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Biomedical subjects

S R Lee

Publications and source records attributed to S R Lee.

At least 73 records · Page 4Linked to original sources
PubMed1995

Increased detection of hepatitis C virus infection in commercial plasma donors by a third-generation screening assay.

BACKGROUND: Routine screening of blood donations with second-generation hepatitis hepatitis C virus (HCV) assays has substantially reduced the occurrence of posttransfusion hepatitis. However, following the development of third-generation assays, several studies indicated that these assays may identify HCV-infected individuals who are not identified by second-generation assays. STUDY DESIGN AND METHODS: The sensitivity of a third-generation HCV enzyme-linked immunosorbent assay (ELISA-3) was compared with a second-generation ELISA (ELISA-2) in a side-by-side study of 9936 commercial blood donors. ELISA-reactive specimens were subjected to supplemental analysis by third-generation recombinant immunoblot assay and polymerase chain reaction. RESULTS: ELISA-3 demonstrated greater sensitivity than ELISA-2, detecting 1 additional recombinant immunoblot assay-positive specimen per 2000 tested. ELISA-3 also detected 1 additional HCV-infectious polymerase chain reaction-positive unit among approximately 10,000 units screened. CONCLUSION: The incremental sensitivity achieved with ELISA-3 can be expected to eliminate approximately 20 infectious donations per week among those made by commercial donors in the United States. In accordance with previous studies, most of the improved sensitivity of ELISA-3 derives from its increased detection of anti-c33c (NS3), rather than from the inclusion of HCV antigen NS5.

Blood Donors↗
PubMed1995

Improved detection of anti-HCV in post-transfusion hepatitis by a third-generation ELISA.

The sensitivity of ORTHO HCV 3.0 ELISA Test System (ELISA 3) for the detection of anti-HCV was compared with the second-generation ELISA, OR-THO HCV 2.0 ELISA Test System (ELISA 2). ELISA 3 differs from ELISA 2 in that it incorporates the HCV recombinant antigen NS5, in addition to recombinant antigens derived from the NS3, NS4 and core regions of the HCV genome. Specimens tested consisted of serial bleeds obtained from 21 individuals undergoing seroconversion following acquisition of post-transfusion HCV infection. ELISA 3 demonstrated significantly greater sensitivity than ELISA 2, detecting seroconversion earlier in 24% (5/21) of cases. Although one of these cases appeared to represent early seroconversion to NS5, most of the improved sensitivity of ELISA 3 appeared to derive from increased detectability of anti-c33c.

Enzyme-Linked Immunosorbent Assay↗
PubMed1995

[Infection status of anisakid larvae in anchovies purchased from local fishery market near southern and eastern sea in Korea].

A survey was carried out on the larval anisakis in anchovies (Engrauris japonica) which were caught from April to June in 1993 at the southern and eastern sea in Korea. Anisakids in anchovies were morphological classified into Anisakis type I and II and Contracaecum type B and C, after fixation in 70% alcohol and clearing in lactophenol. A total of 171 larval anisakids were collected from 150 anchovies (6.9%) out of 2,180 examined. The infection rates showed no relation with length of the anchovies. The numbers of anisakids by organs of anchovies were 96 (56.1%) from the muscle, 65 (38.0%) from the omentum, 7 (4.1%) from the intestine, 2 (1.7%) from the stomach and 1 (0.6%) from the testis. Infection rates of anchovies with anisakids by localities were 5.1% at Taebyon, 8.0% at Sokcho and 9.2% at Chungmu. The larval anisakids in anchovies may infect humans who often eat raw anchovies.

Animals↗
PubMed1995

Mannitol increases cerebral arteriovenous oxygen difference in patients undergoing craniotomy.

BACKGROUND: Monitoring the jugular venous oxygen saturation (SjVO2) and cerebral arteriovenous oxygen difference (AVDO2) is valuable in detecting cerebral ischemia. In the present study, we investigated the effect of mannitol on SjVO2 and AVDO2 in patients undergoing craniotomy. METHODS: We studied 25 ASA class II-III patients undergoing craniotomy. Anesthesia was induced with thiopental, fentanyl and vecuronium. Immediately after induction, a 16-gauge central venous catheter was placed in the internal jugular vein, ipsilateral to the lesion side with cephalic insertion and anchorage in the jugular bulb. Anesthesia was maintained with continuous infusion of fentanyl (10 micrograms/kg/h), 0.5-1% isoflurane in 60% oxygen (oxygen/air) and supplemental dose of vecuronium for muscle relaxation as needed. Samples of arterial and jugular venous blood were obtained for the measurements of SjVO2 and AVDO2 in the following time intervals: (1) normocapnia (PaCO2 38-40 mmHg); (2) hypocapnia (PaCO2 28-30 mmHg); and (3) 30 min after mannitol (0.5 g/kg) infusion. RESULTS: Hyperventilation resulted in a significant decrease in SjVO2 (96% patients) and increase in AVDO2 (88% patients). Hypocapnia followed by mannitol administration led to a further decrease and increase of SjVO2 and AVDO2 in 72% and 68% patients, respectively. CONCLUSIONS: Mannitol may produce a further reduction in SjVO2 accompanied by an increase in AVDO2, suggesting a reduction of cerebral blood flow (CBF) during hyperventilation. Therefore, it should be given cautiously in neurosurgical patients under hyperventilation.

Adult↗
PubMed1994

Evaluation of indeterminate c22-3 reactivity in volunteer blood donors.

BACKGROUND: Approximately 25 percent of blood donor sera that are repeatably reactive for hepatitis C virus (HCV) on second-generation enzyme immunoassay (EIA 2.0) are indeterminate on second-generation recombinant immunoblot assay (RIBA 2.0), and over 76 percent of these results are due to single reactivity to the HCV recombinant antigen c22-3. STUDY DESIGN AND METHODS: Data are presented on 46 volunteer allogeneic blood donors who were reactive on EIA2.0 and c22-3 indeterminate in RIBA 2.0. Index and follow-up samples were evaluated by using a panel of five synthetic peptide EIAs, a prototype strip immunoblot assay that uses synthetic peptides in addition to recombinant protein (RIBA 3.0), and polymerase chain reaction (PCR) for HCV RNA. RESULTS: All 46 donations had normal alanine aminotransferase values; only 2 (4.3%) reacted for antibody to hepatitis B core antigen. With a panel of 12 synthetic peptides spanning the entire sequence of the c22-3 recombinant antigen, 33 plasmas (72%) reacted to one peptide or none, including 19 plasmas with reactivity restricted entirely to the N-terminal peptide (1-15 amino acids) of c22-3. With RIBA 3.0, 28 donations (61%) were nonreactive, including 25 that reacted with one peptide or none in EIA. Of these 25 plasmas, 18 reacted with the N-terminal sequence only. All 46 index donations were tested by PCR; the single PCR-positive unit reacted with four HCV peptides, was positive by RIBA 3.0, and reacted for antibody to hepatitis B core antigen. Twenty-six index donors were successfully recalled 3 to 7 months after their index donation. None seroconverted to positivity in RIBA 2.0, 1 was nonreactive, and 25 remained positive for c22-3 only. The restricted epitope reactivity in peptide EIA and RIBA 3.0 was maintained over time in all cases. All 26 of the follow-up samples tested negative by PCR. CONCLUSION: On the basis of the restricted peptide reactivity and PCR negativity of index and follow-up samples, it is concluded that the majority of c22-3 RIBA 2.0-indeterminate results are due to nonspecific cross-reactivity to restricted (principally, N-terminal) regions of HCV core antigen.

Alanine Transaminase↗
PubMed1992

Improved detection of hepatitis C virus antibodies in high-risk populations.

Sera from 483 patients at high (group 1, n = 313) and lower (group 2, n = 170) risk for exposure to hepatitis C were tested for antibodies to hepatitis C using first-generation (c100-3) and second-generation enzyme-linked immunosorbent assays and four-antigen recombinant immunoblot assay. The second-generation enzyme-linked immunosorbent assay and nitrocellulose-based immunoblot assay differ from c100-3-based systems in the addition of expression products from the NS3/NS4 (c33c, c200) and putative nucleocapsid (c22-3) region of the hepatitis C genome. In group 1, the sensitivity of detection of hepatitis C antibodies was 45%, 55% and 46% by the first- and second-generation enzyme-linked immunosorbent assays and recombinant immunoblot assay, respectively. In group 2, antibodies were detected by each test system in 26%, 32% and 7% of patients, respectively. Most sera (99%) reactive with the first-generation enzyme-linked immunosorbent assay were reactive with the second-generation enzyme-linked immunosorbent assay (in group 1, 89% of these specimens demonstrated reactivity to at least one antigen with the immunoblot assay, compared with only 31% in group 2). An additional 12% (group 1) and 6% (group 2) of specimens demonstrated reactivity with the second-generation enzyme-linked immunosorbent assay only (of these, 75% [group 1] and 9% [group 2] demonstrated reactivity to at least one antigen with the immunoblot assay). Ninety-eight percent of specimens not reactive with both enzyme-linked immunosorbent assay test systems were also nonreactive by recombinant immunoblot assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Hepatocellular↗
PubMed1992

Progeny performance when dams and chicks are fed supplemental zinc.

Three consecutive trials involving approximately 700 to 800 broilers (0 to 28 days) were conducted to examine effects on growth and immunity of chicks after supplementing dams with inorganic Zn versus organic Zn. Offspring from hens fed a basal diet (72 mg Zn/kg) or diets with 152 mg Zn/kg supplemented with ZnO or organic Zn-Met were randomized across four battery brooders. Chicks were fed a starter diet without supplemental Zn containing 100 mg Zn/kg or diets supplemented with 40 mg/kg Zn from ZnO and DL-Met or Zn-Met containing 140 mg Zn/kg. No differences among treatments (P greater than .05) were found in feed conversion or average BW. Supplemental Zn-Met in hen diet increased (P less than .06) cellular immune response in progeny. Embryonic bone weights were higher (P less than .05) in progeny when dams were fed Zn-Met. Zinc as Zn-Met in diets of dams and progeny enhanced primary antibody titers to Salmonella pullorum antigen.

Animals↗
PubMed1991

A comparative study of IgA nephropathy between two institutions in Japan and Korea.

As an approach to the geopathological evaluation of kidney disease, we conducted a comparative study on IgA nephropathy (IgANP) between Saga Medical School (SMS) in Japan and Kosin Medical College (KMC) in Korea for the period 1983-1987. The relative incidence of IgANP among primary glomerular diseases was significantly higher (P less than 0.05) at SMS (103 cases of IgANP among 250 cases of primary glomerular diseases, 41.2%) than at KMC (63 cases among 201 cases, 31.3%). Clinical and histological comparisons of the IgANP between the institutions revealed that the SMS series was generally milder than the KMC series. When the renal manifestations at the time of biopsy for all cases with primary glomerular diseases were compared, asymptomatic urinary abnormalities were more commonly found at SMS than at KMC. This suggests that certain differences in medical practice may exist between the two institutions, as follows: 1) the medical checkup system may be more efficient, 2) the accessibility to medical service may be easier, and 3) the biopsy criteria may be more liberal in Japan/SMS than in Korea/KMC. Thus, the real differences in incidence and severity of IgANP between the two institutions could be smaller than those reported here.

Adult↗
PubMed1990

Purification and secondary structure determination of simian immunodeficiency virus p27.

We have developed a novel method for the expression and purification of p27, the major core protein of simian immunodeficiency virus. Circular dichroism measurements of purified p27 were used to determine the relative amounts of alpha-helix, beta-sheet and unordered secondary structural elements. These empirically determined values appear to be inconsistent with previously published theoretical models based on homology comparisons.

Circular Dichroism↗
PubMed1990

Comparative evaluation of an immunofluorescent antibody test, enzyme immunoassay and western blot for the detection of HIV-1 antibody.

Screening blood and blood products for human immunodeficiency virus type 1 (HIV-1) antibody is predominantly performed by enzyme immunoassay (EIA), and results must be confirmed by the more immunospecific Western blot (WB) assay. This study evaluated an HIV immunofluorescent antibody (IFA) test relative to WB assay for use in confirming EIA designated HIV-1 antibody-positive sera. Specimens from seroconversion and CDC panels as well as clinical specimens obtained for routine EIA HIV-1 antibody screening were evaluated. Results with 209 specimens indicated that sensitivity and specificity of the Fluorognost-HIV assay were equivalent relative to WB. In addition, the Fluorognost-HIV IFA test was faster and easier to perform than the WB assay, and unlike the WB assay was not prone to indeterminate results.

Adult↗
PubMed1990

A study of adipocyte precursor cells derived from brown adipose tissue: the expression of specific cell surface antigens during their differentiation in culture.

Using cell specific anti-adipocyte sera and an immuno-precipitation procedure, the nature of the cell surface antigens characterizing adipocytes from rat brown adipose tissue was investigated. Initially the ability of anti-sera, raised against adipose plasma membrane preparations of white or brown adipose tissue, to distinguish between membrane preparations derived from either tissue was confirmed. Analysis of the plasma membranes derived from brown adipose and similar preparations labelled with 125I revealed the presence of specific externally disposed mature brown adipocyte-specific antigens. The specifically immunoprecipated antigens had molecular weights of 70,000, 56,000 and 23,000. None of these antigens were cross immunoprecipated by antisera to mature white adipocyte membranes. The presence of the brown adipose specific antigens on the surface of differentiating adipocyte precursor cells derived from rat brown adipose tissue was demonstrated using a labelled-secon antibody cellular immunoassay. The expression of the immunoreactivity associated with these antigens was shown to be an early event in the differentiation programme of the cells in vitro. The functional identity and possible roles of these antigens in the control of brown adipocyte differentiation now becomes accessible to further experimental investigation.

Adipose Tissue↗
PubMed1989

Unusual MR manifestations of neurocysticercosis.

MR and CT features of neurocysticercosis are variable and depend fundametally on the stage in evolution of the infection, location, number and size of the worm. The authors retrospectively evaluated MR images obtained on a 2.0T superconducting unit in 22 neurocysticercosis patients and observed various MR features including some new findings. A variety of MR findings are presented with special reference to six case reports. The features include: (1) a large simple cyst containing both internal septations and a scolex; (2) suprasellar racemose cysts mimicking other cysts, (3) a fourth ventricular cyst readily depicted by aid of CSF flow-void in the sagittal plane; (4) degenerating cysts showing "white target" appearance; (5) granulomatous lesions having a "black target" appearance; and (6) a meningitic form showing Gd-DTPA enhancement of basal cisterns and of a subacute infarct.

Adolescent↗
PubMed1989

Serial studies on the functional affinity and heterogeneity of antibodies of different IgG subclasses to phospholipase A2 produced in response to bee-venom immunotherapy.

High functional affinity and high titer IgG4 antibodies to phospholipase A2 were produced by allergic patients in response to bee-venom immunotherapy. In contrast, the affinity of IgG1 antibodies decreased after immunotherapy, and both the titer and affinity of IgG1 antiphospholipase A2 remained significantly lower compared to IgG4 1 to 2 years after treatment. Analysis of affinity heterogeneity suggested a loss of IgG1 high-affinity antibody-producing clones during immunotherapy and a preferential expansion of IgG4 clones. High-affinity IgE antibodies were found in untreated allergic patients, and preliminary results suggest that immunotherapy may result in an early marked decrease in the affinity of IgE antibodies.

Adolescent↗
PubMed1989

Posterior fossa hemangioblastomas: MR imaging.

The magnetic resonance (MR) imaging findings of 18 surgically proved posterior fossa hemangioblastomas (15 patients) were retrospectively analyzed and correlated with computed tomographic (ten patients) and angiographic (eight patients) findings. Thirteen tumors were located in the cerebellar hemisphere, three in the vermis, and two in the medulla with associated syrinxes. Three patients had von Hippel-Lindau disease, two of whom had multiple cerebellar hemangioblastomas. Seven hemangioblastomas appeared as solid tumors, six as solid masses with central cysts, and five as cysts with mural nodules. Abnormal tumor vessels, with characteristic signal void, were demonstrated in 13 tumors. Associated hemorrhage was present in four tumors. Although angiography is usually required for the diagnosis and preoperative assessment of this tumor, MR imaging demonstration of a posterior fossa mass with abnormal vessels should suggest the diagnosis of hemangioblastoma. Moreover, the combination of a peripheral posterior fossa cyst with a mural nodule supplied by enlarged vessels may be pathognomonic.

Adult↗