PubMed Health⌕ Search

Biomedical subjects

R Strickland

Publications and source records attributed to R Strickland.

15 recordsLinked to original sources
PubMed1990

An ancient group I intron shared by eubacteria and chloroplasts.

Introns have been found in the genomes of all major groups of organisms except eubacteria. The presence of introns in chloroplasts and mitochondria, both of which are of eubacterial origin, has been interpreted as evidence either for the recent acquisition of introns by organelles or for the loss of introns from their eubacterial progenitors. The gene for the leucine transfer RNA with a UAA anticodon [tRNALeu (UAA)] from five diverse cyanobacteria and several major groups of chloroplasts contains a single group I intron. The intron is conserved in secondary structure and primary sequence, and occupies the same position, within the UAA anticodon. The homology of the intron across chloroplasts and cyanobacteria implies that it was present in their common ancestor and that it has been maintained in their genomes for at least 1 billion years.

Anticodon↗
PubMed1990

Thermal laser probe angioplasty: influence of constant tip temperature, plaque composition, and probe/vessel diameter ratio.

Thermal laser angioplasty uses constant laser power, producing widely variable tip temperatures in vivo. Results have been suboptimal. We studied the effect of 50-400 degrees C tip temperatures on depth of ablation at 192 sites on plaqued and normal human aorta in vitro, and the angiographic and histologic response in vivo of 300-400 degrees C at probe/vessel ratios of 0.5-1.0, in 40 normal canine femoral artery segments. In vitro, there was a direct relationship between tip temperature and depth of ablation, r = 0.71 (all segments), r = 0.74 for fibrous plaque, but a poor correlation in fatty plaque r = 0.35. In fibrous plaque, there was proportionately more ablation at tip temperatures greater than 300 degrees C, mean depth 0.62 mm, than at 150-300 degrees C, mean 0.37 mm, (P less than .001). Ablation was similar in plaqued and normal aorta. In vivo, 300 degrees C, 350 degrees C, and 400 degrees C produced similar effects. At probe/vessel ratios less than 0.8, only disruption of internal elastic lamina was observed. At ratios greater than or equal to 0.8, spasm occurred in 39% (7/18), transmural damage in 28% (5/18), and perforation in one of 18. Ablation is not selective for plaque and is highly variable in fatty plaque. Tip temperatures above 300 degrees C produce greater ablation than at lower temperatures. In clinical applications, probe/vessel rations less than or equal to 0.7 may be most appropriate, and it appears that thermal remodeling may contribute more to outcome than plaque ablation.

Angioplasty, Laser↗
PubMed1986

The Montgomery-Asberg Depression Scale: reliability and validity.

The Montgomery-Asberg Depression Scale was evaluated in 44 depressed inpatients. All items of the scale occurred frequently in the sample; the scale exhibited construct validity (internal homogeneity) and concurrent validity relative to the Hamilton Depression Scale and the concepts of endogenous and nonendogenous depression. Sleep disturbance, reduced appetite, and suicidal thoughts, correlated poorly with the remainder of the scale. Reasons for this finding are discussed. Inter-rater reliability was demonstrated between a psychiatrist and a nurse on individual item and total scale scores.

Adult↗
PubMed1984

Comparative diagnostic criteria for melancholia and endogenous depression.

Five scales were evaluated for the diagnosis of melancholia or endogenous depression. Of 21 total items, none appeared in all five scales, but four items occurred in four of the scales: autonomy of mood, prevasive anhedonia, psychomotor change, and guilt. Vegetative changes were represented inconsistently, with anorexia and weight loss in three scales, as was distinct quality of mood. Thereafter, item agreement between the scales fell off. Scale performance was tested in 50 depressive patients. Major differences were found in frequency of melancholia and scale orientation toward inpatients and outpatients. A number of old controversies remain dormant in these scales. Unresolved are the relationship between melancholia and severity of depression; the relevance of precipitating events, previous depressive episodes, type of onset, and adequacy of personality; and whether to classify by category or continuum. The merits of statistically and consensually derived scales also need to be evaluated.

Adult↗
PubMed1984

An evaluation of two doses of isocarboxazid in depression.

Two fixed doses of isocarboxazid were studied over a 4-week period in depressed in-patients. Thirty-five patients completed treatment, 20 of whom received 30 mg isocarboxazid per day, and 15 of whom received 50 mg isocarboxazid per day. No overall difference between the two doses was observed. When patients were subdivided into melancholia/endogenous depression or non-melancholia/non-endogenous depression, the higher dose exerted significantly greater antidepressant effects in the latter groups. Diagnostic type is considered to be an important variable in studies of dose-effect relationships with antidepressant drugs. The side effects of isocarboxazid at the two doses studied did not differ materially, although there was a suggestion of greater anticholinergic effect at 50 mg.

Adult↗
PubMed1984

The Newcastle Endogenous Depression Diagnostic Index: validity and reliability.

The newcastle Endogenous Depression Diagnostic Index of Carney et al. was studied for reliability and validity. Good inter-rater reliability was obtained for diagnostic category and for item scores in 36 patients. The scale showed construct validity with reference to the Hamilton and Montgomery-Asberg rating scales. Concurrent validity was shown relative to other diagnostic scales of endogenous depression. Predictive validity was demonstrated in that endogenous and nonendogenous depressive responded differently to isocarboxazid. The continued use of 5 as the point of separation between endogenous and nonendogenous depression is questionable.

Depressive Disorder↗
PubMed1984

Validation of four definitions of melancholia by the dexamethasone suppression test.

The authors evaluated four sets of diagnostic criteria, the Newcastle Index, DSM-III, RDC, and the Michigan Diagnostic Index, for the diagnosis of melancholia. Forty-nine depressed inpatients, all of whom met RDC for major depression, also received consensus diagnostic assessment for melancholia. The dexamethasone suppression test (DST) was administered before drug treatment began. Results showed that the sensitivity of the DST ranged from 39% to 48%, specificity from 80% to 100%, and diagnostic confidence from 66% to 100%. All four scales received validation, but DSM-III showed the lowest specificity and predictive value.

Adult↗
PubMed1983

Characteristics of schizophrenic and depressed patients excluded from clinical research.

The process of selecting patients for research studies introduces factors that can bias outcome. The authors compared schizophrenic and depressed patients accepted for studies on their clinical research unit with patients admitted to the hospital with the same diagnoses. They found significant differences between the two groups in age, sex, and legal status. The authors conclude that many research populations may not be representative of general patient populations for a number of reasons and argue that research studies also need to focus on patients who do not meet research ward criteria.

Adult↗
PubMed1983

Oral complications associated with bone marrow transplantation in a pediatric population.

The effect of dental evaluation and treatment prior to bone marrow transplantation in 11 pediatric patients was assessed. Oral complications associated with marrow ablative therapy and the immediate posttransplant period (Days 0-35) were also studied. Oral complications during marrow ablative therapy included: xerostomia (2/11 patients) and parotitis (1/11 patients). Oral complications in the immediate post-transplant period (Days 0-35) included: mucositis (11/11 patients); moniliasis (9/11 patients); and stomatitis associated with acute G.V.H.D. (3/9 patients receiving allogenic marrow transplants). The onset of the mucositis in the posttransplant period usually occurred at the nadir of the white blood cell count and resolved when the absolute neutrophil count was approximately 500/m3. The onset of moniliasis in the posttransplant period was usually 1-2 days after the onset of the mucositis. Resolution of the moniliasis usually paralleled resolution of the mucositis. No patient developed an infectious and/or hemorrhagic complication of odontogenic origin.

Adolescent↗
PubMed1983

A double-blind comparison of bupropion and amitriptyline in depressed inpatients.

Bupropion and amitriptyline were compared in a double-blind study of depressed inpatients. Treatment ranged from 2 to 4 weeks: early responders (Hamilton Depression Scale scores less than 10) were often removed from treatment after 2 or 3 weeks. Twenty-two patients completed treatment with bupropion and 18 with amitriptyline. Doses ranged from 450 to 750 mg/day for bupropion and 75 to 225 mg/day for amitriptyline. Overall, bupropion and amitriptyline were equally effective, as measured by the Hamilton Depression and Anxiety scales, Clinical Global Impressions, Zung Depression scale, and the SCL-90. Differences in the side effect profile and in weight change are described.

Adult↗
PubMed1982

Dual system of intestinal thiamine transport in humans.

The transport of thiamine across the intestine has been characterized in rats but has not been adequately studied in humans. To determine the kinetics of thiamine intestinal transport directly in humans, mucosal tissues were obtained during routine endoscopy from normal-appearing sites at the second portion of the duodenum. With 3H-dextran as the marker of adherent volume, the uptake of 14C-thiamine hydrochloride by the excised mucosa was measured in vitro. By this method thiamine uptake was linear with tissue weight and with incubation time up to 5 min. Results showed that at low thiamine concentrations (0.2 to 2.0 microM), uptake was saturable whereas at high concentrations (5 to 50 microM), uptake was linear with thiamine concentrations. Pyrithiamine, anoxia, N-ethylmaleimide, and replacement of sodium chloride by mannitol reduced the uptake of 0.5 microM thiamine by 42%, 37%, 32% and 35%, respectively (p less than 0.05) but had no effect on the uptake of 20 microM thiamine. These data suggest that, as in the rat, the intestinal transport of thiamine in humans proceeds by a coexistent dual system. At physiologic concentrations, thiamine is transported primarily by an energy-requiring, sodium-dependent active process, whereas at higher pharmacologic concentrations thiamine uptake is predominantly a passive process.

Biological Transport, Active↗
PubMedDate not supplied

Neuroticism and personality disorder in depression.

Neuroticism and DSM-III personality disorder were studied in 39 depressed inpatients. Interrelationships between these variables and their relationship to depressive typology were compared. The relationship of neuroticism, DSM-III personality type and adequacy of personality to MAOI treatment are also examined. Neuroticism scores were unaffected by short-term treatment, and no differences in neuroticism were observed between melancholics and nonmelancholics, or between endogenous and nonendogenous depressives. Higher neuroticism scores were associated with DSM-III personality disorder. Personality disorder occurred significantly more often in nonmelancholia; borderline, antisocial and histrionic personality disorders occurred exclusively in nonmelancholia, while passive-aggressive, dependent and avoidant disorders occurred in both kinds of depression. Response to MAO inhibitor treatment was similar in patients with high and low neuroticism, adequate and inadequate personality, DSM-III personality disorder and no DSM-III personality disorder. Ambiguities of Eysenck's neuroticism scale are discussed in relationship to depression.

Antisocial Personality Disorder↗