G proteins in carotid body chemoreception

This study explored the efficacy of hepatic arterial therapy, comparing both injection and infusion of 5-fluorouracil (5-FU) in prolonging the survival of 92 patients with recurrent unresectable hepatic metastasis from colorectal cancer. With respect to pretreatment carcinoembryonic antigen doubling time (CEA-DT), 56 patients were treated with intra-arterial injection, and 36 with intra-arterial infusion. In 21 patients with a CEA-DT of less than 40 days, the cumulative survival of patients treated with arterial injection was significantly longer than that of patients treated with arterial infusion. In 45 patients with a CEA-DT of 40-80 days, the survival curves of patients did not differ from each other. Of the remaining 26 patients with a CEA-DT of more than 80 days, those treated using arterial infusion had an excellent prognosis, in contrast to those treated using arterial injection, with statistical significance. CEA-DT may be useful when choosing a chemotherapy regimen, and may help to accurately establish the prognosis of patients with unresectable hepatic metastasis from colorectal cancer.     

The ultrastructure of Mauthner's neurons in the surviving medulla oblongata of goldfish

Ultrastructure of Mauthner neurons (MN) was studied in fragments of myelencephalon incubated for 0.5-1.5 hours obtained from immature gold fish. Incubation terms increase along with destruction extent and reorganization of cytoplasmic organelles and nucleus with structure of MN afferent synaptic apparatus less disturbed. Specialized synaptic contacts-active zones, cleft contacts and desmosome-like structure are well retained. The data obtained indicate MN viability during the incubation terms studied, which allows to use surviving grafts with MN as a model for studying ultrastructural bases of certain functional changes of neurons and other neurobiological problems.     

Comparison of costs for infusion versus bolus chemotherapy administration--Part two. Use of charges versus reimbursement for cost basis

BACKGROUND: The costs of infusion versus bolus administration of chemotherapy has been a point of controversy as has been the method of quantitating the cost. The present study analyzes the reimbursement for chemotherapy administration by infusion compared with bolus delivery based on reimbursement and relates this to cost based on projected charges and actual charges in a private practice setting. METHODS: Actual reimbursement records were retrieved for selected patients receiving infusion or bolus administration of specific chemotherapy regimens for three tumors: colon carcinoma, breast carcinoma, and lymphoma. All services were included except for radiology and hospitalization. Medicare reimbursement represented 90% of the treatment cycles analyzed. RESULTS: Actual reimbursement per month for each infusion regimen was as follows: colon carcinoma, $528 (5-fluorouracil [5-FU]); breast carcinoma, $621 (doxorubicin and cyclophosphamide [AC]) and $685 (cyclophosphamide, methotrexate, and fluorouracil [CMF]); and lymphoma, $603 (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP]). Actual reimbursement per month for a bolus regimen was colon carcinoma, $393 (5-FU + leucovorin); breast carcinoma, $991 (AC) or $453 (CMF); and lymphoma, $749 (CHOP). Actual reimbursement represents 21-36% of actual charges. Projected charges based on the model system are generally less than the actual charges. CONCLUSIONS: The cost of chemotherapy as defined by reimbursement are substantially less than actual charges and are also less than projected costs based on charges. Data comparing bolus versus infusion reimbursement costs for colon carcinoma, breast carcinoma, and lymphoma indicate that differences between reimbursement for bolus and infusion administration are not substantial.     

Smoking cessation: a four-step plan to help older patients quit

Smokers aged 50 years and older are a vulnerable group of patients, who are likely to have ailments that are complicated by smoking. They can derive significant health benefits from quitting, even though they probably have smoked for many years and are highly addicted. With older patients making multiple office visits each year, doctors can play a pivotal role in helping older smokers to quit. By following a four-step approach--ask about smoking, advise to quit, assist the patient in developing a quitting plan, and arrange for follow-up--physicians can significantly improve the health of their older patients who smoke.     

Extremely low birth weight infants have lower Fc gamma RIII (CD 16) plasma levels and their PMN produce less Fc gamma RIII compared to adults

The authors developed a new apparatus for extracting nitrogen or other inert gases from blood by flushing (sparging) the specimen with another gas. To investigate the utility of the new methodology, the apparatus was used in conjunction with a mass spectrometer to measure the blood N2 content of healthy normobaric, non-smoking, adult volunteers; the mean was found to be 11.7 microliters/ml +/- 0.9 microliter. This compares closely with values cited in the literature. The within-subject variation for repeat samples taken several weeks apart was significantly (P < 0.003) less than the variation between different subjects, suggesting that there may be true differences in N2 content between different individuals. These data must be considered preliminary, a larger study is needed to investigate population differences in detail. The advantages of the new method are discussed.     

Diagnosis based on reliability analysis using monitors and sensors

We develop a process for using monitors or sensors to optimize diagnostic decision trees (DDTs) generated for large systems. We present algorithms for optimizing the diagnosis process, which combines evidence data captured from monitors or sensors into the diagnostic tree generation process to produce DDTs. Since evidence data can be extracted from monitors and sensors, we developed a method for sensor modeling. Our method allows modeling monitors or sensors as an abstract layer on top of a systems fault tree model. This method of modeling allows the designer to graphically link monitors or sensors to the components that they monitor, without impacting the reliability analysis. We use a real system from the industry to demonstrate the practicality and effectiveness of our algorithms and methods.     

Effects of vitamin E and flaxseed on rumen-derived fatty acid intermediates in beef intramuscular fat

To elucidate the effects of dietary vitamin E with or without flaxseed on beef fatty acid composition, 80 feedlot steers were fed 4 diets: Control-E (451 IU dl-α-tocopheryl acetate/head/day), Control+E (1051 IU dl-α-tocopheryl acetate/head/day), Flax-E (10% ground) and Flax+E. Vitamin E had no effect on animal growth or carcass weight (p>0.05), while flaxseed-fed steers had greater average daily gain (p=0.007), final live weight (p=0.005) and heavier carcasses (p=0.012). Feeding flaxseed increased the total n-3 fatty acid content of beef and this response was further accentuated by the inclusion of high levels of vitamin E in the diet. Feeding flax increased levels of some 18:3n-3 partial hydrogenation products including c15- and t13/14-18:1 and several 18:2 isomers (p<0.001) but decreased t10-18:1 (p<0.001). Vitamin E enhanced intramuscular levels of 18:3n-3 and its biohydrogenation products leading to greater accumulations of total n-3 fatty acids in lean ground beef. The consequences of increasing the concentrations of partially hydrogenated products on human health have yet to be investigated.     

Evaluating acid and base catalysts in the methylation of milk and rumen fatty acids with special emphasis on conjugated dienes and total trans fatty acids

Milk analysis is receiving increased attention. Milk contains conjugated octadecadienoic acids (18∶2) purported to be anticarcinogenic, low levels of essential fatty acids, and trans fatty acids that increase when essential fatty acids are increased in dairy rations. Milk and rumen fatty acid methyl esters (FAME) were prepared using several acid-(HCl, BF₃, acetyl chloride, H₂SO₄) or base-catalysts (NaOCH₃, tetramethylguanidine, diazomethane), or combinations thereof. All acid-catalyzed procedures resulted in decreased cis/trans (Δ9c, 11t-18∶2) and increased trans/trans (Δ9t, 11t-18∶2) conjugated dienes and the production of allylic methoxy artifacts. The methoxy artifacts were identified by gas-liquid chromatography (GLC)-mass spectroscopy. The base-catalyzed procedures gave no isomerization of conjugated dienes and no methoxy artifacts, but they did not transesterify N-acyl lipids such as sphingomyelin, and NaOCH₃ did not methylate free fatty acids. In addition, reaction with tetramethylguanidine coextracted material with hexane that interfered with the determination of the short-chain FAME by GLC. Acid-catalyzed methylation resulted in the loss of about 12% total conjugated dienes, 42% recovery of the Δ9c,11t-18∶2 isomer, a fourfold increase in Δ9t,11t-18∶2, and the formation of methoxy artifacts, compared with the base-catalyzed reactions. Total milk FAME showed significant infrared (IR) absorption due to conjugated dienes at 985 and 948 cm⁻¹. The IR determination of total trans content of milk FAME was not fully satisfactory because the 966 cm⁻¹ trans band overlapped with the conjugated diene bands. IR accuracy was limited by the fact that the absorptivity of methyl elaidate, used as calibration standard, was different from those of the other minor trans fatty acids (e.g., dienes) found in milk. In addition, acid-catalyzed reactions produced interfering material that absorbed extensively in the trans IR region. No single method or combination of methods could adequately prepare FAME from all lipid classes in milk or rumen lipids, and not affect the conjugated dienes. The best compromise for milk fatty acids was obtained with NaOCH₃ followed by HCl or BF₃, or diazomethane followed by NaOCH₃, being aware that sphingomyelins are ignored. For rumen samples, the best method was diazomethane followed by NaOCH₃.