Synthesis and evaluation of phenoxy acetic acid derivatives as anti-mycobacterial agents

In present investigation, 2-(4-formyl-2-methoxyphenoxy) acetic acid on condensation with various ketones in methanolic KOH solution yielded the corresponding chalcones (1-3). These corresponding chalcones were reacted with appropriate acid hydrazide in glacial acetic acid led to the formation of phenoxy acetic acid derivatives. All newly synthesized compounds were evaluated for their anti-mycobacterial activities against Mycobacterium tuberculosis H(37)Rv.

Correlation between translation efficiency and outcome of combination therapy in chronic hepatitis C genotype 3

Combination therapy with interferon-alpha (IFN-alpha) and ribavirin (RBV) in chronic hepatitis C demonstrates the best responses against hepatitis C virus (HCV) of genotype 3. Still, it has proven to be ineffective in 20-30% of patients infected with this genotype. In the present study, we analysed the translation efficiency mediated by the internal ribosome entry site (IRES) region in HCV genotype 3 genomes isolated from sustained responders (SR) and non-responders (NR), assuming that this may influence the outcome of treatment. Pretreatment isolates of genotype 3 from 22 individuals (15 SR, seven NR) were selected for such analyses. The IRES region [nucleotide (nt) 1-407] was cloned into a dual luciferase vector and IRES activity assessed following transfection into various cell lines. Low relative translation efficiency was observed for IRES elements derived from SR patients, whereas those of NR patients showed significantly greater translation efficiency (29.7 +/- 13 vs 69.4 +/- 22; P < 0.01). Subsequently, the effect of IFN-alpha plus RBV on IRES-driven translation in vitro was determined. A greater suppressive effect was observed on IRES activity isolated from seven SR patients, when compared with seven NR patients. In conclusion, IRES efficiency in vitro correlated with treatment response for HCV genotype 3. Further studies are warranted to investigate whether IRES efficiency in vitro, or sequence motifs associated with IRES efficiency, will be worthwhile to explore as prognostic tools for other HCV genotypes in the treatment of chronic HCV infection.

Diagnostic MR imaging features of craniocerebral Aspergillosis of sino-nasal origin in immunocompetent patients

BACKGROUND

Craniocerebral invasive Aspergillosis of sino-nasal origin has been reported with a very high mortality due to a peculiarly fulminant clinical course. Early diagnosis based on clinical radiological imaging may have an impact on final clinical outcome. This retrospective study focuses on characteristic MR imaging features of Aspergillosis (of sinonasal origin) in immunocompetent patients.

METHODS

Medical records of patients were reviewed retrospectively during the period from 1991 to 2003 in the two tertiary care hospitals. All the patients had radiological evidence of disease in the paranasal sinuses with or without intracranial extension. Immunocompetence of patients was assessed on clinical and radiological data. MRI scans (n=20) were reviewed by both clinical neurosurgeons and neuroradiologists separately. MRI was done on 1.5 tesla scanners and both T2-weighted and T1 weighted sequences were obtained followed gadolinium enhanced images. Patients were categorized into three types based on their anatomical location on MRI scans; type-1 being intracerebral, type-2 as intracranial extradural and type-3 invading orbit and/or skull base only. All these patient had the epicenter of disease in the nose and/or paranasal sinuses as evident on MR imaging. All patients underwent standard surgical intervention followed by antifungal therapy. Clinical outcome was assessed on Glasgow outcome scale with mean duration of clinical follow up of 13.9 months.

FINDINGS

Mean age of patents (n=20) was 31.1 years with male preponderance (3:1). MRI scans showed evidence of disease in paranasal sinuses including mucosal thickening (n=11) and complete filling of sinuses (n=9). T2-weighted images showed extremely hypo-intense fungal mass (n=19) while T1-weighted images had iso-intense signals (n=18). Gadolinium-enhanced images showed bright homogenous contrast enhancement (n=18) and peripheral ring enhancement pattern (n=2). All patients underwent appropriated surgical procedures depending upon anatomical location followed by standard antifungal therapy. Tissue diagnoses were established by histopathology (n=20) and culture growth (n=5). Overall mortality remained 15 percent.

INTERPRETATION

Craniocerebral Aspergillosis of sinonasal origin has typical MR imaging features. These features include a mass lesion producing hypo-to-iso-intense signals on T1-weighted, extremely low signals (hypo-intense) on T2-weighted images, with bright homogenous enhancement on post-gadolinium T1-weighted imaging. These features in the clinical background may be helpful in early diagnosis and management of Aspergillosis of sino-nasal origin in immunocompetent hosts. Prospective clinical study is required to make firm clinical therapeutic recommendations.

Characterization of protective immunity induced against Schistosoma mansoni via DNA priming with the large subunit of calpain (Sm-p80) in the presence of genetic adjuvants

Despite advances in control via snail eradication and large-scale chemotherapy using praziquental, schistosomiasis continues to spread to new geographic areas particularly in sub-Saharan Africa. Presently, there is no vaccine for controlling this disease. We have concentrated on a functionally important schistosome antigen Sm-p80 as a possible vaccine candidate for schistosomiasis. Here we report the proliferation of spleen cells in response to the recombinant Sm-p80 protein and cytokine (IFN-gamma and IL-4) production by the splenocytes. These spleen cells were obtained from groups of mice that were vaccinated with a DNA vaccine formulation containing Sm-p80 and one of the Th-1 (IL-2 or IL-12) or Th-2 (GM-CSF, IL-4) enhancer cytokines. The splenocytes from the groups of mice vaccinated with Sm-p80 DNA in the presence of Th-2 enhancer cytokines showed moderate but detectable proliferation. The splenocytes obtained from mice vaccinated with Sm-p80 DNA with Th-1 enhancer cytokines IL-2 and IL-12 provided the highest proliferation. The IFN-gamma production by splenocytes was found to follow the similar pattern [(Sm-p80) < (Sm-p80 + IL-4) < (Sm-p80 + GMCSF) < (Sm-p80 + IL-12) < (Sm-p80 + IL-2)], as has been observed for the proliferation and protection data. However, the elevated IL-4 production was inversely correlated to Sm-p80-induced splenocyte proliferation or the protection. These results show again that protective immune response induced by Sm-p80 is of Th-1 type.

Regulation of gene expression in parasitic flatworms

Transcriptional regulation and the role of transcription factors are widely regarded to be the major contributors controlling gene expression in eucaryotes. Translational control is less well understood due to the complexity of the components involved in regulation of protein synthesis at this level. Nevertheless, considerable advances have been made recently in elucidating the major controlling factors within the messenger RNA (mRNA) sequence and the translation machinery. In this article, Ron Podesta and Afzal Siddiqui suggest that protein synthesis in flatworm parasites is controlled post-transcriptionally and that these intracellular regulatory mechanisms are activated/suppressed by effectors of the host's immune response.

Experimental analysis of screw hold as judged by operators v pullout strength

An analysis of the accuracy of the operators' assessments of the hold of bone screws is reported. These assessments of screw hold were compared with measurements from pullout testing. Four operators, encompassing a range of experiences in terms of screw insertion, prepared the pilot holes, and inserted a number of screws, assigning each with a score from 0 to 10 on the basis of how good the hold was felt to be. The pullout strength for each screw was then measured using a tensometer. The results were analysed and correlation coefficients calculated. Significant correlation was observed in all four subjects, with P < 0.001 in two out of the four subjects, and 0.01 > P > 0.001 in the other two. The conclusions were that there is a strong correlation between the subjective assessment of screw hold and actual pullout strength within the four subjects analysed.

Complete surgical excision of intramedullary schwannoma at the craniovertebral junction in neurofibromatosis type-2

Intramedullary spinal schwannomas are extremely rare. We describe a case of a 13-year-old female who was found to have an intramedullary schwannoma at craniovertebral junction along with incidental bilateral acoustic neuromas, which was excised completely. To our knowledge, this is the first report of a case of intramedullary schwannoma in association with NF-2 located at the craniovertebral junction. The literature has been reviewed with emphasis on radiological imaging, histopathological diagnosis and technique to achieve complete microsurgical excision.

Cage versus tricortical graft for cervical interbody fusion

We conducted a prospective, randomised study of 42 cervical interbody fusions undertaken with either an autologous tricortical graft or a cage. The factors assessed in the two groups were: (1) time taken to achieve fusion; (2) neck disability index; (3) pain score; (4) interbody height ratio; (5) interbody angle and (6) the influence of smoking on fusion.

No statistical difference was seen in the time taken to achieve fusion, neck disability index, interbody height ratio, or interbody angles. Smoking did not have any effect on the fusion process. The pain score was significantly lower in the tricortical graft group at six months. We conclude that both methods of fusion give similar results, although tricortical graft fusion is cheaper than cage fusion, and is more effective in reducing the pain score.

Posterior sternoclavicular joint dislocation: the value of intra-operative ultrasound

The sternoclavicular joint dislocates posteriorly if the costoclavicular ligaments, posterior capsule, and anterior capsule have all been disrupted. Diagnosis of a posteriorly dislocated sternoclavicular joint is difficult on clinical examination and with plain X-rays. The treatment objective is to obtain a closed reduction, and failing this an open reduction is indicated. In the intra-operative setting the evaluation of the reduction when performed through closed means can be somewhat difficult, and intra-operative plain films do not give clear answers. Ultrasound as an imaging modality for these injuries was shown to demonstrate the state of the joint in terms of reduction, more clearly than X-rays (P<0.001). It was accurately interpreted by the vast majority of orthopaedic surgeons in an investigation, and is of great value in the intra-operative setting to confirm whether a closed reduction has been successful or not. A case is reported illustrating its use.

Determination of alpha-1 antitrypsin genetic deficiency in duodenal ulcer by polymerase chain reaction

OBJECTIVE

To confirm alpha-1-AT deficiency status in duodenal ulcer using a combination of PCR and restricted enzyme digestion.

METHODS

Fifty patients with endoscopically proven duodenal ulcer and hundred controls with no signs of the disease were included. Alpha-1-AT phenotypes were confirmed by polymerase chain reaction followed by restriction enzyme digestion.

RESULTS

Alpha-1-AT concentration in duodenal ulcer patients showed a mean value of 2.12 +/- 0.11 g/l (range: 0.52-3.95 g/l, p < 0.05). In controls this was 2.47 +/- 0.08 g/l (range: 0.52-5.0 g/l). Among the controls 70% had the MM phenotype, 28% M1 M2 and 2% FM. In duodenal ulcer, MM predominates (70%), followed by M1 M2 (18%), SS (4%), SZ (4%), ZZ (2%) and MZ (2%).

CONCLUSION

Alpha-1 AT deficiency was found in 10% of duodenal ulcer patients. DNA analysis more accurately resolved the phenotypes as S and Z mutations.

Predictors of mortality in brain abscess

OBJECTIVE

Brain abscess carries significant morbidity and mortality. Our objective was to elucidate the clinical presentation of brain abscess and to assess predictors of mortality in these patients.

METHODS

All patients with a brain abscess presenting to the Aga Khan University Hospital, a tertiary care referral center in Karachi, Pakistan, were studied retrospectively. Statistical analysis involved univariate analysis and a logistic regression model.

RESULTS

Among the 66 patients analyzed, a distant metastatic focus of infection was the most commonly identified predisposing factor (29%). Otogenic infection was the commonest contiguous source and sinusitis was noticeably absent. Multiple abscesses were frequent (35%). Streptococci were the most common isolates (39%). Lumbar puncture was performed in 44% and steroids administered in 33%. Treatment was surgical in 58%. Most comatose patients were treated conservatively. Overall mortality was 29%. Univariate analysis identified comatose presentation and identification of a distant focus of infection as predictors of mortality. The logistic regression model, however, identified a distant focus of infection as the only independent predictor.

CONCLUSION

Age greater than 30 years, corticosteroid use, multiple abscesses, performance of lumbar puncture and conservative management had no affect on outcome.

Immediate loading of dental implants in the edentulous mandible: a preliminary case report from an international prospective multicenter study

The ability to predictably achieve long-term osseointegration in patients with compromised anatomical resources has been demonstrated numerous times in modern oral implantology. Recently, clinical attention has focused on new methods of reducing treatment time. One-stage surgical procedures and immediate loading of implants at the time of placement are two techniques that have demonstrated promising clinical results. A prospective clinical study of immediately splinting and loading a new, one-stage implant is currently in progress in the United States and France. An overview of the implant design and presentation of one case study from the University of Pittsburgh demonstrates how this promising technique is performed.

Diagnosis of Strongyloides stercoralis infection

Strongyloides stercoralis infects 30 million people in 70 countries. Infection usually results in asymptomatic chronic disease of the gut, which can remain undetected for decades. However, in patients receiving long-term corticosteroid therapy, hyperinfection can occur, resulting in high mortality rates (up to 87%). Strongyloidiasis is difficult to diagnose because the parasite load is low and the larval output is irregular. Results of a single stool examination by use of conventional techniques fail to detect larvae in up to 70% of cases. Several immunodiagnostic assays have been found ineffective in detecting disseminated infections and show extensive cross-reactivity with hookworms, filariae, and schistosomes. Although it is important to detect latent S. stercoralis infections before administering chemotherapy or before the onset of immunosuppression in patients at risk, a specific and sensitive diagnostic test is lacking. This review describes the clinical manifestations of strongyloidiasis, as well as various diagnostic tests and treatment strategies.

Neoplastic growth of cerebral cavernous malformation presenting with impending cerebral herniation: a case report and review of the literature on de novo growth of cavernomas

BACKGROUND

Cerebral cavernomas are rare vascular anomalies and their expansile growth has been considered to be mainly due to recurrent hemorrhages. They are not generally reported to show aggressive behavior.

CASE DESCRIPTION

A 27-year-old male presented with headache, visual disturbances, and a 17-year history of seizures. He was known to have a temporal lobe lesion on CT scan, consistent with a diagnosis of cavernous malformation but with no relevant family history. Serial clinical and radiological follow-up revealed a progressive increase in the size of the lesion with formation of a growing cyst of 7 cm in diameter, which produced mass effect, resulting in the clinical picture of cerebral herniation. The patient underwent emergency surgical resection with symptomatic relief. There was no evidence of significant hemorrhage at surgery.

CONCLUSION

Cavernous malformations can show expansile growth without any evidence of a presaging hemorrhagic event and, in the manner of a neoplastic lesion, present with raised intracranial pressure and cerebral herniation.

Isolation of a cDNA encoding an IgG immunoreactive antigen (zinc finger protein) of Strongyloides stercoralis

A full length cDNA encoding an IgG immunoreactive antigen of Strongyloides stercoralis is described. A clone containing 1,328 bp insert was selected following screening of S. stercoralis cDNA library with an IgG fraction obtained from a pool of 78 S. stercoralis positive human sera samples. The nucleotide sequence of the 1,328 bp insert was found to be 70.5% A/T, reflecting a characteristic A/T codon bias of S. stercoralis. The nucleotide sequence of this insert identified a cDNA coding for a zinc finger protein. The conceptually translated amino acid sequence of the open reading frame for the IgG immunoreactive antigen of S. stercoralis encodes a 211 amino acid residue protein with an apparent molecular weight of 22.8 kDa and a predicted isoelectric point of 8.71. The diagnostic potential of this IgG immunoreactive antigen of S. stercoralis is also discussed.

The influence of HLA class I alleles and heterozygosity on the outcome of human T cell lymphotropic virus type I infection

The inflammatory disease human T cell lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM/TSP) occurs in only 1-2% of HTLV-I-infected individuals and is associated with a high provirus load of HTLV-I. We hypothesize that a person's risk of developing HAM/TSP depends upon the efficiency of their immune response to the virus, which differs between individuals because of polymorphism in genes that influence this response. Previously we showed that the possession of HLA-A*02 was associated with a lower risk of HAM/TSP, and with a lower provirus load in healthy carriers of HTLV-I. However, HLA-A*02 did not account for all the observed difference in the risk of HAM/TSP. Here we present evidence, in the same study population in Japan, that HLA-Cw*08 was also associated with disease protection (probability value, two-tailed test = 0.002) and with a lower proviral load in healthy carriers. Possession of the A*02 and/or Cw*08 genes prevented 36% of potential HAM/TSP cases. In contrast, HLA-B*5401 was associated with a higher susceptibility to HAM/TSP (probability value, two-tailed test = 0.0003) and with a higher provirus load in HAM/TSP patients. At a given provirus load, B*5401 appeared to increase the risk of disease. The fraction of HAM/TSP cases attributable to B*5401 was 17%. Furthermore, individuals who were heterozygous at all three HLA class I loci have a lower HTLV-I provirus load than those who were homozygous at one or more loci. These results are consistent with the proposal that a strong class I-restricted CTL response to HTLV-I reduces the proviral load and hence the risk of disease.

Phenotypes of alpha 1 antitrypsin in Karachi, Pakistan

OBJECTIVE

To determine serum level of the protease inhibitor, to identify phenotypes and determine their frequencies.

STUDY DESIGN

A prospective study.

SETTING

PMRC, Research Centre, JPMC and the Aga Khan University Hospital, Karachi.

SUBJECTS

Healthy adults without history of peptic ulcer disease and a normal endoscopy.

METHODOLOGY

Quantitative measurement of serum alpha 1 AT was carried out by radial immunodiffusion, phenotyping by iso-electric focusing and confirmation of phenotypes by immuno-fixation and DNA analysis technique.

RESULTS

Serum alpha 1 AT was low in 13.4% of the subjects. MM phenotype predominated followed by SZ, SS,MZ and ZZ. DNA diagnosis accurately resolved the phenotypes as S and Z.

CONCLUSION

Frequency of phenotype associated with total and intermediate deficiency is less in the population.

Cloning and expression of isocitrate lyase from human round worm Strongyloides stercoralis

A full length cDNA (1463 bp) encoding isocitrate lyase (EC 4.1.3.1) of Strongyloides stercoralis is described. The nucleotide sequence of this insert identified a cDNA coding for the isocitrate lyase. The conceptually translated amino acid sequence of the open reading frame for S. stercoralis isocitrate lyase encodes a 450 amino acid residue protein with an apparent molecular weight of 50 kDa and a predicted pl of 6.39. The sequence is 69% A/T, reflecting a characteristic A/T codon bias of S. stercoralis. The amino acid sequence of S. stercoralis isocitrate lyase is compared with bifunctional glyoxylate cycle protein of Caenorhabditis elegans and isocitrate lyases from Chlamydomonas reinhardtii and Myxococcus xanthus. The full length cDNA of S. stercoralis was expressed in pRSET vector and bacteriophage T7 promoter based expression system. S. stercoralis lyase recombinant protein, purified via immobilized metal affinity chromatography, showed a molecular mass of 50 kDa on polyacrylamide gels. The role of isocitrate lyase in the glyoxylate cycle and energy metabolism of S. stercoralis is also discussed.

DDRT-PCR: use of agarose gels for detection of amplified products

The present study focuses on the detection of differentially expressed genes in migrating (healing) and nonmigrating (normal) corneal epithelium on agarose gel using a modified procedure of differential display reverse transcriptase-polymerase chain reaction (DDRT-PCR). Rabbit corneal epithelial organ cultures were used to obtain nonmigrating and migrating samples. RNA was extracted using Trizol LS reagent. PCR was modified in order to allow detection of amplified products on 3% agarose gel with ethidium bromide staining. Products were also resolved on 6% denaturing polyacrylamide-urea gels and observed by silver staining. Agarose gels showed two prominent bands that were heavily expressed in the 458 bp and 587 bp region of the nonmigrating samples. In addition light bands were visible in the region corresponding to 234 bp and 450 bp. In the migrating samples, two light bands were visible in the region of 267 bp and 300 bp. Eight amplicons, six in the nonmigrating corneal epithelial sample and two in the migrating corneal epithelial samples, were also found to be differentially expressed when products were run on 6% denaturing polyacrylamide-urea gels. Thus, DDRT-PCR products can be detected on agarose gels and prove very helpful and economical in the initial studies of DDRT-PCR.

A cDNA encoding the highly immunodominant antigen of Strongyloides stercoralis: gamma-subunit of isocitrate dehydrogenase (NAD+)

A full length cDNA encoding the highly immunodominant 41 kDa antigen of Strongyloides stercoralis (P5), recognized by 83% of human patients [Siddiqui et al. (1997) Parasitol Res 83:655-658], is obtained. A clone containing a 1371 bp insert was selected following screening of the S. stercoralis cDNA library with antibodies specific to antigen P5. The nucleotide sequence of this insert identified a cDNA coding for the gamma-subunit of isocitrate dehydrogenase (NAD+), GenBank Accession Number AF176568. The conceptually translated amino acid sequence of the open reading frame for the gamma-subunit of S. stercoralis isocitrate dehydrogenase (NAD+) encodes a 388 amino acid residue protein with an apparent molecular weight of 43 kDa and a predicted pI of 7.15. The sequence is 71% A/T, reflecting the characteristic A/T codon bias of S. stercoralis. The amino acid sequence of the S. stercoralis gamma-subunit of isocitrate dehydrogenase (NAD+) is compared with those of Caenorhabditis elegans, rat and human NAD(+)-ICDH. The diagnostic potential of the S. stercoralis gamma-subunit of isocitrate dehydrogenase (NAD+) is also discussed.

Priming of a beta-galactosidase (beta-GAL)-specific type 1 response in BALB/c mice infected with beta-GAL-transfected Leishmania major

To determine whether an ongoing response to Leishmania major would affect the response to a non-cross-reacting, non-leishmanial antigen, susceptible BALB/c mice and resistant C3H mice were infected with L. major parasites expressing Escherichia coli beta-galactosidase (beta-GAL); this parasite was designated L. major-betaGAL. BALB/c and C3H mice responded to infection with L. major-betaGAL by mounting a CD4 T-cell response to both parasite antigens and to the reporter antigen, beta-GAL. The phenotypes of these T cells were characterized after generating T-cell lines from infected mice. As expected, BALB/c mice responded to infection with L. major-betaGAL by producing interleukin 4 in response to the parasite and C3H mice produced gamma interferon (IFN-gamma) in response to the parasite and beta-GAL. Interestingly, however, BALB/c mice produced IFN-gamma in response to beta-GAL. Taken together, these results demonstrate that priming of IFN-gamma-producing cells can occur in BALB/c mice despite the fact the animals are simultaneously mounting a potent Th2 response to L. major.