Biomedical subjects

Ariel Schwartz

Publications and source records attributed to Ariel Schwartz.

5 recordsLinked to original sources

PubMed2005

Non-occlusive mesenteric ischemia in chronically dialyzed patients: a disease with multiple risk factors.

BACKGROUND: Non-occlusive mesenteric ischemia (NOMI) can be a fatal complication in dialysis patients. Intradialytic hypotension is usually the precipitating factor. The occurrence of 16 cases in 5 years (1998-2002), compared with only 4 in previous years, led us to investigate other risk factors contributing to NOMI. A control group of stable hemodialysis patients was used for comparison. RESULTS: 20 patients were studied: 17 diagnosed surgically, and 3 clinically. The mean age was 70.8 +/- 1.8 years, and the male:female ratio 7:13. Nineteen patients were on hemodialysis. Clinically overt atherosclerosis was present in 17 patients. Preceding dialysis-associated hypotension was identified in all patients studied and access thrombosis in 6 patients. In all patients, abdominal pain was the presenting symptom. Initial abdominal examination was unimpressive in 16 patients. The hemoconcentration, leukocytosis and metabolic acidosis were the most prominent laboratory findings. 5/11 abdominal sonograms showed intestinal pathology. 2/3 angiographies were diagnostic. Three patients responded to early fluid challenge and did not require surgery. Pathology was related to the area of the superior mesenteric artery in all 15 patients operated. Twelve (60%) patients died from the event. The 1-year mortality rate was 17/20 patients (85%). Possible contributing factors, other than dialysis-associated hypotension, included: high-dose recombinant human erythropoietin (rhEPO) therapy (179 +/- 35 vs. 116 +/- 10 U/kg/week in the control group, p < 0.05); metastatic calcifications (abdominal aorta 14/14, aortic valve 11/18; medial calcification of mesenteric arteries in 2/11 pathology specimens); digoxin, and hypoalbuminemia. CONCLUSIONS: The increased incidence of NOMI in dialysis patients may be related to overly aggressive rhEPO therapy and the unsuspected presence of mesenteric arterial medial calcifications. Identification of patients at risk, prevention of intradialytic hypotension and a controlled increase in dry weight may help to reduce the incidence of NOMI in chronically dialyzed patients.

Aged↗

PubMed2005

An improved technique for mitosis counting.

Mitosis counting remains one of the most valuable prognostic indicators in tumor pathology; however, as currently carried out it is time consuming and not reproducible. In this study, 6 different pathologists, using different microscopes, arrived at widely different mitotic counts on the same slide, ranging from 4 to 16. These differences were mainly due to the different field areas of the various microscopes used and the method used for counting and recording. In evaluating the most active 10 HPF, the count ranged from 10 to 19. Instead, when an average of 40 fields was recorded, the range was 4-11. Using the mitosis/volume index, which expresses the number of mitotic figures per mm2 of viable tumor, the counts ranged from 8 to 10, a marked improvement. However, this method is complicated and not "user-friendly.'' We suggest a variation of the technique by which a 2 mm2 rectangle is drawn on a cover slip and mounted under the microscope, centered on the most mitotically active area of the tumor. The mitoses in that area are counted (=n) and the percent of viable tumor (=x%) is estimated under low magnification. The number of mitoses per mm2 of viable tumor (cs-MAI) is then calculated according to the formula Cs-MAI=100n/2x. Using this modified method, the range of mitoses counted by the different observers was very narrow (9 to 11), and the time required for the counting was only 5-10 minutes.

Female↗

PubMed2004

Ischemic optic neuropathy in dialyzed patients: a previously unrecognized manifestation of calcific uremic arteriolopathy.

Two patients with end-stage renal disease and on long-term hemodialysis presented with hypotension and an acute unilateral loss of vision. A diagnosis of anterior ischemic optic neuropathy (AION) was made quickly, but despite high-dose steroid therapy, significant vision was not recovered. Temporal artery biopsy results showed extensive medial calcification. The possibility that hypotension, when coupled with calcific uremic arteriolopathy in arteries supplying the optic nerve head, will lead to AION in dialyzed patients is discussed. A short review of AION in the dialysis population is given.

Aged↗

PubMed2004

Increased expression of the hPim-2 gene in human chronic lymphocytic leukemia and non-Hodgkin lymphoma.

Pim-1 and Pim-2 are murine proto-oncogenes implicated in lymphomagenesis. The aim of this study was to investigate whether the human Pim-2 (hPim-2) expression is altered in chronic lymphocytic leukemia (B-CLL) and non-Hodgkin's lymphomas (NHL). We analyzed hPim-2 expression in 48 patients with NHL and CLL by quantitative in-situ hybridization, quantitative RT-PCR and FACS analysis. In-situ hybridization revealed a 5.5 +/- 2.2 times higher expression of hPim-2 in NHL over normal lymphocytes (P < 0.001). Similarly, with quantitative RT-PCR, expression in NHL was 1.5 to 2.6 times higher in involved splenic foci compared to nearby uninvolved regions (n = 3). hPim-2 mRNA was increased 3-folds in B-CLL over normal B-cells (P < 0.006). The increased hPim-2 levels correlated with lymphocyte doubling time (DT), in that mRNA levels were two times greater in patients with rapid DT (P < 0.006). Moreover, a significant correlation was found between hPim-2 expression and the Binet staging system of CLL (P < 0.022). The hPIM-2-protein expression was also upregulated in CLL, as assessed by FACS analysis. Therefore, this report provides direct evidence for a linkage of hPim-2 upregulation to NHL and CLL in man. This relationship between hPim-2 and NHL and CLL raises a number of novel mechanistic options for the genesis and/or progression of some types of human lymphomas.

Gene Expression Regulation, Neoplastic↗

PubMed2003

Histologic and immunohistochemical characterization of tumor and inflammatory infiltrates in oral squamous cell carcinomas treated with local multikine immunotherapy: the macrophage at the front line.

Squamous cell carcinomas of the head and neck (SCCHN) are excellent candidates for local immunotherapy owing to their accessibility and their infiltration by mononuclear cells that are susceptible to immunomodulation. A response rate of 25-60% has been reported for treatment with natural IL-2 or a mixture of natural lymphokines. In the present study, biopsies and posttreatment excision specimens from nine patients with operable SCCHN treated systemically with a variety of immunomodulators and locally with natural lymphokines (multikine, CelSci) were analyzed in an attempt to correlate clinical response to histopathological and immunohistochemical changes. Formalin-fixed, paraffin-embedded tissues were stained with antibodies against lymphocytes (CD45, CD3, CD4, CD8, CD20), macrophages (CD68) including dendritic cells (S-100), markers for lymphocyte activation (CD30, HLA-DR), natural killer cells (CD56 and CD57), beta-2-microglobulin and keratin. One patient showed a complete response to treatment and two a partial response. Tumor size was significantly smaller after therapy. Clinical and pathological regression were more prominent in the smaller tumors. Numerous macrophages, both mononucleated and multinucleated, were present along the tumor-stroma interface in the posttreatment specimens of seven patients, most prominently in the three patients with tumor regression. The increase in the number of CD68+ and S-100+ macrophages after treatment was statistically significant. Lymphocytic infiltrates, which showed some increase following treatment, were composed of a mixture of T and B lymphocytes, the former mostly in contact with the tumor and the latter placed more peripherally. CD8+ lymphocytes extended into the tumors, whereas CD4+ lymphocytes showed minimal extension. Intensity of beta-2-microglobulin staining in tumors was significantly higher following therapy and associated with a better outcome. The marked increase in macrophages following treatment may indicate that the macrophage plays a major role in tumor recognition, destruction and clearance. An increase in the number of macrophages in a posttreatment specimen may indicate immunoresponsiveness.

Adult↗