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Biomedical subjects

L Friedman

Publications and source records attributed to L Friedman.

At least 19 recordsLinked to original sources
PubMed1992

Saccadic intrusions into smooth pursuit in patients with schizophrenia or affective disorder and normal controls.

Two types of saccadic intrusions into smooth pursuit eye tracking, anticipatory saccades (AS), and square wave jerks (SWJ), were measured in 23 patients with schizophrenia, 16 patients with affective disorder, and 21 normal controls. Constant velocity (5 degrees and 20 degrees/sec) predictable targets were employed. High resolution infrared oculography was employed to record eye movements. Although most subjects had at least one SWJ, there were no significant group differences, and the highest individual rates of SWJ were seen in the normal control group. On the other hand, AS were never seen in normals, but were present in 25%-44% of patients with either schizophrenia or affective disorder. Both patient groups had significantly more AS than controls, but the two patient groups were not significantly different.

Adult↗
PubMed1992

Effect of the serotonin agonist, MK-212, on body temperature in schizophrenia.

The effects of 6-chloro-2-(1-piperaziny)pyrazine (MK-212), a centrally acting 5-HT1C/5-HT2 agonist, on body temperature and behavior were assessed using a single-blind cross-over design in 23 schizophrenic patients and 22 normal controls. Body temperature was assessed before drug administration and at 30-min intervals for 3 hr. Each subject was administered placebo or MK-212. MK-212 significantly elevated temperature in normal controls. There was no overall MK-212-induced increase in temperature compared to placebo in the schizophrenic patients; however, 13 of 23 (56.5%) patients had a larger increase in temperature after MK-212 than placebo, 3 of 23 (13.1%) had no change, whereas the temperature change after placebo was greater than after MK-212 in 7 of 23 (30.4%) patients. MK-212 produced significant increases in nausea, feeling strange, and arousal but these effects did not differ between groups. These results are consistent with decreased 5-HT2 receptor responsivity in some patients with schizophrenia.

Adult↗
PubMed1992

In vitro effects of the nephrotoxins ochratoxin A and citrinin upon biochemical function of porcine kidney.

Ochratoxin A and citrinin are nephrotoxic mycotoxins found in a variety of foods and feeds. Before studying possible interactions between these two toxins, their individual biochemical effects were examined in vitro by using renal cortical explants derived from male swine of the Hormel-Hanford strain. The following measurements were performed: macromolecule biosynthesis (protein, RNA, and DNA), respiration (14CO2 from [14C]glucose), organic ion (tetraethyl ammonium acetate, i.e., TEA) transport, and membrane perturbation (protein leakage into medium). Levels of the toxins ranged from 0.001 to 1 mM. Ochratoxin A inhibited macromolecule biosynthesis at a lower concentration (0.001 mM) than did citrinin. Protein and DNA synthesis were particularly sensitive to ochratoxin A. Syntheses of protein and DNA were inhibited at ochratoxin A concentrations of 0.01 and 0.001 mM, respectively. RNA synthesis was less sensitive to the mycotoxin; it was inhibited only 60% at 1 mM, the highest concentration of ochratoxin A tested. Citrinin levels of 0.01 mM were required for inhibition of RNA, DNA, and protein synthesis. Inhibition by citrinin was approximately equal for all three classes of macromolecules. Citrinin was more effective than ochratoxin A in the inhibition of respiration and TEA transport; the minimum effective levels of citrinin were 1 and 0.01 mM, respectively. Serious membrane damage as evidenced by increased protein leakage was not caused by either toxin. Stimulation of respiration, perhaps reflective of uncoupling of oxidative phosphorylation, was produced by an ochratoxin A concentration of 1 mM.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Proliferative periosteal processes of phalanges: a unitary hypothesis.

A unitary hypothesis is offered to explain the various proliferative processes occurring around the phalanges. In the past, these have been separately designated as proliferative periostitis, bizarre parosteal osteochondromatous proliferation, and turret exostosis. Because the appearances of these entities depend on temporal factors, breaching of the periosteum, and local anatomic features, we suggest a single term, proliferative periosteal processes of phalanges.

Bone Diseases↗
PubMed1992

Effect of typical antipsychotic medications and clozapine on smooth pursuit performance in patients with schizophrenia.

The effect of typical neuroleptic drugs or clozapine on smooth pursuit eye movements was tested in 13 patients with schizophrenia or schizoaffective disorder with a repeated measures design. Nineteen normal control subjects were also studied. Compared with controls, patients in the unmedicated state had low smooth pursuit gain, had a higher rate of corrective catch-up saccades, and tended to spend less time engaged in the tracking task. The patients did not significantly differ from controls on catch-up saccade amplitude, square wave jerk rate, or anticipatory saccade rate. Medication with clozapine, but not typical neuroleptics, was associated with an increase in median catch-up saccade amplitude. Number of days on clozapine and clozapine dose both correlated significantly with a worsening of oculomotor performance. No effect of medication with typical neuroleptics was found, although there was some evidence suggesting that such an affect may occur after more prolonged treatment.

Adult↗
PubMed1992

Molecular characterization of a Dirofilaria immitis cDNA encoding a highly immunoreactive antigen.

Dirofilaria immitis, a filarial nematode, is the causative agent of canine and feline heartworm disease. Previous research has demonstrated that immunity to D. immitis can be induced in dogs by repeated chemical abbreviation of infections while the parasite is a fourth-stage larva. Sera obtained from dogs immunized in this manner has been effective in passively transferring larval killing and stunting. These immune sera, by comparison to nonimmune sera from infected cohorts, recognize a number of unique D. immitis antigens, some of which are larval specific. In this study immune dog sera were used to screen a D. immitis larval cDNA expression library. Three overlapping cDNA clones, Di22, Di18 and Di16, were obtained that encode a portion of a large molecule, greater than 150 kDa, that is composed of multiples of a 399-bp repeat. This protein when immunoblotted with antibody against a recombinant expressed Di22 fusion protein is found in larval as well as adult extracts and excretory-secretory products, and is seen as a series of ascending subunits, each approximately 15 kDa larger than the previous one. This antigen is highly immunogenic, as evidenced by the strong reactivity of the recombinant expressed Di22 fusion protein with sera from immune dogs, microfilaremic dogs and infected amicrofilaremic dogs. While the function of this antigen is unknown it has significant sequence similarity with an allergen found in Ascaris.

Amino Acid Sequence↗
PubMed1992

Computerized tomographic evaluation of acute distal radial fractures.

To learn whether computerized tomography offered additional useful information over conventional radiographic evaluation of acute distal radial fractures in the younger adult, we scanned 22 consecutive injured wrists. Of the distal radial fractures in 19 wrists, sixteen were defined on plain films as intra-articular. In contrast, computerized tomography demonstrated that all fractures of the distal radius had intra-articular extension. In 3 wrists interpreted as being normal on plain films, despite clinical suspicion of a fracture, fractures were confirmed by computerized tomography. As a result of computerized tomography, injuries were assigned a higher Frykman value in 5 cases, and consideration of alternative patient management became necessary in 5 of the 22 patients.

Acute Disease↗
PubMed1992

Prognostic significance of ventricular premature depolarizations measured 1 year after myocardial infarction in patients with early postinfarction asymptomatic ventricular arrhythmia.

OBJECTIVES: The objective of this study was to examine the relation between death and the frequency of premature ventricular depolarizations measured approximately 1 year after myocardial infarction. BACKGROUND: The reported association between premature ventricular depolarizations and death in the weeks after myocardial infarction is in part the basis for the use of antiarrhythmic drugs. Such an association has not been reported on for observations obtained at a much greater interval after myocardial infarction. METHODS: We examined the association between mortality and premature ventricular depolarization rates measured 1 year after myocardial infarction in patients with asymptomatic ventricular arrhythmia early (between 6 and 90 days, median 28) after infarction, as measured by 24-h ambulatory electrocardiographic recording. The study group consisted of 502 patients enrolled in the Cardiac Arrhythmia Pilot Study during 1983 to 1985. They were followed up during the course of the study and subsequently by a National Death Index search (average follow-up interval 1,080 days). RESULTS: Death was recorded for 87 patients through 1987. Because patients were admitted to the Cardiac Arrhythmia Pilot Study only if they had greater than or equal to 10 ventricular premature depolarizations/h, the arrhythmia rate measured at baseline (that is, early after infarction) was not expected to, and did not, predict mortality. In 360 patients ventricular premature depolarization rates were measured approximately 1 year from their index myocardial infarction while they were not receiving antiarrhythmic therapy. In these patients, who had survived 1 year after the index infarction, the rate of ventricular premature depolarizations/h measured 1 year after infarction was highly predictive of subsequent death (p less than 0.001). Recent heart failure and a history of diabetes mellitus were also strongly predictive of death. CONCLUSION: The prognostic value of ventricular premature depolarizations observed 1 year after a myocardial infarction may be significant even in a sample selected for frequent ventricular premature depolarizations observed early after the event.

Arrhythmias, Cardiac↗
PubMed1992

Effects of advancing age on the efficacy and side effects of antiarrhythmic drugs in post-myocardial infarction patients with ventricular arrhythmias. The CAST Investigators.

OBJECTIVE: To determine the effect of age on the response to anti-arrhythmic drugs. DESIGN: Randomized controlled trial comparing particular drugs. SETTING: Multi-institutional (The Cardiac Arrhythmia Suppression Trial, CAST). PARTICIPANTS: 2,371 patients, age less than 80, with ventricular arrhythmias after a recent myocardial infarction. Subjects classified by age as less than or equal to 55, 56-65, and 66-79 years. INTERVENTION: Upwardly titrated doses of encainide, flecainide or moricizine. After identification of a tolerated and effective dose of one of the drugs, participants were randomized to that drug and dose versus its placebo for up to 10 months. MAIN OUTCOME MEASURES: Efficacy of drug (suppression of ventricular premature depolarizations and/or non-sustained ventricular tachycardia), side effects and mortality. RESULTS: Older patients had more previous MIs, congestive heart failure (CHF), hypertension, NSVT, repolarization abnormalities, digitalis use, and diuretic use. They had less pathologic Q-waves or electrocardiographic injury pattern, and their left ventricular ejection fraction (LVEF) was lower. First dose VPD suppression with the first drug averaged 53% and is not associated with age (P = 0.29). Adverse events including death are more frequent in older patients taking study drugs (P less than 0.001). This trend is consistent in all three study drugs and at varying LVEFs. History of prior MI, low LVEF, VPD (in log scale), and digitalis therapy also correlates with adverse events (all P less than 0.05). Following adjustment for these factors, older age is an independent predictor of adverse events (relative risk 1.30 per decade of age, P less than 0.001). CONCLUSIONS: Older age increases the susceptibility to adverse cardiac events from a class of relatively toxic antiarrhythmic agents.

Adult↗
PubMed1992

A model of ventilatory instability induced in the unrestrained rat.

A classic conditioning paradigm was used to examine the hypothesis that perturbations during sleep in the neonate rat can have a lasting impact on breathing. During the first 4 wk of life, stimuli were presented to rats during behaviorally defined sleep. In a conditioned hypoxic (CH) group, brief periods of hypoxic gas were used as the unconditioned stimulus. Tactile and auditory stimuli were used as the conditioned stimuli. In a conditioned control (CC) group, air was used as the unconditioned stimulus. A third group of unconditioned control (UC) rats was not exposed to the conditioning paradigm. Animals were provided routine care for 3.5 mo; ventilation was then assessed using plethysmography. Conditioning during neonatal life produced increased ventilatory irregularities and apnea during behaviorally defined sleep in adult rats. Both CH and CC rats showed a significantly greater number of apneic events compared with UC rats. Over a 2-h sleep period, CH rats exhibited a total of 105.1 +/- 9.4 (SE) apneic events, CC rats 69.4 +/- 4.2 events, and UC rats 42.1 +/- 3.1 events [F(2,18) = 25.568; P < 0.0001]. These findings suggest that experiences in the first few weeks of life will alter ventilatory patterning in the adult animal.

Acoustic Stimulation↗
PubMed1992

The relationship of structural brain imaging parameters to antipsychotic treatment response: a review.

Over the last decade, a number of studies have attempted to relate brain morphology to treatment response to neuroleptics. This approach has scientific potential to define subtypes of schizophrenia as well as potential clinical utility. In the present report, a review of 33 studies, including a meta-analysis, is provided. Although the overall test of the effect was not significant, the analysis revealed marked heterogeneity in the results of the various studies. The following factors were significant predictors of effect size: age, illness duration and age of onset of the patient cohort, the percentage of patients with marked structural abnormality included in the study overall, the duration of treatment and the degree of symptom improvement in the study overall. The following factors were unrelated to study effect size: date of study, gender, and the presence of a washout period. In future studies, attention to the parameters utilized in the meta-analysis should help to clarify the strength and generality of the relationship between brain morphology and treatment response.

Adult↗
PubMed1992

How and why do patients become more objective? Sterba compared with Strachey.

What Richard Sterba described in his influential paper was not, as some have thought, a lasting alliance between patient and analyst but a momentary dissociative state, accompanying the analysis of transference resistance, in which the patient detaches himself from his strivings and views himself objectively before lapsing back into normal coherence. We also find in the paper a hinted answer to the vexing question of what motivates patients to engage in characteristically psychoanalytic self-scrutiny. Sterba implicitly proposes a problem-solving incentive activated by transference. A comparison with Strachey leads us to ask whether patients progress only by disinhibition of particular strivings through particular resolutions of particular fears, or whether patients also experience a more general liberation that fosters their own, deliberate search for integration.

Defense Mechanisms↗
PubMed1992

Symptomatic calcific tendinitis at unusual sites.

Three cases of symptomatic calcific tendinitis at unusual sites (in the vastus lateralis tendon, the rectus femoris tendon and the flexor carpi ulnaris tendon) are presented. In two, the plain radiographs were nondiagnostic, and the diagnosis was made on the basis of the findings in computed tomography (CT) scans. The value of CT in examining atypical patients is demonstrated.

Adult↗