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Biomedical subjects

R Paul

Publications and source records attributed to R Paul.

At least 199 records · Page 11Linked to original sources
PubMed1988

Evaluation of treatment response to radiotherapy in head and neck cancer with fluorine-18 fluorodeoxyglucose.

Nineteen patients with malignant head and neck tumors were imaged before and during radiation therapy with 18F-2-fluoro-2-deoxy-D-glucose (FDG) to study the effect of radiotherapy (RT) on FDG uptake. All tumor images were FDG-positive before treatment. After RT, a decrement of tumor FDG uptake was found in all but two patients; these were nonradioresponders. There was a significant decrement (p less than 0.001) in uptake ratios after irradiation of 30 +/- 5 Gy among the radioresponsive (CR + PR) but not among the radioresistant (NC + PD) tumors. The administered dose of RT correlated (r = 0.47, p less than 0.05) with the decrement in FDG activity among the CR + PR but not among the NC + PD patients. The biologic half-life of FDG radioactivity in tumor tissue was evaluated by dynamic scintigraphy. A change in the half-life of FDG toward the value observed in normal tissue was associated with treatment response. The results suggest that FDG imaging can be used for follow-up of RT in patients with head and neck cancer.

Deoxy Sugars↗
PubMed1988

[The classification of pervasive developmental disorders and other disorders: toward the DSM-IV].

Forty years after Kanner's groundbreaking work and many publications later, the outlook for children with autism has not changed markedly. Progress in understanding the etiology, let alone in developing new approaches for treatment, has been extremely slow for this and other serious, early onset disturbances. Historically, disagreements over diagnosis and syndrome definition have impeded research efforts. Indeed, in many cases it is impossible, on reading research reports of even a decade ago, to know exactly what population was being studied. DSM-III has broken new ground in its emphasis on developmental disorders viewed within a multiaxial diagnostic scheme. Increased diagnostic precision should facilitate the application of rigorous bio-behavioral research methods, which, in turn may help increasingly to define homogeneous populations. Refinements of nosology should not be mere academic exercises. Rather, they should suggest hypotheses which are amenable to empirical test. DSM-III, in addition to pointing the way out of the era of psychiatric Babel, has suggested empirical studies which have challenged its assumptions. In the field of nosology, this should be considered a major criterion of success. Changes in nomenclature, while sorely needed, should be undertaken with appropriate skepticism and conservatism and should build upon the foundation provided by DSM-III.

Autistic Disorder↗
PubMed1987

[Protoporphyrinemia and iron metabolism in hemodialysis patients].

In 24 patients undergoing haemodialysis, two of them with pseudoporphyria, the total erythrocytic protoporphyrin and in four patients separately the zinc protoporphyrin were investigated. 20 patients showed an increase of the erythrocytic protoporphyrin of low to moderate degree, which only partly is to be ascribed to the zinc protoporphyrin. Since, as a rule, there is no iron deficit in haemodialysis, a secondary damage of the ferrochelatase, which physiologically by administration of iron leads to haem (ferroprotoporphyrin), is assumed as cause of the increase of erythrocytic protoporphyrin. Apart from the toxic lesion in particular a deficiency of the ferrochelatase coenzyme pyridoxal phosphate can be taken into consideration. Diagnostic and therapeutic investigations carrying on are proposed. The erythrocytic protoporphyrin does not only contribute to the pseudoporphyria in haemodialysis.

Adult↗
PubMed1987

Inhibition of vascular smooth muscle cell proliferation in culture by pentosan polysulphate and related compounds.

Pentosan polysulphate (PPS; SP 54; Hemoclar), a highly sulphated semi-synthetic polysaccharide of MW 4.7 kD, was tested in vitro as an inhibitor of rabbit aortic smooth muscle cell (SMC) proliferation and its effects were compared with those of dextran sulphate, laminarin sulphate and heparin fractions. When added to the cell cultures simultaneously with foetal calf serum, all sulphated polysaccharides inhibited cell growth. PPS was five fold more active than heparin and its low molecular weight fractions. A high molecular weight fraction of PPS was the most active inhibitor (IC50: 2.7 micrograms/ml vs 45 micrograms/ml for PPS, and 241 micrograms/ml for heparin). When PPS and heparin were pre-incubated with the cells for three days, then removed before foetal calf serum was added to stimulate growth, their inhibitory effects were comparable with those seen when the compounds were present throughout the growth phase, suggesting that they exert their effect by binding to the cell surface, and not by interacting with the growth factors in serum.

Animals↗
PubMed1987

Organ and tumor distribution of (18F)-2-fluoro-2-deoxy-D-glucose in fasting and non-fasting rats.

Differences in the uptake of (18F)-2-fluoro-2-deoxy-D-glucose ((18F)FDG) in various normal organs and the Rous sarcoma of fasted and unfasted rats were studied at 5, 15, 30, 60, and 120 minutes after i.v. injection. The uptake of (18F)FDG in the tumor, spleen, and testis increased for 120 minutes, while uptake in the other organs was either level (brain, heart, white fat) or cleared off. The uptake was higher in the tumor than in the normal organs. The fraction of viable tumor tissue as measured morphometrically correlated intraindividually with the uptake of (18F)FDG--an increase of 1% of vital tumor corresponded to a 1.01-fold increase in tumor uptake of (18F)FDG. The nutritional state was of importance for the uptake of (18F)FDG into the heart, testis and brown fat. (18F)FDG is taken quantitatively up by the viable parts of the Rous tumor; this may make it possible to follow the response of treatment in individual tumors also in man with (18F)FDG and positron emission tomography (PET).

Animals↗
PubMed1987

A comparison of language characteristics of mentally retarded adults with fragile X syndrome and those with nonspecific mental retardation and autism.

Fragile X syndrome is a recently identified form of mental retardation that is associated with a chromosomal abnormality and inherited in an X-linked manner. Previous studies have suggested that distinctive speech and language characteristics are associated with the syndrome. Twelve adult male residents of an institution for the retarded (aged 23 to 51 years) were compared on a series of speech and language measures to 12 adult males with nonspecific forms of MR who were residents of the same institution and were matched on age and IQ. A second contrast group consisted of similarly matched autistic men. Results revealed that there were no significant differences among the groups' performance, with the exception of increased rates of echolalia in the autistic group. A nonsignificant trend toward poorer performance on expressive measures on the part of the fragile X group was noted. The implications of these findings for further research on the syndrome are discussed.

Adult↗
PubMed1987

Itch and malignancy prognosis in generalized pruritus: a 6-year follow-up of 125 patients.

When 125 patients with generalized pruritus were followed up for 6 years, 66% reported continuing pruritus. In four patients a malignancy had been identified at the time of the initial examination, and four other patients developed malignancies during the follow-up period. Seven of the patients died of the malignancy during the follow-up period. This incidence of malignancies does not differ significantly from the value expected in a general population, matched for age and sex. However, two of the cancers were lymphomas, and this incidence is significantly (p less than 0.01) higher than that expected in a similarly matched population. As a whole our study indicates that no significant overall increase of malignant neoplasms is to be expected in patients with generalized pruritus and, therefore, any general efforts for cancer follow-up screening seem unwarranted in patients with pruritus.

Female↗
PubMed1987

Steroid receptors and response of endometrial cancer to hormones in vitro.

The sensitivity to medroxyprogesterone acetate (MPA) and tamoxifen (T) and their combination was assayed in 13 patients with untreated endometrial cancer by an in vitro ATP-bioluminescence method. The method measures the levels of adenosinetriphosphate (ATP), the basic energy source of living cells. A tumor was considered to respond to the drug, if the proportion of living cells after manipulation was 50% or less from unmanipulated control culture. Estrogen (ER) and progesterone (PR) receptors were assayed by the DCC-method and the results calculated by Scatchard-analysis. ER (greater than or equal to 3 fmol/kg cytosol protein) was present in all tumors and PR (greater than or equal to 10 fmol/kg cytosol protein) in 85% of the tumors. The response rate in vitro to MPA was 67% (8 out of 12 tumors), to T 18% (2 out of 11) and to their combination 69% (9 out of 13). The G1 tumors responded statistically significantly better to MPA (p less than 0.01) and MPA + T (p less than 0.02) as compared to T. MPA produced higher cell kill of G1 than G2 tumors (p less than 0.05). The ER content correlated with the effect of MPA in vitro in 67%, with the effect of T in 18% and with that of their combination in 69% of the tumors. The PR content correlated with the effects of MPA in vitro in 83%, with the effect of T in 36% and with that of their combination in 54% of the tumors. It was concluded that the in vitro ATP-bioluminescence method provides valuable information besides steroid receptor determinations for sensitivity testing of endometrial cancer to hormones.

Adenocarcinoma↗
PubMed1987

Comparison of fluorine-18-2-fluorodeoxyglucose and gallium-67 citrate imaging for detection of lymphoma.

Patients with lymphomas are conventionally imaged with [67Ga]citrate for tumor detection and determination of dissemination. Fluorine-18-2-fluoro-2-deoxy-D-glucose [( 18F]FDG) is a radiopharmaceutical that accumulates into tissues where glucose utilization is enhanced, such as tumors. Six cancer patients (five non-Hodgkin's lymphomas, one endodermal retroperitoneal sinus carcinoma) were imaged with [18F]FDG and [67Ga]citrate whole-body scintigraphies in order to compare the sensitivities of these two tumor imaging radiopharmaceuticals. Among the five untreated lymphoma patients, two 67Ga scans and four [18F]FDG scans were positive; in the patient with the retroperitoneal carcinoma who had a positive [18F]FDG scan before treatment, both scans were negative after treatment. Fluorine-18 FDG may be a more sensitive tumor-detecting radiopharmaceutical for non-Hodgkin's lymphoma than [67Ga]citrate.

Adult↗
PubMed1986

Dynamic (18F)-2-fluoro-2-deoxy-D-glucose (FDG) scintigraphy of normal and tumor-bearing rats.

Five normal rats, 14 rats bearing the Rous sarcoma intrarenally, and four rats with DMBA-induced mammary carcinomas were imaged by dynamic (18F)-2-fluoro-2-deoxy-D-glucose ((18F)FDG) scintigraphy and (99mTc)DTPA renography. The brain, heart, liver, kidneys, and tumor were selected as regions of interest (ROI) for time activity curves; exponential functions were fitted to the decay-corrected curves, which yielded biologic half-lives of (18F)FDG in the ROI. It was found that all organs ROI's exhibited average elimination of activity, whereas activity accumulated in the tumor ROI for the duration of the study (5 h). The (99mTc)DTPA renographies showed that the excretory function in kidneys bearing the Rous sarcoma is severely impaired. This study shows that small laboratory animals can be successfully scintigraphied with a conventional gamma camera using (18F)FDG and that the pharmacokinetics of this radiopharmaceutical may be evaluated.

Animals↗
PubMed1986

Missing hospital records: a confounding variable in retrospective studies.

In retrospective chart reviews there are often a certain number of missing hospital records. To elucidate this variable we compared the outcomes of very low birth weight breech infants with respect to the method of collecting data. A prospective sampling, during the hospital stay, of data was performed in 1979 to 1980 and in 1983 to 1984, and the frequencies of very low birth weight were 1.89 and 1.90, respectively, per 1000 live births. For 1981 to 1982 a retrospective record search was performed with the use of the ordinary medical record search system at this institution. For this period 39 of 52 (75%) hospital records were recovered, giving an apparent frequency of 1.32/1000 live births, which differed significantly from either period studied prospectively. An analysis of demographic data of the three groups revealed that the mean gestational age and the mean birth weights were higher in the period studied retrospectively compared with both periods studied prospectively and that the neonatal mortality rates were higher in the periods studied prospectively (74.1% and 57.1%, respectively) than in the period studied retrospectively (28.2%). It is concluded that the more complicated a clinical case is, the more likely the record will not be found for retrospective chart review. This problem should be kept in mind, and it ought to be a requirement that the number of missing charts be stated in retrospective observational studies.

Adult↗
PubMed1986

Metabolism of 2-[18F]fluoro-2-deoxyglucose in tumor-bearing rats: chromatographic and enzymatic studies.

The activities of hexokinase and glucose-6-phosphatase, as well as the in vivo metabolic products of 2-[18F]fluoro-2-deoxyglucose ([18F]FDG) (45 min after an i.v. injection), were determined from several tissues of Rous sarcoma implanted rats. The HK/G-6-Pase ratio was found to be high in brain and tumor, and low in liver with intermediate values for kidney and muscle. In accordance with the measured enzyme activities about 90% of the 18F was found as [18F]FDG-6-P in brain, heart and tumor, whereas most of its was as [18F]FDG in liver and kidney. In addition three minor metabolites, tentatively identified as nucleotide-derivatives of [18F]FDG, were formed. Our results suggest that at least Rous sarcoma tumor effectively converts [18F]FDG to [18F]FDG-6-P and thus PET studies with [18F]FDG can be applied to tumor diagnosis and to quantitative measurement of glucose utilization in tumor tissue according to the model of Sokoloff.

Animals↗