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K Kopecky

Publications and source records attributed to K Kopecky.

At least 19 recordsLinked to original sources
PubMed2002

The first technique for non-invasive measurements of volumetric ophthalmic artery blood flow in humans.

AIM: To validate the first non-invasive measurements of volumetric ophthalmic artery blood flow in humans. METHODS: The ophthalmic arteries of healthy normal adults were examined by Advanced Technology Laboratories (ATL, a subsidiary of Phillips Medical Systems Inc) high definition imaging (HDI) 5000 colour Doppler imaging ultrasound with a 5-12 MHZ probe. A group of 14 subjects for experiment 1 and a group of 10 subjects for experiments 2 and 3 were selected, with the examined eye chosen randomly. Peak systolic velocities (PSV) and end diastolic velocities (EDV) of the ophthalmic artery and central retinal artery were measured and recorded. Cineloops (cinegraphic videos) of the ophthalmic arteries were then recorded with the ATL HDI 5000 and values for ophthalmic artery blood flow were produced offline using experimental analysis software. Multiple regression analysis was used to compare blood flow measurements with PSV and EDV measurements in the ophthalmic artery. In two follow up experiments, intraobserver variation in obtaining cineloops and the interanalyser variability in cineloop analysis were studied. RESULTS: Volumetric flow correlated with ophthalmic artery PSV and EDV (p = 0.02, r(2) = 0.5). There was no correlation with the cental retinal artery. The intraobserver coefficient of variation in obtaining cineloops was 29.89% for blood flow, 19.07% for diameter, and 22.27% for velocity. The coefficients of variation of the measurements of the two cineloop analysers were 40.21% for blood flow, 22.71% for diameter, and 26.34% for velocity. CONCLUSION: Cineloop analysis produces ophthalmic artery flow measurements which correlate with PSV and EDV, suggesting validity. The intraobserver variation and cineloop analyser variation were found to be in the acceptable range.

Adult↗
PubMed2001

Usefulness of color Doppler ultrasound in the management of a spinal arteriovenous fistula.

BACKGROUND: While color Doppler ultrasonography and microvascular Doppler recordings have been used intraoperatively for spinal cord vascular malformations, they have not been employed for similar spinal cord lesions preoperatively. CASE DESCRIPTION: We report the usefulness of color Doppler ultrasonography through a lumbar laminectomy defect in the management of a spinal arteriovenous fistula. CONCLUSION: Color Doppler ultrasonography should be considered for spinal lesions in which a laminectomy defect is present.

Adult↗
PubMed2001

Blasts from elderly acute myeloid leukemia patients are characterized by low levels of culture- and drug-induced apoptosis.

Increasing evidence suggests that the biology of acute myeloid leukemia (AML) may differ between older and younger patients, with a higher incidence of antecedent myelodysplasia, unfavorable cytogenetic abnormalities, and multidrug resistance seen in the elderly. Abrogation of apoptosis in response to cytotoxic medications is associated with drug resistance in AML, as is expression of bcl-2, an important anti-apoptotic protein. We hypothesized that blasts from elderly (> or = 55 years) and young adult AML patients might have different levels of apoptotic and cell cycle responses to chemotherapeutic agents, as well as different levels of proliferation and of bcl-2 protein expression. Therefore, we cultured bone marrow leukemia samples from previously untreated elderly (n=33) and young (n=21) AML patients for 48 h and then measured apoptosis, bcl-2 protein levels, cell cycle distributions, and expression of a proliferation marker, proliferating cellular nuclear antigen (PCNA) in multi-parametric flow cytometry assays. In some experiments, leukemia samples were exposed to cytarabine (Ara-C) or daunomycin (DNR) for the last 16-18 h of the culture period. In comparison to samples from young patients, cultured samples from elderly AML patients had a higher fraction of viable cells, as measured by Trypan blue exclusion, higher PCNA expression, and significantly less culture-induced and drug-induced apoptosis. The mean apoptosis after culture was 13% for elderly AML samples, versus 20% for young AML samples (P=0.009). Similarly, the mean apoptosis after Ara-C was lower in elderly than in young AML samples, 13 versus 28% (P=0.001), as was the mean apoptosis after DNR, 15 versus 26% (P=0.012). Diminished apoptotic responses in elderly AML cells were not consistently associated with high bcl-2 levels at thaw or bcl-2 levels increased by culture. These data suggest that new therapies should be developed to overcome abrogated apoptosis, particularly in elderly AML patients.

Acute Disease↗
PubMed1999

Role of EUS in the preoperative staging of pancreatic cancer: a large single-center experience.

BACKGROUND: Current methods for staging pancreatic cancer can be inaccurate, invasive, and expensive. Endoscopic ultrasound (EUS) is reported to be highly accurate for local staging of gastrointestinal tumors including pancreatic cancer. The aim of this study was to assess the utility of EUS and CT for staging pancreatic cancer by comparing staging accuracies in surgical patients and evaluating the potential impact of EUS staging and training. METHODS: This was a preoperative comparison of the diagnostic operating characteristics of these procedures in a referral-based academic medical center. Data were collected on 151 consecutive patients referred with confirmed pancreatic cancer between April 1990 and November 1996. All patients had preoperative CT and EUS performed for staging. In patients undergoing surgery, the surgical staging and/or findings were used to confirm EUS and CT staging. RESULTS: Eighty-one (60%) of 151 patients underwent surgery and made up the study subset. In these 81 patients, surgical exploration provided a final T staging in 93% (75 of 81), N staging in 88% (71 of 81) and data on vascular invasion in 93% (75 of 81). In the surgical patient group, with surgical correlation, EUS accuracy for T staging was as follows: T1 92%, T2 85%, T3 93%, and for N staging was: N0 72%, and N1 72%. CT accuracy for T staging was as follows: T1 65%, T2 67%, T3 38%, and for N staging was as follows: N0 52% and N1 100%. CT failed to detect a mass in 26% of patients with a confirmed tumor at surgery. Overall accuracy for T and N staging was 85% and 72% for EUS and 30% and 55% for CT, respectively. The ability to accurately predict vascular invasion was 93% for EUS and 62% for CT (p < 0.001). EUS was 93% accurate for predicting local resectability versus 60% for CT (p < 0.001). Last, the data were divided into two groups for the senior endosonographer's experience: procedures performed between 1990 and 1992 (98 cases) and 1993 and 1994 (53 cases). This analysis revealed that 7 of 9 instances of mis-staging (78%) occurred in the earlier group, during the learning phase for EUS. CONCLUSIONS: EUS is more accurate than CT for staging pancreatic malignancies, including predicting vascular invasion and local resectability. EUS staging was significantly better than CT for T1, T2, and T3 tumors. EUS staging accuracy improved after 100 cases, thus suggesting a correlation between the accuracy of EUS staging and the number of procedures performed.

Adult↗
PubMed1998

The value of ultrasound with ultrasound-guided fine-needle aspiration biopsy compared to computed tomography in the detection of regional metastases in the clinically negative neck.

PURPOSE: Head and neck oncologists have not reached consensus regarding the role of contemporary imaging techniques in the evaluation of the clinically negative neck in patients with head and neck squamous cell carcinoma (HNSCC). The purpose of the present study was to compare the accuracy of ultrasound with guided fine-needle aspiration biopsy (UGFNAB) and computed tomography (CT) in detecting lymph node metastasis in the clinically negative neck. METHODS AND MATERIALS: Sixty-four neck sides of patients with HNSCC were examined preoperatively by ultrasound/UGFNAB and CT at one of five participating tertiary care medical centers. The findings were correlated with the results of histopathologic examination of the neck specimen. RESULTS: Ultrasound with guided fine-needle aspiration biopsy was characterized by a sensitivity of 48%, specificity of 100%, and overall accuracy of 79%. Three cases had nondiagnostic aspirations using UGFNAB and were excluded. CT demonstrated a sensitivity of 54%, specificity of 92%, and overall accuracy of 77%. UGFNAB detected two additional metastases not visualized on CT, whereas CT detected no metastases not seen on UGFNAB. The results of UGFNAB were similar between the participating centers. CONCLUSIONS: Approximately one half of the clinically occult nodal metastases in our patient group were identified by both CT and UGFNAB. Overall, UGFNAB and CT demonstrated comparable accuracy. The sensitivity of CT was slightly better than UGFNAB, but the latter remained characterized by a superior specificity. The results of CT and UGFNAB did not appear to be supplementary. The choice of imaging modality for staging of the clinically negative neck depends on tumor site, T-stage, and experience and preference of the head and neck oncologist. If CT is required for staging of the primary tumor, additional staging of the neck by UGFNAB does not provide significant additional value.

Biopsy, Needle↗
PubMed1995

Treatment of acute myelogenous leukemia in patients over 50 years of age with V-TAD: a Southwest Oncology Group study.

Acute myelogenous leukemia (AML) in the elderly continues to have a poor prognosis and new treatment approaches are needed. This Phase II trial was undertaken to evaluate the complete remission rate and toxicity of a chemotherapeutic regimen including etoposide and 6-thioguanine, combined with reduced doses of cytosine arabinoside and daunorubicin (V-TAD) in individuals greater than 50 years of age with AML. Thirty-five patients, ranging in age from 51 to 80 years (median, 66 years), were registered onto the study. Twenty-nine patients were entered at the first dose level (daunomycin 20 mg/m2 days 1 and 2, ara-C 75 mg/m2 days 1-5, 6-thioguanine 75 mg/m2 every 12 hr days 1-5, and etoposide 50 mg/m2 days 1, 2, and 3) and six patients underwent therapy at the second dose level (ara-C 75 mg/m2 days 1-7 with the remainder of the regimen unchanged). After achieving a complete remission, patients underwent two to three consolidation cycles of chemotherapy. Thirty-one patients were evaluable for response. Thirteen patients (ten of twenty-five at the first dose level and three of six at the second dose level) achieved a complete remission (42%). Median remission duration was 6 months (range 1-21 months). The current regimen, while tolerated, did not result in improved survival compared with prior treatment regimens because of a high incidence of resistant and recurrent leukemia.

Age Factors↗
PubMed1995

Classification and treatment of local septic complications in acute pancreatitis.

BACKGROUND: An international symposium on acute pancreatitis recently developed a clinical classification system for severe acute pancreatitis that classifies all local septic complications into three groups: infected necrosis (IN), sterile necrosis (SN), and pancreatic abscess (PA). Despite the appeal of having three distinct, well-defined labels for this complex process, the clinical utility of this schema has yet to be determined. The purpose of this study was to investigate the prognostic and therapeutic utility of applying this clinical classification system to a large group of surgical patients with local septic complication from acute pancreatitis. PATIENTS AND METHODS: We reviewed the cases of 62 patients with complicated pancreatitis, classifying them into IN (n = 20), SN (n = 14), or PA (n = 28) groups. Ranson's score, APACHE II score, and computed tomography grading were calculated within the first 48 hours of admission. Information on patient demographics, etiology of pancreatitis, operative procedures, timing of intervention, bacteriology, blood loss, intensive care unit days, ventilator days, and morbidity and mortality were also accrued and analyzed. RESULTS: Despite similar demographics and etiology of pancreatitis, patients with necrosis, both IN and SN, were more critically ill than were patients with PA (APACHE II score > 15, 21% versus 0%, respectively), required earlier operative intervention (mean 14 days versus 29 days, P = 0.02), required necrosectomy with drainage (65% versus 4%, P < 0.001) rather than simple drainage (3% versus 86%, P < 0.001), more reoperations (2.3 versus 1.1, P < 0.05), and had a significantly higher mortality rate (35% versus 4%, P < 0.05). In addition, patients with IN required significantly more hospital days, ventilator days, and blood transfusions than either patients with SN or PA (P < 0.05). CONCLUSIONS: We conclude that this classification system allows for the stratification of patients into three distinct groups--infected necrosis, sterile necrosis, and pancreatic abscess--and has both therapeutic and prognostic usefulness.

Abscess↗
PubMed1995

Randomized comparison of pentostatin versus interferon alfa-2a in previously untreated patients with hairy cell leukemia: an intergroup study.

PURPOSE: Therapy of hairy cell leukemia has markedly improved. Interferon alfa-2a and pentostatin are active agents. The National Cancer Institute organized an intergroup trial to compare these agents prospectively in untreated patients. METHODS: Patients were randomized to receive either interferon alfa-2a (3 x 10(6) U subcutaneously three times per week) or pentostatin (4 mg/m2 intravenously every 2 weeks). Patients who did not respond to initial treatment were crossed over. RESULTS: Of 356 patients on study, 313 were eligible. Among interferon patients, 17 of 159 (11%) achieved a confirmed complete remission and 60 of 159 (38%) had a confirmed complete or partial remission. Among pentostatin patients, 117 of 154 (76%) achieved a confirmed complete remission and 121 of 154 (79%) had a confirmed complete or partial remission. Additional patients achieved criteria for complete remission, but lacked confirmatory follow-up evaluation. Response rates were significantly higher (P < .0001) and relapse-free survival was significantly longer with pentostatin than interferon (P < .0001). The median follow-up duration is 57 months (range, 19 to 82). Myelosuppression was more frequent with pentostatin (P = .013). A multivariate logistic regression analysis of the confirmed complete remissions on pentostatin showed the following factors to be important for achieving a complete remission: high hemoglobin level (two-tailed P = .024), young age (P = .0085), and no or little splenomegaly (P = .0029). CONCLUSION: Both agents were well tolerated. Pentostatin produced higher response rates, and the responses were durable. Patient age and clinical status had an impact on outcome with pentostatin. Pentostatin is effective therapy for hairy cell leukemia.

Adult↗
PubMed1994

Physiological perturbation of ocular and cerebral blood flow as measured by scanning laser ophthalmoscopy and color Doppler imaging.

Retinal blood flow regulation in health remains poorly described. We hypothesized that retinal perfusion is controlled to provide constant O2 delivery to that tissue, and that changes in retinal blood flow in response to chemical stimuli parallel changes in carotid and retrobulbar perfusion. Accordingly, in 11 young adults with normal eye examinations, we measured retinal blood flow indices (via scanning laser ophthalmoscopy [SLO] during fluorescein angiography) and carotid, ophthalmic, and central retinal arterial blood flow indices (via Doppler imaging [CDI]) under control, hypoxic (alveolar PO2 = 55 +/- 3 mmHg) and hyperoxic (alveolar PO2 = 655 +/- 18 mmHg) conditions. The three conditions were counterbalanced in order and isocapnia was maintained in each. Retinal arterial mean dye velocity and arteriovenous passage time, as measured by SLO, were slowed by hyperoxia and accelerated by hypoxia, in rough proportion to the changes in arterial O2 content (+/- 10%; p < 0.05). In the seven subjects in which relative measurements of retinal arterial diameters were obtained, neither hypoxia nor hyperoxia significantly altered vessel diameter. At the same time, mean retinal capillary transit velocity was independent of PO2, suggesting that, in health, retinal capillaries may be recruited as PO2 falls. O2-induced changes in carotid, ophthalmic, or central retinal arterial blood flow velocities (via CDI) were not found, though a wide coefficient of variation (30% for CDI vs. 14% for SLO) may have contributed to this failure. We conclude that, under isocapnic conditions, retinal perfusion may be regulated to provide constant O2 delivery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Reduction in transplant-related complications in patients given intravenous immuno globulin after allogeneic marrow transplantation.

Bone marrow transplantation renders patients immunocompetent due to the need for supralethal doses of chemoradiotherapy prior to infusion of the donor stem cells. Multiple immunological deficiencies are seen and patients are at high risk of developing a variety of infections. This period of immunological incompetence usually lasts from 6 to 12 months. In some subsets of patients [those with chronic graft-versus-host disease (GVHD); recipients of unrelated transplants; increasing patient age] persistent T and B cell abnormalities may be seen for years, despite normal serum immunoglobulin levels. This review summarizes a number of trials of intravenous immune globulin (IVIG) therapy to prevent infection following bone marrow transplantation. IVIG has shown benefit in reducing septicaemia, interstitial pneumonia, fatal cytomegalovirus (CMV) disease, acute GVHD and transplant-related mortality in adult recipients of related marrow transplants. Further investigation into dose, schedule and duration of IVIG prophylaxis needs to be conducted.

Bone Marrow Transplantation↗
PubMed1993

Pancreatic cancer presenting with resolving pseudocyst during octreotide therapy.

Pancreatic cancer presenting as acute pancreatitis is relatively uncommon. Pancreatic cancer should be included in the differential diagnosis of "idiopathic" acute pancreatitis, particularly in the elderly. The following case report describes a patient in whom pancreatic cancer presented as acute pancreatitis with pseudocyst formation and subsequent resolution with octreotide therapy. Various implications of this case are reviewed.

Acute Disease↗
PubMed1993

Mononuclear cell reconstitution in the lung after marrow transplantation. Lack of influence of cytomegalovirus pneumonia, irradiation, and graft-versus-host disease.

The number and types of mononuclear cells obtained by bronchoalveolar lavage from 105 marrow transplant patients with and without cytomegalovirus pneumonia were studied to determine whether: (1) CMV pneumonia was associated with local recruitment of lymphocytes and lymphocytes of particular subtypes to the lung, and (2) whether local recruitment was affected by the known risk factors for the development of CMV pneumonia, namely acute graft-versus-host disease and total body irradiation. Results showed a significant increase in the number of lymphocytes (P = 0.014) and in the number of lymphocytes marking for CD8 (P = 0.0045) and CD16 (P = 0.052) in BAL from all patients compared with BAL from normal subjects. However, no significant differences were observed in BAL cellular characteristics between patients with and without pneumonia nor between patients with CMV or other etiologies of pneumonia. There were also no significant differences in BAL characteristics when patients were analyzed for the presence of acute GVHD, the use of TBI, or the type of transplant. These results do not provide evidence for local recruitment of lymphocytes to the lung unique of patients with CMV pneumonia nor to patients with GVHD and CMV pneumonia, in contrast to what is observed in murine CMV pneumonia.

Acute Disease↗
PubMed1993

Production of prostatic lesions in canines using transrectally administered high-intensity focused ultrasound.

High-intensity focused ultrasound is a method of destroying tissue at a point distant from the transducer without injuring intervening tissue. A transrectal probe was developed and used to treat 26 canines in order to determine the feasibility of using this therapy in humans. Lesions of coagulative necrosis which evolved into cystic cavities were produced. Surrounding tissue was preserved without evidence of injury.

Animals↗
PubMed1990

High-dose cisplatin in disseminated melanoma: a comparison of two schedules.

A total of 38 patients with metastatic melanoma received monthly chemotherapy with cisplatin at a dose of 200 mg/m2, per cycle; 14 received 20 mg/m2 cisplatin i.v. on days 1-5 and 24 were given 100 mg/m2 i.v. on days 1 and 8. Objective responses were seen in 2/14 treated on days 1-5 and in 5 of 22 evaluable subjects receiving cisplatin on days 1 and 8, for an overall response rate of 22%. The median survival of all patients was 6 months, with no significant difference observed between the two schedules. Severe neurotoxicity and myelosuppression were more common in patients treated on days 1-5. Two patients treated in this manner were bedridden due to neurotoxicity and four developed grade 4 leukopenia after the first cycle of chemotherapy. Only one patient treated with the divided-dose schedule became leukopenic during the first cycle, and none of the patients were debilitated by neurotoxicity. Thrombocytopenia was statistically more severe. Nausea and vomiting, fatigue, ototoxicity, and paresthesia were seen with equal frequency. Very high doses of cisplatin can be delivered with acceptable toxicity using a divided-dose schedule. As the response rate on this schedule appeared to be comparable with that achieved on the more toxic consecutive 5-day schedule, the former deserves to be tested in diseases known to show a dose response to cisplatin. However, in melanoma, administration of 200 mg/m2 per course did not appear to be associated with a markedly improved response rate, compared with cisplatin alone at "standard" doses.

Adult↗
PubMed1989

Pathogenetic implications of internuclear bridging in myelodysplastic syndrome. An Eastern Cooperative Oncology Group/Southwest Oncology Group Cooperative Study.

Numerous morphologic features have been described in bone marrow and peripheral blood in myelodysplastic syndrome (MDS). We draw attention to a high incidence of a subtle morphologic feature, internuclear bridging (INB), not previously recognized as a morphologic feature in MDS. The occurrence of INB in MDS suggests an underlying abnormality of mitotic division that could explain the impaired production of hematopoietic cells, the addition and deletion cytogenetic changes, and the stepwise disease progression and cytogenetic progression characteristic of MDS. Lack of awareness that INB occurs in MDS may cause confusion of MDS and congenital dyserythropoietic anemia type I, a congenital process also characterized by INB.

Bone Marrow↗