A Study of Membrane Permeability in Haemodialysis

The efficiency of haemodialysis has been determined when a Watson-Marlow (Kiil) dialyser was used repetitively without changing the membranes. Dialysis efficiency was assessed from the clearance of creatinine and of urea from the patient''s blood. No significant deterioration in dialysis could be detected in six dialyses through the same membrane. Leaving the dialyser unit for up to eight hours before washing it out after the completion of each dialysis did not appear to have any effect on dialysis efficiency.It was concluded that repetitive haemodialysis through the same membranes is possible, but careful monitoring of the patient to assess suitability for such treatment, and subsequently at each dialysis, is essential.     

Letter: Limited licensure.

We examined the relationship of leukocyte colony-stimulating activity (CSA) in vitro to neutrophil count in vivo. Using a standard two-layer system, cultures of 10⁶ leukocytes were assayed for their ability to stimulate colony formation by human bone marrow colony-forming cells. The total leukocyte CSA per ml (TLCSA) of blood varied directly with the blood neutrophil count in a group of patients with a wide range in blood neutrophil count, and in two patients recovering from neutropenia in whom serial observations were made. In the latter two patients the rise in TLCSA did not antedate the rise in blood neutrophil count, suggesting that blood leukocyte colony-stimulating factor (CSF) per se probably has little biologic significance. However, release into the circulation of cells which generate CSF could be an important way of controlling the amount of CSF acting within the marrow. In one patient the CSA of dialyzed serum increased after the rise in TLCSA, while undialyzed serum contained no CSA.     

Haemoglobin Rahere (beta Lys-Thr): A new high affinity haemoglobin associated with decreased 2, 3-diphosphoglycerate binding and relative polycythaemia.

A new haemoglobin with increased oxygen affinity, beta82 (EF6) lysine leads to threonine (Hb Rahere), was found during the investigation of a patient who was found to have a raised haemoglobin concentration after a routine blood count. The substitution affects one of the 2, 3-diphosphoglycerate binding sites, resulting in an increased affinity for oxygen, but both the haem-haem interaction and the alkaline Bohr effect are normal in the haemolysate. This variant had the same mobility as haemoglobin A on electrophoresis at alkaline pH but was detected by measuring the whole blood oxygen affinity; it could be separated from haemoglobin A, however, by electrophoresis in agar at acid pH. The raised haemoglobin concentration was mainly due to a reduction in plasma volume (a relative polycythaemia) and was associated with a persistently raised white blood count. This case emphasises the need to measure the oxygen affinity of haemoglobin in all patients with absolute or relative polycythaemia when some obvious cause is not evident.     

Vancomycin-induced neutropenia.

Although rare, neutropenia associated with long-term vancomycin therapy may occur. A 67-year-old woman with cellulitis and sepsis caused by Staphylococcus aureus was treated initially with cefazolin. Despite in-vitro susceptibility of the organism to this drug, the patient remained febrile, and therapy was changed to vancomycin. On day 17 of therapy with this medication neutropenia was noted; it progressed over the next 3 days, and therapy with the drug was stopped. A rise in the neutrophil count occurred within 5 days of discontinuation. Periodic monitoring of the leukocyte count during longterm vancomycin therapy is recommended.     

Possible mechanism for mianserin induced neutropenia associated with saturable elimination kinetics.

Two cases of mianserin induced neutropenia associated with prolonged elimination of the drug were studied. In each case the pharmacokinetic profile suggested saturable elimination kinetics, and the temporal relation of mianserin concentrations and the neutrophil count suggested a direct toxic effect of mianserin on the bone marrow. Until further studies are carried out the plasma mianserin concentration and neutrophil count should be measured in any patient who develops an infection while taking this drug.     

Leucocytosis is not a manifestation of rejection.

The leucocyte response to allograft rejection was retrospectively analysed in 80 rejection episodes that occurred in 50 patients. There was no significant change in leucocyte count in 32 rejection episodes. In 27 there was a fall in leucocyte count of more than 20% and in only 21 was there a rise in count of more than 20%. Thus leucocytosis seems not to be a manifestation of rejection; indeed, it is the least common response, a fall in the count being commoner. The results also suggest that the prognosis for the graft is poorer when the leucocyte count falls significantly.     

Leukocytic shifts following pancreatic resection with a plasma scalpel and cryodestruction]

Two series of experiments were carried out on dogs. In the first series, blood leukocytes count was studied after resection of the pancreas using plasma scalpel. The resection caused two-phase leukocyte reaction: neutrocytosis (phase I) and leukocytosis involving mainly lymphocytes and monocytes (phase II). During the first 24 hours after the resection, a sharp increase of the leukocyte intoxication index (LII) was observed. The second series of experiments was performed using the combination of plasma scalpel and cryodestruction. The graphic curves denoted a sharp fall both in total leukocytic counts and in the different types of leukocytes which were plotted separately (neutrophils, eosinophils, etc.) This can be explained by the absence of the second (lympho-monocyte) reaction. Only a slight increase in LII occurred. These results reflect lower degree of the protection and adaptation reactions of leukocytes, this being in favor of a combination of plasma scalpel and cryodestruction during the operation.     

Plasma lactoferrin in patients with neutropenia

This study examines the role of plasma lactoferrin in the assessment of neutropenia. In particular, we have studied lactoferrin as an inhibitor of granulopoiesis and as an indicator of the size of the total blood granulocyte pool (TBGP). Plasma lactoferrin concentration was determined in a heterogeneous group of 30 patients with neutropenia. Serial plasma lactoferrin levels in a patient with cyclic neutropenia correlated with the cycles of the neutrophil count. Patients with splenomegaly had a grossly elevated lactoferrin:neutrophil ratio. Most chronic idiopathic neutropenia patients had no real clinical problems and a normal plasma lactoferrin level. The results provide further evidence to support the concept that plasma lactoferrin indicates the size of the TBGP and the lactoferrin: neutrophil ratio indicates the degree of granulocyte margination. There was no evidence to suggest that lactoferrin acting as a feedback inhibitor of granulopoiesis caused neutropenia in these patients.     

Infection of small ruminants with Ehrlichia spp. in Sicily

In 1991, the experimental infection of a goat with pooled blood from goats that were positive for anti-Ehrlichia canis, E. risticii, E. equi and E. phagocytophila antibodies was monitored (physical examination, cell blood count, microscopical examination of blood smears, serology) for 180 days. The infection produced a clinical condition characterized by intermittent fever, anaemia and leukopenia with neutropenia during the first 40 days. Recurrent leukocytosis with lymphocytosis was noticed afterwards. A permanent high-level thrombocytosis appeared after the 18th day. During the first week, cytoplasmic basophilic inclusion bodies were seen in smears of peripheral venous blood stained with May-Grunwald-Giemsa, first in mononuclear cells and then in neutrophils (in max 3% of circulating leukocytes). Seroconversion occurred during the 2nd week and the highest antibody titre (IFAT) was registered vs E. equi (10,240) at the 19th day, vs E. canis (320) at the 24th and vs E. risticii (80) at the 30th day. At the end of the observation period the infected goat was still positive for E. equi (titre 160) and E. canis (titre 10) only. The preinoculation serum of the infected goat was reactive with E. phagocytophila antigen (serum was tested for IF antibodies to E. phagocytophila at 1:200 dilution only, because of the limited quantities of antigen available), but the qualitative evaluation of fluorescence showed an increase from the 7th day, maximum intensity between the 14th and the 40th day and passed to negative from the 74th day. Although it was based on microscopy and serology only and not carried out in a SPF goat, the above experiment gave evidence of the existence of species of the E. phagocytophila genogroup in Italy for the first time.     

Antihypertensive effect of Cecropia obtusifolia (Moraceae) leaf extract on rats

A lyophilized aqueous leaf extract of Cecropia obtusifolia proved to be antihypertensive when intravenously administrated to conscious spontaneous hypertensive rats. Forty-five minutes after injection, the maximum fall in arterial pressure (-23.5% relative to preinjection values) was seen and recovery was not complete by the end of the 180 min observation period. The extract was also given to pre-hypertensive SHR and normotensive rats. The fall in blood pressure was more conspicuous in the two SHr groups and was not accompanied by changes in cardiac frequency in any group. This would appear to rule out either a direct or indirect involvement of the heart in regard to the observed hypotension.     

Risk Factors for Severe Neutropenia following Intra-Arterial Chemotherapy for Intra-Ocular Retinoblastoma

Purpose

Intra-arterial chemotherapy is a promising strategy for intra-ocular retinoblastoma. Neutropenia is the most commonly encountered systemic toxicity and in this study we aimed to determine the risk factors associated with the development of severe (≥grade 3) neutropenia.

Methods

Retrospective review of 187 evaluable cycles of melphalan-containing intra-arterial chemotherapy from the first three cycles administered to 106 patients with intra-ocular retinoblastoma from May 2006 to June 2011. Cycles were considered to be evaluable if (1) blood count results were available in the 7 to 14 days post-treatment interval and (2) concurrent intravenous chemotherapy was not administered. Toxicity was assessed via the Common Terminology Criteria for Adverse Events version 4.0.

Results

54 cycles (29%) were associated with grade 3 (n = 43) or grade 4 (n = 11) neutropenia. Multivariate stepwise logistic regression revealed that a higher melphalan dose (>0.40 mg/kg) was significantly associated with severe neutropenia during all 3 cycles (odds ratio during cycle one 4.11, 95% confidence interval 1.33–12.73, p = 0.01), but the addition of topotecan and/or carboplatin were not. Prior treatment with systemic chemotherapy was not associated with severe neutropenia risk in any analysis.

Conclusions

Intra-arterial melphalan-based chemotherapy can cause severe neutropenia, especially when a dose of greater than 0.40 mg/kg is administered. Further study with a larger sample may be warranted.     

Effect of Isovolemic,Isothermic Hemodialysis on Cerebral Perfusion and Vascular Stiffness Using Contrast Computed Tomography and Pulse Wave Velocity

Background

Patients undergoing hemodialysis treatment have a six-fold increased risk for stroke relative to the general population. However, the effect of hemodialysis on cerebral blood flow is poorly studied and confounding factors like blood pressure and ultrafiltration as well as temperature changes have rarely been accounted for. The aim of our study was to use state-of-the-art technology to evaluate the effect of a single dialysis session on cerebral perfusion as well as on vascular stiffness.

Methods

Chronic hemodialysis patients (7 male/3 female, mean age 58 years) were recruited. Cerebral blood flow and arterial pulse wave velocity were measured before and immediately after a hemodialysis session. To exclude effects of volume changes we kept ultrafiltration to a minimum, allowing no change in body weight. Isothermic conditions were maintained by using the GENIUS single-pass batch-dialysis system with a high-flux polysulfone dialyser. Cerebral blood flow was measured by contrast-enhanced computed tomography. Pulse wave velocity was measured using the SphygmoCor (AtCor Medical, USA) device by a single operator.

Results

This study shows for the first time that isovolemic, isothermic hemodialysis neither affected blood pressure or heart rate, nor total or regional cerebral perfusion. There was also no change in pulse wave velocity.

Conclusions

Mechanisms other than the dialysis procedure itself might be causative for the high incidence of ischemic strokes in this patient population. Moreover, the sole removal of uremic toxins does not lead to short-term effects on vascular stiffness, underlying the importance of volume control in this patient population.     

THE COMPARATIVE EFFECT OF BUSULPHAN ('MYLERAN') AND AMINOCHLORAMBUCIL ON HAEMOPOIETIC COLONY FORMING UNITS IN THE RAT

Using the spleen colony assay technique, it has been shown that busulphan (‘Myleran’) in a dose of 10^-2 g/kg (1/2 LD₅₀), causes a marked and prolonged depression (over 90%) in the number of colony forming units per femur (CFU/femur). This depression is apparent before there is any marked reduction of the total cell count per femur and is maximal 2–4 days after an intraperitoneal (i.p.) injection of the drug. It is then followed by a steady recovery, normal values being reached after about 20 days. In contrast, aminochlorambucil (2·5 x 10^-3) g/kg = 1/2 LD⁵⁰) although producing a rapid fall in the marrow cellularity has no discernable effect on the CFU/femur. If, however, a depression of CFUs is first induced by busulphan and, after allowing time for 50% recovery (13 days), aminochlorambucil is now given, a further severe depression of the CFUs/femur occurs resulting in a considerable prolongation of the neutropenia observed in the blood. The possible implications of this in the mode of action of these two drugs, and in the chemotherapy of leukaemia, are discussed.     

Inhibitor of granulopoiesis in human cyclic neutropenia.

Peripheral blood mononuclear cells of a patient with cyclic neutropenia release a high molecular weight substance (over 300,000) inhibiting normal CFU-GM cells to enter the S-phase of cell cycle. The inhibitor was released predominantly in the neutropenic phase of the disease, while in the period of normal granulocyte count the release was lower or undetectable. Also sensitivity of patient's bone marrow CFU-GM cells to similar high molecular weight inhibitor produced by ML-2 cell liner or to human placental ferritin varied within the disease cycle. CFU-GM in the normal granulocyte count period were sensitive to the inhibitors, but CFU-GM in the neutropenic phase were resistant.     

Osteolytic lesion in chronic myelogenous leukaemia

Destructive bone lesion of the femur was observed in one patient from a series of 103 patients with CML. Numerous myeloblasts were seen on touch preparations of the fresh surgical specimen obtained by open biopsy of the affected area. Bone marrow and peripheral blood differential count were compatible with chronic phase of CML at this time. 5 months later blastic crisis developed. Local radiotherapy produced effective palliation of pain but did not prevent blastic transformation of CML. The treatment of blastic crisis was unsuccessful and patient died 3 years after diagnosis of CML, 6 months after the first clinical evidence of bone infiltration.     

Acute severe thrombocytopenia after c7E3 Fab (abciximab) therapy in a patient with unstable angina and stenting of the right coronary artery. Occurrence of subacute stent thrombosis and safe readministration of the GPIIb/IIIa inhibitor tirofiban

This paper reports a case of acute severe thrombocytopenia (platelet count: 1 x 10(9)/liter) occurring within minutes of an initial abciximab bolus during coronary angioplasty and stenting in a patient with unstable angina. After six days with platelets again in the normal range the patient developed stent thrombosis. The stent was reopened and the glycoprotein receptor inhibitor tirofiban (Aggrastat) was administered without any adverse effects on platelet count. Antibodies against heparin-platelet factor 4 complexes could be excluded. Allo- and autoantibodies (IgG, IgA, IgM) directed against platelets with and without binding of abciximab could not be detected by indirect and direct platelet fluorescence antiglobulintest. A possible activation or lysis of the platelets by abciximab could also be excluded by an in vitro bleeding test investigating the effect of abciximab on heparin and citrate blood of the patient and two healthy donors. The mechanisms of abciximab-induced thrombocytopenia in this case remain unclear. The possible mechanisms are discussed.     

Confirming the diagnosis of mild hypertension.

Patients with newly found raised blood pressure are known to have lower pressures at subsequent measurements even when not treated. A study was undertaken to determine the extent to which (a) the number of follow-up measurements and (b) the duration of the intervals between them contributed to this fall in pressure. In 42 general practices 110 patients were identified as having for the first time a diastolic pressure (phase V) greater than 90 and less than 110 mm Hg. Both diastolic and systolic pressures were appreciably lower when measured at return visits when compared with the first measurement. The systolic pressure dropped appreciably in the intervals between the first and the second visits and again between the second and third visits. The diastolic pressure fell appreciably only between the first and second visits. The duration of the interval between visits was not associated with a fall in either systolic or diastolic pressure, but the number of measurements was. This pattern of fall in pressure was not affected by the patient''s age or sex. From these results we conclude that patients with newly identified blood pressures that are mildly raised should be seen at two further visits before a decision about treatment is made. The timing of these follow-up visits is not crucial.     

Clinical Evaluation of a Disposable Artificial Kidney

The in-vivo performance of a new disposable parallel flow countercurrent type of artificial kidney has been compared with that of the modified four-layered Kiil dialyser. The dialysance of urea and endogenous creatinine in the former was significantly better than in the latter for similar blood flow rates, and, moreover, unlike the dialysance with the Kiil dialyser it continued to improve over 12 hours. Among 100 disposable artificial kidneys tested no failure occurred from blood leaks despite the use of high negative pressures in the dialysate compartment. No pyrogen reactions were observed.These new artificial kidneys were ready for use in less than one-seventh of the time taken to prepare the conventional Kiil dialyser. Other advantages are their low priming volumes, the lack of a pump in the blood line, and the reduced risk of infection.     

Oxygen-induced lung microvascular injury in neutropenic rabbits and lambs

We did two studies to see if severe neutropenia might reduce the severity or delay development of O2-induced lung microvascular injury. First, we treated 11 rabbits with nitrogen mustard until their circulating neurophil count decreased to less than 50/microliters of blood, after which the rabbits breathed pure O2 until death; nine other rabbits received no nitrogen mustard and had normal numbers of circulating neutrophils during O2 breathing. All rabbits died of respiratory failure with pulmonary edema, and although chemotherapy decreased the number of neutrophils in the lungs by greater than 90%, it did not influence survival time or extravascular lung water content. To see if severe neutropenia might slow the development of O2-induced lung microvascular injury, we assessed the effects of sustained hyperoxia on lung fluid balance in unanesthetized lambs treated with hydroxyurea, so that their absolute neutrophil count was less than 50/microliters of blood. We measured pulmonary arterial and left atrial pressures, cardiac output, lung lymph flow, and concentrations of protein in lymph and plasma during a 2- to 4-h control period and then daily for 2 to 4 h as the lambs continuously breathed pure O2. After 3 days of hyperoxia, lymph flow doubled and the concentration of protein in lymph increased from 3.3 +/- 0.5 to 4.2 +/- 0.3 g/dl. Tracer studies with 125I-albumin before and 3 days after the start of O2 breathing confirmed the development of increased lung vascular permeability to protein. All lambs died of respiratory failure with pulmonary edema after 3-5 days in O2.(ABSTRACT TRUNCATED AT 250 WORDS)     

Acute dyspnoea and single tracheal localisation of mantle cell lymphoma

We report a case of a 48-year-old Chinese female with end-stage renal disease and chronic anemia on hemodialysis. Clonazepam was prescribed for myoclonus disorder two weeks prior to her hospitalization. Subsequently, she was hospitalized for neutropenic fever with thrombocytopenia and worsening anemia. Bone marrow examination demonstrated a markedly hypocellular marrow (10-20% total cellularity). Clonazepam was discontinued, with gradual improvement of thrombocytopenia, and neutropenia in 1-2 weeks. To our knowledge, this is the first reported case of pancytopenia associated with clonazepam. We recommend patients taking clonazepam to be monitored with regular complete blood count to check for clinically significant pancytopenia or thrombocytopenia.