The cerebral-to-large vessel hematocrit ratio (alpha) was measured using single-photon emission computed tomography (SPECT) in patients with brain tumors. SPECT was performed following intravenous ...injection of 99mTc-labelled red blood cell and 99mTc-labelled human serum albumin with an interval of 72 hr. In a series of seven subjects, the mean value of "alpha" in tumor (0.74 +/- 0.13) was lower than that (0.83 +/- 0.14) in normal brain tissue. This result may be due to the increased flow of red blood cells in tumor.
Histologic analysis of squamous cell carcinoma of the lower alveolus shows 2 basic patterns of tumor spread in relation to the mandible: an infiltrative one and an expansive one. While the tumor ...invades the mandible by destroying the bone or through cortical defects of some spaces in the infiltrative form, the tumor does this only by eroding the bone in the expansive form, in which the degree of bone resorption seems to be proportional to tumor advancement. A comparison between radiologic and histologic features discloses that the radiologically detected bone defects are not necessarily correlated with the patterns of bone involvement. However, most lesions with erosive bone defects show the expansive pattern histologically, and the extent of the radiologically detected bone defect is roughly in accordance with the histologic extent of bone involvement. These results lead us to believe that some squamous carcinoma of the lower alveolus could be treated successfully without sacrificing the continuity of the mandible.
The parameters of an electron cyclotron resonance (ECR) C sub(4)F sub(8)/Ar plasma were measured with a heated Langmuir probe and an 8 mm microwave interferometer. As the ratio of C sub(4)F sub(8) ...gas to Ar gas was increased, the electron density measured with the microwave interferometer decreased, which suggests that a large quantity of negative ions exist in the ECR C sub(4)F sub(8) plasma. An attempt to estimate the negative ion density was then made with the heated Langmuir probe. It was found that the ratio of negative ions to positive ions is from 30 to 80% in the ECR C sub(4)F sub(8) plasma.
Fifty-nine patients with 61 open femoral fractures were treated with immediate locked intramedullary (IM) nailing (group 1; n=15), delayed IM nailing following nonoperative treatment (group 2; n=42), ...and delayed IM nailing following external fixation (group 3; n=7). Sixteen fractures were Gustilo type I, 28 were type II, 7 were type IIIA, 6 were type IIIB, and 4 were type IIIC open fractures. Four (6.6%) deep infections occurred. Significant differences existed in the deep infection rate (DIR) between types I and II and all type III fractures (2.3% for types I and II versus 17.6% for type III). The deep infection rate did not differ significantly among the nailing groups (13.3%, 2.6%, and 15.3% for groups 1, 2, and 3, respectively), nor did the deep infection rate correlate with the degree of fracture comminution, the existence of polytrauma or polyskeletal trauma, or preexistence of superficial or pin-site infections. Seven (11.7%) of these fractures resulted in nonunion, excluding one secondary amputation; the nonunion rate correlated with fracture location. There were no significant differences in the mean fracture healing times between any of the nailing groups. These results suggest that IM nailing for the treatment of type III open femoral fractures should be considered carefully, regardless of whether it is performed immediately or delayed.
We report the case of a 55 year-old right-handed man who presented with a long lasting pure word deafness following left thalamic bleeding. There was no sign of aphasia. The auditory deficit was ...specific for language, while recognition of music and environmental sounds was normal. CT, MRI and PET examinations showed that the lesion was anatomically and functionally confined to the left cerebral hemisphere, mainly the white matter of the temporal and parietal lobes. Wernicke's area was largely preserved. It is proposed that pure word deafness was consequent to the isolation of Wernicke's area from incoming auditory information due to the interruption both of the association fibers from the right auditory area traveling across the corpus callosum and of the left auditory radiations.
Paired stimulation has been used extensively in clinical neurophysiology. We studied change in the sizes of compound muscle action potentials (CMAPs) and compound nerve action potentials (CNAPs) in ...humans after a single electrical stimulus to the peripheral nerve. For the paired stimuli, potentials elicited by the first stimuli were used as the test responses. When the interstimulus intervals were varied, the second potentials underwent refractoriness and then were facilitated up to 20-30 ms, thereafter being depressed for 160-200 ms. When intensities were graded at fixed intervals for motor fibers the maximal effect was obtained with liminal stimulation, but was no longer observed at supramaximal stimulation. When the intensity used to obtain M-responses was half the maximum, maximal facilitations were 35% (CNAP) and 17% (CMAP) of the first potential, the respective maximal depressions being 13% and 42%. When the sizes of the two CNAPs were equalized by adjusting the second stimuli, the CMAP was facilitated (26%) up to 65 ms, thereafter being depressed (13%). These results must be taken into account when making clinical examinations that use paired stimulation.
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