONCLUSION

We conclude that peak systolic velocity in the cavernosal artery as measured on duplex sonography is an accurate predictor of arterial disease in patients with erectile dysfunction. A peak systolic velocity of at least 35 cm/sec indicates normal arterial supply. At peak systolic velocities less than 35 cm/sec, the likelihood and severity of arterial disease increase as the peak systolic velocity decreases, with a peak velocity less than 25 cm/sec indicating a high likelihood of severe arterial disease.

Microsurgical nerve graft repair of the ablated cavernosal nerves in the rat

Erectile dysfunction is a significant complication of radical pelvic surgery in men. Using the rat as an experimental model, we investigated the feasibility of repairing surgically ablated cavernosal nerves. Known fertile male Sprague-Dawley rats were randomly divided into three surgical groups of 30 animals (60 study nerves) per group consisting of nerve ablation, immediate nerve reconstruction, and control groups. The nerve ablation group had 5-mm sections of the cavernosal nerve excised bilaterally. The nerve graft group had 5-mm sections of the cavernosal nerve excised bilaterally, followed by immediate microsurgical reconstruction with an autologous interposition nerve graft utilizing the ipsilateral genitofemoral nerve bilaterally. The anastomoses were performed with 10-O nylon sutures at 16 to 25x magnification. The control group underwent sham operations with the cavernosal nerves being exposed only. Erectile function was evaluated at 1, 2, 4, and 6 months postoperatively. Return of erectile function was defined as tumescence of the corporal bodies with application of direct electrical stimulation (3 V of 5 msec pulses at 20 Hertz) to the proximal cavernosal nerves. The 4- and 6-month electrical stimulation studies resulted in tumescence from 65 and 75% of the grafted nerves, which represented a significant difference compared to the ablated group 11 and 5%, respectively (P less than 0.001 at 4 and 6 months). Behavioral copulatory studies, performed prior to electrical stimulation testing, corresponded closely with the results of electrically induced tumescence. We conclude that in this experimental model immediate nerve graft repair appears to be a successful method of salvaging erectile function when the cavernosal nerves have been divided.

Entubulization repair of severed cavernous nerves in the rat resulting in return of erectile function

Erectile dysfunction is a significant complication of radical pelvic surgery in men. Using the rat as an experimental model, we investigated the feasibility of repairing surgically ablated cavernous nerves utilizing silastic tube nerve growth conduits filled with nerve growth enhancing media. Known fertile male Sprague-Dawley rats were randomly divided into four surgical groups consisting of nerve ablation, immediate nerve reconstruction utilizing the entubulization technique (two groups) and control. The nerve ablation group had five mm. sections of the cavernosal nerve excised bilaterally. The entubulization nerve graft group had five mm. sections of the cavernous nerve excised bilaterally, followed by immediate microsurgical reconstruction with a silastic nerve tube conduit filled with either Matrigel and heparin (MA) or Matrigel and heparin plus acidic fibroblast growth factor (MA/aFGF), interposed between the severed cavernous nerve stumps bilaterally. The control group underwent sham operations with the cavernous nerves being exposed only. Erectile function was evaluated at one, two, and four months postoperatively. Return of erectile function was defined as tumescence of the corporal bodies with application of direct electrical stimulation (four volts of five millisecond pulses at 20 Hertz) to the proximal cavernous nerves. The two and four month electrical stimulation studies resulted in tumescence from 50% and 58% of the entubulization nerve reconstructed nerves with MA/aFGF versus 29% and 30% for the MA only group and only 5% and 11% for the ablated group, respectively. We conclude that in this experimental model immediate nerve graft repair utilizing entubulization techniques with the addition of nerve growth enhancing media appears to be a successful method of salvaging erectile function when the cavernous nerves have been divided.

Cystic testicular mass caused by dilated rete testis: sonographic findings in 31 cases

We reviewed the scrotal sonograms of 31 patients who had a testicular mass consisting of multiple small spherical or tubular anechoic structures in the region of the mediastinum testis. The median age of the patients was 62 years (range, 31-76 years). The abnormality was unilateral in 22 patients and bilateral in nine. Thirty-four (85%) of the 40 involved testicles had coexisting epididymal abnormalities: 32 with epididymal cysts and two with epididymitis. Follow-up sonograms were available in five patients and showed no change up to 4.5 years after the initial diagnosis. Surgical and histologic findings were available in one other patient and showed dilatation of the rete testis. The sonographic appearance and location of the lesions, the frequent presence of an epididymal abnormality, and the surgical and histologic findings in one case suggest that the lesion is due to dilatation of the rete testis, probably associated with obstruction in the epididymis. Recognition of this entity on sonograms may prevent unnecessary orchiectomy.

Cis-acting sequences regulating expression of the human alpha-globin cluster lie within constitutively open chromatin

Current models suggest that tissue-specific genes are arranged in discrete, independently controlled segments of chromatin referred to as regulatory domains. Transition from a closed to open chromatin structure may be an important step in the regulation of gene expression. To determine whether the human alpha-globin cluster, like the beta-globin cluster, lies within a discrete, erythroid-specific domain, we have examined the long-range genomic organization and chromatin structure around this region. The alpha genes lie adjacent to at least four widely expressed genes. The major alpha-globin regulatory element lies 40 kb away from the cluster within an intron of one of these genes. Therefore, unlike the beta cluster, cis-acting sequences controlling alpha gene expression are dispersed within a region of chromatin that is open in both erythroid and nonerythroid cells. This implies a difference in the hierarchical control of alpha- and beta-globin expression.

A PCR-based strategy to detect the common severe determinants of alpha thalassaemia

A rapid and inexpensive polymerase chain reaction (PCR) based strategy is described which detects the three common, severe alpha thalassaemia determinants observed in southeast Asia (--SEA) and the Mediterranean (--MED and -(alpha)20.5). Oligonucleotide primers have been chosen which allow specific identification of both normal (alpha alpha) and abnormal (--) chromosomes using identical conditions in either the same or parallel PCR reactions. This strategy should be useful in the development of screening programmes to identify carriers of alpha thalassaemia (--/alpha alpha) and prenatal diagnosis of the Hb Bart's hydrops fetalis syndrome (--/--) for those populations in which this represents a major cause of perinatal death.

The current cavernosometric criteria for corporovenous dysfunction are too strict

In an attempt to define the hemodynamic and radiographic parameters of normal erectile function 6 patients 20 to 41 years old (mean age 30.3 years) with erectile dysfunction that spontaneously resolved after a comprehensive evaluation were reviewed. The results included normal hormonal assays, normal penile biothesiometry and normal penile brachial index. The sleep tumescence and rigidity tracings were abnormal according to the criteria that sleep erections occur every 90 minutes, are associated with penile rigidity of greater than 550 gm. plus an increase in penile circumference of greater than 1.5 cm. and last longer than 15 minutes. High resolution ultrasonography, pulse wave Doppler ultrasound, dynamic pharmacocavernosometry and dynamic cavernosography were performed. After testing the patients were informed that no organic abnormalities had been detected. No medical or surgical treatment was given. The hemodynamic values are presented as suggested normal parameters: maintenance rate (mean 11 +/- 3 cc per minute), initial decompression rate (mean 59 +/- 17 mm. Hg/30 seconds) and radiographic findings (visualization of the cavernous, external pudendal and deep dorsal veins during pharmacocavernosography, performed at intracorporeal pressures of 100 mm. Hg). All 6 patients had maintenance rates of greater than 5 cc per minute. Of these 6 patients 5 had initial decompression rates of greater than 48 mm. Hg/30 seconds and 4 had 5-minute, post-infusion steady state values of less than 50 mm. Hg, criteria that have been used to define corporovenous dysfunction.

Acute urinary retention secondary to Herpes simplex meningitis

We report a case of acute urinary retention in a 24-year-old man with Herpes simplex meningitis without genital lesions. Since the differential diagnosis in young patients who present with acute urinary retention also includes multiple sclerosis, lumbosacral disk herniation, rheumatological disorders and drug intoxication, a thorough history and careful neurological examination are of paramount importance in distinguishing these syndromes. As part of a directed neurological evaluation prompt performance of lumbar puncture is indicated; a lymphocytic pleocytosis is suggestive of herpetic meningitis. Culture of Herpes simplex virus from the cerebrospinal fluid should be attempted. We recommend conservative management only, typically with intermittent catheterization, since bladder function usually normalizes within 10 to 14 days.

Alpha-thalassemia caused by a large (62 kb) deletion upstream of the human alpha globin gene cluster

We describe a family in which alpha-thalassemia occurs in association with a deletion of 62 kilobases from a region upstream of the alpha globin genes. DNA sequence analysis has shown that the transcription units of both alpha genes downstream of this deletion are normal. Nevertheless, they fail to direct alpha globin synthesis in an interspecific hybrid containing the abnormal (alpha alpha)RA chromosome. It seems probable that previously unidentified positive regulatory sequences analogous to those detected in a corresponding position of the human beta globin cluster are removed by this deletion.

Corpora cavernosa ultrastructure in vascular erectile dysfunction

Open biopsy of the corpus cavernosum was performed in 13 nondiabetic patients with erectile dysfunction. The history and physical examination, sleep rigidity and tumescence monitoring, hormonal assays, duplex ultrasonography with papaverine, and cavernosometry and cavernosography, formed the basis of categorizing each patient into 1 of 5 etiological groups. These groups included neurogenic, moderate arterial, severe arterial, venous and fibrotic causes for organic erectile dysfunction. The cavernous smooth muscle and endothelium in each patient appeared to be normal on light and electron microscopy. We conclude that cavernous biopsy is of limited value to determine therapeutic options in patients with erectile dysfunction.

High resolution ultrasonography and pulsed wave Doppler for detection of corporovenous incompetence in erectile dysfunction

Cavernosometry and cavernosography have been the primary modalities available for detection and mapping of corporovenous incompetence in patients with erectile dysfunction. These procedures are expensive, time-consuming and associated with some morbidity, prompting us to study a less invasive method, high resolution ultrasonography and pulsed wave Doppler ultrasound. We evaluated 13 patients with nonendocrinological, nonneurological erectile dysfunction by high resolution and Doppler ultrasound for flow in the dorsal and cavernosal veins after intracorporeal papaverine. All patients had a nonrigid response to papaverine and a mean maximum cavernous arterial systolic velocity of greater than 25 cm. per second. The 13 patients were subsequently studied by dynamic cavernosometry and cavernosography, which revealed evidence of venous incompetence (12 with dorsal venous leaks and 11 with cavernous venous leaks). Only 5 of the 12 patients with dorsal venous incompetence had flow detected in the dorsal vein by ultrasound and Doppler studies. High resolution and Doppler ultrasound was unable to detect leakage in the cavernous veins. Among the 2 groups of patients with dorsal venous leaks (those with and without flow detectable by Doppler ultrasound) there was no significant difference in mean cavernous artery diameter or mean cavernous arterial maximum velocity. Similarly, there was no significant difference between the 2 groups in induction, maintenance or initial decompression rates on cavernosometry. We conclude that high resolution and Doppler ultrasound cannot replace dynamic cavernosometry and cavernosography as the diagnostic modality for venous incompetence.

Alpha thalassaemia in two Spanish families

Two Spanish families with alpha thalassaemia, including 4 individuals with Hb H disease, are described. DNA mapping shows that, in addition to the common alpha thalassaemia determinant (-alpha 3.7), a different and previously unreported allele is present in each family. In one, there is a deletion of 10.5-12 kb of DNA including both alpha genes (--SPAN). In the other, a deletion of more than 100 kb has removed the entire alpha globin gene complex (--BR).

Sexual impotence caused by vascular disease: diagnosis with duplex sonography

We used duplex Doppler sonography to assess the hemodynamic function of the penis in patients with impotence to determine if there is arterial disease or if the veins are incompetent. The penis was scanned in the flaccid state, then again after erection was induced by intracorporal injection of papaverine. The diameter of each cavernosal artery was measured before and after injection and, by using Doppler sonography, the maximal systolic velocity in each cavernosal artery was measured. The Doppler gate was placed over the dorsal vein to detect any flow in that vein signifying venous leakage. The Doppler gate then was placed over the cavernosal veins in an attempt to detect cavernosal venous incompetence. Forty-five men with impotence were included in the study. In 39 patients, the cause of impotence was confirmed by other studies. The diameter of the cavernosal arteries and the increase in diameter of these arteries after induction of an erection were similar in all diagnostic groups. The peak systolic velocity, however, was decreased in patients with arterial insufficiency as compared with the velocity in normal subjects. In normal subjects, the mean peak velocity was 47 +/- 9 cm/sec; in patients with mild to moderate arterial insufficiency it was 35 +/- 16 cm/sec; in patients with severe arterial insufficiency it was 7 +/- 8 cm/sec. The difference in peak velocities between the right and left cavernosal arteries after papaverine injection (asymmetric arterial response) was significantly larger in patients with mild to moderate arterial insufficiency than in other diagnostic groups. Four patients with venous incompetence had detectable flow in the dorsal vein, but no flow could be detected with Doppler sonography in the cavernosal veins in any patients, including those who were proved to have significant cavernosal venous leaks. Our findings suggest that Doppler measurement of maximal systolic velocity in the cavernosal arteries after papaverine injection is an accurate indicator of arterial function. Asymmetric flow in the cavernosal arteries also suggests some degree of arterial insufficiency. Diameters of the cavernosal arteries and their increase after injection are not predictive of arterial patency. Doppler sonography cannot show cavernosal venous leakage, but in some cases it can show dorsal venous incompetence.