Thyroid hormone influence upon lung surfactant metabolism.

Thyroid administration and thyroidectomy in the rat profoundly affect the morphological characteristics of the type II pneumonocyte and the quantitative harvest of lung surfactant obtained from alveolar washings. The correlation of the ultrastructural changes with quantitative alterations in lung surfactant is evidence that the lamellar bodies within this cell are the source of the surface-active phospholipids utilized at the air-liquid interphase of lung alveoli. Our findings suggest that in the rat, L-thyroxine may be a potent regulator of lung surfactant metabolism.

The P blood group system in pigeon breeders and pigeon breeder's disease.

A blood group P1-like antigen has been found in gram-negative bacilli isolated from pigeon droppings, in pigeon serum, and on pigeon red blood cells. As a probable resident of the environment of the pigeon loft, the antigen stimulated formation of anti-P1 antibody in eight of 11 pigeon breeders who belonged to the P2 blood group. Only one of 11 random hospitalized patients with the P2 blood phenotype had a detectable titer of anti-P1 antibody (P less than 0.01). The titer of anti-P1 antibody was not significantly different in symptomatic vs asymptomatic breeders. The presence or absence of anti-P1 antibody could not be correlated with any band of immunoprecipitates formed between pigeon breeder's serum and crude extract of pigeon droppings. The P antigen was identified in pigeon-dropping extracts of breeders with the P2 blood phenotype by inhibition of hemagglutination. We conclude that anti-P1 antibodies appear to be a component of the immunologic response to avian antigens of pigeon breeders but are probably unrelated to the pathogenesis of pigeon breeder's disease.

Sociopolitical diversity in psychology. The case for pluralism.

Psychology celebrates diversity, recognizes the value and legitimacy of diverse beliefs, and strives to be inclusive. Yet, the profession lacks sociopolitical diversity. Most psychologists are politically liberal, and conservatives are vastly underrepresented in the profession. Moreover, when sociopolitical views guide the research, advocacy, or professional practice of psychologists, those views most often are liberal. The lack of political diversity in psychology has unintended negative consequences for research, policy advocacy, clinical practice, the design and implementation of social interventions, and professional education. It excludes or marginalizes conservatives and conservative views, having detrimental effects on the profession in each of these areas. This article examines the importance of political diversity and the negative consequences of its absence and provides strategies for increasing sociopolitical pluralism in psychology.

The lamellar substructure of osmiophilic inclusion bodies present in rat type II alveolar pneumonocytes.

When rat pulmonary tissues are processed as outlined in this paper, the type II cell's surfactant containing osmiophilic inclusion bodies possess a periodic substructure. This substructure consists of electron-opaque lamellae, 26 A in thickness alternating with 16 A wide electron-translucent zones.

Maturation of nerve conduction velocity and the evoked muscle potential in the dog.

Maximum nerve conduction velocity (NCV) of motor fibers in the ulnar nerve was measured in dogs ranging in age from 12 hours after birth to 32 weeks and older. The evoked muscle potential (EMP) resulting from ulnar nerve stimulation was recorded from an interosseous muscle and measured for latency, duration, and amplitude. There was a sharp increase in NCV from 6.3 +/- 0.28 m/s (mean +/- SEM) in dogs from 12 hours to 1 week of age to 59.04 +/- 1.41 m/s in dogs 32 weeks and older. The latency of the EMP, resulting from stimulating the ulnar at either a proximal or a distal site, decreased markedly after birth to 4 to 5 weeks and then more gradually until 10 to 12 weeks. In dogs between 10 to 12 weeks and 32 weeks and older, latency increased but was never as high as in the newborn. Duration of the EMP followed a similar pattern. Amplitude increased sharply with age, resulting in a final 14- to 18-fold increase by 32 weeks and older.

Failure of neuromuscular transmission after complete nerve section in the dog.

After the ulnar nerve was surgically transected, nerve conduction velocity in the distal segment and the evoked motor unit potential (EMUP) from the interosseous muscle were recorded until neuromuscular transmission failed. In five of the six dogs in the experiment, functional conduction ceased by 4.8 days, as determined by failure of both proximal and distal stimulation of the distal segment to evoke a muscle response. From the time of section until neuromuscular failure, the nerve conduction velocity remained unchanged. The amplitude of the EMUP from the interosseous muscle, however, decreased markedly during this time. Changes in other features of the EMUP are also presented. Fibrillation (denervation) potentials did not appear until the first day that muscle response could not be detected by stimulating the nerve. These data present a principle which would enable a determination of relative extent and progression of peripheral nerve damage.

Sensory nerve conduction velocity of cutaneous afferents of the radial, ulnar, peroneal, and tibial nerves of the cat: reference values.

The mean conduction velocities of the compound action potentials of sensory axons of the cutaneous branches of the radial, ulnar, peroneal, and tibial nerves of the healthy cat were determined by cutaneous stimulation and recorded by averaged evoked response technique. Locations for both stimulation and recording electrodes were identified. Mean conduction velocities were: radial nerve, 83.6 +/- SD 8.3; ulnar nerve, 89.2 +/- 10.3; peroneal nerve, 85.3 +/- 6.8; and tibial nerve, 80.2 +/- 7.9 m/s.

Characteristics of F and H waves of ulnar and tibial nerves in cats: reference values.

The latencies and latency rates of H and F waves were determined by percutaneous stimulation of the ulnar and the tibial nerves of healthy cats. In the ulnar and tibial nerves, the latency rates of H wave evoked compound action potentials were 49.1 +/- 7.3 and 44.1 +/- 2.7 m/s, respectively, and of F waves were 68.1 +/- 9.6 and 57.1 +/- 6.2 m/s, respectively. The H wave response of cats was more variable in latency and amplitude than that reported in the dog.

Spinal-evoked potentials in dogs with acute compressive thoracolumbar spinal cord disease.

Spinal evoked potentials (SpEP) were recorded on an electromyograph from electrodes placed percutaneously in the ligamentum flava at the lumbosacral junction and between the 10th and 11th thoracic vertebrae following tibial nerve stimulation in 31 anesthetized dogs with acute compressive spinal cord injuries. The neurologic status of each dog was determined by clinical examination before SpEP recordings, and the neurologic status was monitored for 2 months in dogs that had surgical or conservative treatment. Two months after spinal injury, the response to treatment (outcome) of each dog was evaluated and graded as favorable (ambulatory and urinary continent) or unfavorable (nonambulatory, urinary incontinent, or euthanatized with confirmation of myelomalacia). Onset latencies, conduction velocities, amplitudes and durations of the wave forms, and the ratio of conduction velocity to combined durations of the first positive (P1) and first negative (N1) waves (CV/DPN index) were determined and were compared with reference data from clinically normal (control) dogs. Single SpEP recordings were of value in determining the prognosis for recovery. Significant differences were not found in the L7-S1 recordings between the reference (control) and spinal injury groups. Analysis of data from the T10-11 recordings indicated significant differences between the reference and spinal injury groups and between the favorable and unfavorable outcome groups within the spinal injury group. A CV/DPN index was less than 30 in dogs with unfavorable outcomes and greater than 30 in dogs with favorable outcomes. Stepwise discriminant analysis of data from the spinal injury group predicted outcome correctly in all dogs.

Sensory nerve conduction velocity of cutaneous afferents of the radial, ulnar, peroneal, and tibial nerves of the dog: reference values.

The mean conduction velocities of the compound action potentials of sensory axons of the cutaneous branches of the radial, ulnar, peroneal, and tibial nerves of the healthy dog were determined by cutaneous stimulation and recorded by averaged evoked response technique. Locations for both stimulation and recording electrodes were identified. Mean conduction velocities were: radial nerve = 65.1 +/- 6.2; ulnar nerve = 69.4 +/- 6.9; peroneal nerve = 64.4 +/- 5.25; and tibial nerve = 63.4 +/- 5.3 m/s +/- SD.

Effects of xylazine and ketamine hydrochloride on the electroencephalogram and the electrocardiogram in the horse.

A continuous series of electroencephalograms (EEG) was obtained from each of 6 mature horses which had been given xylazine and ketamine hydrochloride IV. Electrocardiograms and respiratory rates were also obtained. The EEG of the unsedated standing adult horse displayed a dominant fast activity in the range of 25-35 Hz, 5-30 microV superimposed over slower 1-4 Hz, 10-50 microV activity with occasional 10-14 Hz, 10-40 microV spindle-type activity. The xylazine-sedated horse displayed hypersynchronous EEG patterns, with the dominant activity being 1-3 Hz, 10-70 microV with overlying mixed frequencies of 5-10 Hz, 10-40 microV and 10-14 Hz, 10-40 microV spindle-type activity. Some 25-35 Hz, 5-10 microV activity was present in 5 of the 6 horses. Ketamine administration 3 minutes after xylazine injection caused an increase in high-voltage slow activity. The dominant frequency was 1-3 Hz, 20-100 microV, with superimposed mixed irregular frequencies of 6-10 Hz, 10-50 microV and 10-14 Hz, 10-40 microV spindle-type activity. All horses developed some degree of second-degree atrioventricular (AV) heart block approximately 23 s after xylazine was injected. The second-degree AV heart block disappeared approximately 1 minute and 30 s after ketamine was injected in 4 of the 6 horses. The remaining 2 had second-degree AV heart block throughout the recording period (15 to 18 minutes). Respiration rates were depressed after xylazine was given and became irregular and apneustic after ketamine injection. The cyclic rate of respiration varied from 19 to 30 breaths/minute. Xylazine depressed heart rates from 13% to 41% (mean 29.3%). Heart rates became faster or remained unchanged after ketamine was administered.

Motor nerve conduction velocity and latency in the dog.

Supramaximal percutaneous nerve stimulation was used in motor nerve conduction velocity studies conducted in ten middle-aged, clinically normal dogs. Dogs were separated into two groups; dogs in one group weighted less than or equal to 7.5 kg and dogs in the other group weighted greater than or equal to 15.9 kg. Mean values and SEM were recorded for radial (72.1 +/- 1.9 m/s), median 65.6 +/- 2.1 m/s), ulnar (58.9 +/- 1.0 m/s), tibial (68.2 +/- 1.4 m/s), and peroneal (79.8 +/- 1.8 m/s) nerves. Values for latency, amplitude, and duration for proximal and distal evoked potentials were recorded. Analysis of mean nerve conduction velocity values for all nerves between the two groups indicated no statistical difference (P greater than 0.05). However, the two groups were statistically different (P less than 0.05) when values for distal latency and measurements of nerve length were compared. These data suggest that if latency is substituted for velocity measurements, various populations of dogs must be considered to clarify interpretation.

Effects of fentanyl citrate and droperidol on electroencephalographic findings in dogs.

Electroencephalograms were recorded from 10 dogs before, immediately after, and every 10 minutes (for 60 minutes) after IV injection of 0.005 ml of a fentanyl citrate and droperidol combination/kg of body weight. Narcosis was adequate for recording. At 30 to 40 minutes after injection, tail wagging was the only adverse reaction (EEG artifact) observed. The only changes in EEG activity observed were a slight increase in amplitude of the dominant activity and an increase in spindle-like activity. Daily repetition for 5 days did not alter the EEG pattern or the behavior of the dogs.

Spinal-evoked potentials and spinal conduction velocity of the cat: reference values.

Spinal conduction velocities of the fastest afferent fibers of the spinal cord were calculated from the onset latencies of averaged evoked responses elicited by stimulation of the tibial nerve sensory afferent fibers and were recorded at various sites on the spinal cord. Locations for stimulation and recording electrodes were identified. Waveforms, mean amplitudes, and duration of the evoked spinal potentials were described. The mean conduction velocity of the spinal cord afferents at T12-T13 was 74.25 m/s with a SD of +/- 9.81 m/s. The mean conduction velocity of the spinal cord afferents, determined at the cisterna magna, was 80.66 m/s with a SD of +/- 11.50 m/s. This is a slight increase over the spinal conduction velocity at T12-T13 (P = 0.05).

Experimental hemorrhage in splenectomized and nonsplenectomized dogs.

Ten splenectomized and ten nonsplenectomized conscious dogs were subjected to hemorrhage of 41% of their blood volume over a 15-minute period. Hemodynamic and metabolic variables were monitored for 4 hours after hemorrhage. Mortality (100%) occurred in the splenectomized group. Significant (P < 0.001) hemodynamic responses after hemorrhage included hypotension, tachycardia, low central venous pressure, and decreased ECG voltage of the R wave. Tachypnea was noted in the absence of hypoxia, hypercapnia, and acidosis inthe nonsplenectomized dogs. Significant (P < 0.001) hypocapnia and mean PCO2 values of 13.9 MM of Hg and 23.5 mm of Hg in splenectomized and nonssplenectomized dogs, respectively, was noted. Mean hemoglobin levels were significantly (P < 0.001) decreased after hemorrhage in the splenectomized dogs. The absence of a change in hemoglobin in thenonsplenectomized dogs was attributed to the translocationof extracellular fluid into the vascular space which diluted the high concentration of RBC from splenic contraction. Other changes noted after hemorrhage were hyperglycemia, increased blood cortisol, and increased pyruvate and lacte levels. Changes were not noted in pyruvate-to-lactate ratios.

Electroencephalographic patterns of clinically normal, sedated, and tranquilized newborn foals and adult horses.

To establish a clinically practical procedure for recording the equine EEG, 25 healthy adult horses and 6 newborn foals were used. Recordings were taken with the animals alert and tranquilized, confined in metal stocks, or physically restrained. The dominant alert waveforms of adult horses were fast activity (25 to 40 Hz) with medium-to-low voltages (5 to 40 microV-dominant 10 to 15 microV). Underlying this fast activity was slower (0.5 to 4.0 Hz) activity with medium-to-low voltages (10 to 40 microV). Twelve of the 25 adult horses had EEG frequencies in the alpha frequency range (10 to 15 Hz, 10 to 50 microV). Eight horses were given xylazine and 17 were given acetylpromazine. Those given xylazine had generalized slowing with several distinct frequency patterns (25 to 40 Hz, 5 to 30 microV; 10 to 15 Hz, 10 to 80 microV; and 0.5 to 4.0 Hz, 10 to 90 microV). Horses given acetylpromazine had fast activity (25 to 40 Hz) with medium-to-low voltages (5 to 40 microV). Underlying this activity were slower waveforms (1 to 4 Hz) with medium-to-low voltages (5 to 10 microV). Occasional well-formed spindle activity was observed (10 to 14 Hz, 10 to 50 microV). Acetylpromazine had little effect on the EEG recording, whereas xylazine exerted a substantial effect. All leads were synchronous with lower voltages in the left frontal, right frontal, and transfrontal leads. The alert pattern of a newborn foal was characterized by low frequency (2 to 6 Hz) with medium-to-high voltages (20 to 90 microV).(ABSTRACT TRUNCATED AT 250 WORDS)

Sensory nerve conduction velocity of the dorsal penile nerves of bulls.

Mean conduction velocity of sensory axons of the dorsal penile nerves of clinically normal bulls was determined by recording action potentials evoked by cutaneous stimulation. Locations of stimulating and recording electrodes were standardized. Overall mean +/- SD conduction velocity was 55.1 +/- 5.1 m/s. Mean +/- SD velocity recorded from the distal electrode was 53.3 +/- 4.9 m/s; velocity recorded from the middle electrode was 55.3 +/- 5.0 m/s; and velocity recorded from the proximal electrode was 56.7 +/- 5.1 m/s. Differences among means were not significant. Four bulls had mean conduction velocities of 54.0 m/s and 48.4 m/s before and 3 weeks after castration, respectively.

Granulomatous meningoencephalomyelitis in six dogs.

An acute progressive CNS disease characterized by fever, nystagmus, head tilt, facial paralysis, circling, and cervical pain was studied in 6 mature dogs. The term "granulomatous meningoencephalomyelitis" was proposed for the disease complex, which was characterized pathologically by disseminated granulomatous lesions having a predilection for brainstem structures.

Depressed thyroid function in two tetraplegic dogs.

Rapidly progressing tetraplegia developed in two 6-year-old dogs, both of which had eaten decayed meat sometime during the 24 hours prior to the onset of paralysis. Both dogs were found to have depressed thyroid function, as indicated by extremely low triiodothyronine (T3) and thyroxine (T4) values. Electromyographic studies revealed some abnormal insertional activity but no abnormal potentials when the fore- and hindlimb muscles were at total rest. Nerve conduction velocity was slightly depressed in 1 of the dogs and severely depressed in the other. Recovery was complete in less than 3 weeks in 1 dog, but the other dog was not completely recovered when placed under the owner's care 2 1/2 months after admission.

Myotonia congenita in a Chow Chow pup.

Myotonia congenita was diagnosed in a 12-week-old female Chow Chow that had hindlimb ataxia, a stiff gait, and occasional collapsing. The diagnosis was based on the history, clinical signs, electrodiagnostics, and microscopic examination of biopsied muscle specimens.