Febrile infections and malignant melanoma: results of a case-control study. Several reports have described an inverse relationship between the frequency of infections and various malignancies. In this paper results of a hospital-based case control study on 139 melanoma patients and 271 suitable selected controls are presented, addressing the question of whether this relationship exists with respect to malignant melanoma while simultaneously controlling for the effects of other risk factors. Data on childhood diseases (group I), febrile diseases of adulthood (group II) and common febrile infections within a 5-year period prior to the diagnosis of melanoma (group III) were collected using a standardized interview. Group I diseases did not show a marked influence on the risk of malignant melanoma. Considering group II diseases, a significant protective effect was determined for chronic infectious diseases (OR = 0.32) and also for wound infections, abscesses and furunculosis (OR = 0.21). In group III, herpes simplex infections (OR = 0.45) and influenza/common cold (OR = 0.32) substantially reduced the melanoma risk. This effect was less pronounced for gastroenteritis (OR = 0.52). Analysis of the cumulative influence of infections pointed to a strong dose-response relationship between the frequency of febrile infections in adulthood and malignant melanoma. In particular, the risk reduction was striking when two or more febrile infections were compared to no febrile infections in group II (OR = 0.09) and group III (OR = 0.20). The study confirms the hypothesis that an inverse relationship exists between febrile infections and malignant melanoma, but these results have to be interpreted cautiously due to the inherent limitations of the case-control design.(ABSTRACT TRUNCATED AT 250 WORDS)


Immune pathogenesis of hepatitis B.

Immune pathogenesis of hepatitis B. Available information about the immune pathogenesis of HBV infection in man is very limited. However, the present availability of recombinant sources of the different HBV antigens expressed in the appropriate forms to induce activation of either HLA class I or HLA class II-restricted T cells, provides the necessary tools to investigate directly the mechanisms of liver damage, the role of the different cellular components of the immune system in HBV clearance and the specific nature of the immune defects potentially responsible for the chronic evolution of HBV infection. In addition, improved knowledge of HBV biology suggests a dynamic interpretation of the HBV-immune system interactions, based on which viral mutations as well as direct interferences of HBV with specific immune functions are believed to play a relevant role with respect to the outcome of HBV infection.


PCR analysis of HBV infected sera: relationship between expression of pre-S antigens and viral replication. In order to determine the biological significance of the pre-S antigens in HBV infection, HBsAg sera were tested for the presence of pre-S1 and pre-S2. HBV DNA was detected by spot-hybridization and PCR. The data show a complete correlation between pre-S antigenemia and HBV DNA replication in anti-HBe positive cases. PCR but not spot-hybridization was adequately sensitive to also detect HBV DNA in roughly half of the preS negative sera as well. Thus PCR appears to be a valuable technique for detection of potentially infectious anti-HBe carriers.


Detection of HBV DNA by PCR in serum from an HBsAg negative blood donor implicated in cases of post-transfusion hepatitis B. An HBsAg negative blood donor, and three of her recipients, who developed HBsAg positive post-transfusion hepatitis B, were all positive for serum HBV DNA by polymerase chain reaction (PCR), and by subtype discriminating PCR were found to harbour HBV specifying ayw. Thus HBV specifying ayw. Thus HBV DNA may be detected and sub-typed by PCR in infectious HBsAg negative individuals.


Measurement of anti-HBc IgM levels using the Amerlite anti-HBc IgM assay. The Amerlite anti-HBc IgM assay was evaluated as a tool for determination of antibody levels. With an assay time of 1 hour, the test showed a broad dose response range with high sensitivity and specificity. The software configuration of the analyser can be customized to suit specific research requirements.


Evaluation of a new enhanced luminescence immunoassay for confirming the presence of HBsAg in human serum or plasma. An enhanced luminescence assay was developed to confirm the presence of HBsAg in weakly reactive sera. The test proved reliable in differentiating between truly reactive and falsely reactive samples.


Functions of hepatitis B surface proteins. HBV surface proteins play a number of functional roles in cellular infection, viral synthesis and in immune responses of the host. Three coterminal proteins of differing sizes and three subdomains of the individual molecules can be recognized. In this brief review, functions of the various proteins and domains are described and their significance as potential immunogens is discussed. Although it is apparent that the surface proteins are involved in the development of persistent HBV infections, the underlying mechanisms of liver involvement remain unknown.


Diverging policies for vaccination against hepatitis B. Policies toward vaccination against hepatitis B vary globally according to local prevalence and the population of infected individuals. In the present report, vaccination plans, policies, risks, and experiences of both apparent successes and failures are described. Possible plans, including local vaccine production, are discussed in regard to problems of third-world countries with high HB prevalence. Recommendations are made for vaccination policies in various circumstances.


Immunogenicity and safety of a recombinant hepatitis B vaccine produced in mammalian cells and containing the S and the preS2. A group of 273 health care workers, at risk of HBV infection, underwent vaccination with recombinant HBsAg produced in mammalian cells and containing protein sequences coded by both the S and pre-S2 regions (Genhevac B). Preliminary results show that a very early pre-S2 response occurred which may be useful in post-exposure prophylaxis. This observation, in addition to reduced influence by the vaccination protocol, provides grounds for optimism in spite of the fact that the efficiency spectrum of this vaccine was not superior to that of recombinant vaccines produced in yeast.


Kinetics of anti-HBs after hepatitis B vaccination: a comparison of two recombinant and one plasma-derived vaccines. Geometric mean titers were determined for three groups of medical students who had been vaccinated against hepatitis B with two different yeast-derived recombinant vaccines and one plasma-derived vaccine. The antibody kinetics for the three groups were similar over a period of 4 years. A formula for prediction of titers from the post-booster anti-HBs concentration is provided.


Enhanced luminescent assays for hepatitis markers: assessment of post vaccine responses. A range of solid phase immunoassays have been developed using enhanced chemiluminescence to provide a signal which can be measured in a qualitative or quantitative manner. The "Amerlite" anti-HBs assay has been used routinely to test more than 3000 post-vaccine anti-HBs levels. The results show that 5% of vaccinees are non-responders, but that more than 30% produce antibody levels greater than 1000 mIU/ml.


Hepatitis C viral RNA in serum of patients with chronic non-A, non-B hepatitis: detection by the polymerase chain reaction using multiple primer sets. The recently introduced antibody test for hepatitis C virus (HCV) infection has proven to have certain limitations. Since HCV itself is usually present in clinical specimens at very low titers, a useful assay for the virus must have very high sensitivity. We have developed a simple, highly sensitive assay for HCV RNA based on the polymerase chain reaction (PCR). In this test, RNA extracted from HCV infected serum or plasma is used as the template for double PCR with nested primers. Sensitivity studies demonstrate that this assay is able to detect HCV at or beyond the sensitivity level of chimpanzee infectivity. We tested, with several sets of nested primers, 40 patients with chronic non-A, non-B hepatitis (36 seropositive and 4 seronegative) and found that 35/40 were PCR positive including all 4 seronegative patients. Normal human plasma and plasma from hepatitis B infected patients did not react in this test. This assay has proven to be valuable for determining the presence of HCV in various samples; furthermore, it offers the possibility of diagnosis of HCV infection in seronegative patients.


T cell recognition of hepatitis B envelope proteins. We have studied the T-cell processing pathways of Hepatitis B antigens and the role of specific B lymphocytes. It could be shown that some form of processing by specific B cells is required for class I CTLs. This mechanism differs from class II endosomal processing. In addition, it could be shown that lysis of HBsAg-specific B cells may be partly responsible for chronic HBV carrier states.


HCV infection and chronic active hepatitis in alcoholics. Histological signs of chronic active hepatitis were found in 11/41 (27%) patients with chronic alcoholic liver disease. All these 11 patients tested positive for antibodies to HCV and no other causes of chronic hepatitis were found.


Diagnostic reagents for hepatitis C virus. The development of diagnostic methods for hepatitis C virus is presented. Special attention is paid to the selection of antigenic markers, the type of assay selected and the interpretation of results. A few of the pitfalls and ambiguities of various assays are discussed and possible future methods are described.


Follow-up of patients with hepatitis non-A, non-B: incidence and persistence of anti-HCV depend on route of transmission. Of 32 patients with non-A, non-B hepatitis, 10 (31%) were still anti-HCV-positive 12.8 years after the acute phase of the disease. Seven of the patients (21.9%) still had elevated ALT levels, and among these, 5 out of 5 patients who had been subject to parenteral risk were anti-HCV-positive. In contrast, none of the patients who had not been subject to parenteral risks were positive.


Recombinant immunoblot assay for hepatitis C virus antibody in chronic hepatitis. Testing for hepatitis C virus by ELISA requires confirmation by recombinant immunoblot assay (RIBA). The first-generation RIBA uses the same antigen as used in the ELISA and one further antigen. A second-generation RIBA in which two further antigens are present, detects positivity that is not found by either the ELISA or the original RIBA. Consequently, although it is adequate to test ELISA positive sera with the first-generation RIBA, the second-generation assay is recommended for confirming negativity.


PCR detection of HCV RNA among French non-A, non-B hepatitis patients. Hepatitis C virus (HCV) cDNA was amplified from serum of 26/40 French chronic non-A, non-B hepatitis patients by the nested polymerase chain reaction. Compared with anti-C100, viral cDNA represents a more reliable marker of active HCV replication.


Evaluation of anti-HCV positive blood donors identified during routine screening. Of 30,231 donors tested, 368 (1.2%) were anti-HCV positive. Of these, 254 have been evaluated, with the following results: only 25% have a history of parenteral risk, seroprevalence increases with age and approximately 80% of those that are anti-HCV positive in our population are probably infected with HCV. In addition, an unexpectedly large number of these persons have chronic and/or severe liver disease and will require combined diagnostic approaches for accurate evaluation.


Presence of HCV RNA in serum of asymptomatic blood donors involved in post-transfusion hepatitis (PTH). To study the causes of residual posttransfusion hepatitis, serum from implicated donors was tested by PCR for the presence of HCV RNA. Of 20 anti HCV negative donors, 4 were HCV RNA positive and thus, infective. The results suggest that higher-level investigations are necessary for prospective donors who present blood enzyme abnormalities or other questionable characteristics.


Epidemiology of anti-HCV antibodies in France. Viral Hepatitis Study Group of the French Blood Transfusion Society. The aim of this large survey which covered 173,038 unselected blood donors, was to determine the seroprevalence of anti-HCV antibodies and surrogate markers (ALT and anti-HBc) in France. The results revealed a frequency of 0.63% of anti-HCV positive donors. The correlation with surrogate markers was very poor but since we know nothing about the infectivity of anti-HCV negative donations, screening of surrogate markers must still be performed to prevent post-transfusional hepatitis.


Assay of antibodies to hepatitis C virus protein C100-3 in blood donors from northern Germany. The prevalence of anti-C100-3 increases with age from 0.41% to 1.26%. It is more frequent in donors with elevated ALT (4.5%). Most ALT elevations, however, are not related to anti-C100-3. Low EIA signals (< 3 x cutoff) are often non-specific. The cutoff value should be 2.5 times higher. High EIA signals correlate with ALT elevations.


Chronic viral hepatitis in children.

Chronic viral hepatitis in children. Hepatitis B virus is the most common causative agent of chronic viral hepatitis in children. The disease may take an aggressive course, but remains mostly asymptomatic. HDV infection occurs in about 13% of those children who are chronic carriers and are HBsAg positive. HCV infection is generally related to parenteral risk and generally remains asymptomatic. In addition to describing the course of the various diseases, treatment and control measures are discussed.


Long-term outcome of chronic type B hepatitis in childhood. The course of hepatitis B was followed in 35 children. Various prognostic factors are evaluated. The long-term outcome of the disease is poor, often progressing to cirrhosis.


Repeated course of interferon treatment in chronic hepatitis B in childhood. Ten children affected by HBV chronic hepatitis, not responding to a previous treatment with interferon (IFN), have been treated with a reiterated IFN therapy. The response obtained is not encouraging and only one patient became negative for HBeAg and HBV-DNA.


Effect of prednisone priming followed by alfa-interferon in treatment of children with chronic hepatitis B: an interim analysis of a controlled trial. A six-month analysis of a controlled trial on the treatment of chronic hepatitis B in children shows that prednisone priming followed by alpha-interferon 2A was effective in 6 of 9 treated patients in reducing HBV replication and disease activity.


Association between HLA class I antigens and response to interferon therapy in children with chronic HBV hepatitis. In this preliminary study, children with chronic HBV hepatitis, as was also previously shown for adults, respond to interferon therapy in an HLA class I antigen dependent manner. If this can be confirmed on a large scale, HLA typing may serve as a useful indication of interferon-therapy responders.


Treatment of chronic viral hepatitis anno 1990. The therapeutic efficacy of alpha-interferon therapy in chronic hepatitis is discussed in light of various international studies. Although beneficial to some extent, treatment is of limited value and is accompanied by more-or-less serious side effects. Development of complementary drugs and new therapeutic methods must therefore be continued.


HBcAg induced T-cell independent anti-HBc production in chronic HBsAg carriers. The capacity of the nucleocapsid protein of HBV to function as a T-cell independent antigen in man was studied. When T-cell depleted B-cell cultures were challenged with E coli-derived HBcAg, anti-HBc production was registered in culture supernatants from the majority of chronic HBsAg carriers in a quiescent stage of disease. In contrast, similarly prepared and stimulated cultures from donors with natural acquired immunity to hepatitis B or HB-susceptible controls were non-responsive. Addition of autologous T-cells effectively restored anti-HBc responsiveness in T-cell depleted B-cell cultures from HB-immune donors, demonstrating the T-cell dependency for anti-HBc induction in natural HBV-infection.


Induction of autoantibodies during alpha interferon treatment in chronic hepatitis B. Thirty-two patients with chronic hepatitis B treated with alpha interferon were tested for 12 different antibodies. Only a minority (18%) of cases developed antinuclear antibodies and none developed clinical signs of autoimmune disease. These data suggest that, at the dose regimen used, interferon therapy of chronic hepatitis B is not associated with triggering of autoimmunity.


One course versus two courses of recombinant alpha interferon in chronic C hepatitis. Fifty-five patients with antibodies to HCV and chronic liver disease have been enrolled in the study. Thirty-four patients were treated with recombinant alpha interferon (IFN, 3 MU daily for 10 days followed by 3 MU twice/week for 3 months), and were compared to 21 untreated controls. Alanine aminotransferase (ALT) normalization was observed in a significant proportion of treated patients (52.9%), but 66.6% of them experienced a relapse after discontinuation of the therapy. The evaluation of the early ALT behavior after the 10 days priming with daily IFN administration was useful in predicting the response. The administration of a second IFN course with the same schedule and duration as the first course did not increase the efficacy of the treatment. Increased dosage and/or prolonged administration are probably required.


Interferon therapy of cryptogenic chronic active liver disease and its relationship to anti-HCV. In a randomized controlled trial of Interferon (IFN) in 60 patients (30 treated and 30 controls) with cryptogenic chronic active liver disease, 70% of treated patients showed complete response, but a high rate of biochemical relapse (62%) was noted. In these cases, a second response to higher doses of IFN has been more difficult and less frequent. A response to IFN was found in 88.5% of anti-HCV positive treated patients and only in 25% of anti-HCV negative. We suggest that serum anti-HCV is a suitable test to predict the response to IFN.


Immune pathogenesis of hepatitis A.

Immune pathogenesis of hepatitis A. In an effort to elucidate the mechanism of liver damage resulting from Hepatitis A virus (HAV) infection, we have studied infected skin fibroblasts and autologous lymphocytes from HAV patients. We report here that HLA-restricted virus-specific T cells play an essential role in HAV-related hepatocellular injury.


Interferon alpha 2-b therapy of HCV and nonBnonC chronic hepatitis. Twenty-four patients with HCV and NonBNonC chronic hepatitis--4 with HIV coinfection--were treated with r-IFN alpha for at least six months. In this period 62.5% of patients show a normalization of ALT but not a sustained remission. Non-responders have histologically more severe and long-lasting chronic hepatitis.


Long-term effects of recombinant leukocyte alpha interferon in the treatment of chronic delta hepatitis. A pilot study is described, in which 25 chronic CDH patients were treated with 3 MU recombinant alpha-interferon per week for 4 months. Improvement was transient and no long-term effects were noted. Side effects were well tolerated and reversible so that longer treatment and higher dosages should be possible.


Liver transplantation and hepatitis viruses. Considerations regarding liver transplantation in viral-hepatitis-related acute liver failure and end-stage chronic liver disease are discussed. Parameters of prognosis and indications for transplantation are presented. Differences according to the causative agent are noted, in particular regarding the danger of reinfection. The role of immunoprophylaxis is addressed as is the question of additional antiviral (interferon) treatment.


Antibody to hepatitis C virus in acute, self-limited, type B hepatitis. Sera from 104 patients with self-limited, acute type B hepatitis were tested for the presence of anti-HCV antibodies. The results show that especially drug users with acute type B (and occasionally coinfected with type D) hepatitis commonly are infected with HCV. Furthermore, HCV infection may have preceded infection with the other agents and may be responsible for high ALT levels.


HCV infection in HBsAg positive chronic liver disease. The prevalence of anti-HCV antibodies was determined for a group of 68 patients with various forms of chronic liver disease. All patients that were anti-HCV positive but did not show signs of HBV replication had severe liver disease. We therefore suggest that HCV may be responsible for liver damage in HBsAg positive subjects when there are no evident signs of HBV replication.


HBV and HCV infection in i.v. drug addicts; coinfection with HIV. A group of 122 drug addict patients were studied to evaluate the incidence of HIV, HBV, HCV infections and of laboratory findings of hepatic damage. Our data show that hepatic damage is more frequent in patients affected by HBV-HCV coinfection than those with HBV or HCV infection alone and that HIV positivity supports HBV-HCV coinfection.


HCV and HIV infection among intravenous drug abusers in eastern Sicily. In a study of 175 intravenous drug addicts from Eastern Sicily, 58.3% were found to be anti-HCV positive. In this population, the presence of anti-HCV was independent of HIV infection, age, duration of drug use and the practice of needle sharing. This may indicate that HCV is more readily transmitted (or spread earlier in this population) among drug addicts than is HIV.


Anti-hepatitis C antibody prevalence among intravenous drug addicts in the Catanzaro area. A higher seroprevalence of anti-HCV antibodies (63.4%) was found in 41 intravenous drug addicts (IVDA) when compared to 220 controls (1.8%). Life style is an important risk factor for HCV transmission among IVDA.


Hepatitis C virus (HCV) infection in the Piacenza dialysis center. In a group of 110 dialysis patients, 21% had anti-HCV antibodies. Statistical differences were noted according to method and duration of dialysis as well as the presence of further risk factors.


Preliminary investigation on intrafamilial spread of hepatitis C virus (HCV). To determine the risk of cohabitant HCV infection, we investigated the sera of 101 family members of 53 anti-HCV antibody positive chronic liver disease patients. Altogether 14.8% of the cohabitants were also anti-HCV antibody positive, compared to a prevalence of 1.4% in the general population. These results suggest that hepatitis-C-virus may spread by person-to-person infection.


Involved factors in the intrafamilial spread of hepatitis C virus. To investigate the risk of non-parenteral HCV infection, sera from 302 relatives of 120 anti-HCV positive subjects were tested for the presence of anti-HCV antibodies. For the sake of comparison, sera from 17,000 blood donors were also assayed. The prevalence of HCV positivity was 4.3% in household contacts, compared to 0.78% in the donor population, indicating a significantly higher risk of infection for family members. Close personal contact may not be as critical a factor for infection as is duration of the disease.


Divergent anti-HBc reactivities in HB-immune and chronic HBsAg carriers. We have monitored titers of anti-HBc antibodies in sera from acutely HBV-infected and chronic HBsAg carriers. Our data show that there is a divergence in the specificity of the antibodies in these two populations. We also present preliminary results showing that serum from HB-immune carriers contain antibodies that are multispecific and display autoimmune characteristics, reacting with human serum albumin.


Absence of free core antigen in anti-HBc negative viremic hepatitis B carriers. Using enzyme immune assay and immune electron microscopy, we have examined the sera of immune-suppressed anti-HBc negative HBV-infected patients for the presence of HBcAg. Our results suggest that free HBV core particles are absent or present only in minute amounts in the blood of chronic carriers and that at the most, only minimal amounts of core antigen are found on the surface of the virus particles.


Hepatitis B virus specific transcripts in peripheral blood mononuclear cells. We report on the analysis of HBV transcription in peripheral blood mononuclear cells of chronically infected patients by polymerase chain reaction amplification. Our results suggest that in these cells gene expression occurs either as pregenomic or subgenomic transcripts.


Relapsing hepatitis A in Saimiri monkeys experimentally reinfected with a wild type hepatitis A virus (HAV). Saimiri monkeys were inoculated three times with hepatitis A virus and observed in a follow-up study for sixteen months. The monkeys developed recurrent hepatitis involving liver damage and cycles of HAV antigen shedding in stools. The relapses were presumably due to immune response effects.


Detection of transcriptionally active hepatitis B virus DNA in peripheral mononuclear blood cells after infection during immunosuppressive chemotherapy using the polymerase chain reaction. Using PCR we have studied mononuclear peripheral blood leucocytes (PMBLs) from HBV-infected immunosuppressed patients in order to detect the presence of HBV genomes. Our results indicate that non-transient PMBL infection is common in immunotolerant carriers. In addition, the presence of pregenomic mRNA sequences suggests that virus replication may take place in PMBLs, possibly implicating the latter as a source of virus after replication has ceased in the liver.


The hepatitis B virus X protein transactivation of c-fos and c-myc proto-oncogenes is mediated by multiple transcription factors. We have constructed two expression vectors in order to study the action of the HBV 17 Kd X protein on the c-fos and c-myc promoters. The results show that the promoters contain multiple elements that respond to X protein, suggesting involvement of multiple transcription factors. The exact mechanism of the interaction remains elusive, but our data allow speculation about the factors that may be influenced.


Trans-activation by hepatitis B virus X protein is mediated via a tumour promoter pathway. We have studied the c-myc gene as a possible target of HBV X protein in liver carcinogenesis. Our results indicate that trans-activation by X protein occurs via PKC/AP1 signal transduction, suggesting a possible two-step mechanism in HBV related liver carcinogenesis.


Truncated pre-S/S proteins transactivate multiple target sequences. In order to investigate the transactivational function of HBV truncated preS/S proteins we have constructed two sets of plasmids and have tested their transactivational potential on the c-myc regulatory sequences and the TPA-responsive element. We found that preS/S proteins only become transactivationally active when truncated at the carboxy terminal end. Furthermore, using immunofluorescence microscopy we determined that the proteins are located exclusively in the cytoplasm, apparently ruling out DNA binding and activation of factors in the nucleus.


Variants of hepatitis B virus.

Variants of hepatitis B virus. Variations in the course of disease caused by hepatitis B virus may often be attributed to genomic variants of the virus. It must be kept in mind, however, that other factors, i.e. immunocompetence of the host and new methods of detection such as PCR, may also result in apparently aberrant phenotypic expression. Examples of both situations are presented here and the need is stressed for combined virological, biochemical and clinical studies.


Hepatitis B virus (HBV) genomic variations in chronic hepatitis. Using PCR we have examined the sequence of the pre-C/C region of HBV from sera of anti-HBe positive, chronically HBV-infected patients. The large majority of sera tested contained a mixture of heterogeneous pre-C sequences with 1-3 non-randomly located point mutations. Some of the resultant variant viruses are incapable of synthesizing immunogenic proteins and may be involved in viral persistence in chronic carrier states.


Lack of pre-C region mutation in woodchuck hepatitis virus from seroconverted woodchucks. Woodchuck hepatitis virus, which shares a large degree of homology with human HBV, was examined for indications of mutational variants. No alteration in the pre-C region was found, but as in HBV, viral DNA could still be detected by PCR after seroconversion to anti-WHe.


Potyvirus serology, sequences and biology. Amino acid sequences of the cytoplasmic cylindrical inclusion protein (CIP), large nuclear inclusion protein (NIb), and coat protein (CP) of potyviruses were re-examined in light of reported serological relationships, and correlated with known and deduced biological functions. No obvious correlations were observed between either amino acid sequences or epitopes recognized by monoclonal antibodies and the natural host ranges of the potyviruses examined. Whereas the identified sequence motifs of the RNA helicase (CIP) and replicase (NIb) are predicted to be antigenic, most of the conserved sequences and epitopes in the CIP, NIb and CP were presumed to be maintained for structural rather than functional reasons. Three possible potyvirus clusters are proposed on the basis of the length and composition of the virion surface-exposed amino terminal extension of the CP; these clusters do not correlate with overall CP sequence homology, host range, or vectors, but are of potential evolutionary significance and hence of possible taxonomic value.


Coat protein phylogeny and systematics of potyviruses. The feasibility of applying molecular phylogenetic methods of analysis to aligned coat-protein sequences and other molecular data derived from coat proteins or genomic sequences of members of the proposed taxonomic family of Potyviridae, is discussed. We show that comparative sequence analysis of whole coat-protein sequences may be used reliably to differentiate between sequences of closely related strains, and to show groupings of more distantly related viruses; that coat proteins of putative Potyviridae cluster according to the proposed generic divisions, and, even if some are only very distantly related, the members of the family form a cluster distinct from coat proteins of other filamentous and rod-shaped viruses. Taxonomic revisions based on perceived evolutionary relationships, and the lack of feasibility of erecting higher taxa for these viruses, are discussed.


Application of genome sequence information in potyvirus taxonomy: an overview. The application of protein and nucleic acid sequence analysis in evolutionary and phylogenetic studies is well established. Available sequence information for the 5' untranslated region of potyviruses including the fungus-transmitted barley yellow mosaic virus (BaYMV) RNA-1 suggests that a 12-nucleotide conserved sequence, the "potybox" is unique to this group. Various non-structural proteins of potyviruses share considerable "signature" sequence homology across a broad spectrum of unrelated viruses, which makes their value limited to "supergroup" or "superfamily" identity. However, in potyviruses, the coat-protein N-terminal sequences and 3' noncoding regions are variable among viruses, but similar among strains of the same virus. This suggests that these sequences may be an accurate marker of genetic relatedness. Until complete genome sequences from a large number of potyviruses become available and their value in systematics is tested, coat protein and 3' noncoding regions remain as the choice of taxonomic indicators. The reason being, that cloning and sequencing of the coat-protein gene and 3' noncoding regions are less complicated and time consuming and the sequences show significant differences among the virus species within the family Potyviridae.


Importance of host ranges and other biological properties for the taxonomy of plant viruses. With reference to the confusion regarding the value of biological properties for the taxonomy of plant viruses, following proposal is made. Distinction between viruses should be based on the nucleotide sequences of the genome, whereas that between strains should take also biological characteristics into account.


Clustering Potyviridae species on the basis of four major traits. Cluster analysis was used to examine taxonomic relationships among 31 potyviruses, using four categorical variables; genome segmentation, vector, inclusion bodies produced and host range. Analysis showed that regardless of weight given to genome segmentation, the fungus-transmitted viruses clustered in one group and the rest of the viruses in another at 60% level of similarity. It has been concluded that the creation of one family to include both the bymoviruses and potyviruses seems to be a reasonable compromise at the present time.


Specific infectivity and host resistance have predicated potyviral and pathotype nomenclature but relate less to taxonomy. The names of potyviruses and viral-strains have represented the occurrence of predominant pathotypes on predominant crop genotypes. Thus virus nomenclature, but not viral taxonomy, has been decisively influenced by plant-genotype susceptibility and indirectly by host genetic resistance. REsistance to infection (i.e., host range) continues to serve a practical role in differentiating recognized viruses. Plant genes that confer disease tolerance or viral resistance remain a principal means of viral pathotype differentiation, as well as a principal control measure against major viral pathogens. Degrees of genetic diversity among isolates of recognized viruses should not be underestimated, and any system of viral taxonomy should be prepared for flexibility at the species level.


Sources of resistance to viruses in the Potyviridae. Resistance to 56 viruses in the family Potyviridae in 334 plant species was tabulated. Studies conducted in the last 60 years have elucidated the genetics and usefulness of 135 resistance genes, but no reports on the heritability of other sources of resistance are available. In most of the plant species, resistance to species of Potyviridae was simply inherited, either dominantly (60 genes) or recessively (39 genes). In some cases resistance was conferred by two or more genes. Symbols have been assigned to 86 genes, of which very few are duplicate entities. Resistance genes can be useful in determining relationships among these viruses, as well as for their identification. The role of conventional breeding and biotechnology in transferring genes from one species to another is discussed.


A potyvirus in nature: indistinct populations. Potyviruses occur in nature as a variable population. A number of strains have been reported for many potyviruses. Two or more viruses have been separated from "one virus" isolate. Experimental isolation and/or transmission often results in atypical viral isolates. A virus may be considered as a fuzzy population. We should properly understand the range of variation in one virus. The range of variation as well as typical characteristics of a virus should be included in future descriptions.


Potyvirus taxonomy: potyviruses that affect solanaceous crops. Serology has been the main, or at least an important, tool for differentiating potyviruses that affect solanaceous crops. At present, analysis of the genome by hybridization techniques has supported the differentiation of viruses demonstrated by serology. Phylogenetic groupings, based on nucleic acid sequences, should be combined with serological detection to make the groupings more usable.


Biological variants of tobacco etch virus that induce morphologically distinct nuclear inclusions. The presence of distinctive nuclear inclusions has been used for many years as a diagnostic character for tobacco etch virus (TEV). Cytological examinations of isolates of TEV in both weeds and solanaceous crops from areas widely separated geographically have demonstrated the presence of a variety of nuclear inclusions that vary considerably in form. Such inclusions can, in many cases, be related to differences in symptom expression. It is suggested that distinctive nuclear inclusions may be used to select biological variants of TEV that may be useful in the study and manipulation of closely related "strains" of this potyvirus.


Biological variability of potyviruses, an example: zucchini yellow mosaic virus. Potyviruses present an important variability which may affect biological properties such as host range, symptomatology, virulence towards resistance genes, and transmissibility by vectors. A brief account of this potential is presented and illustrated by some aspects of the biological variability of zucchini yellow mosaic virus (ZYMV).


Designation of potyvirus genera: a question of perspective and timing. It may be premature to subdivide the Potyviridae into genera (Bymovirus, Potyvirus, Rymovirus) since definitive serological and vector interrelationships between them remain to be established. Monogenic proposals for classifying Potyviridae should also be viewed askance until their practical value in agricultural settings can be demonstrated.


Fungal transmission of a potyvirus: uredospores of Puccinia sorghi transmit maize dwarf mosaic virus. Maize dwarf mosaic virus (MDMV) and maize rust, Puccinia sorghi Schw., occur as natural infections on cultivated maize in South Africa. P. sorghi often occurs as a secondary late infection on maize plants which have already been infected with MDMV earlier in the season, either seed or aphid transmitted. When MDMV isolates from maize plants naturally infected by both virus and fungus were propagated by sap inoculation in plant growth rooms, residual uredospores in the sap gave rise to the development of uredia under conditions of high humidity. When uredospores developing on MDMV-B-infected plants were germinated on virus free maize seedlings, these plants became infected with MDMV-B. Similarly, when uredospores, originating from maize plants infected with MDMV-A, were scattered onto virus free maize seedlings, these plants became infected with MDMV-A. The presence of virus on uredospores in infected plant tissue was visualized by indirect immunofluorescence. Identification of virus infection was by DAS-ELISA and immunoelectro-blotting utilizing strain-specific antisera. Virus transmission occurred between closely situated plants which had no actual contact (unaided transmission). MDMV-B transmission by uredospores, to new maize seedlings, has been maintained for three successive years (1988-1991) in a plant growth room. The MDMV-B isolate remained sap and non-persistently aphid transmissible.


Inclusion bodies.

Inclusion bodies. All viruses in the family Potyviridae which have been studied cytologically (currently 111) induce cylindrical inclusions in host cytoplasm. These inclusions are controlled by portions of the virus genome, therefore, viruses which induce them are related. Viruses in other groups do not induce this type of inclusion. Cylindrical inclusions have come to be recognized as one of the main characteristics of the family Potyviridae. They are used in diagnosis of diseases induced by these viruses. For diagnostic purposes the family can be separated into four subdivisions on the basis of differences in cylindrical inclusion morphologies. Assigning viruses to subdivisions assists in virus identification at the specific and in some instances at the strain level.


The usefulness of aphid transmission as a taxonomic criterion for potyviruses. In the past vector relationships have been one of the criteria used for delineating plant virus taxa. The proposed family, the Potyviridae, continues that practice. Aphid transmission of viruses within the genus Potyvirus is a useful characteristic in terms of identification, but is of only limited use in terms of taxonomy. This conclusion is based on a greater understanding of the molecular biology of potyviruses. The molecular basis of aphid transmission is not well understood at the present, but these data suggest that, beyond disease diagnosis, virus identification and characterization, and potential identification of genome microheterogeneity, aphid transmission should only be considered as a minor taxonomic criterion.


Viruses of the Potyviridae with non-aphid vectors. The large majority of members of the family Potyviridae are aphid-transmitted. However, 17 viruses whose vectors are unknown have been classified as members of the genus Potyvirus. Loss of aphid transmissibility has been observed in some strains of several potyviruses. There are currently 11 members of the Potyviridae whose vectors are not aphids. These viruses with non-aphid vectors exhibit most of the characteristics of the family. Viruses of the Potyviridae induce cytoplasmic cylindrical inclusions in their hosts whether their vectors are aphids, non-aphids, or are unknown. The virus genome produces the inclusion protein and thus the viruses have related inclusion body gene sequences. Non-aphid-transmitted viruses of the Potyviridae also are serologically related to aphid-transmitted potyviruses.


Potyviridae: genus Rymovirus.

Potyviridae: genus Rymovirus. The genus Rymovirus of the family Potyviridae is comprised of seven rod-shaped viruses with the shared characteristic of being transmitted by mites. Aside from this distinguishing feature, rymoviruses are similar to aphid-transmitted potyviruses in that they share a similar particle morphology, some similar antigenic determinants, similar physico-chemical properties, the ability to induce the formation of cytoplasmic cylindrical inclusions, and the ability to infect only graminaceous hosts. In vitro translation studies with wheat streak mosaic virus (WSMV) suggest that this rymovirus uses a potyviral proteolytic processing strategy to express the 3' terminal capsid protein. At the molecular level, limited nucleotide sequence data for WSMV show similarities with aphid-transmitted potyviruses in the potyviral capsid protein, large nuclear inclusion and cylindrical inclusion regions. Thus, given the similarities between the rymoviruses and the potyviruses, it is appropriate to include this genus within the family Potyviridae.


How important is genome division as a taxonomic criterion in plant virus classification? The number of nucleic acid components that constitute a virus genome has been used as an important discriminatory character in defining groups of plant viruses. However, with some virus groups, in particular potyviruses, recent results of nucleotide sequencing have reinforced previously deduced tentative relationships among viruses with different numbers of genome parts. A convenient solution is to classify these different types into groups or genera within a family (e.g. Potyvirus and Bymovirus in the family Potyviridae).


Sequence data as the major criterion for potyvirus classification. Recent knowledge of the structure of the potyvirus particle and its components appears to have resolved what was thought to be an intractable problem of plant virology. This review describes how coat-protein and gene sequence data can be used to provide an hierarchical classification of potyviruses. This classification puts the aphid and non-aphid-transmitted potyviruses into a single family, divides this family into four genera that correspond to the four modes of vector transmission, discriminates distinct potyvirus species from strains, and provides a basis for the formation of subgroups composed of closely related species within a genus.


The recombinative nature of potyviruses: implications for setting up true phylogenetic taxonomy. Sequence comparisons reveal that positive-strand RNA viruses not only evolve by divergence from common ancestors but also by interviral recombination. A considerable number of these viruses, exemplified by the family Potyviridae, can in fact, be regarded as successful products of a number of recombination events. It is concluded that the recombinative character of RNA viruses will hamper any attempt to set up a true phylogenetic taxonomy. It is advisable, therefore, to avoid the introduction of any taxon higher-than-family in virus taxonomy.


The general properties of potyviruses.

The general properties of potyviruses. The criteria used during the past three decades for including viruses in the potyvirus group are briefly discussed and evaluated. The biological and physico-chemical properties of the viruses transmitted by aphids, mites, whiteflies, or the fungus Polymyxa graminis are reviewed, and the taxonomic value of their molecular properties in regrouping the viruses into four groups or genera within the family Potyviridae is discussed.


Nomenclature and relationships of some Brazilian leguminous potyviruses related to bean common mosaic and/or passionfruit woodiness viruses. The main Brazilian literature of the last 10 years on potyviruses of leguminous plants related to bean common mosaic virus (BCMV) and/or to passionfruit woodiness virus (PWV) is discussed and summarized. The viruses dealt with are canavalia acronecrosis, mosaico de canavalia, cassia yellow spot, cowpea green vein-banding, cowpea rugose mosaic and cowpea severe mottle. The viruses have similar biological properties, such as a host range restricted mainly to the Leguminosae, aphid transmission, seed transmission in leguminous plants, and various degrees of serological relationships with BCMV and PWV.


Potyviruses, chaos or order?

Potyviruses, chaos or order? At first potyviruses were easily distinguished by biological and serological properties because only a few were known and information on their host ranges was limited. The first evidence of serological cross reaction between two of these viruses was reported in 1951 and was further corroborated for three obviously distinct members of the group in 1960. In 1968 attention was drawn to the fact that some legume and non-legume potyviruses have much wider host ranges than previously known and that within the potyvirus group there is as much biological variation within viruses and overlap between viruses as there is in serology. The concept of continuity within the group was soon supported by others and became known as the "continuum hypothesis." Results with highly sensitive serological methods using polyclonal antisera were conflicting, and nucleic acid hybridization techniques did not unambiguously discriminate between potyviruses. Recent results, obtained with antibodies directed toward epitopes located in the N-termini of the coat proteins of potyviruses, suggest that there are ways to more definitely group strains of one potyvirus and distinguish them from other potyviruses. However, there are exceptions to this rule, as in the case of bean yellow mosaic virus and clover yellow vein virus which are clearly distinct in host range, inclusion bodies, and migration velocity of coat protein, but which still react with antibodies to the N-terminal epitopes of one virus. So the question remains of whether coat-protein properties, especially the serological reactivity of N-termini, which do not alter overall virus integrity when lost, sufficiently represent the genome of a pathogenic virus entity as a single criterion for classification.


Relationships among iris severe mosaic virus (ISMV) isolates. The ISMV isolates studied so far, have been found to be indistinguishable both by serological and hybridization assays. Therefore, the different symptoms induced by these isolates may be based on only minor molecular changes.


A comparison of pepper mottle virus with potato virus Y and evidence for their distinction. Pepper mottle virus (PepMOV) was identified as a distinct potyvirus infecting peppers in Arizona and Florida in the 1970's. The distinction of PepMoV from potato virus Y (PVY) has recently been challenged on the basis of sequence comparisons of the coat proteins and of the 3' nontranslated regions of the viral RNAs. We summarize the biological, cytological, serological, and in vitro translational studies which compare the apparent differences, and also similarities, between PepMoV and PVY. We conclude that although PepMoV may be more closely related to PVY than to other known potyvirus, PepMoV should be maintained as a separate virus on the basis of its distinctive characteristics.


Is pepper mottle virus a strain of potato virus Y? On the basis of serological properties and host plant reactions pepper mottle virus (PepMoV) has been classified as a potyvirus related to, but distinct from, other pepper-infecting potyviruses, potato virus Y (PVY) and tobacco etch virus (TEV). Recent amino acid and nucleotide sequence data show that PepMoV is more closely related to PVY than previously assumed. PepMoV shows a high degree of homology to various PVY strains in both the coat protein and the 3' non-translated sequences, while unrelated potyviruses are generally less homologous in these regions. Detailed coat-protein amino acid sequence and 3' non-translated region (3' NTR) nucleotide sequence comparisons described in this paper confirm the close relationship between PepMoV and PVY and it is concluded that the isolate sequenced indeed represents a strain of PVY. Sequence data for several strains of PVY gave two groups with closer relationships among strains in a group than between groups.


Evidence that pepper mottle virus and potato virus Y are distinct viruses: analyses of the coat protein and 3' untranslated sequence of a California isolate of pepper mottle virus. Pepper mottle virus (PepMoV) is a member of the large and complex genus Potyvirus, and is classically distinguished from other members of the genus by differential host range and cytopathology as well as serology of the coat protein and cytoplasmic inclusion body proteins. Here we report the deduced amino acid sequence of the coat protein of a California potyvirus identified by a variety of classical methods as PepMoV (PepMoV C). Comparison of the 3' untranslated nucleic acid sequence and the deduced coat-protein amino acid sequence of the PepMoV C isolate with those of PVY and other potyviruses indicates that PepMoV C is sufficiently diverged to be considered a distinct virus species. Thus, comparative sequence analyses of the PepMoV C isolate support earlier serological and biological evidence that PepMoV and PVY are distinct viruses.


A viewpoint on the taxonomy of potyviruses infecting sugarcane, maize, and sorghum. The value of taxonomy lies in its ability to communicate concepts and relationships. Our present concepts of the poaceous potyviruses, based on their biology, serology, and biochemistry, identify four viruses that can be distinguished by each characteristic. Identifying these as four distinct viruses has important implications for disciplines such as epidemiology, plant breeding, and diagnostics.


Differentiation of the four viruses of the sugarcane mosaic virus subgroup based on cytopathology. A cytological comparison has been made of representative isolates of johnsongrass mosaic (JGMV), maize dwarf mosaic (MDMV), sorghum mosaic (SrMV) and sugarcane mosaic (SCMV) viruses. These four viruses now encompass the complex of virus strains which were formerly considered as strains of sugarcane mosaic and/or maize dwarf mosaic viruses. The structure of the cytoplasmic cylindrical inclusions induced by these viruses, together with other cytological alterations, allow the four viruses to be distinguished. Pinwheels, scrolls and laminated aggregates were produced only by SCMV whereas JGMV, MDMV, and SrMV produced only pinwheels and scrolls. SrMV produced amorphous cytoplasmic inclusions which are not produced by JGMV and MDMV. The latter two were rather similar in cytological effects except that the SCMV-JG (U.S.A.) isolate of MDMV produced aggregates of needle-like structures in the cytoplasm which were not found with JGMV and the other MDMV isolates. The specific cytological effects induced by these viruses thus corroborate the recent classification of these viruses based mainly on the properties of the coat-protein gene, the 3' noncoding nucleotide sequences, and host reactions.


Present status of the sugarcane mosaic subgroup of potyviruses. Until recently, sugarcane mosaic virus (SCMV) was believed to be a single potyvirus consisting of a large number of strains, differing from each other in certain biological and antigenic properties. The use of affinity-purified polyclonal antibodies directed towards the surface-located, virus-specific amino termini of the coat proteins showed that 17 strains from Australia and the United States represented four distinct potyviruses, namely johnsongrass mosaic virus (JGMV), maize dwarf mosaic virus (MDMV), sorghum mosaic virus (SrMV) and SCMV. Comparisons of strains from each of these four viruses on the basis of reactions on differential sorghum and oat cultivars, cell-free translation of RNAs, morphology and serology of cytoplasmic cylindrical inclusions, amino acid sequence and peptide profiling of coat proteins, 3' non-coding nucleotide sequences, and molecular hybridization with probes corresponding to the 3' non-coding regions, resulted in exactly the same taxonomic assignments as obtained using amino-terminal serology. These results further confirm that the former sugarcane mosaic virus actually consists of four distinct viruses and show that MDMV, SrMV, and SCMV are more closely related to each other than they are to JGMV. Because these four viruses are closely related but distinct, formation of a sugarcane mosaic subgroup in the genus Potyvirus would be appropriate.


Bean yellow mosaic virus subgroup; search for the group specific sequences in the 3' terminal region of the genome. In order to examine relationships among viruses of the bean yellow mosaic subgroup of the Potyvirus genus, several isolates of bean yellow mosaic virus (BYMV) and clover yellow vein virus (C1YVV) were compared by amino acid sequence of the coat protein and nucleotide sequence of the 3' terminal non-coding region. The sequence comparisons showed that BYMV and C1YVV were distinct viruses but had close affinity to each other (85-95% homology among isolates of a virus but 70-77% homology between viruses), justifying establishment of the BYMV subgroup. There was an oligonucleotide consensus sequence present in the 3' terminal non-coding region of all potyviruses examined. This consensus sequence divided the potyviruses into three groups whose significance is not clear.


A proposal for a bean common mosaic subgroup of potyviruses. In order to elucidate the taxonomic positions of bean common mosaic virus (BCMV) and blackeye cowpea mosaic virus (B1CMV), several strains of these viruses were compared on the basis of host ranges, antigenic properties established with antisera to virions and to N-terminal peptide domains of their coat proteins, and high performance liquid chromatographic peptide profiles. The comparison includes three strains of BCMV, viz. NL1, NL3 and NY15, four strains of B1CMV, viz. Fla, Ind, NR, and W, and the Moroccan isolate (Mor) of cowpea aphid-borne mosaic virus (CABMV), formerly designated as B1CMV-Mor. Based on these parameters, Fla, NR, and W are strains of one virus, whereas NL3, Ind and CABMV-Mor (and possibly NL1 and NY15) are separate viruses. In view of these characteristics which allow similar viruses to be separated, we propose that these viruses be included in a bean common mosaic subgroup of the genus Potyvirus.


Serological and biological relationships among viruses in the bean common mosaic virus subgroup. Bean common mosaic virus (BCMV), blackeye cowpea mosaic virus (B1CMV), cowpea aphid-borne mosaic virus (CABMV), azuki bean mosaic virus (AzMV), and peanut stripe virus (PStV) are five species of the genus Potyvirus, family Potyviridae which are seed-transmitted in beans or cowpeas. Eighteen isolates of BCMV, five isolates of B1CMV, four isolates of CABMV, and one isolate each of AzMV, and PStV were compared serologically using a panel of 13 monoclonal antibodies (MAbs) raised against BCMV, B1CMV, CABMV, or PStV in indirect enzyme-linked immunosorbent assay (ELISA). Four MAbs detected all virus isolates; one detected all isolates except those of CABMV. Three MAbs were specific only for serotype A isolates of BCMV. Four MAbs detected all serotype B isolates of BCMV plus all isolates of B1CMV, AzMV, and PStV. None of the antibodies distinguished among these four viruses. However, in biological tests with 11 bean cultivars selected for differentiating BCMV pathotypes, all isolates of B1CMV, AzMV, and PStV could be differentiated from the BCMV serotype B isolates by their reactions on a few bean cultivars in host group I and the cowpea cultivar California Blackeye #5. Potential problems that can arise from the use of nonauthenticated isolates are also discussed.


Strains of bean common mosaic virus consist of at least two distinct potyviruses. Bean common mosaic virus (BCMV) consists of a large number of pathotypes and strains which have largely been identified by their characteristic interactions with a selected number of differential bean cultivars. The relationships among these strains and other potyviruses that infect legumes are complex, with indications that BCMV, blackeye cowpea mosaic virus (BlCMV) and azuki bean mosaic virus (AzMV) may be strains of the one virus. Using high performance liquid chromatographic peptide profiles of coat-protein digests, the NL3 and NY15 strains of BCMV were compared with each other, with the Type and W strains of BlCMV and with the mild mottle strain of peanut stripe virus (PStV). The results suggest that BCMV-NL3 and BCMV-NY15 are distinct potyviruses, not strains of the one virus, and that BCMV-NY15 is a strain of the same potyvirus that includes BlCMV, PStV, AzMV and three potyvirus isolates (74, PM, PN) from soybeans.


A summary of potyvirus taxonomy and definitions. The current taxonomic status of the family Potyviridae is presented with suggestions for resolving some taxonomic problems. Terms such as strain, pathotype, serotype, variant, mutant, and isolate are discussed in relation to the family.


What is a virus?

What is a virus? The earlier reluctance of some plant virologists to use the term "virus species" has been overcome and the species has now been accepted as the basic unit in virus classification. A virus species is a polythetic class of viruses that constitutes a replicating lineage and occupies a particular ecological niche. Because of the polythetic nature of virus species, there is no single property, such as a particular level of genome homology, that could be used as the sole criterion for delineating individual virus species.


Serology of potyviruses: current problems and some solutions. The serological relationships among members of the family Potyviridae are extremely complex and inconsistent. Variable cross-reactivity of polyclonal antisera, unexpected paired relationships between distinct viruses, and lack of cross-reactions between some strains are the major problems associated with the serology of potyviruses. Recent biochemical and immunochemical investigations of coat proteins have established the molecular basis for potyvirus serology and provided explanations for most of the problems with serology of potyviruses. Information from these studies has also formed the basis for the development of several novel approaches to the accurate detection and identification of potyviruses. However, even these novel approaches are not without drawbacks and some of them cannot be applied easily in plant virus laboratories, since they require prior sequence information and facilities for peptide synthesis. These findings suggest that serology is an imperfect criterion for the identification and classification of potyviruses.


Polyclonal reference antisera may be useful for the differentiation of potyvirus species. Attention is directed to the usefulness of polyclonal antisera for the identification of potyviruses on the species level. A scheme for the preparation of such antisera is given.


Proteolytic cleavage of the N-terminal region of potyvirus coat protein and its relation to host recovery and vector transmission. The proteolytic cleavage of potyvirus coat N-terminal region is discussed with relation to host recovery and aphid transmission. The relationship of this coat protein region and the HC, may affect the host range and should be considered in this virus group classification.


Some unusual serological reactions among potyviruses. The determination of relationships among and the identification of potyviruses with polyclonal antibodies does not always lead to a proper conclusion. The potyvirus specific monoclonal PTY 1 does not detect all potyviruses tested.


Serological relationships involving potyviral nonstructural proteins. This report represents a compilation of many of the publications on antigenic properties of potyviral-specified nonstructural proteins. Polyclonal antisera have been prepared for use in characterization of six nonstructural proteins. These include antisera to the cylindrical inclusion proteins of at least 28 potyviruses, to small nuclear inclusion protein (protease) of four potyviruses, to large nuclear inclusion protein (putative replicase) of three viruses, helper component-protease or amorphous inclusion protein of at least four viruses, to the P1 protein (located at the N-terminus of the polyprotein) of one virus, and to the P3 protein (located between helper component protease and cylindrical inclusion protein) of one virus. Monoclonal antibodies also have been prepared to several of these nonstructural proteins. The evidence thus far indicates that cylindrical inclusions of different potyviruses have both conserved and unique epitopes. Nuclear inclusion proteins and amorphous inclusion proteins also may have conserved and unique epitopes. Antigenic relationships of potyviral nonstructural proteins have potential for the identification and classification of potyviruses.


Legal implications of the Patient Self-Determination Act. Passage of the Patient Self-Determination Act provides professional nurses with the opportunity to expand their existing roles of educator and advocate. Institutional policies and procedures implementing the Act should be flexible enough to permit registered nurses to answer questions about the right to refuse medical treatment and how to implement that right. Patients and their families have been asking nurses these questions since before the Quinlan case was decided in 1976.


The Patient Self-Determination Act: the ethical dimensions. Advanced, sophisticated technology, rising health care costs, and consumerism all combined to drive the development of the Patient Self-Determination Act. Ethical implications include, but are not limited, to the principles of autonomy and beneficence. Paternalism is also discussed as a compromise to autonomy. Caring is used to focus on the contextual perspective of both patients and nurses for ethical decision making. Implications for future ethical practice conclude the discussion.


Family perspective on the necessity for advance medical directives. Although our parents made no written advance medical directives before becoming terminally ill, with the support of the nursing staff we were able to assist them in their quest for a natural death with dignity. This article presents some of the dilemas faced by families in making end-of-life decisions. The author acknowledges the importance of permission for and support of the decision making by other health care providers, and reflects that advance directives would have facilitated the process.


Advance care directives: counseling the patient and family in the primary care setting. NPs are in an excellent position to provide primary care patients with the appropriate counseling for the development of required advanced care directives before the onset of serious illness and hospitalization. Discussion of how and whom to counsel assists the NP in undertaking this important responsibility encountered by primary care providers.


Organ donation authorization: an advance medical directive. Primary health care providers may increase the number of organ donations by providing an opportunity for authorization during a health care visit. Lack of authorization prevents many recipients from the benefits of life saving transplants.


Health decisions: maintaining control of health care choices. Advanced technology sometimes prolongs life without improving the quality of life. California's Durable Power of Attorney for Health Care (DPAHC) provides individuals with a tool to maintain control over their future health care should they become unable to make health care decisions. California Health Decisions (CHD) developed a comprehensive workshop designed to inform people about the DPAHC and its options and has played a leadership role in educating health care professionals, the general public, seniors, and employee groups. CHD has set a goal of helping 1 million Californians complete a DPAHC by 1995. This article describes the issues involved in implementing the educational goals to achieve this objective.


Microcontroller-based real-time QRS detection. The authors describe the design of a system for real-time detection of QRS complexes in the electrocardiogram based on a single-chip microcontroller (Motorola 68HC811). A systematic analysis of the instrumentation requirements for QRS detection and of the various design techniques is also given. Detection algorithms using different nonlinear transforms for the enhancement of QRS complexes are evaluated by using the ECG database of the American Heart Association. The results show that the nonlinear transform involving multiplication of three adjacent, sign-consistent differences in the time domain gives a good performance and a quick response. When implemented with an appropriate sampling rate, this algorithm is also capable of rejecting pacemaker spikes. The eight-bit single-chip microcontroller provides sufficient throughput and shows a satisfactory performance. Implementation of multiple detection algorithms in the same system improves flexibility and reliability. The low chip count in the design also favors maintainability and cost-effectiveness.


Upper gastrointestinal complaints and complications in chronic rheumatic patients in comparison with other chronic diseases. The aim of this study was to compare the frequency of upper gastrointestinal (GI) complaints and complications between chronic rheumatic patients who are most often non-steroidal anti-inflammatory drugs (NSAIDs) users and patients with other chronic conditions. In this comparison we took into account known risk factors for upper GI disease. To achieve the study aims we performed a combined cross-sectional and retrospective study. We therefore interviewed by means of a standard questionnaire, an index and a reference group, about current upper GI complaints and previous complications. The former group comprises 578 outpatients of the Department of Rheumatology, the latter of 531 outpatients of the Departments of Internal Medicine, Pulmonology, and Cardiology. Although the number of patients in the index group being chronically treated with NSAIDs was very high (62% versus 9% in the reference group: P < 0.00001), no between-group differences were found for the frequency of several current upper gastrointestinal complaints or for the number of upper gastrointestinal investigations ever performed (35% and 37%: NS) or for the use of gastric drugs (14% and 10%: NS). Risk factors for upper GI complaints were not related to NSAID use but with the use of prednisolone, history of duodenal ulcer disease, family history of peptic ulcer disease and female sex. For peptic ulcer disease, bleeding, and gastric surgery, the only difference between the index and reference groups concerned the frequency of gastric ulcers (6.7% and 2.8%: P < 0.005), which was highest in patients with rheumatoid arthritis. Upper GI bleeding had more often been present in male seropositive rheumatoid arthritis patients (13.2% [corrected] and 4.5%: P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)


A computerized system to evaluate volumetric infusion pumps. A computerized system was developed to examine the performance characteristics of infusion pumps. This system collects solution delivered by an infusion pump through an intravenous needle into a collection vessel. Using an inductor-type weight sensor and a semiconductor type of strain-gauge pressure sensor, the weight of the collection vessel and the pressure at the needle were monitored over a specific period (the sampling time), and changes in pressure, flow rate, and volume of fluid were calculated. This system was applied to five volumetric infusion pumps with different pumping mechanisms. Test conditions involved two different solutions, two sizes of needle gauge, and seven flow rates, for a total of 28 measurements per pump. Results showed considerable variation in the infusion pumps' performances based on differences in these indices. Use of an inductance weight sensor as a means to evaluate gravimetric performance appears to be an improvement over conventional methods, which use analytical balances for data generation. The results indicate that this system will be useful in evaluating the performances of commercially available infusion pumps as well as those in development.


The gastroduodenal safety and efficacy of the fixed combination of diclofenac and misoprostol in the treatment of osteoarthritis. A double-blind, randomized, parallel group study was conducted to compare the gastroduodenal safety and antiarthritic efficacy of a fixed combination of diclofenac 50 mg and misoprostol 200 micrograms with that of a combination of diclofenac 50 mg and placebo in patients with osteoarthritis. Three hundred and sixty-one patients with no significant gastroduodenal lesions were enrolled and received study medication two or three times daily for 4 weeks. Post-treatment endoscopic examination of the gastroduodenal mucosa revealed ulcers in 4% of patients in the diclofenac/placebo group compared with none in the diclofenac/misoprostol group (P = 0.015). There were no clinically or statistically significant differences between the two treatment groups in formal assessments of osteoarthritis after either 2 or 4 weeks. It was concluded that diclofenac/misoprostol was associated with significantly less gastroduodenal damage than diclofenac, whilst being as effective as diclofenac alone in the treatment of osteoarthritis.


Urinary collagen crosslinks reflect the radiographic severity of knee osteoarthritis. The collagen crosslinks deoxypyridinoline and pyridinoline are indices of mature collagen breakdown and reflect increased bone turnover. Urinary levels were found to be significantly raised in a group of 59 women with knee OA compared to 110 female controls from the general population. Levels of the crosslinks correlated significantly with X-ray grade of all subjects including women from the general population with mild, often asymptomatic, disease. These correlations were not diminished after adjustment for age and weight.


Quantitative measurement of ventilation at the mouth and nose with heat sensors. Airflow at the nose and mouth is routinely measured during polysomnography for the evaluation of respiratory disturbances during sleep. The usual monitoring device is a small thermocouple placed in front of the nose and mouth that qualitatively detects airflows in or out. A more accurate pneumotachometer on a tight-fitting mask is less frequently used because of the discomfort that is introduced and its potential interference with sleep. The authors tested ten heat-sensing devices modified to increase accuracy without increasing discomfort. The designs of these ventilation monitors differed in choices of specific heat detector, techniques of mounting on the face, and types of heat-trapping covers employed. The goal was to find a comfortable oronasal monitor and to define a procedure that could identify those units that generate signals approaching quantitative ventilatory flow. The signal from each device was compared with a "standard" signal derived from respiratory belts during contrived respiratory maneuvers that assessed specific potential sensing problems. The devices behaved differently, and design perturbations could be controlled to construct flow detectors to closely match actual flow. The more accurate devices could be as comfortable as commonly used monitors that do not have the enhanced accuracy. The principles and techniques described for improving the measurement of oronasal ventilation by heat sensor can be invoked to develop monitors that can closely measure actual quantitative ventilatory flow.


Sibship size does not increase the risk of developing rheumatoid arthritis. Although the cause of rheumatoid arthritis (RA) is unknown, one hypothesis is that an infectious episode may trigger the disease and this may occur in childhood. Observational studies performed at least 25 years ago have suggested that the incidence of RA is increased in individuals from large families. We therefore tested this hypothesis using data from a case-control study of 218 females with RA aged 35-70 (mean 58.9 years) and 210 similar aged osteoarthritis (OA) females. Information was obtained by postal questionnaire on sibship size, position in family and sex ratio of siblings. No significant differences were found between the cases and controls for any of these variables. This study did not support the hypothesis that early childhood infection as a consequence of overcrowding is an important factor in the development of RA.


Clinical differentiation of oral ulceration in Behçet's disease. Behçet oral ulceration (BOU) is described as being indistinguishable from conventional recurrent oral ulceration (ROU). A clinical comparison between 38 Behçet patients and 38 control ROU cases was effected by completion of a standard questionnaire. Behçet patients reported an increased number of concurrent ulcers and involvement of the soft palate and oropharynx. No differences were detected with respect to duration, frequency, age of onset or family history. In addition, photographs of BOU in 15 patients revealed the concurrence of atypical aphthous and herpetiform varieties. Number, site and appearance of oral ulceration may therefore provide diagnostic features for the development of Behçet's disease.


Injection therapy of superficial rheumatoid nodules. Although intralesional corticosteroid injection of subcutaneous rheumatoid nodules was mentioned in 1968, this simple procedure is not commonly practised. A placebo-controlled, double-blind trial of intralesional corticosteroid injection using 24 rheumatoid nodules from 11 patients was carried out to determine the efficacy and safety of the procedure. Nodules injected with methylprednisolone and lignocaine regressed significantly more than nodules injected with placebo (lignocaine alone). This was consistently shown in all modalities of assessments which included patients' assessments (P < 0.001) and investigator's assessments (P < 0.001) of the percentage change in nodule size, and gross measurements of nodule volumes using a pincer (P < 0.001). Nine of 12 active injections produced > or = 50% loss in nodular volume with complete disappearance of two nodules. This compares with only one out of 12 placebo injections which resulted in > or = 50% loss in nodular volume. The patients found all 12 active injections to be worthwhile compared to only two of 12 placebo injections being worthwhile. The only complication of injection therapy observed was that of pain during the procedure.


Papular mucinosis (scleromyxoedema) complicating diffuse systemic sclerosis: clinical features and electron microscope observations. Papular mucinosis (scleromyxoedema) is an uncommon disorder characterized by generalized papular eruption and cutaneous induration, which may be associated with a variety of extracutaneous manifestations. Although scleroderma and papular mucinosis share many features, they are clinically and histologically distinct entities. We report here a patient with diffuse scleroderma who developed superimposed papular mucinosis. Degranulating mast cells were a prominent ultrastructural finding in the involved skin. The occurrence of scleroderma and papular mucinosis, two uncommon cutaneous indurative diseases, in the same patient has not been described previously.


The evolution of a case of overlap syndrome with systemic sclerosis, rheumatoid arthritis and systemic lupus erythematosus. An unusual case of overlap syndrome which evolved over a 12-year period is described. The patient initially presented with limited cutaneous systemic sclerosis. She then developed seropositive erosive rheumatoid arthritis and subsequently vasculitis with positive lupus serology. There was no evidence that she had mixed or undifferentiated connective tissue disease, and antibody to ribonuclearprotein was negative. This unusual combination of connective tissue disorders in one patient is reported and the literature is reviewed.


Efficiency of a lead-containing tie for radiation protection of the thyroid gland. During fluoroscopy the examiner is usually protected by a radiation-reducing body shield, leaving the thyroid unprotected. The fact that the thyroid is located in a region of the neck usually covered by the shirt collar led to the idea of designing a tie with lead core, providing easy and "decorative" reduction of the radiation dose. Sonographic examinations were carried out in 20 volunteers (10 men, 10 women) to determine the size of the gland and its coverage by such a tie. The reduction of the surface and organ dose was assessed using film dosimetry with scattered radiation, the body of the examiner being simulated by an Alderson phantom. On average 88% of the thyroid gland surface area was covered. Surface dose was reduced to 1%, and organ dose to 10% of the value without the protection tie.


Measuring radiation exposure during percutaneous drainages: can shoulder dosemeters be used to estimate finger doses? Some previous studies have shown remarkably high finger doses to radiologists performing percutaneous drainage under fluoroscopy. To assess the possible need for extra finger dosemeters in addition to the general dosemeter, radiologists' and assistants' radiation exposure at both shoulders and at the third fingers of both hands were recorded using thermoluminescent dosemeters during 27 interventional drainage procedures. Under couch screening was used. Mean dose rates were calculated by dividing the doses by the screening time. The dose rates for the sites measured were correlated with each other. The radiologists' bilateral finger dose rates did not correlate with each other; nor did dose rates between the left shoulder and the right hand. The radiologists' dose rates at both shoulders, however, correlated with each other, as did the shoulder dose rates with the dose rates at the ispilateral hand. The right shoulder dose rates correlated with the left hand dose rates. The assistants' dose rates at the places of measurement all showed significant correlations with each other. It is therefore concluded that radiologists involved in percutaneous drainages should use finger dosemeters on both hands; for assistants this may not be necessary.


Effect of diatrizoate on the function of the isolated perfused rat kidney. The mechanism of the nephrotoxicity of water-soluble contrast media (WSCM) remains ill defined. We have studied the effect of diatrizoate on the isolated perfused rat kidney (IPRK). Emphasis was on the effect of low- and high-dose diatrizoate on glomerular filtration rate (GFR), renal perfusate flow (RPF), fractional excretion of albumin (FE Alb) and fractional reabsorption of sodium (FR Na). The addition of diatrizoate to the IPRK led to a dose-dependent biphasic change in RPF and GFR characterized by an initial transient increase followed by a marked and sustained decrease. Diatrizoate induced a diuresis and a parallel increase in urinary sodium excretion (fall of FR Na). Fe Alb was also increased in kidneys exposed to diatrizoate. Electron microscopy of a control kidney showed preservation of cellular architecture, which contrasted with the observed cytoplasmic vacuolation of proximal tubular cells after perfusion with diatrizoate. This study confirms a direct effect of WSCM on the function of the IPRK. In this experimental model, diatrizoate reproduces the effects observed in vivo on GFR and renal perfusion.


Stage IB cervical carcinoma: a clinical audit. All patients with FIGO Stage IB cervical cancer registered with the Department of Clinical Oncology at the Western General Hospital, Edinburgh, during the 6 years from 1979 to 1984 have been reviewed, as part of a continuing programme of clinical audit. Of the 140 patients with Stage IB disease, 68 (49%) were treated by primary surgery of whom 44 (31%) also received adjuvant radiotherapy. Radical radiotherapy was the definitive treatment for 69 patients (49%). Three patients (2%) were not treated with curative intent. The crude 5-year survival rate for all cases was 72% and the cause-specific 5-year survival rate was 78%. Local tumour control at 5 years was 72%. There was no significant difference in outcome between the surgically treated and irradiated groups of patients. Age, histology and nodal status did not influence outcome. Irradiated patients with bulky tumours fared significantly worse than the other patients who received radical radiotherapy. Multivariate analysis of all patients revealed no significant independent prognostic variables. Primary surgery appears to confer no benefit over radical radiotherapy in terms of either survival or local control. Treatment-related late bladder and bowel morbidity was, however, significantly worse in irradiated patients.


Calcium antagonists protect mice against lethal doses of ionizing radiation. Currently available radioprotectors are poorly tolerated in man and the general use of aminothiol radioprotectors is compromised by their side-effects. In a search for less toxic radioprotective agents, diltiazem, a calcium antagonist with a benzothiazepine structure, was found to protect mice against a lethal (LD100) gamma radiation dose allowing survival of up to 93%. Dihydropyridine calcium antagonists such as nifedipine, nimodipine, isradipine and nitrendipine also provided radioprotection. Calcium antagonists might attenuate radiation-induced injury by inhibiting cellular calcium overload, subsequent to cell membrane damage caused by radiation-generated free radicals. In view of their good tolerance, calcium antagonists may be applied safely in situations of radiation exposure, including radiotherapy and internal radionuclide contamination. These calcium antagonists may also be viewed in other contexts where free radicals are implicated in pathological processes.


Direct coronal computed tomography of the temporomandibular joint in patients with rheumatoid arthritis. Direct coronal computed tomography (CT) of the temporomandibular joint (TMJ) was performed in 26 patients with rheumatoid arthritis (RA) and 26 control subjects. Erosions and cysts of the mandibular condyle had a significantly higher frequency in the RA group than in the control group (p < 0.05) but there was no significant difference in the incidence of other abnormalities. Bone changes were bilateral in RA. A wide range of CT abnormalities was present in patients with RA and in the control group. There are no CT abnormalities specific for RA, but the incidence of erosions and cysts of the mandibular condyle was significantly higher in the RA group and should suggest the diagnosis.


Vasoconstriction by angiographic contrast media in isolated canine arteries. To study the mechanism of the pain produced by contrast media (CM) in peripheral arteriography, we examined the direct effects of low concentrations (1.85-100 mg I/ml) of CM (diatrizoate, iopamidol, ioxaglate, and iotrolan) on helically cut strips of canine blood vessels taken from six different regions. We found that: (a) low concentrations of CM induced vasoconstriction. (b) This occurred immediately after the application of CM and produced sustained constriction. (c) The constriction produced in arteries was dose-dependent. (d) The production and intensity of constriction in the arterial strips differed as follows: cranial mesenteric artery > renal artery > femoral artery > common carotid artery > thoracic aorta > coronary artery. The effects of the CM were, in order of magnitude: diatrizoate > iopamidol > ioxaglate > iotrolan. Differences between CM corresponded with the differences in osmolality of the CM solutions. (e) Low concentrations of meglumine and mannitol also produced vasoconstriction. (f) Constriction caused by all drug samples used was reversible, but the process of relaxation to the original tension was much slower in CM-treated arterial strips than in the other strips. From these results, we confirmed that the incidence and degree of vasoconstriction produced by all drug samples used in this experiment depended on solution osmolality, rather than on chemotoxicity or ionicity. We discuss the physiological mechanism of these results and stress the importance of CM hyperosmolality in vasoconstriction and vascular pain production.


Percutaneous drainage of splenic abscesses: an effective and safe procedure. Percutaneous drainage of splenic abscesses has not yet become a common procedure due to the potential risk of bleeding and the danger of damage to neighbouring organs. We present our experience of percutaneous drainage in eight patients with splenic abscesses. Four patients were treated by therapeutic percutaneous needle aspiration of the fluid collection, and four by percutaneous trocar catheter insertion. All procedures were guided by ultrasound or computed tomography. The procedure was successful in all eight patients with no complications.


One-view versus two-view mammography in baseline screening for breast cancer: a review. Two-view mammography is generally preferred as an initial screening examination because the number of missed carcinomas and false positive results in one-view mammography is considered too large. The present review was performed to assess the difference in screening quality between one- and two-view mammography. Nineteen previous studies were reviewed and differences in sensitivity as well as specificity between two-view and one-view mammography were calculated. The results ranged from -5.7% to 19.4% (median 3.9%), and 2.7% to 36.1% (median 14.8%), respectively, and indicate a higher screening quality of two-view mammography. However, in the studies considered there is a large variation in study population, screening tests used and assessment of disease outcome, which makes the numerical results less conclusive. None of the studies provided adequate information for deciding whether two-view mammography in baseline screening for breast cancer is preferable to one-view mammography. If a screening programme using one-view mammography has already achieved high sensitivity and specificity, the value of an additional craniocaudal view is only marginal.


Sonography in thyroid carcinoma in children. This paper reviews the clinical, sonographic and pathological findings of 20 children with thyroid carcinoma in an attempt to determine the value and limitations of sonography in thyroid neoplasms in this age group. Although sonography is an excellent technique for the evaluation of thyroid disorders and masses, certain limitations must be kept in mind. Microscopic foci of tumour might be missed and sonography cannot predictably differentiate benign from malignant disease. Previous radiation exposure should increase the level of suspicion for malignancy.


Enlarged mediastinal lymph nodes in the fibrosing alveolitis of systemic sclerosis. The aim of this study was to determine the prevalence of enlarged mediastinal lymph nodes in systemic sclerosis (SSc) and relate this to the extent of pulmonary disease and disease activity as judged by high resolution computed tomography (HRCT). The HRCT scans of 78 patients with SSc were reviewed. The extent of lung disease and HRCT pattern were analysed and CT scans examined on soft tissue window settings for evidence of mediastinal lymph node enlargement. Sixty six (85%) patients had evidence of lung involvement on CT. Enlarged mediastinal lymph nodes were present in 21 (32%) patients with lung involvement but in only 1 (8%) patient without. The prevalence of enlarged mediastinal nodes increased with more extensive lung involvement on CT (p < 0.025), but correlated poorly with the type of CT appearance and concurrent erythrocyte sedimentation rate. Mediastinal lymph node enlargement occurs frequently in patients with SSc, particularly if lung involvement is extensive.


Prediction of birthweight by fetal ultrasound biometry. A total of 104 women with singleton pregnancies who were delivered between 37 and 42 weeks gestation had ultrasound scans during the fortnight before delivery. The biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) were measured in all cases. Estimation of fetal weight (EFW) was done by four different methods: using AC alone, AC/BPD, AC/FL and AC/BPD/FL. Results were compared with values of actual birthweights at delivery. There was no significant difference between the mean birthweights of the 47 boy and 57 girl fetuses studied. The EFW(Shepard) method showed the least bias overall: mean percentage error 1.7%, standard deviation (SD) 10.6%. The other three methods significantly underestimated birthweights on average: EFW(Deter), mean error 2.2%, SD 9.3%, p < 0.02; EFW(Campbell), mean error 5.4%, SD 9.5%, p < 0.001; EFW(Hadlock), mean error 5.6%, SD 9.3%, p < 0.001. The percentage error in each group was significantly negatively correlated (p < 0.001) with the scan-delivery interval. Two new equations were generated which gave more accurate predictions for the cases under study using AC, BPD and FL as a combination and also in addition to scan-delivery interval (SDI) in days.


The effect of thin K-edge filters on radiation dose in dental radiography. The use of thin K-edge filters has been found to reduce considerably the radiation dose in intra-oral radiography. The aim of this study was to investigate the effect of filtration on the skin entrance dose and several sites (representing organs or areas of interest within the head) along the central beam axis, at other points within the primary beam and at two points just outside the primary beam. The subject was a sliced head phantom (a human skull embedded in tissue-equivalent material) which was exposed to X rays from a conventional dental X-ray unit in the range of tube voltage 55-85 kVp for each of four filter systems. These were 2.7 mm of aluminium alone (the existing total filtration) or with an added 0.1 mm erbium, 0.1 mm yttrium or 0.05 mm niobium metal foils. Measurements of radiation dose were made using thermoluminescent dosemeters (TLD rods) and were adjusted to simulate the exposure resulting from a typical dental radiograph of a maxillary molar. The results suggest that the use of thin K-edge filters significantly reduces the entrance skin dose and to a certain extent reduces the total dose imparted to the head. However, the dose to the ipsilateral orbit at higher tube voltages may be increased.


The distribution of medical X-ray doses amongst individuals in the British population. This study has estimated the distribution of diagnostic X-ray doses amongst individuals in the British population by sampling the records kept by general practitioners (GPs) on their patients and the records held by the radiology department of a district general hospital. Deceased patients were chosen in the former case in order to evaluate the dose acquired over a complete lifetime. In each case, several hundred records were sampled. The GP data obtained have enabled an estimate to be made of the likelihood of reaching various dose levels in a lifetime. It is estimated that about 1% of the population has received a lifetime effective dose-equivalent of more than 100 mSv. The largest cumulative dose revealed by the samples of GP and radiology department records was about 200 mSv. The GP data have also shown that the last year of life sees a four-fold increase in the number of X-ray examinations experienced compared with the previous 9 years. The hospital data have allowed an estimate to be made of current rates of dose acquisition amongst the population of a District Health Authority.


The use of extracorporeal shock wave lithotripsy for medullary sponge kidneys. A number of patients with medullary sponge kidney recurrently form and pass stones with the risk of developing an obstructive nephropathy. These patients may benefit from extracorporeal shock wave lithotripsy to the medullary collections, as this appears to reduce the frequency of symptomatic stone passage.


In vitro inhibition of struvite crystal growth by acetohydroxamic acid. Struvite (MgNH4PO46H2O) crystals were produced by Proteus mirabilis growth in artificial urine, in the presence and absence of the urease inhibitor, acetohydroxamic acid (AHA). In the absence of AHA, struvite crystals assumed an "X-shaped" or dendritic crystal habit due to rapid growth along their 100 axis. When AHA was present, crystal growth, as monitored by phase contrast light microscopy, was greatly slowed, and the crystals assumed an octahedral crystal habit. Scanning electron microscopy revealed that crystals grown in the presence of AHA were pitted on their surface. This pitting was absent in control samples. While most of this inhibition by AHA was due to lowered urease activity, some crystal growth inhibition occurred in struvite produced in the absence of urease activity through NH4OH titration of artificial urine. We conclude that while AHA is primarily a urease inhibitor, it may also disrupt struvite growth and formation directly through interference with the molecular growth processes on crystal surfaces.


Pyonephrosis: diagnosis and treatment.

Pyonephrosis: diagnosis and treatment. A series of 23 confirmed cases of pyonephrosis initially treated by percutaneous nephrostomy drainage were reviewed. Presentation was extremely variable, ranging from sepsis to asymptomatic bacteriuria. Fever, flank pain and leukocytosis were often absent. Ultrasonography was diagnostic in only 3 of 12 patients. In all, 17 patients had associated nephrolithiasis, and 5 patients ultimately required nephrectomy. Renal urine cultures were positive in 16 of 21 instances, with multiple organisms found in 8 of 21, and added bacteriological data not provided by bladder urine cultures in 11 cases. A pre-existing history of urinary tract infection, hypertension and malignancy was common. Percutaneous drainage was a safe, quick and effective diagnostic and therapeutic method.


Does DNA flow cytometry give useful prognostic information in renal parenchymal adenocarcinoma? DNA ploidy and S-phase fraction (SPF) were measured by flow cytometry on 381 paraffin blocks from 93 unselected primary renal parenchymal adenocarcinomas (RPA). The results were compared with tumour grade and T category and patient survival, with a mean follow-up of 87 months. Only 21% of the tumours were uniformly diploid and ploidy was heterogeneous in 49% of cases. DNA ploidy and SPF were significantly associated with grade, but not T category of disease. Both flow cytometric parameters were significantly related to survival in a univariate analysis. However, when tumour grade was taken into account, both DNA ploidy and SPF lost their prognostic significance. Thus, neither of these parameters gave prognostic information additional to that provided by tumour grade in unselected cases of primary RPA.


Increase in presumptive sensory nerves of the urinary bladder in idiopathic detrusor instability. The density of subepithelial, presumptive sensory nerves in the bladder wall was assessed in 21 women with idiopathic detrusor instability and compared with the density of these nerves in 21 asymptomatic women, using a point-counting technique on sections of bladder biopsies stained for acetylcholinesterase activity. The mean value (+/- S.E.) for the amount of such nerves in patients with detrusor instability (91 +/- 13/mm2) was significantly greater than that from the control group (61 +/- 7/mm2). This suggests that a relative abundance of subepithelial sensory nerves may serve to increase the appreciation of bladder filling, giving rise to the frequency and urgency of micturition which are characteristic of patients with detrusor instability.


Loss of sensory neuropeptides in the obstructed human bladder. This is the first investigation of alterations in the innervation of the obstructed human bladder by nerves containing neuropeptides. The patient groups studied were those with stable detrusor function, those with unstable detrusor function, and those presenting with acute retention of urine. Specimens of bladder tissue were taken from the lateral wall of the bladder below the peritoneal reflection. A total of 23 patients was studied (control, n = 4; acute retention, n = 5; stable obstruction, n = 5; unstable obstruction, n = 9). Substance P, calcitonin gene-related peptide and vasoactive intestinal polypeptide levels in the bladder were quantified by immunoassay. The density of innervation of the bladder detrusor by nerves containing these neurotransmitters and by those containing neuropeptide Y and somatostatin was assessed using both semiquantitative and quantitative immunohistochemical techniques. A reduction in the density of innervation by vasoactive intestinal polypeptide, calcitonin gene-related peptide, substance P and somatostatin-immunoreactive but not neuropeptide Y-immunoreactive nerve fibres was shown in the obstructed bladder. These findings, combined with the significant reduction in substance P content of the obstructed bladder and in particular of the acute retention bladder, indicate that there may be an afferent nerve dysfunction resulting from prostatic bladder outflow obstruction.