Characteristics and composition of peanut oil prepared by an aqueous extraction method

Peanut is one of the crops being tested for NASA's Advanced Life Support (ALS) program for future long-duration human space missions. The ALS program is developing an integrated system for biomass (food, oxygen) production and resource recycling. Oil will be used mainly for cooking and its availability is important for food preparation. Peanut seeds contain 40-50% oil and hence are considered an excellent source of oil. In the ALS environment, a simple, compact, and energy-efficient system is needed. The feasibility of such a method, peanut oil preparation by water extraction, was investigated. The results indicated the important processing conditions to be: a peanut particle size of 0.02 cm or less, a pH of 4, simmering for 20 min plus churning at 65 degrees C for a few hours, and a centrifugation at 6000 x gn to separate the oil. The oil recovery yield was about 80%. The saponification value, specific gravity, refractive index, and viscosity were similar to that of commercial peanut oil except the color was lighter for the water-extracted oil. Gas and thin-layer chromatographic analyses showed that fatty acid and lipid profiles were similar to the commercial peanut oil. The only difference observed was that the oil prepared by the aqueous method had lower linoleic and higher oleic acids than the commercial peanut oil. The oil prepared by this aqueous method appeared to be of high quality.

Positional candidate gene cloning of CLN1

Mutations in the CLN1 gene encoding palmitoyl-protein thioesterase (PPT) underlie the recessive neurodegenerative disorder, infantile Batten disease, or infantile neuronal ceroid lipofuscinosis (INCL). The CLN1 gene was mapped to chromosome 1p32 in the vicinity of a microsatellite marker HY-TM1 in a cohort of Finnish INCL families, and mapping of the PPT gene to the CLN1 critical region (and the discovery of mutations in PPT in several unrelated families) led to conclusive identification of PPT as the disease gene. PPT is a lysosomal thioesterase that removes fatty acids from fatty-acylated cysteine residues in proteins. The accumulation of fatty acyl cysteine thioesters can be reversed in INCL cells by the exogenous administration of recombinant PPT, which enters the cells through the mannose 6-phosphate receptor pathway. Over two dozen PPT mutations have been found in PPT-deficient patients worldwide. In the United States, all PPT-deficient patients show "GROD" histology but the age of onset of symptoms is later in some children due to the presence of missense mutations that result in enzymes with residual PPT activity. Now that INCL is known to be caused by a defect in a soluble lysosomal enzyme, appropriate therapies may be forthcoming. Prospects for therapy include enzyme replacement, stem cell transplantation, gene therapy, and metabolic therapy aimed at depleting the abnormal substrate accumulation in the disease.

Diagnostic pitfalls of fine-needle aspiration cytology and prognostic impact of chemotherapy in thyroid lymphoma

BACKGROUND AND PURPOSE

Fine-needle aspiration cytology (FNAC) is an important method in the evaluation of goiter. However, difficulties are encountered when using this technique to distinguish Hashimoto's thyroiditis from thyroid lymphoma. This study sought to determine the diagnostic sensitivity of FNAC and to determine the effectiveness of chemotherapy in the treatment of thyroid lymphoma.

METHODS

We retrospectively reviewed the clinical manifestations, diagnostic methods, treatment, and prognosis in 14 consecutive patients with histopathology-verified thyroid lymphoma treated in National Taiwan University Hospital from 1981 to 2000.

RESULTS

Eleven of the 14 patients underwent FNAC, which identified six lymphomas, one anaplastic carcinoma, three cases of Hashimoto's thyroiditis, and one case of Riedel's struma. Because all cases were promptly biopsied, the mean survival times for patients with or without the correct initial diagnosis (15 mo vs 43 mo) did not differ significantly (p = 0.098 by Student's t-test). Thyroid lymphoma was diagnosed before 1990 in four patients, three of whom were treated with local radiotherapy and one with surgical resection. The mean survival time of these four patients was 60 days. Thyroid lymphoma was diagnosed after 1990 in 10 patients, nine of whom underwent systemic chemotherapy, with additional adjunctive radiotherapy in three patients. The mean survival time in the nine of these 10 patients with follow-up was 60 months. A significant difference was found in the mean disease-free survival times between patients treated before and after 1990 (60 d vs 60 mo, p = 0.005).

CONCLUSIONS

In this study, FNAC had a sensitivity of only 55%, its major limitation being misdiagnosis of lymphoma as Hashimoto's thyroiditis in three patients. However, such initial misdiagnosis does not affect the prognosis if promptly corrected by histopathology. As evidenced by the improved survival of patients receiving chemotherapy after 1990, we conclude that chemotherapy is effective in the treatment of thyroid lymphoma.

Diabetic ketoacidosis and hypogonadotropic hypogonadism in association with transfusional hemochromatosis in a man with beta-thalassemia major

We report a 23-year-old man with beta-thalassemia major and transfusional hemochromatosis, which manifested as diabetic ketoacidosis and hypogonadotropic hypogonadism. This unusual presentation of diabetic ketoacidosis in hemochromatosis has rarely been reported. Magnetic resonance imaging of the abdomen showed decreased signal intensity in the liver, spleen, and pancreas. In addition, the pituitary gland also showed heterogeneous low signal intensity, compatible with hemochromatosis. He was treated with insulin supplements and pulsatile human chorionic gonadotropin administration. Clinical improvement was noted after hormone replacement. Intensive iron chelation therapy was given to prevent cardiac complications, and to restore his gonadal function. During follow-up, the patient experienced improvement in libido and sexual potency.

Biochemical analysis of mutations in palmitoyl-protein thioesterase causing infantile and late-onset forms of neuronal ceroid lipofuscinosis

Deficiency in a recently characterized lysosomal enzyme, palmitoyl-protein thioesterase (PPT), leads to a severe neurodegenerative disorder of children, infantile neuronal ceroid lipofuscinosis (NCL). Over 36 different mutations in the PPT gene have been described, and missense mutations have been interpreted in the light of the recently solved X-ray crystallographic structure of PPT. In the current study, we assessed the biochemical impact of mutations through the study of cells derived from patients and from the expression of recombinant PPT enzymes in COS and Sf9 cells. All missense mutations associated with infantile NCL showed no residual enzyme activity, whereas mutations associated with late-onset phenotypes showed up to 2.15% residual activity. Two mutations increased the K(m) of the enzyme for palmitoylated substrates and were located in positions that would distort the palmitate-binding pocket. An initiator methionine mutation (ATG-->ATA) in two late-onset patients was expressed at a significant level in COS cells, suggesting that the ATA codon may be utilized to a clinically important extent in vivo. The most common PPT nonsense mutation, R151X, was associated with an absence of PPT mRNA. Mannose 6-phosphate modification of wild-type and mutant PPT enzymes was grossly normal at the level of the phosphotransferase reaction. However, mutant PPT enzymes did not bind to mannose 6-phosphate receptors in a blotting assay. This observation was related to the failure of the mutant expressed enzymes to gain access to 'uncovering enzyme' (N-acetylglucosamine-1-phosphodiester alpha-N-acetyl glucosaminidase), presumably due to a block in transit out of the endoplasmic reticulum, where mutant enzymes are degraded.

Protective effects of tea polyphenols on mild hypobaric hypoxia induced pulmonary free radical metabolic disorder in mice

Objective. To observe the protective effects of natural antioxidant tea polyphenols (TP) on repeated mild hypobaric hypoxia induced pulmonary free radical metabolic disorder in mice. Method. Fourty-two male Kunming mice were randomly divided into three groups (n=14 each): normal control (A); 1500 in mild hypobaric hypoxia (B) and TP protection group (C). The exposure time in hypobaric chamber was 2 h/d, 3d/wk, 8 wk in total. Before hypoxic exposure, TP was orally given to group C at a dose of 100 mg/kg, while distilled water was given to the other two groups. After experiment, the mice were decapitated on the next day and the lung was quickly removed. The malondialdehyde (MDA) concentration, superoxide dismutase (SOD) activity and nitric oxide (NO) content were measured. In addition, Cu, Zn-SOD and inducible NO synthase (iNOS) enzymatic contents in lung were were qualitatively examined by immunohistochemical assaying. Result. Compared with the control group, pulmonary MDA concentration and NO content were significantly increased after chronic mild hypobaric hypoxic exposures (P<0.01) but the MDA formation and NO generation in TP protection group were restored to normal. Pulmonary SOD activity in group B tended to increase. Cu, Zn-SOD expression in endothelial cells of bronchioli and iNOS contents in endothelial cells of bronchioli and endothelial cells and smooth muscle cells in pulmonary interstitial vessels were significantly elevated after repeated mild hypobaric hypoxic exposure. These enzymatic abnormal expressions regained to normal after administration of TP. Conclusion. Natural antioxidant TP had protective effects on repeated mild hypobaric hypoxia induced pulmonary free radical metabolic disorder.

Multiple pleural nodules without effusion--a rare presentation of tuberculous pleurisy

We report a rare case of tuberculous pleurisy presenting with multiple pleural nodules without associated effusion or parenchymal lung lesions. A 62-year-old man had multiple discrete pleural nodules in the right hemithorax on chest radiography without any clinical symptoms. Thoracoscopic biopsy of the pleural nodules revealed a caseous granuloma with acid-fast bacilli. The patient received antituberculous therapy, with resolution of tuberculomas on chest film within 2 months. To our knowledge, only two similar cases have been previously reported in the English literature, and our observation should lead to broadening of the spectrum of the differential diagnosis of multiple pleural nodules.

Polyclonal anticardiolipin antibodies purified from sera of patients with active systemic lupus erythematosus induce apoptosis of the cultured glomerular mesangial cells

OBJECTIVE

To test the effect of anticardiolipin antibodies (aCL) on cultured glomerular mesangial cells with regard to their expression of apoptosis-related genes.

METHODS

aCL purified from active lupus sera by cardiolipin micelles were incubated with cultured rodent mesangial cells (RMC). Morphological changes of the RMC were observed. The genomic DNA was extracted for the detection of apoptosis. The total cell RNA was extracted for detection of Fas, c-myc, p53, and bcl-2 transcripts by reverse transcription-polymerase chain reaction.

RESULTS

aCL (100 GPL-U/0.1 mg protein/ml) bound to RMC more prominent than human IgG (100 microg/ml). The antibodies suppressed RMC proliferation in a dose-dependent manner. The RMC were undergoing apoptosis as evidenced by morphologic changes, fluoresceinannexin V staining and appearance of nucleosome-sized DNA fragments. RMC spontaneously express p53 and c-myc but not Fas or bcl-2. aCL (100 GPL-U/ml) enhanced the expression of Fas but not other apoptosis-related genes and suppressed the intracellular tyrosine phosphorylation.

CONCLUSIONS

Binding of aCL can induce apoptosis of the RMC. The aCL may be implicated in the pathogenesis of lupus nephritis.

Protective effects of tea polyphenols on myocardial free radical metabolic disorder in mice induced by inhalation of pure oxygen under 5500 m hypobaric condition

OBJECTIVE

To observe the protective effects of natural antioxidant tea polyphenols(TP) on myocardial free radical metabolic disorder in mice induced by inhalation of hypobaric pure oxygen under 5500 m hypobaric condition.

METHOD

Forty-two male Kunming mice were randomly divided into three groups (n = 14 each): group A, normal control; group B, inhalation of pure oxygen (> 96 %) at simulated altitude of 5500 m in an animal altitude chamber; group C (TP protection group), same as group B but 100 mg/kg of TP was given orally before the exposure. The exposure time was 2 h/d, 3 d/wk for a total of 8 wk, and distilled water was given to groups A and B before exposure. After experiment, the mice were decapitated on the next day and the heart was quickly removed. Malondialdehyde (MDA) concentration, superoxide dismutase (SOD) activity and nitric oxide (NO) content were measured. In addition, Cu, Zn-SOD and inducible NO synthase (iNOS) enzymatic contents in myocardial tissue were qualitatively examined by immunohistochemical assaying.

RESULT

Compared with the control, MDA concentration, SOD activity and Cu, Zn-SOD enzymatic content in group B were significantly increased (P < 0. 05). But in TP protection group, myocardial MDA formation was significantly decreased (P < 0. 01) and SOD activity and Cu, Zn-SOD expression restored to normal. On the contrary, myocardial NO generation and iNOS expression were significantly reduced after repeated inhalation of hypobaric oxygen at 5500 m. NO metabolism regained to normal after repeated administration of TP.

CONCLUSION

Natural antioxidant TP had protective effects on myocardial free radical metabolic disorder induced by inhalation of hypobaric pure oxygen under 5500 m hypobaric condition.

[Inhibition of Na+/Ca2+ exchange by tetrapeptide FMRFa in intact rat ventricular myocytes]

AIM

To study the effects of Phe-Met-Arg-Phe-NH2(FMRFa) on Na+/Ca2+ exchange and its specificity for Na+/Ca2+ exchange in rat ventricular myocytes.

METHODS

Na+/Ca2+ exchange current and other currents of ion channels were measured using whole cell voltage clamp techniques.

RESULTS

A dose-related inhibition of tetrapeptide FMRFa on Na+/Ca2+ exchange was observed in rat ventricular myocytes. Inward and outward INa+/Ca2+ were inhibited by 60.1% and 56.5%, respectively, at highest concentration (100 mumol.L-1) and its IC50 were 20 mumol.L-1 and 34 mumol.L-1 in inward and outward INa+/Ca2+, respectively. Inward and outward INa+/Ca2+ were inhibited 38.7% and 34.9%, respectively, at FMRFa 5 mumol.L-1. FMRFa 5 mumol.L-1 and 20 mumol.L-1 did not affect L-type calcium current, sodium current, transient outward current and inward rectifier potassium current.

CONCLUSION

These data indicate that FMRFa is a specific inhibitor of Na+/Ca2+ exchange in intact rat ventricular myocytes.

Infantile neuronal ceroid lipofuscinosis: no longer just a 'Finnish' disease

The neuronal ceroid lipofuscinoses (NCLs) are a group of enigmatic neurodegenerative disorders of children that have in common the storage of autofluorescent lipofuscin, or aging pigment, in the brain. With the identification of the three major genes involved in the disorder, the NCLs are now appreciated to represent true lysosomal storage disorders. The most severe (infantile) form of NCL is caused by mutations in a lysosomal thioesterase that removes fatty acids from modified cysteine residues in proteins. Although the disorder was first described in Finland (and the identification of the underlying gene (CLN1) made in this population) defects in CLN1 and the underlying deficiency have been widely reported outside of Scandinavia. In this report, we summarize the relationship of genotype to phenotype in the disorder and evaluate known mutations in light of the recently solved crystal structure of defective enzyme, palmitoyl-protein thioesterase (PPT). We also discuss progress in identifying the fatty acyl cysteine thioesters that accumulate in PPT deficiency and in working toward animal models of NCL. Recent progress in these areas holds promise for the eventual treatment of the disorder.

Increased excretions of beta2-microglobulin, IL-6, and IL-8 and decreased excretion of Tamm-Horsfall glycoprotein in urine of patients with active lupus nephritis

Tubulointerstitial nephritis is a less frequently recognized but important complication of systemic lupus erythematosus. We have investigated the cytokine beta2-microglobulin (beta2M) and Tamm-Horsfall glycoprotein (THG) excretions in the urine of systemic lupus erythematosus patients to identify indices for evaluation of tubulointerstitial inflammation in lupus nephritis (LN). Daily urine was collected from 15 patients with active LN, from 12 patients with inactive LN, and from 17 normal subjects. The amounts of soluble interleukin (IL) 2 receptor, IL-6, IL-8, beta2M, and THG in urine were measured. Beta2M and THG were regarded as indicators of proximal and distal renal tubule function, respectively. The urinary excretions of IL-6 and IL-8 were significantly higher in patients with active LN than in those with inactive LN and in normal individuals. The excretion of soluble IL-2 receptor in all three groups of subjects was not significantly different. On the other hand, the excretion of beta2M in patients with LN was significantly higher than that in normal individuals. The excretion of beta2M in patients with active or inactive LN was not significantly different. The THG excretion was lower in patients with active LN and tubulointerstitial inflammation as compared with patients with inactive LN or normal individuals. Six patients underwent pulse cyclophosphamide therapy during the course of experiments. Five of them showed a decrease in IL-8 and IL-6 excretions in urine after the treatment. The excretions of beta2M and THG in urine, in addition to IL-6 and IL-8, can reflect the renal inflammatory activity in patients with lupus tubulointerstitial nephritis as well as in those having lupus glomerulonephritis.

The crystal structure of palmitoyl protein thioesterase 1 and the molecular basis of infantile neuronal ceroid lipofuscinosis

Mutations in palmitoyl-protein thioesterase 1 (PPT1), a lysosomal enzyme that removes fatty acyl groups from cysteine residues in modified proteins, cause the fatal inherited neurodegenerative disorder infantile neuronal ceroid lipofuscinosis. The accumulation of undigested substrates leads to the formation of neuronal storage bodies that are associated with the clinical symptoms. Less severe forms of PPT1 deficiency have been found recently that are caused by a distinct set of PPT1 mutations, some of which retain a small amount of thioesterase activity. We have determined the crystal structure of PPT1 with and without bound palmitate by using multiwavelength anomalous diffraction phasing. The structure reveals an alpha/beta-hydrolase fold with a catalytic triad composed of Ser115-His289-Asp233 and provides insights into the structural basis for the phenotypes associated with PPT1 mutations.

Class III anti-arrhythmia drug E-4031 potentiates Na+/Ca2+ exchange current in rat ventricular myocytes

AIM

To study the effects of E-4031 on the Na+/Ca2+ exchange currents (INa/Ca).

METHODS

The quasi-steady state current-voltage relationship from the isolated rat ventricular myocytes was measured using whole-cell voltage-clamp techniques with a ramp pulse protocol.

RESULTS

At potential of mV, E-4031 5, 10, and 20 mumol.L-1 increased Ni(2+)-sensitive current from (0.48 +/- 0.12), to (0.78 +/- 0.20), (0.96 +/- 0.16), and (1.15 +/- 0.13) pA/pF, respectively; tetradecanoylphorbol acetate (TPA) 50 nmol.L-1 increased Ni(2+)-sensitive current from (0.60 +/- 0.16) to (1.33 +/- 0.25) pA/pF. Tamoxifen 20 mumol.L-1 completely prevented the current changes induced by E-4031 and TPA.

CONCLUSION

E-4031 stimulates the Na+/Ca2+ exchange via a protein kinase C-dependent pathway.

Chronic myeloid leukemia initially presenting with spontaneous mediastinal hematoma and hemothorax

Spontaneous mediastinal hematoma is rarely seen in hematologic malignancy. We report a case of chronic myeloid leukemia initially presenting with spontaneous hematoma and hemothorax. In addition to a detailed history, computerized tomography of the chest is important in analyzing whether an anterior mediastinal mass lesion is present. Magnetic resonance imaging is helpful in confirming the nature of a mediastinal hematoma. Trauma, vascular disease and coagulopathy should first be ruled out when making a diagnosis of spontaneous bleeding in the thorax. In our patient, the mediastinal hematoma regressed spontaneously after three months. Leukemia should be considered in the differential diagnosis of spontaneous mediastinal hematoma. In leukemia patients with spontaneous mediastinal hematoma, supportive observation and close follow-up may be better than surgery, unless massive hemorrhage or active bleeding in the thorax is suspected.

Second-harmonic generation of the nth-order Bessel beam

We investigate the second-harmonic generation of the nth-order Bessel beam in the nonlinear medium. The analysis is based on the Khokhlov-Zabolotskaya-Kuznetsov wave equation under the second-order approximation in nonlinear acoustics. The theory indicates that for an nth-order Bessel beam, the second-harmonic beam is nearly diffraction-free in the radial direction and behaves as a Bessel beam of the order 2n, and that the axial pressure amplitude is proportional to the square root of propagation distance. A variety of applications in many fields of nonlinear acoustics and nonlinear optics is expected.

Effects of phase aberration on high frame rate imaging

A high frame-rate (HFR) imaging method (about 3750 frames/s for imaging of biological soft tissues at a depth of 200 mm) has been developed recently with limited diffraction beams. This method uses the fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT) to construct images, and can be implemented with simple and inexpensive hardware, compared to the conventional delay-and-sum method where a digital beam former is usually used. In this paper, phase aberration effects are studied for both the high frame rate and the conventional methods by adding random phase shifts to echo signals obtained from an experiment. In the study, two broadband linear arrays were used to construct images of an ATS 539 tissue-equivalent phantom that has a frequency-dependent attenuation of about 0.5 dB/MHz/cm. The first array has 48 elements, a central frequency of 2.25 MHz, an aperture of 18.288 mm, and a width of 12.192 mm in elevation. The second has 64 elements, a central frequency of 2.5 MHz, and a dimension of 38.4 mm x 10 mm. The-6dB pulse-echo bandwidth of both arrays is about 40% of their center frequencies. Radiofrequency (RF) signals were digitized at 20 mega samples/s at a 12-bit resolution to construct images. Results show that phase aberration has about the same effect on both methods in terms of image resolution and contrast, although the high frame-rate method can be implemented with a simpler system.

An X wave transform

Limited diffraction beams such as X waves can propagate to an infinite distance without spreading if they are produced with an infinite aperture and energy. In practice, when the aperture and energy are finite, these beams have a large depth of field with only limited diffraction. Because of this property, limited diffraction beams could have applications in medical imaging, tissue characterization, blood flow velocity vector imaging, nondestructive evaluation of materials, communications, and other areas such as optics and electromagnetics. In this paper, a new transform, called X wave transform, is developed. In the transform, any well behaved solutions to the isotropic-homogeneous wave equation or limited diffraction beams can he expanded using X waves as basis functions. The coefficients of the expansions can be calculated with the properties that X waves are orthogonal. Examples are given to demonstrate the efficacy of the X wave transform. The X wave transform reveals an intrinsic relationship between any well behaved solutions to the wave equation and X waves, including limited diffraction beams. This provides a theoretical foundation to develop new limited diffraction beams or solutions to the wave equation that may have practical usefulness.

Folate-targeted enzyme prodrug cancer therapy utilizing penicillin-V amidase and a doxorubicin prodrug

In antibody-targeted enzyme prodrug therapy, a monoclonal antibody (mAb) covalently linked to an enzyme is commonly exploited to concentrate the enzyme on the tumor cell surface prior to administration of a relatively nontoxic prodrug. The tumor-localized enzyme then converts the prodrug into a cytotoxic agent, which in turn diffuses into the tumor causing localized cell death. In this paper, we have substituted folic acid for the mAb as a mean of delivering an attached enzyme, penicillin-V amidase (PVA), to folate receptor (FR)-positive tumor cells. The enzyme PVA is capable of converting a doxorubicin-N-p-hydroxyphenoxyacetamide prodrug (DPO) into its potent parent drug, doxorubicin. For PVA targeting, each PVA molecule was covalently labeled with three molecules of folic acid via the formation of amide bonds. In vitro binding assays showed that folate-PVA-125I conjugates bind specifically to KB cells (FR-positive tumor cells) but not to A549 cells (FR-negative tumor cells). Moreover, in a series of in vitro cytotoxicity tests, folate-PVA conjugates were found to kill folate receptor positive but not receptor negative cells, and when bound to FR-positive cells, folate-PVA conjugates rendered the DPO prodrug as toxic as free doxorubicin (IC50, approximately 0.6 microM). Finally, preliminary in vivo plasma clearance studies in normal mice revealed that i.v. administered folate-PVA-125I and PVA-125I are both cleared from the blood within a 24 h time period, removing concern that nonspecifically trapped folate-PVA might activate prodrug in nontargeted tissues. In view of the fact that only a small number of folate-PVA molecules are required to mediate killing of target cells in vitro, these data argue that folate-targeted enzyme prodrug therapy should be considered for tumor eradication in vivo.

Ethambutol-induced psychosis: a case report

Clinically, ethambutol (EMB)-induced psychosis is rare. In our review of the literature, most cases of antituberculosis agent-associated psychoses were caused by isoniazid (INH). We report the case of a 51-year-old man with suspected tuberculosis (TB) pleurisy. An anti-TB trial with INH, rifampicin and EMB was given initially. Dizziness, disorientation, and auditory and visual hallucinations developed after seven days of therapy. Laboratory examinations, including routine biochemistry tests, serum titer of antinuclear antibodies, cerebrospinal fluid analysis and computerized tomography of the head showed no abnormal findings. Following discontinuation of anti-TB agents, the psychiatric symptoms subsided. When the patient was challenged with EMB, the same psychiatric symptoms recurred, but resolved again after discontinuation of EMB. It is important to be aware that EMB can induce psychosis when anti-TB medications are prescribed.

Na+/Ca2+ exchange current in myocytes isolated from rat hypertrophied heart

Effects of myocardial hypertrophy on the Na+/Ca2+ exchange current in isolated rat cardiac myocytes were investigated, using whole cell patch techniques. Goldblatt 2-kidney, one-clip technique was used to induce cardiomyocyte hypertrophy. The results demonstrated that the Ni(2+)-sensitive Na+/Ca2+ exchange current density was larger in hypertrophied cells than that in normal cells. At a holding potential of mV, the outward current densities were 1.53 +/- 0.31 pA/pF in normal cells and 2.62 +/- 0.53 pA/pF in hypertrophied cells (P < 0.01). At a holding potential of -100 mV, the inward current densities were 0.42 +/- 0.14 pA/pF in normal cells and 1.12 +/- 0.33 pA/pF in hypertrophied cells (P < 0.001). The results suggest that during myocardial hypertrophy the Na+/Ca2+ exchange current is significantly increased.

Seroprevalence of cytotoxin-associated gene A positive Helicobacter pylori strains in Changle, an area with very high prevalence of gastric cancer in south China

BACKGROUND

Helicobacter pylori, especially the CagA-positive strains, are closely associated with peptic ulcers and gastric cancers. We performed a large scale gastric cancer screening project and examined the prevalence of H. pylori and CagA-positive strains in Changle, China, an area with one of the World's highest gastric cancer mortality. We also compared the prevalence with that in Hong Kong which has one-tenth of the gastric cancer mortality of that in Changle.

METHODS

A total of 2424 subjects in Changle and 523 subjects in Hong Kong had endoscopic examination and venesection. Sera were tested for anti-H. pylori antibody and anti-CagA antibody and correlated with endoscopic findings.

RESULTS

In Changle, 80. 9% of the subjects were H. pylori carriers. Out of 551 carriers, 408 (74%) were positive for anti-CagA antibody. A total of 76% and 87% of the asymptomatic and gastric cancer patients were positive for anti-CagA antibody, respectively (P > 0.05). Compared to Hong Kong, there was a significantly (P < 0.0001) higher prevalence of CagA-positive strains in asymptomatic subjects in Changle (76%) than in Hong Kong (28%), but not in peptic ulcers or gastric cancers.

CONCLUSIONS

Subjects in Changle had a high prevalence of H. pylori infection and a high prevalence of the CagA-positive strains. The contrast in the prevalence of CagA-positive strains, in asymptomatic subjects in two areas with differing gastric cancer mortality, supports the pathogenic role of CagA-positive strains in gastric carcinogenesis.