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Biomedical subjects

B Gonik

Publications and source records attributed to B Gonik.

At least 91 records · Page 5Linked to original sources
PubMed1985

Effect of differences in saturation sensitivity of phospholipid stains on clinical predictivity of L/S ratios.

Owing to the importance of the degree of fatty acid side chain saturation in the ability of lecithin molecules to function as surfactant, we assessed the clinical effectiveness of analytical methods which differ with respect to methodologic influences by saturated and unsaturated phospholipids. The lecithin/sphingomyelin ratios, determined with either cupric acetate or phosphomolybdate as the detection reagent, are compared for their abilities to predict respiratory distress syndrome (RDS), transient tachypnea (TTN), or the absence of respiratory difficulty in neonates. A group of 47 amniotic fluids were analyzed from 25 non-problem cases, 13 cases of TTN and 9 cases of RDS. Receiver operating characteristic analysis shows that in our sample population, the measurement of total lecithin for the prediction of neonatal respiratory distress failed to demonstrate an advantage over the measurement of unsaturated lecithin alone.

Amniotic Fluid↗
PubMed1985

Cardiovascular alterations in severe pregnancy-induced hypertension: relationship of central venous pressure to pulmonary capillary wedge pressure.

The relationship between central venous pressure and pulmonary capillary wedge pressure was studied in 18 patients with severe pregnancy-induced hypertension. Although statistically a linear relationship for the group as a whole could be identified, analysis on a case-by-case basis revealed different results. In 10 patients, a linear correlation between central venous pressure and pulmonary capillary wedge pressure was observed. However, accurate prediction of pulmonary capillary wedge pressure from central venous pressure was not possible even in this group because of large interindividual variations. In seven patients no correlation between central venous pressure and pulmonary capillary wedge pressure could be identified. In the last patient a curvilinear relationship existed between central venous pressure and pulmonary capillary wedge pressure. Additionally, in five cases of pulmonary edema, a negative gradient of colloid osmotic pressure to pulmonary capillary wedge pressure gradient was observed. Our data suggest that central venous pressure is not a clinically reliable predictor of pulmonary capillary wedge pressure.

Central Venous Pressure↗
PubMed1985

Peripartum colloid osmotic pressure changes: effects of controlled fluid management.

A prospective, fluid-controlled study of serially measured colloid osmotic pressure changes in the peripartum period was undertaken. Seventeen patients with uncomplicated pregnancies undergoing elective cesarean section at term were administered a predelivery bolus of 15 ml/kg of lactated Ringer's solution prior to operation. Maintenance crystalloid fluids were infused at 125 to 150 ml/hr both intraoperatively and post partum without the addition of blood or other colloid solutions. Serial colloid osmotic pressure measurements were obtained before hydration, after hydration, after delivery, and at 6 and 24 hours post partum. The results demonstrated a 15.9% decline in colloid osmotic pressure immediately following the hydration bolus (20.7 +/- 1.5 to 17.4 +/- 1.8 mm Hg) (p less than 0.01). A further decline in colloid osmotic pressure to 16.6 +/- 1.7 mm Hg occurred after delivery and represented an overall 22% decrease from the baseline value (p less than 0.05). The lowest mean colloid osmotic pressure value occurred at 6 hours post partum (16.1 +/- 1.1 mm Hg). These data support previous observations that colloid osmotic pressure is uniformly lowered in the immediate postpartum period with peak reductions identified at 6 hours following delivery. In addition, intravenous crystalloid administration during the peripartum interval can substantially influence this decline in colloid osmotic pressure. Although no clinical evidence of cardiopulmonary compromise was observed in this set of normal gravid women, these data may be useful in the management of the parturient patient with established risk factors for pulmonary edema where alterations in the pulmonary capillary wedge pressure-colloid osmotic pressure gradient have been shown to correlate with the development of this complication.

Cesarean Section↗
PubMed1985

The use of amniocentesis in preterm premature rupture of membranes.

Amniocentesis has recently been advocated as a useful diagnostic adjunct in the management of the patient with preterm premature rupture of membranes (PROM). Although studies are limited, transabdominal inspection of amniotic fluid for a mature phospholipid lung profile or evidence of incipient sepsis appears helpful in reducing the risk of prematurity and infection in the gravida and neonate. In addition, amniocentesis in this group of patients is technically feasible if ultrasound is used concomitantly. Limitations to this procedure include the inability to identify neonates at risk for nonpulmonary complications of prematurity such as intraventricular hemorrhage. Physicians should be aware of their individual laboratory and nursery limitations along with current infectious morbidity statistics before initiating this management protocol.

Amniocentesis↗
PubMed1985

Pharmacokinetics of cefotaxime in the postpartum patient.

A scarcity of pharmacokinetic data are available on cefotaxime in the obstetric patient. Fifteen patients received either 1 or 2 gm of cefotaxime after cesarean section. After intravenous administration of the designated dose, serial blood samples were analyzed for cefotaxime and its active metabolite, desacetyl cefotaxime (DCTX), by high-pressure liquid chromatography. The mean (+/- SD) peak concentrations of cefotaxime were 14.1 +/- 7.9 micrograms/ml and 40.0 +/- 32.5 micrograms/ml for the 1- and 2-gm dosage regimens, respectively. Detectable trough concentrations were 0.87 +/- 0.24 and 1.0 +/- 0.26, respectively, with many values falling below the sensitivity limits of the assay (0.5 micrograms/ml). The mean peak concentrations of DCTX for the two doses were 5.5 +/- 1.9 micrograms/ml and 10.9 +/- 6.2 micrograms/ml, respectively. Measurable trough levels for DCTX were more frequently identified, than for cefotaxime, at the end of the dosing interval due to an extended half-life as compared to its parent compound. Pharmacokinetic parameters of cefotaxime demonstrated large volumes of distribution and high clearance rates. Our data suggest altered pharmacokinetics of this agent in the obstetric patient when compared to previous studies in nonpregnant patients. This may be important in the seriously ill gravida where dosage adjustments in cefotaxime administration may be needed.

Adult↗
PubMed1985

Postpartum osteitis pubis.

We have presented a rarely described case of osteitis pubis occurring in a postpartum period. This rapidly progressive, nonsuppurative osteonecrosis of the symphysis pubis is frequently confused with other entities. Because the prognosis for recovery is invariably good, acute intervention is directed at relieving pain by immobility and anti-inflammatory agents.

Adult↗
PubMed1985

Single- versus three-dose cefotaxime prophylaxis for cesarean section.

A prospective randomized study was undertaken in 100 patients undergoing cesarean section to evaluate the efficacy of cefotaxime when given as a single-dose versus the more traditional triple-dose regimen for prophylaxis. Analysis of the results demonstrated no significant differences in febrile morbidity (14 versus 20%) or postoperative endometritis (10 versus 14%) between the single- and triple-dose groups, respectively. Pretherapy aerobic and anaerobic placental cultures were positive in 60% of the overall study population. In those patients who subsequently developed endometritis, seven (58%) had a positive placental culture, suggesting that this technique is relatively nonspecific as a screening procedure. Results of transcervical culture in the endometritis patients most often demonstrated a polymicrobial picture. Several of the organisms cultured were found to be resistant to cefotaxime, supporting the need to better guide antimicrobial therapy by routine endometrial culturing in patients who fail prophylaxis. The results of the present study suggest that single-dose administration of cefotaxime is equally effective as triple-dose therapy in reducing postcesarean section endometritis.

Adult↗
PubMed1985

Amniotic fluid volume as a risk factor in preterm premature rupture of the membranes.

During a prospective study evaluating the expectant management of preterm (26 to 34 weeks) premature rupture of membranes (PROM), the authors compared maternal and neonatal outcome of 17 patients with a marked reduction in amniotic fluid volume with 22 subjects having identifiable pockets of amniotic fluid after membrane rupture. The results demonstrated no significant differences in maternal age, gravidity, cervical dilatation, incidence of labor on admission, use of tocolytics, steroid usage, interval from membrane rupture to delivery, or cesarean section rate. The gestational age at which PROM occurred (31.4 +/- 1.9 versus 29.8 +/- 2.2 weeks) was significantly (P less than .05) more advanced in the adequate fluid patients when compared with the reduced fluid group. Clinical amnionitis was a far more common occurrence in the reduced fluid patients when compared with the adequate fluid group (47 versus 14%, respectively, P less than .05) as was postpartum endometritis (59 versus 18%, P less than .05). The incidence of overt neonatal sepsis was similar between the adequate fluid (14%) and reduced fluid (18%) patients. These results suggest that when a marked reduction in amniotic fluid after PROM is identified, patients are at a three-times greater risk for antepartum amnionitis and postpartum endometritis.

Adult↗
PubMed1985

Influence of menstrual cycle variations on natural killer cytotoxicity and antibody-dependent cellular cytotoxicity to cells infected with herpes simplex virus.

Natural killer cytotoxicity (NKC) and antibody-dependent cellular cytotoxicity (ADCC) represent the ability of human leukocytes to destroy target cells. Those systems have been shown to influence herpes simplex virus (HSV) infections. Prostaglandins are known to inhibit these nonspecific immunologic defenses. Since prostaglandin production varies with the menstrual cycle, this study was undertaken to test for variations in cytotoxic activity against HSV-infected cells during the proliferative, secretory and menstrual phases in 13 normal volunteers. NKC and ADCC activity was not statistically different between the three menstrual phases when testing was done for both mononuclear and polymorphonuclear cells from donor sera. This study suggested that NKC and ADCC cannot be used to explain anecdotal experiences suggesting menstrual variations as a triggering mechanism for HSV recurrences.

Adult↗
PubMed1985

Cardiovascular alterations in severe pregnancy-induced hypertension seen with an intravenously given hydralazine bolus.

The acute cardiovascular effects of a 10 milligram bolus of hydralazine was found to cause a significant increase in heart rate and cardiac index while decreasing mean arterial pressure and systemic vascular resistance index. A wide spectrum of individual responses was seen in terms of peak effects and duration of effects. The role of hydralazine in patients with severe pregnancy-induced hypertension was discussed and possible alternative therapy is suggested.

Adult↗
PubMed1984

Intrapartum to postpartum changes in colloid osmotic pressure.

A study was undertaken to determine the effect of route of delivery on plasma colloid osmotic pressure. Plasma colloid osmotic pressure was measured on admission to the hospital and 8 to 24 hours post partum in 72 patients at term with uncomplicated prenatal histories. Thirty-six patients underwent uncomplicated vaginal deliveries (local anesthesia, 18; conduction anesthesia, 18) and 36 patients had cesarean sections (conduction anesthesia, 18; general anesthesia, 18). The mean (+/- SD) intrapartum colloid osmotic pressure of the overall group was 21.0 +/- 2.1 mm Hg, and it declined significantly (p less than 0.01) to 15.4 +/- 2.1 mm Hg post partum. A comparison of the intrapartum and postpartum reductions in colloid osmotic pressure between patients who underwent vaginal delivery and those who underwent cesarean section revealed no significant differences. Furthermore, the mean reductions in colloid osmotic pressure when all four groups were compared by type of anesthesia were not significantly different. Fifteen patients (20.8%) in the study had a postpartum colloid osmotic pressure of less than 13.6 mm Hg, and five (6.9%) had a postpartum colloid pressure of less than 12.5 mm Hg. Our results indicate that, for normal pregnancy, colloid osmotic pressure is uniformly lowered in the post partum and, in some cases, to levels that have been reported to be dangerously low.

Anesthesia, Obstetrical↗
PubMed1984

Comparative pharmacokinetics of cefoxitin in postpartum normotensive and pregnancy-induced hypertensive patients.

Limited pharmacokinetic data exist on cefoxitin, a semisynthetic cephamycin antibiotic, in the obstetric patient. Thirteen normotensive and five subjects with severe pregnancy-induced hypertension were identified within the first two postpartum days after cesarean section. After a 2 gm intravenous infusion, serial samples of blood were obtained and analyzed for cefoxitin by high-pressure liquid chromatography. Peak cefoxitin concentrations after infusion were 53.3 +/- 18.6 and 50.8 +/- 25.2 micrograms/ml for the normotensive and pregnancy-induced hypertensive groups, respectively. The only significant difference in pharmacokinetic parameters between these groups was a higher serum trough concentration of cefoxitin in the patients with pregnancy-induced hypertension as compared to the normotensive group. Because of diminished trough levels in our study patients, attention may need to be given to the adjustment of dosages in postpartum women with serious infections.

Adult↗
PubMed1984

Cardiovascular alterations in severe pregnancy-induced hypertension: acute effects of intravenous magnesium sulfate.

The central hemodynamic effects of intravenous magnesium sulfate were studied in five patients with severe pregnancy-induced hypertension. All five patients had a Swan-Ganz and a radial artery catheter placed prior to initiation of magnesium sulfate therapy. Four grams of magnesium sulfate was given over 15 minutes followed by a continuous infusion of 1.5 gm per hour. There was a 12.5% increase in cardiac index immediately after the infusion but cardiac index returned to pretherapy values by 15 minutes after infusion. The mean arterial pressure was significantly (p less than 0.01) decreased 30 minutes after the 4 gm loading dose but had returned to baseline values by 1 hour. There were no other significant changes in any of the hemodynamic or oxygen-related variables measured. Our data confirm previous hemodynamic studies in patients with severe pregnancy-induced hypertension indicating a hyperdynamic state with large fluctuations in systemic and pulmonary vascular resistances. In addition, magnesium sulfate has been shown to have a transient hypotensive effect on mean arterial pressure, related to bolus infusion, that is not present with continuous infusion.

Adult↗
PubMed1984

Conservative versus aggressive management of preterm rupture of membranes. A randomized trial of amniocentesis.

Amniocentesis to guide the management of preterm pregnancies complicated by premature rupture of the membranes (PROM) has been adopted at several centers. The purpose of this study was to evaluate this practice prospectively among comparable groups of patients, which has not previously been reported. Forty-seven patients with PROM at 26 to 34 weeks of gestation and an accessible pocket of amniotic fluid by ultrasound examination were randomly assigned to an "amniocentesis group" (N = 25) or to a "no amniocentesis group" (N = 22). Amniocentesis results were utilized when making management decisions in the amniocentesis group, whereas a clinical basis alone was used in the no amniocentesis group. Demographic variables were similar between the two study populations at the time of randomization. There were no antepartum fetal deaths and one neonatal death in each group. Fetal distress, as judged by the fetal monitor tracing, was more frequent in the no amniocentesis group (P less than .05). The number of days the infant remained in the hospital was significantly less in the amniocentesis group (median = 8.5 days, range 2 to 88 days) than in the no amniocentesis group (median = 22 days, range 2 to 110 days, P less than .01). This difference in neonatal hospital days appeared to be mainly due to a slower resolution of the multiple problems of prematurity. No significant differences in these complications were demonstrated individually. No differences in antepartum hospital days, postpartum hospital days, postpartum endometritis, or sepsis were apparent between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Amniocentesis↗
PubMed1984

Analysis in human neonates of defective antibody-dependent cellular cytotoxicity and natural killer cytotoxicity to herpes simplex virus-infected cells.

Human neonatal mononuclear cells (MCs) had low antibody-dependent cellular cytotoxicity (ADCC) compared with cells from adults in a chromium-release assay against Chang liver cells infected with herpes simplex virus (HSV). Polymorphonuclear leukocyte (PMNL) ADCC of neonates was similar to that of adults. In a single-cell agarose conjugation assay IgG antibody to HSV significantly increased conjugation by adult MCs, adult PMNLs, and cord blood PMNLs but not by cord blood MCs. Expression of the high-affinity IgG Fc receptor (FcR) assayed by erythrocyte-antibody rosetting revealed significant differences between adult MC FcR and cord blood FcR. There was no difference in PMNL FcR expression. Human interferon-alpha increased neonatal MC adhesion in the presence of IgG and FcR expression, but it had no effect on MC ADCC. Defective FcR expression and target cell adhesion may partly explain low neonatal MC ADCC. In addition, cord blood cells have a lytic or recycle, as well as an adherence, defect.

Adult↗
PubMed1984

Cytotoxicity of human peripheral blood and colostral leukocytes against Shigella species.

We examined the ability of human peripheral blood leukocytes to kill strains of Shigella sonnei and Shigella flexneri by using a modified bactericidal assay. Antibody-dependent cellular cytotoxicity (ADCC) was demonstrated in the presence of specific rabbit immune serum directed against S. sonnei. With peripheral blood leukocytes from adults, ADCC was found only in the mononuclear cell and purified lymphocyte populations. Monocyte-macrophages and polymorphonuclear leukocytes were unable to demonstrate ADCC. Lymphocyte ADCC, which was not affected by the addition of phenylbutazone (an inhibitor of phagocytosis), was mediated by a non-T, Fc receptor-positive, HNK-1- cell. ADCC (using antiserum directed against virulent S. sonnei) was demonstrated against virulent S. sonnei but not against virulent S. sonnei or virulent S. flexneri. In contrast to leukocytes from adults, both mononuclear and polymorphonuclear cells from neonatal cord blood and from a patient with chronic granulomatous disease mediated anti-Shigella ADCC. Breast milk leukocytes (BMLs) collected 1 to 3 days postpartum were used as effector cells against virulent S. sonnei. The entire BML population, BMLs which did not adhere to plastic and BMLs which passed through nylon wool columns mediated both natural killer cytotoxicity and ADCC. In paired experiments, natural killer cytotoxicity and ADCC were significantly lower (30 to 45% inhibition) but not ablated, when phenylbutazone was added to BMLs and nylon wool-purified BMLs (P less than 0.05). These experiments suggest that colostral leukocytes mediated both extracellular and intracellular bacteriolysis in the presence and absence of specific antiserum. These mechanisms may be active in vivo in protection against shigellosis.

Age Factors↗