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Biomedical subjects

Samir A Shah

Publications and source records attributed to Samir A Shah.

12 recordsLinked to original sources
PubMed2006

Infusion services in the gastroenterology practice.

Gastroenterology practices looking to diversify their services may want to consider infusion therapies as an opportunity to provide a valuable service to patients and create an additional revenue stream. Although patients with gastrointestinal diseases may benefit from such infusions as crystalloid fluids for rehydration or iron for the treatment of inflammatory bowel disease is currently the only infusion therapy likely to be of economic benefit to the practice. The focus of this article is on the infusion of biologic agents, and it is assumed that such therapies will continue to play an important role in the management of inflammatory bowel disease for many years.

Anti-Inflammatory Agents↗
PubMed2006

Force-dependent static dead space of face masks used with holding chambers.

BACKGROUND: Pressurized metered-dose inhalers with valved holding chambers and masks are commonly used for aerosol delivery in children. Drug delivery can decrease when the dead-space volume (DSV) of the valved holding chamber is increased, but there are no published data evaluating force-dependent DSV among different masks. METHODS: Seven masks were studied. Masks were sealed at the valved holding chamber end and filled with water to measure mask volume. To measure mask DSV we used a mannequin of 2-year-old-size face and we applied the mask with forces of 1.5, 3.5, and 7 pounds. Mask seal was determined by direct observation. Intra-brand analysis was done via analysis of variance. RESULTS: At 3.5 pounds of force, the DSV ranged from 29 mL to 100 mL, with 3 masks having DSV of < 50 mL. The remaining masks all had DSV > 60 mL. At 3.5 pounds of force, DSV percent of mask volume ranged from 33.7% (Aerochamber, p < 0.01 compared with other masks) to 100% (Pocket Chamber). DSV decreased with increasing force with most of the masks, and the slope of this line was inversely proportional to mask flexibility. Mask fit was 100% at 1.5 pounds of force only with the Aerochamber and Optichamber. Mask fit was poorest with the Vortex, Pocket Chamber, and BreatheRite masks. CONCLUSION: Rigid masks with large DSV might not be not suitable for use in children, especially if discomfort from the stiff mask makes its use less acceptable to the child.

Administration, Inhalation↗
PubMed2005

Plastic bronchitis: new insights and a classification scheme.

Plastic bronchitis is a rare disease in which there is the formation of large gelatinous or rigid branching airway casts. The history of the disease is reviewed and a classification system is proposed based on our current understanding. This system classifies plastic bronchitis by clinical disease association and cast histology. A summary of the medical literature is included together with guidelines for treatment. The evidence for these treatment decisions is reviewed.

Anemia, Sickle Cell↗
PubMed2005

Explantation of an AcrySof Natural intraocular lens because of a color vision disturbance.

PURPOSE: To describe a patient who complained of color vision disturbance after implantation of a clear intraocular lens (IOL) in one eye and a yellow IOL in the other. DESIGN: Interventional case report. METHODS: A 50-year-old woman complained of binocular imbalance and "yellow vision" in her left eye after implantation of a visible blue light-filtering yellow IOL. A clear IOL had been implanted in her right eye 1 month before. She requested explantation of the yellow IOL. RESULTS: The yellow IOL was exchanged for a clear one, which resolved the unbalanced color vision. CONCLUSIONS: Patients may be intolerant of the color disturbance that results when dissimilarly colored IOLs are implanted. It is advisable to avoid this practice.

Acrylic Resins↗
PubMed2005

Quantification of biopolymer filament structure.

The quantitative analysis of a polymer network is important for understanding its role in biological function. We developed a Matlab program to recognize and segment filaments in a 2-D image, and measure and describe the structure. Our algorithm improved the speed of the Lichtenstein Fiberscore segmentation algorithm by using matrix convolutions, compared filament length by the algorithms of Kulpa, Lichtenstein, and Kimura, and measured the number of branchpoints and Euler number. A user interface was added to easily manipulate algorithm parameters, select images, and visualize results. We used the program to compare the DNA biopolymer network of cystic fibrosis (CF) sputum with mucus from patients without respiratory problems. We also examined an image of fibrin. The images were taken with a laser scanning confocal microscope after staining the specimens with Yo-Yo-1. Computation using matrix convolutions reduced the execution time (Pentium III) of a 512 x 512 TIF image from 18 min to 15s. The Kimura length estimation appeared best at describing filament length because it varied least with filament orientation. The image of CF sputum showed increased filament length, more branchpoints, and more negative Euler number compared to the normal sample. These quantitative descriptions of the network can be correlated to material, mechanical, diffusion, or flow properties, physiological processes, or therapy.

Actins↗
PubMed2005

The role of airway secretions in COPD--clinical applications.

It has been established that mucus hypersecretion and decreased mucus clearance contribute to the morbidity of chronic obstructive pulmonary disease (COPD). Indeed, the classic definition of chronic bronchitis relies on determining the frequency and duration of sputum expectoration. Despite the well recognized importance of this symptom, there are few therapies routinely used to decrease the sputum production or to improve clearance. There are fewer well conducted clinical trials of existing medications and this has led many regulatory agencies, notably the Food and Drug Administration (FDA), to refuse to register these medications or approve their sale. Similarly, airway clearance devices and chest physical therapy have not been well studied in COPD. Carefully conducted studies of interventions to improve airway clearance, similar to those done in cystic fibrosis (CF), may help us to identify effective therapies and possibly novel diagnostic tests for the management of COPD.

Expectorants↗
PubMed2004

Ocular manifestations of inflammatory bowel disease.

Extraintestinal manifestations of inflammatory bowel disease (IBD) occur in one third of patients. Ocular complications are infrequent, occurring in less than 10% of cases, but can be associated with significant morbidity, including blindness. Ocular complaints are often nonspecific; clinical relevance may not be appreciated by patient or physician and, thus, be misdiagnosed. Evaluation of the eye should be a routine component in the care of patients with IBD. Clinicians must be aware of the spectrum of ocular symptoms and know that these complaints may precede a diagnosis of ulcerative colitis (UC) or Crohn's disease (CD). We review ocular pathology in IBD to alert clinicians to the diverse, at times confusing, spectrum of eye disorders associated with these diseases. Clinical manifestations include blurred vision, teary, burning or itchy eyes, ocular pain, photophobia, conjunctival or scleral hyperemia, loss of visual acuity, and possible blindness. Many patients are unaware that IBD has a risk of eye complications and, therefore, patient education is vital.

Colitis, Ulcerative↗
PubMed2004

Smoking and immunomodulators do not influence the response or duration of response to infliximab in Crohn's disease.

OBJECTIVE: Clinical predictors for infliximab response are still unknown. Identifying predictors of response to infliximab in Crohn's disease may improve our selection of patients. METHODS: Two hundred patients with luminal (61%) or fistulous (39%) Crohn's disease and at least 6 months of follow-up following a total of 416 infliximab infusions were evaluated. Clinical response and duration of response were the primary endpoints. RESULTS: Patients with fistulous disease had a higher response rate (83% versus 70%, P = 0.044) and a significantly longer duration of response compared with patients with luminal disease (17.4 versus 10.1 wks, P = 0.017). For luminal disease, nonsmokers and smokers had similar response rates (74% versus 64%, P = 0.5) and similar durations of response (9.4 wks versus 8.4 wks P = 0.6) while patients taking concurrent immunomodulators had similar response rates compared with those not taking immunomodulators (74% versus 71%, P = 0.9) and similar durations of response (10.4 wks versus 10.6 wks, P = 0.9). For fistulous disease, response rates (89% versus 83% P = 0.9) and duration of response (16.9 wks versus 10.1 wks, P = 0.10) were similar between nonsmokers and smokers and concurrent immunomodulators had no effect on response (89% versus 86%, P = 0.9) or duration of response (19.8 wks versus 15.4 wks, P = 0.46). Multivariable analysis confirmed that neither smoking, corticosteroids, immunomodulator therapy, gender, age, age of disease onset, disease duration, nor luminal disease location significantly influenced response or duration of response. CONCLUSIONS: Patients with fistulous disease had a higher response rate and a significantly longer duration of response compared with patients with luminal disease. However, among patients with luminal or fistulous disease, neither smoking nor immunomodulators had any effect on response or duration of response.

Adjuvants, Immunologic↗
PubMed2003

Meckel diverticulum: a geriatric disease masquerading as common gastrointestinal tract disorders.

BACKGROUND: Meckel diverticulum (MD) is traditionally considered a pediatric disease that is associated with intestinal hemorrhage or perforation. Symptomatic MD is rarely a consideration in the geriatric population. OBJECTIVE: To notify clinicians of the clinical variety and diagnostic uncertainty of MD in the elderly, we report 7 cases of complicated MD that presented as common disorders of the gastrointestinal (GI) tract in patients older than 65 years. METHODS: A retrospective record review at 2 university-affiliated hospitals revealed 7 patients older than 65 years with MD and abdominal complaints necessitating laparotomy. The patients represented a subset of 27 adults (age range, 21-89 years; mean age, 39 years) with symptomatic MD who required surgery during a 7-year period. RESULTS: The presenting complaints represented a variety of common GI presentations, including nausea, vomiting, and acute abdominal pain (n = 3); acute abdominal pain with peritonitis (n = 2); crampy abdominal pain lasting several weeks (n = 1); and rectal bleeding (n = 1). Meckel diverticulum was a preoperative consideration in only 2 of 7 cases. The preoperative diagnoses were consistent with common disorders of the GI tract in the elderly, including small-bowel obstruction (n = 2), ischemic colitis (n = 1), unrelenting bleeding in the GI tract (n = 1), perforated viscus (n = 1), diverticulitis (n = 1), and appendicitis (n = 1). In contradistinction to the pediatric age group, only 1 of 7 patients had an MD with ectopic mucosa. CONCLUSIONS: Many different mechanisms can be responsible for complications due to MD in the geriatric population. Misdiagnosis occurs frequently in the elderly because of the poor sensitivity of diagnostic tests, nonspecificity of complaints, and lack of recognition that this anomaly can present in this age group. Clinicians must be cognizant of this common pediatric disease and its varied guises when they are evaluating unexplained acute or intermittent abdominal pain, nausea and vomiting, rectal bleeding, peritonitis, or obstruction in geriatric patients.

Abdominal Pain↗
PubMed2003

Risk of early surgery for Crohn's disease: implications for early treatment strategies.

OBJECTIVES: In this study we aimed to define the rate of early surgery for Crohn's disease and to identify risk factors associated with early surgery as a basis for subsequent studies of early intervention in Crohn's disease. METHODS: We assembled a retrospective cohort of patients with Crohn's disease diagnosed between 1991 and 1997 and followed for at least 3 yr, who were identified in 16 community and referral-based practices in New England. Chart review was performed for each patient. Details of baseline demographic and disease features were recorded. Surgical history including date of surgery, indication, and procedure were also noted. Risk factors for early surgery (defined as major surgery for Crohn's disease within 3 yr of diagnosis, exclusive of major surgery at time of diagnosis) were identified by univariate analysis. Multiple logistic regression was used to identify independent risk factors. RESULTS: Of 345 eligible patients, 69 (20.1%) required surgery within 3 yr of diagnosis, excluding the 14 patients (4.1%) who had major surgery at the time of diagnosis. Overall, the interval between diagnosis and surgery was short; one half of all patients who required surgery underwent operation within 6 months of diagnosis. Risk factors identified by univariate analysis as significantly associated with early surgery included the following: smoking; disease of small bowel without colonic involvement; nausea and vomiting or abdominal pain on presentation; neutrophil count; and steroid use in the first 6 months. Disease localized to the colon only, blood in the stool, use of 5-aminosalicylate, and lymphocyte count were inversely associated with risk of early surgery. Logistic regression confirmed independent associations with smoking as a positive risk factor and involvement of colon without small bowel as a negative risk factor for early surgery. CONCLUSIONS: The rate of surgery is high in the first 3 yr after diagnosis of Crohn's disease, particularly in the first 6 months. These results suggest that improved risk stratification and potent therapies with rapid onset of action are needed to modify the natural history of Crohn's disease.

Adolescent↗