Atherosclerotic vascular disease is more prevalent among black ESKD patients on long-term CAPD in South Africa

Background

Occurrence of cardiovascular disease (CVD) in the setting of chronic kidney disease (CKD) can be described as a “cruel alliance”, with CVD responsible for about half of all deaths among CKD patients. Chronic kidney disease patients are more likely to die from CVD than progress to end stage kidney disease (ESKD). Dyslipidaemia, a known traditional risk factor for CVD, is highly prevalent among CKD patients and with an even higher frequency among ESKD patients on dialytic therapies. Prolonged exposure of continuous ambulatory peritoneal dialysis (CAPD) patients to high glucose concentrations in CAPD fluid have been associated with increased risk of cardiovascular events. In this study, we investigated the relationship of atherosclerotic vascular disease (AsVD) to clinical and echocardiographic parameters among black South Africans with CKD (stage 3) and ESKD on CAPD and haemodialysis (HD).

Methods

This was a cross-sectional study of 40 adult (18–65 years) non-diabetic CKD patients (kidney disease outcome quality initiative [KDOQI] stage 3), 40 ESKD patients on CAPD, 40 ESKD patients on HD and 41 age and sex-matched healthy controls. An interviewer-administered questionnaire was used to obtain information on participants’ sociodemographic and cardiovascular risk factors. Anthropometric parameters were measured. Serum blood samples were analysed for creatinine, albumin and lipid profile; lipoprotein ratios, Framingham’s risk score and the 10-year risk of developing coronary heart disease (CHD) were calculated. Echocardiography was performed on all patients and carotid intima media thickness (CIMT) was measured in both right and left carotid arteries at 1 cm proximal to the carotid bulb. Spearman’s rank correlation and binary logistic regression were conducted to determine the relationship of AsVD to clinical and echocardiographic parameters.

Results

Atherosclerotic vascular disease was most prevalent among ESKD patients on CAPD (70%, n = 28/40). Chronic kidney disease and HD patients exhibited a similar prevalence (47.5%, n = 19/40), while the prevalence in controls was 17.1% (n = 7/41). Presence of AsVD was associated with significantly older age, higher waist hip ratio (WHR), left ventricular mass index (LVMI) and Framingham’s 10-year risk of developing CHD. Significant differences in clinical and echocardiographic parameters were observed when the study groups were compared. Age and LVH independently predicted AsVD.

Conclusion

Atherosclerotic vascular disease was more prevalent among CAPD patients compared to pre-dialysis CKD and HD patients. Among all lipoprotein ratios assessed, non-HDL-C showed the most consistent significant difference between the groups. Age (> 40 years) and presence of LVH were independent predictors of AsVD.

First description of Mycobacterium tuberculosis and M. canettii concomitant infection: report of two cases

We report the first two cases of tuberculous coinfection with Mycobacterium tuberculosis and M. canettii. Both patients were young Djiboutian females with pulmonary tuberculosis (TB). One had a miliary pattern with concomitant human immunodeficiency virus infection. Both recovered completely with a standard four-drug anti-tuberculosis treatment regimen. Due to the different natural reservoirs and routes of infection of these two strains, our study supports the common belief that multiple strains of infection in TB are related to superinfection rather than concomitant infection.

Identification of patients with preeclampsia from normal subjects using wavelet-based spectral analysis of heart rate variability

BACKGROUND

The spectral analysis of the heart rate variability (HRV) shows a decrease in the power of the high frequency (HF) component in preeclamptic pregnancy compared with normal pregnancy; such a decrease is associated with an increase in the low frequency (LF) and the very low frequency (VLF) power. The physiological interpretation is that preeclamptic pregnancy is associated with a facilitation of sympathetic regulation and an attenuation of parasympathetic influence of HR compared with non-pregnancy and normal pregnancy.

OBJECTIVE

To use an efficient nased on spectral analysis non-invasive technique to identify preeclamptic pregnant subjects from normal pregnant in Oman.

METHODS

The soft-decision wavelet-based technique is implemented to find the power of the HRV bands in high resolution manner compared to the classical fast Fourier Transform method. Data was obtained from 20 preeclamptic pregnant subjects and 20 normal pregnant controls of the same pregnancy duration, obtained from Nizwa and Sultan Qaboos University hospitals in Oman.

RESULTS

The soft-decision wavelet method succeeds to identify patients from normal pregnant with specificity, sensitivity and accuracy of 90%, 80% and 85%, respectively, compared to the FFT which results in 75% specificity, sensitivity and accuracy.

CONCLUSION

The LF power obtained by Soft-decision wavelet decomposition is shown to be a successful feature for identification of preeclampsia.

Classification of sleep apnea using wavelet-based spectral analysis of heart rate variability

BACKGROUND

Obstructive Sleep Apnea (OSA) is the cessation of breathing during sleep due to the collapse of upper airway. Polysomnographic recording is a conventional method for detection of OSA. Although it provides reliable results, it is expensive and cumbersome. Thus, an advanced non-invasive signal processing based technique is needed.

OBJECTIVE

The main purpose of this work is to predict the severity of sleep apnea using an efficient wavelet-based spectral analysis method of the heart rate variability (HRV) to classify sleep apnea into three different levels (mild, moderate, and severe) according to its severity and to distinguish them from normal subjects.

METHODS

The standard FFT spectrum analysis method and the soft-decision wavelet-based technique are to be used in this work in order to rank patients to full polysomnography. Data of 20 normal subjects and 20 patients with mild apnea and 20 patients with moderate apnea and 20 patients of severe apnea are used in this study. The data is obtained from the sleep laboratory of Sultan Qaboos University hospital in Oman. Four different classification versions have been used in this work.

RESULTS

Accuracy result of 90% was obtained between severe and normal subjects and 85% between mild and normal and 75% between severe and moderate and 83.75% between normal and patients.

CONCLUSIONS

The VLF/LF power spectral ratio of the wavelet-based soft-decision analysis of the RRI data after a high-pass filter resulted in the best accuracy of classification in all versions.

Calciphylaxis causing digital, gangrene in end stage renal disease: a case report and review

Calcific uraemic arteriolopathy (CUA), a potentially life-threatening vasculopathy of the skin and subcutaneous tissues is rarely associated with advanced chronic kidney disease (CKD) particularly in patients on haemodialysis. It is more frequently reported in whites than in blacks and commonly accompanies hyperphosphataemia, elevated calcium-phosphate product and marked secondary hyperparathyroidism. We report a rare case of CUA that complicated end stage renal disease secondary to obstructive uropathy in a 68 year old Nigerian. The risk factors for CUA, diagnosis, management and our peculiar limitations were reviewed and discussed.

The pattern, clinical characteristics and outcome of ESRD in Ile-Ife, Nigeria: is there a change in trend?

BACKGROUND

The prevalence of chronic renal failure and End Stage Renal Disease (ESRD) has remained high worldwide and the epidemiology has changed significantly in the last decade in industrialised countries. While there have been significant improvements in these patient's outcomes in developed countries, their state and survival is still appalling in developing countries.

OBJECTIVE

To determine the clinical pattern, presentation and management outcomes in our ESRD population over a 19-year period (1989-2007).

METHODS

Seven hundred and sixty patients' records were reviewed. Data on major causes, clinical presentation, management and survival were retrieved and collated. Data was analysed using SPSS package version 16.

RESULTS

Their ages ranged between 15-90 years (mean ± SD; 39.9±1.67years) with male preponderance (70.3%). Major presenting complaints were body swelling and uraemic symptoms in most studied patients. The predisposing conditions included chronic glomerulonephritis, hypertension, obstructive uropathy and diabetes mellitus. Renal replacement therapy offered included HD in 556(73.2%), Continous Ambulatory Peritoneal Dialysis (CAPD) in only 9(1.2%) patients and renal transplantation in only 7(0.9%). Only 38(6.8%) survived on HD for longer than three months while 7(77.8%) CAPD patients and all transplanted patients survived for between six months and four years (p<0.00001). Median duration of survival after diagnosis for all the patients was 2 weeks (range 0-50 months).

CONCLUSION

End stage renal disease is still prevalent with chronic glomerulonephritis and hypertension being the common causes. Prognosis is still grave hence subsidized renal replacement therapy and preventive nephrology should be targeted in such underserved populations.

An appraisal of kidney dysfunction and its risk factors in patients with sickle cell disease

Sickle cell disease (SCD), a genetically inherited disease of blacks, often presents with disabling acute complications which can occasionally be fatal. Its renal manifestations are increasingly being recognized as affected patients now survive to middle and rarely old age. We set out to determine the magnitude of kidney dysfunction in our SCD patient population and evaluate its predictive factors. We reviewed the available case records of SCD patients managed in our hospital. Information on socio-demographic, clinical and laboratory data were retrieved and collated. A total of 374 (99.46%) were reviewed with complete data; the median age was 23 years (range 7-62), while median age at diagnosis of SCD was 4 years (range 0.25-31). 235 patients (68.2%) had no kidney disease while the remaining 139 (37.2%) had proteinuria, hematuria or reduced glomerular filtration rate (GFR) <60 ml/min. The age of patients was a significant predictor of kidney disease (p = 0.002) and correlated with the level of serum creatinine (r = 0.188, p < 0.001), GFR (r = 0.245, p < 0.0001) and the degree of proteinuria (r = 0.174, p = 0.006). Patients with kidney disease had a significantly higher number of crises/hospitalizations (p < 0.001). Seven patients died in all and 4 (57%) of them had end-stage renal disease. We concluded that kidney disease is a common complication of SCD and significantly contributes to mortality. The age of the patients, duration of SCD and frequency of crises/hospitalizations are strong predictors of development of kidney disease.

Patients' satisfaction and opinions of their experiences during admission in a tertiary care hospital in Pakistan - a cross sectional study

Background

It is often felt that developing countries need to improve their quality of healthcare provision. This study hopes to generate data that can help managers and doctors to improve the standard of care they provide in line with the wishes of the patients.

Methods

It was a cross sectional study carried out at a major tertiary care hospital of Karachi. Patients between the ages of 18 and 80 years admitted to the hospital for at least one day were included. Patients in the maternity, psychiatry and chemotherapy wards and those in the ICU/CCU were excluded. A pretested, peer reviewed translation of a validated patient satisfaction scale developed by the Picker Institute of Europe was administered.

Results

A total of 173 patients (response rate: 78.6 %) filled the questionnaire. Patient satisfaction was at levels comparable to European surveys for most aspects of hospital care. However, nearly half the patients (48%) felt they had to wait too long to get a bed in the hospital after presenting to the ER. 68.6% of the patients said that they were never asked for views on the quality of care provided. 20% of the patients did not find anyone in the staff to talk to about their worries and fears while 27.6% felt that they were given emotional support to only some extent. Up to one third of the patients said they were not provided enough information regarding their operative procedures beforehand.

Conclusion

Although several components of patient care equal the quality levels of the west, many sections require considerable improvement in order to improve health care provision. The healthcare team needs to get more involved with the patients, providing them greater support and keeping them informed and involved with their medical treatment. Efforts should be made to get regular feedback from the patients.

Insertion-Deletion Polymorphism in the Angiotensin-Converting Enzyme (ACE) Gene Among Sudanese, Somalis, Emiratis, and Omanis

The angiotensin-converting enzyme (ACE) gene in humans contains an insertion-deletion polymorphism in its intron 16. Because of its involvement with the renin-angiotensin system, the insertion-deletion polymorphism of the ACE gene has been widely investigated in different populations and in case-control studies. However, similar studies for Arab populations are limited in number. Therefore we have investigated the frequencies of the *I and *D alleles of the ACE gene among Sudanese, Somalis, and Arab nationals of the United Arab Emirates and Oman using previously described methods. Our data indicate a preponderance of the *D allele among the Arab and African populations studied (Sudanese, 0.64; Somalis, 0.73; Emiratis, 0.61; and Omanis, 0.71).

A Family Study in Oman: Large, Consanguineous, Polygamous Omani Arab Pedigrees

OBJECTIVE

To establish a suitable human model for the study of the genetics of complex diseases.

METHODS

We have selected an Omani Arab population to provide the statistical power required to study the genetics of complex diseases with confidence. This model consists of five multigenerational highly inbred pedigrees, descending from a small number of founders just a few generations ago with environmental homogeneity, restricted geographical distribution, detailed records and well-ascertained and -validated pedigrees. Stringent criteria were adopted for defining the phenotypes of hypertension, diabetes mellitus, dyslipidemias and obesity. The SOLAR genetic software package was used to draw the pedigree structure.

RESULTS

Outstanding statistical power to detect susceptibility loci was obtained.

CONCLUSIONS

This model represents a large homogeneous human family-based population for the study of genetic and environmental factors contributing to complex diseases.

Blood pressure and its reactivity in the offspring of first cousin hypertensive and first cousin normotensive parents: a preliminary report

The aim of this preliminary study was to determine whether young offspring of first cousin hypertensive parent(s), have higher blood pressure (BP) reactivity in response to their first BP measurement, as compared to the offspring of first cousin normotensive parents. The BP of 135 boys aged 9-10 years was measured, for the first time ever, after a 10-min supine rest, and subsequently, twice at 10-min intervals. The offspring of first cousin hypertensive parent(s) reacted with significantly higher systolic and diastolic BP than the offspring of normotensive first cousin parents in all three measurements. This study indicates that at an early age, the offspring of first cousin hypertensive parents, react with exaggerated BP response at their first casual BP measurement. We hypothesise that familial aggregation of BP may show more expression amongst the offspring of consanguineous marriage of hypertensive parent(s).

Ischemic injury to mitochondrial electron transport in the aging heart: damage to the iron-sulfur protein subunit of electron transport complex III

The aging heart sustains greater injury during ischemia and reperfusion compared to adult hearts. Aging decreases oxidative function in interfibrillar mitochondria (IFM) that reside among the myofibers, while subsarcolemmal mitochondria (SSM), located beneath the plasma membrane, remain unaltered. Aging decreases complex III activity selectively in IFM via alteration of the cytochrome c binding site. With 25 min of global ischemia, complex III activity decreases in SSM and further decreases in IFM in the aging heart. Ischemia leads to a marked decrease in the electron paramagnetic resonance signal of the iron-sulfur protein (ISP) in both SSM and IFM, despite a preserved content of ISP peptide. Thus, ischemia results in a functional decrease in the iron-sulfur center in ISP without subunit peptide loss. In the aging heart, at the onset of reperfusion, IFM contain two tandem defects in the path of electron flow through complex III, providing a likely mechanism for enhanced oxidant production and reperfusion damage.

Physical fitness and fatness among Omani schoolboys: a pilot study

OBJECTIVE

To study the applicability of simple field measurements of physical fitness in a sample of Omani boys and their relationships to selected variables.

METHOD

Two field measures of physical fitness-the time to complete 1.6-km run/walk and the sum of 5 skinfold thicknesses-were correlated with personal and family physical activity-related and other variables in a sample of 109 Omani boys aged 9-11 years.

RESULTS

Obesity in parents, especially in the mother, showed significant correlation with both fitness measures. The waist/buttocks ratio showed no significant correlation with the 1.6-km time. The number of siblings and siblings sharing a room, number of T.V-watching hours and the number of servants in the family showed no correlation with the chosen fitness indices.

CONCLUSION

The results of this pilot study indicate that simple field fitness tests can be used in children and they can yield valuable information related to physical fitness. The same protocol used in this study could be applied to a national study in Oman.

Aging selectively decreases oxidative capacity in rat heart interfibrillar mitochondria

Mitochondrial-derived oxidative injury contributes to cellular aging as well as to reperfusion-induced tissue damage. While the aging-heart suffers greater tissue damage following ischemia and reperfusion than the adult heart, the occurrence of aging-related alterations in mitochondrial oxidative metabolism in the elderly heart has remained uncertain. We determined if aging altered oxidative metabolism in either of the two populations of cardiac mitochondria, subsarcolemmal mitochondria (SSM) that reside beneath the plasma membrane or interfibrillar mitochondria (IFM) located between the myofibrils. SSM and IFM were isolated from 6-month adult and 24- and 28-month elderly Fischer 344 rat hearts. Aging-related alterations were limited to IFM, while SSM remained unaffected. Aging decreased the rate of oxidative phosphorylation in IFM, including when stimulated by electron donors specific for cytochrome oxidase. Cytochrome oxidase enzyme activity was decreased in IFM from aging hearts, while activity in SSM remained similar to adult controls. These findings allow future studies of aging-related decrements in oxidative function to focus upon IFM, while SSM provide an inherent control group of mitochondria that are free of aging-related alterations in oxidative function. The selective alteration of IFM during aging raises the possibility that the consequences of aging-induced mitochondrial dysfunction will be enhanced in specific subcellular regions of the senescent myocyte.

Effects of prolonged ACTH-stimulation on adrenocortical accumulation of lipofuscin granules in aged rats

Subcellular deposition of lipofuscin granules is a marker of aging. Human and rodent adrenal cortices accumulate lipofuscin granules with age, but the mechanism that leads to the accumulation is not known. The ultrastructural appearance of lipofuscin granules resembles that of secondary lysosomes. Since adrenocortical subcellular events are predominantly influenced by ACTH action, we therefore studied the effect of prolonged ACTH-stimulation on adrenocortical accumulation of secondary lysosome-like granules, designated herein as lipofuscin granules. Using aged Fischer 344 male rats as a model, we found that a 7 day ACTH stimulation exerts a reducing effect on adrenocortical lipofuscin accumulation. Thus, adrenocortical accumulation of lipofuscin granules with age in vivo may not be an irreversible process.

Baroreflex sensitivity and the blood pressure response to beta-blockade

The objective of this analysis was to determine whether changes in baroreflex sensitivity (BRS) within 35 hypertensive patients (25 M, 10 F, mean age 47 years) treated with beta-blockade as monotherapy relate to reductions in ambulatory blood pressure (BP) or its variability. BP was recorded intra-arterially directly from the brachial artery before and during submaximal exercise. BRS was determined by the phenylephrine injection technique. MAP and its variability were determined for the awake period of 24-h BP monitoring. Subjects were randomised to one of atenolol, metoprolol, pindolol, or propranolol, and restudied after a mean of 5 months. Beta-blockade increased BRS in 24 patients and decreased BRS in 11. BRS increased from 6.53+/-4.94 to 9.40+/-8.62 ms/mm Hg (mean +/- s.d.) (P<0.01). Waking ambulatory MAP decreased from 125.8+/-15.8 to 106.4+/-16.2 mm Hg (P<0.0001), but its variability did not change. Higher BRS after chronic beta-blockade was associated with a decrease in waking ambulatory MAP (r = -0.55, P<0.001), but not with its variability (r = -0.08). Beta-blockade attenuated the pressor response to exercise, but there was a positive relationship between the effect of beta-blockade on BRS, and on the rise in systolic BP during bicycling (r = 0.63; P<0.001). Any dampening effect of beta-blockade on BP variability at rest in hypertensive patients with the greatest increase in BRS may be offset by increased pressor responses to physical activity such as exercise. Consequently, BP variability is unaffected, even though reductions in ambulatory BP during chronic beta-blockade are inversely related to changes in BRS. BP responses to beta-blockade may be a function of the action of this class of drugs on BRS. However, there is considerable variation, between subjects, in their effect on BRS. This may have implications for other conditions, such as dilated cardiomyopathy, or following myocardial infarction, in which improvement in BRS is one mechanism by which beta-adrenoceptor blockade could improve survival.

Ribosome-lamella complexes in the perineurial cells of neurofibromatosis

Ribosome-lamella complexes are occasionally seen in neoplastic disorders of the hematopoietic system, particularly in hairy cell leukemia. However, these structures are rare in epithelial and mesenchymal cells. In this report three tumors from a patient with neuro-fibromatosis (von Recklinghausen's disease) are examined by electron microscopy. Ribosome-lamella complexes were seen in the perineurial cells. This may be the first report of these complexes in nerve sheath tumors.

Ciliated renal tubular cells in crescentic glomerulonephritis

Numerous cilia were found in the proximal convoluted tubules from a case of crescentic glomerulonephritis. The cilia exhibited the 9 + 2 pattern of organization characteristic of motile cilia. Microvilli were scanty or absent in heavily ciliated cells. The significance of renal cilia is discussed.

Intraductal papilloma of the male breast: an ultrastructural and immunohistochemical study

A case of intraductal papilloma of the male breast was studied by electron microscopy and immunohistochemistry. The major components of this lesion were the epithelial and myoepithelial cells. Intermediate cells showing ultrastructural features of both cell types were also observed. Squamous metaplasia was noted in many areas. Numerous intranuclear helioid inclusions were seen in the tumor cells. The features of this lesion are similar to those of papillomas of the female breast.

Malignant mesenchymoma of the prostate: immunohistochemical and ultrastructural observations

A case of malignant mesenchymoma of the prostate is reported. Immunohistochemical and ultrastructural examination revealed malignant chondro-osteoblastic and rhabdomyoblastic features. A separate incidental prostatic adenocarcinoma was also seen. These lesions should be differentiated from carcinosarcoma in which adenocarcinoma is intermingled with malignant mesenchymal components.

Renal oncocytoma arising from a renal cyst: a case report and review of the literature

Renal oncocytoma accounts for approximately 3 to 4% of all solid renocortical tumors. An unusual case of renal oncocytoma arising from the wall of a simple renal cyst is reported and the literature is reviewed.

Loss of the nocturnal dip and increased variability of blood pressure in normotensive patients with noninsulin-dependent diabetes mellitus

Eleven normotensive diabetics with noninsulin-dependent diabetes mellitus (NIDDM) (mean age 52.5 +/- SD 8.2 years) and 11 controls (mean age 47.4 +/- SD 8.9 years) had their ambulatory blood pressure and heart rate recorded non-invasively by the Oxford Medilog System in standard hospital conditions. The results were averaged as hourly means of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), and heart rate (HR) for the 24-h period and similarly for the 'awake' period (14-16 h) and the 'asleep' period (8-10 h). Hourly means for diabetics and controls showed no differences in blood pressure and heart rate over the 24 h. During sleep, control subjects showed a significant drop in SBP (P < 0.001), DBP (P < 0.001), MAP (P < 0.001) and HR (P < 0.001). However, this nocturnal dip in blood pressure could not be demonstrated in the diabetic group. Blood pressure variability was significantly increased in diabetics compared to controls during waking hours (P < 0.01). These results indicate that in noninsulin-dependent diabetics during sleep there is loss of the nocturnal dip of BP seen in normal subjects, and they have increased BP variability. These may be contributing factors to the development of hypertension and the accelerated target organ damage (TOD) seen in diabetes.

Malignant mixed exocrine-endocrine tumor of the pancreas with unusual intracytoplasmic inclusions

A case of malignant mixed exocrine-endocrine tumor of the pancreas is reported. Electron microscopy revealed abundant neurosecretory granules in most cels. Zymogen granules indicating acinar differentiation were seen in a few cells. Ductal features, including microvilli with prominent filamentous cores and intracytoplasmic mucin granules, were also noted in this lesion. immunocytochemical strains were positive for serotonin and glucagon. Unusual intracytoplasmic fibrillary inclusions are described and their possible origin discussed.

Fibronectin expression on surgical specimens correlated with the response to intravesical bacillus Calmette-Guerin therapy

Attachment of bacillus Calmette-Guerin (BCG) organisms to the bladder during intravesical therapy is thought to be mediated exclusively by the glycoprotein fibronectin, which is expressed variably on epithelial surfaces and on basement membranes. We examined the relationship between the degree of fibronectin expressed on surgical specimens obtained from 50 candidates for BCG therapy and the subsequent clinical response. Immunoperoxidase staining for fibronectin was performed on tumor, nonadjacent normal mucosa and basement membrane tissues, and the intensity of the staining was scored on a scale of 0 to 3+ (control 2+). In the absence of recurrence at quarterly surveillance cystoscopy, a course of Tice BCG therapy consisted of 6 weekly and 12 monthly instillations. Recurrence of noninvasive tumor prompted a second BCG course. Followup ranged from 24 to 66 months (median 40 months). Of the 50 patients (11 with carcinoma in situ) disease progression occurred in 9 (none with carcinoma in situ). Compared to the results for tumors or for basement membranes, the degree of fibronectin expression on normal mucosa was well correlated with the clinical response (r = 0.59, p < 0.001 by Kendall Tau B). Routine assessment of fibronectin expression on the normal mucosa associated with superficial bladder cancer may be useful for predicting the clinical response to BCG therapy.

Increased muscle protein catabolism caused by carbon tetrachloride hepatic injury in rats

This study was undertaken to determine the pathogenesis of muscle atrophy that frequently accompanies liver disease. Hepatic injury was induced in rats by giving weekly intragastric doses of carbon tetrachloride (CCl4) in combination with phenobarbital in the drinking water. Muscle protein catabolism was assessed during three stages of liver injury and compared with pair-fed controls: group A had hepatic necrosis and inflammation without significant fibrosis; group B had cirrhosis as well as necrosis and inflammation; and group C had cirrhosis with minimal necrosis and inflammation. In group A, vastus lateralis white muscle, which contained predominantly fast glycolytic fibers, showed a significant increase in protein catabolic rates compared with pair fed controls (0.95 +/- 0.05 nmol tyrosine released.mg-1.2 h-1 vs. 0.86 +/- 0.04; P less than 0.05). In group B, protein catabolic rates were significantly increased in vastus lateralis white muscles, as well as two muscles that have a mixed fiber composition, diaphragm, and triceps. Protein catabolic rates were not increased in soleus muscle that predominantly contained slow oxidative fibers in either group A or B. In group C rats there was no increase in catabolic rates in diaphragm or vastus lateralis white muscle. None of the muscles from group B had any impairment in protein synthesis. In diaphragms from group B animals, there was a selective reduction in the cross-sectional areas of fast glycolytic fibers (3725 +/- 224 mm2 control vs. 2926 +/- 208 mm2 experimental; P less than 0.01). This study indicated that liver injury characterized by inflammation and hepatocyte necrosis, with or without cirrhosis, was associated with muscle atrophy that selectively affected fast glycolytic fibers. This muscle atrophy was caused by an increase in protein catabolism and was not the result of an inhibition of protein synthesis.

Platelet-derived growth factor expression in mesangial proliferative glomerulonephritis

Proliferation of mesangial cells and expansion of mesangial matrix are common histologic features of proliferative glomerular disease, a frequent cause of renal failure. Proliferation of glomerular mesangial cells occurs in response to platelet-derived growth factor (PDGF), and these cells release PDGF and express PDGF A and B chain mRNAs. However, all studies relating PDGF to potential changes in glomerular structure and function to date have been performed in vitro. To explore the role of PDGF in proliferative glomerulonephritides, we studied the expression of PDGF in vivo in two animal models of IgA nephropathy with different histologic patterns of glomerular injury: either predominant mesangial proliferation or expansion of mesangial matrix. Increased expression of PDGF and PDGF B-chain mRNA in whole kidneys from diseased mice was demonstrated by immunohistochemical techniques and by solution hybridization assay, respectively. Immunohistochemically, PDGF was localized primarily within the mesangial area of glomeruli and to a much lower extent in interstitium. The increased PDGF expression correlated with the degree of hypercellularity and clinical features of the disease. In addition, PDGF expression was increased in some forms of human glomerulonephritis, characterized by mesangial proliferation. These findings suggest that PDGF may be a major contributor to mesangial cell proliferation seen in proliferative glomerulonephritides.

The role of the autonomic nervous system in exercise bradycardia in rats

The origin of the relative bradycardia found in athletes and in chronically exercised animals is still controversial. To further investigate the role of the autonomic nervous system in exercise bradycardia three groups of Sprague-Dawley rats performed swimming exercises daily for 1.5 hr for a total of 45 hrs. The contribution of the sympathetic and parasympathetic systems to the resultant bradycardia was elucidated by differential autonomic blockade using propranolol hydrochloride and atropine sulphate respectively. This procedure permits the determination of the intrinsic heart rates so that it is possible to observe the contributions of the two divisions of the autonomic nervous system in exercise bradycardia. The results showed that both sympathetic and parasympathetic tones of the trained rats were reduced, being respectively 13% and 5% lower than the control groups. It was concluded that the reduction in heart rate in trained rats was mainly due to a reduction in the sympathetic tone.

Platelet activating factor receptor blockade ameliorates murine systemic lupus erythematosus

Untreated 16-week-old MRL/MpJ-lpr/lpr (lpr) mice, when compared to congenic MRL/MpJ-+/+ (+/+) mice, are characterized by a systemic lupus erythematosus syndrome, including severe glomerulonephritis, proteinuria and reduction of renal function. We hypothesized that platelet activating factor (PAF), a potent chemotactic and proinflammatory phospholipid mediator synthesized and released by circulating cells, glomerular mesangial and renal medullary interstitial cells, may play a role in the development of renal injury in lupus mice. We assessed renal PAF synthesis in lpr as well as +/+ mice and the effect of treatment with a PAF receptor blocking agent. Treatment with the PAF receptor antagonist L659,989 for four weeks, starting at 12 weeks of age, significantly reduced acute glomerular infiltration and proliferation, and prevented chronic glomerular histological changes; proteinuria and serum creatinine levels were also significantly reduced in treated mice. Renal PAF production was increased in lpr when compared to +/+ mice, and treatment with L659,989 restored renal PAF synthesis to the control levels. Our results support the hypothesis that PAF can be one of the mediators of glomerular injury characteristic of murine lupus nephritis, and indicate the possible therapeutic utility of PAF receptor antagonists in immunologic renal diseases.

Enzymolysis of glomerular immune deposits in vivo with dextranase/protease ameliorates proteinuria, hematuria, and mesangial proliferation in murine experimental IgA nephropathy

The therapeutic effects of saccharolytic and proteolytic enzymes were investigated in models of IgA nephropathy. Mesangial glomerulonephritis was induced in mice by intravenous injection of preformed soluble immune complexes of dextran sulfate and either IgA (J 558) or IgM (MOPC 104 E) anti-dextran MAb (passive model) or by immunization with DEAE dextran (active model). In the passive model, only 30-40% of dextranase-treated mice given IgA or IgM immune complexes had mesangial Ig or dextran deposits, compared with 100% of saline-treated controls (P less than 0.01). There was no significant difference in mice given only protease. In the active model, dextranase and protease separately each reduced glomerular dextran and C3 deposits, and hematuria (P less than 0.01). Dextranase also reduced the glomerular IgA deposits (20 vs. 100% of saline-treated mice) and the frequency and severity of mesangial matrix expansion (both P less than 0.02), but did not reduce the modest IgG or IgM codeposits. Protease reduced IgG and IgM deposits, proteinuria and mesangial hypercellularity compared with saline (P less than 0.02), but did not diminish IgA, and had no effect on mesangial matrix expansion. The combination of dextranase plus protease attenuated all components of glomerular injury as judged by clinical and pathological parameters, but inactivated dextranase plus inactivated protease had no effect on any parameter. We conclude that enzymatic digestion of antigen and antibody can reduce immune deposits, mesangial proliferation, proteinuria, and hematuria in experimental glomerulonephritis.

Effects of acute and chronic beta-adrenoceptor blockade on baroreflex sensitivity in humans

To determine whether beta-adrenoceptor blockade lowers blood pressure by potentiating arterial baroreflex sensitivity (BRS), we compared the effect of acute i.v. and chronic oral beta-blockade on the BRS (phenylephrine technique) of 51 subjects with essential hypertension. Subjects were randomly assigned in a double-blind protocol to one of atenolol, metoprolol, pindolol or propranolol. There was an increase in BRS, unrelated to changes in heart rate, after both acute and chronic beta-blockade. This effect was most evident in younger and less hypertensive subjects. Decreases in blood pressure after 5-months' treatment were unrelated to increases in BRS, indicating that the hypotensive action of these drugs is not dependent upon augmented baroreflex control of heart rate. Only propranolol, of the 4 beta-blockers, increased BRS significantly after acute and chronic treatment. The acute effect of propranolol was significantly different from that of i.v. metoprolol (P less than 0.008) but the effect of long-term treatment with propanolol was not significantly different from that of the other 3 beta-blockers. We conclude that the impaired reflex regulation of heart rate can be improved in younger and mild-to-moderate hypertensive patients by beta-adrenoceptor blockade. Further studies, involving larger numbers and perhaps fewer drugs are needed to determine the relative importance of lipophilicity and beta 1- or beta 2-receptor selectivity in mediating the increase in baroreflex sensitivity seen with treatment.

Consequences of impaired arterial baroreflexes in essential hypertension: effects on pressor responses, plasma noradrenaline and blood pressure variability

In 62 untreated patients with essential hypertension, arterial baroreflex sensitivity (BRS) for heart rate, i.e. the change in pulse interval in response to a phenylephrine-induced increase in blood pressure, was compared with (1) haemodynamic changes during mental arithmetic, a reaction time test, isometric and bicycle exercise; (2) plasma noradrenaline (PNA) concentrations at rest, and during bicycle exercise and; (3) the variability of ambulatory intra-arterial blood pressure. Subjects with diminished BRS showed the following responses: (1) higher mean arterial blood pressure (MAP) during all four stimuli; (2) a greater pressor response to cycling; (3) tended to have higher PNA concentrations during bicycle exercise and; (4) greater variation in ambulatory blood pressure. Furthermore, an increased pressor response to the reaction time test and increased ambulatory blood pressure variability was seen in younger subjects with reduced BRS. When subjects were subgrouped according to their WHO stage of hypertension, there were significant inverse relationships between BRS and the pressor responses to mental arithmetic, the reaction time test and cycling, and with ambulatory blood pressure variability only in those subjects without ECG or radiographic evidence of left ventricular enlargement (WHO stage I hypertension; n = 42). None of these correlations were present in subjects with one or both of these clinical findings (WHO stage II; n = 20). Pressor responses to the four laboratory stimuli and ambulatory blood pressure variability were similar in both groups, despite significantly higher arterial pressure and significantly lower BRS in WHO stage II subjects. These results suggest that differing mechanisms may be responsible for the regulation of blood pressure variation in these two groups. The arterial baroreflex can buffer acute changes in blood pressure in subjects with WHO stage I hypertension, but this ability is attenuated with progressive reduction of BRS. With the development of clinically evident cardiac adaptation to hypertension (WHO stage II), the contribution of the arterial baroreflex to the regulation of blood pressure is no longer detectable and the influence of cardiac and somatic afferents to reflex circulatory adjustments to activity may predominate.

Factors influencing blood pressure and heart rate variability in hypertensive humans

We examined the influence of baroreceptor reflex sensitivity (the increase in pulse interval in response to a phenylephrine-induced increase in blood pressure), age, blood pressure, and beta-adrenergic receptor blockade on the variability of blood pressure and heart rate in essential hypertension. Fifty-six subjects were studied before treatment; intra-arterial blood pressure was recorded outside the hospital for 24 hours. Variability was defined (from all beats occurring while subjects were awake) as the standard deviation about the average waking value for mean arterial pressure (MAP) or pulse interval. The correlation (r) between baroreceptor reflex sensitivity and blood pressure variability was -0.47 (p less than 0.0002). Baroreceptor reflex sensitivity was the only independent determinant of blood pressure variability on multiple regression analysis. Thirty subjects were restudied after 5 months of beta-adrenergic receptor blockade. Ambulatory blood pressure was lower during treatment, whereas pulse interval, its variability, and baroreceptor reflex sensitivity were higher. Blood pressure variability was unchanged. The variability of MAP was inversely correlated with baroreceptor reflex sensitivity before (r = -0.42, p less than 0.02) and during (r = -0.45, p less than 0.02) treatment, but it was unrelated to the average ambulatory MAP or to the variability of pulse interval either before or during beta-blockade. Sixteen subjects whose average waking ambulatory blood pressure was 140/90 mm Hg or less were not treated. This group of borderline hypertensive subjects had less variable MAP than did the remaining 40 subjects (12.4 +/- 2.3 [SD] vs 14.5 +/- 2.5 mm Hg; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Pressor responses to laboratory stresses and daytime blood pressure variability

We studied 56 patients with essential hypertension to determine whether responses to standardized laboratory mental and physical challenges accurately reflect blood pressure variability during routine daily activities. Four activities were performed in the laboratory: mental arithmetic, a reaction time test, isometric exercise, and submaximal bicycle exercise. Blood pressure was measured directly from a brachial artery catheter. We then recorded intra-arterial ambulatory blood pressure away from hospital over 24 h. A frequency histogram was constructed from all cardiac cycles when subjects were awake. Variability of ambulatory blood pressure was defined as the standard deviation about the mean waking value. The increase in mean arterial pressure (MAP) during each of these four challenges correlated significantly with the variability of mean arterial pressure (highest correlation: reaction time test, r = 0.53, P less than 0.00001; lowest correlation: mental arithmetic, r = 0.26, P less than 0.03), and five subjects who were highly reactive to all four challenges also demonstrated increased blood pressure variability. We therefore conclude that these commonly used laboratory tests can give some information about the behaviour of blood pressure in daily life in some subjects, but overall the variance in blood pressure variability that can be accounted for by the pressor response to these standardized challenges is low.

Carbon dioxide laserabrasion: a new approach to management of familial benign chronic pemphigus (Hailey-Hailey disease)

Familial benign chronic pemphigus (FBCP), or Hailey-Hailey disease, can be a debilitating condition. Treatment is palliative and only excision of lesional skin followed by split-thickness grafting may be curative. The success of surgery is attributed to the removal of adnexal structures and a decrease in sweating and maceration. This is the first report of successful carbon dioxide (CO2) laserabrasion of a patient with FBCP. The procedure spared the underlying adnexae which contributed to the reepithelialization of the epidermis. The selective destructive property of the CO2 laser may contribute to understanding the pathophysiology of FBCP.

Prolonged exposure to M. faeni in strain II guinea-pigs: pulmonary interstitial inflammation

Models of hypersensitivity pneumonitis (HP) should exhibit progression of pulmonary histological abnormalities during continuing challenges. Strain II guinea-pigs were sensitized with Micropolyspora faeni and received 2, 4, or 8 weekly intratracheal (i.t.) particulate M. faeni challenges. Control animals received normal saline (NS). Four days after the last exposure, randomly selected microscopic fields of lung (200/animal) were judged to be normal or abnormal. If abnormal, the location and nature of the abnormalities were determined. Compared with NS treated guinea-pigs, those exposed to 2, 4 and 8 weekly M. faeni challenges exhibited more extensive (P less than 0.001) pulmonary histological abnormalities which involved both the intraalveolar and interstitial compartments. More extensive abnormalities in the 8 week group compared with the 4 week group were caused by increased extent of interstitial mononuclear cell infiltration. The extent of pulmonary interstitial histological abnormalities transiently (four challenges) decreases, but then increases, so that progressive pulmonary inflammation occurs during continuing challenges.

Experimental hypersensitivity pneumonitis: transfer with cultured cells

The importance of antibody and sensitized cells in hypersensitivity pneumonitis (HP) is unknown. In an attempt to create a model suitable for investigation of the mechanisms of HP, we transferred cells and serum from sensitized (Micropolyspora faeni in Freund's adjuvant) strain 2 guinea pigs to naive animals. Cells (peritoneal exudate, lymph node, or spleen) were cultured for 72 hours with either concanavalin A (Con A, 1 microgram/ml) or a soluble extract of M. faeni (10 micrograms/ml). We then injected the cells intravenously (IV) into naive guinea pigs, skin tested with purified protein derivative (PPD), challenged the animals intratracheally (IT) with M. faeni 48 hours after the cell transfer, and killed them 4 days (IT) with M. faeni 48 hours after the cell transfer, and killed them 4 days after IT challenge. We also transferred noncultured cells and antibody-containing serum from sensitized animals. Randomly selected microscopic fields of the lung (150 per animal) were judged to be normal or abnormal. All guinea pigs were maintained in high-efficiency particulate accumulator-filtered air. Compared with control animals that received media IV, there was a substantial increase (P less than 0.01) in the extent of pulmonary abnormalities in the animals receiving lymph node cells or spleen cells cultured with M. faeni, and peritoneal exudate cells cultured with Con A. Findings in recipients of peritoneal exudate cells cultured with M. faeni, or lymph node cells or spleen cells cultured with Con A did not differ from those in the control group. In contrast to cultured cells, noncultured cells and antibody-containing serum did not transfer susceptibility. PPD skin reactivity was present only in recipients of noncultured cells and not in recipients of serum or cultured cells. We conclude that experimental HP can be transferred with cultured cells from sensitized animals and that HP appears to be a cell-mediated process.

Failure of plasma norepinephrine to consistently reflect sympathetic activity in humans

To determine whether venous plasma norepinephrine concentrations consistently reflect changes in sympathetic nervous activity, the influence of mental arithmetic, static handgrip, and submaximal bicycle exercise on intra-arterial blood pressure, heart rate, and plasma norepinephrine was studied in 51 subjects with untreated essential hypertension (mean age, 46 years; range, 16-69 years). At rest, plasma norepinephrine was unrelated to age or blood pressure. Mental arithmetic increased mean arterial pressure from 108 +/- 18 to 127 +/- 18 mm Hg (mean +/- S.D.; p less than 0.001) and heart rate from 69 +/- 7 to 93 +/- 13 beats/min (p less than 0.001) but not plasma norepinephrine (547 +/- 297 to 518 +/- 250 pg/ml). Isometric exercise raised mean arterial pressure from 115 +/- 18 to 148 +/- 21 mm Hg (p less than 0.001) and heart rate from 76 +/- 9 to 95 +/- 13 beats/min (p less than 0.001) but not plasma norepinephrine (683 +/- 253 to 741 +/- 253 pg/ml). Bicycle exercise increased mean arterial pressure from 114 +/- 20 to 146 +/- 26 mm Hg (p less than 0.001), heart rate from 77 +/- 9 to 128 +/- 19 beats/min (p less than 0.001), and plasma norepinephrine from 645 +/- 228 to 1151 +/- 462 pg/ml (p less than 0.001). Both the maximum mean arterial pressure and the peak heart rate attained during bicycle exercise were related to the exercise plasma norepinephrine level (r = 0.33, p less than 0.02 and r = 0.28, p less than 0.03, respectively). Increases in plasma norepinephrine with exercise were not greater in older or more hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardioselective and nonselective beta-adrenoceptor blocking drugs in hypertension: a comparison of their effect on blood pressure during mental and physical activity

The ability of cardioselective and nonselective beta-adrenoceptor blocking drugs, with and without partial agonist activity, to control increases in blood pressure associated with mental and physical activity was compared in 35 subjects with hypertension. Direct measurements of blood pressure and radioenzymatic determinations of plasma norepinephrine were obtained before, during and after four activities, and were repeated after random allocation to treatment with atenolol, metoprolol, pindolol or propranolol. Cardioselective and nonselective drugs modestly reduced the pressor response to reaction time testing, but not to mental arithmetic or isometric exercise. The increase in systolic blood pressure during bicycling was attenuated significantly by the cardioselective drugs atenolol (by 23 mm Hg, or 38%) and metoprolol (21 mm Hg, or 41%), but not by the nonselective agents pindolol (with partial agonist activity) (13 mm Hg, or 20%) and propranolol (10 mm Hg, or 17%) (p less than 0.02 cardioselective versus nonselective; p = NS pindolol versus propranolol). Only bicycle exercise increased plasma norepinephrine concentrations (by 80%). These results suggest that beta-adrenoceptor blocking drugs will not attenuate increases in blood pressure during mental or physical activities unless intense sympathoadrenal activation also occurs. Marked elevations in circulating epinephrine, with or without norepinephrine, and peripheral beta 2-blockade appear necessary for alpha-mediated vasoconstriction to predominate and for the contrasting effects of cardioselective and nonselective drugs to be appreciated.

The ultrastructural heterogeneity of the Reed-Sternberg cell and its resemblance to monocyte-macrophage differentiation in vivo

Hodgkin's disease is a malignant neoplasm that shares many histologic features with granulomatous diseases. We have examined 11 cases of Hodgkin's disease, representing the spectrum of histologic types, using transmission electron microscopy and have compared the morphology of Reed-Sternberg cells to that of the developmental stages described for monocyte-macrophage differentiation in vivo. Ultrastructurally, a close parallelism exists between the cells that typify granulomatous inflammation and Reed-Sternberg cells. It is our contention that the heterogeniety among Reed-Sternberg cells in all types of Hodgkin's disease parallels the diversity of the monocyte-macrophage system.

Ambulatory blood pressure during once-daily randomised double-blind administration of atenolol, metoprolol, pindolol, and slow-release propranolol

Intra-arterial ambulatory blood pressure was measured over 24 hours, in 34 patients with newly diagnosed hypertension, both before and after double-blind randomisation to treatment with atenolol (n=9), metoprolol (n=9), pindolol (n=9), or propranolol in its slow-release form (n=7). The dosage of each drug was adjusted at monthly clinic visits until satisfactory control of blood pressure was achieved (140/90 mm Hg or less by cuff) or the maximum dose in the study protocol was reached. A second intra-arterial recording was made after these drugs had been taken once daily at 0800 for three to eight months (mean 5.0+/-SD 1.4) and was started four hours after the last dose.At the end of the 24-hour recordings blood pressure was significantly lower with all four drugs. The extent to which the drugs reduced blood pressure, however, differed over the 24 hours. Atenolol lowered mean arterial pressure significantly throughout all 24 recorded hours, metoprolol for 12 hours, pindolol for 15 hours, and slow-release propranolol for 22 hours. Neither metoprolol nor pindolol lowered blood pressure during sleep. A significant reduction in heart rate was observed over 20 hours with atenolol, 20 hours with metoprolol, 10 hours with pindolol, and 24 hours with slow-release propranolol. Atenolol, metoprolol, and slow-release propranolol continued to slow the heart rate 24 hours after the last tablet was taken; this effect on heart rate, however, was not sustained throughout the second morning in those patients taking atenolol. Pindolol, the only drug studied that has intrinsic sympathomimetic activity, increased heart rate and did not lower blood pressure during sleep.Atenolol and slow-release propranolol are effective as antihypertensive agents over 24 hours when taken once daily, whereas metoprolol and pindolol may need to be taken more frequently. At times of low sympathetic tone, however, such as during sleep, beta-blockers with intrinsic sympathomimetic activity may raise heart rate and attenuate the fall in blood pressure with treatment.

Effects of long-term, once-daily administration of atenolol on ambulatory blood pressure of hypertensive patients

We measured intraarterial, ambulatory blood pressure over a 24-h period in 12 subjects 24--63 years (mean 47.6) of age with newly diagnosed untreated hypertension. Measurements were performed both before and after 2--9 months of once-daily treatment with atenolol, a cardioselective beta-adrenoceptor antagonist. Significant reductions in arterial pressure (p less than 0.005) during treatment with atenolol (dose range 50--200 mg) were observed over the full 24-h period.

Cuff and ambulatory blood pressure in subjects with essential hypertension

Clinic cuff blood-pressure measurements, obtained on at least three occasions, were compared with mean arterial pressures in 59 patients with borderline or essential hypertension who underwent direct ambulatory monitoring of blood pressure. In 22 patients (group I) mean cuff and ambulatory pressures were similar (+/- 10 mm Hg) while in 32 subjects (group II) cuff pressures were more than 10 mm Hg higher. Groups I and II could not be distinguished on the basis of clinical examination, indices of sympathetic nerve activity, or blood-pressure variability, or by the magnitude of pressure rise during physical or mental exercise. Group II had less cardiovascular target organ damage and better baroreflex sensitivity but there was considerable overlap. There was no reliable way of telling which subjects would have lower ambulatory than cuff pressures. 20 out of 59 subjects classified as hypertensive by cuff measurements had awake ambulatory pressures or less than 140/90 mm Hg.

Adaptation of hypertensives to treatment with cardioselective and non-selective beta-blockers. Absence of correlation between bradycardia and blood pressure control, and reduction in slope of the QT/RR relation

Thirty mild hypertensives were treated for more than two months with either cardioselective (atenolol or metoprolol) or non-selective (propranolol or pindolol) beta-blockers; the patients were assigned to the drugs in a double-blind manner. A procedure was designed to distinguish between the effects of the drugs themselves while treatment continued, and the development of adaptive changes which would persist when the drugs had been eliminated from the body. Though individual responses to treatment varied in both groups, the mean effect of the cardioselective and non-selective drugs in the control of hypertension was similar. There was no evidence of the development of supersensitivity or "rebound". On the contrary, an adaptive bradycardia (that is a fall of not less than 10% in heart rate persisting 52 hours after stopping treatment) was observed at rest in 17/30 patients, and peak heart rates and blood pressures during exercise were lower in both groups than before treatment. Cardioselective drugs induced a significantly greater bradycardia at rest than non-selective, but on exercise increases in heart rate were reduced more by the non-selective drugs, so that the same peak heart rates were reached on exercise in both groups. Adaptation also affected QT. The results suggest that two factors govern the shortening of QT by increases in heart rate, a "metabolic" effect, determined by sympathetic drive, and a "biophysical" effect determined by heart rate. The adrenergic effect is attenuated by acute beta-blockade, or by adaptation to prolonged blockade, leaving a shallow, rate-determined, slope to the QT/RR regression.

The prostatic perineural space and its relation to tumor spread: an ultrastructural study

Prostatic perineural structures were studied by electron microscopy in 31 speciments from benign and malignant lesions. Vascular structures seen in these areas have the ultrastructural characteristics of blood capillaries. No lymphatic channels were observed. Spread of tumor cells occurred by direct extension around the prostatic nerves and not within vascular channels. It is possible that these perineural spaces represent areas of least resistance to tumor invasion. These findings were not reported in previous studies on the ultrastruct of the human prostate.

Assessment of the antihypertensive effect of atenolol with 24 h ambulatory monitoring of blood pressure

1. Twenty-four hour intra-arterial blood pressure measurements and electrocardiograms were obtained from 12 subjects with untreated essential hypertension. 2. The patients kept records of their activity, paying particular attention to times of retiring to bed, and times of waking in the morning. 3. All subjects were treated with a single daily dose of atenolol (50 to 200 mg) for between 2 and 9 months, and then underwent a second 24 h blood pressure study. 4. Arterial blood pressure was lowered significantly throughout the 24 h period with a single daily dose of atenolol.

Baroreflex control of blood pressure and plasma noradrenaline during exercise in essential hypertension

1. Twelve subjects (mean age 46.3 +/- 12.5 years) with mild to moderate hypertension were studied before, during and after bicycle ergometer exercise. 2. Baroreflex sensitivity was determined by the Oxford phenylephrine method; sensitivity at rest was inversely related to intra-arterial pressure and age. Age and resting arterial pressure were not related. 3. Exercise for 5 min at 50 W and 5 min at 75 W raised the mean arterial pressure from 116.4 +/- 18.0 to 150.0 +/- 25.4 mmHg, the heart rate from 73.2 to 126.7 beats/min and the plasma noradrenaline from 541 +/- 142.7 to 1309.8 +/- 543.5 pg/ml (P less than 0.001). 4. The increase in noradrenaline during exercise and the maximum mean pressure achieved were inversely related to resting baroreflex sensitivity (r = -0.68 and -0.77 respectively). Resting values of noradrenaline were not related to baroreflex sensitivity, age, or resting blood pressure. 5. It is possible that the rise in both plasma noradrenaline and arterial blood pressure produced by exercise is controlled by the baroreceptor reflexes; these are less effective in hypertensive subjects and thus the increases in noradrenaline and arterial pressure during exercise are greater in subjects with raised blood pressure.

Ultrastructural observations on gynecomastia

Ten cases of gynecomastia were studied by electron microscopy. The ducts showed proliferation of both epithelial and myoepithelial cells. Intracytoplasmic lumina, previously thought to be a feature of malignant breast lesions, were seen. Squamous metaplasia was observed in some cases. The stroma showed fibroblasts, myofibroblasts, and, occasionally, pericytes. The general morphology of gynecomastia is similar to that of benign lesions of the female breast at the ultrastructural level. The features of the stromal cells reflect the effects of estrogenic stimulation.