Vacuolating toxin gene polymorphism among Helicobacter pylori clinical isolates and its association with m1, m2, or chimeric vacA middle types

BACKGROUND

Helicobacter pylori vacuolating cytotoxin encoded by vacA plays an essential role in H. pylori-related pathogenesis. Specific vacA alleles are believed to be associated with increased virulence. Association among vacA polymorphism, vacA middle genotypes, and various H. pylori-related diseases was thus investigated.

METHODS

Eighty-nine isolates from patients with various gastrointestinal diseases were examined for restriction fragment length polymorphism (RFLP) of the 2.0-kb polymerase chain reaction-amplified vacA middle region. Further genetic heterogeneity was assessed with ureA-ureB RFLP.

RESULTS

Twenty-eight distinct vacA RFLPs were seen among 89 isolates. Each pattern was associated with one specific vacA middle genotype. The association of specific RFLPs with certain clinical manifestations was noted among six common groups. Further RFLP analysis of the 2.4-kb ureA-ureB segment from isolates in four popular vacA RFLPs showed high genetic variation.

CONCLUSIONS

The vacA genetic polymorphism may be associated with different gastrointestinal diseases.

Transient increase in the alpha3-isoform of Na,K-ATPase in rat erythroblastic cells

Using immunoelectron microscopy and isoform-specific antibodies against Na,K-ATPase to study changes in Na,K-ATPase in rat erythroblastic cells during maturation, we unexpectedly observed numerous antigenic sites against the alpha3-isoform in the cytoplasmic phase. There was an increase in the number of alpha3-isoforms after denucleation of the erythroblast. The increase was transient. As the reticulocyte matured into a red blood cell, the number of alpha3-isoforms was reduced drastically. This alpha3-isoform was distributed in a reticular pattern resembling the double layers of endoplasmic reticulum. Western blot analysis confirms the presence of the alpha3-isoform in these cells. X-ray microanalysis of the erythroid series of cells in the bone marrow shows that sodium concentration in the young reticulocyte is higher than that in the nucleated erythroblast. The reason for the transient increase in this pump protein is not clear. It is possible that the increase in sodium concentration in the reticulocyte plays a role in the increase in pump protein synthesis.

Gastric dysrhythmia in uremic patients on maintenance hemodialysis

BACKGROUND

Dyspeptic symptoms are common in uremic patients receiving hemodialysis. Investigators have placed emphasis on the changes in histopathology and physiology of the gastrointestinal tract. But not much data about the gastric myoelectric activity are available. The aim of this study was to assess gastric myoelectric activity in uremic patients undergoing hemodialysis.

METHODS

Fifty-eight subjects were enrolled. They were assigned to: group I, uremic patients undergoing hemodialysis with dyspeptic complaints (n = 20); group II, non-uremic patients with matched dyspeptic complaints (n = 20); and group III, healthy volunteers without dyspeptic complaints (n = 18). Gastric myoelectric activity was measured with abdominal surface electrodes in each person. Patients in group I were measured twice, before (group Ia) and after (group Ib) hemodialysis. The data were compared between the groups.

RESULTS

In the prehemodialysis period there was a significantly lower percentage of normal slow-wave frequency when compared with group III (fasting, 66.54%+/-5.39% versus 84.58%+/-3.63%; P < 0.005; fed, 72.25%+/-4.16% versus 89.06%+/-2.57%; P < 0.01). In the post-hemodialysis period the difference was even more profound (fasting, 46.52%+/-4.26% versus 84.58%+/-3.63%; P < 0.001; fed, 51.49%+/-6.89% versus 89.06%+/-2.57%; P < 0.005). Yet, when compared with group II, a significant difference existed only in the post-hemodialysis period (fasting, 46.52%+/-4.26% versus 67.30%+/-3.46%; P<0.001; fed, 51.49%+/-6.89% versus 70.41%+/-4.39%; P < 0.01). Another finding is that hemodialysis decreased the gastric myoelectric activity after hemodialysis (fasting, 66.54%+/-5.39% versus 46.52%+/-4.26%; P < 0.001; fed, 72.25%+/-4.16% versus 51.49%+/-6.89%; P < 0.005).

CONCLUSIONS

Uremic patients undergoing hemodialysis have impaired gastric myoelectric activity. Interestingly, hemodialysis seems to cause deterioration in gastric myoelectric activity.

Optimized conditions for growth and fermentation of Helicobacter pylori

This study attempted to optimize the growth conditions of Helicobacter pylori by comparing the growth of H. pylori in an anaerobic jar and an incubator. It was found that the primary isolation rate of H. pylori from gastric biopsies was higher in an anaerobic incubator (28/30) than in an anaerobic jar (21/30). In addition, growth rate in the subsequent passage was also higher in an incubator. By comparing different supplements in the liquid media, it was found that most strains grew best in Brucella broth containing 5% fetal calf serum, and some strains grew well with the supplement of 0.2% of beta-cyclodextrin. A large scale culture using a bioreactor indicated that a defoaming agent, polypropylenglycol, profoundly inhibited the growth of H. pylori. However, fermentation could be successfully performed by continuously infusing mixed airs composed of 5% O2, 10% CO2 and 85% N2. Moreover, the production of secreted proteins of H. pylori strains grown in the bioreactor was the same as that in an anaerobic jar. Results presented herein can be used to further optimize conditions for enhancing the growth of H. pylori.

Small-intestinal bacterial overgrowth in patients with liver cirrhosis, diagnosed with glucose H2 or CH4 breath tests

BACKGROUND

Small-intestinal bacterial overgrowth (SIBO) has been considered a predisposing factor of spontaneous bacterial peritonitis in cirrhotic patients by bacterial translocation or hematogenous spread during spontaneous bacteremia. We investigated 45 cirrhotic patients and 28 healthy subjects to assess the prevalence of SIBO and its relationship with the severity of liver dysfunction and the presence of ascites.

METHODS

Bacterial overgrowth was measured by the glucose hydrogen and methane breath test.

RESULTS

SIBO was documented in 16 (35.6%) of the 45 cirrhotic patients and in 1 (3.6%) of the 28 healthy controls. The prevalence of SIBO was significantly higher in patients with Child-Pugh class B or C (50%) than in those with class A (19%) and had no relationship with the presence or absence of ascites.

CONCLUSIONS

We conclude that the prevalence of SIBO in cirrhotic patients is approximately 35.6% and that it is related to the severity of liver disease. There was no difference among various causes of cirrhosis, such as viral, alcoholic, or idiopathic.

Salivary function in patients with reflux esophagitis: effect of cisapride

Saliva plays an important role in esophageal acid clearance. Reduction in salivary function has been considered in the pathogenesis of reflux esophagitis. Cisapride, a prokinetic agent, has been reported effective for treating mild-to-moderate grade gastroesophageal reflux disease. Some studies have shown that cisapride increases saliva volume and acid-buffering capacity. The aim of this study was to evaluate the effect of cisapride on salivary gland function by means of dynamic salivary scintigraphy.

METHODS

Fifty-five patients with endoscopic reflux esophagitis (Savary-Miller Grades I-II) were enrolled in this study. In Group 1 (n = 29), patients were evaluated during the fasting state, both before and after cisapride treatment (5 mg, 3 times/day, before meals, for 2 wk). In Group 2 (n = 26), patients were evaluated during the postprandial state, both before and after cisapride treatment. Uptake ratio (UR) and excretion ratio (ER) of the salivary gland in each group were compared using the paired Student's t-test.

RESULTS

In Group 1, no significant differences were found in UR or ER after cisapride treatment. However, in Group 2, ER increased significantly after treatment (p < 0.01), but UR did not show any significant change.

CONCLUSION

Cisapride can increase the secretion function of salivary glands during the postprandial phase but not the fasting phase.

Presence of immunoreactive alpha 3 subunit isoform of Na,K-ATPase in mitochondria of kidney

BACKGROUND

Sodium-potassium-adenosinetriphosphatase (Na,K-ATPase) is the primary membrane enzyme responsible for the reabsorption of sodium ions in the kidney. It is known that in the nephron the major subunit isoforms of Na,K-ATPase are alpha 1 and beta 1. Previous reports on the presence of alpha 2 and alpha 3 isoforms in the kidney were mixed and controversial.

METHODS

Techniques of ultrathin cryosectioning and immunoelectron microscopy were used to study the distribution of alpha subunit isoforms (alpha 1, alpha 2, alpha 3) and beta subunit (beta 1 isoform) of Na,K-ATPase in renal tubular cells. Western blot analysis was used to show the presence of the alpha 3 isoform in the extract of kidney mitochondria.

RESULTS

We were able to confirm the previous finding that the alpha 1 isoform and the beta 1 isoform were the preponderant isoforms of the alpha and beta subunits of Na,K-ATPase in the basolateral membrane. In addition, we unexpectedly found the presence of the alpha 3 isoform in the mitochondria of rat renal tubular cells. The alpha 2 and alpha 3 isoforms were not observed in either the apical or basolateral membrane.

CONCLUSIONS

Both immunoelectron microscopy and Western blot analysis of the rat kidney mitochondria confirm the presence of the alpha 3 isoform of Na,K-ATPase in the rat kidney mitochondria. The function of this enzyme in the mitochondria is not clear at this time.

Nitro-polycyclic aromatic hydrocarbon contents of fumes from heated cooking oils and prevention of mutagenicity by catechin

According to earlier studies, fumes from cooking oils were found to be mutagenic and several polycyclic aromatic hydrocarbons (PAHs), (benzo(a)pyrene (B(a)P), benz(a)antracene (B(a)A), and dibenz(a,h)anthracene (DB(ah)A)) were identified. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and nitro-polycyclic aromatic hydrocarbons (NPAHs) were extracted from the samples and identified by HPLC chromatography. Extracts from three cooking oil fumes contained 1-nitropyrene (1-NP) and 1,3-dinitropyrene (1,3-DNP). Concentrations of 1-NP and 1,3-DNP were 1.1 +/- 0.1 and 0.9 +/- 0.1 micrograms/m3 in fumes from lard oil, 2.9 +/- 0.3 and 3.4 +/- 0.2 micrograms/m3 in soybean oil, 1.5 +/- 0.1 and 0.4 +/- 0.1 micrograms/m3 in peanut oil, respectively. The preventive effect of three natural antioxidants (gamma-tocopherol (TOC), lecithin (LEC), and catechin (CAT)) for the reduction of mutagenicity and amounts of PAHs and NPAHs of fumes from cooking oils were evaluated. Mutagenicity of cooking oil fumes occurred, and the concentration of B(a)P were significantly reduced (p < 0.05), by adding CAT into cooking oils before heating. B(a)A, DB(ah)A, and two NPAHs were not detected when the concentration of CAT was 500 ppm in all three cooking oil fumes. These results indicate that fumes of cooking oils contained PAHs and NPAHs that may be a risk factor for lung cancer among cooks and the carcinogens could be reduced by adding the natural antioxidant, catechin.

p53 alterations in betel quid- and tobacco-associated oral squamous cell carcinomas from Taiwan

Alterations of p53 have been explored in Taiwanese oral squamous cell carcinomas (OSCCs) consisting of a betel quid (BQ)/tobacco-related subgroup of 36 subjects and a tobacco-related subgroup of 13 subjects. Mutations in conserved exons were found in 12 tumors. Seven mutations were clustered in a hot-spot region mapped to a region between codons 273-282 in exon 8. The incidence of p53 mutation in BQ/tobacco tumors was 22% (8/36). The frequency of p53 allelic loss (21%, 3/14) in BQ/tobacco tumors approximates to the incidence of mutation. This is the first study demonstrating allelic deletion of p53 in such malignancies. Twenty-four of 43 samples showed positive p53 immunostaining. All tumors harboring mis-sense mutations of p53 in conserved exons exhibited nuclear protein accumulation. The incidence of mutation in conserved exons in BQ/tobacco-associated Asian OSCCs (15%) is significantly different from worldwide OSCCs (46%) related primarily to tobacco consumption (P=0.00001).

Transient impact of hemodialysis on gastric myoelectrical activity of uremic patients

Upper gastrointestinal discomforts are common in uremic patients. Investigators have stressed the structural, histopathological, and physiological changes in the gastrointestinal tract in the past decades. Few data are available about the electrophysiological changes in the stomach of uremic patients. It is not known whether hemodialysis alters gastric myoelectrical activity. More interestingly, what is the long-term effect? To address these questions, we measured gastric myoelectrical activity before and after hemodialysis in patients with end-stage renal disease on maintenance dialysis treatment. Twenty-one uremic patients with dyspeptic complaints were enrolled in this study. Gastric myoelectrical activity was measured noninvasively using abdominal surface electrodes (electrogastrography). The paired variables obtained before and after hemodialysis were compared statistically. We also compared the difference between two subgroups defined as new hemodialysis patients and chronic hemodialysis patients. We found that there was a significantly lower percentage of normal slow-wave frequency obtained after hemodialysis in comparison with before hemodialysis (fasting state: 49.1 +/- 4.8% vs 68.1 +/- 5.4%, P < 0.01; fed state: 53.8 +/- 6.9% vs 73.4 +/- 4.1%, P < 0.01). In comparing the subgroups, there were no differences between each EGG variable. We concluded that the hemodialysis itself compromised gastric myoelectrical activity in its immediate effect. However, there were no permanent effects regarding gastric myoelectrical activity itself.

Microsurgical management of intracranial epidermoid cysts

BACKGROUND

Intracranial epidermoid cysts are slow-growing congenital neoplasms that usually spread and adhere to critical neurovascular structures along the basal cistern, particularly the cerebellopontine angle (CPA) and parasellar region. Clinical symptoms include trigeminal neuralgia, headache and dizziness, progressive hemiparesis, unstable gait and hemifacial spasm. With the aid of modern imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), an effective microsurgical approach can be planned preoperatively to completely remove tumors and avoid complications.

METHODS

Twenty-six patients with intracranial epidermoid cysts were microsurgically treated between July 1984 and June 1997. Diagnostic procedures included enhanced CT and/or CT cisternography and MRI. All patients underwent microsurgical treatment for tumor removal.

RESULTS

Total tumor removal was achieved in 12 patients (46.2%), near-total removal in seven (26.9%), partial removal in six (23.1%) and stereotactic biopsy in one patient (3.8%). Postoperative deterioration of the neurologic condition was found in three patients who required further surgery, aseptic meningitis in four patients and communicating hydrocephalus requiring shunting in three patients. The functional prognoses were excellent in 23 patients (88.5%), good in two patients (7.7%) and fair in one patient (3.8%). Among the 26 patients, three died of pneumonia three, six and nine months after surgery, respectively.

CONCLUSIONS

MRI is particularly useful for defining the anatomic limits of tumor tissue and surgical planning. The surgical results were excellent in patients with near-total tumor removal, as well as in patients with total removal. Aggressive surgical tumor removal may result in transient, but significant, cranial nerve palsy and should be avoided. Perioperative administration of steroids and wound protection may be beneficial for preventing the development of postoperative aseptic meningitis and hydrocephalus.

Effect of cisapride on gastric dysrhythmia and emptying of indigestible solids in type-II diabetic patients

BACKGROUND

Abnormal gastric slow-wave frequencies have been observed in diabetic gastroparesis. To evaluate the effect of cisapride on gastric dysrhythmia and emptying of indigestible solids, 20 type-II diabetic patients with symptoms suggestive of gastroparesis were enrolled in this study.

METHODS

Cutaneous electrogastrography, gastric emptying of radiopaque markers, and evaluation of upper gastrointestinal symptoms were performed before and after administration of an 8-week course of cisapride.

RESULTS

The fasting-state percentages of dominant frequency in normal and tachygastric ranges improved significantly after an 8-week course of cisapride treatment (P < 0.01 and P < 0.05, respectively). The post-meal percentages of dominant frequency in the tachygastric range also improved significantly after cisapride treatment (P < 0.05). The upper gastrointestinal symptoms score decreased significantly, and gastric emptying of radiopaque markers also increased significantly after 8 weeks of cisapride treatment (P < 0.01).

CONCLUSIONS

In conclusion, this study showed that cisapride can improve gastric dysrhythmia during both fasting and post-meal phases in patients with diabetic gastroparesis. In addition, upper GI symptoms and gastric emptying of indigestible solids may also show significant improvement after 8 weeks of cisapride treatment.

Evidence for sulfate modification of H-2Dd on N-linked carbohydrate(s): possible involvement in Ly-49A interaction

Murine class I molecules are ligands for Ly-49 molecules, a family of regulatory receptors expressed on murine NK cells. Since soluble sulfated mono- and polysaccharides interfere with the interaction of Ly-49A, a C-type lectin, and its class I ligand, Dd, it is possible that the oligosaccharides on class I molecules are sulfated and participate in Ly-49A binding. In this report, we show that H-2Dd expressed by activated T cells and various tumor cell lines is sulfated, as demonstrated by immunoprecipitation of Dd following Na235SO4 labeling. The 35SO4(-2) label on Dd expressed by a representative tumor cell, NZB1.1, is removed by peptide N-glycosidase F, but is resistant to endoglycosidase H treatment, indicating that the sulfate group is located on mature N-linked oligosaccharides. Two-dimensional SDS-PAGE analysis revealed that all major mature glycosylation variants of the Dd expressed by NZB1.1 are sulfated. Sodium chlorate, a potent inhibitor of ATP-sulfurylase, which prevents the formation of the sulfate donor, 3'-phosphoadenosine 5'-phosphosulfate, inhibited metabolic sulfation of Dd. NZB1.1 binds isolated Ly-49A immobilized on solid phase through an interaction by cell surface Dd, since cell adhesion was blocked by Abs directed against Dd or Ly-49A. Treatment of the Dd-expressing NZB1.1 tumor cells with sodium chlorate reduced their ability to bind immobilized Ly-49A, particularly when Ly-49A density was limiting. These results provide evidence for sulfation of H-2Dd oligosaccharide moieties, and suggest a role for this posttranslational modification in the interaction of Dd with Ly-49A.

Antibody to a Helicobacter pylori species specific antigen in patients with adenocarcinoma of the stomach

This study attempted to identify a possible antibody response to Helicobacter pylori, which is associated with patients with adeno-carcinoma of the stomach. By using proteins of H. pylori as the antigen, pooled sera from gastric cancer and non-cancer patients were used as the first antibody for Western blot analysis. Antibody responses to a 26 kD secreted protein were observed in pooled cancer sera, but not in pooled sera from non-cancer patients. The protein was purified, while amino acid sequences revealed that it was a H. pylori species specific protein. The gene of this protein was cloned and a recombinant protein was expressed in E. coli. In addition, an antibody to the recombinant protein was tested in each individual patient using Western blot analysis. None of the forty non-gastric cancer patients were positive for the antibody to the recombinantly expressed 26 kD species specific protein. Meanwhile, six of the twenty four cancer patients tested positive (0/40 vs 6/24, p < 0.01). Results presented herein demonstrate that the species specific protein of H. pylori can be useful in detecting H. pylori associated with adenocarcinoma of the stomach.

Self-oligomerization of NACP, the precursor protein of the non-amyloid beta/A4 protein (A beta) component of Alzheimer's disease amyloid, observed in the presence of a C-terminal A beta fragment (residues 25-35)

NACP, the precursor protein of the non-amyloid beta/A4 protein (A beta) component of Alzheimer's disease (AD) amyloid, also known as alpha-synuclein, was suggested to seed amyloid plaque formation in AD by stimulating A beta aggregation. We have demonstrated that NACP experienced self-oligomerization only in the presence of a modified A beta fragment (A beta25-35) by using dicyclohexylcarbodiimide. This NACP oligomerization, appearing as a discrete ladder on a Tricine SDS-PAGE, was not observed with other A beta peptides such as the reverse peptide A beta35-25 and A beta1-40, indicating this process was specific not only for the C-terminal peptide sequence of the A beta but also for its orientation. It might be, therefore, suggested that the NACP self-oligomers formed only in the presence of a N-terminally truncated A beta peptide could act as a nucleation center for plaque formation during AD development.

Donor leukocyte infusion as salvage therapy in an adult with relapsed acute lymphoblastic leukemia after allogeneic bone marrow transplantation

Relapse of malignancy after allogeneic bone marrow transplantation remains the major cause of treatment failure in patients with leukemia. While donor leukocyte infusion (DLI) has been used to treat such patients, its use in patients with acute lymphoblastic leukemia is seldom reported. We describe a 35-year-old woman who suffered relapse of acute lymphoblastic leukemia after allogeneic bone marrow transplantation. She received DLI twice as salvage therapy. This patient achieved complete remission following DLI and has remained in remission for more than 11 months without further chemotherapy. We suggest DLI can be used as an initial salvage therapy, without significant toxicity, for patients with relapsed acute lymphoblastic leukemia following bone marrow transplantation.

Surfactant effect on enhancing (S)-naproxen prodrug production from racemic naproxen by lipase

In the enantioselective esterification of racemic naproxen with 4-(2-hydroxyethyl) morpholine by Lipase MY in organic solvents, a productivity improvement of the desired (S)-naproxen ester from 0.42 to 0.72 mM at the reaction time of 130 h was observed, when the surfactant bis (2-ethylhexyl) sodium sulfosuccinate (AOT) was added in the reaction mixture. The presence of a small amount of exogenously added water dramatically activated the enzyme in AOT/cyclohexane-reversed micelles. Desorption of the surfactant molecule from the enzyme mass and solubilization of the enzyme into reversed micelles were used to elucidate an existing maximum of the initial rate of (S)-naproxen synthesis with the water content. Moreover, the effects of alcohol and surfactant concentration on the enzyme activity are reported.

Leptomeningeal malignant melanoma arising in neurocutaneous melanocytosis: a case report

A rare case of histology-proved giant congenital melanocytic nevus (GCMN) with symptomatic leptomeningeal melanocytosis is reported. A 26-year-old man had had a large patch of pigmented nevus over his back and left arm since birth. He had begun to have seizures as well as symptoms and signs of increased intracranial pressure about six months before admission. Serial computed tomography of brain showed hydrocephalus, diffuse leptomeningeal enhancement and multiple well-enhanced, rapid-growing nodules on the surface of the cerebellum and left parietal lobe. Magnetic resonance imaging (MRI) revealed T1 shortening of leptomeninges on precontrast T1 weighted imaging. Skin biopsy was done twice and showed intradermal nevus. Biopsy on one of the intracranial nodules revealed malignant melanoma arising in the melanocytosis. He died one year after the onset of neurologic symptoms. For early diagnosis of neurocutaneous melanocytosis, we suggest 1) MRI, and 2) leptomeningeal biopsy in patients with suspected leptomeningeal malignant melanoma.

Severe granulocytopenia secondary to chlorpromazine despite concurrent lithium treatment: a case report

Severe chlorpromazine-induced granulocytopenia where the white-cell count decreases to below 1,000/mm3 rarely occurs and lithium is known to cause leucocytosis. The use of lithium in the prevention of granulocytopenia induced by drugs is still controversial. This report describes a patient with bipolar disorder suffering from severe granulocytopenia and severe respiratory infection after receiving chlorpromazine 50 to 150 mg per day along with long term lithium therapy. Bone-marrow aspiration and biopsy revealed inhibited maturation of myeloid series in the promyelocyte stage. The findings were consistent with a drug-induced effect. White-cell count return to normal after the discontinuation of chlorpromazine. It was proved in this case that combined lithium therapy had no effect in preventing agranulocytosis induced by chlorpromazine.

Comprehensive gastric emptying study for type-II diabetes mellitus dyspeptic patients

BACKGROUND

Gastrointestinal symptoms without demonstrable lesions in the upper gastrointestinal tract are common in diabetic patients. Scintigraphic liquid- and solid-phase gastric emptying studies and gastric emptying of indigestible particles were performed to determine the gastric emptying function in type-II diabetes mellitus patients with dyspepsia.

METHODS

Twenty type-II diabetic patients with symptoms suggestive of delayed gastric emptying were included. A gelatin capsule containing 10 rod-shaped radiopaque markers was ingested, along with the solid-phase test meal, to assess the emptying of indigestible particles. Scintigraphic liquid-phase gastric emptying studies were performed on a separate day.

RESULTS

There were 7 patients (35%) with delayed liquid-phase gastric emptying, 14 patients (70%) with delayed solid-phase gastric emptying, and 14 patients (70%) with abnormal gastric emptying of indigestible particles. There were only three patients (15%) with normal gastric emptying of both the liquid and solid phase. Furthermore, only one patient showed normal result in all three gastric emptying studies.

CONCLUSIONS

For determining abnormalities in gastric emptying function for type-II diabetic dyspepsia patients, comprehensive gastric emptying studies, including scintigraphic liquid- and solid-phase gastric emptying studies and gastric emptying of indigestible particles, are most helpful.

Mutagenesis of the positively charged conserved residues in the 5' exonuclease domain of Taq DNA polymerase

Taq DNA polymerase from Thermus aquaticus has been shown to be very useful in the polymerase chain reaction method. Taq DNA polymerase has a domain at the amino terminus (residue 1 to 290) that has a 5' exonuclease activity and a domain at the C-terminus that catalyzes polymerase reaction. Taq DNA polymerase is classified into the pol I family which is represented by E. coli DNA polymerase I. The alignment of amino acid sequences for the 5' exonuclease domains of the pol I family DNA polymerases shows six highly conserved sequences called motifs A to F. Motif C contains three positively charged residues such as 74Arg, 82Lys and 85Arg which might be involved in catalysis. In order to understand the function of those residues, they are mutagenized to alanine. The 5' exonucleolytic activities of those mutated 5' exonucleases decreased by 80 to 90%, thereby implying that three positively charged residues play certain roles in the 5' exonuclease catalysis.

Aluminum-induced structural alterations of the precursor of the non-A beta component of Alzheimer's disease amyloid

The precursor of the non-A beta component of Alzheimer's disease amyloid (NACP) is a presynaptic protein whose function has been suspected to be tightly involved in neuronal biogenesis including synaptic regulations. NACP was suggested to seed the neuritic plaque formation in the presence of A beta during the development of Alzheimer's disease (AD). Recombinant NACP purified through heat treatment, DEAE-Sephacel anion-exchange, Sephacryl S-200 size-exclusion, and S-Sepharose cation-exchange chromatography steps appeared as a single band on SDS-PAGE with Mr of 19 kDa. Its N-terminal amino acid sequence clearly confirmed that the protein was NACP. Interestingly, however, the protein was split into a doublet on a nondenaturing (ND)-PAGE with equal intensities. The doublet was located slightly above a 45-kDa marker protein on a 12.5% ND-PAGE. In addition, the size of NACP was more carefully estimated as 53 kDa with high-performance gel-permeation chromatography using a TSK G3000sw size-exclusion column. Recently, Lansbury and his colleagues (Biochemistry 35, 13709-13715) have reported that NACP exists as an elongated "natively unfolded" structure which would make the protein more actively involved in protein-protein interactions and Kim (Mol. Cells 7, 78-83) has also shown that the natively unfolded protein is extremely sensitive to proteases. Here, we report that the structure of NACP could be altered by certain environmental factors. Aluminum, a suspected risk factor for AD, converged the doublet of NACP into a singlet with slightly lower mobility on ND-PAGE. Spectroscopic analysis employing uv absorption, intrinsic fluorescence, and circular dichroism indicated that NACP experienced the structural alterations in the presence of aluminum such as the secondary structure transition to generate about 33% alpha-helix. This altered structure of NACP became resistant to proteases such as trypsin, alpha-chymotrypsin, and calpain. Therefore, it is suggested that aluminum, which influences two pathologically critical processes in AD such as the protein turnover and the protein aggregation via the structural modifications, could participate in the disease.

Incorporating tangent refinement in the Shake-and-Bake formalism

Shake-and-Bake is a direct-methods procedure in which phase refinement and Fourier refinement are alternated repetitively, unconditionally and automatically. The traditional Shake-and-Bake approach invoked a parameter-shift routine to perform phase refinement in an effort to reduce the value of minimal function. In this paper, parameter shift is replaced with the tangent formula as a means of phase refinement. This study shows that the tangent formula is more efficient than parameter shift for small structures when the number of refinement cycles and number of applications of the tangent formula per Shake-and-Bake cycle are chosen very carefully. For larger structures, including the 400 non-H-atom crambin structure, the two methods generally perform with similar efficiency. However, only parameter shift has successfully produced recognizable solutions for the difficult 317 non-H-atom structure gramicidin A.

Characterization of functional interaction of carboxylic acid group of agonists and arginine of the seventh transmembrane domains of four prostaglandin E receptor subtypes

Prostaglandin (PG) E2 binds to four PGE receptor subtypes, EP1, EP2, EP3 and EP4, and induces a variety of functions through the interaction of carboxylic acid of PGE2 and Arg residue in the seventh transmembrane domain of the receptor. To assess the role of the interaction of the carboxylic acid group of agonists and the Arg residue, which can form both ionic bonding and hydrogen bonding as a hydrogen donor, we examined the agonist activities of three types of agonist, PGE2 with a negatively charged carboxylic acid, PGE2 methylester, which is a hydrogen acceptor, and 1-OH PGE2, which can accept as well as donate hydrogen but prefers to donate hydrogen rather than accept it, for four PGE receptor subtypes. Although PGE2 methylester had slightly lower agonist activities than PGE2 for EP1 and EP4 receptors, PGE2 and its methylester showed the same agonist activities for EP2 and EP3 receptors, indicating that PGE2 methylester is a potent agonist for all of the four subtypes. In contrast, 1-OH PGE2 was a very weak agonist for all receptors. These findings demonstrate that the hydrogen bonding interaction of agonists and the Arg residue is generally sufficient for the functional activation of all of the PGE receptor subtypes.

Stereomorphologic observation of bone tissue response to hydroxyapatite using SEM with the EDTA-KOH method

To obtain further information on the interaction of hydroxyapatite (HA) and the bony implantation bed, 20- to 40- mesh dense HA particles were implanted into the tibiae of dogs. Following healing periods of 2 weeks, 1 month, and 3 months, the specimens were retrieved and prepared by either conventional preparatory procedures for scanning electron microscopy (SEM) of the EDTA-KOH method. Under SEM observation, the interparticular osteogenesis among HA particles progressed in a programmed sequence. Ample blood supply and osteoblasts initially presented in the interparticular space. The secretion of bone matrix resulted in the formation of immature bone. This scaffold was then transformed into mature lamellar bone during the following bone remodeling process. The serial changes closely resembled the pattern viewed in controls that did not implant HA. A spatial relationship between bone cells and HA was clearly demonstrated. In particular, the osteoblasts displayed an extremely flat appearance with many microappendages. The microappendages anchored cells to the HA surface and fused with granular material covering the HA crystals. The more characteristic cellular morphology was revealed by the EDTA-KOH method. Microscopic pictures clearly identified the three-dimensional images of ruffled borders of osteoclasts and the slender cytoplasmic processes of osteocytes. This study provided further evidence for the favorable biological response of HA to bone cells as well as the value of the EDTA-KOH method in examining the stereomorphology of bone cells.

Ambulatory 24-hour esophageal manometry and pH-metry in patients with noncardiac chest pain, but no reflux symptoms

The aim of this study is to determine the diagnostic value of 24-hour ambulatory esophageal manometry and pH-metry for patients with noncardiac chest pain (NCCP), but no reflux symptoms. Twenty-four hour ambulatory esophageal manometry and pH-metry was performed on 34 patients with NCCP, but no reflux symptoms. The pressure transducers were located 3, 8, and 13 cm above the lower esophageal sphincter (LES) and the pH probes were located 5 and 20 cm above the LES. An event marker was triggered by the patient for chest pain. Only 17 patients (50%) had at least one pain episode (total 81 episodes, range 1-19 episodes per person) during a 24-hour recording. Twenty-one chest pain episodes (26%) occurred during abnormal motility, whereas 4 episodes (5%) were associated with pH < 4, and 10 episodes (12%) had both abnormalities. The majority of chest pain episodes, 46 out of 81 events (57%), did not have any association with motility or pH abnormalities. Five of 7 patients (71%) with reflux-related chest pain and 8 of 11 patients (73%) with dysmotility-related chest pain had symptom association probability > 95%, indicating a significant association between chest pain and esophageal dysfunction. Our conclusion is that ambulatory esophageal manometry and pH-metry is a useful tool in the evaluation of NCCP, but only a few additional patients with reflux-related chest pain could be found in patients without reflux symptoms.

Correlation between patterns of antral contractility and gastric emptying of radiopaque markers

OBJECTIVES

Gastric clearance of radiopaque markers (ROMs) has been proposed as an easy and noninvasive technique for assessment of gastric emptying. This study was conducted to evaluate the role of antral obliterating contractions in gastric emptying of ROMs in healthy volunteers.

METHODS

Fifteen healthy volunteers, 12 males and three females, aged 21-38 yr, were enrolled in this study. Simultaneous recording of scintigraphic solid phase gastric emptying, gastric clearance of ROMs, and gastric manometry were performed after an overnight fast. The data of scintigraphic solid phase gastric emptying were expressed by half-emptying time (t1/2). The ROMs remaining in the stomach were counted fluoroscopically 2.5 and 4.5 h after the test meal. The time for the appearance of antral obliterating contractions after the meal was calculated.

RESULTS

Six subjects (40%) passed all 10 ROMs after 4.5 h of recording. Among these six subjects, five had antral obliterating contractions 190-251 min (mean 232.2 +/- 24.3 min) after the test meal. There was no significant difference in t1/2 between subjects with or without antral obliterating contractions within the 4.5 h of recording.

CONCLUSIONS

There was a considerable intersubject variation in the time of first antral obliterating contraction after the test meal. In the healthy volunteers, all ROMs were passed when there was a postprandial antral obliterating contraction. However, some of the ROMs still passed from the stomach in the absence of antral obliterating contractions.

The incidence of reflux esophagitis among the Chinese

OBJECTIVES

Very few epidemiological data on reflux esophagitis in Chinese are available in the literature.

METHODS

To evaluate the incidence of reflux esophagitis, upper gastrointestinal endoscopies were performed on 2044 patients (male 1266, female 778; age range 16-82 yr) during a 6-month period.

RESULTS

The overall incidence of reflux esophagitis was 5%, and most of the patients (86.3%) had a mild grade of esophagitis. Hiatal hernia was found in 44 patients (2.2%); those patients were significantly older than those without hiatal hernia (60.3 +/- 10.8 vs. 49.4 +/- 12.1 yr, p < 0.05). Patients with symptoms suggesting gastroesophageal reflux (acid regurgitation, heartburn, and belching) had higher incidence of esophagitis (22.9%, 22.5%, and 24.7%, respectively). The body mass index was significantly higher in patients with esophagitis than in those without esophagitis (25.7 +/- 3.1 vs. 24.0 +/- 3.6, p < 0.05). The male:female ratio for esophagitis was 5.6:1. No esophagitis was found in patients who were less than 21 yr old. However, there was a difference in age group distribution for the incidence of esophagitis. The habit of coffee or tea drinking does not contribute to the development of esophagitis.

CONCLUSIONS

Based on the results of this study, the incidence of endoscopic reflux esophagitis among the Chinese is 5%, which is lower than in Western countries.

High dose chemotherapy with peripheral blood stem cells transplantation in patients with relapsed or refractory lymphomas preliminary reports

High dose chemotherapy with peripheral blood stem cells transplantation (PBSCT) has been used worldwide in the treatment of patients with various hematological malignancies and other solid tumors. It has just come into use as a salvage therapy in various malignancies in Taiwan in recent years. We report eight cases with relapsed or refractory lymphoma treated with high dose chemotherapy and PBSCT. Our results showed all cases but one achieved complete remission. The mean days of white cell recovery were 10 days to > 500/microliter (ranges, 8-16 days) and 12 days to > 1,000/microliter (ranges, 9-19 days). The mean days to platelet transfusion independent, i.e. platelet > 20,000/microliters, was 14 days. No specific side effect was noted except death in one case on D+9 during cytopenia state. Four patients relapsed and died during the follow-up after PBSCT. From our preliminary results we suggest that high dose chemotherapy with PBSCT could be used as a salvage therapy in patients with relapsed or refractory lymphomas with favorable and sustained hematological recovery. Most cases were tolerable with myeloablative chemotherapy and re-achieved remission, however, remission duration was still short and relapse remained the main problem to be overcome. The long term effects of high dose chemotherapy with PBSCT still need further study.

7,7-Difluoroprostacyclin derivative, AFP-07, a highly selective and potent agonist for the prostacyclin receptor

Recently, we cloned cDNAs for the prostacyclin receptor (IP) and the four mouse PGE receptor subtypes, EP1, EP2, EP3, and EP4, and established Chinese hamster ovary cells that stably express each receptor. We examined the agonist potency and selectivity of AFP-07, a 7,7-difluoroprostacyclin derivative, compared with widely used stable prostacyclin analogue, iloprost, using the cells expressing each cloned receptor. AFP-07 strongly displaced the [3H] iloprost binding to the IP receptor-expressing cell membranes, the half maximal concentration for the displacement being 3 nM, which was one order lower than that of iloprost. AFP-07 concentration-dependently stimulated cAMP formation in the IP-expressing cells, the half-maximal concentration for the stimulation being 10 pM, which was one order lower than that of iloprost. On the other hand, AFP-07 showed lower affinity for EP1, EP2, EP3, and EP4 than PGE2, but iloprost had the same affinity as PGE2 for the EP1, These results demonstrate that AFP-07 is a potent and highly selective agonist for the IP receptor.

Comparison of intravenous granisetron with metoclopramide plus dexamethasone in the prevention of nausea and vomiting associated with emetogenic cytotoxic chemotherapy

Fifty-one patients who received their first course of chemotherapy were studied to compare the respective efficacy and safety of granisetron and metoclopramide plus dexamethasone in the prevention of nausea and vomiting induced by emetogenic cytotoxic drugs. The results showed the response rate of antiemesis in the first 24 hours was higher in the metoclopramide plus dexamethasone group than in the granisetron group: 95% vs 84%. For the next six days of the study period, the response rate of the granisetron group was shown to be more effective than that of metoclopramide plus dexamethasone group: 77% vs 60%. Furthermore, the granisetron seemed to display enhanced tolerability with less drug-related side effects and no extrapyramidal effects which appeared in 2 cases of the metoclopramide plus dexamethasone group. In conclusion, a single dose of granisetron can be as effective as the gold standard of metoclopramide plus dexamethasone regimen in preventing and treating acute nausea and vomiting. For preventing delayed nausea and vomiting, granisetron is shown to be more effective than metoclopramide plus dexamethasone.

Major histocompatibility complex class I-dependent cell binding to isolated Ly-49A: evidence for high-avidity interaction

Ly-49A molecules negatively regulate a subset of mouse natural killer (NK) cells, preventing lysis of H-2Dd-expressing target cells. In the present report, we immunoaffinity-purified Ly-49A from the EL4 lymphoma using the A1 monoclonal antibody (mAb) and examined cell adhesion to immobilized Ly-49A. Adhesion was observed by cells expressing relatively high levels of H-2Dd, but not cells expressing very low or no cell surface Dd, while antibodies specific for Dd or Ly-49A inhibited the cell binding, indicating that Dd and Ly-49A mediate the observed adhesion. The density of immobilized Ly-49A was varied and confirmed by ELISA. Cell binding exhibited a threshold Ly-49A density requirement, and above this threshold, increases in Ly-49A density resulted in substantial increases in cell adhesion to a high maximum cell binding. The density of Ly-49A homodimers required to mediate cell adhesion was found to be quite low: 140-250 molecules/microm2. These results suggest that the avidity of Ly-49A for Dd is relatively high and indicate that small changes in Ly-49A density near the threshold result in large changes in stable Ly-49A receptor engagement. The relatively sharp threshold and marked density dependence presented here for Ly-49A receptor engagement may explain the observation that relatively small differences in Ly-49A expression level on NK cells result in significant differences in functional outcome, i.e. whether a target cell expressing a low level of Dd is spared from lysis or not.

Detection of EBV in tumor tissue and peripheral blood by polymerase chain reaction in patients with nasopharyngeal carcinoma

Sixty-nine untreated patients with a pathologically verified nasopharyngeal carcinoma were selected for the study of detection of EBV in nasopharyngeal tumor and peripheral blood by polymerase chain reaction (PCR). Primers were directed to conserved regions of EBV genome encoding capsid protein gp 220 (Bam HI L region). A distinct 239 bp band of the PCR products indicated the presence of EBV. Results showed that EBV DNA was obtained in 91.3% of 69 NPC patients and 16.7% of 18 healthy individuals on nasopharyngeal tissue, and the difference was statistically significant between the above two groups. Nevertheless, no EBV DNA was verified from the mononuclear cells of the peripheral blood of the two groups. There was no relationship between the positive EBV DNA and the titer of serological markers. Meanwhile, the positive EBV DNA did not show any relationship with the histology type, tumor and nodal bulk, or even metastasis. Although a high positive rate of EBV DNA was detected in nasopharyngeal tumor of patients, additional environmental and genetic factors must still be considered.

Quantitative X-ray imaging of labelled molecules in tissues and cells

Using cisplatin as a model system, we have been able to demonstrate the feasibility of studying the cellular and subcellular distribution of a labelled molecule containing a single atom of platinum per molecule in bone marrow. An X-ray imaging system consisting of a microcomputer, a 4pi system and a software package was interfaced with an electron microscope enabling the computer to control the beam movements as well as receive signals from the STEM and EDS X-ray detectors. X-ray imaging is useful for both tissue and samples in which the population of cells is not homogeneous. Imaging permits elemental distributions to be measured throughout the sample and not in just randomly selected areas as previously done in X-ray microanalysis. Images are created for not only the element labelling the molecule of interest but also other specified elements present. Three types of maps for imaging labelled molecules are compared and discussed. When the original (collected) data are mapped, the elements of interest are obscured by the continuum. The maps calculated using an internal standard give a concentration distribution on the basis of volume (mmol L(-1) of packed cells). The maps calculated using the continuum normalization method according to Hall produces concentration distribution on the basis of mass (mmolk(-1) dry weight). By recalculating using the 'Peak' or 'Hall' method the continuum problem is removed yielding quantitative images of the intracellular distribution of labelled molecules present in low concentrations.

[Gastric emptying in non-insulin dependent diabetic patients]

Disordered gastrointestinal motility is an often overlooked clinical problem. Delayed gastric emptying of solid and/or liquid meal in patients with both type 1 and type 2 diabetes mellitus occurs in approximately 50% of these patients. Gastric emptying time (GET) was studied in seventy four non-insulin dependent (type 2) diabetic out-patients by using radionuclide gamma-photography with Tc-99m phytate solid experimental meal. Thirty nine of them received Tc-99m phytate liquid test meal on the next day. Forty six normal healthy volunteers acted as controls. The results showed that solid GET in patients with type 2 diabetes mellitus was significantly delayed (149.44 +/- 64.0 min) as compared with that in the control group (88.7 +/- 14.2 min) (p < 0.001). Fifty three among these 74 diabetic patients had delayed solid GET, accounting for 71.6%. Only 5 of 39 (12.8%) diabetic patients showed delayed liquid GET (average 38.7 +/- 35.3 min; control 46.2 +/- 11.1 min). There were no differences in sugar control, duration of the disease, and upper gastrointestinal symptoms between patients with delayed GET and those with normal GET. We concluded that delayed gastric emptying is very common in patients with non-insulin dependent diabetes mellitus and which has no direct correlation to blood sugar control, duration of the disease, and upper gastrointestinal symptoms. Radionuclide solid gastric emptying test is a both safe (low radioactivity) and convenient (non-invasive) diagnostic tool in non-insulin dependent diabetic gastroparesis.

Relationship between C14 urea breath test values and solid-phase gastric emptying time in non-ulcer dyspepsia patients

BACKGROUND

Non-ulcer dyspepsia (NUD) is a poorly understood syndrome often found with endoscopic evidence of gastritis; Helicobacter pylori (Hp) is a common and important cause of gastritis. In the recent literature, gastric hypomotility is thought to be a cause of NUD. Thus, this investigation studied the relationship between Hp and delayed gastric emptying in NUD patients.

METHODS

Using a radionuclide-labelled solid meal to calculate gastric emptying time (GET) of 78 NUD patients. The carbon-14 urea breath test (C14 UBT) was used to quantitate Hp infection.

RESULTS

The prevalence of Hp infection in patients with NUD reached 59%. There was a strong association of Hp infection with advanced age (p = 0.0091). There was no significant difference between solid-phase GET and C14 UBT values among three different age groups (young, middle, old) of NUD patients. There was no difference among sex, age, body weight and solid-phase GET between Hp-positive and Hp-negative NUD patients. However the solid-phase GET was significantly prolonged in patients with NUD, compared with the controls.

CONCLUSIONS

Solid-phase GET is not correlated with the C14 UBT values, and Hp gastric colonization does not account for dyspeptic syndrome in NUD patients.

The effect of Helicobacter pylori infection on gastric emptying of digestible and indigestible solids in patients with nonulcer dyspepsia

OBJECTIVE

There is no general agreement with regard to the effect of Helicobacter pylori infection on gastric emptying in patients with nonulcer dyspepsia.

METHODS

We performed the 14C urea breath test as well as simultaneous recordings of scintigraphic gastic emptying and gastric clearance of radiopaque markers to determine the effect of Helicobacter pylori infection on gastric emptying of digestible and indigestible solids in nonulcer dyspepsia patients.

RESULTS

Sixty patients, 30 males and 30 females, were enrolled in the study. There were 22 patients (36.7%) without and 38 patients (63.3%) with H. pylori infection. Twenty-four of the 60 patients (40%) showed normal and 36 patients (60%) showed delayed gastric emptying of digestible solids. In addition, 21 patients (35%) showed normal and 39 patients (63%) showed delayed gastric emptying of indigestible solids. There was no correlation between delayed gastric emptying of digestible and indigestible solids (p > 0.05, difference not significant). Although not statistically significant, the incidence of delayed indigestible solid emptying was higher than that of delayed digestible solid emptying (65% vs. 60%). Among different patterns of gastric emptying, no difference was noted between the patients with and without H. pylori infection.

CONCLUSION

Delayed gastric emptying of indigestible solids is as common as delayed gastric emptying of digestible solids in nonulcer dyspepsia patients. The status of H. Pylori infection appeared not to influence the incidence of delayed gastric emptying of digestible and indigestible solids.

Gastric clearance of radiopaque markers in non-ulcer dyspepsia patients

BACKGROUND

The use of radiopaque markers has been proposed as an easy, non-invasive method for measuring gastric emptying. In this study we intended to evaluate the effectiveness of this test in determining the gastric motor function in patients with non-ulcer dyspepsia.

METHODS

Simultaneous recording of scintigraphic solid gastric emptying and gastric clearance of radiopaque markers were conducted in 65 non-ulcer dyspepsia patients.

RESULTS

Forty-two patients (64.4%) showed abnormal gastric clearance of radiopaque markers, and 38 patients (58.5%) showed delayed solid gastric emptying. There was no correlation between delayed solid gastric emptying and abnormal gastric clearance of radiopaque markers (p > 0.05). Although the frequency of abnormal gastric clearance of radiopaque markers was higher than that of delayed solid gastric emptying (64.6% versus 58.5%), it was not statistically significant.

CONCLUSIONS

On the basis of the results of our study, gastric clearance of radiopaque markers may be used as an easy, non-invasive screening test for the purpose of detecting gastric motor dysfunction. However, this test is not superior to scintigraphic gastric emptying studies.

X-ray microanalysis and mapping: measuring uptake and intracellular distribution of labeled molecules

X-ray microanalysis is a useful technique for elemental analysis of tissues and cells. This technique utilizes x-rays generated in ultra-thin cryosections of tissue by the electron beam in an electron microscope. The x-rays are characteristic of the various elements, and can be used to measure quantitatively the elemental distribution at subcellular levels. An important application of this x-ray microanalysis and mapping technique is the study of uptake and intracellular distribution of molecules containing an element not normally present in the tissue. It is useful for tissues and samples in which the cell population is not homogeneous. Mapping permits elemental distributions to be measured throughout the sample, not just at selected sites. Maps created are not only for the element of interest but also for other specified elements present. Using an x-ray imaging system and cisplatin as a model, we have been able to demonstrate the feasibility of studying the cellular and subcellular distribution of cisplatin, a molecule containing platinum atom.

Discrepant pattern of solid and liquid gastric emptying in Chinese patients with type II diabetes mellitus

While abnormal gastric emptying has been widely reported in patients with diabetes, its clinical relevance is still uncertain. We conducted scintigraphic gastric emptying studies in patients with Type II diabetes mellitus who had symptoms suggestive of delayed gastric emptying in an attempt to evaluate the incidence of abnormal gastric emptying and to assess the clinical parameters of the different patterns of gastric emptying. Seventy male diabetic patients were included in the study. The patients were divided into four groups according to the results of liquid and solid gastric emptying: group 1, normal liquid and solid emptying (n = 22); group 2, normal liquid but delayed solid emptying (n = 30); group 3, delayed liquid but normal solid emptying (n = 7); group 4, delayed liquid and solid gastric emptying (n = 11). To assess clinical significance, we compared duration of disease, status of blood sugar control, presence or absence of vascular complications and of peripheral neuropathy among the four groups. Of the 70 patients, 18 (25.7%) showed delayed liquid gastric emptying and 41 (58.6%) delayed solid gastric emptying. There were no significant differences in the clinical parameters of the four groups, except that patients with good sugar control were likely to have normal liquid gastric emptying. Based on the results of this study, delayed solid gastric emptying is more common than liquid gastric emptying in symptomatic Type II diabetes mellitus patients. Of the different patterns of gastric emptying, delayed liquid gastric emptying with normal solid gastric emptying is the most unusual. For Type II diabetic patients with symptoms suggestive of delayed gastric emptying, both liquid and solid gastric emptying studies should be performed.

Delayed gastric emptying does not predispose to Helicobacter pylori infection in non-ulcer dyspepsia patients

Non-ulcer dyspepsia is a common disorder in clinical practice. The pathogenesis and predisposing factors that lead to the development of Helicobacter pylori infection are still unclear. The aim of the present study was to evaluate the prevalence of H. pylori infection in non-ulcer dyspepsia patients with delayed gastric emptying and those with normal gastric emptying, and to determine if delayed gastric emptying predisposes to H. pylori infection. A total of 70 patients (29 males, 41 females) aged 18-59 years (mean +/- S.D. 40.5 +/- 11.2 years) took part in the study. A solid-phase scintigraphic gastric emptying study and 14C urea breath test were performed on each patient. There was no statistically significant difference in age between those patients with and without delayed gastric emptying (40.8 +/- 11.9 vs 40.4 +/- 10.5 years), or between those with and without H. pylori infection (40.5 +/- 12.6 vs 40.5 +/- 9.8 years). Of the 70 patients, 45 (64.3%) had delayed gastric emptying and 25 (35.7%) had normal gastric emptying. The overall incidence of H. pylori infection was 58.6%. The incidence of H. pylori infection among patients with delayed gastric emptying was 60% (27/45 patients) and among patients with normal gastric emptying 56% (14/25) patients). The incidence of H. pylori infection in the two groups was not significantly different. The incidence of H. pylori infection in the non-ulcer dyspepsia patients in this study was similar to that of age-matched asymptomatic volunteers in Taiwan. In conclusion, based on the results of this study, delayed gastric emptying does not lead to a predisposition to H. pylori infection in non-ulcer dyspepsia patients.

The effect of coffee on gastric emptying

The effect of coffee on gastric emptying was addressed in a scintigraphic liquid-phase gastric emptying study in patients with non-ulcer dyspepsia. Ninety-three subjects (56 males, 37 females; mean age 40 years, range 17-77 years) diagnosed as having non-ulcer dyspepsia were enrolled in the study. The baseline study was to drink 500 ml of 5% glucose water and the coffee study was to drink 500 ml of 5% glucose water containing 4 g of regular instant coffee. The two studies were performed on separate days. Fifteen of the 93 subjects were chosen at random to undergo repeated coffee studies for evaluation of reproducibility. Overall the 93 subjects showed accelerated gastric emptying, as measured by half emptying time (T1/2) with coffee compared with baseline (35.7 +/- 10.5 vs 45.0 +/- 23.1 min, P < 0.001). However, 68 (73.2%) subjects showed accelerated emptying (-14.8 +/- 19.5 min), while 25 (26.8%) subjects showed delayed emptying (5.9 +/- 4.5 min) after ingestion of coffee. There was no significant difference in the change in gastric emptying with coffee in duplicate measurements from the 15 subjects who had two coffee studies (P = 0.082). We conclude that coffee accelerates liquid-phase gastric emptying in the majority of patients with non-ulcer dyspepsia.

Increased accuracy of the carbon-14 D-xylose breath test in detecting small-intestinal bacterial overgrowth by correction with the gastric emptying rate

To date, there is no general agreement as to which test is to be preferred for the diagnosis of small-intestinal bacterial overgrowth. The 1-g carbon-14 D-xylose breath test has been proposed as a very sensitive and specific test for the diagnosis of bacterial overgrowth. However, in patients with severe gastrointestinal motor dysfunction, the lack of consistent delivery of 14C-D-xylose to the region of bacterial contamination may result in a "negative" result. The aim of this study was to determine whether the accuracy of 14C-D-xylose breath test for detecting bacterial overgrowth can be increased by correction with the gastric emptying rate of 14C-D-xylose. Ten culture-positive patients and ten culture-negative controls were included in the study. Small-intestinal aspirates for bacteriological culture were obtained endoscopically. A liquid-phase gastric emptying study was performed simultaneously to assess the amount of 14C-D-xylose that entered the small intestine. The results of the percentage of expired 14CO2 at 30 min were corrected with the amount of 14C-D-xylose that entered the small intestine. There were six patients in the culture-positive group with a 14CO2 concentration above the normal limit. Three out of four patients with initially negative results using the uncorrected method proved to be positive after correction. All these three patients had prolonged gastric emptying of 14C-D-xylose. When compared with cultures of small-intestine aspirates, the sensitivity and specificity of the uncorrected 14C-D-xylose breath test were 60% and 90%, respectively. In contrast, the sensitivity and specificity of the corrected 14C-D-xylose breath test improved to 90% and 100%, respectively. In conclusion, using the gastric emptying rate of 14C-D-xylose as a correcting factor, we found a higher sensitivity and specificity for the 14C-D-xylose breath test in the detection of small-intestinal bacterial overgrowth than were achieved with the conventional method.

Application of ABO genotyping using polymerase chain reaction method to assess engraftment in bone marrow transplantation--a case report

We described a case of acute promyelocytic leukemia with O blood type who received bone marrow transplantation during a second remission from his HLA identical, B blood type sibling. Using PCR genotyping of the ABO group and analysis of the variable number of tandem repeats of the D1S80 locus, we could quickly document the successful early engraftment in this patient. We emphasize that the use of PCR ABO genotyping is a quick and valuable method which could be applied to assess the engraftment and its follow up in those transplant cases with donors of mismatched blood groups.