Treatment of sleep apnea with a new separated type of dental appliance (mandibular advancing positioner)

We investigated a new separated type of dental appliance (mandibular advancing positioner: MAP) that is mobile and allows free adjustment of mandibular advancement. In 8 adult male patients with sleep apnea syndrome (SAS), the mean apnea index (AI) decreased from 31.1 to 4.2, and the mean apnea hypopnea index (AHI) decreased from 44.2 to 11.7. The distance of mandibular advancement using the Flankfort horizontal plane as a standard ranged in the 8 SAS patients from 1.8 to 5.0 mm by lateral cephalograms. A high positive correlation was observed between the distance of mandibular advancement and the rate of improvement in AI (R2 = 0.878), or the rate of AHI (R2 = 0.861), showing a higher improvement rate with more marked mandibular advancement.

[Therapeutic outline of sleep disorders]

The more sleep disorders become chronic, the more they become resistible for the treatments. Therefore, it is most important that physicians establish the good relationship with patients and correctly diagnose and treat patients who have acute or transient sleep complaints. Physicians can improve patients' quality of life by evaluation of disease, supportive psychotherapy which include Morita therapy and behavior therapy, sleep hygine advice, and appropriate medications. In all patients, it is necessary for physicians to be aware of the physical, psychological and pharmacological factors, social aspects, and environmental factors of patients, because all these factors play an important role in appearance of sleep disorders.

The Neuropeptide Cyclo(His-Pro) Levels are Increased in Diabetic Ketoacidosis and Fall with Treatment in Parallel with Levels of Glucagon

The importance of insulin deficiency and glucagon excess is recognized as critical in the pathogenesis of diabetic ketoacidosis (DKA). The finding of elevated levels of another gut peptide in DKA with potential relevant physiological effects might renew discussion of the pathogenesis of this disorder. Cyclo(His-Pro) is a gut-brain peptide found in gut of rat and man. In pancreas it is localized to alpha cells. A stereospecific hepatic bonding site has been found. We have shown that cyclo(His-Pro) augments the insulin response to oral glucose in rat by decreasing hepatic insulin clearance. In view of cyclo(His-Pro)'s location in alpha cells, the hepatic binding site and action described, we wondered if levels of cyclo(His-Pro) might be elevated in a hyperglucagonemic state such as DKA and whether these levels might correlate with those of glucagon and other commonly followed parameters in DKA. Plasma was collected from 7 nondiabetic controls and 9 patients in DKA before and after 4, 8, 12, and 24 h of therapy and assayed for glucose, HCO3, anion gap, glucagon and cyclo(His-Pro). Cyclo(His-Pro) levels were higher in DKA patients before therapy than controls (15.6 ± 3.2 vs. 8.0 ± 0.2 pmol/ml; p =0.023) as were glucagon levels (201 ± 4 vs. 56 ± 5ng/L; p = 0.006). Cyclo(His-Pro) levels fell significantly with treatment (15.6 ± 3.2 vs 8.1 ± 1.1; p = 0.024) and in parallel with those of glucagon. We conclude that cyclo(His-Pro) levels are increased in patients with DKA before therapy and fall in parallel with those of glucagon. This represents the first report of altered levels of this peptide in a disease state.

Northern analysis of type II iodothyronine deiodinase mRNA in rat Harderian gland

It has been known that type II iodothyronine deiodinase activity is present in rat Harderian gland and the activity is significantly increased by isoproterenol administration. We have performed Northern analyses to study whether the transcript for type II iodothyronine deiodinase is expressed in rat Harderian gland and whether the isoproterenol stimulation of type II iodothyronine deiodinase activity in rat Harderian gland is due to the change in its mRNA level. Northern analyses have demonstrated that type II iodothyronine deiodinase mRNA, approximately 7.5 kb in size, is expressed in rat Harderian gland, and the mRNA levels as well as the deiodinase activities are greater in hypothyroid rats than those in euthyroid rats. Type II iodothyronine deiodinase mRNA levels and the deiodinase activities in Harderian gland were increased by isoproterenol administration, and the increase in the mRNA levels preceded that in the deiodinase activities. These results indicate that 7.5 kb transcript for type II iodothyronine deiodinase is expressed in rat Harderian gland and beta-adrenergic stimulation of type II iodothyronine deiodinase activity is due at least in part to the increase in its mRNA level.

Excessive twitch movements in rapid eye movement sleep with daytime sleepiness

A man who showed excessive twitch movement, such as fragmentary myoclonus (FM) and periodic movements in sleep (PMS) predominantly during REM sleep, is reported. He complained of excessive daytime sleepiness (EDS). After examination, his twitch movements were shown not to accompany narcolepsy, and his EDS were considered to originate from nocturnal sleep disturbance caused by FM and PMS.

Expression and nocturnal increase of type II iodothyronine deiodinase mRNA in rat pineal gland

It has been demonstrated that thyroxine deiodinating activity is present in rat pineal gland, and its activity increases significantly during the night time. We have studied whether mRNA for type II iodothyronine deiodinase is expressed in rat pineal gland and whether the nocturnal rise of pineal T4 deiodinating activity is due to the change in type II iodothyronine deiodinase mRNA level. Reverse transcription-polymerase chain reaction amplification and Northern blot analyses have demonstrated that type II iodothyronine deiodinase mRNA is expressed in rat pineal gland and its mRNA level increases markedly at midnight. These results suggest that the nocturnal rise in pineal T4 deiodinating activity is due to the change in type II iodothyronine deiodinase mRNA level.

Diagnostic use of daytime polysomnography versus nocturnal polysomnography in sleep apnea syndrome

The usefulness of daytime polysomnography (DPSG) in the diagnosis of sleep apnea syndrome (SAS) is examined. Diagnostic use was investigated by conducting DPSG of two different time periods (Group M, 11.00-14.00 h, and Group A, 15.00-18.00 h). The subjects were 30 patients (28 men and two women; mean age, 54.0 years). Nocturnal polysomnography (NPSG) and DPSG were investigated by comparing indices of sleep, apnea index (AI) and arterial oxygen saturation (SaO2). There was no significant difference among these indices but there was a significant positive correlation between NPSG and DPSG in all variables related to sleep apnea. Moreover, there was no significant difference in the frequency of each type of apnea between NPSG and DPSG in either group. These findings suggest that DPSG is useful not only in diagnosing SAS but in evaluating its severity.

Discrete characteristics of antibodies raised against thyrotropin receptor-related peptides whose sequences are not conserved in the luteinizing hormone/chorionic gonadotropin receptor

In order to identify the specific regions in the human TSH receptor for TSAb and thyroid stimulation-blocking antibody (TSBAb), we produced rabbit antibodies raised against several peptides of the extracellular domain of the human TSH receptor, where sequences are not conserved in the LH/CG receptor, and measured the TSAb activity and TSBAb activity of those antibodies using Chinese hamster ovary cells expressing human TSH receptors. Only antisera from rabbits that were immunized with a peptide of amino acid 32-56, including the small insertion near the N-terminal end of the extracellular domain, showed apparent TSAb activities and have been shown to be significantly precipitated by IgG of patients with Graves' disease. TSAb activity positively correlated with the antibody titers against the peptide in those rabbits. In contrast, antisera from rabbits immunized with a peptide of amino acid 352-378, including a part of the large insertion near the C-terminal end of the extracellular domain, showed the obvious TSBAb activities. TSBAb activity also positively correlated with the degree of antibody titers against the peptide in those rabbits. Moreover, this peptide was significantly immunoprecipitated by the IgG from hypothyroid patients who had TSBAb, and the immunoprecipitation of this peptide positively correlated with TSBAb activities. These results suggest that the epitope responsible for TSAb is quite different from that for TSBAb in the extracellular domain of the human TSH receptor.

The bioactive peptide cyclo(His-Pro) may be absorbed following ingestion of nutritional supplements that contain it

OBJECTIVE

Food contains a number of peptides with potential bioactivity. We previously found ng/mliter to mcg/mliter quantities of cyclo(His-Pro)-like immunoreactivity in a number of foods and nutritional supplements. A number of activities have been attributed to cyclo(His-Pro) (CHP), including appetite inhibition and inhibition of insulin secretion in vitro. We wondered whether the cyclo(His-Pro)-like immunoreactivity present in nutritional supplements might be absorbed and, if so, whether parameters of insulin secretion would be altered.

METHODS

After performing a pilot study which suggested some common nutritional supplements contain CHP, a follow-up study was done to confirm and expand the findings of the pilot study. Eight fasting volunteers ingested approximately 250 mL of a CHP-containing supplement one day, and then an equienergetic CHP-free supplement the next.

RESULTS

Blood drawn for CHP, insulin, glucose, and C-peptide a number of times on both days revealed that when volunteers ingested CHP-containing supplements, CHP levels at 120 minutes were significantly higher than baseline (7.69 +/- 0.50 pmol/mL vs. 9.18 +/- 0.48 pmol/mL; p = 0.011 in the CHP group and 7.90 +/- 0.85 pmol/mL vs. 7.22 +/- 0.73 pmol/mL, p > 0.3 in the CHP-free group) and significantly higher than levels achieved when they drank CHP-free supplements. Levels of glucose, insulin, and C-peptide were not different in the two groups.

CONCLUSION

CHP in nutritional supplements may be absorbed when ingested orally and does not grossly affect glucose or parameters of insulin secretion.

Sex and age differences in soluble guanylate cyclase activity in human platelets

Soluble guanylate cyclase is a key enzyme of nitric oxide (NO)-related intracellular signal transduction in platelets. In the present study, we investigated the effects of sex and age on the enzyme activity in human platelets. Soluble guanylate cyclase activity was determined by generation of cyclic GMP in platelet cytosol. No significant differences in the basal activity of soluble guanylate cyclase were observed between in men and women, and between in young and old subjects. However, soluble guanylate cyclase activity in response to sodium nitroprusside, an exogenous NO donor, was higher in young men than in young and old women. Furthermore, the enzyme activity was lower in old than in young men, but there were no differences in female platelets between from young and old subjects. The present data suggest that NO-related signal transduction system in the platelet is affected by sex and age, which, to certain extent, contributes to different sensitivity of human platelets.

A paradoxical elevation of brain cyclo(His-Pro) levels in hyperphagic obese Zucker rats

Several studies suggest a role for endogenous cyclo(His-Pro) or CHP in appetite regulation. In the present study, we have examined the regional brain distribution of CHP in hyperphagic obese Zucker rats and their lean littermates. The data show a significant elevation in the levels of CHP in many brain regions, including hypothalamus of the obese rat. Within the hypothalamus, the lateral hypothalamic (LH) nucleus of obese rats had significantly higher levels of CHP when compared to that of the lean littermates. Administration of dehydroepiandrosterone, a steroid hormone known to decrease food intake and body weight gain, to obese rats led to decrease in the levels of CHP in the LH. These data further suggest a role for the endogenous CHP in attenuating food intake.

A novel analog of TRH, YM14673, causes a decrease in brain TRH receptors in vitro

Biochemical mechanisms by which analogs of thyrotropin-releasing hormone (TRH) produce their potent neuropharmacological actions on the brain remain ill-defined. We tested effects of YM14673, a novel analog of TRH, on TRH receptors in rat brains in vitro. No significant binding of [3H]YM14673 to brain plasma membranes occurred. In contrast, preincubation of membranes with YM14673 caused dose-dependent decreases in TRH binding. This was not due to competition for TRH binding sites or existence of metabolites of YM14673. Preincubation with DN1417 (an another TRH analog), cyclo(His-Pro) or methionine-enkephalin did not affect the binding. Affections of YM14673 on TRH binding were observed when cerebral cortical membranes were studied; those were not seen in membranes prepared from hypothalamus, striatum, midbrain, hippocampus, or pons-medulla. The present data indicate that YM14673 exerts its characteristic neuro-pharmacological functions through interacting with TRH binding sites in the brain.

Biology of enterostatin. II. Development of enzyme-linked immunosorbentassay (ELISA) for enterostatin (Val-Pro-Asp-Pro-Arg), the procolipase activation peptide

Enterostatins belong to a family of pentapeptides (e.g., Val-Pro-Asp-Pro-Arg in pig, horse, dog, and rat; Ala-Pro-Gly-Pro-Arg in human and chicken; and Val-Pro-Gly-Pro-Arg in rat) derived from the amino-terminus of procolipase after the action of trypsin. Pharmacologic studies with Val-Pro-Asp-Pro-Arg have suggested a role for this peptide in appetite regulation and pancreatic insulin secretion. Studies into the distribution of enterostatins or the role of endogenous peptides have not been possible due to the lack of a suitable method for enterostatin assay. To this end, we raised a highly specific antibody and developed an enzyme-linked immunosorbent assay for Val-Pro-Asp-Pro-Arg. Using the newly developed assay we have shown the presence of Val-Pro-Asp-Pro-Arg-like immunoreactivity (2455 +/- 440 pmol/g) in the rat brain.

Attenuation of alcohol-induced hypothermia by cyclo (His-Pro) and its analogs

Acute administration of cyclo (His-Pro) to rats cause a dose-dependent decrease in ethanol-induced hypothermia. Bromination of the imidazole moiety of histidine in cyclo (His-Pro) resulted in a significant increase in its potency to attenuate ethanol hypothermia. In contrast, benzylation of the imidazole moiety of histidine or the substitution of one or both of the amino acids in cyclo(His-Pro) led to a total loss of its thermomodulatory activity. In conclusion, it appears from these preliminary data that it may be possible to design analogs of CHP that may be effective antagonists for ethanol hypothermia.

Augmentation of dietary fat preference by chronic, but not acute, hypercorticosteronemia

Numerous studies have documented a role for corticosterone in appetitive behavior, including caloric intake and dietary fat preference. In the present study, we have examined the mechanism(s) underlying modulation of dietary fat preference by corticosterone. The results of these studies show a) an increased fat preference with increased basal urinary output, or decreased stimulation of corticosterone output on fasting, b) elevation of fat preference following chronic, but not acute, hypercorticosteronemia produced by exogenous corticosterone administration, and c) emergence of hypercorticosteronemia prior to the development of increased fat preference in developing rats. These observations have led us to suggest that increased fat preference after chronic hypercorticosteronemia may be secondary to changes in the levels or actions of agents known to affect fat intake.

Effects of acetazolamide on the sleep apnea syndrome and its therapeutic mechanism

Twenty male patients with sleep apnea syndrome were treated with acetazolamide (AZM), a carbonic anhydrase inhibitor. In 14 of the patient a significant decrease was found in the number of apnea, apnea index and % apnea time (percentage of time spent with apnea to the total sleep time) with improvement in sleep structure, clinical symptoms, such as insomnia, daytime excessive sleepiness and snoring. A significant decrease was also observed in arterial blood pH and HCO-3 in the 14 improved patients. On the other hand, no improvement occurred in the parameters of sleep apnea and sleep with AZM in the remaining six patients. Moreover, metabolic acidosis and an improvement in arterial blood gases did not occur with AZM in the six patients.

Identification of cyclo(His-Pro)-like immunoreactivity in human follicular fluid: correlation with steroid and peptide hormones

OBJECTIVE

The purpose of this study was to evaluate human follicular fluid (FF) for the presence of cyclo(His-Pro)-like immunoreactivity (CHP-LI). After verifying its presence, we quantitated the levels and investigated correlations with other follicular parameters, including hormone levels.

METHODS

Follicular fluid was collected from female volunteers undergoing controlled ovarian hyperstimulation. Fluid was collected by follicular puncture, either transvaginally (in vitro fertilization) or laparoscopically (gamete intrafallopian transfer) at the time of oocyte retrieval (N = 137). Follicular size was determined ultrasonographically. Assays for steroid and peptide hormones were determined with commercially available radioimmunoassay kits. CHP-LI was measured using a previously reported assay; parallel dilution curves and column chromatography aided in immunoidentity.

RESULTS

The mean FF CHP-LI concentration (13.10 +/- 1.83 nmol/L, N = 137) was greater than the corresponding serum values (9.42 +/- 2.45 nmol/L; N = 21) (P < .05). Large follicles (20 mm or greater; 14.45 +/- 1.74 nmol/L) contained significantly more CHP-LI than either medium follicles (16-19 mm; 11.51 +/- 1.88 nmol/L) or small follicles (15 mm or smaller; 10.83 +/- 2.12 nmol/L) (P < .05). Positive correlations were found between FF CHP-LI values and corresponding FF progesterone and prolactin concentrations (r = 0.67 and 0.62, respectively; P < .05).

CONCLUSION

Mean CHP-LI levels in the FF are greater than those in the corresponding serum. We suggest that the neuropeptide may be originating from either peptidase cleavage of precursor peptides or from granulosa cell production.

Does cyclo(His-Pro) act like amphetamine?

In many pharmacologic tests, cyclo(His-Pro) (CHP) appears to act like a dopaminergic agonist and augments the actions of amphetamine (AMP). Therefore, to determine whether CHP is an AMP-like peptide, a comparison between CHP and AMP was made using four separate tests known to be AMP-responsive. These include, food intake, locomotor activity, dopamine uptake and modulation of binding sites for amphetamine and mazindol. A decrease in food intake and increase in spontaneous locomotor activity and stereotypy was observed after peripheral administration of amphetamine but not CHP. Chronic CHP administration resulted into a decrease in striatal amphetamine - and increase in mazindol-binding sites; in contrast, chronic amphetamine decreased both amphetamine - and mazindol-binding sites. These results show a clear dissociation between CHP and AMP suggesting that CHP is not an amphetamine-like peptide.

Role of endogenous cyclo(His-Pro) in cold-induced hypothermia in the desert rat (Mastomys natalensis)

Central administration of exogenous cyclo(His-Pro) (CHP) is known to produce hypothermia in rodents. In the present study, we examined the role of endogenous CHP in cold-induced hypothermia in the desert rat, Mastomys natalensis. The results of these studies show that a rise in hypothalamic CHP content accompanied a decrease in rectal temperature during cold exposure. Immunoneutralization of endogenous CHP resulted in a significant decline in cold-induced hypothermia. In addition, central administration of cyclo(Ala-Gly), a structural analogue of CHP, also led to a decrease in cold-induced hypothermia. The results of these studies show that changes in endogenous CHP levels may affect body temperature regulation.

Corticosterone facilitation of inhibition of fat intake by enterostatin (Val-Pro-Asp-Pro-Arg)

Enterostatin or Val-Pro-Asp-Pro-Arg (VPDPR) is the amino-terminal pentapeptide of procolipase; VPDPR is generated during tryptic activation of procolipase to lipase. In rodents, exogenous VPDPR has been shown to cause a selective decrement in fat appetite. To understand the mechanism(s) underlying the action of this peptide, we have studied the effects of corticosterone, an adrenal hormone known to modulate caloric intake, on VPDPR-mediated inhibition of appetite. The results of this study show a significant increase in the inhibition of total caloric intake by 250 micrograms/kg VPDPR following corticosterone treatment (control, 2.3%; corticosterone treated, 22.7%). Furthermore, the decrement in the caloric intake in corticosterone-treated rats was exclusively due to the loss of fat intake.

Individual differences in the macronutrient preference profile of outbred rats: implications for nutritional, metabolic, and pharmacologic studies

While screening outbred male Holtzman Sprague-Dawley rats for their macronutrient (protein, carbohydrate, and fat) preferences, we noticed substantial group-to-group variation in the preference profile. This led us to analyze preference data on two hundred and seventy rats collected over a three-year period to determine whether preferences could be predicted. The results led us to conclude that observed variations in macronutrient preference profiles may be secondary to genetic heterogeneity in the outbred population. We have also shown that the outcome of the pharmacologic effects of two agents (insulin and enterostatin) on appetitive behavior will vary from animal to animal within a single group. Accordingly, researchers must be aware that the breeding history of the laboratory animal is a major factor in the outcome of the experiment and interpretation of the findings.

Identification of inositol 1,4,5-trisphosphate binding in human pheochromocytoma

An attempt was made to identify a specific binding of inositol 1,4,5-trisphosphate (IP3) to human chromaffin cell tumors. Crude microsomal fractions of pheochromocytomas possessed significant binding sites for [3H]IP3 with high- and low-affinity constants (Kd = 5.46 and 538 nM, respectively). The binding to these sites was rapid, saturable (reached equilibrium by 1 min at 0 degrees C) and reversible. Competition studies with other inositol phosphate analogs indicated the stereotypic specific binding for IP3. Although no significant difference was observed in the binding densities of IP3 between pheochromocytomas and adrenal nonfunctioning adenomas, the values of high-affinity constants were significantly lower in the former than the latter group (5.77 +/- 1.07, n = 5 vs. 11.30 +/- 1.98 nM, n = 4, p less than 0.05). The present data indicate that characteristics of IP3 binding sites are congruous with their receptor functions and that changes in its binding sites may contribute to the biochemical dissimilitudes in pheochromocytomas.

Inhibitory effects of okadaic acid on thyrotropin and prolactin secretion from rat anterior pituitaries

The present study was undertaken to elucidate the effects of okadaic acid, a potent inhibitor of protein phosphatases, on thyrotropin (TSH) and prolactin (PRL) secretion, and on the hydrolysis of inositol phospholipids in rat anterior pituitaries. Preincubation of anterior pituitaries with okadaic acid caused a dose dependent decrease in TRH- and K(+)-induced TSH secretion, whereas basal secretion of TSH was not affected by pretreatment with okadaic acid. In contrast, okadaic acid resulted in a marked inhibition in both basal, and TRH- and K(+)-stimulated PRL release from anterior pituitaries. In addition, pretreatment with okadaic acid caused a slight, but significant decrease in the formation of [3H]inositol phosphate ([3H]IP) in rat anterior pituitaries. The present study suggests that okadaic acid blocks the release of TSH and PRL by inhibiting Ca2+ influx and that inhibitory effects of okadaic acid on PRL release are, at least in part, due to the inhibition of inositol phospholipid hydrolysis.