PubMed Health⌕ Search

Biomedical subjects

L Schultz

Publications and source records attributed to L Schultz.

At least 55 records · Page 3Linked to original sources
PubMed1994

An outcome study: changes in Rorschach variables of adolescents in residential treatment.

Admission Rorschach variables were compared to 2-year reevaluation responses of adolescents (n = 50) in residential treatment using Weiner and Exner's (1991) 27 structural variables. Fifty adolescents who had previously failed to improve in outpatient treatment and multiple hospitalizations were subsequently placed in residential treatment. Following 2 years of residential treatment, they showed positive personality changes as indicated by a reduction in Rorschach indices of impaired functioning. Positive treatment changes in interpersonal awareness were discussed utilizing a social identification index formulated for this population. Results indicate the utility of the Rorschach test-retest method of assessing treatment outcome.

Adolescent↗
PubMed1993

Short-interval amygdala kindling in neonatal rats.

The kindling paradigm provides a powerful tool for studying the generation, propagation and generalization of seizures. Such reproducible quantitative paradigms are a prerequisite for the experimental study of epilepsy in the developing brain. Kindling has been extensively utilized as a model of limbic seizures in the adult rat; amygdala short-interval kindling has been studied in > or = 15-day-old rats. We applied the short-interval kindling method, i.e., stimulation at every 15 min, to 7-12-day-old rats. Stage-5 behavioral seizures were achieved even in 7-day-old rats; however, the progression of behavioral kindling differed somewhat from that of older rats. Correlation of electrographic discharges and behavioral phenomena was inversely related to age. Reliable progressive amygdala discharges were difficult to assess in most < or = 10-day-old rats. Spontaneous seizures occurred relatively frequently in younger age groups. The amygdala short-interval kindling paradigm is reproducibly and reliably applicable to rats during the 2nd postnatal week. The presence of progressive focal to bilateral-generalized seizures suggests a significant functional maturity of the amygdala-limbic circuitry at this age.

Aging↗
PubMed1993

Prognostic significance of electrocardiographic persistent ST depression in patients with their first myocardial infarction in the placebo arm of the Beta-Blocker Heart Attack Trial.

The prognostic significance of ST segment depression in patients with their first acute myocardial infarction was investigated in 1444 patients with an acute myocardial infarction, who were randomly assigned to the placebo arm of the Beta-Blocker Heart Attack Trial (BHAT). Patients were divided retrospectively into three groups based on the presence or absence of > or = 1 mm ST segment depression in two contiguous leads of a 12-lead electrocardiogram obtained during the first few days after admission and at the time of randomization, which occurred at 9.7 +/- 3.3 days after the index myocardial infarction. Group 1 included 392 patients with no ST segment depression, group 2 comprised 713 patients with transient ST segment depression in the first few days after admission or at the time of randomization, and group 3 included 339 patients with persistent ST segment depression in the first few days after admission and at the time of randomization. At a median follow-up of 26 months, the mortality rate was 4.9% in group 1, 7.6% in group 2, and 13.6% in group 3. When Cox regression was used to adjust for baseline differences in other variables, the differences between the three groups continued to be highly significant (p = 0.005; 95% confidence intervals [0.6 and 1.4]). We conclude that persistent and transient ST segment depression in patients with their first myocardial infarction are strong predictors of increased long-term mortality when compared to patients without ST segment depression. These findings should be taken into consideration when stratifying patients at risk in the post-myocardial infarction period.

Electrocardiography↗
PubMed1993

Sequential neuronal and astrocytic changes after transient middle cerebral artery occlusion in the rat.

The temporal evolution and spatial distribution of ischemic cell injury was investigated after transient middle cerebral artery (MCA) occlusion. Male Wistar rats (n = 61) were subjected to 2 h of MCA occlusion induced by advancing a nylon monofilament into the right internal carotid artery. Animals were killed after different durations of reperfusion, ranging from 4 to 166 h (n = 6-11 for each group). Neuronal injury and astrocytic reaction were evaluated using hematoxylin and eosin (H & E) and glial fibrillary acidic protein (GFAP) immunohistochemistry, respectively. Eosinophilic neurons were detected at 4 h of reperfusion in the basal ganglia, and at 10 h of reperfusion in the cortex. Focal brain infarct developed by 46 h of reperfusion, both in the cortex and the basal ganglia, and the volume remained constant between 46 and 166 h of reperfusion. Significant differences in astrocytic reaction were detected between the lesion and the periphery of the lesion at reperfusion times from 46 to 166 h; GFAP staining decreased in the core of the lesion and increased in the peripheral areas. Our data suggest that, after 2 h of MCA occlusion, brain tissue progresses from isolated neuronal injury to infarct with a time course dependent on anatomical site; and astrocytic reactivity, expressed by GFAP staining, reflects the outcome of the ischemic injury.

Animals↗
PubMed1992

CRH gene expression in the fetal rat is not increased after pharmacological adrenalectomy.

A regimen of twice daily metyrapone injections (100 mg/kg), resulted in pharmacological adrenalectomy of pregnant rats and fetuses in utero, i.e. depression of plasma corticosterone and elevation of plasma adrenocorticotropic hormone (ACTH). Toxicity was minimal on days 14-17 of pregnancy, and increased with higher maternal weight and pregnancy progression. Corticotropin releasing hormone (CRH) messenger RNA abundance in the pregnant adults increased significantly within 48 h of metyrapone initiation. No change in CRH gene expression in the paraventricular nucleus of fetuses (days 17-18) was seen, even after 72 h of the regimen. This is compatible with the independence of CRH gene expression of glucocorticoid feedback in the fetal rat.

Adrenalectomy↗
PubMed1992

Corticotropin-releasing hormone-induced seizures in infant rats originate in the amygdala.

The neuroanatomical substrate of seizures induced by picomolar amounts of corticotropin-releasing hormone in infant rats was investigated. Electrographic and behavioral phenomena were monitored in 42 rat pups aged 5 to 22 days. Rat pups carried bipolar electrodes implanted in subcortical limbic structures, as well as cortical electrodes and intracerebroventricular cannulae. The administration of corticotropin-releasing hormone produced age-specific seizures within minutes, which correlated with rhythmic amygdala discharges. Paroxysmal hippocampal and cortical discharges developed subsequently in some rats. Corticotropin-releasing hormone-induced electrographic and behavioral seizures originate in the amygdala.

Aging↗
PubMed1991

Protein disulfide isomerase is essential for viability in Saccharomyces cerevisiae.

Protein disulfide isomerase (PDI) is an enzyme involved in the catalysis of disulfide bond formation in secretory and cell-surface proteins. Using an oligodeoxyribonucleotide designed to detect the conserved 'thioredoxin-like' active site of vertebrate PDIs, we have isolated a gene encoding PDI from the lower eukaryote, Saccharomyces cerevisiae. The nucleotide sequence and deduced open reading frame of the cloned gene predict a 530-amino-acid (aa) protein of Mr 59,082 and a pI of 4.1, physical properties characteristic of mammalian PDIs. Furthermore, the aa sequence shows 30-32% identity with mammalian and avian PDI sequences and has a very similar overall organisation, namely the presence of two approx. 100-aa segments, each of which is repeated, with the most significant homologies to mammalian and avian PDIs being in the regions (a, a') that contain the conserved 'thioredoxin-like' active site. The N-terminal region has the characteristics of a cleavable secretory signal sequence and the C-terminal four aa (-His-Asp-Glu-Leu) are consistent with the protein being a component of the S. cerevisiae endoplasmic reticulum. Transformants carrying multiple copies of this gene (designated PDI1) have tenfold higher levels of PDI activity and overproduce a protein of the predicted Mr. The PDI1 gene is unique in the yeast genome and encodes a single 1.8-kb transcript that is not found in stationary phase cells. Disruption of the PDI1 gene is haplo-lethal indicating that the product of this gene is essential for viability.

Amino Acid Sequence↗
PubMed1991

Corticotropin-releasing hormone is a rapid and potent convulsant in the infant rat.

Corticotropin-releasing hormone (CRH) administered into the cerebral ventricles of rats during the first postnatal week caused a specific and stereotyped behavior sequence: rhythmic chewing and licking (jaw myoclonus) were followed by 'limbic'-type seizures. The onset of the seizures was much more rapid (2-45 min vs 3-7 h) than in adult rats, and the convulsant doses were much lower (50 x 10(-12) mol per gram brain weight vs 750 x 10(-12) mol per gram brain weight in adults). CRH potency in inducing seizures varied inversely with age. CRH-induced seizures occurred prior to any changes in serum corticosterone, and were eliminated by the administration of a CRH antagonist, as well as of phenytoin. Electrocorticographic correlates of CRH-induced behaviors in the infant rat were inconsistent, suggesting a subcortical origin of CRH-induced paroxysmal events in the immature brain.

Aging↗
PubMed1991

Chronic changes in the brain Mg2+ concentration after forebrain ischemia in the rat.

Brain Mg2+ ion concentrations, [Mg2+], were evaluated in three groups of animals subjected to either 8 minutes (n = 10), or 12 minutes (n = 10) of near-complete forebrain ischemia, or sham operation (n = 10), from their 31P NMR spectra. No significant differences were observed in [Mg2+] among sham operated animals prior to or at any time point after surgery. In the 8-min ischemia group, mean [Mg2+] were significantly lower at 48 (0.28 +/- 0.06 mM, p = 0.014) and 72 (0.29 +/- 0.07 mM, p = 0.005) hours post-ischemia when compared to their mean pre-ischemia levels (0.39 +/- 0.08 mM). [Mg2+] was restored to pre-ischemia values at 96 hours after induction of ischemia. In the 12 min ischemia group, [Mg2+] were lower at all time points post-ischemia when compared to their pre-ischemia levels. Our data shows that forebrain ischemia causes a chronic decline of cerebral Mg2+ concentration, and the observed reduction of this cation can be partially attributed to concurrent brain tissue alkalosis.

Animals↗
PubMed1991

Natural history of the first non-Q wave myocardial infarction in the placebo arm of the Beta-Blocker Heart Attack Trial.

Despite extensive investigation, the prognostic significance of the first non-Q wave acute myocardial infarction (AMI), when compared with Q wave AMI, remains controversial. The placebo arm of the Beta-Blocker Heart Attack Trial (BHAT) provides a unique opportunity to compare the long-term cardiac events in patients suffering from their first and uncomplicated Q wave or non-Q wave AMI. Of a total 3837 patients enrolled in the BHAT, 3375 were classifiable in terms of appearance or absence of Q waves during the prerandomization period. Of these, 1444 patients with their first AMI were randomized to placebo. Of these, 1186 experienced a Q wave AMI; the remaining 258 suffered a non-Q wave AMI. At 36 months of follow-up, the mortality was 8.4% in the Q wave AMI group and 7.4% in the non-Q wave AMI group. Sudden death was 5.4% in the Q wave AMI group and 4.7% in the non-Q wave AMI group. The reinfarction rate was 5.5% in the Q wave AMI patients and 7.4% in the non-Q wave AMI patients. More patients developed angina (44.6%) in the non-Q wave AMI group compared with 35.2% in the Q wave AMI group. Despite similar long-term cardiac event rates within the two groups, the 1-year mortality rate for patients with Q wave AMI appeared higher than in the non-Q wave AMI group, 5.2% versus 3.1%, respectively. In contrast, the rate of reinfarction appeared higher at the 12-month follow-up period in the non-Q wave AMI group, 4.7% versus 3.4%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)c

Double-Blind Method↗
PubMed1991

Ontogeny of somatostatin gene expression in rat diencephalon.

Somatostatin gene expression is first detectable, using in situ hybridization, on the 14th fetal day in rat diencephalon. Other structures expressing somatostatin messenger RNA include the anterior basal periventricular nucleus, amygdalo-hippocampal complex, dorsolateral thalamus and distinct areas in the parieto-frontal cortex. Semiquantitative analysis reveals that somatostatin synthesis increases progressively throughout the last third of fetal life and onto postnatal life.

Animals↗
PubMed1990

Effects of propranolol in non-Q-wave acute myocardial infarction in the beta blocker heart attack trial.

Although the beneficial effects of long-term therapy with beta-adrenergic blocking agents in patients recovering from acute myocardial infarction (AMI) are established, the effect of this therapy on the cardiac event rate in patients recovering from a non-Q-wave AMI is unknown. This post hoc analysis of the Beta Blocker Heart Attack Trial (BHAT) evaluates the effects of daily administration of propranolol 180 or 240 mg/day after non-Q-wave AMI. The study population consisted of 601 patients with enzymatically proven non-Q-wave AMI, which represented 17% of the BHAT patients. Of these, 310 patients were randomized to receive propranolol and 291 patients to placebo. There were no significant baseline differences between groups. The median follow-up was 24.6 months. Mortality was 7.8% (sudden death 4.8%) in the propranolol group and 7.9% (sudden death 4.8%) in the placebo group (p greater than 0.99, log rank test). Reinfarction rate was 7.4% in the propranolol group and 6.5% in the placebo group (p greater than 0.63, log rank test). The need for coronary bypass surgery was similar in the 2 groups. However, more patients randomized to placebo developed angina. In this post hoc group analysis of the BHAT, propranolol was not shown to be beneficial in reducing the cardiac event rate in patients recovering from a non-Q-wave AMI.

Double-Blind Method↗
PubMed1990

Fetal and maternal levels of corticosterone and ACTH after pharmacological adrenalectomy.

A paradigm of pharmacological adrenalectomy of pregnant rats and fetuses in utero is described. A regimen of twice daily metyrapone injections (10 mg/100 gm body weight), results in marked depression of serum corticosterone in pregnant and in fetal rats without surgical trauma and stress. The technique should be useful in a wide variety of studies involving the developing brain-adrenal axis.

Adrenal Glands↗