Functional beta-cells derived from umbilical cord blood mesenchymal stem cells for curing rats with streptozotocin-induced diabetes mellitus

INTRODUCTIONThis study aimed to investigate the therapeutic response to injected human umbilical cord blood mesenchymal stem cells (UCBMSCs) among albino rats with streptozotocin (STZ)-induced diabetes mellitus.METHODSControl group (GI; n = 25) rats were fed with standard rat diet. Rats with STZ-induced diabetes mellitus without (GII; n = 25) and with (GIII; n = 25) differentiated human UCBMSCs implantation were the test groups. Rats were sacrificed in Week 11 following implantation. Liver biopsies were sectioned and stained in order to highlight both the presence and function of impregnated cells in the liver tissue.RESULTSHaematoxylin and eosin-stained sections in GI and GII rats showed normal liver architecture while GIII rats showed presence of cell clusters inside the liver tissue and around the central veins. Cell clusters with blue cytoplasm were present in sections in GIII rats but absent in GI and GII rats, indicating the presence of injected differentiated human UCBMSCs. The anti-human insulin immunostaining of GIII rats showed clusters of cells within the liver parenchyma and around central veins, indicating that these cells were active and secreting insulin.CONCLUSIONUCBMSCs are proficient in differentiating into insulin-producing cells in vivo under specific conditions and, when transplanted into the liver of albino rats with STZ-induced diabetes mellitus, were able to secrete insulin and partially control the status of diabetes mellitus in rats.     

The Effect of Subacute Marijuana Smoke Inhalation on Experimentally Induced Dermonecrosis by S. Aureus Infection

Dermonecrosis was induced in ICR mice by subcutaneous implantation of Staphylococcus aureus absorbed onto sterile cotton pellets. This model was used to assess the effects of marijuana smoke, marijuana placebo smoke and $DL⁹-tetrahydrocan-nabinol ($DL⁹-THC) on the local immune response to bacterial infection. Mice were exposed to 40 or 80 “puffs” of marijuana smoke, marijuana placebo smoke or air daily for 4 consecutive days. The estimated dose of $DL⁹THC per day generated from 40 or 80 puffs of marijuana smoke was 3.2 and 6.4 mg/kg, respectively. A group of sentinel (Shelf) control mice were included in each experiment. The necrotic index (NI) of mice exposed to 40 or 80 puffs of marijuana smoke were 67% and 44% of control, respectively. Air exposed mice showed a necrotic index comparable to the shelf control group. In chronically (60 days) exposed mice (80 puffs per day) the necrotic index was about 12% of control, while air-exposed mice were about 40% of control.

Placebo marijuana smoke exposed mice had a NI comparable to that of marijuana smoke exposed mice which suggested that the reduction in NI was unrelated to the pychomimetic component $DL⁹THC. To further explore which of the constituents of marijuana were responsible for the decreased NI, the ethanol extract from marijuana leaves was partioned between water (cannabinoid free) and chloroform (cannabinoid rich). Injection of the cannabinoid free fraction produced comparable decrease in the NI as observed with whole marijuana smoke, while the cannabinoid rich fraction produced no effect. $DL⁹THC at a dose of 10 mg/kg per day did not alter the NI.     

PCR analysis of egyptian respiratory adenovirus isolates, including identification of species, serotypes, and coinfections

Eighty-eight adenovirus (Ad) isolates and associated clinical data were collected from walk-in patients with influenza-like illness in Egypt during routine influenza surveillance from 1999 through 2002. Respiratory Ad distributions are geographically variable, and serotype prevalence has not been previously characterized in this region. Serotype identity is clinically relevant because it predicts vaccine efficacy and correlates strongly with both clinical presentation and epidemiological pattern. Species and serotype identities were determined using several well-validated multiplex PCR protocols culled from the literature and supplemented with a few novel primer sets designed to identify rare types. The isolates included common species B1 serotypes (Ad3 and Ad7), common species C serotypes (Ad1, Ad2, and Ad5), the less common species B2 serotype Ad11, and three isolates of the rare species B1 serotype Ad16. Two isolates that appear to be variant Ad16 were also identified. Fifteen coinfections of multiple adenoviral types, primarily AdB/AdC and Ad3/Ad7 dual infections, were detected. The majority of these were verified using redundant PCR tests targeted at multiple genes. PCR is able to resolve coinfections, in contrast to traditional serum neutralization tests. PCR is also comparatively rapid and requires very little equipment. Application of the method allowed an inclusive determination of the serotypes found in the Egyptian respiratory sample set and demonstrated that coinfections are common and may play a previously unrecognized role in adenovirus pathogenesis, evolution, and epidemiology. In particular, coinfections may influence adenoviral evolution, as interserotypic recombination has been identified as a source of emerging strains.     

New serological assay for detection of putative Helicobacter pylori virulence factors

We evaluated a new immunoblot assay (Helicoblot 2.1) for Helicobacter pylori infection and CagA and VacA status by using serum samples from 222 patients. The test accurately detected H. pylori infection and VacA status, but improvements in the interpretation criteria are required before it can be recommended for determination of CagA status.     

Enzyme-analogue built polymers, 4. On the synthesis of polymers containing chiral cavities and their use for the resolution of racemates

With the aid of a chiral template molecule functional groups could be placed in a highly crosslinked polymer in such a way that they are present in a chiral cavity in a given stereochemistry. By this method methyl, resp. 4-nitrophenyl α-D -mannopyranoside-2,3; 4,6-di-O-(4-vinylphenylboronate) ( 1a , resp. 1b ) were copolymerized to macroporous polymers from which the templates methyl, resp. 4-nitrophenyl α-D -mannopyranoside ( 2a , resp. 2b ) could be split off in return. It could be shown that such polymers with two boronic acid groupings within the chiral cavity possess a good ability for the resolution of racemates of the template used. In the case of the separation of the enantiomers of 2b separation factors up to 2,27 could be obtained. The overall optical enrichment in a chromatographic separation amounted to 87%.     

Treatment of Vitamin B12 Deficiency after Gastric Surgery for Severe Obesity

Background: Vitamin B₁₂ deficiency after gastric surgery for obesity is due to a failure of separation of vitamin B₁₂ from protein foodstuffs and to a failure of absorption of crystalline vitamin B₁₂ in the presence of intrinsic factor. The purpose of this study was to determine which of four oral doses of crystalline vitamin B₁₂ was most effective in treating vitamin B₁₂ deficiency in 102 patients. Methods and Results: At time of entry into the study, the patients had a serum vitamin B₁₂ < 100 pmol L ⁻¹, were 29.9 ± 21.7 months post-op, were 37 ± 8 years old and had a body mass index of 30 ± 6 kg m⁻². Eight (8%) had had a vertical banded gastroplasty and 94 (92%) a gastric bypass. For the first 3 months all patients received 350 μg per day of crystalline vitamin B₁₂ and all increased their serum vitamin B₁₂ levels to over 100 pmol L⁻¹. The patients were then assigned to receive for a further 3 month period one of four oral doses of crystalline vitamin B₁₂-100 μg, 250 μg, 350 μg and 600 μg. Serum vitamin B₁₂ levels were greater than 150 pmol L⁻¹ after 6 months in 83.3% of patients who received 100 μg; 92.3% of patients who received 250 μg; 94.7% after 350 μg and 95.2% after 600 μg (p%0.525). Conclusion: At least 350 μg per day is the appropriate oral dose of crystalline vitamin B₁₂ after gastric surgery for obesity to correct low serum vitamin B₁₂ levels in 95% of patients.     

Effect of polyamine deprivation on the survival of intracranial glioblastoma bearing rats

It has previously been shown that systematic polyamine deprivation results in the almost complete inhibition of the growth of several solid tumors. The same polyamine deficient diet (containing antibiotics for the decontamination of the gastrointestinal tract, the ornithine decarboxylase inhibitor 2-(difluoromethyl)ornithine, and the polyamine oxidase inhibitor N1, N4-bis-(2,3-butadienyl)putrescine; "drug-containing polyamine deficient chow", DC-PDC) was applied for the first time to the treatment of rats with an intracranial tumor. Rats received intracortical grafts of C6 rat glioblastoma cells, and the length of their survival was determined. Treatment with DC-PDC, starting four days after tumor cell inoculation, significantly prolonged the median survival of the glioblastoma-bearing rats. The results underline the general growth inhibitory effect of systematic polyamine deprivation. Since the effect of polyamine restriction on tumor growth is reversible, combinations with cytotoxic drugs have to be found which exploit the changed functions of polyamine deficient tumor cells.     

Photoprotective effects of some quinoxaline 1,4-dioxides in hairless mice

2-benzoyl-3-phenylquinoxaline 1,4-dioxide (BPQ) and other substituted quinoxaline 1,4-dioxides (QdO) were tested for their ability to inhibit the stimulations of ornithine decarboxylase (ODC) enzyme activity and DNA synthesis, two biochemical markers linked to skin tumour promotion by ultraviolet B (UVB) radiation. Topical application of BPQ on the dorsal skin of hairless mice was found to inhibit in a dose-dependent manner UVB-induced ODC activity and DNA synthesis. When applied 20 min before UVB radiation, a dose of 17 mg BPQ applied in 0.4 ml of vehicle inhibited UVB-induced ODC activity and DNA synthesis by 95% and 85%, respectively. This inhibitory effect is dependent on the time of administration of BPQ relative to UVB radiation, with a generally greater inhibition observed when this compound is applied before rather than after UVB treatment. The inhibitory abilities of the other QdO on the ODC and DNA responses induced by UVB radiation greatly varied and appear to be dependent on the structure of the compounds and their metabolic activation in the skin following irradiation. The remarkable effectiveness of BPQ against the ODC and DNA markers of UVB promotion is also observed following multiple applications of this agent. These results suggest that QdO, in particular BPQ and certain derivatives of it, may be useful in protecting the skin against UVB-induced skin damage.