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Biomedical subjects

A Freeman

Publications and source records attributed to A Freeman.

At least 127 records · Page 7Linked to original sources
PubMed1982

The influence of histologic type on the incidence and duration of response in non-Hodgkin's lymphoma.

A group of 227 cases of non-Hodgkin's lymphoma included seven favorable and four unfavorable histologic classes with collective median survival times of 83 and 16 months, respectively. The favorable group included three follicular subgroups (cleaved, mixed, and large noncleaved) and four diffuse classes (small lymphocytic, cleaved, Burkitt's noncleaved, and convoluted lymphocytic). The unfavorable group consisted of four diffuse subgroups (plasmacytoid lymphocytic, mixed, and small and large noncleaved). There were significant differences in collective median survivals between patients in Stage I--II and those in Stage III--IV in both the favorable group (not reached, NR versus 62 months, P less than 0.001) and the unfavorable group (57 months versus 12 months, P less than 0.01). The incidence of complete response to primary treatment was higher in the favorable than in the unfavorable group (75% versus 56%, P = 0.002) and in those with limited as compared with advanced disease. Complete responders in both prognostic groups had longer survival times than did partial or minimal responders. A significant difference in median complete remission duration was found between responders in Stage I--II versus Stages III-IV in the favorable group (not reached versus 40 months, P = 0.001) but not in the unfavorable one (56 months versus 22 months, P greater than 0.05). The absence of relapses after 41 months among complete responders in the favorable but not in the unfavorable group suggests a potential for cure in a proportion of cases from the former group. The incidence of complete response was lower and median remission duration was shorter after secondary as compared with primary treatment. The results of this study confirm the prognostic value of the Lukes and Collins classification system and the importance of initial staging and of achieving a complete response to primary treatment in both the favorable and unfavorable lymphomas.

Antineoplastic Agents↗
PubMed1982

Intrathecal interferon in multiple sclerosis.

Human fibroblast interferon (IFN-beta) was administered by serial lumbar puncture to ten patients with multiple sclerosis (MS). Their clinical courses were compared with those of ten MS control patients who did not receive IFN-beta. As of this writing, the recipients have been followed up for 1.8 to 2.0 years (mean, 1.9 years), and the controls for 1.5 to 1.7 years (mean, 1.6 years). During the study, two recipients suffered four exacerbations, and six controls suffered 11 exacerbations. The recipients' rates of exacerbation during the study were significantly less than their rates both for the entire prestudy duration of the disease and for the 1.8 to 2.0 years immediately preceding entry into the study. The controls' rates of exacerbation before the study and during the study period did not differ significantly. Clinically, the conditions of five recipients and two controls improved, those of three recipients and four controls were unchanged, and those of two recipients and four controls worsened. Headaches, sometimes accompanied by fever and rarely by nausea and vomiting, occurred after injections of IFN-beta. Toxic symptoms usually disappeared within 24, hours; rarely, they persisted for seven to ten days. Each recipient had transient CSF pleocytosis and elevated levels to total protein (the latter remaining elevated in seven). These findings show that intrathecal administration of IFN-beta is feasible in patients with MS, warrant cautious optimism that intrathecal IFN-beta may be effective in altering the course of the disease, and support concepts of a viral or dysimmune cause of MS.

Adolescent↗
PubMed1982

The treatment of acute myelocytic leukemia in patients 30 years of age and younger.

The treatment of acute myelocytic leukemia in childhood and young adults has lagged behind that for acute lymphocytic leukemia. The studies described here were directed towards evaluating the role of intensive chemotherapy in the treatment of this illness. Intensive remission induction therapy combining cytosine arabinoside with an anthracycline antibiotic produced a complete remission rate comparable to that achieved in acute lymphocytic leukemia (45 of 49 patients or 92%). Intensive consolidation chemotherapy produced a median duration of complete remission of 160 weeks with 40% of patients projected to be in remission at 4 years. By contrast, the median duration of remission for patients treated with moderate consolidation/maintenance therapy was 23 weeks with only 10% of patients in remission at 4 years. These studies demonstrate that intensive chemotherapy can be administered to pediatric patients and young adults and that this approach to therapy produces a high remission rate with a 3 year median duration of remission.

Adolescent↗
PubMed1982

First-pass radionuclide angiocardiography in the determination of left-to-right cardiac shunt site in children.

To ascertain if the level of a left-to-right cardiac shunt can be reliably established by first-pass radionuclide angiocardiography with 99mTc-pertechnetate, 102 children have been studied; 19 without a shunt, 26 with an atrial septal defect (ASD), 45 with a ventricular septal defect (VSD), and 12 with a patent ductus arteriosus (PDA). Time-activity curves were generated over the right atrium and ventricle, and several quantitative parameters were derived from the curves. It was concluded that in the absence of right-sided valvular incompetence, the time-activity curves show the greatest abnormality in the cardiac chambers distal to the left-to-right shunt. The right ventricular curve is typically altered in ASD but cannot be relied upon to differentiate VSD or PDA. The identification of ASD is assisted by the use of two of the parameters, the count ratio C4:C1 and time ratio T2-T1.

Adolescent↗
PubMed1982

Radionuclide ejection fraction: comparison of response to treadmill and bicycle exercise.

Most exercise radionuclide studies utilise the supine bicycle ergometer during imaging, although exercise on a treadmill results in greater cardiovascular stress. Twenty-three patients were studied to compare the radionuclide left ventricular ejection fraction (LVEF) estimated immediately following treadmill exercise with that obtained at peak supine bicycle exercise in patients with coronary artery disease (CAD) and patients with normal coronary arteries. In 14 patients with CAD the rest LVEF was 47 +/- 7% (mean +/- SD) by first pass and 49 +/- 10% by equilibrium blood pool techniques. Immediately following maximum treadmill exercise, 13 of the 14 patients with coronary artery disease showed either no change or a decrease in LVEF, the LVEF was 49 +/- 7% (P = NS) and 47 +/- 8% (P = NS) by first pass and equilibrium determinations respectively. In comparison the LVEF during peak supine bicycle exercise decreased significantly to 42 +/- 12% (P less than 0.01). In nine patients with angiographically normal coronary arteries the rest LVEF was 51 +/- 4% by first pass and 54 +/- 6% by equilibrium, increasing to 67 +/- 7% (P less than 0.01) and 64 +/- 7% (P less than 0.01) respectively following treadmill exercise. During peak bicycle exercise LVEF increased in the normal patients to 61 +/- 7% (P less than 0.05). These data suggest that quantitative radionuclide angiography following either maximum treadmill exercise or during peak bicycle exercise can discriminate between patients with coronary artery disease and normal subjects, although the magnitude of left ventricular functional changes are greater during bicycle stress.

Adult↗
PubMed1982

An oral examination of the psychiatric knowledge of medical housestaff: assessment of needs and evaluation baseline.

To assess the psychiatric knowledge of medical housestaff, the authors devised an oral examination based on two simulated clinical encounters and administered it to 26 medical residents. The case material embodied those psychiatric problems known to be common in medical populations, namely depression, delirium, dementia, and "psychogenic" pain. The standardized simulations were punctuated by standardized "open" questions with followup probes. A panel of experienced clinicians developed rating criteria for each question such that responses could be categorized ad "good," "adequate," "inadequate," or "poor," in terms of "what an internist needs to know." Blind raters of the exam achieved an interrater reliability of 0.08. The results indicate major deficits in the knowledge needed for assessment and treatment of these common problems. Only 16% of answers were "good," where as 42% were "inadequate" or "poor". For example, 88% of the doctors could not name three factors that help distinguish organic from "functional" psychosis, and 88% could not list three side-effects of tricyclic antidepressants. The doctors' level of experience was not correlated with test scores, either overall or question by question. These results, together with measures of attitude and skill, have been used to develop a needs-based liaison psychiatry curriculum and to evaluate the effectiveness of that curriculum.

Adult↗
PubMed1982

Time trend analysis of plasma unconjugated and sulfoconjugated estrone and 3 beta-delta 5-steroids in fetal and maternal sheep plasma in relation to spontaneous parturition at term.

Parturition in the sheep is preceded by a complex series of changes in both fetal and maternal plasma-steroid hormone concentrations. Using the chronically catheterized fetal sheep preparation, we measured unconjugated and sulfoconjugated pregnenolone, 17 alpha-hydroxypregnenolone, dehydroepiandrosterone, and estrone in fetal and maternal plasma over the final 20 days before spontaneous vaginal delivery at term. Where appropriate, third degree polynomial functions were fitted to the changing plasma hormone concentration profile. Fetal and maternal plasma pregnenolone and pregnenolone sulfate both fell from maximum values in the last 4 days of gestation. Fetal and maternal plasma estrone and estrone sulfate concentrations underwent a terminal rise over the last 4 days of gestation that was a mirror image of the fall in plasma pregnenolone and pregnenolone sulfate. Maternal 17 alpha-hydroxypregnenolone rose over the last 4 days of gestation. Fetal 17 alpha-hydroxypregnenolone, maternal and fetal plasma dehydroepiandrosterone sulfate, and fetal plasma dehydroepiandrosterone sulfate, and fetal plasma dehydroepiandrosterone showed no trend during the period of study. Maternal plasma dehydroepiandrosterone rose over the last 4 days of gestation. These results support the view that increased activity of placental 17 alpha-hydroxylase and 17-20-desmolase is responsible for the conversion of C-21 steroids to estrogens at term. delta 5-Steroids are present in very high plasma concentrations in fetal sheep plasma and may constitute a more important precursor pool for estrogen biosynthesis than does circulating plasma progesterone.

17-alpha-Hydroxypregnenolone↗
PubMed1981

Intrathecal interferon reduces exacerbations of multiple sclerosis.

Ten patients with multiple sclerosis who were treated with human fibroblast interferon (IFN-B) for 6 months showed a significant reduction in their exacerbation rates compared with their rates before treatment (P < .01). The IFN-B was administered intrathecally by serial lumbar punctures. There was no significant change in the exacerbation rates of ten multiple sclerosis control patients before and during the period of observation. The IFN-B recipients have now been on the study a mean of 1.5 years, the controls, 1.2 years. The clinical condition of five of the IFN-B recipients and one of the control patients has improved, whereas the condition of five of the controls and one of the IFN-B recipients has deteriorated (P < .036). These findings warrant cautious optimism about the efficacy of intrathecal IFN-B in altering the course of multiple sclerosis and support concepts of a viral or dysimmune etiology of the disease.

Adolescent↗
PubMed1981

Is selective therapy of recurrent nephrolithiasis possible?

We evaluated, in 128 patients with recurrent nephrolithiasis, the efficacy of special treatment programs for some of the common causes of nephrolithiasis, chosen on the basis of their ability to correct underlying physicochemical and physiologic derangements. Therapy included sodium cellulose phosphate for 18 patients with absorptive hypercalciuria, thiazide diuretics for 27 patients with absorptive hypercalciuria and for 10 with renal hypercalciuria, orthophosphate for eight patients with hypophosphatemic absorptive hypercalciuria, allopurinol for 21 patients with hyperuricosuric calcium oxalate nephrolithiasis, thiazide and allopurinol for 26 patients with absorptive hypercalciuria with hyperuricosuria, and high fluid intake and/or low calcium diet for 22 patients with normocalciuric nephrolithiasis. Patients in all seven groups had a significant reduction in stone formation during 1.70 to 3.37 years of treatment, as compared with the pretreatment period of three years. Remission was found in 70 to 91 percent of patients and reduced stone formation rate was encountered in 88 to 100 percent. Each treatment program produced a significant decline in stone formation rate from 1.90 to 2.28 stones per year to 0.09 to 0.55 stones per year. The actual number of stones formed during treatment was significantly lower than the number predicted from the pretreatment frequency of stone formation (less than 26 percent). The results provide evidence supporting a selective approach to therapy of nephrolithiasis.

Allopurinol↗
PubMed1981

Laminin and fibronectin in cell adhesion: enhanced adhesion of cells from regenerating liver to laminin.

Laminin, a basement membrane glycoprotein isolated from cultures of mouse endodermal cells and rat yolk sac carcinoma cells, promoted the attachment of liver cells obtained from regenerating mouse liver. Cells from normal mouse liver attached readily to dishes coated with fibronectin but attached poorly to surfaces coated with laminin. Both proteins efficiently promoted the attachment of cells from livers undergoing regeneration. After regeneration, the attachment to laminin returned to the low levels found in animals not subjected to partial hepatectomy but attachment to fibronectin remained high. Immunofluorescent staining of sections of normal liver with antilaminin revealed the presence of laminin in or adjacent to the walls of the bile ducts and blood vessels. After induction of regeneration by partial hepatectomy, increased amounts of laminin appeared in the sinusoidal areas. After carbon tetrachloride poisoning, staining for laminin was especially pronounced in the necrotic and postnecrotic areas around the central veins. This additional expression of laminin was transient. It reached a maximum around 5--6 days after the injury and then gradually disappeared. These findings show that laminin is an adhesive protein. The increase of laminin in regenerating liver and the adhesiveness of cells from such livers to laminin suggest a role for laminin in the maintenance of a proper tissue organization during liver regeneration.

Animals↗
PubMed1980

Incidence of parasitic infestation in black children at Livingstone Hospital.

This study was undertaken to determine the incidence of protozoa and helminthic ova in faecal samples of Black children attending Livingstone Hospital. Specimens were collected from 100 children who presented with, inter alia, a history of worms in the stool or vomitus. Controls consisted of a further 100 patients selected at random who did not have a history of passing worms and whose symptoms were not directly attributable to parasite infestation, e.g. wheezing chest, bloody stools. Results indicate that 66% of the random group were infested compared with 76% of the suspect group. Trichuris trichiuria and Ascaris lumbricoides were the commonest parasites found.

Black or African American↗
PubMed1980

Intestinal ascariasis: new plain film features.

Radiographs from 30 children with intestinal obstruction caused by a bolus of Ascaris worms were analyzed. Worms could be seen outlined against intestinal gas; the interface between worm bolus and adjacent gas shadows was irregular. Gas trapped within the worm bolus had irregular outlines. There were also fine linear radiolucent shadows and small bubbles. Fluid levels were sometimes distorted by a projecting worm bolus, resulting in a hump effect. Some of the radiolucencies were within the worms. These features were used in an analysis of radiographs from 68 children who did not have bolus obstruction. Of 44 children with proven ascariasis, 28 (64%) had suggestive radiologic features. In four of 24 children without Ascaris ova in the stools, confusion with fecal shadows resulted in a false-positive diagnosis on the radiographs. Recognition of the worm infestation in asymptomatic patients is important because intestinal malabsorption may contribute to nutritional deficiency.

Animals↗
PubMed1979

Isonitrile derivatives of polysaccharides as supports for the covalent fixation of proteins and other ligands.

A method for the introduction of side chains containing isonitrile (isocyanide, functional group) on the backbone of polysaccharides and other hydroxylic polymers was developed. The method was based on (a) ionization of some of the hydroxyl groups on the polymer by treatment with a strong base (tert-butoxide) in a polar aprotic solvent (dimethylsulfoxide), and (b) introduction of side chains containing isonitrile groups by nucleophilic attack of the polymeric alkoxide ions on a low molecular weight isonitrile containing a good leaving group in the omega-position, (1-tosyl-3-isocyanopropane). By this method, the side chains containing the-NC functional groups are attached to the polymeric backbone via stable ether bonds. The isonitrile derivatives of cellulose, linear and cross-linked dextran and cross-linked agarose utilized for the covalent fixation of high and low molecular weight ligands by four-component reactions carried out in aqueous medium, at neutral pH.

Cellulose↗
PubMed1979

Hypercalcemia complicating childhood malignancies: a report of seven cases with some pathophysiological considerations.

A group of seven children with different malignant processes presenting with hypercalcemia was studied. Bone destruction, diffuse metabolic abnormalities, abnormal acid-base homeostasis and recurrent hypercalcemia characterized these patients. A different mechanism leading to the production of hypercalcemia and/or bone destruction by cancer cells is considered. The results of this report suggest that parathyroid hormone production (P.T.H.) by the parathyroid glands is normal and that ectopic secretion of PTH or PTH-like material is negligible in these cases.

Acid-Base Imbalance↗
PubMed1979

Multilayer immobilized-enzyme filter reactors: urease bound to nylon fabric filters.

Urease was bound to commercially available nonwoven nylon fabric filters. Multilayer immobilized-enzyme filter reactors were constructed by packing varying numbers of urease-nylon filters in a column. Owing to the relatively open structure and high mechanical strength of the filter fabric, compaction and pressure drop effects were minimal. The reactors could be operated in a wide range of substrate concentrations and flow rates under conditions where mass-transfer limitations could be neglected. The kinetic behavior of the immobilized-enzyme filter reactors could be described by a linear form of the integrated Michaelis-Menten equation using a model based on the sequential action of the enzyme filters.

Acrylamides↗