Brown Bowel Syndrome

The brown bowel syndrome (BBS) is a rare disease characterized by malabsorption and accumulation of lipofuscin in the smooth muscle cells of the muscularis externa of the small intestine. Recently, we incidentally observed a case of BBS in a colon operated on because of a neoplasm. Our ultrastructural investigation, which demonstrated changes in the mitochondria, further supports the significance of mitochondrial damage in BBS.     

Cerebral ventricular enlargement relates to neuropsychological measures in unselected AIDS patients

In a cross-sectional study of unselected Danish AIDS patients various linear measures of cerebral ventricular size obtained by computed tomography were compared with results of neuropsychological test performances. Third ventricular width as well as right and left septum-caudate distances were enlarged in the patients (P less than 0.01). Of 20 patients 15 had at least one abnormal ventricular measurement. Although only one patient was demented, ventricular size correlated inversely with neuropsychological function (r = -0.61, P less than 0.02). The correlation between ventricular size and variation of the reaction time was even closer (r = 0.74, P less than 0.01). It is concluded that neuroradiological signs of central atrophy often occur in AIDS patients.     

Observer variability in the assessment of type and dysplasia of colorectal adenomas,analyzed using kappa statistics

PURPOSE: The aim of this study was to establish the intraobserver and interobserver variability in the assessment of histologic type (tubular, villous, and tubulovillous) and grade of cytologic dysplasia (mild, moderate, and severe) in colorectal adenomas. METHODS: One hundred eighty-seven slides of adenomas were assessed twice by three experienced pathologists, with an interval of two months. Results were analyzed using kappa statistics. RESULTS: For agreement between first and second assessment (both type and grade of dysplasia), kappa values for the three specialists were 0.5345, 0.9022, and 0.4100, respectively. Agreement was better for type than for dysplasia. The strength of agreement was moderate for Observers A and C and almost perfect for Observer B. Agreement between all three observers was seen in 35.2 percent for both type and dysplasia in 61 percent for type and in 47.8 percent for dysplasia. The kappa values for Observer A vs. B and Observer C vs. B were 0.3480 and 0.3770, respectively (both type and dysplasia). Values for type were better than for dysplasia, but agreement was only fair to moderate. CONCLUSION: The interobserver agreement was moderate to almost perfect, but the intraobserver agreement was only fair to moderate. A simpler classification system or a centralization of assessments would probably increase kappa values.Supported by grants from the Danish Cancer Society, Danish Medical Research Council (Grant 12-6355), Thomas Bartholin's Fund, Gundelach Meller's Fund, and Emmy Lange, born Kramp's Fund.     

Use of pseudorandom noise in studies of auditory evoked potentials

The extent to which sensorineural systems such as the auditory system are nonlinear depends on the type of stimulus that is used, and the part of the system from which recordings are made. An estimate of the first-order Wiener kernel of the evoked response from the inferior colliculus to amplitude-modulated tones and noise was obtained by cross-correlating the response with the same pseudorandom noise as was used to amplitude modulate the sounds that were used as stimuli, in order to characterize the linear portion of the system. The shape of these cross-correlograms resembled the potentials evoked to short bursts of the unmodulated tones and noise. The degree of nonlinearity in the response to amplitude-modulated tones and noise was determined, and information about the type of nonlinearity was obtained using the inverse-repeat feature of the pseudorandom noise. Recordings both from the surface and from deep in the nucleus of the inferior colliculus revealed nonlinearities that were predominantly of an even order, but the magnitude of the nonlinearities depended on what stimulus was used, the stimulus intensity, and from which neural structure the recording was made.     

The role of alcohol, tobacco, and dietary factors in upper aerogastric tract cancers: a prospective study of 10,900 Norwegian men

Previous knowledge on risk factors for oral, pharyngeal, laryngeal, and esophageal cancer has been based mainly on case-control studies. In the present study, the impact of alcohol consumption, tobacco smoking, and dietary factors on upper aerogastric tract cancer risk was studied in a cohort of 10,960 Norwegian men followed from 1968 through 1992, in which period a total of 71 upper aerogastric tract cancers occurred. The relative risk (RR) of cancer was 3.9 (95 percent confidence interval [CI] = 2.1-7.1) for the highest consumption group of alcohol and 4.7 (CI = 1.7-13.2) for the highest smoking level, compared with the respective reference groups. Among the dietary items, high consumption of oranges was associated with reduced cancer risk (RR = 0.5, CI = 0.3-1.0), as was high consumption of bread (RR = 0.2, CI = 0.1-0.5). Frequent consumption of beef and bacon increased relative cancer risk bordering on significance. The present results are largely in accordance with previous studies. The decreased risk associated with a high intake of bread deserves further investigation.     

Can vitamin D supplementation reduce the risk of fracture in the elderly? A randomized controlled trial.

Randomized controlled trials have shown that a combination of vitamin D and calcium can prevent fragility fractures in the elderly. Whether this effect is attributed to the combination of vitamin D and calcium or to one of these nutrients alone is not known. We studied if an intervention with 10 microg of vitamin D3 per day could prevent hip fracture and other osteoporotic fractures in a double-blinded randomized controlled trial. Residents from 51 nursing homes were allocated randomly to receive 5 ml of ordinary cod liver oil (n = 569) or 5 ml of cod liver oil where vitamin D was removed (n = 575). During the study period of 2 years, fractures and deaths were registered, and the principal analysis was performed on the intention-to-treat basis. Biochemical markers were measured at baseline and after 1 year in a subsample. Forty-seven persons in the control group and 50 persons in the vitamin D group suffered a hip fracture. The corresponding figures for all nonvertebral fractures were 76 persons (control group) and 69 persons (vitamin D group). There was no difference in the incidence of hip fracture (p = 0.66, log-rank test), or in the incidence of all nonvertebral fractures (p = 0.60, log-rank test) in the vitamin D group compared with the control group. Compared with the control group, persons in the vitamin D group increased their serum 25-hydroxyvitamin D concentration with 22 nmol/liter (p = 0.001). In conclusion, we found that an intervention with 10 microg of vitamin D3 alone produced no fracture-preventing effect in a nursing home population of frail elderly people.     

Physiological abnormalities in hemifacial spasm studied during microvascular decompression operations

The pathophysiology of hemifacial spasm was studied using electrophysiologic recordings made during neurosurgical operations to relieve it by microvascular decompression of the facial nerve near its entrance into the brain stem. Electrical stimulation of the temporal or the marginal mandibular branch of the facial nerve resulted in a response not only from the muscles that were innervated by the branch of the facial nerve that was stimulated, but also from other muscles, as evidenced by EMG recordings. This "lateral spread" of antidromic activity was facilitated by stimulation at a high rate (50 pps): the response increased five- to tenfold within a few seconds. When the repetition rate was reduced to the initial low stimulus rate (2 to 5 pps), facilitation continued for periods lasting from a few seconds to several minutes. The amplitude of the response of the supraorbital reflex (blink reflex), which can be elicited in patients with hemifacial spasm intraoperatively on the affected side despite the use of inhalation anesthesia, also increased after brief stimulation at a high rate (50 pps). After the facial nerve had been decompressed, both the lateral spread response and the blink reflex response were absent. These results support the hypothesis that hemifacial spasm is the result of hyperexcitability of the facial motor nucleus and facilitation of cross-transmissions between cells in the nucleus that innervate different parts of the face.     

Compound action potentials recorded from the exposed eighth nerve in patients with intractable tinnitus.

Compound action potentials (CAP) were recorded directly from the exposed intracranial portion of the eighth nerve in 19 patients undergoing microvascular decompression (MVD) of the eighth nerve for intractable tinnitus. The waveform of the CAPs recorded in patients with tinnitus varied from normal to highly abnormal, but only in 1 patient were there distinct abnormalities in the waveform of the CAP that could not be attributed to the patient's hearing loss. The mean values of the latencies of the N1 and N2 peaks in the CAPs recorded from the exposed eighth nerve in patients with tinnitus and high-frequency hearing loss were virtually indistinguishable from the latencies obtained in patients with similar hearing loss but no tinnitus. There was no statistically significant difference between the latency of peak III in the brainstem auditory evoked potentials (BAEPs) in these two groups of patients, but the latency of peak V was slightly shorter (statistically significant) in the patients with tinnitus than it was in the patients without tinnitus.