Diagnostic role of internal mammary lymph node involvement in tuberculous pleurisy: a multicenter study

BACKGROUND AND OBJECTIVES

Diagnosis of tuberculous pleurisy (TP) may be challenging and it often requires pleural biopsy. A tool able to increase pre-test probability of TP may be helpful to guide diagnostic work-up and enlargement of internal mammary lymph node (IMLN) has been suggested to play a potential role. The aim of the present investigation was to assess role of IMLN involvement in TP in a multi-centric case-control study, by comparing its prevalence and test performance to those observed in patients with infectious, non-tuberculous pleurisy (NTIP), and in controls free from respiratory diseases (CP).

METHODS

A total of 419 patients, from 14 Pulmonology Units across Italy were enrolled (127 patients affected by TP, 163 affected by NTIP and 129 CP). Prevalence, accuracy and predictive values of ipsilateral IMLN involvement between cases and control groups were assessed, as well as concordance between chest computed tomography (CT scan) and thoracic ultrasound (TUS) measurements.

RESULTS

The prevalence of ipsilateral IMLN involvement in TP was significantly higher than that observed in NTIP and CP groups (respectively 77.2%, 39.3% and 14.7%). Results on test performance, stratified by age, revealed a high positive predictive value in patients aged ≤50 years, while a high negative predictive value in patients aged >50 years. The comparison between CT scan and ultrasound showed moderate agreement (Kappa=0.502).

CONCLUSIONS

Evaluation of IMLN involvement plays a relevant role in assessing the pre-test probability of TP. Considering the increasing global prevalence of mycobacterial infections, a tool able to guide diagnostic work-up of suspected TP is crucial, especially where local sources are limited.

Studio della biforcazione carotidea con Angio-TC spirale

Lo studio della biforcazione carotidea con l'accurata valutazione del grado di stenosi appare di fondamentale importanza per l'approccio terapeutico al paziente con malattia cerebrovascolare aterosclerotica. Pur essendo ancor oggi l'angiografia considerata il «gold standard» nello studio della patologia carotidea, altre metodiche meno costose e non invasive, come l'Eco-Doppler e l'Angio-RM, sono state utilmente impiegate.

La crescente diffusione di apparecchiature TC ad acquisizione volumetrica ha permesso lo sviluppo di una nuova metodica di imaging nello studio della biforcazione carotidea: angio-TC. Con tale metodica sono stati studiati 40 pazienti: ove è stato possibile sono stati confrontati i dati angio-TC con quelli di uno studio angiografico digitale, trovando una corrispondenza superiore all'80%.

CT in acute stroke: improved detection of dense intracranial arteries by varying window parameters and performing a thin-slice helical scan

We evaluated the possibility of improving detection of a dense intracranial artery on CT in acute stroke by narrowing window width, varying window level and performing a thin-slice helical scan for the circle of Willis, in some cases followed by postprocessing maximum-intensity projections. We carried out 32 examinations of 31 patients with a documented cerebral ischaemic attack, performing cranial CT within 6 h of the onset of symptoms. Patients with intracranial haemorrhage were excluded, as were patients who went on to thrombolytic therapy. Varying window width and centre level on standard 5 mm thick contiguous axial slices, we detected a dense proximal middle cerebral artery (MCA) in a higher proportion of patients. A 1.1 mm thick helical scan through the circle of Willis improved recognition of a dense distal horizontal segment and the temporoinsular branches of the MCA and of a dense posterior cerebral artery.

[Diagnostic accuracy of teleradiology in thoracic and abdominal diseases]

For one year now, teleradiology has linked the "S. Marcello" Hospital to the Department of Radiology of "Del Ceppo." Hospital in Pistoia, 30 kilometers away. Plain films are digitized (Lumiscan 50, Philips), transmitted over a dedicated standard telephone line and displayed at 1024 x 1024 x 8 bits. To study the diagnostic accuracy of teleradiology in chest and abdominal conditions, we digitized and transmitted to the Pistoia Dept. of Radiology, a sample of 156 (96 chest and 60 abdominal) emergency examinations made in "S. Marcello" Hospital from January through November, 1995. The patients were 81 women (mean age: 69 years) and 75 men (mean age: 66 years); the age range was 17-93 years. Three radiologists independently reviewed the images in the Pistoia Dept. of Radiology on a digital workstation enabled to manipulate images. They filled in some given forms specific for chest and abdominal radiography, which were compared with the same forms filled in by the radiologist in "S. Marcello" Hospital who reviewed plain films. The differences were never clinically important; they concerned emphysema (4 false positives and 2 false negatives), congestion of the hila (2 false positives and 2 false negatives) and abnormal air in small bowel and colon (2 false positives and 2 false negatives). We believe these differences to be related to interobserver variability. The diagnostic accuracy of monitor image interpretation by the three radiologists who reviewed digitized radiographs exceeded 96% for both chest and abdominal examinations, which figure compares with literature data on high resolution workstations.

[Secondary liver lesions studied with double-helix spiral computed tomography: first experience]

The authors report their early personal experience with double-helix spiral CT (CT Twin Elscint) in the study of liver metastases. This work was aimed at optimizing the study technique and at assessing the diagnostic accuracy of this method. The high temperature developed by CT Twin and the presence of a double row of detectors permit to acquire proper length sequences (with 6.5 mm slice thickness) within a short scanning time which is easy for the patient to tolerate without breathing and moving. Two hundred and thirty patients were examined with US for focal hepatic lesions and then submitted to spiral CT: spatial and density resolution were higher with spiral CT than with US, and the former technique permitted the whole liver to be studied without any partial volume artifacts, which allowed us to confirm all the lesions depicted with US and to detect other lesions, missed at US, in 20% of patients. The choice of the proper time between contrast administration and sequence acquisition is sufficient to permit the detection of focal lesions, if the liver is studied in the portal phase. The authors stress the yield of spiral CT, especially with the double-helix technique, in studying liver metastases.

[Teleradiography for diagnosis in emergency care. A clinical experience]

This work was aimed at evaluating the role of teleradiology in a diagnostic emergency room. Over a 6-month period (September 1991-February 1992), 2,000 films made in the emergency room were transmitted to a resident radiologist 1 kilometer away: each examination included patient's data (sex, age, site of trauma, etc.) which were sent by the admitting physician. A teleradiology system (Lumiscan 100 AT&T and Philips) was used. Films were digitized on a 1024 x 1024 x 8-bit image matrix and then transmitted over a dedicated standard phone line to the Department of Radiology. The autograph report was sent by fax to the emergency room. Four radiologists, of varying experience, independently reviewed a sample of 179 digitized radiographs and, 30 days later, the original films on a conventional light-box. The results appear to be encouraging because no significant differences were observed in the performance of any of the radiologists. Good video/films agreement was obtained, together with high sensitivity and specificity. A good result was the relatively small number (0.4% of all examined cases) of false negatives diagnosed on faxed films relative to the actual clinical diagnosis.

[The nimodipine therapy of acute focal cerebral ischemia (minor stroke). A clinical study with an assessment of regional cerebral blood flow by SPECT]

Aim of the study is the evaluation of therapeutic effectiveness of nimodipine in acute focal cerebral ischaemia. Thirty patients affected by minor ischaemic stroke divided in two randomized groups have been studied consecutively: all the patients were treated with standard therapy, nimodipine was delivered in addition only to the patients of the first group. Both clinical evaluation using Mathew scale, modified by Gelmers, and flowmetric evaluation with SPECT were performed at different times. The results haven't shown any significant statistical difference in the effectiveness of the therapy between the two groups even if a positive clinical trend was evidenced in the group treated with nimodipine. The flowmetric study has shown the poor homogeneity of the groups from a physiopathological point of view not-with-standing the two groups were similar for the clinical severity, sex, age and vascular risk factors. We conclude that is advisable to carry out further trials in which the comparison study groups are more numerous and balanced also from a physiopathological point of view.

Serum erythropoietin levels in patients undergoing autologous bone marrow transplantation

Serum erythropoietin (sEpo) levels were serially measured with a radioimmunoassay in 14 patients undergoing autologous bone marrow transplantation (BMT), starting before the institution of the conditioning regimen up to day +45. An increase in sEpo levels was observed soon after starting the chemotherapy regimen, and before an evident fall in hemoglobin (Hb) levels took place. The peak in sEPo levels (221 +/- 181 mU/ml) was reached at day 0 in 9/14 patients, and was delayed up to day + 10 in the remaining five. There was a negative correlation between loge sEpo and Hb values (r = -0.730; p less than 0.01); the regression line of this correlation was comparable to the one obtained in a group of 15 iron-deficiency anemic subjects. Therefore, patients undergoing autologous BMT appear to be able to develop adequately increased sEpo levels in response to the severity of anemia. No correlation was found between sEpo and white blood cell or platelet count. On the other hand, sEpo value at day 0 was significantly related to the day of neutrophil recovery (r = -0.806; p less than 0.001): patients with the highest sEpo levels at day 0 showed significantly faster (p less than 0.001) neutrophil recovery.

Quantitative platelet imaging and comparison of four mathematical models for the evaluation of platelet mean life span in patients with chronic immune thrombocytopenia

BACKGROUND AND METHODS

Twenty-five thrombocytopenic patients underwent quantitative in vivo platelet kinetic studies using a scintillation camera and a computer-assisted imaging system. They fulfilled the criteria for chronic immune thrombocytopenia, and the object of the study was to evaluate platelet sequestration and destruction in the spleen. In this sense, the differences in the distribution of the radiolabelled platelets in the spleen and the liver, as well as the differences in the platelet mean life span (MLS) as computed by different methods were assessed. Serial images of the spleen pool, liver and heart were taken after reinjection of In-111-oxine labelled autologous platelets.

RESULTS AND CONCLUSIONS

The spleen/liver ratio proved to be a more reliable index in indicating the splenectomy outcome that the Z index (see text). Platelet survival curves were analyzed using four mathematical models, and it was found that MLS estimation is model dependent. Thus, it seem advisable to apply at least two different methods when analyzing experimental data.

Binding of recombinant human 125I-erythropoietin to CFU-E from the spleen of anemic mice

Erythroid precursors were obtained from the spleen of mice made anemic with phenylhydrazine and used to study the binding of bioactive 125I-rEp to membrane receptors. Kinetic analysis, using splenic cells obtained at different times following the induction of anemia, showed that the maximum binding was reached at day 3, and decreased thereafter; minimal amounts of 125I-rEp were bound to the splenic cells of normal mice. Splenic cells of day 3 anemic mice were fractionated using continuous Percoll density gradients, resulting in a fraction enriched in CFU-E (delta = 1.065-1072 g/ml) which showed the highest 125I-Ep binding on a per cell basis. The amount of 125I-rEp bound was greatly reduced in the densest fractions, which were comprised of maturing erythroblasts. The binding was time- and temperature-dependent, and a significant correlation was found with cell concentration up to 12 X 10(6). The amount of radioactivity specifically bound rose with increasing concentrations of 125I-rEp until a plateau was reached (2.5 nM), whereas non specific binding increased slightly and linearly. The binding of 125I-rEp was susceptible to competitive inhibition by unlabeled rEp, while other hematopoietic growth factors were ineffective. The calculated receptor density on these purified immature erythroid progenitors was 570 molecules with a Kd = 0.5 nM. Overall, these results suggest that the expression of the Ep receptor is reduced with increasing maturation.

A dot assay for the erythropoietin receptor using human recombinant 125I-erythropoietin

A dot assay was developed for the detection of membrane receptor(s) for erythropoietin (Ep). A relatively homogeneous population of cells bearing the receptor for Ep was generated in the spleen of mice made anemic with phenylhydrazine and crude membrane extracts were prepared from spleen cell suspensions. Aliquots of the membrane extracts were applied to microdishes of nitrocellulose in a volume of 4 microliters. After free reactive sites were blocked, the microdishes were incubated for 2 h at 37 degrees C with 125I-labeled human recombinant Ep (125I-rEp), and nitrocellulose bound radioactivity was determined thereafter. Reproducible curves were obtained, and a significant correlation between bound radioactivity and the amount of membrane proteins applied to the nitrocellulose dishes was found. Specific binding was saturable, reaching a plateau at 2.5 nM. Binding parameters of nitrocellulose-immobilized receptor were not significantly different from the values calculated using intact cells. No appreciable binding of 125I-rEp to control membranes at low Ep-receptor content was observed. Among a panel of growth factors, only unlabeled rEp was able to compete for the binding of 125I-rEp to nitrocellulose-immobilized membrane proteins in a dose-dependent fashion. The technique described herein may be of use in the study of the Ep receptor and as an assay for its purification. Moreover, it may also be of general application in the study of receptor-ligand interactions.

Serotonin incorporation as a marker of murine megakaryocyte proliferation in liquid cultures

We have developed a new in vitro method for the quantitation of murine megakaryocyte proliferation that is based on the unique property of megakaryocytes to incorporate and store [14C]serotonin in cytoplasmic dense granules. The specificity of the assay was demonstrated by autoradiography of whole bone marrow cell suspensions, which showed evidence of grain accumulation only in megakaryocytes. Bone marrow cells were cultured in liquid cultures in the presence of a stimulator of megakaryocyte growth before the addition of 2.5 microM [14C]serotonin. The amount of serotonin incorporated in cells was evaluated after 3 h. Radioactivity peaked at days 6 and 7 and remained high until day 10; there was a linear relationship between the incorporation of serotonin and the number of cells plated. A dose-response curve between the incorporation of serotonin and the concentration of pokeweed mitogen spleen-conditioned medium (PWM-SCM) was observed, with inhibitory effects becoming predominant at the highest concentrations. The proliferation of megakaryocyte progenitors was also stimulated by partially purified interleukin 3, whereas both human recombinant erythropoietin and human recombinant granulocyte colony-stimulating factor (rG-CSF) failed to modify the incorporation of serotonin in comparison with unstimulated cultures. Finally, in parallel experiments we observed a significant correlation between the number of megakaryocytic colonies grown in agar and the radioactivity in liquid cultures. The method described herein is reproducible, sensitive, and easy to perform; it should be useful for the study and purification of factors affecting megakaryocyte proliferation.

Megakaryocyte progenitors in the bone marrow and peripheral blood of patients with myeloproliferative diseases

We studied the behavior in culture of megakaryocyte progenitor cells (CFU-Mk) from peripheral blood (PB) and bone marrow (BM) cells in eight patients with myeloproliferative diseases (MPD). In seven patients we observed megakaryocyte (Mk) colony formation from PB cells, which were generated in the absence of any added stimulator and which did not increase after the addition of a source of Mk-colony stimulating activity (CSA-Mk). The number of BM CFU-Mk was significantly higher in patients than in controls, and in seven out of eight patients the responsiveness to added CSA-Mk was retained. Plasma obtained from six patients did not stimulate normal donors' BM target cells to form Mk colonies. These data demonstrate an expansion of the CFU-Mk pool in MPD patients without increased plasma levels of CSA-Mk, and suggest that PB and BM CFU-Mk of MPD patients might have different kinetic properties.