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Biomedical subjects

H Levy

Publications and source records attributed to H Levy.

160 records · Page 9Linked to original sources
PubMedDate not supplied

Maternal phenylketonuria: an international study.

Maternal phenylketonuria (PKU) syndrome results in multiple congenital anomalies in the offspring, usually consisting of microcephaly, intrauterine growth retardation, dysmorphology, and congenital heart disease. Pregnancies treated preconceptionally with a phenylalanine-restricted diet and control of maternal blood phenylalanine levels within the recommended range result in normal offspring. However, in this 15-year study, several significant factors resulted in microcephaly in 27% of the offspring, and 7% exhibited serious congenital heart disease. These results occurred chiefly in women with mean IQ scores of 83 associated with low socioeconomic status and decreased educational achievement. Another important factor associated with suboptimal control of blood phenylalanine levels during pregnancy was the fact that most pregnancies were not carefully planned and occurred in women off dietary treatment with phenylalanine-restricted products. These results indicate that greater effort must be developed to assist women with PKU in remaining on diet during their reproductive years. It appears that continued adherence to the diet, resulting in normal maternal intelligence, is an important contribution to improved fetal development.

Female↗
PubMedDate not supplied

Spatial-chromatic interactions in C-type horizontal cells of the turtle (Mauremys caspica) retina.

Horizontal cells are second-order retinal neurons that play a key role in spatial information processing. In some cold-blooded vertebrates such as turtles, a subtype of these cells, the chromaticity horizontal cells exhibit color-opponent responses and therefore are considered to be important also for color information processing. To reveal spatial and color interactions, the receptive-field properties of Red/Green and Yellow/Blue chromaticity horizontal cells in the retina of the turtle Mauremys caspica were studied by intracellular recordings from the everted eyecup preparation. We found that the polarity of the photoresponses depended not only upon the wavelength and intensity of the stimulus, but also upon its spatial configuration. Thus, a hyperpolarizing photoresponse that was elicited by full-field stimulation with bright light of wavelength close to the "neutral" one was reversed in polarity to a pure depolarizing one when a small spot or a thin annular pattern were used for stimulation. This finding could not be explained either by different balances between depolarizing and hyperpolarizing inputs to different cells or by stray light that effectively reduced the light intensity in the center of the small spot. Rather, it was found that the depolarizing and hyperpolarizing components were characterized by different receptive-field size and that these differences could account for the dependency of response polarity upon the spatial pattern of the stimulus. These findings indicate that color information processing in turtle C-type horizontal cells is a complex process that depends upon the wavelength and intensity of the light stimulus as well as upon its spatial properties.

Animals↗
PubMedDate not supplied

Does the incidence of group health insurance fall on individual workers?

Economic models predict that the cost of health insurance is borne by workers. In this paper we ask two questions. First, is cost shifting individual-specific: does a worker with higher expected medical expenses bear this cost? Second, how do explicit employee contributions affect cost shifting? We estimate wage change regressions that include as explanatory variables changes in health insurance coverage, changes in employee premium contributions, health status, and an interaction between health insurance changes and health status. We find no evidence of a significant wage offset at either the individual or group level and conclude that changes in health insurance status are not exogenous.

Cost Sharing↗
PubMedDate not supplied

Upper limb functional electrical stimulation for walker ambulation in hemiplegia: a case report.

Electrical stimulation has been sporadically used in the treatment of hemiplegia. Reported benefits include decreasing spasticity, providing a supplementary means for range of motion exercises, increasing strength, and improving local blood flow in a paretic or paralyzed limb. Some studies have also shown functional gains in the hemiplegic upper limb following treatment with electrical stimulation. Nevertheless, there have been very few reports of the use of neuromuscular stimulation to achieve new hemiplegic upper limb activity not possible without the electrical stimulation. This is a case report of a head injury patient who was able to begin ambulation with a walker, without physical assistance, for the first time in the 16 yr since his injury. A new electrical stimulation device (Handmaster) initially used therapeutically, and then functionally, provided a reliable, strong grasp and release and was instrumental in achieving the new level of function. The device proved to be easy to use in the home, giving the patient microprocessor-controlled therapeutic and patterned functional electrical stimulation.

Adult↗
PubMedDate not supplied

Systemic inflammatory response syndrome treatment by powdered sorbent pheresis: the BioLogic-Detoxification Plasma Filtration System.

Systemic inflammatory response syndrome (SIRS) is one of the most common causes of death in intensive care unit patients. The detoxification plasma filtration (DTPF) system (HemoCleanse, Inc., West Lafayette, IN) combines the DT hemodiabsorption system in series with a push-pull pheresis PF system (a suspension of powdered sorbents surrounding 0.5 microm plasma filter membranes). Bidirectional plasma flow (at 80-100 ml/min) across the PF membranes provides direct contact between plasma proteins and powdered sorbents, as well as clearance of cytokines (tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6) at a rate of 15-25 ml/min, without evidence of saturation for 90 minutes. In a U.S. Food and Drug Administration approved study we treated eight patients with SIRS and organ failure with a single DTPF treatment, using powdered charcoal as sorbent in four patients and powdered charcoal and silica in four patients. Treatments proceeded for 6 hours with proper heparin anticoagulation (activated clotting time 250-300 sec) and appeared safe. All patients improved during the treatments and each had increased blood pressure and decreased need for pressor agents. Plasma cytokine levels stabilized or decreased during treatment and were significantly lower the morning after treatment. Multiple organ dysfunction (MOD) and Acute Physiology Chronic Health Evaluation II scores and organ function gradually improved in most patients, and two patients survived for more than 28 days and two for more than 14 days. The DTPF System may prove beneficial in treatment of patients with sepsis.

Adult↗
PubMedDate not supplied

A multicenter, prospective study of the placement of transpyloric feeding tubes with assistance of a magnetic device. The Magnet-Guided Enteral Feeding Tube Study Group.

BACKGROUND: Placement of feeding tubes in the transpyloric position can be helpful in the management of enterally fed patients with pancreatitis, gastric atony, enterocutaneous fistulae, or pulmonary aspiration risk. The attainment of transpyloric position is difficult, and numerous techniques have been proposed to help in achieving this location. Recently, the use of a magnet-tipped feeding tube, dragged into proper position with an external magnet, has been described with an excellent success rate. METHODS: At 10 participating institutions, practitioners were trained in the use of the device. Successful tube placement was determined by abdominal radiograph. RESULTS: One hundred fifty-six tube placements were attempted. Transpyloric position was obtained in 60%. Placement into the third portion of the duodenum or distal was obtained in only 32%. Analysis of the data did not reveal a learning curve at the institutions, and 7 of 10 had a 50% or lower success rate. CONCLUSIONS: Placement of feeding tubes with the assistance of a magnetic device was infrequently successful at the majority of institutions where it was attempted. We report a lower success rate than the original article, which described an 88% success rate of transpyloric intubation. Although this technique has a high failure rate, some individuals seem to be very successful using it, which could reduce the need for endoscopy or transport for the placement of feeding tubes.

Electromagnetic Phenomena↗
PubMedDate not supplied

Turtle C-type horizontal cells act as push-pull devices.

Chromaticity (C-type) horizontal cells in the retina of cold-blooded vertebrates receive antagonistic inputs from cone photoreceptors of different spectral types leading to color opponency. The relative contribution of each spectral type of cones can be selectively altered by chromatic background illumination. Therefore, the spectral properties of C-type horizontal cells are expected to change when the intensity and color of ambient illumination are altered. In this study, we investigated the effects of chromatic background lights upon color opponency in Red/Green (RGH) and Yellow/Blue (YBH) C-type horizontal cells in the everted eyecup preparation of the turtle Mauremys caspica. Photoresponses were elicited by long-wavelength and short-wavelength light stimuli in the dark-adapted state and under conditions of chromatic background illumination. We found that the total voltage range. within which graded depolarizing and the hyperpolarizing photoresponses could be elicited, either increased or decreased depending upon the color of the background light. However, the maximal and minimal potential levels determined respectively by long-wavelength and short-wavelength light stimuli of supersaturating intensity remained unchanged, regardless of the wavelength and intensity of the background. These findings indicate that turtle C-type horizontal cells operate as push-pull devices. A sufficiently bright short-wavelength stimulus can push them all the way to the maximal hyperpolarizing level while a very bright long-wavelength stimulus can pull them towards the most depolarizing potential.

Adaptation, Ocular↗
PubMedDate not supplied

Human type A botulism and treatment with 3,4-diaminopyridine.

3,4-diaminopyridine was evaluated for its ability to improve muscle strength, respiratory function and electromyographic compound muscle action potentials in human botulism. In a double blind, placebo controlled study, 3,4-diaminopyridine failed to improve these parameters in a 31-year old patient with severe food-borne type A botulism. The addition of an anti-cholinesterase medication to the 3,4-diaminopyridine did not add any benefit. Lack of clinical improvement from 3,4-diaminopyridine in this patient differed from some reports of benefit in animals experimentally poisoned with type A botulinum toxin.

4-Aminopyridine↗
PubMedDate not supplied

Efficacy and safety of monoclonal antibody to human tumor necrosis factor alpha in patients with sepsis syndrome. A randomized, controlled, double-blind, multicenter clinical trial. TNF-alpha MAb Sepsis Study Group.

OBJECTIVE: To evaluate the efficacy and safety of anti-tumor necrosis factor alpha monoclonal antibody (TNF-alpha MAb) in the treatment of patients with sepsis syndrome. DESIGN: Randomized, prospective, multicenter, double-blind, placebo-controlled clinical trial. SETTING: A total of 31 hospitals in the United States and Canada. PATIENTS: There were 994 patients with sepsis syndrome enrolled in this clinical trial, and 971 patients were infused with the study drug. INTERVENTION: Patients were prospectively stratified into shock or nonshock groups and then randomized to receive a single infusion of 15 mg/kg of TNF-alpha MAb, 7.5 mg/kg of TNF-alpha MAb, or placebo. Patients received standard aggressive medical and surgical care during the 28-day postinfusion period. OUTCOME MEASURE: Twenty-eight-day all-cause mortality. RESULTS: The distribution of variables describing demographics, organ system dysfunction or failure, preinfusion Acute Physiology and Chronic Health Evaluation II score, number of organs failing at baseline, initial sites of infection, infecting microorganisms, antimicrobials used, and initial invasive procedures was similar among patients in the TNF-alpha MAb and placebo treatment arms. Among all infused patients, there was no difference in all-cause mortality in patients who received placebo as compared with those who received TNF-alpha MAb. In septic patients with shock (n = 478), there was a trend toward a reduction in all-cause mortality, which was most evident 3 days after infusion: 25 of 162 patients treated with 15 mg/kg of TNF-alpha MAb died, 22 of 156 patients treated with 7.5 mg/kg of TNF-alpha MAb died, and 44 of 160 patients in the placebo group died (15 mg/kg: 44% reduction vs placebo, P = .01; 7.5 mg/kg: 48.7% reduction vs placebo, P = .004). At day 28, the reduction in mortality for shock patients was not significant for either dose of TNF-alpha MAb relative to placebo (15 mg/kg, 61 deaths among 162 patients [37.7% mortality]; 7.5 mg/kg, 59 deaths among 156 patients [37.8% mortality]; placebo, 73 deaths among 160 patients [45.6% mortality]; P = .20 for 7.5 mg/kg and P = .15 for 15 mg/kg). Serious adverse events were reported in 4.6% of all infused patients. No immediate hypersensitivity allergic reactions due to TNF-alpha MAb were reported. Serum sickness-like reactions were seen in 2.5% of patients receiving TNF-alpha MAb. CONCLUSIONS: There was no decrease in mortality between placebo and TNF-alpha MAb in all infused patients. In septic shock patients who received TNF-alpha MAb, a significant reduction in mortality was present 3 days after infusion. Although a trend toward reduced mortality continued at 28 days following treatment with TNF-alpha MAb, the difference in mortality among shock patients treated with placebo or TNF-alpha MAb was not significant.

APACHE↗