CLOSED CHAMBER SYSTEM FOR DELIVERY OF ETHANOL TO CELL CULTURES

The accuracy and consistency of the delivery of ethanol to culturedcells is important to determine effects on morphologic, biochemicaland physiologic alterations. Open and closed chamber systemswere evaluated to determine cytotoxic vs sublethal, potentiallyteratogenic effects on neonatal rat cardiac myocytes. The open system employed a variety of cell culture vessels.Cardiac cells were exposed directly to ethanol in the growthmedia at concentrations of 5–50 mM in Petri dishes, multiwellslides and multiwell chambers. Ethanol concentrations in themedia in these open vessels decreased over 60% in a 24 hr incubationperiod. A closed system consisted of tightly sealed plastic containersin which the same vessels were used. The vessels were placedon a platform over a bath of ethanol-water. Cells were acclimatedfor 24 hr with ethanol in the bath at 200% of the final desiredmedia concentration. Ethanol gradually diffused into the mediato reach peak levels of 5, 10,25 or 50 mM at 24 hr. After the24 hr period, ethanol was added to both the media and bath atthe desired concentration. Cells exposed gradually to ethanol in the closed chambers remainedviable, but showed slower division and growth. A period of gradualacclimation is required to induce sublethal cellular effectsrather than lethal effects. The diversity of cell systems andmanipulations of cultures to study the potential teratogeniceffects of ethanol are improved using such a closed chambersystem.     

Chronic renal failure: factors influencing nephrology referral

Factors influencing referral of all 304 patients who developedpersistent renal failure during one year were studied in thestable Grampian population. The annual incidence of chronicrenal failure (CRF) (creatinine     

Use of a Novel Pulse Dye Laser for Rapid Single-Pass Purpura-Free Treatment of Telangiectases

BACKGROUND Purpura-free elimination of telangiectases with a single pass of a pulsed dye laser with a large spot has proved difficult.
OBJECTIVE The purpose of this report was to define parameters that achieve single-pass purpura-free telangiectasia reduction.
MATERIALS Thirty patients between the ages of 23 and 78 years were treated with a pulsed dye laser with a 10-mm spot and fluences ranging from 9 to 10 J/cm². The macropulse width was 20 ms. Each macropulse was composed of eight pulselets. Treatments were carried out over facial areas with discrete telangiectases.
RESULTS Smaller telangiectases (<600 μm) showed transient bluing followed by stenosis. Larger vessels (600–10,000 μm) showed bluing but inconsistent closure. A second pass typically resulted in closure.
CONCLUSION A modified pulsed dye laser was capable of single-pass purpura-free reduction with a 10-mm spot size.     

Multicenter Evaluation of Fixed-Wire PTCA Catheters with Modified Distal Tips: Initial and 2-Month Follow-Up Results

Lesions in the distal portion of coronary arteries are technological challenges with currently available percutaneous transluminal coronary angioplasty (PTCA) equipment. A study was performed at multiple centers to determine if new "fixed-wire" devices with a modified distal tip (a 2-cm flexible tip and 1-cm standard tip) would be useful in these situations. Three hundred twenty-three patients were included in the study, 75% male, mean age 63 ± 11 years. Four hundred ninety-three lesions were attempted; the overall success rate was 85%. Forty-six (14.2%) clinical complications occurred including: 5 deaths (1.1%); 2 nonfatal myocardial infarctions (0.6%); and 6 emergency coronary artery bypass grafting procedures (2.6%). A device malfunction was noted in 32 patients (9.9%), and included: 8 balloon ruptures or perforations (2.0%); 6 bent or damaged tips (1.9%); and 4 shaft/manifold leaks (1.2%). Two-month follow-up assessment for restenosis was done in 352 of 371 (95%) patients and at that time 89% were asymptomatic, had a negative functional test, or patent PTCA site by angiography. The new fixed-wire PTCA catheters with 1- and 2-cm flexible tips hold promise for dilating lesions in distal locations with an acceptable rate of complications. Additional investigation is needed to determine their role in the treatment of coronary artery disease with PTCA.     

Polychlorinated Biphenyl Congeners in Adipose Tissue Lipid and Serum of Past and Present Transformer Repair Workers and a Comparison Group

Polychlorinated Biphenyl Congeners in Adipose Tissue Lipid andSerum of Past and Present Transformer Repair Workers and a ComparisonGroup. FAIT, A., GROSSMAN, E., SELF, S., JEFFRIES, J., PELLIZZARI,E. D., AND EMMETT, E. A. (1989). Fundam. Appl. Toxicol 12, 42-55. The concentrations of individual PCB's were determined inboth serum and adipose tissue lipid from 35 transformer repairworkers currently exposed to PCBs, mainly Aroclor 1260, 17 previoustransformer repair workers, and 56 comparison workers neveroccupationally exposed to PCBs. The analysis used fused-silicacapillary gas chromatography with electron capture detector(FSCGC/ECD) and FSCGC with negative ion chemical ionizationmass spectrometry to verify PCB congener levels. Eighty-ninePCB peaks were identified and confirmed. More congeners weredetected in adipose tissue. In serum approximately 50% of peakswere below the level of detection. Statistical techniques toaccount for left and interval censoring allowed comparison ofconcentration distributions even where data were incomplete.We found that unquantifiable levels were unlikely to contributesubstantially to the true values for total [PCBs] over and beyondthe contribution of the measured values. However, the totalserum [PCBs] determined by FSCGC/ECD greatly exceeded that fromstandard packed cell gas chromatography (PCGC/ECD). The underestimationwas less marked for adipose samples. In serum the total [PCBs]was highest in currently exposed workers and lowest in unexposedworkers, with past-exposed workers clearly intermediate. Inadipose tissue [PCBs] in the currently exposed group was muchhigher than in the other two groups, in whom the distributionof results was broadly similar. In all worker groups hexachlorinatedand heptachlorinated species predominated followed by octachlorinatedand pentachlorinated. The relative distribution of individualPCB congeners in the three groups was similar although the amountsvaried. The seven major peaks in serum and adipose tissue were2,3,5,6,3',4',5'/2,3,4,5,2',4',5' hepta-CB; 2,3,4,2',3',5' hexa-CB;2,4,6,3',4',5'/ 2,4,5,2',4',5'/2,3,4,5,2',5' hexa-CB; 2,3,4,5,2',3',4'hepta-CB; 2,3,4,5,2',3',5',6'/2,3,4,5,6,2',3',5', octa-CB; 2,4,5,3',4',/3,4,5,2',3'penta-CB; and 2,3,4,2',3',4'/2,3,5,6,2',4',5'/2,3,4,5,2',4',6'multi-CB. The distribution of PCB peaks in our populations differsfrom that in capacitor workers (exposed to less highly chlorinatedPCBs) and from Yu-Cheng patients suggesting differing toxicpotentials from PCBs in these three circumstances.     

The relationship between cardiovascular reactivity and heartbeat detection

This experiment tested the hypothesis that inotropic cardiovascular reactivity to stress is related to performance on heartbeat discrimination tasks. The experiment also compared the efficacy of a specific modification of two popular heartbeat discrimination paradigms, Whitehead's and Katkin's. Subjects were 48 male undergraduates who performed both discrimination tasks and then were subjected to mental arithmetic stress. Results indicated that high cardiovascular reactors were better detectors than low reactors. Results also indicated that subjects performed better on the modified Whitehead task than on the modified Katkin task.