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Biomedical subjects

Z Nitzan

Publications and source records attributed to Z Nitzan.

6 recordsLinked to original sources

Successful external version of B-twin after the birth of A-twin for vertex--non-vertex twins.

OBJECTIVE: To determine the optimal intrapartum management of twins, especially those in vertex--non-vertex presentation. STUDY DESIGN: The study population consisted of 408 sets of twins delivered between 1988 and 1992, weighing at birth over 1500 g. According to our protocol, vaginal delivery was attempted in the vertex-vertex presentations. If non-vertex presentation was first, we performed cesarean section. In vertex--non-vertex cases, the first was delivered vaginally and external cephalic version or breech delivery was performed on the second. Apgar scores were compared according to presentation and delivery mode. RESULTS: Vaginal delivery was accomplished in 122 (73%) of 169 vertex--vertex presentations, 96 (68%) of 142 vertex--non-vertex presentations, and 4 (5%) of 99 non-vertex--other presentations. External cephalic version (ECV) of the second twin and subsequent vaginal delivery in vertex--non-vertex was successful in 75% of cases, and internal podalic version and assisted breech delivery were performed in 20 cases, and the remaining two were delivered by cesarean section. Apgar scores were not significantly different among the various groups, and no complications arose from external cephalic version performed on second non-vertex twins. CONCLUSIONS: External cephalic version was found safe for delivering second non-vertex twins in cases where the first twin is in vertex presentation. In our opinion routine cesarean section is thus no longer justified in such cases.

Delivery, Obstetric↗

Activities of amylase, trypsin and lipase in the pancreas and small intestine of the laying hen during egg formation.

1. During a cycle of 14 h artificial light and 10 h darkness, dry matter and enzyme concentrations were measured in the pancreas and gut of egg-forming hens. 2. Dry or fresh pancreas weight did not show significant variation but pancreatic enzyme activities increased gradually from 2 to 22 h after oviposition. 3. Total wet and dry matter contents of the small intestine gradually increased from 2 to 18 h after oviposition and then decreased significantly. Intestinal tryptic activity followed the same pattern whereas intestinal amylase gradually decreased from 2 h after oviposition; intestinal lipase activity tended to decrease during the light period (2 to 10 h after oviposition) and to increase during the dark period (14 to 22 h after oviposition). 4. By contrast, patterns of enzyme activity in the pancreas were similar. It is proposed that modification of the chyme and transit rates during the day may affect pancreatic enzyme fate and distribution in the small intestine. 5. In non-egg-forming birds intestinal contents and enzyme activities were less than in egg-forming birds. The reverse was observed in the case of the pancreas where contents and enzyme activities were increased. A relationship with food intake pattern is discussed.

Amylases↗