Biomedical subjects

Michael Horowitz

Publications and source records attributed to Michael Horowitz.

101 records · Page 6Linked to original sources

PubMed2002

Glycemic, hormone, and appetite responses to monosaccharide ingestion in patients with type 2 diabetes.

To investigate the relative effects of fructose and glucose on blood glucose, plasma insulin and incretin (glucagon-like peptide-1 [GLP-1] and gastric inhibitory peptide [GIP]) concentrations, and acute food intake, 10 (6 men, 4 women) patients with diet-controlled type 2 diabetes (diabetic) (44 to 71 years) and 10 age and body mass index (BMI)-matched (6 men, 4 women) nondiabetic, control subjects with varying degrees of glucose tolerance (nondiabetic), were studied on 3 days. In random order, they drank equienergetic preloads of glucose (75 g) (GLUC), fructose (75 g) (FRUCT) or vehicle (300 mL water with noncaloric flavoring [VEH]) 3 hours before an ad libitum buffet lunch. Mean glucose concentrations were lower after FRUCT than GLUC in both type 2 diabetics (FRUCT v GLUC: 7.5 +/- 0.3 v 10.8 +/- 0.4 mmol/L, P <.001) and nondiabetics (FRUCT v GLUC: 5.9 +/- 0.2 v 7.2 +/- 0.3 mmol/L, P <.05). Mean insulin concentrations were approximately 50% higher after FRUCT in type 2 diabetics than in nondiabetics (diabetics v nondiabetics: 23.1 +/- 0.7 v 15.1 +/- 1.3 microU/mL; P <.0001). Plasma GLP-1 concentrations after fructose were not different between type 2 diabetics and nondiabetics (P >.05). Glucose, but not FRUC, increased GIP concentrations, which were not different between type 2 diabetics and nondiabetics (P >.05). Food intake was suppressed 14% by GLUC (P <.05 v CONT) and 14% by FRUC (P <.05 v CONT), with no difference between the amount of food consumed after GLUC and FRUC treatment in either type 2 diabetics or nondiabetics (P >.05). We have confirmed that oral fructose ingestion produces a lower postprandial blood glucose response than equienergetic glucose and demonstrated that (1) fructose produces greater increases in plasma insulin concentration in type 2 diabetics than nondiabetics, not apparently due to greater plasma incretin concentrations and (2) fructose and glucose have equivalent short-term satiating efficiency in both type 2 diabetics and nondiabetics. We conclude that on the basis of improved glycemic control, but not satiating efficiency, fructose may be useful as a replacement for glucose in the diet of obese patients with type 2 diabetes.

Adult↗

PubMed2002

Microvascular decompression in the management of glossopharyngeal neuralgia: analysis of 217 cases.

OBJECTIVE: Glossopharyngeal neuralgia (GPN) is a rare condition that often presents with the seemingly benign symptom of deep throat pain. Medical management of this condition has not been very effective, and surgical therapy has ranged from nerve sectioning to microvascular decompression (MVD). We present our experience with more than 200 patients who underwent MVD for treatment of GPN at our institution. METHODS: We conducted a retrospective review of our database and identified patients who presented for treatment of presumed GPN. When possible, patients were contacted by telephone for collection of follow-up information regarding symptom relief, complications, functional outcomes, and patient satisfaction. Univariate and multivariate analyses were performed to identify predictors of good outcomes after MVD. Subgroup analyses were performed with quartiles of approximately 50 patients each, for assessment of the effects of improvements in techniques and anesthesia during this 20-year period. RESULTS: We observed GPN to be more common among female (66.8%) than male (33.2%) patients, with an overall mean patient age of 50.2 years (standard deviation, 14.4 yr). The most common presenting symptoms were throat and ear pain and throat pain alone, and the mean duration of symptoms was 5.7 years (standard deviation, 5.8 yr; range, 1-32 yr). Symptoms appeared almost equally on the left side (54.8%) and the right side (45.2%). The overall immediate success rate exceeded 90%, and long-term patient outcomes and satisfaction were best for the typical GPN group (with pain restricted to the throat and palate). Complication rates decreased across quartiles for all categories evaluated. CONCLUSION: MVD is a safe, effective form of therapy for GPN. It may be most beneficial for patients with typical GPN, especially when symptoms are restricted to deep throat pain only.

Adult↗

PubMed2002

Misinterpretation of parahippocampal herniation for a posterior fossa tumor: imaging and intraoperative findings.

Tumors of the hippocampal and parahippocampal gyrus are not uncommon, nor are lesions of the cerebellopontine and ambient cisterns. Lesions in these areas include astrocytomas, meningiomas, gangliogliomas, hamartomas, neurilemomas, epidermoids, and dermoids. Preoperative imaging is an important tool that can help distinguish lesions, making surgical therapy more targeted and appropriate. The authors report a case of a 41-year-old man with right-sided atypical trigeminal neuralgia and a left ambient cistern abnormality that was radiologically interpreted as a mesial temporal lobe or extramedullary ambient cistern mass lesion. Surgical exploration for biopsy revealed an abnormal posterior fossa anatomy and a parahippocampal herniation into the perimesencephalic cistern. Biopsy confirmed the finding of normal brain.

Adult↗

PubMed2002

Effects of exogenous corticotropin-releasing factor on antropyloroduodenal motility and appetite in humans.

OBJECTIVES: Corticotropin-releasing factor (CRF) has been shown to affect GI motor function and appetite in animals. We have evaluated the effects of exogenous CRF on antropyloroduodenal motility and appetite in humans. METHODS: On 2 separate days, six healthy volunteers received, in randomized, double-blind fashion, i.v. CRF as a 1.0-microg/kg bolus (0-5 min) followed by a constant infusion (1.0 microg/kg/h) (5-150 min), or an identical volume of saline. At t = 28 min each subject drank 200 ml of a nutrient liquid containing 20 mg/kg of paracetamol. Antropyloroduodenal pressures were measured with sleeve/sidehole manometry and perceptions of appetite by visual analog scales. Venous blood was obtained for measurements of serum cortisol and paracetamol. At t = 150 min the manometric catheter was removed and subjects offered a buffet meal (150-180 min). The amount and macronutrient content of food consumed were quantified. RESULTS: CRF increased serum cortisol (p < 0.001), the number of isolated pyloric pressure waves (p < 0.05), duodenal pressure waves (p < 0.05), and the percentage of antegrade duodenal pressure waves (p < 0.05). CRF had no significant effect on the number of antral pressure waves, basal pyloric pressure, serum paracetamol concentrations, perceptions of appetite, or food intake. CONCLUSIONS: Intravenous CRF stimulates phasic pyloric and duodenal pressure waves in humans.

Acetaminophen↗

PubMed2002

GI symptoms in diabetes mellitus are associated with both poor glycemic control and diabetic complications.

OBJECTIVE: Diabetes mellitus is associated with an increased prevalence of GI symptoms, but the mechanisms underlying symptoms are poorly defined and controversial. We aimed to determine whether there is a relationship between GI symptoms and both diabetic complications and glycemic control. METHODS: We performed a cross-sectional questionnaire study of 1101 subjects with diabetes mellitus recruited from outpatient clinics (n = 209) and the community (n = 892). Data on eight GI symptom groups, complications of diabetes (retinopathy, neuropathy, nephropathy), and self-reported glycemic control were obtained from a validated questionnaire. Glycated hemoglobin was measured in 463 of the subjects, The association between diabetic complications, glycemic control, and GI symptoms was assessed using logistic regression analysis, adjusted for demographic and clinical factors. RESULTS: Of the 1101 subjects, 57% reported at least one complication. Diabetic complications were independently associated with both symptom complexity (number of symptom groups reported) (adjusted odds ratio = 1.92 per symptom group [95% CI = 1.51-2.45]) and seven of the eight GI symptom groups. For all symptom groups, the association was explained by self-reported symptoms of peripheral neuropathy. Poor glycemic control measured by both self-report and Hb A1c was an independent risk factor for upper GI symptoms, whereas other potential risk indicators, including duration and type of diabetes, were not significant. CONCLUSIONS: GI symptoms in diabetes mellitus may be linked to diabetic complications, particularly peripheral neuropathy, and to poor glycemic control.

Adult↗

PubMed2002

Predictors of turnover of lower gastrointestinal symptoms in diabetes mellitus.

BACKGROUND: Both the natural history of GI symptoms and factors influencing symptom turnover in diabetes mellitus are unknown. We aimed to determine the natural history of GI symptoms in diabetes mellitus over a 3-yr period. METHODS: Subjects with predominantly Type 2 diabetes on the mailing list of Diabetes Australia were recruited and completed a validated questionnaire (n = 892); of these, 64% completed the questionnaire again 3 yr later. Subjects were classified as never having GI symptoms (abdominal pain, constipation, diarrhea, fecal incontinence), fluctuating (only on one survey), or persistent symptoms. RESULTS: Symptoms more often fluctuated than persisted, but the prevalence at recruitment and 3 yr later was similar. Predictors of symptom turnover varied. In a multivariate model, abnormal sweating and diabetic foot problems predicted symptom turnover for abdominal pain (OR = 2.01, 95% CI = 1.07-3.76 and 2.54, 1.23-5.24, respectively), and paresthesiae ("pins and needles") and foot problems predicted fecal incontinence (OR = 2.24, 1.06-4.75 and 2.38, 1.04-5.45, respectively), but not constipation or diarrhea. Symptom turnover in constipation was associated with depression (OR = 2.73, CI = 1.89-3.94) and neuroticism (OR = 0.57, CI = 0.36-0.89), and depression was associated with abdominal pain (OR = 1.56, CI = 1.02-2.38), but psychological factors were not related to the other symptoms. The odds for symptoms persisting were not generally related to type or duration of diabetes, or self-rated glycemic control. CONCLUSION: The natural history of GI symptoms in diabetes has been described for the first time; symptoms may either persist or fluctuate, but the prevalence is constant because symptom onset is balanced by disappearance. Glycemic control does not seem to predict symptom change.

Chronic Disease↗

PubMed2002

Relationship between the effects of cisapride on gastric emptying and plasma glucose concentrations in diabetic gastroparesis.

BACKGROUND/AIMS: The effect of erythromycin on gastric emptying is attenuated during hyperglycaemia. The aim of this study was to determine in patients with diabetic gastroparesis whether the effect of cisapride on gastric emptying of solids and liquids is influenced by the plasma glucose concentration. METHODS: Nineteen patients with type 1 diabetes mellitus, who had delayed gastric emptying of solids and/or liquids, were studied. On 2 separate days, each patient received cisapride (20 mg) or placebo orally 60 min before scintigraphic measurement of gastric emptying of a mixed solid (ground beef) and liquid (dextrose) meal. The plasma glucose concentrations were measured at -5, 30, 60, 90, and 120 min during each gastric emptying measurement. RESULTS: Cisapride accelerated both solid (retention at 100 min 43 +/- 4 vs. 69 +/- 4%, p < 0.001) and liquid (T50 27 +/- 2 vs. 39 +/- 2 min, p < 0.001) gastric emptying. The mean plasma glucose level was not significantly different after placebo when compared with cisapride (19.5 +/- 1.1 vs. 18.2 +/- 1.0 mmol/l). The change in the 50% emptying time (T50) for liquid, but not solid, emptying was related (r = 0.55, p = 0.01) to the change in the plasma glucose AUC from 0 to 30 min between the placebo and cisapride tests, i.e., the acceleration was greater if the plasma glucose concentration was relatively less during the gastric emptying test performed on cisapride. CONCLUSION: The effect of cisapride on gastric emptying, at least that of liquids, in patients with diabetic gastroparesis appears to be dependent on the plasma glucose concentration.

Adult↗

PubMed2002

Carbohydrate and satiety.

This review focuses on what is known about the effects of carbohydrate on food intake, the potential mechanisms mediating these effects, and the impact of different monosaccharides in humans. The inhibition of subsequent food intake associated with ingestion of carbohydrate appears to result primarily from gastrointestinal signals, including those generated by orosensory stimulation, gastric distension, and perhaps most importantly the interaction of nutrients with receptors in the small intestine. The latter is associated with the release of putative satiety hormones, including glucagon-like peptide-1 and amylin, and slowing of both gastric emptying and small intestinal transit (thereby prolonging gastric distension and increasing the time available for nutrient absorption). The effects of carbohydrate on food intake are dependent on the route of administration (i.e., oral, intragastric, or intraduodenal). Changes in blood glucose and insulin concentrations per se probably do not play a major role in the induction of satiety. Studies relating to the comparative effects of different monosaccharides/carbohydrates have yielded inconclusive results, probably in part owing to substantial differences in methodological approaches.

Animals↗

PubMed2002

Temporary balloon occlusion and ethanol injection for preoperative embolization of carotid-body tumor.

We report on the preoperative embolization of a carotid-body paraganglioma by temporary balloon occlusion and ethanol injection. Complete devascularization was achieved without complication. Resection after a short postembolization interval required artery sacrifice. Histologic evaluation revealed that the tumor contained diffuse ethanol-induced microemboli. Compared with unembolized and polyvinyl-alcohol-embolized carotid-body paragangliomas, our technique resulted in no greater adverse effects on the tumor-vessel interface. This procedure is an effective and promising method of preoperative embolization of carotid-body tumors and warrants further experience and study. In this article, we also review the literature on carotid-body tumor embolization and ethanol embolization.

Adult↗

PubMedDate not supplied

Delayed complications of endovascular stenting for carotid blowout.

Endovascular stents are used in a wide variety of situations including management of acute hemorrhage from a carotid artery blowout. The long-term efficacy of these devices in this setting has not been elucidated. Two cases of carotid stenting for carotid artery blowouts in the face of cervical malignancy and overlying infection were followed over time. In both patients, initial control of carotid bleeding was followed by delayed stent-related complications. Although carotid stents are useful for control of acute carotid blowouts, their long-term efficacy in the setting of head and neck malignancy and overlying infection is suspect.

Aged↗

PubMedDate not supplied

De novo development of a remote arteriovenous fistula following transarterial embolization of a carotid cavernous fistula: case report and review of the literature.

We report a case of a patient who developed a remote dural arteriovenous fistula involving the left sigmoid sinus 4 months after successful transarterial embolization of a carotid cavernous fistula. This rare occurrence has been reported after transvenous embolization, but this represents the first case, to our knowledge, after transarterial coil embolization. We present our findings along with a brief review of the literature.

Carotid Artery, External↗