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Biomedical subjects

R Greenstein

Publications and source records attributed to R Greenstein.

At least 19 recordsLinked to original sources
PubMed2002

Newborn screening compared to clinical identification of biochemical genetic disorders.

A group of 28 patients with inherited metabolic disease (homocystinuria galactosaemia, maple syrup urine disease and biotinidase deficiency) diagnosed by screening were compared with a group of 17 similar patients identified clinically. The rate of hospitalization was similar for the two groups. The patients diagnosed clinically showed a higher incidence of mental retardation and their parents experienced greater stress and found greater difficulty in meeting their child's needs.

Adolescent↗
PubMed2001

Incidence and clinical significance of inducible atrial tachycardia in patients with atrioventricular nodal reentrant tachycardia.

INTRODUCTION: The purpose of this prospective study was to determine the prevalence and clinical significance of inducible atrial tachycardia in patients undergoing slow pathway ablation for AV nodal reentrant tachycardia who did not have clinically documented episodes of atrial tachycardia. METHODS AND RESULTS: Twenty-seven (15%) of 176 consecutive patients who underwent slow pathway ablation for AV nodal reentrant tachycardia were found to have inducible atrial tachycardia with a mean cycle length of 351+/-95 msec. The atrial tachycardia was sustained in 7 (26%) of 27 patients and was isoproterenol dependent in 20 patients (74%). The atrial tachycardia was not ablated or treated with medications, and the patients were followed for 9.7+/-5.8 months. Six (22%) of the 27 patients experienced recurrent palpitations during follow-up. In one patient each, the palpitations were found to be due to sustained atrial tachycardia, nonsustained atrial tachycardia, recurrence of AV nodal reentrant tachycardia, paroxysmal atrial fibrillation, sinus tachycardia, and frequent atrial premature depolarizations. Thus, only 2 (7%) of 27 patients with inducible atrial tachycardia later developed symptoms attributable to atrial tachycardia. CONCLUSION: Atrial tachycardia may be induced by atrial pacing in 15% of patients with AV nodal reentrant tachycardia. Because the vast majority of patients do not experience symptomatic atrial tachycardia during follow-up, treatment for atrial tachycardia should be deferred and limited to the occasional patient who later develops symptomatic atrial tachycardia.

Adult↗
PubMed1999

High prevalence of asymptomatic esophageal motility disorders among morbidly obese patients.

BACKGROUND: Morbid obesity is becoming more prevalent in the industrialized world. Few data exist regarding the resting lower esophageal sphincter pressure (LESP) and esophageal motility in relationship to body mass index (BMI). METHODS: During a 3-year period, 111 of 152 morbidly obese patients seeking bariatric surgery completed esophageal manometric testing and questionnaire regarding esophageal symptoms. Manometric parameters included wave amplitude and duration of esophageal contractions, percentage of peristaltic function, and resting LESP. Questionnaire data included age, sex, medications, prior medical conditions, and esophageal symptoms. RESULTS: 88 (79%) of the patients were female; 23 (21%) were male. The mean age was 39.8 years (+/- 9.9), the mean BMI was 50.7 kg/m2 (+/- 9.4). There was a lack of correlation between BMI and LESP (r = 0.04). Abnormal manometric findings were observed in 68/111 (61%) patients: 28 (25%) had only hypotensive lower esophageal sphincter (LESP < 10 mm Hg); 16 (14%) had nutcracker esophagus (amplitude >180 mm Hg), 15 (14%) had nonspecific esophageal motility disorders, 8 (7%) had diffuse esophageal spasm (DES), and 1 (1%) had achalasia. Patients with DES had a significantly higher BMI than those with other motility disorders (P < 0.05). Dysphagia was reported in 7 (6%) patients and chest pain in 1 patient. Heartburn and/or regurgitation (gastroesophageal reflux disease, GERD) was noted in 35 patients (32%), of whom 18 (51%) had a hypotensive resting LES. 40 of 68 patients (59%) with abnormal motility tracings did not report any esophageal symptoms. CONCLUSION: Morbid obesity per se does not imply an abnormality of LESP. In addition, a majority of morbidly obese patients who were considering bariatric surgery had no esophageal symptoms but were found to have abnormal esophageal manometric patterns. These findings add support to the suggestion that morbidly obese patients may have abnormal visceral sensation.

Adult↗
PubMed1997

Isolyte S, a physiologic multielectrolyte solution, is preferable to normal saline to wash cell saver salvaged blood: conclusions from a prospective, randomized study in a canine model.

OBJECTIVES: The purpose of this study is to compare normal saline with Isolyte S as the wash solutions during high-volume cell saver autologous blood transfusion. Normal saline, the standard wash solution in cell saver autologous blood transfusion, is associated with acid-base and electrolyte derangements. Isolyte S is a physiologic, balanced multielectrolyte crystalloid solution that approximates the electrolyte content of plasma. DESIGN: Open-label, prospective, randomized study. SETTING: Research laboratory in a Department of Veterans Affairs medical center. SUBJECTS: Fourteen mongrel dogs, weighing 22 to 23 kg each. INTERVENTIONS: Fourteen mongrel dogs were prospectively randomized to receive normal saline (n = 7) or Isolyte S (n = 7). Animals were anesthetized, received heparin for anticoagulation, and underwent 18 cycles of cell saver autotransfusion. In each cycle, 125 mL of blood was arterially withdrawn, and washed with either normal saline (mEq/L) (sodium 154, chloride 154) or Isolyte S (mEq/L) (sodium 141, potassium 5, magnesium 3, chloride 98, phosphate 1, acetate 28, and gluconate 23). The washed blood was retransfused. MEASUREMENTS AND MAIN RESULTS: Acid-base and electrolyte analyses were performed throughout the study on the systemic blood of each group and compared. By the end of the study, the Isolyte S group had a normal pH and an increased bicarbonate concentration (mEq/L: normal values 24 to 32; normal saline 9.0 +/- 1.9 vs. Isolyte S 13.2 +/- 3.0 [p < .01]) and an increased magnesium concentration (mg/dL: normal values 1.6 to 2.4; normal saline 1.6 +/- 0.2 vs. Isolyte S 2.2 +/- 0.2 [p < .0001]). Additionally, the Isolyte S group had a lower chloride concentration (mEq/L: normal values 95 to 110; normal saline 130 +/- 9 vs. Isolyte S 117 +/- 7 [p < .02]) and a lower potassium concentration (mEq/L: normal values 3.5 to 5.0; normal saline 4.4 +/- 0.5 vs. Isolyte S 3.7 +/- 0.3 [p < .01]). There were no significant differences between normal saline or Isolyte S in the values of PCO2, lactic acid, sodium, total and ionized calcium, inorganic phosphorus, total protein, albumin, hemoglobin, and hematocrit. CONCLUSIONS: Fewer systemic acid-base and electrolyte derangements were observed when blood was washed with Isolyte S. Differences between the normal saline and Isolyte S groups are ascribed primarily to the constituents of the wash solution. We conclude that Isolyte S, a physiologic, balanced, multielectrolyte solution, should be considered as the wash solution in high-volume autologous cell saver blood processing and transfusion.

Animals↗
PubMed1996

Maternal serum screening for birth defects: results of a Connecticut regional program.

Second trimester maternal serum screening provides a method to identify pregnancies at high risk for fetal Down's syndrome, trisomy 18, open neural tube defects, and a variety of other chromosomal and nonchromosomal fetal anomalies. Results are presented for a regional program to identify high-risk pregnancies using alpha feto-protein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3) analyses (triple marker testing). A total of 27,140 women received screening. Using a midtrimester Down's syndrome risk of 1:270 to define the high-risk group, 5.26% of women of all ages were screen-positive for Down's syndrome resulting in the eventual detection of approximately 72% of the affected fetuses. The detection rate for patients under 35 at estimated date of delivery was 61% and for women 35, or older, the detection rate was 100%. A separate protocol to screen for trisomy 18 identified 0.2% of pregnancies, with 38% of the trisomy 18 cases present in this group. Over 3% of women screen-positive for Down's syndrome or trisomy 18 had a serious fetal chromosome anomaly. In addition, 2.89% of women had an elevated AFP (greater or equal to 2.0 multiples of median). This component of the screening resulted in the identification of 86% of the neural tube defects, 75% of the ventral wall defects, and also some of the other various fetal anomalies present in the screened population. Since both laboratory and clinical data are combined to generate patient-specific risks, there is a need for quality control elements that go beyond that normally required for a clinical laboratory alone. We stress the need for comprehensive follow-up programs to evaluate screening programs and maintain high quality.

Biomarkers↗
PubMed1996

The impact of managed care on genetic testing laboratories in the United States.

The traditional activities of clinical genetics programmes have focused on service, education and research. These activities have been funded on a fee-for-service basis often supplemented by service and research grants from private and government sources. Developing changes in health care financing threaten this approach to funding of genetics programmes in general and of genetics laboratories in particular. The evolution of managed health care requires new strategies for delivery of clinical and laboratory services with an emphasis on adaptability. Strategies may include development of alliances among related laboratories, subcontracting with large, multiservice laboratories and developing formalized marketing plans.

Clinical Laboratory Techniques↗
PubMed1995

New syndrome of hydrocephalus, endocardial fibroelastosis, and cataracts (HEC syndrome).

We report on two unrelated male infants with similar findings of communicating hydrocephalus, endocardial fibroelastosis (EFE) and congenital cataracts, who died at 4 months of age. Both mothers reported an upper respiratory infection during the first trimester of pregnancy which was further complicated by polyhydramnios in the third trimester. The infants were diagnosed with bilateral congenital nuclear cataracts at birth. Serologic tests for toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus, syphilis, and galactosemia screens were negative. Chromosome analyses were normal. Both children developed communicating hydrocephalus between one and three months after birth. Patient 1 died suddenly at 4 months following an upper respiratory infection. Patient 2 developed congestive heart failure and also died at 4 months. At autopsy, both infants had enlarged hearts with endocardial fibroelastosis. No identifiable organism could be isolated. We discuss the association of birth defects in widely separated organ systems in these patients and suggest that this may represent a genetic syndrome; however, a viral etiology cannot entirely be excluded. We believe this is a distinct disorder and propose the acronym HEC for hydrocephalus, EFE and cataracts.

Abnormalities, Multiple↗
PubMed1995

Remote communication from a mobile terminal: an adjunct for a computerized intensive care unit order management system.

OBJECTIVES: To develop and implement a fully mobile computer terminal that interfaces with our computerized intensive care unit (ICU) local area network and order management system. This system can provide access to the entire network and to order review and entry and during ICU bedside rounds. DESIGN: Descriptive report. SETTING: Surgical ICU in Department of Veterans Affairs Medical Center. SYSTEM CONFIGURATION: A parallel local area network was configured for the remote mobile computer system. A proprietary remote transmission system (Altair II, Motorola) was used. This high-throughput system minimizes interference and errors by using licensed, nonshared, radiofrequency spectra. CONCLUSION: The resulting mobile system is an economical and time-efficient adjunct to an established ICU computerized network and order management system. Clinical working bedside rounds are now routinely conducted with the mobile terminal, providing immediate access to full network resources.

Computer Terminals↗
PubMed1994

Long-term follow-up of a patient transplanted for Hunter's disease type IIB: a case report and literature review.

Unlike most other storage diseases and despite clinical experience, the indications for bone marrow transplantation in Hunter's disease remain controversial. The case of a 14-year-old male with mucopolysaccharidosis type IIB is presented, who received an allograft from his HLA-identical sibling. The donor had been off therapy for acute lymphoblastic leukemia for 3 years. The patient experienced minimal difficulties with his transplant and was fully engrafted by day 42, with no signs of acute or chronic graft-versus-host disease. Now, more than 3 years after BMT, the patient has experienced significant subjective and objective improvement in his disease. The iduronate-2-sulfatase levels in the serum are now approximately 10% of normal control. Urinary glycosaminoglycans were negative. The posttransplant marrow was evaluated for donor-recipient source using VNTR analysis with the polymerase chain reaction (PCR). This showed a PCR-detectable subpopulation of residual patient marrow cells remaining, suggesting a state of stable mixed chimerism. The patient continues to show signs of amelioration of his disease. These results may be of value in determining the proper therapy for a patient with mild Hunter's disease, and may also be pertinent to the future application of recombinant enzyme therapy or gene therapy.

Adolescent↗
PubMed1994

Federal and nationwide intensive care units and healthcare costs: 1986-1992.

OBJECTIVES: To establish Department of Veterans Affairs' intensive care unit (ICU) costs from a database and to use this information to validate the Russell equation, the most commonly used method of calculating ICU costs. To compare and trend Department of Veterans Affairs' and nationwide (USA) ICU and healthcare costs. DESIGN: Comparison study. SETTING: Database analysis of Department of Veterans Affairs' and nationwide ICUs over a 6-yr period (1986-1992), with biennial evaluations. MAIN MEASURES: Costs and bed occupancies of Department of Veterans Affairs' and nationwide hospitals and ICUs, as well as United States national health expenditures and gross domestic product. RESULTS: Fifty percent to Department of Veterans Affairs' ICU funds were used for nurse and physician salaries. Department of Veterans Affairs' ICU direct and indirect cost ratios have remained constant (2:1). The Russell equation is valid, providing that the "inpatient only" cost variable is used. ICU costs were consistently lower in the Department of Veterans Affairs' than nationwide, as compared by the Russell equation. A smaller fraction of the hospital budget was allocated to the ICU in the Department of Veterans Affairs than in nationwide institutions. Despite an increasing nationwide ICU patient workload, the percentage of ICU fund allocations has not increased. Health care in the United States increases at a rate greater than the increase in gross domestic product. Healthcare delivery costs are increasing at a greater rate nationwide than in the Department of Veterans Affairs. The percentage increase in ICU cost per day, both in the Department of Veterans Affairs and nationwide, was less than the increase in healthcare costs. The percent of the gross domestic product, national health expenditure, and hospital cost used by the ICU has increased minimally during the course of this study. CONCLUSIONS: The Department of Veterans Affairs has the only national ICU line item cost database available. For the Russell equation calculation to be accurate, inpatient only costs should be used. Until customized Health Care Financing Administration analyses become available, nationwide ICU costs are best determined by the Russell equation. Department of Veterans Affairs' ICUs have a consistent cost advantage over nationwide ICUs. Increases in United States healthcare delivery costs continue to exceed the increase in gross domestic product. Cost containment is already occurring in critical care.

Bed Occupancy↗
PubMed1994

Critical care medicine: observations from the Department of Veterans Affairs' intensive care units.

OBJECTIVES: To study the critical care medicine programs of the Department of Veterans Affairs. DESIGN: Survey study. SETTING: Data were obtained from 85% (113/133) of the acute care hospitals of the Department of Veterans Affairs. MAIN MEASURES: Intensive care unit (ICU) administrative and patient demographics, physician training and certification, participation in critical care medicine programs and research. RESULTS: Analyses were performed on 78% (2021) of Department of Veterans Affairs' ICU beds. Mortality (%) was highest in medical ICUs (11.7 +/- 0.8) and lowest in coronary care units (5.0 +/- 0.5) and surgical ICUs (5.5 +/- 0.5). The average length of stay (days) was highest in medical ICUs (5.6 +/- 0.6) and lowest in combined medical-coronary care units (4.2 +/- 0.4) and coronary care units (4.3 +/- 0.5). The majority of ICU directors have internal medicine training. A minority of ICU directors are formally trained in critical care medicine or are board eligible or certified in critical care medicine. The majority of fellows in the ICU are pulmonary or cardiac fellows; a minority are critical care medicine fellows. Accredited critical care medicine fellowship training programs were found in only 17% (19/113) of responding Department of Veterans Affairs' institutions. Seventy-three percent (82/113) of ICUs in responding hospitals had published fewer than five publications between 1987 and 1990. CONCLUSIONS: The results of this study suggest that the Department of Veterans Affairs would benefit from increasing the number of critical care medicine board eligible/certified directors, and increasing the program's participation in accredited critical care medicine fellowship training programs and research endeavors. Overall, however, we conclude that the Department of Veterans Affairs' critical care medicine program is at least comparable to nationwide ICUs in the parameters evaluated.

Critical Care↗
PubMed1993

Variable clinical expression of mosaic trisomy 16 in the newborn infant.

Trisomy 16 is common in embryos and fetuses aborted early during development. Mosaicism for trisomy 16 is sometimes encountered during prenatal diagnosis, particularly with chorionic villi biopsy specimens, and, until recently, was thought to be confined to the placenta. However, recently, several liveborn infants with trisomy 16 mosaicism have been described. We report on an additional liveborn infant with trisomy 16 mosaicism and compare the clinical findings with those of the previously reported cases in an attempt to delineate a mosaic trisomy 16 syndrome. Cytogenetic analysis from our patient showed that there was a different proportion of abnormal cells in different tissues and that the anomaly was undetectable in blood lymphocyte cultures. This observation was consistent with some of the previous reports. DNA analysis of parents and child was carried out using a polymorphic dinucleotide marker that maps to the long arm of chromosome 16. This analysis showed that the extra chromosome 16 in the infant was maternal in origin and suggested that the nondisjunction was probably a first meiotic division error. Our results suggest that an investigation of multiple tissues is required before concluding that mosaicism is confined to the placenta. We conclude that a finding of trisomy 16 mosaicism at prenatal diagnosis should be regarded with extreme caution. This diagnosis may be associated with a highly variable phenotype that may occasionally be compatible with extrauterine life.

Abnormalities, Multiple↗
PubMed1993

Neurofibromatosis type 1: magnetic resonance imaging findings.

The purpose of this study was to determine the locations and characterize the types of brain abnormalities noted on brain magnetic resonance imaging in patients with probable and definite neurofibromatosis type 1. Patients with definite neurofibromatosis type 1 (n = 17) were studied when clinically indicated, and patients with probable neurofibromatosis type 1 (n = 9) were studied to evaluate for asymptomatic optic pathway glioma. Of the 26 patients evaluated, 14 (53%) had high-intensity signal abnormalities and 11 (42%) had significant structural abnormalities. Subsequent clinical follow-up has confirmed conversion to a definite neurofibromatosis type 1 diagnosis in three of the four cases of probable neurofibromatosis type 1 who had high-intensity signal abnormalities. The most common locations of high-intensity signal lesions were in the globus pallidus of the basal ganglia and cerebellar white matter. Tortuous or thickened optic nerves and/or optic chiasm were seen in eight cases. Brain magnetic resonance imaging scans frequently reveal high-intensity signal lesions and structural abnormalities in selected patients with both probable and definite neurofibromatosis type 1. These findings may allow for a definitive diagnosis in clinically probable cases.

Adolescent↗
PubMed1992

Effect of omeprazole on gastric first-pass metabolism of ethanol.

Some commonly used H2-receptor antagonists affect gastric first-pass metabolism of ethanol and lead to unexpectedly high blood alcohol concentrations after consumption of alcohol. To investigate whether omeprazole--a substituted benzimidazole recently approved for clinical use--has a similar harmful effect, we administered a moderate dose of ethanol (0.3 g/kg body wt) orally to seven normal volunteers before and after one week of omeprazole administration (20 mg daily). No significant effect of the drug was found on either mean peak blood alcohol concentrations or on areas under the blood alcohol curve; neither did these parameters differ significantly before or after an acute dose of omeprazole (13.2 mg/kg body wt) in rats, whether ethanol (0.25 g/kg body wt) was administered intragastrically or intravenously. In vitro, omeprazole in concentrations likely to occur in the gastric lumen (0.01-1.0 mM), did not affect gastric alcohol dehydrogenase activity of humans or rats. Thus omeprazole does not affect gastric first-pass metabolism of ethanol and can be considered as a safe choice for the treatment of patients who do not refrain from alcohol consumption during therapy.

Adult↗
PubMed1991

Measurement of tissue lithium concentration by lithium magnetic resonance spectroscopy in patients with bipolar disorder.

Measurements of the lithium concentration in the occipital pole of the head and calf muscle of nine patients with bipolar disorder in remission were performed using in vivo lithium-7 nuclear magnetic resonance spectroscopy (7Li NMR). 7Li NMR measurements were performed on a 1-m-bore, 1.85-T, superconducting magnet supplemented with a multinuclear spectrometer, using 11.5-cm-diameter surface coils. The average lithium concentration in the occipital pole was 0.36 +/- 0.10 mEq/L, whereas in the muscle it was 0.50 +/- 0.17 mEq/L, both lower than the average serum lithium concentration (0.79 +/- 0.23 mEq/L). The average brain/serum lithium concentration ratio was 0.47 +/- 0.12 whereas the average muscle/serum lithium concentration ratio was 0.66 +/- 0.20. There was a positive correlation between the brain versus serum and brain versus muscle lithium concentrations. The hypothesis is advanced that the minimal effective concentration of brain lithium concentration for maintenance treatment of bipolar disorder is around 0.2-0.3 mEq/L.

Adult↗