Effects of an air-powder abrasive device used during periodontal flap surgery in dogs

An air-powder abrasive system, the Prophy-Jet, is a commercially available product product intended for use during dental prophylaxis procedures. The purpose of this investigation was to assess the effects on periodontal tissues when the device is used as an adjunct to hand instrumentation in root preparation during periodontal surgery. The degree of tissue injury was assessed by evaluating clinical healing and by histometric analysis of the intensity of the inflammatory response at selected healing times. Surgical sites subjected to Prophy-Jet treatment tended to have slightly lower histometric inflammation scores than control sites treated by hand instrumentation alone. As judged by the inflammatory response and clinical healing, additional effects to surgical exposure of tissues of the periodontium were benign. Use of the Prophy-Jet instrument during periodontal surgery is effective and well tolerated.     

The aetiology of purulent meningitis in highland children: a bacteriological study

Of 155 highlands children with purulent culture-positive meningitis studied from March 1980 to September 1984, 84% were aged twelve months or less and 92% were infected with either Haemophilus influenzae, Streptococcus pneumoniae or both organisms. Other pathogens were Neisseria meningitidis (8 isolations), Streptococcus pyogenes (2 isolations) and Streptococcus agalactiae and Klebsiella species (1 of each). Among H. influenzae isolates, serotype b strains predominated (83%) and most (96%) belonged to biotype I or II. Infections due to non-b haemophili included serotype a (9 strains), serotype f (1 strain) and non-serotypable variants (3 strains). Of 67 S. pneumoniae strains 22% were resistant to benzylpenicillin, with minimal inhibitory concentrations of 0.1-1.0 micrograms/ml. The commonest serotypes were types 5 (11 isolates), type 7 (9 isolates) and types 2, 6 and 46 (6 of each). No resistance to chloramphenicol was detected in either H. influenzae or S. pneumoniae and only one of 56 strains of H. influenzae was insensitive to betalactam antibiotics. The known case fatality rate in this study was 37%. More children with pneumococcal infection died (46%) than those with haemophilus infection (30%), though the difference was not statistically significant; 79% of all deaths occurred in children aged less than twelve months. There is an urgent need for H. influenzae and S. pneumoniae vaccines that are effective in young children.     

A model of the interaction between O2 and CO2 exchange and cardiopulmonary control in the duck.

A simple model was used to predict resting blood gases and ventilation of ducks at sea level and at altitude. Unique features of the gas exchange model were the use of (1) empirical hyperbolic equations to predict the CO₂ content of blood and plasma, (2) plasma CO₂ content and P_CO2 to predict the pH-dependent hemoglobin affinity for O₂ and (3) gas contents in the mass balance equations. We utilized literature data to describe ventilatory sensitivity to blood gases and the relation of arterial-venous oxygen content differences to blood flow. The model predicted values within 4% of observations.     

Common features of three inversions in wheat chloroplast DNA

Summary We have determined the DNA sequences of regions involved in two of the three inversions known to have occurred during the evolution of wheat chloroplast DNA. This establishes the extent of the second largest of the three inversions. Examination of these sequences suggests that although short repeated sequences are present, the endpoints of the second and third inversions are not associated with repeated sequences as long as those associated with the first inversion. However the endpoints of all three inversions are all adjacent to at least one tRNA gene, and there is evidence that three of the tRNA genes have been subjected to partial duplication, possibly at the time of inversion. This suggests that tRNA genes might be involved with rearrangements of chloroplast DNA, as has also been postulated for mitochondrial DNA.     

Malignant hepatoma associated with acquired hepatic cutaneous porphyria.

A 60-year-old woman with a three-year history of an acquired hepatic cutaneous porphyria was discovered to have a porphyrin-producing malignant hepatoma. An attempt was made to treat her with fluorouracil perfused through a hepatic artery catheter. It did not produce shrinkage of the tumor, but the patient remains alive and ambulant a year after the infusion, although her skin lesions (scarring, bulla formation, and hyperpigmentation) on the fingers, back of hands, and face persist and she continues to excrete abnormally high quantities of porphyrin in her feces.     

Multislice proton magnetic resonance spectroscopic imaging in X-linked adrenoleukodystrophy

Multislice proton magnetic resonance spectroscopic imaging permits metabolic analysis of brain tissue in vivo by data acquisition in four oblique axial slices, each 15-mm thick and divided into 0.8-ml single-volume elements. We applied this technique to the systematic study of 25 patients with adrenoleukodystrophy: 3 with the severe childhood or adult cerebral form of the disease, 5 with adrenomyeloneuropathy, 12 with no demonstrable neurological involvement, and 5 women heterozygous for adrenoleukodystrophy who had some degree of neurological disability. Abnormalities on magnetic resonance spectroscopic imaging included a reduction in N-acetyl aspartate, an increase in cholin-containing compounds, and at times, an increase in lactate. Five patients showed abnormalities in the presence of normal-appearing magnetic resonance images, and in 8 other patients the alterations on spectroscopic images were more severe than those demonstrable by magnetic resonance imaging. Correlation with clinical course suggests that an increase in the choline-containing compounds is associated with an active demyelinative process, whereas such compounds are not elevated in lesions that are stable. We conclude that magnetic resonance spectroscopic imaging is a more sensitive indicator of early neurological involvement thatn is magnetic resonance imaging, and that the character of abnormalities detected by the former technique may serve as a gauge of the degree of activity of the demyelinating process and as a guide to the selection and evaluation of therapeutic approaches.     

Endoscopically defined treatment strategies in patients with locally advanced esophageal cancer

Sixty-five consecutive, locally advanced esophageal cancer patients were treated by the West Side Medical Center Esophageal Service at the Cook County and University of Illinois hospitals. Each patient was prospectively evaluated with multiple endoscopies including esophagogastroduodenoscopy, bronchoscopy, nasopharyngoscopy, and laryngoscopy. Twenty-four patients (37%) had endoscopic findings that significantly altered therapeutic regimens. Patients identified as having an obvious or impending esophageal fistula or poor performance status were treated in a palliative fashion. Forty (61.5%) patients were considered candidates for treatment with multimodal therapy which included radiation, chemotherapy, and surgery. There was a response rate of 82.5% and a 1-year disease-free survival of 88.9% which was statistically significant when compared to the other patient treatment groups. These data illustrate the necessity of multiple endoscopic evaluation of locally advanced esophageal cancer patients for stratification into appropriate treatment groups. Aggressive treatment afforded selected patients excellent relief of presenting symptomatology, as well as an improved, more acceptable, disease-free survival.Presented at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), Phoenix, Arizona, USA, 3 April 1993