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M Smith

Publications and source records attributed to M Smith.

At least 703 records · Page 39Linked to original sources
PubMed1993

The role of cartilage-derived antigens, pro-coagulant activity and fibrinolysis in the pathogenesis of osteoarthritis.

Superficial fraying, splitting and fibrillation of articular cartilage as a consequence of ageing or mechanical injury is not always associated with joint pain. However, similar cartilage lesions accompanied by synovitis and engorgement of the subchondral vasculature generally is; the disorder being known as osteoarthritis (OA). In this hypothesis it is contended that the progression of early cartilage fibrillation to symptomatic OA arises as a consequence of the antigenic nature of cartilage components which when released into synovial fluid and the circulation can stimulate leukocytes (to a varying degree) to produce a number of factors some of which promote blood coagulation. While it is known that with ageing hyper-coagulation and plaque deposition is increased, the augmentation of this process by factors released by activated leukocytes is considered to exacerbate the problem. These haematological events may be particularly relevant in individuals whose leukocytes are hypersensitive to the cartilage-derived antigens, and whose fibrinolytic system is less capable of mobilizing the thrombi deposited in synovial tissues and the subchondral vascular tree.

Animals↗
PubMed1993

Primary trabeculectomy in young adults.

BACKGROUND: Younger patients are thought to have a poor surgical prognosis after trabeculectomy. The authors investigate the surgical outcome of young adult patients after primary trabeculectomy. METHODS: The authors reviewed the charts of all patients 15 to 40 years of age who had undergone primary trabeculectomy without the use of antimetabolites between January 1985 and January 1992 at Wills Eye Hospital. Failure was defined before the data collection as intraocular pressure (IOP) more than 25 mmHg without medication, IOP more than 21 mmHg with medication, or when further glaucoma surgery was indicated. Patients in whom preoperative IOPs were 21 mmHg or lower were classified as successes when the IOP was reduced by at least 33% of the preoperative measurement. RESULTS: After a mean follow-up of 36.8 +/- 21.8 months, among the 31 patients with uncomplicated glaucomas (juvenile, pigmentary, low tension, chronic angle closure), 26 (83.9%) were considered successes. After a mean follow-up of 42.3 +/- 26.5 months, among the 11 patients with other types of glaucoma (inflammatory, traumatic, associated with irido-corneal endothelial syndrome or mesodermal dysgenesis), 7 (63.6%) were considered successes. CONCLUSIONS: The success rate of the uncomplicated group compares favorably with the 75% to 90% success rates of trabeculectomy commonly cited for primary glaucomas in older patients. Primary trabeculectomy in young adults may have a favorable outcome despite no antimetabolite therapy.

Adolescent↗
PubMed1993

Loss of visual acuity after trabeculectomy.

BACKGROUND: Glaucoma filtration surgery can result in loss of visual acuity by a variety of mechanisms. The existence of "wipe-out" (loss of the central visual field in the absence of other explanation) as a cause of postoperative loss of visual acuity has been debated. This study defines the incidence and etiology of visual acuity loss within 3 months of trabeculectomy. METHODS: The authors reviewed 508 eyes of 440 patients who underwent trabeculectomy to find cases of postoperative visual acuity loss (2 or more Snellen lines or a category change) and randomly selected a control group of 85 eyes to analyze the risk factors for each cause of visual acuity loss. RESULTS: Forty-two eyes (8.3%) showed loss of visual acuity after 3 months, caused mainly by lens opacification (n = 16), hypotony maculopathy (n = 6), and "wipe-out" (n = 4). Older patients (P = 0.0108), those in whom the visual field preoperatively showed macular splitting (P = 0.0084) and those who had severe hypotony (intraocular pressure [IOP] < or = 2 mmHg) on the first postoperative day (P = 0.0246) were more likely to experience "wipe-out." Older age (P = 0.0495) and shallow anterior chamber (P = 0.0003) were correlated to the development of lens opacification. Hypotony maculopathy was associated with coronary artery disease (P = 0.0397) and systemic hypertension (P = 0.0118). CONCLUSIONS: Lens opacification was the main cause of early visual acuity loss after trabeculectomy, followed by hypotony maculopathy. "Wipe-out," although rare, does exist, and older patients with advanced visual field defects are at increased risk.

Age Factors↗
PubMed1993

Salmonella enteritidis outbreak in a restaurant chain: the continuing challenges of prevention.

In 1990, a Salmonella enteritidis (SE) outbreak occurred in a restaurant chain in Pennsylvania. To determine its cause(s), we conducted a case-control study and a cohort study at one restaurant, and a survey of restaurants. Egg dishes were associated with illness (P = 0.03). Guests from one hotel eating at the restaurant had a diarrhoeal attack rate of 14%, 4.7-fold higher than among those not eating there (P = 0.04). There were no differences in egg handling between affected and unaffected restaurants. Eggs supplied to affected restaurants were medium grade AA eggs from a single farm, and were reportedly refrigerated during distribution. Human and hen SE isolates were phage type 8 and had similar plasmid profiles and antibiograms. We estimate the prevalence of infected eggs during the outbreak to be as high as 1 in 12. Typical restaurant egg-handling practices and refrigeration during distribution appear to be insufficient by themselves to prevent similar outbreaks.

Adolescent↗
PubMed1993

Psychogeriatric outreach to rural families: the Iowa and Virginia models.

Elderly residents of rural areas are at significant risk for mental health problems, yet have less access to mental health services. Thus, most mental health problems among rural elderly remain either undiagnosed or untreated. We describe two models of mental health outreach programs to rural elderly in Iowa and Virginia, serving demographically, culturally, and epidemiologically different populations in geographically and economically dissimilar regions. Programs are compared on the basis of initiation, community partnerships, target population, target region, clinical disciplines involved, coordinating discipline, referral sources, operational model, initial home assessment, care planning, sustainability, cost, patient demographics, and primary and secondary diagnosed. Outreach programs are argued to be effective models of delivering services to geographically and/or socially isolated elderly populations. The experiences of our programs, though limited to rural populations, may be of relevance to any outreach program attempting to serve elderly presenting with or at risk for mental health problems.

Aged↗
PubMed1993

A double-blind study of the effectiveness of low level laser treatment of rotator cuff tendinitis.

Thirty-five patients with rotator cuff tendinitis were randomly allocated to active (CB Medico Master III 830 nm Ga As AL diode) laser or dummy laser treatment twice weekly for 8 weeks. Movement range, painful arc score, resisted movement score and responses to visual analogue scales for night pain, rest pain, movement pain and functional limitation were measured second weekly. All responses improved from baseline but there was no difference between the two groups. These results fail to demonstrate the effectiveness of laser therapy in rotator cuff tendinitis.

Adolescent↗
PubMed1993

Laparoscopically harvested omental free flap to cover a large soft tissue defect.

OBJECTIVE: The omentum has been a very important tool in the armamentarium of the reconstructive surgeon. It has lost much of its value because of the morbidity associated with laparotomy. Laparoscopic surgery has become a popular technique and allows operations to be performed with minimal morbidity. The possibility of harvesting the omental free flap with the laparoscope and its use in reconstructive surgery has been demonstrated. SUMMARY BACKGROUND DATA: Since the first laparoscopic cholecystectomy was performed, many surgeons have learned the procedure. Other surgical specialties have also benefited from this technique. The omentum provides a large amount of vascularized tissue and excellent wound coverage. It can be transferred as a pedicle flap, or as a free flap, using microvascular technique. METHODS: The procedure was developed and refined in an animal model. One team harvested the omentum with laparoscopic assistance, while the other team prepared the recipient vessels. After completion of the microvascular transfer, the dogs were observed for 14 days. At that time, the omental tissue was examined for gross and histologic changes. A clinical case is also presented. RESULTS: Gross and microscopic studies documented the viability of this approach. The patient tolerated the procedure well and had an unremarkable postoperative course. CONCLUSIONS: Experimental and clinical evidence shows that the omentum can be successfully harvested as a free flap using laparoscopic assistance. This technique may prove to be of clinical significance and very useful for reconstructive surgery with less morbidity.

Animals↗
PubMed1993

Pediatric sexuality: promoting normal sexual development in children.

Since the sexual revolution of the 1960s there has been an openness regarding sexual exploration that has resulted in an increase of sexually transmitted diseases and teenage pregnancies. Clinicians can mitigate the unhealthy results of such exploration through a therapeutic relationship with their patients. This article provides practical ways to approach and educate the pediatric patient and parent regarding normal sexual growth and development and the promotion of healthy, responsible sexual behavior. Using developmental theories as a foundation, sexuality is examined from birth through the adolescent years.

Adolescent↗
PubMed1993

Identification of two laccase genes in the cultivated mushroom Agaricus bisporus.

A cDNA library was constructed in lambda gt11 using mRNA from 11-d-old mycelium of Agaricus bisporus. Three clones containing laccase sequence were identified using an affinity-purified anti-laccase antibody. From one of these clones, a 333 bp sequence was used to identify further cDNA clones (including one which is close to full length) and a genomic clone. The coding sequences found were of two similar but not identical versions with differences at 36 out of 520 residues of deduced amino acid sequence. The laccase genes each encode a sequence expressed as a 2.3 kb mRNA, specifying a 520 residue polypeptide including a 19 amino acid residue signal peptide that is absent from the N terminus of the mature (extracellular) protein. The coding sequence of lcc1 is interrupted by 14 short introns. The lcc1 and lcc2 genes are not allelic as they do not segregate in uninucleate spores derived from a four-spored basidium. Comparison of the deduced amino acid sequences with that of the other fungal laccases that have been cloned, and with the very similar ascorbate oxidases from higher plants shows that whilst some sequence is absolutely conserved at and around the amino acid residues involved in copper binding, the overall sequence similarities are low.

Agaricus↗
PubMed1993

An evaluation of gastric emptying times in pregnancy and the puerperium.

In a controlled study, gastric emptying was measured during the three trimesters of pregnancy and after delivery, using an indirect paracetamol absorption technique. The peak plasma paracetamol concentration, time to reach the peak, and the area under the plasma paracetamol concentration-time curve, were determined. As compared to nonpregnant controls, there were no significant differences in the gastric emptying times of women in the three trimesters of pregnancy and of mothers from 18 h after delivery onwards. Gastric emptying was significantly delayed in mothers within 2 h after delivery (p < 0.01); median (range) values of peak paracetamol concentration, time to reach the peak and the area under the paracetamol concentration-time curve for this group were 12.5 (0.2-30.5) mg.l-1, 120 (30-120) min and 3.8 (0.1-16.6) mg.l-1 x h respectively, and 20.8 (8.6-64.5) mg.l-1, 40 (10-120) min and 13.5 (5.5-28.8) mg.l-1 x h respectively, for the nonpregnant control group (p < 0.01). Repeated measurements of gastric emptying in these women on the second postpartum day showed no significant delay.

Acetaminophen↗
PubMed1993

A technique of awake fibreoptic intubation. Experience in patients with cervical spine disease.

We report our experience of 58 patients undergoing awake fibreoptic intubation for cervical spine surgery. Topical anaesthesia was administered using a 'spray as you go' technique. The tracheas of 57 patients were intubated successfully. The mean time from starting topical anaesthesia to intubation was 16.1 min (SEM 1.0). The procedure was associated with cardiovascular stability, a low incidence of severe cough and had a high patient acceptance. There was a low failure rate amongst trainees. The minimum mean arterial oxygen saturation was 92.9% (SEM 1.1). There was no relationship between the time taken to intubation and the episodes of desaturation or the grade of laryngeal visibility at direct laryngoscopy. This method of producing topical anaesthesia for awake fibreoptic intubation is recommended.

Adolescent↗
PubMed1993

Identification and regional localization of a highly polymorphic dinucleotide repeat D11S614 to the interval in 11q23.3 flanked by recurrent translocation breakpoints.

A highly informative dinucleotide repeat polymorphism has been identified at the D11S614 locus on chromosome 11q23. Ten different alleles have been observed at this locus, and the heterozygosity frequency is approximately 85%. Physical localization of this marker in a panel of somatic cell hybrids containing chromosome 11 translocations showed that it maps to 11q23.3, within the interval between the recurrent t(4;11) leukaemia breakpoint and the t(11;22) Ewing's sarcoma breakpoint. This physical mapping data is consistent with the genetic mapping which indicates tight linkage to other markers in the q23.3 region including PBGD, CD3D and D11S29. Regional localization of highly informative markers such as D11S614 will facilitate integration of the genetic and physical maps.

Alleles↗
PubMed1993

Growth and cholesterol oxidation by Mycobacterium species in Tween 80 medium.

Mycobacterium strain DP was isolated from marine coastal sediment and tested for its ability to oxidize cholesterol in Tween 80-cholesterol (2.59 mM) medium. Strain DP degraded cholesterol to 4-cholesten-3-one (cholestenone), 4-androsten-3,17-dione (AD), 1,4-androstadien-3,17-dione (ADD), testosterone, and 1-dehydrotestosterone (DHT). Cholesterol disappeared in about 4 days. Cholestenone, AD, testosterone, and DHT accumulations were transient with peak concentrations of 300, 600, 30 to 40, and 21 microM. ADD production peaked after 6 days with a concentration of 1,100 microM. Peak ADD concentrations and production rates compared well with those reported for strain NRRL B3683 on cyclodextrin medium. Tween 80 medium was superior to finely dispersed cholesterol particles for both strains. In comparison, NRRL B3683 (patented for its ability to accumulate AD and ADD) on Tween 80 medium transiently accumulated more AD (approximately 1,000 microM) than did strain DP, but ADD accumulations (200 microM) were significantly lower than those for strain DP. Strain DP could be adapted to grow on ADD, which was initially inhibitory at 3.25 mM. ADD-adapted strain DP cultures produced approximately four times as much DHT from ADD than unadapted cultures did from cholesterol, showing that additional manipulation might enhance testosterone production. We believe that ADD toxicity might account for the low ADD accumulations by NRRL B3683 in Tween 80 medium.

Androstadienes↗
PubMed1993

Differential regulation of the human immunodeficiency virus type 2 enhancer in monocytes at various stages of differentiation.

We have demonstrated that stimulation of the human immunodeficiency virus type 2 (HIV-2) enhancer in T cells is dependent upon at least four cis-acting elements, including two purine-rich binding sites, PuB1 and PuB2, which are capable of binding members of the ets family of proto-oncogenes, the pets (peri-ets) site, which lies just upstream of the PuB2 site, and a single kappa B site (D. M. Markovitz, M. Smith, J. M. Hilfinger, M. C. Hannibal, B. Petryniak, and G. J. Nabel, J. Virol. 66:5479-5484, 1992). In this study, we examined the regulation of the HIV-2 enhancer in cells of monocytic lineage. We found that in immature monocytic cell lines, the HIV-2 enhancer is markedly induced by phorbol esters and that all four cis-acting elements are required for activation. In mature monocytic cells, constitutive activity is high, with only modest stimulation following phorbol ester treatment. Mutation of any of the four cis-acting elements resulted in greatly reduced basal expression in mature monocytes. This is in contrast to HIV-1, in which developmentally controlled expression of the enhancer in monocytes is mediated largely through the kappa B sites alone [G. E. Griffin, K. Leung, T. M. Folks, S. Kunkel, and G. J. Nabel, Nature (London) 339:70-73, 1989]. Further, we demonstrated that although both Elf-1, an ets family member with significant similarity to the drosophila developmental regulatory protein E74, and Pu.1, a monocyte- and B-cell-specific member of the ets family, bind the purine-rich enhancer region, Elf-1 is the protein which binds predominantly in vivo. A nuclear factor(s) which binds the pets site, an element which has been described only in HIV-2, was detected in extracts of all of the monocytic cells tested. These findings indicate that the mechanism by which cellular factors regulate HIV-2 enhancer function in monocytic cells differs significantly from that of HIV-1 and may offer a partial explanation for the differences in the biological and clinical characteristics of the two viruses.

Base Sequence↗
PubMed1993

Mutational and functional analysis of dominant SPT2 (SIN1) suppressor alleles in Saccharomyces cerevisiae.

The Saccharomyces cerevisiae SPT2 gene was identified by genetic screens for mutations which are suppressors of Ty and delta insertional mutations at the HIS4 locus. The ability of spt2 mutations to suppress the transcriptional interference caused by the delta promoter insertion his-4-912 delta correlates with an increase in wild-type HIS4 mRNA levels. The SPT2 gene is identical to SIN1, which codes for a factor genetically defined as a negative regulator of HO transcription. Mutations in SPT2/SIN1 suppress the effects of trans-acting mutations in SWI genes and of partial deletions in the C-terminal domain of the largest subunit of RNA polymerase II. Nuclear localization and protein sequence similarities suggested that the SPT2/SIN1 protein may be related to the nonhistone chromosomal protein HMG1. To assess the significance of this structural similarity and identify domains of SPT2 functionally important in the regulation of his4-912 delta, we have studied recessive and dominant spt2 mutations created by in vitro mutagenesis. We show here that several alleles carrying C-terminal deletions as well as point mutations in the C-terminal domain of the SPT2 protein exhibit a dominant suppressor phenotype. C-terminal basic residues necessary for wild-type SPT2 protein function which are absent from HMG1 have been identified. The competence of these mutant SPT2 proteins to interfere with the maintenance of the His- (Spt+) phenotype of a his4-912 delta SPT2+ strain is lost by deletion of internal HMG1-like sequences and is sensitive to the wild-type SPT2+ gene dosage. Using cross-reacting antipeptide polyclonal antibodies, we demonstrate that the intracellular level of the wild-type SPT2 protein is not affected in presence of dominant mutations and furthermore that the reversion of the dominance by internal deletion of HMG1-like sequences is not mediated by altered production or stability of the mutant polypeptides. Our results suggest that the products of dominant alleles directly compete with the wild-type protein. On the basis of primary sequence similarities, we propose that an HMG-box-like motif is required for SPT2 function in vivo and that this motif also is necessary for the dominant suppressor phenotype exhibited by some mutant SPT2 alleles.

Alleles↗