Clinical evaluation of a light energy conversion toothbrush

A blind, two-way crossover clinical trial was carried out to compare the effectiveness of plaque removal between a new, light energy conversion toothbrush incorporated with a semiconductor of TiO2 (test) and a similar toothbrush without the semiconductor (control). The study was completed by 73 school children aged 13-15 years. Each toothbrush was used for a period of 3 weeks. The mean differences between baseline plaque scores and after subjects used the test and control brushes were analyzed by the paired t-test. The Soladey 2 toothbrush showed significantly more reduction of plaque on the buccal surfaces of all teeth than the control brush. There was no significant difference in the plaque removing ability of the two brushes on the lingual aspects of the mandible and on the lingual surfaces of the maxillary posterior sextant. As the buccal surfaces are more likely to allow light to reach the semiconductor during brushing than the lingual areas, it is possible that the reported photocatalytic property of the semiconductor may be involved in some way in the observed reduction of plaque.     

Status of ‘bifidus growth stimulating factor’ of human milk

Bifidus growth stimulating activity (BA) was estimated in 80 samples of colostrum and mature milk of vegetarian and non vegetarian mothers. For comparison buffalo and cow milk samples were also analysed. The results revealed that vegetarian and non- vegetarian food habits did not influence the BA. The colostrum was found to have 1.6 times higher BA compared to mature milk. The BA of human milk was approximately 28 times higher than buffalo and 45 times higher compared to cow milk. It was observed that about 43–45% of BA was distributed in serum phase and remaining in colloidal phase.     

Rosette formation with mouse erythrocytes. IV. T, B and third population cells in human tonsils.

Mononuclear cells from twenty human tonsils and peripheral blood lymphocytes were examined for T, B and 'third population cells'. Compared with peripheral blood lymphocytes, tonsils were found to have a higher proportion of B lymphocytes with surface IgM, IgD and IgA. Mouse erythrocyte rosette-forming cells were also present in increased proportions. However, 'third population cells' were found in very low proportions. Phagocytic cells as determined by latex ingestion and peroxidase staining were also present in low proportions. The lack of 'third population cells' in human tonsils may establish this organ as one of particular interest in the study of lymphocyte subpopulations because T and B lymphocytes can be purified without contaminating 'third population cells'. The role of the third population of lymphocytes in antibody-dependent cytotoxicity and spontaneous cytotoxicity may be supported by the absence of these functions along with absence of the 'third population' cells from tonsilar lymphoid cells.     

Tyrosine phosphorylation of guanosine triphosphatase activating protein by activation via surface IgG in human B cells

In this study, we analyzed tyrosine phosphorylation of guanosine triphosphatase (GTPase) activating protein in human B cells stimulated through surface IgG, using Western blot and immunoprecipitation. Stimulation through surface IgG induced the tyrosine phosphorylation of GTPase-activating protein (GAP) and two associated proteins, a 190-Kd protein and a 62-Kd protein, within 1 minute and in a dose-dependent manner. This tyrosine phosphorylation was blocked by Genistein (Extrasynthese, Genay, France). These data suggest that GTPase- activating protein is involved in a signal transduction pathway initiated from surface IgG in human B cells.     

Hodgkin lymphoma, multiple myeloma, soft tissue sarcomas, insect repellents, and phenoxyherbicides

OBJECTIVE: The objective of this study was to determine if there is an additional risk of developing Hodgkin lymphoma, multiple myeloma, or soft tissue sarcoma as a consequence of exposure to a combination of phenoxyherbicides, rubber gloves, DEET (N, N-diethyl-m-toluamide), and sunlight compared with each of the individual chemicals. METHODS: This was a population-based study of men with specific cancers and age, province-matched control subjects. RESULTS: No additional risk from these combinations of exposures of developing these three types of tumor was found in contrast to non-Hodgkin lymphoma. CONCLUSIONS: The mechanisms by which phenoxyherbicides contribute to the risk of multiple myeloma and non-Hodgkin lymphoma may be different.     

Tumor necrosis factor alpha and pulmonary function in Saskatchewan grain handlers

OBJECTIVE: The objective of this study was to estimate the contribution of lifestyle (cigarettes) and tumor necrosis factor (TNF) alpha polymorphisms at position 308 of the tumor necrosis factor alpha gene promotor (TNF-308*1/*2) to pulmonary function among grain handlers. METHODS: Employed male grain handlers (157) provided occupational and respiratory symptom information, pulmonary function measurements, and DNA for genotyping. RESULTS: The genotypes of 101 were TNF-308*1/*1, 47 were *1/*2, and nine were *2/*2. Current smokers whose genotype was *2/*2 or *1/*2 had lower values compared with other combinations of genotype and smoking status. Among *1/*1 homozygotes, current smokers had better percent of predicted forced expiratory volume in 1 second (P = 0.04) mean values than nonsmokers and better percent of predicted forced vital capacity than exsmokers (P = 0.017) or nonsmokers (P = 0.008). CONCLUSIONS: These results indicate the complexity of determining which workers will develop acute and chronic adverse pulmonary conditions in response to exposure to grain dust and the toxins in cigarette smoke interacting with their genotype.     

Salt preference across different phases of menstrual cycle

It is well established that women experience food craving for particular foods and gain weight in relation to phases of menstrual cycle. In this study, the preference for different concentrations of salt sprayed on bland popcorn was assessed in 55 healthy women (age 18 to 22 yrs). Salt solutions of 0, 1, 2, 3 and +3 molar strength were used. Samples of sprayed popcorn were consumed in random order and preference marked on a Likert scale. It was observed that women preferred unsalted popcorn in the menstrual phase more than in the luteal phase. The preference for salted popcorn was most during the luteal phase and was proportionate to the strength of the salt solution used. Statistical analysis revealed significant differences in the preference rating between the menstrual phase and the other two phases. There was no significant difference in preference between the luteal and follicular phases.     

Very small embryonic-like stem cells with maximum regenerative potential get discarded during cord blood banking and bone marrow processing for autologous stem cell therapy

Very small embryonic-like stem cells (VSELs) are possibly lost during cord blood banking and bone marrow (BM) processing for autologus stem cell therapy mainly because of their small size. The present study was conducted on human umbilical cord blood (UCB, n=6) and discarded red blood cells (RBC) fraction obtained after separation of mononuclear cells from human BM (n=6), to test this hypothesis. The results show that VSELs, which are pluripotent stem cells with maximum regenerative potential, settle along with the RBCs during Ficoll-Hypaque density separation. These cells are very small in size (3-5 μm), have high nucleo-cytoplasmic ratio, and express nuclear Oct-4, cell surface protein SSEA-4, and other pluripotent markers such as Nanog, Sox-2, Rex-1, and Tert as indicated by immunolocalization and quantitative polymerase chain reaction (Q-PCR) studies. Interestingly, a distinct population of slightly larger, round hematopoietic stem cells (HSCs) with cytoplasmic Oct-4 were detected in the "buffy" coat, which usually gets banked or used during autologus stem cell therapy. Immunohistochemical studies on the umbilical cord tissue (UCT) sections (n=3) showed the presence of nuclear Oct-4-positive VSELs and many fibroblast-like mesenchymal stem cells (MSCs) with cytoplasmic Oct-4. These VSELs with nuclear Oct-4, detected in UCB, UCT, and discarded RBC fraction obtained after BM processing, may persist throughout life, maintain tissue homeostasis, and undergo asymmetric cell division to self-renew as well as produce larger progenitor stem cells, viz. HSCs or MSCs, which follow differentiation trajectories depending on the somatic niche. Hence, it can be concluded that the true stem cells in adult body tissues are the VSELs, whereas the HSCs and MSCs are actually progenitor stem cells that arise by asymmetric cell division of VSELs. The results of the present study may help explain low efficacy reported during adult autologous stem cell trials, wherein unknowingly progenitor stem cells are injected rather than the pluripotent stem cells with maximum regenerative potential.