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Biomedical subjects

J A Sherman

Publications and source records attributed to J A Sherman.

At least 19 recordsLinked to original sources
PubMed2002

FDG-PET. A possible prognostic factor in head and neck cancer.

Previous studies have shown that high uptake of (18)F-fluoro-2-deoxy-glucose in head and neck cancer, as determined by the standardized uptake value on positron emission tomography scan, was associated with poor survival. The aim of this study was to confirm the association and to establish whether a high standardized uptake value had prognostic significance. Seventy-three consecutive patients with newly diagnosed squamous cell carcinoma of the head and neck underwent a positron emission tomography study before treatment. Age, gender, performance status tumour grade, stage, maximal tumour diameter and standardized uptake value were analyzed for their possible association with survival. The median standardized uptake value for all primary tumours was 7.16 (90% range 2.30 to 18.60). In univariate survival analysis the cumulative survival was decreased as the stage, tumour diameter and standardized uptake value increased. An standardized uptake value of 10 was taken as a cut-off for high and low uptake tumours. When these two groups were compared, an standardized uptake value >10 predicted for significantly worse outcome (P=0.003). Multivariate analysis demonstrated that an standardized uptake value >10 provided prognostic information independent of the tumour stage and diameter (P=0.002). We conclude that high FDG uptake (standardized uptake value>10) on positron emission tomography is an important marker for poor outcome in primary squamous cell carcinoma of the head and neck. Standardized uptake value may be useful in distinguishing those tumours with a more aggressive biological nature and hence identifying patients that require intensive treatment protocols including hyperfractionated radiotherapy and/or chemotherapy.

Carcinoma, Squamous Cell↗
PubMed2001

A rapidly expanding lesion in the neck: unusual presentation of Castleman's disease.

We report a painless but rapidly enlarging 9 cm x 4 cm lobulated hard neck mass. CT scanning suggested lymphoid tissue that was not confirmed by cytopathology. Histopathological analysis of the excision specimen detected Castleman's disease, extending to the resection margin. Postoperative radiotherapy was administered. The patient remains disease-free after 44 months.

Adult↗
PubMed2000

Lack of correlation between water hardness and salivary calculi in England.

Our aim was to test the hypothesis that residents of hard water areas are at increased risk of developing salivary calculi. The evidence based on figures from the Hospital Episode Statistics database for the years 1991 to 1994, suggests that there is no such association. For example, in the South West Water area (soft water) the incidence was 28.92/million/year compared with Yorkshire (hard water) 31.64/million/year. The correlation coefficient shows that water hardness is not significantly associated with either the incidence of salivary calculi (r = 0.02, P = 0.9) or that of sialadenitis (n = 2.4, P = 0.4). The lack of association holds for both men and women independently. However, the two conditions have similar patterns of incidence (r = 0.5, P = 0.05), suggesting some common but unknown similarity in aetiology.

Calcium↗
PubMed2000

Management of severe postnasal haemorrhage: the Kingsley splint revisited.

Postnasal haemorrhage accompanying severe craniofacial trauma may have catastrophic consequences if not arrested promptly. The airway has usually been secured and the cervical spine stabilized, but apart from fluid replacement, other attempts to control haemorrhage in the resuscitation room of the accident and emergency department may be to no avail. We wish to draw attention to a simple device that was introduced over 100 years ago and which may rapidly aid haemostasis and prevent the onset of hypovolaemic shock.

Adult↗
PubMed2000

Ultracision: the harmonic scalpel and its possible uses in maxillofacial surgery.

We report on the potential uses and benefits of a new development in incisive technology. The harmonic scalpel uses high-frequency mechanical energy to offer the surgeon controlled and precise incision and haemostasis. Vessels up to 2 mm in diameter may be sealed by coaptation with the blade before division. No special training or precautions are required before using this self-cleaning device. It produces considerably less smoke or smell than either diathermy or laser, which reduces the need for instrument exchanges and smoke evacuation. We think that it will be useful for tongue resections and possibly for neck dissections.

Equipment Design↗
PubMed2000

Effects of deprivation on engagement in preferred activities by persons with developmental disabilities.

This study examined the effects of deprivation on engagement in activities for 3 adult men with developmental disabilities. First, an assessment was conducted to identify a high- and a low-preference activity for each participant. Second, the high-preference activity was made available following three amounts of deprivation of the activity (15 min, 2 hr, and 1 to 4 days); the low-preference activity was made available following the schedule of deprivation that produced the highest level of engagement by each participant in the high-preference activity. The results were that 1 to 4 days of deprivation produced the highest average amounts of engagement in the high-preference activity for each participant; this amount of deprivation did not produce high engagement in the low-preference activities. Third, the deprivation procedures and results were replicated when high-preference activities were presented by teachers during the participants' daily activities when their engagement had been quite low.

Adult↗
PubMed1998

Reducing disruptive behavior of a group-home resident with autism and mental retardation.

A treatment package consisting of a DRO procedure, token fines, and prompted relaxation was used to reduce the agitated-disruptive behavior of a person with autism and mental retardation living in a community group home. The agitated-disruptive behaviors (cursing, hitting, kicking, throwing objects, and verbal threats) were measured during three different activities in a group home. The baseline rates of the agitated-disruptive behavior during one of these activities was relatively low, during another was moderate, and during the third was high. DRO procedures were partially implemented by a peer with Down syndrome and mental retardation during a portion of the study. Effects of the DRO procedures were as follows: During each activity an initial reduction of agitated-disruptive behavior was dependent on choosing an appropriate DRO interval, with shorter DRO intervals required during activities in which the baseline rates of the agitated-disruptive behavior were higher. Once shorter DRO intervals had been used to reduce agitated-disruptive behavior, longer DRO intervals were effective in maintaining those reductions. Reductions were maintained for up to 6 months.

Adult↗
PubMed1998

The radiosurgical approach to biopsy.

The use of radiosurgery to remove a lesion for biopsy facilitates the time and effectiveness of the procedure. The hemostatic properties of the radiowave affords the practitioner a better field of visibility, enabling the procedure to be done in a safe, timely fashion.

Biopsy↗
PubMed1997

Expression of retinoic acid receptors in normal, dysplastic and malignant oral epithelia.

Chemoprevention with retinoic acid (RA) derivatives may reduce the incidence of transformation of potentially malignant oral lesions, and help prevent development of second primary tumours in the upper aerodigestive tract. At present, little is known about the mechanisms by which RA derivatives modify cell proliferation and differentiation. RA interacts with two classes of nuclear receptors: the retinoic acid receptors (RARs) and retinoid X receptors (RXRs). We have used immunohistology to localise these receptors on normal epidermis and oral mucosa. The distribution of RAR and RXR suggests that RA may exert complex growth regulatory effects on oral mucosa. Increased levels of RAR and RXR, together with alterations in the patterns of expression of these receptors, were seen when dysplastic and malignant epithelia were compared to normal oral mucosa. These findings suggest that expression of RAR and RXR receptors is modulated in epithelia showing altered growth regulation.

Carcinoma, Squamous Cell↗
PubMed1996

Regulation of the mRNA-binding protein AUF1 by activation of the beta-adrenergic receptor signal transduction pathway.

In both cell culture based model systems and in the failing human heart, beta-adrenergic receptors ( beta-AR) undergo agonist-mediated down-regulation. This decrease correlates closely with down-regulation of its mRNA, an effect regulated in part by changes in mRNA stability. Regulation of mRNA stability has been associated with mRNA-binding proteins that recognize A + U-rich elements within the 3'-untranslated regions of many mRNAs encoding proto-oncogene and cytokine mRNAs. We demonstrate here that the mRNA-binding protein, AUF1, is present in both human heart and in hamster DDT1-MF2 smooth muscle cells and that its abundance is regulated by beta-AR agonist stimulation. In human heart, AUF1 mRNA and protein was significantly increased in individuals with myocardial failure, a condition associated with increases in the beta-adrenergic receptor agonist norepinephrine. In the same hearts, there was a significant decrease (approximately 50%) in the abundance of beta1-AR mRNA and protein. In DDT1-MF2 cells, where agonist-mediated destabilization of beta2-AR mRNA was first described, exposure to beta-AR agonist resulted in a significant increase in AUF1 mRNA and protein (approximately 100%). Conversely, agonist exposure significantly decreased (approximately 40%) beta2-adrenergic receptor mRNA abundance. Last, we demonstrate that AUF1 can be immunoprecipitated from polysome-derived proteins following UV cross-linking to the 3'-untranslated region of the human beta1-AR mRNA and that purified, recombinant p37AUF1 protein also binds to beta1-AR 3'-untranslated region mRNA.

Base Sequence↗
PubMed1995

The traY gene product and integration host factor stimulate Escherichia coli DNA helicase I-catalyzed nicking at the F plasmid oriT.

F plasmid conjugative transfer is initiated by the introduction of a site- and strand-specific nick within the plasmid origin of transfer (oriT). Genetic studies have shown nick formation to be dependent on both the traI and traY genes. However, highly purified TraIp, the traI gene product, nicks oriT in a site- and strand-specific manner in the absence of the traY gene product (TraYp) in vitro (Matson, S.W., and Morton, B.S. (1991) J. Biol. Chem. 266, 16232-16237). Analysis of the oriT region has revealed binding sites for TraYp and the host protein integration host factor (IHF). To explore possible interactions occurring at oriT, highly purified TraIp, TraYp, and IHF were incubated with a supercoiled oriT-containing DNA substrate. A marked enhancement of the nicking reaction catalyzed by TraIp was observed in a reaction that required both TraYp and IHF. In addition, TraIp was able to nick a linear oriT-containing double-stranded DNA substrate when IHF and TraYp were present in the reaction; such a substrate is not nicked by TraIp alone. Individual protein concentration requirements for the supercoiled and linear nicking reactions were similar, and the reactions occurred at equal velocity, suggesting that they are biochemically identical. Concentrations of TraYp and IHF that yield half-maximal activity in the nicking assays compare well with the reported KD values for the IHF and TraYp binding sites in oriT. These data, coupled with data presented in the accompanying report, suggest that TraYp and IHF bind independent of one another, forming a nucleo-protein complex with oriT that can be recognized and nicked by TraIp.

Bacterial Proteins↗
PubMed1995

Alternative voices.

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Complementary Therapies↗
PubMed1994

Escherichia coli DNA helicase I catalyzes a sequence-specific cleavage/ligation reaction at the F plasmid origin of transfer.

Recent studies have shown that the Escherichia coli F plasmid-encoded traI gene product (TraIp), also known as DNA helicase I, catalyzes the formation of the site- and strand-specific nick that initiates F plasmid DNA transfer. Scission of the phosphodiester bond at the nic site within the origin of transfer (oriT) is accompanied by the covalent attachment of TraIp to the 5'-phosphate of the nicked DNA strand. This mechanism suggests that TraIp may also be capable of catalyzing a DNA ligation reaction using the energy stored in the protein-DNA intermediate. To test this possibility, an in vitro assay was designed that utilized short single-stranded DNA oligonucleotides of different lengths derived from the region within oriT that spanned the nic site. Purified TraIp was capable of efficiently cleaving single-stranded DNA that contained a nic site, and upon cleavage, the protein became covalently linked to the 5'-end of the nic site. When TraIp was incubated with two oligonucleotides of different length that contained the nic site, there was formation of novel recombinant products resulting from a TraIp-catalyzed cleavage/ligation reaction. Furthermore, the cleavage and ligation reactions were both sequence-specific. These data suggest that TraIp plays an important role in the initiation and termination of conjugative DNA transfer.

Base Sequence↗