Radiological and histopathological examination of early tissue reactions to absorbable hemostatic agents in the rabbit brain.

Topical hemostatic agents are widely and safely used in neurosurgery. The purpose of this study was to compare and analyse the early tissue reactions to two hemostatic agents, oxidized regenerated cellulose and gelatin sponge, in rabbit brain by magnetic resonance imaging and histopathologic sections. Bilateral identical parenchymal lesions were made in the frontal regions of each hemisphere in 13 rabbits. Hemostasis was achieved using oxidized regenerated cellulose or gelatin sponge, one agent being used on each side. Cranial magnetic resonance imaging was performed 24 h postoperatively and there was no statistical difference in edema formation at the site of the lesions. Histopathologic examinations indicated that pericapillary edema and endothelial distortion were common in both groups but that there was additional tissue degeneration evident in the regions where gelatin sponge had been used. Oxidized regenerated cellulose seemed to cause greater tissue distortion in magnetic resonance images than gelatin sponge but in contrast, histological examination of lesions in which oxidized regenerated cellulose had been used revealed less tissue degeneration than histopathologic examinations of lesions in which gelatin sponge had been used.     

Neurosyphilis presenting with status epilepticus.

Three patients with neurosyphilis are reported. The first and third patients presented with convulsive status epilepticus and the second with non-convulsive status after penicillin administration. In all cerebrospinal fluid and the serum Venereal Disease Research Laboratory Test (VDRL) and Treponema Pallidum hemagglutination (TPHA) or fluorescent treponemal antibody absorption test (FTA-ABS) were positive, but HIV serology was negative. Their EEGs showed periodic, lateralized, epileptiform discharges (PLEDs) just after SE. The first and third patients had no history of epilepsy. Seizures started as focal motor attacks but then secondarily generalized. The first patient's cranial MRI showed cerebral atrophy and hyperintensity involving bilateral medial and anterior temporal regions, more prominent on the left and which disappeared after penicillin treatment. The second case, after receiving penicillin, had nonconvulsive SE, a clinical presentation suggesting a Jarisch-Herxheimer reaction (JHR). Her cranial MR revealed moderate cortical atrophy and widespread confluent hyperintense foci mainly in both periventricular areas, corona radiata and centrum semiovale. MRI of the third case showed a large, left sylvian, arachnoid cyst without mass effect. Executive dysfunction was observed in follow-up neuropsychological tests in all patients. When investigating status epilepticus, neurosyphilis as a cause must not be forgotten.     

Extensive colonization of the porcine colonic epithelium by a spirochete similar to Treponema innocens.

Specimens of colonic mucosa from two pigs with diarrhea were examined by light and electron microscopy. The epithelial surfaces of both pigs were extensively colonized by large spirochetes morphologically compatible with Treponema hyodysenteriae or Treponema innocens. The microorganisms were intimately attached end-on to the luminal cells. A weakly beta-hemolytic spirochete similar to T. innocens was isolated from the colon of one of the pigs.     

Effects of single doses of alcohol and caffeine on cigarette smoke puffing behavior

Puffing behavior (number of puffs, puff duration, puff volume, peak pressure, peak flow, peak latency, and puff interval) and pre- to postsmoking delta tidal CO difference were measured in female subjects in order to assess separate and combined effects of ethanol and caffeine. The subjects smoked two cigarettes of their habitual brand in a preliminary familiarizing session and in each of the subsequent four test sessions. The treatments administered after smoking the first cigarette in the test sessions were: alcohol placebo and caffeine placebo; alcohol placebo and caffeine; alcohol and caffeine placebo; alcohol and caffeine. Test-retest reliability across the first cigarette of each session (which was not smoked under the influence of the treatments) was remarkably high for all the puffing parameters. Ethanol in the dose of 0.7 g/kg intensified cigarette smoking of the second cigarette by increasing delta tidal CO, average puff volume, and total puff volume per cigarette, whereas 0.5 g/kg ethanol and 5 mg/kg caffeine given alone or combined with ethanol failed to influence puffing behavior consistently.     

Inverse correlation between the proportion of salivary bacteria inhibiting Streptococcus mutans and the percentage of untreated carious teeth

To evaluate the role of inhibitory substances produced by bacteria in the oral cavity, we estimated, by a deferred test on Todd-Hewitt agar enriched with hemin and vitamin K, the proportion of bacteria that inhibited or stimulated the growth of Streptococcus mutans and Porphyromonas gingivalis , from the saliva of 109 patients (54 males and 55 females) attending our dental clinics. The patients, aged from 8 to 75 years old (mean: 31±18 years), were randomly selected whatever the reason for their visit. The results, evaluated with the Spearman rank test, indicated that there was no statistically significant ( P >0.05) correlation between the proportion of salivary bacteria inhibiting or stimulating P. gingivalis with the Community Periodontal Index of Treatment Needs (CPITN), the number of carious, missing and filled teeth, or with the decayed, missing and filled teeth index (DMFT). Also, no statistically significant correlation was observed between the proportion of salivary bacteria stimulating the growth of S. mutans and the above mentioned health indexes. However, a statistically significant ( P <0.005) negative correlation was found between the percentage of cultivated bacteria that inhibit S. mutans and the percentage of untreated carious teeth as well as with the CPITN. The results thus indicate a possible role for inhibitory substances produced by bacteria in the maintenance of oral health.     

Mediastinal lymphangioma

Mediastinal lymphangioma is an uncommon benign tumor accounting for 0.7 to 4.5% of all mediastinal masses. Lymphangiomas consist of dilated cystic lymph spaces lined by single layers of endothelium and do not undergo malignant change. Most mediastinal lymphangiomas are asymptomatic. There are no specific radiological findings. Surgical excision is the treatment of choice and the prognosis is excellent.