DUNBID, the Delft University neutron backscattering imaging detector

In the search for low-metallic land mines, the neutron backscattering technique may be applied if the soil is sufficiently dry. An advantage of this method is the speed of detection: the scanning speed may be made comparable to that of a metal detector. A two-dimensional position sensitive detector is tested to obtain an image of the back scattered thermal neutron radiation. Results of experiments using a radionuclide neutron source are presented. The on-mine to no-mine signal ratio can be improved by the application of a window on the neutron time-of-flight. Results using a pulsed neutron generator are also presented.

Esophageal manometry and pH monitoring: gastroenterologists' adherence to published guidelines

GOALS

To determine whether gastroenterologists use esophageal manometry (EM) and esophageal pH recording (pHR) in accordance with published guidelines.

STUDY

Questionnaires were mailed to 900 randomly selected gastroenterologists nationwide. Each questionnaire requested demographic information and contained 11 case scenario-based questions, followed by a choice of management options.

RESULTS

A total of 275 completed questionnaires (30.6%) were returned. 63.6% and 64.4% of respondents were aware of published guidelines regarding the use of EM and pHR, respectively. The majority of respondents ordered EM appropriately: 1) to confirm a suspected diagnosis of achalasia (97.1%); 2) to establish a diagnosis of connective tissue disease (89.7%); 3) as part of the preoperative evaluation for anti-reflux surgery (74.6%); and 4) to ensure the proper placement of pH probes (69.4%). EM was rarely ordered for the initial workup of noncardiac chest pain. The majority of responding gastroenterologists would order pHR for the evaluation of: 1) endoscopy-negative patients being considered for anti-reflux surgery (79.1%); 2) patients with recurrent GERD symptoms after anti-reflux surgery (62.5%); 3) endoscopy-negative patients with GERD symptoms refractory to proton pump inhibitor (PPI) therapy; and 4) patients with extraesophageal manifestations of GERD that are refractory to PPI therapy (88.7%).

CONCLUSIONS

The majority of gastroenterologists in our study order EM and pHR in accordance with published guidelines. However, EM appears to be used less than expected for preoperative evaluation before anti-reflux surgery and for ensuring the proper placement of pH probes. In addition, the use of pHR to evaluate persistent GERD symptoms after anti-reflux surgery was less than anticipated.

Determination of hydrogen content in bulk samples using the neutron activation method

The applicability of a new irradiation facility for bulk hydrogen analysis based on the activation method using thermal and epithermal neutrons has been tested for cylindrical samples of 8 cm diameter and 10 cm high. A definite correlation was found between the relative excess flux values, R and the total hydrogen contents, N(H) of the samples. Analytical expressions obtained for R vs. N(H) function indicate the possible use of this method even in the case of approximately kg weight and liter sample dimensions. The large sample has a special advantage if the determination of the hydrogen concentration, C(H) is in question.

Detection of enteric viruses, Giardia and Cryptosporidium in two different types of drinking water treatment facilities

In this study, two types of drinking water treatment facilities (two conventional drinking water treatment plants (DWTPs) and two compact units (Cus)) were compared referring to their production capacity. Water samples were collected from three main points: (a) different water treatment steps (b) washings of sand filters and (c) distribution system at different distances from the water treatment plants. Both viruses and protozoa were concentrated from each water sample by adsorption and accumulation on the same nitrocellulose membrane filters (0.45 microm pore size). Enteroviruses were detected by plaque infectivity assay in BGM cells and HAV, HEV and Norovirus were detected by RT-PCR. Giardia and Cryptosporidium were detected by conventional staining methods and PCR. The results revealed that enterovirus load at the intake ranged between 10-15 PFU/L for the two compact units and between 4.5 and 75 PFU/L for the two conventional DWTPs. The virus load in distribution system of the first type DWTPs at 1 km from the plant was the same as that of the intake. Viruses in the other type of treatment plants CUs at 1, 5 and 7 km, were much reduced. Investigation of raw water sediments of the two DWTPs showed enterovirus counts between 12 and 17.5 PFU/L. Virus count was reduced in sand of filters after washing. Giardia cysts were equally detected by microscopy and PCR in only intake samples of EL-Hawamdia CU (33.3%) and Meet Fares DWTP (50%). Cryptosporidium oocysts were equally detected by microscopy and PCR in intake samples of Abo EL-Nomros CU (100%), EL-Hawamdia CU (66.7%) and Fowa DWTP (50%). At Meet Fares DWTP three positive intake samples for Cryptosporidium were detected by PCR, compared with only two positive samples by microscopy. Giardia cysts and Cryptosporidium oocysts were detected in raw water sediment and sand of filters before washing. Only one sample from Meet Fares DWTP sand of filters after washing was positive for both Giardia and Cryptosporidium. It can be concluded that the poor microbial quality of the water may be due to improper operational skills and management of the various water treatment plants (especially at the two high capacity treatment plants).

Chemical and biological evaluation of the essential oils of different Melaleuca species

The essential oils of the fresh leaves of M. ericifolia, M. leucadendron, M. armillaris and M. styphelioides were isolated by a hydrodistillation method and analysed by a gas chromatography/mass spectrometry (GC/MS) technique. The essential oil of M. ericifolia contained methyl eugenol (96.84%) as a major constituent, whereas M. leucadendron was rich in 1,8-cineole (64.30%). The essential oil of M. armillaris was rich in 1,8-cineole (33.93%) followed by terpinen-4-ol (18.79%), whereas M. styphelioides was rich in caryophyllene oxide (43.78%) and (-) spathulenol (9.65%). The essential oils of these species possessed antimicrobial and antifungal activities. M. ericifolia exhibited the highest inhibitory effects against Bacillus subtiles and Aspergillus niger. The antiviral activities of the essential oils against Herpes simplex virus type 1 (HSV-1) were studied in African green monkey kidney cells (Vero) by a plaque reduction assay. The volatile oil of M. armillaris was more effective as a virucidal (up to 99%) than that of M. leucadendron (92%) and M. ericifolia (91.5%). The effects of the essential oils on the antioxidant system status in carbon tetrachloride treated animals were studied. The essential oil of M. armillaris exhibited a marked antioxidant effect, it improved vitamin E, vitamin C and superoxide dismutase parameters so it can be used as a free radical suppressor.

Light and electron microscopic studies of Myxobolus stomum n. sp. (Myxosporea: Myxobolidae) infecting the blackspotted grunt Plectorhynicus gaterinus (Forsskal, 1775) in the Red Sea, Egypt

A new myxosporean parasite, Myxobolus stomum n. sp., is described from the oral cavity and lips of the blackspotted grunt Plectorhynicus gaterinus (Forsskal, 1775) in the Red Sea, Egypt. The parasite was observed as tiny aggregates of whitish cysts hardly noticed within the muscles of the oral cavity, especially within the lips. The spores were subspherical and measured 8.5x6.5 microm. Polar capsules were equal, pear-shaped, occupied about half of the spore length and measured 4.4x2.4 microm. Histological evaluation of the infection revealed no significant impact on the host. The ultrastructure of the plasmodial wall and sporogenesis of the present species followed the usual pattern valid for most studied myxosporean species.

Myocarditis: an expected health hazard associated with water resources contaminated with Coxsackie viruses type B

Enteroviruses, especially Coxsackie B viruses (CBVs), are responsible for approximately 50% of cases of viral myocarditis. In the present study, serum samples (160) were collected from acute myocarditis patients at different age groups and 104 samples of the same age groups as a control. Cholesterol, LDH, CPK, and GOT were measured for all serum samples (264). Also, to study the source of virus transmission, 72 water and 72 wastewater samples were collected from water and wastewater treatment plants at intakes and outlets. Water and wastewater samples were concentrated by filtration through Zeta-plus filter cartridges and reconcentrated by the PEG-6000 precipitation method. Serum, water, and wastewater samples were inoculated in BGM cells for three successive passages. RT-PCR with enterovirus primers was carried out directly for serum samples and for 1st and 3rd cell culture passages. The positive samples were used for neutralization assay using anti-CBV sera pool to determine the CBV followed by neutralization with separate antisera. The results showed that 50 (31.25%) serum samples from acute myocarditis patients and two (1.4%) samples from the controls were positive for enterovirus RT-PCR. For water and wastewater samples enteroviruses were present in 63.8% and 8.3% for intake and outlet of water treatment plants and, 66.6% and 47.2% for intake and outlet of wastewater treatment plants, respectively. The level of CBV serotypes was varied where CBV3 was dominant for all age groups of myocarditis patients and CBV2 and CBV5 were also detected while CBV2 was the main CBV in water samples and CBV2, 3 and 5 were detected in wastewater samples. The integration of cell culture-PCR reduces the time required for virus detection and enhances the sensitivity of the test.

Evaluation of three concentrations of tebufenpyrad for the control of Varroa destructor (Acari: Varroidae)

We evaluated three concentrations of tebufenpyrad (17.5, 15 and 12.5%) in strip formulations for controlling varroa mites, Varroa destructor Anderson and Trueman (2000), in honey bee colonies. We also included colonies treated with Apistan, CheckMite+, and untreated colonies in our evaluation. The three concentrations we evaluated reduced varroa populations but also reduced the amount of brood and adult bees when compared with untreated colonies and colonies treated with Apistan or CheckMite+. Alternative delivery methods, lower concentrations of tebufenpyrad, and the evaluation of related compounds are logical next steps in evaluating the varroacidal potential of tebufenpyrad and related compounds.

Primary diagnosis and REAL/WHO classification of non-Hodgkin's lymphoma by fine-needle aspiration: cytomorphologic and immunophenotypic approach

The Revised European American lymphoma (REAL) and World Health Organization (WHO) classification of non-Hodgkin's lymphoma (NHL) relies on the constellation of cytologic, phenotypic, genotypic, and clinical characteristics of NHL. For the most part, the classification does not rely on architectural pattern for classification of neoplasms. This classification makes it possible to diagnose and classify lymphomas by fine-needle aspiration (FNA). In this study, we attempted to evaluate the accuracy of FNA in diagnosing and classifying NHL within the context of the REAL/WHO classifications. Cases included only those in which FNA was the primary diagnosis, followed by a surgical biopsy for confirmation. Flow cytometry (FCM) for phenotyping was carried out whenever material was available. Two groups of pathologists were identified. Group A consisted of pathologists with background training in cytopathology and/or hematopathology (three pathologists). Group B consisted of experienced surgical pathologists with no training in cytopathology and/or hematopathology (four pathologists). Seventy-four cases were included in the study. FCM phenotyping was performed in 53 cases (71%). Large cell lymphoma constituted 63% of the cases. The remaining lymphomas included Burkitt's, small lymphocytic, lymphoblastic, follicle center cell, Ki-1, mantle cell, marginal zone, and natural killer cell lymphoma. The diagnosis of lymphoma was rendered for all cases. The correct classification was seen in 63% of the cases. Classification was more accurate in immunophenotyped than in nonimmunophenotyped cases (84% vs 33%; P = 0.00004). Group A pathologists showed higher incidence of proper classification than group B (80% vs 56%; P = 0.046). The diagnosis and classification of NHL can be achieved in a large number of cases on FNA material. This accuracy can be increased if cytomorphologic criteria are established for different entities of NHL aided by FCM for phenotyping.

The role of coxsackieviruses infection in the children of insulin dependent diabetes mellitus

In the present study, there were two groups of diabetic patients. The first group was newly diagnosed diabetic patients of less than one year duration of disease. They were 40 patients. The second group was diabetic patients with more than one year duration of disease. They were 30 patients. The control group was 30 normal healthy children. Evidence of virus infection was detected by tissue culture isolation, neutralization test, RT-PCR, IgM, and IgG specific antibodies for coxsackie B viruses. There was significant increase in percent of tissue culture isolation of EV in group I more than group II while the percent in the two groups were significantly increased than the control group. Identification of the type of EV by neutralization test revealed that most of the type cases were Coxsackie B4 virus and one case was Coxsackie B6 virus (the most important diabetogenic strain). Viral RNA detection by PCR was done and revealed that most of cases in group I diabetic patients were positive for enterovirus while one case in group II of diabetic patients was positive. As regards Coxsackie virus B IgM antibodies positivity, there was increase in the percent in group I than group II, as it is a marker of acute infection. As regards Coxsackie virus B IgG antibodies positivity, there was no significant difference between group I and group II of diabetic patients, as it is a marker of past infection and it persists for years after the first episode.

Incidence and prognostic significance of right bundle branch block complicating acute myocardial infarction

The incidence and hospital courseofacute myocardial infarction wereobserved among randomly selected 560 patients. The mean age of the patients was 53 +/- 6.67 years with male-female ratio 2.6:1. The incidence of right bundle branch block (RBBB) was 15% (84 out of 560 patients). New RBBB, old RBBB and RBBB of indeterminate age were observed in 33 (39.25%), 23 (27.40%) and 28 (33.25%) cases respectively. RBBB was isolated in 50 (60%) cases and bi-fascicular in remaining 34 (40%) cases. The rate of use of thrombolytic was greater in RBBB group than non-RBBB group (52% vs 30.67%, P < 0.05). The complications were more frequently observed in patients with RBBB: in-hospital mortality, 27.40% vs 10.90% (P < 0.01); use of temporary pacemaker, 15% vs 9% (P < 0.05); and heart failure, 50% vs 35% (P < 0.05). In sub-group analysis, in-hospital mortality rate was higher among bi-fascicular group than isolated RBBB group (P < 0.05). Thus it appeared from the results that the incidence of RBBB is relatively common i.e. 15% over all (84 out of 560) and 5.90% new (33 out of 560) and despite greater use of thrombolytics, some specific in-hospital complications were significantly higher in patients with RBBB than without, RBBB.

gamma/delta peripheral T-cell lymphoma of the breast diagnosed by fine-needle aspiration biopsy

Gamma/delta T-cell lymphoma is a rare neoplasm that is not well characterized and is associated with a poor prognosis. We report a case of gamma/delta peripheral T-cell lymphoma that appeared as a breast lump in a 35-yr-old woman. The patient was examined for a 2-mo history of a right-sided breast mass with associated hepatosplenomegaly 2 yr in duration. A fine-needle aspiration biopsy (FNAB) was performed, and the diagnosis of lymphoma was rendered. The patient received two cycles of CHOP and is alive with persistent disease. FNAB showed evidence of polymorphous lymphoma, consisting of medium-size to large cells with immature chromatin. Flow cytometric immunophenotyping showed expression of CD2, CD3, and CD7 with lack of expression of CD1a, CD4, CD5, CD8, and CD56. Flow cytometry also showed predominant expression of the gamma/delta T-cell receptor. Cytogenetic analysis showed 48XX+i7(q11.2),+7(3). Our case indicates that gamma/delta peripheral T-cell lymphoma can be diagnosed by FNAB. This rare entity requires further investigation.

Partial sequence at 2BC region of HAV isolated from stool of acute sporadic HAV patients

More than 20 hepatitis A virus (HAV) strains that can be distinguished from each other are known till now. In the present study, a cytopathic strain of HAV (HA-10) was isolated in Egypt from stool of acute sporadic cases. The isolated strain showed CPE in early stages of adaptation in cell culture. Accordingly, the first step in the work was to confirm the presence of HAV, the second step was to prove that no enteric virus is associated with the isolate and finally to try to know the reason for that rapid adaptation in cell culture. So, RT-PCR was carried out for different regions of the viral RNA (5'ntr, VP1, VP1/2A, 2B and 2B/2C) also, enterovirus primers (5'ntr) were used. Reference HAV strains such as HM-175, HAS-15, MBB and 18F were used for comparison. Segment of 2BC region of the viral RNA was sequenced and compared with the nucleotide sequence of the reference HAV strains at the same region. The results revealed that HA-10 isolate react with all HAV primers and similar in this behavior with 18F and HM-175 strains. The nucleotide sequencing showed that there are 16 mutations in HA-10, two of them in 2B and the others in 2C region which may explain the reason for the highly adaptation of HA-10 isolate than 18F. As a result of this study, HA-10 may give us a highlight on HAV replication and also, the isolated strain may be useful for vaccine development.

A phase II study of weekly alternating chemotherapy in extensive-stage small cell lung cancer

Despite the recent development of new chemotherapeutic agents with activity in small cell lung cancer (SCLC), the long-term prognosis of patients with extensive-stage disease remains poor and has not improved in the past 20 years. The present study was designed to evaluate the activity and toxicity of weekly, alternating-regimen chemotherapy in patients with extensive-stage SCLC. Patients with previously untreated extensive-stage SCLC and performance status 0-2 were treated with cyclophosphamide 250 mg/m2, etoposide 100 mg/m2, and cisplatin 50 mg/m2 on day 1; vincristine 1 mg/m2 on day 8; and ifosfamide 1.2 gm/m2 on days 8 and 9 with the entire treatment repeated every 14 days. Eighteen patients received chemotherapy for a median of 14 weeks (range, 1-35 weeks). Seventeen patients (94%) required dose delays and 16 patients (89%) required at least one dose reduction due to toxicity. Twelve patients (67%) exhibited an objective response (1 complete response, 11 partial response) with a median duration of response of 18 weeks (range, 8-32 weeks). Median survival was 33 weeks (range, 1-57 weeks) with a 1-year survival rate of 22%. Toxicity was primarily hematologic, including grade 3-4 leukopenia (82% of patients) and anemia (53% of patients). Only 2 patients developed grade 3 peripheral neuropathy and none exhibited grade 3-4 renal insufficiency. This regimen of weekly alternating combination chemotherapy resulted in tolerable toxicity as well as response and survival rates comparable to those achieved with standard chemotherapy in patients with extensive-stage SCLC. However, weekly chemotherapy regimens for the treatment of SCLC remain investigational.

Prediction of adult stature for Japanese population: a stepwise regression approach

The longitudinal growth in stature for 509 males and 311 females was characterized from early childhood to adulthood. A triphasic generalized logistic (BTT) model (Bock et al. [1994] Chicago: SSI) was used through the AUXAL software program. Growth parameters were derived from the estimated distance and velocity curves for each individual. A set of estimated growth parameters, including adult stature, was selected to develop equations, through the forward stepwise regression method, for the prediction of adult stature for Japanese boys and girls.

Adolescent growth events in eight decades of Japanese cohort data: sex differences

The presence of secular trends in sex differences for the onset or takeoff of the adolescent growth spurt and subsequent (adolescent) growth of Japanese boys and girls were investigated using data published in "The Statistical Report of the School Health Survey" of the Ministry of Education, Science, Sports and Culture, Japan. An optimum kernel regression method was used to derive the biological parameters of the adolescent growth curve. The six parameters derived from the regression analysis were age at takeoff (ATO), height at takeoff (HTO), velocity at takeoff (VTO), peak height velocity (PHV), age at PHV (APHV), and height at PHV (HPHV). The sex difference in age at PHV is about 2.1 years. The sex difference in age at takeoff was about 2.1 years starting with the birth year of 1943, but has become almost insignificant with the birth year of 1980. After 1960, the sex difference in mean HPHV varied within 12-13 cm, but the difference in HTO showed a decreasing trend. After the birth year of 1911, the rate of growth at HTO for girls has become markedly greater than for boys. In contrast, the rate of growth at HPHV for girls has become significantly smaller than for boys (P < 0.05). Sex differences in ATO, HTO and VTO were significantly and negatively correlated with differences in APHV and HPHV, but positively correlated with the difference in PHV. The sex difference in PHV had no relationship with the differences in APHV and HPHV.

Spatial requirements of the antagonist binding site of the NK2 receptor

Computer-aided modelling has been used to identify a putative antagonist binding site in the tachykinin NK2 receptor. In order to validate the implied spatial requirements for this region, a series of compounds, based on the potent antagonist GR 149861 have been synthesised and their binding affinities established. Our findings suggest the presence of a large hydrophobic cavity in the putative binding crevice of GR 149861.

Waterborne viruses associated with repeated abortion

In this study we tried to find the role of some waterborne viruses in repeated abortion of women. The study includes maternal blood serum and fetal tissue. The serum of full-term delivered women was taken as a control. All collected samples were inoculated on BGM and Hep2G cells to detect entero and Hepatitis E viruses. Enzyme-linked immunosorbent assay was also carried out for IgM and IgG antibodies against HEV in all serum samples. HEV-Ag was determined by dot-ELISA, which used also for enterovirus typing. Reverse transcriptase polymerase chain reaction was used for detection of entero and HE virus RNAs in the collected serum samples. To follow up the source of virus transmission, the wastewater treatment plant which serves the area of samples population was studied at the intake and the final effluent for the presence of hepatitis E virus and enteroviruses with special reference to coxsackieviruses. Wastewater samples were collected for 1 year and for enterovirus concentration the adsorption-elution on nitrocellulose membrane was used and for HEV, two methods of virus concentration were used, urea arginine phosphate buffer (U-APB) and PEG8000. The results of HEV investigation of aborted women sera was 22% for IgG, 3% for IgM, 20% HEV-Ag, and 16% of HEV-RNA by RT-PCR. For fetal tissue, HEV-Ag was detected in 5% of the collected samples. The detected enteroviruses were coxsackieviruses types 2, 3,4 and 5 in all serum samples and wastewater samples. The results showed also, that virus concentration by U-APB is much better than PEG-8000 but not highly efficient.

Determinants of case fatality rates of meningococcal disease during outbreaks in Makkah, Saudi Arabia, 1987-97

We studied case-fatality rates (CFRs) among cases of meningococcal disease (MCD) admitted to Makkah (Saudi Arabia) hospitals during the period 1988-97. Of 483 cases, 431 (89.2%) were due to strains of serogroup A, 31 (6.4%) to serogroup W135, 16 (3.3%) to serogroup C, and 5 (10%) to serogroup B. Eighty-one patients died (case fatality rate (CFR)) 16.8%, 95% CI 13.5%, 20.4%). The CFR in infections due to serogroup A strains was 14.8%, and for other serogroups it was 32.7% (95% CI 20.3%, 47.1%). The CFR of MCD due to N. meningitidis serogroup A increased steadily with age (P<0.05). Seeking first medical help at a foreign Hajj medical mission and being treated in a non-specialized hospital were associated with a higher case fatality rate.