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Biomedical subjects

M Smith

Publications and source records attributed to M Smith.

At least 991 records · Page 55Linked to original sources
PubMed1988

Lower extremity fractures in paraplegics: pattern, treatment, and functional results.

Eighty-seven lower extremity fractures in 71 paraplegics were retrospectively evaluated to determine adequacy of treatment, functional result, and range of motion of the hip and knee. Most fractures treated closed healed without difficulty, but with a complication rate of 19%. Length of hospitalization averaged almost 3 months in the group treated closed, and residual hip and knee stiffness was the major complication. This was not a problem except in high demand patients, such as wheelchair athletes, in whom decreased range of motion was a significant limitation. Treatment with circular casts produced a high number of complications and is not recommended for patients with insensate skin. Open reduction and internal fixation is recommended for a small subgroup of paraplegics: wheelchair athletes, hip fractures, and those in whom autonomic dysreflexia and/or uncontrollable spasticity due to fracture manipulation is a significant hazard.

Bone Nails↗
PubMed1988

Karl Touton and his "xanthelasmatic giant cell." A selective review of multinucleated giant cells.

The position of the Touton giant cell in relation to the foreign body and Langhans type of giant cell is considered. (A short account of Karl Touton's life is also included.) After reviewing the historical development of the concept of giant cells and current interpretations of their nature, the unitarian view of polykaryons now favored by workers in the field is extended to include also the "xanthelasmatic giant cell" of Touton, whose characteristic appearance is determined merely by the presence of demonstrable lipid in the cytoplasm. It is proposed that Touton cells develop when the stimulus to cell fusion is accompanied also by a factor stimulating lipid uptake. This factor is missing in the development of the other two giant cell "types," but apart from that there are no other significant differences.

Cytoplasm↗
PubMed1988

Use of the subcutaneous terbutaline pump for long-term tocolysis.

Nine patients in preterm labor requiring long-term tocolysis were managed with subcutaneous terbutaline administered via a portable infusion pump. All had failed oral tocolytic therapy and were therefore faced with prolonged hospitalization. In this feasibility study, the patients were treated at home and monitored with portable tocodynamometers and home nursing visits. Uterine activity data were transmitted via telephone to the study center and terbutaline pump infusion rates were adjusted accordingly. Terbutaline pump therapy consisted of a combination of low-dose continuous basal infusion supplemented with intermittent high-dose boluses. Total daily drug dosage remained exceptionally low (less than 3 mg/24 hours). The mean gestational age at initiation of therapy was 29.6 +/- 3.7 weeks, and pregnancy was prolonged an average of 9.2 +/- 4.3 weeks. The minimum gestational age at delivery was 37.3 weeks. Patient tolerance was excellent and, in a total 394 patient-days of therapy, there were no significant complications. We conclude that the portable subcutaneous terbutaline pump may be a promising new method for long-term outpatient tocolysis in patients who cannot be maintained on oral therapy.

Administration, Oral↗
PubMed1988

A rapid droplet method for Sanger dideoxy sequencing.

A method for performing the dideoxy sequence reaction on petri dishes is described. It allows rapid manipulation of clones and provides large amounts of sequence information quickly and without the need for elaborate laboratory equipment.

Base Sequence↗
PubMed1988

Evaluation of two acute cardiac ischemia decision-support tools in a rural family practice.

This study investigated the applicability in a primary care setting of two decision-support tools for evaluating the necessity of admitting patients with suspected acute cardiac ischemic disease to a cardiac intensive care unit. The heart disease predictive instrument (HDPI) of Pozen et al and the electrocardiogram scoring method of Brush et al were applied to records from all patients with cardiac-related diagnoses admitted to a family practice service. A retrospective review of medical records of all patients admitted with suspected acute ischemic heart disease to a rural community hospital family practice service was conducted. Of 147 patients identified, 108 were admitted primarily for suspected ischemia. Twenty-four myocardial infarctions occurred among these 108 patients (22.2 percent). Patients with HDPI probabilities of less than 50 percent were very unlikely to sustain infarction and in no case required intensive intervention for any problem not apparent at admission. Only 15 instances of the four types of complications that the instrument of Brush et al is designed to predict occurred; this incidence was too low to allow statistical testing. In summary, the heart disease predictive instrument reliably identified patients unlikely to require intensive care services in this population. Because of the low incidence of complications in this population, the instrument described by Brush et al was not found to be clinically useful.

Adult↗
PubMed1988

Comparison of methylprednisolone (1 g i.v.) with prednisolone (1 g orally) in rheumatoid arthritis: a pharmacokinetic and clinical study.

Methylprednisolone pulse therapy is often used in patients with severe rheumatoid arthritis (RA). To compare clinical and pharmacokinetic variables of methylprednisolone and oral prednisolone in patients with RA, a controlled crossover study was carried out. Pharmacokinetic variables for methylprednisolone were Vd of 69.9 l, t1/2 of 2.96 h, total plasma clearance of 17.5 l/h. Pharmacokinetic variables for prednisolone were Vd of 47.5 l, t1/2 of 3.08 h and total plasma clearance of 11.3 l/h. During the elimination phase, a secondary rise in methylprednisolone concentration occurred which may be related to enterohepatic circulation. Clinical response to both prednisolone and methylprednisolone was short-lived with neither lasting more than 6 weeks.

Arthritis, Rheumatoid↗
PubMed1988

Nodular thyroid disease in children and adolescents: a high incidence of carcinoma.

Over a period of 32 years from 1954 to 1986, 65 patients under the age of 21 years, 52 girls and 13 boys, were operated for nodular thyroids: the overall incidence of carcinoma was 37 per cent. It was 46 per cent in those patients presenting with a solitary nodule. Among the 24 patients with a malignancy, the carcinoma was of the papillary variety in 63 per cent, follicular in 25 per cent and medullary in 12 per cent. Two thirds of the patients had metastatic disease at the time of presentation. All patients with thyroid carcinoma were treated with total thyroidectomy. Other measures included neck dissection and radioactive iodine. When the eight patients with a history of head and neck irradiation and the three patients with medullary carcinoma were excluded, the incidence of carcinoma was 28 per cent. In summary, in spite of the decline in radiation associated cases, the incidence of carcinoma in nodular thyroid disease in the population under 21 years, remains at the relatively high figure of 28 per cent.

Adenocarcinoma↗
PubMed1988

Carcinoma of the thyroid in patients with autonomous nodules.

Over a period of 25 years (1961-1986), 30 consecutive patients were operated upon for solitary "HOT" nodules. The autonomy of these nodules was substantiated by cytomel nonsuppressibility on 131I or 123I scanning, or TSH stimulated enhancement of the remaining suppressed thyroid tissue (n = 24); or as a solitary toxic hot nodule with suppression of the remaining thyroid tissue (n = 6). Seventeen of these patients were euthyroid and 13 were thyrotoxic and required preoperative preparation with antithyroid medication. Five patients had a history of head and neck irradiation. The population consisted of 24 women and six men. Their ages ranged from 14 to 68 years. The tumors ranged in size from 1.5 to 7 cm. The pathologic findings consisted of "colloid" adenoma in nine patients, follicular adenoma in 19 patients, and a follicular carcinoma in two patients, for an incidence of 6 per cent. It is of interest that neither of the patients with thyroid carcinoma were toxic or had a history of radiation exposure. These findings support the concept that the incidence of carcinoma in truly autonomous "HOT" thyroid nodules is not negligible.

Adenocarcinoma↗
PubMed1987

The peroxide complex of yeast cytochrome c peroxidase contains two distinct radical species, neither of which resides at methionine 172 or tryptophan 51.

The nature of the free radical species observed in the peroxide complex of yeast cytochrome c peroxidase is described for protein variants containing amino acid substitutions at Met-172 and Trp-51. As was the case with Met-172 mutations (Goodin, D.B., Mauk, A.G., and Smith, M. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 1295-1299), Trp-51 can be substituted to give active enzyme. Phe-51-containing enzyme has a higher turnover rate than the original enzyme and exhibits an altered pH dependence. The properties of the isotropic and axial components (Hoffman, B.M., Roberts, J.E., Kang, C.H., and Margoliash, E. (1981) J. Biol. Chem. 256, 6556-6564; Hori, H., and Yonetani, T. (1985) J. Biol. Chem. 260, 349-355) of the EPR signal of the wild-type enzyme-peroxide complex, studied as a function of H2O2 stoichiometry, support proposals (Goodin et al. (1985) and Hori and Yonetani (1985), see above) that two distinct radical species are formed, and spin quantification shows that the isotropic radical is always formed in substoichiometric amounts. The peroxide complexes for proteins containing amino acid substitutions at either Met-172 or Trp-51 exhibit somewhat larger than normal levels of the isotropic radical signal. In addition, these mutants are unlike wild-type enzyme in that the axial EPR signal associated with the peroxide complex is seen only at 10 K and not at 90 K. Thus, neither amino acid can be considered to be the molecular species responsible for either radical signal, but both mutations appear to affect the physical properties of the axial signal representing the major radical species.

Cloning, Molecular↗
PubMed1987

Alloxan-induced hyperglycemia in rabbits and the response of platelets to aggregating agents in vitro and to exposed subendothelium in vivo.

Many patients with diabetes mellitus show increased platelet aggregation and prostaglandin synthesis in response to physiological agents such as ADP and collagen when their platelets are tested in platelet-rich plasma or washed platelet suspensions. However, the relationship between increased platelet aggregation in vitro and increased thrombosis in vivo is difficult to establish with certainty. We have developed an in vivo model system in rabbits which tests the response of platelets in circulating native blood to an arterial vessel wall with limited damage such as might occur in arteries of patients with diabetes mellitus. We have used this model system to investigate whether 5 to 9 weeks of alloxan-induced hyperglycemia increases platelet adhesion and aggregation on a damaged vessel wall in vivo as well as platelet aggregation in vitro. Our results show that rabbit platelet function is not affected by extreme hyperglycemia and suggest that alloxan-induced diabetes in the rabbit may not be a good model for human diabetes mellitus.

Adenosine Diphosphate↗
PubMed1987

Mapping human brain monoamine oxidase A and B with 11C-labeled suicide inactivators and PET.

The regional distributions of monoamine oxidase (MAO) types A and B have been identified in human brain in vivo with intravenously injected 11C-labeled suicide enzyme inactivators, clorgyline and L-deprenyl, and positron emission tomography. The rapid brain uptake and retention of radioactivity for both 11C tracers indicated irreversible trapping. The anatomical distribution of 11C paralleled the distribution of MAO A and MAO B in human brain in autopsy material. The corpus striatum, thalamus, and brainstem contained high MAO activity. The magnitudes of uptake of both [11C]clorgyline and L-[11C]deprenyl were markedly reduced in one subject treated with the antidepressant MAO inhibitor phenelzine. A comparison of the brain uptake and retention of the 11C-labeled inactive (D-) and active (L-) enantiomers of deprenyl showed rapid clearance of the inactive enantiomer and retention of the active enantiomer within MAO B-rich brain structures, in agreement with the known stereoselectivity of MAO B for L-deprenyl. Prior treatment with unlabeled L-deprenyl prevented retention of L-[11C]deprenyl. Thus, suicide enzyme inactivators labeled with positron emitters can be used to quantitate the distribution and kinetic characteristics of MAO in human brain structures.

Adult↗
PubMed1987

Development of cell systems to study viral gene transcription at the initial phase of Epstein-Barr virus infection.

Two infection systems have been introduced in order to study viral gene expression at the initial period of Epstein-Barr virus (EBV) infection which leads to immortalization. The data indicate that major viral gene expression in tonsil lymphocytes at 2 days post-infection (p.i.) with EBV is very similar to that observed in latently infected cells. Both tonsil lymphocyte and BJAB cell (lymphoblastoid cells free of EBV genome) infection with EBV induced similar viral gene transcription. Twelve cDNA clones were prepared from poly(A) RNA of tonsil lymphocytes infected with EBV 2 days p.i. by hybridization with BamHI fragments of EBV DNA. Some cDNAs were derived from primary transcripts of the BamHI-WYHK region, suggestive of splicing of a large transcript. It is possible that a number of cDNA clones may be derived from cellular genes. The derivation of these cDNA clones is being studied.

Bacteriophage lambda↗
PubMed1987

Rapid RFLP screening procedure identifies new polymorphisms at albumin and alcohol dehydrogenase loci.

A rapid screening procedure for restriction fragment length polymorphisms (RFLPs) is reported. DNA from ten individuals is pooled and compared to DNA isolated from a cell line containing a single chromosome 4. This single chromosome-containing line is an obligate hemizygote for chromosome 4 RFLPs so that only one band corresponding to a single allele will appear on a Southern blot. In the pooled DNA sample lane bands corresponding to both alleles will be seen. The technique allows for efficient detection of RFLPs with easier use of large numbers of enzymes. It provides estimates of allele frequencies and disequilibrium. New RFLPs for albumin and alcohol dehydrogenase detected with this technique are described.

Albumins↗
PubMed1987

Acid burns of the rectum and colon. Report of a case.

The case of a patient with acid burns of the large bowel from a self-administered enema of 95 percent sulfuric acid solution is reported. The authors were unable to find a similar case in the English medical literature. The patient presented in metabolic acidosis, and flexible sigmoidoscopy was of limited value. Peritoneal signs warranted early laparotomy, which revealed coagulation necrosis of the anus, rectum, and colon up to the hepatic flexure without any free perforation. The extent of damage was more severe than seen in the upper digestive tract from acid ingestion. Juxtaposed small bowel and the appendix sustained serosal burns. Subtotal proctocolectomy and perineal resection were done and the patient made an uneventful recovery. Early laparotomy is warranted, irrespective of endoscopic findings, for appropriate surgical correction.

Administration, Rectal↗
PubMed1987

Bulimia: prevalence and component factors in college women.

Using a measure of bulimia (BULIT) that has demonstrated validity and reliability, the prevalence of bulimia among three samples of college females was found to range from 2.0 to 3.8%. These percentages are substantially lower than most previous reports would suggest. Factor analysis of the BULIT data revealed that the binging factor accounted for 63% of the variance. Other factors identified include vomiting, negative feelings about overeating, menstruation problems, preference for high caloric/easily ingested food, and weight fluctuations. The intercorrelations among the factors were examined and the implications of these data for the proposed revised DSM-III criteria for bulimia are discussed.

Adult↗
PubMed1987

Restriction enzyme map of herpesvirus of turkey DNA and its collinear relationship with Marek's disease virus DNA.

The genome of herpesvirus of turkey (HVT) was shown to consist of long and short unique regions flanked by inverted repeats (J. Cebrian, Kaschka-Dietrich, C., Berthelot, N., and Sheldrick, P., 1982, Proc. Natl. Acad. Sci. USA 79, 555-558). In this paper we report the construction of the linkage map of HVT DNA for BamHI, HindIII, and PstI restriction endonucleases. The maps were constructed by hybridization of 19 cloned BamHI fragments of HVT DNA to electrophoretically separated digests of genomic DNA. Our results indicate that the terminal and internal inverted repeats (TRL and IRL) flanking the long unique sequences (UL) are spanned by BamHI-F fragment and a -F-related terminal fragment, respectively, whereas the terminal and internal inverted repeats (TRS and IRS) flanking the short unique sequences (US) are mostly contained in BamHI-A fragment. Both BamHI-A and -F showed a heterogeneity in size, suggesting the presence of amplification of certain sequences in the inverted repeats. We also report that the HVT genome is collinear with the genetically related Marek's disease virus (MDV) genome, as determined by hybridization of labeled cloned HVT DNA fragments with electrophoretically separated MDV DNA fragments.

Animals↗