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Objective: To determine whether circulating fetal levels of the vasodilator atrial natriuretic peptide (ANP) are reduced in pregnancies complicated by intrauterine growth retardation (IUGR)., Design: Prospective observational study., Setting: University teaching hospital and research laboratory., Subjects: 25 normal singleton pregnancies delivered at term by spontaneous vertex delivery (n = 16) or by elective caesarean section (n = 9), and a series of 14 singleton pregnancies complicated by IUGR., Intervention: Measurement of ANP by radio-immunoassay in maternal venous, umbilical artery, and umbilical vein plasma from a series of normal, and IUGR pregnancies., Main Outcome Measures: Comparison of plasma ANP levels between the three groups; relation between fetal ANP, PO2 and pH., Results: Mode of delivery did not influence either maternal, umbilical artery or umbilical vein plasma ANP levels in normal term singleton pregnancies. Umbilical vein ANP levels were significantly higher in the IUGR group when compared with normal pregnancies at term (mean 66 95%, CI 36-122 vs mean 37, 95% CI 29-47 pg/ml, P = 0.03) and were inversely related to umbilical artery pH (R2 = 65%; P = 0.003)., Conclusions: These data suggest that umbilical vein ANP levels are elevated in pregnancies complicated by IUGR, and rise appropriately in response to the stress of acidosis. In the absence of any receptor or second messenger defect within feto-placental vascular smooth muscle, these data suggest that ANP is not directly implicated in the vascular pathophysiology of IUGR.

Objective: To characterize the pattern of renin containing cells (RCC) within the human kidney between 20 weeks of gestation and 6 months of postnatal life., Design: Descriptive study using paraffin-embedded blocks of kidney stored following postmortem examination., Methods: Sections of kidney were stained immunocytochemically using an antibody to human renin; the proportion of RCC within each of three zones (superficial, middle and deep) of the cortex, and their anatomical relation to individual glomeruli were determined. The cases were divided into five groups for analysis to gestational or postnatal age., Results: Fetal RCC were usually at the vascular pole of the most mature glomeruli within the deeper areas of the cortex and were occasionally located within glomeruli. This distribution persisted until birth, even when the kidney was histologically mature. By contrast there were fewer RCC in neonatal and infant kidneys and, as in adult kidneys, these were located predominantly in the superficial cortex., Conclusion: The change in RCC distribution around the time of normal birth may relate to the transition to independent renal function. The location and density of RCC during fetal life may influence renal perfusion and amniotic fluid production.

The acardiac fetus is a rare entity found only in monozygotic multiple pregnancy. Although the acardiac fetus is non-viable, the perinatal mortality rate for the normal fetus may be as high as 50 per cent, and is usually associated with fetal heart failure and hydrops fetalis, or as the result of prematurity. In this communication, we describe a case of spontaneous cessation of blood flow to an acardiac fetus and discuss the management of this condition with special reference to optimizing the outcome for the normal fetus.

Paired maternal and fetal atrial natriuretic peptide concentrations were measured in 62 percutaneous umbilical blood samplings performed principally for the assessment and treatment of rhesus isoimmunization. Pretransfusion fetal atrial natriuretic peptide levels were significantly higher than maternal atrial natriuretic peptide levels (median 117 pg/ml vs median 32 pg/ml; p less than 0.001); paired pretransfusion fetal and maternal atrial natriuretic peptide samples showed a weak correlation with each other (R2 = 17%; p = 0.002). Fetal atrial natriuretic peptide levels correlated inversely with hematocrit (R2 = 14%; p = 0.003), but not with albumin or gestational age. Paired pretransfusion and posttransfusion (median = 134 pg/ml) fetal atrial natriuretic peptide levels (n = 38) showed a significant rise after transfusion (p less than 0.001); this rise was related to the percentage of fetoplacental blood volume transfused (R2 = 33%; p = 0.035). In a subgroup of 26 procedures, change in fetal atrial natriuretic peptide levels was weakly correlated with transient reductions in the Doppler systolic/diastolic ratio of the umbilical artery (R2 = 14%; p = 0.07). These data support work in animals that indicate a role for atrial natriuretic peptide in the human fetus, but these data do not confirm that atrial natriuretic peptide modulates fetoplacental vascular impedance in the human fetus.

Objective: To determine the ability of a sensitive one step urine test to detect human chorionic gonadotrophin in women with suspected complications of early pregnancy., Design: Test on women presenting to accident and emergency department with gynaecological problems over six months. Results were validated using a quantitative assay for human chorionic gonadotrophin in serum and urine., Setting: Accident and emergency department and gynaecology wards of a university teaching hospital., Subjects: 130 unselected women., Main Outcome Measures: Detection of human chorionic gonadotrophin by one step test, presence of ectopic pregnancy, and results of quantitative analysis of chorionic gonadotrophin in serum and urine., Results: 79 women had a positive urine test result and 51 a negative result. All 12 women with ectopic pregnancy had a positive test result, although urinary concentration varied from 191 IU/l to 47,800 IU/l. Only one woman, who had a faintly positive result, was found not to be pregnant on subsequent examination. The sensitivity and negative predictive values of the urine test were 100% respectively. 33 women were sent home from the accident and emergency department with normal clinical findings after a negative urine test result. All these women had undetectable concentrations of chorionic gonadotrophin in matched samples of urine and serum., Conclusions: A simple, rapid one step test for chorionic gonadotrophin should be available for the initial evaluation of emergency gynaecological problems. The additional cost of the test is offset by not admitting those patients whose clinical findings are normal and who have a negative urine test result and by reducing the number of women requiring quantitative assays of chorionic gonadotrophin.

A prospective observational study of postoperative infection after gynecologic surgery assessed the need for antibiotic prophylaxis with special reference to the urinary tract. Catheterization requirements in the postoperative period were compared with the development of urinary tract infection after excluding both preoperative and postoperative bacteriuria. Forty-six of 115 patients (40%) developed a urinary tract infection in the postoperative period. Furthermore, this was not clearly related to the need for postoperative catheterization. Significant wound and vaginal vault infections were uncommon, indicating that antibiotic prophylaxis should be directed specifically at the urinary tract.

Receptors for angiotensin II (AII) and atrial natriuretic peptide (ANP) were characterized in a membrane fraction from resistance-type artery from human placentae. Placentae from normal pregnancies and pregnancies complicated by intrauterine growth retardation (IUGR) were studied. High- and low-affinity receptors for AII (dissociation equilibrium constant (Kd) 1.7 and 15.7 nmol/l respectively) and ANP (Kd 0.2 and 55.5 nmol/l respectively) were identified; these parameters were unchanged in IUGR, but there was a reduction in high-affinity receptor number by approximately 50% for AII and 80% for ANP in this condition. Both peptides may have a role in the regulation of fetoplacental blood flow. The alterations in IUGR are consistent with sustained activation of the fetal renin-angiotensin system and suggest altered vascular responsiveness to ANP.

We have identified two classes of membrane receptor for atrial natriuretic peptide (KD (dissociation constant) 0.2, 70.1 nmol/L) and angiotensin II (KD 1.7 nmol/L, 15.2 nmol/L) in human fetoplacental vasculature. In addition, in the isolated perfused placenta atrial natriuretic peptide inhibited the vasoconstrictor action of angiotensin II. These findings suggest that atrial natriuretic factor may regulate fetoplacental blood flow.

A prospective study of 34 patients treated with 39 courses of intravenous vancomycin, was undertaken in order to assess toxicity. Six patients received vancomycin alone and 27 courses were associated with aminoglycoside administration either concurrently or within two weeks of the first dose of vancomycin. Hearing loss was slight and uncommon; patients were unaware of its occurrence. Tinnitus and dizziness was noted by two patients and resolved on withdrawal of vancomycin. Diminution of renal function was seen both during (7%) and after (9%) vancomycin therapy. A striking feature of these patients with renal deterioration was the severity of their underlying disease. No evidence of synergistic toxicity between vancomycin and aminoglycosides was seen.

Nasal carriage and antibiotic sensitivities of coagulase-positive and coagulase-negative staphylococci were assessed among medical students of three different years. Although carriage rates did not change, there was a trend towards multiple resistance with increasing hospital exposure. Gentamicin resistance in Staphylococcus albus showed a similar trend. The relevance of these findings to current views on the origin of gentamicin resistance is discussed.

Three patients with normal renal function developed ototoxicity during vancomycin therapy. This is an uncommon occurrence and the literature is reviewed. Assumptions on "safe' levels of vancomycin are questioned.

Four women with tuberculous meningitis in association with pregnancy are described to illustrate both the serious nature and varied presentation of this condition. Mortality or neurological morbidity may occur more frequently during pregnancy, but in general correlate closely with delay in diagnosis and initiation of appropriate therapy. Treatment often needs to be started empirically, and neurosurgical intervention may prove life saving.