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Biomedical subjects

D Kohelet

Publications and source records attributed to D Kohelet.

32 records · Page 2Linked to original sources

Reduced platelet counts in neonatal respiratory distress syndrome.

Platelet counts were studied in preterm infants with the respiratory distress syndrome (RDS), excluding patients with significant perinatal and postnatal hypoxia. Counts fell to a nadir on day 4 (p less than 0.000). Exploratory analysis indicated that severity of RDS (levels of FiO2 and mean airway pressure), airleak syndrome, grade of intraventricular hemorrhage (IVH) and low platelet count on day 1 were correlated with low platelet count on days 4 and 5. Further analysis by stepwise removal of each variable demonstrated statistically that FiO2 exerted a unique influence on the change in platelet count between day 1 and days 4/5 (p less than 0.002). It is concluded that the severity of RDS is strongly associated with the fall in platelet count in the first few postnatal days. The effect of IVH on platelet count may be secondary to the effect of the RDS.

Age Factors↗

Effect of gentamicin on the auditory brainstem evoked response in term infants: a preliminary report.

Seven essentially healthy term infants who received gentamicin starting on the 1st day of life for prolonged rupture of membranes and maternal fever were compared with nine healthy term infants to determine whether this drug induces alterations in the auditory pathway. The auditory pathway was studied on the 3rd day of life by analyzing brainstem auditory evoked potentials elicited by a click stimulus presented at the infant's ears. Latencies of components III and V, interval I-III, and interval I-V were significantly prolonged in the gentamicin group, indicating impairment of the central component of the auditory pathway. Peak and trough serum gentamicin levels all fell within the recommended therapeutic range. The study indicates that short course gentamicin therapy in healthy newborn infants can lead to abnormality of auditory function.

Bacterial Infections↗

Platelet counts in maternal and umbilical venous blood at the time of delivery.

Platelet count in 38 paired maternal venous and umbilical venous specimens were determined at delivery. Umbilical values were significantly higher than simultaneous maternal values (p = 0.004), and a significant relationship was demonstrated between umbilical values and maternal values (r = 0.54, p = 0.0004). Associations between platelet counts and acid-base variables were found to be insignificant in the mother and the umbilical cord.

Adolescent↗

High-frequency oscillation in the rescue of infants with persistent pulmonary hypertension.

High-frequency oscillatory ventilation (HFOV) was used to treat 41 infants with persistent pulmonary hypertension of the newborn (PPHN). Of the 37 patients who showed early improvement on HFOV, three died. The remaining 34 patients demonstrated, within one hour of the switchover to HFOV, a rise in mean arterial/alveolar oxygen tension ratio (PaO2/PaO2) from 0.093 +/- 0.041 (SD) to 0.132 +/- 0.051 (p less than .001), and a fall in mean PaCO2 from 42 +/- 10 to 34 +/- torr 9 (p less than .01). Mean airway pressure (Paw) fell significantly (p less than .01) within 12 h. The mean duration of conventional mechanical ventilation before starting HFOV was longer in 13 patients who developed bronchopulmonary dysplasia (BPD) than in 21 non-BPD patients (44.7 +/- 32.3 vs. 19.1 +/- 15.6 h, p less than .002), as was the duration of exposure to Paw greater than 15 cm H2O during that treatment mode (31.8 +/- 21.3 vs. 9.5 +/- 6.0 h, p less than .001). HFOV is often effective in the treatment of patients with PPHN, and early initiation of this type of mechanical ventilation may be associated with a reduced incidence of BPD.

Birth Weight↗

Reduction of platelet counts induced by mechanical ventilation in newborn infants.

The association between platelet counts and mechanical ventilation was assessed in 61 newborn infants with respiratory distress syndrome, 10 infants with congenital diaphragmatic hernia, and 10 infants with tracheoesophageal fistula. A significant decrease in platelet counts was observed during mechanical ventilation: (mean +/- SD) reduction of 39% +/- 5%, 42% +/- 5.6%, and 11.9% +/- 5.4% in the three groups, respectively, independent of other causes. In the group with congenital diaphragmatic hernia, there was a significant correlation between mean airway pressure and the reduction in platelet counts. In a subsequent series of experiments, platelet counts were recorded before and during ventilation in rabbits. A significant mean decrease of 37.3% in platelet counts was associated with ventilation with either air or pure oxygen. Results of these studies indicate that mechanical ventilation itself may cause a major decrease in platelet count in newborn infants.

Animals↗

Neonatal bacteremia. A 4-year prospective study.

During the 4-year period 1978-81, 14,527 neonates were born at Assaf Harofeh Hospital, including 793 (5.5%) premature infants. During the same period, 41 bacteremias were recorded, making an overall incidence rate of 2.8/1,000 live births. Thirty of the 41 bloodstream infections occurred in premature infants (incidence rate 38/1,000) and 11 in full-term infants (incidence rate 0.8/1,000). The overall case fatality rate was 19.5%, and in the premature group it was 26.7%. Aside from prematurity, the most common underlying conditions were respiratory distress syndrome and prolonged rupture of membranes. Premature infants were at much greater risk of becoming bacteremic (relative risk 47) than were full-term infants. The risk increased with a decrease in the weight of the infants. Of 43 pathogens, 31 were gram-negative (72.3%), and 11 were gram-positive (25.4%). The most common of the gram-negative pathogens belonged to the Klebsiella-Enterobacter group--19 of 43 (44.2%). Among the gram-positive pathogens, Enterococcus was most common--4 of 43 (9.3%). No increased incidence of Group B Streptococcus infections was noted. The Klebsiella-Enterobacter group had by far the highest incidence in our hospital, and the bacteremia caused by these pathogens was nosocomial in nature in all but one case.

Cross Infection↗

Vitamin D resistant rickets with alopecia: a form of end organ resistance to 1,25 dihydroxy vitamin D.

A 4-year-old girl presented with severe clinical and radiological rickets, and alopecia since the age of 1 year. Laboratory studies revealed: hypocalcaemia, hypophosphataemia, secondary hyperparathyroidism, abnormally low intestinal calcium absorption, and markedly elevated circulating 1,25(OH)2D3 levels. A normal calcaemic response to parathyroid extract was obtained. Treatment attempts with vitamin D2, 1 alpha (OH)D3 and 1,25(OH)2D3 were totally ineffective. Intestinal resistance to the action of 1,25(OH)2D3 appeared well established in this case. Refractoriness of bone to this hormone seems less certain. From this new entity of 'Vitamin D resistant rickets due to end organ unresponsiveness', six cases have been hitherto reported in the literature. However, only two have enough resemblance to our case, to constitute a distinct and well defined nosologic subunit. The molecular basis of this disorder(s) remains to be elucidated.

Alopecia↗

Factors affecting plasma bilirubin in preterm infants ventilated for respiratory distress syndrome.

OBJECTIVE: To evaluate the contribution of various factors to plasma bilirubin level in preterm infants with a birth weight of < 1500 gm in need of mechanical ventilation for respiratory distress syndrome (RDS) during their first week of life. METHODOLOGY: A total of 50 very low birth weight (< 1500 gm) preterm infants consecutively admitted to the neonatal intensive care unit were studied. Plasma bilirubin levels were determined every 8 hours for the first week of life. Data relating to daily body weight, daily fluid intake, age at onset of gavage feeds, daily caloric intake, and grade of intraventricular hemorrhage (IVH) were collected. Data relating to mechanical ventilation were collected every 4 hours as follows: fractional inspired O2, arterial PO2, arterial PCO2, and mean airway pressure. An arterial/alveolar PO2 ratio and a corrected oxygenation index were computed for the first 2 days of life. A bilirubin index (BI), defined as the ratio of peak plasma bilirubin level to birth weight1/3, was used to study the association between bilirubin and the above variables. A BI was also used as a criterion for starting and discontinuing phototherapy. Multiple linear regression analysis was used to model BI. RESULTS: IVH (p < 0.0001), age at onset of gavage feeds (p < 0.003), oxygenation index (p < 0.007), and gestational age (p < 0.05) made a significant contribution to variations in BI (37.16%, 43.71%, 48.99%, and 53.33%, respectively). CONCLUSION: Hyperbilirubinemia in ventilated preterm infants with RDS is most likely multifactorial; entities quite distinct from RDS (such as nutrition and IVH) may significantly contribute to its variation.

Aging↗

Preincubation with intravenous lipid emulsion reduces chemotactic motility of neutrophils in cord blood.

Neutrophils from cord blood of healthy term infants were isolated and incubated for 30 min with varying concentrations of intravenous lipid emulsion (ILE) solution (4, 8, 20 mg/ml). In vitro assay of chemotaxis was performed after incubation for 120 min with endotoxin-activated serum (EAS). Neutrophil random motility was unchanged after ILE incubation yet chemotactic factor (EAS)-stimulated motility was significantly reduced in a dose-related pattern.

Cell Movement↗