Adsorptive removal of tannin from aqueous solutions by cationic surfactant-modified bentonite clay

The removal of tannin from aqueous media by cationic surfactant-modified bentonite clay was studied in a batch system. The surfactant used was hexadecyltrimethylammonium chloride. Adsorbent characterizations were investigated using X-ray diffraction, infrared spectroscopy, surface area analysis, and potentiometric titration. The effects of pH, contact time, initial solute concentration, adsorbent dose, ionic strength, and temperature on the adsorption of tannin onto modified clay were investigated. The adsorbent exhibited higher tannin removal efficiency (>99.0%) from an initial concentration of 10.0 micromol/L at pH 3.0. Adsorption capacity decreased from 90.1 to 51.8% with an increase in temperature from 10 to 40 degrees C at an initial concentration of 25.0 micromol/L. The adsorption process was found to follow pseudo-first-order kinetics. Film diffusion was found to be the rate-limiting step. Tannin adsorption was found to decrease with increase in ionic strength. The tannin equilibrium adsorption data were fitted to Langmuir and Freundlich isotherm models, the former being found to provide the best fit of the experimental data. The maximum monolayer adsorption capacity for tannin was 69.80 micromol/g at 30 degrees C. Comparison of adsorption capacity of the modified clay with reported adsorbents in the literature was also presented. Adsorbed tannin on modified clay can be recovered by treatment with 0.1 M NaOH solution. Regeneration experiments were tried for four cycles and results indicate a capacity loss of <10.0%. From the results it can be concluded that the surfactant-modified clay could be a good adsorbent for treating tannin-contaminated waters.

Clinical outcome of nerve injuries associated with supracondylar fractures of the humerus in children: the experience of a specialist referral centre

Between 1998 and 2002, 37 neuropathies in 32 patients with a displaced supracondylar fracture of the humerus who were referred to a nerve injury unit were identified. There were 19 boys and 13 girls with a mean age of 7.9 years (3.6 to 11.3). A retrospective review of these injuries was performed. The ulnar nerve was injured in 19, the median nerve in ten and the radial nerve in eight cases. Fourteen neuropathies were noted at the initial presentation and 23 were diagnosed after treatment of the fracture. After referral, exploration of the nerve was planned for 13 patients. Surgery was later cancelled in three because of clinical recovery. Six patients underwent neurolysis alone. Excision of neuroma and nerve grafting were performed in four. At follow-up, 26 patients had an excellent, five a good and one a fair outcome.

Management of suspected scaphoid fractures in accident and emergency departments--time for new guidelines

INTRODUCTION

The objectives of this work were to assess the clinical knowledge of clinicians in the accident and emergency (A&E) departments in England & Wales and evaluate the current trend for the acute management of radiologically normal, but clinically suspected, fractures of the scaphoid.

SUBJECTS AND METHODS

We conducted a telephone survey on 146 A&E senior house officers (SHOs) in 50 different hospitals. This survey assessed the clinicians' experience, their clinical and radiological diagnostic methods, and their initial treatment of suspected scaphoid fractures.

RESULTS

The majority (55.8%) of SHOs performed only one clinical test to diagnose suspected scaphoid fractures. Overall, 41% were unable to cite the number of the radiographic views taken and only 10% of departments have direct access to further radiological investigation. There is wide variation in the early treatment of this injury, with the scaphoid cast used most commonly (46%). The majority of SHOs (89%) were unable to describe the features of immobilisation. The mean follow-up period was 10 days, and 53% of cases were followed-up by the senior staff in A&E. Of SHOs, 54% were not aware of any local guidelines for the management of suspected scaphoid fractures in their departments, and 92% were not aware of the existence of the 1992 British Association for Accident and Emergency Medicine (BAEM) guidelines.

CONCLUSIONS

The clinical knowledge and the management of suspected scaphoid fractures in A&E are unsatisfactory. We, therefore, suggest that the dissemination of up-to-date guidelines could help to educate clinicians to provide better care to the patients.

Impacted knife injury of the orbit, maxilla and oropharynx

Injuries in the maxillofacial region with knife in situ are not common. We report a rare case with knife impacted in the orbit, maxilla and soft palate. Removal was possible only by surgical intervention. Despite the deep penetration, the knife had not injured major structures and hence there was no untoward complication in the outcome.

Rotational osteotomies for congenital radioulnar synostosis

In five children, six forearms with a fixed pronation deformity secondary to congenital radioulnar synostosis were treated by a derotation osteotomy of the distal radius and the midshaft of the ulna.

There were three boys and two girls with a mean age of 4.9 years (3.5 to 8.25) who were followed up for a mean of 29 months (18 to 43). The position of the forearm was improved from a mean pronation deformity of 68° (40° to 80°) to a pre-planned position of 10° of supination in all cases. Bony union was achieved by 6.3 weeks with no loss of correction. There was one major complication involving a distal radial osteotomy which required exploration for a possible compartment syndrome.

Successful excision of neurogenic heterotopic ossification around the hip in cerebral palsy

We present the case of an 11-year-old girl with cerebral palsy, who developed bilateral spontaneous ankylosis of the hips as a result of heterotopic ossification following hip surgery. This was treated successfully by a combination of surgical excision, single dose radiotherapy and bisphosphonate treatment at five months from the time of the original surgery. A review of the literature shows that a combination treatment can be recommended in severe cases of heterotopic ossification to prevent recurrence. A review of neurogenic heterotopic ossification is presented. (Hip International 2005; 15: 123-7) KEY WORDS: Neurogenic heterotopic ossification, Hip reconstruction, Ankylosis, Cerebral palsy.

Assessment of vertebral scalloping in neurofibromatosis type 1 with plain radiography and MRI

AIM

To evaluate vertebral scalloping in patients with neurofibromatosis type 1 (NF-1) and spinal deformity using plain radiographs and magnetic resonance imaging (MRI), and to determine the possible aetiological association with neurofibromas, dural ectasia and lateral meningocoeles.

MATERIAL AND METHODS

Nineteen patients with NF-1, who had full spine radiographs and whole-spine MRI, were retrospectively reviewed. Dystrophic features and their relationship to the curve were recorded from radiographs. A comparison was then made between the dystrophic features evident on radiographs and adjacent soft-tissue abnormalities identified on MRI.

RESULTS

Dystrophic changes were documented in 16 patients on plain radiographs and in all patients on MRI. Rib pencilling was the most common finding on radiographs. In 80% of the cases with scoliosis, scalloping was seen on the concavity of the curvature. In all patients with kyphoscoliosis, scalloping was contiguous to the apex of kyphosis. Twenty-four areas of scalloping were identified on MRI. Scalloping usually developed in the concavity of the scoliotic curve or at levels unrelated to the curve. Scalloping was evident in combination with dural ectasia or neurofibroma in 15 cases. The presence of dural ectasia was confirmed in 75% of the cases of posterior scalloping and in 25% of those of lateral scalloping. The presence of neurofibromas was recognized in 25% of the cases of anterior or lateral scalloping. Dural ectasia was identified in two patients without associated scalloping. Lateral meningocoeles were not related to the development of scalloping.

CONCLUSION

Whereas posterior scalloping was commonly associated with dural ectasia, anterior and lateral scalloping were commonly the result of primary mesodermal dysplasia.

Unusual cause of deep vein thrombosis following dynamic hip screw fixation

We report a case of profunda femoris false aneurysm following internal fixation of an intertrochanteric neck of femur fracture, caused by proximal migration of a fracture fragment. The case is unique in that the mode of presentation was that of deep venous thrombosis, due to extrinsic compression of the venous system by the false aneurysm. (Hip International 2004; 14: 262-4).

Molecular characterization of serotype G9 rotavirus strains from a global collection

Between 1992 and 1998, serotype G9 human rotavirus (RV) strains have been detected in 10 countries, including Thailand, India, Brazil, Bangladesh, Malawi, Italy, France, the United States, the United Kingdom, and Australia, suggesting the possible emergence of the fifth common serotype worldwide. Unlike the previously characterized reference G9 strains (i.e., WI61 and F45), the recent G9 isolates had a variety of gene combinations, raising questions concerning their origin and evolution. To identify the progenitor strain and examine the on-going evolution of the recent G9 strains, we characterized by genetic and antigenic analyses 16 isolates obtained from children with diarrhea in India, Bangladesh, the United States, and Malawi. Specifically, we sequenced their VP7 and NSP4 genes and compared the nucleotide (nt) and deduced amino acid sequences with the reference G9 strains. To identify reassortment, we examined the products of five gene segments; VP4, VP7, and NSP4 genotypes (genes 4, 9, and 10); subgroups (gene 6); electropherotypes (gene 11); and the genogroup profiles of all of the recent G9 isolates. Sequence analysis of the VP7 gene indicated that the recent U.S. P[6],G9 strains were closely related to the Malawian G9 strains (>99% nt identity) but distinct from G9 strains of India ( approximately 97% nt identity), Bangladesh ( approximately 98% nt identity), and the reference strains ( approximately 97% nt identity). Phylogenetic analysis identified a single cluster for the U.S. P[6],G9 strains that may have common progenitors with Malawian P[6],G9 strains whereas separate lineages were defined for the Indian, Bangladeshi, and reference G9 strains. Northern hybridization results indicated that all 11 gene segments of the Malawian P[6],G9 strains hybridized with a probe derived from a U.S. strain of the same genotype and may have the same progenitor, different from the Indian G9 strains, whereas the Bangladesh strains may have evolved from the U.S. G9 progenitors. Overall, our findings suggest that much greater diversity among the newly identified G9 strains has been generated by reassortment between gene segments than through the accumulation of mutations in a single gene.

Detection and characterization of novel rotavirus strains in the United States

We recently established a rotavirus strain surveillance system in the United States to monitor the prevalent G serotypes before and after the anticipated implementation of a vaccination program against rotavirus and to identify the emergence of uncommon strains. In this study, we examined 348 rotavirus strains obtained in 1996 to 1997 from children with diarrhea in 10 U.S. cities. Strains were characterized for P and G types, subgroups, and electropherotypes by using a combination of monoclonal antibody immunoassay, reverse transcription-PCR, and hybridization. The four strains most commonly found worldwide comprised 83% of the isolates (P[8]G1, 66.4%; P[4]G2, 8.3%; P[8]G3, 6.9%; P[8]G4, 1.4%), but 9.2% were unusual strains (P[6]G9, 5.5%; P[8]G9, 1.7%; P[6]G1, 1.4%; and P[4]G1 and P[8]G2, 0. 3% each). Strains not typeable for P or G type accounted for 5.5% of the total, while 2.3% of the strains had more than one G type (mixed infections). All P[6]G9 strains tested had short electropherotypes and subgroup I specificity and were detected in 4 of 10 cities, while P[8]G9 strains had long electropherotypes and subgroup II VP6 antigens. Both sequence analysis of the VP7 open reading frame (about 94 to 95% amino acid identity with the VP7 gene of G9 prototype strain WI61) and binding to a G9-specific monoclonal antibody strongly suggest that U.S. G9 strains belong to serotype G9. The high detection rates of unusual rotaviruses with G9 (7.2%) or P[6] (6.9%) specificity in multiple U.S. cities suggest the emergence of new strains or inadequate diagnosis in the past. The epidemiologic importance of these strains remains to be determined.

Lack of maternal antibodies to P serotypes may predispose neonates to infections with unusual rotavirus strains

Rotavirus (RV) strains infecting newborns often have unique neutralization antigens (P serotypes) on their outer capsids that are distinct from those found on RV strains that cause diarrhea in older children. We examined the hypothesis that unusual RV strains preferentially infect newborns because the newborns lack maternal neutralizing antibodies to these strains. To test this hypothesis, sera and saliva samples collected from neonates infected with 116E-like (P[11]G9) strains in the maternity ward of the All India Institute of Medical Sciences (AIIMS) hospital in New Delhi were tested for neutralizing antibodies against common RV strains and those infecting newborns and these titers were compared with those of newborns who did not become infected (controls). The infected neonates had significantly lower levels of cord blood neutralizing antibodies to 116E than the controls, suggesting that immunity to neonatal RV infection is acquired transplacentally through maternal antibodies. Further, this study confirmed the immunogenicity of the AIIMS neonatal strain 116E, a vaccine candidate, in its ability to evoke a potent RV-specific immunoglobulin A and neutralizing antibody response in serum and saliva among the infected babies. Our findings have important implications for the development of an effective RV vaccine. In India, where G9 strains are common in the community, the use of 116E as a vaccine, together with the rhesus tetravalent vaccine, may provide a broader protection against all the circulating RV serotypes, including serotype G9, which is not represented in the current rhesus RV tetravalent vaccine (G1-G4).

Sequence analysis demonstrates that VP6, NSP1 and NSP4 genes of Indian neonatal rotavirus strain 116E are of human origin

We have sequenced the genes encoding the inner capsid protein VP6 and the nonstructural proteins NSP1 and NSP4 of the Indian neonatal serotype P8[11]G9 human/bovine reassortant candidate vaccine rotavirus strain 116E. These three genes share a high degree of sequence and deduced amino acid homology with human prototype strain Wa. Our results confirm and extend those of previous RNA-RNA hybridization studies which suggested that these genes are of human origin, and will facilitate examination of the host immune response to 116E induced by natural infection and vaccination.

Sequence analysis of NSP4 gene of human rotavirus allows classification into two main genetic groups

The rotavirus nonstructural glycoprotein NSP4 may represent the first identified viral enterotoxin. We have sequenced reverse transcription-polymerase chain reaction (RT-PCR)-generated fragments of 16 NSP4 genes of human rotavirus (HRV) strains from six different countries, representing seven different G and P type combinations. Based on the amount of sequence divergence between these and 11 previously sequenced NSP4 genes of human and animal rotaviruses, three distinct genetic groups could be recognized. Most strains within a group were closely related to each other at the nucleotide (nt) and amino acid (aa) levels (usually <10% divergence) but more distantly related (maximum 30.0% nt divergence and 24.7% aa divergence) to members of the other groups. Intergroup variation occurred in two highly variable regions of NSP4 (aa 16-34 and aa 131-148). The NSP4 "toxic peptide" (aa 114-135) exhibited aa variation at its carboxy terminus both within and between genetic groups. The largest group (genetic group II) contained HRV strains of subgroup II specificity (including genotypes P[8]G1, P[8]G3, P[6]G3, and P[8]G5 and serotype P8[11]G9), and the smaller group (genetic group I) contained HRV strains of subgroup I specificity (genotype P[4]G2). The NSP4 sequence of the rhesus rotavirus vaccine strain was distinct from all other strains and formed the third group (genetic group III). The NSP4 genes of animal rotaviruses UK, NCDV, and SA11 (genetic group I) and YM (genetic group II) and two possible human-animal rotavirus reassortant strains, Brazilian P[8]G5 and Indian P[11]G9 (genetic group II), could also be classified into one of these groups, suggesting a close evolutionary relationship between human and animal NSP4 genes. These results will facilitate studies of the host immune response to NSP4, which may be relevant to future HRV vaccine design.

Review of G and P typing results from a global collection of rotavirus strains: implications for vaccine development

Candidate rotavirus vaccines have been prepared with reassortant strains specifically to protect against the 4 major rotavirus G serotypes (G1 -4). Many studies using P (VP4) genotyping methods have indicated that, worldwide, rotavirus strains of the 4 common G serotypes are each associated with 1 P genotype: GI, G3, and G4 are associated with P[8], and G2 is associated with P[4]. In contrast, G and P genotyping of rotavirus in specimens from India revealed that a high percentage of the childhood diarrhea strains belong to genotype P[6], and the most common strain had an unusual G serotype, G9. Similarly, in all regions surveyed in Brazil, apparent reassortants of genotype P[8], G5 were found in children with gastroenteritis. These studies indicate that while rotavirus strains have limited diversity in many settings, reassortment between common and uncommon serotypes or animal strains can arise in some settings and, thus, lead to unusual diversity.

Unusual diversity of human rotavirus G and P genotypes in India

Between April and December 1993, we determined P and G genotypes of group A rotavirus strains obtained from children admitted to diarrhea treatment centers in five Indian cities. From a total of 63 rotavirus-positive specimens, we identified 10 different strains with five different G genotypes and four distinct P types by using reverse transcription-PCR. The common worldwide strains G1P8, G2P4, G3P8, and G4P8 were underrepresented among Indian children (33%), whereas strains of P type 6 (G1P6, G2P6, G3P6, G4P6, and G9P6), which primarily infect asymptomatic newborns but are rare in children with diarrhea were common in India (43%). Of these, G9P6, a strain not previously reported to be found in children with diarrhea, was the most prevalent (22%). Eleven percent of the strains were nontypeable, and another 11% of the specimens had mixed infections. Using digoxigenin-labeled, genotype-specific hybridization probes, we confirmed all G9 strains and mixed infections tested and identified three nontypeable strains (one G9 and two P8). The epidemiological significance of G9 rotavirus strains, if confirmed in other settings, may have important implications for vaccine development.

Characterization of rotavirus strains from newborns in New Delhi, India

Between 1986 and 1993, 72% of rotavirus strains isolated from newborns at five hospitals in New Delhi, India, had long electropherotypes, subgroup II VP6 antigens, and G and P genotypes (G9P11) identical to those of prototype strain 116E. A novel strain with a G9P6 genotype, representing 13% of the isolates, was identified. These results demonstrate that G9P11 and G9P6 rotavirus strains are common in nurseries in New Delhi.

Effect of exposure of foetal red cells to hydrogen peroxide

Foetal and adult red cells were exposed to H2O2 vapours using two different modes of exposure. There was a two-fold increase in adult (P < 0.05) and three-fold increase in foetal (P < 0.05) cells after 8 h of exposure to H2O2 using the Cohen and Hochstein technique. When the H2O2 was generated in situ by the glucose-glucose oxidase technique, there was also an increase in formation of methaemoglobin in both cell types (P < 0.05). In the presence of sodium azide in both cell types, methaemoglobin was generated and there was a progressive increase in the formation of methaemoglobin with time of exposure in both cell types (P < 0.05) using either the Cohen and Hochstein procedure or the glucose-glucose oxidase procedure. There was significant difference in the methaemoglobin formation between the adult and foetal red cells throughout the period of exposure (P < 0.05). The ability of both cell types to reduce methaemoglobin the presence of added substrates (glucose, inosine, adenosine, lactate and sorbitol) showed an enhanced reduction of methaemoglobin in adult red cells for lall the substrates added and a slower rate of reduction of methaemoglobin to functional haemoglobin in foetal cells. There was significant difference in the percentage drop in the methaemoglobin formation between the adult and foetal red cells with all added substrates (P < 0.05). Our results showed that the foetal cells were more susceptible to oxidative stress than adult red cells.

Spleen in sickle cell anemia: comparative studies of Nigerian and U.S. patients

Anecdotal reports have attributed persistent splenomegaly in African sickle cell anemia (SS) patients to the effects of malaria. However, no comparative studies of patients in malarial and nonmalarial regions have been conducted, and few studies of malaria antibody titers have been reported. In the present study, age- and sex-matched Nigerian patients (n = 310), while it was found only in 8% of U.S. patients (n = 100) from Georgia. There was significant linear correlation between spleen size and Hb levels and with serum immunoglobulins in the Nigerian group. However, serum complement levels (C3 and C4) were not affected by spleen size. In both groups, patients with splenomegaly had fewer circulating pitted red cells than their counterparts without splenomegaly. The mean +/- SE of IgG-specific malaria antibody titer among the Nigerian patients without palpable spleens was 9,386 +/- 2,036; 9,334 +/- 2,980 in those with spleens between 1 and 5 cm, 16,201 +/- 4,502 in those with spleens between 6 and 10 cm, and 22,445 +/- 8,456 in those with spleens above 10 cm. Coexistent alpha-thalassemia did not influence the prevalence of splenomegaly among the Nigerian SS patients. This study provides additional evidence that malaria plays a significant role in the persistence of splenomegaly in African patients.

A new variant, HB Muscat [alpha 2 beta (2)32(B14)Leu----Val] observed in association with HB S in an Arabian family

The silent Hb Muscat with a Leu----Val replacement at position beta 32 was discovered by reversed phase high performance liquid chromatography in two members of an Arabian family from Oman; in one person Hb Muscat occurred with Hb S and in the other with Hb A. Hb Muscat is slightly unstable but its presence has no apparent adverse effect on the health of its carriers. Additional hemoglobin abnormalities observed in this family were a common alpha-thalassemia-2 (-3.7 kb) and Hb S. The beta S haplotypes in the heterozygous carriers and the two sickle cell anemia patients were #19 (Benin) and #20 (Bantu); the latter likely originated from an East African population.

Hb Coimbra or alpha 2 beta (2)99(G1)Asp----Glu, a newly discovered highoxygen affinity variant

We have identified a new high oxygen affinity hemoglobin variant in members of a Portuguese family; it is characterized by an Asp----Glu replacement at codon 99 of the beta chain which is in the alpha 1 beta 2 interface. The altered functional properties of Hb Coimbra likely result from the inability to form a hydrogen bond between beta 99Glu and alpha 42Tyr; such a bond is formed in deoxy Hb A between the normally occurring beta 99Asp and alpha 42Tyr. The two affected members of the family have a distinct erythrocytosis with hemoglobin levels of 18 to 20 g/dl. The mutation in the beta-globin gene (GAT----GAA at codon 99) resulting in the Asp----Glu replacement is the seventh type at this specific location. A review of the many variants of the alpha and beta chains identifies primarily aspartic acid and glutamic acid residues as being most frequently replaced; it is speculated that codons GAC and GAT (for Asp), and GAG and GAA (for Glu) are most susceptible to mutational events.