Differential effects of scopolamine on nocturnal cortisol secretion, sleep architecture, and REM latency in normal volunteers: relation to sleep and cortisol abnormalities in depression

Scopolamine (SCOP) (3.0 mu/kg and 6.0 micrograms/kg) and saline were administered intramuscularly at 11:00 PM to eight normal male volunteers in a randomized design, and the effects on the sleep electroencephalogram (EEG) and nocturnal cortisol secretion (via blood sampling every 15 min) were evaluated. Compared to saline, SCOP produced a significant dose-related delay in rapid eye movement (REM) latency. In contrast, neither dose of SCOP significantly affected nocturnal plasma cortisol concentrations. These results suggest that the central cholinergic system that regulates the onset of REM sleep is more sensitive to dysregulation than the cholinergic system that controls the degree of nocturnal cortisol secretion. If central cholinergic overactivity is responsible for both the REM sleep latency and cortisol abnormalities in depressed patients, then our findings with SCOP might help explain why the incidences of these abnormalities are different.     

Evidence for a distinct nigropallidal dopaminergic projection in the squirrel monkey

Injections of the retrograde fluorescent tracer fast blue in the striatum (STR) and nuclear yellow in the internal segment of the globus pallidus (GPi) in the squirrel monkey (Saimiri sciureus) revealed a nigropallidal projection whose cellular origin was largely distinct from that of the nigrostriatal pathway. Neurons containing the tracer injected in GPi were scattered throughout the substantia nigra-ventral tegmental area complex where they formed approximately 20-25% of the total number of retrogradely labeled cells. Only about 5-10% of all positive neurons were double-labeled after STR-GPi injections. In experiments combining the use of the fluorescent tracer propidium iodide with immunofluorescence, the majority of neurons projecting to GPi displayed tyrosine hydroxylase immunoreactivity. Hence, in addition to their important role at striatal level, midbrain dopaminergic neurons may influence directly the output neurons of the basal ganglia at pallidal level in primates.     

Cytoplasmic loop of beta-adrenergic receptors: synaptic and intracellular localization and relation to catecholaminergic neurons in the nuclei of the solitary tracts

Pharmacological studies suggest that beta-adrenergic receptors (beta AR) in the medial nuclei of the solitary tracts (m-NTS) facilitate presynaptic release of catecholamines and also function at postsynaptic sites. We have localized the antigenic sites for a monoclonal antibody against a peptide corresponding to amino acids 226-239 of beta AR in the m-NTS of rat brain. By light microscopy, immunoperoxidase labeling for this antibody was detected in somata and proximal processes of many small cells that were distributed throughout the rostrocaudal extent of the m-NTS. Electron microscopy confirmed the cytoplasmic localization of beta AR in perikarya and proximal dendrites of neurons. Immunoreactivity occurred as discrete patches associated with cytoplasmic surfaces of plasma membrane and with irregularly-shaped saccules with clear lumen in the immediate vicinity. Select regions of nuclear envelopes, mitochondrial membranes, and rough endoplasmic reticulum were also immunoreactive along their cytoplasmic surfaces. In contrast, the Golgi apparatus was labeled, but infrequently. Immunoreactivity was also detected at numerous post- and occasional presynaptic membrane specializations of select axodendritic junctions. Dual labeling for the beta AR-antibody by the immunoperoxidase method and for a rabbit antiserum against the catecholamine-synthesizing enzyme, tyrosine hydroxylase (TH), by the immunoautoradiographic method within the same sections, further established the precise cellular relations between beta AR and catecholaminergic neurons. Immunoreactivity for beta AR was detected in numerous perikarya and proximal dendrites that did not show detectable levels of TH. However, a few cells were dually labeled for both antigens, as seen by both light and electron microscopy. The TH-labeled terminals formed synapses at junctions both with and without beta AR-like immunoreactivity. These results from the single and dual labeling studies: (1) confirm biochemical predictions that amino acids 226-239 of beta AR protein reside intracellularly; (2) provide the first ultrastructural evidence for beta AR localization within both pre- and postsynaptic membrane specializations of a subset of catecholaminergic synapses; and (3) suggest select intracellular sites that may be involved with synthesis and/or internalization and degradation of the receptor protein.     

Heart size and function of soldiers, athletes, and sedentary men

This study compares the heart sizes and left ventricular masses of soldiers (n = 11) with age- and body size-matched groups of sedentary men (n = 10) and accomplished athletes (n = 11). Echocardiography revealed that active duty soldiers (A) who met minimal fitness standards and pentathletes (P) had greater average left ventricular (LV) end-diastolic volumes (A = 10%, NS; P = 28%, p less than 0.05), stroke volumes (A = 29%, NS; P = 44%, p less than 0.01), and LV masses (A = 22%, NS; P = 76%, p less than 0.01) than sedentary subjects. Athletes had an average LV wall thickness which was 23% (p less than 0.05) greater than that of soldiers and 32% (p less than 0.01) greater than that of sedentary men. The LV wall thickness to radius ratio (h/r) was similar between soldiers and sedentary men, but in athletes the h/r was greater (p less than 0.01) than in the less conditioned subjects. These data suggest that soldiers who meet minimal standards of fitness exhibit cardiac morphometric features consistent with endurance conditioning. However, the soldiers studied were significantly less (p less than 0.001) conditioned than the competitive athletes. These data suggest that improvements in aerobic and cardiac conditioning could be achieved through a greater emphasis on physical training.     

The endoscopic bronchial picture of patients with pulmonary tuberculosis of various age groups

Endoscopic pictures of the bronchi were studied in 509 new cases of pulmonary tuberculosis. Tuberculosis of the bronchi and its aftereffects such as cicatricial lesions were detected in 31.1 per cent of the children and adolescents, 7.9 per cent of the adults at the age of 18 to 29 years, 9.0 per cent of the adults at the age of 30 to 55 years and 14.7 per cent of the adults at the age of 56 to 75 years. Nonspecific endobronchitis was diagnosed in 27.9 per cent of the children and adolescents, 44.9 per cent of the adults at the age of 18 to 29 years, 46.3 per cent at the age of 30 to 55 years and 44.1 per cent at the age of 56 to 75 years. The incidence and nature of tuberculosis of the bronchi and nonspecific endobronchitis were not related to the patients' age.     

Leprosy and hepatitis B surface antigen

An ELISA technique has been developed to detect HBsAg in the sera of leprosy patients. Out of ninety-two serum samples taken from untreated leprosy patients, 10 samples were positive for HBsAg. The ELISA used in the present investigation is a low cost, reliable and sensitive marker of HBsAg. It is better than lesser sensitive (haemagglutination and counterimmunoelectrophoresis), costly and hazardous (radioimmunoassay) techniques and is therefore recommended for routine use.     

Recovery of memory after severe closed head injury: dissociations in recovery of memory parameters and predictors of outcome

This study examined selective reminding and recognition memory performance of 21 severe closed-head injured patients tested within 6 months of regaining consciousness and then again after at least 1 year. Performances on selective reminding parameters were highly correlated and patients performed significantly worse at both testings than did hospitalized controls matched for age, education, and sex. Patients improved from testing 1 to testing 2 on only four of six memory variables. Average Impairment Rating at testing 1 was a marginally better predictor of memory performance at testing 2 than was length of coma. Results are discussed in terms of (a) utility of selective reminding parameters and predictors of outcome and (b) dissociations in recovery of memory parameters.