Effects of a gel containing 0.4 percent stannous fluoride on dentinal hypersensitivity.
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Adult↗
Biomedical subjects
D L Jones
Publications and source records attributed to D L Jones.
Pregnancy related to infertility diagnosis, number of attempts, and age in a program of in vitro fertilization.
Three hundred nineteen infertility patients who did not become pregnant with standard therapies presented to Norfolk for in vitro fertilization between January 1981 and December 1983. There were 560 laparoscopic cycles with 105 pregnancies. The pregnancy rate was 18.8% by cycle, 24.5% by transfer, and 33% by patient. The overall pregnancy rate was found to be independent of infertility diagnosis, age, and number of attempts.
Age Factors↗
Characterisation of the under-agarose method for quantifying migration of highly purified human monocytes.
Optimal conditions governing migration towards chemotactic agent (MTCA) and random migration of purified human monocytes under agarose have been determined. These include an incubation period of 20 h, use of blood group AB pooled human serum, 0.75% agarose type I, pH between 6.8 and 7.2 and performance in 35 mm Falcon plastic petri dishes. A discontinuous Percoll density gradient was used to give monocyte purity of 83 +/- 10% and viability 97-99%. The use of highly purified monocytes was found to be essential, as increasing lymphocyte: monocyte ratio caused inhibition of migration.
Blood Physiological Phenomena↗
The range of blood pressures in Australian children.
Blood pressure, height and weight were measured in 9851 Australian schoolchildren selected at random in three age groups - 5-7, 8-10 and 11-13 years. It was found that the median values of systolic and of diastolic blood pressures rose with age. However, the effect of age virtually disappeared when pressures were corrected for the effect of weight and Quetelet index (weight/height) which suggested that blood pressure is related to size rather than to age; obesity also seemed to have an individual effect. These data do not determine the level of blood pressure in a child at which treatment is indicated, but provide standard ranges to be used in clinical assessment and as the basis for further epidemiological studies.
Adolescent↗
Pacing threshold changes after transvenous catheter countershock.
The serial changes in pacing threshold and R-wave amplitude were examined after insertion of a countershock catheter in 12 patients referred for management of recurrent ventricular tachyarrhythmias. In 6 patients, values before and immediately after catheter countershock were monitored. Pacing threshold increased (from 1.4 +/- 0.2 to 2.4 +/- 0.5 V, mean +/- standard error of the mean, p less than 0.05) while the R-wave amplitude decreased (bipolar R wave from 5.9 +/- 1.1 to 3.4 +/- 0.7 mV, p less than 0.01; unipolar R wave recorded from the distal ventricular electrode from 8.9 +/- 1.8 to 4.6 +/- 1.2 mV, p less than 0.01; and proximal ventricular electrode from 7.7 +/- 1.5 to 5.0 +/- 1.0 mV, p less than 0.01). A return to control values occurred within 10 minutes. In all patients, pacing threshold increased by 154 +/- 30% (p less than 0.001) during the first 7 days that the catheter was in place. It is concluded that catheter countershock causes an acute increase in pacing threshold and decrease in R-wave amplitude. A catheter used for countershock may not be acceptable as a backup pacing catheter.
Adult↗
Total disconnection of the right ventricular free wall: physiological consequences in the dog.
We recently described a new surgical procedure involving total disconnection and subsequent reattachment of the right ventricular free wall ( RVFW ) to confine electrically induced arrhythmic activity to the diffusely diseased RVFW of patients with arrhythmogenic right ventricular (RV) dysplasia. Although no major adverse effects were noted in patients with previously akinetic right ventricles, the consequences of this procedure are unknown in patients with a normally contractile RVFW . This study examined the physiologic consequences of RVFW disconnection in 15 mongrel dogs. Measurements were obtained before surgery, at 30 minutes following surgery, and following a 15-day recovery period. After surgery, the RVFW was electrically isolated from sinus rhythm. At follow-up, left ventricular (LV) pressure, dP/dt, and cardiac output were reduced to 52 mm Hg, 704 mm Hg/sec, and 1.18 L/min, respectively, during sinus rhythm. These values were increased to 76.2 mm Hg, 890 mm Hg/sec, and 1.69 L/min, respectively, when the RVFW was paced in synchrony with sinus rhythm. These studies show that the loss of RVFW contraction depressed hemodynamic function of the normal heart, which is partially compensated by contraction of the left ventricle. Electrical stimulation of the RVFW synchronously with the left ventricle returned cardiac performance toward normal. Finally, this preparation provides a model for independent assessment of the contribution of the RVFW to cardiac function.
Animals↗
The interrelationship between plasma 5-ene adrenal androgens in normal women.
Plasma concentrations of 5-androstene-3 beta,17 beta-diol (ADIOL) dehydroepiandrosterone (DHA) dehydroepiandrosterone sulphate (DHAS) and cortisol were measured by radioimmunoassay in a group of women aged between 27 and 88 years of age. There was a significant negative correlation with increased age for all three adrenal androgens but not for cortisol. The decrease in adrenal androgens was not related to an excessive divergence from ideal body weight. There was a highly significantly positive correlation between plasma concentrations of all three adrenal androgens which supports a metabolic interrelationship.
Adult↗
Adrenal androgen concentrations in breast tumours and in normal breast tissue. The relationship to oestradiol metabolism.
Concentrations of ADIOL, DHA and DHAS were measured in human breast tumours and normal tissue from the same breast and related to 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) activity in these tissues. ADIOL and DHA were significantly higher in tumour tissue compared to normal tissue from the same breast (paired t-test: P less than 0.05 and P less than 0.01 respectively) whereas the difference between concentrations of DHAS in normal tissue and tumour tissue was not significant. There was a positive correlation between ADIOL and DHA in both tissues (P less than 0.001) but for DHAS the relationship was only significant in normal tissue (ADIOL:DHAS, P less than 0.001; DHA:DHAS, P less than 0.002). An increase in 17 beta-HSD activity was associated with an increase in DHAS concentrations in both normal and tumour tissue (P less than 0.01 and P less than 0.001 respectively) and with an increase in DHA concentrations in normal tissue (P less than 0.05). These results might be explained by an impairment in the balance between sulphatase and sulphotransferase activity in breast tumours.
17-Hydroxysteroid Dehydrogenases↗
Injections of phentolamine into the anterior hypothalamus-preoptic area of rats blocks both pressor and drinking responses produced by central administration of angiotensin II.
There are conflicting reports of a possible contribution of noradrenergic projections to the rostral hypothalamus to drinking and blood pressure regulation. The present study investigated the effects of injecting phentolamine into the anterior hypothalamus-preoptic region on drinking and blood pressure responses elicited by injecting angiotensin II into a lateral cerebral ventricle of the rat. Angiotensin II (250 ng or 25 ng) elicited water intakes averaging 9.25 +/- 0.52 ml and 4.35 +/- 0.44 ml respectively in 15 min with latencies of less than 3 min. Phentolamine, an alpha-adrenergic antagonist, injected into the rostral hypothalamus produced a dose-dependent reduction in water intake and number of laps taken accompanied by an increased latency to drink. In the urethane anaesthetized rat, angiotensin II produced significant increases in blood pressure. Injections of phentolamine into rostral hypothalamic sites in which drinking responses to angiotensin II were attenuated, also attenuated the pressor response to angiotensin II. These results indicate that alpha-adrenergic input to the rostral hypothalamus is involved in both the pressor and drinking responses elicited by central angiotensin II.
Angiotensin II↗
Surgical repair of Wolff-Parkinson-White syndrome: a new closed-heart technique.
The conventional operation for ablation of accessory pathways in Wolff-Parkinson-White (WPW) syndrome requires an endocardial approach and necessitates cardiopulmonary bypass and hypothermic cardiac arrest. Cryosurgical ablation of these pathways from the epicardial surface has been described but limited to superficial accessory pathways. We report a new closed-heart technique combining dissection of the atrioventricular (AV) pad and cryosurgery. Six patients with WPW syndrome underwent operation for ablation of accessory pathways associated with disabling tachyarrhythmia refractory to medical management. All pathways were located in the left lateral AV sulcus as determined by preoperative and intraoperative electrophysiological assessment. The heart was exposed through a median sternotomy. The AV fat pad and its vascular contents were dissected away from the atrium at the site of the pathway. A small segment of the ventricle adjacent to the sulcus was exposed. The fat pad was retracted to avoid cryoinjury to the coronary vessels. A cryoprobe, 1.5 cm in diameter, was applied to the exposed AV junction (-60 degrees C for 2 minutes) to create transmural fibrosis. After ablation of the pathway was verified, the chest was closed. All 6 patients have remained free from preexcitation during short-term follow-up. This simplified technique is applicable to patients with free wall accessory pathways. This group constitutes the majority of symptomatic patients with WPW syndrome at our institution.
Adolescent↗
Ventricular fibrillation: the importance of being coarse?
Ventricular fibrillation (VF) has been classified electrocardiographically as "fine amplitude" or "coarse amplitude" VF. It has been suggested that coarse VF represents increased "synchronization" of myocardial activation which could result in lower thresholds for defibrillation. To test the "synchronization" differences between coarse VF and fine VF, we induced VF in ten normal anaesthetized dogs. Standard limb lead and His bundle electrograms were recorded simultaneously with 12 bipolar epicardial electrograms (eight dogs) and six lead ECG (two dogs). Activation "synchronization" was assessed by calculating the standard deviations (SD) of electrogram activation times during one coarse VF and one fine VF cycle. Less synchronization during VF was indicated by a 50% larger SD (CVF: 29.3 +/- 1.1 msec, FVF: 32.6 +/- 1.6 msec) compared to ventricular pacing (21.2 +/- 1.6 msec) and 500% larger than sinus rhythm (6.5 +/- 0.5 msec). Coarse VF and fine VF did not differ. In addition, the 6-lead ECG recorded during early VF had episodes of coarse VF and fine VF occurring simultaneously. The amplitude of all electrograms diminished over 15 minutes until only fine VF could be recorded. We conclude that coarse VF does not reflect greater synchronization of activity than fine VF early in fibrillation (five minutes). Rather, differences are due to lead orientation. Later in the fibrillation bout, fine VF probably reflects metabolically induced degeneration of cellular excitability.
Animals↗
Surgical correction of the Wolff-Parkinson-White syndrome in the closed heart using cryosurgery: a simplified approach.
The conventional operation for ablation of accessory atrioventricular (AV) pathways in the Wolff-Parkinson-White syndrome requires an endocardial approach to the AV groove and necessitates the use of cardiopulmonary bypass and induced cardiac arrest. The feasibility of creating transmural atrial fibrosis at the level of the AV anulus in the closed heart in dogs without damaging the vascular contents of the AV fat pad was demonstrated. This was done by dissecting the fat pad from the atrium and applying a cryoprobe to the exposed atrial-anular region after retraction of the fat pad. The technique was then applied to successfully ablate 12 left parietal wall accessory pathways in 11 patients with the Wolff-Parkinson-White syndrome. This simplified approach to any parietal wall accessory pathway does not require cardiopulmonary bypass or induced cardiac arrest and may broaden the indications for this operation.
Adolescent↗
Changes in pacing threshold and R wave amplitude after transvenous catheter countershock.
Transvenous electrode catheter countershock in patients with recurrent ventricular tachyarrhythmias may be followed by transient bradycardia and require temporary pacing with a catheter. The serial changes in R wave amplitude and stimulation threshold after catheter countershock in 11 halothane-anesthetized open chest dogs ranging in weight from 11.8 to 24 kg were studied. Ventricular fibrillation was electrically induced and followed by catheter defibrillation using nonsynchronized trapezoidal waveform (65% tilt) current discharge in incremental doses (5 to 50 J). Significant decreases in bipolar R wave amplitude (8.3 +/- 1 versus 2 +/- 0.2 mV, p less than 0.001) and increases in stimulation threshold (1 +/- 0.1 versus 2.3 +/- 0.4 V, p less than 0.001) were observed using the countershock catheter 15 seconds after countershock; these changes persisted for up to 10 minutes. To determine whether these changes were localized to the defibrillating catheter and whether they were species-specific, a second electrode catheter was positioned in the right ventricle distant from the countershock catheter in five pigs. Increases in stimulation threshold were observed only at the countershock catheter, suggesting that changes were secondary to local changes at the catheter-myocardium interface. No significant change in R wave amplitude or stimulation threshold was observed at the countershock catheter in three pigs given transthoracic shocks (60 to 250 J). It is concluded that current discharge through the countershock catheter results in a significant temporary reduction in R wave amplitude and an increase in pacing threshold. This may make pacing through the countershock catheter unreliable after shock delivery.
Animals↗
Survey confirms freedom from anaplasmosis.
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Letter↗
Adrenal androgen concentrations in endometrium and plasma during the menstrual cycle.
Concentrations of 5-androstene-3 beta, 17 beta-diol (androstenediol), dehydroepiandrosterone (DHA) and DHA sulphate (DHAS) were measured in endometrium and plasma from normal premenopausal and perimenopausal women (average ages 37 and 48 years respectively) at different stages of the menstrual cycle. Plasma levels did not vary with the stage of the cycle for any of the three steroids. Mean plasma levels of androstenediol ranged between 2.03 and 2.92 nmol/l for premenopausal women and 1.38 and 1.58 nmol/l for perimenopausal women while mean concentrations of DHA were 20.80-36.41 nmol/l (premenopausal women) and 13.87-19.07 nmol/l (perimenopausal women). The values for DHAS were more variable and ranged between 3.20 and 4.56 and 2.94 and 4.25 mumol/l for pre- and perimenopausal women respectively. In premenopausal women endometrial tissue concentrations of androstenediol and DHA increased three to fourfold in the secretory phase while no increase was observed in DHAS. There was a similar increase in androstenediol but not DHA or DHAS during the secretory phase for perimenopausal women. A significant positive correlation was found for tissue androstenediol and DHA in both groups of women but the relationship between DHAS and the other androgens was significant only for perimenopausal women. We suggest that the increase in androstenediol and DHA concentrations could be due to an increase in a receptor or binding protein, possibly progesterone dependent, present in secretory phase endometrium.
Adult↗
[Surgical section of the bundle of Kent in the closed heart].
The conventional operation for ablation of accessory pathways (AP) in the WPW syndrome requires an endocardial approach and necessitates cardiopulmonary bypass and hypothermic cardiac arrest. Cryosurgical ablation of AP from the epicardial surface has been described but was limited to superficial AP. We report a new closed-heart technique combining dissection of AV pad and cryosurgery. Eight patients with WPW syndrome, aged 6-56, underwent surgery for ablation of AP associated with disabling tachyarrhythmia refractory to medical management. All AP were located in the left lateral AV sulcus as determined by preoperative and intraoperative electrophysiological assessment. The heart was exposed through a median sternotomy. The AV fat pad and its vascular contents were dissected away from the atrium at the site of the AP, sacrificing some atrial vessels. The dissection left some fat adherent to the thin-walled atrium close to the level of the mitral annulus. A small segment of the ventricle adjacent to the sulcus was exposed. The fat pad was retracted to avoid cryo-injury to the coronary vessels. A cryoprobe (1.5 cm diameter) was applied to the exposed AV junction (-60 degrees C for 2 minutes) to create transmural fibrosis. After verification of AP ablation, the chest was closed. All 8 patients have remained free of preexcitation during short term follow-up (1 to 8 months). This simplified technique is applicable to patients with free-wall AP, a group constituting the majority of symptomatic WPW patients at our institution.
Adult↗
Respiratory disease amongst Aborigines in the Pilbara.
Aboriginal communities have a high prevalence of upper and lower respiratory tract disease. One thousand two hundred and eighty seven West Australian Aborigines and 265 non-Aborigines were examined. Twenty nine per cent of Aborigines had lower respiratory tract abnormalities. Amongst 635 Aboriginal children less than 15 years of age, 23% had lower respiratory tract signs--four times the prevalence in 174 non-Aborigines. Twenty six per cent of Aborigines under 10 years of age had signs of otitis media, compared to 3% amongst non-Aborigines. Two hundred and thirty eight (53%) of Aboriginal children less than 10 years of age had nasal discharge, compared to 1.6% of the non-Aboriginal children.
Adolescent↗
Inhibition of 3-beta-hydroxy steroid dehydrogenase activity in first trimester human pregnancy with trilostane and WIN 32729.
The effects of equivalent doses of two inhibitors of the 3-beta-hydroxy steroid dehydrogenase enzyme system--WIN 24540 (trilostane) and WIN 32729--on the secretion of progesterone in early human pregnancy are described. Patients and controls less than 12 weeks pregnant were given a single dose of either drug and the resultant hormonal changes monitored for 7 1/2 h. A consistent fall in plasma progesterone concentrations occurred at all doses and, at the highest dose, they fell to less than 50% of pre-treatment levels. However, whilst with trilostane the associated increase in plasma concentrations of pregnenolone was always accompanied by a rise in plasma DHA concentrations, with WIN 32729 there appeared to be no adrenal effect at the lower dosage levels. These data demonstrate inhibition of progesterone secretion in human pregnancy using non-hormonally active steroids. The pattern of steroid precursors indicates that while both drugs inhibit 3-beta-hydroxy steroid dehydrogenase activity, WIN 32729 is more selective and only interferes with adrenal steroid biosynthesis at high doses.
3-Hydroxysteroid Dehydrogenases↗