beta-Lactamase production in experimental endocarditis due to aminoglycoside-resistant Streptococcus faecalis

We used a beta-lactamase-producing (beta L+) strain of Streptococcus faecalis that also had high levels of resistance to all aminoglycosides to induce experimental endocarditis in rats. The rats were treated for five or 10 days with procaine penicillin, vancomycin, gentamicin, rifampin, or ciprofloxacin (alone or in various combinations), or with penicillin plus clavulanic acid. The levels of penicillin in serum and vegetations declined rapidly in the beta L+-infected rats treated with procaine penicillin alone, unlike the sustained levels of penicillin in either beta L- -infected rats treated with procaine penicillin or beta L+-infected rats treated with penicillin plus clavulanic acid. For the beta L+-infected rats, the enterococcal counts in vegetations were significantly reduced (greater than 3 log10 cfu/g) only by vancomycin and by penicillin plus clavulanic acid. The efficacy of the latter regimen probably resulted from the inhibition of penicillin inactivation by clavulanic acid in vegetations infected with the beta L+ strain. Our in vivo findings document the biologic significance of beta-lactamase production.     

The progressive nature of childhood asthma

Asthma is the most common chronic disease in childhood. It has been repeatedly stated that childhood asthma is a self-limiting disorder, but this is a misleading and often inaccurate generalization. Prospective studies have demonstrated that many patients who had seemingly outgrown their disease experienced symptoms again as they grew older. In addition, recent evidence suggests that, despite the lack of clinical manifestation of asthma, there is a persistence of bronchial hyperreactivity for several years. A number of epidemiologic studies have identified factors that seem to be associated with the persistence of asthma into later childhood or adult life. Information about the effects of treatment of asthma on the natural history of the disease is vital. While treatment greatly reduces the morbidity from asthma, it is not known whether early recognition and aggressive treatment of the disease have any influence on the outcome of the disease later in life.     

The musculoskeletal manifestations of cystic fibrosis

Twenty-seven patients with CF and joint complaints were reviewed. Twelve patients had arthritis, 11 had HPO, and four had symptoms of mechanical neck and back pain. We have confirmed the association of CF with an episodic form of arthritis. For the first time, we have reported that a subgroup of these patients later develop persistent synovitis with progressive asymmetric, erosive disease. The etiology of CF arthritis is unclear, but may relate to chronic infection and immune complex mechanisms. CF arthritis can be contrasted with CF induced HPO, which is associated with worse lung disease, a male predominance, and an older mean age of onset of symptoms. Mechanical neck and back pain may relate to an associated scoliosis or kyphosis in CF.     

Comparative study of histamine and exercise challenges in asthmatic children

Fifty asthmatic children were tested with both a standardized treadmill exercise and a histamine inhalation on 2 separate days. Ninety per cent had a positive response to histamine, whereas 74 per cent had demonstrable exercise-induced bronchoconstriction. There was a close relationship between responsiveness to histamine and exercise, because all patients who responded to histamine had exercise-induced bronchoconstriction. Eight children (16 per cent) responded to histamine only. Although prechallenge pulmonary function has an effect on the incidence of exercise-induced bronchoconstriction, it does not appear to influence the responsiveness to histamine. Therefore, when provocation testing is being done for the purpose of diagnosing asthma, histamine is preferable to exercise.     

Treatment of Complicated Urinary Tract Infections With an Emphasis on Drug-Resistant Gram-Negative Uropathogens

Complicated urinary tract infection is a challenging infection, since cure is difficult and either persistence or recurrence is common. The challenge is frequently increased because complicated urinary tract infection is often caused by gram-negative bacilli resistant to multiple antimicrobial drugs. In this review, we approach the therapy of complicated urinary tract infection with an emphasis on those caused by antimicrobial drug-resistant gram-negative uropathogens.     

Therapy vs no therapy for bacteriuria in elderly ambulatory nonhospitalized women

This prospective randomized study was undertaken to determine the efficacy of antimicrobial therapy compared with no therapy for bacteriuria in elderly ambulatory nonhospitalized women. Sixty-one women (mean age, 85.8 years) with bacteriuria were in the no therapy control group and 63 women (mean age, 85.8 years) with bacteriuria were in the therapy group; none had symptoms of urinary tract infection. One short course of antimicrobial therapy achieved a cure rate of 68.3% (43 of 63 women cured) two weeks after treatment. During the six-month follow-up period, ten (16.4%) of 61 women in the no therapy group and five (7.9%) of 63 women in the therapy group developed symptomatic urinary tract infection. At the time of six-month follow-up, 19 (34.5%) of 55 women in the no therapy group and 35 (63.6%) of 55 women in the therapy group did not have bacteriuria. We conclude that for asymptomatic bacteriuria in elderly ambulatory nonhospitalized women, short-course antimicrobial therapy is effective at two-week follow-up and that antimicrobial therapy can eliminate bacteriuria in most of these women for at least a six-month period.     

A role for ciliary neurotrophic factor as an inducer of reactive gliosis, the glial response to central nervous system injury.

Within the central nervous system (CNS) ciliary neurotrophic factor (CNTF) is expressed by astrocytes where it remains stored as an intracellular protein; its release and function as an extracellular ligand are thought to occur in the event of cellular injury. We find that overexpression of CNTF in transgenic mice recapitulates the glial response to CNS lesion, as does its injection into the uninjured brain. These results demonstrate that CNTF functions as an inducer of reactive gliosis, a condition associated with a number of neurological diseases of the CNS.     

Comparison of duplex ultrasonography and venography in the diagnosis of deep venous thrombosis

Sixty-five patients with suspected deep venous thrombosis (DVT) in 68 limbs were entered consecutively into a study to compare venography with duplex ultrasonography scanning. Both tests were performed on 64 limbs, venography being contraindicated in four. Overall, duplex scanning correctly identified 86 per cent of DVTs diagnosed on venography and correctly excluded 80 per cent with negative venograms. Nearly all errors arose in the diagnosis of calf DVT. In the femoral vein duplex scanning had a specificity of 100 per cent and a sensitivity of 95 per cent. In addition, duplex scanning provided data on the limb not undergoing venography. Of 55 limbs that underwent bilateral duplex scanning, five had thrombus in the femoropopliteal segment and a negative contralateral venogram. In addition, three Baker's cysts were diagnosed. Duplex scanning can be used in patients in whom venography is contraindicated and may also provide information about the contralateral limb. We regard femoropopliteal duplex scanning as sufficiently accurate that treatment can be initiated on the basis of the scan. Duplex scanning should replace venography as the standard method of diagnosing femoropopliteal DVT; radiographic studies should now be required only when the scan result is in doubt.     

Complications after percutaneous endoscopic gastrostomy removal.

We report two cases of complications after percutaneous endoscopic gastrostomy (PEG) removal. The first was persistence of a gastrocutaneous fistula that required operative closure. The second patient developed pneumoperitoneum after an attack of vomiting 3 weeks after PEG removal. Laparotomy showed separation of the stomach from the posterior abdominal wall, with peritonitis. These cases highlight the need for careful monitoring of patients even after tube removal.