Cytotoxic,mutagenic, and cell-cell communication inhibitory properties of DDT,lindane, and chlordane on Chinese hamster cellsin vitro

The cytotoxicity, mutagenicity, andin vitro inhibition of metabolic cooperation of DDT, lindane, and chlordane were studied with Chinese hamster V79 cells. The results showed differential cytotoxicity of these three pesticides (lindane < DDT < chlordane). There was no detectable mutagenic activity of any of these pesticides, using two genetic markers (6-thioguanine and diphtheria toxin resistance). DDT and lindane, however, were shown to have properties similar to 12-O-tetradecanoylphobol-13-acetate (a powerful mouse skin tumor promoter). Above what appeared to be a threshold level, there was a clear dose response of DDT and lindane in thein vitro cell-cell communication assay. Chlordane, which was the most cytotoxic pesticide tested, did not inhibit metabolic cooperation as significantly as did DDT or lindane. The role of these pesticides in carcinogenesis was speculated as being their tumor promoting properties, either at non-cytotoxic levels by mimicing TPA-like membrane alterations or at cytotoxic levels by mimicing partial hepatectomy.     

Reading, Demographic, Social and Psychological Factors Related to Pre-adolescent Smoking and Non-smoking Behaviors and Attitudes

The purpose of this study was to examine reading, demographic, social and psychological factors related to pre-adolescent smoking and non-smoking behaviors and attitudes. The school-home humanistic education program was implemented in a large, urban public school system. It stressed responsible decision-making, increased self-esteem and the inter-relationships among the acquisition of knowledge of the consequences of smoking, personal feelings, family relationships and behavior. The results showed that family involvement was necessary to affect smoking attitudes and behaviors. Of all the variables studied, reading had a most pervasive relationship. Peer influence and self-esteem also were related to smoking knowledge, smoking attitude, future smoking intentions and the "purchase" of cigarettes. Two of several conclusions drawn from the results are: 1. Family involvement is necessary to affect attitudes and behaviors. 2. Health education research that does not investigate the relationship between program outcomes and reading achievement may be misleading.     

Department of pharmacy-initiated program for streamlining empirical antibiotic therapy

The outcome of a department of pharmacy-initiated "streamlining" study designed to promote cost-conscious modifications of empirically selected antibiotic therapy is described. Two hundred forty-one evaluable adult patients started on restricted-use antibiotics at this university-affiliated community private teaching hospital were enrolled in a 9-week prospective streamlining study. Patients were alternately assigned to a Control (i.e., no pharmacist-initiated streamlining recommendations offered based on culture and susceptibility reports) or a Pharmacist Intervention group (i.e., pharmacist offers recommendations to streamline therapy). A statistically significant greater number of patients had their empiric antibiotic treatment courses modified to more appropriate antibiotic choices after receipt of culture and susceptibility reports among private prescribers in the Pharmacist Intervention group (83%) than in the Control group (38%) (p = .006). Additionally, pharmacists were overall successful in gaining prescriber acceptance for 64% of recommended changes of empiric antibiotic treatment courses before the receipt of culture and susceptibility reports (e.g., dose and/or frequency changes). There was no program effect observed with respect to improved physician response to microbiologic data that would allow streamlining empirical antibiotic choices in the Housestaff (i.e., medical or surgical residents), or infectious disease consultant prescriber groups. Projected overall annual cost savings that would be achieved as a result of continued efforts by pharmacists directed at streamlining empirical "restricted" antibiotic regimens is approximately +40,000.     

Detection of distinct Epstein-Barr virus genotypes in NPC biopsies from southern Chinese and Caucasians.

Using the polymerase chain reaction (PCR) to analyze paraffin sections from 12 Caucasian patients, we detected only the prototype F Epstein-Barr virus (EBV) in 10 specimens from patients with nasopharyngeal carcinoma (NPC). This is in contrast to the higher frequency of association of "f" variants in NPC biopsies from Southern Chinese. The results of EBV genotyping support evidence that the EBV strains associated with NPC in the Southern Chinese population differ from those found in Caucasians. DNA sequencing confirmed that a simple point mutation is responsible for the restriction-fragment-length polymorphism which distinguishes the prototype F virus from the "f" variant.     

A high-performance liquid chromatographic assay for CI-973, a new anticancer platinum diamine complex,in human plasma and urine ultrafiltrates

Summary CI-973 is a new platinum compound with antitumor properties that is currently undergoing phase II clinical trials. A high-performance liquid chromatographic (HPLC) assay was developed and validated for ultrafiltrates of human plasma and urine to support phase I clinical trials. Plasma ultrafiltrate (0.5 ml) was extracted using C18 solid-phase cartridges. Urine was diluted 10-fold and extracted first with SAX solid-phase cartridges and then with C18 cartridges. For both matrices, the eluate from the C18 cartridges was injected directly. A Whatman PAC 10 column (4.6×250 mm, 10-m particle size) and ultraviolet detection at 205 nm were used for both analyses. The mobile-phase buffer was 0.05m sodium perchlorate (pH 2.3). The mobile-phase acetonitrile: buffer ratio, column temperature, and flow rate were 8911 (v/v), 40°C, and 2.0 ml/min, respectively, for the plasma ultrafiltrate assay and 8515 (v/v), 50°C, and 1.0 ml/min, respectively, for the urine ultrafiltrate assay. Standard curves were linear from 0.25 to 500 g/ml and from 1.0 to 250 g/ml for the plasma and urine assays, respectively. The accuracy of the assay lay within 4.5% of the nominal values, and the precision was 6.2%; the recovery of CI-973 varied from 79.2% to 105%. CI-973 remains stable in plasma for at least 6 h, at room temperature, in ultrafiltrates of both matrices for at least 15 days at –72°C, and in water for at least 6 months at –72°C.     

Doppler velocimetry of intraplacental fetal arteries

Doppler velocimetry of the umbilical and intraplacental fetal arteries was studied by color flow mapping in 39 normal pregnancies. The systolic-diastolic ratio (S/D) and pulsatility index of the intraplacental fetal artery downstream to the umbilical artery decreased significantly with advancing gestational age, and its S/Ds were persistently lower than those of the umbilical artery. The difference in the S/D between the umbilical artery and its intraplacental downstream branches decreased with advancing gestational age and approached zero as the pregnancy progressed to term. We conclude that intraplacental fetal arteries, possibly fetal arteries in main stem villi, can be imaged by color flow mapping and that there is a significant "resistance gradient" between the intraplacental fetal artery and the umbilical artery. Intraplacental fetal artery velocimetry using color flow mapping may give further insights into the umbilical-placental circulation.     

Artificial liver

Without transplantation, approximately 90% of patients with fulminant hepatic failure die. If patients receive a liver transplant, there is often a lag between the need for and the availability of a donor liver. Therefore, there is a definite need for a liver support system to support the patient's own liver function in fulminant hepatic failure and while awaiting transplantation. We have developed an artificial liver system that not only eliminates lipophilic toxins such as phenols, fatty acids, and mercaptans, but also hydrophilic ones such as ammonia. This artificial liver system consists of a monitor, an extracorporeal blood circuit that uses a hydrophilic polysulfone high-flux dialyzer to remove water-soluble metabolites, and a novel hydrophilic liquid membrane filter to remove lipophilic toxins. In more than 100 in vitro experiments using porcine (5 I) blood, the system was evaluated for its ability to remove toxins that are normally increased in hepatic failure. We found that phenol, cresol, and short- and medium-chain fatty acids can be almost completely eliminated from the blood within 5 h. In animal experiments using pigs, we also found no significant changes of blood gases, liver parameters, electrolytes, and blood cell counts.     

Growth of vascularized composite mandibular allografts in young rabbits

Forty-one hemimandible allografts were transplanted in young rabbits immunosuppressed with cyclosporine. The majority of the grafts demonstrated normal wound healing, and growth of hair, bone, and teeth. The mandibular body and the premolars showed significant growth in length. The allografted mandibles functioned sufficiently that the rabbits took oral nourishment soon after surgery. Long-term survival was limited by a toxic "wasting syndrome" specific for rabbits under treatment with cyclosporine.     

Modification of Gastric Banding,Using a Fundal Suture

Many forms of gastric banding have been described and high reoperation rates reported. These can be mainly attributed to excess vomiting associated both with and without stenosis. Reflux oesophagitis and the ‘sump’ effect may be other causes. This paper examines the problems associated with banding leading to revisional surgery and introduces a new technique, ‘fundal supporting suture’, to correct these problems. Preliminary results on 126 bandings without the modification and 22 with the modification are presented.