Search PubMed⌕ Search

Biomedical subjects

M M Meguid

Publications and source records attributed to M M Meguid.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Nutritional concepts and considerations in head and neck surgery.

Assessment and correction of malnutrition is a major contribution to the improvements in the pre- and postoperative management of patients with head and neck cancer over the past 20 years. These patients are often in a poor nutritional status and thereby are at a higher operative risk secondary to the local and systemic effects of the tumor and its treatment. This article reviews current data emphasizing preoperative nutritional assessment, modalities available for nutritional therapy in head and neck cancer patients, and indications for perioperative use of these modalities.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Home enteral nutrition via gastrostomy in advanced head and neck cancer patients.

We investigated whether home enteral feeding via a tube gastrostomy would enable patients with advanced malignant disease, who were unable to maintain themselves nutritionally via the oral route, to be independent of the hospital setting. Thirty-nine patients with advanced upper gastrointestinal and head and neck cancer had a tube gastrostomy placed. Before discharge, the patient was trained in the care and use of the gastrostomy feeding tube. Ten patients died of their disease before they could be discharged. During the 6-month period before gastrostomy insertion, the mean weight loss of the remaining 29 patients was 12.8%, and the mean body weight was less than 90% of ideal body weight. Prior to operation, the mean serum albumin and total lymphocyte count were 3.7 g/L and 1,087/mL, respectively. At discharge the mean caloric intake was 1.48 times resting energy expenditure. Home enteral nutrition was provided for a median of 94 days and resulted in stabilization of nutritional indices. During their median survival of 176 days, the 29 patients were admitted a total of 52 times. Twenty-eight percent of the patients were never re-admitted after gastrostomy and were adequately maintained at home, whereas 24% needed to be re-admitted once. Only 48% were re-admitted twice to assist in their nutritional management. Twenty patients received temporary home nursing services to aid in their transition. Four patients eventually resumed oral intake, and their feeding gastrostomies were removed.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy Intake↗
PubMedDate not supplied

Nicotine alters the usual reciprocity between meal size and meal number in female rat.

Tobacco smoking reduces appetite and body weight (BW). Cessation of smoking leads to hyperphagia and weight gain. Daily food intake (FI) is a function of meal number (MN) and meal size (MZ), i.e., FI=MNxMZ. Under normal conditions, the female Fischer rat has a periodic reciprocal fluctuation between MZ and MN corresponding to phase of estrous cycle. Wide fluctuations between MZ and MN compensate each other to keep FI constant. Nicotine (5 mg/kg BW/day) was infused via osmotic minipump for 7 days. Controls received saline. FI, MZ, and MN were measured by an Automated Computerized Rat Eater Meter. Nicotine significantly decreased BW and FI via a decrease in MZ without compensatory increase of MN. Nicotine cessation led to hyperphagia, normalizing BW loss via an increase in MZ, which exceeded a compensatory decrease in MN. Nicotine significantly prolonged the estrous cycle by an extension of proestrous phase. Nicotine significantly lengthened the intermeal interval (IMI), delaying the start of the next meal and simultaneously decreasing subsequent MZ. Stopping nicotine led to normalization of IMI and MZ. Data show that nicotine alters the usual reciprocal regulation between MZ and MN and leads to a prolongation of the estrous cycle.

Animals↗
PubMedDate not supplied

Gender differences in tumor-induced anorectic feeding pattern in Fischer-344 rats.

Gender differences of feeding pattern in normal male and female rats are well recognized. Differences in gender-related feeding patterns have also been established following a variety of experimental manipulations, such as hypothalamic lesions, nicotine infusion, and total parenteral nutrition administration. Anorexia is a common feature during tumor growth. The present study examined whether the feeding indices constituting the feeding patterns differed with the development of cancer anorexia in male and female rats. Sixteen male and 15 female Fischer-344 rats had their food intake (FI) and feeding indices, meal number (MN) and meal size (MZ), continuously measured by a computerized rat eater meter. Viable methylcholanthrene (MCA) sarcoma cells (10(6)) were inoculated subcutaneously in 10 male (M-TB) and 8 female (F-TB) Fischer rats, while the rest were controls and received an equal volume of vehicle. Tumor-bearing (TB) rats became anorectic by Day 18, when the weight of the tumor was approximately 8% of the total body weight (BW). A notable decrease in BW was observed in both M-TB and F-TB. A decrease in FI resulted from different feeding indices between male and female rats. In male rats, lower FI was due to a decrease in both MN and MZ. In female rats, lower FI was solely due to a decrease in MN. The data show that gender differences in feeding patterns, which are an external manifestation of biochemical changes in the brain, occur following development of cancer-related anorexia suggesting that besides other factors, cancer anorexia is also influenced by sex-related hormones.

Animals↗
PubMedDate not supplied

Effect of estradiol and progesterone on daily rhythm in food intake and feeding patterns in Fischer rats.

The product of meal number x meal size, over time, is food intake. Because estrogens modulate feeding activity via their action on the hypothalamus, and because there is a diurnal rhythm in the expression of cytoplasmic estrogen receptors and in estrogen binding activity, the present study examined the effects of ovariectomy and later hormone therapy on acute changes in body weight, and on the meal number-to-meal size relationship as reflected by food intake in the dark/light feeding patterns, in adult female rats in the intact state and after ovariectomy. Twelve female Fischer rats were randomized into ovariectomy and sham operation groups. A rat eater meter measured the feeding indexes for 15 days before and 25 days after ovariectomy, and later for 35 days with hormone therapy. We report: (a) mean body weight gain was linear before and up to ovariectomy, while exponential after ovariectomy; (b) increase in daily food consumption is mainly via an increase in food intake during the light phase; (c) light phase meal number remains unchanged, meal size significantly increases, with the resultant increase in overall food intake; (d) during the dark phase, meal size also significantly increases, but is accompanied by a proportional decrease in meal number, resulting in unchanged dark-phase food intake; and (e) estrogen restoration with either estradiol valerate or estradiol-progesterone combination, reversed the above changes. Data show that in the female Fischer 344 rat: (a) changes in daily rhythm in food intake are brought about by differential effects of the hormones on both meal size and meal number in both the total daily levels as well as in the dark-to-light distribution; (b) estadiol appears to have a tonic inhibitory effect on the light phase meal size and a phasic effect on the dark phase meal size and number, but no significant effect on the light-phase meal number; and (c) in the Fischer rats, progesterone augments estradiol's effect on these indicies.

Animals↗
PubMedDate not supplied

Differential feeding patterns induced by tumor growth and by TPN.

The effects of anorexia induced by early tumor, and anorexia induced by total parenteral nutrition (TPN) on food intake and the indexes of food intake, were investigated in rats infused with saline after jugular catheter placement and concomitant inoculation with methylcholanthrene (MCA)-induced tumor cells on day 0, and in rats without catheters receiving tumor only. Tumor became palpable around day 10 and increased to represent 6-8% of host body weight by day 26. On day 18, food intake started to decrease. Catheter-bearing rats were then randomized to saline controls (n = 9) for 11 d or to TPN-100 (n = 9) for 4 d providing 100% of daily caloric needs. Both then received saline until day 26. Food intake and feeding indexes were continuously measured using the Automated Computerized Rat Eater Meter (ACREM) and data was analyzed using ANOVA and regression analysis. In controls (both with and without catheter) the tumor induced a specific feeding pattern which consisted of a significant (P < 0.01) decrease in food intake via a significant (P < 0.05) decrease in meal size. A non-significant decrease in meal number and meal duration occurred. Two other feeding-related activities, meal consumption rate and intermeal sniffs, also decreased. Infusion of TPN-100 into the already anorectic rat led to a further significant (P < 0.0001) decrease in food intake via a significant decrease in both meal size (P < 0.0001) and in meal number (P < 0.0001). A decrease in all other feeding indexes also occurred, resulting in a different feeding pattern. After stopping TPN-100, the TPN-100-induced feeding pattern returned to that of the tumor-induced feeding pattern. That the tumor-induced feeding pattern differs from the TPN-100-induced feeding pattern suggests that the mechanisms whereby these two factors induce anorexia may also differ.

Animals↗
PubMedDate not supplied

First annual Arnar-Stone lecture: The importance of the endocrine and metabolic responses to shock and trauma.

Trauma and shock result in activation of a wide variety of endocrine and metabolic systems. Based upon experimental work demonstrating metabolic deficits, a variety of metabolic therapies have been developed to assist in the treatment of patients with shock or trauma. Evidence to date is inconclusive as to whether this therapy will be of significant benefit to critically ill patients. Some of the senior author's previous research has been analyzed as it relates to important health policy issues. We suggest that a peer review mechanism be set up within organized professional groups to assess major research trends and develop informed opinions on key research subjects within their domain. These peer review assessments must be effectively communicated to Congress and the executive branch of the government, as well as to the general public, if support commensurate with the importance of the research is to be achieved.

Hormones↗
PubMedDate not supplied

Reduced metabolic complications in total parenteral nutrition: pilot study using fat to replace one-third of glucose calories.

The limitations of glucose-based TPN solutions are high glucose concentration, high osmolality, lack of fat, and essential fatty acids, which result in glucose intolerance and hepatotoxic effects. We replaced one-third of the calories in a standard amino acid-glucose solution with Liposyn 10% for 14 days in 23 critically ill men who needed total parenteral nutrition. Serial measurements included weight, albumin, glucose, triglyceride concentrations, and liver function tests. Serum osmolality was calculated, and found to remain constant. Body weight and serum albumin were maintained. Minor changes occurred in hepatic enzymes which were physiologically insignificant. Glycosuria occurred in 15%. Adverse side effects of hypoglycemia, hyperosmolar coma, and hypertriglyceridemia were avoided. Our results show that the addition of fat reduced glucose and hepatic related metabolic complications.

Adult↗
PubMedDate not supplied

Pneumothorax following attempted nasogastric intubation for nutritional support.

Nasogastric intubation is a routine procedure, performed daily by both medical and nursing staff. It is a simple procedure, but not without complications which can be life threatening. We present an unusual, life threatening complication which occurred when nasogastric intubation using a no. 8 polyurethane tube with its metal stilet resulted in a pneumothorax after intubation of the endotracheal tree in the presence of a cuffed endotracheal tube. We emphasize that the presence of a cuffed endotracheal tube should not be considered a safeguard against pulmonary intubation during nasogastric placement of a feeding catheter.

Aged↗
PubMedDate not supplied

The effect of nutritional status on morbidity after elective surgery for benign gastrointestinal disease.

The effect of nutritional status on the morbidity and mortality of major gastrointestinal surgery for benign disease was studied in 32 patients. Malnutrition was defined as a serum albumin less than 3.5 g/dl and a recent weight loss greater than 10%, in addition to any two of the following: weight for height, midarm circumference or triceps skin-fold thickness less than 10th percentile. The morbidity and mortality in the 17 malnourished patients was 59% and 29%, respectively, compared with 20% and 7% in 15 well-nourished patients matched for age and operative procedure (p less than 0.05). After operation, the mean duration of inadequate oral nutritional intake period (IONIP, defined as a caloric intake greater than 60% requirement) was 11.9 days +/- 2.9 (SEM) in well-nourished patients compared with 30.5 days +/- 3.7 in the malnourished group. The longer IONIP in malnourished patients was a consequence of the higher morbidity in this group, thus warranting the consideration of supportive (postoperative) parenteral nutrition in malnourished patients who undergo major gastrointestinal surgery for benign disease.

Adolescent↗
PubMedDate not supplied

Plasma carotenoid profiles in normals and patients with cancer.

Most human cancers arise in epithelial tissues, which are critically dependent on vitamin A for normal differentiation and proliferation. Dietary carotenoids consist of individual retinoids--pro-vitamin A precursors and non-pro-vitamin A precursors-displaying different biological activity. Although epidemiological data suggest that low serum vitamin A levels were associated with an increased risk of cancer, it is not known whether one specific or all vitamin A carotenoids are involved. To assess whether the plasma carotenoids are related to the nutritional or cancer-bearing state, a study was conducted to measure total and individual carotenoids in four groups: cancer-bearing, malnourished; cancer-bearing, well-nourished; non-cancer, malnourished; and well-nourished volunteers of comparable age and sex. There was no difference in total carotenoids and pro-vitamin A precursors between the well-nourished--both normal volunteers and cancer patients. Malnourished cancer and non-cancer patients had significantly (p less than 0.05) lower value of both. Most of the circulating carotenoids in all groups were the non-pro-vitamin A precursors. Both malnourished cancer and non-cancer patients had lower values than well-nourished (p less than 0.05). Differences were related to nutritional state, rather than presence of cancer.

Adult↗