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Biomedical subjects

S S Baker

Publications and source records attributed to S S Baker.

At least 37 records · Page 2Linked to original sources
PubMed1995

Carbon dioxide laser ptosis surgery combined with blepharoplasty.

BACKGROUND: Repair of levator aponeurosis pathology has become accepted technique for the correction of acquired ptosis. Extensive experience with carbon dioxide (CO2) laser blepharoplasty has been obtained. OBJECTIVE: CO2 laser blepharoplasty techniques are expanded to repair acquired ptosis. METHODS: A step-wise outline of laser surgical technique is presented. RESULTS: A retrospective serial study of 82 patients is reviewed and compared favorably with other reported series. Improvement in appearance and reduction of asymmetry to less than 1 mm was observed in 69 patients (84%). Thirteen patients had more than 1 mm of asymmetry and eight underwent surgical revisions. No long-term complications such as chronic exposure keratitis were noted. CONCLUSIONS: The CO2 laser repair of acquired ptosis by aponeurotic surgery can be combined with blepharoplasty surgery. Improved intraoperative hemostasis, decreased operating time, and improved appearance in the immediate postoperative period are achieved with this technique.

Blepharoptosis↗
PubMed1995

Lateral canthal tendon suspension using the carbon dioxide laser. A modified technique.

BACKGROUND: The "tarsal strip" procedure was developed to correct lower eyelid ectropion caused by lateral canthal tendon laxity. OBJECTIVE: The "tarsal strip" procedure is improved by using the carbon dioxide (CO2) laser. METHODS: The CO2 laser was used to perform lateral canthotomy. Patients were evaluated postoperatively for subjective improvement in preoperative symptoms. Complications such as epithelial inclusion cysts were actively sought. RESULTS: Thirty-one patients (60 lids) were followed for an average of 12 months. Preoperative symptoms resolved in 86% (N = 27), improved in 7% (N = 2), and did not change in 7% (N = 2). Two patients required additional surgery. Complications were not observed in this study. CONCLUSION: The modified "tarsal strip" procedure using the CO2 laser provides many advantages compared with the original procedure. A clean dissection improves visibility and allows easy identification of the lateral tarsal plate. The lateral canthal angle is preserved and epithelial inclusions are prevented because the conjunctival mucosa is not violated.

Adult↗
PubMed1995

Advancing clinical privileges for nutrition support practitioners: the dietitian as a model.

The specialty of nutrition relies heavily on trained practitioners to assess patient nutritional status, define nutritional goals, and recommend therapeutic strategies to achieve those goals. To facilitate the timely delivery of nutrition care, the dietitians at the University of Massachusetts Medical Center expanded clinical privileges. With the support of the Nutrition Department, the multidisciplinary Nutrition Support Service, and the Nutrition Advisory Committee, dietitians write orders for diets, oral and parenteral nutrient supplementation; and custom mix parenteral nutrition solutions, tube feedings, transitional feedings, balance studies, blood glucose monitoring, and home care orders (parenteral and enteral). Dietitians also order laboratory tests such as chemistries, indirect calorimetry, and bone densitometry. Clinical privileges are a permanent part of each dietitian's appointment to the Health Professional Staff and are granted by the Chancellor/Dean of the Medical University.

Dietetics↗
PubMed1995

Occupational therapy and the person with diabetes and vision impairment.

Diabetes affects 5.2% of the population; many of those persons experience loss of vision as one complication of the disease. Occupational therapists are treating these persons, often for other resulting complications (such as stroke or amputations), or are being asked to adapt techniques or equipment (such as insulin-drawing devices) needed for diabetes management. Because no guidelines exist for occupational therapy with persons with diabetes or vision loss or both, occupational therapists may be unsure of appropriate treatment approaches. Among the approaches described in the occupational therapy literature, common ones include collaboration with other professionals and incorporation of one or more aspects of the diabetes regimen into the person's life-style. When addressing persons who have both diabetes and vision loss, therapists consider their own knowledge base as well as the persons' needs in managing their diabetes. Treatment ideas include enhancing the visual environment or incorporating tactile and auditory feedback with self-management tasks such as testing blood glucose levels. Collaboration with and referral to diabetes and low-vision professionals are adjuncts to therapy and ensure a comprehensive and ongoing diabetes management program.

Activities of Daily Living↗
PubMed1995

Functional encopresis: symptom reduction and behavioral improvement.

This study assessed the relationship between functional encopresis and accompanying problems: emotional, behavioral, and social. Symptom resolution and changes in these concomitant problems were studied. Seventy-six children, 6 to 12 years of age, enrolled in this "self-selected," nonequivalent, control (contrast) group research design with 38 children in each group. Using the Child Behavior Checklist, children were tested before treatment and 6 months later. The results showed that children with encopresis had significantly more emotional/behavioral problems and poorer social competence before treatment than children in the contrast group; combined medical and psychotherapeutic intervention led to a significant reduction in soiling frequency, and children with encopresis experienced significantly fewer behavioral problems and significantly improved social competence after treatment. There was a small group of children for whom treatment was difficult. The data suggest that highly elevated behavior problem scores, especially in association with parental negativeness, may be related to poor treatment outcome.

Behavior Therapy↗
PubMed1994

The treatment of enophthalmos by orbital injection of fat autograft.

OBJECTIVE: To evaluate the effects of retro-orbital intramuscular cone injection of fat in the treatment of posttraumatic enophthalmos in both patients with intact globes and those patients who have had globes removed. DESIGN: Case series. SETTING: Private practice involving an otolaryngologist and an ophthalmologist. PATIENTS: Three groups of patients were treated: group 1 included those patients with an intact globe; group 2, patients with an orbital implant following enucleation; and group 3, patients with no orbital implant following enucleation. INTERVENTION: Autogenous fat was harvested from the abdomen using a microsuction lipectomy technique. The fat was injected into the intramuscular cone in the retrobulbar or retroimplant space using a 14-gauge needle. OUTCOME: Sustained improvement of enophthalmos measured by Hertel's exophthalmometry in those patients with an intact globe. Subjective appearance of prosthesis by physician and patient were used for end points in patients whose globes were removed. RESULTS: In group 1, all patients were able to maintain a correction to within 1 mm of the normal eye. In groups 2 and 3, all patients had a subjective improvement in appearance, but they had development of enophthalmos if the prosthesis was decreased in size. Seven patients (64%) required multiple injections. CONCLUSION: Retro-orbital injection of fat autografts allows correction of persistent posttraumatic enophthalmos.

Adipose Tissue↗
PubMed1994

Extracellular glutathione peroxidase mRNA and protein in human cell lines.

Extracellular glutathione peroxidase (E-GPx) and cellular glutathione peroxidase (C-GPx) are selenoenzymes encoded by two distinct genes. Using specific immunoprecipitations of [75Se]selenium metabolically labeled human cell lines in culture, it was found that Caco-2, Hep3B, Hep G2, and Caki-2 synthesize C-GPx and E-GPx and secrete E-GPx. HBL-100, BT-20, and MCF-7 synthesize only C-GPx. The relationship between Se status (as determined by C-GPx activity) and E-GPx and C-GPx mRNA steady-state levels was investigated in Hep G2, Caco-2, and Caki-2. The most Se-deficient Hep G2, Caco-2, and Caki-2 cells had 8.7 +/- 2.6, 11.2 +/- 4.9, and 9.4 +/- 5.0%, respectively, of C-GPx activity of the replete cells. The steady-state levels of mRNA were measured by Northern and slot blot hybridization analysis. By Northern analysis, a single band was present at 1.0 and 1.80 kb for C-GPx and E-GPx mRNA, respectively, in all three cell lines. Scanning densitometry of the blots revealed that the most Se-deficient cells had 30-50% C-GPx mRNA and 60-80% E-GPx mRNA of the replete cells. It is concluded that, in addition to previously examined human cell lines, Hep3B and Caco-2 make and secrete E-GPx while HBL-100 and BT-20 do not. The slightly reduced levels of G-GPx and E-GPx mRNA in Se-deficient human cell lines can only partially account for the decreased C-GPx activity in Se-deficient human cell lines.

Blotting, Northern↗
PubMed1994

The 5'-region of Arabidopsis thaliana cor15a has cis-acting elements that confer cold-, drought- and ABA-regulated gene expression.

Previous nuclear run-on experiments indicated that the cor15a (cold-regulated) gene of Arabidopsis thaliana L. (Heyn) has a cold-inducible promoter (Hajela et al., Plant Physiol 93: 1246-1252, 1990). The data presented here indicate that the 5' region of cor15a between nucleotides -305 and +78 (relative to the start of transcription) contains a cis-acting element(s) that can impart cold-regulated gene expression. Histochemical staining experiments indicated that the cor15a promoter is inactive, or very weakly active, in most of the tissues and organs of plants grown at normal temperature and that it becomes activated throughout most of the plant in response to low temperature. Notable exceptions to this general pattern include constitutive activity of the promoter in anthers of control grown plants and apparent inactivity of the promoter in the roots and ovaries of cold-treated plants. Histochemical staining experiments also indicated that low temperature regulation of cor15a does not involve the synthesis of a regulatory molecule that can spread throughout the plant and induce cor gene expression at normal growth temperature. Finally, gene fusion experiments indicated that the 5' region of cor15a between nucleotides -305 and +78, in addition to imparting cold-regulated gene expression, can impart ABA- and drought-regulated gene expression.

Abscisic Acid↗
PubMed1993

Selenium regulation of glutathione peroxidase in human hepatoma cell line Hep3B.

Glutathione peroxidase is an important enzyme in cellular antioxidant defense systems, detoxifying peroxides and hydroperoxides. As a component of the glutathione cycle, it protects the liver from reactive oxygen metabolites. Selenocysteine is present at the catalytic site of glutathione peroxidase, and selenium availability regulates glutathione peroxidase enzyme activity. Hep3B cells, a well-differentiated human hepatoma-derived cell line, exhibited time-dependent decrease in glutathione peroxidase activity (nmol NADPH oxidized/min/mg protein, mean +/- SE) when incubated in selenium-free medium for 10 days (Day 0, 21.8 +/- 7.3; Day 2, 10.9 +/- 1.2; Day 4, 7.9 +/- 0.8; Day 6, 4.0 +/- 0.7; Day 8, 4.5 +/- 0.6; Day 10, 1.6 +/- 0.4). With the reintroduction of selenium, glutathione peroxidase activity returned. A second human hepatoma cell line, HepG2, demonstrated a similar pattern when depleted of and then repleted with selenium. To assess protein synthesis, glutathione peroxidase activity was measured in deficient and replete Hep3B cells incubated with and without selenium and with and without cycloheximide. Deficient cells (mean +/- SE) (4.9 +/- 0.2) showed an increase in glutathione peroxidase activity after 24 h in selenium-containing medium (11.6 +/- 0.2), but not when cycloheximide was included in the medium (6.9 +/- 0.5) or when cycloheximide and no selenium was included (5.3 +/- 0.8). Replete Hep3B cells (40.1 +/- 1.1) demonstrated decreased glutathione peroxidase after 24 h in medium without selenium (34.0 +/- 1.4), medium with both cycloheximide and selenium (34.0 +/- 2.6), and medium without selenium and containing cycloheximide (37.6 +/- 1.3). These data suggest that protein synthesis is needed for selenium repletion to exert control on glutathione peroxidase activity. Using a cDNA for human glutathione peroxidase (GPx1), selenium-deficient and replete Hep3B cell RNA was analyzed by Northern blot. mRNA for GPx was quantified by densitometry. The steady-state mRNA level for glutathione peroxidase in deficient cells was 40% of that in replete cells. Nuclear run-on studies to determine the rate of GPx-specific mRNA synthesis showed no difference between nuclei from selenium-replete and selenium-deficient cells. This finding eliminated the possibility of differential transcription rates as an explanation for the observed reduction in mRNA brought about by selenium deficiency and suggested instead a stabilization of mRNA in selenium-replete cells. While selenium deficiency decreased mRNA levels by 60%, glutathione peroxidase enzyme activity decreased by 93%, suggesting a co- and/or post-translational control mechanism in addition to the effect on mRNA stability.

Carcinoma, Hepatocellular↗
PubMed1993

Caco-2 cell metabolism of oxygen-derived radicals.

Reactive oxygen metabolites have been associated with gastrointestinal injury and may play a role as mediators of inflammation. The effect of oxygen metabolites on Caco-2 cell viability (trypan blue exclusion and 51Cr release), hexose monophosphate shunt activity, and glutathione was assessed. Caco-2 cells were incubated with amino acid oxidase, xanthine oxidase, menadione, and t-butylhydroperoxide in the presence and absence of superoxide dismutase, catalase, mannitol, and butylated hydroxytoluene. With amino acid oxidase, trypan blue exclusion decreased (P < 0.01) and 51Cr release, oxidized glutathione, and shunt activity increased (P < 0.05). The addition of catalase attenuated these changes. Trypan blue exclusion decreased (P < 0.005) and 51Cr release, oxidized glutathione, and shunt activity increased (P < 0.01) with xanthine oxidase. The addition of superoxide dismutase caused a further increase in 51Cr release, oxidized glutathione, and shunt activity (P < 0.01), which was prevented by the addition of catalase or mannitol. t-Butylhydroperoxide did not effect 51Cr release or trypan blue exclusion, but oxidized glutathione and shunt activity increased (P < 0.01). The increase in shunt activity was prevented by preincubation with butylated hydroxytoluene (P < 0.01). Menadione did not alter trypan blue exclusion or 51Cr release, but caused an increase in oxidized glutathione and shunt activity (P < 0.001). The increase in shunt activity was attenuated by preincubation with butylated hydroxytoluene (P < 0.001). Menadione also caused a depletion of total glutathione.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromium Radioisotopes↗
PubMed1993

"Dust thou art...".

Explore the source record for details and available documents.

Absorptiometry, Photon↗
PubMed1991

Rat enterocyte injury by oxygen-dependent processes.

Neutrophils migrate to areas of inflammation and, when stimulated, produce O2-, H2O2, and other reactive O2 metabolites. To assess the effects of stimulated neutrophils on enterocytes, rat enterocytes were incubated with peripheral neutrophils. To assess cell viability, trypan blue exclusion and lactate dehydrogenase and protein release were measured. When 10(6) enterocytes/mL were incubated with 2.5 x 10(5) neutrophils/mL stimulated with phorbol myristate acetate, trypan blue exclusion decreased and lactate dehydrogenase and protein release increased. With the addition of 0.10 mg/mL of superoxide dismutase, trypan blue exclusion further decreased and lactate dehydrogenase and protein release increased. This suggests that H2O2- or H2O2/O2(-)-derived metabolites are more damaging to isolated enterocytes than O2-. To test this hypothesis, enterocytes were incubated with xanthine and increasing concentrations of xanthine oxidase in the presence and absence of superoxide dismutase. With increasing concentrations of xanthine oxidase, the cell number decreased and protein release increased. With the addition of superoxide dismutase, fewer cells were present, suggesting that cell lysis occurred. Protein release was further increased by the addition of superoxide dismutase. Enterocytes were then incubated with leucine and increasing concentrations of amino acid oxidase. With increasing concentrations of amino acid oxidase, trypan blue exclusion decreased and protein and lactate dehydrogenase release increased. These effects were ameliorated by the addition of 500 IU catalase/mL. These data suggest that O2- and H2O2, whether created by stimulated neutrophils or an enzyme-generating system, are damaging to isolated enterocytes. Superoxide dismutase did not offer enterocytes protection.

Animals↗
PubMed1990

Short-term malnutrition in neonatal rabbits: effect on function and synthesis of free radical metabolizing enzymes in the gastrointestinal tract.

Oxygen-derived free radicals are an important component of gastrointestinal injury in necrotizing enterocolitis (NEC). To assess the effect of a 72-h fast on the ability of neonatal small bowel to metabolize free radicals, the activity of superoxide dismutase (SOD), catalase, and the glutathione cycle were quantitated in mucosal scrapings from proximal and distal small bowel of fed and fasted neonatal rabbits. Hexose monophosphate shunt activity, quantitated in enterocytes from fed and fasted neonatal rabbits, was significantly less, p less than 0.01, in fasted animals. SOD activity was lower in distal small bowel from fasted animals than fed. The two mechanisms available to metabolize H2O2, catalase and the glutathione cycle, were significantly lower in both proximal and distal small bowel from fasted animals than in those from fed animals. To determine if fasting caused decreased enzyme activity at the level of gene expression, gastrointestinal tract DNA, RNA and protein, and specific mRNA levels for catalase, glutathione peroxidase (GPx), and SOD were quantitated. DNA, total RNA, and mRNA for SOD were lower in mucosal scrapings from fasted animals. However, mRNA for catalase, and GPx were not lower in fasted animals. Thus, a 72-h fast in neonatal rabbits causes a regional-specific decrease in SOD activity, which may be explained by decreased transcription. Changes in transcription do not completely account for regulation of catalase and glutathione cycle enzymes.

Animals↗
PubMed1989

Short term neonatal starvation altered cholera toxin binding in rabbits.

Acute neonatal malnutrition alters lumenal glycoproteins as demonstrated by altered lectin binding. To determine the effect of a 72-h fast on lumenal glycolipids, specifically the monosialoganglioside GM1, we quantitated cholera toxin (CT) binding and adenylate cyclase activity. The calculated number of specific sites for CT binding to microvillus membrane (MVM) from newborn rabbits fasted for 72 h was decreased in MVM from proximal small bowel (7 +/- 0.8 x 10(8)/micrograms protein) compared to 72-h control neonatal rabbits (18 +/- 3.3 x 10(8) micrograms protein). In distal small bowel there was no difference in the calculated receptor sites/micrograms MVM protein between fasted (8 +/- 1.7 x 10(8)) and fed (11 +/- 4 x 10(8)) groups. MVM prepared from proximal small bowel of fed animals bound significantly more CT than MVM prepared from distal small bowel of fed animals. The affinity for CT was the same in all MVM preparations. Neuraminidase treatment of MVM resulted in increased CT binding in fed and fasted rabbit proximal and distal MVM preparations, but the greatest increase occurred in MVM prepared from proximal small bowel from fasted animals. There was no difference in adenylate cyclase activity in fed, fasted, and proximal or distal small bowel crude membrane preparations. Refeeding (120 h) resulted in normalization of CT binding in MVM from proximal small bowel of fasted animals. We conclude a 72-h fast in neonatal rabbits resulted in decreased regional CT binding in MVM prepared from proximal small bowel of fasted animals, but no change in adenylate cyclase activity. Refeeding reverses CT binding abnormalities.

Adenylyl Cyclases↗
PubMed1989

Short-term malnutrition in neonatal rabbits: effect on gastrointestinal epithelial proliferation.

We determined DNA synthesis, cell turnover and cell migration in 72-h fasted and control neonatal rabbits because acute neonatal malnutrition causes specific regional alterations in brush border structure and function. Decreased cell turnover and/or migration might partly explain these observations. We injected fed and fasted neonatal rabbits with [3H]thymidine. At 1 and 72 h after injection we assessed cell proliferation and migration. Villus height was less in proximal small bowel from fasted rabbits (PF) than in fed controls (PC). Villus height was lower in proximal than in distal small bowel from fasted rabbits (DF). DNA synthesis, as measured by incorporation of [3H]thymidine into DNA, was less in PF and DF than in PC and distal small bowel from fed rabbits (DC) whether expressed per microgram DNA or per intestinal segment. Similarly, thymidine kinase activity was lower in PF and DF than in PC and DC. For both fed and fasted rabbits, more cells were present in the proliferative zone from proximal small bowel than in that from distal. Small bowel labeling index was less in PC than in DC, and less in DF than in DC. The ratio of the number of cells in the proliferative zone to the number of cells in crypt was greater in PC than in DC and greater in DF than in DC. The migration zone was significantly greater in PC than in PF and greater in the fed group in the proximal small bowel than in the distal small bowel. Thus, a 72-h fast in neonatal animals resulted in decreased DNA synthesis and cell migration. Regional alterations in cell proliferation occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Retrobulbar anesthesia and orbicularis akinesia.

After noting that simple retrobulbar injection often caused orbicularis akinesia, we evaluated this phenomenon prospectively. A total of 50 patients were given a standard injection using 3 cc of a 50-50 mixture of 0.75% bupivacaine and 2% lidocaine with epinephrine and hyaluronidase. The entire 3 cc was injected into the muscle cone through an inferolateral lid entry using a 35-mm retrobulbar needle of either 23- or 27-gauge. Injection was considered successful if orbicularis function was sufficiently reduced to proceed with an intraocular case after a single retrobulbar injection. If facial nerve block was necessary or if the patient's lid moved during surgery, then the procedure was considered a failure. Of the 50 patients, 44 achieved adequate akinesia of the orbicularis after retrobulbar injection alone, giving a success rate of 88%. Benefits of this method include lower drug volume. decreased chance for direct nerve damage during a facial nerve block, less pain, less ecchymosis, and less edema following surgery.

Anesthesia, Local↗