Fatal complications of systemic lupus erythematosus--an autopsy study from north India

Systemic lupus erythematosus (SLE) is a multisystem, autoimmune disease with varied clinical manifestations and outcome. It may prove fatal due to disease activity or intercurrent infections. In recent years, earlier diagnosis and better treatment modalities have resulted in a change in the pattern of organ involvement and mode of death in the west. This aspect of the disease is unknown in India. Hence, in this autopsy series of SLE, the organ involvement and cause of death have been studied. Twenty five cases of clinically diagnosed SLE have been analysed retrospectively. Renal involvement was invariably present (96%) with class IV being the commonest lesion in 60% cases. Disease activity was noted in 60% cases. Pleuro pulmonary lesions were seen in 92% cases with infection being the commonest. Pulmonary infections included bacterial pneumonias (13), disseminated tuberculosis (3), pulmonary mucormycosis (1) and aspergillosis (1). Massive pulmonary haemorrhage in 5 cases and acute lupus pneumonitis in one, contributed to the demise of the patient. Vasculitis was evident in single organ in 9 cases, in two or more organs in 3 cases with systemic vasculitis significantly attributing to morbidity in 1 case. Active disease was the cause of death in 60% cases and infection in 40%.

Role of NH(2)- and COOH-terminal domains of the P protein of human parainfluenza virus type 3 in transcription and replication

The phosphoproteins (P proteins) of paramyxoviruses play a central role in transcription and replication of the viruses by forming the RNA polymerase complex L-P and encapsidation complex (N-P) with nucleocapsid protein (N) and binding to N protein-encapsidated genome RNA template (N-RNA template). We have analyzed the human parainfluenza virus type 3 (HPIV3) P protein and deletion mutants thereof in an in vitro transcription and in vivo replication system. The in vitro system utilizes purified N-RNA template and cell extract containing L and P proteins coexpressed via plasmids using a recombinant vaccinia virus expression system. The in vivo system takes advantage of minigenome replication, which measures luciferase reporter gene expression from HPIV3 minigenomes by viral proteins in a recombinant vaccinia virus expression system. These studies revealed that the C-terminal 20-amino-acid region of P is absolutely required for transcription in vitro and luciferase expression in vivo, suggesting its critical role in viral RNA synthesis. The N-terminal 40-amino-acid region, on the other hand, is essential for luciferase expression but dispensable for transcription in vitro. Consistent with these findings, the C-terminal domain is required for binding of P protein to the N-RNA template involved in both transcription and replication, whereas the N-terminal domain is required for the formation of soluble N-P complex involved in encapsidation of nascent RNA chains during replication. Coimmunoprecipitation analysis showed that the P protein forms a stable homooligomer (perhaps a trimer) that is present in L-P and N-P complexes in the higher oligomeric forms (at least a pentamer). Interestingly, coexpression of a large excess of N- or C-terminally deleted P with wild-type P had no effect on minigenome replication in vivo, notwithstanding the formation of heterooligomeric complexes. These data indicate that P protein with a deleted terminal domain can function normally within the P heterooligomeric complex to carry out transcription and replication in vivo.

Analysis of RNA secondary structure in replication of human parainfluenza virus type 3

The terminal RNA regions of the genomic and antigenomic RNAs of the paramyxoviruses and rhabdoviruses are known to contain sequences essential for RNA replication and transcription. The 3'- and 5'-termini of human parainfluenza virus type 3 (HPIV3) genomic RNA, termed leader and trailer sequences, respectively, are capable of forming stable stem-loop structures. Additionally, the 17 terminal bases of the leader and trailer are complementary and therefore also capable of forming a helical structure. We investigated the roles of the stem-loop structure and terminal complementarity in HPIV3 RNA replication and transcription in vivo using a minigenome containing all RNA elements necessary for these processes. By mutational analysis, we show that the RNA secondary structure features present at the termini of HPIV3 have no discernible role in replication or transcription. Rather, the primary sequence of these regions is what is critical in promoting replication. Interestingly, a mutation at leader base 24 was found to revert a mutation at leader position 5 but probably not via RNA secondary structure restoration.

Specific phosphorylated forms of glyceraldehyde 3-phosphate dehydrogenase associate with human parainfluenza virus type 3 and inhibit viral transcription in vitro

We previously reported specific interaction of cellular glyceraldehyde 3-phosphate dehydrogenase (GAPDH), the key glycolytic enzyme, and La protein, the RNA polymerase III transcription factor, with the cis-acting RNAs of human parainfluenza virus type 3 (HPIV3) and packaging of these proteins within purified virions (B. P. De, S. Gupta, H. Zhao, J. Z. Drazba, and A. K. Banerjee, J. Biol. Chem. 271:24728-24735, 1996). To gain further insight into these molecular interactions, we analyzed the virion-associated GAPDH and La protein using two-dimensional gel electrophoresis and immunoblotting. The GAPDH was resolved into two major and one minor molecular species migrating in the pI range of 7.6 to 8.3, while the La protein was resolved into five molecular species in the pI range of 6.8 to 7.5. The GAPDH isoforms present in the virions were also detected in the cytoplasmic fraction of CV-1 cell extract, albeit as minor species. On the other hand, the multiple molecular forms of La protein as seen within the virions were readily detected in the total CV-1 cell extract. Further analysis of virion-associated GAPDH by in vivo labeling with [(32)P]orthophosphate revealed the presence of multiple phosphorylated species. The phosphorylated species were able to bind specifically to the viral cis-acting 3' genome sense RNA but failed to bind to the leader sense RNA, as determined by gel mobility shift assay. In contrast, the La protein isoforms present within the virions were not phosphorylated and bound to the viral cis-acting RNAs in a phosphorylation-independent manner. The GAPDH isoforms purified from the CV-1 cell cytoplasmic fraction inhibited viral transcription in vitro. Consistent with this, flag-tagged recombinant GAPDH synthesized by using the vaccinia virus expression system also inhibited viral transcription. Together, these data indicate that specific phosphorylated forms of GAPDH associate with HPIV3 and are involved in the regulation of virus gene expression.

Precise mapping of the replication and transcription promoters of human parainfluenza virus type 3

The terminal RNA regions of the genomic and antigenomic RNAs of the paramyxoviruses and rhabdoviruses are known to contain sequences essential for directing RNA replication and transcription. The 3' terminus (leader region) of the negative-sense, genomic RNA of the rhabdoviruses and paramyxoviruses is known as the leader (Le) promoter and directs synthesis of positive-sense replication and transcription products. The 3' terminus of the antigenome is termed the trailer complementary (TrC) promoter and directs the synthesis of genomic RNA. By creating mutations in the corresponding regions of an HPIV3 minireplicon in which the viral protein coding sequences were replaced by the luciferase gene, we were able to precisely define the elements of the leader promoter involved in directing positive-strand replication of HPIV3. Nucleotides 1 through 12 (from the terminus) formed a domain critical for replication. The region from nucleotides 13 through 55 was important but not crucial for replication, while G residues at positions 79, 85, and 91 comprised another domain critical for replication. It was also shown that the TrC promoter is similar, though not identical, to the Le promoter. Nucleotides 1 through 12 of the TrC promoter were critical for synthesis of genomic RNA, though specific positions behaved differently from the corresponding positions of the Le promoter. While many of these mutations could not be analyzed for transcription because they completely abrogated genomic RNA synthesis (the template for transcription), we were surprised to find that no mutations in the leader promoter which decreased replication had any significant effect on transcription. However, mutations in the intergenic sequence and gene start signal following the leader and preceding the luciferase message severely decreased transcription, but not replication.

The phosphoprotein of rabies virus is phosphorylated by a unique cellular protein kinase and specific isomers of protein kinase C

The phosphoprotein (P) gene of rabies virus (CVS strain) was cloned and expressed in bacteria. The purified protein was used as the substrate for phosphorylation by the protein kinase(s) present in cell extract prepared from rat brain. Two distinct types of protein kinases, staurosporin sensitive and heparin sensitive, were found to phosphorylate the P protein in vitro by the cell extract. Interestingly, the heparin-sensitive kinase was not the ubiquitous casein kinase II present in a variety of cell types. Further purification of the cell fractions revealed that the protein kinase C (PKC) isomers constitute the staurosporin-sensitive kinases alpha, beta, gamma, and zeta, with the PKCgamma isomer being the most effective in phosphorylating the P protein. A unique heparin-sensitive kinase was characterized as a 71-kDa protein with biochemical properties not demonstrated by any known protein kinases stored in the protein data bank. This protein kinase, designated RVPK (rabies virus protein kinase), phosphorylates P protein (36 kDa) and alters its mobility in gel to migrate at 40 kDa. In contrast, the PKC isoforms do not change the mobility of unphosphorylated P protein. RVPK appears to be packaged in the purified virions, to display biochemical characteristics similar to those of the cell-purified RVPK, and to similarly alter the mobility of endogenous P protein upon phosphorylation. By site-directed mutagenesis, the sites of phosphorylation of RVPK were mapped at S(63) and S(64), whereas PKC isomers phosphorylated at S(162), S(210), and S(271). Involvement of a unique protein kinase in phosphorylating rabies virus P protein indicates its important role in the structure and function of the protein and consequently in the life cycle of the virus.

Involvement of actin microfilaments in the transcription/replication of human parainfluenza virus type 3: possible role of actin in other viruses

Multifunctional involvement of actin microfilaments during viral infection has been documented in many studies. The molecular mechanism underlying this important host-virus interaction, however, remains poorly understood. We have investigated the role of actin microfilaments in the life cycle of human parainfluenza virus type 3 (HPIV3), a paramyxovirus that causes severe respiratory illness in children. In vitro transcription with purified viral ribonucleoprotein (RNP) complex showed a requirement of cellular actin, in the polymeric form, for mRNA synthesis in vitro. This was further confirmed by using recombinant actin, which interacted with the viral RNP and also activated mRNA synthesis in vitro. Consistent with the role of the polymeric form of actin, the actin microfilaments of the cytoskeletal framework participate in the virus replication in vivo. Biochemical and immunological analyses revealed the association of viral RNPs with cytoskeletal framework during early stages of infection, and involvement of these RNPs in the synthesis of mRNAs and genome-length RNA. Immunofluorescent labeling and confocal microscopy showed that the viral nucleocapsids colocalize with the actin microfilaments. Treatment of cells with cytochalasin D, which depolymerizes actin microfilaments, inhibited viral RNA synthesis and RNP accumulation. These data indicate that actin microfilaments play a critical role in HPIV3 life cycle, specifically at the level of viral transcription and replication. Involvement of the cytoskeletal framework in the life cycle of several viruses containing RNA and DNA genomes is reviewed.

MRI of the brain in HIV-positive patients: what is the value of routine intravenous contrast medium?

Our purpose was to assess the value of routine administration of intravenous gadolinium-DTPA (Gd-DTPA) for cranial MR in a series of human immunodeficiency virus (HIV)-positive patients. Two radiologists retrospectively reviewed 150 consecutive examinations of 104 patients. All patients underwent unenhanced and contrast-enhanced images. Each radiologist independently assessed first the unenhanced images alone and then the pre- and postinjection images together. Then both reviewed the complete study and produced a consensus report. The history, investigations and management were collated separately and were unknown to the radiologists. Contrast-enhanced T1-weighted images showed new focal abnormalities, not seen on the T2-weighted or unenhanced images in 15 (14 %) patients, but almost always in the context of abnormal unenhanced images. In only 2 patients (2 %) did contrast medium reveal abnormalities when the unenhanced study had been considered normal. In only 1 of these (1 %) was the new finding, cytomegalovirus diffuse ependymal enhancement, of clinical importance, although the diagnosis of encephalitis was made on routine examination of cerebrospinal-fluid. The other revealed a toxoplasma lesion in a patient known to have resolving disease. Meningeal disease not suspected on the unenhanced images was shown in 2 patients (2 %). In these case the unenhanced images were abnormal in other respects. Intravenous Gd-DTPA was helpful to the radiologist in making a radiological diagnosis in 11 patients (11 %), usually by improving characterisation of a lesion seen on the unenhanced images. The contribution of intravenous Gd-DTPA in this series does not warrant recommending its use in every case.

Optimal replication activity of vesicular stomatitis virus RNA polymerase requires phosphorylation of a residue(s) at carboxy-terminal domain II of its accessory subunit, phosphoprotein P

The phosphoprotein, P, of vesicular stomatitis virus (VSV) is a key subunit of the viral RNA-dependent RNA polymerase complex. The protein is phosphorylated at multiple sites in two different domains. We recently showed that specific serine and threonine residues within the amino-terminal acidic domain I of P protein must be phosphorylated for in vivo transcription activity, but not for replication activity, of the polymerase complex. To examine the role of phosphorylation of the carboxy-terminal domain II residues of the P protein in transcription and replication, we have used a panel of mutant P proteins in which the phosphate acceptor sites (Ser-226, Ser-227, and Ser-233) were altered to alanines either individually or in various combinations. Analyses of the mutant proteins for their ability to support replication of a VSV minigenomic RNA suggest that phosphorylation of either Ser-226 or Ser-227 is necessary for optimal replication activity of the protein. The mutant protein (P226/227) in which both of these residues were altered to alanines was only about 8% active in replication compared to the wild-type (wt) protein. Substitution of alanine for Ser-233 did not have any adverse effect on replication activity of the protein. In contrast, all the mutant proteins showed activities similar to that of the wt protein in transcription. These results indicate that phosphorylation of the carboxy-terminal domain II residues of P protein are required for optimal replication activity but not for transcription activity. Furthermore, substitution of glutamic acid residues for Ser-226 and Ser-227 resulted in a protein that was only 14% active in replication but almost fully active in transcription. Taken together, these results, along with our earlier studies, suggest that phosphorylation of residues at two different domains in the P protein regulates its activity in transcription and replication of the VSV genome.

Carboxy-terminal five amino acids of the nucleocapsid protein of vesicular stomatitis virus are required for encapsidation and replication of genome RNA

The encapsidation of vesicular stomatitis virus (VSV) genome RNA, a prerequisite step to the replication process by the nucleocapsid protein (N) was studied by its ability to package VSV leader RNA in vitro in a RNase-resistant form. The VSV leader RNA was derived from the SP6 transcription vector while the N protein was made in rabbit reticulocyte lysate. The in vitro encapsidation was carried out by translating N mRNA in the presence of 32P-labeled presynthesized leader RNA. The RNA encapsidation property of the N protein was completely abrogated when the C-terminal five amino acids (VEFDK-COOH) were deleted. Systematic mutational analyses within the C-terminal five amino acid regions reveal that the RNA encapsidation activity was lost in all mutants except K --> A and K --> R, indicating that C-terminal five amino acids, in particular the lysine residue play critical role in genome RNA encapsidation. To correlate the in vitro encapsidation abilities of these mutant N proteins with genome RNA replication, we have used a full-length cDNA clone of VSV genome RNA to rescue infectious virions from cells expressing L, P, and wt or mutant N proteins and measured the recovery of plaque forming units. The results indicate that the N mutants that are defective in in vitro encapsidation of leader RNA do not support replication, establishing the requirement of C-terminal five amino acids of the N protein in viral replication.

Pentazocine-induced fibromyositis and contracture

We report a case of myopathy, accompanied by widespread contractures predominantly involving the elbow and knee joints, following long-standing pentazocine abuse.

Spermatocytic seminoma: a cytology and histology case report with review of the literature

Fine-needle aspiration cytology (FNAC) findings are described in a case of spermatocytic seminoma occurring in a 52-yr-old male, involving the left testis. The smears showed three populations of cells (small, medium, and large), with a preponderance of medium-sized cells showing visible nucleoli. The background was clean, in contrast to the "tigroid" substance seen in classical seminoma. Low mitotic rate and absence of lymphocytes were the other features helpful in diagnosis. Because of these distinct morphological features, a preoperative diagnosis of spermatocytic seminoma was possible, with subsequent confirmation on histopathology. The case is being reported because of the rarity of this tumor, and because there have been only a few reported cases of FNAC diagnosis.

Human parainfluenza virus type 3 up-regulates major histocompatibility complex class I and II expression on respiratory epithelial cells: involvement of a STAT1- and CIITA-independent pathway

Human parainfluenza virus type 3 (HPIV3) infection causes severe damage to the lung epithelium, leading to bronchiolitis, pneumonia, and croup in newborns and infants. Cellular immunity that plays a vital role in normal antiviral action appears to be involved, possibly because of inappropriate activation, in the infection-related damage to the lung epithelium. In this study, we investigated the expression of major histocompatibility complex (MHC) class I and II molecules on human lung epithelial (A549) and epithelium-like (HT1080) cells following HPIV3 infection. MHC class I was induced by HPIV3 in these cells at levels similar to those observed with natural inducers such as beta and gamma interferon (IFN-beta and -gamma). MHC class II was also efficiently induced by HPIV3 in these cells. UV-irradiated culture supernatants from infected cells were able to induce MHC class I but not MHC class II, suggesting involvement of released factors for the induction of MHC class I. Quantitation of IFN types I and II in the culture supernatant showed the presence of IFN-beta as the major cytokine, while IFN-gamma was undetectable. Anti-IFN-beta, however, blocked the HPIV3-mediated induction of MHC class I only partially, indicating that viral antigens, besides IFN-beta, are directly involved in the induction process. The induction of MHC class I and class II directed by the viral antigens was confirmed by using cells lacking STAT1, an essential intermediate of the IFN signaling pathways. HPIV3 induced both MHC class I and class II molecules in STAT1-null cells. Furthermore, MHC class II was also induced by HPIV3 in cells defective in class II transactivator, an important intermediate of the IFN-gamma-mediated MHC class II induction pathway. Together, these data indicate that the HPIV3 gene product(s) is directly involved in the induction of MHC class I and II molecules. The induction of MHC class I and II expression by HPIV3 suggests that it plays a role in the infection-related immunity and pathogenesis.

Hyponatraemia and seizures after ecstasy use

A patient presented to our unit with seizures and profound hyponatraemia after ingestion of a single tablet of ecstasy. The seizures proved resistant to therapy and ventilation on the intensive care unit was required. Resolution of the seizures occurred on correction of the metabolic abnormalities. The pathogenesis of seizures and hyponatraemia after ecstasy use is discussed. Ecstasy use should be considered in any young patient presenting with unexplained seizures and attention should be directed towards electrolyte levels, particularly sodium.

Phlegmonous inflammation of gastrointestinal tract autopsy study of three cases

Three cases of Phlegmonous inflammation of gastrointestinal tract detected at necropsy are described. Predisposing factors were seen in all three cases. These were chronic alcoholism with submissive hepatic necrosis (HbsAg and HbcAg positive) in Case 1, Indian Childhood cirrhosis in Case 2 and acute on chronic Budd Chiari syndrome in Case 3. In case 1 and 3 the inflammation was limited to the large intestine where as in Case 2 it was seen both in the stomach and large intestine. In two of the three cases blood culture grew Staphylococcus aureus (Case 1) and gram negative organisms (Case 2).

Specific interaction of heterogeneous nuclear ribonucleoprotein particle U with the leader RNA sequence of vesicular stomatitis virus

The 3' ends of the genome and antigenome RNA of vesicular stomatitis virus (VSV) serve as the promoter sites for the RNA-dependent RNA polymerase in the initiation of transcription and replication, respectively. The leader RNA, the first transcript synthesized during the RNA synthetic step, contains sequences to initiate encapsidation with the nucleocapsid protein, which is a prerequisite for replication. It also plays a role in the inhibition of cellular RNA synthesis. To search for a specific cellular factor(s) which may interact with the leader RNA sequences and regulate these processes, we used a gel mobility shift assay to identify such a protein(s). By using nuclear extract, it was found that in addition to the previously reported La protein, a 120-kDa nuclear protein specifically interacts with the leader RNA. Biochemical and immunological studies identified the 120-kDa protein as heterogeneous nuclear ribonucleoprotein particle U (hnRNP U), which is involved in pre-mRNA processing. We also demonstrate that hnRNP U is associated with the leader RNA in the nuclei of VSV-infected cells and also packaged within the purified virions. By double immunofluorescence labeling and confocal microscopy, hnRNP U appears to colocalize with the virus in the cytoplasm of infected cells. These results strongly suggest that hnRNP U plays an important role in the life cycle of VSV.

General practitioner requests for upper abdominal ultrasound: their effect on clinical outcome

Many radiology departments offer direct access upper abdominal ultrasound (US) scanning to general practitioners (GPs). We aimed to examine the influence of the scan results on the subsequent management and clinical outcome of these patients. A retrospective review was performed on all the patients referred for primary upper abdominal US (n = 82) from a single Birmingham GP practice, of 10,000 patients, between 1991 and 1996. The follow-up period from US was mean 27.9 months, SD 18.2 months. 79 referrals complied with published guidelines. 77 referrals were for suspected gallstone disease. 23 (28%) patients had clinically relevant positive findings. 18 of the positive scans. 16 of whom had gallstones, were subsequently referred to hospital. Of those with gallstones, 15 underwent cholecystectomy, of whom 12 had no further upper abdominal symptoms. Of the 59 negative scans, eight cases (14%) were subsequently referred to hospital. Treatment was changed as a result of review and investigation in only two of these eight cases. The remaining 51 were diagnosed solely on history and clinical examination. 28 of the 51 had self-limiting symptoms which required minor or no treatment. In conclusion, direct access upper abdominal US is considerably reducing the requirement for hospital outpatient referrals from GPs. Positive scans are generally followed by referral to secondary care services with good clinical outcome.

External clues to inner malformations

A malformation is a morphological defect of an organ, or a larger region of the body resulting from an intrinsically abnormal developmental process. In this analysis of 1421 neonatal autopsies performed between 1984 and 1993, 243 (17.1%) cases showed malformations. The data was analysed to find external cues to internal malformations. Twenty three (85%) of the 27 neonates with various facial abnormalities had associated internal malformations in the form of cardiac (n = 11; 40%), renal (n = 7; 25%), or gastrointestinal (n = 3; 11%) abnormalities and diaphragmatic hernia (n = 2). Sixty seven neonates had neural abnormalities. These were associated with cardiac (n = 7; 10%), renal (n = 12; 18%) or gastrointestinal (n = 7; 10%) abnormalities; 43 cases, however, did not have any associated malformations. Renal malformations (n = 66) had highest association with skeletal abnormalities (n = 9; 22%). As many as 45(76%) of the 59 cases with cardiac abnormalities had no external anomalies. Five cases of hypoplastic lungs were seen, all associated with external malformations.

Pouchitis: risk factors, etiology, and treatment

A Medline literature review of pouchitis has been conducted, and relevant information from this search and the authors' own experience has been used to produce an overview on pouchitis at the current time. Particular attention is given to etiology, pathophysiology, and clinical management.

Involvement of actin microfilaments in the replication of human parainfluenza virus type 3

Several studies indicate that paramyxoviruses require a specific cellular factor(s) for transcription of their genomic RNAs. We previously reported that the cellular cytoskeletal protein actin, in its polymeric form, participates in the transcription of human parainfluenza virus type 3 (HPIV3) in vitro. In the present study, we investigated the role of the polymeric form of actin, i.e., the actin microfilaments of the cytoskeletal framework, in the reproduction of HPIV3 in vivo. Pulse-chase labeling analyses indicate that the viral nucleocapsid-associated proteins, NP and P, are present predominantly in the cytoskeletal framework during infection. By in situ hybridization, we found that viral mRNAs and genomic RNA were synthesized from the nucleocapsids that were bound to the cytoskeletal framework. Double immunofluorescent labeling and confocal microscopy of the cytoarchitecture revealed that the viral nucleocapsids are specifically localized on the actin microfilaments. Treatment of cells with the actin-depolymerizing agent, cytochalasin D, resulted in the inhibition of viral RNA synthesis and ribonucleoprotein accumulation. These results strongly suggest that actin microfilaments play an important role in the replication of HPIV3.

Elderly patients' satisfaction with hospital care

OBJECTIVES

The aim of this study was to assess patient satisfaction with the geriatric services of a district general hospital and to examine whether there was a difference in satisfaction between patients in hospital and those who had been recently discharged.

METHODS

A structured and validated patient satisfaction questionnaire was administered before discharge to hospitalised patients with a mental test score of 8 or more. It was also administered to a group of patients in the community who had been discharged from hospital not more than 72 hours earlier. The questionnaire was designed to assess seven separate areas, and contained 51 statements with which patients were asked to agree or disagree. Statistical analysis was by the Mann-Whitney U test and p < 0.05 was taken as significant. A total of 134 elderly patients (> 72 years) were surveyed over a four-month period.

RESULTS

Satisfaction with the hospital geriatric service was high in both groups of patients. However, patient satisfaction differed between the two groups in three areas: interpersonal aspects; access, availability and convenience of the health services; and financial aspects.

RNA polymerase of vesicular stomatitis virus specifically associates with translation elongation factor-1 alphabetagamma for its activity

An RNA-dependent RNA polymerase is packaged within the virions of purified vesicular stomatitis virus, a nonsegmented negative-strand RNA virus, which carries out transcription of the genome RNA into mRNAs both in vitro and in vivo. The RNA polymerase is composed of two virally encoded polypeptides: a large protein L (240 kDa) and a phosphoprotein P (29 kDa). Recently, we obtained biologically active L protein from insect cells following infection by a recombinant baculovirus expressing L gene. During purification of the L protein from Sf21 cells, we obtained in addition to an active L fraction an inactive fraction that required uninfected insect cell extract to restore its activity. The cellular factors have now been purified, characterized, and shown to be beta and gamma subunits of the protein synthesis elongation factor EF-1. We also demonstrate that the alpha subunit of EF-1 remains tightly bound to the L protein in the inactive fraction and betagamma subunits associate with the L(alpha) complex. Further purification of L(alpha) from the inactive fraction revealed that the complex is partially active and is significantly stimulated by the addition of betagamma subunits purified from Sf21 cells. A putative inhibitor(s) appears to co-elute in the inactive fraction that blocked the L(alpha) activity. The purified virions also package all three subunits of EF-1. These findings have a striking similarity with Qbeta RNA phage, which also associates with the bacterial homologue of EF-1 for its replicase function, implicating a possible evolutionary relationship between these host proteins and the RNA-dependent RNA polymerase of RNA viruses.

Basic amino acid residues at the carboxy-terminal eleven amino acid region of the phosphoprotein (P) are required for transcription but not for replication of vesicular stomatitis virus genome RNA

The phosphoprotein (P) of vesicular stomatitis virus (VSV) serotypes New Jersey [P(NJ)] and Indiana [P(I)] contains a highly conserved carboxy-terminal domain which is required for binding to the cognate N-RNA template as well as to form a soluble complex with the nucleocapsid protein N in vivo. We have shown that the deletion of 11 amino acids from the C terminal end of the P(I) protein abolishes both the template binding and the complex forming activity with the N protein. Within this region, there are conserved basic amino acid residues (R260 and K262) that are potential candidates for such interactions. We have generated mutant P proteins by substitution of these basic amino acid residues with alanine and studied their role in both transcription and replication. We have found that the R260A mutant failed to bind to the N-RNA template, whereas the K262A mutant bound efficiently as the wild-type protein. The R260A mutant, as expected, was unable to support mRNA synthesis in vitro in a transcription reconstitution reaction as well as transcription in vivo of a minigenome using a reverse genetic approach. However, the K262A mutant supported low level of transcription (12%) both in vitro and in vivo, suggesting that direct template binding of P protein through the C-terminal domain is necessary but not sufficient for optimal transcription. Using a two-hybrid system we have also shown that both R260A and K262A mutants interact inefficiently with the L protein, suggesting further that the two point mutants display differential phenotype with respect to binding to the template. In addition, both R260A and K262A mutants were shown to interact efficiently with the N protein in vivo, indicating that these mutants form N-P complexes which are presumably required for replication. This contention is further supported by the demonstration that these mutants support efficient replication of a DI RNA in vivo. Since the transcription defective P mutants can support efficient replication, we propose that the transcriptase and the replicase are composed of two distinct complexes containing (L-P2-3) and L-(N-P), respectively.

Phosphorylation within the amino-terminal acidic domain I of the phosphoprotein of vesicular stomatitis virus is required for transcription but not for replication

Phosphorylation by casein kinase II at three specific residues (S-60, T-62, and S-64) within the acidic domain I of the P protein of Indiana serotype vesicular stomatitis virus has been shown to be critical for in vitro transcription activity of the viral RNA polymerase (P-L) complex. To examine the role of phosphorylation of P protein in transcription as well as replication in vivo, we used a panel of mutant P proteins in which the phosphate acceptor sites in domain I were substituted with alanines or other amino acids. Analyses of the alanine-substituted mutant P proteins for the ability to support defective interfering RNA replication in vivo suggest that phosphorylation of these residues does not play a significant role in the replicative function of the P protein since these mutant P proteins supported replication at levels > or = 70% of the wild-type P-protein level. However, the transcription function of most of the mutant proteins in vivo was severely impaired (2 to 10% of the wild-type P-protein level). The level of transcription supported by the mutant P protein (P(60/62/64)) in which all phosphate acceptor sites have been mutated to alanines was at best 2 to 3% of that of the wild-type P protein. Increasing the amount of P(60/62/64) expression in transfected cells did not rescue significant levels of transcription. Substitution with other amino acids at these sites had various effects on replication and transcription. While substitution with threonine residues (P(TTT)) had no apparent effect on transcription (113% of the wild-type level) or replication (81% of the wild-type level), substitution with phenylalanine (P(FFF)) rendered the protein much less active in transcription (< 5%). Substitution with arginine residues led to significantly reduced activity in replication (6%), whereas glutamic acid substituted P protein (P(EEE)) supported replication (42%) and transcription (86%) well. In addition, the mutant P proteins that were defective in replication (P(RRR)) or transcription (P(60/62/64)) did not behave as transdominant repressors of replication or transcription when coexpressed with wild-type P protein. From these results, we conclude that phosphorylation of domain I residues plays a major role in in vivo transcription activity of the P protein, whereas in vivo replicative function of the protein does not require phosphorylation. These findings support the contention that different phosphorylated states of the P protein regulate the transcriptase and replicase functions of the polymerase protein, L.

Intravenous contrast media: are they being administered safely in radiology departments?

A recent Royal College of Radiologists (RCR) publication is entitled Advice on The Management of Reactions to Intravenous Contrast Media. This study aims to determine whether radiology departments are adhering to the essential points, covered in the guidelines, regarding prevention, early recognition and prompt treatment of adverse reactions, and whether they are adequately equipped for the proposed contrast media reaction management protocols. A questionnaire was formulated and sent to the superintendent radiographers of 295 radiology departments in the United Kingdom of whom 233 (79%) replied. This was specifically directed at the use of intravenous contrast media in intravenous urography. In almost all departments there was provision for basic life support training, regular checking of equipment and drugs, and prompt access to emergency medical help. Certain "first line" drugs and monitoring equipment were not instantly accessible in the majority of institutions. Most departments did not adequately supervise post-injection patients and did not conform to the guidelines referring to the administration of intravenous contrast to children. Certain areas of the guidelines are being neglected by many radiology departments and there is still much to be done to improve the safety of intravenous contrast medium injection.

Pulmonary capillary haemangiomatosis as a cause of pulmonary hypertension in Takayasu's aortoarteritis

Pulmonary hypertension is known to occur in Takayasu's aortoarteritis. It may be either due to pulmonary arterial involvement or elevated left ventricular end diastolic pressure, or both. In our case, the cause of pulmonary hypertension was a recently described rare lesion termed pulmonary capillary haemangiomatosis. This entity has a very distinct histopathologic picture. Although 19 cases have been reported in the English literature, this is the first report on pulmonary capillary haemangiomatosis producing pulmonary hypertension in Takayasu's aortoarteritis.

Phosphorylation of Sendai virus phosphoprotein by cellular protein kinase C zeta

The phosphoproteins (P) of nonsegmented negative strand RNA viruses are viral RNA polymerase subunits involved in both transcription and replication during the virus life cycle. Phosphorylation of P proteins in several negative strand RNA viruses by specific cellular kinases was found to be required for P protein function. In the present study, using bacterially expressed unphosphorylated P protein of Sendai virus, a mouse parainfluenza virus, we have shown that the major cellular kinase that phosphorylates P protein in vitro is biochemically and immunologically indistinguishable from protein kinase C (PKC) zeta isoform. PKC zeta was packaged into the Sendai virion and remained associated with purified viral ribonucleoprotein, where it phosphorylated both the P and the nucleocapsid protein in vitro. When PKC zeta-specific inhibitory pseudosubstrate peptide was introduced into LLC-MK2 cells prior to Sendai virus infection, production of progeny virus was dramatically attenuated, and kinetic analysis revealed that primary transcription was repressed. These data indicate that phosphorylation of the Sendai virus P protein by PKC zeta plays a critical role in the virus life cycle.

In vitro induction of multiple shoots and plant regeneration in cotton (Gossypium hirsutum L.)

Induction of multiple shoots in cotton (Gossypium hirsutum L. cv. Anjali-LRK 516) has been achieved with cotyledonary nodes devoid of cotyledons and apical meristems. Explants from 35-day-old seedlings yielded the maximum number of shoots (4.7 shoots/explant) using Murashige and Skoog (MS) basal medium supplemented with 6-benzylaminopurine and kinetin (2.5 mg/1 each). Explants from 35-day-old seedlings raised in glass bottles produced a higher number of multiple shoots (8.3 shoots/explant) than those grown in glass tubes and cultured on the same shoot induction medium. Elongation of multiple shoots was obtained on liquid or agar MS basal medium without phytohormones. In vitro shoots were rooted on half-strength agar-solidified MS basal medium or with 0.05 or 0.1 mg/1 naphthaleneacetic acid. Hardening and survival of tissue culture plantlets was 95% under greenhouse conditions.

Expression and purification of vesicular stomatitis virus N-P complex from Escherichia coli: role in genome RNA transcription and replication in vitro

The nucleocapsid protein (N) and phosphoprotein (P) genes of vesicular stomatitis virus (VSV), Indiana serotype, were coexpressed in Escherichia coli BL21(DE3) by using the expression vector pET-3a. The coexpression resulted in the formation of N-P complex. The purified N-P complex was found to inhibit transcription in vitro mediated by viral ribonucleoprotein (RNP) complex in a dose-dependent manner. However, addition of uninfected mammalian cell extracts together with the N-P complex to the transcribing RNP resulted in the synthesis of full-length negative-strand genome RNA. These results indicate that the N-P complex regulated transcription and a cellular factor(s) in combination with the N-P complex may switch the RNA polymerase from transcription to replication mode.

An infectious clone of human parainfluenza virus type 3

A full-length clone of the human parainfluenza virus type 3 (HPIV-3) genome (called pHPIV-3) was constructed, and recombinant, infectious HPIV-3 was generated by transfecting pHPIV-3 and support plasmids encoding the HPIV-3 NP, P, and L proteins into HeLa cells infected with a vaccinia virus recombinant which expresses T7 RNA polymerase. T7 RNA polymerase promoters on the transfected plasmids direct the synthesis of transcripts encoding the NP, P, and L proteins and a full-length, positive-sense copy of the HPIV-3 genome. Generation of virus was dependent on transfection of pHPIV-3 and the HPIV-3 P- and L-encoding plasmids. However, a plasmid encoding the NP protein was not required since NP was expressed from pHPIV-3. Recovered virus was neutralized by anti-HPIV-3 antisera and shown to contain specific base substitutions characteristic of pHPIV-3. Recombination was shown to occur during recovery, as viruses with two distinct genotypes and phenotypes were isolated. The ability to produce infectious HPIV-3 engineered to contain specific alterations within the HPIV-3 genes and cis-acting elements expedites the study of all aspects of the virus replication cycle. Additionally, analysis of mutations may lead to the identification of attenuating genotypes, a key step in the development of a live virus vaccine.

Role of cellular kinases in the gene expression of nonsegmented negative strand RNA viruses

Nonsegmented negative strand RNA viruses package an RNA-dependent RNA polymerase composed of two subunits, a large protein L and a phosphoprotein P, for transcription and replication of their genome RNAs. The RNA polymerase activity resides within the L protein, while the P protein acts as a transcription factor or transactivator of the polymerase. Since P protein is heavily phosphorylated and phosphorylation is known to regulate function of many viral as well as cellular proteins, the role of phosphorylation of P protein in the gene expression of this group of RNA viruses has recently been investigated. Through expression in bacteria the P protein was produced in large quantity in the nonphosphorylated form and involvement of cellular kinase(s) in its phosphorylation was studied. Casein kinase II and/or protein kinase C have been shown to play a critical role in the activation of P protein in transcription. These findings have opened up a new avenue for studying an important regulatory step in virus gene expression that may lead to the development of an effective antiviral agent.

Phosphorylation of canine distemper virus P protein by protein kinase C-zeta and casein kinase II

Transcription by nonsegmented negative-strand RNA viruses is mediated by the viral RNA-dependent RNA polymerase and transcriptional cofactor P. The P protein is activated by phosphorylation, an event initiated by cellular kinases. The kinase used differs among this group of RNA viruses; vesicular stomatitis virus and respiratory syncytial virus utilize casein kinase II (CKII), whereas human parainfluenza virus type 3 utilizes PKC isoform zeta (PKC-zeta) for activation of its P protein. To identify the cellular kinase(s) involved in the phosphorylation of the canine distemper virus (CDV) P protein, we used recombinant CDV P in phosphorylation assays with native kinase activities present in CV1 cell extracts or purified CKII and PKC isoforms. Here, we demonstrate that the CDV P protein is phosphorylated by two cellular kinases, where PKC-zeta has the major and CKII the minor activities. In contrast, the P protein of another member of the morbillivirus genus, measles virus, is phosphorylated predominantly by CKII, whereas PKC-zeta has only minor activity. Selective inhibition of PKC-zeta activity within CV1 cells eliminated permissiveness to CDV replication, indicating an in vivo role for PKC-zeta in the virus replication cycle. The broad tissue expression of PKC-zeta parallels the pantropic nature of CDV infections, suggesting that PKC-zeta activity is a determinant of cellular permissiveness to CDV replication.

Intracranial fungal granuloma

BACKGROUND

Intracranial fungal granulomas are uncommon and their pathogenesis, clinical picture, and effectiveness of therapy remains unclear.

METHODS

Thirty-two cases were studied retrospectively in two groups: (1) Rhinocerebral group (22 cases) had a chronic paranasal sinus (PNS) disease with secondary involvement of skull base, cranial nerves, and/or brain. The granulomas were adherent to dura, firm, avascular, and tough, requiring a knife to cut. (2) Primary intracranial group (10 cases) had no detectable PNS lesion at initial presentation. The granulomas were soft, suckable, and contained pus or necrotic material.

RESULTS

Postoperative and overall mortality were 37.5% and 50%, respectively. Meningoencephalitis was the most common cause of death. Altered sensorium, pus in the granuloma, and/or severe brain edema were poor prognostic factors. All survivors except four have symptomatic residual or recurrent lesions.

CONCLUSION

Early diagnosis with MRI or stereotactic biopsy, radical surgery, and high dose and chronic suppressive chemotherapy may improve overall results in these cases.

Phosphorylated states of vesicular stomatitis virus P protein in vitro and in vivo

We have previously shown that the phosphoprotein (P) of vesicular stomatitis virus (VSV), New Jersey serotype (PNJ) is phosphorylated by casein kinase II, within the N-terminal domain I (P1 form), whereas the C-terminal domain II is phosphorylated by a protein kinase activity associated with the L protein (P2 form) (D. J. Chattopadhyay and A.K. Banerjee, Cell 49, 407, 1987; A.M. Takacs et al., J. Virol. 66, 5842, 1992). In the present studies, we have mapped the corresponding P1 and P2 phosphorylation sites in the P protein of the well-studied Indiana serotype (PIND) and compared that with the two previously designated NS1 and NS2 forms present in vivo. The PIND expressed in Escherichia coli in an unphosphorylated form (P0) was used as substrate for recombinant casein kinase II (CKII). By site-directed mutagenesis, the CKII-mediated phosphorylation sites in the P protein were mapped at S60, T62, and S64 within the acidic domain I in vitro. In contrast, using BHK cell extract as the source of CKII or expressing P protein in COS cells labeled with 32PI, the phosphorylation sites were mapped at S60 and S64 with no phosphorylation at T62 residue. We used a peptide mapping technique by which the phosphorylation sites within domain I and domain II were determined. Using this method we demonstrated that the P1 and P2 forms are similar, if not identical, to the previously designated NS1 and NS2 forms, respectively. The domain II phosphorylating kinase activity, associated with the L protein, is shown to be present also in the N-RNA complex, indicating that this activity is of cellular origin. By site-directed mutagenesis, we have shown that S226 and S227 are involved in phosphorylation within domain II. We also demonstrate that the P1 and P2 forms are interconvertible and arise by phosphorylation/dephosphorylation of the phosphate groups in domain II, confirming the precursor-product relationship between the two phosphorylated forms of P protein.

Spinal extradural cavernous haemangioma

A case of spinal extradural cavernous haemangioma without a vertebral lesion is reported. Clinical and radiological features of the lesion are discussed. Relevant literature is reviewed.