Accentuated antibody response to paramyxoviruses in individuals infected with human immunodeficiency virus

Sera from 31 human immunodeficiency virus (HIV)-infected patients, representing different clinical stages of HIV infection, were assayed for antibodies against measles and mumps viruses by various serological tests and compared to 23 healthy controls. Sera from four patients (two primary, one asymptomatic, and one acquired immunodeficiency syndrome) exhibited a pronounced antibody response to measles as detected by haemagglutination inhibition and radioimmuno-precipitation assay. The RIPA-positive sera showed increased reactivity to all the viral components and in particular to the haemagglutinin (HA) protein of the virus (Fig. 1). Three of these positive patients also showed a similar response to mumps virus. One of the control sera also showed an increase in antibody titre in measles serological tests. The measles antibodies were shown not be anti-HIV antibodies crossreacting with paramyxoviruses. The reactivity to haemagglutinin was still present when using nonglycosylated measles virus antigen grown in the presence of tunicamycin. Whether the accentuated antibody response is due to polyclonal activation mediated by HIV or to reactivation of the viruses remains to be answered.     

Adaptation and remodeling of vascular wall; biomechanical response to hypertension

Living organs, tissues, and cells functionally adapt themselves to mechanical demands, and remodel by changing geometry, structure, and properties. The key factor for this phenomenon is “Mechanical Stress”. Major stresses applied to blood vessels inside the body are: (1) hoop stress induced by blood pressure, that is normal stress in the wall circumferential direction, (2) wall shear stress developed by blood flow, and (3) axial stress by elongation in the axial direction. This review article deals with biomechanical studies on the responses of arterial and venous wall to the elevation of blood pressure. One of the specific biomechanical manifestations to arterial wall adaptation in response to hypertension is wall hypertrophy. This restores circumferential wall stress, i.e. hoop stress, at in vivo operating pressure to a normal value, and changes arterial stiffness to an optimal level. Vascular smooth muscle cells are activated by hypertension. Essentially similar phenomena are also observed in venous wall.     

Renal vascular response to angiotensin II inhibition in intensive antihypertensive treatment of essential hypertension

Introduction

High blood pressure (BP) leads to target organ damage. It is suggested that regression of early organ lesions is possible on condition of BP normalization. The study objective was to assess whether permanent reduction of BP to the recommended values modifies renal vascular response to acute angiotensin II inhibition in the Doppler captopril test (DCT) in patients with essential hypertension (EH).

Material and methods

Twenty-nine persons (58 kidneys) were found eligible for the study: 18 patients with EH and 11 healthy volunteers constituting the control group. Glomerular filtration rate estimation (eGFR), 24-h ambulatory BP monitoring (ABPM) and DCT with evaluation of renal resistive index change (ΔRI) were performed before and after a 6-month period of intensive antihypertensive therapy (IAT). Additional ABPM was performed at the end of IAT.

Results

The mean IAT period was 8.5 ±2.4 months. The mean 24-h values of systolic and diastolic BP in the EH group were significantly lower in the IAT period than at the beginning and at the end of the study. Significantly lower systolic and diastolic BP (p < 0.05) and improvement of renal function (eGFR 121 ±38 vs. 139 ±40 ml/min, p < 0.001) were found after IAT as compared to initial values. Before IAT, ΔRI was significantly lower in the EH group as compared to the controls, but no such differences were found after IAT.

Conclusions

In EH patients, intensive BP lowering to the recommended values was associated with improvement of renal function and normalisation of renal vascular response to acute angiotensin II inhibition.     

Biochemical response to dacron vascular prosthesis.

Dacron vascular prostheses were examined under both light and electron microscopes from 1 to 1184 days after implantation in the thoracic aorta of 96 dogs. Each Dacron fiber of the implanted prostheses was found to be covered with a single layer, which closely resembled the outer half leaflet of plasma membrane. The control experiment in vitro revealed that when untreated Dacron fibers were dipped into a solution of lecithin, the fibers became covered with monomolecular leaflets of lecithin micelles. On the basis of the in vivo and in vitro findings, it was suggested that the implanted Dacron fibers of vascular prosthesis were covered at an early stage with a monomolecular micelle layer of phospholipid or phospholipoproteins originating from the living body, and thus became adapted to the living body.     

Augmented vasoconstrictor response to changes in vascular transmural pressure in patients with essential arterial hypertension

The vasoconstrictor response to increase in venous transmural pressure in subcutaneous tissue was studied in 9 patients with essential arterial hypertension. Subcutaneous blood flow was measured on the distal part of the forearm and at the lateral malleolus by the local ¹³³Xe washout technique. Increase in venous transmural pressure was obtained by lowering the area under study 40cm below midaxillary line in the recumbent subject. Average mean arterial pressure ± 1 S.E. was 133 ± 6 mmHg. The fractional increase in vascular resistance induced by arteriolar constriction was more pronounced in the hypertensive patients than in a normotensive control group. “Minimal vascular resistance” in the papaverine relaxed vascular bed was higher in the hypertensive patients than in the controls. Distensibility of the papaverine relaxed resistance vessels was diminished in the patients. Follow-up studies after 6–18 months of anti-hypertensive treatment indicate that the vasoconstrictor response as well as “minimal vascular resistance” are normalized, whereas the distensibility of the papaverine relaxed arterioles remained unaltered in the hypertensive patients. The results indicate that the arteriolar smooth muscle cells of hypertensive patients are subjected to reversible hypertrophy whereas the reduced distensibility of the resistance vessels is due to irreversible structural changes.     

Sex differences in endocrine response to hyperthermia in sauna

Neuroendocrine response was investigated during and after a single 20 min bath in sauna (80 ^oC) in a group of 8 healthy men and 8 healthy women. In an additional group of 8 young men, the dynamics of plasma ACTH and Cortisol levels were studied during a 30 min sauna exposure (90 ^oC). This dynamic study showed a biphasic response of plasma Cortisol which decreased during the initial phase of sauna bath (15 min) and increased thereafter, reaching its maximum 15 min after the end of bathing. Maximal increase in plasma ACTH levels occurred 15 min earlier. In the first sauna exposed group the increase in body temperature was the same (about 2 ^oC) in both sexes. Nevertheless, the elevation in plasma ACTH concentration was significantly more pronounced in women than in men. In the plasma collected at the end of sauna bath inside the sauna room, a significant rise in both adrenaline and noradrenaline levels was found. Though the catecholamine responses were similar in both groups, the increase in heart rate during sauna bath was significantly higher in women. Sauna–induced prolactin release was also more pronounced in women compared with men. Thus hyperthermia induced by sauna exposure resulted in a more pronounced neuroendocrine activation in women compared with men. Moreover, it is evident that repeated blood sampling is necessary to reveal the sauna–induced activation of some hormonal systems.     

Regional vascular reactions of the internal organs in response to interoceptive stimuli in normal conditions and in experimental hypertension

Summary The results of experiments Indicate that the reflex changes appearing in the esserial pressure are competed or varied (by renifestation and combinntion) segional vsertiular rascrios, often oppesire in direnion. The simalading comprative ondy of vascular reactions in several internal orgars, namely in the kidney, live amall intestine, and spleen, may shed light on the peculiarity of each of the interoceptive reflexes studied. As distinct from normal animals, in the animals with experimental hypertension, vasoconstrictor reactions developed in internal organs (particularly in the kidneys and liver) in response to reflex influences from the receptor zones. (Presented by Active Member AMN SSSR N. N. Gorev) Translated from Byulleten' éksperimental'noi Biologii i Meditsiny, Vol. 56, No. 11, pp. 56–61, November, 1963.     

Failure of chronic administration of the angiotensin I-converting enzyme inhibitor, Teprotide (SQ 20881), to affect the ultrastructure of the adrenal cortex and the aldosterone secretion in the rat

Administration of Teprotide (SQ 20881), an angiotensin I-converting enzyme inhibitor for up to 10 weeks at a dose of 3 mg. per kg., subcutaneously, twice a day in the rat, effected no change in the ultrastructure of the adrenal cortex nor in the concentration of serum aldosterone. A significant increase (p less than 0.05) in renin granulation indices which was already apparent after 3 weeks of treatment with Teprotide was even more definitive after 10 weeks (p less than 0.01). Moderate renal hypertrophy was present in rats receiving the drug for 3 weeks. Findings pertaining to aldosterone production differed from those reported following acute administration of Teprotide wherein a decrease in the production of serum aldosterone and an increase in plasma renin activity was observed. It has been suggested that decreased aldosterone production following acute administration of Teprotide is a consequence of decreased stimulus of the zona glomerulosa due to diminished synthesis of angiotensin II. If this is the case, mechanisms other than angiotensin II stimulation of the zona glomerulosa must control aldosterone synthesis, perhaps through hormones of the adrenal cortex. Another possibility could be that angiotensin II synthesis may be obtained, after an interval, through an alternative pathway.     

A practical approach to vascular pathology in pulmonary hypertension

Pulmonary hypertension (PH) is the common physiological denominator in an otherwise heterogeneous disease. While pulmonary hypertension itself is not a pathologists' diagnosis, various patterns of pulmonary vasculopathy may be recognized in pulmonary hypertension. These patterns of vasculopathy are at the basis of classification, as they point towards (groups of) risk factors and aetiology. However, as surgical lung biopsy is a high risk procedure in PH, the role for histopathological evaluation is now mainly in retrospective evaluation on explanted lung or tissue obtained at autopsy, taking clinical work-up, including haemodynamic parameters and HRCT imaging, into account. Such multidisciplinary evaluation and classification may help assess the prognosis, including risk of recurrence in a transplant, and possible risk of PH in family members. More generally, systematic evaluation may identify clues as to pathogenesis and may help to fill the knowledge gap between histopathology and non-invasive diagnostic procedures such as imaging. This will hopefully eventually lead to a patho-physiologic rationale for classification, and to improved treatment strategies. This review aims to offer some practical guidelines for pathologists, pointing out pitfalls along the way.     

Differential endocrine response in rams to intracerebroventricular infusion of genistein

The intracerebroventricular infusions of genistein (total 40 mug) were made in male sheep (November) to test its influence on melatonin, growth hormone (GH) and luteinizing hormone (LH) secretion. The analysis of the results encompassed 3 similar periods: before the infusion (afternoon hours) the first (evening hours) and the second (night hours) halves of the treatment. The night plasma concentration of melatonin in genistein-infused rams was significantly lower than that noted during the respective period in vehicle-infused rams. Plasma GH concentration increased significantly in both vehicle- and genistein-infused rams during the night hours, as compared with the concentrations noted during the afternoon and evening, however, genistein significantly stimulated the amplitude of GH pulses in these latter. The LH concentration was significantly lower during the second part of genistein treatment, than in vehicle-infused rams. The frequency and amplitude of LH pulses clearly tended to decrease following genistein infusion. In conclusion, genistein, acting at the central nervous system level in sexually active rams is able to reduce the secretion of melatonin and LH and has also a slight stimulatory effect on the amplitude of GH pulses.     

Pulmonary endocrine cells in hypertensive pulmonary vascular disease

A study was made of the number of pulmonary endocrine cells, immunoreactive for gastrin-releasing peptide (bombesin) or calcitonin, in the terminal bronchioles of 39 cases of pulmonary vascular disease. In 25 of these, the form of vascular disease was plexogenic pulmonary arteriopathy, primary in 12 and secondary in 13, while the remaining 14 subjects had a wide range of other varieties of hypertensive pulmonary vascular disease. We found that pulmonary endocrine cells, especially those containing bombesin, were increased in number in both the primary and secondary forms of plexogenic pulmonary arteriopathy but not in other varieties of pulmonary hypertension. The prominent bombesin-containing cells were found in cases with cellular plexiform lesions but occurred even more prominently at an earlier stage when vascular smooth muscle cells were migrating from the inner media into the intima.     

Abnormal vasopressin and aldosterone response to furosemide in essential hypertension

Plasma concentrations of arginine vasopressin (AVP), angiotensin II (AII), aldosterone (Aldo), urinary output (V), osmolar clearance (Cosm), free water clearance (CH2O), fractional excretions of sodium (FENa) and potassium (FEK), urinary sodium excretion rate (U-Na) and serum potassium (S-K) were determined in 9 patients with essential hypertension (group I) and 13 normotensive healthy control subjects (group II) before and three times during the first 4 hours after an intravenous injection of 40 mg of furosemide. AVP, AII, Aldo, V, Cosm, FENa, FEK and U-Na increased in both groups. However, the elevation in AVP was significantly more pronounced and the rate of increase in Aldo was significantly slower in group I than in group II. There were no significant differences in AII, V, Cosm, CH2O, FENa, FEK and U-Na between the groups. S-K was significantly reduced only in group I. AVP and AII were not significantly correlated to each other or to blood pressure. It is suggested that the responsiveness of the renal tubules to AVP is reduced in essential hypertension and that the larger increase in AVP might be a compensatory phenomenon. The slower increase in Aldo in essential hypertension could be attributed to the reduction in S-K.