Multicentric giant cell tumor around the knee

A case of multicentric giant cell tumor with synchronous occurrence in all three bones around the knee is reported here in view of its rarity. A 33-year-old average built male reported with complaints of severe pain, gradually increasing swelling around the right knee. A 3 × 2 cm swelling was present on the lateral aspect of the distal end of the right femur and a 3 × 3 cm swelling on the proximal part of the right tibia. Plain X-ray of right knee showed subarticular eccentrically located expansile lytic lesion in the lateral tibia condyle, lateral condyle of femur and patella. Fine needle aspiration cytology and subsequent histology ascertained the diagnosis of giant cell tumor of the bone. The patient was treated successfully with curettage, bone grafting and methyl methacrylate cementing (Sandwich technique).

Thermal study of accumulation of conformational disorders in the self-assembled monolayers of C8 and C18 alkanethiols on the Au111 surface

The thermal stability of short alkanethiol CH(3)(CH(2))(7)SH (C(8)) and long C(18) self-assembled monolayers (SAMs) is investigated using grazing angle reflection-absorption infrared spectroscopy, cyclic voltammetry, and molecular dynamics simulation. We track the disordering of SAM by untilting and gauche defect accumulation with increasing temperature in the 300-440 K range, a range of interest to tribology. Molecular dynamics simulation with both fully covered and partially covered C(6), C(8), and C(18) monolayers brings out the morphological changes in the SAM, which may be associated with the observed thermal stability characteristics. The molecular dynamics simulations reveal that short-chain C(6) and C(8) alkanethiols are more defective at lower temperature than the long-chain C(18) alkanethiol. With increasing temperature disorder in the SAM, as reflected in both untilting and gauche defect accumulation, tends to saturate at temperatures below 360 K for short-chain SAMs such that any further increase in temperature, until desorption, does not lead to any significant change in conformational order. In contrast the disorder in the long-chain C(18) SAM increases monotonically with temperature beyond 360 K. Thus, in a practical range of temperature, the ability of a SAM to retain order with increasing thermal perturbations is governed by the state of disorder prior to heat treatment. This deduction derived from molecular dynamics simulation helps to rationalize the significant difference we have observed experimentally between the thermal response of short- and long-chain thiol molecules.

Chemotherapy of leprosy

The WHO MDT regimens have proved highly successful in preventing relapse of leprosy cases. It has indirectly lad to marked reduction in prevalence of disabilities. For PB leprosy, rifampicin 600 mg monthly and 100 mg dapsone daily for a total of 6 months therapy is required. For MB leprosy clofazimine 300 mg once monthly, supervised and 50 mg daily self administered is added. For single skin lesion the current WHO recommendation is 600 mg rifampicin + 400 mg ofloxacin + 100 mg minocycline given as a single dose for adults. Dose adjustment for children and clinical information have been discussed in a nutshell. A number of trials are going on, some are yet to be completed which do offer the prospect of perhaps simplifying therapy and improving with shorter duration.

Thermal stability of perfluoroalkyl silane self-assembled on a polycrystalline aluminum surface

Thermal stability behavior of 1H, 1H,2H,2H-perfluorooctyl trichlorosilane self-assembled on aluminum substrates is characterized using a grazing-angle Fourier transform infrared spectrometer, Fourier transform-Raman spectroscopy, and contact angle measurements. The self-assembled monolayer (SAM) is heated quasi-statically from room temperature to above 633 K with a heating rate of 1 K/s. Variations in peak frequencies, integrated areas of intensities of symmetric and antisymmetric CF2 stretches, and the relative tilt angle of the SAM are reported. We find that the conformational order in the SAM is not disrupted because of thermal cycling when the peak temperature is below 423 K. When the peak temperature is between 423 and 603 K, the cycling results in only a partial retention of the original order. When the peak temperature is above 603 K, the process is completely irreversible. Surface-enhanced Raman spectroscopy and contact angle measurements support these observations. We confirm these trends for a longer chain (1H,1H,2H,2H-perfluordecyl trichlorosilane) molecule of the same family using the same techniques. We discuss the possible reasons for the changes in light of the tilting-untilting and uncoiling-coiling of the helical silane monolayer.

Invitro comparative evaluation of aminoglycosides at a cancer centre

A comparative study of in vitro activity of amikacin, gentamicin, netilmicin, tobramycin and isepamicin was done. A total of 200 clinical isolates of Gram negative organisms from various clinical sources were tested. E.Coli was the most frequently isolated organism followed by Pseudomonas spp., Klebsiella spp., Proteus spp., Acinetobacter spp. and Enterobacter spp. Of the 5 aminoglycosides tested, isepamicin showed the highest numbers of susceptible isolates followed by amikacin, netilmicin, gentamicin and tobramycin. MIC 90 value of isepamicin was lower as compared to amikacin.

Posture-related tachycardia in older patients with hyponatremia

Hyponatremia (HN) is the commonest electrolyte abnormality in elderly patients. Its etiology in this setting is poorly understood. In this study, the authors aim to compare the hemodynamic and hormonal responses of a group of older patients with a predisposition to HN with a group of age-matched controls. We assessed hemodynamic and hormonal responses to postural challenge in 15 patients over age 65 with serum sodium concentrations of less than 130 mM (mean 128.7 mM) and 15 age-matched controls with normal sodium concentrations. Patients remained recumbent for 1 h and stood for the second. Blood was drawn at baseline and at 15 min intervals. Blood pressure (BP) and pulse rates (PR) were monitored electronically. Plasma arginine vasopressin (AVP), atrial natriuretic peptide (ANP), renin and aldosterone were determined periodically during the study period. No difference in BP between groups was noted. PR increased significantly in the HN group only within 3 min of standing (from 71 +/- 4 to 86 +/- 5, P<0.01) and remained significantly higher than controls until 90 min (87 +/- 5 vs. 69 +/- 4, P<0.01). While plasma AVP levels increased significantly following 30 min standing and remained elevated for both HN and control groups, it did not differ significantly between the two. Baseline plasma ANP levels were significantly higher in HN patients compared with controls and remained significantly higher (P<0.05) throughout the study. There was no significant difference in plasma renin or aldosterone levels between groups during the study period. We have demonstrated differing autonomic and hormonal responses to orthostatic challenge between HN patients and age-matched controls. Water retention due to the syndrome of inappropriate anti-diuretic hormone secretion (with reset osmostat) may lead to raised ANP levels in this older cohort of patients. Further physiological studies are required to clarify the precise mechanism of these varying responses.

Regulation of nitric oxide production by murine peritoneal macrophages treated in vitro with chemokine monocyte chemoattractant protein 1

Monocyte chemoattractant protein 1 (MCP-1) is an important mediator of monocyte/macrophage recruitment and activation at the sites of chronic inflammation and neoplasia. In the current study, the role of nitrogen monoxide (NO) in the activation of murine peritoneal macrophages to the tumoricidal state in response to in vitro MCP-1 treatment and the regulatory mechanisms involved therein were investigated. Murine peritoneal macrophages upon activation with MCP-1 showed a dose- and time-dependent production of NO together with increased tumoricidal activity against P815 mastocytoma cells. N-monomethyl-l-arginine (L-NMMA), a specific inhibitor of the l-arginine pathway, inhibited the MCP-1-induced NO secretion and generation of macrophage-mediated tumoricidal activity against P815 (NO-sensitive, TNF-resistant) cells but not the L929 (TNF-sensitive, NO-resistant) cells. These results indicated l-arginine-dependent production of NO to be one of the effector mechanisms contributing to the tumoricidal activity of MCP-1-treated macrophages. Supporting this fact, expression of iNOS mRNA was also detected in the murine peritoneal macrophages upon treatment with MCP-1. Investigating the signal transduction pathway responsible for the NO production by the MCP-1-activated murine peritoneal macrophages, it was observed that the pharmacological inhibitors wortmannin, H-7 (1-(5-isoquinoline sulfonyl)-2-methyl piperazine dihydrochloride), and PD98059 blocked the MCP-1-induced NO production, suggesting the probable involvement of phosphoinositol-3-kinase, protein kinase C, and p42/44 MAPkinases in the above process. Various modulators of calcium and calmodulin (CaM) such as EGTA, nifedipine, TMB-8 (3,4,5-trimethoxybenzoic acid-8-(diethylamino)octyl ester), A23187, and W-7 (N-(6-aminohexyl)-5-chloro-1-napthalenesulfonamide) were also found to modulate the in vitro macrophage NO release in response to MCP-1. This observation indicated the regulatory role of calcium/CaM in the process of MCP-1-induced macrophage NO production. Similarly, the role of serine/threonine and protein tyrosine phosphatases in the above pathway was suggested using the specific inhibitors of these phosphatases, okadaic acid and sodium orthovanadate.

Identification of Candida dubliniensis based on the specific amplification of mitochondrial cytochrome b gene

Candida dubliniensis, a recently described Candida species, is frequently isolated from oral candidiasis in human immunodeficiency virus infected individuals. To detect the organism rapidly, we have developed specific oligonucleotide primers based on the sequences of mitochondrial cytochrome b gene. These primers selectively amplified DNA only from C. dubliniensis; the DNAs of all pathogenic Candida species tested, as well as those of medically relevant yeasts such as Cryptococcus neoformans, and Trichosporon cutaneum, were not amplified. This is the first report describing the effectiveness of cytochrome b gene in PCR based detection of an organism, and we hope the system will be useful as a microbiological tool for rapid detection of C. dubliniensis.

Inhibition of hyphal growth of Candida albicans by activated lansoprazole, a novel benzimidazole proton pump inhibitor

The effect of activated lansoprazole (AG 2000), a novel benzimidazole proton pump inhibitor, against hypha formation of Candida albicans was examined in hypha-forming medium pH 7 (HFM7) after 20 h. AG 2000, at 50-800 microM, did not inhibit germ tube formation. However, it inhibited elongation of germ tubes to form hyphae and favored conversion of germ tubes to resume yeast growth at concentrations of > or =200 microM. Pre-treatment of AG 2000 with a sulfhydryl reagent (1:1), such as 2-mercaptoethanol. blocked the inhibitory property of AG 2000 on hypha formation.

Molecular phylogenetics of the genus Rhodotorula and related basidiomycetous yeasts inferred from the mitochondrial cytochrome b gene

Phylogenetic relationships of basidiomycetous yeasts, especially of the genus Rhodotorula, were studied using partial sequences of the mitochondrial cytochrome b gene. The results demonstrated that the basidiomycetous yeasts under investigation distributed into two main clusters: one containing Tremellales, Filobasidiales and their anamorphs and the other containing Ustilaginales, Sporidiales and their anamorphs. This clustering in turn correlates with cell wall biochemistry, presence or absence of xylose, and septal ultrastructure, dolipore or simple pore. Bullera, Bulleromyces, Filobasidiella, Cryptococcus and Trichosporon, yeasts of the former cluster, contain xylose in the cell wall and have dolipore septa. In contrast yeasts of the latter cluster, which included Bensingtonia, Erythrobasidium, Leucosporidium, Malassezia, Rhodosporidium, Rhodotorula, Sporidiobolus, Sporobolomyces and Ustilago, have no xylose in the cell wall and have a simple pore septum. Yeasts of the latter group could be further divided into four clades (A-D). Species of Rhodotorula were distributed in all of these clades, indicating the polyphyletic nature of the genus. A limited number of Rhodotorula species demonstrated identical sequences, for example Rhodotorula bacarum and Rhodotorula foliorum, Rhodotorula fujisanensis and Rhodotorula futronensis, Rhodotorula glutinis var. dairenensis and Rhodotorula mucilaginosa. However, all the other test species of the genus Rhodotorula were well separated based on their 396 bp nucleotide sequences. These results demonstrate the effectiveness of the use of cytochrome b sequences for both species identification and the study of phylogenetic relationships among basidiomycetous yeasts.

Typing of Candida albicans isolates by sequence analysis of the cytochrome b gene and differentiation from Candida stellatoidea

Including type strains, mitochondrial cytochrome b genes of 32 strains of Candida albicans and 6 strains of Candida stellatoidea, presently treated as a synonym for C. albicans, were partially sequenced. Analysis of 396-bp nucleotide sequences of the strains under investigation divided C. albicans isolates into three types: type I, type II, and type III; however, strains of C. stellatoidea represented distinct type IV isolates. Deduced amino acid sequences of type I, type II, and type III were identical and differed from that of type IV by one amino acid. Genotypes (rDNA type) of the test strains were also checked. Cytochrome b typing did not correlate with genotyping, and different genotypes occurred for one cytochrome b type. This study shows that cytochrome b gene sequences are useful for analyzing the genetic relatedness of C. albicans isolates and effective for differentiating C. stellatoidea from C. albicans.

Identification and phylogenetic relationship of the most common pathogenic Candida species inferred from mitochondrial cytochrome b gene sequences

We sequenced a 396-bp region of the mitochondrial cytochrome b gene of the most common clinically important Candida species: Candida albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, and C. lusitaniae. The recently described species of Candida, C. dubliniensis, associated with mucosal candidiasis in human immunodeficiency virus-infected individuals, was also included. Two to five strains of each species were examined. Some species represented intraspecies variation, which was not more than 1.8% (DNA). However, interspecies variations were more than 10 and 7%, respectively, for DNA and amino acid sequences. Multiple alignments of nucleotide and deduced amino acid sequences revealed species-specific nucleotides and amino acids. Nucleotide- and amino acid-based phylogenetic trees were constructed and are discussed. Using the database, it is possible to identify presumptive Candida species within a working day.

Effect of pH, carbon source and K+ on the Na+-inhibited germ tube formation of Candida albicans

The effect of pH, carbon source and K+ on the Na+ -inhibited germ tube formation of the pathogenic fungus Candida albicans was examined in the arginine-phosphate modified (APM) medium. All C. albicans cells formed germ tubes in APM medium at pH 5.0-9.0. Na+ inhibited germ tube formation in a concentration dependent manner ranging from 0.2 to 1.0 M, and was further influenced by the pH of the medium. The inhibitory effect of Na+ was lowest at pH 8.0, and germ tube formation ceased at 1.0 M Na+ for any pH (4.0-9.0). At pH > or = 6.0, non-germ tube-forming cells did not show yeast growth; whereas at pH < or = 5.0, Na+ inhibited only germ tube formation but did not inhibit yeast growth. The inhibitory effect of Na+ was stronger in glucose medium than in galactose medium as carbon source. K+, at 0-0.8 M, had almost no effect on germ tube formation. However, in the presence of Na+, a very low concentration of K+ (0.5 mM) was able to release the cells from Na+ arrest and produced an increase in the rate as well as the percentage of germ tube formation. Intracellular Na+/K+ ratios increased with the increase in extracellular Na+ concentration, whereas the ratios decreased and remained within nontoxic levels when the extracellular K+ concentration was increased.

Efficacy of single-dose ROM therapy plus low-dose convit vaccine as an adjuvant for treatment of paucibacillary leprosy patients with a single skin lesion

The recent World Health Organization multicentric field study on the treatment of paucibacillary (PB) leprosy patients with single skin lesion (SSL) and a single dose of rifampin-ofloxacin-minocycline (ROM) brought new hope to those who are engaged in the eradication of leprosy from India. Being encouraged by the WHO report, we undertook the present hospital-based study and found that PB leprosy patients with SSL were morphologically and histopathologically heterogeneous. The histological spectrum of SSL ranged from indeterminate through tuberculoid (TT) to borderline tuberculoid (BT) leprosy, and most patients had active BT leprosy. Ninety new, untreated PB leprosy patients with SSL were included in the present study for comparative assessment of the efficacies of ROM and ROM plus Convit vaccine therapies. Children, pregnant women, lactating mothers and patients with any thickening of nerves were excluded. All patients were bacteriologically negative (skin-smear test) but lepromin reactive. The patients were divided into two groups after proper matching for morphological and histological status of SSL: a) The test group included 60 patients and the control group included 30 patients. The test group was given a single dose of ROM initially and two injections of low-dose Convit vaccine, one initially and the other at the end of 3 months. b) The control group was given only a single dose of ROM initially. Both groups were followed clinically every 2 weeks for 6 months and retested for histological, bacteriological and lepromin status at the end of 6 months. Thereafter, they were followed clinically every month for another 6 months. In the test group, the SSL resolved in 33.3%, regressed in 48.3%, and remained active in 18.3% of the patients, while the granuloma disappeared in 70% of the cases. Only one patient developed neuritis, and in another patient the disease relapsed on the eighth month. On the other hand, the SSL in the control patients resolved, regressed and remained active in 13.3%, 63.3% and 23.3% of the cases, respectively, while the granuloma disappeared in 53.3% of the cases. In the seven patients who remained active, the disease course was progressive, and two of them developed neuritis. The clinical outcome of the patients treated with ROM plus low-dose Convit vaccine was statistically superior to those treated with single-dose ROM therapy alone.

Activation of murine bone-marrow derived macrophages in vitro with Thymosin-alpha-1 to tumoricidal state: a comparative study on normal and tumour-bearing hosts

The present investigation establishes the ability of Thymosin alpha l (T alpha l) to activate murine bone-marrow derived macrophages (BMDMs) in vitro to tumoricidal state with concomitant release of NO, TNFalpha and IL-1. The T alpha l-induced cytotoxicity and the secretion of soluble lytic factors were both dose- and time dependent. BMDMs cultured from the Dalton's Lymphoma bearing mice (DL-BMDMs) exhibited reduced cytolytic activity towards DL-tumour target cells on activation with T alpha l as compared to the BMDMs obtained from normal mice (N-BMDMs). The DL-BMDMs displayed enhanced TNFalpha and IL-1 release as compared to the N-BMDMs when treated with T alpha l. On the other hand, it is observed that the production of NO and the expression of iNOS was higher in the N-BMDMs as compared to the DL-BMDMs on treatment with T alpha l. Although T alpha l could trigger the tumoricidal functions of BMDMs from normal and DL-tumor bearing hosts, the progressive growth of DL-tumour in ascitic form leads to an alteration in the antitumour response of macrophages. These observations further suggest that a disregulation in the production of inflammatory cytokines like TNF-alpha, IL-1 and the inhibition of NO production in response to DL growth may mutually contribute in explaining the tumour-induced immunosuppression as observed in the DL-bearing mice.

Glycaemic index of parboiled rice depends on the severity of processing: study in type 2 diabetic subjects

OBJECTIVE

To study the influence of parboiling and the severity of the process on glycaemic and insulinaemic responses to rice in type 2 diabetes. Moreover, to examine changes in starch structure related to parboiling, which may affect the metabolic responses and digestibility.

DESIGN

Nine type 2 diabetic subjects ingested four test meals: white bread (WB) and three meals of cooked polished rice of the same variety being non-parboiled (NP), mildly traditionally parboiled (TP) and severely pressure parboiled (PP). The participants ingested the test meals (50 g available carbohydrates) on separate occasions after an overnight fast.

SETTING

Outpatient clinic, Dept. Endocrinology and Metabolism, Aarhus University Hospital, Denmark.

RESULTS

All three rice samples elicited lower postprandial plasma glucose response (NP: 335+/-43; TP: 274+/-53; PP: 231+/-37 mmol/1*180 min.; means+/-s.e.m.) than white bread (626+/-80; P<0.001), within rice samples PP tended to be lower than NP (P=0.07). The glycaemic indices were: NP: 55+/-5, TP: 46+/-8 and PP: 39+/-6, and lower for PP than NP (P<0.05). The insulin responses were similar for the three rice meals, which were all lower than that to white bread (P<0.001). Differential scanning calorimetry showed the presence of amylose-lipid complexes in all rice samples and of retrograded amylopectin in PP. Amylose retrogradation was not detected in any of the rice samples.

CONCLUSIONS

All rice test meals were low-glycaemic in type 2 diabetic subjects. There was no effect of TP on glycaemic index, whereas PP reduced the glycaemic index by almost 30% compared to NP.

SPONSORSHIP

The Royal Veterinary and Agricultural University, Aarhus University Hospital, Danish International Development Assistance (DANIDA), Ministry of Foreign Affairs and the 'Konsul Johannes Fogh-Nielsens og Fru Ella Fogh-Nielsens Legat' foundation.

Measurement of surface alpha contamination using electret ion chambers

Electret ion chambers are inexpensive, light-weight, commercially available, passive charge-integrating devices for accurate measurement of different radiations. Performance of electret ion chambers for surface alpha contamination measurement was evaluated. Ion chambers of two types and electrets of three thicknesses were used for the study. Calibration of the electret ion chambers was performed using reference alpha standards of different energies and radioactivities. Effects of various parameters such as chamber dimensions, electret thickness, alpha particle energy, position of alpha source from the chamber centerline, source localized or uniformly distributed, level of alpha contamination, Mylar window covering the chamber, and ambient radon and gamma radiation on the response of the electret ion chambers were determined. Suitable combinations of chambers and electrets to measure surface alpha contamination were determined.

Fungistatic and fungicidal activities of murine polymorphonuclear leucocytes against yeast cells of Paracoccidioides brasiliensis

Recently, a novel culture medium for detecting live yeast cells of Paracoccidioides brasiliensis was developed by Kurita et al. Using this culture medium, murine peritoneal polymorphonuclear leucocytes (PMN) were examined for fungistatic and fungicidal activities against P. brasiliensis yeast cells. The magnitude of the antifungal effect of PMN varied depending upon the fungal isolates used. PMN exhibited a killing effect on P. brasiliensis isolate Bt-4 in 2 h of coculture. In contrast, the other three fungal isolates employed were resistant to killing by PMN. However, PMN considerably suppressed the growth of isolates Tatu and Recife in a long-term assay (approximately 72 h). The growth of isolate Bt-9 was also suppressed by PMN during the first 24 h, but was found to be considerably promoted at 72 h of coculture. Interferon-gamma (IFN-gamma), but not tumour-necrosis factor-alpha, significantly augmented the antifungal activity of PMN. IFN-gamma-treated PMN exhibited a killing effect on isolates Tatu, Recife and Bt-9 after 24 h of coculture, and showed an enhanced killing effect on isolate Bt-4. Contact between PMN and fungal cells was required for PMN to exert the antifungal effect. Our results suggest that PMN, whether activated with cytokines or not, might play a critical role in host resistance in early infection with this fungus by buying time for development of more effective immunologic responses.

Influenza virus nucleoprotein interacts with influenza virus polymerase proteins

Influenza virus nucleoprotein (NP) is a critical factor in the viral infectious cycle in switching influenza virus RNA synthesis from transcription mode to replication mode. In this study, we investigated the interaction of NP with the viral polymerase protein complex. Using coimmunoprecipitation with monospecific or monoclonal antibodies, we observed that NP interacted with the RNP-free polymerase protein complex in influenza virus-infected cells. In addition, coexpression of the components of the polymerase protein complex (PB1, PB2, or PA) with NP either together or pairwise revealed that NP interacts with PB1 and PB2 but not PA. Interaction of NP with PB1 and PB2 was confirmed by both coimmunoprecipitation and histidine tagging of the NP-PB1 and NP-PB2 complexes. Further, it was observed that NP-PB2 interaction was rather labile and sensitive to dissociation in 0.1% sodium dodecyl sulfate and that the stability of NP-PB2 interaction was regulated by the sequences present at the COOH terminus of NP. Analysis of NP deletion mutants revealed that at least three regions of NP interacted independently with PB2. A detailed analysis of the COOH terminus of NP by mutation of serine-to-alanine (SA) residues either individually or together demonstrated that SA mutations in this region did not affect the binding of NP to PB2. However, some SA mutations at the COOH terminus drastically affected the functional activity of NP in an in vivo transcription-replication assay, whereas others exhibited a temperature-sensitive phenotype and still others had no effect on the transcription and replication of the viral RNA. These results suggest that a direct interaction of NP with polymerase proteins may be involved in regulating the switch of viral RNA synthesis from transcription to replication.

Influenza virus polymerase basic protein 1 interacts with influenza virus polymerase basic protein 2 at multiple sites

Three polymerase proteins of influenza type A virus interact with each other to form the active polymerase complex. Polymerase basic protein 1 (PB1) can interact with PB2 in the presence or absence of polymerase acidic protein. In this study, we investigated the domains of PB1 involved in complex formation with PB2 in vivo, using coexpression and coimmunoprecipitation of the PB1-PB2 complex with monospecific antibodies. Results show that PB1 possesses at least two regions which can interact independently and form stable complexes with PB2. Both of these regions are located at the NH2 terminus of PB1; the COOH-terminal half of PB1 is not involved in interacting with PB2. Deletion analysis further demonstrated that the interacting regions of PB1 encompass amino acids (aa) 48 to 145 and aa 251 to 321. Linker insertions throughout the PB1 sequences did not affect complex formation with PB2. Deletion and linker-insertion mutants of PB1 were tested for polymerase activity in vivo. For this analysis, we developed a simplified assay for viral polymerase activity that uses a reporter chloramphenicol acetyltransferase gene containing the 5' and 3' ends of influenza viral promoter and nontranslating regions (minus sense) of the NS gene joined to a hepatitis delta virus ribozyme at its 3' end. This assay demonstrated that all deletion mutants of PB1 exhibited either background or greatly reduced polymerase activity irrespective of the ability to interact with PB2 and that all linker-insertion mutants except one at the extreme COOH end (L-746) of PB1 were also negative for viral polymerase activity. These results show that compared with complex formation of PB1 with PB2, the polymerase activity of PB1 was extremely sensitive to structural perturbation.

The medical care services at cross-roads

Our hospitals of all types and sizes present a dismal picture and have miserably failed to meet the rising demands of its consumers, in terms of technology, quality, quantity and cost of care. The situation prevailing has been documented in various press reports and cases registered to the consumer forums in the country. The author while presenting the maladies involving the hospitals has made an attempt to analyse the cause and effect relationship of the maladies and suggested remedial measures. More emphasis has been laid on economic use of resources, cost containment, training and motivation of all categories of staff, and introduction of quality management techniques to improve functional efficiency for better output, in terms of quality, quantity, cost of care and consumer satisfaction.

Mutational analysis of the conserved motifs of influenza A virus polymerase basic protein 1

Influenza virus polymerase complex is a heterotrimer consisting of polymerase basic protein 1 (PB1), polymerase basic protein 2 (PB2), and polymerase acidic protein (PA). Of these, only PB1, which has been implicated in RNA chain elongation, possesses the four conserved motifs (motifs I, II, III, and IV) and the four invariant amino acids (one in each motif) found among all viral RNA-dependent RNA or RNA-dependent DNA polymerases. We have modified an assay system developed by Huang et al. (T.-J. Huang, P. Palese, and M. Krystal, J. Virol. 64:5669-5673, 1990) to reconstitute the functional polymerase activity in vivo. Using this assay, we have examined the requirement of each of these motifs of PB1 in polymerase activity. We find that each of these invariant amino acids is critical for PB1 activity and that mutation in any one of these residues renders the protein nonfunctional. We also find that in motif III, which contains the SSDD sequence, the signature sequence of influenza virus RNA polymerase, SDD is essentially invariant and cannot accommodate sequences found in other RNA viral polymerases. However, conserved changes in the flanking sequences of SDD can be partially tolerated. These results provide the experimental evidence that influenza virus PB1 possesses a similar polymerase module as has been proposed for other RNA viruses and that the core SDD sequence of influenza virus PB1 represents a sequence variant of the GDN in negative-stranded nonsegmented RNA viruses, GDD in positive-stranded RNA virus and double-stranded RNA viruses, or MDD in retroviruses.

Status of nitric oxide free radicals in diabetic neutrophils: effect of diabetic serum factor on the generation of these species in normal neutrophils and their relation to lysosomal degranulation

Normal polymorphonuclear leukocytes (PMNL) in contrast to diabetic PMNL, generated significant amounts of .NO and NO2 when challenged with opsonised zymosan. Diabetic neutrophils, on the other hand, responded either weakly or insignificantly to the same stimulants. However, in resting state the levels of .NO and NO2 were higher in diabetic as compared to normal PMNL. Diabetic serum factor (DSF) provoked a significant generation of .NO and NO2 in normal PMNL, a phenomenon found parallel to the enhancement in cytosolic cathepsin D activity in normal cells on insult with DSF.

Effect of tri-ortho-cresyl phosphate on hen nervous system

Correlation of tri-ortho-cresyl phosphate (TOCP) toxicity with clinical symptoms and inhibition patterns of neurotoxic esterase (NTE) in different regions of the central nervous system was studied in hens. The total content of NTE in spinal cord and peripheral nerves was relatively much lower than that of the brain, about 29 and 4.8 per cent respectively. Brain and spinal cord NTE was inhibited to 75 and 67 per cent respectively on day 1 post-TOCP treatment, and 91 and 84 per cent respectively on day 2, while the activity of the enzyme in peripheral nerve was inhibited to 92 per cent on day 1. However, the clinical manifestations of paralysis appeared after 7-8 days of TOCP treatment. It can be concluded that the presence of NTE in very low quantities in the peripheral nerves and its almost complete inhibition as compared to that of brain and spinal cord, could be of great significance in the development of neurotoxicity.

Agenesis of posterior urethra in a male child and its operative reconstruction

An 8-year-old boy passing urine through both fecal and urinary outlets since birth is reported. Investigations showed absence of the posterior urethra. A surgical procedure for reconstruction of the posterior urethra is described. The embryological explanation is also discussed.

A 14-kilodalton inner membrane protein of Vibrio cholerae biotype e1 tor confers resistance to group IV choleraphage infection to classical vibrios

Choleraphage phi 149 differentiates the two biotypes, classical and el tor, of Vibrio cholerae. This phage cannot replicate in V. cholerae biotype el tor cells because the concatemeric DNA intermediates produced are unstable and cannot be chased to mature phage DNA. A V. cholerae biotype el tor gene coding for a 14,000-Da inner membrane protein which destabilizes the concatemeric DNA intermediates by hindering their binding to the cell membrane has been identified. Presumably, a 22,000-Da V. cholerae biotype el tor protein might also have a role in conferring phage phi 149 resistance to cells belonging to the biotype el tor. A nucleotide sequence homologous to the 1.2-kb V. cholerae biotype el tor DNA coding for both the 14,000- and 22,000-Da proteins is present in all strains of classical vibrios but is not transcribed. The nucleotide sequence of the gene coding for the 14,000-Da protein has been determined.

An unusual case of heteropagus twinning

A 3-day-old boy baby presented with a cystic umbilical swelling covered mostly by skin and partly by amnion. On the surface, an early embryo-like structure was attached (facial features and limb buds). The deeper aspect of it was composed of large cystic and tubular structures and solid organs resembling liver and spleen. It was labeled as acardiac amorphous parasitic twin, the first of its kind to be reported.

Urine level of trace elements in some adults in Bangladesh under a workplace environment

The urine level of trace elements has been investigated in some normal adults under different workplace environments in Bangladesh. The samples were collected from 58 subjects, randomly selected from about 500 adults working in 10 different workshops and factories located in Dhaka city. Samples were analyzed by the external beam PIXE method. Proton beams of 2.5 MeV energy and 20 nA intensity were used for sample irradiations. For 40 microC irradiations, the concentration of 14 elements in total (K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Sr and Mo) in different groups were measured by comparison with a calibration curve obtained from the NBS Orchard Leaf standard (SRM 1571). The results from different workplaces are reported in terms of amount of excretion per unit volume of the sample collected. They, however, do not reflect the total daily excretion level of different subject groups.

Subtotal cystectomy and antirefluxing hepaticoduodenostomy for choledochus cyst in children

Total cystectomy with Roux-en-Y hepaticojejunostomy for choledochus cyst often causes malabsorption and other problems as a result of jejunal biliary diversion bypassing the duodenum. Restoration of near normal anatomy can only return the normal physiological harmony and assure normality. A simple antirefluxing hepaticoduodenostomy has proved successful.

Cultivation of Mycobacterium leprae in artificial culture medium

A novel procedure in the cultivation of M. leprae in combined Dubos-Lowenstein-Jenson medium after addition of thyroxine sodium is being reported. This has been found to be successful as the organisms, after multiplying vigorously in the thyroxine containing Dubos medium, have produced a visible colony on the surface of Lowenstein-Jensen medium during 8-16 wks of incubation at 37 degrees C. The enhanced growth of this recalcitrant organism is due to stimulating effect of thyroxine as well as supply of ready-made basic nutrients in the synthetic Dubos medium. Intradermal inoculation of the bacterial suspension from the subculture into the foot pad of cortisone treated mouse revealed an early appearance of specific histological lesion of leprosy with infiltration of nerve fibres by lepra cells. The methodology, described here for in-vitro cultivation, may open out a new era in the preparation of purified vaccine, the study of in-vitro drug sensitivity, and as such ensure rapid eradication of leprosy.

Abortive replication of choleraphage phi 149 in Vibrio cholerae biotype el tor

Choleraphage phi 149 adsorbed irreversibly to Vibrio cholerae biotype el tor cells, and 50% of the injected phage DNA bound to the cell membrane. Although no infectious centers were produced at any time during infection, the host macromolecular syntheses were shut off and the host DNA underwent chloramphenicol-inhibitable degradation. Synthesis of monomeric phage DNA continued similar to that observed in the permissive host. However, the concatemeric DNA intermediates produced were unstable and could not be chased to mature phage DNA. Pulse-labeling of UV-irradiated infected cells at different times during infection allowed identification of phage-specific proteins made in this nonpermissive host. Although most of the early proteins were made, only some of the late proteins were transiently synthesized.

Selective devascularisation of stomach and lienopulmopexy for prevention of bleedings in portal hypertension in children

Dissatisfied with different operative procedures for prevention of recurrent bleedings in childhood portal hypertension, many surgeons nowadays treat their patients conservatively during episodic attacks and advocate one of the shunt procedures in adolescence when the splenic vein becomes sufficiently widened (more than 1 cm). Even then mortality cannot be avoided in some bad risk patients especially those living in remote villages lacking facilities for blood transfusion and high speed transport service. In this situation thoracic transposition of spleen and lienopulmopexy was advocated by Nylander and Turumen, Auvert, M. Bettex and others. We prefer a further simpler procedure and perform selective devascularisation of stomach and lienopulmopexy. It allows rapid development of collaterals between splenic pulps on the portal side and subpleural venous plexus on the systemic side to achieve effective gastric devascularisation to prevent further bleeding without hindering the existing portal flow through the liver to avoid the possible occurrence of encephalopathy. Of 21 operated cases one died on the 5th postoperative day and the remaining 20 are doing well. 1/2-5 1/2 years' follow-up revealed negligible morbidity and no recurrence of bleeding in any of them. Both procedures work on the same principle.

Multielement proton-induced X-ray emission analysis of betel leaves, betel nuts, and lime

Proton-induced X-ray emission (PIXE) method was employed to study the concentration of heavy elements in betel leaves, betel nuts, and mineral lime consumed in Bangladesh. The samples were collected from different parts of Bangladesh and analyzed by the thicktarget external beam technique of the PIXE method. The samples were exposed to the proton beam as 1-mm thick pellets and irradiated with 2.0-MeV protons having 20-nA beam intensity. The concentration of some 15 elements (K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, and Pb) was measured by comparison with a calibration curve constructed from the NBS orchard leaf standard SRM 1571. The validity of the procedure has been established by comparative measurements of Cu and Zn with atomic absorption spectrophotometry. The significance of the results is discussed in view of their implications in health and disease.

Multielement proton-induced X-ray emission analysis of Bangladeshi tobacco

The concentration of 12 different elements in cigarette tobacco of different brands, commercially made in Bangladesh, was determined using the proton particle-induced x-ray emission (proton PIXE) method. In all the present experiments, proton beams of 2.0 MeV (on the target in air) and about 30 nA current were used for characteristic x-ray excitation. The concentration of the elements (K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb and Sr) was determined by comparison with a calibration obtained from the NBS orchard leaf standard, SRM 1571. The results have been compared with available data on some foreign brands of tobacco and the probable reasons for the difference in the contents of some of the elements found in the Bangladeshi brands are discussed.