Effects of modified constraint induced therapy on upper limb function in subacute stroke patients.

OBJECTIVE: To examine the feasibility and efficacy of a modified constraint induced therapy protocol on stroke patients. METHODS: This study was carried out during the period from August 2001 to January 2002 at the Riyadh Medical Complex, Riyadh, Kingdom of Saudi Arabia. Six stroke patients with subacute cerebrovascular accident (<6 months) were included in the study. Three male and 3 female patients with a mean age of 54.3+/-6.9 years (range 45-67 years), and mean duration of hemiparesis of 4.7 months (range 2.3-5.8 months). They were divided randomly into 3 groups of 2 patients. The first 2 patients (constraint induced therapy group) participated in half an hour of physical and occupational therapy sessions 3 times per week for 10 weeks. During the same period, their unaffected arms and hands were restrained 5 days per week for 5 hours identified as times of frequent use. The second 2 patients (traditional therapy group) received regular therapy administered after 10 weeks. The last 2 patients (control group) received no therapy. The Fugl-Meyer Assessment of Motor Recovery After Stroke (Fugl), Action Research Arm Test (ARA), Wolf Motor Function Test (WMFT), and Motor Activity Log (MAL) were administered to the patients. RESULTS: Patients receiving modified constraint induced therapy exhibited substantial improvement on the Fugl, ARA, and WMFT, as well as increases in amount and quality of use of the limb using the MAL. While patients receiving traditional physical and occupational therapy, and no therapy patients exhibited few improvements. CONCLUSION: Modified constraint induced therapy may be an efficacious method of improving function and use of the affected arms in stroke patients exhibiting learned nonuse.

Emergence of a new clone of toxigenic Vibrio cholerae O1 biotype El Tor displacing V. cholerae O139 Bengal in Bangladesh.

The emergence of Vibrio cholerae O139 Bengal in 1993, its rapid spread in an epidemic form, in which it replaced existing strains of V. cholerae O1 during 1992 and 1993, and the subsequent reemergence of V. cholerae O1 of the El Tor biotype in Bangladesh since 1994 have raised questions regarding the origin of the reemerged El Tor vibrios. We studied 50 El Tor vibrio strains isolated in Bangladesh and four other countries in Asia and Africa before the emergence of V. cholerae O139 and 32 strains isolated in Bangladesh during and after the epidemic caused by V. cholerae O139 and 32 strains isolated in Bangladesh during and after the epidemic caused by V. cholerae O139 to determine whether the reemerged El Tor vibrios were genetically different from the El Tor vibrios which existed before the emergence of V. cholerae O139. Analysis of restriction fragment length polymorphisms in genes for conserved rRNA, cholera toxin (ctxA), and zonula occludens toxin (zot) or in DNA sequences flanking the genes showed that the El Tor strains isolated before the emergence of V. cholerae O139 belonged to four different ribotypes and four different ctx genotypes. Of 32 El Tor strains isolated after the emergence of O139 vibrios, 30 strains (93.7%) including all the clinical isolates belonged to a single new ribotype and a distinctly different ctx genotype. These results provide evidence that the reemerged El Tor strains represent a new clone of El Tor vibrios distinctly different from the earlier clones of El Tor vibrios which were replaced by the O139 vibrios. Further analysis showed that all the strains carried the structural and regulatory genes for toxin-coregulated pilus (tcpA, tcpI, and toxR). All strains of the new clone produced cholera toxin (CT) in vitro, as assayed by the GM1-dependent enzyme-linked immunosorbent assay, and the level of CT production was comparable to that of previous epidemic isolates of El Tor vibrios. Further studies are required to assess the epidemic potential of the newly emerged clone of V. cholerae O1 and to understand the mechanism of emergence of new clones of toxigenic V. cholerae.

Evaluation of a non-radioactive chemiluminescent method for using oligonucleotide and polynucleotide probes to identify enterotoxigenic Escherichia coli.

We compared the applicability of an enhanced chemiluminescent (ECL) method for using gene probes with that of radioactive probes to identify enterotoxigenic Escherichia coli (ETEC) in stools of Bangladeshi children with diarrhoea. Colony blots of E. coli isolates were hybridized using both [alpha-32P]-dCTP labelled and fluorescein-11-dUTP labelled polynucleotide and oligonucleotide gene probes for heat-labile enterotoxin (LT), and heat-stable enterotoxin (ST). Analysis of 1,620 isolates obtained from 540 patients gave similar results by both radioactive and chemiluminescent probes. The ECL method was faster than the radioactive method. Both polynucleotide and oligonucleotide probes could be used by the ECL method. Hybridization and detection by the ECL method appeared to be a convenient alternative to radioactive probes for screening E. coli isolates for ETEC.

Molecular analysis of rRNA and cholera toxin genes carried by the new epidemic strain of toxigenic Vibrio cholerae O139 synonym Bengal.

Vibrio cholerae O139 synonym Bengal recently caused large epidemics of cholera-like disease in Bangladesh and India. We compared the restriction fragment length polymorphisms of ctxA and rRNA genes (ribotypes) in 27 isolates of V. cholerae O139 from patients in Bangladesh and India with those of 48 isolates of V. cholerae O1 from patients and 21 V. cholerae isolates from surface waters in Bangladesh, which included 2 O139 and 19 other non-O1 isolates. Ribotyping of the isolates with BglI revealed that all 29 isolates of O139 vibrios belonged to a single ribotype, suggesting a clonal nature of the infection. However, the O139 vibrios comprised two ctxA genotypes and carried three or more copies of the ctxA gene, and the chromosomal locations of these copies were unlike those of the El Tor or classical vibrios. Analysis of the restriction fragment length polymorphisms of the rRNA genes suggested that V. cholerae O139 isolates are more closely related to El Tor strains of V. cholerae O1 than were 19 other non-O1 vibrios and 33 classical V. cholerae O1 isolates that were studied. However, further studies are needed to determine whether V. cholerae O139 originated from mutations and genetic changes in a V. cholerae O1 strain or was due to the acquisition of virulence genes by a previously unknown V. cholerae non-O1 strain.

Clonal relationships among classical Vibrio cholerae O1 strains isolated between 1961 and 1992 in Bangladesh.

In Bangladesh, the replacement of classical Vibrio cholerae by the E1 Tor biotype in 1968 and the reappearance of the classical biotype and its coexistence with the E1 Tor biotype after 1982 were never adequately explained. We have analyzed 23 classical V. cholerae isolates collected between 1961 and 1968, 14 classical isolates collected between 1982 and 1992 from the capital city, Dhaka, and 6 classical V. cholerae isolates collected from two southern districts of Bangladesh and studied restriction endonuclease cleavage patterns of rRNA genes (ribotypes) to investigate the clonal relationships among the isolates. Southern blots of total DNA digested with restriction enzyme BamHI, BglI, EcoRI, HindIII, or PstI were probed, using a cloned Escherichia coli rRNA operon. While restriction enzymes BamHI, EcoRI, and PstI failed to differentiate the isolates on the basis of ribotyping, BglI and HindIII produced digestion patterns that allowed differentiation. Ribotyping the isolates with BglI and HindIII revealed five different clones (ribotypes IA, IB, IIA, IC, and IIC) of classical vibrios in Bangladesh. Strains belonging to ribotypes IA and IB were isolated in Dhaka before 1968, and one ribotype (IA) was again isolated between 1982 and 1992. Ribotype IIA was isolated in 1988 and 1989, when both clones (IA and IIA) of classical vibrios coexisted with the EI Tor vibrios. Isolates belonging to ribotypes IC and IIC were collected in the southern districts of Bangladesh and were clearly different from those collected in Dhaka between 1968 and 1992 by ribotyping analysis with BglI. These results support the previous assumption that classical vibrios were never completely replaced in Bangladesh and also demonstrate the existence of more than one genetically different clone of classical V. cholerae.

Differentiation of Shigella flexneri strains by rRNA gene restriction patterns.

We studied the restriction endonuclease cleavage patterns of rRNA genes (ribotypes) of 72 clinical isolates of Shigella flexneri representing eight serotypes to determine whether ribotyping could be used to distinguish S. flexneri strains and to compare the discriminating ability of the method with that of serotyping. By using a cloned Escherichia coli rRNA operon as the probe, Southern blot hybridization of restriction endonuclease-digested total DNA was carried out. Ribotyping of the isolates with each of the five restriction endonucleases BamHI, EcoRI, HindIII, PstI, and SalI generated reproducible restriction patterns. However, HindIII produced the optimum digestion pattern of the rRNA genes and was more useful than the other enzymes used in differentiating strains. Analysis of the 72 isolates showed 11 different HindIII cleavage patterns of their rRNA genes. Four of these HindIII-generated ribotypes could be further differentiated into two to four subribotypes by using PstI. The results indicate that ribotyping has an application for differentiation of S. flexneri strains and can complement serotyping. Definition of strains in terms of both serotype and ribotype may be of greater use in epidemiological studies.

Evaluation of a DNA probe to identify enteroaggregative Escherichia coli from children with diarrhoea in Bangladesh.

Six hundred and seventy-five Escherichia coli isolates obtained from 225 diarrhoeal children less than five years of age were tested for adherence to HeLa cells and for hybridisation with DNA probes for genes conferring aggregative adherence (AggA), localised adherence (LA) and diffuse adherence (DA) to assess the usefulness of a recently developed DNA probe for AggA of enteroaggregative E. coli (EAggEC). The strains were further analysed with the DNA probes for heat--labile enterotoxin (LT), heat--stable enterotoxin (ST), Shiga--like toxins (SLT I and SLT II) and for enteroinvasiveness and adherent strains were all negative for these properties. The HeLa cell assay and DNA probe assays showed excellent agreement in identifying LA and DA positive isolates. However, significant disparities occurred in the case of AggA positive isolates, and the DNA probe failed to identify 31.9% (15 of 47) of the EAggEC identified by the HeLa cell adherence assay. The failure of the DNA probe to identify all the EAggEC indicated that there may be a high degree of genetic heterogeneity for the expression of AggA, and development of more DNA probes is necessary to detect all the possible genetic variants of EAggEC.

Enterotoxigenic Escherichia coli diarrhoea: acquired immunity and transmission in an endemic area.

Enterotoxigenic Escherichia coli (ETEC) are an important cause of diarrhoea in developing countries. Studies were made, in an endemic area of Bangladesh, of household contacts of patients with diarrhoea associated with E. coli producing heat-stable and heatlabile toxins (ST/LT) or heat-stable toxin (ST) only. It was found that 11% of contacts were infected in the 10-day study period, and that both the rate of infection and the proportion of infected persons with diarrhoea decreased with increasing age, suggesting the development of immunity. ETEC of the same serotype as that of the index patient were found in 9% of water sources used by index households, in a small number of food and drinking water specimens from the index homes, and in faeces from 3 healthy calves. The rate of infection of household members was highest in houses where there was contaminated food or water, which suggests that infection may take place in the home when contaminated water is brought in.