The influence of oxygen tension, temperature, and hemoglobin concentration on the rheologic properties of sickle erythrocytes

With the use of micromanipulation techniques, the shear modulus or "rigidity" mu, the recovery time tc, and the unfolding time tf for individual sickle cells have been measured at different oxygen tensions, temperatures, and cell densities. In these experiments, the partial pressure of oxygen was varied from 156 to 40 mm Hg and the temperature was controlled at 25 degrees C or 37 degrees C. Three mean cellular hemoglobin concentrations were studied: 29 g/dL, 33 g/dL, and 46 g/dL. The lighter cells (29 and 33 g/dL) exhibited at most a threefold increase in rigidity as the pO2 was decreased from 156 to 40 mm Hg. At 25 degrees C, the densest cells (46 g/dL) also exhibited a threefold increase. However, at 37 degrees C, the rigidity of these cells increased eightfold between 156 to 40 mm Hg. Compared with normal cells, this gives a rigidity that is 18 times larger. In contrast to the values for mu, the values for tc and tf remained essentially unchanged (within the accuracy of the experiments) for the lighter cells and could not be measured for the densest cells.     

Lymphocyte depletion during treatment with intensive chemotherapy for cancer

Recently we have observed an increased incidence of opportunistic infections in patients treated with intensive chemotherapy for cancer. Because T-cell depletion is associated with similar clinical events in human immunodeficiency virus infection and after bone marrow transplantation, we have analyzed peripheral blood lymphocyte populations in a series of patients during treatment with intensive chemotherapy for cancer. Although neutrophil, monocyte, and platelet numbers consistently recovered to greater than 50% of pretreatment values after each sequential cycle of therapy, lymphocyte numbers did not recover within the same time period. B cells decreased rapidly from a mean value of 149 +/- 46/mm3 before chemotherapy to 4 +/- 1/mm3 during chemotherapy (P = .01). CD4+ T cells decreased from a mean of 588 +/- 76/mm3 before chemotherapy to 105 +/- 28/mm3 during chemotherapy (P = .0002) and CD8+ T cells decreased from a mean of 382 +/- 41/mm3 before chemotherapy to 150 +/- 46/mm3 during chemotherapy (P = .0009). Natural killer cell numbers did not show significant declines (171 +/- 30/mm3 before, 114 +/- 24/mm3 during, P = .19). Based on the history of opportunistic complications in patients with other disorders who display similar degrees of CD4+ T-cell lymphopenia and preliminary observations in this population, immune incompetence could surface as a dose-limiting toxicity for highly dose-intensive chemotherapy regimens.     

Characterization of colony-stimulating activity produced by human monocytes and phytohemagglutinin-stimulated lymphocytes

Human colony-stimulating activity (CSA) may support the proliferation of both human and murine granulocyte-macrophage progenitor cells (CFU- C) or, in the case of human urinary CSA, may only stimulate murine bone marrow CFU-C. CSA produced in the culture media of monocytes and macrophages and phytohemagglutinin-stimulated lymphocytes from human peripheral blood was characterized for both human and mouse marrow CFU- C stimulating activities. During the initial phase of a long-term cultures of monocytes, both human- and mouse-active CSA (MnCM-HM) were produced. In later phases of culture, however, only mouse-active CSA (MnCM-M) was produced. Fractionation on Sephadex G-150 revealed two functionally distinct species from MnCM-HM and lymphocytes conditioned medium, a high molecular weight factor (MW greater than 150,000) which stimulated mouse but not human colony formation, and a low molecular weight species (MW 25,000-35,000) which was active against both mouse and human target cells. However, MnCM-M revealed only one high molecular weight species (greater than 150,000), active only on mouse marrow. The possible biologic significance of such an activity is discussed.     

Quantifying the effects of absorbed dose from radioembolisation on healthy liver function with [99mTc]TcMebrofenin

European Journal of Nuclear Medicine and Molecular Imaging - To quantify the effects of absorbed radiation dose on healthy liver parenchyma following radioembolisation (RE) using...     

Characterization of mice expressing Ins1 gene promoter driven CreERT recombinase for conditional gene deletion in pancreatic β-cells

Gene manipulation using Cre-loxP recombination has proven to be an important approach for studying the impact of gene expression on pancreatic β-cell biology. We report the generation of a transgenic mouse line that enables a highly specific system for conditional gene manipulation within β-cells and achieve tissue specific and temporally regulated deletion of the Ctnnb1 (β-catenin) gene in pancreatic β-cells. cDNA encoding Cre recombinase fused to modified estrogen receptor (CreERT) under control of mouse insulin 1 gene promoter (Ins1) was used to construct the mouse line Tg(Ins1-Cre/ERT)1Lphi, also termed MIP1-CreERT. In a cross of MIP1-CreERT with a ROSA26/LacZ reporter strain, tamoxifen [Tmx] - dependent β-galactosidase expression occurred within pancreatic β-cells but not in other organ systems. Intraperitoneal glucose tolerance tests and glucose-stimulated changes in β-cell cytoplasmic calcium concentration were not adversely affected in adult MIP1-CreERT. A mouse line with floxed Ctnnb1 gene (Ctnnb1f/f) was crossed with the MIP1-CreERT line to generate a mouse model for inducible β-cell specific deletion of β-catenin gene (Ctnnb1f/f:MIP1-CreERT). Ctnnb1f/f:MIP1-CreERT mice and Ctnnb1f/f littermate controls, were injected with Tmx as adults to knock down β-catenin production in the majority of pancreatic β-cells. These mice showed normal glucose tolerance, islet cyto-architecture and insulin secretion. A novel protein fraction of 50Kd, immunoreactive with anti-β-catenin was observed in islet extracts from Ctnnb1f/f:MIP1-CreERT[Tmx] mice but not MIP1-CreERT-negative Ctnnb1f/f[Tmx] controls, indicating possible presence of a cryptic protein product of recombined Ctnnb1 gene. The MIP1-CreERT mouse line is a powerful tool for conditional manipulation of gene expression in β-cells.     

The presence of allele D of angiotensin-converting enzyme polymorphism is associated with diabetic nephropathy in patients with less than 10 years duration of Type 2 diabetes.

AIM: To investigate the association between angiotensin-converting enzyme gene I/D polymorphism and diabetic nephropathy (DN) in patients with Type 2 diabetes mellitus (DM) taking into consideration the known duration of DM. METHODS: Cross-sectional study with 982 patients categorized according to urinary albumin excretion (UAE) into normoalbuminuria (UAE < 20 microg/min or < 17 mg/l, 24-h timed urine or spot random sterile urine, respectively), incipient DN (UAE 20-199 microg/min or 17-174 mg/l) and overt DN (UAE > 200 microg/min or > 174 mg/l or dialysis). Patients were further grouped regarding presence of the D allele (DD/ID vs. II) and DM duration (< or = 10 years or > 10 years). RESULTS: Incipient DN was diagnosed in 17.3% (n = 170), and 20.7% (n = 203) had overt DN (macroalbuminuria, n = 129; dialysis, n = 74). Genotype distribution (DD/ID/II) was similar in patients with incipient (49/92/29) or overt DN (77/89/37) if compared with patients without DN (181/308/120, P = 0.172). In patients with DM < or = 10 years, having the D allele (DD/ID) resulted in an odds ratio (OR) of 2.66 (95% CI: 1.12-6.58, P = 0.015) for incipient DN, and 3.19 (95% CI: 1.18-9.30, P = 0.012) for overt DN. In patients with longer DM duration, the D allele did not increase the risk for incipient (OR 0.68, 95% CI 0.36-1.29, P = 0.206) or overt DN (OR 0.67, 95% CI 0.39-1.17, P = 0.138). CONCLUSION: The DD/ID genotypes were associated with incipient or overt DN in patients with DM < or = 10 years.     

Hypoxic hepatitis in children after cardiac surgery

<正>To the Editor: Hypoxic hepatitis(HH), also known as ischemic hepatitis or shock liver, is a liver injury characterized by necrosis of centrilobular hepatocytes with a rapid increase in serum aminotransferase levels. The incidence rate of HH among patients in the intensive care unit(ICU) was found to be 0.9%-11.9% [1]. Occurrence of HH appears to have a significant impact on the clinical outcome.     

Peripheral blood immune response elicited by beta-lactoglobulin in childhood cow's milk allergy

Several studies analyzing the immune responses in patients with cow's milk allergy (CMA) have used T-cell lines or T-cell clones that require prolonged in vitro cell culturing and may result in a switched cell phenotype and function. We investigated immune responses to beta-lactoglobulin (b-LG) in peripheral blood mononuclear cells after a short in vitro antigen stimulation in children with acute CMA (both IgE-mediated and non-IgE-mediated forms) and in those who outgrew an IgE-mediated CMA. Healthy controls were also investigated. Peripheral blood mononuclear cells were assayed for IL-13, IFN-γ, IL-4, and IL-10. Although b-LG induced a cytokine production and/or cell proliferation almost in all children, included healthy controls, differences were observed among the four groups. Children with IgE-mediated CMA had a marked Th2-response, with high IL-13 production and proliferation, but low IFN-γ; by contrast, children with non-IgE-mediated CMA produced no, or very low, IL-13 and cell proliferation. Children, who outgrew CMA, showed a shift to a Th1-response, with reduced IL-13 and increased IFN-γ. IL-10-responses were high in all groups, with the highest level in healthy children; by contrast, IL-4 was undetectable in all children. This study highlights the use of shortly stimulated peripheral blood cells to investigate the food-induced immune responses.     

Recombinant LH supplementation to recombinant FSH during the final days of controlled ovarian stimulation for in vitro fertilization. A multicentre, prospective, randomized, controlled trial

BACKGROUND: The purpose of this multicentre, multinational trial was to study whether rLH supplementation to recombinant FSH (rFSH) during the late follicular phase increased pregnancy rates. METHODS: After down-regulation with nafarelin, 526 women were randomized on Day 1 of stimulation to use either rFSH (Gonal-F) alone (n = 261) or to continue after Day 6 of stimulation with both rFSH (Gonal-F) and rLH (Luveris) (n = 265) from Day 6. The starting dose of rFSH was 150-225 IU/day according to age below or above 35 years. RESULTS: Ongoing pregnancy rate at week 10-12 was 28.7% after rFSH alone and 27.2% after rFSH + rLH. This showed no evidence of a difference. Administration of rLH significantly (P< 0.001) increased serum LH. Ongoing pregnancy rates in patients with low LH levels (<33 percentile) on Days 1 and 6 of stimulation showed no difference between the group treated with rFSH only (23.9% low Day 1 LH; 22.1% low Day 6 LH) versus rFSH + rLH (25.0% low Day 1 LH; 28.9% low Day 6 LH). CONCLUSIONS: Supplementing rFSH with daily doses of 75-150 IU of rLH during the second half of the follicular phase showed no evidence of increasing the ongoing pregnancy rates in the general population. (ClinicalTrials.gov, trial number: KF02-035/03).