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R L Jones

Publications and source records attributed to R L Jones.

At least 163 records · Page 9Linked to original sources
PubMed1991

The value of submucous needle aspiration in the prediction of surgical resection line of bronchogenic carcinoma.

The fiberoptic bronchoscope was used to perform a series of SMNAs from the tumor site in the bronchial tree toward the carina to decide on an appropriate surgical line of resection in 20 patients. The line of resection was examined histologically for tumor invasion. Of the 20 patients who underwent surgery 16 had lobectomies and four had pneumonectomies. Eighteen patients had no evidence of tumor invasion at the surgical resection site. Of the remaining two, one had a cancer-positive SMNA proximal to the resection line and demonstrated tumor cells in the surgical resection line. The second demonstrated tumor cells in the right lower and upper lobes with sparing of the right bronchus intermedius. This patient underwent lobectomy with subsequent resection of the remaining right upper lobe. On the basis of this experience we conclude that SMNA is effective in predicting the optimal surgical line of resection in lung carcinoma.

Biopsy, Needle↗
PubMed1991

Reported practice behaviors for medical care of patients with diabetes mellitus by primary-care physicians in Pennsylvania.

OBJECTIVE: To compare the American Diabetes Association standards for the medical care of diabetic patients with reported care patterns. RESEARCH DESIGN AND METHODS: These standards were compared with reported care patterns obtained from a stratified random telephone survey of general practitioners, family physicians, and general internists in Pennsylvania. A total of 610 physicians completed the survey for a response rate of 73%. RESULTS: All primary-care physicians reported measurement of glycosylated hemoglobin, routine referrals to eye doctors, and patient self-monitoring of blood glucose less than recommended. Nearly all physicians performed foot exams, but the exams were infrequent for many of the physicians. Significant and independent differences (P less than 0.05) were noted between different groups of physicians. Older physicians and general practitioners reported patterns of care most different from the recommended standards for referral to eye doctors, measurement of glycosylated hemoglobin, and use of patient self-monitoring of blood glucose. General practitioners reported the lowest frequency of foot exams. CONCLUSIONS: Educational programs on diabetes for primary-care physicians should focus on reported behaviors most different from recommended standards and may need to target subgroups of physicians to achieve a more uniform level of care for all diabetic patients.

Blood Glucose Self-Monitoring↗
PubMed1990

Crystal and solution structures of the oligonucleotide d(ATGCGCAT)2: a combined X-ray and NMR study.

A combined crystal-structure determination and NMR analysis of the octanucleotide d(ATGCGCAT)2 is reported. The X-ray analysis shows that the structure is A-form duplex in crystal state. The NMR study shows that in solution this sequence is B-type. The conformational results from each technique are presented in detail. The implications of these findings in terms of conformational flexibility and ligand binding are discussed.

Base Sequence↗
PubMed1990

DNA sequence dependent binding modes of 4',6-diamidino-2-phenylindole (DAPI).

The interactions of DAPI with natural DNA and synthetic polymers have been investigated by hydrodynamic, DNase I footprinting, spectroscopic, binding, and kinetic methods. Footprinting results at low ratios (compound to base pair) are similar for DAPI and distamycin. At high ratios, however, GC regions are blocked from enzyme cleavage by DAPI but not by distamycin. Both poly[d(G-C)]2 and poly[d(A-T)]2 induce hypochromism and shifts of the DAPI absorption band to longer wavelengths, but the effects are larger with the GC polymer. NMR shifts of DAPI protons in the presence of excess AT and GC polymers are significantly different, upfield for GC and mixed small shifts for AT. The dissociation rate constants and effects of salt concentration on the rate constants are also quite different for the AT and the GC polymer complexes. The DAPI dissociation rate constant is larger with the GC polymer but is less sensitive to changes in salt concentration than with the AT complex. Binding of DAPI to the GC polymer and to poly[d(A-C)].poly[d(G-T)] exhibits slight negative cooperativity, characteristic of a neighbor-exclusion binding mode. DAPI binding to the AT polymer is unusually strong and exhibits significant positive cooperativity. DAPI has very different effects on the bleomycin-catalyzed cleavage of the AT and GC polymers, a strong inhibition with the AT polymer but enhanced cleavage with the GC polymer. All of these results are consistent with two totally different DNA binding modes for DAPI in regions containing consecutive AT base pairs versus regions containing GC or mixed GC and AT base pair sequences. The binding mode at AT sites has characteristics which are similar to those of the distamycin-AT complex, and all results are consistent with a cooperative, very strong minor groove binding mode. In GC and mixed-sequence regions the results are very similar to those observed with classical intercalators such as ethidium and indicate that DAPI intercalates in DNA sequences which do not contain at least three consecutive AT base pairs.

Base Sequence↗
PubMed1990

Epidemiologic study of salmonellae shedding in the feces of horses and potential risk factors for development of the infection in hospitalized horses.

A study was designed to identify epidemiologic factors associated with the development and spread of salmonellae in horses in a veterinary teaching hospital, through a case-control study and a longitudinal follow-up prospective study. In the case-control study, 44 horses shedding salmonellae in feces were compared with 99 control horses not shedding salmonellae in feces; regarding breed, sex, age and initial diagnosis, none of the odds ratios for study factors was significant. The factors found to be associated with fecal shedding of salmonellae in the prospective study included diarrhea at the time of admission to the hospital, fever while hospitalized, and a change in diet while hospitalized. Horses identified to be shedding salmonellae in feces were not limited to those with clinical signs of salmonellosis; however, spread of salmonellae from a shedder without clinical signs of disease to other hospitalized horses was not identified. The most common serovars of Salmonella isolated were oranienburg and newport.

Animals↗
PubMed1990

Iron storage disease in parents and sibs of infants with neonatal hemochromatosis: 30-year follow-up.

Neonatal hemochromatosis (NH), an uncommon and generally fatal disorder of infancy, is defined by hepatic disease of antenatal onset, generally manifest at birth, and by stainable iron in a tissue distribution like that seen in heritable adult-onset hemochromatosis (HH). It is not known if parents and sibs of infants with NH are at risk of iron storage disease in later life. We provide 30-year follow-up for iron overload of a family in which 6 of 9 children died in utero or early in the neonatal period. Four of the 6 came to autopsy, where severe liver disease was found; in 3 of the 4, autopsy material could be reviewed. These 3 children had NH. Studies 30 years later did not identify HH or other iron storage disease in the parents or surviving sibs. These findings suggest that first-degree relatives of persons with NH are not necessarily at increased risk of iron storage disease in later life.

Aging↗
PubMed1990

The feasibility of using Chinese hamsters as an animal model for aneuploidy.

The utility of Chinese hamsters as a test species for aneuploidy analysis was studied using four chemicals--vincristine, methyl 2-benzimidazole carbamate (MBC), nocodazole, and cyclophosphamide. Ten or more male Chinese hamsters were used per dose and bone marrow was removed at intervals of 6-96 hr. Slides were coded and 50-100 metaphases were analyzed per animal. A metaphase with more than 22 chromosomes was classified as a hyperploid cell, and the data were evaluated by using a one-tailed Fisher's exact test. In experiments using vincristine, MBC, and nocodazole, the frequencies of hyperploid cells were 0.43, 1.14, and 0.91%, respectively, for the control groups. In the experiment using cyclophosphamide, the control value frequency was 3.75%. The treated groups showed no significant increase in hyperploid frequencies when compared to concurrent controls at each of the treated times, except the value at 24 hr for the group that had been treated with vincristine at 0.75 mg/kg. However, this increase was not significant when compared to the overall value for pooled controls, with or without the cyclophosphamide control. Therefore, no significant effects due to chemical treatment were obtained in the present study. The results illustrate the extent of animal-to-animal as well as experiment-to-experiment variability in hyperploid frequencies and the importance of incorporating concurrent controls in assays for aneuploidy.

Aneuploidy↗
PubMed1990

Phosphorus in waters from sewage sludge amended lysimeters.

In surface waters, phosphorus (P) concentrations exceeding 0.05 mg liter(-1) may cause eutrophic conditions. This study was undertaken to measure total P concentrations in runoff and tile drainage waters from land receiving either inorganic fertilizer or anaerobically digested sewage sludge. Total P was measured in runoff and tile drainage waters during 2 years of sample collections from instrumented, large-scale lysimeters planted to corn (Zea mays L.). During the 3 years prior to monitoring P concentrations, six of the lysimeter plots had been amended with anaerobically digested sewage sludge which supplied 5033 kg P per ha. Additional sludge applications supplied 1058 and 1989 kg P per ha during the first and second years of monitoring operations, respectively. Another six lysimeters were annually treated with fertilizer which included P applications amounting to 112 kg ha(-1). For years 1 and 2, respectively, annual losses from lysimeters treated with sewage sludge were 4.27 and 0.35 kg P per ha in runoff and 0.91 from 0.91 and 0.51 kg Per P per ha in drainage waters. Parallel annual losses of P from lysimeters treated with superphosphate were 2.15 and 0.17 kg ha(-1) in runoff and 0.53 and 0.35 kg ha(-1) in tile drainage waters. Sludge applications did not significantly change absolute soil contents of organic P, but did decrease the per cent of total P present in organic forms. Sludge and soil, respectively, contained 21 and 36% of their total P contents in organic forms. In sludge and soil about 85 and 64% of their respective total inorganic P contents were associated with the Al and Fe fractions. Sludge applications significantly increased soil contents of P in the saloid (water-soluble plus P extracted with 1 N NH(4)Cl), Al, Fe and reductant soluble P fractions, but contents of Ca-bound P were not changed. Total P contents of the soil below a depth of 30 cm were not affected by sludge incorporated to a depth of about 15 cm by plowing.

Journal Article↗
PubMed1990

In vivo lens density measurements using the IntraOptics opacity lensmeter.

We evaluated 589 eyes using the IntraOptics opacity lensmeter 701. Twenty-one eyes contained poly(methyl methacrylate) intraocular lenses. The patients in the phakic group (578 eyes), who had no ocular pathology other than refractive error or cataracts, averaged 60.3 years of age, had an average visual acuity of 20/30, and displayed an average lens density as measured with the opacity lensmeter of 22.09. The data were analyzed for the effect of age upon density using various regression models. The best fit was obtained with an exponential model: Density = 6.2 x e(0.02 x Age), with a correlation coefficient of 0.759. The average density for the pseudophakic group (mean age = 68.5) was 9.23. Neither cortical nor posterior subcapsular cataracts were well recorded. Our results indicate that the IntraOptics opacity lensmeter is a rapid and accurate instrument for documenting nuclear cataract changes. The opacity lensmeter may prove useful not only as a clinical tool for monitoring cataract progression but also as an "electronic" second opinion.

Adolescent↗
PubMed1990

Predictive equation for assessing energy expenditure in mechanically ventilated critically ill patients.

Traditional formulas, such as the Harris and Benedict equation (HBE), do not accurately predict energy expenditure (EE) in mechanically ventilated, critically ill patients (MVCIP). The purpose of this study was to develop a predictive EE equation to assess EE requirements in MVCIP. A portable metabolic cart was used to measure indirectly EE in 112 MVCIP. Patients were studied at rest and for 30 min on the first or second day of ICU admission. No nutrition was received during the study period. Variables investigated were: age, BSA, Acute Physiology and Chronic Health Evaluation (APACHE II) score, sepsis score, Injury Severity Score (ISS), respiratory rate (f), tidal volume (VT), minute ventilation, mean arterial pressure, heart rate, body temperature (Temp), and outcome. Patient age, APACHE II score, sepsis score, ISS, and BSA were 50 +/- 20 yr, 16 +/- 7, 11 +/- 6, 32 +/- 14, and 1.80 +/- 0.27 m2, respectively. Correlation and multiple regression analyses were used with EE as the dependent variable. A predictive equation (EE [kcal/day] = 945 BSA -6.4 age + 108 Temp + 24.2 f + 817 VT -4349) was determined from variables that contributed greater than 3% to the variance of EE: BSA (52%), age (10%), f (5%), VT (5%), and Temp (3%). The HBE underestimated measured EE by 34 +/- 19% and in 79 patients deviated greater than 15%. Using the new equation, only 15 patients' EE deviated greater than 15% from measured EE. The new predictive EE equation can accurately assess EE in MVCIP.

Adult↗
PubMed1990

Heat Shock Inhibits alpha-Amylase Synthesis in Barley Aleurone without Inhibiting the Activity of Endoplasmic Reticulum Marker Enzymes.

The effects of heat shock on the synthesis of alpha-amylase and on the membranes of the endoplasmic reticulum (ER) of barley (Hordeum vulgare) aleurone were studied. Heat shock, imposed by raising the temperature of incubation from 25 degrees C to 40 degrees C for 3 hours, inhibits the accumulation of alpha-amylase and other proteins in the incubation medium of barley aleurone layers treated with gibberellic acid and Ca(2+). When ER is isolated from heat-shocked aleurone layers, less newly synthesized alpha-amylase is found associated with this membrane system. ER membranes, as indicated by the activities of NADH cytochrome c reductase and ATP-dependent Ca(2+) transport, are not destroyed by heat stress, however. Although heat shock did not reduce the activity of ER membrane marker enzymes, it altered the buoyant density of these membranes. Whereas ER from control tissue showed a peak of marker enzyme activity at 27% to 28% sucrose (1.113-1.120 grams per cubic centimeter), ER from heat-shocked tissue peaked at 30% to 32% sucrose (1.127-1.137 grams per cubic centimeter). The synthesis of a group of proteins designated as heat-shock proteins (HSPs) was stimulated by heat shock. These HSPs were localized to different compartments of the aleurone cell. Several proteins ranging from 15 to 30 kilodaltons were found in the ER and the mitochondrial/plasma membrane fractions of heat-shocked cells, but none of the HSPs accumulated in the incubation medium of heat-shocked aleurone layers.

Journal Article↗
PubMed1990

Measuring intracellular ca levels in plant cells using the fluorescent probes, indo-1 and fura-2 : progress and prospects.

Recent advances in the development of methods for measuring cytoplasmic Ca(2+) levels in higher plant cells are discussed. Emphasis is placed on the new generation of Ca(2+)-sensitive fluorescent dyes particularly fura-2 and indo-1. These dyes offer many advantages for the measurement of cytosolic Ca(2+) levels. They can be introduced into cells in a nonintrusive manner, their K(d) for Ca(2+) matches plant cell cytoplasmic Ca(2+) levels, and shifts in their emission (indo-1) or excitation (fura-2) spectra following Ca(2+) binding permit accurate quantitation of Ca(2+) activities. Examples of cytoplasmic Ca(2+) levels measured in plants with fura-2 and indo-1 are presented, and the prospects for applying more advanced technologies to fluorescent dye measurement are discussed.

Journal Article↗
PubMed1990

Calcium and proton transport in membrane vesicles from barley roots.

Ca(2+) uptake by membrane fractions from barley (Hordeum vulgare L. cv CM72) roots was characterized. Uptake of (45)Ca(2+) was measured in membrane vesicles obtained from continuous and discontinuous sucrose gradients. A single, large peak of Ca(2+) uptake coincided with the peak of proton transport by the tonoplast H(+)-ATPase. Depending on the concentration of Ca(2+) in the assay, Ca(2+) uptake was inhibited 50 to 75% by those combinations of ionophores and solutes that eliminated the pH gradient and membrane potential. However, 25 to 50% of the Ca(2+) uptake in the tonoplast-enriched fraction was not sensitive to ionophores but was inhibited by vanadate. The results suggest that (45)Ca uptake was driven by the low affinity, high capacity tonoplast Ca(2+)/nH(+) antiporter and also by a high affinity, lower capacity Ca(2+)-ATPase. The Ca(2+)-ATPase may be associated with tonoplast, Golgi or contaminating vesicles of unknown origin. No Ca(2+) transport was specifically associated with the distinct peak of endoplasmic reticulum that was identified by NADH cytochrome c reductase, choline phosphotransferase, and dolichol-P-man-nosyl synthase activities. A small shoulder of Ca(2+) uptake in the plasma membrane region of the gradient was inhibited by vanadate and erythrosin B and may represent the activity of a separate plasma membrane Ca(2+)-ATPase. Vesicle volumes were estimated using electron spin resonance techniques, and intravesicular Ca(2+) concentrations were estimated to be as high as 5 millimolar. ATP-driven uptake of Ca(2+) created 800- to 2000-fold concentration gradients within minutes. Problems in interpreting the effects of Ca(2+) on ATP-generated pH gradients are discussed and the suggestion is made that Ca(2+) dissipates pH gradients by a different mechanism than is responsible for Ca(2+) uptake into tonoplast vesicles.

Journal Article↗
PubMed1990

The interaction of unfused polyaromatic heterocycles with DNA: intercalation, groove-binding and bleomycin amplification.

A number of unfused-aromatic cations have been found to bind to DNA by intercalation and to amplify the bleomycin catalysed cleavage of DNA. These molecules are more similar in structure to unfused minor-groove binding compounds such as netropsin and DAPI than to fused-ring intercalators such as proflavine. An analysis of DAPI interactions with specific sequence DNA polymers has indicated that the binding modes for the molecule are sequence dependent: minor groove binding in sequences of three or more AT base pairs and intercalation in mixed or pure GC base pair sequences. As with other unfused intercalators which bind with their cationic side chains in the major groove, the amidinium groups of DAPI are in the major groove in the GC intercalation complex. DAPI is, thus, a good bleomycin amplifier in GC sequences but its minor-groove binding mode in AT sequences leads to bleomycin inhibition.

Base Sequence↗