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Biomedical subjects

S Ma

Publications and source records attributed to S Ma.

At least 199 records · Page 11Linked to original sources
PubMed1992

[Interphase cytogenetic studies of human X chromosome].

The chromosome in situ hybridization with human X chromosome alpha satellite DNA probe (pBamX7) on human lymphocyte metaphases and interphase nuclei was performed for interphase cytogenetic studies. The individuals with numerical or structural abnormalities of X chromosome were studied. The results showed that the probe hybridized specifically to the centromeric region (p11----q11) of X chromosome. The number of silver grain clusters in interphase nuclei was correlated with that of X chromosome. Most of the clusters located near the nuclear membrane where inactive X chromatins (Barr-bodies) were usually found. The method of ascertaining the number of X chromosomes by in situ hybridization was much more reliable than that by counting the number of Barr-bodies. The modified R-banding technique was introduced and the significance of this work was also discussed.

Chromosome Aberrations↗
PubMed1992

A new method for clitoroplasty in male-to-female sex reassignment surgery.

Sex reassignment surgery has proved to be the best resolution for primary transsexuals. In 1980, Dr. Rubin stated that preservation of the glans to reconstruct the clitoris in male-to-female sex reassignment surgery gave good cosmetic and functional results. In his series, Rubin used the corpus spongiosum as the vascular pedicle of the neoclitoris, but urine leakage is a complication. From 1988 to the present, the dorsal portion of the glans penis with the dorsal neurovascular pedicle has been used here for clitoroplasty in nine male-to-female primary transsexuals. All neoclitorides survived well, with good preservation of light touch and sexual sensation. No urine leakage has occurred. Six patients who were followed reported sexual satisfaction.

Adult↗
PubMed1991

Xenogeneic osteogenin, a bone morphogenetic protein, and demineralized bone matrices, including human, induce bone differentiation in athymic rats and baboons.

Subcutaneous implantation of xenogeneic demineralized bone matrix does not initiate endochondral bone differentiation. Dissociative extraction in 4 M guanidine-HCl or 6 M urea has shown that the apparent species-specificity of intact bone matrix resides in its insoluble immunogenic component, since there is homology in solubilized osteogenic proteins amongst mammals. To further investigate the species-specificity and cross-species reactivity of bone matrix components, baboon and human demineralized bone matrix (DBM) and bovine osteogenin, purified greater than 50,000-fold and with an apparent molecular mass of 28-42 kilodaltons, were implanted in the subcutaneous space of athymic and euthymic rats and into the rectus abdominis of 16 baboons (Papio ursinus). Baboon DBM was also implanted in athymic and euthymic mice. Alkaline phosphatase activity and histology of implants harvested at day 11 and 30 showed that baboon and human DBM induced endochondral bone differentiation both in athymic rats and baboons. Bovine osteogenin in conjunction with baboon insoluble collagenous matrix induced extensive bone differentiation in athymic rats and baboons. Baboon and human DBM did not induce bone differentiation in euthymic rats and, in athymic mice, baboon DBM failed to induce bone differentiation, determining instead the recruitment of multinucleated giant cells. The results indicate that in rodents bone differentiation induced by intact bone matrix is species specific and that T-cell functions are not a requirement for bone induction, although immunologically competent rats block bone differentiation from xenogeneic matrix. Bone differentiation induced by human DBM in baboons suggests that intact bone matrices may not be species-specific amongst primates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Developmental Regulation of the (1,3)-beta-Glucan (Callose) Synthase from Tomato : Possible Role of Endogenous Phospholipases.

Activity levels of UDP-glucose: (1,3)-beta-glucan (callose) synthase in microsomal membranes of pericarp tissue from tomato fruit (Lycoperisicon esculentum Mill, cv Rutgers) were determined during development and ripening. Addition of the phospholipase inhibitors O-phosphorylcholine and glycerol-1-phosphate to homogenization buffers was necessary to preserve enzyme activity during homogenization and membrane isolation. Enzyme activity declined 90% from the immature green to the red ripe stage. The polypeptide composition of the membranes did not change significantly during ripening. The enzyme from immature fruit was inactivated by exogenously added phospholipases A(2), C, and D. These results suggest that the decline in callose synthase activity during ontogeny may be a secondary effect of endogenous lipase action.

Journal Article↗
PubMed1991

Histologic comparison of regeneration in human intrabony defects when osteogenin is combined with demineralized freeze-dried bone allograft and with purified bovine collagen.

A bone-inductive protein, osteogenin, has been isolated from long bones of humans and offers promise as a grafting material. Studies, however, suggest that osteogenin must be combined with a bone-derived matrix in order to initiate bone differentiation. The purpose of this study was to determine if osteogenin combined with demineralized freeze dried bone allograft (DFDBA), a bone-derived matrix, and with a bovine tendon-derived matrix will enhanced regeneration of intrabony defects in humans. The tendon-derived matrix and DFDBA used alone served as controls. The ability of each material to form a new attachment apparatus was evaluated independently in submerged and nonsubmerged environments in 2 patient populations. Lymphocyte testing was performed to assess development of an immune reaction to osteogenin. The most apical level of calculus on the root served as the histologic reference point to measure regeneration. Biopsies were obtained at 6 months and regeneration was measured histomorphometrically by 2 blinded evaluators. Serial sections from 36 submerged defects in 8 patients and 50 nonsubmerged defects in 6 patients were submitted for statistical analysis. Mean results indicate that osteogenin combined with DFDBA significantly enhanced regeneration of a new attachment apparatus and component tissues in a submerged environment. DFDBA plus osteogenin and DFDBA alone formed significantly more new attachment apparatus and component tissues than either the tendon-derived matrix plus osteogenin or the tendon-derived matrix alone in both submerged and nonsubmerged environments. There were no significant differences between the tendon-derived matrix plus osteogenin and the tendon-derived matrix alone in either the submerged or nonsubmerged environment. Osteogenin does not impair normal lymphocyte blastogenesis at 6 months postsurgical challenge.

Alveolar Bone Loss↗
PubMed1991

[Clinical application of Chinese forearm flap: 5-year review].

Twenty-nine patients treated with the Chinese forearm flap from 1985 to 1989 were reviewed. This flap was used for soft tissue defect reconstruction in 19 cases, and phallus reconstruction in 10 patients. There were two cases of total flap failure and two cases of partial failure. Twenty cases used sensory flaps. Donor site complications included partial loss of the skin graft with tendon exposure in one patient (3.4%), limitation of range of movement of the wrist joint in one case (3.4%), and paresthesia over the radial site of the hand in 12 patients. On functional evaluation, 20 patients demonstrated no significant loss of strength in the donor extremity.

Adult↗
PubMed1991

[Studies on warming the middle-jiao and analgesic effect of flos Caryophylli].

The effects of water extract and ether extract of Flos Caryophylli have been investigated by four experimental gastric ulcer models, choleresis in rats, two diarrhea models in mice, two pain stimulations in mice, and acute liver injury induced by CCl4 in rats. The results suggest that the action of Flos Caryophylli on dispelling the cold by warming the middle-jiao and curing abdominalgia is related to its anti-ulcer, choleresis increasing, anti-diarrhea and analgesic functions.

Analgesics↗
PubMed1990

The chromosomal complements of cleaved human embryos resulting from in vitro fertilization.

Chromosome preparations were made from 25 cleaved abnormal human embryos at the two- to eight-cell stage after in vitro fertilization. Morphologically, these embryos showed either variable degrees of degeneration or an abnormal number of pronuclei before first cleavage. Among 14 successfully karyotyped embryos, only 3 had a normal chromosomal complement. Eleven showed chromosomal abnormalities, including triploidy, haploidy, and mosaicism. This finding documents a high incidence of chromosomal errors in morphologically abnormal early preimplantation embryos.

Chromosome Aberrations↗
PubMed1990

Ambient temperature modulation of fenfluramine-induced thermogenesis in the rat.

The anti-obesity drug fenfluramine, promotes loss of weight by reducing food intake; however, there is controversy as to whether the drug can also elevate expenditure of energy. Resting consumption of oxygen (VO2) was measured in conscious rats to determine whether the injection of fenfluramine increased metabolic rate and whether prior fasting, or ambient temperature altered the response. Regardless of whether the rats were fed or had been fasted for 22 hr, in a thermoneutral environment (28 degrees C), the intraperitoneal injection of dl-fenfluramine (20 mg/kg) caused a raised oxygen consumption. This elevation was sustained to the end of the 60-min period of measurement after the injection, at which point the colonic temperature was found to be increased. This metabolic response to fenfluramine was largely attenuated when the drug was administered at 23 degrees C, and the colonic temperature of the rats was decreased by 60 min after the injection. At 4 degrees C, the injection of fenfluramine inhibited thermogenesis against cold, the oxygen consumption fell and the rats exhibited hypothermia. It was concluded that fenfluramine can increase the metabolic rate, but that this effect is not conditional on associated food intake, as has been reported. Rather, the ambient temperature governs whether stimulation or inhibition of thermogenesis will be evoked. These metabolic effects of fenfluramine explain, in part, its divergent effects on body temperature, reported previously.

Anesthesia↗
PubMed1990

Use of experimental aneurysms to evaluate wrapping materials.

Experimental venous pouch aneurysms in rats were wrapped with muscle, bovine collagen, muslin, cotton, or polyvinyl alcohol. The rats were killed 6 or 12 weeks later, and the aneurysms were compared with control aneurysms. Bovine collagen and muscle were reabsorbed and the aneurysms were similar to the control group. Cotton, muslin, and polyvinyl alcohol caused fibrosis around the aneurysm. However, giant aneurysms were found in the muslin and polyvinyl alcohol group. Cotton appears to be the most suitable material for wrapping aneurysms. The experimental venous pouch aneurysm model in rats can be used to evaluate wrapping materials.

Animals↗
PubMed1990

Mid-term effects of neodymium: YAG transscleral cyclocoagulation in glaucoma.

Neodymium: YAG (Nd:YAG) transscleral cyclocoagulation successfully lowers intraocular pressure (IOP) over the short term in animals and humans. Twenty-eight eyes with uncontrolled glaucoma were prospectively followed over a mean period of 21.9 months. Mean pretreatment IOP was 47.5 mmHg. Mean posttreatment IOP was 19.9 mmHg (P less than 0.005). Mean (+/- standard deviation) number of treatments was 1.86 (+/- 1.11) Mean number of drugs used before and after treatment was 3.28 and 2.48, respectively (P less than 0.01). A total of 10.7% eyes went phthisical. Thirty percent of eyes with vision and good IOP control (i.e., less than 21 mmHg) lost some vision after the procedure. Neodymium:YAG transscleral cyclocoagulation appears to be an effective method of controlling IOP over the mid-term, but is associated with significant complications.

Evaluation Studies as Topic↗
PubMed1990

Bifurcation analysis of nonlinear retinal horizontal cell models. II. Network properties.

1. We have previously presented a model of horizontal-cell soma isolated from fish retina. The model consists of a synaptic conductance representing input from photoreceptors in parallel with voltage-dependent membrane currents. Membrane-current models are based on I-V curves measured in isolated fish horizontal cells. Bifurcation theory was used to analyze model properties. The major findings of this study were 1) the inward Ca2+ current must be inactivated to account for horizontal-cell resting potentials and hyperpolarizing responses to light stimuli in a background of dark, and 2) the synaptic conductance controls the bifurcation structure of the model, with bistable behavior occurring at small and monostable behavior occurring at larger values of the synaptic conductance. The synaptic conductance at the point of transition from bistable to monostable behavior corresponds to the activation of as few as 100 synaptic channels. Thus tonic synaptic input from photoreceptors and inactivation of the inward Ca2+ current act to "linearize" responses of isolated horizontal-cell models. 2. The model described in this paper extends these analyses to large networks of horizontal cells in which each cell is coupled resistively to its nearest neighbors and is modeled with the use of the full complement of nonlinear membrane currents. Network responses to arbitrary patterns of conductance change (simulating inputs from photoreceptors), current-, or voltage-clamp stimuli are computed using the Newton iteration. The Newton descent direction is computed using either conjugate gradient (CG) or preconditioned CG algorithms. 3. An analysis of network stability properties is performed. Network I-V curves are computed by voltage-clamping the center node and computing the current required to maintain the clamp voltage. Computations are performed on networks of model cells in which the Ca2+ current is fully activated and the synaptic conductance is zero, thus making each cell as nonlinear as possible. Coupling conductance values slightly greater than 100 pS provide a current shunt sufficient to prevent the generation of Ca2+ action potentials in the network. This coupling conductance corresponds to the conductance of as few as two gap-junction channels and is more than two orders of magnitude less than the coupling known to exist between pairs of cultured horizontal cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Squamous cell carcinoma of the lip.

We reviewed 39 cases of squamous cell carcinoma of lip from 53 consecutive patients with carcinoma of the lip. The retrospective review includes age, location, risk factors, TNM classification, histologic differentiation, treatment methods, recurrent disease, site of recurrence, and follow-up status. Results reveal prognosis is related to original tumor size, local recurrence, and presence of cervical metastasis. Aggressive surgical treatment is recommended for identifiable poor prognostic lesions and includes surgical excision, prophylactic suprahyoid neck dissection, and possible radical neck dissection.

Adult↗
PubMed1990

Treatment of 910 cases of atrophic gastritis with wei you decoction.

In treatment of 910 cases of chronic atrophic gastritis with Wei You Decoction, the overall effective rate was 96.9%. The disease was considered as due to deficiency of vital energy with stagnation of cold, and therefore treatment was to invigorate blood circulation. The Wei You Decoction had functions of replenishing vital energy, warming the middle burner, invigorating blood circulation, and resolving stasis, thus reversing the morbid process in the gastric mucosa. It was nontoxic, and the side-effects were minimal. The therapeutic effect was prompt and persistent. No malignant change was observed after taking the drug.

Adult↗
PubMed1989

Purification and partial amino acid sequence of osteogenin, a protein initiating bone differentiation.

Osteogenin was purified from bovine bone matrix and its activity monitored by an in vivo bone induction assay. The purification method utilized extraction of the bone-inducing activity with 6 M urea, followed by chromatography on heparin-Sepharose, hydroxyapatite, and Sephacryl S-200. Active fractions were further purified by preparative sodium dodecyl sulfate gel electrophoresis without reduction. Osteogenin activity was localized in a zone between 30 and 40 kDa. The amino acid sequences of a number of tryptic peptides of the gel-eluted material were determined. Reduction and alkylation of purified osteogenin in 7 M guanidine hydrochloride resulted in the total loss of biological activity. Sodium dodecyl sulfate gel electrophoresis under reducing conditions revealed a broad band with an apparent molecular mass of 22 kDa.

Amino Acid Sequence↗
PubMed1989

Prophylactic antibiotics in surgical treatment of axillary hyperhidrosis.

A randomized, prospective, double-blind study designed to compare the effectiveness of the use of cloxacillin with the result of nontreatment in patients undergoing surgical intervention of axillary hyperhidrosis was conducted from August 1987 to October 1987 at the Veterans General Hospital, Taipei, Taiwan. Forty-two patients were enrolled in this study. Fifty wounds (25 patients) were control subjects, and 34 wounds (17 patients) received cloxacillin. The positive bacterial culture rates of the tissues and draining from patients in the treatment group compared with the control group was statistically significantly lower (p less than 0.01). No significant differences presented in relation to age, sex, complication rate, fever index, and length of hospital stay. Prophylactic antibiotic is of no value in elective surgical intervention of axillary hyperhidrosis.

Adolescent↗
PubMed1989

Reconstruction of anorectal angle after abdominoperineal resection of rectum and anus--an animal model.

Voluntary control of the bowel movements is a social necessity. Lack of control relegates one to psychological debility and the possible need for a permanent colostomy. Anorectal angle plays an important role in fecal continence. In the normal individual, this angle lies in the range of 60 to 105 degrees. Perineal colostomy, once proposed for patients who had received abdominoperineal resection (APR), has been abandoned because of frank incontinence. This study used a canine model. The anorectal angle, external sphincter, internal sphincter, and the puborectalis were all destroyed after APR. The colon was pulled through the perineal defect. Enteropexy, gracilis muscle transfer, and perineal colostomy were performed to restore the anorectal angle. Barium enema was performed preoperatively and postoperatively. The anorectal angle was reconstructed within normal ranges after abdominoperineal resection of the rectum and anus.

Abdomen↗