Glycogen accumulation in renal tubules, a key morphological change in the diabetic rat kidney

Patients with diabetic nephropathy, characterised pathologically by glomerulosclerosis, may account for up to 40% of end-stage renal cases. The short-term (within 3 months) streptozotocin- or alloxan-induced rat model is often used but glomerulosclerosis is seldom reported and it is unclear what the primary renal lesions are. Diabetic rats were studied at 1, 3 and 6 months after a single injection of alloxan. Both methacrylate and paraffin-embedded renal sections were obtained and stained with PAS and haematoxylin. A morphometric study was performed with stereological methods to obtain the volumes and lengths or diameters of renal tubules and glomeruli. A key morphological change associated with sustained hyperglycaemia was the accumulation of glycogen granules in about half of the distal tubules and thin segments starting from 1 month after the experiment, which was then extended to about half of the proximal tubules at 6 months. Renal hypertrophy was seen with a 9% increase in the tubule diameter but not in the total length; glomerular morphology was basically unaffected. Further studies are needed to establish whether glomerulosclerosis would occur in longer term and whether this animal model would be appropriate to study the human condition of diabetes mellitus in terms of renal damage.

Tyrosine kinase inhibitor AG1024 exerts antileukaemic effects on STI571-resistant Bcr-Abl expressing cells and decreases AKT phosphorylation

Chronic myelogenous leukaemia (CML) is a clonal malignancy of the pluripotent haematopoietic stem cell, characterised by an uncontrolled proliferation and expansion of myeloid progenitors expressing a fusion oncogene, BCR-ABL, the molecular counterpart of the Ph1 chromosome. The tyrosine kinase (TK) activity of BCR-ABL is known to activate several major signalling pathways in malignant cells, including Ras, JAK/STAT and PI3K/Akt with evidence of proteasome-mediated degradation of other targets such as the DNA repair protein DNA-PKcs and cyclin-dependent kinases inhibitor p27. Targeting these abnormalities by blocking TK of BCR-ABL with STI571 provided a promising approach for the therapy of CML. The recent development of resistance to STI571 illustrates, however, that the use of other TK inhibitors could be of major interest for therapeutic purposes. To this end, the TK inhibitor Tyrphostin AG1024 was used to evaluate effect on regulation of BCR-ABL expression, inhibition of cell proliferation and tumour formation in vivo in human and murine BCR-ABL expressing cell lines. Tyrphostin AG1024 was shown to downregulate expression of BCR-ABL and P-Akt, and to upregulate DNA-PKcs expression. In addition, Tyrphostin AG1024 was able to inhibit cell proliferation, and delay tumour growth in vivo. Thus, AG1024 is able to interfere with three major targets of BCR-ABL in leukaemic cells. Interestingly, Tyrphostin AG1024 was also effective against cells resistant to STI571 by distinct mechanisms including Bcr-Abl mutation. Therefore, these data suggest that Tyrphostin AG1024 could represent the basis of a novel therapy for STI571 refractory CML.

[Effects of methyl jasmonate treatment on the hydrolytic activity and phosphorylation level of plasma membrane H+-ATPase in mung bean (Vigna radiata L.) hypocotyls]

Employing both protein kinase inhibitors and phosphatase inhibitors to investigate the effect of MeJA (methyl jasmonate) on the H+-ATPase hydrolytic activity of plasma membrane, and the regulations involved with phosphorylation and dephosphorylation of plasma membrane H+-ATPase after treatments with MeJA. 3 d-old etiolated mung bean (Vigna radiata L.) seedlings were harvested and the hypocotyls (1-2 cm in length) under the hook were used to prepare the plasma membrane vesicles by means of aqueous two-phase partition. Hydrolytic activities of plasma membrane H+-ATPase were determined in responding to the treatment with MeJA. H(+)-ATPase activity stimulated by MeJA and FC was up to 30%, and the combination of MeJA and FC did not show significant additive effect. The phosphatase inhibitors, okadaic acid and cantharidin, enhanced MeJA-induced increase of the enzyme activity to 60% and 50%, respectively. Staurosporine and cheleythrine, two inhibitors of protein kinase, abolished completely the stimulative effect of MeJA on PM H+-ATPase activity (Fig. 2). The results from gamma-(32)P tracer experiments showed that treatment with MeJA and FC increased the level of isotope labeling on PM H+-ATPase. Okadaic acid and cantharidin could enhance the labeling of gamma-(32)P on PM H+-ATPase induced by MeJA and FC. Both MeJA- and FC-induced increase in gamma-(32)P level were inhibited when cheleythrine was applied (Fig. 3). Ca2+ strongly stimulated the PM H+-ATPase and the increase of the enzyme activity was two times higher than that of the control. But Ca2+ had no enhancement of the enzyme activity induced by FC and MeJA. In the presence of Ca2+, Okadaic acid could increase the MeJA stimulation slightly, but cantharidin had not any significant effect on the enzyme activity. Staurosporine and cheleythrine showed no effect on MeJA-induced increase in PM H+-ATPase, and which activity was similar to the control after treatment with either inhibitor (Figs. 5, 6). The changes in hydrolytic activity of H+-ATPase stimulating by MeJA is probably related to reversible phosphorylation, and the protein kinase is Ca2+-independent, phosphatase is Ca2+-dependent.

[Clinical features of 23 cases of AIDS complicated by tuberculosis]

OBJECTIVE

To discuss the clinical features, treatment and prognosis of patients with AIDS complicated by tuberculosis(TB).

METHODS

The clinical features of 23 patients with AIDS complicated by tuberculosis admitted from 1997 to July 2004 were retrospectively analyzed.

RESULTS

Of the 23 patients, most (94.3%) were young or middle-aged, and 11 (47.8%) died within half a year. The main HIV transmission was via sexual contact in 15 (65.2%) patients. Loss of body weight by 5 - 15 kg was present in all patients, cough for over 1 month in 15 (65.2%), and multiple opportunistic infections were complicated in most cases. Out of the 23 cases, 14 (60.9%) showed only pulmonary TB, and 8 (34.8%) showed lymph node TB. In 12 cases with infiltrated pulmonary TB, X-ray showed bilateral infiltration and no cavity formation was found. Slightly positive PPD test was found in 2 (8.7%) cases, and positive acid-fast bacilli was detected in sputum in 1 case (4.4%). The pre-treatment CD(4)(+) cell number in 23 patients was much lower than that in AIDS patients without complicated TB (P < 0.05). The pre-treatment CD(4)(+) cell number in patients died shortly after diagnosis was much lower than that in survived patients (P < 0.05). The HIV RNA level in the 23 patients was much higher than that in patients without complication of TB (P < 0.05). The mortality in patients treated with therapy against both TB and HIV was much lower than that in patients untreated or treated only with anti-TB therapy (P < 0.05).

CONCLUSIONS

For patients with AIDS complicated by TB, the high negative rate in PPD test and the atypical chest X-ray manifestations are common. However, lymph node TB is quite common with high mortality. The pre-treatment CD(4)(+) level decreases significantly, and is associated with mortality. The TB bacilli may accelerate HIV virus duplication. It is suggested that the patients be treated with a combination of anti-TB and anti-HIV therapies.

Characterization of Iron Catalysts Prepared by Chemical Vapor Deposition on Nonzeolitic Supports

Chemical vapor deposition (CVD) of FeCl3 has been used to deposit Fe3+ ions on the surface of sulfated zirconia (SZ) and silica-alumina (SA). Upon exposure to FeCl3 vapor most Brønsted acid sites and silanol groups are replaced by Fe, as evidenced by IR. With SZ the concentration of the acid sites and thus the retention of Fe increase with the sulfate loading up to approximately 45% of a monolayer, followed by an abrupt decrease at higher loadings. This indicates condensation of sulfate groups to polysulfates, which is in line with a lower number of Brønsted sites per sulfate. Release of HCl due to the reaction of Brønsted sites with FeCl3 peaks at 85 degrees C for SZ but only at 345 degrees C for SA. After replacing Cl- by OH- and calcining, the materials were tested as De-NOx catalysts and characterized by temperature-programmed reduction (TPR) with H2 or CO. Mononuclear and dinuclear oxo-ions of Fe coexist with Fe oxide particles in calcined Fe/SA, resulting in a low selectivity for NOx reduction. During reduction of Fe/SA up to 800 degrees C, a significant fraction of the Fe forms a chemical compound with SA, possibly an aluminate. In Fe/SZ the Fe dramatically increases the reducibility of the sulfate groups, from 57% partial reduction to SO2 in the absence of Fe, to 90% deep reduction to S2- ions in its presence. Formation of Fe sulfide is indicated by the enhanced sulfur retention upon reduction. Fe/SZ is active for NOx reduction with isobutane. Catalysts with low Fe content that are prepared by controlled sublimation are superior to those prepared by impregnation. At 450 degrees C and GHSV = 30,000 h(-1), 65% of NOx is reduced to N2 in excess O2.

n-3 polyunsaturated fatty acids decrease mucosal/epidermal reactions and enhance antitumour effect of ionising radiation with inhibition of tumour angiogenesis

The purpose of this study was to evaluate the effect of n-3 polyunsaturated fatty acids (n-3 PUFAs) on normal tissue (lip mucosa) and tumour growth when combined with ionising radiation. The oral region (snout) of C57 black mice was irradiated with 16.5 Gy and n-3 PUFAs (100 microl) were injected intravenously for 2 weeks. After exposure to irradiation, the degree and duration of the acute reactions decreased significantly when mice were treated with n-3 PUFAs as compared to the control group. Interestingly, the range of the reactions in the n-3 PUFAs-treated group compared favourably to the group receiving amifostine (27.5 mg/kg i.v.). the effect of n-3 PUFAs was further evaluated in HEP-2 human carcinoma xenograft transplanted in nude mice. An inhibition of tumour growth was observed when mice were treated with n-3 PUFAs alone and this effect was maximal when combined with irradiation. Similar results were obtained using eicosapentaenoic acid. The effect of n-3 PUFAs was associated with inhibition of angiogenesis and tumour proliferation, and significantly decreased expression of cyclooxygenase-2. In conclusion, n-3 PUFAs administration decrease mucosal response, while moderately enhancing the antitumour effect of irradiation. The magnitude of the differential effect suggests that n-3 PUFAs need to be further investigated in the clinic.

Effect of gastrin on differentiation of rat intestinal epithelial cells in vitro

AIM: To investigate the effect of gastrin on differentiation of IEC-6 cell line in vitro.

METHODS: IEC-6 cells were incubated with gastrin. On day 7 after treatment, cell morphology was examined by light microscope, and on day 20, the cellular ultrastructures were examined by electron microscope. After exposure to gastrin for 6 hours, villin mRNA was analyzed by reverse transcription-polymerase chain reaction, and on day 7, the expression of villin was examined by immunocytochemical analysis with laser confocal microscope.

RESULTS: After exposure to gastrin, IEC-6 cells showed differentiated phenotypes as villas enterocytes and contained an abundance of plasma, small nuclei with nucleoli, and were arranged regularly. There were numerous microvilli around edge of the cells, and several cells showed columnar structures. Villin mRNA expression in cytoplasm was increased in comparison with control.

CONCLUSION: Differentiated characteristics of villus enterocytes and phenotypic changes of rat intestinal epithelial cells (IEC-6) are induced by gastrin, and the effects of gastrin are correlated to increased villin expression.

[The inhibitory effect of anti-streptococcus mutans immunoglobulin of yolk on glucan synthesis of Streptococcus mutans]

OBJECTIVES

To observe the inhibitory effect of anti-Streptococcus mutans Hen-egg-yolk (IgY) on glucan synthesis of Streptococcus mutans.

METHODS

Determine the glucan with anthrone method after using the different titer of IgY on S.mutans and S.sobrinus.

RESULTS

The inhibitory effect of antibody on S.mutans and S.sobrinus synthesis glucan had a similar tendency. The effect of inhibit glucan synthesis was influenced by the titer of antibody. High titer with high inhibition. Begin with the group of 1:16 titer, the group of 1:2 titer showed the highest inhibition (P<0.05).

CONCLUSION

The antibody can reduce synthesis of glucan from S.mutans and S.sobrinus.