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Biomedical subjects

M Shapiro

Publications and source records attributed to M Shapiro.

At least 19 recordsLinked to original sources
PubMed2007

Assessment of dietary nutrients that influence perception of intra-oesophageal acid reflux events in patients with gastro-oesophageal reflux disease.

BACKGROUND: Gastro-oesophageal reflux disease symptoms are most commonly reported postprandially, suggesting that some diet components are likely to induce symptoms more than others. AIMS: To determine which of the various dietary nutrients is a strong predictive factor for symptom generation in association with an acid reflux event. METHODS: Subjects with typical heartburn symptoms were evaluated by the gastro-oesophageal reflux disease Symptom Checklist, demographics questionnaire, upper endoscopy and pH testing. During the pH study, patients completed a detailed 24-h dietary intake record. This included time of meals, description of food components and the amount and type of food preparation. RESULTS: Fifty gastro-oesophageal reflux disease patients completed all stages of the study. A total of 112 (78%) symptoms were considered as sensed reflux event. Body mass index did not correlate with having perceived reflux. Patients who consumed more cholesterol, saturated fatty acids and had more percentage calories from fat were significantly more likely to experience a perceived reflux event. Regression analysis and beta-coefficient were specifically significant for cholesterol. CONCLUSION: Of all dietary nutrients, cholesterol enhances the most the perception of intra-oesophageal acid reflux events in patients with gastro-oesophageal reflux disease.

Adult↗
PubMed2006

Phase I trial of oral MAC-321 in subjects with advanced malignant solid tumors.

PURPOSE: MAC-321 is a novel taxane that has demonstrated exceptional activity in human xenograft models when administered intravenously and orally. Preclinical studies of MAC-321 have shown antitumor activity in MDR-expressing and paclitaxel-resistant tumors. This phase I dose escalation study was performed to determine the safety, tolerability, and pharmacokinetic profile of orally administered MAC-321 given once every 21 days. Preliminary antitumor activity of MAC-321 was also examined. METHODS: Key eligibility criteria included adult subjects with refractory solid tumors or solid tumors for which conventional therapy was unsuitable or did not exist, good performance status (ECOG ( 2), and adequate hematologic, hepatic, and renal functions. Plasma pharmacokinetic (PK) sampling was performed during the first cycle of therapy. RESULTS: Five dose levels of MAC-321 ranging from 25 to 75 mg/m(2) were evaluated in 18 subjects (four women and 14 men). MAC-321 was well tolerated at the first three dose levels (25, 37, 50 mg/m(2)). Two subjects developed dose-limiting toxicities (DLTs) at 75 mg/m(2); one subject with grade 3 and one subject with grade 4 neutropenia with fever. Three subjects treated at an intermediate dose level of 60 mg/m(2) had no DLTs. However, the study was terminated prior to completion of the maximal tolerated dose cohort after subjects treated with intravenous MAC-321 in a concurrent study experienced life-threatening toxicities. Other common toxicities included grades 1-2 fatigue and grades 1-2 diarrhea. There was substantial interpatient variability in the PK parameters. MAC-321 was rapidly absorbed with a mean C (max) value of less than 1 h. Mean C (max) and AUC values generally increased in a dose-related manner. The median terminal phase elimination half-life was 45 h (range 20-228 h). Disease stabilization was seen in four subjects with the following tumors: mesothelioma (14 cycles), chondrosarcoma (12 cycles), small cell carcinoma (10 cycles), and prostate carcinoma (6 cycles). CONCLUSIONS: MAC-321 can be safely administered orally once every 21 days up to a dose of 60 mg/m(2). The major DLT was neutropenic fever. Four subjects had disease stabilization.

Administration, Oral↗
PubMed2006

Quantum control of internal conversion in 24-vibrational-mode pyrazine.

Quantum control of the S(2)-->S(1) internal conversion in a complete 24-mode dimensionality model of pyrazine is demonstrated. The fully quantum mechanical study makes use of the recently developed "QP algorithm" for performing accurate computations of projected quantum dynamics and the role of overlapping resonances in control. The results are extremely encouraging, demonstrating active control over internal conversion so as to almost completely suppress the process over time scales of approximately 50-100 fs [well in excess of the natural internal conversion times (approximately 20 fs)] or to accelerate it to complete internal conversion in less than 5 fs. A number of new diagnostics are introduced to demonstrate the significance of overlapping-resonance contributions to control. Control is far better than for a reduced dimensionality model of pyrazine, presumably because of the increased degree of overlap between bound state resonances existing in the full dimensionality case.

Journal Article↗
PubMed2006

Turbulent inertial gelation and acoustic quasi-gelation of submicron aerosol particles.

Inertial turbulent and acoustic orthokinetic particle coagulation mechanisms have physical similarity. We consider analytically and numerically coagulation of discrete compact and fractal submicron agglomerated particles, governed by these mechanisms via Smoluchowski equation. Existence of the inertial turbulent coagulation is mathematically proven. A new gelation scenario is revealed for both of the above coagulation mechanisms. Turbulent inertial gelation is manifested by means of a multi-modal relay-type run-away particle size growth, including formation of infinite set of secondary maxima in volume fraction distribution. When acoustic coagulation mechanism is much stronger than the Brownian coagulation, acoustic coagulation occurs as a quasi-gelation process, with a run-away particle size growth, characterized, however, by a finite set of secondary maxima. The effect of acoustic field on coagulation is shown to be more pronounced for fractal agglomerates than that for compact agglomerated particles.

Journal Article↗
PubMed2006

The extent of oesophageal acid exposure overlap among the different gastro-oesophageal reflux disease groups.

BACKGROUND: Studies have demonstrated that patients with Barrett's oesophagus have the highest oesophageal acid exposure profile, followed by erosive oesophagitis and non-erosive reflux disease patients, but the exact extent of overlap remains unknown. AIM: To determine the extent of overlap in oesophageal acid exposure among the different gastro-oesophageal reflux disease groups. METHODS: A total of 121 patients with gastro-oesophageal reflux disease underwent an upper endoscopy and were classified as having Barrett's oesophagus, erosive oesophagitis and non-erosive reflux disease-all (non-erosive reflux disease-positive and functional heartburn). Subsequently, patients underwent pH testing and overlap in oesophageal acid exposure among the different gastro-oesophageal reflux disease groups was determined. RESULTS: Of those enrolled, 24 had Barrett's oesophagus, 30 erosive oesophagitis and 28 were non-erosive reflux disease-positive. Mean oesophageal acid exposure time was 224.8 +/- 35, 134.3 +/- 21.9 and 141.3 +/- 19.8 min for Barrett's oesophagus, erosive oesophagitis and non-erosive reflux disease-positive respectively. Per cent overlap for total, upright and supine time between non-erosive reflux disease-positive and erosive oesophagitis was 47.4%, 64.7% and 81.8%, between Barrett's oesophagus and erosive oesophagitis was 47.8%, 40.7% and 24%, and between Barrett's oesophagus and non-erosive reflux disease-positive was 31.6%, 37.5% and 20.8% respectively. CONCLUSIONS: Our study demonstrated a high oesophageal acid exposure overlap between patients with non-erosive reflux disease-positive and erosive oesophagitis, Barrett's oesophagus and erosive oesophagitis, as well as Barrett's oesophagus and non-erosive reflux disease-positive patients.

Adult↗
PubMed2006

Acute and chronic brain infarcts on MR imaging in a 20-year-old woman with acute posterior multifocal placoid pigment epitheliopathy.

A 20-year-old woman recently diagnosed with acute posterior multifocal placoid pigment epitheliopathy developed headaches, weakness, and paresthesias. MR imaging of the brain revealed an acute infarct (demonstrated by diffusion-weighted images) in the head of the right caudate nucleus, a chronic infarct with encephalomalacia in the body of the corpus callosum, and multiple foci of abnormal signal intensity in the white matter of the centrum semiovale.

Acute Disease↗
PubMed2005

Porous agglomerates in the general linear flow field.

We calculate the flow within and around a porous spherical agglomerate suspended in the general linear flow field, and also the flow induced by its rotation. We use the Stokes equations exterior to the particle and the Brinkman equations inside it. The effect of particle permeability on the flow is expressed via the Brinkman parameter beta = r(0)/square root of k, where r0 is particle radius and k is its permeability. With translational creeping motion of porous spheres in a quiet fluid investigated by Debye and Bueche [P. Debye, A.M. Bueche, J. Chem. Phys. 16 (6) (1943) 573-579], this study provides information necessary for investigating dynamics of porous particles moving in creeping shear flows under the action of external forces and torques. The agglomerate flow field solutions are used to calculate the effective viscosity of a dilute suspension of porous solid aggregates, which generalizes the well-known Einstein's equation for solid suspensions. The agglomerate effective viscosity diameter is proposed which allows using the Einstein's formula evaluation of the agglomerates suspension viscosity.

Journal Article↗
PubMed2005

Scaling in activated escape of underdamped systems.

Noise-induced escape from a metastable state of a dynamical system is studied close to a saddle-node bifurcation point, but in the region where the system remains underdamped. The activation energy of escape scales as a power of the distance to the bifurcation point. We find two types of scaling and the corresponding critical exponents.

Journal Article↗
PubMed2005

Systematic review: proton-pump inhibitor failure in gastro-oesophageal reflux disease--where next?

Proton-pump inhibitor failure has become a common clinical dilemma in gastrointestinal clinics and has been increasingly encountered at the primary care level as well. Underlying mechanisms are diverse and may overlap. Most patients who have proton-pump inhibitor failure are likely to originate from the non-erosive reflux disease phenotype. Currently, available diagnostic modalities provide limited clues to the exact underlying cause. Treatment relies primarily on escalating dosing of proton-pump inhibitors. However, new insights into the pathophysiology of proton-pump inhibitor failure are likely to provide alternative therapeutic options.

Biological Availability↗
PubMed2005

Mobility of permeable fractal agglomerates in slip regime.

Hydrodynamic drag and mobility of fractal aggregates in the slip creeping flow regime are calculated. A theoretical continuum model of the gas slip flow past and within agglomerates is developed. It accounts for effects of flow rarefaction and porous fractal structure upon the molecular mean free path, apparent viscosity, and effective permeability of agglomerates. It is shown that flow rarefaction significantly diminishes the aggregates' drag to an extent that cannot be predicted by the Cunningham's drag correction factor. The developed model allows calculation the agglomerates' transport properties in a wide range of fractal dimensions. For low D(f) agglomerates the drag force agrees with the Friedlander's expression based on the Epstein's single sphere drag in the free molecular regime.

Journal Article↗
PubMed2005

Enlarged mesenteric lymph nodes in asymptomatic children: the value of the finding in various imaging modalities.

The purpose of this study was to determine the prevalence of enlarged mesenteric lymph nodes in asymptomatic children. We prospectively studied 189 consecutive asymptomatic children from the outpatients' nephrological clinics who were referred for abdominal ultrasound. For comparison, we retrospectively reviewed the abdominal CT studies of 99 children, performed following blunt abdominal trauma. The children of both groups were divided into four subgroups according to their ages. The size, the number and the morphology of mesenteric lymph nodes were assessed. On abdominal ultrasound, enlarged mesenteric lymph nodes were detected in 55 of 189 asymptomatic children (29.1%). The longitudinal diameter of the lymph nodes ranged between 5 mm and 19 mm. These lymph nodes were arranged in clusters (three to nine in number in a cluster). All the lymph nodes were oval-shaped, flattened, and without any discomfort following graded transducer compression. On abdominal CT, enlarged mesenteric lymph nodes were diagnosed in 28 of the 99 children (28.3%). These lymph nodes measured more than 5 mm and were arranged in clusters (three or more in number). In seven of these children associated minimal mural thickening of the terminal ileum was seen. The presence of enlarged mesenteric lymph nodes in asymptomatic children of all ages and in both sexes is a common, non-specific finding and should be evaluated only in the appropriated clinical context.

Adolescent↗
PubMed2003

Quantitative expression analysis of a Glyptapanteles indiensis polydnavirus protein tyrosine phosphatase gene in its natural lepidopteran host, Lymantria dispar.

In the present study, expression of a newly identified Glyptapanteles indiensis polydnavirus (GiPDV) gene encoding a putative protein tyrosine phosphatase (PDVPTP) was monitored in vivo in the parasitized host, L. dispar, using one step RT-PCR. Expression levels of the PDVPTP transcript were also evaluated in various host tissues at different times post parasitization (pp) using RT quantitative competitive PCR (RT-qcPCR). Expression levels varied, with the most abundant transcript detected in host haemolymph 2 h pp. The high expression level in host haemolymph at an early stage of parasitization suggested a potential role for viral PDVPTP in disruption of the host immune system and protection of the endoparasitoid egg from encapsulation. Additionally, the PDVPTP gene or its homolog(s) mapped to more than one GiPDV genomic DNA segment, which may account for its increased level of expression in the absence of virus replication.

Animals↗
PubMed2003

Diagnosing small bowel Crohn's disease with wireless capsule endoscopy.

BACKGROUND: The small bowel is the most commonly affected site of Crohn's disease (CD) although it may involve any part of the gastrointestinal tract. The current methodologies for examining the small bowel are x ray and endoscopy. AIMS: To evaluate, for the first time, the effectiveness of wireless capsule endoscopy in patients with suspected CD of the small bowel undetected by conventional modalities, and to determine the diagnostic yield of the M2A Given Capsule. PATIENTS: Seventeen patients (eight males, mean age 40 (15) years) with suspected CD fulfilled study entry criteria: nine had iron deficiency anaemia (mean haemoglobin 10.5 (SD 1.8) g%), eight had abdominal pain, seven had diarrhoea, and three had weight loss. Small bowel x ray and upper and lower gastrointestinal endoscopic findings were normal. Mean duration of symptoms before diagnosis was 6.3 (SD 2.2) years. METHODS: Each subject swallowed an M2A Given Capsule containing a miniature video camera, batteries, a transmitter, and an antenna. Recording time was approximately eight hours. The capsule was excreted naturally in the patient's bowel movement, and the data it contained were retrieved and interpreted the next day. RESULTS: Of the 17 study participants, 12 (70.6%, six males, mean age 34.5 (12) years) were diagnosed as having CD of the small bowel according to the findings of the M2A Given Capsule. CONCLUSIONS: Wireless capsule endoscopy diagnosed CD of the small bowel (diagnostic yield of 71%). It was demonstrated as being an effective modality for diagnosing patients with suspected CD undetected by conventional diagnostic methodologies.

Adult↗
PubMed2002

Cluster of neonatal infections in Jerusalem due to unusual biochemical variant of Enterobacter sakazakii.

Reported here is a cluster of infections due to a nitrate-negative variant of Enterobacter sakazakii, which occurred among premature neonates at the Hadassah Hospital, Mount Scopus, Jerusalem, in December 1999-January 2000. Pulsed-field gel electrophoresis showed cluster isolates to be identical but unrelated to previous systemic isolates recovered in 1993 and 1998. The organism was not isolated from infant formula powder, but it was recovered from prepared formula and from a kitchen blender. Elimination of the environmental focus, a change to factory-prepared infant formula, and isolation of affected infants terminated the event. Faecal carriage of Enterobacter sakazakii was observed for up to 18 weeks, emphasising the potential for cross-infection.

Bacteremia↗
PubMed2002

Identification of amplified clonal T cell populations in the blood of patients with chronic graft-versus-host disease: positive correlation with response to photopheresis.

Chronic graft-versus-host disease (cGVHD) is a multiorgan disorder with skin manifestations resembling scleroderma. Since photopheresis, a treatment that induces an anticlonotypic immune response, has proven to be effective in both cutaneous T cell lymphomas with circulating clonal T cells and in cGVHD, we have searched for circulating clonal T cell populations in patients with cGVHD, and determined whether T cell clonality in the blood is associated with therapeutic response. We screened blood samples from 27 patients after HLA-matched allogeneic bone marrow transplantation (allo-BMT), 10 without cGVHD and 17 with extensive cGVHD, for clonal T cell receptor gamma (TCR gamma) gene rearrangements using fluorescent-based polymerase chain reaction (PCR) and automated high-resolution capillary electrophoresis. Amplified populations of clonal T cells with unique TCR gamma gene rearrangements were found in six of 10 (60%) allo-BMT patients without cGVHD and 13 of 17 (76.5%) allo-BMT patients with cGVHD (P = 0.41), as compared to none of 10 (0%) healthy controls. Twelve patients with cGVHD were treated by photopheresis, and the presence of amplified populations of clonal T cells was found to be associated with a cutaneous response to photopheresis, as eight of eight (100%) clone-positive vs none of four (0%) clone-negative patients experienced a clinically significant cutaneous response to treatment (P = 0.001). Our findings suggest that patients with cGVHD that have detectable expanded clonal T cell populations in their peripheral blood, may be more likely to respond to treatment by photopheresis.

Adult↗