Retinal burns occurring at cataract extraction

Paramacular changes presumably induced by operating microscope light have been described previously in six patients who had undergone extracapsular cataract extraction with posterior chamber lens implantation. Twelve additional patients are reported, including pseudophakes and nonpseudophakes, macular and paramacular burns, and no visual loss and severe visual loss. Burns occurred in spite of filters and light barriers used in some cases. Light sources were tungsten bulb or halogen/fiberoptic. Three cases had essentially normal preoperative angiography. Currently recommended safety measures have not eliminated this complication.

Trace element levels in human alcoholic brain

Copper, magnesium, zinc and manganese levels in the temporal cortex of human alcoholic and control brains were measured by atomic absorption spectrophotometry using both the flame and graphite furnace. All of the 21 alcoholics were male with a mean age of 54.1 years; the 19 male controls had a mean age of 60.2 years. The only statistically significant change in ion levels was an increase in manganese concentration (expressed both as microgram/g wet weight and ng/mg protein) in the alcoholic group when compared to the control group. Five of the alcoholics had malignancies, while 16 of the controls had systemic malignancies. Covariance analysis showed there was no effect of age on the level of manganese in the temporal cortex.

Effects of 6-methoxytetrahydro-beta-carboline on 5-hydroxytryptamine binding in rat brain

6-MeOTHBC competes for 5-HT binding sites in rat brain in-vitro and in-vivo. The beta-carboline is significantly more active at the type 1 [3H]-5-HT, than the type 2 [3H]spiperone receptors, in-vitro. Following injection, 6-MeOTHBC significantly decreases [3H]-5-HT binding in the cortex. The ineffectiveness on [3H]spiperone binding in-vivo corresponds with the low affinity in-vitro. The effect of 6-MeOTHBC on central 5-HT binding may be a significant aspect of its 5-HT-ergic activity.

Prolactin response to single and multiple doses of haloperidol in schizophrenic patients

Serum prolactin and blood levels of haloperidol were assessed in schizophrenic patients after single acute oral doses of haloperidol and during fixed dose treatment with this medication. Although significant intrapatient correlations between prolactin responses to different doses of haloperidol were found, no statistically significant interpatient relationship between haloperidol dose and prolactin response emerged. There were statistically significant relationships between steady-state plasma and red cell haloperidol levels (measured by radioreceptor or gas liquid chromatographic techniques) and serum prolactin response, but not between blood levels after the acute haloperidol dose and prolactin response.

Serotonin levels and platelet uptake during premenstrual tension

Premenstrual tension was studied in 16 females, using both biochemical and psychological parameters during the pre- and postmenstrual phases. Uptake of serotonin (5-HT) and the levels of 5-HT in platelet-rich plasma and platelet-poor plasmas were determined. Degrees of distress experienced pre- and postmenstrually were quantified via the Moos menstrual distress questionnaire. The mean Vmax was significantly lower during the premenstrual (tension) phase (8.2 +/- 0.9 pmol/min) as compared to the postmenstrual (normal) phase (14.4 +/- 3.2 pmol/min). There was no significant difference in the Km values. A highly significant (p less than 0.001) reduction in the levels of 5-HT in platelet-rich plasma (-23.2%) and platelet-poor plasma (-19.1%) was found during the premenstrual phase. There were correlations between the kinetic parameters of 5-HT uptake and some of the Moos symptoms.

Kinetic evaluation of platelet monoamine oxidase following relaxation in chronic anxiety

The effect of relaxation training, utilizing EMG biofeedback, on platelet monoamine oxidase (MAO) activity was examined in patients with a history of chronic anxiety. Anxiety scores and MAO activity were significantly lowered after 4 weeks of therapy. Kinetic studies, using phenylethylamine as substrate, indicated a significant increase of the Km constant while the Vmax showed no significant or consistent variation. It is thought that this phenomenon represents an adaptive response by the individual to maintain a homeostatic level of the biogenic amines.

The residual effect of chronic neuroleptic treatment on the neuroleptic binding assay in rats

Chronic chlorpromazine administration to rats (25 mg/Kg/day) for 30 days followed by a washout period of 10 days resulted in an increase in both the measured maximum number of binding sites, Bmax, and the apparent dissociation constant, Kd, for the binding of 3H-spiroperidol to neural membranes of the brain. When membrane suspensions were progressively diluted before the binding assay, it was found that the apparent Bmax did not change with dilution, remaining higher in membranes of chlorpromazine-treated rats than in controls. The apparent increase in Kd, on the other hand, was found to be an artifact of the assay. Thus extrapolation of the measured or apparent Kd value to infinite dilution resulted in identical value for Kd regardless of the treatment.

Various inputs modify caudate neuronal activity

This study investigates the input of substantia nigra (SN), dorsal raphe (DR), and medial lemniscus (ML) on caudate nucleus (CN) neurons as well as a non-specific-polysynaptic input (acoustic AC). Ninety-one units demonstrating spontaneous activity were recorded extracellularly using anesthetized rats. SN, DR, ML, and AC stimulation altered the spontaneous discharges in 79%, 90%, 86%, and 85% of the CN neurons, respectively. Only ML stimulation elicited patterns of time-locked responses in 16% of the CN units. The CN neurons showed high convergence to the four types of stimulation. Based on these results, interconnections and interrelations between SN, DR, ML, and the CN are suggested.

Ultrastructural localization of LH-RH-immunoreactive synapses in the hamster accessory olfactory bulb

Electron microscopic immunocytochemistry was used to localize luteinizing hormone-releasing (LH-RH) immunoreactivity within the male golden hamster accessory olfactory bulb. Two LH-RH-immunoreactive fiber populations were identified in the accessory olfactory bulb. A superficial system of immunoreactive axons was localized to the vomeronasal nerve and glomerular layers, and a periventricular system appeared in granule cell and periventricular layers. LH-RH-immunoreactive varicosities were observed to contain large reactive vesicles (80-120 nm) as well as a variable degree of cytoplasmic reaction product. Additionally, small vesicles with unreactive lumens and mitochondria were often present. Intravaricose segments of immunoreactive fibers invariably displayed fewer reactive vesicles than did varicosities. Within both glomerular and periventricular layers, some LH-RH-immunoreactive varicosities were observed to form asymmetric contacts characterized by prominent postjunctional densities. In the glomerular layer, these junctions could be identified as synaptic by several features. The presence of LH-RH-immunoreactivity in presynaptic elements supports a neuromodulatory role for LH-RH. As the accessory olfactory system is critically involved in the initiation of mating behavior of the male golden hamster, LH-RH-immunoreactive synapses in the accessory olfactory bulb may function to regulate reproductive behavior.

Effects of neuroleptics on platelet monoamine oxidase activity

Platelet MAO activity in schizophrenics was significantly decreased, by about 15%, after 3 weeks of treatment with haloperidol. Treatment with thioridazine or butaperazine also tended to decrease platelet MAO activity. The neuroleptic-induced decrease began to appear within a few days of treatment and did not show tolerance over 1-2 months of treatment with haloperidol. Platelet MAO activity of schizophrenic patients measured during drug-free base-line was not significantly different from that of normal controls, but MAO activity of schizophrenics was significantly lower than normals after 3 weeks of treatment with neuroleptics. The extent of decrease in platelet MAO activity correlated negatively with base-line prolactin and its increase after 24 hr. With PEA as substrate, the decrease in activity correlated positively with steady state plasma haloperidol.

Cholinesterase enzymes in the blood of patients with Alzheimer's disease

Plasma pseudocholinesterase activity was about 100% higher in patients with Alzheimer's type dementia than in similar age controls. Red cell acetylcholinesterase activity tended to be lower in patients than controls. Administration of lecithin substantially increased plasma choline levels but did not alter activity of either of the cholinesterase enzymes.

Catecholamines and anxiety

Plasma catecholamines and heart rate were determined in drug-free groups of anxious patients and normal controls before and 20 min after intramuscular injection of 0.01 mg/kg of 1/1000 diluted epinephrine. Levels of anxiety after the injection were determined via the State Anxiety Scale of State Trait Anxiety Inventory. Both groups showed substantial increases in plasma levels of epinephrine and norepinephrine and heart rate after the injection. However, there were no significant differences between anxious patients and controls on plasma catecholamines and heart rate before or after the injection and post injection levels of State Anxiety. The anxious subjects showed a significant correlation between post injection heart rate and State Anxiety.

Electrophysiological support in favor of multiple opiate receptors in the caudate and the central gray of the rat

1. The present study compares the direct actions of morphine on two brain sites known to be rich in opiate receptors, namely, the caudate nucleus and the central gray. Recordings and morphine injections were made through a multibarrel glass micropipette using microiontophoresis. 2. Four different patterns of neuronal response to increasing currents of morphine were recorded in both brain regions. 3. Differences in the response to morphine between the two sites were detected in morphine-dependent rats. While the caudate neurons exhibited super-sensitivity to morphine, the neurons in the central gray displayed tolerance, and in some instances, dependence was evident when naloxone was administered. 4. The distribution of spontaneously active neurons within these two brain areas was found to be different in morphine-naive and morphine-dependent rats. 5. The electrophysiological findings of this study support the hypothesis of multiple opiate receptors.

Caudate neuronal response to microiontophoretically injected morphine in naive and morphine-dependent rats

1. The response of caudate nucleus neurons to morphine was found to be dose-dependent and could be divided into two classes: neurons which responded monophasically either by increase or decrease in their firing rate, and neurons whose response can be described as biphasic, exhibiting increase followed by decrease in their firing rate or vice versa, with the increase in morphine concentration. These responses were found in both naive and morphine-dependent rats. 2. Naloxone antagonized the effects of morphine in 74 out of 102 neurons tested. 3. Caudate neurons of morphine-dependent rats showed super-sensitivity to morphine compared to naive rats. 4. Differences were found in the distribution of the spontaneously active neurons between naive and morphine-dependent rats, indicating the existence of two different opiate receptor populations within the caudate nucleus.

Depression, antidepressants, and plasma DBH

Plasma levels of dopamine-beta-hydroxylase (DBH) were determined in 16 unmedicated patients with major depressive episodes (nonpsychotic) and in an equal number of normal subjects, before and after 4 weeks of treatment with tricyclic antidepressants. Some eight patients were treated with amitriptyline, and the remainder received desipramine. The controls remained medication free during the entire experimental period. Degrees of depression were quantified before and after treatment with the Hamilton Rating Scale of Depression (HRSD). There were no significant differences between the depressed patients and the controls on levels of DBH. Similarly, there were no within-group, pre-posttreatment differences on the enzyme levels in either group. Pre- and posttreatment HRSD scores did not correlate with corresponding plasma DBH levels. Plasma levels of amitriptyline, nortriptyline (product of amitriptyline in the body), and desipramine at the end of 4 weeks of treatment also failed to correlate with the enzyme levels.

Periaqueductal gray neurons response to microiontophoretically injected morphine in naive and morphine-dependent rats

The attempt of this study was to investigate the direct effects of increasing doses of morphine on the neuronal activity of the periaqueductal gray in morphine-naive and morphine-dependent rats. The microiontophoresis technique was used for this purpose. The four different responses induced by morphine exhibited dose-related patterns. Naloxone antagonized these responses in about 40% of the cases. Differences were found in the sensitivity of the neurons of morphine between naive and morphine-dependent rats. The phenomena of acute tolerance, chronic tolerance and dependence have been found. The results of this study indicate the presence of different neural populations in the periaqueductal gray in relation to their response to morphine, supporting the notion that subpopulations of opiate receptors exist within this brain area.

Catecholamines and monoamine oxidase activity in anxiety

Levels of platelet monamine oxidase activity, state anxiety and trait anxiety were quantified twice in 20 drug-free subjects with generalized anxiety and an equal number of healthy drug-free controls at 4-week intervals. Fifteen subjects in each groups also had plasma epinephrine and norepinephrine measured. The index group received relaxation training during the interval between the two evaluation sessions. Post-relaxation training values for monoamine oxidase, epinephrine, norepinephrine and the anxiety levels were found to be significantly lower than the pre-treatment values for the index group. No significant changes were seen in the control group values. For the index group, catecholamine levels and monoamine oxidase activity were seen to correlate significant before and after relaxation training.

Human brain monoamine oxidase: one molecular entity-multiple binding sites?

Monoamine oxidase (MAO) of human brain cortex was partially characterized by using different substrates and inhibitors. Two Km values were calculated for each of the three substrates tested, i.e., phenethylamine (PEA) benzylamine (BA) and 5-hydroxtryptamine (5-HT). Clorgyline and 5-HT, both known as MAO-A occupants, were able to abolish the second (high) Km deamination of PEA. 5-HT, while non-competitively inhibiting the deamination of low BA concentrations, competitively inhibited the deamination of high concentrations of this type B substrate. The kinetics of 5-HT deamination showed positive cooperation which indicates the involvement of subunits in the enzyme structure. The ability of some phospholipids to change the enzyme behaviour was considered as indication that these molecules might play a role in determining the ratio between the so-called A and B types of MAO, and in the regulation of the enzyme's activity.