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Biomedical subjects

R L Hanson

Publications and source records attributed to R L Hanson.

156 records · Page 9Linked to original sources
PubMed1970

Inhibition of phosphofructokinase by quinone methide and alpha-methylene lactone tumor inhibitors.

The plant-derived tumor inhibitors taxodone, taxodione, vernolepin, eupacunin, and euparotin acetate each inhibit the sulfhydryl enzyme, phosphofructokinase. The substrates, fructose-6-phosphate and adenosine triphosphate, protect the enzyme from this, inhibition as does the addition of dithiothreitol to the inhibitors. Incubation of taxodione with phosphofructokinase is associated with the loss of about one sulfhydryl group per inhibitor molecule, and the substrates protect six sulfhydryl groups per protomer of 93,000 daltons.

Adenosine Triphosphate↗
PubMedDate not supplied

Family and genetic studies of indices of insulin sensitivity and insulin secretion in Pima Indians.

BACKGROUND: The present analyses were conducted to examine the extent to which insulin sensitivity and insulin secretion, assessed using simple indices derived from an oral glucose tolerance test, are influenced by genetic factors, and to assess whether these genetic factors overlap with those influencing susceptibility to type 2 diabetes in Pima Indians. METHODS: Indices calculated from fasting and 2-h post-load insulin (I(0), I(120)) and glucose (G(0), G(120)) concentrations included insulin sensitivity index [ISI(0)=10(4)/(I(0).G(0))] and corrected insulin response [CIR(120)=I(120)/[G(120).(G(120)-70 mg/dl)]]. Heritability (h(2)) was determined using variance components methods in 1421 non-diabetic individuals from 446 sibships. Among 595 individuals in 186 sibships, genome-wide quantitative trait linkage analyses of ISI(0) and CIR(120) were conducted and affected-sibling analyses of diabetic siblings stratified by prediabetic measurements of ISI(0) and CIR(120) were also performed. RESULTS: Both ISI(0) (h(2)=0.37+/-0.06) and CIR(120) (h(2)=0.25+/-0.07) were moderately heritable. Modest evidence for linkage with CIR(120) (logarithm of odds (LOD)=1.6) was observed on chromosome 1q in a region previously shown to have linkage with young-onset diabetes in Pimas. When diabetic siblings were stratified by CIR(120), evidence for linkage in this region was strongest (LOD=1.5) among those with a low CIR(120). Additional regions with modest evidence for linkage with ISI(0) were observed on chromosomes 9p (LOD=2.0) and 14p (LOD=1.7). CONCLUSIONS: The present analyses suggest that insulin sensitivity and insulin secretion are influenced by genetic factors in Pima Indians. The linkage analyses suggest that the putative diabetes-susceptibility gene on chromosome 1q affects insulin secretion. Published in 2001 by John Wiley & Sons, Ltd.

Arizona↗
PubMedDate not supplied

Detection of nitroaromatic compounds on coal combustion particles.

Mutagenic and nonmutagenic extracts of fly ash from fluidized bed combustion were analyzed to determine the compounds responsible for the direct mutagenic activity (mutagenic activity that does not require added metabolic enzymes in the Salmonella mutagenicity assay). Some nitro derivatives of polycyclic aromatic hydrocarbons which are direct acting mutagens were detected by tandem triple quadrupole mass spectrometry. Treatment of a mutagenic and a nonmutagenic extract with excess N2O4 resulted in 28- and 3200-fold increases, respectively, in direct mutagenicity in Salmonella typhimurium strain TA98 and an increase in the relative abundance of nitroaromatic compounds. Polycyclic aromatic compounds were also detected and tentatively identified by gas chromatography-mass spectrometry. Since, previous studies have shown that polycyclic aromatic hydrocarbons may react with NO2 to form direct-acting mutagens, it appears that the direct-acting mutagens in these fly ash extracts may be products of reactions of polycyclic aromatic hydrocarbons with NOX in the combustion gases.

Coal↗
PubMedDate not supplied

Subjective distresses of nasogastric tube feeding.

Health care professionals assume that tube feeding is an unpleasant, distressing experience for patients, which is only partially substantiated by experience. Thirty patients were interviewed via a tube feeding and hospital experience checklist (a 47-item interview schedule). Common experiences were operationally defined as those felt by at least 50%; subjectively distressful experiences were those identified by patients as causing distress. The most common and most distressful experiences of nasogastric tube feeding were: sensory irritations and sensory deprivation. The psychosensory irritation experiences were: thirst, sore nose or throat, dry mouth, runny nose, a tube in the nose, taking food through a tube, breathing through the mouth, breathing with a tube in the nose, taking food in a treatment type container, and taking food with a different texture and smell than usual. The psychosensory deprivation experiences were: an unsatisfied appetite for certain foods, deprivation of tasting, chewing, swallowing food, and drinking liquids, limited mobility, and deprivation of regular food. Except for burping, gastrointestinal symptoms were not common though they were usually distressful. This information has been used to develop teaching programs which are being tested for effectiveness in reducing distress associated with nasogastric tube feeding.

Adult↗
PubMedDate not supplied

Predictive criteria for length of nasogastric tube insertion for tube feeding.

This study was aimed at identifying non-invasive techniques and criteria for predicting the proper length for insertion of a nasogastric tube for tube feeding so that the tube tip would be located in the fundus or body for the stomach. A review of literature and existing practices revealed unsubstantiated and discrepant methods currently in use and justified the need for this research. The study involved relating several external body measurements to a measurement from the tip of the nose to the lower esophageal sphincter, via the esophagus, in 99 adult cadavers and 5 normal adult volunteers. A variety of analyses including stepwise multiple regression, were used and are presented. A formula is presented and is stated to provide a 91% confidence level of tube tip placement in the stomach between 1 and 10 cm. This is compared to a confidence level of 72% using the traditional nose to ear to xiphoid measurement. The formula is ( (NEX-50cm) /2)) + 50cm where NEX is the distance from the tip of the nose to the earlobe to the xiphoid. Two methods for simple mechanical clinical application are described.

Adolescent↗
PubMedDate not supplied

Effects of diet temperature on tolerance of enteral feedings.

Nasogastric tube feedings administered at three temperatures were studied for effect on gastric motility, total gastrointestinal transit time, diarrhea, and subjective sensations in normal volunteers. Following a period of base-line observation, six volunteers received tube feedings at one of three temperatures: cold (8-11 degrees C), room (23-26 degrees C), or warm (36-39 degrees C). There was no significant difference between the temperature of the feeding and gastric motility patterns in selected postfeeding periods. Administration of diets at all three temperatures resulted in a similar decrease in the frequency of gastric contraction and similar patterns of return of gastric activity. After cold feedings two subjects experienced cramping accompanied by diarrhea. No gastrointestinal disturbances were reported following warmer infusions.

Cold Temperature↗