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P Stark

Publications and source records attributed to P Stark.

At least 55 records · Page 3Linked to original sources
PubMed1997

BCR-ABL transcripts in bone marrow aspirates of Philadelphia-negative essential thrombocytopenia patients: clinical presentation.

One of the diagnostic criteria of essential thrombocythemia (ET) is the absence of the Philadelphia chromosome (Ph-neg). On the molecular level, Ph-neg ET patients may carry BCR-ABL transcript. The natural history of BCR-ABL positive Ph-neg ET patients is undetermined. We examined the BCR-ABL status by reverse transcriptase two-step nested polymerase chain reaction in bone marrow aspirates of 25 Ph-neg ET patients. We found 12 BCR-ABL positive and 13 BCR-ABL negative patients in the study group. The comparison showed that the two groups had similar clinical and laboratory characteristics, except for a significant increased patients' age and decreased polymorphonuclear cell count in the BCR-ABL positive group. During a median follow-up of 20 and 22.5 months for the BCR-ABL negative and positive groups, respectively, there was neither blastic transformation nor unrelated death in both groups. We conclude that it is important to look for BCR-ABL transcript in Ph-neg ET patients and to follow them closely to investigate the nature of this translocation in this group of patients.

Adult↗
PubMed1997

Thrombotic complications in essential thrombocythemia with relatively low platelet counts.

Essential thrombocythemia (ET) is often associated with thrombotic and hemorrhagic complications, mostly at platelet counts exceeding 600 x 10(9)/L. There are, however, a few reports of such complications in ET at considerably lower platelet levels and the therapeutic approach to affected patients with relatively low platelet counts is still controversial. In the present study, the first to directly address the issue of hemostatic manifestations at relatively low platelet counts, we have determined the lowest platelet counts associated with such manifestations in 56 consecutive ET patients. Clinical manifestations related to ET were recorded in 46 (82%) patients. Of the symptomatic patients, 32 (70%) had symptoms at platelet counts lower than 600 x 10(9)/L, 23 (50%) at counts lower than 500 x 10(9)/L, 10 (22%) at counts lower than 400 x 10(9)/L, and 6 patients (13%) at platelet counts as low as 300-350 x 10(9)/L. Severe complications occurred at platelet counts lower than 600 x 10(9)/L in 10 patients (22%), lower than 500 x 10(9)/L in 7 (15%), and at lower than 400 x 10(9)/L in 2 (4%). Thrombotic neurologic symptoms were the most common (31 patients, 67%), followed by peripheral vascular symptoms (17 patients, 37%); hemorrhagic complications were relatively rare (3 patients, 7%). In most cases, cessation or improvement of clinical manifestations was observed only after further reduction in platelet counts. In conclusion, thrombotic manifestations, including severe ones, are not uncommon in ET at relatively low platelet counts. We recommend that symptomatic patients with relatively low platelet counts be treated and the platelet counts further reduced well into the lower normal range.

Adult↗
PubMed1997

Levels of proteins C and S do not decline subsequent to first line chemotherapy in lymphoma patients.

Thromboembolic complications and decrease in protein C and S have been observed in patients while receiving combination chemotherapy for breast cancer. We investigated whether initial cytotoxic treatment of non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) is also associated with changes in these anticoagulant parameters. For this purpose 25 patients with intermediate to high grade NHL and seven with HD, undergoing primary treatment with cytotoxic drugs were evaluated at three time-points: pre-therapy, mid-therapy and post-therapy. In contrast to the breast cancer patients, no significant changes in protein C, protein S and antithrombin III levels were observed in the NHL patients during the various stages of therapy. However in HD patients, the mean protein C values had a tendency to be higher at mid-therapy compared to pre-therapy and protein S levels had a tendency to be higher at mid-therapy compared to post-therapy. In lymphoma patients receiving primary cytotoxic treatment we did not find changes in anticoagulant parameters that can explain a chemotherapy-induced hypercoagulable state, as has been reported in breast cancer patients.

Adolescent↗
PubMed1997

[Early postoperative changes in systolic and diastolic function at rest and during stress in patients with hypertrophic obstructive cardiomyopathy (HOCM) after myectomy].

INTRODUCTION: In this study systolic and diastolic function in patients with hypertrophic obstructive cardiomyopathy (HOCM) and intractable complaints to medication were investigated before and after a mean of 7 months after myectomy. METHODS: Investigations in 19 patients with HOCM included echocardiography, Swan-Ganz-thermodilution-catheter and radionuclide-angiography. RESULTS: Myectomy resulted in a reduction of the intraventricular gradient at rest (40.1 +/- 43.3 versus 7.6 +/- 12.0 mm Hg, p < or = 0.005) and under provocation (92.4 +/- 67.1 versus 21.3 +/- 26.5 mm Hg, p < or = 0.001). Echocardiographically determined basal septal thickness was reduced (24.9 +/- 6.3 versus 20.1 +/- 6.8 mm; p < or = 0.05) and diastolic diameter increased (40.4 +/- 5.2 versus 44.8 +/- 7.1; p < or = 0.05). Exercise tolerance increased from the maximally achieved 64.5 +/- 19.2 to 89.5 +/- 24.0 W (p < or = 0.001). Symptomatic status (NYHA) improved (1.7 +/- 1.4 versus 2.8 +/- 0.3 (p < or = 0.001). Systolic parameters showed at rest an increase in isovolumetric contraction time (65 +/- 39 versus 112 +/- 50 ms, p < or = 0.01), in time to peak ejection (109 +/- 40 versus 188 +/- 42 ms, p < or = 0.001), and a reduced left ventricular ejection fraction (72 +/- 12 versus 64 +/- 11%, p < or = 0.01). Analysis of regional ejection fraction revealed a significant reduction of ejection fraction in the basal septal region (p < or = 0.05). Increase of global and regional ejection fraction under exercise was still preserved. Mean pulmonary capillary wedge pressure was significantly reduced at rest (11.8 +/- 3.8 versus 8.6 +/- 2.4 mm Hg, p < or = 0.05) as well as under exercise (27.0 +/- 7.1 versus 20.4 +/- 6.8 mm Hg, p < or = 0.01), whereas left ventricular enddiastolic volume index (63 +/- 19 versus 72 +/- 17 ml*m-2, p < or = 0.05) was significantly increased. CONCLUSIONS: In patients with HOCM, myectomy reduces intraventricular gradient, increases exercise capacity, and is accompanied by improved diastolic function parameters, while systolic function parameters are generally reduced.

Adult↗
PubMed1997

Characterization of pulmonary nodules and mediastinal staging of bronchogenic carcinoma with F-18 fluorodeoxyglucose positron emission tomography.

OBJECTIVE: To evaluate F-18 fluorodeoxyglucose positron emission tomography (PET) in terms of its sensitivity and specificity in diagnosing malignant pulmonary nodules and staging bronchogenic carcinoma. METHODS: A retrospective review of any patient that presented to the VA Palo Alto Health Care System with a pulmonary nodule between 9/94 and 3/96 revealed 49 patients (four female, 45 male) age 37-85 (mean 63) with 54 pulmonary nodules who had: chest CT scan, PET scan; and tissue characterization of the nodule. Characterization of each nodule was achieved by histopathologic (N = 44) or cytopathologic (N = 10) analysis. Of the 49 patients, 18 had bronchogenic carcinoma which was adequately staged. Mediastinal PET and CT findings in these 18 patients were compared with the surgical pathology results. N2 disease was defined as mediastinal lymph node involvement by the American Thoracic Society's classification system. Mediastinal lymph nodes were interpreted as positive by CT if they were larger that 1.0 cm in the short-axis diameter. RESULTS: Sensitivity and specificity for the diagnosis of malignant pulmonary nodules using PET was 93 and 70%, respectively. All nodules (N = 3) that were falsely positive by PET scan were infectious in origin. All nodules (N = 4) that were falsely negative by PET were technically limited studies (outdated scanner, no attenuation correction, hyperglycemia) except for one case of metastatic adenocarcinoma. The sensitivity and specificity of PET in diagnosing N2 disease was 67 and 100%, compared with 56% and 100% for CT scan (not statistically significant). However, one more patient with N2 disease was correctly diagnosed by PET than by CT scan. CONCLUSION: PET is a valuable tool in the diagnosis and management of pulmonary nodules and may more accurately stage patients with bronchogenic carcinoma than CT scanning alone.

Adult↗
PubMed1997

Chromosome 22.

Explore the source record for details and available documents.

Chromosomes, Human, Pair 22↗
PubMed1996

Effects of lobar atelectasis on the distribution of pleural effusion and pneumothorax.

Atelectasis is known to change the retractility of the involved part of the lung and the pleural pressure adjacent to it. Consequently, pleural effusions or pneumothoraxes will change their distribution and preferentially migrate toward the site of atelectasis. This alteration will often result in an atypical distribution of pleural liquid or gas. The radiological implications of this phenomenon are discussed herein.

Humans↗
PubMed1996

Optimization of thoracic spiral CT: effects of iodinated contrast medium concentration.

PURPOSE: To determine the effect of varying iodine concentration on arterial enhancement and perivenous artifact during thoracic spiral computed tomographic (CT) scanning. MATERIALS AND METHODS: One hundred thirty-eight outpatients received 15.0 g (n = 76) or 22.5 g (n = 62) of iodine (300 mg/mL iodine) while undergoing thoracic spiral CT. Patients received either undiluted contrast medium, 1:1 normal saline dilution, or 3:1 normal saline dilution. Contrast medium was injected at a flow rate determined to deliver the entire iodine dose within 40 seconds. Attenuation was measured within arteries and veins. Three blinded thoracic radiologists independently graded perivenous artifact and arterial enhancement. RESULTS: Perivenous artifacts were statistically significantly reduced with successive iodine dilution (P < .002). Arterial enhancement was statistically significantly better with 15.0 g of iodine diluted 1:1 when compared with the same iodine dose undiluted or diluted 3:1 (P < .01). Arterial enhancement achieved with 15.0 g of iodine diluted 1:1 was not statistically significantly lower than that achieved with 22.5 g of iodine diluted 1:1 (P > .31); however, venous artifact was greater with 22.5 g of iodine (P < .004). CONCLUSION: Reduced iodine concentration appears to diminish perivenous artifact and to result in improved arterial enhancement during thoracic spiral CT.

Adult↗
PubMed1996

Pneumothorax ex vacuo.

Pneumothorax ex vacuo is a little-known complication of lobar collapse. In this condition, acute bronchial obstruction from mucous plugs, aspirated foreign bodies, or malpositioned endotracheal tubes causes acute lobar collapse and a marked increase in negative intrapleural pressure around the collapsed lobe. As a result, gas is drawn into the pleural space around the collapsed lobe while the seal between the visceral and parietal pleura of the adjacent lobe or lobes remains intact. The pneumothorax spontaneously resolves when the bronchial obstruction is relieved and the lobe reexpands. Recognition of pneumothorax ex vacuo is crucial in directing treatment to relieve the bronchial obstruction rather than inserting a chest tube into the pleural space.

Adolescent↗