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J D Bennett

Publications and source records attributed to J D Bennett.

At least 37 records · Page 2Linked to original sources
PubMed1996

E2F binding is required but not sufficient for repression of B-myb transcription in quiescent fibroblasts.

We have previously shown in mouse NIH3T3 fibroblasts that transcription of the B-myb gene, which encodes a transcription factor required for S phase entry, is repressed through a promoter E2F site in G0/early G1. Transcription repression at this stage of the cell cycle was correlated with binding of a specific p107/E2F complex to this site. We report here, however, that transfection of cells with the known components of this complex, p107, E2F-4 and DP-1, did not repress the B-myb promoter in cycling NIH3T3 cells, although p107 inhibited transcription transactivation by E2F-4/DP-1. To establish definitively the contribution of E2F to repression, the effects of further mutations within and surrounding the E2F site were examined. It was evident that E2F binding and repression were closely correlated, lending greater weight to the contention that E2F itself is implicated in this activity. These studies also identified a closely linked site, designated the downstream repression site (DRS), which was not required for E2F binding or transactivation but which was necessary for repression. These findings indicated that E2F-dependent repression and activation are independently regulated phenomena and suggest that repression involves additional interactions determined by the promoter context.

3T3 Cells↗
PubMed1996

Characterization of Newcastle disease virus vaccines by biological properties and sequence analysis of the hemagglutinin-neuraminidase protein gene.

Six commercially available monovalent Newcastle disease virus (NDV) live-vaccines were examined for their biological and genomic stability in comparison to their stated parent virus. Thermostability of the hemagglutinin at 56 degrees C for 5 min was consistently observed among the majority of the vaccine viruses. One exception was a recently developed NDV vaccine isolated from turkeys that had a thermostability of 15 min. Neuraminidase activity, as measured by elution rate of agglutinated red blood cells, varied among vaccine viruses and correlated with that of the parent isolate. Virulence as measured by intracerebral pathogenicity index ranged from 0 to 0.39 among NDV vaccine-type viruses, well within the range of avirulent lentogens. Sequence of the fusion protein cleavage site from all the NDV vaccine isolates examined was consistent with that for lentogens. The entire hemagglutinin-neuraminidase gene sequence was 98% similar among all the NDV vaccine viruses examined and phylogenetic classification of commercial vaccine types correlated with their respective parent virus. Consequently, the commercially produced NDV vaccines reported here appear relatively stable when mass produced in avian embryonated eggs.

Amino Acid Sequence↗
PubMed1996

High tracheostomy and other errors--revisited.

Timely cricothyrotomy may be life-saving, but it is not without its complications. Together with tracheostomy performed too high, there are high incidences of stenosis and voice changes afterwards-often neglected because the patient has so many other problems. Jackson warned of these problems over 70 years ago-his message is still relevant.

Cricoid Cartilage↗
PubMed1996

Cricothyrotomy: the anatomical basis.

Cricothyrotomy is an important surgical technique. We studied the anatomy of the cricothyroid membrane in 13 adult fresh cadavers preserved at 45 degrees F and examined at 70 degrees F. The working dimensions of the cricothyroid membrane were measured for emergency cricothyrotomy and placement of an airway tube. The vertical measurement ranged from 8-19 mm (mean 13.69 +/- SE 0.96 mm) and the maximal width between the cricothyroid muscles ranged between 9 and 19 mm (mean 12.38 +/- SE 0.91 mm). The distance from the upper limit of the cricothyroid membrane to the vocal cord was 9.78 +/- SE 0.52 mm. Eight subjects (62%) had an artery delineated transversely across the cricothyroid membrane. Two subjects (15%) had sclerosis of the cricothyroid joint. To promote the safe use of cricothyrotomy, the anatomy of the cricothyroid membrane is defined and clinically relevant data are presented.

Cadaver↗
PubMed1995

Cell-cycle regulation of human B-myb transcription.

We demonstrate here that activity of the human B-myb promoter is regulated during the cell cycle by the E2 transcription factor (E2F). Comparison of the human B-myb promoter sequence with that of its murine counterpart revealed an evolutionally conserved sequence that contains an E2F-binding site. In transiently transfected murine NIH3T3 and human HaCaT cells, luciferase (Luc) reporter activity directed by the human B-myb promoter was found to increase significantly in late G1/S phase of the cell cycle. Mutation of the promoter E2F site resulted in significantly greater Luc activity in NIH3T3 and HaCaT cells made quiescent by serum deprivation, indicating that E2F repressed transcription of this gene during G0. Analysis of E2F DNA-binding activity in G0 HaCaT cells revealed a distinct complex that apparently contained neither the retinoblastoma gene protein, pRb, nor the related p107 protein. De-repression of transcription in S phase was accompanied by the disappearance of this G0 E2F complex and the appearance of a distinct complex containing p107. In addition, complexes containing pRb were detected at both stages of the cell cycle.

3T3 Cells↗
PubMed1995

Longitudinal computed tomography of the scaphoid: a new technique.

Computed tomography is increasingly utilized for the evaluation of scaphoid fracture, nonunion, and deformity. We have developed a new technique of positioning patients while performing longitudinal computed tomography of the scaphoid. With the wrist positioned in radial deviation and neutral flexion, greater patient comfort is provided and immobilization of the wrist is not required. A reproducible image can be obtained with attention to the alignment of the scanning plane to the longitudinal axis of the scaphoid on the scout image, and verified with the "target sign". High resolution images, which clearly demonstrate the abnormalities of the scaphoid, can be produced even if the patient has a cast on the wrist or if there is hardware in situ.

Carpal Bones↗
PubMed1995

The Burn Wheel: a practical guide to fluid resuscitation.

During preparation for mass casualties of burn victims in the Gulf War (1990-91), a 'Battlefield Burns Table' was devised to allow rapid calculation of fluid replacement. By standardizing weights and using only Hartmann's Solution BP, a regimen could be prescribed by the non-specialist without resort to mathematical calculations. By means of a revolving disc, this has now been refined for use in a civilian setting where expert burn advice may not be immediately available.

Burns↗
PubMed1995

Characterization of Newcastle disease virus isolates by reverse transcription PCR coupled to direct nucleotide sequencing and development of sequence database for pathotype prediction and molecular epidemiological analysis.

Degenerate oligonucleotide primers were synthesized to amplify nucleotide sequences from portions of the fusion protein and matrix protein genes of Newcastle disease virus (NDV) genomic RNA that could be used diagnostically. These primers were used in a single-tube reverse transcription PCR of NDV genomic RNA coupled to direct nucleotide sequencing of the amplified product to characterize more than 30 NDV isolates. In agreement with previous reports, differences in the fusion protein cleavage sequence that correlated genotypically with virulence among various NDV pathotypes were detected. By using sequences generated from the matrix protein gene coding for the nuclear localization signal, lentogenic viruses were again grouped phylogenetically separate from other pathotypes. These techniques were applied to compare neurotropic velogenic viruses isolated from an outbreak of Newcastle disease in cormorants and turkeys. Cormorant NDV isolates and an NDV isolate from an infected turkey flock in North Dakota had the fusion protein cleavage sequence 109SRGRRQKRFVG119. The R-for-G substitution at position 110 may be unique for the cormorant-type isolates. Although the amino acid sequences from the fusion protein cleavage site were identical, nucleotide sequence data correlate the outbreak in turkeys to a cormorant virus isolate from Minnesota and not to a cormorant virus isolate from Michigan. On the basis of sequence information, the cormorant isolates are virulent viruses related to isolates of psittacine origin, possibly genotypically distinct from other velogenic NDV isolates. These techniques can be used reliably for Newcastle disease epidemiology and for prediction of pathotypes of NDV isolates without traditional live-bird inoculations.

Amino Acid Sequence↗
PubMed1995

Emergency drug therapy. Drugs and routes of administration.

Management of medical emergencies requires a thorough knowledge of specific medications and their routes of administration. This article briefly discusses the medications that should be included in a basic emergency cart and routes in which to administer them.

Dental Care↗
PubMed1995

Insertion of subcutaneous central venous infusion ports by interventional radiologists.

OBJECTIVE: To evaluate the safety and efficacy of radiologic implantation of subcutaneous chest wall infusion ports by interventional radiologists, rather than surgeons, at a tertiary care hospital. PATIENTS AND METHODS: Review of radiology department and hospital records for 38 patients (ranging in age from 21 to 70 years), in whom a total of 41 infusion ports had been inserted between January 1992 and January 1994. RESULTS: All of the implantations were successful. The only acute complication was pneumothorax, which occurred in one patient; insertion of a chest tube was required. There were no cases of hematoma, air embolism or arterial puncture. The infusion ports remained in place for 12 to 492 days (for a mean of 167 catheter days per patient). Total follow-up was 6863 catheter days. The overall incidence of catheter-related infection was 1.3/1000 catheter days; removal of the port was necessary in eight cases. Occlusion of the catheter occurred in two cases, one after 21 days and the other after 308 days. Neither migration nor fracture of the catheter tip occurred. Overall, removal of the port was required because of catheter-related complications in nine cases (22%); in these cases the port was removed after a mean of 181 (range 21 to 420) days. CONCLUSIONS: Because the success and complication rates observed here were similar to those reported for insertions performed in the operating room, the authors conclude that central venous infusion ports can be safely and efficiently implanted by interventional radiologists.

Adult↗
PubMed1994

Primary amyloidosis of the larynx.

The history, examination and operative findings of primary amyloidosis of the larynx are very suggestive of carcinoma, indicating the need for careful histological examination. Staining with Congo red shows a characteristic birefringence. Systemic amyloidosis may be present.

Aged↗