Alterations in serotonin binding sites after 5,7-dihydroxytryptamine treatment in the rat spinal cord

The 5-HT1B subtype of serotonin (5-HT) receptor regulates the release of 5-HT in the rat spinal cord. In an attempt to confirm the presynaptic location of the 5-HT1B receptor, serotonergic nerves were destroyed neurochemically with 5,7-dihydroxytryptamine (5,7-DHT) administered intrathecally. At 3, 7 and 14 days post 5,7-DHT, competitive radioligand binding assays were performed using 2 nM [3H]5-HT and varying concentrations of trifluoromethylphenylpiperazine (TFMPP), a drug which interacts with 5-HT1B and 5-HT1A binding sites (affinity of 5-HT1B site greater than 5-HT1A site for TFMPP). The decrease in 5-HT1B sites that was expected was not observed at any time following the lesion. However, the binding capacity of the 5-HT1B site, as well as the 5-HT1A site, increased significantly by 7 and 14 days postlesion, respectively. Thus, it appears that an up-regulation of 5-HT1B sites occurred that may have obscured the ability to observe a reduction in a small population of sites located on the serotonergic nerve terminals.

Effect of nalidixic acid on DNA repair in rat hepatocytes

Nalidixic acid, a DNA topoisomerase inhibitor, has been reported to inhibit DNA repair in some mammalian systems. To investigate the effect of nalidixic acid on DNA repair in cultured rat hepatocytes, DNA damage was induced by ultraviolet light or N-methyl-N-nitro-N'-nitrosoguanidine. The presence of aphidicolin, a DNA polymerase alpha inhibitor resulted in a decrease in DNA repair. Nalidixic acid had no inhibitory effect. Neither aphidicolin nor nalidixic acid induced DNA repair. These results indicate that nalidixic acid does not damage DNA or inhibit DNA repair processes in hepatocytes.

A canine model of controlled thrombotic vascular occlusion

The authors developed a reproducible canine model of arterial thrombotic occlusion. Operative isolation and occlusion of the external iliac arteries (EIA) were combined with balloon de-endothelialization and thrombin injection to induce bilateral thrombosis in 13 dogs. After three to nine days, 26 of 26 vessels contained isolated, discrete thrombi. Arterial blood flow reconstituted at the superficial/deep femoral artery bifurcation in 100% of cases, which limited the distal extent of thrombosis. Arterial dimensions measured intraoperatively showed thrombus volumes to be (mean +/- SD) 1332.1 +/- 243.1 mm3 (right) and 1335.9 +/- 246.8 mm3 (left). A 2-mm hot tip probe powered by an Argon laser was used to recanalize the occlusion in four vessels. Thrombo-ablation volumes accomplished by a single pass of the laser probe averaged 172 +/- 19.7 mm3 per vessel yielding thrombo-ablation energies between 2.6 and 3.5 J/mm3. Quantification of thrombi and simultaneous monitoring of both occluded segments by aortography as well as the large size of the EIA are advantages of this model, which is recommended for studies of thrombotic vascular occlusive disease.

The employment of mothers and the outcomes of their pregnancies: an Australian study

One of the more dramatic structural changes in a number of western industrial societies has involved the increased participation of women in the paid labour force. Little is known about the health consequences of this change. This paper reports the findings of a prospective longitudinal study of 8,556 pregnant women who were interviewed on three occasions; early in their pregnancy, shortly after the birth of the baby and some six months later. Additional data were derived from the medical record of the delivery. The findings suggest that employed women and housewives differ in their health behaviour (e.g. number of missed appointments, attendance at antenatal classes, smoking) and emotional health in pregnancy, but that there are no significant differences between employed women and housewives in their physical health or pregnancy outcomes. Although none of the differences was statistically significant, virtually all of the indices of outcome were slightly more favourable for the housewives than for the employed women.

The significance of chemically-induced hepatocellular altered foci in rat liver and application to carcinogen detection

This review describes the pathogenesis and significance of chemically-induced hepatocellular altered foci in rat liver. The measurement of induction of foci can be used for carcinogen detection and the measurement of the modulation of foci by chemicals other than the inducing agent identifies enhancers or inhibitors of liver carcinogenesis.

Unemployment and reproductive outcome. An Australian study

The Mater-University of Queensland Study involves the follow-up of 8556 pregnant women who were enrolled at their first clinic visit. This analysis compares four groups of women categorized according to their own and their partners' employment status. Group 1 comprised women unemployed, partners not unemployed. Group 2 comprised women not unemployed with unemployed partners. Group 3 comprised women and partners who were both unemployed. In group 4 neither partner was unemployed. Initial analysis showed that there was a significant association between birthweight and birthweight for gestational age, and unemployment as reported by mothers. After adjustment for lifestyle variables (principally smoking) there were no remaining statistically significant associations.

Socio-economic status and pregnancy outcome. An Australian study

A prospective cohort of 8556 pregnant women attending the Mater Misericordiae Mothers' Hospital in Brisbane was examined to consider the impact of socio-economic status on pregnancy outcome. The indicators of socio-economic status selected were family income, maternal education and paternal occupational status. Pregnancy outcomes considered were preterm delivery, low birthweight, low birthweight for gestational age, and perinatal death. Subsidiary analyses were also undertaken for Apgar scores, time to establish respiration, need for mechanical respiration and admission to intensive care. Before adjustment, the main consistent association was between the occupational status of the father and three measures of perinatal morbidity. Initial adjustment for the mother's socio-demographic background and weight/height ratio reduced the strength and statistical significance of the above associations, while further adjustment for lifestyle variations between the three status groups further reduced the above associations to marginal statistical significance. The findings suggest that observed class differences in pregnancy outcome are attributable to the mother's personal characteristics (height/weight, parity) and her lifestyle.

A prospective longitudinal study of social, psychological and obstetric factors in pregnancy: response rates and demographic characteristics of the 8556 respondents

This paper introduces the Mater Misericordiae Mothers' Hospital-University of Queensland Study of Pregnancy, a prospective study of 8556 pregnant women interviewed at their first clinic visit, and subsequently interviewed some days after the birth of the baby and again 6 months later. Additional data were derived from the medical record of the pregnancy and delivery. The study was designed to assess the impact of social, psychological and obstetric factors on pregnancy outcome. We present here details of the study design, sampling, response rates and demographic characteristics of the sample.

Cardiopulmonary bypass with profound hypothermia. An optimal preservation method for multiorgan procurement

Numerous techniques have been devised for the harvesting of individual organs during a multiorgan procurement operation. Cardiopulmonary bypass with profound hypothermia (PH) has been employed in successful harvesting of heart-lung, kidney, pancreas, and liver grafts. This report summarizes our experience using CPB-PH for the harvesting of multiple organs from 10 brain-dead donors during the period from July 1983 to January 1988. Organs harvested included 10 heart-lungs, 17 kidneys (3 kidneys were not harvested due to anatomy and elevated creatinine), 1 liver, and 1 pancreas. Mean ischemic time for the distantly procured heart-lung grafts was 281 +/- 10 min. Adequate pulmonary function, as assessed by arterial blood gases, was observed in each heart-lung recipient (mean PO2 was 119 +/- 46 mmHg, 164 +/- 47 mmHg, 130 +/- 30 mmHg, 114 +/- 26 mmHg at immediate post-CPB, 6 hr postop, 24 hr postop, and postextubation, respectively). Mean length of intubation was 34 +/- 8 hr. Mean creatinines of kidney recipients at days 2, 7, and current creatinine were 7.4 +/- 3.6 mg%, 3.6 +/- 2.4 mg%, and 1.6 +/- 0.66 mg%, respectively. Eight kidney recipients (47%) required dialysis, (2 patients required only a single dialysis). Ninety-four percent of the kidney transplant patients are alive, and 88% (15/17) have functioning kidneys. One liver and 1 pancreas were harvested during this time period. Preservation was satisfactory in both the pancreas (Johns Hopkins Hospital) and liver (Dr. Thomas Starzl, personal communication). The technique of CPB-PH has resulted in excellent function of heart-lung grafts. Follow-up of the transplanted kidneys, liver, and pancreas utilizing this technique shows equal or better function compared with standard techniques. This technique offers other advantages in addition to satisfactory multiorgan preservation. Placement of an unstable patient on CPB ensures adequate organ perfusion and allows for a gradual yet uniform cooling of all organ systems. Cooling to a core temperature of 10-15 degrees C requires 30 min, during which time preliminary intraabdominal and mediastinal dissection can be carried out. Following cessation of CPB and subsequent exsanguination, organs can be more easily dissected in a near-bloodless field. This technique does not preclude additional crystalloid organ flushing. Since multiorgan procurement occurs with virtually every donor, this technique may be the optimal method providing excellent preservation, ease of dissection, and better control of hemodynamics during the operation.

Digital subtraction spinal cord angiography in patients undergoing thoracic aneurysm surgery

Thoraco-abdominal aortic replacement can be associated with a high incidence of paraplegia. Because the major source of blood supply to the thoraco-abdominal spinal cord is through the anterior spinal artery of Adamkiewicz, reimplantation of intercostal and lumbar arteries could reduce the risk of this operation. We used intraarterial digital subtraction angiography (DSA) for preoperative localization of the anterior spinal artery in 12 patients. This vessel was successfully located in 9 patients, with DSA providing good quality images in all patients. Preoperative knowledge of the origin of this vessel was helpful in the planning of the operation in all patients, but its efficacy as a routine procedure was not established.

The molecular nature of spontaneous and chemically induced mutations in the hypoxanthine-guanine phosphoribosyl transferase gene in rat liver epithelial cells

The molecular nature of mutations in 6-thioguanine-resistant hypoxanthine/guanine phosphoribosyl transferase (HGPRT)-deficient clones of an adult rat liver (ARL) epithelial cell line mutated by benzo[a]pyrene or aflatoxin B1 was studied. DNA from these clones or spontaneous HGPRT-deficient mutants was subjected to Southern blotting using an HGPRT probe following DNA digestion with the restriction enzymes BamH1, EcoR1, HindIII or XbaI. With either the chemically induced or spontaneous mutants, no difference in restriction fragment pattern was observed between any of the mutants and their wild-type parent. However, differences were found between two lines ARL 6 and ARL 14 and the lines ARL 18, ARL 19 and DNA from Fischer rat hepatocytes. Although the variants did not display loss of HGPRT activity. It is suggested that deletion or loss of a pseudogene sequence could be the basis for the alterations in restriction fragment patterns.

Congenital arteriovenous malformations: tailored embolotherapy

Congenital arteriovenous malformations (AVMs) involving the pelvis or an extremity were occluded in 16 symptomatic patients, who subsequently underwent tailored embolotherapy. An additional 11 patients did not undergo embolization due to unfavorable vascular anatomy or lack of significant symptoms. Permanent occlusive agents including isobutyl cyanoacrylate, particles of polyvinyl alcohol foam, and coils were used to embolize the multiple feeding vessels and, when possible, the nidus of the AVM. All patients experienced dramatic reduction in pain and resolution of ulceration and bleeding, with a mean follow-up period of 41 months. Symptoms recurred in four patients but again resolved with repeat embolization. The authors conclude that selective and repetitive embolization is highly effective in palliation of symptomatic congenital AVMs.

Genotoxicity of carcinogens in human hepatocytes: application in hazard assessment

Evaluation of chemical genotoxicity has been used in assessing human cancer hazard, based on the observation that most human carcinogens are known to be DNA-reactive. The availability of data on the DNA-reactivity of compounds in metabolically competent human cells would assist hazard assessment by providing direct information of human genotoxicity. To evaluate the reliability of human hepatocytes for this purpose, the induction of DNA repair by DNA-reactive carcinogens of several structural classes and related noncarcinogens was studied. All the carcinogens elicited DNA repair synthesis, whereas the noncarcinogens did not. These studies provide additional support for the use of human hepatocytes in a DNA repair test in the investigation of genotoxicity. The demonstration of genotoxicity in human cells is suggested to provide important information for hazard assessment.

Evidence for cyclophosphamide-induced transitional cell carcinoma in a renal transplant patient

Cyclophosphamide treatment has been associated with bladder cancer in a number of case reports but no causal relationship has been proved since nearly all of these patients were treated with the drug for malignant disease. We describe a patient who received cyclophosphamide after cadaveric renal transplantation to prevent rejection. Transitional cell carcinoma developed in the native bladder and in the donor transplanted ureter (20-year-old donor) 13 years later despite no identifiable risk factors. This case strengthens the argument that cyclophosphamide has a carcinogenic potential on the urinary tract epithelium.

Should we perform carotid endarterectomy synchronously with cardiac surgical procedures?

From Jan. 1, 1979 through July 31, 1987, 63 patients had carotid endarterectomy (CEA) concurrently with cardiac surgical procedures including coronary artery bypass grafting (CABG) in 61, CABG plus mitral value replacement in one, and aortic valve replacement in one. Among the 62 patients having CABG, unstable angina had been present in 36 (58%), left main coronary artery disease in 21 (34%), and both unstable angina and left main coronary artery disease in 13 (21%). Indications for carotid surgery included previous stroke, amaurosis fugax, or hemispheric transient ischemic attacks (TIAs) in 33 patients (52%); bilaterally significant carotid disease was noted in 48% of the patients. Major neurologic complications occurred in three patients (4.8%), including perioperative stroke in two (3.2%) (fatal in one) and a TIA in a third patient. Bilateral carotid lesions, a contralateral total carotid occlusion, previous cerebrovascular symptoms, and intraaortic balloon pump support did not increase neurologic risk. Seven patients died postoperatively (11%). The mortality rate was 2.8% in patients younger than 65 years vs 22% in patients 65 years or older, 19% in patients with left main coronary artery disease vs 7.3% in patients without, 13.3% in men vs 5.6% in women, 25% in patients with a history of congestive heart failure vs 7.8% in patients without failure, and 6.2% in patients with unilateral carotid disease, 17% in patients with bilateral carotid disease, and 23% in patients with bilateral disease including a contralateral carotid occlusion. A mortality predictive index (MPI) was developed to summarize individual risk for a fatal outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic disease associated with pregnancy

Our experience with the management of two patients with life-threatening aortic disease during pregnancy is presented with a review of the literature. One of our patients had intimal disruption caused by trauma; the other had probable Ehlers-Danlos type IV syndrome, causing an acute dissection of the descending thoracic aorta and eventually requiring replacement of the aorta from the left subclavian artery to common iliac arteries. The challenge of treating both the pregnant woman and the fetus was managed successfully by an emergent cesarean section followed by Dacron graft replacement of the descending thoracic aorta. The literature reviewed disclosed that aneurysm expansion producing symptoms and dissection is most common during the third trimester and during labor and delivery in patients with or without Marfan's syndrome. Half of the aortic dissections in women less than 40 years of age occur in association with pregnancy. The available evidence indicates that patients with known valvular or aortic disease should have surgical repairs during the first or second trimester and thereafter have delivery by cesarean section. However, patients with acute aortic problems near term appear to be better managed by cesarean section followed promptly by treatment of the aortic disease.