Ouabain-inhibiting activity of aldosterone antagonists

It has been suggested that endogenous substances (known as ouabain-like factors, OLF), secreted from the central nervous system in response to salt and water retention, inhibit the cell membrane Na+/K+ pump in the renal tubules and reduce sodium reabsorption. However, by also acting upon vascular smooth muscle cells, they may induce cell Na+ and Ca++ accumulation, vasoconstriction and systemic hypertension. Recently, an endogenous Na+/K+ pump inhibitor was isolated from human plasma; this inhibitor is indistinguishable from the cardiac glycoside ouabain based on biochemical and immunological criteria. Its plasma concentration is close to the therapeutic range for ouabain (around 0.4 nmol/L). Since plant ouabain promotes natriuresis, vasoconstriction, and hypertension; endogenous ouabain may therefore control extracellular fluid volume and blood pressure. The highest plasma concentrations of endogenous ouabain and OLF were found in congestive heart failure, aldosterone producing adenoma, human and animal models of volume expanded hypertension (reduced renal mass and DOCA-salt hypertension), and in Milan hypertensive rats (MHS). Aldosterone antagonists (canrenone and canrenoate) exert both agonist and antagonist effects on the digitalis receptor site of the Na+/K+ pump. They are effective antihypertensive agents in animal models of hypertension sustained by OLF (reduced renal mass-Na+ and DOCA-salt hypertension in rats). Moreover, in a subgroup of essential hypertensives, 4 weeks of canrenoate administration reduced blood pressure, heightened red blood cell Na+/K+ pump activity, and antagonized ouabain-induced vasoconstriction. None of these effects was seen in the other hypertensives. These data suggest that aldosterone antagonists stimulate the Na+/K+ pump inhibited by endogenous ouabain and exert their antihypertensive action at least in part through this mechanism.

Lung abscess due to Streptococcus mitis: case report and review

Streptococcus mitis is a bacterium traditionally regarded as a normal commensal of the oropharynx, skin, and intestinal and genital tracts. To our knowledge, we describe the first case of bilateral lung abscesses caused by S. mitis in an immunocompetent host. The abscesses were successfully treated with clindamycin and gentamicin. Our case illustrates that S. mitis should be considered a cause of pulmonary abscesses.

[Pressure and metabolic effects of terazosin in essential hypertension]

To assess the efficacy and safety of different doses of the alpha-1 blocker terazosin on long-term therapy, 12 essential hypertensives (7 males, 5 females, aged 27-61) were investigated. The study was conducted according to the Latin square design and each patient underwent 4 periods of treatment with 2, 5, 10 mg/day terazosin and placebo, in a double-blind, randomized order. Each treatment lasted 4 weeks. In comparison to placebo, a fall in diastolic pressure was observed already with the 2 mg/daily dose, with a decrease > 10 mmHg in 7 patients (responders). Body weight increased in a dose dependent manner, while atrial natriuretic peptide, serum glucose and insulin during oral glucose tolerance test, total cholesterol, HDL and LDL cholesterol, triglycerides were unaffected. It is concluded that terazosin is effective and safe in essential hypertensives already at 2 mg daily dose. Further reduction in blood pressure at higher doses is likely to be counteracted by salt and water retention.

Malignant pleural effusion from prostatic adenocarcinoma resolved with hormonal therapy

A 73-year-old man presented with dyspnea, right-sided pleural effusion, and bilateral pulmonary infiltrates. The pleural fluid revealed adenocarcinoma cells that stained positively for prostatic specific antigen (PSA), which confirmed this uncommon metastatic involvement from prostate cancer. The dyspnea, effusion, and infiltrates disappeared after therapy with flutamide and leuprolide was started. This report demonstrates both the usefulness of immunocytochemical staining for PSA in ascertaining the origin of malignant pleural effusion in men and the effectiveness of the aforementioned endocrine therapy in such setting.

Interactions between insulin and sodium homeostasis in essential hypertension

It has been proposed, therefore, that hyperinsulinemia may favor the development of hypertension through sodium retention, sympathetic nervous system activation, and vascular hypertrophy. In insulin-resistant hypertensive subjects, insulin infusion during euglycemic clamp promotes a transient sodium retention by stimulating proximal tubular Na+ reabsorption, but chronic hypertension usually is not associated with extracellular fluid and plasma volume expansion. In essential hypertensive subjects, intracellular potassium is decreased and intracellular sodium increased, which is consistent with insulin resistance. The latter is also associated with high red blood cell Li+/Na+ exchange, and chronic insulin treatment in insulin-dependent diabetics induces a slight increase in Li+/Na+ CT. This is a functioning mode of the Na+/H+ exchange, and its increase may reflect either an increased number of transport units or abnormal kinetic properties. Experiments in vitro and in vivo suggested that any change in insulin concentration and insulin sensitivity may affect Li+/Na+ and Na+/H+ counter-transport. High Li+/Na+ and Na+/H+ CT are associated with a significant cardiac and vascular remodeling in essential hypertension, insulin-dependent diabetes, and familiar hypertrophic cardiomyopathy. Reduced insulin sensitivity is associated with salt-sensitive hypertension. Finally, insulin potentiates the effects of other agonists (eg, thromboxane A2, angiotensin II) on vascular contraction and cell growth. These data indicate that insulin may play a role in the pathogenesis of hypertension and its major complications by amplifying the effects of sodium, vasoconstrictors, and growth factors.

Fish oils and their possible role in the treatment of cardiovascular diseases

The multifactorial origin of arteriosclerotic cardiovascular diseases is well recognized. It recently has been shown that n-3 fatty acids (FA), contained in fish oils, may correct some of the most important cardiovascular risk factors and may interfere with key steps in the formation of the atherosclerotic plaque. These findings have raised such interest that many reports have been published with somewhat conflicting results. In hypertensive patients, randomized controlled studies have confirmed that n-3 FA may reduce systolic blood pressure by 5 mmHg and diastolic by 4 mmHg. The decrease in pressure, which could be larger if dietary sodium restriction is added, is probably due to the shift of balance between vasoconstrictive and vasodilator eicosanoids toward vasodilatation. n-3 FA correct endogenous hypertriglyceridemia, but the effects on low-density lipoprotein and high-density lipoprotein cholesterol are less clear cut, since an increase in low-density lipoprotein and a decrease in high-density lipoprotein may be observed in selected patients. As far as the glucose metabolism in patients with diabetes mellitus is concerned, inhibition of the beta cell by n-3 FA has been reported. n-3 FA reduce platelet aggregation, blood viscosity, plasma levels of fibrinogen, PF4 and beta-thromboglobulin and increase capillary flow and red cell membrane fluidity, but their long-term effects on cardiovascular mortality are largely unknown. Medium-term studies, however, have shown a decreased risk of myocardial reinfarction and of restenosis after percutaneous transluminal coronary angioplasty with n-3 FA supplementation. Pure, highly concentrated triglycerides and ethyl esters of n-3 FA are available and will allow further investigations on the dose-response ratio in humans.

Other fungal arthritides

Fungi are not a common cause of musculoskeletal infection; however, reports of fungal bone and joint infections have lately surged and are expected to increase more. There is evidence of an increasing incidence of pathogenic and opportunistic fungal infections and emergence of new species of disease-causing fungi, particularly in immunosuppressed patients. Distribution is worldwide, signs of infection can be mild, and chronic evolution as well as delayed diagnosis are common.

Ototoxicity of erythromycin in man: electrophysiologic approach

Ototoxicity is probably the least acknowledged adverse reaction of erythromycin. The mechanism of erythromycin ototoxicity is still unknown. Here we report on two new cases of erythromycin-induced hearing loss. In both of them, serial evoked auditory brainstem potentials (EABPs) were obtained. The recorded EABPs showed absence of waves I to III during treatment with erythromycin, and normalization of all EABP waves after the administration of erythromycin had been stopped. Our findings support the hypothesis that erythromycin-induced hearing loss is attributable to a functional disorder in the peripheral parts of the auditory system.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) and enalapril

A 69-year-old woman with a history of diabetes and hypertension, was referred to the Hospital of Laredo because of hyponatraemia. She had weakness and slight dyspnoea with no evidence of extracellular fluid volume depletion or oedema. Serum sodium level on admission was 125 mol l-1, plasma osmolality 270 mosmol kg-1, simultaneous urine osmolality was 580 mosmol kg-1 and urine sodium 32.6 mmol l-1. She had been treated with enalapril (20 mg) daily for 4 months. She was diagnosed with the Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) that was reversed after cessation of treatment with enalapril and reappeared on reintroduction of the drug at the same daily doses.

[Hypertension and arteriosclerosis]

Arterial hypertension is a major risk factor for atherosclerosis. The mechanisms involved include elevation of blood pressure, increased velocity of the sphygmic wave and increased blood flow turbulence. These hemodynamic features however do not fully explain the link between hypertension and atherosclerosis. An important role is also played by humoral factors including catecholamines, the renin-angiotensin-aldosterone system, serotonin, endothelin, platelets and endothelium-derived growth factors. Furthermore in the last few years great relevance has been attributed to hyperinsulinemia (accompanied by hypercholesterolemia and hypertriglyceridemia) that is frequently found in hypertensive subjects. Several recent reports on the antiatherogenic effect of some antihypertensive agents that could slow down the progression of atherosclerotic lesions in hypertensive subjects are promising.

Aortic bypass graft infection due to Aspergillus: report of a case and review

Aspergillus is a rare cause of aortic graft infection. A recent case is reported and a review of seven other cases described in the literature since 1966 is presented. Infections of both thoracic and abdominal aortic grafts have been reported. Infection occurred from 5 weeks to 3 years after surgery. Underlying immunosuppressive disorders were not present. The most common presenting symptoms were back pain, fever, and embolic phenomena. Pseudoaneurysm of the vascular prosthesis with contiguous vertebral osteomyelitis was frequently seen. Blood cultures were always negative. Laboratory findings were nonspecific. The diagnosis was not anticipated in any case. Aspergillus was isolated in culture of specimens of the vertebral bone, excised graft, or peripheral emboli. Aspergillus fumigatus was the species most frequently isolated. Infection may have occurred intraoperatively as a result of contamination with airborne fungal spores. Optimal treatment included early removal of the graft with extraanatomical bypass plus prolonged antifungal therapy. Delayed surgical intervention and medical therapy alone were associated with high mortality rates. Aspergillar vascular infection should be suspected in patients with aortic grafts who develop persistent back pain, fever, or arterial embolization, and whose blood cultures are sterile.

Is the routine measurement of ionized calcium worthwhile in patients with cancer?

This study was undertaken to analyse the relationship between total calcium (TCa) and ionized calcium (ICa) in patients with cancer, and to assess the clinical value of routine measurements of ICa in these patients. Serum TCa, ICa, albumin, proteins and creatinine were measured in 188 adult patients with solid malignant tumours. Most of them were out-patients, the Karnofsky score being 80 or above in 67%. The correlation coefficient between ICa and TCa was 0.85 (P less than 0.001) and did not improve after correcting TCa for protein concentration with several published formulae. Although TCa measurements had a global diagnostic accuracy (percent of patients correctly classified) of 90%, they failed to identify a substantial proportion of patients with increased levels of ICa (57% for uncorrected TCa, and 27-57% for protein-corrected TCa). However, the finding of slightly increased ICa levels did not seem to predict the development of frank hypercalcaemia and did not impair the prognosis. According to these results, the routine measurement of ICa in unselected patients with cancer has no clinical usefulness.

[Doxazosin for the treatment of arterial hypertension]

Hypertension is often associated to other risk factors, such as abnormal lipid and carbohydrate metabolism, which should be considered for the choice of antihypertensive drug treatment. Doxazosin is a postsynaptic alpha-1 adrenoceptor blocker suitable for once a day treatment regime. It seems to induce fewer side effects than older drugs of the same class and it may improve lipid and carbohydrate profile, thereby reducing the risk of coronary artery disease. To verify its effects on blood pressure, serum lipids and glucose tolerance, doxazosin (1-8 mg od) was given for 8 weeks to 32 patients suffering from essential hypertension, of whom 16 had fasting serum cholesterol higher than 6 mmol/l and/or fasting serum triglycerides higher than 1.9 mmol/l. Sitting and standing blood pressure were significantly reduced (from 163 +/- 18/101 +/- 6 mmHg to 147 +/- 19/94 +/- 8, p less than 0.001 and from 162 +/- 18/107 +/- 9 to 145 +/- 18/95 +/- 8, p less than 0.001, respectively) at a mean daily dose of 5 mg. Normotension or a good hypotensive response was achieved in 60% of the patients. The daily dose which turned out to be effective in 50% of the patients was 7 mg. The drug treatment was well tolerated and orthostatic hypotension was never observed either on starting treatment or on increasing dosage. Blood lipids and glucose tolerance were not significantly affected. Doxazosin is therefore an effective antihypertensive agent suitable for use in patients with essential hypertension alone or combined with hyperlipidemia.

Tuberculous peritonitis: a study comparing cirrhotic and noncirrhotic patients

Tuberculous peritonitis is a rare disease, which often goes unrecognized because of the subtle clinical clues and its insidous onset. We retrospectively analyzed the records of 37 cases of tuberculous peritonitis diagnosed over a 15-year period, and compared the clinical and diagnostic features of cirrhotic and noncirrhotic patients. In cirrhotic patients, tuberculous peritonitis can simulate ascites from liver disease or spontaneous bacterial peritonitis. The diagnosis is difficult in these patients because the ascitic fluid may not be of the exudative type as a result of the low albumin level in serum, and lymphocytes do not predominate in all cases. Adenosine deaminase (ADA) activity in ascitic fluid was elevated (higher than 40 U/L) in all 11 patients (four patients with hepatic cirrhosis). The time required to achieve a correct diagnosis was significantly longer in cirrhotic than in noncirrhotic patients. The overall mortality was 13%, with deaths occurring exclusively among cirrhotic patients. We emphasize that tuberculous peritonitis in cirrhotic patients can present an atypical picture. A considerable element of suspicion is necessary.

The clinical spectrum of hypocalcaemia associated with bone metastases

Malignancy-related hypocalcaemia has received less attention in the literature than the opposite perturbation, hypercalcaemia. Only, scarce and contradictory data exist about hypocalcaemia associated with bone metastases (BMH). We have reviewed the clinical records of 155 patients with bone metastases of solid tumours, 122 of which were followed during the whole course of the disease until death. The frequency of hypocalcaemia ranged from 5 to 13%, depending on the formula used to correct calcium values for protein concentration. BMH was almost exclusively limited to patients with osteoblastic metastases. The frequency of BMH among patients with prostate carcinoma was 13-27%, depending on the formula used. Only two of 60 patients with lytic bone lesions presented hypocalcaemia, and in both cases it was rather mild. The development of hypocalcaemia did not seem to imply a worse prognosis, at least in patients with carcinoma of the prostate. Thus, the prevalence of BMH appears to be higher than is usually considered. Adequate attention should be given to this disorder because of the potentially deleterious effects on several organ systems.

Plethysmographic effects of doxazosin in essential hypertensive patients

In the treatment of hypertensive patients with peripheral vascular disease, alpha 1-adrenoceptor blockers may be considered first-choice drugs since they reduce the total peripheral resistance and do not decrease the plasma volume. As a preliminary step, we investigated the plethysmographic effects of doxazosin (1-8 mg for 6 weeks) on calf flow in 32 uncomplicated hypertensive patients. Despite the fall in sitting and standing blood pressure (from 163 +/- 18/101 +/- 6 to 147 +/- 19/94 +/- 8 mmHg and from 162 +/- 18/107 +/- 9 to 145 +/- 18/95 +/- 8 mmHg, respectively; both P less than 0.001) the calf flow was not decreased at rest and after ischaemia. Resting resistance was not significantly reduced (from 49.5 +/- 35 to 38.9 +/- 33 mmHg/100 ml per min) but its fall was significantly correlated with the fall in mean blood pressure (rs = 0.35, P less than 0.05). These findings confirm that doxazosin may be useful in the treatment of hypertension complicated by peripheral artery disease.

Outreach to ethnic minorities with Alzheimer's disease: the challenge to the community

This article seeks to outline an outreach strategy to link dementia-affected ethnic minority elderly and their caregivers to community support resources and services. The strategy is based on the combined application of what has been termed culture free principles (appropriately translated, but more universally active approaches) and culture fair (culturally specific) techniques. The strategy calls for the separation of socioeconomic indicators from cultural dynamics. For example, many ethnic minority groups share poverty and attendant underclass status. Languages and customs vary considerably, particularly as related to helpseeking and helptaking behaviors both within and between the four major groups: American Indian/Native Americans, Asian Americans, Blacks, and Hispanics. Natural social network linkages are detailed as part of the overall effort.

Depressive symptoms and their correlates among immigrant Mexican women in the United States

Correlates of depressive symptomatology and caseness are examined for a survey sample of N = 1825 poor Mexican immigrant women in San Diego County, California. The Center for Epidemiologic Studies--Depression (CES--D) checklist is tested against a variety of demographic variables as well as health status and service utilization rates. Statistically significant associations were found between CES--D and education, years in the United States, income, marital status and number of adults in household. Also significant were associations with health status, confidant support and recent, traumatic life event. Utilization rates point to medical doctors as the major source of formal treatment and a heavy reliance on family and friends. The implications of the high disorder rates for diagnosis and treatment among immigrants are discussed.