Immunodiagnosis of childhood ALL with monoclonal antibodies to myeloid and lymphoid associated antigens

Sixty-five cryopreserved leukemic samples from children diagnosed and treated as having acute lymphocytic leukemia (ALL) were retrospectively examined for the presence of lymphoid and myeloid associated antigens by indirect immunofluorescence using monoclonal antibodies. Expectedly, the majority of these specimens expressed antigens known to be expressed on lymphoid, and not myeloid malignancies. These included the common acute lymphoblastic leukemia antigen (CALLA), the p32 B-cell associated antigen, and T-cell associated antigens. Leukemic cells from the 8 remaining patients expressed antigens known to be present on both myeloid and lymphoid leukemias. These included HLA/DR, and the antigens identified by BA-1 and BA-2. Cells from 2 of these 8 patients reacted with antibodies that define antigens present on normal and malignant myeloid cells. Both specimens reacted with 1G10, an anti-granulocyte antibody, and one reacted with 5F1 which reacts with monocytes, nucleated red blood cells, megakaryocytes and platelets. One of these patients relapsed while receiving ALL therapy, and the morphology of her leukemic cells became characteristic of acute monocytic leukemia (AMoL). The second patient failed ALL therapy but responded to standard acute nonlymphocytic leukemia (ANLL) therapy, clearing her peripheral blasts. Thus these studies confirm that cell surface phenotyping with monoclonal antibodies can recognize ALL cells that express myeloid rather than lymphoid associated antigens and demonstrate that the malignant cells display a clinical behavior consistent with the diagnosis of ANLL.     

The comparative activity of twelve 4-quinolone antimicrobials against gram-positive and gram-negative anaerobes

The minimal inhibitory concentrations (MICs) of twelve 4-quinolone antimicrobials were determined for the Bacteroides fragilis group (50), Bacteroides melaninogenicus (20), Bacteroides bivius (10), Fusobacterium spp. (10), anaerobic Gram-positive cocci (50) and Clostridium spp. (20). MICs were determined using an agar dilution technique in Mueller-Hinton agar supplemented with 10% lysed horse blood. The inoculum used was approximately 10(4) colony-forming units, contained in 10 microliter of Mueller-Hinton broth, which was applied to the agar plates using a multipoint inoculator. Following inoculation, plates were incubated at 37 degrees C for 48 h in an anaerobic atmosphere. The MIC of each antimicrobial for each isolate examined was determined as the lowest concentration of the antimicrobial which completely inhibited growth of the inoculum. The minimum concentrations required to inhibit the growth of 50% (MIC50) and 90% (MIC90) of the organism examined were also determined. All of the more recently synthesised 4-quinolones showed increased activity against the anaerobic bacteria used in this study. Ciprofloxacin and ofloxacin were the most active compounds examined (Bacteroides fragilis group MIC90 ciprofloxacin 4 micrograms/ml; ofloxacin 4 microgram/ml; Bacteroides melaninogenicus MIC90 ciprofloxacin 2 micrograms/ml, ofloxacin 2 micrograms/ml; Bacteroides bivius MIC90 ciprofloxacin 16 micrograms/ml, ofloxacin 32 micrograms/ml; Fusobacterium spp. MIC90 ciprofloxacin 2 micrograms/ml, ofloxacin 4 micrograms/ml; Clostridium spp. MIC90 ciprofloxacin 1 microgram/ml, ofloxacin 1 microgram/ml and anaerobic Gram-positive cocci MIC90 ciprofloxacin 4 micrograms/ml, ofloxacin 4 micrograms/ml).     

Neuron numbers in sensory cortices of five delphinids compared to a physeterid, the pygmy sperm whale

With its large mass and enormous gyrification, the neocortex of whales and dolphins has always been a challenge to neurobiologists. Here we analyse the relationship between neuron number per cortical unit in three different sensory areas and brain mass in six different toothed whale species, five delphinids and one physeterid. Cortex samples, including primary cortical areas of the auditory, visual, and somatosensory systems were taken from both hemispheres of brains fixed in 10% buffered formalin. The samples were embedded in paraffin, sectioned at 25 microm thickness and stained with cresyl violet. Because cortical thickness varies among toothed whale species, cell counts were done in cortical units measuring 150mum in width, 25 microm in thickness, and extending from the pial surface to the white matter. By arranging the delphinid brains according to their total mass, 834-6052 g, we found decreasing neuron numbers in the investigated areas with increasing brain mass. The pigmy sperm whale (Kogia breviceps), a physeterid with an adult brain weight of 1000 g had a distinctly lower neuron number per cortical unit. As had been expected, an increase in adult brain weight in delphinid cetaceans (family Delphinidae) is not correlated with an increase in neuron number per cortical unit.     

Assessment of regional left ventricular function: accuracy and reproducibility of positioning standard short-axis sections in cardiac MR imaging

The assessment of regional left ventricular (LV) function with cardiac magnetic resonance (MR) cine techniques requires a standardized section positioning. A simple selective short-axis method for selective positioning of three short-axis sections (basal, midcavity, apical) was tested for its accuracy, compared with accepted criteria, in 21 volunteers (mean age, 32 years +/- 11) and in 23 patients with myocardial infarction (mean age, 56 years +/- 12). Reproducibility of section positioning and of regional LV parameters was tested in the volunteers. Among the six accuracy criteria defined for standard sections, the selective short-axis approach had an average accuracy of 90.9% in volunteers and 87.7% in patients, compared with 92.1% and 90.6%, respectively, for a multisection approach covering the whole LV. There was very good reproducibility of the selected intersection gap (r = 0.89, P < .001) and of measured midcavity end-diastolic diameters in vertical (r = 0.83, P < .001) and horizontal (r = 0.85, P < .001) long-axis orientations. The proposed method produces standardized short-axis section positions that meet the recommendations for cardiac imaging. The study was approved by the local ethics committee, and all subjects gave written informed consent.     

Arterial oxygen desaturation kinetics during apnea

PURPOSE: To quantify the rate of arterial oxygen desaturation during apnea in freedivers. METHODS: Ten freedivers and ten controls undertook five maximal face immersion apneas in 10 degrees C water separated by 2 min of recovery. Electrocardiogram (ECG), blood pressure, and pulse oximetry were recorded continuously. Peripheral blood flow was measured by calf plethysmography every 30 s, and venous blood samples were collected at rest and after apneas 1, 3, and 5. The blood was analyzed for hematocrit (Hct), lactate, and hemoglobin (Hb) concentration. The arterial oxygen saturation (SaO(2)) data were curve fitted with both a sigmoid and two-slope continuous function. RESULTS: Apnea duration increased with successive attempts, with freedivers achieving significantly longer maximal apneas (trained 246 +/- 44 s, untrained 129 +/- 39 s, P < 0.001). Compared with controls, freedivers displayed a significant change from baseline in heart rate (trained -27.2 +/- 9.5 bpm, untrained -19.7 +/- 9.3 bpm, P < 0.001) and mean arterial pressure (MAP) (trained 48 +/- 20.7 mm Hg, untrained 37 +/- 10.0 mm Hg, P = 0.002), but no difference existed in peripheral blood flow, Hct, lactate, or Hb. The maximal slope of the SaO(2) sigmoid curve was not significantly different between the groups (trained -0.16 +/- 0.05%.s(-1), untrained -0.15 +/- 0.06%.s(-1), P = 0.26), but the DeltaSaO(2(/Deltat obtained from the two-slope continuous model indicated that 85% of the variance in the freedivers DeltaSaO(2)/Deltat could be explained by the apnea-induced bradycardia, preapnea vital capacity, and Hb concentration. CONCLUSIONS: The sigmoidal function provided no quantifiable difference in the rate of oxygen desaturation. The two-slope continuous method, however, indicated that freedivers who had larger oxygen stores and produced the largest bradycardia were able to slow the DeltaSaO(2)/Deltat to two to three times that of the least marked response.