Pneumonia following closed head injury.

Pneumonia is common among patients with artificial airways in place. Most prior studies of such pneumonia involve a heterogeneous group of patients, usually with major medical or surgical illnesses. We studied the incidence of pneumonia in a group of patients with isolated closed head injury (CHI) in an effort to determine the pattern of the problem in the absence of other injuries and to determine whether the pattern of development of pneumonia in these patients was comparable to that in more heterogeneous groups of mechanically ventilated patients.

Evaluation of the Biolog automated microbial identification system.

Biolog's identification system was used to identify 39 American Type Culture Collection reference taxa and 45 gram-negative isolates from water samples. Of the reference strains, 98% were identified to genus level and 76% to species level within 4 to 24 h. Identification of some authentic strains of Enterobacter, Klebsiella, and Serratia was unreliable.

Cost reduction in diagnosing Pneumocystis carinii pneumonia. Sputum induction versus bronchoalveolar lavage as the initial diagnostic procedure.

Sputum induction (SI) is a sensitive and specific method for diagnosing Pneumocystis carinii pneumonia (PCP) in patients with AIDS. Although less expensive than bronchoscopy with bronchoalveolar lavage (BAL), SI followed by BAL does not necessarily reduce costs compared with BAL alone. Cost analysis demonstrates that the cost of diagnosing PCP is dependent on the prevalence of PCP (PCPprevalence) in the studied population, the sensitivity of SI (SIsensitivity) for diagnosing PCP, and the relative costs of SI and BAL (SIcost and BALcost) for diagnosing PCP.

Effects of pulmonary function of oral high frequency oscillation in normal and asthmatic subjects.

High frequency jet devices are not only used as 'internal percussors' to aid clearance of pulmonary secretions, but are also a mode of ventilatory support. As physical stimuli can cause bronchospasm in asthmatic individuals, we hypothesized that direct airway vibration may induce bronchospasm. To ascertain whether an airway vibration jet device could cause bronchoconstriction, we exposed eight asthmatic and six normal subjects to 5 min of jet-induced airway vibration or placebo treatment with cross-over at 3 h.

A microfermentation test for the rapid identification of yeasts.

The accuracy and speed of a microfermentation test (MFT), developed as a supplementary aid to other yeast identification systems, were compared with the conventional fermentation method in identifying 15 yeast species. The MFT significantly reduced the incubation period required to obtain a definitive identification. The method is easy to perform and the media and space requirements are minimal.

Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems.

Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia.

Complications associated with mechanical ventilation.

A constellation of adverse effects and complications may be associated with mechanical ventilation, although in many instances the causal role of the ventilator itself has not been established. Complications occur with greater frequency than is generally appreciated, and tend to be under-reported in the medical literature. Among the potential adverse physiologic effects of positive-pressure ventilation are decreased cardiac output, unintended respiratory alkalosis, increased intracranial pressure, gastric distension, and impairment of hepatic and renal function.

Mechanism of transport and distribution of organic solvents in blood.

Little is known about the mechanism of transport and distribution of volatile organic compounds in blood. Studies were conducted on five typical organic solvents to investigate how these compounds are transported and distributed in blood. Groups of four to five rats were exposed for 2 hr to 500 ppm of n-hexane, toluene, chloroform, methyl isobutyl ketone (MIBK), or diethyl ether vapor; 94, 66, 90, 51, or 49%, respectively, of these solvents in the blood were found in the red blood cells (RBCs).

Cloning and nucleotide sequence of bisC, the structural gene for biotin sulfoxide reductase in Escherichia coli.

Clones of the Escherichia coli bisC locus have been isolated by complementing a bisC mutant for growth with d-biotin d-sulfoxide as a biotin source. The complementation properties of deletions and Tn5 insertions located the bisC gene to a 3.7-kilobase-pair (kbp) segment, 3.

Nonpathogenic isolates of Yersinia enterocolitica do not contain functional inv-homologous sequences.

Previous studies have demonstrated a correlation between the ability of isolates of Yersinia enterocolitica to cause disease and to invade tissue culture cells in vitro. Two genes, inv and ail, isolated from a pathogenic strain of Y. enterocolitica have each been shown to confer this invasive phenotype upon Escherichia coli.

Gram staining apparatus for space station applications.

A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens.

Pulse oximetry versus arterial blood gas specimens in long-term oxygen therapy.

Portable pulse oximeters are now widely available for the assessment of arterial oxygenation, and the U.S. Medicare program considers saturation readings to be acceptable substitutes for arterial PO2 in selecting patients for long-term oxygen therapy (LTOT).

Home respiratory care in different countries.

Home respiratory care (provision of respiratory care services in patients' homes rather than in institutions or providers' offices) includes long-term oxygen therapy and home ventilatory assistance. I review the selection of patients, the role of physicians and other health care professionals, the types of equipment used, the administrative structures, and sources of payment or reimbursement in different countries. Because more has been published about home respiratory care in France and the United States, current practices in these two countries are reviewed in some detail; where available, information about long-term oxygen therapy and home ventilatory assistance in other countries is also included.

Single-dose efficacy and safety of zindotrine, a new oral bronchodilator.

Zindotrine, a new bronchodilator, may be an alternative to theophylline in treating reversible airflow obstruction. Efficacy and cardiovascular effects of a single 300 mg oral dose of zindotrine were compared with placebo in a two-period, double-blind, crossover trial. Twelve subjects with airflow obstruction reversible after isoproterenol and theophylline completed the trial.

The relation among pulmonary function, chest roentgenographic abnormalities, and smoking status in an asbestos-exposed cohort.

To clarify the clinical value of the International Labor Office (ILO) roentgenographic classification of pneumoconiosis in assessing asbestos-exposed persons, we determined the relationships among spirometric values, radiographic evidence of parenchymal pulmonary fibrosis and/or pleural thickening, and cigarette smoking history in 684 consecutively enrolled male plumbers and pipefitters participating in a larger cross-sectional prevalence study. The subjects were mainly marine pipefitters (35%), plumbers (24%), and steamfitters/welders (23%); 28% had never smoked, 39% were ex-smokers, and 33% currently smoked cigarettes. Mean values for FVC and FEV1 were 95.

The performance of four pleural drainage systems in an animal model of bronchopleural fistula.

In order to compare the performance of four pleural drainage units (PDU [Emerson Post-Operative Pump, Pleur-Evac, Sentinel Seal, Thora-Klex]), we created an animal model of bronchopleural fistula that simulated the type of air leak seen clinically (mean maximal flow = 5 L/min). The PDU were tested at 0 cm (water seal), -20 cm and -40 cmH2O suction. Compared to water seal, -20 cmH2O suction significantly increased the ability of all four PDU to evacuate air via the chest tube and abolished small differences in chest tube air leak seen among the PDU at water seal.

Total lung capacity. An insensitive measure of impairment in patients with asbestosis and chronic obstructive pulmonary disease?

The total lung capacity (TLC) is frequently used as a measure of respiratory impairment in patients with asbestosis. Because asbestosis and chronic obstructive pulmonary disease (COPD) exert opposite effects on the TLC, it may be an insensitive measure of impairment in patients with both abnormalities. To assess this, we compared asbestos-exposed patients with functional evidence of COPD and radiographic evidence of interstitial fibrosis (group 1) to those with interstitial fibrosis alone (group 2).

Severe precocious emphysema in intravenous methylphenidate (Ritalin) abusers.

Intravenous (IV) drug abuse is known to cause pulmonary tale granulomatosis. Reports have documented a syndrome of pulmonary vascular sclerosis in long-term IV methylphenidate users. Although this would be expected to produce restrictive lung disease, we hereby report six patients who have severe obstructive lung disease.

Comparison of high-frequency jet ventilation with conventional mechanical ventilation for bronchopleural fistula.

In seven patients with acute respiratory failure and a bronchopleural fistula, the authors compared gas exchange and volume of gas lost via the chest tube during conventional mechanical ventilation (CV) and high-frequency jet ventilation (HFJV). After the initial comparison, patients were randomized to HFJV or CV, unless one mode of ventilation was clearly superior based on preestablished criteria. In six of the seven patients, oxygenation deteriorated after the switch from CV to HFJV.