Noninvasive ultrasonic carotid angiography: prospective validation by contrast arteriography

A technique for the beat-by-beat measurement of stroke volume is described. Aortic blood velocity signals are obtained from a catheter-mounted electromagnetic velocity transducer and analysed by a purpose-built analog computer. The stroke volume is computed by integration of each period of systolic forward flow using the velocity signal as its sole input. Automatic compensation of flowmeter drift is incorporated and inappropriate triggering of integration by diastolic artefact is prevented by applying both amplitude and duration criteria for the recognition of systolic forward flow. Early diastolic reverse flow is excluded from integration. The cardiac output, mean aortic flow per beat, and interbeat interval are also computed from the velocity signal. With aortic pressure as an additional input signal the mean arterial pressure per beat and systemic vascular resistance can be computed. The computer outputs are calibrated by a manual method. Preliminary studies comparing values for the cardiac output measured by this system and the direct Fick technique have indicated an excellent correlation between the two methods.     

Decreasing postpartum sexual abstinence time

Postpartum sexual abstinence time can be safely shortened for most patients when episiotomy repair is done meticulously with fine PGA suture on small needles. The time preferred by patients for resumption of intercourse seems to be between the second and third postpartum week. We have seen no ill effects from this, and we feel that sexual intercourse at these early dates does not influence the healing of the episiotomy in any way.     

Regional selectivity to ochratoxin A, distribution and cytotoxicity in rat brain

Ochratoxin A (OTA) a chlorodihydro-isocoumarin linked through an amide bond to phenylalanine, is a mycotoxin found as a contaminant in foodstuffs and shown to be nephrotoxic, teratogenic, immunosuppressive, genotoxic, mutagenic and carcinogenic in rodents. Ochratoxin A is known to induce teratogenic effects in neonates (rats and mice) exposed in utero, characterised by microcephaly and modification of the brain levels of free amino acids. Since OTA has been found to accumulate in the brain according to the duration of exposure to doses in the range of natural contamination of feedstuffs, experiments were designed to determine more precisely the structural target of OTA in the brain. After intracerebral injection, OTA (403 ng/10 microl) was not found in the following parts of the brain: the frontal cortex (FC), striatum (ST), ventral mesencephalon (VM) and the cerebellum (CB) in contrast to the rest of the brain, probably due to the detection limit of 0.1 ng/g of tissue. However lactate dehydrogenase (LDH) was increased in extracellular space in the VM to a greater extent than in the rest of the brain, indicating that this structure could be one of the targets of OTA in the brain. Contents of free amino acids were morever similarly modified in the VM and in the rest of the brain. Male rats were given OTA (289 microg/kg per 24 h) by gastric intubation for 8 days and the main brain structures analysed for OTA content and cytotoxicity. OTA was found in the following structures in decreasing order: rest of the brain (50.3%), cerebellum (34.4%), VM (5.1%), striatum (3.3%) and hippocampus (2.9%) of the total OTA amount found in the brain, which represents 0.022% to 0.028% of the given dose. Interestingly cytotoxicity as measured by lactate dehydrogenase (LDH) release in the extracellular space was much more pronounced in the VM, hippocampus, and striatum than in the cerebellum, whereas no cytotoxicity was observed in the rest of the brain. Similarly deoxyribonuclease (DNase) activity in relation to possible necrotic cells was increased in the VM and cerebellum. Altogether these results designated the ventral mesencephalon, hippocampus, striatum and cerebellum as the main OTA-targets in the brain of adult rats and excluded the rest of the brain.