Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004610 (bacteremia)
 13,199 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leptomeningitis due to type b Haemophilus influenzae can be produced in infant rats (up to three weeks of age) by intranasal inoculation, and in animals up to three months of age by intraperitoneal inoculation. In infant animals, the pathogenesis appears to mimic the disease in human infants. Immunologic experiments indicate that antibody directed against the type b capsule (actively or passively acquired) will protect against bacteremia (by any route of inoculation) and the subsequent development of meningitis. However, antibody directed against other surface structures of H. influenzae b (alone or with anticapsular antibody) will protect against sustained bacteremia after any route of inoculation. Evaluation of antibiotic activity against this infection in rats is unreliable due to a marked age-dependent increase in antibiotic clearance. A means of mimicking human pharmacokinetics in rats is proposed. The rat model is useful for the study of H. influenzae meningitis provided certain limitations are recognized.
 ...
PMID:Experimental meningitis in the rat: Haemophilus influenzae. 639 47

Over a three year period, we encountered seven homosexual men who developed pneumonias due to S. pneumoniae or H. influenzae in the absence of apparent risk factors. When compared to heterosexual controls, the homosexual group had a much higher frequency of bacteremia, complicated primary infections, multilobar involvement, required longer antibiotic therapy, and took longer to defervesce. Three of our seven homosexual patients fulfilled criteria for the acquired immunodeficiency syndrome (AIDS); two of the others had generalized lymphadenopathy and the other two likely AIDS-related abnormalities. Overall they presented with a spectrum of clinical findings. Two of the patients developed other opportunistic infections associated with AIDS. Since recovery from these pyogenic pneumonias requires an appropriate antibody response, our patients may have had a defect in B-cell function. Moreover, these observations suggest that functional B-cell abnormalities may occur in AIDS and syndromes premonitory of AIDS.
 ...
PMID:Community-acquired bacterial pneumonias in homosexual men: presumptive evidence for a defect in host resistance. 654 7

The incidence of acute epiglottitis treated in Melbourne, Australia at the Royal Children's Hospital (RCH) has increased from an average of 14 cases per year during 1975-79 to 49 cases per year during 1980-81. Less marked increases have occurred for H. influenzae meningitis and bacteremia and H. influenzae (untyped) isolation from respiratory tract cultures. A review of 171 cases of acute epiglottitis showed no significant differences between the 1975-79 and 1980-81 patients with respect to sex, age, seasonal incidence, prodromal length, prodromal symptoms, geographical location, polymorphonuclear cell count, or disease severity. Patients treated in 1980-81 had fewer complications (12% versus 22%, p less than 0.02), and a shorter hospital stay (3.0 versus 3.3 days, p less than 0.003). The increased incidence of H. influenzae type b infections may be due to an increased bacterial presence within our community.
 ...
PMID:Acute epiglottitis in childhood: report of an increased incidence in Victoria. 659 5

Between 1976 and 1981 Haemophilus influenzae was identified in 16 women with postpartum bacteremia and 36 neonates with bacteremia or meningitis. H. influenzae was also recovered from neonatal or genital cultures of 50 additional patients. By counter-immunoelectrophoresis 17% of neonatal isolates from blood or cerebrospinal fluid (CSF) were type b. All remaining strains (94% overall) were nontypable (NT). Of the NT blood or CSF isolates, 38% belonged to biotype 4. Of all the NT biotype 4 isolates referred to the Centers for Disease Control during the study, 82% were of genital, neonatal, or maternal origin, a finding that suggests that this isolate is a genital biotype. Clinical disease was similar to that observed in patients infected with group B Streptococcus except for the infrequent (11%) occurrence of meningitis. Maternal bacteremia resulted in mild febrile illness, while neonatal bacteremia was associated with a high incidence of shock, respiratory distress (50%), and death (30%). H. influenzae bacteremia in these two patient groups was rare in Houston before 1976, but since then it has been responsible for 2.5% of cases of significant bacteremia. NT H. influenzae should be recognized as a definite neonatal, maternal, and genital pathogen.
 ...
PMID:Nontypable Haemophilus influenzae (biotype 4) as a neonatal, maternal, and genital pathogen. 660 Aug 49

A total of 42 strains of Haemophilus influenzae type b isolated from pediatric patients were sensitive in vitro to temocillin (90% minimal inhibitory concentration = 0.25 microgram/ml). No difference in mean minimal inhibitory concentration between beta-lactamase producer (0.25 microgram/ml) and nonproducer (0.23 microgram/ml) strains was found. Various dosages of ampicillin or temocillin for the treatment of infant rats with ampicillin-resistant H. influenzae bacteremia and meningitis yielded no difference in cure rates. These results suggest that temocillin may not be as effective as other new cephalosporins for the treatment of H. influenzae type b infections.
 ...
PMID:Comparative in vitro and in vivo activity of temocillin (BRL 17421) and ampicillin against Haemophilus influenzae type b. 660 Sep 9

To determine the protective efficacy of human hyperimmune globulin to Haemophilus influenzae type b disease in an infant rat model, we compared hyperimmune globulin containing 600 mug of anti-polyribophosphate (PRP) antibody per ml to conventional immune globulin containing 66 mug of anti-PRP antibody per ml. The hyperimmune globulin was fractionated from the pooled plasma of 55 adult donors immunized with PRP, the capsular polysaccharide of H. influenzae type b. The disappearance of passively administered antibody was biphasic, with a linear first-order disappearance curve during the first 7 days. The initial half-life for anti-PRP antibody was 2.38 days in rats nasally colonized but not detectably bacteremic with H. influenzae type b and significantly longer (half-life, 10.3 days; P < 0.01) in noncolonized animals. Hyperimmune globulin afforded 10 times the protection of conventional globulin against bacteremia and meningitis. Globulin depleted of anti-PRP antibody offered no protection. The initial serum antibody levels and the levels during the 8-day observation period predicted protection. Rats maintaining serum antibody levels greater or equal to 50 ng/ml to day 8 had a 10% bacteremia and 5% meningitis incidence in contrast with 95% bacteremia (P < 0.001) and 55% meningitis (P < 0.001) in rats with less than 50 ng of anti-PRP antibody per ml. We conclude that studies of the pharmacology and efficacy of hyperimmune globulin are warranted in high-risk children unable to respond to active immunization.
 ...
PMID:Efficacy of human hyperimmune globulin in prevention of Haemophilus influenzae type b disease in infant rats. 660 Oct 60

Possible route(s) by which encapsulated bacteria invade the blood from the nasopharynx include (i) the direct invasion of submucosal blood vessels and (ii) clearance via lymphatics to regional nodes followed by bloodstream invasion. These possibilities were investigated in rats after intranasal inoculation with 10(5) Haemophilus influenzae type b. Within 24 h of inoculation, 10 of 42 rats with sterile blood cultures had similar numbers of H. influenzae b recovered from both cervical (local) and periiliac (distant) lymph nodes, which suggested early bacteremic spread. When virtually continuous blood cultures were obtained for 30 min after inoculation with 10(8) H. influenzae b, early transient bacteremia was documented in four of eight rats. Also, we found no significant difference in bacteremia among rats whose cervical lymph nodes had been removed surgically compared with sham-operated rats. These findings favor the hypothesis of a rapid, perhaps direct invasion of pharyngeal blood vessels as an initial determinant of the systemic spread of H. influenzae b.
 ...
PMID:Pathogenesis of bloodstream invasion with Haemophilus influenzae type b. 660 68

The hypertonic and aerobic culture media in the BACTEC system were compared for the detection of Haemophilus influenzae bacteremia in children. Of 1,611 blood cultures, 30 were positive for this pathogen. The aerobic and hypertonic media gave positive results in 28 and 29 cultures, respectively. Within the first 12 h, H. influenzae was detected in the hypertonic medium in 48.5% of the positive cultures as compared to 35% for the aerobic medium. Importantly, after the first 12 h, the hypertonic medium yielded positive results sooner than did the aerobic medium, the difference being statistically significant (P less than 0.01). The hypertonic medium yielded positive results earlier than the aerobic medium in nine cultures; the reverse was seen in only one culture. Furthermore, the aerobic medium gave negative growth index readings despite growth, as shown by microscopy and subculture, in 43% of the total cultures in contrast to only 13% for the hypertonic medium, a significant difference (P less than 0.05). Thus, the present study indicates a distinct advantage of hypertonic medium compared with aerobic medium in the automated BACTEC system for earlier detection of H. influenzae bacteremia and is recommended for those age groups in which this pathogen plays a predominant role.
 ...
PMID:Advantages of BACTEC hypertonic culture medium for detection of Haemophilus influenzae bacteremia in children. 660 69

Serum antibody against polyribosylribitol phosphate, the capsular antigen of Haemophilus influenzae type b, confers protection against experimental Haemophilus infection. Antibodies against noncapsular antigens are also protective, but the antigenic specificity of the protective antibodies remains unknown. Antilipopolysaccharide antibody was prepared by immunization of rabbits with boiled H. influenzae type b cells. Antilipopolysaccharide antibodies present in these sera did not protect against experimental Haemophilus bacteremia in infant rats. Antisera were also prepared by immunization of rabbits with live H. influenzae type b bacteria. After absorption of anticapsular and antilipopolysaccharide antibodies, these sera contained antibody to several outer membrane proteins which were accessible on the intact bacterial surface as detected by radioimmune precipitation. These absorbed sera prevented experimental Haemophilus bacteremia in infant rats. Thus, antibodies against noncapsular, non-lipopolysaccharide determinants, possibly against one or more outer membrane proteins, confer protection against experimental H. influenzae type b disease. In contrast, antibodies against lipopolysaccharide are ineffective.
 ...
PMID:Further studies of the role of noncapsular antibody in protection against experimental Haemophilus influenzae type b bacteremia. 660 98

To investigate the role of complement in immunity to capsule-deficient Haemophilus influenzae, rats were depleted of C3 with cobra venom factor and challenged with three different strains of capsule-deficient H. influenzae. Two of them (Rd and U1) did not elaborate type b capsular antigen, whereas the other (S2) elaborated 0.16% of the amount made by its type b parent strain. Depletion of C3 significantly enhanced early intravascular bacterial survival after intravenous inoculation and strikingly increased the susceptibility of rats to infection with capsule-deficient H. influenzae. After intraperitoneal inoculation with strain Rd or U1, C3-depleted rats developed bacteremia, whereas control rats did not; challenge with strain S2 resulted in transient bacteremia in normal rats and in death in C3-depleted animals. To determine whether the greater virulence of strain S2, as compared with strain Rd or U1, was accounted for by the small amounts of capsular antigen it elaborated, we also compared its relative virulence to that of three genetically closely related capsule-deficient variants elaborating either small amounts of type b capsule or producing no detectable b antigen. No difference in virulence was observed among these four variants; all C3-depleted rats inoculated developed bacteremia of similar magnitude followed by similar mortality rates. These studies demonstrate a significant role for complement in host defense mechanisms against capsule-deficient H. influenzae and suggest that interstrain differences of virulence are not attributable to residual elaboration of small amounts of type b capsule.
 ...
PMID:Participation of complement in host defense against capsule-deficient Haemophilus influenzae. 660 26


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>