Learning and attention reveal a general relationship between population activity and behavior.

Prior studies have demonstrated that correlated variability changes with cognitive processes that improve perceptual performance. We tested whether correlated variability covaries with subjects' performance-whether performance improves quickly with attention or slowly with perceptual learning. We found a single, consistent relationship between correlated variability and behavioral performance, regardless of the time frame of correlated variability change. This correlated variability was oriented along the dimensions in population space used by the animal on a trial-by-trial basis to make decisions. That subjects' choices were predicted by specific dimensions that were aligned with the correlated variability axis clarifies long-standing paradoxes about the relationship between shared variability and behavior.

MyD88-dependent dendritic and epithelial cell crosstalk orchestrates immune responses to allergens.

Sensitization to inhaled allergens is dependent on activation of conventional dendritic cells (cDCs) and on the adaptor molecule, MyD88. However, many cell types in the lung express Myd88, and it is unclear how signaling in these different cell types reprograms cDCs and leads to allergic inflammation of the airway. By combining ATAC-seq with RNA profiling, we found that MyD88 signaling in cDCs maintained open chromatin at select loci even at steady state, allowing genes to be rapidly induced during allergic sensitization. A distinct set of genes related to metabolism was indirectly controlled in cDCs through MyD88 signaling in airway epithelial cells (ECs). In mouse models of asthma, Myd88 expression in ECs was critical for eosinophilic inflammation, whereas Myd88 expression in cDCs was required for Th17 cell differentiation and consequent airway neutrophilia. Thus, both cell-intrinsic and cell-extrinsic MyD88 signaling controls gene expression in cDCs and orchestrates immune responses to inhaled allergens.

High-dose naloxone infusions in normals. Dose-dependent behavioral, hormonal, and physiological responses.

Hypotheses of involvement of the endogenous opioid system (EOS) in the regulation of human behavior suggest that functional blockade of the EOS should have behavioral consequences. Clinical administration of the opiate receptor antagonist naloxone hydrochloride, however, has had little or inconsistent behavioral effects in normals. This may be attributable to the use of doses insufficient to yield a complete EOS blockade. To assess this explanation, normals were administered increasing doses of naloxone hydrochloride (0.3 to 4 mg/kg) in a single-blind design. Significant dose-dependent behavioral, hormonal, and physiological effects were found. With increasing doses of naloxone, volunteers demonstrated increasingly dysphoric affects, a deterioration of performance on memory testing, increasing systolic BP and respiratory rate, and increasing plasma cortisol and growth hormone levels. These results are consistent with the expected effects of increasing EOS blockade, and thus suggest that lower doses of naloxone used in previous clinical studies may not have been sufficient to produce a complete EOS blockade. Specifically, they suggest involvement of the EOS in the tonic regulation of normal human mood, memory, BP, respirations, and plasma growth hormone and cortisol levels.

Naloxone and Alzheimer's disease. Cognitive and behavioral effects of a range of doses.

There have been conflicting reports on the effects of naloxone hydrochloride in patients with dementia of the Alzheimer type (DAT). In addition, none of the naloxone studies in DAT used doses of 2.0 mg/kg or more, the amount necessary to produce reliable cognitive and behavioral changes in young normal subjects. In a randomized, double-blind, placebo-controlled study, 12 patients with DAT were administered naloxone hydrochloride in doses of 5 micrograms/kg, 0.1 mg/kg, and 2.0 mg/kg, with detailed evaluation of its behavioral and cognitive effects using measures selected for their potential relevance to DAT and the known effects of blockade of endogenous opiate systems. None of the measures of motor performance, attention, memory, learning, or recognition showed improvement with naloxone. Increased inappropriate verbal productions were noted after 0.1 mg/kg of naloxone hydrochloride. Patients became irritably activated after this dose, which may account for the altered verbal behavior in this study and also for some of the changes suggesting cognitive improvement in prior studies. Differences in the sensitivity and dose dependency of the behavioral effects in patients with DAT compared with prior studies in young normal subjects merit further investigation.

Clinical studies of the endogenous opioid system.

The role of the endogenous opioid system in humans was studied using three clinical research strategies. High doses of the opiate antagonist naloxone (up to 4 mg/kg) were administered to normal volunteers. Dose-dependent increases in self-ratings of tension-anxiety and anger-hostility were observed, supporting the hypothesized involvement of the endogenous opioid system in the modulation of human mood and feelings of well-being. Accompanying dose-dependent increases in systolic blood pressure and respiratory rate were found, suggesting that the lower doses of naloxone utilized in previous clinical studies were not sufficient to block the endogenous opioid system. CSF opioid activity in psychiatric patients and normals was measured using a sensitive radioreceptor assay developed by the authors. Results suggest diminished endogenous opioid system activity in some schizophrenics, and a relationship between opioid activity and state change in manic-depressive illness and anorexia nervosa. A complex but consistently observed relationship between ratings of anxiety and CSF opioid activity in normals and patients is consistent with basic science and clinical data suggesting interactions between CNS noradrenergic and opioid systems. General surgery was used as a strategy for studying the relationship of the endogenous opioid system to stress in humans; robust increases in levels of plasma beta-endorphin immunoreactivity accompanying surgical stress and an inverse relationship between patient levels of plasma beta-endorphin immunoreactivity and postoperative analgesic requirement were observed. These data support the involvement of the endogenous opioid system in the human stress response and suggest that hormonal stress response and endogenous opioid system activity may relate to human endogenous analgesic mechanisms.

High dose naloxone in depression.

The behavioral effects of a 2 mg/kg iv bolus infusion of naloxone were compared with a placebo infusion using a double-blind design in a small group of inpatient depressives (n = 6) and normals (n = 8). Naloxone produced consistent and significant worsening in the rated signs and subjective symptoms of depression in the patients. In the normals, lesser changes in Hamilton depression and BPRS total scores were observed while none of the subjective scales were significantly altered. The data suggest that depressives manifest a more marked and subjectively more intense response to naloxone compared to normals. Further studies are required to confirm this preliminary finding and to clarify its relationship to the pathogenesis of depression.

Endogenous opioid regulation of hypothalamo-pituitary-adrenal axis activity in schizophrenia.

We utilized a naloxone challenge strategy to investigate the functioning of the endogenous opioid system (EOS) in schizophrenia. Patients with schizophrenia, who were on neuroleptic medication or drug-free, demonstrated a significantly larger serum cortisol response to opioid blockade by naloxone than did age- and sex-matched normal controls. Patients, but not normal controls, also demonstrated an inverse relationship between baseline cortisol and the magnitude of the response. This enhanced cortisol response is consistent with tonic hyperactivity of the EOS in schizophrenia.

Behavioral change in a cancer patient following intrathecal beta-endorphin administration.

A patient with a disseminated malignancy received 3 mg of synthetic beta-endorphin administered intrathecally by lumbar puncture. A marked behavioral syndrome characterized by confusion, hypomanic/manic behavior, and psychosis followed drug administration and persisted for more than 2 days.

Plasma cortisol and beta-endorphin immunoreactivity in nonmajor and major depression.

Plasma cortisol levels of 28 hospitalized patients meeting Research Diagnostic Criteria for major or nonmajor (minor or intermittent) depression were significantly higher than those of eight normal subjects. In contrast, plasma beta-endorphin immunoreactivity was significantly lower in patients with nonmajor depression than in those with major depression or in normal subjects. A low ratio of plasma beta-endorphin to cortisol immunoreactivity was found to characterize patients in both groups. Through the use of only this ratio, a post-hoc analysis identified 25 depressed patients and seven controls. These findings have implications for psychiatric diagnosis and the involvement of the endogenous opioid system in the pathogenesis of depression.

Herbal and complementary and alternative medicine therapies for liver disease. A focus on Chinese traditional medicine in hepatitis C virus.

This article presents herbal and alternative therapies used in the treatment of liver disease, both as adjunctive or complementary treatment to Western pharmaceutical strategies, and as an alternative treatment in liver disease, particularly for Hepatitis C Virus. There is a special emphasis on traditional Chinese herbal medicine.

Free radical scavenging systems and the effect of peroxide damage in aged human skin fibroblasts.

One prominent theory of aging postulates an accumulation of cell damage resulting from nonenzymatic chemical reactions between important cellular components and free radicals. Fibroblast lines derived from skin biopsies of psychiatric patients ranging in age from 22 to 70 were evaluated soon after adaptation to culture. No significant correlation was found between donor age and the detoxification enzyme activities of superoxide dismutase (SOD) or aryl hydrocarbon hydroxylase (AHH) or susceptibility to damage by oxygen metabolites as measured by cell viability or lactate dehydrogenase (LDH) leakage.

High-dose naloxone in older normal subjects: implications for Alzheimer's disease.

The behavioral and cognitive effects of naloxone HCl, in doses of 5 micrograms/kg, 0.1 mg/kg, and 2.0 mg/kg administered as an IV bolus, were assessed in a double-blind, placebo-controlled, randomized study of eight normal subjects ranging in age from 44 to 74 years (mean 63). Naloxone produced mild behavioral effects with slight cognitive impairment after the 2.0 mg/kg dose only. The threshold, dose dependency, characteristics, and magnitude of these behavioral effects were similar to what has previously been reported in young normal subjects, but markedly different from those observed in patients with dementia of the Alzheimer type (DAT) matched in age to the current study sample. These data suggest that the metabolic fate of naloxone is not substantially affected by age within the range studied. The findings of this study provide further support for a role for endogenous opiate systems in the modulation of behavior and cognition, and suggest that the unusual behavioral sensitivity of patients with DAT to naloxone cannot be accounted for by the effect of age.

Acute effects of high-dose thyrotropin releasing hormone infusions in Alzheimer's disease.

Thyrotropin releasing hormone (TRH) was administered intravenously to ten patients with Alzheimer's Disease (AD) in a high-dose paradigm, thought to maximize central nervous system effects and potentially produce facilitation of cholinergic function, a known property of the neuropeptide. Acute effects of TRH on behavioral, cognitive and physiologic measures were assessed after patients received 0.1 mg/kg TRH, 0.3 mg/kg TRH and placebo, the higher TRH dose and placebo being given in a randomized, double-blind fashion. Patients showed statistically significant increases in arousal and improvement in affect, as well as a modest improvement in semantic memory, all after receiving the higher TRH dose. Both TRH doses produced transient rises in systolic blood pressure, with no effect on diastolic blood pressure, heart rate or temperature. This study suggests that high-dose TRH can be safely administered to AD patients and is neurobehaviorally active; further studies are needed to determine the extent and mechanism of the cognitive and psychobiological properties of this peptide in AD and other neuropsychiatric disorders.

TRH attenuates scopolamine-induced memory impairment in humans.

The brain tripeptide thyrotropin-releasing hormone (TRH) has been demonstrated to facilitate cholinergic neurotransmission. To test its interaction with the cholinergic system in humans, high-dose TRH (0.5 mg/kg) or placebo was administered intravenously (IV) to normal controls pretreated with scopolamine (0.5-0.75 mg IV), a centrally active muscarinic antagonist, which has been used to model aspects of the memory impairment of normal aging and of dementia. Compared to placebo, TRH markedly attenuated scopolamine-induced impairment of some measures of memory, most notably on a selective reminding task. This cognitive study is the first in humans to suggest a neuromodulatory effect of a peptide on the cholinergic system, and suggests a facilitatory role for TRH in human memory processes.

Treatment of endometriosis with an antigonadotropin, Danazol. A laparoscopic and histologic evaluation.

Antigonadotropin (Danazol) was administered to 39 patients with endometriosis diagnosed at laparoscopy and confirmed by laparoscopic biopsy. None of the patients had surgical resection of the lesion prior to the treatment. While on the drug, all patients developed evidence of ovarian suppression both in regard to ovulation and steroidogenesis. The results were evaluated by repeat laparoscopy and biopsy. The extent of the disease was documented before and after treatment by photography and drawing. There was marked decrease in the extent of endometriosis after treatment: 59% of patients had no evidence of disease, 26% had peritoneal adhesions and hemosiderin deposits but no active endometriosis, and 15% had residual endometriosis. Histology in the latter group revealed atrophic changes in the uterine and ectopic endometrium and the evidence of a healing process.

Necessity of formal genetic screening in artificial insemination by donor.

After observing abnormal offspring following artificial insemination by donor, several authors recently have proposed intensive genetic screening of donors. The screening would be beyond that practiced by most infertility specialists. To determine the necessity for formal genetic investigation of donors, the authors analyzed the outcome of artificial insemination pregnancies in which donors were screened with careful medical and family histories, but were not subjected to formal pedigree analysis, karyotyping, or extensive metabolic screening. Fewer than 10% of potential donors were disqualified for genetic reasons. The study, limited to ascertaining the presence or absence of overt anomalies evident at birth, showed that such malformations were not more frequent in artificial insemination pregnancies (1.7%) than in controls (2.3%). It is concluded that extensive and formalized genetic screening is probably not necessary provided a thorough medical history is obtained. In addition, a practical approach to identifying donors at increased risk for siring abnormal offspring is offered.

ACTH 1-24-induced potentiation of norepinephrine contractile responses in aortic strips from spontaneously hypertensive (SH) and normotensive (WKY) rats.

Norepinephrine (NE)-induced contractile responses were less in aortic strips from SH compared to WKY rats. ACTH 1-24 potentiated NE responses in both SH and WKY aortic strips. This effect was more potent in SH aortic strips. NE-induced contractions in SH aortic strips were less sensitive to changes in external Ca2+ levels than were those of WKY aortic strips. ACTH 1-24 did not potentiate NE responses under low external Ca2+ conditions in SH aortic strips or under high external Ca2+ conditions in WKY aortic strips. The greater sensitivity of NE responses following ACTH 1-24 in SH aortic strips may imply that this peptide is modulating a mechanism related to an impaired contractility and that Ca2+ plays a key role in the observed effects.

Hormonal effects of high dose naloxone in humans.

Utilizing a double-blind crossover design, the hormonal effects of high dose, 2 mg/kg, were compared to low dose, 0.4 mg (approx. 5 micrograms/kg), naloxone administration in physically healthy humans. A significant naloxone dose effect on plasma cortisol levels was found (p less than 0.001), but no significant effect on plasma or serum levels of prolactin, follicle stimulating hormone, luteinizing hormone, norepinephrine or epinephrine. These results confirm involvement of the endogenous opioid system (EOS) in the tonic regulation of the hypothalamicpituitary-adrenal axis, but fail to find evidence of EOS involvement in the regulation of adrenal medullary function or the gonadotrophic axis in man. The results are however consistent with a continuing action of naloxone as an EOS antagonist even at high doses in man.

The pH of cervical mucus and the postcoital test.

In this study, 25 women with 28-day cycles were considered for a total of 44 menstrual cycles. The women were subjected to the Sims-Huhner postcoital test at 6.2 hours after intercourse during the periovulatory period. Each couple was instructed to abstain from sexual intercourse for 4 days prior to the test. Samples of cervical mucus were obtained and evaluated for quantity, viscosity, elasticity, ferning, cellularity, pH, and the postcoital status of the spermatozoa (percentage motility and grade). The pH measurements were made by the use of phenaphthazine paper. After the establishment of the pH measurements the patients were divided into two groups (low and high pH) and statistically compared on the basis of the spermatozoal postcoital test results. The results obtained revealed significant differences (P < 0.01) between the low pH (less than or equal to 6.0) and high pH (greater than or equal to 6.1) groups with respect to percentage motility and grade of recovered spermatozoa. Ejaculate characteristics of the males corresponding to the two different pH groups showed no significant differences (P > 0.05).

Twenty-four to ninety-six-hour storage of human spermatozoa in test-yolk buffer.

The feasibility of a simple, inexpensive technique of short-term (24- to 96-hour) preservation of human spermatozoa in TEST-yolk buffer is demonstrated. Preservation of spermatozoa for up to 72 hours would require no addition of antibiotics. There is little loss of motility when semen is added to TEST-yolk buffer and kept in a standard refrigerator. Such semen would then be available for multiple inseminations during the periovulatory period. One objection to this procedure is that it is necessary to dilute semen 1:1 in TEST-yolk buffer, resulting in a 50% lower sperm density, and this may be objectionable when oligospermia is present. Results obtained in this study are in agreement with similar studies performed on domestic animals.