PubMed Health⌕ Search

Biomedical subjects

N Fishback

Publications and source records attributed to N Fishback.

16 recordsLinked to original sources
PubMed2000

Arterial repair with synthetic patch by using titanium clips.

BACKGROUND: Vascular closure staple (VCS) clips made of titanium were originally developed for microvascular anastomoses. There is limited experience with their applicability to vascular reconstruction in larger vessels. This study compares VCS clips to standard sutures in arterial repair using a synthetic patch. METHODS: In an experimental study with pigs, two sequential 10-mm abdominal aortotomies were allocated randomly to synthetic patch (polytetrafluoroethylene) repair with VCS clips or continuous 6-0 polypropylene sutures. Angiographic, macroscopic, and microscopic results were assessed after 2 months. RESULTS: There were no significant differences in the patency rate, vessel diameter at the repair site, or healing indices. The mean (SD) clamp time was 8.7 (3.0) minutes for clip repair and 14.3 (7.4) minutes for suture repair (p = 0.04), and the times required for the vessel reconstruction were 5.3 (1.3) and 9.3 (3.0) minutes, respectively (p = 0.009). CONCLUSION: Patched arterial repair with VCS clips is faster than sutured reconstruction with comparable results after 2 months of follow up.

Animals↗
PubMed1998

Ureteral repair with titanium staples: comparison with suture closure.

OBJECTIVES: Vascular closure staple (VCS) clips made of titanium were initially developed for microvascular anastomoses with little knowledge of their effectiveness in larger tubular tissue structures. This study compares VCS clips and sutures in the closure of longitudinal ureterotomy incisions. METHODS: In 9 pigs, 1-cm-long anterior, longitudinal ureterotomy incisions were randomly assigned to closure with either 4-0 interrupted polyglactin sutures or VCS clips. RESULTS: Clip closure was significantly faster (74+/-28 versus 534+/-182 seconds). All 18 ureters were patent and without signs of leakage, calculus formation, or stenoses after 3 months. Clip closure resulted in slightly but not statistically significantly less narrowing of the duct lumen, but there was no difference in wall thickness at the repair site. At histologic examination, all 18 incisions healed without signs of acute inflammation or marked fibrosis. CONCLUSIONS: Ureterotomy closure with VCS clips results in wound healing that is as effective as suture closure, with a comparable degree of narrowing. The time required for clip closure is only about 1/7 that required for suture closure.

Animals↗
PubMed1998

Arterial reconstruction with vascular clips is safe and quicker than sutured repair.

BACKGROUND: Non-penetrating, arcuate-legged vascular-closure staple clips made of titanium were initially developed for microvascular anastomoses with little experience of their use in larger vessels. The purpose of this study was to compare vascular-closure staple clips to sutured anastomoses in common iliac arteries in a porcine model. METHODS: In an experimental study, transected iliac arteries on both sides of 11 pigs were randomly assigned to end-to-end anastomosis performed with vascular-closure staple clips or interrupted 6-0 polypropylene sutures. Angiographic, macroscopic and microscopic results were assessed after 2 months. RESULTS: There was no significant difference in the patency rate, tensile strength of the anastomoses, vessel diameter at the repair site, intimal thickness or wall thickness of the arteries after either method of closure. The mean (s.d.) clamp time was 19.8 (6.1) minutes for clip repair, and 36.0 (6.9) seconds for suture repair (P < 0.001). The times required for the reconstruction of the anastomoses were 17.4 (6.1) and 35.5 (7.1) minutes, respectively (P < 0.001). CONCLUSIONS: Arterial anastomoses performed with vascular-closure staple clips are faster than sutured anastomoses, and result in comparable wound healing when assessed for patency, tensile strength, degree of narrowing and intimal reaction.

Anastomosis, Surgical↗
PubMed1997

Common bile duct repair with titanium staples. Comparison with suture closure.

BACKGROUND: Vascular Closure Staple (VCS) clips made of titanium were initially developed for microvascular anastomoses with little experience of their use in larger tubular structures. This study compares VCS clips and sutures in the closure of supraduodenal choledochotomy. METHODS: In nine pigs, two longitudinal incisions of the common bile duct (CBD) were randomly assigned to closure with 4-0 interrupted polyglactin sutures or VCS clips. RESULTS: Clip closure was significantly faster (116 +/- 28 vs 581 +/- 88 s). All nine CBDs were patent and without signs of calculus formation after 3 months. Clip closure resulted in slightly less narrowing of the duct lumen and thinner scar at the repair site. At histological examination, all 18 incisions had healed without signs of fistula formation or marked fibrosis. CONCLUSIONS: Choledochotomy closure with VCS clips results in as good or better wound healing than suture closure, with a comparable degree of narrowing. The time required for clip closure is only about one-fifth that of suture closure.

Animals↗
PubMed1997

Arterial and venous repair with vascular clips: comparison with suture closure.

PURPOSE: Nonpenetrating, arcuate-legged titanium vascular closure staple (VCS) clips were initially developed for microvascular anastomoses with little experience of their use in larger vessels. The purpose of this study was to compare the VCS clips with standard suture closure of arteriotomies and venotomies in common iliac vessels of pigs. METHODS: In nine pigs, longitudinal 1 cm iliac arterial and venous incisions were repaired with VCS clips on one side and continuous 6-0 polypropylene suture on the other, and the macroscopic and microscopic results were assessed after 3 months. RESULTS: The time required for vessel repair was significantly shorter with clips than with sutures both in arteries (51 +/- 9 vs 414 +/- 36 seconds) and in veins (100 +/- 32 vs 439 +/- 45 seconds). There was no significant difference in the inner diameter, intimal thickness, or intima-to-media height ratios of the arteries or veins after either method of closure. CONCLUSIONS: Repair of 1 cm incisions in small-diameter arteries and veins with VCS clips results in wound healing as good as that achieved with standard suture closure, when assessed for patency, leakage, degree of narrowing, and intimal reaction. The time required for clip closure is considerably shorter than for suture closure.

Animals↗
PubMed1996

A quick and simple method to close vascular, biliary, and urinary tract incisions using the new Vascular Closure Staples: a preliminary report.

Traditional suture reconstruction of tubular organs creates a perforating needle injury, leaves suture material on the endothelial or mucosal surfaces, and is cumbersome when done endoscopically. One alternative method of reconstruction of tubular organs could use the new nonpenetrating clip to create an everted closure. In five pigs, a longitudinal incision of the infrarenal aorta, inferior vena cava, left ureter, gallbladder, and the common bile duct (in two) was closed with Vascular Closure Staples (VCS-clips). Four weeks after surgery, all ten blood vessels remained patent with no thrombosis. There was a well-healed wound with continuous intimal layer. The ureteral, gallbladder, and common bile duct wounds healed without leakage or obstruction in all animals. There was complete mucosal bridging of the wound, although in some specimens one or two clips were exposed to the lumen. The VCS-clips are easily and quickly applied and are safe insofar as can be determined by short-term follow-up.

Animals↗
PubMed1996

Pleomorphic (giant and spindle cell) carcinoma is genetically distinct from adenocarcinoma and squamous cell carcinoma by K-ras-2 and p53 analysis.

Pleomorphic carcinoma (PC) of lung is a poorly differentiated epithelial neoplasm predominantly composed of pleomorphic giant and/or spindle tumor cells. The WHO classification of lung cancer recognizes spindle cell carcinoma and giant cell carcinoma as separate neoplasms related to squamous cell carcinoma (SqC) and large cell carcinomas, respectively. Further, the presence of foci of SqC or adenocarcinoma (AdC) in, respectively, 10% and 45% of PC produces additional uncertainty as to the distinctive nature of this tumor type. In this study, the authors tested the hypothesis that PC is an entity separate from SqC or AdC by evaluating the mutational spectrum seen in these tumor types. This is performed by documenting and comparing mutation type and rate of K-ras-2 and p53 genes in PC, SqC, and AdC. Comparative DNA sequence and immunohistochemical analysis were performed on 22 PC, 42 SqC, and 97 AdC. Archival formalin-fixed, paraffin-embedded tissues formed the basis of the study. Immunohistochemical staining with p53 antibody (DO-7) revealed statistically significant differences in the intensity and frequency of staining of PC (weak, 86% of cases) versus SqC (strong, 52% of cases) and AdC (strong, 27% of cases) (P < .001). Topographic genotyping with subsequent polymerase chain reaction (PCR) and sequence analysis of K-ras-2 showed mutations in significantly fewer cases of PC (9%, 2 of 22 cases) than in AdC (36%, 35 of 97 cases) or SqC (0%, 0 of 42 cases) (P < .001). Pleomorphic carcinoma also showed significantly fewer p53 point mutations (14%, 3 of 22 cases) than did AdC (27%, 26 of 97 cases) of SqC (43%, 18 of 42 cases) (P < .01). Finally, the p53 mutations in PC were more common in exon 7, whereas those in SqC and AdC were more frequent in exon 8. These findings reveal significant differences in the pattern and frequency of genetic mutations between PC and pulmonary SqC and AdC and are in keeping with the separate histopathologic classification of these tumors.

Adenocarcinoma↗
PubMed1996

Analysis of p53, K-ras-2, and C-raf-1 in pulmonary neuroendocrine tumors. Correlation with histological subtype and clinical outcome.

Neuroendocrine tumors of lung, including typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small cell lung carcinoma (SCLC) constitute a spectrum of malignancies in which the pathologist at times has difficulty in discerning tumor subtype and aggressiveness in a reproducible fashion. Therefore, 59 primary neuroendocrine lung tumors including 10 TCs, 26 ACs, 15 LCNECs, and 8 SCLCs were selected from cases collected from 1976 to 1988 and immunostained for p53 protein. All of these tumors were also genotyped for specific point mutational damage affecting p53 (exons 5, 7, and 8; with ACs additionally sequenced for p53 exon 6); 13 tumors for K-ras-2 (exon 1); and 31 tumors for c-raf-1 (exon 15) growth-regulatory genes. Genotyping was performed on topographically selected, minute tumor samples removed from unstained formalin-fixed, paraffin-embedded tissue sections (topographic genotyping) using polymerase chain reaction and direct sequencing. The distribution of p53 immunohistochemical staining had four patterns: negative in TCs, one-half of ACs, 3 of 15 LCNECs, and 1 of 8 SCLCs; less than 10% but more than five tumor cells per 10 high power fields (focal) in a subset (7 of 26) of aggressive ACs; 10 to 49% of tumor cells (patchy) in a subset (6 of 26) of ACs with a higher grade of aggressiveness; and 50 to 100% of tumor cells (diffuse), exclusively seen in LCNECs (12 of 15) and SCLCs (7 of 8). Three patterns of immunohistochemical staining intensity of p53 protein were seen: negative, weak or mild, and moderate to marked. SCLCs and LCNECs accounted for cases of moderate to marked staining and were the only ones to have mutations in p53 exons 5, 7, or 8. No mutations were found in AC and TC, showing absent to weak staining and no staining, respectively. The difference in distribution and staining intensities between LCNEC and SCLC compared with AC and TC was statistically significant (P < 0.001). Patients having AC with patchy p53 immunostaining usually had survival limited to 3 years, whereas those having AC with focal p53 immunostaining subsequently developed metastatic or recurrence of AC disease (P < 0.05). The absence of point mutations in cases with patchy or focal immunostaining suggests increased expression of wild-type p53 tumor suppressor protein likely in response to growth deregulation in a more aggressive subtype of AC. A novel hypothesis is presented in regard to these findings. K-ras-2 and c-raf-1 gene sequence analysis showed no evidence of point mutational change in any of the tumors studied. The TC and AC categories are therefore genetically distinct from the higher grade neuroendocrine SCLC and LCNEC. Immunohistochemistry for p53 on AC lung tumors may be helpful to delineate cases at higher risk for aggressive behavior. Additionally, although LCNEC is categorized as a non-small-cell carcinoma, it is more akin genetically and immunohistochemically to SCLC.

Carcinoid Tumor↗
PubMed1996

Immunohistochemical study of metalloproteinases and their tissue inhibitors in the lungs of patients with diffuse alveolar damage and idiopathic pulmonary fibrosis.

Immunohistochemical and confocal microscopic studies of the localization of matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs), and type IV collagen were made in lung tissues from patients with normal pulmonary histology (n = 3), diffuse alveolar damage (n = 14), and idiopathic pulmonary fibrosis (n = 12). Pretreatment with pepsin revealed otherwise undetectable MMP- and TIMP-immunoreactive sites. In normal lung, MMP-2, MMP-9, TIMP-1, and TIMP-2 were localized in ciliated cells, endothelial cells, pneumocytes, macrophages, and smooth muscle cells; fibroblasts showed a strong reaction only for MMP-2. Only TIMP-2 showed co-localization with type IV collagen. Myofibroblasts and epithelial cells expressed increased reactivity for MMPs and TIMPs in both disorders. The reactivities for MMPs and TIMPs were stronger in diffuse alveolar damage. MMP-2 showed focal co-localization in capillary endothelial and disrupted epithelial basement membranes, suggesting activation of collagenolysis. A protective effect against this lysis was suggested by the extensive co-localization of TIMP-2 with type IV collagen and fibrillar collagens. Alveolar buds showed increased reactivity for MMPs and TIMPs in their lining epithelial cells, myofibroblasts, and their basement membranes; however, their matrices were mostly unreactive. These findings emphasize the complexity of the roles of MMPs and TIMPs in collagen turnover in diffuse alvcolar damage and idiopathic pulmonary fibrosis.

Adolescent↗
PubMed1996

Update on lymphoid interstitial pneumonitis.

Lymphoid interstitial pneumonitis (LIP) involves a clinicopathologic pattern of pulmonary disease characterized by diffuse interstitial reactive lymphoid infiltrates. In adults, it occurs most commonly in autoimmune diseases, such as Sjögren's syndrome (0.9% of these patients) and primary biliary cirrhosis, whereas in children it is usually seen in HIV infection. Dysproteinemias (hyper- and hypogammaglobulinemia) are found in more than 60% of patients. Children can show CD8-lymphocytosis in bronchoalveolar lavage fluid, lung tissue, peripheral blood, and salivary gland, associated with HLA-DR5 haplotype. Radiographically, most patients with LIP have reticulonodular infiltrates, with or without patchy areas of consolidation. CT scans can show both small nodular and ground glass patterns, patterns that are diagnostically nonspecific. Reduced lung volumes and diffusing capacities are consistent and sensitive indicators of disease in LIP. In an experimental model, diffusing capacity was the single most sensitive functional index of disease progression. Microscopically, LIP is part of a spectrum of pulmonary lymphoid proliferations, ranging from follicular bronchitis-bronchiolitis and pulmonary lymphoid hyperplasia (the latter in AIDS patients), proliferations largely limited to airways, to low-grade malignant lymphoma. These patterns may be difficult to differentiate from each other. It appears that LIP sometimes evolves to lymphoma; the frequency of this evolution is probably low but is difficult to assess because low-grade lymphomas may mimic LIP. A relatively high frequency of LIP patients have Epstein-Barr virus DNA in their lungs but not all patients with LIP show this finding, suggesting other possible etiologies.

Adult↗
PubMed1995

Extramedullary hematopoiesis presenting as posterior mediastinal mass: a study of four cases.

We present four cases of extramedullary hematopoiesis occurring in the posterior mediastinum. The patients are two women and two men between the ages of 20 and 87 years. Two patients presented with a history of thalassemia, and one had a history of anemia of undetermined etiology. One patient was asymptomatic, and the posterior mediastinal mass was detected during a routine chest radiographs. Surgical resection of the mass was performed in one patient, whereas a biopsy was performed in the other three. Histologically, all the cases showed the typical features of extramedullary hematopoiesis, namely the presence of numerous lymphocytes admixed with megakaryocytes and red cell precursors. Follow-up information ranging from 2 mo to 3 years showed that all patients are alive and well.

Adult↗
PubMed1995

Pulmonary involvement in systemic lupus erythematosus.

Pulmonary disorders in systemic lupus erythematosus involve a variety of clinical presentations and pathologic patterns, which can be difficult to diagnose due to systemic dysfunction, infection, or complications of therapy. The causes of dyspnea in systemic lupus erythematosus are multifactorial, and the clinical manifestations of lung disease widely vary. Biopsy is frequently relied on to evaluate and diagnose pulmonary disease in systemic lupus erythematosus. The patient who has systemic lupus erythematosus-associated lung disease is effectively treated with various immunosuppressive drugs, in conjunction with careful evaluation of the patient's systemic involvement, drug-induced complications, and the ever-present threat of infection.

Adult↗
PubMed1994

Pulmonary lymphomatoid granulomatosis. Evidence for a proliferation of Epstein-Barr virus infected B-lymphocytes with a prominent T-cell component and vasculitis.

Similarities have been noted in the histologic patterns of lymphomatoid granulomatosis and Epstein-Barr virus associated lymphoproliferative disease involving the lung. Epstein-Barr virus has also been identified by polymerase chain reaction in most cases of lymphomatoid granulomatosis; however, the precise cellular localization of Epstein-Barr virus sequences has not been extensively studied. We analyzed 10 cases of lymphomatoid granulomatosis involving the lung by immunohistochemistry and combined immunohistochemistry with in situ hybridization for Epstein-Barr virus, CD20, and CD45RO. All cases were selected from the files of the Armed Forces Institute of Pathology and met the clinical and histologic criteria for the diagnosis of lymphomatoid granulomatosis, grades 1 through 3. In all 10 cases, immunohistochemistry showed that most of the cells--small to medium-sized lymphocytes--were T cells (CD45RO+); however, a much smaller population of medium-sized to large atypical cells were B cells (CD20+). In each case, combined immunohistochemistry and in situ hybridization confirmed the presence of Epstein-Barr virus sequences within B (CD20+) cells and the absence of Epstein-Barr within T-cells (CD45RO+). Polymerase chain reaction analysis for immunoglobulin heavy-chain gene rearrangement identified a monoclonal pattern in six of nine cases tested, whereas analysis for T-cell receptor gamma-chain gene rearrangements was negative in three cases tested. On the basis of these findings, we hypothesize that most cases of lymphomatoid granulomatosis involving the lung represent a proliferation of Epstein-Barr virus infected B-cells with a prominent T-cell reaction and vasculitis, distinguishing these cases from angiocentric "T-cell lymphomas" in other sites, such as the head and neck.

Adult↗
PubMed1993

Mediastinal paragangliomas. A clinicopathologic and immunohistochemical study of 16 cases.

BACKGROUND: Paragangliomas of the mediastinum are rare neoplasms. Because of their rarity, the spectrum of morphologic and immunohistochemical features and biologic behavior of these tumors in this location has not been delineated. METHODS: A retrospective study of 16 cases of mediastinal paragangliomas was undertaken to evaluate their clinicopathologic and immunohistochemical features. RESULTS: The patients were 10 men and 6 women whose ages ranged from 16-69 years of age (mean, 42.5 years). Twelve tumors were located in the posterior mediastinum, and three tumors were located in the anterior mediastinum. In one case, the exact location of the tumor within the mediastinum was not available. Microscopically, the nesting pattern (zellballen) was the most commonly encountered. Areas of stromal hyalinization were also frequent and were marked in two tumors. In two cases there was a prominent spindle cell component, and two cases showed granular cell changes in the cytoplasm of the tumor cells. Cellular pleomorphism was observed in the majority of cases. Occasional mitoses were seen in a few cases. Immunohistochemical studies in 10 cases showed chromogranin reactivity in 10 of 10 cases, S-100 protein in 9 of 10 cases, leu-enkephalin in 6 of 10 cases, and neurofilament protein in 5 of 10 cases. Keratin was negative in all cases studied. All patients underwent surgical resection of their tumors, and one patient underwent adjuvant radiation therapy. Follow-up information ranging from 1-168 months (mean, 84.5 months) was obtained in 12 patients. Nine patients (75%) were alive and well at last follow-up. In one patient the tumor metastasized to spinal space and bone marrow, and another patient died with metastases to lymph node, lung, and pelvis 14 years after initial diagnosis. CONCLUSIONS: The only parameter found to correlate with aggressive behavior was the extent of circumscription and/or local infiltration of the tumor at initial resection. No clinical, histologic, or immunohistochemical features were otherwise found to separate aggressive from indolent clinical behavior. Regular follow-up is recommended in these patients due to the potential for these tumors to metastasize.

Adolescent↗
PubMed1992

Mucinous (so-called colloid) carcinomas of lung.

We present 24 cases of primary mucinous (so-called colloid) carcinomas of the lung. The patients were between 33 and 81 yr old (median: 57 yr), including 15 men and nine women. The lesions were discovered incidentally on chest X-ray, where they presented in diverse forms. No predilection for a particular lobe or pulmonary segment was observed. The tumors varied from 0.5 to 10 cm in greatest diameter. Grossly, the tumors were poorly circumscribed, soft, tan-to-gray mucoid lesions. Microscopically, they showed intra-alveolar pools of mucin containing small clusters of atypical cells floating in the mucin, and foci of neoplastic columnar epithelium lining scattered alveoli. Seven cases showed areas of solid, well-differentiated malignant glands adjacent to pools of mucin. In two cases, lymph node metastases were found at surgery. Eleven (57%) of 19 patients were alive over a follow-up period ranging from 2 to 192 mo; one of them had metastases to bone and another had intrapulmonary recurrence. Eight patients died with/of their tumors, two of them with known metastases to bone and/or brain, and one with recurrence after 2 yr of initial diagnosis. No follow-up was obtained in five patients. Although the extent of clinical evaluation varied, no other primary neoplasms (i.e., breast, gastrointestinal tract, or other organs where primary mucinous carcinomas are known to occur) were observed. These tumors probably represent a variant of bronchioloalveolar carcinoma and share the prognosis of that neoplasm. However, because of their often bland cytologic features and paucity of malignant cells, they may be difficult to diagnose as neoplasms.

Adenocarcinoma, Mucinous↗