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Biomedical subjects

D Lowry

Publications and source records attributed to D Lowry.

16 recordsLinked to original sources
PubMed2006

True ileal amino acid digestibility of goat and cow milk infant formulas.

Goat milk is used as an alternative to cow milk for the production of infant formulas. However, little is known about the protein quality and, specifically, about the digestible AA pattern of goat milk formulas compared with their cow milk counterparts. In this study, the true ileal AA digestibility of a goat milk infant formula was compared with a premium cow milk infant formula. The 3-wk-old piglet was used as a model for the 3-mo-old infant. Both milk formulas were prepared as described by the manufacturer, with titanium dioxide added as an indigestible marker. The formulas were fed to the piglets over a 2-wk trial period. Digesta from the terminal ileum were collected post euthanasia and analyzed for AA content, along with samples of the formulas. True AA digestibility was determined after correcting for endogenous AA loss at the terminal ileum of pigs fed an enzyme-hydrolyzed casein-based diet, followed by ultrafiltration (5,000 Da) of the digesta. Total urine and feces collection was also undertaken to determine the nitrogen retention from the diets. The true ileal AA digestibility was similar between the goat and cow milk infant formulas for all AA except Gly and Trp. There was no significant difference in the nitrogen retention of piglets fed the two different formulas. The goat milk infant formula and the premium cow milk infant formula were similar in terms of protein quality.

Amino Acids↗
PubMed2006

Mineral retention in three-week-old piglets fed goat and cow milk infant formulas.

Goat milk and cow milk are commonly used in infant formula preparations and, as such, understanding the nutritional characteristics of infant formulas made from these milks is important. In this study, a goat milk infant formula was compared with an adapted (whey-enhanced) cow milk infant formula with respect to mineral absorption and deposition using the 3-wk-old piglet as a model for the 3-mo-old infant. Equal numbers of piglets (n = 8) were fed either the goat milk formula or the cow milk formula. The mineral composition of the prepared goat milk formula was higher than that of the prepared cow milk formula for most minerals, including calcium (75.1 vs. 56.7 mg/100 mL) but excluding iron, which was higher in the prepared cow milk formula (0.92 vs. 0.74 mg/100 mL). The amounts of calcium, phosphorus, and manganese absorbed by the piglets were significantly higher for the goat milk formula, whereas the amounts of zinc, iron, and magnesium absorbed were significantly higher for the cow milk formula. Apparent mineral absorption, relative to intake, was statistically higher in the cow milk formula for calcium and phosphorus, although the actual differences were very small (less than 1.3%). For copper, zinc, iron, and magnesium there was no significant difference between treatments in apparent mineral absorption, whereas for manganese, absorption was higher for the goat milk infant formula. The absolute mineral deposition was higher in piglets fed the goat milk formula for calcium, phosphorus, and manganese, whereas iron deposition was higher in the piglets fed cow milk formula. For all other minerals tested, there were no significant differences between treatments. The goat milk infant formula provided a pattern of mineral retention in the 3-wk-old piglet very similar to that of the adapted cow milk infant formula. The minor differences observed between the 2 appeared to be due to the different mineral contents of the 2 formulas.

Absorption↗
PubMed2005

Randomized, double-blind comparison of growth in infants receiving goat milk formula versus cow milk infant formula.

OBJECTIVE: To compare growth of infants fed goat milk infant formula (GMF) or cow milk infant formula (CMF) and to compare tolerability and safety of the two formulas. METHODS: The study was conducted in Auckland, New Zealand. This was a double-blind randomized controlled trial. Newborn term infants were randomized within 72 h of birth to GMF or CMF. Milk formula powder in single serve sachets were reconstituted and fed to infants from trial commencement until age 168 days. No other formula given from randomization until age 168 days. Infant weight, length and head circumference were measured at birth and age 14, 28, 56, 84, 112, 140 and 168 days. Bowel motion frequency and consistency, sleeping and crying patterns and adverse events were also measured. RESULTS: Seventy-two infants were randomized, 36 each to GMF or CMF, with 62 infants completing the intervention. At enrollment the average weight of infants in the GMF group (mean +/- SD) was 3.33 +/- 0.43 kg and in the CMF group 3.43 +/- 0.47 kg; and at study completion 8.07 +/- 0.90 kg (GMF) and 7.87 +/- 0.99 kg (CMF). The difference in average weight gain over the study period for the GMF group versus the CMF group was not significant (+309 g; 95% CI = -49 to +668, P = 0.09). Median daily bowel motion frequency was greater in the GMF group than the CMF group (2.4 vs 1.7, P = 0.01). There were no group differences in bowel motion consistency, duration of crying, ease of settling, or frequency of adverse events. CONCLUSION: Growth of infants fed GMF is not different to that of infants-fed CMF.

Animals↗
PubMed2001

Antiquity of the biological sulphur cycle: evidence from sulphur and carbon isotopes in 2700 million-year-old rocks of the Belingwe Belt, Zimbabwe.

Sulphur and carbon isotopic analyses on small samples of kerogens and sulphide minerals from biogenic and non-biogenic sediments of the 2.7 x 10(9) years(Ga)-old Belingwe Greenstone Belt (Zimbabwe) imply that a complex biological sulphur cycle was in operation. Sulphur isotopic compositions display a wider range of biological fractionation than hitherto reported from the Archaean. Carbon isotopic values in kerogen record fractionations characteristic of rubisco activity methanogenesis and methylotrophy and possibly anoxygenic photosynthesis. Carbon and sulphur isotopic fractionations have been interpreted in terms of metabolic processes in 2.7 Ga prokaryote mat communities, and indicate the operation of a diverse array of metabolic processes. The results are consistent with models of early molecular evolution derived from ribosomal RNA.

Archaea↗
PubMed2001

Sulfur isotope analysis of sulfide and sulfate minerals by continuous flow-isotope ratio mass spectrometry.

A continuous flow method (CF-IRMS) for the rapid determination of the sulfur isotope composition of sulfide and sulfate minerals has significant advantages over the classic extraction method in terms of the reduced sample quantity and a rapid analytical cycle of less than 8 min/ analysis. For optimum performance, the technique is sensitive to a number of operating parameters, including sample weight and the O2 saturation of the Cu-reduction reactor. Raw data are corrected using a calibration based on five international and internal standards ranging from -17.3 to +20.3 per thousand, which requires monitoring in order to correct the effect of changing delta18O of the sample gas on the measured mass 66 values. Measured sulfur contents are within 1-1.5% of expected values and the reproducibility of delta34S values is +/-0.1 per thousand (1sigma). The technique has been used successfully for more than 1000 analyses of geological samples with a wide range of delta34S from -20 to +20 per thousand.

Journal Article↗
PubMed2000

Genetic counseling for women with an intermediate family history of breast cancer.

Women with a family history of breast cancer often over-estimate their personal risk for cancer and may view themselves as candidates for genetic testing even when the likelihood of an informative test result is low. We report here on genetic counseling of women with an intermediate family history of breast cancer, defined as women who have one or more biological relatives with breast cancer but whose pedigree suggests a low likelihood of autosomal dominant transmission. A genetic counseling protocol based on traditional genetic counseling strategies was developed with additional components added to address the needs of women with moderately increased breast cancer risk. These additional components included information about non-genetic risk factors, comparisons of high and moderate risk pedigrees, and evaluation of personal risk based on both genetic and nongenetic risk factors. Most participants liked the genetic counseling and found it useful. At baseline, participants over-estimated both their personal risk of breast cancer and that of the average woman. After counseling, estimates of personal and average risk of breast cancer were lower, although both remained higher than actual risk. Most participants reported that they felt less worried about breast cancer after receiving their personal-risk estimate. At baseline, most women judged themselves to be candidates for genetic testing and expressed interest in testing. The number who considered themselves candidates for testing was reduced after counseling (60% versus 82%) but still constituted a majority. Similarly, interest in testing was partially reduced by counseling (60% versus 91%). We conclude that genetic counseling can help women with an intermediate family history of breast cancer to develop more accurate views of their risk, reduce their breast cancer worry, and aid some of them in developing a more realistic view of genetic testing.

Adolescent↗
PubMed1998

Topical retinoic acid reduces skin papilloma formation but resistant papillomas are at high risk for malignant conversion.

Retinoic acid (RA) was topically applied to the skin of Sencar mice during the promotion phase of specific tumor induction protocols that produce papillomas at low (12-O-tetradecanoylphorbol-13-acetate promoted, TPA) or high (mezerein-promoted) risk for premalignant progression and malignant conversion. RA consistently reduced the yield of papillomas and carcinomas in both protocols, but the frequency of malignant conversion in papillomas that emerged during RA treatment was not reduced. When TPA was reapplied after cessation of RA treatment, the number of papillomas increased 2-fold, suggesting that RA had not eliminated initiated cells. In vitro, RA prevented the emergence of transformed keratinocytes in an assay that mimics malignant conversion, suggesting that RA can suppress conversion if applied during the stage of premalignant progression. Examination of tumor markers at weeks 14 and 22 of the tumor-induction experiments in vivo indicated that papillomas evolving during RA treatment exhibited a phenotype of high progression risk, even in the TPA-promoted groups. In the majority of these tumors, the alpha6beta4 integrin and retinoid X receptor alpha transcripts were detected suprabasally, indicating an advanced state of premalignant progression. RA-treated tumors also expressed higher levels of transcripts for transforming growth factor (TGF)-beta1 and localized TGF-beta1 peptide in the basal portions of the tumor fronds. Because up-regulated expression of TGF-beta1 suppresses papilloma formation, these studies suggest a mechanism whereby RA can prevent papilloma eruption via a TGF-beta intermediate, but papillomas resistant to RA may have altered TGF-beta signaling and progress to carcinomas at an increased frequency.

Administration, Topical↗
PubMed1998

Cooperation of p53 loss of function and v-Ha-ras in transformation of mouse keratinocyte cell lines.

We previously demonstrated that after transduction with the v-Ha-ras oncogene and grafting onto nude mouse hosts, primary epidermal keratinocytes with a null mutation in the p53 gene form tumors with increased growth rates and predisposition to malignant conversion relative to p53 wild-type keratinocytes (Weinberg WC, et al., Cancer Res 54:5584-5592, 1994). To further explore the cooperation between p53 loss of function and activation of the ras oncogene, cell lines were established from the normal epidermises of newborn and adult p53-null mice, and parallel subclones were reconstituted with the p53val135 temperature-sensitive mutant. Reconstituted lines C, G, N, and V demonstrated functional p53 transcriptional activator activity at the wild-type-permissive temperature of 32 degrees C, compared with the hygromycin-selected control line X and parental p53-null lines NHK4 and AK1b. Hygromycin-selected subclones, but not the parental lines, made normal skin in vivo; all cell lines made carcinomas after introduction of v-Ha-ras, independent of p53 status. These cell lines were compared in vitro at 32 degrees C to maximize the amount of p53val135 in the wild-type conformation. Expression of v-Ha-ras did not consistently alter p53-mediated transcriptional activity, suggesting tat ras acts downstream or independently of p53. No correlation was observed between p53-mediated transcriptional activity and in vitro growth rates, colony formation after exposure to ultraviolet light, or suppression by normal neighboring keratinocytes. However, keratinocyte cell lines devoid of p53 and expressing v-Ha-ras formed colonies in soft agar; this was blocked at 32 degrees C in all cell lines reconstituted with p53val135. These keratinocyte lines provide a model for exploring the role of p53 and the interaction of p53 and ras in keratinocyte transformation.

Animals↗
PubMed1998

A comparison of the neuromuscular blocking effects and reversibility of cisatracurium and atracurium.

The neuromuscular blocking effects and the reversibility of cisatracurium 0.1 or 0.15 mg.kg-1 were compared with those of atracurium 0.5 mg.kg-1 during anaesthesia with propofol, nitrous oxide and isoflurane. Neuromuscular block was monitored using train-of-four stimulation while recording the mechanomyographic response of the adductor pollicis muscle. The block was either allowed to recover spontaneously or was antagonised with neostigmine 50 micrograms.kg-1 at 10% or 25% recovery of the first twitch of the train-of-four. The median times to maximum block were 2.7, 2.2 and 1.5 min following cisatracurium 0.1 and 0.15 mg.kg-1 and atracurium 0.5 mg.kg-1, respectively. After cisatracurium 0.1 mg.kg-1 had been given, the median time to recovery of the train-of-four ratio to 0.8 ('adequate recovery') was 74 min during spontaneous recovery, 48 min after reversal with neostigmine when the first twitch of the train-of-four had returned to 10% of control and 50 min after reversal when the first twitch of the train-of-four had returned to 25% of control. These times for cisatracurium 0.15 mg.kg-1 and atracurium 0.5 mg.kg-1 were 90, 66 and 57 min and 75, 56 and 54 min, respectively. Administration of neostigmine significantly shortened the time to adequate recovery for both drugs but there were no significant differences in the case of either neuromuscular blocking drug between the groups of patients given neostigmine at 10 or 25% recovery of the first twitch of the train-of-four.

Adolescent↗
PubMed1996

Improved postoperative analgesia with preoperative piroxicam.

PURPOSE: Piroxicam like other Non-Steroidal Anti-Inflammatory drugs can be used to provide postoperative analgesia. With a half-life of 50 hr given preoperatively its' analgesic effect should continue postoperatively. This study compared the effects of 20 mg piroxicam given at different times in the perioperative period on postoperative analgesic requirement. METHOD: Following ethical committee approval and written informed consent, 60 ASA I and II patients presenting for inpatient gynaecological laparoscopic surgery were given either 20 mg piroxicam or a placebo po two hours preoperatively, immediately before induction of anaesthesia or one hour postoperatively in a randomised double bind manner. RESULTS: Postoperative Visual Analogue Pain Scores were lower on admission to the recovery ward in patients given piroxicam preoperatively (Group 1), than in the other two treatment groups (groups 2 and 3). Pain scores were 2.72 vs 4.25 vs 6.67 respectively (P < 0.001). Pain scores did not differ at any other times. Time to first analgesic request was greater in the group 1 than in the other two treatment groups; 141 (61) min vs 115 (147) in Group 2 and 30 (36) min in Group 3. Nine patients in Group 1 requested further analgesia compared with 15 in Group 2 and 16 in Group 3. There were no piroxicam-induced side-effects. CONCLUSION: Piroxicam given two hours preoperatively reduced pain scores, time to first analgesia and postoperative analgesic requirements compared with administration prior to induction or one hour postoperatively.

Adult↗
PubMed1988

The expression and modulation of IL-1 alpha in murine keratinocytes.

Murine and human keratinocytes produce an IL-1-like factor that appears to be similar if not identical to monocyte-derived IL-1. IL-1 may be an important mediator in cutaneous inflammatory responses, however, little is currently known concerning factors that may modulate IL-1 expression in keratinocytes. To address this issue we examined the effect of LPS, UV, and the cell differentiation state on murine keratinocyte IL-1 mRNA expression. Our results indicated that as with the murine P388D1 monocyte cell line, PAM 212 keratinocytes constitutively express abundant amounts of IL-1 alpha mRNA. On exposure to LPS (100 micrograms/ml) for 8 h there was more than 10 times the increase in PAM 212 IL-1 alpha mRNA which was accompanied by a sixfold increase in supernatant IL-1 activity. Similarly UV irradiation had a significant effect on keratinocyte IL-1 alpha expression. High dose UV (300 mJ/cm2) inhibited PAM 212 IL-1 alpha expression at 4, 8, 24, 48 h post-UV whereas a lower dose of UV (100 mJ/cm2) inhibited UV at 4 and 8 h post-UV, but induced IL-1 expression at 24 and 48 h post-UV. The expression of IL-1 alpha varied with the differentiation state of the keratinocytes. Freshly removed newborn murine keratinocytes were found to constitutively express IL-1 alpha mRNA. Keratinocytes grown in low [Ca2+] tissue culture media (0.05 mM) for 6 days, functionally and phenotypically become undifferentiated and express increased quantities of IL-1 alpha mRNA, whereas cells grown in high [Ca2+] media (1.2 mM) for 6 days become terminally differentiated and IL-1 expression ceased. Keratinocytes cultured for 3 days in low [Ca2+] conditions expressed an intermediate level of IL-1 alpha. In contrast, little or no IL-1 beta mRNA was detected in either the PAM 212 cells or newborn murine keratinocytes. Thus LPS, UV, and cell differentiation state have a significant effect on expression of IL-1 alpha in murine keratinocytes.

Animals↗
PubMed1983

Effect of a self-care education program on medical visits.

A prospective, randomized, controlled trial of self-care educational interventions was conducted in a health maintenance organization to determine their effect on ambulatory care utilization. Statistically significant decreases in total medical visits and minor illness visits were found in each of three experimental groups as compared with a control group. These decreases averaged 17% and 35%, respectively. These results were most clearly linked to a system of written communications emphasizing personal decision making about the use of medical care. The addition of a nurse counseling session to the written materials may increase cost savings and appears to be attractive to "high utilizers." A telephone information service was offered but not used. It is estimated that the decreases in utilization could result in a savings of approximately $ 2.50 to $ 3.50 for each dollar spent ona nurse counseling session to the written materials may increase cost savings and appears to be attractive to "high utilizers." A telephone information service was offered but not used. It is estimated that the decreases in utilization could result in a savings of approximately $ 2.50 to $ 3.50 for each dollar spent on the educational interventions. Self-care education systems may have important effects on medical care costs, physician satisfaction, and patient confidence.

Ambulatory Care Facilities↗
PubMed1972

A note on some reinforcing properties of university lectures.

Contingency management systems in university courses have sometimes assigned the role of reinforcing stimulus to lectures and demonstrations. Attending a lecture was made contingent upon having previously finished certain course assignments. The present paper investigated some variables that control student attendance at lectures. Attendance remained high throughout each course at those class meetings where quizzes contributing to course grades were given or where impending quizzes were discussed. Attendance at lectures over the reading assignments or over material unrelated to course quizzes rapidly declined. When students were given course credit for attending these lectures, or when the lectures included information for future quizzes, attendance increased. When attending these lectures was made contingent upon having completed certain assignments the prior week, no increase in assignment completion was noted and the attendance at the lectures decreased even further. All lectures were given during one class meeting each week. Attendance at the other class meetings during the week remained stable.

Journal Article↗
PubMedDate not supplied

Reevaluation of serum-plasma differences in total cholesterol concentration.

We measured total cholesterol levels in serum and disodium ethylenediaminetetraacetate (EDTA) plasma samples obtained from 84 healthy medical students during their entrance physical examinations and 48 adults from a cholesterol screening program who were resampled because they had initial values of 5.17 mmol/L (200 mg/dL) or higher. Plasma cholesterol concentrations were 4.7% lower than those in serum samples. The plasma and serum values were highly correlated (r = .994), however, suggesting that measurements in EDTA plasma can be converted readily to equivalent serum concentrations. Thus, the negative bias in EDTA plasma was greater than the 3% value cited in the National Cholesterol Education Program Guidelines, probably because the amount of EDTA now provided in evacuated blood collection tubes is 50% greater than in those used when the 3% value was established. These findings are relevant to the interpretation of both cholesterol screening measurements and follow-up lipoprotein analyses.

Adult↗