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Biomedical subjects

M Nitzan

Publications and source records attributed to M Nitzan.

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

A measurement of pulmonary blood volume increase during systole in humans.

Pulmonary blood volume increase during systole was measured in patients by analysing chest images obtained during ECG gated radionuclide angiography examination. The difference in the total radiation counts between systole and diastole in regions of interest, which included the lungs and the left ventricle, was measured and the relative pulmonary systolic blood volume increase (SBVI)-the ratio between the pulmonary SBVI and the cardiac stroke volume-was calculated. The relative pulmonary SBVI, which is a measure for the compliance of the pulmonary blood vessels, was found to be 0.26-0.85, and the average value was 0.57 +/- 0.15. The relative pulmonary SBVI was inversely correlated with the patient age (r = 0.27, p < 0.05) and with the left ventricular ejection fraction and stroke volume (r = 0.36, p < 0.01) due to decreased arterial compliance for older patients and for increased pulmonary blood volume respectively. The correlation coefficients were not high, indicating that the compliance of the patients is determined mainly by other individual factors. Radionuclide plethysmography enables qualitative assessment of pulmonary arterial compliance.

Aging↗
PubMed1994

Hearing impairment in idiopathic hypoparathyroidism and pseudohypoparathyroidism.

Sensorineural hearing impairment is a lesser known feature of hypoparathyroidism. The hearing of 20 patients with idiopathic hypoparathyroidism was investigated by pure-tone audiometry. Bilateral sensorineural hearing loss was found in three (15%). Sensorineural hearing loss is considered to be associated with a prolonged low calcium level in the inner ear fluid and is a possible complication of hypoparathyroidism.

Adolescent↗
PubMed1994

Benign transient hyperphosphatasemia.

Benign transient hyperphosphatasemia (BTHP) was diagnosed in nine children who were examined in the Pediatric Department at Beilinson Medical Center during 2 years. The characteristic features of this disorder are: a) elevation of serum alkaline phosphatase (AP) of 3-50 fold the upper normal value for age, usually discovered during mild upper respiratory or gastrointestinal infection, and sometimes by routine laboratory workup; b) no clinical or laboratory evidence of bone or liver disease; c) the elevated AP is of liver and bone origin; and d) AP returns to normal range within 12 weeks. BTHP usually occurs in infants but may appear also in adults. Recognition of this benign entity will prevent extensive unnecessary laboratory workup.

Acute Disease↗
PubMed1993

A randomized, double-blind study comparing cefixime and trimethoprim-sulfamethoxazole in the treatment of childhood shigellosis.

We compared the clinical and bacteriologic response of 5-day treatment with cefixime, 8 mg/kg per day, with the response to trimethoprim-sulfamethoxazole (TMP-SMX), 10-50 mg/kg per day, the currently recommended therapy. Of the assessable children with acute, culture-proven shigellosis, 38 received cefixime and 39 received TMP-SMX. Pretreatment data on the two study groups were similar. In the first group, all isolates were susceptible to cefixime; in the TMP-SMX group, 32 isolates were resistant and 7 were susceptible to TMP-SMX. Clinical response (day 5) showed cure, improvement, and failure in 89%, 8%, and 3%, respectively, of the cefixime group, and in 25%, 44%, and 31%, respectively, of the TMP-SMX-resistant group (p < 0.001). Bacteriologic cure (day 3) occurred in 78% and 23% of the cefixime and TMP-SMX-resistant groups, respectively (p < 0.001). Clinical or bacteriologic relapse (day 12) was infrequent in both groups. The response to treatment of the cefixime and the TMP-SMX-susceptible groups was similar. No significant side effects were noted. We conclude that cefixime is superior to TMP-SMX in the treatment of suspected shigellosis in areas with a high rate of resistance to TMP-SMX.

Adolescent↗
PubMed1993

Systemic meningococcal infections in patients with acquired complement deficiency.

Congenital deficiency of the late components of the complement may predispose the individual to systemic meningococcal infection. Assuming that patients with acquired complement deficiencies may also have an increased risk of contracting meningococcal infections, a retrospective and prospective study to assess this association was conducted. Over 20 years (1970-1989), 30 patients with meningococcemia or meningococcal meningitis, proven by blood or CSF culture, were treated at the Beilinson Medical Center. Only one patient died of the infection. Risk factors were found in three patients (10%). One had a congenital deficiency of C7, and two had acquired complement deficiency due to systemic lupus erythematosus (SLE) and membranoproliferative glomerulonephritis (MPGN). These latter two patients had low serum concentration of C3 and C4 and reduced complement hemolytic activity before onset of the infection. Since the incidence of culture-proven systemic meningococcal infection in the Jewish population in central Israel is 1/100,000, and the prevalence of SLE and MPGN is, at most, 250/100,000, the finding of two patients with meningococcal infection and these rare disorders is over 100 times the expected incidence. We conclude that patients with acquired complement deficiency are at significant risk of meningococcal infection.

Adolescent↗
PubMed1992

[Transient hyperphosphatasemia of infancy].

Transient hyperphosphatasemia of infancy was diagnosed in 4 children hospitalized during a 6-month period (0.3% of all hospitalized children). The characteristic features of this disorder are: 1. elevation of serum alkaline phosphatase (of both liver and bone origin) up to 3-30 times the upper limit of normal for age (usually discovered during intercurrent infection); 2. return of the serum alkaline phosphatase to normal in a few weeks; 3. no residual clinical or laboratory evidence of bone or liver disease. The child is usually less than 5 years old. Recognition of the benign nature of this disorder prevents extensive laboratory workup and unnecessary anxiety.

Alkaline Phosphatase↗
PubMed1992

ECG gated radionuclide plethysmography--a method for the assessment of pulmonary systolic blood volume increase.

During cardiac systole the stroke volume of blood which is ejected from the right ventricle increases the pulmonary blood volume. This systolic pulmonary blood volume increase is measured by using ECG gated chest scintigrams obtained with 99Tcm-labelled red blood cells. The total radiation counts in a region of interest that includes either the right or the left lung increases during systole. On the average, the increase of the total pulmonary systolic radiation was found to be 62% of the systolic radiation decrease in the left ventricle region of interest. The discrepancy between the value of the systolic pulmonary blood volume increase and that of stroke volume is attributed to blood flow from the lungs into the left atrium during the cardiac systole period.

Adult↗
PubMed1992

Sudden infant death syndrome in the Tel Aviv and Petah Tikva districts.

We studied the epidemiology and incidence of the sudden infant death syndrome (SIDS) in the Tel Aviv and Petah Tikva districts during the period April 1980 to March 1983. Sixty-nine infants were diagnosed as SIDS and 38 of them had autopsies. Four cases were excluded because their autopsy revealed other diagnoses. When calculating for 24,183 live births per year during the study period, the rate of SIDS was found to be 0.47-0.90:1,000 live births. Other epidemiologic characteristics were: female:male [corrected] ratio 1:1.3; peak incidence at 2-4 months age, with 80% before age 6 months; increased incidence during the autumn and winter months (85% of SIDS cases); and highest incidence between midnight and 8:00 AM (84% of SIDS cases). None of the infants had a history of a previous apparent life-threatening event. Birthweight of infants who died of SIDS was not significantly different from that in the general population. No statistical relation to DTP (diphtheria, tetanus, pertussis) vaccination was found. Half the cases had mild respiratory illness during the week that preceded the sudden death. The incidence of parental cigarette smoking was higher than in the general population (56.5% vs. 36-53%; P less than 0.005) as well as the incidence of maternal smoking during pregnancy. We conclude that the incidence of SIDS in Israel is relatively low. The epidemiologic characteristics of SIDS in Israel are very similar to the presentation of the syndrome in other countries.

Age Factors↗
PubMed1991

In-flight esophageal variceal bleeding en route for liver transplantation: a case report and review of the literature.

Esophageal variceal bleeding owing to portal hypertension is a potential threat in pediatric patients awaiting liver transplantation. We report a case of a three-year-old boy with severe congenital hepatic fibrosis, Caroli's disease, and portal hypertension who developed a life-threatening variceal hemorrhage for the first time in his life during commercial air transport to a liver transplantation center. Factors precipitating variceal bleeding are discussed, particularly those resulting from changes in altitude. It is recommended that prophylactic treatment for variceal bleeding be at least considered in children awaiting liver transplantation prior to prolonged air transportation. Because of differences in capabilities of treatment providers in various locales, and because there are as yet no conclusive data, the treatment of choice must be decided on an individual basis. Equipment for treating in-flight hemorrhage should be available.

Aerospace Medicine↗
PubMed1990

The prognosis of convulsions during childhood shigellosis.

We examined the long-term outcome in 111 children who had convulsions during shigellosis and were followed for 3-18 years after the incident. No deaths or persistent motor deficits occurred as sequellae. Poor coordination of fine hand movements were noted in 3.3% of the 92 children who had no pre-existing neurological abnormality. Only 1 child developed epilepsy by the age of 8 years. Of the children 15.7% had recurrent febrile seizures. The only risk factor identified for febrile seizures following convulsions in shigellosis was a previous history (P less than 0.01). These observations suggest that convulsions in shigellosis have a favourable prognosis, and do not necessitate long-term follow up.

Child↗
PubMed1990

Vestibular evoked potentials with short and middle latencies recorded in humans.

Following success in recording short latency vestibular evoked potentials in experimental animals, we have succeeded in our attempts to record such potentials in human subjects. The stimuli were repetitive, short steps of high intensity angular acceleration (10,000 degrees/sec2) with short rise times which would synchronously activate many neurons of the vestibular pathway. Stringent control procedures ensured that the recorded activity was not an artefact. Short latency vestibular evoked potentials were recorded in 10 normal subjects with peak latencies of 3.5, 6.0 and 8.4 msec and amplitudes of 0.5 microV. Middle latency potentials were also recorded with latencies of 8.8, 18.8 and 26.8 msec and amplitudes of 15 microV. These responses were absent in a cadaver and in patients with bilateral dead labyrinths. In normal subjects, these vestibular evoked potentials were not affected by white noise. In conclusion, short and middle latency vestibular evoked potentials were recorded in normal human subjects.

Adolescent↗
PubMed1990

Transient renal acidification defect during acute infantile diarrhea: the role of urinary sodium.

We studied urinary acidification daily during the hospital course of 16 infants with acute gastroenteritis and metabolic acidosis. Urine pH value on admission was higher than 5.5 in 14 (87%) patients. We hypothesized that inappropriate urinary acidification was due to sodium deficiency and inadequate sodium delivery to the distal nephron. Forty-one urinary samples were collected during metabolic acidosis. The mean pH of 24 urine samples with sodium concentration less than 10 mmol/L was significantly higher than the pH of 17 samples with sodium concentration greater than 10 mmol/L (6.04 +/- 0.06 vs 5.19 +/- 0.1; p less than 0.001). The urine ratios of titratable acid to creatinine and of total acidity to creatinine were significantly higher in urine samples containing more sodium (p less than 0.02), whereas the ammonium/creatinine ratio was not. After administration of furosemide or correction of the sodium deficit, appropriate acidification was observed. We conclude that impaired urinary acidification is frequently found during metabolic acidosis in infants with acute gastroenteritis and results from a sodium deficit rather than from transient distal renal tubular acidosis.

Acidosis, Renal Tubular↗