Biomedical subjects

M C Martini

Publications and source records attributed to M C Martini.

At least 19 recordsLinked to original sources

PubMed1998

The spatial distribution of visual attention in hemineglect and extinction patients.

We studied the visual field distribution of speed and accuracy of manual responses to small brief light flashes, in patients with left hemineglect or extinction resulting from right hemisphere vascular lesions and in brain-damaged and healthy control subjects. All patients with right hemisphere lesions showed a greater impairment in both the speed of response and the detection rate in the contralesional than in the ipsilesional hemifield. This interfield difference increased with the eccentricity of stimulus presentation and was especially pronounced in neglect patients who showed a paradoxical increase in speed of response and detection rate at increasingly larger eccentricities in the ipsilesional hemifield. We hypothesize that both the contralesional slowing down and the ipsilesional speeding up of the response depends upon an exaggerated gradient of attention towards the ipsilesional hemifield. To assess whether these abnormalities concern automatic or controlled attentional processes, in a second experiment, we manipulated the predictability of the side of the stimulus presentation by using blocked rather than randomized stimulus presentations. This resulted in a speeding up of responses in both hemifields thus showing that the patients were able to focus attention to the side of stimulus presentation voluntarily. However, there was no modification of the contra-ipsilesional differences which, therefore, are likely to be related to abnormal automatic processes rather than controlled attention.

Aged↗

PubMed1998

Consumption of exogenous bifidobacteria does not alter fecal bifidobacteria and breath hydrogen excretion in humans.

The hypothesis that consumption of bifidobacteria by humans would increase colonic bifidobacteria and decrease breath hydrogen excretion was examined. A commercially available strain of bifidobacteria was tracked through the gastrointestinal tract. We determined that a 12-d feeding period of 10(10) cells of exogenous bifidobacteria daily was adequate to achieve a stable number of exogenous bifidobacteria in the colon. A 12-d washout period was chosen because the exogenous bifidobacteria could no longer be detected at that time. A double-blind crossover study used both male and female subjects. The order of treatment with skim milk alone or skim milk + bifidobacteria was randomized. Breath hydrogen excretion (micromol/L) and fecal counts of total bifidobacteria [log colony forming units (CFU)/g feces] were not significantly different between males and females and were not affected by consumption of exogenous bifidobacteria. Calculations based on the numbers of exogenous bifidobacteria consumed and the fecal numbers of exogenous bifidobacteria excreted suggested that numbers of the exogenous strain increased within the gastrointestinal tract. These data suggest that it is difficult to permanently alter total colonic bifidobacteria and affect physiologic function (net hydrogen in the colon as reflected by breath hydrogen) by feeding bifidobacteria, although the percentage of the total bifidobacteria represented by the exogenous strain can be affected.

Administration, Oral↗

PubMed1997

Cholesterol-lowering effects of modified animal fats in postmenopausal women.

OBJECTIVE: In an attempt to improve the nutritional value of animal fats (including milkfat and lard), two technological approaches (i.e., cholesterol removal by steam distillation and linoleic acid enrichment by addition of safflower oil) were tested for cholesterolemic effects in a cohort of 29 older women (age 68 +/- 7 years). METHODS: Test fat sources were incorporated into crackers, cookies, cheese, ice cream, whipped topping, sour cream, baking shortening, and table spreads. Subjects were permanent residents of a convent where meals were prepared in a centralized kitchen, allowing test fats to be provided in daily food menu items. The foods containing test fats were introduced into three sequential dietary treatment periods, each lasting 4 weeks, in the following order: cholesterol-reduced animal fat (CRAF): fatty-acid modified, cholesterol-reduced animal fat (FAMCRAF); and-unaltered animal fat (AF). Subjects were offered menu items cafeteria style and encouraged to make food selections consistent with their habitual diets, which were recorded daily. RESULTS: Fasted blood lipid profiles determined at the end of each treatment period showed that FAMCRAF reduced mean plasma total cholesterol, LDL cholesterol, and apolipoprotein B concentrations relative to AF (p < 0.05). Mean HDL cholesterol concentrations were not influenced by diet. DISCUSSION: Relative to native products, animal fats modified by cholesterol removal and linoleic acid enrichment reduced plasma total and LDL cholesterol concentrations in a predictable manner similar to that based on studies of men.

Aged↗

PubMed1996

Implicit redundant-targets effect in visual extinction.

Patients with left visual extinction as a result of unilateral right hemisphere damage were tested on a redundant-targets effect paradigm (RTE). LED-generated brief flashes were lateralized either to the left or to the right visual hemifield or presented bilaterally. Subjects were asked to press a key as fast as possible following either unilateral or bilateral stimuli and immediately afterwards to report on the number of stimuli presented. As previously found in normal subjects, bilateral stimuli were responded to faster than unilateral ones, and this was evidence of a RTE. The main thrust of this study was that extinction patients showed a RTE not only for correctly perceived bilateral stimuli but also in trials in which they extinguished the stimulus on the field contralateral to the lesion. This result is compatible with a preserved processing of the extinguished input at least up to the stage at which it may interact with the input from the normal side to yield a speeded motor response. Interestingly, the implicit redundancy gain of extinction patients was found to fit a coactivation (i.e. neural) rather than a probabilistic model.

Aged↗

PubMed1996

Input and response determinants of visual extinction: a case study.

We have studied a patient, CZ, with contralateral visual extinction due to a large ischaemic frontal-parietal-temporal lesion in the right hemisphere. We found that manipulation of intensity of the visual stimulus had little effect while an increase in eccentricity substantially increased extinction rate. An important factor was represented by the hemifield of stimulus presentation: when double stimuli were presented to the contralesional (left) hemifield, the leftmost stimulus was consistently extinguished while when stimuli were presented to the ipsilesional (right) hemifield, extinction was absent. Such effect was specific to hemifield rather than to head- and trunk-defined hemispace. Manipulation of response-related variables affected extinction to a large extent: In particular, the use of nonverbal responses diminished extinction considerably. This suggests that an important component of extinction may be represented by an impaired access of visual information to the left hemisphere. Finally, the RT results confirmed previous evidence of an ipsilesional attentional bias favouring the rightmost stimuli both in the contralesional and in the ipsilesional hemifield.

Brain Ischemia↗

PubMed1996

Oral tramadol and buprenorphine in tumour pain. An Italian multicentre trial.

In this multicentre trial tramadol and buprenorphine were compared for the treatment of neoplastic pain no longer responsive to non-steroidal antiinflammatory drugs. A total of 131 adults (86 M, 45F) were treated with tramadol (one 100-mg slow-release tablet every 8-12 h), or buprenorphine (one sublingual 0.2-mg tablet every 6-8 h). The trial was to continue for up to six months. Most patients started treatment with 2-3 tablets/day in both groups, and the mean treatment period was 58 days for tramadol and 51 for buprenorphine. Almost all dose changes needed were made in the first fortnight in both treatment groups, and the largest number of patients dropped out because of inadequate pain relief or progression of the underlying disease. The results achieved in the first two weeks persisted throughout the rest of the trial, and the investigator's assessments on each patient's clinical chart corresponded closely with those that patients made in their own daily diaries. In the four hours after the first dose both drugs virtually halved the severity of pain (measured using a visual analogue scale), and this relief lasted throughout treatment. By the end of the first week the proportion of patients with strong/unbearable pain in the tramadol group had fallen significantly (from 98.4% to 48.1%, p < 0.05), as compared to a drop from 92% to 66.7% for buprenorphine. The quality of sleep also tended to improve in the tramadol group, with the proportion of patients enjoying good or deep sleep rising from 37% to 50%, as compared to 33% to 40-44% with buprenorphine. Karnofsky's and Spitzer's indices reflecting the quality of life did not change in the tramadol group; in the buprenorphine group the Karnofsky index dropped slightly after a fortnight (p < 0.05 between treatments). In the first two months of the trial the number of patients with no/moderate pain rose continuously in the tramadol group (71% and 80% after one and two months); the rise was less marked in the buprenorphine group (number of patients with mild/moderate pain, 45% and 65%). In both the short term and in the longer term, it was found that the levels of efficacy and acceptability were always significantly better in the tramadol group than in the buprenorphine group. General and biological safety in both drugs was good. The most typical side-effects were those characteristic of opioids (nausea and/or vomiting, drowsiness). Adverse reactions were reported in 17 patients taking tramadol (25%) and in 16 taking buprenorphine (26%). There were six drop-outs in the first group (9%) and seven in the second (11%). Serious symptoms arose more frequently in the buprenorphine group (19% cf. 10%). No signs of dependence or tolerance were noted.

Adult↗

PubMed1995

The University of Minnesota Cancer Prevention Research Unit vegetable and fruit classification scheme (United States).

High vegetable and fruit (V&F) intake has been associated with a lower risk of many cancers. However, the specific V&F, the active compounds present in V&F, and the dose at which they confer protection are unknown. Standard methods for assessing, classifying, and quantifying V&F exposures in epidemiologic studies have not been established. Differences among studies occur due to inherent differences among V&F, and across dietary assessment methods, study populations, etiologic hypotheses, and analytic methods. The V&F classification scheme presented here characterizes and quantifies V&F consumption for elucidating risk relationships, identifying chemopreventive compounds present in V&F, and facilitating identification of potential biomarkers of V&F intake. Broad criteria define which plant foods count as V&F. Formation of food groups is based on proposed biological mechanisms of action. Five main groups are included: Total V&F; Total Vegetables; Total Fruits; and two groups orthogonal to these -- the Botanical and Phytochemical groups. Subgroups are specified within each main group. V&F exposure is quantified as the absolute amount consumed (weight) or as the number of household servings. This classification scheme has public health applications and may be used to examine associations with chronic diseases other than cancer.

Eating↗

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↗