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Biomedical subjects

M C Martini

Publications and source records attributed to M C Martini.

At least 37 records · Page 2Linked to original sources
PubMed1995

Reperfusion-induced arrhythmias and lethality are reduced by a 2KDa heparin fragment.

The influence of a low molecular weight heparin (Oligo-H, m.w. 2KDa) on ventricular arrhythmias and lethality induced by heart reperfusion following a 5 min coronary occlusion was studied in anesthetized rats. Both intravenous (i.v.) and subcutaneous (s.c.) injection of the compound dose- and time-dependently prevented the reperfusion syndrome: in all saline-pretreated animals post-ischemic reperfusion induced ventricular tachycardia (VT), which degenerated into ventricular fibrillation (VF) in 25 out of 30 rats, with a mortality rate of 73%; on the other hand, in rats i.v. or s.c. pretreated with Oligo-H (20 mg/kg, 30 and 90 min, respectively, before coronary occlusion), VT occurred in 4 out of 10-11 animals and degenerated into VF in 2-3 out of 10-11 animals, with a mortality rate of 18-20%. Even more effective was a low molecular weight dermatan sulfate (Oligo-DS, m.w. 2.1KDa). In rats treated with lidocaine, used as reference compound, at the dose of 5 mg/kg i.v. 10 min before coronary occlusion, VT occurred in 2 out of 10 animals and degenerated into VF in 1 out of 10 animals, with a mortality rate of 10%. It is concluded that low molecular weight glycosaminoglycans significantly reduce the consequences of heart reperfusion.

Animals↗
PubMed1995

Vegetables, fruits, and legumes: effect on urinary isoflavonoid phytoestrogen and lignan excretion.

OBJECTIVE: To compare the effect of vegetable, fruit, and legume consumption on urinary isoflavonoid phytoestrogen and lignan excretion. DESIGN: After 4 days of data collection, during which subjects consumed their habitual diets, subjects were randomly placed on four 9-day controlled experimental diets with each subject receiving each diet in a random order. SUBJECTS: Seven men and three women, aged 20 to 35 years, were recruited from the University of Minnesota Twin Cities community. INTERVENTIONS: All subjects consumed four experimental diets in an assigned random order: a controlled basal diet, a legume/allium diet (containing garbanzo beans, garlic, and onions), and diets low or high in vegetables and fruits (containing apples, pears, potatoes, and carrots). MAIN OUTCOME MEASURES: Urine samples that were collected while subjects consumed their habitual diets and during the last 3 days of each feeding period were analyzed for isoflavonoid and lignan content using isotope dilution gas chromatography-mass spectrometry. STATISTICAL ANALYSIS PERFORMED: The effect of vegetable and fruit intake on urinary isoflavonoid and lignan excretion was analyzed using the general linear model procedure. Post hoc comparisons were made using Duncan's multiple range test. RESULTS: Subjects excreted more of the lignan enterodiol on the high vegetable/fruit diet compared with the basal and legume/allium diets (P = .03); more of the isoflavonoids O-desmethylangolensin (O-DMA), genistein, and sum of isoflavonoids on the legume/allium diet compared with the other controlled diets (P < .05); and more of the isoflavan equol on the basal and legume/allium diets compared with the high vegetable/fruit diet (P < .01). Subjects who excreted higher levels of equol on the basal and legume/allium diets also consumed more of the milk-based pudding provided as part of the controlled diets. CONCLUSIONS: Urinary lignan and isoflavonoid excretion changed in response to alterations in vegetable, fruit, and legume intake under controlled dietary conditions.

Adult↗
PubMed1995

Urinary lignan and isoflavonoid excretion in men and women consuming vegetable and soy diets.

Urinary lignan and isoflavonoid excretion were examined in 11 men and 9 women consuming four nine-day controlled experimental diets: basal (vegetable free), carotenoid vegetable (carrot and spinach), cruciferous vegetable (broccoli and cauliflower), and soy (tofu and textured vegetable protein product). Three-day urine collections (Days 7-9) were analyzed for lignans and isoflavonoids with use of isotope-dilution gas chromatography-mass spectrometry. Urinary excretion of the lignans enterodiol and enterolactone was higher during the carotenoid and cruciferous vegetable diets than during the basal diet (p = 0.0001), suggesting that these vegetables may provide a source of mammalian lignan precursors. Urinary excretion of the isoflavonoids equol, O-desmethylangolensin, daidzein, and genistein was higher when subjects consumed soy diets than when they consumed the other test diets (p < 0.02). Gender differences in lignan excretion were observed. Men excreted more enterolactone (p = 0.006) and less enterodiol (p = 0.013) than women, implying a gender difference in colonic bacterial metabolism of lignans. There was no effect of gender on isoflavonoid excretion.

4-Butyrolactone↗
PubMed1995

Fecal lignan and isoflavonoid excretion in premenopausal women consuming flaxseed powder.

Lignans and isoflavonoids are diphenolic compounds found in plant foods, particularly whole grains and legumes. They have been shown to have anticarcinogenic properties in animal and cell studies, and have been associated with reduced cancer risk in epidemiological studies. In order to perform further epidemiological and metabolic studies on these compounds, it is necessary to be able to monitor concentrations in biological samples. In this study, we examined the effects of consumption of flaxseed, a concentrated source of lignans, on fecal lignan excretion and evaluated the effect of high lignan consumption on fecal excretion of isoflavonoids. Thirteen women were studied for two diet periods of three menstrual cycles each in a cross-over design. During the control period, they consumed their usual diets; during the treatment period they consumed their usual diets supplemented with 10 g/day ground flaxseed. Feces were collected on days 7-11 of the last menstrual cycle in each diet period. Five-day fecal composites were analyzed for lignans and isoflavonoids by isotope dilution gas chromatography-mass spectrometry. Fecal excretion of the lignans enterodiol, enterolactone, and matairesinol increased significantly with flax consumption, from 80.0 +/- 80.0 (SD) to 2560 +/- 3100; 640 +/- 480 to 10,300 +/- 7580; and 7.33 +/- 10.0 to 11.9 +/- 8.06 nmol/day, respectively. There were no differences in fecal excretion of the isoflavonoids, daidzein, equol, genistein, and O-demethylangolensin.

Adult↗
PubMed1994

Urinary lignan and isoflavonoid excretion in premenopausal women consuming flaxseed powder.

Lignans and isoflavonoid phytoestrogens, produced from plant precursors by colonic bacteria, may protect against certain cancers. We examined the effects of flaxseed consumption on urinary lignans and isoflavonoids. Eighteen women consumed their usual omnivorous diets for three menstrual cycles and their usual diets supplemented with flaxseed powder (10 g/d) for three cycles in a randomized crossover design. Three-day urine samples from follicular and luteal phases were analyzed for lignans and isoflavonoids by isotope-dilution gas chromatography--mass spectrometry. Excretion of the lignans enterodiol and enterolactone increased with flaxseed from 1.09 +/- 1.08 and 3.16 +/- 1.47 to 19.48 +/- 1.10 and 27.79 +/- 1.50 mumol/d, respectively (P < 0.0002). Enterodiol and enterolactone excretion varied among subjects in response to flaxseed (3- to 285-fold increase). There were no differences in excretion of isoflavonoids (daidzein, genistein, equol, and O-desmethylangolensin) or the lignan matairesinol with flaxseed. Excretion was not altered by phase of menstrual cycle or duration of flaxseed consumption.

Administration, Oral↗
PubMed1994

Effect of the menstrual cycle on energy and nutrient intake.

Midfollicular and midluteal dietary intakes of 18 women were evaluated between four and six ovulatory menstrual cycles. Phase lengths were established by basal body temperatures and urinary luteinizing hormone excretion. Midfollicular and midluteal diet records were collected 6-8 d after menstrual onset and 6-8 d after ovulation, respectively. Significant increases in energy [0.66 MJ (159 kcal), P = 0.003], protein (6.1 g, P = 0.02), carbohydrate (15.3 g, P = 0.04), and fat (8.6 g, P = 0.002) intakes were observed in midluteal phase when compared with midfollicular phase. Intakes of vitamin D, riboflavin, potassium, phosphorus, and magnesium also were significantly higher during midluteal phase (P < 0.05). These results support the regulation of food intake by menstrual cycle hormones and suggest that it is essential to consider phase of menstrual cycle in studies of nutrient intake performed in premenopausal women.

Adult↗
PubMed1994

Plasma carotenoids as biomarkers of vegetable and fruit intake.

Higher intakes of vegetables and fruits are associated with a lower risk of certain human cancers. A biomarker of vegetable and fruit intake would be a valuable research tool. A cross-sectional study assessed the association between plasma carotenoid concentrations and intakes of vegetables and fruits. Plasma carotenoids (alpha-carotene, beta-carotene, lutein, beta-cryptoxanthin, and lycopene) were measured in 50 male and 49 female participants, aged 18-37 years, with a wide range of habitual vegetable and fruit intakes. Dietary intakes were assessed via a food frequency questionnaire. Intake of vegetables and fruits and high carotenoid foods were measured. The sum of the plasma carotenoids (excluding lycopene) was highly correlated with intake of total vegetables and fruits (r = 0.59). Of the individual plasma carotenoids, plasma alpha-carotene had the highest correlation with intakes of both total vegetables (r = 0.50) and total fruits (r = 0.58). Intakes of foods with high carotenoid contents were correlated with their corresponding plasma concentrations as follows: high beta-carotene foods (r = 0.41); high lutein foods (r = 0.46); and high lycopene foods (r = 0.11). Multiple regression analyses showed that intake of total vegetables and fruits was the most significant determinant of each plasma carotenoid except lycopene. The utility of combining the plasma carotenoids as biomarkers of vegetable and fruit intake was assessed by a stepwise regression of total vegetable and fruit intake on plasma carotenoids. Significant determinants of intake of total vegetables and fruits were alpha-carotene, beta-cryptoxanthin, lutein, and energy intake (R2 = 0.53).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Modified epidermal lipid composition in air-exposed culture of non-bullous congenital ichthyotic erythroderma (NBCIE) keratinocytes.

Emerged epidermal cultures on dead de-epidermized dermis (DED) constitute an excellent model for in vitro reproduction of dermatoses linked to a keratinocyte defect. We used such cultures for studies of non-bullous congenital ichthyotic erythroderma (NBCIE). Keratinocytes of normal and pathological origin were expanded in submerged cell cultures and frozen keratinocytes from the resulting cell bank were subsequently used for seeding on DED. Lipid extracts from 14 day emerged cell cultures were assayed qualitatively and quantitatively using thin layer chromatography and compared with the neutral and non-polar lipid profiles obtained from normal epidermis extracts and with those from the plantar stratum corneum of healthy donors and untreated NBCIE patients. The ichthyotic cultures were found to contain significantly elevated levels of n-alkanes, as were the lipid extracts from the patients' plantar horny layer. Our results demonstrate that a major marker of the NBCIE epidermis can be reproduced under the emerged culture conditions. They also indicate that the characteristic n-alkane increase in NBCIE is indeed endogenous and not merely related to possible contamination from topical treatments.

Air↗
PubMed1993

Comparative effects of exogenous lactase (beta-galactosidase) preparations on in vivo lactose digestion.

Microbial-derived beta-galactosidase (beta-gal) enzyme preparations improve in vivo lactose digestion and tolerance through enhanced gastrointestinal digestion of lactose. Three different beta-gal preparations, Lactogest (soft gel capsule), Lactaid (caplet), and DairyEase (chewable tablet) and placebo were fed to lactose maldigesters with either 20 g or 50 g of lactose to compare the efficacy of these products and to further establish a dose-response relationship for use. All enzyme preparations dramatically reduced both the peak and total breath hydrogen production when fed with milk containing 20 g of lactose. Four capsules of Lactogest, two caplets of Lactaid, or two tablets of DairyEase (each treatment containing approx 6000 IU) reduced total hydrogen production significantly (P < 0.05) below that observed with two capsules of Lactogest (containing approx 3000 IU) in a stoichiometric manner. Symptoms were significantly (P < 0.05) less severe with all the beta-gal products. In contrast, with 50 g of lactose in water, peak and total hydrogen production was modestly, but not significantly reduced by the enzyme treatment. Furthermore, symptom scores for bloating, cramping, nausea, pain, diarrhea, and flatus were not different between treatments and the control. The 50-g lactose dose appeared to overwhelm the ability of either 3000 or 6000 IU of beta-gal to assist significantly with lactose digestion. Results from these studies demonstrate the relative equivalency of chewable, caplet, and soft-gel beta-gal products, based on IUs of enzyme fed.

Administration, Oral↗
PubMed1993

Effect of flax seed ingestion on the menstrual cycle.

Lignans are a group of phytochemicals shown to have weakly estrogenic and antiestrogenic properties. Two specific lignans, enterodiol and enterolactone, are absorbed after formation in the intestinal tract from plant precursors particularly abundant in fiber-rich food and are excreted in the urine. We evaluated the effect of the ingestion of flax seed powder, known to produce high concentrations of urinary lignans, on the menstrual cycle in 18 normally cycling women, using a balanced randomized cross-over design. Each subject consumed her usual omnivorous, low fiber (control) diet for 3 cycles and her usual diet supplemented with flax seed for another 3 cycles. The second and third flax cycles were compared to the second and third control cycles. Three anovulatory cycles occurred during the 36 control cycles, compared to none during the 36 flax seed cycles. Compared to the ovulatory control cycles, the ovulatory flax cycles were consistently associated with longer luteal phase (LP) lengths (mean +/- SEM, 12.6 +/- 0.4 vs. 11.4 +/- 0.4 days; P = 0.002). There were no significant differences between flax and control cycles for concentrations of either estradiol or estrone during the early follicular phase, midfollicular phase, or LP. Although flax seed ingestion had no significant effect on LP progesterone concentrations, the LP progesterone/estradiol ratios were significantly higher during the flax cycles. Midfollicular phase testosterone concentrations were slightly higher during flax cycles. Flax seed ingestion had no effect on early follicular phase concentrations of DHEA-S, PRL, or sex hormone-binding globulin. Our data suggest a significant specific role for lignans in the relationship between diet and sex steroid action, and possibly between diet and the risk of breast and other hormonally dependent cancers.

4-Butyrolactone↗
PubMed1991

Lactose digestion from yogurt: influence of a meal and additional lactose.

Lactose in yogurt is better digested than lactose in other dairy foods by lactase-deficient individuals, in part because of intraintestinal activity of yogurt microbial beta-galactosidase (beta-gal). The survival and activity of yogurt beta-gal depend on gastrointestinal transit, pH, and viability of the yogurt culture. To evaluate the ability of yogurt beta-gal to digest lactose when yogurt is consumed with food or with additional lactose, 22 healthy lactose-maldigesting individuals were fed 10 test meals. Results of breath-hydrogen expiration, incidence of symptoms, and enzyme and lactose content of gastric aspirates indicate that the consumption of a meal with yogurt does not inhibit, and may slightly improve, lactose digestion from yogurt. However, yogurt beta-gal appears unable to assist in the digestion of additional lactose beyond that normally present in yogurt.

Adult↗
PubMed1991

Strains and species of lactic acid bacteria in fermented milks (yogurts): effect on in vivo lactose digestion.

Lactose in yogurt with live bacteria is better tolerated than lactose in other dairy foods, partly because of the activity of microbial beta-galactosidase (beta-gal), which digests lactose in vivo. To evaluate the ability of different strains and species of lactic acid bacteria to digest lactose in vivo, yogurts (containing mixtures of strains of Streptococcus salivarius subsp thermophilus and Lactobacillus delbrueckii subsp bulgaricus) and fermented milks (containing individual species of S thermophilus, L bulgaricus, L acidophilus, or Bifidobacterium bifidus) that varied in microbial beta-gal activity were produced. Selected products were fed to healthy people who cannot digest lactose, and breath hydrogen production was monitored. All yogurts dramatically and similarly improved lactose digestion, regardless of their total or specific beta-gal activity. The response to fermented milks varied from marginal improvement with B bifidus milk to nearly complete lactose digestion with L bulgaricus milk. The results suggest that total beta-gal was not the limiting factor in promoting lactose digestion, perhaps because of a limited rate of intracellular substrate transport.

Adult↗
PubMed1990

Megestrol acetate: phase II study of a single daily administration in advanced breast cancer.

A new formulation of megestrol acetate, a semisynthetic oral progestin used in the hormonal treatment of breast cancer, allows the administration of 160 mg of the drug in a single daily dose. Sixty-nine postmenopausal patients with advanced breast cancer have been treated with this regimen: five patients received megestrol acetate as first-line treatment of their metastatic disease, while all the others had been previously treated with one or more regimens of chemotherapy and/or hormone therapy. The median duration of the treatment for evaluable patients was 3 months (range 1-13+). Among 65 evaluable patients 2 complete responses and 12 partial responses (objective response rate 21.5%; 95% confidence limits 12.31%-33.49%) were observed. Median duration of response was 7 months (range 2-12+). Responses were observed both in visceral and in non-visceral sites of disease. Twenty-nine patients obtained a stabilization of disease (44.7%), and twenty-two progressed (33.8%). Median duration of stabilization was 4 months (range 3-13+). Median survival for all patients from the start of megestrol acetate was 9 months (range 1-22+). The most common side effect of therapy was weight gain, occurring in 36% of patients. Megestrol acetate on a single-daily-dose schedule can be considered as an interesting hormonal treatment for advanced breast cancer, especially in the clinical instance of patients who, after having obtained a remission or stabilization of disease with tamoxifen, need further palliative treatment.

Body Weight↗
PubMed1988

Reduced intolerance symptoms from lactose consumed during a meal.

Lactose digestion from and tolerance to lactose-containing beverages consumed with food was evaluated in 12 lactase-deficient subjects by breath-hydrogen techniques. Peak hydrogen production after a milk-based food supplement was delayed 2 h as compared with a lactose solution. Addition of a breakfast meal further delayed peak hydrogen production by 1 h. Hydrogen production was significantly lower (p less than 0.03) for the first 4 h after ingestion of the supplement plus meal compared with the supplement alone. Nine subjects experienced intolerance symptoms after consumption of the supplement alone but only three experienced them after consumption of the meal plus supplement. Severity of symptoms was significantly reduced with the ingestion of the supplement compared with an equal lactose load and was further reduced with the consumption of food, presumably due to delayed gastric emptying. Thus, lactose malabsorbers should consume food simultaneously with lactose-containing beverages to reduce intolerance symptoms.

Adult↗
PubMed1987

Lactose digestion by yogurt beta-galactosidase: influence of pH and microbial cell integrity.

Lactase-deficient subjects more effectively digest lactose in yogurt than lactose in other dairy products, apparently due to yogurt microbial beta-galactosidase (beta-gal) which is active in the GI tract. We evaluated the effects of buffering capacity of yogurt, gastric pH, and microbial cell disruption on beta-gal activity and lactose digestion. Three times more acid was required to acidify yogurt than to acidify milk. Yogurt beta-gal was stable at pH 4.0 but inactivated at lower pH. When yogurt was sonicated to disrupt microbial cell structure, only 20% activity remained after incubation at pH 4.0 for 60 min. In vivo gastric pH remained greater than 2.7 for 3 h after ingestion of yogurt. Acidified milk alone or with disrupted yogurt microorganisms caused twice as much lactose malabsorption as did acidified milk containing intact yogurt microorganisms. The results provide a possible explanation for the survival of beta-gal activity from yogurt in the GI tract.

Adult↗
PubMed1987

Lactose digestion from flavored and frozen yogurts, ice milk, and ice cream by lactase-deficient persons.

Lactose digestion from and tolerance to flavored and frozen yogurts, ice cream, and ice milk were evaluated (20 g lactose/meal) in lactase-deficient subjects by use of breath hydrogen techniques. Unflavored yogurt caused significantly less hydrogen production than milk (37 vs 185 delta ppm X h, n = 9). Flavored yogurt was intermediate (77 delta ppm X h). Subjects were free of symptoms after consuming flavored and unflavored yogurts. Of seven commercial yogurts tested, all contained significant levels of microbial beta-galactosidase (beta-gal). In addition, eight subjects were fed meals of milk, ice milk, ice cream, and frozen yogurts with and without cultures containing high levels of beta-gal. Peak hydrogen excretion after consumption of frozen yogurt with high beta-gal was less than one-half of that observed after the other five test meals and intolerance symptoms were absent. Tolerance to frozen yogurt, produced under usual commercial procedures, was found to be similar to that of ice milk and ice cream.

Adult↗