Monoclonal antibodies to human pancreatic carcinoma

Hybridoma cultures were produced by the fusion of SP2 mouse myeloma cells with spleen cells from mice immunized with human pancreatic carcinoma cells. After limiting dilutions, three monoclonal antibodies, YPan1, YPan2, and YPan3, which bound to immunizing cells but not to normal human skin fibroblasts, were further characterized. The three monoclonal antibodies were found to bind to all seven pancreatic carcinoma cell lines but not to other carcinoma cell lines tested except some colon carcinoma cell lines. When human tissue sections were examined using immunohistochemical techniques, the three monoclonal antibodies identified antigens in the pancreatic carcinomas and some normal pancreases, but only YPan1 showed strong positive staining. No cross-reactivity was seen in sections of other carcinomas tested except some colon carcinomas. The results suggest that these monoclonal antibodies may be usefully applied to the detection of pancreatic carcinomas.     

A New Algorithm for Minimizing Pacemaker Polarization Artifact: Universally Applicable in Permanent Pacing Systems

Polarization artifacts that result from pacing may interfere with analysis of paced evoked responses during, e.g., automatic threshold tracking. We have developed a method for reduction of such artifacts that relies on the introduction of pacing stimuli during the refractory period of unipolar or bipolar paced captured beats after previous identification of a refractory period "template" or baseline. The refractory pacing stimuli cannot capture the heart, and thus any deviation from the template is due to polarization artifact alone. The artifact amplitude is measured and the precharge duration of the triphasic stimulus waveform is changed each time until artifact is minimized, as detected by repeated reversals in the polarily of the polarization artifact. In a series of 11 patients with unipolar and bipolar permanent pacing leads, mean initial artifact before balancing was 1.44 ± 0.84 mV, which was reduced to 0.44 ± 0.30 mV after balancing (P = 0.001). Initial precharge duration was 3.2 msec by design; mean final precharge duration was 3.30 ± 0,34 msec. This algorithm is universally applicable in permanent pacing systems, as it is valid in unipolar and bipolar pacing and it does not require an intrinsic cardiac rhythm.     

Simultaneous differentiation and quantitation of erythroblasts and white blood cells on a high throughput clinical haematology analyser

After the neonatal period, the presence of nucleated red blood cells (NRBC) in peripheral blood is indicative of pathology. Despite the clinical utility of such measurements, automated NRBC counting has hitherto not been available on routine automated blood cell counting analysers. To address this, an automated method for the analysis of NRBC was developed and incorporated into the Abbott Cell Dyn 4000 (CD4000) haematology analyser. The system white blood cell (WBC) reagent was specifically formulated to preserve concomitantly white blood cell (WBC) morphology, rapidly lyse red blood cell and NRBC membranes, and subsequently stain NRBC nuclei with a nucleotide specific fluorochrome dye (Kim et al. 1996a). The fluorochrome itself does not permeabilize the membrane of intact viable white blood cells. The sample is processed by flow cytometry and the signals generated from an argon-ion laser light source are analysed. Axial light loss (AxLL), intermediate angle light scatter (IAS) and red fluorescence (FL3) are used to discriminate between particles of various types. By using these discriminators in a three-dimensional approach, NRBC form a discrete cluster which can easily be separated from leucocytes and enumerated as a distinct cell population during the optical WBC differential analysis. Consequently, accurate absolute WBC counts and differentials can be obtained even in the presence of NRBC. Background ‘noise’ (both fluorescent and non-fluorescent) from platelets, Howell-Jolly bodies, basophilic stippling, RNA from lysed reticulocytes, and DNA from leucocyte and megakaryocytic fragments are essentially eliminated (Kim et al. 1996b). While the membranes of intact and viable leucocytes remain impermeable to the passage of the fluorochrome stain, leucocytes with damaged membranes are permeable to the dye and generate FL3+ signals. Such cells, which are commonly seen as a consequence of sample ageing as well as in some distinctive pathologies, are identified by the algorithm (using their AxLL signal size) and are labelled as non-viable. Moreover, because non-viable leucocytes are retained in the WBC count and differential analyses, the CD4000 is further able to provide both numerical and graphical data regarding the relative frequency of viable and non-viable components. This additional information can serve as valuable ‘decision-drivers’ in the laboratory data review process.     

Cutaneous B-cell lymphoma—a clinical, pathological and immunohistochemical study

Eleven cases of cutaneous B-cell lymphoma (CBCL) were studied. The ages at presentation ranged from 34 to 79 years (mean = 59·9 years). Six patients were female and five male. Five of the 11 patients had a solitary tumour and the other six had multiple tumours at initial presentation. According to Burg's classification, six cases were at stage I, two stage II, two stage III and one was at stage IV at initial presentation. Abnormalities in laboratory data were rare, except for serum lactic dehydrogenase values. Epidermotropism was not detected, and the area mainly affected by neoplastic cells was the reticular dermis (seven cases) and suhcutis (four cases). Biopsy-specimens from the patients analysed by immunohisiochemical techniques on paraffin or cryostat sections showed CD20 and/or CD22 positivity. Biopsy specimens from two patients which showed CD 10 positivity were diffuse large cell types by the working formulation and presented as pre-B-cell lymphoma. At least two groups of CBCL were demonstrable on the basis of prognosis. One was a benign low-grade lymphoma presenting with solitary tumours, mature B-cell markers and intermediate-grade pathology, and the other was a high-grade lymphoma with multiple tumours, pre-B-cell or mature B-cell markers and a poor prognosis.     

Single Coronary Artery

A 54-year-old postmenopausal female, with systemic arterial hypertension and insulin dependent diabetes mellitus, had exertional chest discomfort. At cardiac catheterization, a single coronary artery arising from the right sinus of Valsalva was seen (Fig. 1). This condition is extremely rare, discovered in < 0.05% of the general population. Transesophageal echocardiography using color flow imaging documented that the left anterior descending coronary artery was anterior to the pulmonary artery (Fig. 2).     

Solid-phase peptide synthesis without side-chain hydroxyl protection of threonine

A peptide containing four threonine residues was synthesised by the solid-phase method using fluorenyl-methoxycarbonylamino acid reactive esters or coupling by preactivation with 1-hydroxybenzotriazole and Castro's reagent. In two separate experiments the synthesis was carried out with or without protection of the side-chain hydroxyl group of threonine as the tert-butyl ether. Comparison of the crude peptides after deprotection and detachment from the synthesis resin suggests that side-chain protection of threonine is unnecessary under the synthetic conditions employed.     

Dialysate and substitution fluid quality for on-line haemodiafiltration and haemofiltration

Summary: A multicentre study concerning the fluid quality for on-line haemodiafiltration/haemofiltration (GDF/HF) treatment was carried out to assure safety and biocompatibility, and a standard for fluid quality has been established. Endotoxin (ET) concentration in the substitution fluid of not less than 1 IU/L caused minimally, yet significantly greater body temperature rises than those less than 1 IU/L (0.52 ± 0.49 vs 0.08 ± 0.40°C, P > 0.01) when 20L of volume was replaced by 4h post dilution HDF treatment. the post treatment plasma levels for tumour necrosis factor-α but not interleukin-6 were correlaed with the amplitude of temporal body temperature rise ( r = 0.75, P > 0.01). By sticking to the standard for on-line HDF/HF treatment that calls for the ET levels in the proportioned dialysate before and the substitution fluid after serial ultrafiltration to be > 50 IU/L and 1 IU/L, respectively, no such deleterious symptoms as fever and hypotension have been observed. Moreover, no enhancement of the plasma ET levels was detected after the first and 6 months of on-line HDF treatment. In conclusion, the newly established advisory standard assures safety and improved biocompatibility of the on-line HDF/HF treatment.     

Electrical Alternans of Pacemaker Spike Amplitude: an Unusual Manifestation of Permanent Pacemaker Generator Malfunction

A case of electrical alternans of pacemaker stimulus amplitude is presented, with constant alternation of large and small amplitude pacemaker spikes without loss of ventricular capture, due to a defect in the oscillator hybrid of a rate programmable Medtronic unit. This represents an unusual electrocardiographic manifestation of pacemaker generator malfunction which, to our knowledge, has not been reported previously.     

Long-Term Stability of Defibrillation Thresholds with Intrapericardial Defibrillator Patches

From March 1982 to May 1, 1992, 105 consecutive patients underwent initial implant of cardioverter defibrillators (ICD) at our institution. Twenty-nine patients (23 male and 6 female, average ejection fraction 32.24%) with ICD systems implanted via thoracotomy and either intra- or extrapericardial patches, had one or more revisions including 56 generator changes or staged implant procedures, three patch revisions, one patch lead fracture without revision, and one sensing lead revision. The time between pulse generator revisions averaged 19.5 months. Initial defibrillation threshold mean was 12.8 joules (n = 25); at first revision, 14.46 joules (n = 29), (P = NS); by fifth revision, 15.0 joules (n = 2), (P = NS). One patch was noted to be crinkled at 70 months; one patch had migrated by 39 months, and two patch leads had fractured at the costal margin by 69 and 90 months. One patient with marginal defibrillation thresholds had an additional patch placed at revision to an upgraded ICD unit. Once acceptable defibrillation threshold (DFT) is obtained, the long-term intrapericardial DFT remains stable unless a specific problem occurs. As a small, nonstatistically significant increase in DFT may occur, caution must be exercised in patients with marginal DFTs.     

Transesophageal Echocardiographic Diagnosis of Aortic Graft Dehiscense at Coronary Anastomoses and Pseudonaneurysm Rupture into Right Atrium

We describe a case of aortic graft dehiscence at coronary anastomoses with rupture into the right atrium of the pseudoaneurysm complicating aortic graft replacement. These were diagnosed by intraoperative transesophageal echocardiography.