Passion and cadence: a commentary on the report to the Congress of the United States by the Office of Technology Assessment entitled Adolescent Health.
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Adolescent↗
Biomedical subjects
M I Cohen
Publications and source records attributed to M I Cohen.
Weakness of short-term synchronization among respiratory nerve activities during fictive vomiting.
In decerebrate, paralyzed cats, phrenic (PHR) and lumbar abdominal (ABD) nerve discharges during both neural respiration and fictive vomiting (FV) were subjected to spectral and coherence analyses. During respiration, PHR discharge exhibited high-frequency oscillation (HFO), manifested as a narrow spectral peak (range 57-90 Hz) in autospectra and left-right coherence spectra. During FV, the following occurred: 1) the HFO peak disappeared and was replaced by a broad peak with higher modal frequency (range 84-120 Hz), indicating elimination of inputs from the medullary inspiratory pattern generator. 2) Left-right PHR coherence spectra had no distinct peaks, indicating that correlations between opposite PHR discharges were now not frequency specific. 3) Although ABD and PHR autospectra were similar, PHR-ABD coherences were near zero, indicating lack of common inputs on a short time scale. 4) Nonzero coherences between ABD nerves were confined to ipsilateral pairs. Thus coherence analysis indicates that the outputs of the vomiting pattern generator are temporally dispersed on a short time scale and are not necessarily common to different motoneuron populations.
Abdomen↗
The pediatrician's role in the diagnosis and treatment of substance abuse.
Abuse of drugs and alcohol is pervasive in our society. The role of the pediatrician as a health-care provider from birth through young adulthood includes recognizing the stigmata in newborns of prenatally ingested drugs as well as being able to treat neonatal drug withdrawal syndromes. Questioning about drug use and other closely related topics should be incorporated into all health-care maintenance visits, starting at the age of 10 y, with parental participation and anticipatory guidance being offered. Physical examination and laboratory testing are not as helpful in confirming an impression of substance abuse as a comprehensive interview and a full appreciation of the warning signs of substance abuse. Treatment of the problematic user with a multidisciplinary team that understands adolescent development and behavior as well as the problem of substance abuse is crucial. The decision to treat the teen in an ambulatory or inpatient setting is determined by the extent of abuse, underlying medical problems and psychopathology, and the degree of family dysfunction. The pediatrician must not avoid addressing these issues with patients. If, however, upon identifying an adolescent or a newborn with a drug problem, the pediatrician feels uncomfortable or ill-prepared to manage the patient, appropriate professional referrals are warranted. Despite exercising the referral option for treatment, as advocate for child and family, the pediatrician remains professionally bound to track all drug abuse-related referrals while continuing to participate in the general ongoing care of the patient and family. Finally, the pediatrician should retain a public advocacy role in the community by offering educational, preventive, and supportive efforts in the continuing struggle against drug abuse.
Adolescent↗
Adolescent health: is it now on the nation's agenda?
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Adolescent↗
Predicting success on conditional release for insanity acquittees: regionalized versus nonregionalized hospital patients.
This research compared the outcomes of two cohorts of insanity acquittees: one group was treated solely in the maximum security state forensic hospital before their release to the community (nonregionalized) and the other group was treated at the state forensic hospital and transferred for further treatment at less secure state regional hospitals (regionalized). This research describes the outcome of a group of insanity acquittees (regionalized patients) never previously studied. The applicability of a prediction model based on earlier research of insanity acquittees was tested on the patients. Findings on four outcome indicators are reported: rearrests within five years after release, overall functioning in the community five years after release, rehospitalizations for mental illness, and successful completion of the terms of the five-year conditional release (nonrevocation). Discriminant analysis was performed on the four outcome variables. The model was found to accurately predict the four types of outcome from 69 percent to 94 percent accurately for the nonregionalized insanity acquittees and from 87.5 percent to 95.8 percent for the regionalized patients. This model is currently being adapted to classify patients into potential high- and low-risk groups at the time of conditional release for the purpose of determining the intensity of outpatient supervision.
Cohort Studies↗
Fast rhythms in phrenic motoneuron and nerve discharges.
1. Fast rhythms in discharges of individual phrenic (PHR) motoneurons were studied by spectral and interval analyses; and they were compared, using coherence analysis, with similar rhythms in whole-PHR nerve discharge. The purpose of this study was to ascertain the origin of the two rhythms, manifested as distinct spectral peaks, in PHR motoneuron and nerve discharge: medium-frequency oscillations (MFO, usual range 20-50 Hz); and high-frequency oscillations (HFO, usual range 50-100 Hz). 2. In paralyzed artificially ventilated cats, unit recordings were taken from 1) 26 isolated single PHR fibers (in 8 sodium pentobarbital-anesthetized cats) and 2) 27 identified PHR motoneuron somata in the spinal cord (in 5 decerebrate cats). Simultaneous whole-PHR activity was monophasically recorded from the contralateral PHR nerve for 1 and from both PHR nerves for 2. 3. The signals were subjected to time- and frequency-domain analyses. The latter included a novel application of coherence analysis to the study of population synchrony. 4. The autospectra of all PHR units showed prominent MFO peaks in the frequency range of the nerve MFO spectral peaks, as well as harmonic peaks, indicating the presence of this type of fast rhythm in the units' discharges. Spectral analysis of the augmenting PHR activities in different segments of the inspiratory (I) phase showed that the frequency of unit MFO and of nerve MFO rose during the course of I. Further, cycle-triggered histogram and interval analysis indicated that the frequencies of unit MFO autospectral peaks were very close to the peak firing rates of the units during the portion of I analyzed. Thus unit MFO spectral peaks reflected the rhythmic and augmenting discharges of the motoneurons, and similar nerve MFO peaks reflected the superposition of individual motoneuron discharges. 5. The coherences of motoneurons' MFOs to nerve MFOs were low or zero, indicating that only partial and weak MFO correlations occurred within the PHR motoneuron population. 6. In those cats (n = 11) that had clear PHR nerve HFO spectral peaks, about one-half of the recorded PHR motoneurons had HFO, as indicated by HFO peaks in the unit autospectra and/or the unit-nerve coherences. 7. For motoneurons having HFO, the coherence between unit and nerve HFOs was substantial, particularly when the latter were strong, indicating HFO correlations among a number of PHR motoneurons. 8. In the light of theoretical considerations on the generation of aggregate rhythms from superposition of unitary rhythms, these observations indicate the following.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Progression of experimental infantile hydrocephalus and effects of ventriculoperitoneal shunts: an analysis correlating magnetic resonance imaging with gross morphology.
Although previous ultrasonographic studies did monitor ventricular enlargement successfully in experimentally-induced models of feline hydrocephalus, the resolution of neuroanatomic detail was relatively poor after placement of a ventriculoperitoneal (VP) shunt because the skull had ossified over the coronal sutures. Therefore, the present study employed magnetic resonance imaging to follow the progression of ventriculomegaly more accurately, as well as to evaluate the compensatory effects of VP shunting. Hydrocephalus was induced in kittens between 7 and 10 days old by injection of kaolin into the cisterna magna. Age-matched controls received similar injections of saline. At 9 to 14 days after the kaolin injection, the hydrocephalic animals received VP shunts. Anesthetized kittens were scanned at various intervals before and after shunt placement and were killed for morphological correlation. The features observed on the magnetic resonance imaging scans were consistent with the gross morphological changes that accompanied ventricular enlargement. The lateral ventricle began to enlarge as early as 1 day after the kaolin injection, and within 3 days, both the occipital and temporal horns, along with the 4th ventricle, showed signs of moderate dilatation. By 5 days, a bilateral communication had been established through the septum pellucidum. Continued expansion of the ventricular system occurred from 6 to 20 days after injection, to the point where the cerebral cortex was reduced to less than 25% of its original thickness. The internal capsule was stretched and edematous, the caudate nucleus was compressed ventrolaterally, and the cerebellar hemispheres were eroded and/or compressed. Animals in which shunts were successfully placed demonstrated a dramatic improvement in behavior, and a reduction of about 50% in the size of the lateral ventricles within 2 days. In some cases, the lateral ventricles became slit-like within 1 week. When they were killed, about half of the animals that received shunts exhibited mild to moderate ventriculomegaly. These results indicate that magnetic resonance imaging is an excellent method for visualizing the morphological changes associated with this animal model, that these alterations occur soon after the onset of hydrocephalus, and that VP shunting can successfully reduce ventriculomegaly.
Animals↗
Effects of contralateral superior laryngeal nerve stimulation on dorsal medullary inspiratory neurons.
The effects of superior laryngeal nerve (SLN) stimulation on phrenic (PHR) nerve activity and on activity of dorsal respiratory group (DRG) inspiratory (I) neurons contralateral to the stimulus were examined in decerebrate, paralyzed cats. Stimulation caused bilateral PHR suppression followed by recovery at ca. 30 ms. Most DRG neurons (70%) contralateral to the stimulus were inhibited, but average onset of inhibition lagged that of PHR suppression. This contrasts sharply with the observation in an earlier study that inhibition of ipsilateral I neurons on the average preceded PHR suppression. The remaining neurons (30%) were not inhibited. Only 22% of contralateral neurons were excited by SLN stimulation, in contrast to 52% of ipsilateral neurons. Thus, contralateral DRG I neurons do not mediate the onset of bilateral PHR suppression by SLN stimulation and are probably inhibited through a longer pathway than that for the ipsilateral unit responses.
Action Potentials↗
Dorsal medullary inspiratory neurons: effects of superior laryngeal afferent stimulation.
In decerebrate paralyzed cats ventilated with a cycle-triggered pump, we examined the responses of inspiratory (I) neurons in the region of the ventrolateral nucleus tractus solitarius (NTS) to single electrical stimuli delivered to the ipsilateral superior laryngeal nerve (SLN). Sixty-five I neurons were classified as: I(-), I(0), I(+, early), I(+, late) or I(other) on the basis of responses to lung inflation, and as I(bulbophrenic) or I(non-bulbophrenic) on the basis of evidence of an excitatory projection to the contralateral phrenic motoneuron pool. The peristimulus histograms of contralateral phrenic activity showed an early peak of excitation with average latency of 4.9 +/- 0.1 ms (mean +/- S.E.M.), followed by depression at 7.3 +/- 0.2 ms, start of recovery from depression at 22.7 +/- 1.0 ms, and recovery to control levels at 28.4 +/- 1.1 ms. The peristimulus histograms of ipsilateral I unit activity showed an initial excitation (latency 2.9 +/- 0.3 ms), followed by spiking silence (latency 6.0 +/- 0.6 ms) and recovery to control discharge frequency at 38.8 +/- 3.6 ms. This time of inhibition was significantly longer than the time of phrenic depression, suggesting that other bulbophrenic excitatory projections are able to rapidly compensate for decreased NTS output. Subgroups of I neurons, as classified by lung inflation tests, did not differ significantly with respect to these timing variables. In contrast, latencies of excitation for I(bulbophrenic) neurons were significantly less than for I(non-bulbophrenic) neurons.
Action Potentials↗
Inspiratory-modulated neurons of the rostrolateral pons: effects of pulmonary afferent input.
In decerebrate, paralyzed cats ventilated with a cycle-triggered pump, firing of inspiratory (I) and I-modulated neurons in the pontine respiratory group was markedly increased by withholding lung inflation, indicating strong inhibition by lung afferents. Spectral analysis showed that only a small minority of I-modulated neurons had high-frequency oscillations (HFO), in contrast to medullary I neurons, indicating that the pontine neurons are not closely linked to medullary I networks.
Action Potentials↗
Changes in frequency content of inspiratory neuron and nerve activities in the course of inspiration.
In decerebrate paralyzed cats, the spectra and coherences of inspiratory (I) nerve activities and of medullary I neuron discharges were compared between different stages of I. The correlated high-frequency oscillations (HFOs) in the activities had common time courses of frequency and strength, which were influenced by lung afferent input; whereas the time courses for the uncorrelated medium-frequency oscillations (MFOs) depended on individual activity patterns. These results indicate that HFOs are characteristic of the common I pattern generator, whereas MFOs are specific to individual activities.
Action Potentials↗
Patient care, resident stress, and government regulation.
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Humans↗
Follow-up after release of insanity acquittees, mentally disordered offenders, and convicted felons.
The authors compared 127 insanity acquittees in the state of Maryland with a matched prisoner control group of 127 convicted felons and a comparison group of 135 mentally disordered prisoners transferred for hospital treatment. Subjects were followed from five to 17 years after discharge from hospital or release from prison. Subsequent arrests, hospitalizations, employment, and functioning of these large cohorts were studied and compared. The study focused on outcome data at five years after release. The authors found that, at five years postrelease, 54.3 percent of the insanity acquittees, 65.4 percent of the prisoner control group, and 73.3 percent of the mentally disordered prison transfers were rearrested. At 17 years postrelease, rearrest rates increased to 65.8 percent of the insanity acquittees, 75.4 percent of the prisoner controls, and 78.4 percent of the prison transfers. Significantly more mentally disordered prison transfers than NGRIs were rehospitalized during the follow-up period. Overall, the prison transfers had significantly poorer outcomes on nearly all variables studied compared with the other two groups. The authors conclude that although there were a substantial number of rearrests among insanity acquittees, that group had a statistically significantly lower rate of criminal activity compared with the other two groups of offenders.
Adult↗
Fast rhythms in the discharges of medullary inspiratory neurons.
The discharges of 44 medullary inspiratory (I) neurons in decerebrate paralyzed cats were studied using interval and spectral analysis. Most neurons had a rhythm in their discharge. In 31 the rhythm was at the frequency of, and coherent to, the high-frequency oscillations (HFOs) of I nerves, and in 7 the rhythm was in the range of medium-frequency oscillations (MFOs), with no coherence to nerve MFOs. Thus, correlated HFOs are characteristic of the I system at all levels, whereas MFOs are uncommon in medullary neurons and seem to be unrelated to general mechanisms.
Action Potentials↗
Third-trimester fetal sonography: meconium simulating a presacral mass.
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Adult↗
Abdominal fluid collections: percutaneous aspiration and drainage.
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Ascitic Fluid↗
Hypoventilation caused by ventilator valve rupture.
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Adult↗
High-frequency and medium-frequency components of different inspiratory nerve discharges and their modification by various inputs.
In decerebrate paralyzed cats, spectral analysis was performed on simultaneous recordings of efferent inspiratory nerves (phrenic, recurrent laryngeal, hypoglossal). Spectral peaks were present both in the high-frequency (HFO) range (50-100 Hz) and the medium-frequency (MFO) range (20-50 Hz). Different activities were coherent only in the HFO range, indicating that the HFOs arise in a common inspiratory pattern generator that drives the different motoneuron populations, whereas the MFOs are specific to different systems.
Animals↗