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Biomedical subjects

H Rogers

Publications and source records attributed to H Rogers.

At least 37 records · Page 2Linked to original sources

A series of novel, highly potent and selective agonists for the kappa-opioid receptor.

1. This paper describes the opioid receptor pharmacology and in vivo activity of several novel benzene-acetamidopiperidine and benzeneacetamidopiperazine analogues. 2. These compounds all showed potent, naloxone-reversible, full agonist activity in the field-stimulated rabbit vas deferens, indicating that they are kappa-opioid agonists; but showed very little activity in the rat or hamster vas deferens, indicating good selectivity with regard to mu- and delta-opioid receptors. 3. They were all potent antinociceptive agents, the most potent compound, GR 103545, having an ED50 value in the mouse abdominal constriction test of 0.25 micrograms kg-1 s.c. The compounds also produced sedation and diuresis, but had little effect on respiration rate or gastrointestinal motility. 4. It is concluded that the seven novel compounds described are all potent and selective agonists for the kappa-opioid receptor.

Abdomen↗

The selectivity of the opioid antagonist, naltrindole, for delta-opioid receptors.

In the mouse vas deferens, naltrindole gave pKB values of 9.7, 8.3, and 7.5 at the delta-, mu-, and kappa-sites and in binding assays, pIC50 values of 9.6, 7.8 and 7.2 at the same sites. The affinity of naltrindole for the delta binding site was increased in the presence of sodium ions and 5'-guanylylimidophosphate. Naltrindole is, thus, a potent opioid antagonist with marked selectivity for the delta-opioid receptor.

Animals↗

The relationship of agraphia to the severity of dementia in Alzheimer's disease.

Impairment of writing ability was studied in 20 patients with mild to moderate dementia caused by early-onset Alzheimer's disease. A multicomponent analysis was made of a brief narrative writing sample obtained from each patient, and this writing proficiency score was compared with results of standard tests of cognitive function as well as ratings of the degree of dementia. In these patients, significant correlations were observed between this brief test of narrative writing ability and the severity of dementia. An analysis of writing proficiency appears to be a simple means of assessing the severity of dementia caused by Alzheimer's disease. Further studies are needed to show the potential usefulness of such measures of agraphia in subtyping this disease.

Aged↗

Phase II trial of idarubicin in patients with advanced lymphoma.

A phase II trial of idarubicin was performed in 24 patients with advanced lymphoma. The drug was administered in a dose of 10-15 mg/m2 i.v. or 15-70 mg/m2 p.o. (single dose) every 3 weeks. There were four partial responses and four minor responses. All but one of the responders had received prior doxorubicin therapy. The toxicities were myelosuppression, nausea and vomiting, and alopecia. Two patients with compromised cardiac function were observed to have further deterioration in the ejection fraction as measured by gated cardiac scan after idarubicin therapy. Further assessment of the activity of idarubicin against lymphoma is recommended in less heavily pretreated patients. The cardiac toxicity should be carefully monitored in future studies.

Antibiotics, Antineoplastic↗

Short-term stability of single motor unit recordings in motor neuron disease: a macro EMG study.

Thirty five individual macro EMG motor unit potentials in 13 patients with motor neuron disease were recorded every 15 minutes during a 2 hour period. No significant change in amplitude or area was seen in 15 control units in nine patients or in 20 units in 11 patients receiving RX77368 0.2-0.3 mg/kg. The findings provide no evidence for an action of this long acting TRH analogue on the peripheral territory of motor units in motor neuron disease.

Adult↗

Subacute administration of a TRH analogue (RX77368) in motorneuron disease: an open study.

Sixteen patients with motor neuron disease received RX77368, a TRH analogue, IV, repeatedly over 1-12 weeks (median 2 weeks). Slight to moderate improvement in bulbar function, particularly speech, was reproduced or persisted with repeated infusions in 8 of 12 responders over a median of 18 days (range 14-90) during the period of study. Cramps (5/9) and spasticity (5/8) improved for a median of 14 days (range 7-35) and 7 days (range 2-14) respectively. The highest benefit/side effect ratio was seen with 0.2 mg/kg (0.15 mg/kg in those with severe bulbar palsy) every 3-4 days. Long term studies with this analogue in MND are indicated.

Activities of Daily Living↗

Evoked potentials following diazepam or fentanyl.

The effects of fentanyl or diazepam on somatosensory, visual and brainstem auditory evoked potentials were studied in 13 healthy patients scheduled for elective surgery. Following control recordings of evoked potentials, either diazepam 20 mg or fentanyl 200 micrograms was administered intravenously. Evoked potentials were then recorded twice in the subsequent hour. No significant changes occurred in the latency or amplitude of somatosensory, visual or brainstem auditory evoked potentials. Although dose-related changes in evoked potential latencies and amplitudes have been demonstrated with both the inhalational and intravenous anaesthetics, these changes did not occur with diazepam or fentanyl used alone. An anaesthetic technique based on these two drugs would be suitable when intra-operative evoked potential monitoring is required to assess ischaemia and preservation of evoked responses.

Adult↗

Eicosanoid synthesis by human urinary bladder mucosa: pathological implications.

Biopsies of human urinary bladder mucosa obtained during cystoscopy were shown to release eicosanoids in the following order: prostacyclin (PGI2), prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha) and thromboxane A2 (TXA2). The total and the relative amounts of eicosanoids released were similar to those reported for the rat urinary bladder. These eicosanoids may play a role in modulating the tone and contractility of the bladder as well as affecting cytoprotection of the mucosa. In view of the abundant release of eicosanoids by the bladder, caution must be exercised when considering urinary eicosanoid excretion as reflecting production by the systemic vasculature and/or the kidneys.

Dinoprost↗

Failure of long term high-dose lecithin to retard progression of early-onset Alzheimer's disease.

We conducted a six-month, randomized, double-blind trial of lecithin therapy in early-onset Alzheimer's disease. We hypothesized that such therapy would retard the progression of the clinical and neuropsychological manifestations of this illness. Of the 73 referred patients, 37 met strict requirements for diagnosis and compliance. The 21 placebo and 16 lecithin-treated patients (mean age 63 years) had a comparable degree of severity of dementia (mean Clinical Dementia Rating 1.6). Lecithin therapy produced an increase in mean plasma choline levels from a baseline of 15.9 to 28.8 nmol/ml. Patients were evaluated by the physician using clinical assessments (CDR, Lawton ADL and other rating scales) and by the neuropsychologist who determined the outcome of therapy on a battery of tests (Mini Mental State Examination, Wepman Aphasia Screen, Verbal Fluency Test, Verbal Selective Reminding Test and Spatial Memory Test). Only 6 (37.5%) of the 16 lecithin-treated patients were considered by the neurologist to be clinically stable or improved as compared to 12 (57.1%) of the 21 patients given placebo (difference -19.6%, 95% confidence limits of -51% to 12%). The neuropsychologic scores showed no differences in the stability of the dementing process over time between the lecithin-treated (50.0%) and placebo (47.6%) groups. On the basis of these clinical and neuropsychological findings, it appears that lecithin alone has no important therapeutic effect in early-onset Alzheimer's disease.

Alzheimer Disease↗

Evoked potentials during isoflurane anaesthesia.

Somatosensory, visual and brainstem auditory evoked potentials were recorded in 10 unpremedicated patients anaesthetized with isoflurane in oxygen. Recordings were made at 0.5%, 1.1% and 1.65% (six patients) end-tidal isoflurane concentration. There were statistically significant increases in the latencies of the somatosensory (N20), visual and brainstem auditory potentials (waves III and V) with increasing concentrations of isoflurane. The central conduction time was prolonged. Amplitudes of the somatosensory and visual potentials were reduced with increasing concentrations of isoflurane. The effects of isoflurane on evoked potentials are similar to those of halothane and enflurane. It is possible that changes in evoked potential measurements may be useful as a neurophysiological indicator of anaesthetic depth.

Anesthesia, Inhalation↗

A phase II study of ifosfamide in children with recurrent solid tumours.

Twenty children with recurrent or unresponsive tumours (10 Wilms', 3 rhabdomyosarcoma, 4 Ewings's, 1 osteosarcoma, 1 hepatoblastoma, 1 hepatoma) and one untreated patient with renal carcinoma were given ifosfamide as a 24-h infusion (5 mg/m2), with mesna as uroprotective. The number of courses ranged from 1 to 13 (median 3), and the interval between them was 2-3 weeks. Sixteen of these patients had previously received cyclophosphamide. Complete clinical responses were seen in 3 cases (2 Wilms' and 1 Ewing's) and lasted 5, 7, and 9 months. Partial responses were seen in 3 instances, mixed response or stable disease in 4, and progressive disease in 11. Treatment was well tolerated in most patients, with no cystitis or severe myelosuppression, but 2 children developed transient neurological symptoms and 1 became hypertensive. Nausea and vomiting were controlled by high-dose dexamethasone in most children. Plasma ifosfamide levels were estimated by means of gas-liquid chromatography in 10 patients. Peak concentrations ranged from 38 to 125 micrograms/ml (median 80). The elimination half-life, at 2.5-5.2 h (median 3.2) was shorter than previously reported in adults. Future studies should test the possibility that ifosfamide-containing combination chemotherapy may be more effective than the regimens, usually including cyclophosphamide, that are currently used as front-line treatment of embryonal and Ewing's sarcoma.

Adolescent↗

One-dimensional peptide mapping of the subunits of pertussis toxin.

Pertussis toxin (pertussigen) purified from the cytoplasmic fraction of Bordetella pertussis strain 18334, phase 1, consisted of five subunits which included an additional subunit (S1a) not previously reported. Subunits S1, S1a and S2 showed extensive structural homology when analysed by one-dimensional peptide mapping, indicating that the latter two were probably derived from proteolytic cleavage of the largest subunit, S1. Subunits S3 and S4,5 generated only a limited number of peptides following chemical and enzymic degradation, but these subunits differed structurally from each other and from those showing structural homology.

Bacterial Toxins↗

Single-dose pharmacokinetic and pharmacodynamic comparison of polymer-matrix (Slow Trasicor) and Oros dosage forms of oxprenolol in healthy volunteers.

Oxprenolol was administered in single doses by mouth to healthy volunteers either in a polymer-matrix slow-release formulation (Slow Trasicor) or in osmotic drug-delivery systems (oxprenolol Oros). Plasma oxprenolol concentrations and heart rates after exercise were measured. Plasma concentrations of the drug were maximal at 3 h but negligible at 24 h after administration of Slow Trasicor. Following ingestion of the Oros systems measurable concentrations were maintained throughout 24 h. Significant reduction of exercise-induced tachycardia persisted for 24 h after administration of oxprenolol Oros. With Slow Trasicor heart rate responses had returned to baseline values by this time. The osmotic drug-delivery systems appear to sustain significant beta-adrenoceptor blockade for 24 h after a single oral dose.

Adult↗