PubMed Health⌕ Search

Biomedical subjects

F Stein

Publications and source records attributed to F Stein.

At least 37 records · Page 2Linked to original sources
PubMed1994

Prolongation of the prothrombin time after organophosphate poisoning.

Prolongation of the prothrombin time owing to a transient reduction in factor VII activity is described in a 14-month-old child with organophosphate poisoning. Correction after vitamin K administration suggested an organophosphate-related effect on vitamin K-dependent factor VII activity. Historically, coagulation screening has not been routinely recommended after organophosphate intoxications. We suggest, however, that routine screening in such patients may be important. A brief review of organophosphate poisoning and the unique features of our case are presented.

Acetylcholinesterase↗
PubMed1993

Infrared tympanic thermometry in the pediatric intensive care unit.

OBJECTIVES: To determine the performance of two different commercially available, noncontact infrared tympanic thermometers in predicting core body temperature as measured by pulmonary artery catheters in pediatric intensive care unit (ICU) patients. The performance of the tympanic thermometers was compared with the performance of an indwelling rectal probe and digital axillary temperature determinations. DESIGN: Prospective, consecutive sample, unblinded study. SETTING: Pediatric ICU of a tertiary care children's hospital. PATIENTS: Twenty patients requiring pulmonary artery catheter monitoring for clinical management. INTERVENTIONS: Temperature measurements were made using each infrared tympanic thermometer unit in the core mode. These values were compared with simultaneously obtained pulmonary arterial, digital axillary, and rectal probe temperatures. MEASUREMENTS AND MAIN RESULTS: Bias and variability of each method compared with the pulmonary arterial temperature were calculated. Bias did not vary with temperature measured or age of the patient. Indwelling rectal probes showed the least bias and variability and axillary temperature the most. Neither infrared tympanic thermometer had clinically important bias; one model had variability similar to that of the rectal probes, and the other model had significantly greater variability. CONCLUSIONS: In a pediatric ICU population, rectal probes reflect core temperature better than axillary determinations and both infrared tympanic models estimated core body temperature better than digital axillary temperature. One of the tympanic systems (Thermoscan Pro-1 infrared tympanic thermometer) performed in a similar way to the indwelling rectal probes and may be used to estimate core temperature in situations where a pulmonary artery catheter is not in place. The other test tympanic system (First Temp) had greater variability than the rectal probes.

Adolescent↗
PubMed1993

Barbiturates and hyperventilation during intracranial hypertension.

OBJECTIVE: The purpose of this study was to determine the effect of hyperventilation alone and hyperventilation plus barbiturate therapy on intracranial pressure, global and regional cerebral blood flow rates, cerebrovascular resistance, and cerebral perfusion pressure in adult dogs with and without intracranial hypertension induced by epidural balloon. DESIGN: Prospective, randomized, controlled study. SETTING: An animal laboratory of a university hospital. Four sequential global and regional cerebral blood flow determinations were made in each animal during monitoring of heart rate and systemic arterial pressure, during respiratory control and arterial blood gas monitoring, intracranial pressure monitoring, and with or without inflation of an epidural balloon catheter. SUBJECTS: Acute mongrel dogs obtained from the Baylor Center for Comparative Medicine. Five groups of animals were studied. In group 1, the response to hyperventilation was assessed in dogs without increased intracranial pressure. In group 2, the response to hyperventilation was assessed in animals with acute intracranial hypertension. In group 3, the response to hyperventilation plus barbiturate therapy was assessed in dogs without increased intracranial pressure. In group 4, the response to hyperventilation plus barbiturate therapy was assessed in dogs with acute increased intracranial pressure. In group 5, a group of dogs with increased intracranial pressure was treated with neither hyperventilation nor barbiturates. INTERVENTIONS: Hyperventilation, hyperventilation plus barbiturate therapy, or no interventions were studied in these experimental paradigms. MEASUREMENTS AND MAIN RESULTS: The main outcome measures were changes in intracranial pressure and/or changes in regional or total cerebral blood flow. A significant decrease in intracranial pressure and cerebral blood flow rate was produced by hyperventilation alone in groups with intracranial hypertension. Combined hyperventilation and barbiturate therapy resulted in a significant further decrease in cerebral blood flow rate in animals with normal and increased intracranial pressure, but no greater decrease in intracranial pressure was seen compared with treatment with hyperventilation alone. Cerebral perfusion pressures remained normal despite significant decreases in cerebral blood flow rates. CONCLUSIONS: These studies suggest that barbiturate administration in this model of intracranial hypertension was no more effective in reducing increased intracranial pressure than hyperventilation alone.

Acute Disease↗
PubMed1992

Severe laryngotracheobronchitis complicating measles.

OBJECTIVE: To determine the incidence of severe measles-related laryngotracheobronchitis in patients hospitalized during a recent measles epidemic and to evaluate factors associated with severity of airway injury and its management. DESIGN: Clinical description of patient series. SETTING: Children's hospital and county general hospital, Houston, Tex. PATIENTS: One hundred twenty-four children (aged 1 month to 19 years) admitted with a diagnosis of measles. INTERVENTIONS: None. MEASUREMENTS/RESULTS: Twenty-seven patients had significant laryngotracheobronchitis, including 10 who had not received appropriate immunization. Six patients required endotracheal intubation for relief of upper airway obstruction. The median age of patients requiring intubation was 12 months (range, 4 to 24 months). Two patients died of complications of superinfection. Two patients survived but required prolonged intubation. Two patients underwent early diagnostic laryngoscopy and bronchoscopy and required shorter artificial airway maintenance. CONCLUSIONS: Severe laryngotracheobronchitis frequently occurs in patients younger than 2 years hospitalized with measles and may be related to bacterial or viral super-infection. Early diagnostic laryngoscopy and bronchoscopy for injury assessment and possible endotracheal tube exchange are recommended and, in some severe cases, tracheostomy should be considered to shorten artificial airway maintenance and decrease the incidence of airway complications.

Adolescent↗
PubMed1991

Cerebral blood flow velocities by transcranial Doppler during parabolic flight.

Microgravity is produced for 20 to 30 seconds in NASA's KC-135 aircraft at the end of a 2 G pullup for each of 40 parabolas per flight. Continuous transcranial Doppler ultrasound, arterial blood pressure, and acceleration levels were recorded for 12 male and 8 female healthy subjects without known cardiovascular or cerebrovascular disease. Recordings were made throughout 10 parabolas per subject in each of the supine, sitting, and standing postures. The data were digitized for off-line analysis using Fast Fourier Transform and other signal processing methods. A phase lag in changes to transcranial Doppler waveforms from the onset of acceleration was more pronounced in the standing position than in the sitting position. There was less of a phase lag in the supine position. These ultrasound changes preceded the more delayed variations in arterial blood pressure. The KC-135 provides a unique short-term environment that allows measurement of the human response to variations in acceleration but limits physiological monitoring of responses to a steady state of microgravity.

Acceleration↗
PubMed1990

Transcranial Doppler studies of flow velocity in middle cerebral artery in weightlessness.

Physiological adaptation to weightlessness requires changes in cardiovascular system parameters to maintain homeostasis in the presence of cephalic fluid shifts. The cerebral circulation must respond immediately to these systemic changes or impairment of cerebral function will occur. Blood flow velocities of the middle cerebral artery were measured by transcranial Doppler (TCD) ultrasound in NASA's KC-135 aircraft from four healthy subjects in the supine position. Transcranial Doppler data with accompanying acceleration information were analyzed in three segments in each parabola. Cardiac cycles for each segment of all 20 parabolas were pooled for individual subjects. A Student's t test on the data revealed statistically significant differences in the mean and peak frequencies, systolic/diastolic ratios and Doppler power between positive 2 gz and microgravity (10(-2) gz) as well as between positive 2 gz and negative 2 gz. Velocity waveform profiles differed for the first one third of each segment, with a more resistive waveform developing during the last two thirds. Changes in systemic arterial resistance and/or raised intracranial pressure may contribute to these TCD waveform changes.

Adaptation, Physiological↗
PubMed1990

Bioavailability of enteric-coated sodium fluoride tablets as affected by the administration of calcium supplements at different time intervals.

The gastrointestinal absorption of enteric-coated (EC) tablets of sodium fluoride (NaF) with respect to different time schedules of administration of calcium supplements in solution was tested. It was found that the simultaneous administration of these two medications under these formulations did not interfere with fluoride absorption. The calcium was also well absorbed as shown by the rise in serum ionized calcium concentration. Other schedules were studied as well, such as EC NaF tablets taken 1 hour after or 3 hours before the administration of calcium supplements. No superiority was shown, on the contrary, compared with the simultaneous administration of both medications. It was concluded that EC tablets of NaF and calcium supplements in solution can be provided simultaneously to enhance compliance.

Adult↗
PubMed1990

Development of methods to analyse transcranial Doppler ultrasound signals recorded in microgravity.

During space flights, several clinical syndromes may be the result of changes in cerebral circulation. The purpose of the paper is to describe the development and initial evaluation of a system for recording, processing and displaying transcranial Doppler ultrasound (TCD) waveforms from the middle cerebral artery (MCA) in microgravity. Volunteers were repeatedly subjected to 15-20 s intervals of microgravity ('near zero gravity') during flights on the KC-135 military aircraft. Continuous TCD recordings from the MCA were stored on magnetic tape. The paper describes the system that was developed to digitise the Doppler ultrasound data and markers that corresponded to the various levels of microgravity, obtain the maximum and mean Doppler waveforms, identify the waveforms and quantify them. The results demonstrate the feasibility of making TCD recordings in a microgravity environment and illustrate excellent performance of the system and its ease of operation. Quantitative waveform analysis of the recordings from the first subject studied in the supine position showed statistically significant changes in MCA velocity waveforms during microgravity.

Cerebral Arteries↗
PubMed1989

Teaching stress management techniques to a schizophrenic patient.

This paper describes a stress management training program used with a 26-year-old schizophrenic man attending an outpatient day care program. In a seven-session program the patient was taught to use various techniques in muscle relaxation and biofeedback to decrease anxiety and to cope with stress. The patient's improvement on 7 of the 20 items of the State-Trait Anxiety Inventory demonstrated the effectiveness of even a short-term stress management program.

Adult↗
PubMed1987

A clinical correlation between hypozincemia and tinnitus.

We examined a group of 115 patients suffering from tinnitus and have attempted to find a statistically significant correlation between the tinnitus experienced and low blood zinc levels (hypozincemia). No particular correlation could be made between the nature of the tinnitus experienced and hypozincemia except for the continuation of head noises, these being more frequently associated with hypozincemia when they are intermittent. Two hypotheses of pathogenesis are proposed to explain this phenomenon and are based on the importance of zinc to the syntheses of enzymes and proteins.

Adolescent↗
PubMed1987

[The zinc sulfate overload test in patients suffering from tinnitus associated with low serum zinc. Preliminary report].

This work studies the efficiency of the zinc overloading in the treatment of patients suffering from tinnitus with hypozincemia. The authors have positive results about 52% of cases: in 15% there was a good amelioration and in 37% there was a little but significant amelioration of their symptoms. The authors have also found on that this type treatment with zinc of overloading is more efficient in males than in females. It is also more efficient in types of tinnitus of a continuous character than in other types.

Adult↗
PubMed1986

The Perlman familial nephroblastomatosis syndrome.

In 1973, Perlman et al described a familial syndrome of bilateral renal hamartomas with or without nephroblastomatosis, macrosomia, islet cell hypertrophy, unusual facies, and early lethality. Two additional sibs were recently reported by Neri et al [1984]. We report on two sibs with polyhydramnios, fetal ascites, and abdominal muscular hypoplasia, visceromegaly, and subsequent development of Wilms tumor in one of them. Delineated features of this syndrome include visceromegaly, macrosomia, renal hamartomas, nephroblastomatosis, cryptorchidism in males, unusual facial appearance, polyhydramnios, fetal ascites, and Wilms tumor but do not include hemihypertrophy, omphalocele or umbilical abnormalities, aniridia, or other conditions known to be associated with Wilms tumor. This condition should be considered primarily in the differential diagnosis of fetal ascites without hydrops and possibly in the differential diagnosis of familial Wilms tumor, polyhydramnios, congenital hepatomegaly, or nephromegaly.

Adult↗
PubMed1985

Radiographic examination of the hand and wrist.

Radiographs have an essential role in the treatment of the injured hand. Positioning for routine views must be standardized so that pathology is not missed. When physical findings indicate, special views that demonstrate areas not seen on routine views should be obtained.

Carpal Bones↗
PubMed1985

Foreign body injuries of the hand.

Retained foreign bodies and puncture wounds are common injuries to the hand. A detailed history and physical examination prior to treatment are essential. If surgical removal of a foreign body or surgical exploration of a puncture wound is decided upon, it must be performed under adequate anesthesia and tourniquet control.

Emergencies↗