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Biomedical subjects

A S Krupnick

Publications and source records attributed to A S Krupnick.

10 recordsLinked to original sources
PubMed2004

Myocardial tissue engineering and regeneration as a therapeutic alternative to transplantation.

Ischemic cardiomyopathy leading to congestive heart failure remains the leading source of morbidity and mortality in Western society and medical management of this condition offers only palliative treatment. While allogeneic heart transplantation can both extend and improve the quality of life for patients with end-stage heart failure, this therapeutic option is limited by donor organ shortage. Even after successful transplantation, chronic cardiac rejection in the form of cardiac allograft vasculopathy can severely limit the lifespan of the transplanted organ. Current experimental efforts focus on cellular cardiomyoplasty, myocardial tissue engineering, and myocardial regeneration as alternative approaches to whole organ transplantation. Such strategies may offer novel forms of therapy to patients with end-stage heart failure within the near future.

Animals↗
PubMed2001

Multiparameter flow cytometric approach for simultaneous evaluation of T lymphocyte-endothelial cell interactions.

Since vascular endothelium is now recognized as an immunologically active tissue, a better understanding of the relationship between endothelial cells and T lymphocytes is critical to the field of solid organ transplantation. Investigations of endothelial cell-T cell interactions have been limited by methodology. We developed a flow cytometric method allowing for concurrent investigation of multiple cell populations within the same culture that can be applied to these complex interactions. Allogeneic CD8+ or CD4+ T cells labeled with 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) were added to a murine endothelial cell monolayer, in which endothelial proliferation was not inhibited by irradiation or addition of a cell cycle-blocking agent. At specific time points, the coculture was analyzed by flow cytometry. T-cell proliferation could be detected by gating on the T-cell subset and evaluating the CFSE fluorescence peaks. By directly analyzing cellular division, we minimized erroneous interpretation of the data encountered by previous studies, which utilized (3)H-thymidine incorporation as sole measure of proliferation. Further subgating on cells that divided facilitated the study of CD8+ lymphocyte activation, differentiation, and acquisition of effector function. By gating on the endothelial cell population, phenotypic changes such as upregulation of surface MHC molecules or immune-mediated apoptosis could be detected. In conclusion, we present a flow cytometric approach that could have important applications for clinical immunological monitoring in allogeneic or xenogeneic transplantation, and might provide the requisite information to better tailor immunotherapy to prevent chronic rejection.

Animals↗
PubMed2001

A simple method for culturing mouse vascular endothelium.

Vascular endothelium is an important site for a wide array of immunological processes such as inflammation, atherosclerosis and allograft rejection. Culture methods of mouse vascular endothelium would provide an important in vitro correlate to immunological murine in vivo models. We describe a simple method to culture mouse vascular endothelium from thoracic aorta. Our cultured cells express typical phenotypic (CD105, CD31, CD106), morphological and ultrastructural (intercellular junctions, Weibel-Palade bodies) markers of vascular endothelium. They also possess functional receptors for uptake and processing of acetylated low-density lipoproteins. The mouse vascular endothelium within our system expresses high levels of MHC class I and MHC class II after activation with IFN-gamma. In addition, these cells express the accessory molecules CD80 and CD54, while they lack constitutive expression of CD86 and CD40, providing them the means to function as antigen presenting cells. Alloreactive CD4(+) and CD8(+) T lymphocytes demonstrate evidence of DNA synthesis after co-culture with activated vascular endothelium indicating their commitment to proliferation. In conclusion, we describe a simple culture system to isolate and grow mouse vascular endothelium, which provides a powerful tool to study biological interactions in vitro.

Animals↗
PubMed2001

Emergent lung retransplantation after discovery of two primary malignancies in the donor.

A 50-year-old woman underwent single lung transplantation for advanced chronic obstructive pulmonary disease. Shortly after the procedure, it was discovered that the donor suffered from both a renal cell carcinoma and a spindle-cell sarcoma of the ascending aorta, which had metastasized to the spleen. The patient was emergently listed for a retransplantation and underwent bilateral lung transplantation after a new donor became available 4 days after the initial transplantation procedure. After 24 months, the patient is without evidence of malignancy. This case illustrates the role of immediate retransplantation for patients who have inadvertently received thoracic organs from donors harboring occult malignancies.

Adult↗
PubMed2000

Hand-assisted laparoscopic vertical banded gastroplasty: early results.

BACKGROUND: Minimally invasive hand-port-assisted laparoscopic vertical banded gastroplasty has the potential to reduce postoperative complications after bariatric surgery. METHODS: We analyzed the postoperative course of 46 hand-port-assisted laparoscopic vertical banded gastroplasties (LVBG) completed between January 1998 and April 1999. RESULTS: The operating time for the LVBG was shorter (140.8 +/- 6.0 vs 180.2 +/- 6.3 min; p < 0.05). Individuals were able to ambulate sooner (1.36 +/- 0.09 vs 2.44 +/- 0.16 days; p < 0.05), and start oral intake earlier (2.7 +/- 0.27 vs 3.7 +/- 0.17 days; p < 0.05) than the open vertical banded gastroplasty (VBG) controls. Three staple line leaks were detected in this group. Two leaks resolved without clinical sequelae, but one patient developed intraabdominal sepsis. This complication extended the average hospital stay to 6.8 +/- 2.00 days, as compared to 7.71 +/- 0.18 days for historical controls. By discounting this patient from the analysis, we arrive at a more representative length of hospitalization of 4.82 +/- 0.34 days (p < 0.05). CONCLUSIONS: LVBG offers a good alternative to the standard open VBG. Although this procedure has a relatively short learning curve, it should be done at centers with an interest in bariatric surgery.

Adult↗
PubMed2000

The long-term results of resection and multiple resections in Crohn's disease.

Crohn's disease is a panenteric, transmural inflammatory disease of unknown origin. Although primarily managed medically, 70% to 90% of patients will require surgical intervention. Surgery for small bowel Crohn's is usually necessary for unrelenting stenotic complications of the disease. Fistula, abscess, and perforation can also necessitate surgical intervention. Most patients benefit from resection or strictureplasty with an improved quality of life and remission of disease, but recurrence is common and 33% to 82% of patients will need a second operation, and 22% to 33% will require more than two resections. Short-bowel syndrome is unavoidable in a small percentage of Crohn's patients because of recurrent resection of affected small bowel and inflammatory destruction of the remaining mucosa. Although previously a lethal and unrelenting disease with death caused by malnutrition, patients with short-bowel syndrome today can lead productive lives with maintenance on total parenteral nutrition (TPN). This lifestyle, however, does not come without a price. Severe TPN-related complications, such as sepsis of indwelling central venous catheters and liver failure, do occur. Future developments will focus on more powerful and effective anti-inflammatory medication specifically targeting the immune mechanisms responsible for Crohn's disease. Successful medical management of the disease will alleviate the need for surgical resection and reduce the frequency of short-bowel syndrome. Improving the efficacy of immunosuppression and the understanding of tolerance induction should increase the safety and applicability of small-bowel transplant for those with short gut. Tissue engineering offers the potential to avoid immunosuppression altogether and supplement intestinal length using the patient's own tissues.

Adrenal Cortex Hormones↗
PubMed1998

Changing presentation and management of neutropenic enterocolitis.

OBJECTIVE: To characterize the current clinical presentation and management of neutropenic enterocolitis. DESIGN: Retrospective review of records of oncology unit patients requiring general surgical consultation for abdominal complaints in a 1-year period. SETTING: Oncology unit of a tertiary care, university teaching hospital. PATIENTS AND INTERVENTIONS: Fourteen patients diagnosed as having neutropenic enterocolitis were managed conservatively with operation reserved for failure of conservative therapy. MAIN OUTCOME MEASURES: Clinical data from patients at the time of presentation and during treatment for neutropenic enterocolitis. RESULTS: All 14 patients diagnosed as having neutropenic enterocolitis were receiving chemotherapy for solid tumors or leukemias. Seven patients were undergoing stem cell or autologous bone marrow transplantation. Presenting symptoms and physical examination findings were nonspecific. All patients except one had neutropenia at the time of diagnosis. Computed tomographic scans of the abdomen were the most useful confirmatory study for the diagnosis of neutropenic enterocolitis. All patients except one had resolution of neutropenic enterocolitis with conservative therapy. One patient whose course of conservative management failed had protracted neutropenia and required operation for resection of bowel with full-thickness necrosis. CONCLUSIONS: Neutropenic enterocolitis has evolved from a complication of patients with leukemia to a disease of patients receiving high-dose chemotherapy for many malignancies, solid as well as hematologic. Diagnosis of neutropenic enterocolitis continues to be a challenge, as patients typically present with nonspecific gastrointestinal tract symptoms. Neutropenia and computed tomographic scan findings are useful adjuncts in diagnosing neutropenic enterocolitis. Timely conservative treatment frequently allows resolution of neutropenic enterocolitis without operation.

Adult↗
PubMed1997

Use of abdominal ultrasonography to assess pediatric splenic trauma. Potential pitfalls in the diagnosis.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of abdominal ultrasonography (US) for screening and grading pediatric splenic injury. SUMMARY BACKGROUND DATA: The use of abdominal US has increased rapidly as a method of evaluating organ damage after blunt abdominal trauma. Despite US's increasing use, little is known about its accuracy in children with splenic injury. METHODS: Children (N = 32) suffering blunt abdominal trauma who were diagnosed with splenic injury by computerized tomography (CT) scan prospectively were enlisted in this study. Degree of splenic injury was evaluated by both CT and US. The ultrasounds were evaluated by an initial reading as well as by a radiologist who was blinded as to the results of the CT. RESULTS: Twelve (38%) of the 32 splenic injuries found on CT were missed completely on the initial reading of the US. When the ultrasounds were graded in a blinded fashion, 10 (31%) of the splenic lacerations were missed and 17 (53%) were downgraded. Seven (22%) of the 32 splenic fractures were not associated with any free intraperitoneal fluid on the CT scan. CONCLUSIONS: This study has shown that US has a low level of sensitivity (62% to 78%) in detecting splenic injury and downgrades the degree of injury in the majority of cases. Reliance on free intraperitoneal fluid may be inaccurate because not all patients with splenic injury have free intra-abdominal fluid. Based on these findings, US may be of limited use in the initial assessment, management, and follow-up of pediatric splenic trauma.

Abdomen↗
PubMed1996

Distribution of distant metastases from newly diagnosed non-small cell lung cancer.

BACKGROUND: The purpose of our study was to determine the incidence and locations of M1 disease at presentation in patients with non-small cell lung cancer to help design appropriate preoperative imaging algorithms. METHODS: All patients with non-small cell lung cancer seen between 1991 and 1993 were identified, and records were reviewed. For patients with M1 disease, the sites of distant metastases and the methods of diagnosis were recorded. RESULTS: Of 348 patients identified, 276 (79%) had M0 disease and 72 (21%) had M1 disease. In 40 of 72 patients (56%), M1 disease was detected via chest or abdominal computed tomography (CT). Brain, bone, liver, and adrenal glands were the most common sites of metastatic disease, in decreasing order. Brain metastases often occurred as an isolated finding, although isolated liver metastases were uncommon. CONCLUSIONS: M1 disease was common at presentation, and was often detectable via chest CT. The incremental yield of abdominal CT over chest CT was very small, and therefore abdominal CT is not an effective method of screening for metastases if chest CT has been performed.

Adenocarcinoma↗