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Objective To determine the spectrum and antibiotic susceptibility patterns of microorganisms causing acute community-acquired lung abscess. Design A prospective survey. Setting Medical emergency department and wards of a tertiary teaching hospital. Patients Thirty-four adult patients with both clinical and radiologic features compatible with a diagnosis of acute community-acquired lung abscess who had received less than 48 h of antibiotic therapy. Interventions Microbiologic specimens obtained by percutaneous lung aspiration and with a protected specimen brush via fiberoptic bronchoscopy were submitted for aerobic and anaerobic culture. Main outcome measures Identification of all microorganisms, including anaerobes, and determination of antibiotic susceptibility. Results A mean of 2.3 bacterial species per patient was isolated, anaerobes alone being isolated in 44% of cases, aerobes alone in 19%, and mixed aerobic and anaerobic isolates in 22%. Aerobic Gram-negative pathogens were uncommon. In seven patients, Mycobacterium tuberculosis was identified; in two it was associated with other bacteria. In four patients, no organisms were isolated. All the nonmycobacterial isolates were susceptible to amoxicillin-clavulanate and in addition the anaerobes were all susceptible to chloramphenicol and almost all to a combination of penicillin and metronidazole. Among the anaerobes, the level of resistance to penicillin, metronidazole, and clindamycin individually was 21%, 12%, and 5%, respectively. Conclusions Community-acquired acute lung abscess is usually caused by multiple anaerobic and less frequently aerobic Gram-positive microorganisms, which should respond to empirical therapy with amoxicillin-clavulanate, chloramphenicol, or a combination of penicillin and metronidazole. Tuberculosis, which may be indistinguishable from an acute lung abscess, occurred in 21% of patients in our study. Most bacterial pathogens are sensitive to conventional antimicrobial therapy and further investigation with percutaneous lung aspiration or bronchoscopy is indicated only when there is lack of early response to therapy or there is the presence of atypical clinical features.

The virucidal activity of several disinfectants containing newer generation quaternary ammonium compounds (QACs) as their active ingredients was evaluated. Disinfectants were used at the manufacturers' recommended dilutions with isolates of feline herpesvirus, feline calicivirus, and canine parvovirus, and a contact time of 10 minutes at room temperature. Detoxification of virus/disinfectant solutions was done by dialysis prior to virus assay in cell cultures. Two of four disinfectants completely inactivated feline herpesvirus, and two significantly reduced the titer of this virus. None of the disinfectants that were tested completely inactivated feline calicivirus. Canine parvovirus was not inactivated significantly by any of the QAC disinfectants. Sodium hypochlorite completely inactivated all viruses.

Objective: To determine whether selective decontamination of the digestive tract exerts any long-term effects on antimicrobial resistance patterns. Design: A surveillance and interventional study comparing the antimicrobial sensitivity patterns of clinically important bacterial isolates the year before a 2-yr, double-blind, randomized, controlled study of selective decontamination of the digestive tract, and for the year thereafter when no use of the regimen was made. Setting: A ten-bed respiratory intensive care unit (ICU) in a 1,200-bed teaching hospital. Patients: All 1,528 patients admitted to the ICU over the 4-yr study period were included. There were 406 patients admitted in the year before the study of decontamination of the digestive tract (65% medical, 23% surgical, and 12% trauma), of whom 76% required mechanical ventilation. There were 719 patients admitted during the 2-yr study of selective decontamination (55% medical, 28% surgical, and 17%trauma), of whom 79.6% required mechanical ventilation. There were 403 patients admitted in the subsequent year (61% medical, 25% surgical, and 14% trauma), of whom 76.9% required mechanical ventilation. Interventions: We performed daily clinical monitoring to detect nosocomial infection, with microbiological investigation when clinically indicated, as well as twice-weekly routine microbiological surveillance sampling. Antimicrobial susceptibility testing using standard laboratory methods was also performed. Selective decontamination of the digestive tract included parenteral cefotaxime and oral and enteral polymyxin E, amphotericin B, and tobramycin. Measurements and Main Results: The occurrence rate of nosocomial infection was 20.6%, 16.6%, and 25.3%, respectively, in the three study periods. In the year after selective decontanmination, there was an increase in the occurrence rate of infection (p=.005), with an associated increase in infections caused by the Enterobacteriaceae, while a reduction in the level of resistance to the third-generation cephalosporins was found (p=.07). There was a progressive increase in the occurrence rate of infections caused by Acinetobacter species (p=.05). Only 11 infections over the 4 yrs were caused by Enterococcus species. Staphylococcal infections were uncommon (5.7% of admissions), and the level of methicillin resistance did not change. No increase in aminoglycoside resistance occurred. Conclusion: No long-term effects on antimicrobial resistance or the spectrum of nosocomial pathogens could be attributed to the use of selective decontamination of the digestive tract over a 2-yr period in a respiratory ICU admitting all categories of patients

The new quinolone antimicrobial agents, particularly those with less activity against anaerobes, selectively prevent colonisation of the alimentary tract by Gram-negative bacilli and staphylococci without substantially affecting the normal anaerobic flora, which preserve the colonisation resistance of the gut. These properties ideally position this class of antibacterial agent for selective decontamination of the digestive tract (SDD) in the prevention of nosocomial infection. The rationale for this procedure is based on the presumption that a significant proportion of infections in compromised patients are endogenous in origin, arising from the host's own microbial flora. If this colonisation by potentially pathogenic microflora within the normal flora can be significantly reduced without being replaced by other more pathogenic microorganisms, the risk of endogenous infection should be minimised. The quinolones have proved to be ideal agents for use in preventing infection in bone marrow transplant and other neutropenic patients. They have been used for SDD in the general intensive care unit population, although the technique has not received widespread acceptance. There have been only 4 reported randomised studies using quinolones as part of SDD regimens and only 301 patients have been evaluated. Although the incidence of ventilator-associated pneumonia has been significantly reduced from 36 to 15%, no effect has been shown on mortality. The cost of using SDD is significantly less with the quinolones than with other regimens, and induction of resistance has not been noted. The new quinolones, and in particular the more recently developed agents with extended Gram-positive activity, appear to be ideally suited for SDD, and their careful evaluation in further large, well designed trials is warranted.

A 45-year-old man died 2 months after being bitten on the hand by a dog. He developed the rare but characteristic clinical picture of fulminant septicaemia and peripheral gangrene caused by a Gram-negative bacillus, Capnocytophaga canimorsus, previously known as dysgonic fermenter type 2 (DF-2), which is an occasional commensal in the oral flora of dogs and cats. This disease must be anticipated and dog bites appropriately managed to avoid the mortality associated with infection by this micro-organism. Initial treatment includes appropriate prophylactic antibiotics and debridement, while early exchange transfusion and emergency amputation may be of value in fulminant cases.

Respiratory syncytial virus (RSV) infects humans and cattle causing serious respiratory tract disease in both. The genome of the human and bovine RSV (HRSV and BRSV) codes for two non-structural and eight structural proteins. RSV has also been isolated from naturally infected sheep, but the genome of the ovine RSV (ORSV) has not been characterized and nor has the virus host range been identified. Here we report on the cloning and sequencing of the two non-structural 1C and 1B genes and of the small hydrophobic (SH) protein gene of the ORSV. The nucleotide identity of the ORSV 1C gene to those of subgroups A and B of HRSV was 70% and 65% respectively whereas the predicted amino acid identity was 68% and 69% respectively. The ORSV 1B gene had a 70% and 72% nucleotide identity with that of subgroups A and B of the HRSV respectively, and 79% predicted amino acid identity with both HRSV subgroups. The identity level of these two ORSV 1C and 1B genes to those of the BRSV could not be determined since these two BRSV genes have not been sequenced. The SH protein of RSV is a structural protein expressed on the surface of infected cells. In common with HRSV and BRSV subgroups, the ORSV SH had the three proposed domains with the C-terminal domain least conserved among the viruses. In the latter domain, the ORSV SH gene had a nucleotide identity of 68 to 69% and 47 to 51% with those of the BRSV and HRSV, respectively, and a predicted amino acid identity of 56% and 33 to 47% with those of BRSV and HRSV, respectively. Defining the genes and their products should help determine which genes and gene products are most suitable for use as diagnostic tools or as vaccine candidates.

Objective: To evaluate the efficacy of the technique of selective decontamination of the digestive tract in preventing the development of secondary infection and its influence on morbidity and mortality rates in multiple trauma patients with chest injuries requiring intermittent positive-pressure ventilation. Design: Prospective, double-blind, randomized study. Setting: A multidisciplinary respiratory intensive care unit (ICU) in a 1,500-bed teaching hospital. Patients: Seventy-two patients (mean Injury Severity Score of 29.5) who were intubated for >48 hrs and remained in the ICU for >5 days. Interventions: Patients were randomized on admission to receive selective decontamination therapy or placebo. All patients received intravenous cefotaxime for 72 hrs and the treatment group received oral and enteral selective decontamination with amphotericin B, polymyxin E, and tobramycin (n = 39), while the placebo group received a placebo containing oral paste and enteral solution (n = 33). Measurements: Secondary infection was determined clinically and microbiologically and surveillance cultures were monitored for gastrointestinal colonization. Results: The patient groups were fully comparable for age, severity of illness, and compromising factors. There was no difference in the number of patients infected (11 treatment group vs. 11 placebo), infections (17 vs. 16) and deaths (5 vs. 3); the duration of ICU (15.5 vs. 14.2 days) and hospital stays (26.3 vs. 25.5) were also similar. Microbiological surveillance cultures confirmed effective elimination of aerobic Gram-negative bacilli, and infections in the treatment group were largely due toStaphylococcus aureusandStaphylococcus epidermidis. Conclusion: We have been unable to show any benefit from the use of selective decontamination of the digestive tract in the prevention of secondary infections in multiple trauma patients. (Crit Care Med 1994; 22:33-39)

To evaluate the efficacy of the technique of selective decontamination of the digestive tract (SDD) in preventing secondary infections in patients with neurologic diseases requiring intensive care.Randomized, double-blind, placebo-controlled trial using amphotericin B, polymyxin E, and tobramycin applied to the oropharynx and enterally; all patients received intravenous cefotaxime for 72 h.Respiratory ICU.Forty patients with neurologic diseases requiring ventilation for48 h and ICU stay5 days. Neurologic diagnosis included acute inflammatory demyelinating neuropathy (15), meningoencephalitis (10), status epilepticus (6), tetanus (6), and myasthenia gravis (3).Microbiologic surveillance samples of oropharyngeal and tracheal secretions, gastric aspirates, stool, urine, and any other potentially infected sites were taken at the time of ICU admission and twice weekly thereafter until 3 days after discharge from the unit. The SDD was applied every 6 h to the oropharynx and enterally.Effective decontamination of the gastrointestinal tract was achieved in the patients receiving the active regimen; however, there was no reduction in the incidence of infections (11 in the active group vs 10 in placebo), and duration of ICU stay (30.1 +/- 22.5 vs 20.6 +/- 17.7 days) and hospital stay (49.3 +/- 31.9 vs 40 +/- 33.4 days) were unaffected as was the mortality (15 percent vs 15 percent).SDD did not reduce the incidence of secondary infection in patients with neurologic disease, nor did it affect morbidity or mortality; however, it adds considerably to the cost of patient care.

Selective decontamination of the digestive tract (SDD), by means of non-absorbable antibiotics, to prevent infection in intensive-care units (ICUs) remains controversial; there is evidence that the regimen reduces the incidence of secondary infection, but no convincing reduction in morbidity or mortality has been shown and the costs and effect on microbial resistance patterns need further study. In a double-blind, placebo-controlled trial, we have tried to find out whether SDD should be used routinely in all ICU patients at high risk of secondary infection. All patients admitted to the ICU who were thought likely to stay in the unit for at least 5 days and to need intubation for longer than 48 h were enrolled and randomly allocated to groups receiving placebo or SDD (amphotericin, colistin, and tobramycin applied to the oropharynx and enterally); all patients received intravenous cefotaxime for 72 h. Of 322 patients randomised, 83 were withdrawn (80 ICU stay or duration of intubation too short, 3 protocol violations). 239 medical, trauma, and surgical patients completed the trial period (114 SDD, 125 placebo). There were no differences between SDD and placebo groups in incidence of infection (30 [26%] vs 43 [34%] patients; p = 0.22), duration of ICU stay (mean 16.2 [14.3] vs 16.8 [12.3] days), hospital stay (29.9 [SD 25.0] vs 31.9 [22.2] days), or mortality (21 [18%] vs 21 [17%]). SDD substantially increased the costs of intensive care. Mechanisms other than bacterial colonisation of the gut may bring about substantial numbers of secondary infections in ICUs. Routine use of SDD in multidisciplinary ICUs cannot be recommended.

OBJECTIVE: To measure the metabolic requirements of patients with severe tetanus who require mechanical ventilation. DESIGN: Prospective, consecutive, open study using routine monitoring. SETTING: A multidisciplinary ICU in a large teaching hospital. PATIENTS: Five consecutive patients (age range 30 to 54 yrs) with severe tetanus. Four patients had clinical evidence of sympathetic nervous system overactivity. INTERVENTIONS: All patients were mechanically ventilated and appropriately treated for severe tetanus. Sympathetic nervous system overactivity was reduced by the administration of sedatives. MEASUREMENTS AND MAIN RESULTS: Measurements of metabolic rates were made using an indirect calorimetry device. Each of the five patients had three 8-hr periods of continuous metabolic monitoring for each of three levels of daily enteral nutritional support. The measured metabolic rates varied from 1310 to 2050 kcal/24 hrs (predicted 1280 to 1770 kcal/24 hrs). The variations from predicted basal metabolic rates varied from -6.3% to +10.5%. CONCLUSIONS: The measured metabolic rates of patients with severe tetanus who are appropriately sedated are relatively constant and are within 10.5% of the predicted basal metabolic rates.

Two cases of severe community-acquired pneumonia requiring EPPV and complicated by the development of lung abscess were successfully treated with early surgical drainage. This procedure may be a life-saving measure in certain instances. (Chest 1991; 99:1280-82)

The clinical features of 18 patients with Klebsiella pneumoniae requiring intensive care unit (ICU) management are presented. All patients required ventilatory support; 17 were given constant positive pressure ventilation and 10 required greater than 10 cm positive end expiratory pressure. The clinical picture was characteristic: pre-existing medical disease, clinical features of severe pneumonia and copious purulent bronchial secretions, Gram--ve organisms on Gram's stain and lobar consolidation on the chest radiograph were common. Septicaemic shock, confusion and uncompensated metabolic acidosis were the presenting clinical features predicting a poor outcome. Antimicrobial chemotherapy, that combined an aminoglycoside and a third generation cephalosporin to ensure adequate early antibiotic serum levels, may help to improve the prognosis.

Tetanus is a disease caused by the exotoxin, tetanospasmin, produced by germination and proliferation of the anaerobic organism Clostridium tetani. This ubiquitous organism occurs as spores in organic material particularly soil and the feces of various animals and man. Tetanospasmin has a predilection for neural tissue and forms an irreversible bond to synaptosomes both in the spinal cord and central nervous system. The toxin ascends intra-axonally in motor and autonomic nerve fibers although a small amount may reach the brain via the circulation. The exact central site of action of tetanospasmin has not been elucidated, but evidence suggests that the predominant site is the inhibitory neurones. Here, the major effect may result from its influence on the release of the inhibitory neurotransmitters GABA and glycine which allow inhibited stimuli to the motor and autonomic nervous system.

Despite improvements in immunosuppressive therapy, pulmonary infections remain an important cause of morbidity and mortality in renal transplant recipients. Over a 12-year period (1 January 1977 to 31 December 1988) we prospectively assessed the value of fibreoptic bronchoscopy in diagnosing radiographic pulmonary shadows in this group of patients. Forty-eight bronchoscopies were performed on 46 patients. A definitive diagnosis was established in 28/48 (58%) procedures (and was partially definitive for one of two organisms ultimately identified in another). The procedure failed in 19/48 (40%), although in 15 of these, the radiographic shadows resolved on antibiotics (9) or spontaneously (3) or autopsy revealed acute pneumonia (3). In four instances a specific diagnosis was made by alternative means. Clinically useful information which led to changes in management was obtained in 17/48 (35%) procedures and bronchoscopy was thought to have favourably influenced survival in 16/48 (33%). Fibreoptic bronchoscopy is in our experience a safe (only one pneumothorax and no significant haemorrhage) and useful technique in evaluating pulmonary shadows in renal transplant recipients.

Amikacin was introduced as the primary aminoglycoside in our hospital to prevent the further development of multiply resistant Gram-negative organisms. This study compares clinical and microbiological data before and after institution of this policy to evaluate the influence on clinical outcome in patients as well as changing resistance patterns in the respiratory ICU. Patient populations were similar in terms of severity of illness (Acute Physiology and Chronic Health Evaluation II scores), age, ventilation, invasive procedures, and the incidence of various diseases. We found that the rate of amikacin resistance increased from 8.5% to 39.6% with an increase in resistance to tobramycin (19.3% to 33.3%) and netilmicin (23.9% to 47.9%) over the same period despite minimal usage of these drugs. The clinical outcome was similar in the periods contrasted. Our findings suggest that restricting aminoglycosides to amikacin only resulted in increasing Gram-negative resistance although there was no significant effect on patient outcome.

Study objective To evaluate the efficacy of the technique of selective decontamination of the digestive tract (SDD) in preventing secondary infections in patients with neurologic diseases requiring intensive care. Design Randomized, double-blind, placebo-controlled trial using amphotericin B, polymyxin E, and tobramycin applied to the oropharynx and enterally; all patients received intravenous cefotaxime for 72 h. Setting Respiratory ICU. Patients Forty patients with neurologic diseases requiring ventilation for >48 h and ICU stay >5 days. Neurologic diagnoses included acute inflammatory demyelinating neuropathy (15), meningoencephalitis (10), status epilepticus (6), tetanus (6), and myasthenia gravis (3). Interventions Microbiologic surveillance samples of oropharyngeal and tracheal secretions, gastric aspirates, stool, urine, and any other potentially infected sites were taken at the time of ICU admission and twice weekly thereafter until 3 days after discharge from the unit. The SDD was applied every 6 h to the oropharynx and enterally. Measurements and results Effective decontamination of the gastrointestinal tract was achieved in the patients receiving the active regimen; however, there was no reduction in the incidence of infections (11 in the active group vs 10 in placebo), and duration of ICU stay (30.1 ±22.5 vs 20.6 ± 17.7 days) and hospital stay (49.3 ±31.9 vs 40 ±33.4 days) were unaffected as was the mortality (15 percent vs 15 percent). Conclusions SDD did not reduce the incidence of secondary infection in patients with neurologic disease, nor did it affect morbidity or mortality; however, it adds considerably to the cost of patient care.

The spectrum of pathogens and the microbiologic investigations used to obtain a diagnosis in 178 patients with severe pneumonia (88 percent requiring intermittent positive-pressure ventilation) are reviewed. Ninety-five patients had primary pneumonia, 31 had nosocomial pneumonia, 24 were immunocompromised patients, and 28 had aspiration pneumonia. While the spectrum of isolates conformed to the usual patterns for the different types of pneumonia, the incidence of Gram-negative infections (15 percent), predominantly Klebsiella pneumoniae, Staphylococcus aureus , (8 percent), and Legionella pneumophila (5 percent) in primary pneumonia was much higher than in community or general hospital-based studies, and only one case of Mycoplasma pneumoniae was identified. Gram stain of sputum or tracheal aspirate taken on intubation in primary pneumonia was reliably predictive of the causative organisms in both Gram-positive and Gram-negative infections when compared with infections proven by blood culture. Serologic studies were valuable in patients in whom no positive microbiologic diagnosis was evident; however, fiberoptic bronchoscopy contributed minimally to the microbiologic diagnosis in this group of patients. The cause of severe primary pneumonia differs from less severe disease, and this should be recognized when selecting empiric antibiotic therapy.

A cytopathic strain of bovine viral diarrhea virus (BVDV) was purified from infected cell culture fluids by isopycnic density-gradient centrifugation. Genomic RNA was extracted and tailed with adenine residues at the 3′ end with poly-A polymerase. Double-stranded complementary DNA (cDNA) was synthesized, using the poly-A-tailed RNA as a template and oligo-dT as a primer, and then cloned into the pUC9 plasmid. Virusspecific cDNA sequences, varying in length from 0.5 to 2.5 kilobases (kb), were obtained. One BVDV-specific sequence of cloned cDNA, 1.1 kb in length and with an internal Pst I restriction endonuclease cleavage site, was selected for use as a probe. The cloned cDNA insert was removed from the plasmid either with or without flanking plasmid sequences and labeled with 32P-nucleotides by nick translation for use as hybridization probes for BVDV. The performance of probes of smaller fragments of the insert was compared to that of the intact sequence in hybridization assays. In addition, 2 methods of specimen preparation were compared to establish optimum parameters for hybridization. The hybridization assay was 10–100 times more sensitive than infectivity assays for BVDV in infected cell cultures. Freezing of specimens reduced by lo-fold the sensitivity of hybridization for BVDV target sequences. The probes prepared from the cloned cDNA hybridized with all cytopathic and noncytopathic BVDV strains tested but not with uninfected cell cultures, cellular ribosomal RNA, bovine coronavirus, bluetongue virus, or bovine adenovirus 3. Probes prepared with native plasmid DNA did not hybridize with BVDV or uninfected cell cultures. Probes of 1.1 kb, 0.6 kb, and 0.5 kb hybridized with equal sensitivity to target sequences in the dot blot system. The presence of flanking plasmid sequences did not improve the hybridization performance of the probes. Hybridization results with specimens prepared by RNAsin and heat treatment were similar to those obtained after Nonidet P-40 and formaldehyde treatment.

Of 458 patients admitted to a respiratory ICU over a 1-yr period, 65% required positive-pressure ventilation and 10% received continuous positive airway pressure by face mask. The average ICU stay was 7 days. The overall mortality of 19% depended largely on the medical disease precipitating admission but also increased in patients over 60 yr of age. Of 359 patients discharged from the hospital, 226 were followed for at least 18 months. Of these, 65% made a full recovery, 21% partially recovered, and 13% died.

Three patients with respiratory failure resulting from miliary tuberculosis had a characteristic clinical presentation that included a long history of a prominent cough, dyspnea, weight loss, tachycardia, tachypnea, pulmonary adventitious sounds, and hepatomegaly. Hematologic investigation showed a normal white cell count with marked left shift in the morphology of white cells in all three patients, and evidence of disseminated intravascular coagulation in one patient. In only one patient was the initial sputum positive for acid-fast bacilli; in the others, invasive diagnostic procedures including lumbar puncture, bone marrow trephine, and open-lung biopsy were necessary for diagnosis. Miliary tuberculosis should be suspected in patients with adult respiratory distress syndrome of unknown etiology. Simple diagnostic procedures such as sputum, bronchial brushings, and urine examination should be followed by bone marrow trephine, liver biopsy, transbronchial lung biopsy, and lumbar puncture if physical signs of meningitis are present.

Acid fast bacilli are seldom identified by direct staining of sputum smears in patients with miliary tuberculosis, so that delays in diagnosis are common. We report 41 patients with miliary tuberculosis who had negative sputum smears and who underwent bronchoscopy, bronchial brushing, and transbronchial biopsy. In two patients the procedure was repeated. A definitive diagnosis was obtained from bronchoscopy in 34 patients (83%). Bronchial brushings yielded Mycobacterium tuberculosis in 24 of 42 bronchoscopies (57%), 13 from direct smear and a further 11 from culture only. Transbronchial biopsies were diagnostic in 30 of 41 procedures (73%), 28 from histological appearances, one from direct smear of the biopsy specimen, and another exclusively from culture. A rapid diagnosis was established in most patients (27/34), either by direct smear of brushings or biopsy specimens only (5), by histological examination only (14), or by both direct smear of brushings and biopsy specimens only (5), by histological examination only (14), or by both direct smear of brushings and histological examination (8). The diagnosis was confirmed later in a further seven patients by culture of brushings or specimens; in five of these non-caseating granulomas were initially found by histological examination. Fibreoptic bronchoscopy is a valuable technique for rapidly establishing the diagnosis of miliary tuberculosis.

Two vaccine, two respiratory (infectious bovine rhinotracheitis [IBR]), and two genital (infectious pustular vulvovaginitis [IPV]) strains of infectious bovine rhinotracheitis virus were compared by neutralization kinetics using late 19 S antibody (AB). The two vaccine strains were indistinguishable from one another, but were neutralized far more rapidly than the other four strains when either anti-IBR or anti-IPV 19 S AB was used. The two IPV strains were indistinguishable from one another, but were neutralized significantly more rapidly than the two IBR strains when anti-IBR 19 S AB was used. The 2 IBR strains were neutralized at a similar rate with the latter globulin preparation. Almost identical results were obtained with anti-IPV 19 S AB, except that one IPV strain was neutralized at a rate similar to the IBR strains. However, when early and late rabbit 7 S AB were used, IBR strains could not be distinguished from IPV strains by neutralization kinetics. Preliminary experiments indicated that both early and late 19 S rabbit antibodies neutralized the homologous strain more rapidly than the heterologous strain, but the difference was more noticeable with late 19 S AB. It was also determined that neutralization of IBR-IPV virus by specific early and late 19 S rabbit AB and early 7 S rabbit AB was markedly enhanced by guinea pig complement. Neutralization of this virus by late 7 S AB, however, was only slightly enhanced by complement. These results suggest that vaccine strains of IBR-IPV virus may be distinguished by neutralization kinetics with late 19 S rabbit AB, and that genital and respiratory strains may possibly also be distinguishable with some 19 S AB preparations.

In four years' use of the flexible fibreoptic bronchoscope in diagnosing sputum-negative pulmonary tuberculosis, of 275 patients with tuberculosis suspected from chest radiographic appearances, 89 (32.4%) were shown to have active disease. In 60 (67.4%) of these patients the diagnosis was made from samples obtained through the fibreoptic bronchoscope (56 from bronchial brushings, four from transbronchial biopsy samples). Of the 56 positive bronchial brushings, 35 were positive on direct smear and 21 only on culture. Transbronchial biopsy exclusively accounted for only four of the 60 positive diagnoses. In the remaining 29 patients, the diagnosis was made from further sputum or biopsy specimens in 15, from the response to treatment in 12, and at necropsy in two. In six of 10 patients with military tuberculosis, bronchial brushings were positive on direct smear.

Thirty-nine asthmatic patients required mechanical ventilation (IPPV) for status asthmaticus over a seven and a half year period. We reviewed their clinical records with particular emphasis on the events leading to intermittent positive pressure ventilation (IPPV) and the long-term courses of those patients who survived IPPV. Long delays by patients before seeking medical attention, incomplete assessment of acute attacks, underuse of corticosteroids prior to admission and overuse of sedation were important factors often influencing the necessity for IPPV. Four patients died during IPPV. Of the 35 who survived, 32 were regularly followed in our Respiratory Clinic. Nine patients subsequently died, eight undoubtedly from asthma. Serial measurements of forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV 1 ) were retrospectively analyzed to determine patterns of asthma. Of the 23 patients still alive, 14 have well controlled asthma, five have a pattern of persistent airflow obstruction, two have markedly labile asthma, and two have gradually deteriorating airflow obstruction. By contrast, seven patients who died sufficiently long after IPPV to enable categorization of their patterns showed either markedly labile asthma or gradually deteriorating airflow obstruction. None had relatively constant ventilatory function at either normal or suboptimal levels. We suggest that patterns of asthma are useful guides in detecting patients at high-risk. Patterns characterized by markedly labile asthma or gradually deteriorating airflow obstruction appear to be associated with an increased risk of sudden death from asthma.

The use of biotinylated DNA hybridization probes for clinical detection of bovine herpesvirus-1 was investigated. Biotinylated DNA hybridization probes were prepared from bovine herpesvirus-1 DNA purified from infected cell cultures. The viral DNA was nick translated in the presence of biotin-dUTP with DNA polymerase to incorporate biotin into the newly synthesized strand. The probe was tested for specificity in in situ hybridization assays with bovine herpesvirus-1 DNA. Hybridization was detected using avidin-fluorescein single sandwich systems and an avidin-globulin with anti-globulin-fluorescein double sandwich system. Hybridization was detected by specific fluorescence of infected cells. Fluorescence was present only in bovine herpesvirus-1-infected cell culture and not in noninfected cell culture or cell cultures infected with several other viruses. The assay was performed in 6 hr.

A paramyxovirus related to parainfluenza 2 (PI2) virus was recovered from the lungs of two dead Ottoman vipers from a zoological collection. Snakes of other species in the collection were unaffected. Histologic examination of the vipers' lungs revealed interstitial pneumonia, and degeneration and hyperplasia of bronchial and atrial epithelia. Scattered vacuoles, some of which contain eosinophilic inclusion bodies, were seen in the cytoplasm of several cells of affected epithelial tissues. The virus recovered from pulmonary tissues of the snakes replicated optimally at 30 C in a variety of cell cultures and hemagglutinated chicken erythrocytes. Viral hemagglutination was inhibited by PI2 virus antiserum, but not by antisera to PI1, PI3, respiratory syncytial, and canine distemper viruses. Indirect immunofluorescence with PI2 antiserum specifically stained inclusions in the epithelial cells of respiratory tissues and infected cell cultures.

In three cases of pulmonary tuberculosis associated with the adult respiratory distress syndrome the clinical features, which were similar to those of patients with miliary tuberculosis and adult respiratory distress syndrome, included a history of cough, fever, and dyspnoea on effort, and the physical signs of fever, tachypnoea, pulmonary adventitious sounds, tachycardia, and hepatomegaly. In these cases the radiological features, though suggestive of diffuse pulmonary oedema, were more prominent on the side in which the cavitatory lesion appeared. The diagnosis of tuberculosis was made easily from direct examination of sputum. Despite early ventilatory support and antituberculous therapy, two of the three patients died. Postmortem examination of the lungs in these cases showed evidence of acute alveolar damage (loss of type 1 pneumocytes and the presence of hyaline membranes within alveolar ducts) and of chronic alveolar damage (interstitial and alveolar fibrosis).

SUMMARY: Hybridization of various Streptomyces cattleya aerial mycelium negative (Amy-) mutants with a probe containing the gene for argininosuccinate synthetase (pTG17) has revealed the presence of two different types of mutants (stable and unstable). Stable mutants appear to have lost all or part of the region covered by the probe, while the unstable mutants demonstrate no detectable changes in this region. In one group of stable mutants (those demonstrating a partial loss of sequences hybridizing to the probe), a 4·17 kb extrachromosomal element was detected, which hybridized with the pTG 17 probe. The significance of this finding is discussed with reference to the genetic instability of the genus Streptomyces.

Postmortem examination of a captive-bred American kestrel (Falco sparverius) showed numerous white necrotic foci 1-2 mm in diameter throughout the liver and spleen. The results of light and spleen. The results of light and electron microscopic studies and experimental transmission to a captive American kestrel and a barred owl (Strix varia) suggests a herpesvirus similar to those dsecribed for owls and other falcons in the U.S. This is the first report of a naturally occurring case of inclusion body disease of falcons in the American kestrel.

This study evaluates mandatory minute volume (MMV) weaning in patients with pulmonary pathology. When weaning criteria were fulfilled, 22 patients were randomised to MMV and 18 to a control intermittent mandatory ventilation (IMV) group. With IMV weaning the ventilator rate was decreased by two breaths per minute at 3-4 hourly intervals during daylight hours. In the MMV group a target of 75% of the ventilator minute volume was set. All weans were considered complete four hours after the cessation of mechanical support, and were deemed successful if no further ventilation was required. The success rate was 86% in the IMV and 89% in the MMV group. MMV weaning was rapid (4.75 + 1.5 hrs) and proved less demanding on the ICU staff by providing a safe trial of spontaneous respiration, while retaining the facility for partial ventilation.

Of 81 adult patients with community-acquired pneumonia, bacterial infections were found in 37%, mycoplasma and viral infections in 21%, and tuberculosis in 6%; no pathogen could be identified in 46% of cases. More than one agent was identified in 12% of patients. Streptococcus pneumoniae, the most common pathogen, was found in 63%, Haemophilus influenzae in 26,7%, Staphylococcus aureus in 6,7%, and other Gram-negative organisms in 10% of patients with proven bacterial pneumonia. Most clinical and radiographic features were of little value in differentiating between different aetiological agents, but Gram-stained sputum gave a valuable early guide to therapy in 60% of cases of proven bacterial pneumonia. Blood culture was positive in 13,6% of cases. All the organisms conformed to their usual sensitivity patterns. Since Strept. pneumoniae is the predominant pathogen, penicillin should be the drug of choice in the immediate 'blind' treatment of community-acquired pneumonia.

In an open study to determine the efficacy, safety and tolerance of intravenously administered imipenem/cilastatin (Tienam 500; Logos) in the treatment of septicaemia, 34 patients were given this thienamycin antibiotic in doses ranging from 1.5 g to 2 g daily for an average of 8.6 days (range 3-44 days). Based on clinical assessment, the study drug appeared to be effective in treating the septicaemia in 28 out of 34 patients and bacteriologically assessed eradication of the isolated pathogen was proven in 24 out of 34 patients. The drug appeared to be well tolerated in all but 4 patients, 3 of whom developed mild phlebitis and 1 a skin rash.

Isoniazid (INH) is used in most prophylactic and therapeutic antituberculosis regimens because of its effectiveness and low cost. Despite the vast amounts of this drug dispensed in the RSA, INH overdose appears to be rare. Acute INH poisoning requires recognition and specific therapy to prevent mortality. Two patients with INH overdose recently treated successfully in the Groote Schuur Hospital Respiratory Intensive Care Unit are described. The pharmacology of INH, clinical features of INH poisoning and the intensive care management are discussed.

The 4-year experience with flexible fibre-optic bronchoscopy at Groote Schuur Hospital is presented. A total of 809 patients were bronchoscoped, follow-up data on 705 being available. The procedure was performed for a wide variety of indications, suspected malignant disease and tuberculosis being the two most common. The diagnostic rate in these conditions was 74% and 71% respectively. Other indications included the evaluation of diffuse pulmonary lesions, shadows on the chest radiographs in immunocompromised patients, use in the intensive care unit, investigation of haemoptysis with a normal chest radiograph, inspection of the airway, bronchography and clearance of secretions.

Conservative management of blunt chest trauma reduces morbidity in selected patients. We present a retrospective analysis of 50 patients with blunt chest trauma who were treated in the Respiratory Unit of Groote Schuur Hospital, Cape Town, during 1980. Conservative management was not possible in 21 patients because of severe associated injuries. The remaining 29 patients were treated either with continuous positive pressure ventilation (CPPV) or continuous positive airway pressure (CPAP) by face-mask and thoracic extradural analgesia. The conservatively treated patients spent less time in the Intensive Care Unit and had fewer complications. Thoracic extradural analgesia provides optimal pain relief with resultant increase in vital capacity and an improvement in arterial blood gas levels. Current management of blunt chest trauma is directed at early withdrawal of continuous ventilatory support as soon as this can be replaced either with thoracic extradural analgesia and CPAP by mask, or with CPAP by mask alone.

A herpesvirus was isolated from the liver of a captive-bred American kestrel (Falco sparverius) which had died of inclusion body disease. Initial isolation was achieved in chicken embryo fibroblasts after three blind passages. Cell-adapted virus produced a distinct rounding of CEF cells within 24 to 48 h. Biologic and serologic tests suggested that the kestrel virus is similar to falcon herpesvirus and pigeon herpesvirus and is at least partially related to owl herpesvirus. However, serologic tests indicated that the kestrel herpesvirus is neither related to infectious laryngotracheitis virus nor to a herpesvirus from a psittacine bird; (Eupsittula canicularis) with Pacheco's parrot disease. This is the first report on the recovery of a herpesvirus similar to falcon herpesvirus from an American kestrel with naturally-occurring inclusion body disease, and on the serologic comparison between falcon herpesvirus and a psittacine herpesvirus.

A 25-year-old refrigeration technician died 85 days after accidental massive anhydrous ammonia inhalation; the case history and autopsy findings are described. The latter included bronchiectasis and obliterative bronchiolitis, but interstitial fibrosis and emphysema were conspicuously absent. The roles of dosage, infection, and healing are discussed.

Postoperative pulmonary complications, the most common of which are atelectasis and pneumonia, are due largely to the pathophysiological effects on the lungs of anaesthesia and surgery as well as pre-existing disease, in particular chronic obstructive airways disease (COAD). Pre-operative assessment, including pulmonary function tests, will allow the prediction of the risk of pulmonary complications. Active measures can then be introduced to reduce these complications.

Secondary drowning is a respiratory distress syndrome which develops after a latent period following apparently successful resuscitation from near-drowning. Eighteen cases of near-drowning have been reviewed and one case history is presented in detail to illustrate the importance of anticipating the development of this syndrome. Successful management of these patients involves ventilatory support and careful monitoring of the neurological and cardiovascular status. Because many doctors are unaware of the syndrome and because it has a good prognosis if recognized and treated early, a review of the clinical features and treatment is warranted.