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Biomedical subjects

R W Martin

Publications and source records attributed to R W Martin.

At least 163 records · Page 9Linked to original sources
PubMed1988

Conservative excision of penile melanoma.

Penile melanoma is a rare disease, especially in younger men. Most authorities advocate aggressive surgical management by partial or radical phallectomy and in some cases inguinal lymph node dissection. A 27-year old man with a clinical stage I, Clark's level II, microinvasive (less than 0.76 mm) superficial spreading penile melanoma underwent conservative resection and skin grafting without inguinal node dissection. He has normal penile function and is disease free 5 years following surgery. We believe that in clinical stage I, microinvasive penile melanoma, local excision without inguinal node dissection should be the treatment of choice.

Adult↗
PubMed1988

A program of uterine activity monitoring and its effect on neonatal morbidity.

In a recent study 34 patients at high risk for preterm delivery who received uterine activity monitoring were compared with 33 similar patients who attempted to detect contractions by palpation. The incidence of preterm delivery was significantly reduced among those using the uterine activity detection device, although all patients in both groups had the same prenatal care and educational intervention. When short-term neonatal morbidity associated with preterm delivery was compared between the two groups, adverse effects decreased significantly among those in the monitored group (p = 0.001). The majority of short-term morbidity in both groups was noted in those delivering preterm and thus was gestational age related. No significant difference was found in neonatal morbidity between the groups when the infants were delivered at less than 37 weeks' gestation. Uterine activity monitoring, which is effective in preventing preterm birth, is also efficacious in decreasing short-term neonatal morbidity.

Female↗
PubMed1988

Meperidine and normeperidine distribution in the rhesus monkey.

Previous work has shown that both meperidine and normeperidine are transferred across the placenta to the fetus. Little is known in primates, however, about the tissue deposition of these compounds. Four pregnant, dated rhesus monkeys within one week of term were anesthetized for cesarean delivery. An equal mixture of meperidine and normeperidine was administered as an intravenous bolus 10 minutes before delivery (1.25 mg/kg). The infants were then sacrificed at 20 minutes after birth and the concentration of the compounds in various organ systems were analyzed by gas-liquid chromatography and mass spectroscopy (GLC-MS). The infant serum 20 minutes after delivery revealed a meperidine concentration of 2.23 micrograms/ml and a normeperidine level of 0.67 micrograms/ml (3:1). In contrast, the tissues analyzed showed a much higher concentration of the metabolite in the liver (1:7), gallbladder (1:3), and brain (1:2). Other tissues, such as muscle and kidney, demonstrated equal levels of the two compounds. The authors conclude that normeperidine is quickly transferred to fetal tissues and to a greater degree than the parent compound in certain organs. The increased distribution, particularly in the brain, could account for the toxic actions in the cerebrum of the derivatives of meperidine.

Animals↗
PubMed1988

Abdominal pregnancy: current concepts of management.

Nine cases of early and six cases of advanced abdominal pregnancy managed at the University of Mississippi Medical Center over a 20-year period are reviewed. An incidence of one abdominal pregnancy in 4857 deliveries occurred in this series. A perinatal mortality rate of 83% and no maternal mortality were noted, in contrast to published rates of 40-95% and 0.5-18%, respectively. Important current concepts of management include difficulty in diagnosis, predisposing risk factors, suggestive signs and symptoms, the diagnostic role of ultrasound, and the appropriate surgical management of parturients with this ominous pregnancy complication.

Adolescent↗
PubMed1987

Prevention of preterm birth by ambulatory assessment of uterine activity: a randomized study.

Tocodynamometry, used on an ambulatory basis, has been shown to detect uterine activity. The objective of this study was to assess the effectiveness of ambulatory tocodynamometry in the early identification of preterm labor. In this investigation 67 women at risk for preterm labor were randomly divided into two groups: 34 received a uterine activity monitor while 33 patients used palpation. Approximately two thirds of the study sample developed preterm labor. Upon diagnosis of preterm labor, parturients in the control group had cervical dilatation of less than 3 cm (p less than 0.001) and effacement of greater than 50% more often than the monitored group (p less than 0.01). As a result there was a significant decrease in the number of patients who responded to tocolytic therapy in the unmonitored group. Among those with preterm labor the time gained in utero was greater in the monitored group (8.2 +/- 2.7 weeks) compared to the control group (4.2 +/- 2.9 weeks) (p less than 0.05). Subsequently 29 of 34 monitored patients attained term (36 completed gestational weeks) versus only 18 of the 33 patients in the unmonitored group (p less than 0.01). Although the sample size is relatively small, uterine activity monitoring in these very high risk patients resulted in an increased number of suitable candidates for tocolysis and allowed a significantly greater percentage of women to reach term.

Ambulatory Care↗
PubMed1987

Tocolysis with oral magnesium.

Seventeen patients in whom uterine activity responded favorably to parenteral magnesium sulfate were given oral magnesium gluconate for continued tocolysis. The mean serum magnesium level before therapy was 1.44 +/- 0.22 mg/100 ml, whereas 2 hours after initiation of oral magnesium it was 2.16 +/- 0.32 mg/100 ml (p less than 0.05). One patient had nausea without vomiting or diarrhea. These data suggest that magnesium ingested orally can raise the serum magnesium level significantly.

Administration, Oral↗
PubMed1987

Third-trimester biparietal diameter as a predictor of fetal lung maturity.

The major fetal risk associated with elective delivery is unexpected fetal lung immaturity and the development of hyaline membrane disease soon after birth. Prior to elective vaginal or abdominal delivery it has become standard obstetric practice to predict fetal lung maturity by the analysis of amniotic fluid obtained by amniocentesis or vaginal pool sample following preterm rupture of membranes. A correlation between third-trimester fetal biparietal diameter and the lecithin/sphingomyelin (L/S) ratio has been established by several investigators. In order to determine if a threshold BPD could be consistently correlated with fetal lung maturity, we retrospectively examined the hospital and laboratory records of a group of 115 nondiabetic parturients in whom BPD measurements and amniotic fluid analysis for L/S ratio had been performed for various clinical indications. A threshold BPD of greater than or equal to 9.2 cm in all parturients who underwent elective repeat cesarean delivery was associated with no hyaline membrane disease (HMD). Two of the three neonates who developed HMD had mature L/S ratios but were products of pregnancies complicated by third-trimester hemorrhage. A review of our present data suggests that about one-third of clinically-indicated amniocenteses in the absence of maternal diabetes or third-trimester hemorrhage could potentially be avoided without adverse neonatal impact. Possible therapeutic application of this finding requires further prospective study.

Amniotic Fluid↗
PubMed1986

External cephalic version of the breech presentation under tocolysis.

External cephalic version with tocolysis at or near term has been advocated to avoid cesarean birth for breech presentation. In our institution this maneuver was successfully performed in 207 of 304 parturients without major complications, and all but six had vertex presentation at delivery. The success of version was inversely correlated with gestational age but was not correlated with ease of version, number of attempts, or placental location. When this 3-year period was compared with the previous three years (1979 to 1981), there was a significant reduction in the number of breech presentations during labor, whereas the total delivery rate remained relatively constant over the 6-year period. It appears that in a carefully selected population, external version near term can be used safely to reduce the need for abdominal birth because of breech presentation.

Breech Presentation↗
PubMed1986

Correlation of neonatal acid-base status with Apgar scores and fetal heart rate tracings.

In this study the immediate neonatal acid-base status, obtained via a double-clamped segment of umbilical cord, in 75 term, singleton vaginal deliveries was compared to electronic fetal heart rate recordings and Apgar scores. Of 75 neonates, 59 had 1-minute Apgar scores greater than or equal to 7 and 52 had an initial pH greater than 7.20. Six of the 16 neonates with a 1-minute Apgar score less than 7 demonstrated a low pH (less than 7.20). At 5 minutes only eight of 75 neonates had Apgar scores less than 7 with six of the eight having pH values less than 7.20. Of those neonates with Apgar scores greater than or equal to 7 and pH less than 7.20 (seven neonates at 1 minute, two at 5 minutes), none had metabolic acidosis. Eighteen fetal heart rate tracings were considered abnormal; acidosis was confirmed in eight (44%) by pH criteria, yet only three of the eight neonates had low Apgar scores. Our investigations suggest that the combination of fetal heart rate monitoring, cord blood pH, and Apgar assessment is better than any one parameter alone as an evaluation of fetal status just after delivery.

Apgar Score↗
PubMed1986

An endoscopic micromanipulator for multiplanar transesophageal imaging.

We have developed an esophageal probe with a precision micromanipulator and a transversely oriented 32 element ultrasonic array which operates at 3.5 MHz. The probe allows us to obtain multiple two-dimensional images of the heart with known angular relationships between them over a series of cardiac cycles. Our ultimate purpose is to acquire images for left ventricular volume estimation with a three-dimensional reconstruction method. Technical details of the probe design are given. In vitro tests have shown that the imaging plane can be angulated within 1.5 degree root mean square error. In vivo results with dogs have demonstrated its ability to obtain multiplanar short axis images of the heart.

Animals↗
PubMed1986

Failure of glucocorticoid feedback in males of a population of small marsupials (Antechinus swainsonii) during the period of mating.

In an investigation of the factors leading to the increase in the concentration of plasma free glucocorticoid, which results in immunosuppression and death after mating of all males in natural populations of a small shrew-like marsupial, the dusky antechinus (Antechinus swainsonii), the integrity of the glucocorticoid feedback control of the concentration of plasma cortisol was examined by use of dexamethasone-suppression tests. Injection of 0.2 mg dexamethasone/kg i.m. caused a marked fall in the concentration of plasma cortisol 17 h later, approximately 2 months and 2 weeks before the annual mating period in mid-July. However, the same dose had no significant effect on the increased concentration of plasma cortisol characteristic of the mid- to late July mating period. Injection of 100 i.u. ACTH/kg i.m. caused a significant increase in the concentration of plasma cortisol 6-7 h later on all occasions, indicating that the responsiveness of the adrenal cortex to ACTH did not change. Pretreatment with dexamethasone had no effect on the ACTH-stimulated cortisol concentration, ruling out a possible direct effect of dexamethasone on adrenocortical secretion in this species. Dexamethasone also reduced the concentration of plasma testosterone when the level was low, before the mating period, but not when the level was high, at the beginning of the mating period. It is concluded that, in association with a rapid increase in the concentration of plasma testosterone, an increase in aggression and intense mating activity, glucocorticoid feedback control of ACTH secretion is impaired.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗