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Biomedical subjects

J M Hopkinson

Publications and source records attributed to J M Hopkinson.

At least 37 records · Page 2Linked to original sources
PubMed1992

Milk production by mothers of premature infants: influence of cigarette smoking.

The volume of milk produced by mothers who smoked cigarettes (n = 11) and control subjects who did not smoke (n = 29) was compared after the delivery of their preterm infants (28 to 32 weeks gestation). Milk production was significantly less among those who smoked, with or without adjusting for age, race, parity, gravidity, weight-for-height, prior nursing experience, customary alcohol and caffeine intake, infant birth weight, and pumping frequency. Each mother maintained her milk production using an electrical breast pump and without the stimulus of her infant suckling at the breast. Daily frequency and duration of breast pump usage were similar in the two groups. At 2 weeks postpartum, 24-hour milk volumes were 406 +/- 262 mL for mothers who smoked and 514 +/- 338 mL for control subjects. Between 2 to 4 weeks postpartum, the mean change in 24-hour milk volume (milliliters per 24 hours) of control subjects increased (+113 +/- 179 mL, P < .005), whereas milk volume of mothers who smoked cigarettes remained unchanged (-47 +/- 122 mL, P = .25). The percentage change in milk volume between 2 and 4 weeks for the combined groups was significantly related to four factors: pumping frequency, change in daily pumping frequency, day of initiation of pumping, and smoking status. Total and protein nitrogen, lactose, calcium, and phosphorous concentrations did not differ in milks from mothers who smoked cigarettes and mothers who did not smoke.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Vitamin K in colostrum and mature human milk over the lactation period--a cross-sectional study.

Vitamin K was quantitated in the milk of four groups of 15 mothers from 1 d to 6 mo postpartum in a cross-sectional study. Concentrations were 7.52 +/- 5.90 and 6.36 +/- 5.32 nmol/L (3.39 +/- 2.66 and 2.87 +/- 2.40 micrograms/L) in colostrum and mature milk, respectively. Differences between colostrum and mature milk or among samples of mature milk collected at 1, 3, and 6 mo were not statistically significant. Because of significantly increased volumes of milk over the lactation period, approximately twice as much vitamin K was delivered in mature milk as in colostrum. Within normal ranges, concentrations of vitamin K in milk were not predicted by dietary intake of vegetables or fat. Vitamin K was correlated with fat in colostrum and was localized in the lipid core of the milk fat globule but was not associated with membranes. Vitamin K in human milk is insufficient to meet recommended intakes for infants aged less than 6 mo. Population and clinical studies are needed to assess the vitamin K status of exclusively breast-fed infants and to evaluate current recommendations.

Adult↗
PubMed1990

Quantitation of vitamin K in human milk.

A quantitative method was developed for the assay of vitamin K in human colostrum and milk. The procedure combines preparative and analytical chromatography on silica gel in a nitrogen atmosphere followed by reversed phase high performance liquid chromatography (HPLC). Two HPLC steps were used: gradient separation with ultraviolet (UV) detection followed by isocratic separation detected electrochemically. Due to co-migrating impurities, UV detection alone is insufficient for identification of vitamin K. Exogenous vitamin K was shown to equilibrate with endogenous vitamin K in the samples. A statistical method was incorporated to control for experimental variability. Vitamin K1 was analyzed in 16 pooled milk samples from 7 donors and in individual samples from 15 donors at 1 month post-partum. Vitamin K1 was present at 2.94 +/- 1.94 and 3.15 +/- 2.87 ng/mL in pools and in individuals, respectively. Menaquinones, the bacterial form of the vitamin, were not detected. The significance of experimental variation to studies of vitamin K in individuals is discussed.

Adult↗
PubMed1989

State of the art vitamin K in human milk.

Breast-feeding is the sole source of vitamin K for most of the world's children and breast-fed infants are at risk for vitamin K-responsive hemorrhagic disease of the newborn (HDNB). Recent advances in high performance liquid chromatography methodology have made possible the first quantitative studies of vitamin K in human milk. Although much progress has been made, much remains to be done. Innovative improvements in methodology are needed, as detection of nanogram quantities of vitamin K in milk is at the limit of current methodology. Additional studies are needed over the lactation period. A better understanding of colostrum is needed with regard to other nutrients as well as vitamin K. Vitamin K in the milk of mothers who gave birth prematurely has not been measured. The significance of menaquinones as a vitamin K source to the infant is undetermined. The mechanism regulating vitamin K secretion into milk has not been investigated. The localization of vitamin K in milk is undetermined as is the relationship of vitamin K to other milk lipids. The effects of fat-soluble vitamins in the diet on vitamin K concentrations in milk is unknown. The pharmacokinetics of vitamin K supplementation of mothers is particularly important in cultures where vitamin K is not routinely administered at birth. Finally, most critical at this point is our ignorance about the relationship of the maternal vitamin K status to the vitamin K status of the infant. As breast milk is the sole source of vitamin K for most of the world's infants, HDNB remains a very real threat to the health of infants and warrants concentrated study.

Female↗
PubMed1989

Fluid flow through dural puncture sites. An in vitro comparison of needle point types.

Leakage of artificial cerebrospinal fluid through human dura was measured in vitro after puncture by spinal needles. Fluid loss tailed off in all cases and ceased within 5 minutes in 10% of punctures made with a 22-gauge needle, 28% made with a 26-gauge and 65% made with a 29-gauge needle (p less than 0.05). The fluid loss was not reduced by alignment of the level of the needle parallel to the longitudinal direction of the fibres. Whitacre point needles of 22 gauge produced lower fluid loss than a 22-gauge Quincke point needle inserted across the fibres (p less than 0.05). Leakage rate was related to needle size, but not related to the alignment of a Quincke point. Little or no leakage occurred with 29-gauge needles.

Anesthesia, Spinal↗
PubMed1988

Benign axillary epithelial lymph node inclusions--a histological pitfall.

We present two cases of axillary epithelial lymph node inclusions in the presence of benign and malignant breast disease. Although the presence of lymph node inclusions is well recognized at other sites in the body, their presence in the axillary nodes of women with breast disease necessitates close attention. This is particularly true in women with malignant breast disease as misinterpretation may lead to inappropriate treatment.

Adult↗
PubMed1988

Milk production by mothers of premature infants.

Milk volume, day of initiation of pumping, duration and frequency of milk expression, and length of night rest interval were evaluated for the first month postpartum in 32 healthy, nonsmoking women (ages 20 to 38 years) who delivered at 28 to 30 weeks' gestation. Early milk volumes were related negatively to the delay between delivery and the initiation of milk expression (r = -.48, P less than .02). Average milk volumes at 2 weeks and 4 weeks postpartum were 493 +/- 330 and 606 +/- 369 mL/d (mean +/- SD), respectively, and were not related to the absolute frequency or duration of pumping or to night rest interval. Volume changes between weeks 2 and 4 postpartum were correlated with the absolute frequency (r = .49, P less than .01) and duration of pump use (r = .42, P less than .05) during this interval and with changes in frequency (r = 0.56, P less than .002) or duration (r = 0.49, P less than .05) between the first 2 and the second 2 weeks postpartum. Optimal milk production was associated with five or more milk expressions per day and pumping durations that exceeded 100 min/d.

Adult↗
PubMed1987

Variation in lymphoma incidence within Yorkshire Health Region.

The spatial distribution of new cases of lymphoma occurring in Yorkshire between 1978 and 1982 has been studied. Administrative districts were used as the basis for analysis and differences in age standardised incidence rates between districts were determined. Excessive rates for NHL were found to occur in Scarborough, York and Leeds districts. In addition an analysis contrasting broadly urban and rural districts showed an excess of NHL in rural areas, particularly of the follicular subtypes.

Adolescent↗
PubMed1981

Pulmonary metastases from a basal cell carcinoma.

Although basal cell carcinomas are the commonest malignant condition of the skin (Borel 1973) pulmonary metastases are rare; it appears that only 30 authenticated cases have been reported (Sakula 1977). A further case is described of a man aged 64 who presented severe dyspnoea and who for 12 years had harbored an untreated ulcerating lesion of the abdominal wall shown histologically to be a basal cell carcinoma. Chest radiography showed metastatic disease confirmed histologically to be identical to the ulcerating skin lesion. Unfortunately, because of the severe respiratory condition, no definitive treatment was indicated and the patient died of respiratory failure 2 weeks following discharge.

Abdominal Muscles↗