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Biomedical subjects

T A Stellato

Publications and source records attributed to T A Stellato.

At least 19 recordsLinked to original sources

Musculoskeletal findings in obese subjects before and after weight loss following bariatric surgery.

OBJECTIVE: To determine the point prevalence of painful musculoskeletal (MSK) conditions in obese subjects before and after weight loss following bariatric surgery. DESIGN: Longitudinal, interventional, unblended. SUBJECTS: Forty-eight obese subjects (47 women, one man, mean age 44+/-9 years; mean body mass index (BMI) 51+/-8 kg/m(2)) recruited from an academic medical center bariatric surgery program. MEASUREMENTS: Comorbid medical conditions; MSK findings; BMI; Western Ontario McMaster Osteoarthritis Index (WOMAC) for pain, stiffness and function; and SF-36 for quality of life. METHODS: Consecutive subjects were recruited from the University Hospitals of Cleveland Bariatric Surgery Program. Musculoskeletal signs and symptoms and non-MSK comorbid conditions were documented at baseline and at follow-up. SUBJECTS completed the SF-36 and the WOMAC questionnaires. Analyses were carried out for each MSK site, fibromyalgia syndrome (FMS) and for the cumulative effect on the spine, upper and lower extremities. The impact of change in comorbid medical conditions, BMI, physical and mental health domains of the SF-36 on the WOMAC pain subscale score was evaluated. SF-36 outcomes were compared to normal published controls. RESULTS: Forty-eight subjects were available for baseline and a follow-up assessment 6-12 months after gastric bypass surgery. They lost an average of 41+/-15 kg and the mean BMI decreased from 51+/-8 to 36+/-7 kg/m(2). Baseline comorbid medical conditions were present in 96% before surgery and 23% after weight loss. There was an increased prevalence of painful MSK conditions at baseline compared to general population frequencies. Musculoskeletal complaints had been present in 100% of obese subjects before, and 23% after weight loss. The greatest improvements occurred in the cervical and lumbar spine, the foot and in FMS (decreased by 90, 83, 83 and 92%, respectively). Seventy-nine percent had upper extremity MSK conditions before and 40% after weight loss. Before surgery, 100% had lower extremity MSK conditions and only 37% did after weight loss. The WOMAC subscale and composite scores all improved significantly, as did the SF-36((R)). Change in BMI was the main factor impacting the WOMAC pain score. CONCLUSION: There was a higher frequency of multiple MSK complaints, including non-weight-bearing sites compared to historical controls, before surgery, which decreased significantly at most sites following weight loss and physical activity. These benefits may improve further, as weight loss may continue for up to 24 months. The benefits seen with weight loss indicate that prevention and treatment of obesity can improve MSK health and function.

Adult↗

Crohn's disease of the foregut.

Historically, Crohn's disease of the esophagus, stomach, and duodenum has been reported only rarely. With more frequent use of upper endoscopy, however, upper gastrointestinal involvement has been found to be more common than previously suspected. The surgeon with an interest in Crohn's disease needs to be familiar with all areas that are potentially affected in this perplexing and sometimes devastating disease. This article examines the literature on foregut Crohn's and discusses the incidence, clinical manifestations, diagnosis, medical management, surgical indications, and operative techniques.

Crohn Disease↗

Laparoscopic implant instrument for the placement of intramuscular electrodes in the diaphragm.

We have developed an endoscopic instrument that will allow a surgeon to safely, dependably and accurately place intramuscular (IM) electrodes in the diaphragm. This instrument has been used to implant 28 IM electrodes in the diaphragms of eleven acute and four chronic dogs. All electrodes achieved full activation of the diaphragm muscle, producing tidal volumes up to 130% V(TCRIT), the critical volume necessary for basal ventilatory support, with unilateral stimulation. The surgeon is able to control the angle of the IM electrode insertion needle, which enables the needle to approach the diaphragm at an angle that is parallel to the surface of the muscle. This insures good control over the depth of needle penetration into the muscle, which greatly reduces the risk of accidentally passing the needle through the diaphragm and entering the thorax. Endoscopic placement of IM electrodes into the diaphragm opens opportunities to provide cost effective negative pressure ventilation to patients who are unable to effect sufficient ventilation by central nervous system (CNS) control of respiration.

Animals↗

The role of fluorodeoxyglucose and positron emission tomography in the evaluation of pancreatic disease.

BACKGROUND: The difficulties involved in the timely and accurate diagnosis of pancreatic disease are well known. The usual imaging modalities usually identify abnormalities but may not always differentiate malignancy from other condition such as scar tissue or chronic inflammation. The purpose of our study was to determine if fluorodeoxyglucose positron emission tomography (FDG PET) can accurately diagnose pancreatic disease. METHODS: The records of 15 patients presenting with pancreatic disease were retrospectively reviewed. The diagnosis suspected by imaging modalities was compared with the final tissue diagnosis. Two patients were excluded because no tissue was obtained. RESULTS: Adenocarcinoma was diagnosed in 9 patients. A mass consistent with this diagnosis was seen in 8 of 9, 6 of 9, 6 of 8, and 5 of 5 patients by PET, computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasound (EUS), respectively. Chronic pancreatitis (CP) was diagnosed in 2 patients. The unique appearance on FDG PET made the diagnosis in both these patients. Both patients with CP were thought to have a malignancy by CT and EUS and 1 of 2 by ERCP. Neuroendocrine tumors were diagnosed in 2 other patients. One of 2 was seen by FDG PET and both by CT. CONCLUSIONS: FDG PET can accurately differentiate a pancreatic adenocarcinoma from chronic pancreatitis in a patient with a suspicious pancreatic mass. Thus, FDG PET may help in establishing a diagnosis and subsequently managing a patient with pancreatic disease.

Adenocarcinoma↗

Laparoscopic placement of electrodes for diaphragm pacing using stimulation to locate the phrenic nerve motor points.

Laparoscopic mapping of the phrenic nerve motor points using test stimulation was conducted for the implant of epimysial electrodes for diaphragm pacing in dogs. Both visual assessment of muscle activation and measurements of recruitment were useful for identifying an implant location resulting in a mean electrode placement approximately 14 mm from the phrenic nerve motor points in 16 dogs. Postmortem analysis of the stimulus test site locations and corresponding recruitment curves suggested that the phrenic nerve motor points could be predicted during the laparoscopic procedure to within 4.5 mm of the anatomical motor point.

Animals↗

Staple penetration and staple histological response for attaching an epimysial electrode onto the abdominal surface of the diaphragm using a laparoscopic approach.

BACKGROUND: Laparoscopic stapling was found to be a viable option for attaching epimysial electrodes onto the abdominal surface of the diaphragm. Stapling was preferable to suturing due to its simplicity and speed. METHODS: Of the two staplers tested in this study, the Ethicon Endopath was preferred over the Autosuture Endo Hernia because the staples did not penetrate the diaphragm when an electrode tab thickness greater than 0.75 mm was used. RESULTS: The thickness of the electrode tab was an important factor in determining staple penetration but large variation in penetration depth indicated that other factors may also play a role. An electrode tab thickness of 1.0-1.25 mm was suggested to minimize the risk of diaphragm perforation. CONCLUSIONS: The histological reaction to staples implanted up to 14 months was unremarkable, reflecting the safety of laparoscopic staples for permanently anchoring electrodes on the diaphragm.

Abdominal Muscles↗

Cholescintigraphy in the diagnosis of bile leak after laparoscopic cholecystectomy.

Bile leaks are a recognized complication of laparoscopic cholecystectomy (LC). Different diagnostic approaches have been employed when this condition is suspected. We present our experience with cholescintigraphy as a primary imaging technique for the detection of bile leaks. The medical records of all patients who had cholescintigraphy after LC during a 58-month period were reviewed. Patients were selected for cholescintigraphy if fever unusual abdominal pain, nausea, vomiting, or jaundice were present beyond 36 hours after LC. Bile leaks were suspected in 25 out of 744 patients (3.36%). The nuclear imaging study was true positive in 7 cases and true negative in 18 cases, for a 100 per cent sensitivity, specificity, and accuracy in the detection of bile leaks. Five patients were treated by endoscopic retrograde cholangiopancreatography with stent and/or sphincterotomy, and two patients underwent exploratory laparotomy. None of the patients who underwent endoscopic retrograde cholangiopancreatography required peritoneal drainage. We conclude that cholescintigraphy is sensitive and accurate in the diagnosis of bile leaks. Its use along with a high index of suspicion of a bile leak may prevent the development of bile peritonitis.

Adult↗

Laparoscopic surgery in a small animal model. A simplified technique of retroperitoneal dissection in the rat.

BACKGROUND: An adequate laparoscopic small-animal model would benefit surgical oncologic research. Immunobiologic data and reagents available for the rodent make them an ideal species. We developed a simple, inexpensive, reproducible technique for laparoscopic surgery in rodents. METHODS: Carbon dioxide pneumoperitoneum is achieved in anesthetized animals. Through a 0.5-cm midline incision a 4.8-mm bronchofiberscope is inserted into the peritoneal cavity and secured with a purse-string suture (PSS). Three additional PSSs are made to introduce the dissectors. Under fiberscopic vision, a blunt dissection of the retroperitoneum exposes the inferior vena cava and aorta. Necropsy 24 h after verifies the adequacy of dissection. RESULTS: Eighteen animals survived. The only death resulted from bleeding. Mortality was 5.26%. Surgical time was 24.72 +/- 8.93 min with all animals active 2 h postlaparoscopy. CONCLUSIONS: Laparoscopic surgery (LS) can be done inexpensively without sophisticated equipment. The rodent is ideal for examining the immunologic consequences of laparoscopic surgery and pneumoperitoneum.

Animals↗

Flexible endoscopy as an adjunct to laparoscopic surgery.

The combination of flexible endoscopy and laparoscopy has allowed a creative approach to management of both benign and malignant gastrointestinal diseases. Historically, attempts to incorporate intraluminal endoscopy with laparoscopy were made early in the historical development of laparoscopy, especially as an aid to stage gastric cancer. The most common modern application is that of flexible choledochoscopy by laparoscopic cholecystectomy. Other innovative uses include localization of tumors, control of upper gastrointestinal bleeding, gastric tumor excision and biliary decompression, and bowel resection. With imagination guided by sound surgical principles, the combined use of laparoscopy and intraluminal endoscopy should expand the boundaries of general surgery.

Bile Ducts↗

Human aberrant crypt foci with carcinoma in situ from a patient with sporadic colon cancer.

Aberrant crypt foci are putative preneoplastic lesions found in the colons of carcinogen-treated rodents and at an increased frequency in humans at increased risk for colon cancer. There is a strong association between aberrant crypt foci and colon cancer, including many shared phenotypic and genetic alterations. The aim of this study is to present further evidence of a relationship between aberrant crypt foci and colon cancer in humans. Multiple aberrant crypt foci from a single patient were identified in unembedded colonic mucosa. Histological sections of the aberrant crypt foci and adjacent mucosa were evaluated for dysplasia, proliferative activity, and pigment-laden macrophages that were characterized with histochemical techniques. The first patient with sporadic colon cancer identified with aberrant crypt foci with carcinoma in situ is described. It is interesting that this 99-year-old patient had multiple carcinomas in situ, pseudomelanosis coli, and two metachronous colon cancers. These data lend support to the hypothesis that aberrant crypt foci are precursors of some colon cancers.

Aged↗

The clinical spectrum of Clostridium difficile colitis in immunocompromised patients.

Clostridium difficile colitis is a nosocomial infection that continues to cause significant hospital morbidity despite adequate treatment. This morbidity may be especially costly in the immunocompromised patient who now makes up a greater percentage of hospitalized patients. The purpose of this study was to evaluate if patients in immunocompromised states are at risk for relapse of Clostridium difficile colitis, and to determine the efficacy of metronidazole in these patients. A retrospective chart review was conducted of patients with Clostridium difficile colitis over a 1-year period between 1990 and 1991. From this study group, 114 patients were identified who had both positive Clostridium difficile toxin assays of fecal specimens and documented in-house clinical infection. There were 67 immunocompromised patients (59%) in the study group. Oral vancomycin was given alone in 41 (36%) patients, metronidazole was used in 36 (32%) patients, and a combination was given in 15 (13%) patients. Twenty-two (19%) patients received no antibiotic therapy and had their preceding antibiotics terminated. Twelve (10.5%) patients had documented relapses, and all had an immunocompromising condition. There was no statistically significant difference in relapse rates between the vancomycin and metronidazole-treated patients. We conclude that metronidazole, with its significantly lower cost, should be used as first-line therapy in immunocompromised patients.

Anti-Bacterial Agents↗

Open versus laparoscopic surgery: a comparison of natural antitumoral cellular immunity in a small animal model.

The scope of laparoscopic surgery has extended to the treatment of cancer. The immunological impact of laparoscopic surgery as compared with open surgery has not been well characterized. A paucity of information is available about differences or similarities of these two methods regarding natural antitumoral cellular immunity, namely, natural killer cell cytotoxicity. This study compared the activity of natural killer cells in rats subjected to pneumoperitoneum, open dissection of the retroperitoneum, and laparoscopic dissection of the retroperitoneum. When compared to control animals, rats subjected to pneumoperitoneum did not show any change in natural killer cell activity. Conversely, the groups of open surgery and laparoscopic surgery revealed significantly decreased natural killer cell cytotoxicity compared with controls (P < 0.0167). When the laparoscopic and the open surgical groups were compared to each other, no difference was found. In this study, both open and laparoscopic surgery had a suppressive effect upon the natural antitumoral cellular immunity. Pneumoperitoneum did not have an immune suppressive effect on natural killer cell activity. In this model, the advantages of laparoscopic surgery do not apply to natural antitumoral cellular immunity.

Animals↗

Laparoscopic liver biopsy to evaluate hepatic dysfunction in patients with hematologic malignancies: a useful tool to effect changes in management.

Hepatic dysfunction is common in patients who receive intensive chemotherapy and it is important to determine the etiology in order to institute appropriate therapy. The role of laparoscopic liver biopsy in patients with neutropenia, thrombocytopenia, or both was evaluated as a mean of making treatment decisions and as a determinant of clinical outcome. Laparoscopic liver biopsy was performed in 29 subjects who were receiving intensive cytotoxic therapy with or without bone marrow transplantation. One to three direct-vision laparoscopic liver biopsies were performed in each patient using a Tru-cut needle during general anesthesia. Platelet concentrate transfusions were usually given before, during, and immediately after biopsy. Bleeding was controlled with spatula electrocautery. Thirty-two biopsies were obtained in 29 patients. At the time of liver biopsy, white blood cell and platelet counts ranged from 0 to 14,300/microliters (median: 2500/microliters), and 1000 to 47,000/microliters (median: 20,000/microliters), respectively. Bleeding at the liver biopsy site was readily controlled during the procedure without clinical evidence of significant bleeding; no procedure-related complications were noted and no patients required re-exploration. All biopsies were informative and the lesions observed in 32 biopsies revealed graft-versus-host disease (n = 5), hepatic candidiasis (n =1), hepatic veno-occlusive disease (n = 3), cholestasis (n = 19), hemosiderosis (n = 26), toxic injury (n = 8), hepatic steatosis (n = 4), granuloma (n = 1), viral infection (n =1), and malignancy (n = 1). Laparoscopic liver biopsy has been proven to be an effective means of assessing the cause of liver dysfunction in patients who were thrombocytopenic and immunosuppressed. The diagnosis obtained at laparoscopic liver biopsy altered therapy in nine of 29 (31%) patients.

Adult↗

Modulation of O6-alkylguanine alkyltransferase-directed DNA repair in metastatic colon cancers.

PURPOSE: Carmustine (BCNU) resistance has been correlated with tumor expression of the DNA repair enzyme O6-alkylguanine-DNA alkyltransferase (AT). It has been shown that streptozotocin will deplete AT activity of human colon cancer cells in vitro and potentiate BCNU cytotoxicity. This clinical trial was conducted to determine whether streptozotocin can be used as a modulator of AT in metastatic colorectal cancers and thereby overcome clinical resistance to BCNU. PATIENTS AND METHODS: Fifteen patients with fluorouracil-resistant metastatic colon or rectal cancers were treated sequentially with 2 g/m2 of streptozotocin followed 5 1/2 hours later by BCNU. Sequential biopsies of metastases before and after streptozotocin were conducted to determine whether streptozotocin depletes tumor AT. Peripheral-blood mononuclear cells (PBMCs) were evaluated as a surrogate tissue for prediction of baseline AT levels and streptozotocin posttreatment modulation of the AT in metastases. RESULTS: Streptozotocin treatment led to a 78% (range, 69% to 89%) decrease in the AT levels in colon cancer metastases; however, myelosuppression and hepatic toxicity limited the BCNU dose to 130 mg/m2. A similar decrease in AT levels of PBMCs was found; however, the absolute levels of AT in PBMCs at baseline and following streptozotocin were not predictive of the levels expressed in metastases from the same patient. Despite the decrease in tumor levels of AT, no clinical responses were observed. CONCLUSION: Streptozotocin decreases but does not fully deplete AT activity in metastatic colorectal cancers and the residual AT level in metastases is sufficient to maintain clinical resistance to BCNU. We have also demonstrated that sequential computed tomography (CT)-directed biopsies of colorectal cancer metastases can be used to evaluate strategies to investigate modulators of AT-directed repair. AT levels of PBMCs do not predict for the AT level or degree of modulation achieved in the metastatic tumor.

Adult↗

Carcinoembryonic antigen in human colonic aberrant crypt foci.

BACKGROUND/AIMS: Aberrant crypt foci are putative preneoplastic lesions that, by definition, are identified microscopically in whole-mount preparations of colonic mucosa. Because the identification of hexosaminidase as a marker for rat aberrant crypt foci in histological sections facilitated their characterization, a similar marker for human foci in histological sections was sought. METHODS: Human aberrant crypt foci were marked in whole-mount preparations, embedded in paraffin, and evaluated for their expression of carcinoembryonic antigen with two monoclonal antibodies. RESULTS: Elevated expression of carcinoembryonic antigen was detected in 39 of 42 (93%) aberrant crypt foci from 15 patients. The expression of carcinoembryonic antigen assisted in the evaluation of longitudinal sections of foci, where dysplasia is more readily detected in these small lesions. The expression of carcinoembryonic antigen was related to the sizes of the foci (P = 0.0085, generalized Fisher's Exact Test) but not to the presence or degree of dysplasia. CONCLUSIONS: The overexpression of immunohistochemically demonstrable carcinoembryonic antigen is, to date, the only described alteration in most of these putative precursors of human colon cancer that differs from the expression in contiguous, normal crypts at the histological level and thus facilitates the identification of aberrant crypts in histological sections for further characterization.

Adult↗

Long-term intramuscular electrical activation of the phrenic nerve: safety and reliability.

The safety and reliability of a system for long-term intramuscular electrical activation of the phrenic nerve was evaluated in seven dogs. In this system, electrodes are implanted bilaterally into the diaphragm without directly contacting the phrenic nerve using a laparoscope to direct placement. Five dogs underwent chronic bilateral intramuscular diaphragm stimulation (IDS) for 61 to 183 days at stimulus parameters selected to evoke at least 120% of the animal's basal ventilation. Two dogs maintained as controls did not undergo chronic stimulation. The safety and reliability of the system was evaluated in terms of tissue responses to the electrode, alterations in diaphragm muscle, pulmonary function, electrode reliability, and cardiac activation. (The efficacy of long-term intramuscular activation of the phrenic nerve is addressed in a companion paper.) No adverse responses to the electrode or stimulation were found. The histochemistry of chronically stimulated diaphragm suggested transformation towards type I (oxidative metabolism) muscle fibers. Two IDS electrodes dislodged out of a total of 32 IDS electrodes implanted. Both electrodes dislodged within seven days of implant. All IDS electrodes had stable and repeatable recruitment properties. No IDS electrode mechanical failures were found and no electrode corrosion was observed. We conclude from these experiments that intramuscular activation of the phrenic nerve will present a minimal risk to human patients who are good candidates for clinical studies using this technique.

Animals↗

Long-term intramuscular electrical activation of the phrenic nerve: efficacy as a ventilatory prosthesis.

The efficacy of a system for long-term intramuscular activation of the phrenic nerve as a ventilatory prosthesis was evaluated in seven dogs. (The safety and reliability of this system is addressed in a companion paper.) Five dogs underwent chronic bilateral intramuscular diaphragm stimulation (IDS) for 61 to 183 days at stimulus parameters selected to evoke at least 120% of the animal's basal ventilation. Two dogs maintained as controls did not undergo chronic stimulation. The ability of IDS to provide long-term ventilation without diaphragm fatigue was evaluated in terms of the ventilatory capacity of IDS, the effects of chronic IDS on diaphragm contractile properties, and the phrenic nerve recruitment properties of chronic IDS electrodes. Hemidiaphragms with electrodes placed within 2 cm of the phrenic nerve trunk could be completely activated by 25 mA pulses having a 100 microsecond pulse width. The tidal volume evoked by IDS in this study was 167% (+/- 48 s.d.) of that required for full-time basal ventilation without diaphragm fatigue. Evoked tidal volume increased after 8 to 9 weeks of chronic IDS for stimulus pulse intervals longer than 50 mS. Electrode recruitment properties were stable for both active and passive implanted electrodes. We conclude from these studies that with properly placed electrodes IDS is capable of providing reliable full-time ventilatory support without fatiguing the diaphragm.

Animals↗