Estimation of muscular fatigue under electromyostimulation using CWT.

The aim of this study is to investigate muscular fatigue and to propose a new fatigue index based on the continuous wavelet transform (CWT) which is compared to the standard fatigue indexes from literature. Fatigue indexes are all based on the electrical activity of muscles [electromyogram (EMG)] acquired during an electrically stimulated contraction thanks to two modules (electromyostimulation + electromyography recording) that can analyze EMG signals in real time during electromyostimulation. The extracted parameters are compared with each other and their sensitivity to noise is studied. The effect of truncation of M waves is then investigated, enlightening the robustness of the index obtained using CWT.

A mixed FES/EMG system for real time analysis of muscular fatigue.

In this article, we present a functional electrical stimulator allowing the extraction in real time of M-wave characteristics from resulting EMG recodings in order to quantify muscle fatigue. This system is composed of three parts. A Labview software managing the stimulation output and electromyogram (EMG) input signal, a hardware part amplifying the output and input signal and a link between the two previous parts which is made up from input/output module (NIdaq USB 6251). In order to characterize the fatigue level, the Continuous Wavelet Transform is applied yielding a local maxima detection. The fatigue is represented on a scale from 0 for a fine shaped muscle to 100 for a very tired muscle. Premilary results are given.

Acute complete splenic infarction in a patient with Hirschsprung's disease and literature review of complete splenic infarction.

Here we report a case of Hirschsprung's disease presenting with acute complete splenic infarction due to thrombus in the splenic vena. MTHFR C677T (methylenetetrahydrofolate) gene homozygote mutation was a risk factor for thrombosis. According to our knowledge, this is the first report for a Hirschsprung's disease patient with acute complete splenic infarct due to isolated splenic vein thrombosis accompanied by MTHFR C677T gene homozygote mutation.

Gastric cancer and other organ cancer history in the parents of patients with gastric cancer.

A case-control study in a population from the Eastern Black Sea region of Turkey was performed to evaluate the risk of gastric cancer development in patients with gastric cancer reporting gastric cancer or other organ cancer history in their parents. Gastric cancer and/or other organ cancer history in the parents were found in 215 of 1240 patients with gastric cancer versus 73 of 1240 controls (odds ratio (OR) 3.35, P<0.001). The frequency of gastric cancer history among the parents was significantly different between the patients and the controls (148 versus 25, respectively; OR 6.59, P<0.001). The frequency of other organ cancer history was not significantly different between the patients and the controls (63 versus 48, respectively; OR 1.33, P>0.05). The frequency of gastric cancer history was significantly higher than the frequency of other organ cancer history in the parents of the patients (OR 4.51, P<0.001). Gastric cancer history was significantly higher in first- to third-degree relatives of the patients reporting gastric cancer and/or other organ cancer history in their parents than in the controls (OR 14.72, P<0.001). Familial clustering of gastric cancer defined by the presence of at least four cancer cases in family members, including parents, was reported by 12% of the patients. Overall, the result of this study of gastric cancer and other organ cancer history in the parents of patients with gastric cancer may suggest a genetic susceptibility for gastric carcinoma. A high risk of gastric cancer occurred in subjects reporting a gastric cancer history in their parents, and there was a higher predisposition to gastric cancer compared with other organ cancer in relatives and a familial clustering of the disease.

A filter design method for minimizing ringing in a region of interest in MR spectroscopic images.

Magnetic resonance spectroscopic imaging (MRSI) requires a relatively long time to sample k-space (the spatial frequency domain), effectively lowpass filtering the resulting reconstructed image. Ringing is especially problematic when a region of interest (ROI) is close to a bright region outside the ROI, since the bright region tends to create a ringing artifact into the ROI due to the lowpass nature of the data. In this paper, we propose a method that reduces the effect of a stronger signal region on a weaker signal in a nearby ROI by designing a postprocessing filter that steers the strong interference away from the ROI. The proposed method is computationally simple both in the design stage and in applying it to images. We present experiments that illustrate the value of the technique.

Stomach cancer history in the siblings of patients with gastric carcinoma.

A case-control study in the population of the Eastern Black Sea region of Turkey was conducted to learn the incidence of stomach cancer in the siblings of patients with gastric carcinoma. Among 1240 patients with gastric carcinoma, 168 had sibling(s) with a history of stomach cancer versus 19 cases in the control group matched according to age and gender (OR 10.07, P < 0.0001). The frequency of a history of stomach cancers and cancer of other organs in first- to third-degree relatives was 60.7% and 38.0%, respectively, of 168 sibling cases with gastric carcinoma (P < 0.0001). Fifty-two point three per cent of sibling cases having a history of cancer in other organs in their relatives also reported stomach cancer in the same-degree relatives. The number of stomach cancers in the first- to third-degree relatives of sibling cases was higher than the number of other organ cancers in the same-degree relatives (P < 0.01). Familial clustering of stomach cancer was reported in 12.5% of sibling cases. The study of stomach cancer history in the siblings suggests: the presence of a genetic susceptibility, high risk of the disease occurrence in the siblings of patients, higher predisposition to gastric than to other organ cancers in the relatives, and not infrequent familial clustering.

Is hepatitis C virus genotype 4 predominant in Saudi Arabia?

Hepatitis C virus (HCV) genotype 4 is believed to be predominant in the Middle East including Saudi Arabia (SA). We attempted to genotype 80 HCV isolates from different parts of SA by direct sequencing of a variable 222bp fragment from the NS5B region. The phylogenetic analysis of the NS5B sequences was complemented by direct sequence analysis of the conserved 5'-NCR region for HCV type-specific polymorphism. All 80 NS5B sequences separated into 3 clades which comprised 6 type 1b variants, 30 type 4 variants (24 of type 4a and 6 of type 4c or d) and 44 type 3 variants. Apart from two definitive type 3b variants the other 42 type 3 NS5B sequences formed 4 clusters with low similarity to type 3a-f HCV sequences from the database. The precise subtyping of these 42 type 3 variants awaits sequencing of longer HCV RNA stretches. Our results indicate that HCV type 4 may not be the only dominant genotype in SA.

Viral aetiology and epidemiology of acute respiratory infections in hospitalized Saudi children.

A total of 1429 Saudi children of either sex and under 5 years of age who were admitted to King Khalid University Hospital, Riyadh during a three year period (April 1993-March 1996) with complaints suggestive of acute respiratory tract infections (ARTI) were investigated for viral aetiology of the infection. Viruses could be detected in 522 (37 per cent) cases with respiratory syncytial virus (RSV) the most commonly detected (79 per cent) followed by parainfluenza type 3 (8 per cent). Detection of influenza A, B and adenoviruses accounted for 6 per cent, 3 per cent and 2 per cent respectively. Except for parainfluenza virus type 3 the peak of activity of the respiratory viruses was during the winter months (October-February). Parainfluenza virus type 3 could be detected all year round but epidemics can occur in the hottest months of the year (June-August) when the temperature can exceed 40 degrees C. Association between clinical manifestation, type of causative agent, and age was evaluated in 137 infected Saudi children in the first year of the study (April 1993-March 1994). The majority of our cases presented with bronchiolitis (58 per cent) while only 26 per cent had bronchopneumonia. There was a significant association between bronchiolitis and lower age groups (0-6 months), with RSV as the major causative agent of bronchiolitis cases (88 per cent).

Infection with hepatitis viruses (B and C) and human retroviruses (HTLV-1 and HIV) in Saudi children receiving cycled cancer chemotherapy.

Serological markers of hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphotropic virus type 1 (HTLV-1), and human immunodeficiency viruses (HIV-1 and HIV-2) were studied in 53 Saudi children (31 males, 22 females; 1-12 years of age) receiving cycled cancer chemotherapy and in 168 healthy Saudi children taken as control. Exposure to HBV in the patients was similar to that in the control (6 per cent HBsAg in patients v. 7 per cent in the control; 19 per cent exposure rate in patients v. 20 per cent in control). None of our patients was vaccinated against HBV prior to chemotherapy. The fact that among the 10 HBV exposed patients five patients were anti-HBs-positive is in favour of vaccinating Saudi oncology patients against HBV prior to chemotherapy. In contrast to the situation with HBV the prevalence of anti-HCV in the patients (11 per cent) was significantly higher than that in the control (1 per cent) (P = 0.003). None of our patients or the control were anti-HTLV-1 or anti-HIV-positive. The results of this study stress the need for an awareness of HCV problem in Saudi oncology patients. Strict measures of screening blood donors for all blood-borne viruses and, in particular, for HCV in addition to the use of disposable equipment in management of cancer patients are items that should be implemented as soon as possible.

Detection of human papillomavirus DNA in skin warts from immunocompromised patients but not in semen from men whose wives have abnormal cervical cytology.

The epidemiology of human papillomaviruses (HPV) was studied in 61 immunocompromised patients (e.g. renal and cardiac transplants; Bowen's disease; genital cancer) undergoing therapy at the University Hospital of Wales at Cardiff U.K. Warts from various sites of these patients were studied for the presence of HPV types 6, 11, 16 and 18 using the dot-blot DNA hybridization technique. Four HPV-16 and one HPV-11 was detected. The presence of HPV-16 in our study is quite significant since it suggests the potential occurrence of genital HPV types in skin warts in immunocompromised patients and hence the need for screening such patients against HPV types. HPV, mainly types 16 and 18 are usually associated with genital cancer, cervical malignancies and cervical intraepithelial neoplasia. The semen of the husband of 30 women with cervical abnormalities and the semen of 30 husbands (control) of wives with normal cervix were tested for HPV-6, 11, 16 and 18. No HPV-DNA could be detected in all of the 60 specimen. This suggests that specimens were either truly negative for any of those types or because virus DNA could present in a small amount less than 5 pg/microliters in some patients. Whether semen plays a role in transmitting HPV is still controversial.

Hepatitis C virus antibodies in high-risk Saudi groups.

The recombinant-based enzyme immunoassay developed by Ortho Diagnostic System for the detection of antibodies of hepatis C virus (HCV) was used to determine the extent of exposure to HCV in healthy Saudi subjects (500 males; 260 females) without liver disease and with no history of percutaneous exposure to blood and in Saudis who are considered at high risk for contracting the disease: hemophiliacs (28), thalassemics (78), hemodialysis patients with renal failure (65) and patients with sexually transmitted diseases (STD) (220). The results show that HCV is endemic in the Saudi population with an overall frequency of 5.3% in healthy Saudi adults which is at least 5 times higher than what has been reported from Western Europe and the United States. Seropositivity rate in the high-risk groups ranges from 15.9% in patients with STD to 78.6% in hemophiliacs. These data underscore the urgent need for routine anti-HCV screening of blood donations in order to reduce the frequency of postransfusion non-A, non-B hepatitis and its sequelae in the Saudi population.

PIP: Non-A, non-B hepatitis, recently renamed as hepatitis C virus (HCV), accounts for over 90% of hepatitis cases worldwide associated with blood transfusions. Application of a recombinant-based enzyme immunoassay for the detection of antibodies to HCV to a sample of 500 male Saudi blood donors and 260 healthy Saudi pregnant women indicated that HVC is endemic in the Saudi population. Anti-HCV was detected in 28 (5.6%) of the blood donors and 12 (4.6%) of the pregnant women, for an overall frequency of 5.3% in healthy Saudi adults who had never received blood transfusions. This rate is at least 5 times higher than that reported for the US and Western Europe. Also assessed was the HCV rate in subsamples of Saudis considered at risk of this infection. Here, anti-HCV was detected in 22 (78.6%) hemophiliacs, 26 (33.3%) patients with thalassemia and sickle cell disease, 17 (26.1%) hemodialysis patients with renal failure, and 35 (15.9%) individuals with a sexually transmitted disease. The prevalence of anti-HBc ranged from 28% in blood donors to 46% in hemophiliacs. The significantly higher prevalence of HCV in patients with sexually transmitted diseases than in blood donors suggests that this disease is transmitted through heterosexual contact as well as blood transfusions. Given the high baseline level of HCV infection in the Saudi population and the possibility of serious sequelae (e.g., chronic active hepatitis, cirrhosis, and hepatocellular carcinoma), routine anti-HCV screening of blood donations is urged.

Seroepidemiology of enteric fever and brucellosis in a developing country.

The seroepidemiology of infection due to S. typhi and Brucella spp. in a sub-tropical, developing country of the Middle East was investigated in 130 children of age less than 1 to 15 years, 117 young adults (16-30 years) and in a further 40 adults (greater than 30 years) using an agglutination test to detect antibodies to of S. typhi, B. abortus and B. melitensis. Only 4.5% of the children's and adult's sera respectively showed the presence of antibodies to both O and H antigens of S. typhi with reciprocal titers greater than or equal to 80. Prevalence rates of 11.6%, 11.3% respectively in children and adults of antibodies to B. abortus with reciprocal titers greater than or equal to 80 and similarly 13.1%, 12.4% to B. melitensis were found. The usefulness of a single Widal test to diagnose enteric fever in a non-endemic area and the agglutination test in the diagnosis of brucellosis in an endemic area was investigated. Of 244 patients with suspected enteric fever, the sera of 100 showed reciprocal antibody titers 80 to both O and H antigens and included in these were 8 patients with concurrent culture positivity. Among 138 children and adults with suspected brucellosis, 29 culture proven cases where serologically confirmed and a further 90 were detected serologically. The sera of all the culture proven cases exhibited antibody reciprocal titer greater than or equal to 640. A similar antibody response was noted in seventy-two of the culture negative cases diagnosed serologically for brucellosis. In culture proven, cases B. melitensis was the isolate. Comparative evaluation indicated the potential usefulness of the Rose Bengal Antigen Slide Agglutination Test (Brucelloside Test) as a screening test in the serodiagnosis of human brucellosis.

An outbreak of acute hepatitis A infection in rural Saudi Arabia.

In areas of hyperendemicity of hepatitis A virus (HAV) infection, acquisition of immunity occurs relatively early in life. In such populations epidemic outbreaks are rare. A recent HAV infection outbreak occurred in the Al-Dahnah district in Saudi Arabia. In thirty day period, 23 children and adolescents were diagnosed by clinical examination. 19 of these were positive for IgM anti-HAV. Concomitant acute infections with the Epstein Bar Virus (EBV) was documented in 4 of these patients. A limited epidemiological survey suggested that the source of infection might have been a contamination of one of the tankers which delivered water supplies to the various houses. In a transitional period of development the rapid improvement in socio economic status and standards of living may increase the susceptible pool. Therefore a greater surveillance is needed to identify and contain such possible outbreaks.

Chlamydia trachomatis as a cause of abortion.

The possible role of C. trachomatis as a causative agent of abortion in humans was investigated using the tissue culture method for the isolation of chlamydia. Two cases of spontaneous abortion and another seven of recurrent abortion due to C. trachomatis were positively identified. Among those with recurrent abortion were four patients with history of second trimester abortion.

Viral meningitis and encephalitis in Saudi Arabia.

The laboratory confirmation of twelve clinically diagnosed cases of aseptic meningitis and encephalitis is described. Among three cases of aseptic meningitis one was due to mumps in a 14-month infant and the other two attributable to Cocksackie B-1. Herpes virus encephalitis due to HSV-1 was conclusively identified by IF monoclonal test from brain biopsy in tissue culture, and a further four cases also of HSV-1 encephalitis by virus isolation from CSF and presence of significant levels of herpes virus antibody in CSF and serum. Measles encephalitis was identified in four pediatric patients with one based on the isolation of measles virus from the CSF and in the other three with significant CSF/serum ratios to measles virus.

Rubella and cytomegalovirus (CMV) infections: laboratory aspects of investigation of antenatal, congenital, persistent, and subclinical infections.

Rubella specific IgM tests carried out on pregnant women with history of rubella contact or rubella-like rash indicated the presence of rubella-IgM by the second week after contact, persistence to 3-4 weeks followed by a decline and non-detectability around 8-9 weeks and at delivery. Laboratory investigation of cases of rubella infection in infants and children, including clinically proven and suspected congenital rubella revealed distinct patterns of combinations of positivity and negativity of IgM and IgG antibodies. Three cases of persistence of rubella specific IgM antibodies with one even up to 3 years in congenital rubella and a case of CMV-IgM persistence in congenital CMV are described. Rubella-IgM and CMV-IgM were detected in the serum of two patients aged 12 years and 24 years with CMV mononucleosis. Utilization of rubella-IgM/CMV-IgM tests enabled the identification of four cases of subclinical rubella and one of subclinical CMV in a pediatric population.

Genital herpes simplex virus infections: laboratory confirmation in diverse patient groups.

The laboratory diagnosis of genital herpes simplex virus (HSV) infections in various patient groups with diverse clinical manifestations including asymptomatic pregnant women with history of genital herpes and in a high prevalence group consisting of male patients with recurring genital ulcerations is described. HSV was detected by conventional cell culture and also by a CPE-enhancement technique using human embryonic lung fibroblasts (MRC-5) and Vero cells with subsequent typing of isolate by HSV type-specific monoclonal antibodies. A definite improvement in HSV diagnosis was noted by the use of the CPE-enhancement technique with the reduction of turn-around time to 24 h at which 61.1% and 50% isolation rates were detected in MRC-5 cells in comparison to 38.9% and 16.6% by conventional cell culture in the high prevalence patient population and asymptomatic pregnant women, respectively. Delayed development of CPE and reduced isolation rates were detected using Vero cells. Follow-up sampling of subsequent episodes of genital ulcerations in those with history of recurrence but an initial negative cell culture result, increased the isolation rate substantially and enabled the confirmation of diagnosis of genital HSV infection.

Indirect haemagglutination (IHA) test in the serodiagnosis of amoebiasis.

Among 72 patients clinically suspected of Entamoeba histolytica (E. histolytica) infections, 39 positive cases (54%) were detected serologically by the indirect hemagglutination (IHA) test. Parasitologically, microscopic examination of three consecutive stool specimens from all these patients indicated positivity for E. histolytica cysts and or trophozoites in 10 of the patients with IHA antibody titers greater than or equal to 1:128, which is of clinical significance. Another 2 patients were parasitologically positive but showed low IHA antibody titres (1:32-1:64); follow up indicated response to treatment with metronidazole. The highest serological positivity (100%) were detected in patients with liver abscess, all were clinically proven cases of extra-intestinal amoebiasis. IHA antibody levels of clinical significance were seen in all four patients with chronic dysentery with parasitological evidence of E. histolytica in their stools. In a group of patients with abdominal pain nine positives were detected serologically, four of which were positively diagnosed concurrently by parasitology; the remaining five patient's sera showed high IHA antibody titres with absence of cysts or trophozoites in stools, indicative possibly of persistence of antibodies from past infection. The serologic determination of E. histolytica IHA antibodies in a control group consisting of normal healthy school children and adults of both sexes without any clinical evidence of amoebiasis showed the absence of any positive titres of clinical significance; low titres (1:32-1:64) were detected in 5.2% of 232 sera tested. Parasitological examination of three consecutive stool specimens from all individuals in the control group showed the presence of cysts of E. histolytica in just two among 232 tested (0.9%).