Antigen-specific tolerance as a therapy for experimental autoimmune encephalomyelitis.

The effects of neuroantigen-specific tolerance on the induction and effector stages of EAE were examined. Tolerance induced by the i.v. injection of syngeneic splenocytes coupled with purified neuroantigens or encephalitogenic peptides of MBP and PLP using ethylene carbodiimide was extremely effective in both prevention and treatment of acute and relapsing forms of EAE in Lewis rats and SJL/J mice. The unresponsiveness is rapidly-induced, dose-dependent, long-lasting, efficient, MHC class II-restricted, and exquisitely antigen-specific. This procedure targets only effector cells bearing clonotypic receptors specific for the autoantigen/autoepitope and thus does not depend upon the autoimmune response being dominated by a restricted T cell repertoire. Moreover, it does not require that the response to the autoantigen be dominated by recognition of a specific epitope(s) within a particular autoantigen, or even the identification of the specific autoantigen. The results also demonstrate the usefulness of peripheral tolerance induced by antigen-coupled syngeneic splenocytes for identifying the fine specificity of autoimmune T cell responses which appear to change during the progression of relapsing EAE. Thus, this technique offers major advantages over many other currently employed immunoregulatory strategies and is therefore relevant for establishment of therapeutic protocols for the antigen-specific treatment of human T cell-dependent autoimmune disorders.


EAE: a model for immune intervention with synthetic peptides.

The cellular and molecular requirements for the autoimmune disease EAE are being defined in increasing detail through intense scrutiny of critical autoantigenic peptides, class II MHC molecules, and alpha beta TCRs involved in the disease process. This study has led to novel immunotherapeutic approaches, many of which are based on the administration of synthetic peptides. Since short peptides are understood to be the minimal antigenic units bound by MHC molecules for recognition by T cells, they are attractive experimental tools for finely modulating specific immune responses. It is clear that a large number of defined peptides can dramatically influence the course of EAE. Table IV lists a number of potential mechanisms which may mediate disease prevention. Increasing evidence supports the idea that prevention of autoimmune disease can result from MHC-blockade by peptides which competitively bind to class II molecules. However, for some peptides such as the perplexing partial agonist Ac1-11[4A], the mechanism by which these precisely defined units act is not yet fully understood. Numerous hurdles hinder immediate clinical application of peptide-based immunotherapy. Nevertheless, the knowledge gained by probing experimental autoimmunity with defined peptides promises to inspire original and practical approaches to treating human autoimmune disease.


Comparison of Hoechst 33342 and propidium iodide as fluorescent markers for sperm fusion with hamster oocytes.

Hamster oocytes were loaded with the DNA dyes Hoechst 33342 or propidium iodide. Oocytes incubated in 10 mumol Hoechst 333421(-1) showed intracellular fluorescence within 10-20 s of exposure, as did hamster and guinea-pig spermatozoa. Impaled oocytes to which acrosome-intact hamster spermatozoa were bound before injection of Hoechst 33342 showed dye transfer to adhering spermatozoa within 2 min of injection. Oocytes loaded passively with Hoechst 33342 showed dye transfer to bound, acrosome-intact hamster spermatozoa within 10 min. On ultra-structural examination, no bound, acrosome-intact hamster spermatozoa (n = 311) were found to be fused. By contrast, oocytes incubated with 10 mumol propidium iodide l-1 showed no intracellular fluorescence after 2 h, although in approximately 50% of oocytes, fluorescence developed rapidly in the first polar body. Oocytes injected with propidium iodide showed intracellular fluorescence but no dye transfer to bound, acrosome-intact hamster spermatozoa. Oocytes impaled on pipettes containing propidium iodide showed no dye transfer to unlabelled oocytes with which they were brought into contact, whereas in similar experiments using Hoechst 33342 detectable dye transfer to an adjacent oocyte occurred within 10 min. Oocytes loaded with propidium iodide transferred propidium iodide to fusion-competent guinea-pig spermatozoa during in vitro fertilization. Normally, between 20 and 40 spermatozoa bound per oocyte, and the percentage of spermatozoa showing dye transfer varied between 0 and 41%. Dye transfer occurred within 5-45 min. Only those nuclei that showed propidium iodide transfer subsequently decondensed, suggesting that dye transfer is correlated with fusion. The presence of fused spermatozoa was confirmed by ultrastructural examination of oocytes. In separate experiments, hamster and guinea-pig spermatozoa showed detectable fluorescence from propidium iodide within 20 s of osmotic rupture or membrane stripping by detergent, suggesting the lag in dye transfer to sperm nuclei during fertilization reflects a delay in sperm-oocyte fusion following adhesion. This evidence suggests that Hoechst 33342 could be an unreliable marker for sperm-oocyte fusion in fertilization because of its capacity for passive movement from oocyte to spermatozoon. This problem can be overcome using oocytes injected with propidium iodide. With this technique, it was possible to show that fusion-competent guinea-pig spermatozoa that are held in pipettes will fuse with hamster oocytes when placed mechanically against the oocyte surface.


Characterization of equine zona pellucida glycoproteins by polyacrylamide gel electrophoresis and immunological techniques.

This study was designed to explore the composition of the equine zona pellucida (EZP) by one- and two-dimensional polyacrylamide gel electrophoresis (1D- and 2D-PAGE), silver staining and immunoblotting techniques. Antral follicles palpable on frozen-thawed equine ovaries were aspirated with a needle and syringe, and the resultant follicular fluid, cellular material and oocytes were pooled. Oocytes were placed in Petri dishes, moved by narrow-bore pipette to droplets of phosphate-buffered saline (PBS) and mechanically cleaned of cumulus cells. The EZP from these collected oocytes was solubilized, and then analysed by 1D- and 2D-PAGE. Silver stained 2D-PAGE of the EZP revealed the presence of three EZP glycoprotein families of apparent molecular mass ranges of 93-120 kDa, 73-90 kDa and 45-80 kDa. Immunoblot analysis of EZP glycoproteins resolved by 2D-PAGE using rabbit antisera against pig zonae pellucidae (R alpha HSPZ) confirmed the presence of three EZP glycoprotein families and established the existence of common epitopes between equine and porcine ZP glycoproteins. Further immunodetection using 2D-PAGE-separated glycoproteins illustrated that the 45-80 kDa family is recognized by the monoclonal antibody R5, developed against the porcine ZP glycoprotein of molecular mass 55-120 kDa. Guinea-pig antiserum against endo-beta-galactosidase-treated rabbit ZP 55 kDa glycoprotein (R55K), which specifically recognizes the rabbit ZP glycoprotein with the lowest molecular mass, also recognized the EZP 45-80 kDa glycoprotein family. Guinea-pig polyclonal antisera developed against total heat-solubilized rabbit ZP (GP alpha HSRZ) recognized the 73-90 kDa EZP glycoprotein family exclusively. After heat solubilization and treatment of EZP with endo-beta-galactosidase to remove polylactosaminoglycans, silver stained 1D-PAGE again demonstrated the presence of three glycoproteins with apparent molecular masses of 60, 75 and 90 kDa. The partially deglycosylated 60 kDa equine glycoprotein is recognized on immunoblot by the monoclonal antibody R5; the 75 kDa EZP glycoprotein is recognized by GP alpha HSRZ; and all three EZP glycoproteins separated by 1D-PAGE are recognized by R alpha HSPZ. These data add further support to the concept of cross-species zona pellucida glycoprotein antigenicity.


[Anaphylactic shock due to modified fluid gels: 2 case reports].

Colloid solutions can give severe anaphylactic accidents. We are reporting two cases from our department. a sixty eight years old man perfused with Plasmion solution (Gelatin plasma substitute) before spinal anesthesia, presented sudden hypotension and diffuse skin rush. Second case: a twelve years old girl, receiving a Plasmion solution to correct a hypovolemic shock in I.C.U, presented a severe bronchospasm and a worsening of the hypotension. These accidents are explained by immunologic reactions or by direct histamine release. Their incidence is between 0.01 and 0.8 percent depending on the used solution. They are prevented by an antihistaminic premedication for the gelatin plasma substitutes and by an haptenic inhibition for Dextran (polysaccharide plasma substitutes). The new colloid solutions, based on hydroxyethylstarch, seems to give much less allergic reactions.


Immunohistochemical determination of complement activation in joint tissues of patients with rheumatoid arthritis and osteoarthritis using neoantigen-specific monoclonal antibodies.

Murine monoclonal antibodies specific for neoepitopes expressed by C9 incorporated into membrane attack complexes and by membrane-bound C3b and iC3b have been prepared and characterised. These reagents were used to determine the extent and locus of complement activation in synovial-tissues obtained from patients with rheumatoid arthritis and osteoarthritis. In the four rheumatoid arthritis patients there was extensive deposition of C3 activation products and C5b-9 complexes onto the synovial membrane and the pattern of deposition of both neoantigens in serial tissue sections was very similar. There was less extensive staining for C3 and, particularly, C9 neoepitopes on the apical surface of vessel endothelia. In two of four osteoarthritic patients a similar pattern of C3 and C9 neoepitope deposition was found; in the remaining patients no C5b-9 could be located. Synovial vessel walls, but not synovial cells, from both groups of patients stained extensively for the complement regulatory protein CD59. In synovial membranes from patients with osteoarthritis, C9 appeared to be present predominantly in SC5b-9 complexes whereas in rheumatoid arthritis patients no evidence of S-protein incorporation into membrane attack complexes could be demonstrated, suggesting that in rheumatoid arthritis there is damage to the synovial membrane as a result of complement activation and C5b-9 deposition.


Various responses of lymphocytes to Epstein-Barr virus in patients with common variable immunodeficiency.

The responses of lymphocytes to Epstein-Barr virus (EBV) were investigated in five patients with common variable immunodeficiency (CVID). In three patients with CVID in whom the percentages of CD20+ cells and CD21/EBV receptor+ cells were markedly reduced, PBMCs and/or B cells did not respond (or scarcely) to EBV. This may be due to reduction of B cell numbers or reduction of EBV receptor bearing cells. In one patient with CVID in whom the percentages of CD20+ cells and CD21/EBV receptor+ cells were mildly reduced, PBMCs and/or B cells responded well to EBV and secreted immunoglobulin (Ig). This result shows that the patient's B cells with EBV receptors are sufficient to transduct EBV-signals into the nucleus and to respond to EBV. In another patient in whom the percentages of CD20+ cells and CD21/EBV receptor+ cells were not reduced, PBMCs mildly responded to EBV and scarcely secreted Ig. This result shows that the patient's B cells with EBV receptors may not be sufficient to transduct EBV-signals into the nucleus and to respond to EBV.


In vitro effect of levamisole on the neutrophil activity in rainbow trout (Oncorhynchus mykiss).

An in vitro immunization and cultivation method for fish spleen organ section was used to investigate the effects of levamisole on the neutrophil activity. After 10 days of culture with either 50 micrograms/ml, 25 micrograms/ml, 5 micrograms/ml or no levamisole in the media, the nonspecific defense reactions were measured by determining the metabolic activity of neutrophils by using the nitroblue tetrazolium test, and phagocytic and adherence indexes by incubating the fish cells with suspensions of formalin-killed Staphylococcus aureus. Elevations were found in nonspecific cellular defense in the 5 micrograms/ml levels of levamisole. The 25 micrograms/ml levels instigated a slight elevation in nonspecific cellular defense and the 50 micrograms/ml levels suppressed all indicators, whether levamisole was given alone or combined with Yersinia ruckeri O-antigen or DNP-Ficoll. These antigens are themselves nonspecific cellular defense stimulators, and a synergistic effect was evident when combined with 25 micrograms/ml and 5 micrograms/ml levels of levamisole.


Similar distribution of insulin-like growth factor binding proteins-1, -2, -3 in human fetal tissues.

The actions of insulin-like growth factors (IGFs) are modulated by several specific binding proteins (IGF BPs). Since the anatomical distribution of IGF BPs is likely to dictate IGF bioavailability we used immunocytochemistry to localize IGF BP-1, -2, and -3 in early second trimester human fetal tissues. Primary antisera were directed against hIGF BP-1, bIGF BP-2 and hIGF BP-3 respectively, and showed less than 5% cross-reaction with heterologous IGF BP species. The distribution of immunopositive staining was similar for each IGF BP in many tissues being prominent in the epithelial lining of the gut, kidney and lung; in epidermis, adrenal cortex and pancreatic endocrine tissue; and in association with membranes of skeletal muscle fibres and cardiocytes. Unlike IGF BP-1 -2, IGF BP-3 was barely detectable in liver and absent from epiphyseal chondrocytes. Conversely, IGF BP-3 alone was visualized within neurons of the cerebral cortex. The co-distribution of IGF BPs in many human fetal tissues suggests that they may co-ordinately regulate IGF bioavailability in target tissues and modify IGF: receptor interactions.


Membrane perforation by Entamoeba histolytica: structural implications derived from the sequence of the pore-forming peptide.

The pore-forming peptide amebapore is considered crucial for the cytolytic activity of E. histolytica. Isolation and subsequent molecular cloning of the peptide allowed predictions as to its secondary structure, most of which were confirmed by experimental data. Here, a computer-aided approach is applied to identify, within the peptide, highly amphipathic helical segments predicted to interact with biological membranes. Two putative alpha-helices fulfill the criteria of membrane-seeking domains and in this respect resemble small lytic peptides of various origins.


Cloning and partial characterization of an antigen detected on membrane surfaces of non-pathogenic strains of Entamoeba histolytica.

A novel and unique mAb (318-28) which specifically interacts with a 60 kDa antigen that is found only on the surfaces of non-pathogenic (NP) strains of E. histolytica has been recently characterized. The antigen appears to be present also on (NP) cyst forms of amebas but was not detected on any of the various (P)-strains tested. It was also not found on other Entamoeba species such as Moshkovskii, Laredo, Huff, Coli, Gingivalis, or Invadens. Clinical trails for the differentiation of (P) and (NP) amebas directly from stools using this mAb are in progress. Cloning of the gene encoding for the (NP)-specific antigen was achieved after screening with mAb 318-28 a lambda gt11 expression library of NP strain SAW 1734R. No sequence homology to any known protein was found in data bases.


A rapid colorimetric assay with the tetrazolium salt MTT and phenazine methosulfate (PMS) for viability of Entamoeba histolytica.

A rapid colorimetric assay for viability of E. histolytica trophozoites using the tetrazolium salt MTT and phenazine methosulfate (PMS) was developed. The MTT is normally reduced by dehydrogenases of viable cells and transformed to formazan, a colored compound; the reaction is catalyzed by PMS. Trophozoites of E. histolytica were incubated in the presence of MTT and PMS during 15, 30, 45, 60 and 75 min, at 37 degrees C. Trophozoites killed by heat or cold were used as controls. The formazan produced into the cells was extracted with isopropanol-HCl and the optical density (OD) was measured at 570 nm. There was a linear relation between the number of viable trophozoites and the OD570 (r2 = 0.98). The trophozoites killed by cold or heat did not reduce MTT. The optimal time of incubation with MTT/PMS was 45 min. The MTT/PMS assay for determining viability of E. histolytica trophozoites is reproducible, rapid and easy to perform and it could be useful to study cytotoxicity and susceptibility to drugs.


Structural organization of chromatin during the cell cycle of Entamoeba histolytica trophozoites.

The nuclear division of E. histolytica trophozoites was analyzed by using specific stains for DNA, with the aim to define the sequential changes of chromatin during its life cycle. Furthermore, we characterized the internal structural arrangements of microtubules in the microtubular organizing center (MTOC) and determined the number of chromosomes and its association with the spindle. The MTOC is formed by multiple microtubule-nucleating centers, that are involved in the displacement of DNA during nuclear division. We found the existence of a single MTOC in one pole of the nucleus at early anaphase. Our results lead us to propose a new hypothesis in which it is suggested that metaphase corresponds to the arrangement of condensed DNA bodies, or "chromosomes" around the MTOC and, through the assembly of microtubules, one set of uncondensed chromatin is displaced to the opposite pole of the nucleus, while the other remains condensed and associated to the original MTOC. We observed six chromosomes in our preparations, corroborating previous observations (2,3). Whether or not a new MTOC is formed during nuclear division remains to be clarified.


Modulation of acetylcholine receptor channel by a polar component isolated from toxic Ostreopsis lenticularis extracts.

Methanol extracts obtained from O. lenticularis clones are toxic to mice and inhibit acetylcholine-induced contractions in frog skeletal muscle. Chromatographic fractionation of extracts produced two major fractions with different retention times. Single channel recordings in myocyte membrane patches exposed to more polar fraction showed the appearance of acetylcholine-activated channels whose mean current amplitude was nearly half that of the controls. Channel open times under control and experimental conditions were similar. Thus, this dinoflagellate fraction reduces the ionic conductance of nicotinic receptor channels without altering their lifetime.


Advanced techniques: developing quality drawings.

Just like writing, developing ideas for illustrating your articles is a skill you can learn. With creativity, planning, and a cooperative relationship with a graphic artist you can include drawings that enhance your reader's appreciation of every publication you write.


A survey of invasive Haemophilus influenzae infections.

A survey of invasive H. influenzae infections has been underway in six regions of England and Wales since September 1990. In the first year, there were 433 cases of which 362 (84%) were due to H. influenzae type b (Hib). The majority of Hib infections were in children aged less than 5 years; there being an annual incidence of 26.4/100,000 in this age group. Meningitis occurred in 56% of cases of Hib infection. The results confirm previous evidence of the need to incorporate Hib vaccination into the childhood immunisation schedule. The ongoing survey data will provide useful information to assess the impact of an Hib immunisation programme.


Voluntary testing to measure HIV prevalence in sexually transmitted disease clinics.

Voluntary HIV testing was used to study the extent of HIV-1 infection in patients attending sexually transmitted disease (STD) clinics in England and Wales between 1985 and 1990. Homosexual and bisexual men and 10-20% of heterosexual men and women were invited to complete a study record and have an HIV-1 antibody test. The rate of newly diagnosed HIV-1 infection was higher in homosexual and bisexual men than in heterosexual clinic attenders. It was also higher in patients attending clinics in the South East compared with those attending clinics in other regions. From 1988 onwards, HIV infection was identified in heterosexual men and women who did not report behavioural risk factors associated with increased risk of HIV transmission. In the early years of the study, the proportion that agreed to complete a study record and have an HIV-1 antibody test was high in all groups. This proportion declined in those attending clinics in the South East, particularly among heterosexual men and women, less than 50% of whom agreed to take part in the study in 1989 and 1990. The decline in acceptance rate made voluntary testing unsuitable for monitoring trends in HIV infection. Unlinked anonymous HIV testing, which minimises the effect of participation bias, has become the method of choice for monitoring the prevalence of HIV infection.


Methicillin-resistant Staphylococcus aureus in England and Wales.

Methicillin-resistant Staphylococcus aureus (MRSA) were detected soon after the introduction of methicillin in 1960, and reports of their isolation increased up to 1971. Changes in antibiotic usage were associated with a fall and then, in the early 1980s, a further rise in the number of reports. This article reviews the various surveys that have been conducted to establish the frequency, distribution and strain varieties of MRSA. The first strain to be recognised as epidemic (ie, affecting more than one hospital), was defined by phage typing and antibiogram, confirmed with molecular typing, and designated EMRSA-1. It was first detected in 1981 and became progressively more widespread until it began to decline in 1987. Only three health regions reported this strain in the first quarter of 1991. EMRSA-2 has remained restricted to the South East and South West Thames regions. EMRSA-3 appeared in the South East Thames region in 1987 and has since spread, being reported from eight health regions in the first quarter of 1991. At least 11 other strains of MRSA affecting more than one hospital have been detected and ten endemic strains (restricted to single hospitals) have been identified. Imported strains of MRSA, often introduced following the repatriation of road traffic accident victims, may include strains with epidemic potential and local spread has followed importation in at least two incidents. Continued surveillance of epidemic MRSA strains and the search for simple and widely applicable markers, such as unusual antibiotic resistance patterns or biochemical features, are needed for the prompt application of control measures.


Hazardous incidents and immunity to hepatitis B.

In the period March 1989 to October 1990, Leeds Public Health Laboratory received reports of 2975 needlestick and similar incidents involving National Health Service staff where there was a risk of transmission of hepatitis B virus. Despite an active immunisation programme in the hospitals where staff worked, 50% of those involved showed no evidence of immunity. In reviewing their immunisation programmes, health authorities should take account of those groups of staff who are at risk of exposure and ensure that all those included in the programme are encouraged to take up the offer of immunisation.


The epidemiology of pertussis in the Republic of Ireland.

Epidemiological data on pertussis in the Republic of Ireland have been gathered annually since 1941. However, no detailed analysis of these data has, until now, been carried out. Fifteen epidemics occurred between 1941 and 1989, an average of one per 3.1 years, which is similar to epidemic intervals observed elsewhere. After the introduction of a vaccine in the 1950s, annual pertussis notifications declined, from 175 per 100,000 in 1956 to 7.6 per 100,000 in 1972. Following adverse publicity in 1973, uptake of the vaccine fell to 30% in 1976. Although uptake has increased again in recent years, it has levelled out at only 40-45% and large epidemics of pertussis occurred in 1985 and 1989. At the same time, mortality from pertussis has fallen to almost negligible levels. Most cases occur in children more than one year of age. Changes in the vaccination schedule could have a major impact on the incidence of the disease in the Republic of Ireland. However, if a further decline in the incidence of the disease is to be achieved, parents have to be persuaded of the benefits of pertussis vaccination.


Communicable disease in New Zealand.

Communicable diseases remain a major problem in New Zealand; one which often only comes to the attention of management when an outbreak occurs and health care dollars are required for disease control. Hepatitis B and rheumatic fever remain the two diseases that place New Zealand in the developing nation league. Overall, the impact on mortality is low (only 5% in the 1-14 year age group) as is the impact on potential years of life lost. Morbidity figures are not known with any degree of accuracy as they are dependent on a notification system acknowledged to be deficient and hospital discharge data which include only a fraction of cases for a few serious diseases. The main preventive action hinges on the childhood immunisation programme which has undergone recent change. The true impact of environmental hygiene measures, health promotion and education has not been evaluated.


Antibiotic-resistant pneumococci in the United Kingdom.

Pneumococcal pneumonia and meningitis remain common infections with significant morbidity and mortality. For many years, penicillins or cephalosporins, erythromycin and chloramphenicol have been the mainstay of chemotherapy for these and other pneumococcal infections. Resistance to these antimicrobial agents has increased worldwide and resistant pneumococci are now isolated with increasing frequency in the United Kingdom. This article reviews the results of antimicrobial susceptibility and serotyping studies carried out over the last five years on UK isolates of Streptococcus pneumoniae referred to the Streptococcus and Antibiotic Reference Laboratories of the Division of Hospital Infection for serotyping or confirmation of antibiotic resistance. During this period there has been a marked increase in the referral of pneumococcal isolates resistant to one or more of the antimicrobials commonly used for treatment. The implications for antimicrobial therapy and vaccination policy are discussed.


Hepatitis A and travel abroad: a study of notifications in Birmingham.

One hundred and seventy-two cases of viral hepatitis A (or 'infective hepatitis' or 'infective jaundice' judged to be viral hepatitis A) were notified in Birmingham in the 15 months from January 1990 to March 1991. Forty patients had travelled abroad in the three months prior to onset, 30 of whom had been to the Indian subcontinent. A survey of general practitioners attending to patients going abroad indicated that human normal immunoglobulin (HNIG) was rarely given to intending travellers, whereas other recommended immunisations often were. Furthermore, a sizeable proportion of travellers did not attend their general practitioners prior to departure. Interventions aimed at encouraging attendance, and the administration of HNIG prior to travel to endemic areas, could reduce the incidence of hepatitis A substantially, particularly in areas with a large population of Asian origin.


Giardiasis--a cause of travellers' diarrhoea.

A surveillance programme using postal questionnaires was set up to monitor giardiasis in Bristol. Ninety-seven questionnaires were returned from 117 index cases in the first year. Cases appeared to fall into one of three main groups, namely, pre-school children (23 cases), those who travel abroad (22 cases had travelled in the month prior to the onset of their symptoms), and those who engaged in recreational water use prior to the onset of their illness (44 out of 66 cases aged 10 years or more). Routine surveillance data can indicate important routes of transmission of giardiasis in the local community.


Heterosexually acquired HIV-1 infection: cases reported in England, Wales and Northern Ireland, 1985 to 1991.

By the end of 1991, there had been 417 reports of AIDS and 1620 reports of HIV-1 infection in persons in England, Wales and Northern Ireland who probably acquired their infection through sexual intercourse between men and women. Between 1986 and 1991, the proportion of AIDS cases attributable to heterosexual transmission increased from 2% to 14% and of diagnosed HIV-1 infections from 4% to 23%. Reported HIV-1 infections inadequately reflect the extent of infection as only individuals choosing to be tested can be reported. HIV-1 infection acquired during heterosexual intercourse may be the result of transmission from partners who were infected by routes other than heterosexual transmission (first generation transmission) or of transmission from infected partners who were themselves infected through heterosexual intercourse (second generation transmission). Of the 417 cases in which AIDS was acquired through heterosexual intercourse, 42 (10%) were categorised as due to first generation transmission, 328 (79%) as second generation transmission--abroad, and 47 (11%) as second generation transmission--UK. Transmission categories could be allocated to 1438 of the 1620 reports of HIV infection: 17% were categorised as first generation, 74% as second generation--abroad, and 9% as second generation--UK. Heterosexual transmission of HIV infection is increasing, both in individuals acquiring their infection abroad as well as those who become infected in the United Kingdom.


Second generation heterosexual transmission of HIV-1 infection.

Reports of 217 HIV-1 infected persons have been investigated. Initially, 122 were described as having no identified risk of HIV infection and 95 were described as probably infected through heterosexual intercourse. The sexual partners of 34 of these 95 cases were reported as having acquired their infection heterosexually in the UK but information on the risk status of the sexual partners of the remaining 61 cases was lacking. Telephone follow-up through microbiologists and clinicians resulted in the recategorisation of 132 cases. Interviews were conducted with 22 HIV infected heterosexuals without a major risk for HIV infection, either in themselves or their sexual partners, and who had no evidence of heterosexual exposure outside the UK. Interviews confirmed the categorisation of 15 cases (9 male, 6 female) as due to second generation HIV-1 infection ie, infection acquired through heterosexual intercourse in the UK with a partner who also became infected through heterosexual intercourse. A possible chain of transmission is described involving three of these 15 cases.


Vaccine efficacy in a measles immunisation programme.

During a measles outbreak in Northern Ireland (between October 1988 and March 1989) it was noted that a proportion of cases had occurred in children who had previously been vaccinated against measles. A study was, therefore, set up to provide a rapid estimate of vaccine efficacy. Vaccine efficacy was calculated to be 94% (95% confidence limits, 91% to 96%). Investigation of the computerised records at 31 December 1991 revealed that 94% of children in the study cohort had received measles vaccine. As vaccination coverage increases, a higher proportion of cases of measles will, inevitably, have a history of vaccination.


Meningococcal infections in England and Wales: 1991.

There were fewer reports of cases of meningococcal infection in England and Wales during 1991 than in 1990. The number of isolates received at the Meningococcal Reference Laboratory decreased by 102 (7%), largely due to fewer strains being received from South West Thames, North East Thames and North Western regions. Group C infections showed a greater decrease than group B, with 16% fewer strains reported in 1991 than in 1990. Eight per cent of the strains received during 1991 showed reduced susceptibility to penicillin (MIC > 0.16mg/l).


A survey of emergency penicillin treatment for meningitis.

The case fatality rate for meningococcal meningitis has changed little in recent years. A study of persons admitted to hospital in Bristol with suspected meningitis found that only five of the 41 cases admitted in 1991 were given penicillin prior to admission. Possible reasons for this include lack of awareness of the need, reluctance to give injections to children, uncertainty about dosage, failure to carry injectable penicillin and diagnostic uncertainty.


Nosocomial transmission of tuberculosis in AIDS care centres.

Outbreaks of tuberculosis in centres for the care of patients with AIDS, including outbreaks involving drug-resistant strains of Mycobacterium tuberculosis, have been reported from a number of countries and present special problems. Transmission of infection may be facilitated by procedures commonly used with AIDS patients, and recognition of the diagnosis in an infectious case may be delayed. Although no similar outbreaks have been identified in the United Kingdom, it may be timely to review the policy and procedures used in this country in the light of experience elsewhere.


U1 snRNP targets an essential splicing factor, U2AF65, to the 3' splice site by a network of interactions spanning the exon.

A description of cellular factors that govern alternative splicing of pre-mRNA is largely incomplete. In the case of the rat preprotachykinin gene, splicing of the alternative exon E4 occurs by a poorly understood mechanism in which exon selection is under the positive control of U1 snRNP. Because the binding of U1 snRNP to the 5' splice site of E4 is coincident with the selection of the 3' splice site of E4, this mechanism would appear to involve interactions that bridge across the exon. In this work, a UV cross-linking strategy was used to identify possible RNA-protein interactions involved in the proposed exon-bridging model. Of particular interest is a prominent 61-kD protein, p61, that binds to the 3' splice site of E4 in a manner that is clearly facilitated by a downstream 5' splice site and U1 snRNP particles. The identity of p61 is the essential splicing factor U2AF65, on the basis of copurification and selective binding to polypyrimidine tracts. These results indicate a model in which exon selection is positively regulated by the communication of U1 snRNP and U2AF65. That is, a natural deficiency in binding U2AF65 to the 3' splice site that leads to exon skipping might be overcome by a mechanism in which U1 snRNP facilitates the binding of U2AF65 through a network of template-directed and exon-bridging interactions.


Translational control by poly(A) elongation during Xenopus development: differential repression and enhancement by a novel cytoplasmic polyadenylation element.

One characteristic of oocyte maturation and embryogenesis in Xenopus laevis is the activation of translationally repressed (masked) maternal mRNAs by cytoplasmic poly(A) elongation. At maturation, poly(A) elongation is controlled by two cis-acting elements in the 3'-untranslated regions (UTRs) of responsive mRNAs, the hexanucleotide AAUAAA and the cytoplasmic polyadenylation element (CPE), consisting of UUUUUAU or other similar sequences. To investigate poly(A) elongation and translational activation during embryogenesis, we have focused on Cl2 RNA, a representative transcript that undergoes these processes. By injecting radiolabeled Cl2 RNA into fertilized eggs and allowing development to proceed, we found that maximal polyadenylation of this RNA is reached by the 4000-cell blastula stage and that it requires two cis-acting elements, the hexanucleotide AAUAAA and a novel CPE, which is dodecauridine. Interestingly, a shortening of the distance between the two elements changes the timing of maximal polyadenylation to the four-cell stage. The injection of a chloramphenicol acetyl transferase (CAT)-Cl2 chimeric RNA into fertilized eggs not only results in embryonic polyadenylation of the transcript but also 5- to 15-fold more CAT activity compared with eggs injected with CAT RNA or CAT-Cl2 chimeric RNA that is prevented from undergoing poly(A) elongation by a mutation in the polyadenylation hexanucleotide. However, eggs injected with a CAT-Cl2 chimeric RNA that is preadenylated but that cannot undergo further poly(A) elongation contain no more CAT activity than eggs injected with the same RNA without a poly(A) tail, suggesting that the process of poly(A) elongation, and not poly(A) tail length, is important for translation. Finally, we show that precocious poly(A) elongation of Cl2 RNA during oocyte maturation is prevented by a large "masking" element that includes the dodecauridine CPE. The dual role of the CPE in both repression and activation of poly(A) elongation is discussed.


Ribosomal protein L4 and transcription factor NusA have separable roles in mediating terminating of transcription within the leader of the S10 operon of Escherichia coli.

Ribosomal protein L4 of Escherichia coli autogenously regulates both transcription and translation of the 11-gene S10 operon. Transcription regulation occurs by L4-stimulated premature termination at an attenuator hairpin in the S10 leader. This effect can be reproduced in vitro but depends on the addition of transcription factor NusA. We show that NusA is required to promote RNA polymerase pausing at the termination site; such paused transcription complexes are then stabilized further by r-protein L4. The L4 effect is observed even if the protein is added after the NusA-modified RNA polymerase has already reached the pause site. Genetically separable regions of the S10 leader are required for NusA and L4 action: The attenuator hairpin is sufficient for NusA-dependent pausing, but upstream elements are necessary for L4 to prolong the pause.


[Synthesis, structure and function of alpha-fetoproteins and their importance in medicine].

Alpha-fetoprotein (AFP) is a specific glycoprotein which is synthesised in the fetal liver and released into the blood stream together with the closely related protein, albumin. It has been proposed that AFP functions as a carrier of essential fatty acids to certain developing cells and as a possible immunosuppressor. In man its synthesis is under the strict and complicated control of transcription of a single gene on chromosome 4. The concentration of AFP in fetal serum is greatest at about 13 weeks gestation and then decreases up to birth. During pregnancy AFP passes into the amniotic fluid and also across the placenta, so that the concentration of AFP in maternal serum increases during pregnancy in a characteristic way. Greater than normal increases may indicate certain pathological states in the fetus. Serum concentrations of AFP in the newborn infant decrease rapidly to reach levels typical for adults (< 10 micrograms/L) usually by the end of the first year. Raised concentrations of serum AFP appear in a large proportion of patients with primary hepatoma and in a smaller percentage of patients with other malignant diseases (tumours of the testis, ovary, bronchi, gastrointestinal tract). In addition, increases in serum AFP are found in other illnesses accompanied by damage to hepatocytes in the liver (hepatitis, cirrhosis etc.). Certain differences in the structure of the oligosaccharide portion of the molecule have been shown between AFP synthesized by benign or by malignant cells and between AFP synthesised by hepatocytes or by cells of endodermal origin. These differences have been used as an aid in the diagnosis of liver diseases where serum AFP is elevated. Since AFP is not strictly specific for a certain type of carcinoma, its determination is primarily used in medicine for monitoring the effects of therapy and surgery on the course of malignant conditions which initially showed increased levels of serum AFP.


Herbal medicine "sho-saiko-to" induces in vitro granulocyte colony-stimulating factor production on peripheral blood mononuclear cells.

The herbal medicine "Sho-saiko-to (Xiao-Chai-Hu-Tang)" has been used in China for about 3000 years for the treatment of pyretic diseases. This medicine is now available as one of the prescribing drugs approved by the Ministry of Health and Welfare of Japan, and has also been widely used for patients with chronic viral liver disease as one of biological response modifiers in the field of Japan's Western Medicine. However, its mode of action has not been fully described. In the present in vitro study, we added "Sho-saiko-to" (TJ-9, Tsumura, Tokyo) to the culture of peripheral blood mononuclear cells (PBMC) obtained from healthy volunteers, and observed a dose-dependent increase in the production of granulocyte colony-stimulating factor (G-CSF). The same experiment was conducted using other herbal medicines "Dai-saiko-to" (TJ-8) and "Saiko-keishi-to" (TJ-10) which showed similar effects, or "Sho-seiryu-to" (TJ-19) which consists of very different compounds and shows different efficacy. The increases of G-CSF production were similar when "Sho-saiko-to" (TJ-9) or one of the 2 reference drugs (TJ-8 and 10) was added, whereas the increase when the control drug "Sho-seiryu-to" (TJ-19) was added, was quite small. This result shows that G-CSF induction is not a common effect of herbal medicines, but a specific effect of TJ-8, 9, and 10. Among these 3 drugs the increase produced by "Sho-saiko-to" was the largest. Based on this result, we conclude that administration of "Sho-saiko-to" may be useful not only for the treatment of chronic liver disease, but also for malignant diseases and acute infectious diseases where G-CSF is efficacious.


Natural killer cell frequency and function in patients with monoclonal gammopathies.

We evaluated the frequency and the functional activity of peripheral blood mononuclear cells (PBMCs) with natural killer (NK) cell phenotype in patients with monoclonal gammopathies. CD16+ and CD56+ PBMCs were strongly increased in monoclonal gammopathies of undetermined significance (MGUS) and multiple myeloma (MM). Furthermore, increased frequency of CD16+/CD3+ PBMCs was found in 7/15 patients with MGUS, indicating that T lymphocytes with NK-like phenotype are expanded in at least a subset of these patients. However, despite the increased frequency of PBMCs with natural killer phenotype, the functional NK activity was as comparable in both MGUS and MM patients as in normal individuals. The discrepancy between the expansion of circulating NK cells and the normal NK activity in patients with monoclonal gammopathies requires further investigation. However, at least in some MGUS patients, this discrepancy could be accounted for by the expansion of PBMCs with the rare phenotype CD16/CD3 which have been reported not to mediate significant NK activity.


[Endoscopic surgery in neoplasms of Vater's ampulla].

Twenty patients with tumors located in the ampulla of Vater underwent an endoscopic papillo-sphincterectomy. Four of them were palliative procedures and 16 were curative. The patients complaints were: obstructive jaundice, pain on the right hypochondrium, digestive hemorrhage or neoplastic syndrome. The mean age was 72.6 years ranging from 54 to 87. Ten were males and 10 females. The overall mean survival was 36.2 months (S.E.+ - 5.6) ranging between 9 and 50 months. The actuarial survival 18 months after the procedure was 63.5% (S.E.+ - 13%). The survival correlated with the macroscopic shapes according to Tasaka. A comparative analysis was made between the results obtained with palliative endoscopic surgery and radical open surgery.


The British Paediatric Surveillance Unit: activities and developments in 1990 and 1991.

The British Paediatric Surveillance Unit is a joint undertaking of the British Paediatric Association, the PHLS Communicable Disease Surveillance Centre and the Department of Epidemiology at the Institute of Child Health, London. It provides an active case reporting system which aims to facilitate the surveillance of rare childhood infections and other conditions. Cards with a menu of up to twelve reportable disorders are sent monthly to more than 1100 paediatricians throughout the United Kingdom and Ireland. The average response rate is 90%. Reported cases are followed up according to study protocols. Since its inception in 1986, the Unit has facilitated the study of a wide range of disorders, including HIV infection and AIDS, Reye's syndrome, Kawasaki disease, congenital rubella, neonatal herpes, congenital toxoplasmosis and acute rheumatic fever, and the number of new applications for surveys has increased in 1992-3. Several European paediatric organisations have expressed interest in setting up similar schemes in their own countries.


The epidemiology of pertussis in England and Wales.

Recovery in the uptake of whole-cell pertussis vaccine from 30% in 1978 to 91% in 1992 has resulted in a major reduction in the incidence of pertussis and in the proportion of cases occurring in pre-school children. This has been accompanied by a decline in pertussis mortality rates, with no deaths reported since September 1990. Seventy-four per cent of the 50 fatal cases reported since 1980 have been infants under one year of age, demonstrating the importance of completing primary immunisation as early as possible after birth. There is no evidence, as yet, that introduction of the accelerated immunisation schedule in June 1990 has reduced the proportion of cases occurring in infants, suggesting that the decline in mortality during the last two years is largely due to indirect protection provided by the current high level of vaccine-induced herd immunity. If 90% coverage is sustained and there is no significant waning of immunity with age, the circulation of Bordetella pertussis should be sufficiently reduced to interrupt the four year epidemic cycle for the first time in the United Kingdom. The hypothesis that vaccine-induced immunity has a serotype-specific component is supported by recent changes in serotype prevalence which have followed the increase in vaccine coverage. Given the successful reinstatement of whole-cell vaccine in the UK immunisation programme, the case for replacing it with a new acellular preparation will require careful evaluation.


Serotype specificity of vaccine-induced immunity to pertussis.

Two large epidemics of pertussis occurred in Britain during 1977-79 and 1981-83, following a decline in vaccine uptake in the mid-1970s. Serotype 1,3 predominated during both epidemics but serotypes 1,2 and 1,2,3 constituted 32% (243 of 769) of the isolates from unvaccinated children compared with only 10% (9 of 86) of the isolates from vaccinated children (p < 0.005). Whole-cell vaccines, although effective against infection with all serotypes, have a higher efficacy against serotypes 1,2 and 1,2,3 than against serotype 1,3. These data suggest that not only should acellular vaccines contain agglutinogens specific for each serotype but trials should demonstrate efficacy against all three serotypes.


The surveillance of communicable disease in the European Community.

This article summarises the existing international structures in Europe which collate data produced by surveillance systems in individual countries. The surveillance of influenza, tuberculosis, and other infections in Europe is undertaken by the World Health Organisation (WHO), the European Community (EC), and national and international organisations set up to study specific diseases. The surveillance of foodborne infections, rabies, travel-associated legionellosis and AIDS/HIV is undertaken by WHO collaborating centres or WHO/EC programmes. Research into immunisation and sexually transmitted diseases other than HIV is carried out through EC concerted action programmes. The Maastricht treaty, if ratified, may lead to changes in the way communicable disease surveillance is undertaken in the EC.


Food safety: action to protect the consumer.

Food safety issues have been headline news frequently in recent years. A review of food legislation was started in 1984 and led to the Food Safety Act 1990. This Act, which may prove to be the last major piece of independent British food law, provides food authorities with new powers to prevent the distribution of contaminated food and ensure that proper practices are being carried out by food businesses, and establishes a registration system for food businesses. Other developments include a new system for the inspection of food premises and plans to introduce a requirement for hygiene training for food handlers. The process of European harmonisation will require a further series of changes--forthcoming proposals provide for quality standards for laboratories, and more frequent inspection requirements covering a wide range of products.


Surveillance of HIV infection by voluntary testing in England.

Eighteen laboratories, which together provide primary HIV antibody testing for 43% of the population in England, collaborated in a study to record epidemiological information for all individuals voluntarily tested by them over a five year period. From the 184,113 individuals who had a first test during the study period, it is estimated that 1 in 12 adults in London, and 1 in 50 outside London have been voluntarily tested for HIV since testing became widely available in 1985. The majority of those tested were individuals whose perceived risk was heterosexual exposure. Infection in this group was concentrated in individuals whose partner had an identified risk and in those who had lived in or visited Africa. The rise in antibody prevalence observed in the latter group during 1990/91 may have been partly due to infection recently acquired in the UK. Antibody prevalence in heterosexuals without a high risk partner or a history of exposure abroad also rose during the study period, suggesting a recent increase in transmission through casual heterosexual exposure in the UK. The study also provided strong evidence of continuing high risk behaviour among homosexual men, particularly in the younger age groups. Homosexuals aged under 30 years and living in London had the greatest risk of acquiring HIV infection since 1988.


Regulation of muscle gene expression in Crustacea over the moult cycle.

Muscle growth in Crustacea may occur during specific stages of the moult cycle, focused around ecdysis when the old cuticle is shed and the new cuticle expands. In order to determine the moult stages in which sarcomeric proteins are synthesized and the regulatory factors involved, actin mRNA levels have been measured in the muscles of two crustaceans. These levels have been followed throughout the moult cycle and in response to passive stretch of walking leg muscle in vivo and to exogenous ecydsteroids applied to muscle preparations in vitro. Actin mRNA levels in both claw and leg muscles were elevated during the pre and postmoult stages of the moult cycle. However, varying patterns of expression are found in claw and leg muscle at specific stages of pre and postmoult. There was no increase in actin mRNA expression in extensor leg muscles in vitro after 6 hours exposure to elevated premoult levels of ecdysteroids. Immobilization of intemoult walking legs to maintain the extensor muscle in continuous passive stretch did not result in increased levels of actin mRNA after 5 days. These results are discussed in relation to the regulation of muscle growth over the moult cycle and to the molecular processes which may be responsible for controlling muscle protein synthesis.


The cytoplasmic translational inhibitory RNA of chick embryonic muscle: cloning and sequence of a subspecies which is antisense RNA.

A cytoplasmic translation inhibitory ribonucleoprotein (iRNP), about 10-12S in size and containing a heterogeneous class of RNA (iRNA) in the 60-140 nucleotide size range, has been previously isolated from 13-14 day old chick embryonic leg and breast muscle. Both iRNA and iRNA are potent inhibitors of mRNA translation in vitro. A cDNA library for iRNA was prepared in pUC18 vector. The 114 nucleotide insert of one clone was subcloned in pBluescript vector. The in vitro transcript of this insert (only the 5'-3' orientation and not the reverse orientation) showed inhibition of muscle poly(A)+ mRNA translation in vitro. The derived sequence of the iRNA indicates that it is a new sequence in which 27 nucleotides at the 3' and 5' ends can form base paired stem. Hybridization experiments and sequence analysis indicate that this iRNA has complementary (antisense) sequence to a highly conserved domain of the 28S eukaryotic rRNA and to a 5' leader segment of a muscle mRNA. These results suggest that iRNA mediated translational inhibition may act as a novel mechanism of controlling cellular mRNA levels in embryonic muscle and thus, acts in conjunction with the transcriptional control of myogenesis.


Isolation and functional comparison of Dmyd, the Drosophila homologue of the vertebrate myogenic determination genes, with CMD1.

We have isolated a cDNA clone, called Dmyd for Drosophila myogenic determination gene, from a 0-16 hour Drosophila embryo library that encodes a protein with structural and functional characteristics similar to the members of the vertebrate MyoD family (Paterson et al 1991). Dmyd encodes a polypeptide of 332 amino acids with 82% identity to MyoD in the 41 amino acids of the putative helix-loop-helix region and 100% identity in the 13 amino acids of the basic domain proposed to contain the essential recognition code for muscle specific gene activation. The gene is unique and maps to 95A/B on the right arm of the third chromosome. Low stringency hybridizations indicate Dmyd is not a member of a multigene family, similar to MyoD in vertebrates. Dmyd is a nuclear protein in Drosophila, consistent with its role as a nuclear gene regulatory factor, and is proposed to be a transiently expressed marker for a unique subset of muscle founder cells. We have used an 8kb promoter fragment from the gene, which contains the first 55 amino acids of the Dmyd protein, joined to lac Z to follow myogenic precursor cells into muscle fibers using antibodies to beta-galactosidase and Dmyd. Unlike the myogenic factors in vertebrate muscle cells, Dmyd appears to be expressed at a much lower level in differentiated Drosophila muscles so it cannot be followed continuously as a muscle marker. This is reflected in the loss of expression of Dmyd RNA in 12-24 hour embryos, a major period of early myogenesis, as well as in the undetectable level of the nuclear antigen in primary cultures of embryonic and adult Drosophila muscle. Functional differences between Dmyd and CMD1 are described and explained in terms of a model which may give insight to the nature of homo and heterodimer formation in the bHLH family of proteins.


[Endoscopic palliative treatment of malignant bile duct obstruction by endoprosthesis].

Endoscopic positioning of a large biliary endoprosthesis has become a well codified procedure for palliative treatment of primary or metastatic malignant bile duct obstruction. Authors' experience, regarding 47 patients treated by this technique from February 1992, is reported. Furthermore, either absolute or site-related per cent rate of successful positioning of endoprosthesis, efficacy of procedure, early and late complications and mean survival are reported. Results confirm the effectiveness of the procedure in reducing jaundice resulting from malignant bile duct obstruction and low complication rate; early detection and treatment of prosthetic obstruction with subsequent cholangitis, that is the most important factor responsible for death, depend upon close collaboration between physician and endoscopist.


Palliation of malignant bile duct obstruction: our experience with endoscopic 14 French prostheses.

We evaluated the efficacy of wide 14F endoprostheses endoscopically placed in en patients with malignant extrahepatic bile duct stenosis. Large-bore stents were successfully placed in all patients. There were no early complications. Stent clogging occurred in two patients after one month and after three months in another patient. Seven patients remained free of symptoms after a mean follow-up period of 4.5 months.


Histamine dependence of pentagastrin-stimulated gastric acid secretion in rats.

Does gastrin stimulate gastric acid secretion by direct action on oxyntic cells, by releasing histamine, or by being potentiated by histamine? Previous studies in the mouse pointed to gastrin-regulated histamine release. Guinea pig and rat are well known to vary in their sensitivity to histamine. Therefore, the effects of histamine and pentagastrin were compared quantitatively on isolated, lumen-perfused, stomach preparations from these species in the absence and presence of histamine H2-receptor blockade. The loss of potency of histamine in the rat was mirrored by a loss of potency of pentagastrin consistent with the idea that pentagastrin acts by releasing histamine. In the rat, a well-defined pentagastrin curve was obtained in the presence of histamine H2-receptor block as though pentagastrin acts both directly on the oxyntic cell and indirectly by releasing histamine. It was not necessary to invoke a potentiating interaction between histamine and pentagastrin at the oxyntic cell; the two effects appeared simply to add. Potentiation was observed, however, between other combinations of stimuli, for example, between vagal nerve and pentagastrin stimulation. The physiological consequences of these results are discussed.


Regulation of histamine release from oxyntic mucosa.

The regulation of histamine release from oxyntic mucosa is complex because of two potential sources of histamine: mast cells and enterochromaffin-like (ECL) cells. A gastrin-responsive histamine pool was identified in the rat oxyntic mucosa two decades ago, but these ECL cells from the rat have not yet been isolated or characterized in vitro. In vivo studies in canine and human mucosa have been more difficult because of the high content of histamine in mast cells. Using enzyme-dispersed canine oxyntic mucosal cells, we have studied regulation of histamine release from a mast cell-depleted fraction prepared by sequential elutriation and density gradient. Histamine-like immunoreactivity was demonstrated, using peroxidase-anti-peroxidase immunohistochemistry. After short-term culture, histamine was released in response to gastrin, cholecystokinin, carbachol, and forskolin. Somatostatin potently and effectively inhibited the response to gastrin. The cultures used for these studies also contained somatostatin cells, and, furthermore, the response to gastrin was enhanced by incubation with monoclonal antibodies to somatostatin. The latter findings suggested that somatostatin was acting in these cultures by a paracrine route. This pattern contrasts with that obtained in previous studies of canine oxyntic mucosal mast cells.


[Endoscopic recanalization with alcohol in the treatment of dysphagia of neoplastic origin].

Nineteen patients with dysphagia were treated by endoscopic injection of ethanol, to induce tumoral necrosis. Dysphagia was present in patients with inoperable, unresectable or recurrent esophagogastric cancer. Prior treatment, patients had a mean dysphagia grade of 3.22. After the first session, they had a mean of 2.05. An optimum dysphagia grade mean was 1.47. The period intertreatment was X 45 days. There were no complications associated with the method. The results suggest this therapy is a good palliative procedure that, in a short time and with a low cost, can improve the life quality in selected patients.


Ventricular arrhythmias in aortic valve disease before and after surgery.

In order to evaluate the incidence and prognostic value of ventricular arrhythmias in patients with aortic valve disease, 24 hour ambulatory electrocardiographic recordings were obtained in 374 patients without coronary artery disease (aortic stenosis n = 194, aortic regurgitation n = 103, combined aortic stenosis and regurgitation n = 77). Following aortic valve replacement, repeat recordings were obtained in a subgroup of 96 patients at 13 +/- 4 days and 18 +/- 7 months. Ventricular arrhythmias were classified in all cases according to Lown and were compared with clinical, echocardiographic and hemodynamic data. Preoperatively, ventricular premature beats were observed in 329 patients (88%), and were found to be frequent (>30 ventricular premature beats/hour) in 83 (22%). Multiformity was found in 105 (28%), couplets in 75 (20%) and ventricular tachycardia in 45 (12%). The occurrence of ventricular arrhythmias was not related to the type or severity of the valve lesions. Patients with severe ventricular arrhythmias (Lown class 3 or 4: 36.5%) had a higher ventricular wall thickness (interventricular septum thickness 14.2 +/- 1.8 mm vs. 11.9 +/- 2.0 mm, p < 0.01, a higher LV mass (178 +/- 32 g/m2 vs. 142 +/- 35 g/m2, p < 0.001) and a lower left ventricular ejection fraction (48% +/- 9% vs. 56.5% +/- 10%, p < 0.001); while in patients with aortic regurgitation a higher end-diastolic LV volume (224 +/- 38 ml/m2 vs. 178 +/- 42 ml/m2, p < 0.02) and a higher end-systolic LV diameter (56 +/- 7 mm vs. 46 +/- 8 mm, p < 0.02) were observed.(ABSTRACT TRUNCATED AT 250 WORDS)


Correlation of epidermal growth factor receptor and c-erbB2 oncogene product to known prognostic indicators of colorectal cancer.

Both epidermal growth factor receptor (EGFr) and the oncogene product of c-erbB2 have been shown to be expressed by human malignancies, and in some cases to relate to clinical outcomes. This study investigates the correlation between the presence of these receptor proteins and known prognostic indicators of colorectal cancer. Indirect immunoperoxidase staining of 32 freshly frozen surgical specimens revealed an overall expression of EGFr and c-erbB2 of 43% and 38%, respectively. A significantly higher rate of EGFr expression was found in tumours of more advanced stage (Dukes C and D), poor differentiation and those exhibiting vascular and lymphatic invasion. The presence of the c-erbB2 protein did not correlate with any of these variables. Expression of these molecules appeared to be independent and positive staining for both receptors occurred in only 19% of cases. EGFr may play a future role as a prognostic tool in colorectal cancer.


Differential immunoreactivity of her-2/neu oncoprotein in prostatic tissues.

To investigate HER-2/neu oncoprotein immunoreactivity, monoclonal antibody TA1 immunohistochemical examination of flash-frozen radical prostatectomy specimens was performed (n = 35). All prostatic specimens contained benign prostatic hyperplasia (BPH) and/or prostatic intraepithelial neoplasia (PIN), as well as prostatic carcinoma (CaP). HER-2/neu oncoprotein immunoreactivity in BPH tissues was not significantly different than that for the PIN basal cell layer (P = 0.10) or for the PIN luminal cells (P = 0.17). There was significantly more HER-2/neu oncoprotein immunoreactivity in BPH than in areas of CaP (P < 0.001). There was no significant difference in the amount of immunoreactivity present in PIN basal cells when compared to the PIN luminal cells (P = 0.49). Both the PIN basal cells and luminal cells stained for the HER-2/neu oncoprotein to a higher degree than cells in the CaP areas (P < 0.001 in both cases). HER-2/neu oncoprotein immunoreactivity is present at a significantly higher degree in BPH and PIN than in malignant prostatic epithelium.


Is the relationship between angiogenesis and metastasis in breast cancer real?

The suggested link between angiogenesis in breast cancer and metastasis remains unsubstantiated. We tested this relationship in primary breast carcinomas from 37 patients with a median follow-up 9.5 years (Cohort 1) and 50 patients with a median follow-up of 1.5 years (Cohort 2). Angiogenesis was assessed by counting vessel density after immunohistochemical staining of vascular endothelium for factor VIII. Patients were grouped according to whether metastasis (defined as spread to axillary lymph nodes, distant sites or both) had occurred. The mean +/- SD scores in Cohort 1 when metastasis was absent and present, respectively, were 15.6 +/- 4.9 (n = 21) and 14.1 +/- 3.7 (n = 16). In Cohort 2 the scores were 15.4 +/- 5.8 (n = 26) and 14.5 +/- 4.9 (n = 24). There was no significant difference between these scores in either cohort. Multivariate analysis demonstrated lymph node involvement (P < 0.001) and tumour size (P < 0.001) but not angiogenesis score (P > 0.05) to predict distant metastasis. This evidence argues against any prognostic significance of angiogenesis in breast carcinoma.


[Ex situ-in vivo hepatic resection. Technique and initial results].

Extracorporeal liver surgery has been proposed with the aim to increase the resectability rate in patients with advanced tumors. In order to avoid the inherent section of the hepatic pedicle we propose ex situ-in vivo liver surgery. The surgical procedure comprises complete mobilization and exteriorization of the liver which is rocked on the axis of the porta hepatis following section of the hepatic veins. Protection of the liver parenchyma against prolonged ischemia is obtained through cold portal perfusion (UW solution) and the use of an heat exchanger on which liver resections and vascular procedures are performed. The procedure also encompasses the use of veno-venous bypass during liver vascular exclusion. This procedure was performed in 2 patients with tumoral invasion of the 3 main hepatic veins and in 1 patient whose hemangioma was surrounding the hepatocaval confluence. Duration of hypothermic ischemia was 205, 225 and 230 minutes respectively. Postoperative course was uneventful in the 3 cases with an hospital stay of 25, 28 and 18 days. Ex situ-in vivo liver surgery allows completion of a surgical treatment in patients whose tumor appears unresectable with the use of conventional technics. This procedure may constitute an alternative to liver transplantation in highly selected cases.


Antibody-directed therapy of multidrug-resistant tumor cells.

The major obstacle to effective cancer chemotherapy is the resistance of tumor cells to cytostatic agents. Tumor cells frequently express a multidrug-resistance (MDR) phenotype. In an effort to devise new strategies to overcome MDR, antibody-directed approaches for the eradication of MDR cells have been developed. Experimental data have shown that multidrug-resistant tumor cells can be efficiently killed by monoclonal antibodies, immunotoxins, or bispecific antibodies. The current experimental results indicate that an antibody-directed therapeutic approach to eradication of MDR cells might be a promising adjunct to conventional chemotherapy of cancer patients.


Endolaparoscopic palliation of pancreatic cancer.

Two patients with advanced pancreatic cancer were palliated for both duodenal and biliary obstruction without laparotomy. The techniques of endoscopic biliary stent and laparoscopic gastrojejunostomy are described. This combination achieved rapid palliation with minimum morbidity. Patients with advanced pancreatic cancer and a limited life expectancy benefit greatly from the shortened hospital stay and convalescence this manner of treatment offers.


Sexually transmitted diseases in England and Wales: 1981-1990.

Data provided by genito-urinary medicine clinics, microbiology laboratories and other reports reveal a consistent picture of the epidemiology of sexually transmitted diseases in England and Wales during the 1980s. The number of new cases increased by 21% between 1981 and 1990; most of this increase being due to genital herpes, genital warts and 'non-specific genital infection' (including that due to Chlamydia trachomatis). The increase in attendance rates for new cases was much higher for women (37%) than for men (2%) during the last decade, with the former experiencing more sequelae. Gonorrhoea and syphilis declined steadily until 1989 but cases of gonorrhoea have increased since then, especially in homosexual males. These data emphasise the need for renewed efforts toward the prevention and control of sexually transmitted diseases, particularly among adolescents, women and homosexual men.


Bacterial infection and human cancer: association or causation?

Environmental factors such as diet, industrial pollution, smoking and viruses account for some 80% of cancers and more than one-quarter of all non-accidental deaths. Little attention has been paid to the relationship between bacterial infection and cancer but there is growing evidence to support this link. For some sites, such as stomach and colorectum, the evidence is relatively strong, whereas for others, such as biliary tract and bladder, it is more circumstantial.


Benign prostatic hyperplasia. Its natural history, epidemiologic characteristics, and surgical treatment.

Benign prostatic hyperplasia is a nonmalignant enlargement of the prostate that is due to both epithelial and stromal hyperplasia. Although the exact origin of this condition is not well defined, it is thought to arise as microscopic nodules in the periurethral tissue of the prostate gland as early as the late '20s. With advancing age and the presence of androgens, this histologically identifiable hyperplastic tissue progresses to a macroscopic state, which is a palpably enlarged prostate. This enlarged prostate causes clinically significant obstruction of the bladder outlet in many men, necessitating therapeutic intervention. Currently, prostatectomy is the standard treatment with successful long-term results. Nevertheless, much information has become available recently on its indications, outcomes, associated morbidity and mortality, and effect on quality of life. Because of these findings as well as the rising healthcare costs and the desire among patients to avoid surgery if possible, there is much enthusiasm for developing less expensive, less invasive, but effective treatments for symptomatic benign prostatic hyperplasia. To appreciate the tremendous advances being made with regard to the treatment of benign prostatic hyperplasia, it is necessary to have a complete understanding of the disease process itself and its traditional therapies. This clinical report provides a comprehensive review of the natural history, epidemiologic characteristics, and outcomes of both open and transurethral surgery for benign prostatic hyperplasia.


Urinary trypsin inhibitory activity for the diagnosis of bacterial infection: a prospective study in 690 patients.

During the acute phase response, interleukin-1 induces production of inter-alpha-trypsin inhibitor. The measurement of urinary trypsin inhibitory activity which results from the effects of inter-alpha-trypsin inhibitor degradation products is easy, quick and inexpensive. We conducted a prospective study to investigate its value as a diagnostic tool in comparison with C-reactive protein. Comparisons were made in 690 consecutive patients at admission to a department of internal medicine. The level of urinary trypsin inhibitory activity was significantly higher in patients with bacterial infection (mean = 123 IU/g creatinine) than in patients with either viral infection (34 IU), cancer (50 IU), elevated erythrocyte sedimentation rate without infection (45 IU), miscellaneous non-inflammatory diseases (27 IU) or in non-organic controls (19 IU) (Dunnet's test, p << 0.01). The receiver operating characteristic curve showed that sensitivity and specificity of urinary trypsin inhibitory activity were higher than those of C-Reactive protein for the diagnosis of bacterial infection. For levels > or = 60 IU, sensitivity was 75% and specificity 89%. Urinary trypsin inhibitory activity levels fell within 2 days in patients treated for acute bacterial infection. Urinary trypsin inhibitory activity could be a useful marker of bacterial infection particularly in patients with fever of unknown origin and/or elevated erythrocyte sedimentation rate.


Antibodies to non-structural hepatitis C virus antigens: a link with liver disease activity?

The aim of our study was to evaluate the aetiopathogenetic role of hepatitis C virus (HCV) in the genesis of chronic liver disease and hepatocellular carcinoma and the relationship between presence of circulating antibodies against non-structural HCV antigens and disease activity. Using a new enzyme-immunoassay capable of detecting, either separately or together, circulating antibodies to structural and non-structural hepatitis C virus antigens, we tested 208 chronic hepatitis B surface antigen (HBsAg) carriers and 144 patients suffering from chronic liver disease. Among the chronic HBsAg carriers with normal transaminase activity, there were 4% who proved to be anti-HVC positive, compared with 14.5% among those with high serum transaminase. Among subjects with chronic liver disease, 20% of patients with chronic persistent hepatitis, 54% with chronic active hepatitis, 35% with liver cirrhosis and 47% with hepatocellular carcinoma proved to be anti-HCV positive. With regard to the aetiology of liver disease, 13% and 25% of chronic HBV infected patients, with or without anti-delta virus superinfection respectively, had anti-hepatitis C virus antibody. This prevalence was 22% among alcoholic liver disease and 89% among patients with cryptogenic liver diseases. The percentage of subjects with circulating antibodies against non-structural HCV proteins was higher among HBsAg chronic carriers with raised alanine aminotransferase and among patients with chronic active hepatitis and hepatocellular carcinoma. Many subjects with chronic liver disease have circulating anti-HCV antibodies. Anti-HCV positive subjects, especially those with antibodies to non-structural antigens, are more frequently found among patients with aggressive liver diseases. Among HBsAg chronic carriers the prevalence of anti-HCV was lower in "healthy carriers" and HBeAg positive rather than in HBeAg negative subjects with high alanine aminotransferase. We therefore suggest that there may be a relation between HCV replication, activeness of the liver disease and presence of antibodies to non-structural viral antigens.


1-Phenyl-3-trimethylaminopropyl carbodiimide: a new inhibitor of thymidylate synthase.

Thymidylate synthase (EC 2.1.1.45) from methotrexate-resistant Lactobacillus casei was inactivated by 1-phenyl-3-trimethylaminopropyl carbodiimide (PTC), 1-phenyl-3-dimethyl aminopropyl carbodiimide (PDC), and 1-ethyl-3-dimethyl aminopropyl carbodiimide (EDC). In the presence of excess PTC, the inactivation followed pseudo-first order kinetics; the second order rate constant was approximately 200 M-1min-1 at 30 degrees C. The rate of inactivation by PTC was faster than that by either PDC or EDC. Concentrations of the substrate dUMP greater than 0.15 mM, or of the product dTMP greater than 1.6 mM completely protected the enzyme from inactivation by PTC, but 10 mM dUrd provided very little protection. The rate of inactivation of EDC was reduced by only 40% in the presence of 50 mM dUMP. Nucleophiles (sulfanilic acid, glycine methyl ester, or glycine ethyl ester) had no effect on the rate of inactivation by PTC. The complete inactivation of thymidylate synthase by PTC was accompanied by the incorporation of approximately 2 mols of 14C-PTC per mol of enzyme. Although carbodiimides normally modify carboxyl groups in proteins, results from sulfhydryl group titrations and from reversible modification of sulfhydryl groups by methyl methanethiosulfonate suggest that two of the four cysteine residues of thymidylate synthase were modified by PTC.


Kinetics and mechanism of proteinase-binding of pregnancy zone protein (PZP). Appearance of sulfhydryl groups in reactions with proteinases.

Proteinase binding by pregnancy zone protein (PZP), an alpha-macroglobulin involves bait region cleavages, association of dimeric-PZP into tetrameric and reaction of internal gamma-glutamyl-beta-cysteinyl thiol esters of PZP with proteinase side chains. The product is an equimolar enzyme-PZP(tetramer) covalently linked complex with four free sulfhydryl groups. The kinetics of the appearances of sulfhydryl groups during the reaction of PZP with chymotrypsin has been investigated using stopped-flow and conventional mixing techniques over a broad concentration range. Thiol ester cleavages followed double exponential decays corresponding with two steps. The faster one resulted in the appearance of three sulfhydryl groups with an observed rate constant, k(obs) = k1.1 + k1.2 delta E, dependent on the excess concentration of chymotrypsin, delta E, and k1.1 = 0.03 s-1 and k1.2 = 4 x 10(4) M-1 s-1. The last sulfhydryl group appeared in a slower step, with similar concentration dependence and k2.1 approximately 0.003 s-1 and k2.2 approximately 5 x 10(3) M-1s-1. Covalent binding of the enzyme apparently was simultaneous with the faster thiol ester cleavage step. Based on these and previous results a model of the reaction mechanism of the proteinase binding reaction of PZP is proposed. It consists of four major steps: (i) Bait region cleavage of PZP-dimers by the enzyme, (ii) fast association of enzyme-PZP(dimer) species with native PZP or with another enzyme-PZP(dimer) compound resulting in release of one of the associated enzyme molecules (iii) reaction of an average of three thiol esters of the enzyme-PZP(tetramer) intermediate with the associated internal enzyme molecule or with an external one. In this step one enzyme molecule becomes covalently linked to the PZP-(tetramer), three sulfhydryl groups appear and the enzymic activity of the bound enzyme molecule decreases to the level of that of the final complex. (iv) Hydrolysis of the last thiol ester and in the presence of excess enzyme, degradation of enzyme-PZP(tetramer) complexes and formation of fragments some of which are the size of PZP(dimer) with enzyme bound.


Neonatally administered capsaicin induces functional disturbances in the carotid afferent pathway to the nucleus tractus solitarius.

The effect of neonatal capsaicin treatment on chemo- and/or barosensory input to the medulla was studied in 35-40-day-old rats. By means of responses evoked in the nucleus tractus solitarius by stimulating the ipsilateral sinusal nerve, the excitability of slow-conducting carotid afferent fibers and the effect of substance P microinjection into the fourth ventricle were evaluated. Neonatal capsaicin resulted in reduced amplitude of the late component of the evoked responses, increased chronaxie values in the strength-duration paradigm, and increased sensitivity of evoked responses to the inhibitory effect of intracerebroventricular administered substance P. The results indicate that capsaicin given early in life leads to functional disturbances of chemo- and/or barosensory input to the nucleus tractus solitarius, involving both the slow-conducting primary afferents and the receptors for substance P of the second-order cells of the sensory pathway.


Inhibitory effect of aryl thienyl-ketones and -thioketones on arachidonic acid-induced malondialdehyde formation in human platelets: biological data and molecular modelling.

A series of anti-thrombotic aryl thienyl-ketones and -thioketones was assayed in vitro for their inhibitory effect on malondialdehyde (MDA) production induced by arachidonic acid in human platelets. For several compounds MDA formation was strongly inhibited indicating that the anti-platelet target was situated on the cyclooxygenase pathway. A comparison between the inhibition constant Ki and the IC50 values revealed competitive inhibition kinetics. The molecular structure of one active compound was analysed by X-ray diffraction and theoretical calculations to provide information on its electronic and lipophilic properties.


Inhibition of gastric H+, K(+)-ATPase by quercetin.

The effects of the naturally occurring flavonoid, quercetin, on gastric H+, K(+)-ATPase were investigated. Quercetin inhibited hog gastric H+, K(+)-ATPase and K(+)-stimulated p-nitrophenyl phosphatase (K(+)-pNPPase) activity in a dose dependent manner with IC50 values of 2.3 microM, and 6.0 microM respectively. The inhibition of H+, K(+)-ATPase by quercetin is competitive with ATP and is noncompetitive with K+. The steady-state phosphorylation level of the enzyme was also dose-dependently reduced by quercetin with an IC50 value of 4.5 microM. These results suggest that quercetin reduces the phosphorylated enzyme level by competition with ATP, and thereby inhibits the H+, K(+)-ATPase activity.


The role of fibrin fibrils in the dissociation of a cell surface protease-inhibitor complex and evidence for the recapture of the inhibitor protein.

Colonic epithelial cells possess a cell surface protease referred to as guanidinobenzoatase (GB). Active GB can be located by the fluorescent active site directed competitive inhibitor 9-amino acridine (9AA) followed by fluorescence microscopy. The cell surface GB can be transferred to fibrin fibrils, which have a higher affinity for GB than the cell surface. The cytoplasm of colonic epithelial cells contains a protein which inhibits membrane bound GB, forming a latent form of GB or GB-inhibitor complex. This complex can also be dislodged from the epithelial cell surface due to the high affinity of fibrin for GB, with the consequent dissociation of the enzyme-inhibitor complex and solubilisation of the inhibitor. This use of fibrin has led to the demonstration of the transfer of a selective inhibitor protein from one cell surface (the donor) to a second cell surface (the target).


Algebraic least squares estimates of inhibitor constants.

When the data has a constant coefficient of variation, appropriately weighted least squares estimates of the parameters for competitive inhibition in both enzyme and binding experiments can be obtained algebraically. The algorithms are presented and justified.


Some amines as inhibitors of pea diamine oxidase.

The inhibition of pea diamine oxidase (DAO; EC 1.4.3.6) by some amines and chelating agents has been studied. Ethylenediamine (competitive, Ki = 5.2 mmol.l-1), cis-1,2-diaminocyclohexane (noncompetitive, Ki = 2.9 mmol.l-1) and trans-1,2-diaminocyclohexane (competitive, Ki = 3.6 mmol.l-1) are weak inhibitors whereas diethylenetriamine (noncompetitive, Ki = 7.2 mumol.l-1), triethylenetetraamine (partial noncompetitive, Ki = 0.57 mumol.l-1) are potent inhibitors. The chelating agents 1,10-phenanthroline (Ki = 0.031 mmol.l-1), and 2,2'-bipyridyl (Ki = 0.058 mmol.l-1) are noncompetitive inhibitors. The pH-inhibition profile for the inhibitors indicates that the protonated forms are the active species.


Direct recovery and molecular analysis of DNA and RNA from soil.

A simple method for the recovery of DNA and direct detection of nif and Tn5 sequences in soil has recently been presented by Selenska and Klingmüller. On the basis of that method we have developed a procedure for the recovery and separation of DNA and RNA from the same soil sample. A 550 bp sequence from the Kmr gene of Tn5 was identified by PCR amplifications in total DNA and RNA, isolated from soil inoculated with a nitrogen-fixing Enterobacter agglomerans 19-1-1, which carries this transposon. Hence, not only the presence of the Kmr gene of Tn5 but also its expression (mRNA synthesis) in the analyzed environmental samples was detected. The authenticity of the products of PCR amplifications of DNA and mRNA was confirmed by the PhotoGene hybridization technique.


[The tumor markers CEA, AFP and CA125 in patients with endometrial carcinoma].

The plasma concentration of CEA, AFP and CA125 in 54 women with endometrial carcinoma and 12 with atypical hyperplasias, were investigated. In 20 of the patients the tumor markers were studied again 11 months after the surgical treatment. Elevation of CEA, AFP and CA125 levels was found in the third, and especially in the forth phase of the illness. Essential similarities between the histological differentiation and the levels of the tumor markers were not observed. The supposition was that the study of the CEA, AFP and CA125 is not a reliable criterion for the early diagnosis of the endometrial carcinoma. They have a prognostic significance only in patients of the second clinical phase after a surgical treatment. It is recommended two of the markers to be used, mostly CEA and CA125 and the study to be performed several times.


Lethal effect of a bait for Rhodnius prolixus (Hemiptera: Reduviidae), the vector of Chagas' disease, containing hexachlorocyclohexane (HCH), under laboratory conditions.

The lethal effect of a bait containing an aqueous hexachlorocyclohexane (HCH) suspension at the concentration of 1g/l and maintained at room temperature was studied in the laboratory over a period of 12 weeks. The suspension was placed in a latex bag hanging inside a 1000-ml beaker tightly covered with nylon netting, and left there with no changes for 85 days. Sixteen groups of R. prolixus bugs, consisting on average of 30 specimens each, were successively exposed to the bait and observed at different intervals for one week each. The mortality rate was 100% for all groups, except for the 16th, whose mortality rate was 96.7%. As the groups succeeded one another, mortality started to occur more rapidly and was more marked at the 6- and 24-h intervals. Later tests respectively started at 6:00 a.m. and 6:00 p.m. showed that diurnal and nocturnal periodicity in the offer of food had no effect on mortality. First- and 2nd- instar nymphs and adults male were more sensitive and 5th- instar nymphs were more resistant to the active principle of the bait.


[Our experience in the prenatal echographic diagnosis of spinal dysraphism in the fetus].

The investigation consists of 141 cases of prenatal diagnosing structural and chromosomal anomalies of the fetus. Seventeen of the cases, quoted above, concern spinal dysraphism (spina bifida, occipital meningocele, meningoencephalocele). It has been made an analysis of ultrasound signs at this group of defects which turned out the most useful for the definite diagnosis. According to the literary survey and author's experience are formed two main groups of indices at echo-sounding study--direct and indirect. There have been considered the technics of echoscopy in searching the signs of different terms of pregnancy. It has been made a partial comparison of the reliability in the two groups ultrasound signs with this in biochemical diagnosis of spinal dysraphism in the fetus.


[Effect of dietary protein levels on the genesis of repair tissue in rats].

The objective of this study was to verify if the diet protein level affects the genesis of the repair tissue in rats submitted to a poly-chloro-vinyl (PVC) sponge implantation, as well as to analyse the possible alterations in the synthesis of the mucopolysaccharides acids (glucosaminoglycans) by the histophotometry technique. Forty five Wistar weanling male rats, at 21 days of age, were divided into three experimental groups; the groups were fed diets al 6%, 15% and 40% protein level from casein source, during at 69 days period. The animals which received the low protein diet (6%) presented an inhibition in the evolution and maturation of the granulation tissue mainly in the 4th, 7th and 10th days after the sponge PVC implantation. It was also observed that there was less infiltration of the inflammatory cells, less fibroblasts proliferation, reduction of the collagen fibers synthesis, neovascularization decreased and an inhibition of the mucopolysaccharide acids synthesis.


[Strategy for monitoring and implementing methods for correcting child growth and development in rural areas of Sonora. Mexico].

An appropriate health technology to facilitate child growth and development in a rural area is presented and documented. Because mother's adequate behavior related to child's care does not produce immediate behavioral or physical changes it is necessary to create a long term social system of consequences. This was achieved joining a longitudinal measurement system with a program to train mothers to identify and deal with health and development issues. During four years, data were collected on weight-length development and morbidity twice a year and simultaneously skills were taught to diagnose treatment and prevent growth and development problems. After the third session child development and anthropometry data became the base of a system to assess maternal behavior, providing consequences for links in the behavior chains associated with child care. This system made organization and participation of the community in primary health care programs more likely, which implied a better score in each child growth and development chart.


Glomerular permeability to macromolecules in gentamicin-treated rats.

1. To determine the effect of gentamicin on the functional properties of the glomerular barrier, 44 Wistar rats received daily doses of 80 mg/kg body weight for 6 days. Glomerular permeability to neutral dextrans and albumin was evaluated by day 6 and albuminuria was determined on the 1st, 3rd and 5th days of treatment. 2. Treatment induced an intense increase in albuminuria from 74 micrograms/24 h to 11.5 mg/24 h on the 5th day of treatment (N = 11). This increase was associated with the presence of large amounts of albumin in elements of the glomerular filter and in the apical region of the proximal tubular cells (N = 4). Fractional clearances of neutral dextrans having molecular radii in the range of 18-41 A were not significantly different in control (N = 5) and gentamicin-treated rats (N = 7). 3. These results show that gentamicin, a polycation at pH 7.4, produces an increase in the glomerular permeability to negatively charged macromolecules in rats, probably due to interaction of the polycation with negative changes in the glomerular filter.


Calcium currents in solitary hair cells isolated from frog crista ampullaris.

Some properties of Ca2+ currents in hair cells isolated from frog semicircular canals by enzymatic or mechanical treatment were studied by using the whole-cell configuration of the patch-clamp technique. After blocking the large outward K+ currents by substituting Cs+ for K+ and adding tetraethylammonium to the pipette filling solution, voltage- and time-dependent inward currents were clearly detectable in the presence of 4 mM Ca2+ in the extracellular solution. Ca2+ current was recruited at test potentials more positive than -60 mV, showed a rapid activation, and exhibited no inactivation during 150-ms depolarizing pulses. The maximal amplitude was attained at about -20 mV, with an average value of about 80 pA. When Ca2+ in the extracellular solution was replaced with Ba2+, the magnitude of inward currents increased about twofold. Ba2+ currents were blocked more effectively by Cd2+ than by Ni2+, were suppressed by 0.5 microM omega-conotoxin, and were virtually unaffected by amiloride. The dihydropyridine Bay K 8644 caused a marked voltage-dependent increase in inward currents. The present data suggest that hair cells from frog crista ampullaris are endowed with a homogeneous population of Ca2+ channels having several properties similar to those described for neuronal L channels. Since these channels are recruited in a range of potentials close to the resting level, it is suggested that they subserve the control of both resting and evoked transmitter release from the basal pole of the hair cells.


Organization of afferent projections to the ventral and dorsal regions of the cat lateral vestibular nucleus: an HRP study.

Topical organization of afferent projections to Deiters' nucleus originating from cortical, subcortical, brainstem, and spinal cord structures has been revealed in the cat by microiontophoretic injection of horseradish peroxidase (HRP) into the ventral (NVLV) and dorsal (NVLD) regions of the nucleus and subsequent study of retrograde axonal transport of the enzyme. Differences between afferent inputs to the ventral and dorsal parts of the nucleus, considered as representative of the forelimb and hindlimb regions of the structure, have been observed. The trajectories of labeled fiber systems of the nucleus mentioned have been described. Computer reconstruction of the cat lateral vestibular nucleus (NVL) according the contours drawn from frontal sections of the brain has been carried out.


Some humoral immunological aspects of the rheumatoid arthritis correlated with the ultrastructural changes of the rheumatoid synovial fluid.

We performed serologic and synovial investigations in rheumatoid (Latex 1/1280, 1/640, negative and Waaler Rose 1/1024, 1/512, negative), non-rheumatoid and control lots. The immunological results were correlated with ultrastructural changes found in the synovial fluid (SF) at the same titres of rheumatoid factor (RF). The pathologic values of the circulating immune complexes (CIC) (mean = 108.05 U), IgM (mean = 420 UI/ml), IgG (mean = 355.36 UI/ml), and anti-collagen II antibodies (mean = 558.6 U) were present at high titres of RF (Latex 1/1280, Waaler Rose 1/1024). These cases had also major ultrastructural changes of the nucleus and cytoplasm. We inferred from this the implication of the immune factors in the etiology and pathology of the Rheumatoid Arthritis (RA). The high, titres of RF were correlated with pathologic values of the C-reactive-protein (CRP) (mean = 13.31 mg%) and alpha-1-acid glycoprotein (A-1-GA) (mean = 158.3 mg%). The decline of the complement fraction C3 from the synovial fluid in RA confirms the immune character of the rheumatoid synovitis and may be useful in the diagnosis process. The significantly lower concentrations of the protease inhibitors alpha-1-anti-trypsin (A-1-AT) (mean = 165.1 mg%) and alpha-2-macroglobulin (A-2-M) (mean = 129.6 mg%) in synovial fluid suggest a diminution of the anti-proteasic activity due to local immune conflict.


[The laparoscopic management of ectopic pregnancy].

Twenty-five ectopics pregnancies were treated successfully by laparoscopic approach from november 1990 to april 1992. The technics used were: salpingostomy, salpingectomy and taking out trophoblastic tissue exclusively. At the present time, two out of eight women who have wanted become pregnant, have delivered a healthy babies. We concluded that the ectopic pregnancy is efficiently managed by laparoscopy with advantages such as: minimal scar, short time in the hospital, quickly return to total activity, low costs, etc.


[The treatment of ectopic pregnancy with local and intramuscular methotrexate or expectant management].

Ten patients with ectopic pregnancy, probably non complicated, diagnosed by transvaginal sonography and serial determinations of subunit B of human chorionic gonadotrophin, were treated with a single injection of methotrexate intraovular (5 cases), intramuscular (3 cases) or with expectant management. We obtained clinical resolution and undetectable hormone levels in seven patients and three underwent additional surgery.


Human antibodies to dengue and yellow fever do not react in diagnostic assays for hepatitis C virus.

Hepatitis C virus (HCV) is a recently described causative agent of the great majority of post-transfusion non A-non B hepatitis and is classified within the Flaviviridae family. Due to a high prevalence of anti-HCV and other flaviviruses circulating in Brazil, such as dengue and yellow fever, we investigated the possibility of serological cross-reactivity between these viruses. Different panels of human sera positive for dengue type 1 (9 cases) and type 2 (7 cases) from 6 patients naturally infected with yellow fever and from 94 adults vaccinated against the 17D strain of yellow fever were tested against HCV antigens used in diagnostic assays. Two enzyme immunoassay systems were tested: one, an in-house test using recombinant antigens from core, NS3 and NS5 regions of the HCV genome (Research Foundation for Microbial Disease of Osaka University, Japan); and another, using synthetic peptides representing immunodominant epitopes of structural core and non-structural NS4 and NS5 HCV regions (INNOTEST HCV Ab, Innogenetics, Belgium). A line immunoassay (INNO-LIA HCV Ab, Innogenetics, Belgium) was used as a confirmatory test. In this, HCV antigens are coated as discrete lines on a nylon strip with plastic backing. Besides 4 control lines on each strip, a total of 6 HCV lines are present: line A consists of several NS4 epitopes, line B consists of several NS5 epitopes and lines C-F contain several core epitopes. This test not only confirms but differentiates antibodies to hepatitis C virus. No positive results were detected with these tests, indicating that hepatitis C infection can be evaluated by current assays in regions where flaviviruses are endemic.


Cytomorphological and immunocytochemical evaluation of fine needle aspirates from high grade non-Hodgkin's lymphomas.

1. Fine needle aspirates from ten patients with high-grade malignant non-Hodgkin's lymphomas were analyzed by cytomorphology and immunocytochemistry. 2. The following morphologic diagnoses were made: lymphoblastic lymphoma (3 cases), Burkitt's lymphoma (3 cases), mixed small and large cell lymphomas with predominance of large cells (2 cases), and centroblastic lymphoma (2 cases). Immunocytochemistry showed a B-cell phenotype in five cases and a T-cell phenotype in four. One case of lymphoblastic lymphoma was negative for the T and B cell markers used. 3. The results of histological and immunohistochemical analyses performed on surgical biopsies from 8 patients confirmed the morphological diagnosis in all cases. Two cases of Burkitt's lymphoma were submitted only to cytological and immunological diagnosis. 4. The high diagnostic accuracy of combined cytomorphology and immunocytochemical assessment of fine needle aspirate samples validates the use of the technique in the diagnostic work-up of high-grade non-Hodgkin's lymphomas.