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Biomedical subjects

D J Jones

Publications and source records attributed to D J Jones.

At least 55 records · Page 3Linked to original sources
PubMed1994

Detection of ketorolac enantiomers in human plasma using enantioselective liquid chromatography.

A high-performance liquid chromatographic method for the determination of the enantiomers of ketorolac in human plasma has been developed. Plasma samples containing ketorolac were acidified and extracted into diethyl ether. The ethereal extract was evaporated to dryness and the residue reconstituted in mobile phase before injection onto a Chiral-AGP column. The mobile phase was 2-propanol-20 mM potassium dihydrogenphosphate buffered to pH 7 (0.5:99.5, v/v). Detection was by ultraviolet absorbance at 320 nm. The detection limit was 5 ng/ml for each enantiomer. The method has been applied to determine the concentration of ketorolac enantiomers during an infusion of the racemic drug and has proven to be rapid and sensitive.

Analgesics, Non-Narcotic↗
PubMed1994

Colectomy and ileorectal anastomosis in patients with Crohn's disease.

Eighty-three patients underwent colectomy and ileorectal anastomosis for Crohn's disease of the large bowel. There were two postoperative deaths and seven anastomotic leaks. Fifty-two patients retained a functioning anastomosis with a mean follow-up of 8 years. Forty had an excellent or good functional result. The cumulative proportion of patients with a functioning ileorectal anastomosis was 77 and 63 per cent at 5 and 10 years respectively. Patients presenting with perforating Crohn's disease had a significantly increased risk of failure of the anastomosis. Perianal Crohn's disease following ileorectal anastomosis was significantly related to the need to defunction or excise the rectum.

Adolescent↗
PubMed1994

Nasal masks for domiciliary positive pressure ventilation: patient usage and complications.

BACKGROUND: Nasal mask discomfort is a major factor in compliance with treatment by nasal intermittent positive pressure ventilation (NIPPV) and nasal continuous positive airway pressure (CPAP). METHODS: A study of skin complications resulting from mask usage, with particular reference to predisposing factors, was carried out in 66 patients by means of a postal questionnaire. An effective means of managing ulceration at the nasal bridge while continuing therapy is described. RESULTS: Some disruption of treatment due solely to mask discomfort was experienced by 35 patients (53%), consisting of broken skin or open sores in 11 cases (17%). CONCLUSIONS-Although complications resulting from nasal mask usage are common, early identification of patients at risk of developing such complications and appropriate intervention will result in improved patient compliance.

Adult↗
PubMed1994

Cardiac electrophysiologic effects of diltiazem in dogs receiving either enflurane or chloralose anesthesia.

Previously we have described impaired myocardial conduction in patients receiving diltiazem and enflurane. The present study examines the possible mechanism(s) which may account for our clinical observation and presents methods of reversing adverse interactions. Nineteen mongrel dogs were randomized into two exposure groups: enflurane or chloralose anesthesia. Stepwise increasing doses of diltiazem were administered until predetermined endpoints were reached. Sinus and atrioventricular (AV) node function was assessed at all levels of diltiazem infusions, and after reversal drugs. Depression of AV nodal conduction and refractoriness after diltiazem administration was greater during enflurane anesthesia when compared with chloralose. There was severe sinus node dysfunction in enflurane-anesthetized animals. These effects were only reversed by isoproterenol. Patients may be at increased risk for severe sinus node depression when diltiazem is administered during enflurane anesthesia. This is due to a potent interaction between diltiazem and enflurane on the sinoatrial node.

Anesthesia, Inhalation↗
PubMed1994

The impact of ractopamine, energy intake, and dietary fat on finisher pig growth performance and carcass merit.

An experiment was conducted to determine the effect of ractopamine, energy intake, dietary fat level, and sex on performance and carcass composition in finishing pigs. Three hundred six barrows and gilts were used in a factorial arrangement of treatments replicated over three seasons. Treatments consisted of two ractopamine levels (0 vs 44.7 mg/d), two sexes (barrows and gilts), two levels of fat addition (0 vs 5% added fat), and four energy intake levels (8.3, 8.9, 9.5, and 10.1 Mcal of ME/d for barrows and 7.7, 8.3, 8.9, and 9.5 Mcal of ME/d for gilts). Diets were formulated to maintain an equal lysine (28.5 g/d) intake at each feeding level through cornstarch dilution of the basal (7.7 Mcal of ME/d) diets. Pigs were fed daily based on a standard feed intake curve and prior weekly body weights. At slaughter (104 kg), carcass measurements and TOBEC HA-1 scanner measurements were recorded. Dietary fat addition improved live weight and lean efficiency (grams of carcass lean gain/kilogram of feed, P < .05). Dietary fat addition did not affect growth rate or carcass composition. Increasing energy intake resulted in a linear increase in average daily gain for both barrows and gilts (P < .01). Dietary ractopamine influenced the response of lean tissue accretion, lean tissue accretion efficiency, and fat tissue accretion to energy intake. Pigs with no added ractopamine demonstrated increased lean tissue accretion and improved efficiency and decreased fat tissue accretion with increasing energy intake (up to 9.5 Mcal of ME intake for barrows and 8.9 Mcal of ME intake for gilts). In contrast, pigs with added ractopamine did not respond to increasing energy intake and demonstrated increased fat tissue accretion with increasing energy intake. The response to ractopamine for growth was greatest from d 6 to 22 on test or during the test gain period of 7 to 18 kg. After d 22, the response of ractopamine declined linearly. These results indicate that ractopamine increases growth rapidly at the onset of feeding until a plateau is reached, after which there is a linear decline in growth response.

Adipose Tissue↗
PubMed1994

Shame and depression proneness among female adult children of alcoholics.

Although recent clinical literature has posited that both shame and depression are important aspects in the treatment of adult children of alcoholics (ACAs), proneness to shame and depression in this group remains underexamined. This study tests the hypotheses that ACAs are more prone to shame and depression than non-ACAs. The sample consisted of 60 women--30 ACAs and 30 non-ACAs--who were 22 to 55 years old during the study period and had begun treatment within the past 6 months. The dependent measures were the Depression Proneness Rating Scale and the Adapted Shame/Guilt Scale. Female ACAs were found to be more depression prone than non-ACAs (p < .05), and the difference was not explained by any of the other variables studied. Contrary to expectations, they were not found to be more shame prone. The results are discussed as they relate to alternative hypotheses, clinical implications, and future research.

Adult↗
PubMed1993

6-Hydroxydopamine treatment of neonatal rats. I. Effects on the development of the spinal cord noradrenergic system.

The spinal cord contains noradrenergic (NA) pathways which descend from cell bodies in the medulla oblongata and pons to terminate at all levels in the spinal gray matter. The present studies sought to determine the patterns of postnatal development of pre- and postsynaptic elements of NA transmission in the spinal cord. Significant presynaptic development is evident at birth as reflected by substantial high-affinity uptake of norepinephrine (NE) into synaptosomes (0.65-0.90 pmol/mg protein). There is a subsequent increase in uptake on postnatal day (PND) 5, followed by a decrease in 5-10 days to essentially adult levels, starting on PND 20 (0.30-0.35 pmol/mg protein). This decrease in NE uptake occurs coincident with increases in the density of postsynaptic alpha 1 and beta adrenergic receptors and also NE-stimulated accumulation of 3',5'-cyclic adenosine monophosphate (cAMP). Peaks in the development of alpha 1 receptors (PND 10) and beta receptors (PND 20) and NE-stimulated cAMP accumulation (PND 15) were also followed by decreases to adult levels. The neurotoxin 6-hydroxydopamine (6-OHDA) was administered at birth to determine the effects of denervation on the development of the spinal NA systems. At each day following 6-OHDA, synaptosomal uptake of [3H]NE was reduced by two-thirds compared with control values. alpha 1 and beta adrenergic receptor binding are uniformly increased along with a parallel increase in NE-stimulated accumulation of cAMP. While uniformly increased over control, the pattern of postnatal increases and decreases in receptors and cAMP accumulation is maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-3-isobutylxanthine↗
PubMed1993

6-Hydroxydopamine treatment of neonatal rats. II. Effects on the development of the hindlimb flexor reflex.

The flexor reflex (FR) of the hindlimb was measured in rats at various ages between postnatal days (PND) 12-45, in vehicle-treated control rats and in rats treated with 6-hydroxydopamine (6-OHDA) (100 mg/kg, i.p.) on the first and second days after birth. The hindlimb FR was elicited by graded electrical stimulation of the footpad (0.1-2.0 mA) and quantified by the amplitude of the flexion in grams. The half maximal FR response was evoked by 1.2 mA and was 2-3 g in animals at PND 12-17 and 9-10 g in animals on PND 30 and 45. A similar age dependency was evident in the maximum hindlimb FR evoked by 2.0 mA; the maximum FR was 4.7 +/- 0.5 g on PND 12 and 24 +/- 2 g on PND 45. In rats treated with 6-OHDA, the strength of the FR was similar to that of the controls up to PND 15. However, the FR was increased 25% by PND 17 and 200% by PND 45 in the 6-OHDA-treated animals, versus controls. Pretreatment with clonidine (100 micrograms/kg, i.p.), which activates alpha 1 receptors under the current experimental conditions, did not enhance the FR in control animals. However clonidine pretreatment caused an increase of 400-800% in the FR in the 6-OHDA-treated animals at PND 15 and beyond. Our companion paper demonstrated that as early as PND 5, there was a significant increase (P < 0.05) in alpha 1 receptors in the spinal cord of 6-OHDA-treated animals, versus the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1993

The administrative and clinical rationale for the total organization approach to continuous quality improvement.

In our view TQM and CQI represent important innovations in the continuing effort to develop higher performance organizations. Never before has the need been so great to improve quality while at the same time constraining, or reducing, costs. An increasing number of health care organizations can document their experiences that as quality goes up, costs can come down. The contribution of these new approaches is in some sense the wedding of many long established methodologies--the scientific method, statistical quality control, planning, joint problem solving, participative management, and empowerment of the work force. While this recognition could lend support to those who label this new model a fad, that perception denies the linkage of TQM/CQI to the greater stream of innovations pushing us toward ever-greater organizational excellence. Can we not take the philosophy and methods that are potentially useful and try them experimentally? Let our empirical tests tell us of their contribution. We believe the concepts and procedures of TQM/CQI will help us to be better in years to come, even though we highly respect our starting point.

Economic Competition↗