奥美拉唑对家兔肾脏内髓集合管细胞H+/K+交换功能的影响

目的探讨奥美拉唑对家兔肾脏IMCD细胞H+/K+交换的影响,以及经洗涤处理是否解除这种影响.方法原代培养家兔肾脏IMCD细胞单层,在100 μmol/L奥美拉唑缓冲液中孵育25 min, 洗涤组则在奥美拉唑缓冲液孵育后,用不含奥美拉唑的缓冲液洗涤IMCD细胞;对照组在不含奥美拉唑的缓冲液孵育25 min;CECF/AM荧光探针法测定各组IMCD细胞H+/K+交换.结果奥美拉唑组的H+/K+交换为(0.016±0.006) dpHi/min(n=8);与对照组的(0.053±0.008) dpHi/min(n=8)相比,相差非常显著(P<0.001);洗涤组的H+/K+交换为(0.016±0.006) dpHi/min(n=6),与对照组(n=6)的(0.052±0.009)dpHi/min相比,相差非常显著(P<0.001).结论 100 mol/L的奥美拉唑对家兔IMCD细胞的H+/K+交换有显著影响,而且洗涤处理不能解除这种抑制.因而,肺心病合并上消化道出血患者使用奥美拉唑时,应综合考虑其利弊.     

The effects of high dose of parathyroid hormone on fetal osteoclasts and their precursors in vivo: An ultrastructural-cytochemical study

Background: It is not well known how the immediate precursors of osteoclast develop into osteoclasts in the fetus. This ultrastructural-cytochemical study was designed to clarify the formation process of the osteoclasts and their increased activities in the fetal mouse limb buds after administration of high dose parathyroid hormone (PTH). Methods: Twenty-four or forty-eight hours after the high doses of PTH were injected into amniotic fluid of the pregnant C₃H mice, the femoral limb buds of embryos were dissected out. Tartrate-resistant acid phosphatase (TRAP) reactions were performed while preparing specimens for electron microscopy. Results: Both control and PTH-given preosteoclasts and osteoclasts exhibited TRAP-positivities in dense bodies and vesicles. As effects of PTH, a binucleated preosteoclast of tandem fashion was observed. More osteoclastic hyperactivities were observed in the diaphyseal bone marrow. An osteoclast with a large cytoplasm exhibited two sets of clear zones and ruffled borders. Some osteoclasts demonstrated prominent amoeboid figures, while other osteoclasts developed large cytoplasmic vacuoles, which contained pieces of calcified chondroid bars. Conclusions: Our results revealed the progression of maturation from young preosteoclasts to osteoclasts. An existence of a peculiar binucleated preosteoclasts suggested one of the processes for multinucleation of the osteoclast. Quite remarkable osteoclastic hyperactivities were obviously the effects of high dose PTH. Our results also indicated the endophagocytic ability of the osteoclast. How PTH affected the osteoclasts and their precursors in the diaphyseal bone marrow can be speculated. © 1995 Wiley-Liss, Inc.     

Serum IgG, IgA, IgM, and IgE levels and allergy in Filipino children in the United States

The serum levels of IgE, IgG, IgA, and IgM of 27 American-born Filipino children 5 to 17 years of age were measured and found to be significantly higher than those of a control group of 24 Caucasian children of similar age distribution and attending the same general pediatric clinics. The geometric mean of serum IgE of the Filipinos was 227 U. per milliliter and of the Caucasians, 69 U. per milliliter (p < 0.01). The geometric means of other serum immunoglobulin levels of the Filipinos by comparison with the Caucasians were: IgG, 1,303 and 1,010 mg. per 100 ml. (p < 0.01); IgA, 195 and 120 mg. per 100 ml. (p < 0.001); and IgM, 141 and 92 mg. per 100 ml. (p < 0.02), respectively. The incidence of atopic disease was higher in the Filipino study group (48 per cent) than in the Caucasian control group (25 per cent); eczema was especially prevalent in the Filipino group. Elevated serum IgE levels were associated with atopic disease in both racial groups; however, there was no correlation between serum level of IgG, IgA, or IgM and atopy.     

An estimate of the minimal frequency of cytolytic T lymphocyte effector cells generated in allogeneic reactions.

A 'micro' modification of the standard 51Cr release assay was developed. With this assay, significant cytolysis was obtained employing 100--200 51Cr-labeled target cells and fewer than 100 lymphocytes obtained from mixed leukocyte cultures. A minimal estimate as to the actual frequency of effector cells was determined for both primary (1 cell in 30) and secondary (1 cells in 8) cytolytic T lymphocyte populations.     

Circulating immune complexes during immunotherapy.

Chronic immunization may lead to the production of circulating immune complexes (CICs). This study was undertaken to determine the presence of circulating IgG immune complexes in 95 subjects with allergic rhinitis/asthma receiving immunotherapy, 46 individuals with similar diagnosis but not on immunotherapy, and 64 healthy controls. Modified Raji cell and murine leukemia cell (L-1210) assays, selected for a high density of Fc receptors and devoid of Epstein-Barr virus membrane antigen, were used. Other immunological parameters such as immunologlobulins G, A, M, E, and rheumatoid factor activity were also studied. The CIC concentrations in the treated group did not differ significantly from the untreated group, although both groups did have a significantly higher concentration than the healthy controls. The presence of CICs has no relationship with age or sex of patients, dosage of allergen administered, number and nature of allergens received, period between the time of last injection and the blood sampling, and the duration of immunotherapy. Serum IgG, IgA, IgM, and rheumatoid factor activity did not differ between the treated and untreated groups. IgE was significantly higher in the treated group when compared with the untreated, and IgE levels in treated patients with elevated CICs were significantly increased compared with CIC-negative treated patients. These data suggest that CICs are present in serum of atopic diseases such as allergic rhinitis/asthma. Significantly, an association of elevation of CICs with immunotherapy could not be demonstrated.     

Advanced 1H Solid‐State NMR Spectroscopy on Hydrogels, 1

Summary: The nature of the pH dependent collapse of poly(methacrylic acid) (PMAA) hydrogels is investigated using recent ¹H solid‐state NMR methods. In aqueous solution, PMAA changes from an expanded conformation at high pHs to a compact contracted form at low pHs, where hydrogen bonds play a central role. In solid‐state ¹H NMR spectra, recorded under fast magic angle spinning (MAS), dried PMAA samples previously collapsed at low pHs show characteristic signals in the spectral region of the carboxylic acid protons. With the aid of 2D ¹H‐¹H double‐quantum (DQ) MAS NMR spectra, three signals can be distinguished at 8, 10.5 and 12.5 ppm, which are attributed to free carboxylic groups and two different types of hydrogen bonded forms, respectively. The 12.5 ppm signal arises from the hydrogen bond with the shortest H? H distance, corresponding to the form that is most stable with respect to increasing temperature and pH. The weaker hydrogen‐bonded form (with a signal at 10.5 ppm) requires a slightly lower pH, while the free acid signal (at 8 ppm) emerges under the most acidic medium. Moreover, the stabilities of the hydrogen‐bonded carboxylic acid dimers can be inferred from the proton‐proton distances within the dimers, i.e. (275 ± 5) pm and (295 ± 15) pm for the protons at 12.5 and 10.5 ppm, respectively, which are determined by means of DQ MAS sideband patterns. Both the stability of the hydrogen bonds and the acidity of the protons may be related to the stereochemistry and the conformation of the PMAA chains.

     

Histamine downregulates CD14 expression via H2 receptors on human monocytes

Lipopolysaccharide (LPS) binds to LPS-binding protein (LBP) in plasma and is delivered to the cell surface receptor CD14 on human monocyte. LPS is transferred to the transmembrane signaling receptor toll-like receptor (TLR) 4. In the present study, the effect of histamine on the expression of CD14 on human monocytes was investigated. Histamine concentration- and time-dependently decreased the expression of cell surface CD14, whereas histamine did not decrease mRNA for CD14 nor increase soluble CD14 (sCD14). The inhibitory effects of histamine on CD14 expression were antagonized by H2-receptor antagonist, but not by H1 and H3/H4 antagonist. The effects of selective H2-receptor agonists, 4-methylhistamine and dimaprit, on CD14 expression mimicked that of histamine indicating that histamine regulated CD14 expression through the stimulation of H2-receptors. The pretreatment with histamine partially inhibited the LPS-induced TNF-alpha production in human peripheral blood mononuclear cells (PBMC). Such inhibition might be due to the down-regulation of CD14 expression on monocytes by histamine.     

The effects of thermochemotherapy using cyclophosphamide plus hyperthermia on the malignant pleural mesothelioma in vivo

The human malignant pleural mesothelioma is related to the use of asbestos in the majority of cases. Though the use of asbestos has been prohibited since the 1990s, the incidence of pleural mesothelioma is still increasing because of a latency period of at least 20 years. This study investigated the benefit of single therapy with cyclophosphamide or hyperthermia or the combination of both on cells of a human pleural mesothelioma cell line, xenotransplanted subcutaneously in the paw of mice. A CONTROL group received the same volume of physiological saline. The oxygenation of tumours was measured, tumour growth was followed over 3 weeks, immunohistochemical studies and a light and electron microscopic evaluation were performed. Chemotherapy or hyperthermia alone was only temporarily effective. The greatest benefit was achieved using combined thermochemotherapy consisting of cyclophosphamide plus hyperthermia: 50% of this group had partial remissions, and 67% responded to this therapy. After 3 weeks tumours grew again. Superior effects could be achieved by performing additional cycles of chemotherapy or adding another drug or radiation for instance. This study shows promising results in the treatment of malignant pleural mesothelioma.     

Growth resistance-sized arteries in response to bladder hypertrophy in the rat: time-course,DNA-synthesis and LDH-isoform pattern

Bladder growth was induced by partial urethral obstruction. Bladder hypertrophy was evident at 53 h after obstruction and continued over a 6 weeks period. Small bladder arteries were taken from fixed anatomical locations of the bladder circulation, mounted in a small vessel myograph and the optimal diameter for maximal isometric force development was determined (L_max, K⁺=125 mm stimulation). Bladder hypertrophy was associated with an enlarged L_max from 53 h onward (compared with sham-operated controls) and L_max continued to increase until 10 days after urethral obstruction. Between 10 days and 6 weeks no further increase of the diameter was observed. Increased diameters in vitro were accompanied by a transiently increased [³H]Thymidine uptake in the small arteries which peaked at 53 h after obstruction but was still above background at 10 days. At this time point, small arterial growth was associated with a significant relative increase in the M isoform of LDH as determined with agarose electrophoresis on tissue homogenates. Thus organ growth induced small vessel growth in the rat is characterized by a rapid onset, increased but transient DNA-turnover and LDH-isoform changes. The latter mimic changes seen in other types of smooth muscle growth.