Utility of intradermal smear in the diagnosis of malaria

The objective of this preliminary study was to evaluate the usefulness of the intradermal smear test in the diagnosis of malaria. One hundred cases of suspected malaria (having received no prior antimalarials) were investigated. Both peripheral blood film (PBF) and intradermal smears (IDS) were simultaneously prepared and patients placed on antimalarial therapy. The slides were repeated for the next 2 days. At admission, 70 cases were positive on PBF--59 were Plasmodium falciparum (PF) and 11 were Plasmodium vivax (PV) whereas surprisingly 62 cases were positive on IDS at admission--61 were PF, one was PV. IDS identified two more cases of PF [P value (not significant)] but failed to identify any new cases of PV (P value NS). On subsequent days IDS positivity for PF was higher than for PBF (P < 0.05 for day 1 and P < 0.001 for day 2). However, the PV yield was poor for any further statistical evaluation on subsequent days. We conclude that IDS is simple, easy to perform, requires no special infrastructure compared to PBF, and is a helpful diagnostic tool in cases where malaria is strongly suspected but peripheral blood slides are repeatedly negative due to prior use of antimalarial therapy. IDS may be added to routine PBF in malaria (especially PF).

Maintenance and impacts of an inoculated mer/luc-tagged Pseudomonas fluorescens on microbial communities in birch rhizospheres developed on humus and peat

Antagonistic bacteria represent promising biocontrol agents for improving forest production in seedling nurseries or forest soils. The fate of an introduced mer/luc-tagged antagonistic Pseudomonas fluorescens 31K3 was monitored in the rhizosphere of silver birch (Betula pendula) seedlings grown in microcosms containing forest humus or nursery peat. The inoculated strain (10(8) cfu g(-1) soil) was unable to establish in significant numbers in either soil type and turned nonculturable in humus. Detection in both soils was possible only via luminescence of enrichment cultures 80 days post-inoculation. Despite low P. fluorescens survival, inoculation had a positive effect on seedling growth. Limited impact of inoculation on the indigenous microbial communities was identified following analyses of respiration and denitrification potential, community-level physiological profiles and molecular fingerprinting of fungi and eubacteria, and Pseudomonas community structures. The minor changes observed in the indigenous microbial communities, including mycorrhiza development, were not consistent between humus and peat growth substrates. It was concluded that the rhizosphere-related microbial communities developed in both of these highly organic soil systems are highly buffered against introduction of foreign bacteria.

Chemistry of single-walled carbon nanotubes

In this Account we highlight the experimental evidence in favor of our view that carbon nanotubes should be considered as a new macromolecular form of carbon with unique properties and with great potential for practical applications. We show that carbon nanotubes may take on properties that are normally associated with molecular species, such as solubility in organic solvents, solution-based chemical transformations, chromatography, and spectroscopy. It is already clear that the nascent field of nanotube chemistry will rival that of the fullerenes.

Effects of angiotensin converting enzyme inhibitor on renal function in patients of membranoproliferative glomerulonephritis with mild to moderate renal insufficiency

AIM

To determine the effect of enalapril, angiotensin-converting-enzyme inhibitor (ACE-I) on progression of renal insufficiency in primary membranoproliferative glomerulonephritis with mild to moderate renal insufficiency.

METHOD

Thirty patients with histopathologically proved MPGN having hypertension (grade I and II of JNC-VI criteria of hypertension) and mild to moderate impairment of renal function (creatinine clearance varying from 30-80 ml/min, significant albuminuria and serum creatinine 1.2-3.0 mg/dl) were initially treated with diuretics and 3-blockers to bring down BP < 140/90 mm Hg. These patients were then randomly divided into three groups of 10 each, group I--Control; group II--Nifedipine and group III--Enalapril. In group II and III Nifidepine 30 mg/day and in group III Enalapril 10 mg/day respectively were added in addition and treatment was continued for nine months. These patients were followed up monthly for drug efficacy, side effects and any adverse drug reaction.

RESULTS

Out of 30, 28 patients completed the study. At the end of nine months of treatment the patients of control group revealed significant increase in serum creatinine (1.65 +/- 0.38 to 2.17 +/- 0.31 mg/dl), blood urea (34.0 +/- 3.9 to 40.0 +/- 3.1 mg/dl), and 24 hours albuminuria (3.6 +/- 0.6 to 4.2 +/- 0.6 gm) and decrease in creatinine clearance (60.3 +/- 13.3 to 37.5 +/- 11.8 m/min); however, in enalapril group there was decrease in serum creatinine (1.72 +/- 0.45 to 1.24 +/- 0.58 mg/dl), blood urea (34.6 +/- 4.7 to 28.1 +/- 6.7 mg/dl) and 24 hours albuminuria (3.3 +/- 1.0 to 1.6 +/- 1.1 gm) and increase in creatinine clearance (56A +/- 15.8 to 77.1 +/- 23.5 ml/min). The patients on nifedipine showed statistically nonsignificant changes in creatinine clearance, blood urea and serum creatinine; while albuminuria increased from 3.0 +/- 1.3 to 3.9 +/- 0.4 gm/24 hours (p < 0.01). The blood pressure was well controlled in all patients. None of the patient had side effects leading to withdrawal of drugs. No adverse drug reaction was noted.

CONCLUSION

ACE-I (enalapril) provided protection against the progression of renal insufficiency in patients of MPGN having hypertension with mild to moderate renal impairment. The renoprotective effects of ACE inhibitor (enalapril) is associated with substantial decrease in albuminuria.

Cell-specific association and shuttling of IkappaBalpha provides a mechanism for nuclear NF-kappaB in B lymphocytes

Mature B lymphocytes are unique in containing nuclear Rel proteins prior to cell stimulation. This activity consists largely of p50-c-Rel heterodimers, and its importance for B-cell function is exemplified by reduced B-cell viability in several genetically altered mouse strains. Here we suggest a mechanism for the cell specificity and the subunit composition of constitutive B-cell NF-kappaB based on the observed properties of Rel homo- and heterodimers and IkappaBalpha. We show that c-Rel lacks a nuclear export sequence, making the removal of c-Rel-containing complexes from the nucleus less efficient than removal of p65-containing complexes. Second, the nuclear import potential of p65 and c-Rel homodimers but not p50-associated heterodimers was attenuated when they were complexed to IkappaBalpha, leading to a greater propensity of heterodimers to be nuclear. We propose that subunit composition of B-cell NF-kappaB reflects the inefficient retrieval of p50-c-Rel heterodimers from the nucleus. Cell specificity may be a consequence of c-Rel-IkappaBalpha complexes being present only in mature B cells, which leads to nuclear c-Rel due to IkappaBalpha turnover and shuttling of the complex.

Microcosm-based analyses of Scots pine seedling growth, ectomycorrhizal fungal community structure and bacterial carbon utilization profiles in boreal forest humus and underlying illuvial mineral horizons

We report on the identity of indigenous mycorrhiza forming fungi and rhizosphere/mycorrhizosphere bacterial community carbon source utilization profiles of Scots pine (Pinus sylvestris L.) seedlings grown in boreal forest humus (O) or illuvial (B) mineral horizon containing microcosm growth systems. Based on rDNA (ITS)-RFLP analyses, a total of 10 fungal RFLP taxa were identified from pre-morphotyped mycorrhizas on 7-month-old seedling roots. Hierarchical cluster analysis, including corresponding RFLPs of known fungal species, confirmed root colonization by eight mycorrhizal species. In the O horizon, roots were colonized by e.g. Suillus bovinus, Suillus variegatus, Cenococcum geophilum, Piloderma croceum, Thelephora terrestris and Russula vinicolor. Mycobiont diversity in the mineral B horizon was lower but included Piceirhiza bicolorata and both Suillus species which produced extensive extramatrical mycelium. In comparison to non-colonized soils, rhizosphere and mycorrhizosphere compartments supported significantly higher numbers of bacteria (mean range 10(8)-10(11) cells g(-1) fresh weight (fw)). Specific rhizosphere/mycorrhizosphere 'niche'-linked bacterial communities were detected following multivariate analyses (PCA and CA) of bacterial carbon utilization profiles (Biolog(R) GN microplate). Distinct preferences for amino and carboxylic acids were identified in mineral B horizon rhizospheres whereas a wider range of carbon sources were utilized in the fungal-dominated mycorrhizospheres irrespective of soil types.

Conformational switching of Escherichia coli RNA polymerase-promoter binary complex is facilitated by elongation factor GreA and GreB

BACKGROUND

The initiation arrest at a modified lambdaPR promoter is caused by irreversible divergence of the reaction pathway into productive and arrested branches. Escherichia coli GreA and GreB induce cleavage of the nascent transcript and relieve arrest in elongation. They also reduce abortive synthesis at several promoters and relieve initiation arrest. Their mechanism of action during initiation, and its relationship to the branched initiation pathway are unknown.

RESULTS

The Gre factors mitigated initiation arrest only when they were added to the binary complex of the holoenzyme bound to the lambdaPR promoter, prior to RNA synthesis. They exerted little effect when they were added to ternary initiation complexes. They accelerated the exchange of the binary complex with its free components by 6-9-fold. When they are present, a high concentration of the initiating nucleotide increased yield of the full-length transcript, whereas a low concentration did not.

CONCLUSIONS

All the results presented above can be explained by a model where the productive and arrested pathways diverge at the binary complex stage. The Gre factors relieve the initiation arrest by introducing reversibility between subspecies of the binary complex that are precursors of the two pathways. RNA cleavage is unlikely to cause relief of initiation arrest.

Modification of the properties of elongating RNA polymerase by persistent association with nascent antiterminator RNA

Nascent RNA encoded by putL, a cis-acting antitermination site of bacteriophage HK022, increases readthrough of terminators by directly modifying the transcript elongation complex. To characterize the interaction between the antiterminator RNA and RNA polymerase, we stalled the elongation complex downstream of putL and determined the sensitivity of the transcript to ribonuclease cleavage. Part of PutL RNA was protected from cleavage by wild-type polymerase, but not by a mutant with a defect in put-dependent antitermination. We also exposed the stalled complex to oligonucleotides complementary to putL RNA, restarted transcription, and measured antitermination. Some, but not all, complementary oligonucleotides inhibited antitermination. Finally, cleavage of the RNA between putL and the 3'-end released putL RNA from the stalled complex and prevented antitermination.

IkappaB family members function by different mechanisms

The IkappaB family of proteins regulates NF-kappaB-dependent transcription by inhibiting DNA binding and localizing these factors to the cell cytoplasm. IkappaBalpha does this by shifting the balance between nuclear import of Rel proteins and their export from the nucleus. Here we show that, unlike IkappaBalpha, IkappaBbeta and IkappaBepsilon appear to sequester p65 or c-Rel in the cytoplasm by inhibiting nuclear import. Furthermore, because IkappaBbeta does not undergo nucleocytoplasmic shuttling, it cannot remove nuclear proteins like IkappaBalpha does. We conclude that the mechanism of action differs among IkappaB family members.

Heptad-repeat regions of respiratory syncytial virus F1 protein form a six-membered coiled-coil complex

The Respiratory Syncytial Virus (RSV) fusogenic glycoprotein F(1) was characterized using biochemical and biophysical techniques. Two heptad-repeat (HR) regions within F(1) were shown to interact. Proteinase-K digestion experiments highlight the HR1 region (located proximal to the fusion peptide sequence) of the F(1) protein to which an HR2-derived (located proximal to the membrane-spanning domain) peptide binds, thus protecting both the protein and peptide from digestion. Solution-phase analysis of HR1-derived peptides shows that these peptides adopt helical secondary structure as measured by circular dichroism. Sedimentation equilibrium studies indicate that these HR1 peptides self-associate in a monomer/trimer equilibrium with an association constant of 5.2 x 10(8) M(-2). In contrast, HR2-derived peptides form random monomers in solution. CD analysis of mixtures containing peptides from the two regions demonstrate their propensity to interact and form a very stable (T(m) = 87 degrees C), helical (86% helicity) complex comprised of three HR1 and three HR2 members.

Functional analysis of the murine TCR beta-chain gene enhancer

The TCR beta-chain gene enhancer activates transcription and V(D)J recombination in immature thymocytes. In this paper we present a systematic analysis of the elements that contribute to the activity of the murine TCR beta enhancer in mature and immature T cell lines. We identified a region containing the beta E4, beta E5, and beta E6 motifs as the essential core of the TCR beta enhancer in pro-T cells. In mature cells, the core enhancer had low activity and required, in addition, either 5' or 3' flanking sequences whose functions may be partially overlapping. Mutation of any of the six protein binding sites located within the beta E4-beta E6 elements essentially abolished enhancer activity, indicating that this core enhancer contained no redundant elements. The beta E4 and beta E6 elements contain binding sites for ETS-domain proteins and the core binding factor. The beta E5 element bound two proteins that could be resolved chromatographically and that were both essential for enhancer activity.

Effects of Pinus sylvestris root growth and mycorrhizosphere development on bacterial carbon source utilization and hydrocarbon oxidation in forest and petroleum-contaminated soils

The hypothesis that Pinus sylvestris L. root and mycorrhizosphere development positively influences bacterial community-linked carbon source utilization, and drives a concomitant reduction in mineral oil levels in a petroleum hydrocarbon- (PHC-) contaminated soil was confirmed in a forest ecosystem-based phytoremediation simulation. Seedlings were grown for 9 months in large petri dish microcosms containing either forest humus or humus amended with cores of PHC-contaminated soil. Except for increased root biomass in the humus/PHC treatment, there were no other significant treatment-related differences in plant growth and needle C and N status. Total cell and culturable bacterial (CFU) densities significantly increased in both rhizospheres and mycorrhizospheres that actively developed in the humus and PHC-contaminated soil. Mycorrhizospheres (mycorrhizas and extramatrical mycelium) supported the highest numbers of bacteria. Multivariate analyses of bacterial community carbon source utilization profiles (Biolog GN microplate) from different rhizosphere, mycorrhizosphere, and bulk soil compartments, involving principal component and correspondence analysis, highlighted three main niche-related groupings. The respective clusters identified contained bacterial communities from (i) unplanted bulk soils, (ii) planted bulk PHC and rhizospheres in PHC-contaminated soils, and (iii) planted bulk humus and rhizosphere/mycorrhizosphere-influenced humus, and mycorrhizosphere-influenced PHC contaminated soil. Correspondence analysis allowed further identification of amino acid preferences and increased carboxylic/organic acid preferences in rhizosphere and mycorrhizosphere compartments. Decreased levels of mineral oil (non-polar hydrocarbons) were detected in the PHC-contaminated soil colonized by pine roots and mycorrhizal fungi. These data further support our view that mycorrhizosphere development and function plays a central role in controlling associated bacterial communities and their degradative activities in lignin-rich forest humus and PHC-contaminated soils.

Polymerase arrest at the lambdaP(R) promoter during transcription initiation

During transcription initiation by Escherichia coli RNA polymerase, a fraction of the homogeneous enzyme population has been kinetically shown to form two types of nonproductive complexes at some promoters: moribund complexes, which produce only abortive transcripts, and fully inactive ternary complexes (Kubori, T., and Shimamoto, N. (1996) J. Mol. Biol. 256, 449-457). Here we report biochemical isolation of the complexes arrested at the lambdaP(R) promoter and an analysis of their structure by DNA and protein footprintings. We found that the isolated promoter-arrested complexes retain a stoichiometric amount of sigma(70) subunit. Exonuclease III footprints of the arrested complexes are backtracked compared with that of the binary complex, and KMnO(4) footprinting reveals a decrease in the melting of DNA in the promoter region. Protein footprints of the retained sigma(70) have shown a more exposed conformation in region 3, compared with binary complexes. This feature is similar to that of the complexes arrested in inactive state during transcription elongation, indicating the existence of a common inactivating mechanism during transcription initiation and elongation. The possible involvement of the promoter arrest in transcriptional regulation is discussed.

Cytoplasmic sequestration of rel proteins by IkappaBalpha requires CRM1-dependent nuclear export

Rel and IkappaB protein families form a complex cellular regulatory network. A major regulatory function of IkappaB proteins is to retain Rel proteins in the cell cytoplasm. In addition, IkappaB proteins have also been postulated to serve nuclear functions. These include the maintenance of inducible NF-kappaB-dependent gene transcription, as well as termination of inducible transcription. We show that IkappaBalpha shuttles between the nucleus and the cytoplasm, utilizing the nuclear export receptor CRM1. A CRM1-binding export sequence was identified in the N-terminal domain of IkappaBalpha but not in that of IkappaBbeta or IkappaBepsilon. By reconstituting major aspects of NF-kappaB-IkappaB sequestration in yeast, we demonstrate that cytoplasmic retention of p65 (also called RelA) by IkappaBalpha requires Crm1p-dependent nuclear export. In mammalian cells, inhibition of CRM1 by leptomycin B resulted in nuclear localization of cotransfected p65 and IkappaBalpha in COS cells and enhanced nuclear relocation of endogenous p65 in T cells. These observations suggest that the main function of IkappaBalpha is that of a nuclear export chaperone rather than a cytoplasmic tether. We propose that the nucleus is the major site of p65-IkappaBalpha association, from where these complexes must be exported in order to create the cytoplasmic pool.

An unusual case of choriocarcinoma following live term pregnancy

Post-term choriocarcinoma is an infrequent event with poor prognosis. The diagnosis is usually delayed due to failure to recognise the mode of presentation of this disease. Being a rare occurrence, limited data is available regarding its clinical features. The choriocarcinoma in our patient presented as an isolated huge pedunculated growth over the uterine serosa without intrauterine involvement and distant metastasis.

Cell-specific activation of nuclear factor-kappaB by the parasite Trypanosoma cruzi promotes resistance to intracellular infection

The transcription factor nuclear factor-kappaB (NF-kappaB) is central to the innate and acquired immune response to microbial pathogens, coordinating cellular responses to the presence of infection. Here we demonstrate a direct role for NF-kappaB activation in controlling intracellular infection in nonimmune cells. Trypanosoma cruzi is an intracellular parasite of mammalian cells with a marked preference for infection of myocytes. The molecular basis for this tissue tropism is unknown. Trypomastigotes, the infectious stage of T. cruzi, activate nuclear translocation and DNA binding of NF-kappaB p65 subunit and NF-kappaB-dependent gene expression in epithelial cells, endothelial cells, and fibroblasts. Inactivation of epithelial cell NF-kappaB signaling by inducible expression of the inhibitory mutant IkappaBaM significantly enhances parasite invasion. T. cruzi do not activate NF-kappaB in cells derived from skeletal, smooth, or cardiac muscle, despite the ability of these cells to respond to tumor necrosis factor-alpha with NF-kappaB activation. The in vitro infection level in these muscle-derived cells is more than double that seen in the other cell types tested. Therefore, the ability of T. cruzi to activate NF-kappaB correlates inversely with susceptibility to infection, suggesting that NF-kappaB activation is a determinant of the intracellular survival and tissue tropism of T. cruzi.

Multiple neurilemmomas of the penis

A 10-year-old male with multiple small swellings over the shaft of the penis for 2 years was found to have multiple neurilemmomas on histopathologic examination. The case is reported in view of the extreme rarity of the entity.

Caudal duplication--a case report

Caudal duplication is a rare entity due to incomplete separation of mono-ovular twins. It is usually associated with various congenital malformations involving mainly the genitourinary and gastrointestinal tracts. We report such a case operated upon successfully in which there was no other associated anomaly.