Pediatric peripheral blood progenitor cell collection: haemonetics MCS 3P versus COBE Spectra versus Fresenius AS104

BACKGROUND: An increasing number of apheresis machines are becoming available for peripheral blood progenitor cell (PBPC) collection in children. STUDY DESIGN AND METHODS: At the Children's Hospital of Florence (Italy), three apheresis machines were evaluated: MCS 3P (Haemonetics) (10 procedures in 4 patients, aged 10–12 years, weight 23.5-64 kg), Spectra, (COBE) (8 procedures in 3 patients, aged 4–17 years, weight 19–59 kg), and AS104 (Fresenius) (24 procedures in 9 patients, aged 2–16 years, weight 13.6-60 kg). For PBPC quantitative analysis, CD34 cytofluorimetry was employed. Relevant variables analyzed included efficiency of CD34+ cell extraction and enrichment, mononuclear cell purity and red cell contamination of the apheresis components, and platelet count decreases after leukapheresis. RESULTS: No significant differences in CD34+ cell-extraction abilities were found. However, the AS104 provided consistently purer leukapheresis components in terms of mononuclear cell and CD34+ cell enrichment (441 +/− 59%, vs. 240 +/− 35% and 290 +/− 42% for MCS 3P and Spectra, respectively). Postapheresis platelet counts dropped the least with the AS104. The smallest patient who underwent apheresis with MCS 3P (the only machine working on discontinuous flow and hence with greater volume shifts) weighed 23.5 kg and tolerated the procedure well, with no signs of hemodynamic instability. No significant complications were observed. CONCLUSION: All machines seem to have comparable PBPC extraction efficiency, but the AS104 seems to give the component with the greatest PBPC enrichment. This feature might be relevant for further ex vivo cell processing (CD34+ cell selection, expansion, and so on).     

Recombinant human interleukin-3 stimulation of hematopoiesis in humans: loss of responsiveness with differentiation in the neutrophilic myeloid series

Recombinant human (rh) interleukin-3 (IL-3) stimulated the proliferation and differentiation of erythroid, granulocyte, macrophage, eosinophil (Eo), and mixed colonies as well as megakaryocytes from human bone marrow cells. rh IL-3 was a weaker stimulus than rh granulocyte-macrophage colony-stimulating factor (GM- CSF) for day 14 myeloid cell colonies. At day 7 of incubation, rh IL-3 stimulated a few G, M, and Eo clusters but no colonies. This loss of responsiveness of myeloid cells to rh IL-3 was accentuated with further differentiation of the cells. rh IL-3 stimulated very few or no clones after five-day incubation with enriched promyelocytes and myelocytes, whereas rh GM-CSF was an efficient stimulus. Responsiveness to rh IL-3 was completely lost in postmitotic mature neutrophils. Incubation of these cells with rh IL-3 did not result in enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) of tumor cells or superoxide anion production after stimulation with formyl-methyl-leucyl-phenylalanine (FMLP), although they could be stimulated by rh GM-CSF. In addition, preincubation of neutrophils with different concentrations of rh IL-3 failed to increase or decrease their response to rh GM-CSF. In contrast to neutrophils, mature Eos could be stimulated by rh IL-3 to kill antibody-coated tumor cells. These results show that cells of the neutrophilic myeloid series lose their responsiveness to h IL-3 as they differentiate and suggest that although h IL-3 may be an important therapeutic agent to use for hematopoietic regeneration in vivo, the lack of stimulation of mature neutrophil function makes it an unlikely sole candidate as adjunct therapy for treatment of infectious diseases.     

Massive hemoptysis: control by embolization of the thyrocervical trunk

A case of recurrent hemoptysis following bronchial artery embolization is presented. The bleeding was successfully controlled by embolization of the thyrocervical trunk.     

Pneumocystis carinii pneumonia studied by gallium-67 scanning

The validity and reliability of gallium-67 (Ga-67) scanning for diagnosis and follow-up of Pneumocystis carinii pneumonia (PCP) were assessed in 34 patients thought to have pulmonary complications of acquired immunodeficiency syndrome (AIDS). Overall sensitivity was 94% and specificity 74%. Among patients with normal or equivocal chest radiographs at the time of admission, sensitivity was 86% and specificity 85%. The authors consider Ga-67 scanning a valid and reliable adjunct in the diagnosis of PCP in AIDS patients with respiratory symptoms when the chest radiograph is normal or equivocal.     

Endothelial cell seeding of polytetrafluoroethylene vascular prostheses coated with a fibroblastic matrix

One of the most serious problems with endothelial cell (EC) seeding of prosthetic materials is the poor adhesion and stability of the cells. Although several substrates that improve the initial adhesion have been assayed, the EC are lost within a limited period of time. In this study we attempted to modify the hydrophobic conditions of expanded polytetrafluoroethylene (ePTFE) by treating it with ethanol prior to seeding. In addition, we created a fibroblastic matrix that was also fixed by ethanol to the prosthetic material. In vitro studies were carried out at intervals of 24 hours and 15 days after seeding. EC from umbilical cord vein and fibroblasts from skin were seeded onto disks of PTFE with a porosity of 30 µm. The results obtained show that treatment of ePTFE with ethanol prior to EC seeding modifies its permeability, preventing cellular adhesion. The seeding of fibroblasts onto ePTFE allows a coating to form at 24 hours. The EC seeded onto this matrix adhere to it, forming a monolayer that persisted throughout the entire study period. The fibroblastic matrix allows the long-term survival of the EC on ePTFE.Supported by a grant from the CICYT SAF 92-0875.     

Digital subtraction angiography of the thoracic aorta

Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.     

Morphologic effects following massive exchange transfusions with a stroma-free hemoglobin solution. II. Kidney.

The effects on renal morphology of exchange transfusion with stroma-free hemoglobin solutions (SFHS) were compared in rats to the results obtained using an asanguineous resuscitative fluid containing albumin. Animals underwent 75 per cent blood volume replacement, and tissue collected at intervals after the exchange transfusion was examined by light and electron microscopy. Urine volumes, osmolarity, and pH also were determined, and serum creatinine and blood urea nitrogen were measured both before and after exchange transfusion. Hemoglobin was filtered through the renal glomerular basement membrane, and a portion was reabsorbed into the proximal tubular cells in the form of absorption droplets. Unabsorbed hemoglobin was excreted in the urine. Despite a distention of proximal and distal tubules 5 hours after exchange transfusion with SFHS, there was no ultrastructural evidence of renal parenchymal damage. Proximal tubular cells of albumin-exchanged animals contained fewer protein absorption droplets and no intraluminal material. The apparent higher rate of glomerular filtration of hemoglobin over albumin probably reflected the dissociation of hemoglobin into dimers, resulting in a diuresis. Urine volumes were 3 times greater in SFHS-exchanged animals than in albumin-treated rats, and the urine was relatively hypoosmolar in the former. The greater urine volumes in SFHS-treated animals also were associated with a large reduction in intravascular fluid volume. There was no alteration of serum creatinine or blood urea nitrogen after exchange transfusion with albumin and only a mild elevation in blood urea nitrogen in SFHS-treated rats. The latter most likely was a result of prerenal hypovolemia. SFHS, even when exchange-transfused in massive quantities, does not appear to affect renal function or ultrastructural morphology adversely. However, the rapid disappearance of hemoglobin from the intravascular space, the consequent loss of intravascular fluid volume, and the diuresis induced by its administration are complications which must be overcome before the product can be a useful adjunct in the treatment of hemorrhagic shock.     

Sir Kenelm Digby (1603-1665): diplomat, entrepreneur, privateer, duellist, scientist and philosopher

Kenelm Digby was a man with widely differing interests. He studied at Oxford but left without a degree. At the age of 20, he was involved in a dramatic street brawl in Madrid; the following year saw him as a successful privateer in the Mediterranean and adjacent Atlantic waters, and he was then appointed a naval administrator with lucrative trade monopolies. He practised medicine without formal qualifications and gained notoriety by promoting the use of 'sympathetic' powder for healing wounds. Befriended by King James I and his son who succeeded him, he became chancellor to Queen Henrietta and was knighted by King James I on 21 October 1623 and appointed to the Privy Council. At one time, he even spent a brief time in prison, but he later became a founding member of the Royal Society and published two major philosophical treatises as well as a popular cookbook. He designed and manufactured wine bottles with tapered necks for simpler pouring and square sides for easy stacking. He dabbled in mathematics and corresponded with Fermat of 'Last Theorem' fame. In 1641, he challenged a French nobleman who publicly cast a slur on the British King to a 'digladiation' (a sword duel) and quickly dispatched him. He was a friend and admirer of Sir Thomas Browne whose 'Religio Medici' he helped to publish. The Cowlishaw Library holds a 1659 5th edition copy of this remarkable book, with Digby's name on the spine. Truly, Digby must qualify as a Renaissance man.     

Noninvasive localization of infrainguinal arterial occlusive disease in diabetics

A retrospective review of 101 diabetics without aortoiliac disease was carried out to analyze the ability of various noninvasive tests to predict the level of significant (>50% stenosis) infrainguinal arterial disease. Patients were studied with anklebrachial indices (ABI), toebrachial indices (TBI), segmental pulse volume recordings (PVR), segmental pressures (SEGP), segmental Doppler waveforms (DWF), and arteriography. Results were classified as normal, disease at the femoropopliteal level, infrapopliteal level, or both levels (multilevel), or noninterpretable. Our findings for the entire study showed that, as a single test, DWF appears to have the best angiographic correlation, although the summed diagnosis of combined DWF and PVR data is superior in distinguishing multilevel disease from isolated tibial disease. SEGP are of very limited use in diabetics, even in multimodality testing, and we no longer include that test in our routine evaluation of diabetics.