Does the pineal gland have a role in the psychological mechanisms involved in the progression of cancer?

Psychological factors, e.g., depression and psychological stress have been implicated in the progress of cancer. Similarly, the pineal gland and its principal secretion, melatonin, are known to influence the initiation and progress of cancer. Furthermore, changes in melatonin secretion have been linked with psychological stress and depression, and both the pineal gland and the cerebral cortex act via the limbic system in producing their effects. Both psychological stress and melatonin affect the immune system, as does the hypothalamus and the autonomic nervous system. The pineal gland has both a direct effect on cancer, and via the immune system. Psychological treatment and melatonin treatment have both been found to alleviate the course of cancer clinically. It is thus hypothesized that the pineal gland, and melatonin, are involved in the mechanism of psychological effects in the promotion of the progress of cancer.

Post-traumatic regeneration, neurogenesis and neuronal migration in the adult mammalian brain

Unlike the peripheral nervous system (PNS), the mammalian central nervous system (CNS) clearly lacks the robust regenerative characteristics and capacity of the former. Despite this fact, two unique regions of the adult mammalian CNS possess such regenerative potential and are capable of active regeneration following injury or structural compromise. These unique areas are the olfactory system and the neurohypophyseal system of the endocrine hypothalamus. Furthermore, it has been clearly demonstrated that primordial neuroblasts regarded as stem cells emerge from the subependymal parenchyma of the walls and floor of the third cerebral ventricle, migrate to the ventricular surface and undergo compensatory synaptogenesis within one week following hypophysectomy. In situ hybridization studies have unequivocally demonstrated that the up-regulation of nitric oxide synthase (NOS) is essential for neural (axonal) regeneration and neuronal (stem cell) migration to occur. Moreover, neuronal migration is reliably inhibited following the administration of the NO antagonist, nitroarginine. The current investigation serves to confirm a remarkable degree of plasticity and regeneration in the adult mammalian neurohypophyseal system coupled with the emergence of primordial neuroblasts that undergo apparent differentiation, migration and compensatory synaptogenesis in response to the up-regulation of NO that occurs following the trauma of hypophysectomy. Evidence from the current investigation appears to confirm that specialized glia of the neurohypophyseal system, the so-called pituicyte, proliferate following hypophysectomy and may serve as a growth matrix or structural template that may target and direct regenerating Supraoptic (SON) and Paraventricular (PVN) axons toward endothelial primordia in the regenerating neural stem and lobe.

Human corticotropin-releasing hormone test in patients with hypothalamo-pituitary-adrenocortical disorders

To assess the diagnostic usefulness of a synthetic human corticotropin-releasing hormone (CRH) formulation (Code No. MCI-028), we administered 100 micrograms of the peptide intravenously to 183 patients with hypothalamo-pituitary-adrenocortical (HPA) disorders, and obtained the following findings. Among the 183 patients, data from 125 patients were suitable for analyzing the effects of the test. In patients with Cushing's disease, high plasma adrenocorticotropic hormone (ACTH) and cortisol levels increased further in response to MCI-028, while in patients with adrenal Cushing's syndrome, low ACTH and high cortisol values remained unchanged. In patients with pituitary-type hypopituitarism or isolated ACTH deficiency, low ACTH and cortisol levels responded poorly or insignificantly to MCI-028, whereas those with hypothalamic hypopituitarism showed delayed and considerable degree of responses of plasma ACTH and little increase in plasma cortisol levels. In Addison's disease, high plasma ACTH increased further in response to MCI-028, but low cortisol levels did not change. In patients with Cushing's syndrome soon after successful surgical treatment, plasma ACTH responsiveness was low or different depending on the clinical course of the patient. Patients treated with high doses of glucocorticoids for non-endocrine diseases tended to show impaired ACTH and cortisol responsiveness to MCI-028. Side effects, including the transient flushing which was observed most frequently in this study, did not cause any clinical problems.

Function tests on the neuroendocrine hypothalamo-pituitary system following acute midbrain syndrome, with special reference to computertomographical and magnetic resonance imaging results

Seventeen patients underwent a neuroendocrinological function test at a mean 6.3 years following a severe craniocerebral trauma (CCT) accompanied by midbrain syndrome. An insulin hypoglycaemia test (IHT) and the combined pituitary anterior lobe test (CPALT) were applied. Whereas the IHT as maximum stimulator of the hypothalamo-pituitary system (HPS) showed an adequate reserve capacity, the CPALT yielded a partial limitation of the secretion dynamic in the somatotropic, adrenocorticotropic axis as well as a dysfunction in the FSH secretion. Neuroradiological tests could not establish substantial injury in the regio hypothalamica in any patient.

Intrahypothalamically transected neurosecretory axons do not regenerate in the absence of glial cells

Fifteen days after transection of the hypothalamo-neurohypophysial tract at the lateral retrochiasmatic hypothalamic area, neurosecretory axons had vigorously regenerated into transplants of explanted hypophysial neural lobe, to a lesser extent into sciatic nerve transplants, and least into optic nerve transplants. Regenerating axons were always closely associated with the specific glial cells of these grafts. When these glial cells were killed by cryotreatment prior to transplantation, neurosecretory axons did not regenerate into the abundant extracellular matrix of the transplants, including persisting basal lamina tubes in neural lobe and sciatic nerve grafts. The presence of viable glial cells is a prerequisite for neurosecretory axon regeneration.

Restoration and maintenance of spermatogenesis by HCG therapy in patients with hypothalamo-hypophyseal damage

Both gonadotropins are necessary to induce spermatogenesis in man and to recover hypophysectomized males. The patients who suffer from tumoral or traumatic hypothalamo-hypophyseal lesion use to have low endogenous gonadotropins (opposite to hypophysectomized patients), which can produce a minor involution of spermatogenesis. Three patients with postpubertal hypogonadotropic hypogonadism and oligozoospermia were studied. Two of them were operated on for chromophobous adenoma of pituitary, and the other patient had traumatic hypothalamo-hypophyseal lesion. The three patients were treated with 5000 IU HCG/week, associated with testosterone enanthate, in two cases and with bromocryptine in the remaining one. All the patients had normalized spermiogram, but when HCG was interrupted, the sperm count regressed to pretreatment levels in spite of the maintenance of treatment with testosterone or bromocryptine. Minimal amounts of FSH together the testosterone supplied by Leydig cell under the HCG stimulus, are able to recover and maintain the spermatogenesis in these patients.

Sexual precocity with hypothalamic hypopituitarism

Two girls, one with septo-optic dysplasia and the other with posttraumatic brain damage, had the unusual combination of human growth hormone, thyrotropin, adrenocorticotrophic hormone, and vasopressin deficiencies that were associated with sexual precocity in one patient and early sexual maturation in the second patient, and of adult follicle-stimulating hormone and luteinizing hormone concentrations. At autopsy, the first patient had optic nerve aplasia, a normal pituitary gland, and some disorganization of myelinated fibers in the hypothalamus. The second patient had a normal thyrotropin and prolactin response to thyrotropin-releasing hormone, plus hyperphagia, deranged thirst mechanism, and temperature instability. These findings suggest that the lesion may be a defective hypothalamic regulation of pituitary hormone secretion. Congenital or traumatic hypothalamic-pituitary lesions may not affect all releasing factors or trophic hormones in a similar fashion.