Dependence of cat vestibulo-ocular reflex direction adaptation on animal orientation during adaptation and rotation in darkness

Four series of experiments investigated how adaptive changes in direction of the cat's vestibulo-ocular reflex (VOR) vary with position of the animal during adaptive training and postadaptive testing. In all experiments VOR was measured electrooculographically during rotations about earth-horizontal and vertical axes in the dark before and after 2 h of adaptation in which 0.25 Hz sinusoidal whole body rotation about a horizontal/vertical axis was paired with synchronous 0.25 Hz rotation of a visual pattern about a vertical/horizontal axis, respectively. In upright sagittal (US) experiments, coupling of pitch rotation with visual pattern rotation about an earth vertical axis yielded an adaptive horizontal VOR response to pitch rotation whose gain had a local maximum at 0.25-0.5 Hz plus a sustained rise for frequencies below 0.1 Hz. When post-tests were done with the animal rolled 90 degrees onto its side and rotated about the earth vertical axis (pitch relative to the cat), the low frequency rise was eliminated and the 0.25 Hz peak was reduced. In on side sagittal (SS) experiments, where training was done in the latter (on side) position, training produced only the 0.25 Hz peak without the low frequency rise, indicating that the rise is due to coupling of otolith input to horizontal VOR. Again the 0.25 Hz peak was reduced when testing was done with the cat oriented 90 degrees from the training position (in the US position). This indicates that the cross-coupled canal-ocular reflex response is modulated or gated by the position of the animal with respect to gravity.(ABSTRACT TRUNCATED AT 250 WORDS)

Dynamics of adaptive change in vestibulo-ocular reflex direction. II. Sagittal plane rotations

Alert cats were rotated sinusoidally (0.25 Hz) in their sagittal plane while viewing optokinetic motion in their horizontal plane. Vertical and horizontal vestibulo-ocular reflex (VOR) was measured in the dark before and after 2 h of these adaptation stimuli in upright or onside orientation of the cat. Onside exposure produced maximal adaptive horizontal VOR at the training frequency. Upright exposure produced highest gain at lower frequencies. A cat with inoperative vertical canals adapted only to upright exposure. We conclude that in the presence of horizontal image rotation either vertical canal or otolith stimulation can produce adaptation in VOR direction and stimulation of both produces complex adaptation dynamics.

Spatial and temporal response properties of the vestibulocollic reflex in decerebrate cats

Vestibulocollic reflex responses of several neck muscles in decerebrate cats were studied during angular rotations of the whole body in a large number of vertical and horizontal rotation planes, at frequencies from 0.07 to 1.6 Hz. Vestibulocollic responses were compared to eye muscle and forelimb muscle vestibular responses. Electromyographic activity was recorded by fine wires inserted in biventer cervicis, complexus, longus capitis, obliquus capitis inferior, occipitoscapularis, rectus capitis major, splenius, lateral rectus, and triceps brachii. At frequencies of approximately 0.5 Hz and above, neck muscle electromyographic response gains were sinusoidal functions of stimulus orientation within a set of vertical or horizontal planes, and a muscle's response phase remained constant across rotation planes, or reversed by 180 degrees. Response patterns at high frequencies were consistent with vestibulocollic reflex activation by semicircular canals through brain circuitry that modifies canal dynamics. At frequencies of approximately 0.5 Hz and above, the stimulus orientation in which a given neck muscle's response was maximal remained nearly constant across frequencies. Thus, we used responses to rotations at high frequencies to calculate axes of maximal response of each muscle in three-dimensional space. Lateral rectus, obliquus, and to a lesser extent, splenius and longus capitus were activated predominantly by horizontal rotations. Biventer was activated predominantly by pitch, triceps predominantly by roll, and complexus, occipitoscapularis, and rectus major significantly excited by rotations in all three coordinate planes. In some cases, at frequencies less than 0.5 Hz, neck muscle response phase varied depending on the vertical plane in which the cat was rotated, and the optimal response plane was poorly defined and varied with frequency. These responses indicated that, at some frequencies, neck muscle activity can result from summation of inputs with differing spatial orientation and dynamics (spatial-temporal convergence). Differences between responses to vertical and horizontal rotations suggested that low-frequency spatial-temporal convergence behavior of the vestibulocollic reflex during vertical rotations was due to convergent semicircular canal and otolith receptor inputs.(ABSTRACT TRUNCATED AT 400 WORDS)

Prevention of alcohol-related problems in urban middle-aged males

More than 30,000 individuals have been investigated in the continuous screening and intervention study in Malmö. Large subsamples of individuals with different levels of GGT (gamma-glutamyltransferase) have been characterized. GGT has proven to be a useful and simple tool in tracing, identifying, treating and controlling heavy drinkers. Furthermore, GGT seems to be a new and strong indicator of alcohol-related disabilities and short term mortality in the male population. Individuals with GGT in the tenth deecentile of the GGT distribution have been randomly selected for treatment or control. Results and follow-up for 60 months in the intervention study with randomized controls in middle-aged heavy drinkers indicate a significant reduction in alcohol consumption, sick absence, hospitalization and mortality. Thus, the intervention program seems to be effective in preventing complications of alcoholism on an individual basis.

Use of the anterior cricoid split operation in infants with acquired subglottic stenosis

Ten infants with acquired subglottic stenosis were treated successfully using the anterior cricoid split operation. Eight had been preterm infants who required endotracheal intubation and assisted ventilation for the respiratory distress syndrome. Two had been born at term; 1 required mechanical ventilation for aspiration of meconium and the other intubation for obstructive apnea. All had been extubated successfully in less than 2 wk and were discharged home with no signs of subglottic stenosis. These infants were referred at 2 to 13 months of age for evaluation of upper airway obstruction. By bronchoscopy, we confirmed severe subglottic stenosis in each of the infants. The anterior cricoid split procedure requires a single midline vertical incision through the anterior cartilaginous ring of the cricoid cartilage and the upper 2 tracheal rings. Our postoperative management included 7 to 10 days of endotracheal intubation, mechanical ventilation, neuromuscular blockade, sedation, and total parenteral nutrition. All were extubated at the end of this period without evidence of stridor or obstructive apnea. One patient developed a subglottic granuloma at the level of the cricoid cartilage 4 months after the operation; this was successfully excised with the carbon dioxide laser. The other 9 patients remain asymptomatic 1 month to 1 yr after the surgical repair.

Spatial and temporal response properties of secondary neurons that receive convergent input in vestibular nuclei of alert cats

Responses to rotation in many vertical and horizontal planes were studied in electrically identified secondary vestibular neurons of alert cats. This report concerns secondary neurons that gave responses which could not be explained as due to a summation of semicircular canal inputs. These cells responded to sinusoidal rotation of the cat in any vertical plane, and response phase depended on the plane of rotation. The responses were modeled as the result of summation of two inputs that differed in their spatial orientations and dynamics. Response dynamics and a comparison of responses to vertical and horizontal rotations showed that some cells were sensitive to rotation with respect to gravity. Their responses both to gravity and horizontal rotations argue that these secondary neurons received convergent otolith and canal inputs. Some cells also had oculomotor related discharges and/or responded weakly to neck rotation.

Optimal response planes and canal convergence in secondary neurons in vestibular nuclei of alert cats

Responses to natural stimulation were studied in electrically identified secondary vestibular neurons of awake cats. A class of neurons was identified whose response dynamics and responses to rotations in several vertical and horizontal planes indicated that they received semicircular canal input. Each canal neuron had clearly defined planes of maximal and null sensitivity to rotation. The orientation of these planes indicated that 44% of the neurons received input from one pair of canals, 40% from two, and 16% from all 3 canal pairs. Many cells also had oculomotor-related discharges and/or responded weakly to neck rotation.

Premature mortality in middle-aged men: serum cholesterol as risk factor

Serum cholesterol as risk factor for premature mortality; 0--6, mean 3 years after a screening investigation in 10,000 middle-aged men (46--48 years at screening) was studied with respect to category of death. Serum cholesterol was reciprocally correlated to cancer deaths and to alcohol-related deaths, and strongly positively correlated to deaths in coronary heart disease. The men who died of cancer did not have lower body weight, nor was there any association with serum triglycerides. The inverse correlation to serum cholesterol did not differ between the cancer deaths occurring early, and those occurring later after screening. Part of the cholesterol/cancer death relationship may be explained by the presence of an otherwise occult malignancy at screening, but it cannot be excluded that the development of some cancers may be associated with a state of low serum cholesterol.

Comparison of gamma-glutamyltransferase and questionnaire test as alcohol indicators in different risk groups

gamma-Glutamyltransferase (gamma-GT) and a Malmö modification of the Michigan Alcoholism Screening Test (Mm-MAST) were compared in subsamples of a health screening population of urban middle aged males with characterized levels of alcohol consumption and in the total group of deaths 0-6 years after the screening investigation. The questionnaire was markedly superior to gamma-GT in identifying the alcohol consumption in the known alcoholics but not in the other study groups. gamma-GT may be indicative of alcohol related health disturbances and may be used in their early recognition and as biochemical feedback in their further treatment and control in individuals. It may therefore be of value particularly as an instrument in a programme aimed at prevention of alcohol-related health complications.

Comparison of gamma-glutamyltransferase and other health screening tests in average middle-aged males, heavy drinkers and alcohol non-users

Physical and biochemical health screening variables were compared in matched, middle-aged male samples of (a) ideological teetotallers, (b) average men, (c) self-reported alcohol abstainers, (d) low gamma-glutamyltransferase (GGT) activity, and (e-f) high GGT activity with or without admitted alcohol consumption background. The alcohol non-user groups and the individuals with low GGT had significantly lower mean values of relative body weight, pulse, systolic and diastolic blood pressure, haematocrit, serum urate, triglyceride, cholesterol, and zero and 120 min blood glucose than individuals with elevated GGT and alcohol overconsumption. The average men had intermediate levels. The frequency of increased values of the same tests was notably higher in the subjects with elevated GGT and heavy alcohol consumption than in the teetotallers and the other groups; and was lowest in the teetotallers.

Oculomotor reflexes after semicircular canal plugging in cats

The horizontal ocular reflexes of cats were studied before and after plugging all 6 semicircular canals (2 cats) or the horizontal canals only (2 cats). After plugging, the vestibulo-ocular reflex (VOR) was virtually absent in the cats with all canals plugged; a small phase-advanced VOR was detectable only at high velocities of rotation. There was no VOR recovery over several months. A compensatory cervico-ocular reflex (COR) appeared within a few days of plugging in all cats, and increased in gain slowly over time. The cats with horizontal canals plugged had little VOR during yaw rotation with the head pitched near 30 degrees down from the stereotaxic plane. When the head was pitched nose up from this null plane, a horizontal VOR appeared and increased as the sine of pitch angle, indicating that the cats relied on normal or increased coupling of vertical canals to horizontal eye movers for generation of compensatory eye movements. Periods of compensatory and anticompensatory eye movements were recorded during downward pitched yaw.

Hospitalization and alcohol-related morbidity within three years after screening in middle-aged men

All men living in Malmö who were born in 1926-1929 were invited for a health screening examination which included, among many other things, measurement of gamma-glutamyltransferase (GGT). They were followed up and within three years after the screening 963 of 4571 men had been hospitalized. They had 17158 hospital days or almost 6 days per individual each year. The impact of alcohol on the admissions was analysed both according to the International Classifications of Diseases and a new design where all the diagnoses were grouped and coded in conditions which were judged to be alcohol-related, potentially alcohol-influenced and non-alcohol-related. Of the total days in hospital, alcohol psychosis and alcoholism accounted for 13.6 per cent. Altogether 29.2% of the days were caused by alcohol-related and potentially alcohol-influenced conditions. GGT values at the screening investigation were significantly increased in 25% of the hospitalized men. Alcohol-related admissions were seven times as many in men with GGT values in the highest quintile compared with those who had values in the lowest quintile.

Cyclophosphamide, doxorubicin, vincristine, and low-dose continuous infusion bleomycin in non-Hodgkin's lymphoma: Cancer and Leukemia Group B Study No. 7804

Fifty-eight evaluable patients with non-Hodgkin's lymphoma were treated with a low dose, 120-hour continuous intravenous infusion of bleomycin in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone. Pharmacokinetic data, obtained in six patients, confirm that steady-state plasma concentrations of bleomycin can be attained even with the administration of 2 units/day of the drug. Neither clinical pulmonary toxicity nor subclinical pulmonary changes, as determined by serial measurement of the single breath carbon monoxide-diffusing capacity, were observed. Compared to similar chemotherapeutic programs utilizing bolus administration of bleomycin, pulmonary toxicity may be reduced. Response frequencies among 37 previously untreated patients were similar to those obtained using the same chemotherapeutic agents but with intravenous bolus administration of bleomycin. In addition, 18 of 21 patients who had received prior chemotherapy responded. Low dose, continuous intravenous infusion of bleomycin may improve the therapeutic index of combination chemotherapy programs for non-Hodgkin's lymphoma.

Two-hour glucose and insulin responses after a standardized oral glucose load in relation to serum gamma-glutamyl transferase and alcohol consumption

In a population study of 4,763 middle-aged men, the 120-min responses of blood glucose as well as plasma IRI in OGTTs were studied in subgroups of the screening population with different levels of gamma-glutamyl transferase (GGT) and/or defined alcohol consumption levels. In the group with low GGT (below the median, n - 2,196), both 120-min blood glucose and plasma IRI tended to be lower than in the whole screening cohort and there was a significantly smaller number of cases with 120-min blood glucose greater than or equal to 7.0 mmol/l. In a group of ideological alcohol abstainers the values of fasting as well as 120-min blood glucose were largely the same as in the average middle-aged men. In members of the study population with increased screening GGT, however, both fasting and especially, 120-min values of blood glucose and plasma IRI were higher than in the average males, particularly in the cases in which the interview revealed chronic heavy alcohol consumption as the predominant underlying factor associated with elevated GGT. In these individuals, the prevalence of 120-min screening OGTT blood glucose values greater than or equal to 7.0 mmol/l was 26%, in comparison with 13% in the average men and 9% in the individuals with screening GGT left of the median. This indicates that GGT and alcohol consumption are of clinical importance both for the results and interpretation of OGTTs.

Low cholesterol level as risk factor for noncoronary death in middle-aged men

Eighty-six deaths occurred zero to five years (mean, 2.5 years) after the screening investigation in 10,000 middle-aged men in Malmö, Sweden. The men were 47 to 50 years old at the time of the screening and represented 75% of their total birth-year cohorts in Malmö. The mortality showed two peaks, one at the higher end of the cholesterol distribution and the other and more pronounced one at the lower end of the cholesterol distribution. The first peak corresponded to the cardiovascular deaths while the second peak corresponded to the noncoronary death causes, including alcohol-related deaths.

Alcohol consumption and premature death in middle-aged men

All the men living in Malmö born in 1926-9 were invited for a screening examination which included an assessment of alcohol consumption and measurement of gamma-glutamyltransferase (GGT) activity. They were followed for up to four years (median 2) and their mortality assessed. Sixty-two deaths occurred, 41 (0.9%) among the 4571 men who attended the screening investigation and 21 (1.3%) among the 1609 who did not respond to the invitation. Evidence of alcohol abuse or an alcohol-related cause of death was present in 25 (61%) of the deaths among the attenders and 13 (62%) of those among the non-responders. GGT values at the screening investigation were significantly increased in 19 (46%) of those who died, but established risk factors, such as cholesterol and triglyceride concentrations and blood pressure, had little predictive value. Measurement of GGT provided an objective index of alcohol consumption, though the full clinical importance of a raised value needs further assessment. The finding that heavy alcohol consumption was the single most important factor associated with premature death in these middle-aged men has important implications for prevention.

Morbidity of childhood near-drowning

An assessment of morbidity in near-drowning was made from a review of emergency room and hospital records of 72 patients, ages 9 months to 20 years, who suffered near-drowning during the period January 1972 through June 1974. Fifteen patients (21% evidenced severe anoxic encephalopathy; the remainder had no detectable neurologic deficits. Hypoxemia was demonstrated in 56 patients. Severe acidosis was not present unless respiratory failure occurred. Neither electrolytes, red blood cell hemolysis, nor cardiac arrhythmias presented a problem. Respiratory complications included pulmonary edema, aspiration pneumonia, atelectasis, shock lung, pneumothorax, and pneumomediastinum. All children requiring cardiopulmonary resuscitation in the emergency room suffered anoxic encephalopathy. The occurrence of seizures, fixed and dilated pupils, flaccid extremities, and lack of response to deep pain in the emergency room had almost universal correlation with resultant severe anoxic encephalopathy, as did a submersion period of six or more minutes. The morbidity of near-drowning is significant with regard to the number of children affected and the severity of the central nervous system insult received. The statement by the American Heart Association that resuscitative efforts in children should be continued for periods longer than ten minutes needs reevaluation, since neurologic recovery did not occur in any child requiring cardiopulmonary resuscitation (CPR) in the emergency room. More importantly, new methods of cerebral resuscitation need to be developed and established. In short, medical personnel need to think in terms of cardiopulmonary cerebral resuscitation (CPCR) rather than in terms of CPR.