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Biomedical subjects

L Long

Publications and source records attributed to L Long.

At least 73 records · Page 4Linked to original sources

[Experimental study of internal radiation with yttrium-90 microspheres in the treatment of mouse transplanted hepatoma].

The effect of yttrium-90 microspheres in the treatment of mouse transplanted hepatoma H22 was studied. Seventy BALB/C mice with hepatoma H22 were randomly divided into 7 groups (A, B, C, D, E, F, G) and treated respectively with 37, 18.5, 14.8, 11.1, 7.4, 3.7 and 0 MBq/cm3 internal radiation by intratumoral injection of Y-90 microspheres. Dose-dependent therapeutic effects were observed. In group A and B, the tumor growth was markedly retarded and eventually un-palpable. Histological examinations showed complete necrosis of the tumor. In groups C,D, E,F, the tumor growth was also inhibited. However, patchy necrosis could be seen amid apparently normal tumor cells. Only isolated, spotty foci of necrosis were present in the untreated control tumors. The results indicate that a tumor of 1 cm diameter can be effectively treated by internal radiation with 18.5MBq Y-90 microspheres injected into the tumor.

Animals↗

Characterization of cDNAs encoding the murine A+U-rich RNA-binding protein AUF1.

A+U-rich elements (ARE) serve to control the degradation of some proto-oncogene and lymphokine mRNAs. The protein, AUF1, which consists of two polypeptides of 37 and 40 kDa (p37 and p40, respectively) when purified from cytosol, has been implicated in ARE-directed mRNA turnover due to its binding to ARE. Molecular cloning of a cDNA (p37AUF1) corresponding to human p37 predicted a polypeptide containing two non-identical RNA recognition motifs (RRM) and a C-terminal Gln-rich domain [Zhang et al. Mol. Cell. Biol. 13 (1993) 7652-7665]. Two cDNAs, designated muAUF1-3 and muAUF1-7, were isolated from a murine fetal cDNA library, using as a probe, a fragment of the p37AUF1 cDNA encoding RRM1 and approximately half of RRM2. The muAUF1-3 open reading frame (ORF) was very homologous to human p37AUF1 with the greatest homology between the corresponding RRMs and the C-terminal Gln-rich motif. Clone muAUF1-7 was highly homologous to muAUF1-3, but was truncated within the region encoding the RNP-1 box in RRM2. Clone muAUF1-3 encoded 19 amino acids in RRM1 not encoded by either muAUF1-7 or human p37AUF1. Such alterations in sequence could modify the RNA-binding properties of these proteins and have concomitant effects on ARE-directed posttranscriptional processes.

Adenine↗

Paracrine growth stimulation by hepatocyte-derived insulin-like growth factor-1: a regulatory mechanism for carcinoma cells metastatic to the liver.

Tumor H-59 is a subline of the Lewis lung carcinoma which is highly and preferentially metastatic to the liver. We used this carcinoma model to investigate the role of paracrine growth regulation by liver-derived factors in this organ-selective pattern of metastasis. We observed that serum-free medium conditioned by primary cultures of mouse hepatocytes was highly and specifically mitogenic for H-59 cells but had little effect on the proliferation of a second subline, i.e., carcinoma M-27, which is metastatic only to the lung. This mitogenic activity was hepatocyte-specific and could be blocked or depleted by a monoclonal antibody to insulin-like growth factor 1 (IGF-1). IGF-1 could in turn be detected in hepatocyte conditioned medium by the Western blot assay, and when added to serum-deprived cells, IGF-1 could stimulate the proliferation of H-59 but not M-27 cells. Furthermore, when expression of the IGF-1 receptor was analyzed by the Northern blot assay, we found that H-59 cells expressed significantly higher levels of mRNA transcripts encoding IGF-1 receptor. A ligand binding assay revealed that the number of IGF-1 binding sites on H-59 cells was 3.4-fold higher than that on M-27 cells. The results identify IGF-1 as the growth factor mediating the proliferative effect of hepatocyte conditioned medium and suggest that paracrine growth stimulation by hepatocyte-derived IGF-1 is a potential mechanism of selection in the process of liver colonization by these carcinoma cells.

Animals↗

Evaluation of active compression-decompression CPR in victims of out-of-hospital cardiac arrest.

OBJECTIVE--Active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) appears to improve ventilation and coronary perfusion when compared with standard CPR. The objective was to evaluate potential benefits of this new CPR technique in patients with out-of-hospital cardiac arrest in St Paul, Minn. DESIGN--Ten-month, prospective, randomized parallel-group design. SETTING--St Paul, Minn, population 270,000. PATIENTS--All normothermic victims of nontraumatic cardiac arrest older than 8 years who received CPR. MAIN OUTCOME MEASURES--Return of spontaneous circulation, admission to the intensive care unit (ICU), return of baseline neurological function (alert and oriented to person, place, and time), survival to hospital discharge, survival to hospital discharge with return of baseline neurological function, and complications. RESULTS--Seventy-seven patients received standard CPR and 53 patients received ACD CPR. The mean emergency medical services call response interval was less than 3.5 minutes. When all patients were considered, a higher percentage of ACD CPR patients had a return of spontaneous circulation and were admitted to the ICU vs standard CPR (45% vs 31%, and 40% vs 26%, respectively), but these trends were not statistically significant (P < .10 and P < .10). No statistically significant differences were found between hospital discharge rates (12 [23%] of 53 for ACD CPR vs 13 [17%] of 77 for standard CPR), return to baseline neurological function (10 [19%] of 53 for ACD CPR vs 13 [17%] of 77 for standard CPR), or return to baseline neurological function at hospital discharge (nine [17%] of 53 for ACD CPR vs 12 [16%] of 77 for standard CPR). Return of spontaneous circulation, ICU admission, and neurological recovery in both CPR groups were highly correlated with downtime (time from collapse to emergency medical system personnel arrival to the scene in witnessed arrests). With less than 10 minutes' downtime, survival to the ICU was 59% (19/32) with ACD CPR and 33% (16/49) with standard CPR (P < .02), return to baseline neurological function was 31% (10/32) with ACD CPR and 20% (10/49) with standard CPR (P = .27), and hospital discharge rate was 38% (12/32) with ACD CPR and 20% (10/49) with standard CPR (P = .17). Complication rates in patients admitted to the hospital were similar in both groups. CONCLUSIONS--This study demonstrates that ACD CPR appears to be more effective than standard CPR in a well-defined subset of victims of out-of-hospital cardiac arrest during the critical early phases of resuscitation. Based on this study, a larger study should be performed to evaluate the potential long-term benefits of ACD CPR.

Aged↗

Continuous passive motion in computer assisted auscultation of the knee.

A study of physiological patellofemoral crepitus (PPC) signal recorded from adolescent knees has yielded information which suggests that decay time of PPC amplitude due to continuous passive motion (CPM) activity is a consistent and useful signature variable for a given knee. The PPC vibrational signal was induced in each case by 1 min of static load on the patella and postural variables during the examination were carefully controlled. The speed of CPM has been noted as a factor directly influencing the rat of PPC amplitude decay; specifically, a higher CPM speed contributes to an increased decay constant at a cost of increased inter-subject variability. It is proposed that CPM might form an important basis for the ultimate development of a computer-based auscultation technique for diagnosis of patellofemoral joint disorders.

Acceleration↗

An immunohistochemical study of neuropeptide Y positive sites in the developing human hippocampal formation.

Neuropeptide Y (NPY)-positive sites were evaluated by immunohistochemistry in the hippocampal formation of human fetuses aged from 15 to 41 weeks of gestation. Immunopositive cells and fibers were identified in the hippocampus as early as 15 weeks of gestation. These cells were localized in the polymorphic and pyramidal layers and their numbers increased with the age of the fetuses. NPY-positive cells were observed to be closely apposed to blood vessels and some NPY fibers, present mainly in the polymorphic layer, would infiltrate the alveus.

Binding Sites↗

Purification, characterization, and cDNA cloning of an AU-rich element RNA-binding protein, AUF1.

The degradation of some proto-oncogene and lymphokine mRNAs is controlled in part by an AU-rich element (ARE) in the 3' untranslated region. It was shown previously (G. Brewer, Mol. Cell. Biol. 11:2460-2466, 1991) that two polypeptides (37 and 40 kDa) copurified with fractions of a 130,000 x g postribosomal supernatant (S130) from K562 cells that selectively accelerated degradation of c-myc mRNA in a cell-free decay system. These polypeptides bound specifically to the c-myc and granulocyte-macrophage colony-stimulating factor 3' UTRs, suggesting they are in part responsible for selective mRNA degradation. In the present work, we have purified the RNA-binding component of this mRNA degradation activity, which we refer to as AUF1. Using antisera specific for these polypeptides, we demonstrate that the 37- and 40-kDa polypeptides are immunologically cross-reactive and that both polypeptides are phosphorylated and can be found in a complex(s) with other polypeptides. Immunologically related polypeptides are found in both the nucleus and the cytoplasm. The antibodies were also used to clone a cDNA for the 37-kDa polypeptide. This cDNA contains an open reading frame predicted to produce a protein with several features, including two RNA recognition motifs and domains that potentially mediate protein-protein interactions. These results provide further support for a role of this protein in mediating ARE-directed mRNA degradation.

Amino Acid Sequence↗

[Methotrexate-citrovorum factor individualized reduced dose therapy for ectopic pregnancy: report of 20 cases].

In twenty patients with ectopic pregnancy who received treatment using methotrexate-citrovorum factor in an individualized reduced dose regimen 17 cases were successfully treated, 4 required one course of therapy, 8 required two courses, 4 required three courses, only 1 required four courses, according to the difference in the speed of hCG reduction. The success rate was 85.0%, two cases got intrauterine pregnancy within 6 months after the treatment. Three ruptured cases during treatment were operated upon. The pathologic findings at the ectopic site were chorionic bleeding, necroses, with dissolution of trophoblastic cells.

Adult↗

Treatment of ovarian malignant germ cell tumors with preservation of fertility.

Conservative operation and postoperative chemotherapy were given to 15 patients with malignant germ cell tumors of the ovary with the preservation of fertility and ovarian functions. Four patients, one with endodermal sinus tumor and three immature teratoma, had full term deliveries after the operation. The possibility was discussed to preserve young women's fertility and ovarian function in treating their malignant germ cell tumors.

Adolescent↗

[Diagnostic errors in dysfunctional uterine bleeding. Analysis of 24 cases].

This paper reports 24 cases of genital organic diseases which were misdiagnosed as dysfunctional uterine bleeding during 1984-1990. These include small submucous uterine myoma 5 cases, Granulosa cell tumor of ovary 2 cases, leiomyosarcoma of uterus 1 case, ectopic pregnancy 7 cases, carcinoma of endometrium 4 cases, abortion 3 cases, choriocarcinoma 2 cases, altogether there were 9 patients with malignant tumors in the series. The author point out that it is possible to reduce the misdiagnosis rate by emphasizing history, diagnostic curettage, ultrasonography, hysteroscopy and blood hCG determination.

Adult↗

Immunosuppressive effects of fish oil in normal human volunteers: correlation with the in vitro effects of eicosapentanoic acid on human lymphocytes.

We have studied the effects of dietary supplementation with fish oil on immunological parameters in a group of six normal volunteers, four of whom received a fish oil extract (total EPA dose of 2.4 g/day, which is on the lower range of clinically effective doses) for 6 weeks and two of which received a placebo (olive oil) for an identical period of time. Each volunteer was followed up for a period of 23 weeks after the dietary intervention was ended. All volunteers were boosted with tetanus toxoid (TT) at the onset of the trial. Several immune parameters were followed longitudinally, including NBT reduction and lysozyme release to test neutrophil function; lymphocyte subpopulations; mitogenic responses to phytohemagglutinin (PHA), concanavalin A (Con A) and anti-CD3; IL-2 release after PHA and pokeweed mitogen (PWM) stimulation; immunoglobulin and anti-TT antibody (ATT) synthesis by stimulated lymphocytes; and serum levels of immunoglobulins and of ATT. No consistent changes were observed in neutrophil function tests, mitogenic responses to PHA and Con A, and lymphocyte subsets. The mitogenic response to anti-CD3 and the release of IL-2 after stimulation with PHA and PWM appeared reduced as a consequence of fish oil ingestion, and levels of serum immunoglobulins decreased in three of the volunteers receiving fish oil supplementation. The systemic humoral response after the TT booster appeared not to be influenced by the ingestion of fish oil. However, in those subjects who were given fish oil supplementation, the specific in vitro response of their peripheral blood lymphocytes to TT appeared to be compromised at Week 3. This could reflect the need for progressive accumulation of EPA in lymphocyte membranes for the suppressive effect to be detectable, but it could also reflect a differential sensitivity to the effects of fish oil of circulating B lymphocytes vs. bone marrow B lymphocytes. All the parameters apparently affected by fish oil ingestion were also affected by the incubation of normal lymphocytes with EPA in vitro. In conclusion, low doses of fish oil may have a mild immunosuppressive effect affecting both T and B cell functions. These observations stress the need for more extensive trials designed to determine whether immunosuppressive effects can be consistently elicited and for studies aimed at determining the mechanisms by which omega-3 fatty acids affect the immune system.

Adult↗

Residential mobility differences among developed countries.

"Micro-level theories of why households change residence contrast with macro-level approaches that relate the level of spatial mobility to development. This article compares the rate of residential mobility in 16 [developed] countries or other areas and examines both regional variations within countries and changes in rates of local and nonlocal moving. Hypotheses that explain why countries differ in rates of residential mobility are examined."

Demography↗

Measuring migration distances: self-reporting and indirect methods.

Methods of determining distance covered in migration are discussed. "Two approaches for doing so are simply to ask movers how far they moved or to infer distance from localities of origin and destination. The former has been used in Health Interview Surveys, and the latter is applied to Current Population Surveys; both are national surveys conducted by the U.S. Census Bureau. The two approaches appear to produce consistent results and offer ways of increasing comparability of data and research findings on geographical mobility."

Americas↗

Migration distances: an international comparison.

Comparing the level or amount of migration within different countries has been a longstanding problem because the local administrative areas commonly used as the basis for measuring migration vary greatly in size and significance within and between countries. Distance moved is a critical aspect of most concepts of migration, and measuring it would facilitate cross-national comparisons. Apparently only the United States, Great Britain, and Sweden have measured migration distances for the country as a whole, and this information is used as the basis for comparative analysis of spatial mobility.

Adolescent↗