Empty virus-like particle-based enzyme-linked immunosorbent assay for antibodies to hepatitis E virus

Hepatitis E, an enterically transmitted non-A, non-B hepatitis, is a serious viral infection that occasionally causes large epidemics in developing countries. In developed countries, the disease only appears sporadically due to the transmission routes, and it is considered to be less important. The hepatitis E virus (HEV) cannot grow in cultured cells and no reliable assay system has ever been developed. In addition, the present diagnostic are not perfect, and actual rates of HEV infection may be underestimated. Highly purified empty virus-like particles (VLPs) of HEV have been produced by the use of a recombinant baculovirus vector in insect cells. Using these VLPs as an antigen, an enzyme-linked immunosorbent assay (ELISA) for antibodies to HEV was developed. A panel of 164 sera that were randomized and coded, and sera collected periodically from three patients with hepatitis E were used for the evaluation. The sensitivity of the assay was shown to be equal to or better than that obtained in previous research that used the same serum panel. The ELISA demonstrated that the serum IgM level of the patients was highest at the onset of the clinical illness and then rapidly decreased. In contrast, a high level of circulating IgG antibody titers lasted for more than 4 years. In Japan, a non-endemic country, the prevalence of the IgG class antibody to HEV in healthy individuals was found to range from 1.9% to 14.1%, depending on the geographical area. Only one out of 900 (0.1%) serum samples was IgM-positive. The IgM class antibody to HEV was detected in 10.8% of non-A, non-B, and non-C acute hepatitis patients in northeast China, whereas none of the patients in Korea had the IgM antibody. The ELISA utilizing the VLPs is sensitive and specific in its detection of the IgM and IgG antibodies to HEV. The ELISA is therefore useful for diagnosing HEV infection and for seroepidemiological study of hepatitis E.

Empty virus-like particle-based enzyme-linked immunosorbent assay for antibodies to hepatitis E virus

Hepatitis E, an enterically transmitted non-A, non-B hepatitis, is a serious viral infection that occasionally causes large epidemics in developing countries. In developed countries, the disease only appears sporadically due to the transmission routes, and it is considered to be less important. The hepatitis E virus (HEV) cannot grow in cultured cells and no reliable assay system has ever been developed. In addition, the present diagnostic are not perfect, and actual rates of HEV infection may be underestimated. Highly purified empty virus-like particles (VLPs) of HEV have been produced by the use of a recombinant baculovirus vector in insect cells. Using these VLPs as an antigen, an enzyme-linked immunosorbent assay (ELISA) for antibodies to HEV was developed. A panel of 164 sera that were randomized and coded, and sera collected periodically from three patients with hepatitis E were used for the evaluation. The sensitivity of the assay was shown to be equal to or better than that obtained in previous research that used the same serum panel. The ELISA demonstrated that the serum IgM level of the patients was highest at the onset of the clinical illness and then rapidly decreased. In contrast, a high level of circulating IgG antibody titers lasted for more than 4 years. In Japan, a non-endemic country, the prevalence of the IgG class antibody to HEV in healthy individuals was found to range from 1.9% to 14.1%, depending on the geographical area. Only one out of 900 (0.1%) serum samples was IgM-positive. The IgM class antibody to HEV was detected in 10.8% of non-A, non-B, and non-C acute hepatitis patients in northeast China, whereas none of the patients in Korea had the IgM antibody. The ELISA utilizing the VLPs is sensitive and specific in its detection of the IgM and IgG antibodies to HEV. The ELISA is therefore useful for diagnosing HEV infection and for seroepidemiological study of hepatitis E.

The pck rat: a new model that resembles human autosomal dominant polycystic kidney and liver disease

BACKGROUND

The pck rat is a recently identified model of polycystic kidney disease (PKD) and liver disease (PLD) that developed spontaneously in the rat strain Crj:CD/SD. Its pattern of inheritance is autosomal recessive.

METHODS

To characterize this new model, we studied pck rats derived from F9 breeding pairs from Charles River Japan and control Sprague-Dawley rats. Blood and tissues (kidneys, liver, and pancreas), obtained from these rats at 1, 7, 21, 70, and 182 days of age, were used for biochemical determinations, light and electron microscopy, and immunohistochemistry.

RESULTS

The pck rats develop progressive cystic enlargement of the kidneys after the first week of age, and liver cysts are evident by day 1. The renal cysts developed as a focal process from thick ascending loops of Henle, distal tubules, and collecting ducts in the corticomedullary region and outer medulla. Flat and polypoid epithelial hyperplasia were common in dilated tubules and cysts. Apoptosis was common and affected normal, as well as dilated tubules, but less frequently cysts lined by flat epithelium. The basement membranes of the cyst walls exhibited a variety of alterations, including thinning, lamellation, and thickening. Focal interstitial fibrosis and inflammation were evident by 70 days of age. Segmental glomerulosclerosis and segmental thickening of the basement membrane with associated effacement of the podocyte foot processes were noted in some rats at 70 days of age. The PKD was more severe in male than in female pck rats, as reflected by the higher kidney weights, while there was no gender difference in the severity of the PLD. Mild bile duct dilation was present as early as one day of age. With age, it became more severe, and the livers became markedly enlarged. Even then, however, there was only a mild increase in portal fibrosis, without formation of fibrous septae. Slight elevations of plasma blood urea nitrogen levels were detected at 70 and 182 days of age.

CONCLUSIONS

The pck rat is a new inherited model of PKD and PLD with a natural history and renal and hepatic histologic abnormalities that resemble human autosomal dominant PKD. This model may be useful for studying the pathogenesis and evaluating the potential therapies for PKD and PLD. The identification of the pck gene may provide further insight into the pathogenesis of autosomal dominant PKD.

Laboratory culture of the myxomycetes: formation of fruiting bodies of Didymium bahiense and its plasmodial production of Makaluvamine A

Laboratory cultures of more than 100 strains of myxomycetes were investigated, and the spore germinations of six strains were observed. The plasmodium of the myxomycete Didymium bahiense was cultured on oatmeal agar plates in a laboratory. The formation of fruiting bodies was observed in a plate culture. From the cultured organisms, a marine sponge metabolite, makaluvamine A (1), was isolated and identified on the basis of spectral data.

Secretion of hen egg white lysozyme from Kluyveromyces lactis

Hen egg white (HEW) lysozyme was correctly processed and efficiently secreted from an alternative yeast, Kluyveromyces lactis. We constructed secretion vectors using PHO5, PGK, and LAC4 promoters, and found that the highest secretion was obtained under the direction of the PGK promoter in non-selective rich medium. K. lactis secreted HEW lysozyme with two-fold higher efficiency than S. cerevisiae, estimated by using a K. lactis-S. cerevisiae shuttle vector.

Empty virus-like particle-based enzyme-linked immunosorbent assay for antibodies to hepatitis E virus

Hepatitis E, an enterically transmitted non-A, non-B hepatitis, is a serious viral infection that occasionally causes large epidemics in developing countries. In developed countries, the disease only appears sporadically due to the transmission routes, and it is considered to be less important. The hepatitis E virus (HEV) cannot grow in cultured cells and no reliable assay system has ever been developed. In addition, the present diagnostic are not perfect, and actual rates of HEV infection may be underestimated. Highly purified empty virus-like particles (VLPs) of HEV have been produced by the use of a recombinant baculovirus vector in insect cells. Using these VLPs as an antigen, an enzyme-linked immunosorbent assay (ELISA) for antibodies to HEV was developed. A panel of 164 sera that were randomized and coded, and sera collected periodically from three patients with hepatitis E were used for the evaluation. The sensitivity of the assay was shown to be equal to or better than that obtained in previous research that used the same serum panel. The ELISA demonstrated that the serum IgM level of the patients was highest at the onset of the clinical illness and then rapidly decreased. In contrast, a high level of circulating IgG antibody titers lasted for more than 4 years. In Japan, a non-endemic country, the prevalence of the IgG class antibody to HEV in healthy individuals was found to range from 1.9% to 14.1%, depending on the geographical area. Only one out of 900 (0.1%) serum samples was IgM-positive. The IgM class antibody to HEV was detected in 10.8% of non-A, non-B, and non-C acute hepatitis patients in northeast China, whereas none of the patients in Korea had the IgM antibody. The ELISA utilizing the VLPs is sensitive and specific in its detection of the IgM and IgG antibodies to HEV. The ELISA is therefore useful for diagnosing HEV infection and for seroepidemiological study of hepatitis E.

Localization of parathyroid glands in hemodialysis patients using Tc-99m sestamibi imaging

Tc-99m sestamibi parathyroid imaging was performed in 28 patients with chronic renal failure to localize abnormal parathyroid glands in patients receiving hemodialysis, and compared the localization with ultrasonography and magnetic resonance (MR) imaging.

METHODS

We imaged 28 patients with secondary hyperparathyroidism using Tc-99m sestamibi (about 600 MBq) at 10 min and 2-3 h following radiotracer injection. In addition, mediastinal images were recorded at approximately 1 h following injection to identify ectopic parathyroid glands. All patients also were evaluated with ultrasonography and MR imaging.

RESULTS

Tc-99m sestamibi scans demonstrated focal uptake in 60 glands of the 28 patients, and was categorized as slight uptake in 71.7% (43/60), and intense uptake in 28.3% (17/60). Seventeen of the 28 patients underwent parathyroidectomy. A total of 64 glands were resected. Sestamibi imaging was more sensitive for localizing abnormal parathyroid glands than ultrasonography or MR imaging. Histologic evaluation of 27 resected parathyroid glands revealed that the number of oxyphil or chief cells was not proportional to sestamibi uptake.

CONCLUSION

Our data indicate that Tc-99m sestamibi imaging should be used initially to localize abnormal parathyroid glands in hemodialysis patients with secondary hyperparathyroidism, prior to MR imaging or ultrasonography. Sestamibi uptake in parathyroid glands may not correlate with the degree of hypercellularity of oxyphil cells.

Immunomodulatory constituents from an ascomycete, Emericella aurantio-brunnea

Fractionation monitored by the immunomodulatory activity of the AcOEt extract of an Ascomycete, Emericella aurantio-brunnea, afforded two known fungal sesterterpenes, variecolin (1) and variecolactone (2), two new variecolin congeners named variecoacetals A (3) and B (4), and a new sesquiterpenetriol diester named emeremophiline (5), as the immunosuppressive constituents of this fungus. The absolute configuration of 1, which was previously not determined, was determined to be (2S,3S,6R,10S,11R,14S,15R,16S) from the NMR spectral data of the (6R,7R)-dimethyl-1,3,5-trioxacycloheptyl derivative of 1 (7). The absolute configurations of the other variecolin congeners, 2-4, and variecolol (6) are also proposed from biosynthetic considerations.

Malignant pheochromocytoma lacking clinical features of catecholamine excess until the late stage

A malignant pheochromocytoma is described in a 71-year-old man. Osseous metastases became manifest 12 years after successful removal of the primary tumor which originated in paraganglionic tissue near the right adrenal gland. Although the patient had no symptoms of catecholamine excess initially, hypertension, tachycardia and excessive sweating appeared several months before his death, concomitantly with a sharp increase in noradrenaline secretion due to an accelerated growth of metastatic tumors. Since there is no histologic criterion of malignancy in this neoplasm, it would be prudent to consider every case of pheochromocytoma as potentially malignant and to follow-up carefully for a long time after removal of the primary tumor.

Antibody-induced modulation of the leukocyte CD11b integrin prevents mild but not major renal ischaemic injury

BACKGROUND

CD11/CD18 beta(2) integrins are involved in leukocyte adhesion to the activated endothelium, and therefore represent a possible therapeutic target in the prevention of ischaemic acute renal failure (ARF).

METHODS

To assess the effect of an anti-CD11b monoclonal antibody (mAb) in ischaemic ARF, uninephrectomized Fischer rats were subjected to 45 or 60 min of warm renal ischaemia, then received 1 mg of anti-CD11b mAb 5 min before reperfusion.

RESULTS

After 45 min of ischaemia, renal function tests at 24 and 48 h were less altered in mAb-treated than in control rats, but after 60 min of ischaemia the same level of renal insufficiency was observed in the two groups. In parallel, milder tubular necrosis and less leukocyte infiltration were observed in the treated group after 45 min of ischaemia, but no difference was seen after 60 min compared to the control group. The mAb was detected on blood neutrophils up to 48 h after infusion and a marked down-regulation of CD11b expression on neutrophil surfaces was documented by flow cytometry.

CONCLUSION

These results indicate that anti-CD11b mAb administered prior to reperfusion decreases moderate ischaemic ARF but fails to prevent renal injury secondary to prolonged ischaemia in this model.

Colopsinols D and E, new polyhydroxyl linear carbon chain compounds from marine dinoflagellate Amphidinium sp

Colopsinols D (1) and E (2), two new polyhydroxyl linear carbon chain compounds, have been isolated from the cultured marine dinoflagellate Amphidinium sp. The structures of 1 and 2 were elucidated on the basis of two-dimensional NMR and FAB-MS/MS data.

Prostate specific antigen adjusted for transition zone volume: the most powerful method for detecting prostate carcinoma

BACKGROUND

Several methods for the identification of patients with prostate carcinoma have been proposed to enhance the clinical usefulness of prostate specific antigen (PSA). However, it remains unclear which method is superior in practical use. The authors attempted prospectively to identify the most powerful method with which to detect prostate carcinoma, especially among patients with intermediate PSA levels.

METHODS

Between October 1997 and August 1999, systematic sextant biopsies were performed on 281 patients, including 147 with PSA levels between 4.1 ng/mL and 10.0 ng/mL. The clinical values of PSA, the free PSA to total PSA ratio (free/total PSA ratio), alpha-1-antichymotrypsin-PSA complex (PSA-ACT), the calculated derivatives, PSA density (PSAD), and PSA density of the transition zone (PSATZD) for the detection of prostate carcinoma were compared by using receiver operating characteristic (ROC) curves and logistic regression analyses.

RESULTS

According to ROC curve analysis, PSATZD had the greatest area under the curve in the overall patient population and in patients with intermediate PSA levels. In patients with intermediate PSA levels, at the sensitivity of 90%, PSATZD would have prevented unnecessary biopsies in 68 of 117 patients who were without prostate carcinoma, whereas PSA, free/total PSA ratio, and PSA-ACT would have prevented unnecessary biopsies in 25, 28, and 25 patients, respectively. Stepwise logistic regression analysis showed that PSATZD and findings on digital rectal examination were significant independent predictors.

CONCLUSIONS

PSATZD had the most useful validity in the differentiation between prostate carcinoma and benign prostatic enlargement in the overall patient population and in patients with intermediate PSA levels.

Tracking of individual nanocrystals using diffracted x rays

We demonstrated dynamical observation of an individual nanocrystal in supercooled liquid water with the guidance of x-ray diffracted spots from the nanocrystal itself. This new system, which we call diffracted x-ray tracking, monitored small Brownian motions (D=0.68 mrad(2)/s at 233 K) of a single nanoparticle in real time and real space.

Prostate specific antigen adjusted for transition zone volume: the most powerful method for detecting prostate carcinoma

BACKGROUND

Several methods for the identification of patients with prostate carcinoma have been proposed to enhance the clinical usefulness of prostate specific antigen (PSA). However, it remains unclear which method is superior in practical use. The authors attempted prospectively to identify the most powerful method with which to detect prostate carcinoma, especially among patients with intermediate PSA levels.

METHODS

Between October 1997 and August 1999, systematic sextant biopsies were performed on 281 patients, including 147 with PSA levels between 4.1 ng/mL and 10.0 ng/mL. The clinical values of PSA, the free PSA to total PSA ratio (free/total PSA ratio), alpha-1-antichymotrypsin-PSA complex (PSA-ACT), the calculated derivatives, PSA density (PSAD), and PSA density of the transition zone (PSATZD) for the detection of prostate carcinoma were compared by using receiver operating characteristic (ROC) curves and logistic regression analyses.

RESULTS

According to ROC curve analysis, PSATZD had the greatest area under the curve in the overall patient population and in patients with intermediate PSA levels. In patients with intermediate PSA levels, at the sensitivity of 90%, PSATZD would have prevented unnecessary biopsies in 68 of 117 patients who were without prostate carcinoma, whereas PSA, free/total PSA ratio, and PSA-ACT would have prevented unnecessary biopsies in 25, 28, and 25 patients, respectively. Stepwise logistic regression analysis showed that PSATZD and findings on digital rectal examination were significant independent predictors.

CONCLUSIONS

PSATZD had the most useful validity in the differentiation between prostate carcinoma and benign prostatic enlargement in the overall patient population and in patients with intermediate PSA levels.

Relationship between cancer cell proliferation and thallium-201 uptake in lung cancer

Although thallium-201 (201Tl) uptake is related to perfusion in many normal tissues, the biologic rationale for 201Tl uptake in tumors is uncertain. To determine if tumor uptake is related to cell proliferation, we correlated the relative retention of 201Tl in lung tumors with expression of Ki-67, an indicator of cell proliferation.

METHODS

Sixty patients with lung tumors, included small cell carcinoma (n = 8) and non-small cell carcinoma (n = 52), underwent 201Tl single photon emission computed tomography (SPECT) imaging. The 201Tl lesion uptake was determined on early and delayed images and the radiotracer retention index (RI) was calculated. Tumor specimens were obtained at surgery or bronchoscopy. The cell proliferation ratio was estimated with MIB-1, a monoclonal antibody that recognized the nuclear antigen Ki-67.

RESULTS

The average 201Tl index was 2.13+/-0.61 (early) and 2.46+/-0.83 (delayed). The average RI was 17.44+/-35.01. Overall, the 201Tl index (delayed) and the cancer cell proliferation were correlated (r = 0.70, p < 0.0001). Of interest, there was a significant correlation (r = 0.872, p < 0.0005) between the 201Tl index on delayed images and the cell proliferation ratio in patients with small cell but not non-small cell lung carcinoma. The 201Tl index (delayed) was significantly higher (p < 0.0001) in patients with small cell lung carcinoma than in patients with non-small cell lung carcinoma.

CONCLUSION

201Tl imaging appears to be useful for evaluating patients with small cell lung carcinoma but not non-small lung carcinoma, and is correlated with the monoclonal antibody MIB-1, a marker of cell proliferation.

The functional analysis of 4.5S RNA in ribosomal translocation

4.5S RNA is a stable 114-nucleotide RNA of the bacterium Escherichia coli (E. coli). We found that 4.5S RNA have the ability of binding EF-G using gel mobility shift assay. Increasing in the concentration of GDP increase the binding activity of 4.5S RNA to EF-G. Based on these data, we propose that 4.5S RNA release EF-G from ribosome.

Isolation of a pandemic O3:K6 clone of a Vibrio parahaemolyticus strain from environmental and clinical sources in Thailand

Application of an immunomagnetic enrichment method selective for Vibrio parahaemolyticus serovar K6 allowed isolation of a strain belonging to the pandemic O3:K6 clone of V. parahaemolyticus from fresh shellfish not implicated in a clinical case in southern Thailand. Arbitrarily primed PCR profiles of this strain, clinical O3:K6 strains isolated from sporadic diarrhea cases in the same area, and a standard pandemic O3:K6 strain were indistinguishable.

Structure-activity relationships for the Ca2+-releasing activity of 6-hydroxy-beta-carboline analogues in skeletal muscle sarcoplasmic reticulum-the effects of halogen substitution at C-5 and C-7

This study of structure-activity relationships of 6-hydroxy-beta-carboline analogues has been performed on the basis of quantitative measurement of Ca2+-releasing activity in the sarcoplasmic reticulum of skinned fibres of skeletal muscle. Substitution of halogens for hydrogens at the C-5 and C-7 positions and further introduction of a methyl group into the N-9 position of 6-hydroxy-beta-carboline resulted in Ca2+-releasing activity. The 50% effective concentrations of 5,7-dibromoeudistomin D, 5,7-dichloroeudistomin D, 5,7-diiodoeudistomin D, 9-methyl-5,7-dibromoeudistomin D, 9-methyl-5,7-dichloroeudistomin D, 9-methyl-5,7-diiodoeudistomin D, and caffeine were 5.6 x 10(-6), 6.3 x 10(-6), 7.8 x 10(-6), 2.1 x 10(-6), 2.0 x 10(-5), 3.7 x 10(-5), and 4.7 x 10(-4) M, respectively, indicating that these analogues are 10-200 times more potent than caffeine. Substitution of bromine by chlorine or iodine at the C-5 and C-7 positions markedly reduced the activity of the analogues with a methyl group at the N-9 position. These results suggest that halogens at the C-5 and C-7 positions in the beta-carboline skeleton are essential for Ca2+-releasing activity and that an N-9 methyl group also affects the activity of these analogues. Thus, these 6-hydroxy-beta-carboline analogues might become powerful tools for studying the molecular mechanism of Ca2+ release in the sarcoplasmic reticulum.

Successful emergency treatment with a transjugular intrahepatic portosystemic shunt for life-threatening Budd-Chiari syndrome with portal thrombotic obstruction

We report successful treatment of acute severe Budd-Chiari syndrome with portal venous thrombosis. The prognosis of patients with this condition is poor, because the therapeutic options are limited. A 38-year-old woman with polycythemia vera was admitted in a critical condition, and Budd-Chiari syndrome complicated by portal venous thrombosis was diagnosed. Tissue plasminogen activator and urokinase were infused systemically and were partially effective. Transjugular intrahepatic portosystemic shunting to reduce the high portal venous pressure was performed successfully and, eventually, her general condition improved. Our experience indicates that emergency transjugular intrahepatic portosystemic shunting is an effective therapeutic modality for controlling portal hypertension in patients with severe Budd-Chiari syndrome with portal venous thrombosis.

Pandemic spread of an O3:K6 clone of Vibrio parahaemolyticus and emergence of related strains evidenced by arbitrarily primed PCR and toxRS sequence analyses

Vibrio parahaemolyticus O3:K6 strains responsible for the increase in the number of cases of diarrhea in Calcutta, India, beginning in February 1996 and those isolated from Southeast Asian travelers beginning in 1995 were shown to belong to a unique clone characterized by possession of the tdh gene but not the trh gene and by unique arbitrarily primed PCR (AP-PCR) profiles (J. Okuda, M. Ishibashi, E. Hayakawa, T. Nishino, Y. Takeda, A. K. Mukhopadhyay, S. Garg, S. K. Bhattacharya, G. B. Nair, and M. Nishibuchi, J. Clin. Microbiol. 35:3150-3155, 1997). Evidence supporting a hypothesis that this clone emerged only recently and is spreading to many countries was obtained in this study. Of 227 strains isolated in a hospital in Bangladesh between 1977 and 1998, only 22 strains isolated between 1996 and 1998 belonged to the new O3:K6 clone (defined by the serovar, the tdh and trh typing, and AP-PCR profiles). The O3:K6 strains isolated from clinical sources in Taiwan, Laos, Japan, Thailand, Korea, and the United States between 1997 and 1998 were also shown to belong to the new O3:K6 clone. The clonality of the new O3:K6 strains was also confirmed by analysis of the toxRS sequence, which has been shown to be useful for phylogenetic analysis of the members of the genus Vibrio. The toxRS sequences of the representative strains of the new O3:K6 clone differed from those of the O3:K6 strains isolated before 1995 at least at 7 base positions within a 1,346-bp region. A new PCR method targeted to 2 of the base positions unique to the new O3:K6 clone was developed. This PCR method could clearly differentiate all 172 strains belonging to the new O3:K6 clone from other O3:K6 strains isolated earlier. One hundred sixty-six strains belonging to 28 serovars other than O3:K6 were also examined by the new PCR method. The tdh-positive and trh-lacking strains that belonged to the O4:K68 and O1:K untypeable serovars and were isolated in three countries and from international travelers beginning in 1997 gave positive results. The AP-PCR profiles of these strains were nearly identical to those of the new O3:K6 clone, and their toxRS sequences were 100% identical to that of the new O3:K6 clone. The results suggest that these strains may have diverged from the new O3:K6 clone by alteration of the O:K antigens. In conclusion, this study presents strong evidence for the first pandemicity in the history of V. parahaemolyticus and reports a novel toxRS-targeted PCR method that will be useful in epidemiological investigation of the cases associated with the current pandemic spread.

[Revolution of the health care delivery system and its impacts on laboratory testing in the United States]

Failure to slow the exponential growth of total health care expenditures in the United States through the government policies resulted in a rapid and progressive penetration of managed care organizations(MCOs) in the early 1990s. Diagnostic testing is viewed as a "commodity" rather than a medical service under the managed care environment. Traditional hospital-based laboratories are placed in a downward spiral with the advent of managed care era. A massive reduction of in-house testing resulted from shorter lengths of patients' hospital stay and a marked decrease in admission under the dominance of managed care urges them to develop strategies for restoring tests deprived by the managed care-associated new businesses: consolidation and networking, participation in the outreach-testing market, and point-of-care/satellite laboratory testing in non-traditional, ambulatory settings are major strategies for survival of hospital laboratories. A number of physicians' office laboratories(POLs) have been closed owing to regulatory restrictions imposed by the Clinical Laboratory Improvement Amendments of 1988(CLIA '88), and to the expanded penetration of MCOs which limit reimbursement to a very few in-house procedures. It seems likely that POLs and hospital laboratories continue to reduce test volumes, while commercial reference laboratories(CRLs) gain more tests through contracting with MCOs. In the current stream of managed care dominance in the United States, clinical laboratories are changing their basic operation focus and mission in response to the aggressively changing landscape. Traditional laboratories which are unwilling to adapt themselves to the new environment will not survive in this country.

A novel mutation of the MEN1 gene in a Japanese kindred with familial isolated primary hyperparathyroidism

OBJECTIVE

To determine whether familial isolated hyperparathyroidism (FIHP) is a variant of multiple endocrine neoplasia type 1 (MEN1) we analyzed the MEN1 gene in such a kindred.

DESIGN AND METHODS

The study included the 70-year-old proband and nine relatives. Blood was drawn for biochemical evaluation and germline mutation analysis by direct sequencing of the MEN1 gene amplified by PCR. A hyperplastic parathyroid gland obtained from a family member served for a loss of heterozygosity (LOH) study.

RESULTS

Three members from two generations in this kindred were found to have primary hyperparathyroidism, while none had clinical or biochemical evidence of MEN1, MEN2 or hyperparathyroidism--jaw tumor syndrome. Analysis of germline DNA in the proband showed a missense mutation (GGC-->GAC) at codon 305 in exon 7 of the MEN1 gene that predicts an amino acid change from glycine to aspartic acid (G305D). This mutation segregated with primary hyperparathyroidism in the kindred, and, in addition, there were two asymptomatic mutant-gene carriers at relatively advanced ages. In contrast, the mutation was not detected in genomic DNA from five unaffected individuals and from 50 healthy subjects. The LOH study showed a loss of the wild-type allele, which confirmed that a functional defect of the MEN1 gene product, menin, is etiological for FIHP.

CONCLUSIONS

FIHP is a genetically heterogeneous disease with a subset linked to MEN1, most likely representing a variant of MEN1. The late onset and the reduced penetrance of disease found in this kindred may be related to the site and the type of mutation, although the precise mechanism involved is unknown at present.

Technetium-99m tetrofosmin parathyroid imaging in patients with primary hyperparathyroidism

OBJECTIVE

To confirm the clinical significance of 99mTc-tetrofosmin imaging for the localization of hyperfunctioning parathyroid glands in patients with primary hyperparathyroidism.

METHODS

All patients were imaged with 99mTc-tetrofosmin at 10 minutes and 2 hours after radiotracer injection, and with ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI). The parathyroid/thyroid uptake ratio of 99mTc-tetrofosmin (P/T uptake ratio) was calculated.

PATIENTS

Twenty patients with primary hyperparathyroidism were referred to our clinic, underwent surgical neck exploration or mediastinotomy and were diagnosed as having parathyroid adenoma. These patients were investigated for the preoperative localization by 99mTc-tetrofosmin scintigraphy.

RESULTS

99mTc-tetrofosmin imaging demonstrated focal uptake in 19 out of 20 patients with parathyroid adenoma. Two of the lesions were ectopic. US identified 17 parathyroid glands. CT and MRI initially detected 17 parathyroid glands. However, two additional parathyroid glands were localized on repeated CT and MRI in tandem with the results of the 99mTc-tetrofosmin imaging. Thus, the sensitivity and specificity of tetrofosmin imaging were 95% (19/20) and 95% (19/20); US, 85% (17/20) and 94% (16/17); initial CT, 85% (17/20) and 94% (16/17); and initial MRI, 88% (17/20) and 94% (16/17), respectively. The P/T uptake ratio at 2 hours after tetrofosmin injection was correlated with the serum concentration of intact PTH (rs=0.47, p<0.05) and the resected tumor weight (rs=0.53, p<0.05).

CONCLUSION

99mTc-tetrofosmin scintigraphy is useful for localization of parathyroid adenoma. Tetrofosmin uptake depends on the tumor weight and serum intact PTH levels.

Control of endodermal endocrine development by Hes-1

Development of endocrine cells in the endoderm involves Atonal and Achaete/Scute-related basic helix-loop-helix (bHLH) proteins. These proteins also serve as neuronal determination and differentiation factors, and are antagonized by the Notch pathway partly acting through Hairy and Enhancer-of-split (HES)-type proteins. Here we show that mice deficient in Hes1 (encoding Hes-1) display severe pancreatic hypoplasia caused by depletion of pancreatic epithelial precursors due to accelerated differentiation of post-mitotic endocrine cells expressing glucagon. Moreover, upregulation of several bHLH components is associated with precocious and excessive differentiation of multiple endocrine cell types in the developing stomach and gut, showing that Hes-1 operates as a general negative regulator of endodermal endocrine differentiation.