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Biomedical subjects

J C Morrison

Publications and source records attributed to J C Morrison.

At least 253 records · Page 14Linked to original sources
PubMed1989

Detection of glucose intolerance in pregnancy.

Between 6 and 28 weeks of gestation, 2-hour postprandial blood glucose determinations were performed on 66 pregnant patients who had no history of diabetes. Each patient received two methods of carbohydrate loading on separate occasions in a random, crossover fashion. One group received a 100-g carbohydrate meal and then a 50-g glucose load (Glucola). The order of the test regimens was reversed for the second group. The average 2-hour postprandial glucose value following a meal was 103.1 +/- 3.7 mg/dL, and the mean value for the 2-hour postprandial glucose following Glucola was 102.5 +/- 3.8 mg/dL. The difference in glucose values obtained with the two methods was not statistically significant. A 12% incidence of emesis was encountered after Glucola but none was encountered after the meal. The 100-g carbohydrate meal is recommended as the method of testing for glucose intolerance.

Adolescent↗
PubMed1988

Controlled vascular corrosion casting of the rabbit eye.

We have refined the technique of vascular corrosion casting with methacrylate to permit the reproduction of physiological states of vascular tone and to produce sturdy castings of ocular microvasculature. The method entails careful maintenance of homeostasis up to the moment of plastic perfusion, avoidance of vascular rinsing or fixation with the attendant anoxia, reduction of the viscosity of the casting resin without impairing the properties of the resultant polymer, addition of a cross-linking agent to increase the strength of the plastic, and injection at physiological temperature and pressure. This casting regimen reproduces the normal anatomical conditions of blood vessels and can be used to demonstrate altered conditions of vascular tone. In all instances, the second, untouched eye serves as a control for unilateral manipulations. Special problems of replicating the ocular vasculature are related to the intraocular pressure, which opposes the vascular perfusion pressure and constitutes an impediment to perfusion.

Animals↗
PubMed1988

Evaluation of the B-protein assay in cancer management.

Previous data have suggested that the B-protein assay might prove to be useful in the assessment of patients with cancer after various therapeutic modalities. The assay's effectiveness was evaluated by prospective study of 133 patients with cervical, uterine, or ovarian cancer. After therapy, B-protein levels remained elevated in 17 nonresponding patients who eventually died of the disease. In contrast, 88 patients experienced a significant reduction in B-protein levels measured 90 days after treatment. Among this group, 25 patients demonstrated elevated B-protein levels during the 2-year follow-up period and all were confirmed to have persistent or recurrent disease. These data indicate that monitoring serum B-protein levels can be beneficial in the posttherapeutic management of gynecologic malignancies.

Biomarkers, Tumor↗
PubMed1988

Adnexal mass occurring with intrauterine pregnancy: report of fifty-four patients requiring laparotomy for definitive management.

Fifty-four cases in which surgical intervention during pregnancy was required for definitive therapy of adnexal masses were reviewed. The calculated incidence of adnexal masses that required surgical intervention during pregnancy in our primary population (patients who were not referred for evaluation of an already identified mass) was one case per 1300 live births. A malignant tumor was found in 5.9% of the pregnant patients who underwent exploratory celiotomy for therapy of an adnexal mass. Those pregnant women who underwent emergency celiotomy because of hemorrhage or torsion as a complication of an adnexal mass spontaneously aborted or underwent premature delivery more frequently than those patients who underwent elective celiotomy for removal of the mass (p less than 0.001). On the basis of this review, we recommend that pregnant women with persistent adnexal masses undergo elective extirpation of the mass in the second trimester of pregnancy.

Adnexal Diseases↗
PubMed1988

Comparison of oral ritodrine and magnesium gluconate for ambulatory tocolysis.

Magnesium sulfate has been administered intravenously to arrest preterm labor but the oral form of this drug cannot be used for continual tocolysis. This trial involved the administration of oral magnesium gluconate to determine its effectiveness compared with that of ritodrine hydrochloride in 50 patients whose labor had been arrested by parenteral therapy. Group A (n = 25) received 1 gm of oral magnesium gluconate every 2 to 4 hours for tocolysis and group B (n = 25) received 10 mg of ritodrine every 2 to 4 hours. The number of patients who progressed to 37 weeks' gestation was similar (group A, 21 versus group B, 19) and the time gained in utero was not different (group A, 6.4 weeks versus group B, 5.9 weeks). There was a trend toward more side effects with the use of ritodrine (40%) compared with magnesium gluconate (16%), but the numbers were too small to reveal a significant difference. These data suggest that magnesium gluconate used as an oral tocolytic is as effective as a beta-agonist in patients whose labor is arrested initially with intravenous therapy.

Administration, Oral↗
PubMed1988

Light microscopy of the exfoliation syndrome.

The exfoliation syndrome affects all structures of the ocular anterior segment, as well as the conjunctiva and occasionally, nonocular structures. The exfoliative material has been shown by a series of light microscopic and gross anatomic studies to be only loosely adherent to the anterior lens capsule, zonules and anterior vitreous face, and firmly adherent to the equatorial lens capsule and posterior epithelium of the iris and the nonpigmented ciliary epithelium. Electron microscopy demonstrates that, in these latter regions, exfoliation material consisting of characteristic, cross-banded fibrils embedded in an amorphous matrix, is present both within the epithelial cells and associated with a disorganized, reduplicated basement membrane. These findings suggest that the material arises from the epithelium of the lens, iris and ciliary body, possibly the result of an underlying metabolic disorder. From these areas, the material enters the aqueous humor and later deposits on the anterior lens capsule, zonules, vitreous face, anterior surface of the iris, and trabecular meshwork. Histochemical studies demonstrate the presence of glycosaminoglycans, which may comprise the interfibrillar portion of the exfoliative material. Other studies demonstrate histochemical similarities between exfoliative material and zonules and are supported by recent work suggesting that the exfoliative fibrils are related to the microfibrillar portion of elastin. Although some reports suggest similarities between exfoliative material and amyloid, a majority of histochemical studies do not support this possibility.

Amyloid↗
PubMed1988

The extracellular matrix composition of the monkey optic nerve head.

The presence and distribution of laminin, heparan sulfate proteoglycan and collagen types I, III and IV were immunohistologically determined in cynomolgus monkey optic nerve heads using the avidin-biotin-peroxidase complex technique. Collagen types I and III were detected within the collagenous plates of the scleral lamina cribrosa, in the septa and pia mater of the postlaminar optic nerve and in blood vessel walls in all regions of the optic nerve head. Collagen type IV, laminin and heparan sulfate proteoglycans were all localized to the margins of the collagenous laminar plates of the scleral lamina cribrosa and along the margins of the optic nerve septa and the pia mater. All three components also appeared beneath the blood vessel endothelium throughout the optic nerve head. Within the lamina cribrosa, collagen types I and III occupy the core of the scleral laminar plates and may provide structural support for optic nerve bundles exiting the eye. The distribution of collagen type IV, laminin and heparan sulfate proteoglycan corresponds to basement membranes from two sources: vascular endothelial cells and glial cells lining the axonal bundles. Abnormalities of these substances may influence optic nerve function and susceptibility to elevated intraocular pressure by altering their mechanical support functions within the nerve head, by interfering with axonal nutrition, or both.

Animals↗
PubMed1988

Severe medical illness complicating cesarean section.

The care of the perioperative cesarean birth patient who has serious medical illnesses has changed in the past decade. The increasing sophistication of monitoring has allowed the obstetrician and anesthesiologist better to modify certain physiologic parameters that are important in the care of the patient whose physiology has been altered by surgery or disease. As an increasing segment of the obstetric population becomes older, and with better survival of medical diseases, the profession as a whole will be challenged by these patients. It will become more important that a certain subset of physicians develop the skills necessary to undertake the care of these patients and that the special needs of these patients be recognized.

Acute Kidney Injury↗
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

Vaginal birth after cesarean section: the demise of routine repeat abdominal delivery.

In light of the abundant very favorable data and considerable published patient experience regarding vaginal birth after cesarean for selected gravidas, the authors are moved to repeat with emphasis the question asked by Dr. Danforth in his recent treatise on cesarean delivery: "The question now is not whether the dictum of automatic repeat cesarean section is still valid, but rather why we continued to adhere to it for more than 60 years, as though it had been carved in stone." From recently published American data, it is obvious that more providers and more patients must be convinced of the safety, efficacy, and cost effectiveness of a selective program of trial of labor and vaginal delivery following previous cesarean birth if we are to effect a significant reduction in this nation's cesarean birth rate. The policy of "once a cesarean section, always a cesarean section" should be applied correctly only to its intended group of patients with previous uterine fundal or upper-segment incisions. As the advisability of insisting on a trial of labor for all parturients who have no contraindications becomes a signal part of the fabric of obstetric practice in the United States and the remainder of the world, we shall witness the demise of routine repeat abdominal delivery.

Cesarean Section↗
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

The effect of storage conditions on amniotic fluid phosphatidylglycerol concentration.

In certain high-risk gestations, phosphatidylglycerol in the amniotic fluid is reported to be useful in predicting respiratory distress syndrome of the neonate in high-risk patients. This study of amniotic fluid phosphatidylglycerol was performed to determine the degradation of phosphatidylglycerol in both the supernatant and the lamellar bodies of amniotic fluid samples collected from normal term pregnant patients. The objective of the study was to discover whether phosphatidylglycerol retained its stability when measured in transported and stored amniotic fluid. The results of the study showed that phosphatidylglycerol remained stable in all amniotic fluid samples stored at various temperatures over a 3-week period.

Amniotic Fluid↗
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

Generic drugs and the prescribing physician.

While generic substitution is not a new phenomenon, a number of factors have combined to markedly increase generic drug use. The most important factor is a 1984 law, the Drug Price Competition and Patent Term Restoration Act, which facilitates the entry into the marketplace of generic versions of brand name drugs. This law and Food and Drug Administration (FDA) policies are designed to approve for marketing generic drug products that are therapeutically equivalent to their brand name counterparts. With increased availability of generic drugs, physicians have expressed the need for more information about the FDA process for determining that generic versions of brand name drug products are both safe and effective and that generic drug products will produce the same therapeutic results as those achieved by the brand name products. This article describes FDA procedures for approving generic drug products and examines issues important to the prescribing physician, in particular, therapeutic equivalence. The article also describes the role of the states in generic substitution and the availability of information from the FDA on the therapeutic equivalence of drug products.

Drug Prescriptions↗
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↗