Biomedical subjects

K H Rizk

Publications and source records attributed to K H Rizk.

3 recordsLinked to original sources

PubMed1992

Effect of recreational exercise on midtrimester placental growth.

OBJECTIVE: The purpose of our study was to test the hypothesis that regular recreational exercise increases the rate of growth in placental volume in the midtrimester of human pregnancy. STUDY DESIGN: Serial measurements of placental volume were obtained between the fourteenth and twenty-sixth gestational week in 18 subjects who exercised regularly throughout the midtrimester and in 16 matched controls with an ultrasonographic system equipped with a fixed-base, articulated-arm, 3.5 MHz B-mode transducer. RESULTS: Placental volumes were significantly greater in the women who maintained a regular exercise regimen throughout the midtrimester. At 16 weeks (mean +/- SD) volumes were 141 +/- 34 cm3 and 106 +/- 18 cm3 in the two groups. This difference increased at 20 weeks (265 +/- 67 cm3 vs 186 +/- 46 cm3) and again at 24 (410 +/- 87 cm3 vs 270 +/- 58 cm3) weeks' gestation because of a significant between-group difference in the rate of growth in placental volume over this time interval (34 +/- 8 cm3/wk vs 21 +/- cm3/wk). CONCLUSION: We conclude that the hypothesis is correct and speculate that the change in growth rate represents an adaptive response to the intermittent stimulus of a reduction in regional blood flow.

Adult↗

PubMed1992

The billing process: improving efficiency and effectiveness.

Physician practices as well as hospital and other health care institutions must work diligently to maintain viability given the economic severity of today's health care arena. Operational reviews, system reviews, and periodic internal audits all contribute to helping a practice be as efficient and effective as possible. Practices must make a conscious and continual effort to work toward meeting their established objectives. Versatile and flexible computerized systems seem to be a frequently chosen alternative for practices of all sizes to maximize reimbursement and streamlining the operational aspects of the practice. If the decision is made to purchase a computer system, it will require a team of energetic, enthusiastic people committed throughout the scope of the project. System conversion and implementation may take from two weeks to six months depending on vendor, practice size, and specialty. Ample training, conversion, and installation assistance must be arranged with the vendor. Dedication, hard work, and long hours are crucial to ensure success. The system's return on investment can be realized, yielding financial controls and operational stability. The end result is to make the practice more efficient, giving the physician more time to concentrate on the optimal mission--patient care.

Accounts Payable and Receivable↗

PubMedDate not supplied

Second-trimester placental volumes predict birth weight at term.

OBJECTIVE: To test the hypothesis that second-trimester placental growth is a major determinant of size at birth in healthy, active women. METHODS: Three serial measurements of fetal morphometry and placental volume were obtained between the 14th and 26th weeks of an accurately dated singleton pregnancy in 40 subjects. RESULTS: Second-trimester placental volumes were variable, increasing from (mean +/- standard deviation) 130 +/- 35 to 248 +/- 67 and to 375 +/- 92 cm3 at 16, 20, and 24 weeks, with an average growth rate of 31 +/- 8 cm3/weeks. At delivery, fresh placental volumes and birth weights were also variable, ranging between 304-823 cm3 and 2.6-4.4 kg, respectively. Significant correlations (r > 0.79) were present between second-trimester placental volume or growth rate and placental volume at delivery and birth weight, corrected for gestational age and infant sex. However, correlations between second-trimester fetal biometry and both corrected birth weight and birth weight percentile were poor (r < 0.45). CONCLUSION: Second-trimester placental volumes and growth rates are good predictors of size at birth in healthy, active women. We speculate that this technique may have real value as an early screening tool to identify cases at risk of anomalous third-trimester growth.

Adult↗