Anemia-inducing factor in the early stage of hookworm infection.
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Anemia↗
Biomedical subjects
H Lee
Publications and source records attributed to H Lee.
Effects of interactions between cooling and rewarming conditions on survival of cells.
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Blood Preservation↗
Establishment and characterization of a diethylnitrosamine-initiated woodchuck hepatocyte cell line.
Woodchucks free from woodchuck hepatitis virus were treated with diethylnitrosamine in vivo for 2 months, and then hepatocytes obtained by enzymatic perfusion were cultured with the hepatopromoter phenobarbital. This in vivo-in vitro procedure gave rise to proliferating epithelial cell foci, from one of which the presently described hepatocyte cell line (WLC-3) was established and characterized. WLC-3 cells possess morphological and biochemical features of differentiated hepatocytes, including glucose-6-phosphatase activity and albumin production. Histopathological analysis of the tumor which developed transitorily in nude mouse subcutis after inoculation of the cell line revealed glandular structures comprising cells of hepatocellular-like morphology. This is the first established woodchuck hepatocyte cell line free from woodchuck hepatitis virus and is therefore expected to be useful for studying the mode of gene expression and viral proliferation of woodchuck hepatitis virus and the mechanisms underlying woodchuck hepatitis virus-related hepatocarcinogenesis.
Adenosine Triphosphatases↗
Hepatitis B vaccination of newborn infants: clinical study of new vaccine formulation and dose regimen.
To investigate the efficacy in anti-HBsAg response with half the recommended adult dose in a standard vaccination schedule or with a full dose in reduced number of vaccination schedule, 201 healthy newborn infants were randomized to receive either 2.5 micrograms Hevac B vaccine at birth [1, 2 and 14 months in Group I (101)] or 5 micrograms at birth [2 and 14 months in Group II (100)]. Anti-HBsAg responses in the two groups were compared. Passively acquired anti-HBsAg positivity rates at birth were 51.5 and 45.0% in Groups I and II, respectively. Cumulative anti-HBsAg seroconversion rates in Group I were 12.2, 76.6, 82.6 and 86.4% at 2, 4, 14 and 16 months, while the rates in Group II were 2.5, 62.5, 73.7 and 91.0%, showing no significant difference (p greater than 0.05). Significant difference in seroconversion rates at the 2-month follow-up stage between passively acquired anti-HBsAg-negative and -positive groups was observed (11.9 vs. 2.6%). Significant rise in anti-HBsAg titer at 16 months following the booster at 14 months was noted: 36.4 mIU per ml before, 546.4 mIU per ml after in Group I and 25.3 mIU per ml before, 782.6 mIU per ml after in Group II. The booster, 12 months after the primary vaccination series, is therefore considered imperative for maximum effectiveness of hepatitis B active immunization.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
In vivo fluorine-19 MR imaging: relaxation enhancement with Gd-DTPA.
The lack of a naturally occurring background signal from fluorine in magnetic resonance (MR) imaging makes fluorinated compounds potentially attractive candidates for tissue-specific MR contrast agents. Problems associated with the in vivo use of fluorinated compounds are toxicity, which limits the amount of agent that can be used; multiple resonance lines; and an excessively long T1, which leads to long sequence TRs and consequently long imaging times. Many fluorinated agents also possess complex MR spectra that result in chemical shift artifacts if not corrected. The authors demonstrate the use of an extracellular fluorinated agent with a single MR peak for selective imaging of a brain abscess in an animal model and show that the image signal per unit of acquisition time can be enhanced through the use of a T1 relaxation agent, gadolinium diethylenetriamine-pentaacetic acid (DTPA). Trifluoromethylsulfonate was administered at a fluorine-19 dose of 4 mmol/kg, and fluorine images of the induced abscess were acquired before and after the injection of a standard dose of Gd-DTPA (0.1 mmol/kg); non-section-selected projection images were used. Typical imaging times were less than 5 minutes. The signal enhancement factor achieved was approximately four (4.0 +/- 0.8) with use of a 500/12 (TR msec/TE msec) spin-echo sequence.
Animals↗
Diffusion imaging with the MP-RAGE sequence.
Diffusion-weighted magnetic resonance (MR) images obtained with conventional spin-echo techniques are known to be sensitive to subject motion because of long image acquisition times. To reduce the acquisition time, use of a magnetization-prepared rapid gradient-echo (MP-RAGE) sequence modified for diffusion sensitivity was studied. In this sequence, a preparation phase with a 90 degrees-180 degrees-90 degrees pulse train is used to sensitize the magnetization to diffusion. Centric-ordered phase encoding, short TRs (5.2-6.5 msec), and small flip angles (5 degrees-8 degrees) are necessary to minimize saturation effects from tissues with short relaxation times. Phantom studies with various concentrations of copper sulfate (T1 ranging from 2,459 to 90 msec) were performed to validate that the diffusion-weighted signal obtained with the MP-RAGE sequence was independent of relaxation time. Diffusion-weighted images of water, isopropyl alcohol, and acetone were acquired to confirm the accuracy of measured diffusion coefficients. Brain images of healthy normal volunteers were obtained to demonstrate motion insensitivity and general image quality of the technique. The results indicate that accurate diffusion-weighted images can be obtained with a diffusion-weighted MP-RAGE sequence, with imaging times of about 1 second.
1-Propanol↗
Application of reduced-encoding imaging with generalized-series reconstruction (RIGR) in dynamic MR imaging.
Dynamic MRI has proven to be an important tool in studies of transient physiologic changes in animals and humans. High sensitivity and temporal resolution in such measurements are critical for accurate estimation of dynamic information. Fast imaging, often involving expensive hardware, has evolved for use in such cases. We demonstrate herein the possibility of accelerated data acquisition schemes on conventional machines using standard pulse sequences for dynamic studies. This is achieved by combining reduced-encoded dynamic data (typically 30 to 40 phase encodings) with a priori high-resolution data via a novel constrained image reconstruction algorithm. Such an approach reduces image acquisition time significantly (by a factor of 3 to 4 in the examples described here) without loss in the accuracy of information.
Animals↗
Predicting bioaccumulation potential: a test of a fugacity-based model.
Clams (Macoma nasuta) from an unpolluted site in Yaquina Bay, Oregon were exposed in the laboratory for 28 days to 6 field-contaminated sediments (treatments) which varied widely in concentration of 10 organic pollutants. Mean accumulation factors (AF = (concentration in tissue/lipid, %/100)/(concentration in sediment/total organic carbon, %/100] of 8 neutral organic compounds (DDE [p,p'], 2,2',3,5'6-pentachlorobiphenyl, 2,3',4,4',5-pentachlorobiphenyl, Aroclor 1254, pyrene, chrysene, benzo[a]pyrene, benzo [b, (k)]fluoranthene) were homogeneous across treatments. Statistically significant differences were detected between some treatment AFs for DDD [p, p'] and benz[a]anthracene, and between some chemicals within treatments (experimentwise alpha = 0.05). Accumulation factors were less than 2 and less variable in highly polluted, organically enriched sediments (total organic carbon greater than or equal to 3.69 +/- 0.044%), but sometimes exceeded 2 in clams exposed to surficial (0-2 cm deep) sediments with low pollutant concentration and low organic carbon content (less than or equal to 0.86 +/- 0.037%). These results suggest that the AF model may provide reasonable estimates of bioaccumulation potential of hydrophobic neutral organic compounds in organically enriched, polluted sediments.
Animals↗
The tumor suppressor p53 can reduce stable transfection in the presence of irradiation.
The tumor suppressor p53 is believed to play an essential role in maintaining genome stability. Although it is currently unknown how p53 is involved in this important biological safeguard, several previous publications indicate that p53 can help to maintain genome integrity through the recombination-mediated DNA repair process. The integration of linearized plasmid DNA into the host chromosome utilizes the same repair process, and the frequency can be measured by clonogenic assays in which cells that were stably transfected by plasmid integration can be scored by their colony-forming abilities. To gain insight into whether p53 has a direct role in plasmid integration into the host chromosome, we determined the frequency of stable transfection with CHO cells expressing either wild-type or mutant p53 in the presence and absence of irradiation. We found that low-dose irradiation ( approximately 50 to 100 cGy) increased stable transfection frequencies in CHO cells regardless of their p53 status. However, the increase of transfection frequency was significantly lower in CHO cells expressing wild-type p53. Our data thus suggest that wild-type p53 can suppress plasmid DNA integration into the host genome. This p53 function may play a direct and significant role in maintaining genome stability.
Animals↗
Prevalence of human foamy virus-related sequences in the Korean population.
The possible association of human foamy virus (HFV) with human thyroid disorders such as Graves' disease (GD) has been a topic of controversy due to the inconsistent results reported by several groups of investigators. Here we report the investigation of the presence of HFV-related sequences in the Korean population. DNA was obtained from peripheral blood lymphocytes from 24 GD patients and 23 healthy blood donors and subjected to PCR amplification using three sets of nested primers derived from gag, env, and LTR regions of the HFV genome. Contrary to previously reported studies, our analysis identified HFV-related sequences in the genomes of both healthy individuals and the GD patients. However, the nature of the HFV genome present in each group appeared to be different. We detected all 3 regions of HFV-related sequences in 29% of the HFV-positive GD patients, while no samples in the control group amplified all three regions. This suggests that the LTR may be used as a tool for screening for HFV in GD patients. Our data favor the hypothesis of a relationship between GD and the presence of HFV-related sequences, though in a complex way.
Adult↗
Recent advances in understanding thyroid hormone receptor coregulators.
Thyroid hormones (L-triiodothyronine, T3; L-tetraiodothyronine, T4) regulate normal cellular growth and development, and general metabolism as well. Their various actions are mediated by the thyroid hormone receptor, a ligand-dependent transcriptional factor belonging to the nuclear hormone receptor superfamily. The recent discovery of coregulators (coactivators, corepressors, and cointegrators) has greatly enhanced our understanding of thyroid hormone receptor functions. Hence we review and discuss, in brief, the potential role of thyroid hormone receptor coregulators involved in diverse cellular activities.
Animals↗
Orienting-reflex behavior and clinical psychopathology.
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Age Factors↗
Peritoneal lymphomatosis: CT findings.
BACKGROUND: Diffuse peritoneal tumor infiltration is well recognized on computed tomography (CT) and is usually associated with carcinomatosis. The purpose of this investigation was to analyze the CT findings of peritoneal spread from primary gastrointestinal lymphomas. METHODS: Abdominal CT scans in eight patients with peritoneal lymphomatosis were retrospectively reviewed. Patients were 12-75 years old (mean = 48 years); with six patients were male and two were female. Pathologic evidence of primary lymphoma was available by colonoscopic biopsy of the terminal ileum in seven cases and by gastroscopic biopsy of the stomach in one case. All patients had non-Hodgkin's lymphoma. We analyzed CT findings in view of presence or loculation of ascites, abnormal patterns of mesentery and omentum, presence of peritoneal enhancement, presence of low attenuation and location of lymph nodes, and primary gastrointestinal lymphoma. RESULTS: Although ascites was present in all patients, there was no loculation. The involvement of mesentery was present in seven patients, and the stellate pattern was the common type (4/7). The involvement of omentum was present in seven patients, and the common type was omental cake (3/7). Peritoneal enhancement was present in six patients. Enlarged lymph nodes were present in six patients, mainly at the retroperitoneum and mesentery, and showed centrally low attenuation in half the patients. CONCLUSION: Patterns of tumor involvement of mesentery, omentum, and peritoneum seen in peritoneal lymphomatosis are indistinguishable from those seen in peritoneal carcinomatosis or tuberculous peritonitis. However, ascites without any loculation or septation and diffuse distribution of enlarged lymph nodes were helpful signs of peritoneal lymphomatosis.
Adolescent↗
Serological and molecular survey for HTLV-I infection in a high-risk Middle Eastern group.
To define the extent of human T-cell leukaemia virus (HTLV-I) infection among a group of Jewish immigrants to Israel with an increased frequency of adult T-cell leukaemia, various serological and molecular screening methods, including enzyme-linked immunosorbent assay (ELISA) for anti-HTLV-I, ELISA for antibody to recombinant HTLV-I p40tax protein, and molecular detection of infection by polymerase chain reaction (PCR) amplification of HTLV-I proviral DNA from peripheral blood mononuclear cell DNA, were used. By HTLV-I ELISA the overall rate of infection was 12% (24 of 208) among immigrants from Khurusan, northeastern Iran; no HTLV-I carriers were detected among 111 unselected Jewish immigrants from other parts of Iran. There was unexplained clustering of HTLV-I infection within a cohort of 32 elderly women of similar geographic origin in a home for old people--14 were seropositive by ELISA and 19 of 29 were positive by PCR. The findings in this newly identified high-risk population suggest that in addition to ELISA, other screening techniques may be required to detect all carriers in high-risk populations.
Aged↗
Expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in human preeclamptic placenta: possible implications in the process of trophoblast apoptosis.
Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) was originally identified as a receptor for oxidatively modified low-density lipoprotein. It has been reported that oxidative stress and hyperlipidemia play important roles in the etiology of preeclampsia, and that placental oxidative stress may stimulate syncytiotrophoblast apoptosis in preeclampsia. In this study, we examined the expression of LOX-1 in the human placentas of normal pregnancies and in preeclampsia using immunohistochemistry and Western blot analysis, and proposed that LOX-1 has a role in trophoblast apoptosis. To analyze apoptotic activity, the expression of the specific caspase cleavage site within cytokeratin 18 was assessed immunohistochemically using the monoclonal antibody M30 CytoDeath. Both LOX-1 and M30 immunoreactivity occurred predominantly in syncytiotrophoblasts. A significantly higher number of LOX-1 and M30-positive cells were found in preeclamptic placentas than in normal placentas. The number of M30-positive cells correlated with the apoptotic index of trophoblasts determined by TdT-mediated dUTP nick-end labeling (TUNEL). Syncytiotrophoblasts showing apoptotic activity were immunopositive to LOX-1 by double immunohistochemical fluorescence. We suggest that the functional role of syncytiotrophoblasts in placental dysfunction results from the localization and upregulation of LOX-1 in the preeclamptic placenta, possible implications in upregulation of syncytiotrophoblast apoptotic activity in preeclampsia.
Adult↗
Use of haloperidol in a "hard-core" chronic schizophrenic population.
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Adolescent↗
Barriers to progress in urinary incontinence: achieving quality assessments.
Urinary incontinence is a major care problem in nursing homes. Despite legislation aimed at decreasing its incidence, minimal progress has been made to achieve this goal. Obtaining an accurate assessment about the level and pattern of incontinence will assist caregivers in developing plans to reduce it. This article identifies barriers the authors have encountered in obtaining accurate records in a research project and strategies implemented to overcome these barriers.
Aged↗
Automation and system integration of scanning tomographic acoustic microscope.
The Scanning Tomographic Acoustic Microscope (STAM) is an instrument capable of performing subsurface imaging of microscopic specimens. Designed around the Scanning Laser Acoustic Microscope (SLAM), the STAM incorporates numerous hardware and software advances which allow automated imaging of the acoustic properties of thick specimens at high resolution. With these modifications the STAM is shown to be capable of image formation for tissue characterization and nondestructive evaluation (NDE) of microscopic specimens. This paper describes the design and operation of the STAM hardware, and software algorithms developed to permit high resolution imaging. Examples are provided to demonstrate the capability of multiple angle and multiple frequency tomographic reconstructions.
Acoustics↗