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Biomedical subjects

R D Strickland

Publications and source records attributed to R D Strickland.

At least 19 recordsLinked to original sources
PubMed1998

Cancer grading by Fourier transform infrared spectroscopy.

Thirty-nine freeze-dried tissue samples from 17 lymphoid tumors (nine malignant non-Hodgkin's lymphomas) were studied by Fourier transform infrared (FTIR) spectroscopy. The absorbance ratio A1121/A1020 increased, along with the emergence of an absorbance pulse at 1121 cm-1, with increasing clinicopathological grade of malignant lymphoma. An increasing A1121/A1020 ratio from benign to malignant is evident in literature spectra from several different tissues; however, the present study is the first to comment on this effect and to propose it as an index of the cellular RNA/DNA ratio after subtraction of overlapping absorbances, if present, due to collagen or glycogen. Absorbance attributable to collagen increased with lymphoma grade and was greater in benign inflammatory tumors than in low-grade lymphomas. The A1121/A1020 trend observed here may form the basis of a universal cancer-grading parameter to assist with cancer treatment decisions and may also be useful in the analysis of cellular growth perturbation induced by drugs or other therapies. Our spectral findings may potentially be applied to cell clusters and discrete areas of tumor tissue sections using the FTIR microscope, allowing correlation with morphology and a high degree of spatial resolution.

Collagen↗
PubMed1984

Evaluation of size and dynamics of the inferior vena cava as an index of right-sided cardiac function.

To define normal criteria of size and dynamics of the inferior vena cava (IVC) and its clinical value in assessing right-sided cardiac function, 2-dimensional (2-D) and M-mode echocardiography (echo) were performed in 175 subjects, who were classified into 3 groups: group 1-80 normal subjects; group IIA--65 patients with documented right-sided cardiac disease, and group IIB--30 patients with cardiac disease but no right-sided abnormality. The IVC was adequately imaged in 175 of 185 subjects (95%). There was good correlation between M-mode and 2-D echo (r = 0.84) and long- and short-axis (r = 0.88) measurements. The IVC diameter during expiration was: group 1-9 to 28 mm (mean 18.2 +/- 4.6); group IIA--15 to 40 mm (mean 23.1 +/- 4.8) and group IIB-8-24 mm (mean 15.6 +/- 3.7). Collapsibility index (inspiratory decrease in diameter) was: group I-37 to 100% (mean 55.8 +/- 15.9); group IIA--0 to 39% (mean 13.5 +/- 10.5); and group IIB--44 to 100% (mean 60.4 +/- 13.1). A and V waves could be measured in 120 of 151 cases (79%). Both A and V waves were less than 125% of its diameter in group I. The A wave was absent in 34 patients; 30 (88%) were in atrial fibrillation. Among 8 patients with tricuspid regurgitation, 5 (63%) had V waves greater than 125%. There was no correlation between diameter or collapsibility index and age, sex, rhythm or body surface area.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Phenytoin-induced agranulocytosis after treatment for a gunshot wound to the face.

A case of phenytoin-induced agranulocytosis is presented. This syndrome is characterized by a decrease in the blood neutrophil count to very low levels. Patients are generally asymptomatic, but they may become febrile and develop an infection, which is frequently fatal. Practitioners treating trauma patients or other patients in whom phenytoin treatment is initiated should be aware of the potential development of agranulocytosis.

Adult↗
PubMed1982

Detection of ischemic myocardial injury in patients with normal, or moderately elevated, serum CK and AST activities.

It is still undecided in clinical medicine if an increased serum CK-MB level indicates irreversible myocardial damage. We measured CK and AST activities on three serum samples obtained during the first 24 hours following admission of patients with a clinical history suggesting myocardial ischemia. Isoenzymes were not separated when CK and AST activities were less than 300 U/L and 35 U/L respectively, but were fractionated when the enzyme activities doubled during the first 24 hours even within their normal ranges. Over a three-year period this doubling occurred in 30 patients, one of whom was admitted twice to the hospital. The serum CK-MB fractions of these patients were 6% or greater in 26 and less than 6% in 5 admissions. The final clinical diagnosis given to the patients on 20 of these 26 admissions was acute subendocardial infarction. None of the five patients with a CK-MB fraction less than 6% had a clinical diagnosis of acute myocardial infarction. A comparative study of 102 patients with higher average enzyme activities but without doubling of both enzymes during a 24-hour period, did not yield a CK-MB of 6% or greater. None of this group of patients was diagnosed clinically as having had acute myocardial infarction.

Aspartate Aminotransferases↗
PubMed1979

Abnormal enzyme phenotype (E1a E1f): normal response to succinylcholine.

The enzyme serum cholinesterase responsible for the hydrolysis of the muscle relaxant succinylcholine exists in the form of several variants. These may be identified in serum by using substances which inhibit their activity to different degrees. The heterozygote for the atypical and fluoride resistant enzymes (E1a E1f) is one of the phenotypes which has been reported to be sinsitive to succinylcholine. A case is described where succinylcholine given on two separate occasions did not induce apnoea in an individual phenotyped as E1a E1f by at least five methods of inhibition. This is the first reported example of such insensitivity to the drug in this phenotype. Temperature activities for the patient's serum over the range of 20 degrees C to 45 degrees C differed from that of an established E1a E1f phenotype used as a control. There was a progressive inactivation of the control serum at temperatures higher than 35 degrees C, as previously reported for this phenotype. Activity in the serum of the subject of this study did not exhibit the peak activity at 35 degrees C but continued to rise and probably reached a peak between 40 degrees C and 45 degrees C. The significance of these results in the context of current methods of phenotyping is discussed.

Adolescent↗
PubMed1979

Lipoidal bladder concretion: an unusual autopsy finding in acute lymphoblastic leukemia.

The occurrence of a large (2.3 gm.), wax-like, creamy white concretion in the bladder of a 7-year-old girl who died of acute lymphoblastic leukemia is reported. Lipids constituted 40% of the total weight and triglycerides accounted for 95% of the total lipids. The fatty acid composition of the individual lipid classes showed a predominance of saturated fatty acids (75 to 80%). Factors influencing the pathogenesis of the material are discussed. A review of the literature on childhood leukemia showed no reference to such lipid abnormalities and the occurrence of this type of concretion has not been reported previously.

Child, Preschool↗
PubMed1977

Subsensitivity of beta responses during therapy with a long-acting beta-2 preparation.

The question whether some tolerance or subsensitivity of various beta receptors develops during therapy with long-acting oral beta-2 agents has practical and theoretical importance. We applied a strong beta-2 stimulus (terbutaline, 5.0 mg orally) at weekly intervals for up to three weeks in 19 stable asthmatics and bronchitics while commencing 5.0 mg terbutaline three times daily. The evening dose was omitted before each morning challenge. Challenges were continued at one and two weeks off terbutaline in some patients to test return of beta function. Patients received no ephedrine for two weeks before the study but were allowed aminophylline or isoproterenol inhalations up to 18 and 4 hr before challenges, respectively. Pulmonary function, pulse, and blood pressure were monitored at 0, 60, 120, and 180 min, and metabolic parameters measured at 0 and 180 min. There was significant drug tolerance in the drop and minimum diastolic pressure reached, rise in lactate, cyclic AMP, and blood glucose, and drop in eosinophils. Peak FEV1 and V50 dropped slightly, but vital capacity and minimal airway resistance did not change significantly. During continuous therapy this slight bronchial subsensitivity is probably obscured by elevated baseline function. It might assume importance during periods of excessive inhaler use or abrupt drug withdrawal.

Asthma↗
PubMed1977

Biological activity of dilute isoproterenol solution stored for long periods in plastic bags.

The effect of long-term storage in polyvinyl chloride bags on the biological activity and the chemical stability of isoproterenol was studied. A freshly prepared solution of isoproterenol, isoproterenol solution stored for six months and isoproterenol stored for 30 months were infused into the coronary circulation of 14 isolated rabbit hearts; heart rates were determined. Spectrophotometric studies to determine stability at various pH levels were also done. Aging of the solutions at pH 4 and at a concentration of 4 microgram/ml caused no significant impairment of their potency. Solutions above pH 6 were unstable.

Animals↗
PubMed1977

Apparent theophylline half-life fluctuations during treatment of acute left ventricular failure.

The administration of theophylline in a 63-year-old man with arteriosclerotic heart disease and chronic bronchitis is discussed to illustrate the pharmacokinetics of theophylline in an abnormal host state. The case demonstrates that clearly acute congestive heart failure and its treatment may dramatically affect the kinetics of theophylline elimination. Possible explanations for this phenomenon are presented, and the therapeutic implications are discussed.

Administration, Oral↗