PubMed Health⌕ Search

Biomedical subjects

P Kirchner

Publications and source records attributed to P Kirchner.

At least 19 recordsLinked to original sources
PubMed1998

Prospective investigation of positron emission tomography in lung nodules.

PURPOSE: Solitary pulmonary nodules (SPNs) are commonly identified by chest radiographs and computed tomography (CT). Biopsies are often performed to evaluate the nodules further. An accurate, noninvasive diagnostic test could avoid the morbidity and costs of invasive tissue sampling. We evaluated the ability of fluorine-18 deoxyglucose positron emission tomography (FDG-PET) to discriminate between benign and malignant pulmonary nodules in a prospective, multicenter trial. METHODS: Eighty-nine patients who had newly identified indeterminate SPNs on chest radiographs and CT were evaluated with FDG-PET. PET data were analyzed semiquantitatively by calculating standardized uptake values (SUVs) as an index of FDG accumulation and also by a visual scoring method. PET results were compared with pathology results. RESULTS: Sixty SPNs were malignant and 29 were benign. Using SUV data, PET had an overall sensitivity and specificity for detection of malignant nodules of 92% and 90%. Visual analysis provided a slightly higher, but not statistically significant, sensitivity of 98% and lower specificity of 69%. For SPNs < or = 1.5 cm (34 of 89), the sensitivity and specificity of SUV and visual analysis were 80% and 95% and 100% and 74%, respectively. CONCLUSION: FDG-PET can accurately characterize indeterminate SPNs. PET imaging provides a noninvasive method to evaluate indeterminate SPNs, which can reduce the need for invasive tissue biopsy.

Aged↗
PubMed1992

Hypofrontality in neuroleptic-naive patients and in patients with chronic schizophrenia. Assessment with xenon 133 single-photon emission computed tomography and the Tower of London.

The "hypofrontality hypothesis" has been supported by many neuroimaging studies, but not all, perhaps because of heterogeneity of samples. The present study examined three different samples that permitted assessment of a variety of confounders, such as effects of long-term treatment, chronicity of illness, and presenting phenomenology: (1) 13 neuroleptic-naive schizophrenic patients, (2) 23 nonnaive schizophrenic patients who had been relatively chronically ill but were medication free for at least 3 weeks, and (3) 15 healthy normal volunteers. Regional cerebral blood flow was measured using single-photon emission computed tomography with xenon 133 as the tracer. The control condition consisted of looking at undulating colored shapes on a video monitor, while the experimental task was the Tower of London. We observed the Tower of London to be a relatively specific stimulant of the left mesial frontal cortex (probably including parts of the cingulate gyrus) in healthy normal volunteers. Both the neuroleptic-naive and the nonnaive patients lacked this area of activation, as well as a related one in the right parietal cortex (representing the circuitry specifically activated by the Tower of London). Decreased activation occurred only in the patients with high scores for negative symptoms. These results suggest that hypofrontality is related to negative symptoms and is not a long-term effect of neuroleptic treatment or of chronicity of illness.

Adult↗
PubMed1992

Immunological evaluation of pediatric cancer patients receiving recombinant interleukin-2 in a phase I trial.

Immunological evaluations were performed on 14 pediatric cancer patients who received human recombinant interleukin-2 (rIL-2) as a bolus intravenous infusion every 8 h for 5 consecutive days in a phase I trial. Three-to-four patients were treated at dose levels of 10, 30, 60, and 100 x 10(3) Cetus U/kg. Six of the patients had stage D neuroblastoma; the remainder had other solid tumors or leukemias. Infusion of rIL-2 was associated with a rapid margination of IL-2-responsive cells followed by demargination and heightened proliferative and cytotoxic activity after therapy was completed. The predominant phenotypic change in circulating peripheral blood mononuclear cells (PBMC) was an increase in CD2 expression by CD56+ natural killer (NK) cells. Appearance of CD2+ CD56+ cells in the circulation correlated with increased lymphokine-activated killer (LAK) cell activity as defined by the ability to kill NK-resistant Daudi tumor cells in vitro. Sustained LAK activity appeared to be dependent on the bioavailability of rIL-2 in vivo as well as in vitro. After rIL-2 therapy, PBMC that were highly responsive to rIL-2 (activated and "poised" LAK cells) persisted for at least 72 h. In the patients tested, increased lysis of autologous and/or allogeneic, histologically similar tumor cell lines was also observed after therapy. The immunoenhancing effects of rIL-2 occurred even at the lower doses used in this study. However, an objective tumor response was not observed in any of the patients.

Adolescent↗
PubMed1992

[Rapidity versus reliability: a critical analysis of the rapid diagnosis of mycobacterial infections with the polymerase chain reaction (PCR)].

In this contribution we analyzed the reliability and the diagnostic value of the results obtained by direct amplification of mycobacterial DNA from patient specimens. Presently, the PCR-method is not as sensitive as recommended culture techniques. In cases of low concentration of mycobacteria in specimens (microscopic negative!) false-negative PCR-results are not rare.

DNA, Bacterial↗
PubMed1991

Relative accuracy of three scintigraphic methods for determination of right ventricular ejection fraction: a correlative study with ultrafast computed tomography.

The accuracy of three scintigraphic methods for determination of right ventricular ejection fraction (RVEF) was tested in 29 patients using ultrafast computed tomography (UFCT) as the gold standard. RVEF measurements by the ECG-gated first-pass approach showed excellent correlation with the UFCT results (r = 0.96, y = 0.06 + 0.91x), while both the standard gated acquisition blood-pool imaging (r = 0.71, y = 0.14 + 0.59x) and the nongated first-pass curve approach (r = 0.63, y = 0.18 + 0.37x) significantly underestimated RVEF. The error can be ascribed to partial inclusion of the atrial activity in the region assigned to the right ventricle. The tricuspid valve plane was found to move by a distance equal to 9%-33% (mean = 20%) of the right ventricular long-axis between systole and diastole. This translational motion was more pronounced with higher EFs.

Adult↗
PubMed1990

Successful treatment with an unrelated-donor bone marrow transplant in an HLA-deficient patient with severe combined immune deficiency ("bare lymphocyte syndrome").

An 8-month-old white female infant with Pneumocystis carinii pneumonia had a normal blastogenic response to mitogens but no response to a variety of antigens, as well as a poor response to allogeneic cells in one-way mixed lymphocyte culture assays. The patient's mononuclear cells had defective class I (HLA-A, -B, -C) and absent class II (HLA-D) antigen expression on their surface, thus establishing the diagnosis of HLA-deficient severe combined immune deficiency (bare lymphocyte syndrome). Family HLA typing, in vitro stimulation of patient mononuclear cells, and sequence-specific oligonucleotide probe hybridization allowed the patients HLA phenotype to be determined. An unrelated bone marrow donor whose phenotype matched at all but a single A locus was found. The patient was conditioned with busulfan and cyclophosphamide, followed by infusion of T-cell-depleted bone marrow cells. The patient has been infection free with a successful marrow graft documented by HLA typing and chromosomal analysis. Sequence-specific oligonucleotide probe hybridization allows determination of the HLA phenotype in patients with HLA-deficient severe combined immune deficiency which, in turn, makes marrow transplantation an option for the reconstitution of these patients' immune system.

Bone Marrow Transplantation↗
PubMed1990

Antihypertensive treatment with cilazapril. Resting and exercise blood pressure, hormones and enzymes.

The effects of the angiotensin-converting enzyme (ACE) inhibitor cilazapril (Ro 31-2848) on resting and exercise blood pressure (BP) as well as on hormonal and enzyme activities were evaluated following a more than one year long-term treatment. After an initial placebo wash-out (mean sitting BP 151/101), n = 13 hypertensive patients were on cilazapril treatment (1.25, 2.5 or 5 mg/d; in 2 cases with 25 mg hydrochlorothiazide additionally) for 78 (70 to 82) weeks (phase A, mean sitting BP 137/91). Thereafter, they underwent a second placebo wash-out of 4.4 (1 to 10) weeks (phase B, mean sitting BP 137/94) again followed by cilazapril treatment of 9.5 (4 to 14) weeks (phase C, mean sitting BP 137/91) to titrate the minimum antihypertensive dose. At the end of each phase, blood pressure was measured at rest and during isotonic (bicycle) and isometric (handgrip) exercise, and hormones and enzymes were evaluated 4 h post-dose.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1985

Persistence and progression of immunologic abnormalities in haemophilia.

Immunologic parameters in 51 patients with haemophilia treated with cryoprecipitate from volunteer donors or with commercial lyophilized concentrate were studied on 2-7 occasions. Concentrate users had significantly decreased mean T4 (helper)/T8 (suppressor) lymphocyte ratios when the initial (1.5 +/- .43) and most recent (1.25 +/- .60) values were compared (p less than .001), whereas in cryoprecipitate users mean values remained normal. Of the 22 concentrate users with initially normal T4/T8 ratios, 10 became abnormal during the study, an incidence of 45%. Fifteen of 28 (54%) patients with abnormal T4/T8 ratios had elevated circulating immune complexes (CIC), whereas all 16 patients with normal T4/T8 ratios had normal levels of CIC. Six patients have persistent lymphadenopathy.

Antigens, Surface↗
PubMed1985

Gallium accumulation in the stomach. A frequent incidental finding.

Accumulation of tracer by the stomach is a frequent incidental occurrence on gallium scans. Gastric concentration of Ga-67 equal to or greater than that seen in the liver was observed in approximately 10% of patients in a large series. Although a few of these patients had known or subsequently demonstrated gastric pathologic conditions, most had no clinically or radiographically identifiable gastric disease.

Gallium Radioisotopes↗
PubMed1982

Parenteral tiapamil treatment of arrhythmias in cardiac patients.

27 cardiac patients with different types of arrhythmias were treated in the coronary care unit with tiapamil administered by intravenous infusion. Special attention was given to determining the antiarrhythmic effects in patients with acute coronary insufficiency. In the group of 15 patients with ventricular extrasystoles (VEs; Lown classification III-V). 9 patients had acute myocardial infarction and 1 patient had coronary artery disease. In the group with supraventricular extrasystoles (6 cases). 1 patient had experienced anterior infarction. The third group comprised 6 patients with combined ventricular (Lown V) and supraventricular extrasystoles. In 1 case, the arrhythmia was due to acute anterior infarction. 2 patients had experienced reinfarction and one patient had crescendo angina pectoris. ECG and hemodynamics were monitored continuously before, during and for 20 h following therapy. In patients with VEs alone, the median frequency fell from 612 to 459/h at the third hour of infusion. The median VE/sinus beat quotient decreased from 0.125 to 0.0108 (p less than 0.01) in the third hour of treatment, and increased to 0.1029 after the completion of therapy. VE suppression was particularly marked in the 10 patients with coronary artery disease, 7 of these demonstrating a reduction by over 90%. Similar results were obtained in patients with supraventricular arrhythmias and mixed forms. The preliminary results show that tiapamil may be an effective antiarrhythmic agent in supraventricular and particularly in ventricular extrasystoles, and that its spectrum of antiarrhythmic action merits detailed investigation in larger numbers of patients.

Adult↗
PubMed1981

[Management of supraventricular and ventricular arrhythmias with the intravenous administration of the calcium antagonist Tiapamil (Ro 11-1781) (author's transl)].

27 cardiac patients with a mean age of 58.5 years (S.D. +/- 9.43) were treated in the coronary care unit with tiapamil, a new Ca2+ antagonist, by intravenous infusion. The following arrhythmias were identified: ventricular premature complexes (VPCs, Lown class 3--5) in 15 patients, supraventricular premature complexes (SVPCs) in 6 patients, and mixed VPCs (Lown grade 5) plus SVPCs in 6 patients. ECGs and hemodynamic parameters were continuously monitored prior to, during and up to 24 hours after the therapy. In patients with VPCs, the median frequency of VPCs decreased from 612.0 to 64.0 at the 3rd hour of therapy (p less than 0.01). Between the 13th and the 24th hour after tiapamil, without therapy the median VPCs increased to 459.0. The median "VPCs/sinusal" beats ratio was decreased from 0.125 to 0.0108 (p less than 0.01) at the 3rd hour and returned to 0.1029 from the 9th to the 20th hour after stopping tiapamil. The results in the patients with SVPCs, or with VPCs + SVPCs were similar. Tiapamil did not affect the central venous pressure and decreased the median blood pressure from 130/80 to 110/75 mm Hg (p less than 0.10). The effects of tiapamil against all types of cardiac arrhythmias can therefore be defined as good. 1/27 patients presented hypotension that required therapy with dopamine, and mild subjective complaints (mainly headache) were reported in 6 patients. No complications occurred. The results show that tiapamil is effective both against SVPCs and VPCs, and thus its spectrum of action differs from that of other Ca2+ antagonists.

Adult↗
PubMed1979

The role of gallium-67 scanning in the clinical staging and preoperative evaluation of patients with carcinoma of the lung.

Gallium-67 scanning was evaluated in 100 patients with proved carcinoma of the lung. It was valuable in separating primary from secondary lung tumors, determining the extent of contralateral hilar or mediastinal lymph node involvement, and detecting distant organ metastases. In addition to multiplane whole-body Ga-67 tomographic scanning, colloid liver scans, bone scans, and computerized axial tomography scans of the brain were obtained to determine the presence of distant metastasis. The gallium scan detected 11 of 12 occult metastases and identified 7 of 7 liver, 9 of 14 brain, 4 of 4 soft tissues, 1 of 4 contralateral lung, and 9 of 11 bone metastases. The whole-body gallium scan accurately detected or excluded extrathoracic metastatic disease in 11 of 12 patients examined postmortem within three months of a gallium scan. An approach is recommended using gallium scanning along with chest roentgenograms for clinical staging and preoperative evaluation of patients with carcinoma of the lung. Specific organ scans should be reserved for the occasional symptomatic patient with a negative gallium scan or for clarification of an indeterminate gallium scan.

Bone Neoplasms↗
PubMed1977

Changes in canine bladder perfusion with distension.

Using a radioisotope-labeled microsphere technique, canine bladder perfusion was investigated. Blood flow was measured in in flaccid and distended conditions. A slight decrease in total bladder blood flow was recorded. There was a relative decrease in bladder mucosal flow with distension. There was no difference in perfusion of dome versus trigone.

Animals↗