Search PubMed⌕ Search

Biomedical subjects

N M Morris

Publications and source records attributed to N M Morris.

At least 19 recordsLinked to original sources
PubMed1997

Preparation of thin sections for Fourier Transform-Infrared microscopy: a new embedding medium for cellulosic samples.

Fourier Transform-Infrared [FT-IR] microscopy is a combination of instrumentation from which information can be derived about the structure and composition of materials; however, it presents unique problems for sample preparation. Traditional methods of preparing fiber cross sections employ embedding media such as methacrylates, epoxides and polyvinyl alcohols, all of which have groups in common with the cellulose molecule, and absorb in the same regions of the IR spectrum. Therefore, a new embedding method employing polystyrene has been developed for the preparation of cross and longitudinal sections of cellulosic fibers. Although polystyrene is a strong IR absorbing material, it can be completely removed from specimens prior to analysis. In addition, FT-IR spectra of cross sections have better resolution than conventional preparation methods employing ground samples prepared in a KBr disk.

Cellulose↗
PubMed1997

Respect: its meaning and measurement as an element of patient care.

The purpose of this article is to suggest systematic observation of provider-patient interactions as part of the evaluation of the quality of patient care provided in managed-care settings. There have been many calls for the inclusion of patient satisfaction measures in outcome evaluations. Patient satisfaction is very important since it relates to appropriate service utilization, yet the measurement of patient satisfaction is not enough. An example of systematic observation, the "Clinic Observation Record" (COR), was used by trained observers in an early evaluation of federally-funded family planning clinics, along with a measure of patient satisfaction (PATSAT). Including time spent in the clinic, which was important but played a relatively minor role, the COR (in a regression analysis) accounted for 36% of the variance in the PATSAT score for patients in 34 clinics. Personal interactions with the doctor and nurse were the most important elements contributing to patient satisfaction. Improvements in the ways patients were addressed, introduced to staff, and treated, as well as in the clinic environment, were needed in many of the clinics observed.

Attitude of Health Personnel↗
PubMed1995

Childhood precursors of age at first intercourse for females.

Age at first intercourse for a sample of adult white women using variables measured during childhood is predicted. Childhood predictors were measured at birth, and ages 5 and 9-11, using existing public-use data on the women. Median age at first intercourse for the sample was 17.5 years. Early family predictors, early developmental characteristics, and temperamental characteristics during childhood together could predict about a fourth of the variance in age at first intercourse. The strongest predictors were motor skills and nightmares at age 5, church attendance with family at age 9, and domineering and mature personality at age 9.

Adolescent↗
PubMed1995

Androgen effects on women's gendered behaviour.

Test of the applicability of the hormonal theory of sex-dimorphic behaviour to adult women is achieved in this study by assembling measures of prenatal and adult androgen exposure, and a broad measure of gendered behaviour on a sample of white women aged 27-30. Androgen exposure in the second (and no other) trimester of fetal life, combined with and in interaction with adult androgens, masculineses women's behaviour and explains a substantial proportion of the within-sex variance in women's adult gendered behaviour.

Adult↗
PubMed1993

[Risk factors for low birth weight and intrauterine growth retardation in Santiago, Chile].

An epidemiologic case-control study to ascertain the determinants of low birthweight was carried out in Santiago, Chile, from January to December 1989. The cases were defined as livebirths < 2500 g. The controls were livebirths > or = 2500 g of birthweight. All cases and a random sample (1:1) of controls were selected among 8,254 singleton births occurring at the El Salvador Hospital in the Eastern area of Santiago. These deliveries represented 50% of institutional deliveries in the area. Home deliveries (2%) and private hospital deliveries were not included in the study. Information was obtained from hospital medical records by six trained medical students. Some information could not be obtained from the hospital medical records. Thus the second step in data collection was the tracking of all the selected subjects to their referring neighborhood health centers. For the analysis, the data were divided into 3 case (outcome) categories: 453 subjects were the total case group. From these, 153 were the IUGR case group and 300 were the LBW preterm case group. The general control group consisted of 605 normal birthweight infants. 565 were the IUGR control group and 40 were the preterm control group. A total of 25 risk factors showed a significant crude odds ratio for at least one of the groups. In the multivariate logistic regression analysis eight variables: No. of pregnancies, previous adverse outcomes, previous LBW, pregnancy maternal weight, No. of visits, month of first prenatal care visit, maternal smoking and intrahepatic cholestasis of pregnancy, were significantly associated with LBW after adjustment by confounding. Eight risk factors: IUGR in previous pregnancies, Previous adverse outcome, Maternal smoking, intrahepatic cholestasis, maternal pregnancy weight, maternal height, month first prenatal visit, No. of visit, were significant to IUGR. Only two variables: pregnancy weight, divorced mother, were significantly associated with low birth weight in the preterm group. The most relevant risk factors were included in stepwise logistic regression models carried out for the outcome LBW for the general group, term group and preterm group, in order to adjust by confounding. Adjusted odds ratios were then obtained. Prenatal care related factors and maternal adverse obstetric factors were at higher significance for LBW in the general and IUGR groups. Only nutritional factors were related to LBW in preterm group. Women who delivered a LBW or IUGR infant were more likely to have fewer pregnancies, a history of previous LBW, lower prepregnancy weight and lower gestational weight gain. ICP was associated with an elevated risk of LBW that was independent of gestational age.

Case-Control Studies↗
PubMed1992

Primary care arrangements and access to care among African-American women in three Chicago communities.

African-American women of child-bearing age residing in three high-risk communities in Chicago were surveyed regarding their primary care arrangements and access to care (n = 552). This study examined factors which differentiated women who used office-based practices from those who used institutional settings (community clinics, health department clinics, hospital-based clinics) for primary care. Results of multivariate analysis indicate that women who used office-based practices were more likely than those who used institutional settings to see the same provider, to walk to their provider, to have less travel time and to walk in without an appointment. They were less likely to be hospitalized in the past year and less likely to report the availability of family planning at their usual source of care. Satisfaction with care, insurance status and sociodemographic characteristics were not associated with use of a particular facility type. Implications for organizing comprehensive health services for this population are discussed.

Adolescent↗
PubMed1991

Maternal satisfaction with primary care for children with selected chronic conditions.

One hundred forty mothers of children with chronic illnesses seen in two pediatric specialty clinics of a major urban teaching hospital were surveyed regarding their primary care arrangements and satisfaction with care received. Three dimensions of maternal satisfaction were measured: general satisfaction, satisfaction with access to care and satisfaction with doctor conduct (physician humaneness and technical quality). Results of multivariate analyses indicate that receipt of anticipatory guidance, access to care during evening hours and having a child in excellent reported health status were significantly associated with at least two of the three dimensions of maternal satisfaction. Findings have implications for organizing comprehensive, accessible primary care in the community, which is consistent with recent trends in child health policy. Results supported the need for enrichment of primary care for children with chronic illnesses to allow for physician continuity, provision of information and advice to families and extended office hours.

Baltimore↗
PubMed1991

Biophysical alteration of lung surfactant by extracts of cotton dust.

Byssinosis, a lung disease that can affect cotton mill workers, may be caused in part by lipopolysaccharides (LPS) from Gram negative bacteria. In vitro, LPS complexes with sheep lung surfactant (SLS). To determine whether LPS in extracts of cotton dust alters the biophysical characteristics of lung surfactant, aqueous extracts (1.0% w:v) of sterile surgical cotton (SSC) and a bulk raw cotton dust (1182DB) were prepared. Aliquots of the soluble extracts were incubated with SLS and studied by sucrose gradient centrifugation, surface tension analysis, and high pressure liquid chromatography (HPLC). The chromatography was employed to analyse for 3-hydroxymyristate (3-HM), a fatty acid indicating LPS. Also, purified Enterobacter agglomerans LPS and 3-HM as controls and as mixtures with SLS, were studied by HPLC. Sucrose gradient centrifugation showed that SLS-SSC, SLS-1182DB, and the SLS control had similar densities that differed from the remaining controls. The SLS-1182DB exhibited a floccule absent in the other samples. Surface tension values of SLS-SSC and SLS-1182DB differed significantly from all controls but only slightly from one another. 3-Hydroxymyristate was detected by HPLC in the 3-HM control, EA-LPS, SLS-EA-LPS, and SLS-1182DB, but not in SLS-SSC or the remaining controls. Apparently, 3-HM was below the HPLC detection range in SSC. The data indicate that LPS in the 1182DB, SSC and EA-LPS samples complexed with SLS. Floccule development in SLS-1182DB but not in SLS-EA-LPS suggests a further component(s) present in the bulk raw cotton dust, as well as LPS, which complexes with SLS. The data suggest that biophysical alterations to lung surfactant may play a part in the pathogenesis of byssinosis.

Animals↗
PubMed1988

3-Hydroxymyristic acid as a measure of endotoxin in cotton lint and dust.

A series of samples consisting of purified cellulose, purified cellulose spiked with endotoxin, and cotton lint and dust samples from the Human Panel Acute Exposure Studies at Clemson, South Carolina, were extracted with pyrogen-free water and with phenol-water. Phenacyl esters of the dried, hydrolyzed extract were prepared and chromatographed on a high performance liquid chromatograph. A peak assigned to the phenacyl ester of 3-hydroxymyristic acid appears in the chromatograms of extracts of celluloses that have been spiked with endotoxins and not in those of unspiked celluloses. This peak also appears in the extracts of cotton lint from samples that cause the greatest decrement in lung function in the Clemson human exposure studies. The area of this peak increases with increasing amounts of endotoxin and may serve as a measure of endotoxin concentration in cotton lint and dust, at least when fairly high levels of endotoxin (0.50 micrograms or greater) are present. The effect of extraction method on the determined amount of endotoxin is discussed.

Cellulose↗
PubMed1987

Marital sex frequency and midcycle female testosterone.

The purpose of the study was to attempt to replicate a finding of Persky et al. (1978) that midcycle peak values of testosterone (T) in women predicted differences in frequency of intercourse among married couples. Luteinizing hormone (LH), total testosterone (TT), and free testosterone (FT) values from 10 to 14 daily midcycle blood samples donated by 43 volunteering wives were analyzed against sexual activity patterns reported by the couples over a longer period of time. All couples were contracepting by means other than exogenous hormones or the rhythm method. Each morning through three menstrual cycles husbands and wives recorded independently and on separate forms answers to a series of questions concerning sexual activity in the previous 24 hr. Wives also recorded basal body temperatures (BBT). We designated midcycle values of TT and FT according to several definitions of midcycle. Total testosterone levels at the day of the BBT nadir and the day before the nadir correlated significantly with average intercourse frequency. Correlations with FT were statistically significant regardless of which midcycle measure was used; the day before the BBT nadir gave the highest correlation, 0.618, p = 0.01. Mean testosterone (TT or FT) values were not significantly related. We conclude that female midcycle total testosterone or free testosterone is indexing some unobserved event that affects the frequency of intercourse of couples. We speculate that this event affects the motivation of females, which influences the set point of the compromise frequency characteristic of couples.

Adult↗
PubMed1986

Gas chromatographic determination of the fatty acid composition of endotoxins from different bacteria.

Endotoxins from four bacterial species extracted by three different procedures were acid-methanolyzed and the methyl esters of the fatty acids were analyzed by packed-column gas chromatography. There were qualitative and quantitative differences in the fatty acid profiles of the lipopolysaccharides isolated from four Gram-negative bacteria. Our data show considerable lot-to-lot variations in amounts of four methyl esters from the same bacterial serotype extracted by the same procedure and in the same bacterial serotype extracted by different procedures. These results indicate that extraction and perhaps culture conditions, as well as bacterial species, affect the fatty acid composition of endotoxins, hydrolyzed and derivatized by these procedures.

Bacteria↗
PubMed1985

Serum androgenic hormones motivate sexual behavior in adolescent boys.

In order to separate hormonal from social effects on adolescent male sexual behavior, serum hormone assays were performed and questionnaire data on sexual motivation and behavior were collected on a representative sample of 102 boys in grades 8, 9, and 10 of a public school system. Free testosterone was a strong predictor of sexual motivation and behavior, with no additional contribution of other hormones. Including measures of pubertal development and age (indexing the effects of social processes) indicated no additional effects. Free testosterone, therefore, appears to affect sexual motivation directly and does not work through the social interpretation of the accompanying pubertal development.

Adolescent↗
PubMed1985

Calorimetric and potentiometric studies on the binding of calcium by phytic acid.

Potentiometric as well as thermal titrations of phytic acid and its calcium complexes have been conducted using both the batch and titration microcalorimeters. For phytic acid, the experimental values by either method are in excellent agreement. For the calcium complexes, the total number of groups and the total heat evolved are in agreement but the placement of the curves is different due primarily to the differences in calcium concentration. Binding of calcium by phytic acid is endothermic for the pH range 2.0-12.0 while the heat of dilution of 1 M CaCl2 is exothermic. The binding at pH greater than 11 gives a value of 22.5 +/- 0.9 kcal mol-1. The same enthalpy of binding (22.3 +/- 0.6 kcal mol-1) could be calculated for the entire pH range studied which requires a knowledge of the observed heat of binding, the thermal titration curves of the acid and its calcium complex, and the change in the hydrogen ion environment. Inspection of the thermal binding curves at pH greater than 11 indicates that a number of step-binding constants are involved and that 5.2 mol calcium are bound/mole phytic acid. This value has been confirmed by atomic absorption spectroscopy. Both the thermal and the potentiometric curves are reversible either by the instantaneous injection of acid or base or by continuous titration. Values for the ionization constants (as pK') and the enthalpy of ionization (as delta Hi) have been estimated by computer assisted curve fitting.

Calcium↗