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Biomedical subjects

D L Jones

Publications and source records attributed to D L Jones.

At least 91 records · Page 5Linked to original sources
PubMed1995

Calpain immunoreactivity in baker's yeast, lobster and wheat germ.

The immunoreactivities of mu-calpain and m-calpain in wheat germ, lobster tail meat, and three strains of yeast were analysed by Western blotting using mouse anti-mu-calpain and rabbit anti-m-calpain. The occurrence of multiple bands may be due to either autolyses or the interactions between the calpains and other molecules. The results suggest not only a ubiquitous distribution and a universal regulatory role of calpain in eukaryotes, but also an evolutional conservation of calpain.

Animals↗
PubMed1995

Immunoreactivity of S-100 protein in baker's yeast, lobster, and wheat germ.

The immunoreactivity of S-100 proteins in three strains of yeast and wheat germ was observed by analysis of Western blotting with rabbit anti-bovine S-100. A high level of activity was exhibited in wheat germ, whereas a very low level was found in lobster tail meat. The occurrence of multiple bands may be due to the interactions between S-100A and S-100B and/or other molecules. The highly evolutionally conserved S-100 may play an important role in cellular signal transduction and cell growth in yeast and wheat germ.

Animals↗
PubMed1995

Developing an outcomes infrastructure for nursing. The Outcomes Taskforce.

An infrastructure to support the evaluation of patient care sensitive to the intervention of nursing personnel is being developed within a major health maintenance organization. In addition to traditional administrative measures of care, the database infrastructure will include measures of the patient's functional status, knowledge and engagement in care and psychosocial well-being. These measures are believed to be particularly sensitive to the independent intervention of the nurse. Reported here are the structures in place to monitor and support the reliability and validity of the administrative data elements; algorithm elements created to account for missing data; the model for the first generation of successful practice reports and the results of a study establishing the content validity of the clinical data elements.

Costs and Cost Analysis↗
PubMed1995

Immunoreactivities of PKC delta, eta, zeta in baker's yeast, lobster and wheat germ.

Varied immunoreactive bands of protein kinase C delta (PKC delta), PKC eta, and PKC zeta were detected in crude extracts of wheat germ, lobster tail meat, and three strains of baker's yeast by analysis of Western blots. Protease-deficient and Fleischmann's Active Dry yeasts exhibited immunoreactivity of PKC delta, whereas wheat germ and Fleischmann's RapidRise yeast displayed immunoreactivities of both PKC delta and PKC zeta. Lobster tail meat showed immunoreactivities of PKC eta and PKC zeta. These positive and negative immunoreactivities reflected evolutionary conservation and divergence, respectively, of these PKC isozymes in eukaryotes.

Animals↗
PubMed1994

Time and frequency domain analyses of heart rate variability during orthostatic stress in patients with neurally mediated syncope.

The role of autonomic balance during upright tilt in patients with neurally mediated syncope is unclear. To assess the characteristics of autonomic tone during orthostatic stress, 15 patients (mean age 32 years) with recurrent episodes of syncope (> or = 2) and a positive response to a 30-minute 60 degrees upright tilt were compared with the following control groups: (1) 15 patients (mean age 33.5 years) with > or = 2 episodes of recurrent syncope and a negative tilt response, and (2) 15 age- and sex-matched healthy volunteers (mean age 34 years) with no previous history of presyncope or syncope. Time domain measurements assessed were mean RR interval, standard deviation of normal RR intervals, and percentage of normal consecutive RR intervals differing by > 50 ms. Frequency domain measurements of the low-frequency (LF) and high-frequency (HF) bands were obtained, and the LF/HF ratio was also calculated. All variables were calculated in the supine position and during the first 5 minutes of upright tilt. No significant difference was observed in the time and frequency domain variables in the supine position between control groups with a negative head-up tilt response and the group with a positive response. The percentage of normal consecutive RR intervals differing by > 50 ms during the first 5 minutes of head-up tilt was significantly higher in the group with positive tilt tests than in the controls (25 +/- 12% vs 7 +/- 4%, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Interhemispheric control of manual motor activity.

The interhemispheric control of manual motor processes is reviewed, focusing on the clinical evidence from patients with commissurotomies and with agenesis of the corpus callosum. There is little evidence for a role of the corpus callosum in transferring explicit motor commands. Rather, the corpus callosum seems important for transferring lateralised information (such as verbal or visuospatial activity) of the pre-motor variety. Also, the corpus callosum may become very significant when movement begins: there appears to be a transcallosal passage of corollary motor signals and feedback sensory signals that are used to control asychronous bimanual movements and to inhibit the opposite hemisphere from interfering when a simple unimanual movement is required.

Attention↗
PubMed1994

Pronounced increase in defibrillation threshold associated with pacing-induced cardiomyopathy in the dog.

Progressive changes in myopathology after implantation of an automatic defibrillator could compromise device efficacy. The influence of heart failure development on the defibrillation threshold was evaluated by means of a rapid ventricular pacing model of heart failure in dogs. After transvenous pacemaker lead implantation, adult mongrel dogs were randomly assigned to either the control (n = 7) or rapidly paced group (240 beats/min, n = 6). Seventeen days after implantation, triplicate determinations of the defibrillation threshold were made with three epicardial electrodes. The average defibrillation threshold was four times higher in the rapidly paced group, 13.3 +/- 2.0 joules (mean +/- SEM), than in the control group, 3.3 +/- 0.7 joules (p < 0.01), and was significantly correlated with ventricular weight (r = 0.70, p < 0.01). Both defibrillation threshold energy per gram of ventricle and ventricular weight corrected for body weight were significantly higher in rapidly paced dogs compared with control dogs. It was concluded that myocardial hypertrophy and heart failure may profoundly increase defibrillation energy requirements.

Animals↗
PubMed1994

Long-term neurosensory deficits associated with bilateral sagittal split osteotomy versus inverted 'L' osteotomy.

Ten cases of bilateral sagittal split osteotomies and nine cases of intraoral inverted "L" osteotomies were examined for postsurgical neurosensory disturbances. Neurosensory tests included brushstroke direction, temperature, and light touch. All patients completed a short questionnaire that elicited subjective information with respect to neurosensory symptoms and their perception of the surgical results. Analysis of the data obtained from the tests of neurosensory disturbances revealed no significant differences between the two surgical groups. The variance of the scores on each of the neurosensory disturbances measures was significantly greater (p < 0.01) for the BSSO group. Analysis of the data from the questionnaire indicated that BSSO patients were significantly more likely to report postsurgical hypoesthesia of the lip (p < 0.01) and chin (p < 0.001) than the intraoral inverted "L" osteotomies group. None of the intraoral inverted "L" osteotomies group reported a moderate level of hypoesthesia of the lower lip or the chin, 66% reported no lip hypoesthesia, and 89% indicated no hypoesthesia in the chin area. In contrast, 33% of the BSSO group reported moderate hypoesthesia of the lip, and 22% reported moderate hypoesthesia of the chin. All patients in both groups expressed satisfaction with the surgical outcome, and had not changed their opinion on having the surgery. Although the tests of neurosensory disturbances revealed some disparity between the groups, the differences were not statistically significant. However, the subjective impressions of the groups differed regarding postsurgical neurosensory disturbances; the BSSO group related significantly more symptoms.

Adult↗
PubMed1994

Hard and soft tissue predictability with advancement genioplasties.

Variability in soft tissue response to genial advancements has been noted in the literature. Although many factors may influence the results, little attention has been paid to bony vertical movement in conjunction with the bony horizontal movement of the chin and its effect on horizontal soft tissue movement. Eighteen patients who underwent isolated genial advancements were studied preoperatively and for at least 6 months after surgery. It was noted that the further the chin was advanced the less the soft tissue followed the advancement. In addition, vertical movement of the chin greatly influenced the overall result. The more the bony chin is shortened, the thicker the soft tissue chin becomes; the reverse is true when it is lengthened. Finally, horizontal resorption/stability appears to be influenced by the amount of dissection rather than the amount of advancement.

Cephalometry↗
PubMed1994

Combination biphasic waveform plus sequential pulse defibrillation improves defibrillation efficacy of a nonthoracotomy lead system.

OBJECTIVES: We hypothesized that combining biphasic waveform and sequential pulse defibrillation techniques would lower the defibrillation threshold of a nonthoracotomy lead system in humans below that obtained with biphasic or sequential pulse defibrillation alone. BACKGROUND: Previous studies have shown that sequential pulse monophasic shocks and biphasic waveform shocks are more effective than single monophasic shocks for ventricular defibrillation. METHODS: Thirteen patients aged 48 to 71 years undergoing nonthoracotomy defibrillation lead testing participated in the study. Transvenous electrodes were positioned in the right ventricular apex, superior vena cava and coronary sinus. A cutaneous patch electrode was placed on the left chest wall. All electrodes were connected to an external defibrillator. In random order, defibrillation threshold measurements were made for biphasic defibrillation alone, sequential defibrillation alone and combined biphasic plus sequential defibrillation. RESULTS: The mean defibrillation threshold-delivered energy was 18.0 +/- 11.9 J for biphasic defibrillation and 16.3 +/- 9.0 J for sequential defibrillation. Biphasic plus sequential defibrillation significantly reduced the threshold energy to 10.2 +/- 5.3 J (p < 0.001). Threshold peak voltage and current values showed corresponding reductions. The combined waveform resulted in a greater reduction in defibrillation threshold in patients with threshold energies > 18 J versus those with threshold values < or = 18 J for sequential (p = 0.001) or biphasic (p < 0.01) waveform alone. The nonthoracotomy lead implantation rate was improved from 62% with each of the single techniques (biphasic waveform or sequential pulse defibrillation) to 85% with the combined waveform. CONCLUSIONS: Adding biphasic waveform to sequential pulse defibrillation significantly reduced the defibrillation threshold compared with either technique alone, and nonthoracotomy lead system implantation can be enhanced by this combined technique.

Aged↗
PubMed1994

Time-frequency structure of the high-resolution ECG.

This study considers the problem of representing high-resolution ECG (HRECG) signals in the time-frequency plane using spectrotemporal mapping (STM). High-resolution ECG signal components overlap in both time and frequency. The central issue with STM techniques is whether sufficient time-frequency resolution exists to discriminate normal and abnormal QRS signals. The trade-off between signal resolution in time and in frequency must be made without a priori knowledge of the HRECG's time-frequency structure. A simulation experiment was performed to examine the time-frequency distribution of normal, abnormal low-level (late potentials), and bundle branch block components of the QRS. Results suggest that discrimination of these signals with STM is problematic. Signals and noise within the HRECG ensemble can, however, be easily distinguished. This observation forms the basis of a new optimally filtered ensemble averaging technique for signal-to-noise ratio enhancement.

Electrocardiography↗
PubMed1994

Allocation of attention to programming of movement sequences in Parkinson's disease.

The allocation of attention to the programming and execution of movement sequences was examined in Parkinson's disease (PD). The time taken to initiate and execute sequences of one, three, and five button taps was examined, while also varying the hand used (left or right) and the attentional resources that could be allocated to sequencing (using single- versus dual-task conditions). These results showed that performance anomalies in PD were most apparent with the preferred right hand under single-rather than dual-task conditions. Subjects suffering from PD may tend to divert attention from the right hand under single-task conditions, and perhaps with short sequences, as well as being less likely to prepare sequences of more than three movements in advance with that hand. These effects were unlikely to reflect asymmetric pathology. If the right hand of such subjects has in some respects now come to behave more like a "clumsy" left hand, this may reflect a deliberate strategic choice in an attempt to cope with a movement impairment.

Aged↗
PubMed1994

Bretylium decreases and verapamil increases defibrillation threshold in pigs.

BACKGROUND: Patients with ischemic heart disease may require antianginal and/or antiarrhythmic regimes. These patients may also be candidates for implantable defibrillators. The effects of antiarrhythmics, such as bretylium, or calcium antagonists, such as verapamil, nifedipine, or diltiazem on internal defibrillation efficacy have been inconsistent or are unknown. METHODS AND RESULTS: The effects of bretylium and verapamil on the energy requirements for ventricular defibrillation threshold (DFT) were determined in 92 open-chest anesthetized pigs. Triplicate DFTs were determined before and after intravenous administration of saline or one of four doses of verapamil, or saline or one of three doses of bretylium, in a balanced random order. Bretylium elicited a dose dependent reduction of DFT (F = 2.72 at 3 degrees and 36 degrees of freedom). DFT was significantly reduced with the highest dose of bretylium, (from 5.9 +/- 0.6 J to 4.7 +/- 0.6 J, mean +/- S.E.M.; P < 0.01). However, cardiac massage was sometimes needed at this dose due to low blood pressure immediately after defibrillation. In contrast, there was a positive correlation between DFT and serum verapamil concentration (r = 0.54, P < 0.001). The highest dose of verapamil significantly increased DFT (from 6.3 +/- 0.6 J to 8.2 +/- 1.1 J; P < 0.05), at a serum verapamil concentration of 86.6 +/- 6.8 ng/mL. CONCLUSIONS: These data indicate that bretylium decreases while verapamil increases the minimum energy requirement for internal defibrillation. Caution is warranted in patients who may be hemodynamically comprised and may be candidates for bretylium therapy or in patients who have marginal DFT value who might be candidates for verapamil therapy.

Animals↗
PubMed1994

Phosphorylation of endogenous substrates of yeast protein kinase C regulated by lipid-triton micelles.

In the DE-52 fraction 19 of the crude cytosolic extract of Saccharomyces cerevisiae, the 31-kDa endogenous substrate(s) of protein kinase C were detected by SDS-polyacrylamide gel electrophoresis and autoradiography. Phosphorylation of the substrate(s) depended on Ca2+, phosphatidylserine and diacylglycerol. It was also enhanced by phosphatidylinositol, phosphatidylethanolamine and phosphatidylglycerol (dioleoyl), but inhibited by arachidonic acid and sphingosine.

Arachidonic Acid↗
PubMed1994

The effect of stannous fluoride on dentinal hypersensitivity.

Many agents have shown varying degrees of effectiveness on pain resulting from exposed dentine. One which has shown some promising results is stannous fluoride (SnF2). The purpose of the following paper is twofold: to review and summarise the clinical literature pertaining to the relative effectiveness of solutions or gels containing SnF2 in controlling pain associated with dentinal hypersensitivity; and to statistically re-evaluate these studies in combination, in order to develop recommendations for the optimal use of SnF2 for hypersensitivity. Seven blinded clinical studies were identified and reviewed. Five of these compared 0.4 per cent SnF2 gel solution to an identical placebo. One compared a 0.4 per cent SnF2 gel solution and a 0.717 per cent F solution to an aqueous placebo. The final study compared a 0.717 per cent F solution to an aqueous placebo. Statistical power analysis and a combined meta-analysis were used to ensure adequate internal consistency and to contribute to an overall consensus of the efficacy across time. It was concluded that the 0.717 per cent F solution provides a virtually immediate and definable effect, which seems to continue for several months. This effect was present in all subjects used in the study. This solution was applied directly to the sensitive area for one minute and allowed to remain for 3-5 minutes. An additional one minute application was applied if needed. The effect of the 0.4 per cent SnF2 gel appears to be more gradual, perhaps involving a different mechanism of action. This solution requires approximately two to four weeks of continuous treatment to be effective. It was concluded that an effective strategy involving the use of stannous fluoride gel includes the application of the 0.717 per cent F solution in the office, effectively providing immediate relief. The patient would then use the 0.4 per cent SnF2 gel at home in order to achieve the long-term effect. In order to control episodic pain while the gel is developing its effect, a small amount of the 0.717 per cent F solution could be given to the patient for occasional symptomatic application.

Dentin Sensitivity↗
PubMed1994

Squamous cell carcinoma of the larynx and pharynx in horses.

Medical records were reviewed for 11 horses with squamous cell carcinoma of the larynx and/or pharynx. The average age at presentation was 15.3 years. No breed or sex predilection was present. At presentation, 6 of 11 horses were dyspneic and 4 horses had inspiratory stridor. Endoscopy was performed in all cases and was more useful in demonstrating a mass in the laryngopharyngeal region than laryngeal or guttural pouch radiography. Surgical excision was attempted in 3 horses and in 1 horse alleviated clinical signs for 4 months. Ten horses were euthanatized and 1 horse died. Results of this study indicated that laryngopharyngeal squamous cell carcinomas are difficult to surgically excise due to their location, size and invasiveness. Treatment is often not attempted because of the advanced state of the disease at the time of presentation.

Anesthesia, General↗