Sharon Grundfest-Broniatowski

Quantitative classification of breast tumors in digitized mammograms.

The goal of this study was to develop a technique to distinguish benign and malignant breast lesions in secondarily digitized mammograms. A set of 51 mammograms (two views/patient) containing lesions of known pathology were evaluated using six different morphological descriptors: circularity, mu R/sigma R (where mu R = mean radial distance of tumor boundary, sigma R = standard deviation); compactness, P2/A (where P = perimeter length of tumor boundary and A = area of the tumor); normalized moment classifier; fractal dimension; and a tumor boundary roughness (TBR) measurement (the number of angles in the tumor boundary with more than one boundary point divided by the total number of angles in the boundary). The lesion was segmented from the surrounding background using an adaptive region growing technique. Ninety-seven percent of the lesions were segmented using this approach. An ROC analysis was performed for each parameter and the results of this analysis were compared to each other and to those obtained from a subjective review by two board-certified radiologists who specialize in mammography. The results of the analysis indicate that all six parameters are diagnostic for malignancy with areas under their ROC curves ranging from 0.759 to 0.928. We observed a trend towards increased specificity at low false-negative rates (0.01 and 0.001) with the TBR measurement. Additionally, the diagnostic accuracy of a classification model based on this parameter was similar to that of the subjective reviewers.

Role of angiography and embolization for massive gastroduodenal hemorrhage.

The role of mesenteric angiography and embolization for massive gastroduodenal bleeding is unclear. We reviewed the records of patients who underwent angiography for acute, nonmalignant, and nonvariceal gastric or duodenal hemorrhage that was documented but not controlled by endoscopy. Fifty patients were identified over a 7-year period ending in March 1998. Only 17 patients (34%) were originally admitted to the hospital with gastrointestinal bleeding. All required treatment in the intensive care unit (mean 15 days) with a mean APACHE III score of 79 (29% predicted hospital mortality), and 32 (64%) had organ failure. A mean of 2.1 endoscopies were performed to locate the source of acute duodenal bleeding in 37 (74%) and gastric bleeding in 13 (26%). An average of 24.3 units of packed red blood cells were transfused per patient. Twenty-five patients (50%) were found to have active bleeding at angiography; all were treated by embolization as were 22 who underwent empiric embolization. Twenty-six patients (52%) were successfully treated by embolization and thus spared imminent surgery. Multiple variables were compared between those who were successfully treated by embolization and those considered failures. Time to angiography was considerably shorter (2.5 vs. 5.8 days, P <0.017) and fewer total units of packed red blood cells were used (14.6 vs. 34, P <0.003) in those who were successfully treated. There was also a strong trend toward using fewer units of packed red blood cells for transfusion prior to angiography (11.2 vs. 17.1, P <0.08). No differences were found that could be attributed to gastric vs. duodenal sources, number of comorbid diseases, organ failure, APACHE score, age, or whether active bleeding was found at angiography. A total of 20 patients (40%) died including 9 of 17 patients operated on in an attempt to salvage angiographic failure. In summary, angiographic embolization should be performed early in the course of bleeding in otherwise critically ill patients.

Trends in bile duct injuries from laparoscopic cholecystectomy

Bile duct injuries are a serious complication of cholecystectomy Laparoscopic cholecystectomies (LC) were originally associated with an increased incidence of injuries Patients referred to a tertiary center were reviewed to assess the trends in the number, presentation, and management Seventy-three patients were referred over a 6-year period with a maximum of 17 patients referred in 1992, but the number has not declined substantially over time The persistent number of referrals is a consequence of ongoing injuries One third of injuries were diagnosed at LC, and the use of cholangiography has not mcreased The number of cystic duct leaks has not decreased and they represent 25% of all cases The level of injury has remained unchanged with Bismuth types I and II in 3 7% and types III and IV in 38% Excluding patients with cystic duct leaks, 58% were referred after a failed ductal repair Definitive treatment with biliary stenting was successful in 37%, and 34 patients (47%) required a bihary-entenc anastomosis Complications occurred in 18 patients (25%) including seven with postoperative stricture or cholangins No biliary reoperations have been performed at a mean follow-up of 36 months

Role of differential neuroaxial blockade in the evaluation and management of pain in chronic pancreatitis

Role of differential neuroaxial blockade in the evaluation and management of pain in chronic pancreatitis

Dynamic Laryngotracheal Closure for Aspiration: A Preliminary Report†

Objectives/Hypothesis An estimated 500,000 patients per year in the United States. are affected by stroke‐related dysphagia. Approximately half experience aspiration, which can lead to pneumonia or death. Aspiration may result from many factors, including delayed transport of the bolus, faulty laryngeal elevation, and poor coordination or inappropriate timing of vocal cord closure. Interventions carried out to protect the lungs are usually irreversible, destructive to the upper airway, and rarely prevent the need for enteral tube feeding.

Does core needle breast biopsy accurately reflect breast pathology

BACKGROUND Core needle breast biopsy (CB) has replaced excisional biopsy as the initial diagnostic biopsy procedure for many suspicious breast lesions; however, CB remains a sampling procedure. The purpose of this study was to determine the degree of agreement between histology obtained at CB and that obtained at a subsequent excisional procedure (EP). We hypothesized a high degree of agreement. METHODS Data were collected prospectively for 3035 CBs performed by breast radiologists using either ultrasound or stereotactic guidance between January 1995 and July 2002, 1410 (46%) of which had a subsequent EP within 1 year. Histologic categories were defined as invasive breast cancer, duct carcinoma in-situ, atypia/lobular carcinoma in-situ, and benign. The principal histology (PH) from CB and EP was identified and compared. RESULTS Overall, there was moderate agreement (kappa=0.669) between CB and EP histology. Complete agreement occurred in 1168 (83%) procedures. For the remaining 242, the PH was identified only at CB for 78 (5%) procedures, and only after EP for 164 (12%) procedures. CONCLUSIONS Although the majority (83%) of CB and EP demonstrated exact histologic agreement, CB was diagnostic for 1246 (88%) procedures.

Voluntary control of an ileal pouch by coordinated electrical stimulation. A pilot study in the dog.

Heal reservoirs were constructed in four dogs under general anesthesia and stimulated by means of a constant current generator that produced pulse trains at frequencies between 6 Hz and 1.67 kHz. Stimulation at 6 Hz with 50 ms pulses between amplitudes of 15 and 25 mA uniformly produced pouch contraction and reservoir emptying. Stimulation at other frequencies did not cause pouch emptying although pressure increases were sometimes observed. Such electrical stimulation may be useful for voluntary control of intestinal reservoirs when used as replacement for urinary bladder or colon. The mechanism by which the intestinal contraction is preduced appears to be different than that produced by slow wave pacing

Race is a Fundamental Prognostic Indicator for 2325 Northeastern Ohio Women with Infiltrating Breast Cancer

Abstract:  The goal of this research was to determine if race, independent of socioeconomic status, is a prognostic indicator for women diagnosed with infiltrating breast cancer. We hypothesized that black patients would present with breast cancers having less favorable prognostic indicators relative to white patients, regardless of socioeconomic status. Using data collected prospectively in our institutional review board approved breast center patient registry and 2000 Census Tract data for northeastern Ohio, we compared tumor size, node status, hormone receptor status, clinical outcomes, and socioeconomic status for patients who were self‐described as either black or white and who had been diagnosed with infiltrating breast cancer. The chi‐square test, t‐test, log‐rank test, and Cox proportional hazards analysis were used to analyze the data. Kaplan‐Meier outcome curves were generated. Data were available for 2325 women, including 313 who were black and 2012 who were white. Compared to white patients, black patients were more likely to have positive axillary nodes and to have hormone receptor‐negative tumors. Black patients were also more likely to have positive axillary nodes associated with smaller tumors. Independent of socioeconomic status, black patients were more likely to have poorer overall survival and disease‐free survival rates for breast cancer relative to white patients. The prognostic significance of race was not dependent on a concomitant relationship with socioeconomic status. 

Toward a Bioartificial Pancreas: Diffusion of Insulin and IgG Across Immunoprotective Membranes with Controlled Hydrophilic Channel Diameters

Research continued toward a bioartificial pancreas (BAP). Our BAPs consist of a perforated nitinol scaffold coated with reinforced amphiphilic conetwork membranes and contain live pancreatic islets. The membranes are assemblages of cocontinuous hydrophobic domains and hydrophilic channels whose diameters were varied by the MW of hydrophilic segments between crosslinks (M(c,HI) = 32, 44, and 74 kg x mol(-1)). We studied the diffusion rate of insulin, BSA, and IgG across the membrane of the BAP in the absence of islets. Membranes of M(c,HI) = 74 kg x mol(-1) showed rapid insulin and BSA transport and negligible IgG diffusion. BAPs containing approximately 300 mouse islets showed appropriate response upon glucose challenge in vitro. The BAP implanted into diabetic mice reduced hyperglycemia and maintained islet viability for at least 4 d.

Excitation thresholds for nerve pedicles: A preliminary report

Ongoing Interest in the rehabilitation of paralyzed musculature in the head and neck has focused on the electronic stimulation of nerve-muscle pedicles that have been relmplanted Into the Incapacitated effector(s). Despite visual and histochemical evidence of reinnervation, It Is still not known whether the excitability of a nerve-muscle pedicle (or for that matter a direct nerve Implant) Is equivalent to or better than that of reinnervated or normal muscle. Such Information Is necessary for the eventual construction of an Implantable stimulator. Eighteen rabbits were anesthetized with Intramuscular xylazine and ketamine and the ansa hypoglossi nerve was cut on one side. A crossover nerve-muscle pedicle was brought in from the opposite sternothyroid muscle to the sternohyoid in nine animals; the other nine received a direct nerve Implant. After a minimum neurotization period of 3 months and reexploration, an electrical stimulator capable of delivering square wave pulses of variable amplitude and width was used to determine the thresholds of contraction of the nerve pedicles, an Intact motor nerve of similar size, a normal muscle, and the relnnervated strap In 16 evaluable rabbits. Strength duration curves were established. The data Indicate that thresholds for nerve pedicles are equivalent to those of normal nerves and are significantly lower than those of muscle.