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Biomedical subjects

M Osman

Publications and source records attributed to M Osman.

At least 91 records · Page 5Linked to original sources
PubMed1981

Cytochemical localization of adenylate-cyclase in embryonic mouse molars.

The cytochemical method of HOWELL and WHITFIELD (1972) and the revised cytochemical medium of KEMPEN et al. (1978) has been used to investigate the localization of adenylate-cyclase activity in 18, 19 and 20 day old first embryonic mandibular molars. Membrane associated precipitate granules were observed in preameloblasts and odontoblasts localized in the area where preodontoblasts become post-mitotic. Heat inactived teeth and the samples incubated in media without substrate were negative for membrane bound lead deposits. A correlation may exist between high adenylate-cyclase activity and the terminal differentiation of odontoblasts.

Adenylyl Cyclases↗
PubMed1981

Behavior of odontoblasts and basal lamina of trypsin or EDTA-isolated mouse dental papillae in short-term culture.

Embryonic mouse first mandibular molars (day 18), containing the first overtly differentiated odontoblasts, were treated with EDTA or trypsin, to obtain isolated dental papillae. Trypsin dissociation was accompanied by disappearance of the basal lamina. EDTA-treatment removed the basal lamina from the basal surface of the epithelium, but left it associated with the dental papillae. EDTA- or trypsin-isolated dental papillae were grown for three to 24 h at the top of a plasma clot. Trypsin-isolated dental papillae rapidly lost their typical morphology, and the post-mitotic odontoblasts never became functional. EDTA-isolated dental papillae remained covered by the basal lamina for 15 to 18 h. During this period, the typical morphology was maintained, and post-mitotic odontoblasts secreted predentin. Preodontoblasts and odontoblasts went through the basal lamina and migrated at the outer surface of the basal lamina (i.e., at the side facing away from the enamel organ).

Animals↗
PubMed1981

Reconstitution of the basement membrane from the inner and outer dental epithelia of trypsin-isolated mouse molar enamel organs.

Trypsin-isolated embryonic mouse enamel organs were cultured on top of plasma coagulum. Inner and outer dental epithelia in contact with the plasma coagulum synthesized a new basement membrane as revealed by electron microscopy and 3H-glucosamine autoradiography. The outer dental epithelium in contact with air did not redeposit a basement membrane. The plasma coagulum had beneficial effects on basement membrane reconstitution and maintenance by inhibiting the process of keratinization.

Animals↗
PubMed1981

[3H]glucosamine and [3H]proline radioautography of embryonic mouse dental basement membrane.

[3H]proline and [3H]glucosamine radioautography was performed to analyze the labeling pattern of mouse embryonic dental basement membrane before and during odontoblast terminal differentiation. Sixteen- and eighteen-day-old first lower molars and trypsin-isolated enamel organs, as well as EDTA-isolated dental papillae, were used. Continuous labeling for 12 to 24 hr was required with [3H]proline to obtain a clear labeling of epithelial-mesenchymal junction in intact tooth germs or accumulation of surface label in trypsin-isolated enamel organs. With [3H]glucosamine, after 6-hr labeling, the epithelial-mesenchymal junction was heavily labeled and the trypsin-isolated enamel organs accumulated substantial amounts of surface label, corresponding to the redeposited basement membrane. At Day 16 stage, these labels always had a uniform distribution and decreased during chase without any redistribution. At Day 18 stage, when the terminal differentiation of odontoblasts occurred the label accumulated in a unique pattern: much more label was at the epithelial surface corresponding to the top of the cusps than in the apical parts. During chase and only in intact tooth germs epithelial surfaces which had labeled poorly during pulse became labeled, but those labeling heavily during pulse lost label. This pattern existed only in the presence of mesenchyme. EDTA treatment of [3H]glucosamine-labeled teeth enabled us to obtain isolated dental papillae with surface label. Distribution of this label was exactly the same as that for the epithelial-mesenchymal junction of intact teeth. During chase, these dental papillae completely lost the surface label. The mesenchyme seen to control the synthesis and/or the degradation of epithelially derived [3H]glucosamine-labeled material.

Animals↗
PubMed1980

Effect of Lippes loop on sperm recovery from human fallopian tubes.

Recovery of human sperm from the fallopian tubes after natural insemination have been studied in sixty women; out of these, thirty cases were fitted with the Lippes loop, type C, for at least six months. The mean sperm count/high power field (HPF X 400) and percentage of motile sperm in the cervical mucus in both control and Lippes loop groups showed no significant differences. No sperm were recovered from the fallopian tubes of the Lippes loop group, while fourteen control cases had a positive recovery of sperm from the tubal washings. The mean number of white blood corpuscles in the tubal washings of Lippes loop-fitted cases was found to be significantly higher than in control cases. The phagocytic capacity of these cells may explain the low incidence of sperm recovered from the fallopian tubes in such cases.

Adult↗
PubMed1980

Therapeutic value of indomethacin in threatened abortion.

One hundred cases of threatened abortion were randomly allocated to four lines of treatment namely, long acting progesterone, antispasmodic, indomethacin and placebo. The lowest success rate was encountered in the indomethacin treated group; symptoms of intolerance were common and three cases out of sixteen turned into missed abortion. Indomethacin does not offer any advantage over other lines of treatment in threatened abortion.

17 alpha-Hydroxyprogesterone Caproate↗
PubMed1980

Does discarding the first few millilitres of breast milk improve the bacteriological quality of bank breast milk?

The bacteriology of 20 paired samples of breast milk was analysed to find out if discarding the first few millilitres would reduce the amount of bacterial contamination in breast milk donated to a hospital milk bank. The first sample was the initial 2-3 ml collected from the opposite breast to that first suckled by the baby, and the second was a midstream sample from the same breast. There was no significant difference in the colony counts between the paired samples, and in no instance did the bacterial flora of the second sample differ from that of the first.

Bacteria↗
PubMed1979

Bacteriological criteria for feeding raw breast-milk to babies on neonatal units.

Aerobic cultures of 207 samples of drip breast-milk from seventy mothers in hospital showed that 6 (3%) were sterile and 170 (82%) contained only the commensal organisms coagulase-negative staphylococci and Streptococcus viridans. 25 (15%) grew potential pathogens--Staphylococcus aureus in 13 (6%); enterobacteria in 15 (7%); and group-B streptococci in 3 (2%). It is proposed that milk with commensals in any numbers may be considered for use unheated but not milk containing any potential pathogens.

Aerobiosis↗
PubMed1979

[Role of dental pulp in the histogenesis of the enamel organ].

The histological study of in vitro cultured associations between dental pulps and outer dental epithelium showed that the predontoblasts initiated the histogenesis of the enamel organ and particularly the differentiation of the inner dental epithelium.

Animals↗
PubMed1979

3H-glucosamine electron microscope autoradiography after isolated labeling of the enamel organ or the dental papilla followed by reassociated toothgerm culture.

Electron microscope autoradiography was performed after isolated labeling with 3H-glucosamine of the enamel organ or the dental papilla of Swiss mice followed by reassociated toothgerm culture for 9.30 h and 19 h. After these two time intervals in case of an enamel organ labeling, numerous silver grains were observed in the intercellular spaces of the stellate reticulum indicating a concentrating and storing role of the latter. After dental papilla labeling, an almost complete absence of radioactivity was noted at 19 h. suggesting that 3H-glucosamine is not stored by the dental papilla. A clear labeling of the basement membrane area and of the adjacent aperiodic filamentous material found on the pulpal side was only observed after enamel organ labeling with 3H-glucosamine, suggesting an epithelial origin of the glycosaminoglycans found in these structures.

Animals↗