Erythrocyte swelling and membrane hole formation in hypotonic media as studied by conductometry.

Hypoosmotic swelling of erythrocytes and the formation of membrane holes were studied by measuring the dc conductance (G). In accordance with the theoretical predictions, these processes are manifested by a decrease in G followed by its increase. Thus, unlike the conventional osmotic fragility test, the proposed methodological approach allows investigations of both the kinetics of swelling and the erythrocyte fragility. It is shown that the initial rate of swelling and the equilibrium size of the cells are affected by the tonicity of a hypotonic solution and the membrane rheological properties. Because the rupture of biological membranes is a stochastic process, a time-dependent increase in the conductance follows an integral distribution function of the membrane lifetime. The main conclusion which stems from reported results is that information about rheological properties of red blood cell (RBC) membranes and the resistivity of RBCs to a certain osmotic shock may be extracted from conductance signals.

A novel approach for assessments of erythrocyte sedimentation rate.

INTRODUCTION: Previous studies have shown that the dispersed phase of sedimenting blood undergoes dramatic structural changes: Discrete red blood cell (RBC) aggregates formed shortly after a settling tube is filled with blood are combined into a continuous network followed by its collapse via the formation of plasma channels, and finally, the collapsed network is dispersed into individual fragments. Based on this scheme of structural transformation, a novel approach for assessments of erythrocyte sedimentation is suggested. METHODS: Information about erythrocyte sedimentation is extracted from time records of the blood conductivity measured after a dispersion of RBC network into individual fragments. RESULTS: It was found that the sedimentation velocity of RBC network fragments correlates positively with the intensity of attractive intercellular interactions, whereas no effect of hematocrit (Hct) was observed. CONCLUSION: Thus, unlike Westergren erythrocyte sedimentation rate, sedimentation data obtained by the proposed method do not require correction for Hct.

Laparoscopic accessory splenectomy using intraoperative gamma probe guidance.

In cases of accessory splenic tissue in postsplenectomy patients, it is of utmost importance to localize the accessory spleen prior to surgery. Several studies have shown the feasibility of laparoscopic resection of accessory splenic tissue using preoperative scintigraphy. We present the cases of three postsplenectomy patients with accessory splenic tissue causing relapsing hematologic disease. Accessory spleens were diagnosed and localized preoperatively by positive uptake of heat-damaged Tc99m-labeled red blood cells using scintigraphy. Two patients with relapse of immune thrombocytopenic purpura and one with hemolytic anemia underwent handheld gamma probe-assisted laparoscopic accessory splenectomy. One patient with immune thrombocytopenic purpura recovered his platelet count at 3-year follow-up. The other patient had a relapse of disease within 3 months despite successful removal of the accessory spleen. The patient with hemolytic anemia had postoperative relapse; two accessory spleens were identified on radionuclide investigation. The use of intraoperative nuclear imaging can greatly aid in localization and provide confirmation of complete laparoscopic excision of the nuclear focus. The technique is especially useful in cases of a small accessory spleen, by avoiding a major open procedure and contributing to good postoperative results.

The role of erythrocyte aggregation in the abnormal hemorheology of multiple myeloma patients.

OBJECTIVES: The aim of this study is to clarify whether increased aggregation of red blood cells (RBCs) of multiple myeloma (MM) patients is caused by changes in plasma chemical composition or is associated with alterations in RBC properties and in addition, to suggest an approach to revert the enhanced aggregation in MM toward normal. MATERIALS AND METHODS: 40 blood samples of MM patients and suspensions of control RBCs in MM plasma were examined. In addition, RBC aggregation in MM blood was studied in the presence of dextrans with mean molecular weights of 9.6 and 40 kDa (D9.6 and D40). A method based on electrical and dielectric properties of cellular suspensions was used to study RBC aggregation. In this method, a lower aggregation index demonstrates a higher aggregability. RESULTS: The mean values of aggregation index for whole blood of healthy individuals, control cells in MM plasma and MM blood sample are 19.0, 7.2 and 3.2%, respectively. The kinetics of RBC aggregation slow down with the decrease in the fraction of MM plasma. No correlation was found between RBC aggregation and the immunoglobulin plasma level. Addition of D9.6 to MM blood reverts the enhanced aggregation toward normal. DISCUSSION: The findings that RBC aggregation changes in the following order: MM blood > normal RBCs in MM plasma > control blood sample, suggest that surface-active plasma molecules play a role in enhanced aggregation in MM. The surface concentration of these molecules and hence RBC aggregability is reduced in the presence of dextrans due to their competitive adsorption onto RBC membrane. Because the end-to-end distance of D40 is quite comparable with the Debye length, the effect of this particular dextran on RBC aggregation is negligible.

Longitudinal melanonychia associated with hydroxyurea therapy in a patient with essential thrombocytosis.

Occurrence of skin lesions during long-term therapy with hydroxyurea are well described, but there have been only a few case reports of longitudinal melanonychia associated with hydroxyurea treatment. We report herein longitudinal melanonychia associated with hydroxyurea therapy in a subject with essential thrombocytosis. The prolonged time lapse (1 year) between initiation of hydroxyurea therapy and the onset of the longitudinal melanonychia should be noted.

Pigmented purpuric dermatosis (Schamberg's purpura) in an infant.

Purpura in an infant is usually an alarming sign of a systemic (infectious, hematologic-oncologic or immunologic) disease. Chronic purpuric dermatoses have not been reported in infants and, therefore, are not considered in the differential diagnosis of purpuras in this age. We report on a female infant with progressive purpura who underwent extensive laboratory investigations to rule out a systemic disease. Based on the laboratory findings and clinical course, the diagnosis of Schamberg's purpura was established.

Gluteal manifestation of advanced Hodgkin's disease.

Hodgkin's disease (HD) is a nodal malignancy with a characteristically axial pattern of spread and with contiguous progression via lymphatic channels. Even when dissemination occurs beyond the lymphoreticular system, certain patterns of associated spread are frequently evident. We describe a case of nodular sclerosis HD with a 12-year indolent course and late involvement of the gluteal muscle. Initially, stage was IVb with spleen and bone marrow involvement, complicated by a Coomb's positive hemolytic anemia. Following chemotherapy, the patient had a partial response with the subsequent long course of slowly progressive disease invading first the urinary bladder and, later, the gluteus. Involvement of the gluteal muscle is a rare event in HD. Spread to the gluteus occurred most likely by contiguity, via retroperitoneal lymph nodes.

Type I Gaucher disease due to homozygosity for the 259T mutation in a Bedouin patient.

A 26-year-old Bedouin with moderate thrombocytopenia and enlarged spleen and liver was diagnosed as having type I Gaucher disease based on the presence of Gaucher cells in the bone marrow biopsy and enzymatic determination of glucocerebrosidase activity. Molecular analysis excluded 10 common mutations in the glucocerebrosidase gene. Homozygosity for the C --> T mutation in nucleotide 259 of the cDNA (1763 genomic) was detected by digestion with restriction enzyme StyI after an amplification of a portion of exon 3 by mismatched primers. This is the first known case of homozygosity for this mutation. The fact that it produces a very mild phenotype, confirms a previous suggestion that 259T can be classified as a "mild" mutation. Association of the 259T mutation with the "Pv 1.1 +" haplotype is consistent with a common origin of the mutated alleles.

Wide distribution of granulophysin epitopes in granules of human tissues.

BACKGROUND: The identification and characterization of granule membrane proteins are becoming increasingly important in understanding the packaging and secretory function of granules and characterizing diseases involving granules. A granule membrane protein, granulophysin, has recently been identified in the membranes of platelet dense granules, organelles that contain stored ADP, ATP, serotonin, and calcium. Antibodies that recognize granulophysin also stain granules of monocytes, neutrophils, and lymphokine activated killer cells. EXPERIMENTAL DESIGN: In the present study, the distribution of epitopes recognized by antigranulophysin monoclonal antibodies in human tissues was investigated using immunohistochemistry on paraffin sections. Quantitation of the protein was also performed by enzyme-linked immunosorbent assay. The protein was also analyzed in various tissues using Western blotting. RESULTS: Granulophysin was localized to the granules of skin melanocytes, neurons, endocrine gland cells, exocrine glands (except mucin producing cells), and surface lining cells. Analysis by Western blots revealed a typical staining pattern for granulophysin in lung, adrenal gland, liver, brain, prostate, and pituitary. Atypical bands were present in the pancreas head (47 kDa) and skeletal muscle (34 kDa). A clear distinction was demonstrated between granulophysin and synaptophysin through both immunochemistry and blotting, despite the known cross-reactivity of these two proteins. CONCLUSIONS: The findings demonstrate that granulophysin is a widely distributed protein that is frequently associated with granules. We speculate that it may be critical in granule function.

Familial thrombotic thrombocytopenic purpura in a Bedouin family.

A 24-year-old Beduin pregnant woman in her 22nd week of gestation was treated successfully by plasmaphereses and steroids as soon as the diagnosis of TTP was confirmed by the clinical and laboratory criteria needed. Her sister died due to complications of TTP in pregnancy five years earlier while her other sister recuperated from TTP during pregnancy. However, fetal loss ensued. Thus, family history in pregnant women presenting with toxemia of pregnancy--like--syndrome may be the first clue to familial TTP.

Leukophysin: a 28-kDa granule membrane protein of leukocytes.

A membrane glycoprotein of human platelet dense granules, called granulophysin, with serologic homology to synaptophysin has recently been identified. To determine if this protein was present in granulated leukocytes, we examined several cell types for the presence of the protein by indirect immunofluorescence. Antigranulophysin mAb staining was detected in a granular pattern in the cytoplasm of permeabilized IL-2-stimulated CD3+ peripheral lymphocytes, neutrophils, U937 monocytes, and mast cells. Immunohistochemistry of human lymph nodes showed cytoplasmic staining of macrophages, neutrophils, and some dendritic cells. Induction of granule exocytosis in granulated CD3+ lymphocytes after stimulation with PMA and calcium ionophore A23187 resulted in a redistribution of the reactive epitope from the cytoplasm to the plasma membrane. Subcellular fractions contained two peaks of reactivity; the first peak coincided with N-benzyloxycarbonyl-L-lysine thiobenzyl ester-esterase activity in dense granules whereas the second peak was present in lighter fractions. The affinity purified protein from both peaks was identical in Western blot analysis and had a molecular mass of 28 kDa under reducing conditions. The protein could only be solubilized in detergent suggesting that it was an integral membrane protein. We have named this protein leukophysin to differentiate it from the 40-kDa granulophysin of platelets. Monocytes contained a protein with identical m.w. to leukophysin, whereas a protein of a slightly higher m.w. was detected in neutrophils. We propose that leukophysin is a common granule membrane protein of leukocytes.

[Treatment of aplastic anemia with antithymocyte globulin].

Acquired aplastic anemia is usually fatal. During recent years autoimmune disturbances have been implicated in bone marrow depression. This has led to a novel therapeutic approach based on immune suppression to enable bone marrow recovery. We report 4 adult patients who were treated with antithymocyte globulin.

Thrombocytopenia as an epiphenomenon to excessive weight loss after gastric operation (bypass, gastroplasty).

Two females that had lost much weight after gastric operation for obesity exhibited thrombocytopenia associated with a doubling of platelet IgG concentration, suggesting a relationship with immune thrombocytopenia.