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Biomedical subjects

R Kaplan

Publications and source records attributed to R Kaplan.

At least 163 records · Page 9Linked to original sources
PubMed1980

Phase II study of L-asparaginase in the treatment of pancreatic carcinoma.

L-Asparaginase was given to ten patients with advanced nonresectable pancreatic carcinoma because of the demonstration of in vitro sensitivity of the tumor to the drug. No therapeutic value was demonstrated for L-asparaginase. Toxicity was significant, mainly as evidenced by increasing mental confusion and early signs of a coagulopathy. On the basis of this limited study, L-asparaginase seems to have no value in advanced pancreatic carcinoma. The usefulness of L-asparaginase as primary therapy in patients with less advanced disease remains to be determined.

Adenocarcinoma↗
PubMed1979

Anatomical accuracy of echocardiographically assessed left ventricular wall thickness.

1. A comparison of direct measurement and M-mode echocardiography in the determination of posterior left ventricular wall thickness was performed in 26 subjects, of whom 21 underwent cardiac bypass surgery; the remainder came to necropsy. 2. In the surgical group a close correlation was demonstrated between direct measurement of posterior wall thickness and the echocardiographic end-diastolic dimension (r = 0.76, P less than 0.001). 3. The necropsy measurement of posterior wall thickness correlated with the echocardiographic end-systolic dimension (r = 0.99, P less than 0.001). 4. These findings confirm that the echocardiographic measurement of posterior wall thickness accurately reflects the anatomical dimension.

Blood Pressure↗
PubMed1979

The successful use of "high level" PEEP in near fatal Endrin poisoning.

The insecticide Endrin is a highly toxic chlorinated hydrocarbon which can cause severe CNS and respiratory derangement. Death usually follows intoxication within 24 hours. A 19-year-old male developed convulsions and gross pulmonary edema after the ingestion of Endrin. His trachea was intubated and constant positive pressure ventilation with PEEP of up to 28 cm H2O was instituted. The patient survived and recovery appeared to be complete. Severe pulmonary edema is not a common finding in patients who have Endrin poisoning. The use of PEEP above 15 cm H2O is a controversial issue; however, we believe that it contributed significantly to the survival of our patient.

Adult↗
PubMed1979

Collagenolytic activity of crevicular fluid and of adjacent gingival tissue.

The fluid in and gingival tissue lining periodontal pockets were collected from male patients undergoing periodontal therapy. The collagenolytic activity of the crevicular fluid, and the ability of the gingiva in culture to degrade (a) an exogenous collagen substrate, and (b) endogenous collagen newly synthesized and labeled with H3-hydroxyproline, were related to the severity of gingival inflammation. Although inflammation appeared to have only a slight effect on gingival collagenolytic activity and on the turnover of collagen newly synthesized in culture, a marked effect was observed on the collagenase activity in the crevicular fluid. This study suggests that the collagen destructive activity of the periodontal lesion can be assessed by monitoring crevicular fluid collagenolytic activity.

Adult↗
PubMed1978

Infantile stimulation induces brain lateralization in rats.

The hypothesis tested was that the effects of early experiences are asymmetrically distributed in the two brain hemispheres. Litters were either handled or not handled between birth and weaning, and the weanlings were reared in either laboratory cages or enriched environments between 21 and 50 days. When approximately 135 days old, animals within each of the four treatment groups had a right neocortical ablation, a left neocortical ablation, a sham operation, or no surgery. About 1 month later, all animals were given the open-field test for emotionality and exploratory behavior. Ablating either the right or left neocortex increased the activity scores of nonhandled controls, but there was no evidence of lateralization. However, the groups handled in infancy did show lateralization. Ablating the left brain did not significantly increase activity, but ablating the right brain caused extreme scores: handled rats without enrichment experience were the most active, and handled rats also placed into the enriched environment had near-zero scores in the open field.

Animals↗
PubMed1978

Initial levels of CEA and their rate of change in pancreatic carcinoma following surgery chemotherapy and radiation therapy.

CEA levels and their rate of change in 41 patients with pancreatic carcinoma following surgery, chemotherapy and radiation therapy were determined. Surgical resection, though not curative, was associated with a decrease in CEA level, with approximately half these levels returned to normal. No correlation with survival was noted. CEA levels are increased by obstructive jaundice. Radiation alone or in combination with 5-Fluorouracil did not change CEA levels in patients with locally unresectable pancreatic carcinoma. CEA levels progressively increased in patients with widespread metastatic pancreatic carcinoma, who expired from their disease.

Alkaline Phosphatase↗
PubMed1978

Effect of prednisolone on motor end-plate fine structure: a morphometric study in hamsters.

The fine structure of quadriceps motor end-plates in hamsters was analyzed quantitatively one, two, four, seven, and thirty-two weeks following intraperitoneal injections of prednisolone. Except for transient increases in postsynaptic length and membrane profile concentration after prednisolone administration at dosages of 4 mgper kilogram of body weight for one week and 2 mg per kilogram for four weeks, mean values for various measurable profiles in the presynaptic and postsynaptic regions showed no significant differences between control and treated animals.

Animals↗
PubMed1978

An interdisciplinary course for optometry students specializing in vision training.

The practice of primary-care optometry often necessitates interaction with professionals from varied backgrounds. This is especially true in the area of vision training, in which close coordination between professionals in schools, agencies, and clinics is necessary. Too often a communcation problem prevents beneficial interdisciplinary liaison. One way of ensuring that optometrists acquire communication and interaction skills is to provide seminars and courses in schools and colleges of optometry. The program described in this paper has helped optometry students refine their communication and referral skills.

Child↗
PubMed1977

Molecular characterization of limulin, a sialic acid binding lectin from the hemolymph of the horseshoe crab, Limulus polyphemus.

The sialic acid binding lectin, limulin, was isolated by gel filtration and ion-exchange chromatography from the hemolymph of Limulus polyphemus. When the purified protein was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of beta-mercaptoethanol, two major protein bands were observed. These two bands, subsequently found to contain carbohydrate as well, corresponded to molecular weights of 25 000 and 27 000. Amino acid sequence analyses were performed on both the intact protein and isolated cyanogen bromide fragments. The following primary structural features were noted in the amino-terminal region of limulin: (1) the absence of histidine and alanine from the NH2-terminal 50 residues; (2) the presence of five of the total eight prolines of the molecule between positions 13 and 30; and (3) a possible carbohydrate attachment site consisting of only the amino acids proline and serine between residues 13 and 19. The resultsof cyanogen bromide cleavage studies confirmed the presence of 2 methionine residues per subunit, at positions 25 and 58 respectively. No sequence heterogeneity was observed in this study. While it is quite possible that limulin plays some role in the defense mechanisms of the horseshoe crab, there is no obvious sequence homology between this invertebrate lectin and vertebrate immunoglobulins.

Agglutinins↗
PubMed1977

Accumulation of nucleotides by starved Escherichia coli cells as a probe for the involvement of ribonucleases in ribonucleic acid degradation.

The acid-soluble ribonucleic acid degradation products formed by Escherichia coli cells starved for a carbon source have been identified. They comprise oligonucleotides, nucleoside diphosphates, 5'- and 3'-nucleoside monophosphates, nucleosides, and free bases. The majority of these products are excreted phates, nucleosides, and free bases. The majority of these products are excreted into the medium, and only small and constant amounts are kept in the pool. During carbon starvation at elevated temperatures, mutants deficient in ribonuclease I do not form oligonucleotides and 3'-nucleoside monophosphates, and mutants that contain a modified form of polynucleotide phosphorylase do not accumulate nucleoside diphosphates. 5'-Nucleoside monophosphates do accumulate, however, in a mutant containing thermoabile ribonuclease II, under conditions where more than 95% of all enzyme activity had been destroyed. The data presented confirm the participation of ribonuclease I and polynucleotide phosphorylase in the final steps of ribonucleic acid degradation and indicate that an exonuclease forming 5'-nucleoside monophosphates is also involved.

Endonucleases↗