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PubMed1978

Differential expression of an equivalent clonotype among BALB/c and C57BL/6 mice.

The primary anti-phosphorylcholine (PC) response in BALB/c, C57BL/6, and congenic and recombinant inbred strains of these parental types has been examined in the splenic focus system. The frequencies of PC-specific precursors were shown to vary among these strains from 2 to 20 precursors per 10(6) splenic B cells. The distribution of these frequencies suggests that elements closely linked to or within the major histocompatibility complex may play a role in the determination of this parameter, although additional experiments are necessary to adequately assess this possibility. Moreover, all strains tested, regardless of immunoglobulin allotype, expressed monoclonal antibodies indistinguishable from the TEPC 15 myeloma protein (T15) clonotype. Further, the frequency of this clonotype in a given strain did not appear related to allotype, since both high and low T15 frequencies were found among strains of either the BALB/c (a(1)) or C57BL/6 (a(2)) allotype. The examination of normal serum for the T15 idiotype, however, revealed that only mice of the BALB/c allotype (a(1)) expressed the T15 idiotype in detectable quantities. After immunization with Diplococcus pneumoniae, sera from mice of the a(1) allotype consistently contained large quantities of the T15 idiotype, whereas sera from mice of the a(2) allotype exhibited various degrees of cross-reactivity with anti-T15 antibody. These results suggest that: (a) the allotype of an individual, although closely related to serum levels of an idiotype, is unrelated to the proportion of the precursor population which expresses that idiotype and; (b) the serum expression of a given idiotype may reflect regulatory processes, which act either during or before antigenic stimulation, rather than the actual clonotype representation in the repertoire. These findings indicate that distinctions must be made between the expression of idiotypic determinants within precursor B-cell populations and elements which regulate the subsequent appearance of those idiotypes in serum antibodies.

Animals↗

PubMed1975

Role of macrophages in Wesselsbron and Germiston virus infections of mice.

Mice develop age-dependent resistance to intraperitoneal infection with Wesselsbron virus, but not with Germiston virus. This resistance correlates with the capacity of peritoneal macrophages from older mice rapidly inacativated the infectivity of Wesselsbron virus, whereas Germiston virus replicated in these cells. Peritoneal macrophages from older mice protected cell cultures against Wesselsbron virus infection, but macrophages from newborn mice did not. Electron microscopic observations suggested that Wesselsbron virus was actively phagocytosed by macrophages, whereas Germiston virus entered the cells by other means and thus, presumably, circumvented the normal killing mechanisms of these cells. Germiston virus may also have directly impaired these killing functions, however, in that the ability of macrophages to kill phagocytosed Diplococcus pneumonaie was significantly less after macrophages were exposed to the virus.

Age Factors↗

PubMed2003

Characterization of an O-glycosylated plaque-associated protein from Alzheimer disease brain.

In this work we characterized a 90-kDa glycoprotein from Alzheimer disease (9OAzgp) brain extracts that is recognized by the GalNAc-specific lectin from Amaranthus leucocarpus (ALL), as determined through Western blot. The 90Azgp was purified by electro-elution, and its amino acid sequence determined from peptides obtained after trypsin digestion through MALDI-TOF (Matrix-assisted laser desorption ionization-time of flight), and compared with the relative values obtained from the NCBInr (Swiss-Prot 10/01/2001) database. The 90Azgp showed 32% and 42% homology with the KIAA0310 protein from human brain and the human gastric mucin, respectively. Presence of O-glycosidically linked glycans in the proteins recognized by ALL was confirmed by inhibition of the lectin-glycoprotein interaction through hapten-inhibition assays and also by elimination of the O-glycosidically linked glycans after treatment with O-glycanase from Diplococcus pneumoniae. Electron transmission microscopy confirmed that the receptor recognized by the lectin is processed in the Golgi apparatus of AD neurons. Although the specific role of this glycoprotein has not been identified, considering that the presence of this lectin receptor co-localized with neuritic plaques and in AD sprouting neurons, it could suggest that the O-glycosyl-protein identified by the A. leucocarpus lectin participates in the pathogenesis of neurodegenerative diseases.

Aged↗

PubMedDate not supplied

Meningococcal pneumonia.

A patient with meningococcal pneumonia which developed following therapy for an earlier episode of pneumococcal pneumonia is presented. This entity is most frequently associated with an antecedent viral respiratory illness and/or a concurrent infection with Hemophilus influenzae or diplococcus pneumoniae. The characteristics of this disease are discussed and the possible pathogenetic mechanisms reviewed.

Adult↗

PubMed1996

Different clinical manifestations of meningococcaemia: three patient reports.

Neisseria meningitidis, a ubiquitous Gram-negative diplococcus, is responsible for a spectrum of clinical manifestations. This is illustrated by the history of three patients recently admitted to our hospital. Because of the possibly rapid and dramatic evolution, awareness for meningococcal diseases remains obligatory. Adequate antibiotic treatment instituted as soon as the diagnosis is suspected and early application of aggressive supportive care can lead to more favourable outcome.

Adult↗

PubMed1994

Emendation of the description of Acidaminococcus fermentans, a trans-aconitate- and citrate-oxidizing bacterium.

Ruminal fluid which was enriched with trans-aconitate yielded a gram-negative diplococcus (strain AO) which was identified by 16S ribosomal DNA sequence analysis as Acidaminococcus fermentans. In contrast to the original description, the A. fermentans type strain and strain AO were found to utilize citrate as an energy source and to produce hydrogen and hydrogen sulfide. The descriptions of the genus and species are emended accordingly.

Aconitic Acid↗

PubMed2004

Neisseria meningitidis accelerates ferritin degradation in host epithelial cells to yield an essential iron source.

In order to colonize humans and cause disease, pathogenic bacteria must assimilate iron from their host. The vast majority of non-haem iron in humans is localized intracellularly, within the storage molecule ferritin. Despite the vast reserves of iron within ferritin, no pathogen has been demonstrated previously to exploit this molecule as an iron source. Here, we show that the Gram-negative diplococcus Neisseria meningitidis can trigger rapid redistribution and degradation of cytosolic ferritin within infected epithelial cells. Indirect immunofluorescence microscopy revealed that cytosolic ferritin is aggregated and recruited to intracellular meningococci (MC). The half-life of ferritin within cultured epithelial cells was found to decrease from 20.1 to 5.3 h upon infection with MC. Supplementation of infected epithelial cells with ascorbic acid abolished ferritin redistribution and degradation and prevented intracellular MC from replicating. The lysosomal protease inhibitor leupeptin slowed ferritin turnover and also retarded MC replication. Our laboratory has shown recently that MC can interfere with transferrin uptake by infected cells (Bonnah R.A., et al., 2000, Cell Microbiol 2: 207-218) and that, perhaps as a result, the infected cells have a transcriptional profile indicative of iron starvation (Bonnah, R.A., et al., 2004, Cell Microbiol 6: 473-484). In view of these findings, we suggest that accelerated ferritin degradation occurs as a response to an iron starvation state induced by MC infection and that ferritin degradation provides intracellular MC with a critical source of iron.

Cell Division↗

PubMed1978

The use of bacteria for the functional characterization of human lymphocyte subpopulations in various lymphoid organs.

In a haemolytic plaque assay staphylococcal strain Cowan 1 was shown to induce polyclonal antibody secretion in human blood lymphocytes, whereas Haemophilus influenzae and Escherichia coli gave low responses. Diplococcus pneumoniae and haemolytic streptococci generally did not activate blood cells. All five bacteria could activate spleen, tonsil and adenoid cells both to polyclonal Ig secretion and increased DNA synthesis. Thus blood cell reactivity does not necessarily reflect the response pattern in other lymphatic organs. The adenoid was shown to contain lymphocytes more responsive to bacteria normally residing in nasopharynx than cells residing in other lymphatic organs. On the other hand, spleen and mesenteric lymph node contain a subpopulation of cells highly responsive to bacteria such as Escherichia coli normally residing in the bowel. Therefore, we conclude that there exists a functional compartmentalization of lymphocytes in distinct secondary lymphoid organs.

Adenoids↗

PubMed1990

Fine specificity and isotype expression of anti-PC antibodies in BALB/c, MRL/Mp-lpr/lpr, and -(+)/+ mice at different ages.

The MRL/Mp congenic mouse strains develop autoimmune disease with age. We have investigated age- and autoimmune-related changes in fine specificity, isotype spectra and T15 idiotype expression of the anti-phosphorylcholine (PC) response in BALB/c, MRL/Mp- + and -lpr congenic mice and in (BALB/c x MRL/Mp-lpr) F1 hybrids. Two groups of anti-PC antibodies with distinct fine specificity are elicited in the memory response. Group I antibodies recognize the PC moiety and express the T15 idiotype. Antibodies of group II are specific for phenyl-phosphorylcholine and are found predominantly in the memory response. In the MRL/Mp-lpr and - + strains only a minor population of antibodies expresses the T15 idiotype at all ages. However, a third group of antibodies was observed which binds to PC-coated proteins and to Diplococcus pneumoniae R-36A. This binding was not inhibited by PC-chloride and appeared mainly in the memory response at old age. The isotype distribution among anti-PC antibodies was similar in all strains analysed. In the initial response primarily mu, gamma 3 and gamma 1 isotypes were produced, while in the memory response gamma 1 was dominant. Thus autoimmune defects and ageing result in altered anti-PC antibody and idiotype profile, probably related to altered states in both the T- and B-cell compartments.

Age Factors↗

PubMed1962

Pharmacology and chemotherapy of ampicillin--a new broad-spectrum penicillin.

The pharmacology and chemotherapy of a new penicillin, 6[D(-)-alpha-aminophenylacetamido] penicillanic acid, are described. It is non-toxic, is absorbed orally and is distributed throughout the body in a manner similar to other penicillins. It is eliminated unchanged from the body in high concentrations in the bile and urine. Almost all of the antibiotic can be accounted for in the urine and intestinal contents 2 hr after intramuscular administration but not after oral administration. It is concluded that the antibiotic is not metabolized within the body. Studies with infected animals show that it is as effective as the existing oral penicillins against Staphylococcus pyogenes Smith (penicillin sensitive), Streptococcus pyogenes Group A and Diplococcus pneumoniae. It is ineffective against penicillin-resistant Staphylococci. When tested in mice infected with the gram-negative organisms, Salmonella tryphimurium and Klebsiella pneumoniae, it was considerably more active than tetracycline and chloramphenicol.

Ampicillin↗

PubMed1976

Isolation of a penicillinase producing strain of Neisseria gonorrhoeae.

A gram-negative diplococcus with the qualifications of a gonococcus was isolated from the urethra of a male infected with gonorrhoea in the Far East. The strain proved to be resistant to penicillin G and ampicillin as judged by the paper disc sensitivity test. The resistance was found to be caused by a powerful production of penicillinase which not only acted on penicillin G and ampicillin, but also on methicillin and partly on cephalosporin (cephalotin) by the test employed.

Ampicillin↗

PubMed1979

Orbital abscess in two neonates, deriving from conjunctival malformations.

A report is given of two infants who developed an orbital abscess within their first month of life. Generally they were unaffected, and malignancies were initially suspected. Ultrasonography showed partly cystic, partly solid lesions. The likely infectious foci were conjunctival malformations, a mucosal fistula in case No. 1, a conjunctival cyst in case NO. 2. There was rapid and complete recovery after surgery. The infections were caused by Staph. aureus and by diplococcus pneumoniae, respectively. Additional findings: Infant No. 1 had a fibroma of the tongue. Infant No. 2 had pes equino-varus.

Abnormalities, Multiple↗

PubMed1972

Clinical and in vitro evaluation of cephapirin, a new cephalosporin antibiotic.

Cephapirin sodium, a cephalosporin for parenteral use, was evaluated in vitro and in 27 patients. Cephapirin had activity equivalent to cephalothin against 25 strains each of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus aureus; 10 strains each of Diplococcus pneumoniae, Pseudomonas species, and Enterobacter species; and 8 strains of Proteus species other than P. mirabilis. All strains of S. aureus and D. pneumoniae and most strains of E. coli, K. pneumoniae, and Proteus species were inhibited by concentrations of cephapirin achieved in the serum. Of 27 patients (20 with pneumonia, 2 with S. aureus empyema, and 5 with miscellaneous infections), 25 responded to cephapirin therapy. The only major toxicity thought to be drug-related occurred in a patient who developed reversible bone marrow depression with leukopenia, neutropenia, and anemia. Although cephapirin was painful on intramuscular injection, phlebitis and pain were absent in patients treated intravenously. In a controlled comparison of intravenously administered cephalothin and cephapirin in four additional patients, the latter caused much less pain than the former and caused no phlebitis.

Acetamides↗

PubMed1972

In vitro studies of tobramycin, an aminoglycoside antibiotic.

Tobramycin is an aminoglycoside antibiotic which has excellent antibacterial activity against Pseudomonas, Staphylococcus aureus, and many members of the Enterobacteriaceae. Most strains of Serratia, Providence, Streptococcus, and Diplococcus pneumoniae were resistant to concentrations of tobramycin which could be achieved in man. Tobramycin was effective against certain Pseudomonas strains resistant to gentamicin. The growth medium used to determine the inhibitory level of tobramycin had a significant effect upon the minimal inhibitory concentration. Calcium and magnesium ions inhibited the bactericidal effect of tobramycin. Tobramycin and carbenicillin acted in a synergistic manner. Ethylenediaminetetraacetic acid did not act in a synergistic manner with tobramycin. Broth-dilution susceptibility tests and disc-diffusion tests in agar (10-mug discs) showed excellent correlation except with Proteus strains.

Aminoglycosides↗

PubMed1972

7-(Alpha-(1-methyl-4-pyridinothio)-acetamido) cephalosporanic acid.

7-[alpha-(1-Methyl-4-pyridiniothio)-acetamido] cephalosporanic acid, referred to herein as BL-S 217, is a new broad-spectrum semisynthetic cephalosporin that offers several advantages over cephalothin. A comparison of the activity in vitro of these antibiotics indicates that BL-S 217 is about eightfold more effective against Streptococcus pyogenes and Diplococcus pneumoniae. Against gram-negative bacteria, BL-S 217 possesses a broader antibacterial spectrum than cephalothin, particularly against members of the Enterobacteriaceae family; e.g., BL-S 217 inhibited over 20% more strains of both Escherichia coli and Klebsiella than cephalothin and also showed some advantage in tests against Salmonella and Enterobacter. Overall, of 208 strains of Enterobacteriaceae tested, 172 were susceptible to BL-S 217 compared to 149 for cephalothin. BL-S 217 was less bound to human serum proteins than cephalothin and gave higher peak blood levels in mice after intramuscular administration. The LD(50) of BL-S 217 in mice after subcutaneous administration was in excess of 4,000 mg/kg. When administered by the same route to mice experimentally infected with cephalothin-sensitive bacterial strains, this new cephalosporin was 20 times more effective than cephalothin in S. pyogenes and D. pneumoniae infections and 3 to 4 times more efficacious in an E. coli infection. Its therapeutic efficacy was comparable to that of cephalothin in infections produced by strains of Staphylococcus aureus, Klebsiella pneumoniae, and Proteus mirabilis.

Acetamides↗

PubMed1972

Effect of interferon inducers and interferon on bacterial infections.

The effect of interferon inducers and exogenous L-cell interferon on the infection of mice by Pasteurella tularensis or Diplococcus pneumoniae was investigated. The results indicate that the degree of protection is dependent on the type of inducer used. A variety of defense mechanisms with limited nonspecific activity appear to be involved.

Animals↗

PubMed1979

Clindamycin in treatment of aspiration pneumonia in children.

Twenty-eight patients with anaerobic pleuropulmonary infections were treated with clindamycin alone or clindamycin with gentamicin. Sixteen of the patients presented with pneumonitis, nine with necrotizing pneumonia, and three with lung abscesses. The average length of treatment was 13.8 days, and the duration of temperature after initiation of therapy was 3.1 days. The predominant isolates were anaerobic gram-positive cocci (23 isolates), Bacteroides melaninogenicus (14), Bacteroides fragilis (9), and Fusobacterium nucleatum (11). The most frequent aerobic isolates were alpha-hemolytic streptococci (12), Diplococcus pneumoniae (12), Pseudomonas aeruginosa (9), Klebsiella pneumoniae (7), group A beta-hemolytic streptococci (5), Staphylococcus aureus (9), and Escherichia coli (6). All patients responded to the therapy and were cured of the infection. There were no side effects observed from the administration of clindamycin. None of the patients developed any blood dyscrasia, liver damage, diarrhea, or colitis. Clindamycin appears to be effective in the treatment of mixed aerobic and anaerobic pleuropulmonary infections in children, alone or with an aminoglycoside when indicated.

Adolescent↗

PubMed1972

Ampicillin and tetracycline in the treatment and prophylaxis of chronic bronchitis.

Ampicillin and tetracycline, in doses of 2 g a day, were compared in the treatment of acute exacerbations of chronic bronchitis. Seventy-nine patients were followed for 3 to 29 months and were treated for 118 exacerbations. Clinical improvement occurred after 10 days of treatment with either drug in over 80% of the cases. Haemophilus influenzae and Diplococcus pneumoniae were eradicated from the sputum more than 60% of the time, but in general there was a poor correlation between bacteriological clearing and clinical response. The effect of chemoprophylaxis with ampicillin and tetracycline in doses of 1 g a day on the frequency of acute exacerbations of bronchitis was compared with that of a placebo. Seven hundred eighty prophylactic regimens, consisting of one capsule every 12 hr for 5 days beginning with the first sign of a cold, were prescribed for 76 patients. Irrespective of the regimen, an acute exacerbation of bronchitis was encountered at approximately 13% of the follow-up visits to the clinic.

Ampicillin↗