Persistent Hypotension Associated with Hypermedullipinemia: A New Syndrome

A new syndrome is described in a patient with advanced renal insufficiency. This consists of severe and persistent hypotension causing weakness but associated with a clear mental status. Also present is evidence for decreased vascular reactivity. The hypotension was not orthostatic. The hypotension was associated with a circulating vasodepressor substance having the characteristics of medullipin I. The medullipin appears to have been derived from the remaining right kidney. Hypotension existed despite the presence of major prohypertensive mechanisms, including an endstage kidney, hyperreninemia and hyperaldosteronemia. It is likely that hypotension due to hypermedullipinemia is an entity occurring in the human being.     

Secondary hypertension. An overview of its causes and management.

Primarily hypervolaemic, high output forms of hypertension, with features indicating or strongly suggesting fluid overload as the cause of elevated cardiac output, resulting from renal disease with reduced glomerular filtration rate causing sodium retention, renal tubular causes of sodium retention, greatly excessive sodium intake and low renin hypertension, can be treated by reduction of sodium intake and potentiation of its excretion by diuretic therapy, removal of the cause (e.g. aldosteronoma), and calcium antagonists. Excessive vasoconstriction resulting from noradrenaline (norepinephrine) in neurogenic hypertension, phaeochromocytoma, orthostatic hypertension and alpha-adrenergic drug administration; angiotensin excess due to renal ischaemia brought about by aortic coarctation, renal arterial and arteriolar stenosis, intraluminal obstruction, external renal compression, renin-producing tumours, intrinsic kidney diseases and excessive renin substrate; and vascular structural disorders such as atherosclerosis, arteriolitides and fibrosis with or without calcification of major arteries may also induce hypertension. Secondary hypertension of uncertain mechanism may occur in hyperparathyroidism, hyper-or hypothyroidism, or acromegaly. All are best treated by appropriate correction of the endocrine excess or deficiency. It may also occur in pregnancy, where the mechanism may involve prostaglandin-thromboxane imbalance or calcium deficiency; calcium deficiency with some evidence of benefit from calcium supplements; and the recumbent hypertension paradoxically associated with autonomic failure. Excellent responses to specific correction of the underlying cause or pathogenetic mechanism is usual in young individuals but less frequent in older patients.     

Association of ambient air‐pollution levels with acute asthma exacerbation among children in Singapore

BACKGROUND: Air-pollution levels have been shown to be associated with increased morbidity of respiratory diseases. METHODS: Data for ambient air-pollutant levels, meteorologic factors, and hospitalization or emergency room (ER) visits for acute asthma in Singapore children over a 5-year period (1990-4) were obtained and analyzed for associations by time-series methods. RESULTS: Throughout this period, the annual mean and 24-h mean levels for sulfur dioxide (SO2), nitrogen dioxide (NO2), and total suspended particles (TSP) and maximum 1-h daily average for ozone were generally within the air-quality guidelines established by the World Health Organization (WHO). However, positive correlation between levels of each of these pollutants and daily ER visits for asthma was observed in children aged 3-12 years, but not among adolescents and young adults (13-21 years old). The association with SO2 and TSP persisted after standardization for meteorologic and temporal variables. An adjusted increase in 2.9 ER visits for every 20 microg/m3 increase in atmospheric SO2 levels, lagged by 1 day, was observed on days when levels were above 68 microg/m3. With TSP, an adjusted increase of 5.80 ER visits for every 20 microg/m3 increase in its daily atmospheric levels, lagged by 1 day, was observed on days with levels above 73 microg/m3. Similar results were also obtained after controlling for autocorrelation by time-series analysis. CONCLUSIONS: These associations were observed even though the overall levels of all pollutants were generally within the air-quality guidelines established by the WHO. These findings suggest that asthmatic children are susceptible to increased levels of air pollutants, particularly SO2 and TSP, although the ambient levels are generally within "acceptable" ranges.     

Survival and developmental disability in infants with birth weights of 501 to 800 grams, born between 1979 and 1994

OBJECTIVE: Because the survival rate has increased for extremely low birth weight neonates, many have raised the concern that the rate of developmental disability among survivors will also increase. To address this concern, we analyzed changes over time in survival and major neurosensory impairment in a sample of extremely low birth weight infants born between July 1, 1979, and June 30, 1994. METHODS: The study sample included 513 infants with birth weights of 501 to 800 g who were cared for in either of the two neonatal intensive care units that serve a 17-county region in northwest North Carolina and who were born to mothers residing in that region. At 1 year of age (corrected for gestation), survivors were examined by a pediatrician and were tested using the Bayley Scales of Infant Development. Major neurosensory impairment was defined as cerebral palsy, a Bayley Mental Developmental Index <68, or blindness. A total of 209/216 (97%) of survivors were examined at 1 year of age. Epoch of birth was defined as follows: epoch 1, July 1, 1979 to June 30, 1984; epoch 2, July 1, 1984 to June 30, 1989; and epoch 3, July 1, 1989 to June 30, 1994. RESULTS: Survival rates for epochs 1, 2, and 3 were, respectively, 24/120 (20%), 63/175 (36%), and 129/218 (59%). In contrast, the proportions with a major neurosensory impairment did not increase over time; rates for successive epochs were 6/24 (25%), 17/61 (28%), and 26/124 (21%). Rates of cerebral palsy were 3/24 (13%), 12/61 (20%), and 9/124 (7%); rates of delayed mental development were 4/24 (17%), 12/61 (20%), and 17/124 (14%); and rates of blindness were 2/24 (8%), 0/62, and 5/124 (4%), respectively. CONCLUSIONS: This analysis suggests that the increasing survival of extremely low birth weight neonates since the late 1970s has not resulted in an increased rate of major developmental problems identifiable at 1 year of age.     

Marrow transplantation with or without donor buffy coat cells for 65 transfused aplastic anemia patients

Sixty-five multiply transfused patients with severe aplastic anemia were given cyclophosphamide followed by grafts anemia were given cyclophosphamide followed by grafts from HLA-identical siblings. The effect of the administration of viable donor buffy coat cells following the marrow inoculum was evaluated with regard to graft rejection and survival. Results in 43 patients so treated are presented along with those in 22 concurrent patients given marrow alone. Most patients given buffy coat had positive in vitro tests of sensitization indicating a high risk for graft rejection, while all but one of the patients given marrow alone had negative tests. Thirty of the 43 (70%) patients given marrow and buffy coat are alive between 10 and 61 mo (median 36) after grafting; 4 died after graft rejection and 6 with acute or chronic graft-versus-host disease (GVHD). Eleven of the 22 (50%) patients given marrow alone are alive between 29 and 65 mo (median 52); 7 died after graft rejection and 3 with GVHD. The addition of buffy coat cell infusions to the marrow inoculum reduced the risk of rejection and increased survival in the currently reported transfused patients when compared to patients grafted before 1976. However, there was an increased risk of chronic GVHD. Recipients of marrow from female donors survived slightly better (73%) than recipients of male marrow (58%).     

Clinical significance of cognitive performance by hypertensive patients

Fifty-four subjects with uncomplicated essential hypertension and 54 normotensive subjects were compared with regard to a widely employed clinical index of cognitive dysfunction (the Average Impairment Rating) calculated from neuropsychological tests that discriminate between brain-damaged and neurologically normal persons. Hypertensive subjects exhibited lower mean scores on this index when education was ignored, but results were not the same for highly educated and less well educated groups. There were no differences between exceptionally well educated hypertensive and normotensive subjects, but in the less well educated group, hypertensive subjects performed more poorly than normotensive subjects. The percentages of hypertensive and normotensive subjects scoring in a cognitively impaired range on the Average Impairment Rating were low and did not differ for either education group. These data indicate the important role of subtle differences in education level with respect to positive or negative findings for studies comparing hypertensive and normotensive subjects and illustrate the important role of clinical neuropsychological indices of cognitive dysfunction when one wishes to make meaningful inferences regarding cerebral cortical function in hypertensive subjects.