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Biomedical subjects

M I Cohen

Publications and source records attributed to M I Cohen.

At least 55 records · Page 3Linked to original sources
PubMed1989

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↗
PubMed1988

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↗
PubMed1987

Intracellular potentials and discharge patterns of expiratory neurons in the caudal ventral respiratory group: influence of phasic pulmonary afferent input.

In decerebrate paralyzed cats, the membrane potential (MP) patterns of 12 augmenting expiratory (E) neurons in the caudal ventral respiratory group, and phrenic and recurrent laryngeal activities, were compared for inspiratory (I) phases with and without lung inflation. No-inflation produced, in the MPs of E neurons, larger hyperpolarization during I and during early E (associated with increased early-E laryngeal activity), suggesting an increase of inhibitory inputs from I neurons and early-E neurons, respectively.

Action Potentials↗
PubMed1987

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↗
PubMed1986

A comparison of techniques for improved visualization of the arteries of the distal lower extremity.

Intraarterial prostaglandin E1, tolazoline, nitroglycerin, and tourniquet-induced reactive hyperemia were directly compared by paired analysis for their efficacy in improving visualization of distal lower extremity vessels during routine arteriography in 101 limbs (52 patients). Nitroglycerin and reactive hyperemia were equal in their effect and statistically superior to both tolazoline and prostaglandin E1. Tolazoline was superior to prostaglandin E1, which had little or no effect. Intraarterial nitroglycerin in a dose of 200 micrograms appears to be the method of choice for augmenting visualization of the distal arterial vascular system in lower-extremity arteriography.

Alprostadil↗
PubMed1985

Value of computed tomography in the detection of complications of Crohn's disease.

Abdominal and pelvic computed tomography (CT) scans were performed on 17 patients with suspected complications of Crohn's disease. CT was superior to conventional barium studies and colonoscopy in demonstrating mural, serosal, and mesenteric pathology such as bowel wall thickening (100%), abscess (59%) and phlegmon (6%) formation, and fibro-fatty proliferation of the mesentery (41%). While not advocated as the primary means of evaluating Crohn's disease, CT can provide information vital to the management of complications of this disease.

Abscess↗
PubMed1985

Responses of early and late onset phrenic motoneurons to lung inflation.

In anesthetized or decerebrate cats that were paralyzed and ventilated with a cycle-triggered pump, we produced changes in activity of the whole phrenic nerve and of individual phrenic motoneurons (fibers or cells in the spinal cord) by withholding lung inflation during the inspiratory (I) phase. The neurons were classified into early- and late-onset types (discharge onset less or greater than 80 msec, respectively, after whole phrenic onset). Both unit and whole phrenic activity exhibited a variety of responses to inflation (excitation, depression, or no effect); but there were no consistent differences between responses of early- and late-onset neurons. The distribution of responses was quite different from that of dorsal respiratory group (DRG) I neurons (Cohen and Feldman, 1984); in particular there was no group of phrenic neurons corresponding to the late-onset I-beta neurons (I neurons excited by inflation). We conclude that the inputs to late-onset phrenic neurons are not predominantly or exclusively from late-onset DRG neurons.

Animals↗
PubMed1985

Responses of recurrent laryngeal motoneurons to changes of pulmonary afferent inputs.

In decerebrate, paralyzed cats ventilated with a cycle-triggered pump, the discharges of the recurrent laryngeal (whole nerve or single fibers) and phrenic nerves, and the changes produced by pulmonary afferent inputs (lung inflation), were compared. When lung inflation was in phase with neural inspiration, four types of laryngeal fiber activities were observed: (a) phasic-inspiratory; (b) tonic-inspiratory; (c) expiratory-inspiratory; (d) early-expiratory. The firing patterns during inspiration were plateau-like, whereas the phrenic pattern was augmenting. When inflation was withheld, the plateau patterns usually became augmenting, indicating inhibition of laryngeal inspiratory activity by pulmonary afferents. Secondary effects of withholding inflation were (a) increases of early-expiratory activity (both whole nerve and individual fiber), indicating increased post-inhibitory rebound excitation; (b) decreased activity of tonic-inspiratory and expiratory-inspiratory fibers during early neural expiration, indicating increased inhibition by early-expiratory neurons. The discharge patterns of different types of laryngeal motoneuron, as well as their changes with inflation, are interpreted in relation to the function of regulating airway resistance.

Afferent Pathways↗
PubMed1985

Benign breast lesions with malignant clinical and mammographic presentations.

Nine cases of benign breast disease in which mammograms had been false-positive were collected at Northwestern Memorial Hospital. In all but one case the patients had presented initially with questionable masses that required biopsies with requests for frozen section diagnoses. Included in the study were three cases of indurative mastopathy, three cases of fibrocystic disease with sclerosing adenosis, and one case each of sclerosing papillary proliferation, infarcted intraductal papilloma, and fat necrosis with foreign body giant cell reaction. The mammographic and histologic findings for all cases were reviewed. Indurative mastopathy is a poorly known entity with radiologic features highly suggestive of malignancy. As described previously (Cancer 47:561, 1981), the lesion consists of a central nidus of elastosis with irregular projections radiating into the adjacent breast tissue. Peripheral areas of the infarcted papilloma and sclerosing papillary proliferation could be confused with infiltrating carcinoma in frozen sections. Familiarity of pathologists with these lesions is essential for avoiding the overdiagnosis of carcinoma.

Adult↗
PubMed1985

Caudal medullary expiratory neurone and internal intercostal nerve discharges in the cat: effects of lung inflation.

In midcollicular decerebrate, thoracotomized, paralysed cats that were ventilated by a cycle-triggered pump and had an expiratory load, recordings were taken from expiratory neurones in the nucleus retroambigualis of the caudal medulla and from the internal intercostal nerves at T8-T9 levels. Expiratory neurone and internal intercostal activities had augmenting patterns of two types: (a) step-ramp (one-third of the neurones): a large initial increase of activity synchronous with inspiratory termination, followed by a ramp increase throughout the expiratory phase; (b) ramp (two-thirds of the neurones): a steady rise of activity without a sharp initial increase, discharge usually starting after a delay (as much as several hundred milliseconds) from the onset of expiration. Both types of unit pattern could occur together with each type of internal intercostal pattern. At the end of expiration, unit activity shut off abruptly just prior (0-120 ms) to the onset of phrenic discharge. The effects of pulmonary afferent discharge on unit and internal intercostal activities were evaluated by use of inflation tests: withholding inflation during the preceding inspiratory phase; maintaining inflation at the end-inspiratory level during expiration. Both tests produced lengthening of expiratory phase duration (TE), but their effects on activity differed. Following no-inflation during inspiration, the discharge onset delay was lengthened for most ramp neurones, but for only a minority of step-ramp neurones; the slope of activity augmentation did not change on the average; and the peak (end-expiratory) discharge frequency was only slightly increased. The predominant effect of maintained expiratory inflation was reduction of activity slope for ramp neurones and for a minority of step-ramp neurones, as well as increase of peak frequency; there was a moderate increase of discharge onset delay for ramp neurones, but not for step-ramp neurones. The lengthening of TE produced by no-inflation in the preceding inspiration was associated with lengthening of the durations of both the discharge onset delay and the discharge burst, but there was no correlation between changes of these two variables. We observed a 'reversal phenomenon': moderate inflation facilitated activity, whereas higher inflation levels depressed activity, as demonstrated by: comparison of effects of maintained expiratory deflation (removal of the expiratory load) and of maintained expiratory inflation, both of which reduced activity; comparison of effects of phasic expiratory inflations having different magnitudes.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1985

Indurative mastopathy: a cause of false-positive mammograms.

Indurative mastopathy is a benign, elastotic lesion of the breast characterized by a stellate appearance, with surrounding compressed and distorted ducts causing a pseudo-infiltrative pattern. In previously reported cases of benign sclerosing lesions of the breast there has been no evidence of local recurrence of metastasis following excisional biopsy. The significance of identifying indurative mastopathy lies in recognizing its benign nature despite clinical, radiographic, and gross histologic features that are indistinguishable from malignancy, thereby saving the patient additional surgery or radiotherapy once an excisional biopsy has been performed.

Adult↗
PubMed1985

Mammography in women less than 40 years of age.

Carcinoma of the breast in women less than 40 years old is a significant problem, representing 7.4 per cent of the total number of carcinomas of the breast at our institution. It is apparent that mammography in this age group is of value in confirming the clinical suspicion of a malignant condition of the breast and in evaluating the remainder of the parenchyma of the breast for clinically occult lesions. However, one cannot over emphasize that a negative result from the mammogram should not delay biopsy in the presence of clinically suspicious lesions (1, 4). It is obvious that a larger series of patients is necessary to define the role of mammography in "young women."

Adult↗
PubMed1984

Hypoglossal motoneuron responses to pulmonary and superior laryngeal afferent inputs.

In decerebrate, paralyzed cats ventilated with a cycle-triggered pump, the inspiratory discharges of the hypoglossal (whole nerve or single fibers), phrenic, and recurrent laryngeal nerves were compared, and the effects of pulmonary and superior laryngeal afferent inputs were observed. During lung inflations in phase with neural inspiration, hypoglossal and recurrent laryngeal activities differed from phrenic with respect to (a) burst onset times: both preceded the phrenic; (b) overall pattern: phrenic, augmenting; hypoglossal, decrementing; recurrent laryngeal, plateau-like. When inflation was withheld, the phrenic pattern was not markedly changed, but both hypoglossal and recurrent laryngeal became augmenting; the marked increase of hypoglossal activity (both whole nerve and single fiber) indicated strong inhibition by lung afferents. Superior laryngeal electrical stimulation evoked excitation of the contralateral phrenic (latency 4.1 msec) and the ipsilateral whole hypoglossal (latency 5.3 msec), followed by bilateral inhibitions (durations 20-30 msec); most hypoglossal fibers showed only inhibition. We conclude that, although both hypoglossal and phrenic outputs are driven by the inspiratory pattern generator(s), their promotor systems differ with respect to influences from central and peripheral inputs.

Afferent Pathways↗
PubMed1984

Special considerations for the health care of adolescents with chronic illnesses.

While issues of independence, sexuality, and identity are important for all adolescents, they become of particular concern for chronically ill teenagers because of the interaction of rapid developmental change in these areas with the stresses of chronic illness. Unlike adults with chronic diseases who often need to be rehabilitated so that they can function independently again and resume their sexual lives, adolescents need to be habilitated; they have no prior experience to draw on. Chronically ill children can be sheltered and protected from many stresses by their families, but as they move into the adolescent years, they must be allowed to gradually take over responsibility for their actions. This takes practice, and some mistakes are inevitable. In addition, teenagers with chronic illnesses deserve assistance to help them maximize their strengths and develop a positive self-identity. Health professionals have a significant role to play in encouraging independence, preventing adverse consequences of sexual behavior, and enhancing the self-image of their chronically ill adolescent patients.

Adolescent↗
PubMed1984

Accessory hemiazygos continuation of left inferior vena cava: CT demonstration.

The first CT description of accessory hemiazygos continuation of a left-sided inferior vena cava is presented. This venous anomaly appears as a mediastinal mass on plain chest films and may simulate an aortic dissection on CT or angiography. Careful attention to the various abnormal vascular pathways will obviate the need for further invasive testing.

Aortic Dissection↗