Recombinant erythropoietin improves exercise capacity in anemic hemodialysis patients

The objective of this study was to quantitate the improvement in exercise capacity produced in anemic chronic hemodialysis (HD) patients after correction of their anemia with recombinant human erythropoietin (rHuEPO). The maximal exercise capacity and quadriceps strength of 19 anemic HD patients was tested before and after correction of the anemia with rHuEPO. A progressive work exercise protocol (PWET) on a cycle ergometer was used to compare measurements of maximal oxygen uptake (VO2max), maximal heart rate, and subjective assessment of fatigue during the test. Measurements of quadriceps strength were performed before the cycle ergometer studies. At baseline, all patients had reduced VO2max (15.3 +/- 5.4 mL/kg/min) and maximal exercise heart rates (138.5 +/- 23.9 beats/min). rHuEPO increased the mean hematocrit from 21.2% to 35%, and this was associated with a 17% increase (P less than 0.0005) in the VO2max. At any specified work load, rHuEPO treatment decreased heart rate, minute ventilation, and the subjective perception of fatigue. Both isometric and isokinetic measurements of quadriceps strength were improved following administration of rHuEPO. The maximal exercise heart rate was decreased in comparison to the baseline measurements (P less than 0.04), suggesting that in contrast to normal subjects, HD patients stop exercise before oxygen transport limitations are reached. In this unselected group of chronic HD patients, rHuEPO produced clinically significant improvements in both aerobic exercise capacity and isometric and isokinetic quadriceps strength. The improvement in aerobic capacity was substantially less than would have been expected from the correction of a comparable degree of anemia in non-HD patients. None of the 19 treated patients attained the exercise performance level predicted for a sedentary normal subject.     

Central nervous system decompression sickness: latency of 1070 human cases

Many aspects of central nervous system (CNS) decompression sickness (DCS) are poorly understood, including the temporal pattern of its presentation and the pathogenic mechanisms involved in the development of the disease. Using case histories and clinical series published in the literature and retrieved from treatment center records, this study is an attempt to define the interval between surfacing from a hyperbaric exposure and the onset of symptoms of CNS DCS. The results of 1070 cases of human CNS DCS were included in the study. The results show that the disease generally occurs rapidly: over 50% became symptomatic within 10 min of returning to 1 ATA, and in only 15% of cases was the onset of symptoms delayed for more than 1 h. Cerebral DCS had a more rapid onset than spinal cord disease: 50% of cerebral cases became apparent within about 3 min and a similar proportion of spinal cord cases within about 9 min from surfacing. The influence of these results on the diagnosis and treatment of dysbaric illness, on the safety of certain diving practices, and on possible pathogenic mechanisms is discussed.     

Experimental studies on the comparative infectivity and pathogenicity of Streptococcus suis type 2. I. Porcine and human isolates in pigs

Piglets between 1 and 40 days of age were inoculated with varying numbers and with different isolates of Streptococcus suis type 2 by the intranasal, intravenous and subarachnoid routes. Less than 100 organisms of an isolate cultured from apparently normal pigs caused subclinical infection in 1-day-old piglets after intranasal inoculation. This infection was naturally transmitted between litter mates. Intravenous inoculation of a similar isolate in 7-week-old pigs resulted in a sub-clinical bacteraemia in 3 of 8 piglets. One other piglet developed a bacteraemia 7 days after inoculation and concurrently developed signs of lameness and nervous dysfunction. Ten piglets were inoculated by the subarachnoid route with a porcine isolate and two with an isolate from a person with clinical disease. Only the latter two pigs developed the classical signs of nervous disease associated with infection by S. suis type 2. It is concluded that strains of S. suis type 2, of varying pathogenicity for both pigs and man, are endemic in New Zealand. It is suggested that the occurrence of disease is associated with both exposure to a pathogenic strain and other, as yet undetermined, secondary factors.     

Flexion-distraction injuries of the lumbar spine and associated abdominal trauma

Recent experience with flexion-distraction injuries of the lumbar spine associated with blunt abdominal trauma and the use of a lap belt alone has caused us to review our experience over the last 7 years. Eighteen patients were identified, with an average age of 22 years, and an average followup of 34 months. Fifteen were involved in motor vehicle accidents, with 11 being single-vehicle accidents. Of note, 12 of the 15 were rear seat passengers with lap belts only. Twelve patients suffered abdominal injury, seven requiring operative intervention, mainly for hollow viscus injury. In three patients, a delay of 24 hours or more occurred before recognition of intra-abdominal pathology requiring surgical therapy. One patient had an unrecognized spinal fracture for 2 weeks after abdominal surgery for a perforated viscus. The spinal injury was carefully assessed and analyzed for prognostic factors. Six were graded excellent, five good, four fair, and one poor. One case of paraplegia associated with avulsion of the spinal cord from distraction is reported. Prognostic factors included the amount of facet joint involvement and the degree of initial kyphosis. Those having greater than 17 degrees of kyphosis had a poor prognosis. Early recognition of the constellation of injuries involving the spine and abdomen associated with the use of the lap belt is recommended with surgery to the spinal fracture as outlined.     

Alzheimer's disease: identical phenotype of familial and non-familial cases

Summary Ninety outpatients with Alzheimer's disease according to ICD-10 diagnostic draft criteria were studied to test the hypothesis that cases with a familial aggregation are different from cases without such an aggregation with respect to cognitive impairment. In all cases the diagnosis of Alzheimer's disease was confirmed by prospective observation within 12 months of initial evaluation. Patients were divided into two groups: one consisting of 23 patients with a familial aggregation, the other consisting of 67 patients without secondary cases among first-degree relatives. By means oft-tests differences in impairment of cognitive functions between the groups were calculated. The results did not yield statistically significant differences between the groups for any of the neuropsychologically investigated cognitive deficits. Thus the hypothesis that the presence of a familial aggregation may lead to a distinct phenotype in Alzheimer's disease was not confirmed.     

Variations in pregnancy outcomes by race among 10-14-year-old mothers in the United States.

This study used the 1983-86 U.S. Linked Live Birth-Infant Death Files to examine variations in pregnancy outcomes among 38,551 U.S. resident black and white adolescents ages 10 through 14. The birth rate was 4.29 per 1,000 for blacks, more than 7 times the rate for whites (.59 per 1,000). Black mothers had higher proportions of very low and low birth weight infants than did whites (very low birth weight: 3.7 versus 2.6; low birth weight: 15.0 versus 10.5). Neonatal and infant mortality rates were higher among very low birth weight and low birth weight white infants. Neonatal and infant mortality rates were similar for normal birth weight infants of both races, but were 3.7 to 7.4 times higher among black infants with birth weights more than 4,250 grams. Logistic regression indicated that black mothers were at higher risk for having infants who were low birth weight, very low birth weight, small for gestational age, preterm, and very preterm. There were no differences by race for neonatal, postneonatal, and infant mortality. While the risk for poor pregnancy outcomes is great among young adolescents, young black adolescents appear to be particularly vulnerable. Attempts to reduce unintended pregnancies in this group should receive highest priority.     

Active and passive surveillance for communicable diseases in child care facilities, Seattle-King County, Washington.

OBJECTIVES: The purpose of this study was to develop and evaluate models for public health surveillance of illnesses among children in out-of-home child care facilities. METHODS: Between July 1992 and March 1994, 200 Seattle-King County child care facilities participated in active or enhanced passive surveillance, or both. Reporting was based on easily recognized signs, symptoms, and sentinel events. Published criteria were used in evaluating surveillance effectiveness, and notifiable disease reporting of participating and nonparticipating facilities was compared. RESULTS: Neither surveillance model was well accepted by child care providers. Enhanced passive and active surveillance had comparable sensitivity. Reporting delays and the large amount of time needed for data entry led to problems with timeliness, especially in terms of written reporting during active surveillance. CONCLUSIONS: Widespread active public health surveillance in child care facilities is not feasible for most local health departments. Improvements in public health surveillance in child care settings will depend on acceptability to providers.