Formulation of Ebastine Fast-Disintegrating Tablet Using Coprocessed Superdisintegrants and Evaluation of Quality Control Parameters.

Ebastine is a long-acting, nonsedating, second-generation antihistaminic drug that prevents histamine action, mainly in immediate hypersensitivity. This project was aimed to formulate and characterize orodispersible tablets of ebastine, utilizing different proportions of three disintegrants, namely crospovidone, sodium starch glycolate, and coprocessed superdisintegrant. Initially, fifteen trial batches of ebastine orodispersible tablets were outlined using the central composite design of Minitab software. The tablets were formulated by the direct compression method. The compressed tablets were then evaluated for precompression and postcompression physicochemical parameters, such as angle of repose, Carr's index, Hausner's ratio, hardness, thickness, weight variation, drug content, friability, wetting time, disintegration time, dispersion time, and water absorption ratio. The in vitro dissolution test was conducted according to Indian Pharmacopeia 2018, with the help of the rotating paddle method using 0.5% w/v sodium lauryl sulfate buffer in 0.1 N HCl. For the optimized batch (8th batch), all the physicochemical parameters like angle of repose (33.77°), Carr's index (19.34%), Hausner's ratio (1.24), weight variation (202.5 mg), hardness (4.3 kg/cm2), friability (0.44%), thickness (3.16 mm), dissolution (95.78%), and drug content (101.67%) were within the acceptable limit as per Indian Pharmacopeia 2018. The wetting time, disintegration time, dispersion time, and water absorption ratio were reported to be 25.1 seconds, 16.0 seconds, 38.6 seconds, and 91.92%, respectively. Hence, the results suggested that orodispersible tablets of ebastine can be formulated. Furthermore, the mixing of crospovidone, sodium starch glycolate, and coprocessed super disintegrants can result in excellent desirable properties in the orodispersible tablet.

A luteinizing hormone-releasing hormone agonist decreases biological activity and modifies chromatographic behavior of luteinizing hormone in man.

The effect of the luteinizing hormone-releasing hormone (LHRH) agonist, [D-Trp6,Pro9-NEth]LHRH (LHRHA), on luteinizing hormone (LH) bioactivity was assessed with a rat interstitial cell assay in four men during a 14-d treatment period. Biologic/immunologic (B/I) ratios were unchanged initially with treatment but by day 12 had fallen to levels lower than basal values. Frequent sampling on day 12 revealed blunted gonadotropin responsiveness to LHRHA and absence of spontaneous LH pulsations. Despite continued administration of LHRHA, human chorionic gonadotropin administration resulted in elevated B/I ratios and testosterone levels. Further characterization of the serum immunoreactive LH by Sephadex chromatography revealed a later elution profile during treatment with LHRHA. Thus, LHRHA appears to act, in part, by modification of the bioactivity of LH in man.

Splanchnic metabolism of alanine in intact man. Effects of somatostatin and somatostatin plus insulin.

We examined splanchnic metabolism of alanine in 15 normal males under three sets of conditions: infusion of saline (control studies); infusion of somatostatin (SRIF) (bihormonal deficiency of insulin and glucagon); and infusion of somatostatin plus insulin (selective glucagon deficiency). Net splanchnic alanine uptake (NSAU) remained stable over 2 h during infusion of saline. Infusion of SRIF was associated with a fall in estimated hepatic plasma flow (EHPF) whether or not insulin was infused concomitantly. With SRIF only, arterio-hepatic venous alanine differences increased such that NSAU remained stable over 2 h, despite the fall in EHPF. In contrast, with selective glucagon deficiency, NSAU fell significantly after 2 h, an effect consequent on a fall in EHPF and a delayed fall in arterio-hepatic venous (A-HV) alanine differences. Our studies are compatible with a role for basal glucagon in maintenance of splanchnic extraction of alanine in normal man. However, the SRIF-initiated fall in EHPF may exert an influence on A-HV alanine differences independent of changes in pancreatic hormone secretion.

Cloning and expression of IDDM-specific human autoantigens.

A DNA cloning approach was taken to identify islet cell protein antigens that are recognized specifically by insulin-dependent diabetes mellitus (IDDM) sera. A human islet cDNA library was generated and screened with diabetic sera. In this article, identification of two clones is described. Proteins expressed by these lambda phages appeared to react specifically with newly diagnosed diabetic sera. Islet cell antibody 12 (ICA12) was tested by Western blotting. ICA512 was not reactive with sera in the Western format but was specifically immunoprecipitated by diabetic sera from an Escherichia coli extract.

Pancreatic islet cell cytoplasmic antibody in diabetes is represented by antibodies to islet cell antigen 512 and glutamic acid decarboxylase.

The presence of serum islet cell cytoplasmic antibodies (ICAs) is a standard autoimmune marker for insulin-dependent diabetes mellitus (IDDM). The antigenic molecule(s) responsible for ICA has not been identified, although antibodies to the 65-kDa isoform of glutamic acid decarboxylase (GAD65) do contribute. We tested 129 IDDM sera for antibodies to ICA512 (anti-ICA512), antibodies to GAD (anti-GAD), and ICAs; we tested for inhibition of ICAs with purified recombinant ICA512 and sheep brain GAD; and we tested for immunofluorescence reactivity on COS7 cells transfected with cDNA clones encoding ICA512 and GAD65. The results were that anti-ICA512 antibodies contribute to ICA reactivity and that these, in combination with anti-GAD antibodies, account for most ICA reactivity in IDDM. Anti-ICA512 antibodies were present at a frequency of 51% in 61 patients with early-onset IDDM (age of onset < or = 20 years) of short duration (< or = 1 month) but only in 9% of 68 patients with an onset age of > 20 years and/or a disease duration of > 1 month. The frequency of anti-GAD antibodies in these sera was similar irrespective of duration or age of onset. Anti-ICA512 and anti-GAD antibodies were demonstrable by indirect immunofluorescence on transfected COS7 cells, and ICA could be inhibited using either recombinant ICA512 or purified brain GAD. We conclude that anti-ICA512 and anti-GAD antibodies contribute to ICA reactivity and that anti-ICA512 antibodies account for the increased frequency of ICA reactivity in early-onset IDDM of short duration.

Human islet glucokinase gene. Isolation and sequence analysis of full-length cDNA.

Pancreatic islet glucokinase (ATP:D-hexose-6-phosphotransferase) cDNAs were isolated from a human islet cDNA library in lambda-gt11. One clone (hlGLK2), 2723 bp plus additional poly(A) residues, appeared to be full length because its size was consistent with a single 2.9-kb glucokinase mRNA on Northern-blot analysis of islet RNA. This cDNA contained an open reading frame of 1395 bp from an ATG codon at position 459, encoding a predicted protein of 465 amino acids (52,000 M(r)). Comparison of the nucleotide sequences of the human islet glucokinase cDNA with that of the recently isolated human liver glucokinase cDNA revealed that the two cDNAs differed completely on their 5'-ends, followed by an identical 2204-bp overlap extending to the 3'-ends. The 5'-ends of islet and liver glucokinase cDNAs predicted proteins that differ by 15 NH2-terminal residues. The overall sequence identity (70%) between the first exons of the human islet and rat islet cDNAs suggested that the islet promoter regions, like the liver promoter regions, have been conserved through evolution. Thus, NH2-terminal differences for human liver and islet enzymes might be explained by use of alternate promoters between the two tissues, analogous to the NH2-terminal differences of the rat liver and rat islet enzymes. If so, this relationship predicts important tissue-specific regulatory functions of these regions. Variations in the glucokinase gene are likely to occur in humans. Isolation of a human islet glucokinase cDNA has provided the sequence necessary to determine whether these variants are important determinants in the genetic predisposition for diabetes mellitus.

ICA512 autoantibody radioassay.

As part of a general program of screening islet expression libraries we have identified a clone from a lambda gt11 human islet expression library that reacts with human diabetic sera and, upon sequencing, was determined to be the neuroendocrine islet autoantigen ICA512 (islet cell antigen 512). In the current communication, we describe the development of a radioassay for autoantibodies to ICA512 (ICA512AA) using in vitro transcribed and translated protein for production of labeled antigen. Our initial results indicate that this radioassay is significantly more sensitive than the enzyme-linked immunosorbant assay, which uses a COOH-terminal fragment of ICA512. The ICA512AA radioassay uses a 96-well format with membrane separation of antibody bound from free antigen and should be readily adaptable to automated large-scale screening. Only 7 microliters of serum is required for triplicate determinations. In order to determine the specificity and sensitivity of this assay and estimate its positive predictive value, we have studied 42 new-onset diabetic patients, 33 first-degree relatives of diabetic patients followed to diabetes, 694 islet cell antibody-negative (ICA-) relatives, and 205 normal control subjects. Thirty-eight percent of new-onset patients and 48% of relatives followed to diabetes express autoantibodies to ICA512 exceeding the 99th percentile of the normal control subjects. In contrast, only 1.4% of ICA- first-degree relatives were positive for ICA512 autoantibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of the LIM/homeodomain gene islet-1 and single nucleotide screening in NIDDM.

Islet-1 (Isl-1) is a unique transcription factor that binds to the enhancer region of the insulin gene. To evaluate this gene in non-insulin-dependent diabetes mellitus (NIDDM), a full-length human Isl-1 cDNA was isolated and the genomic structure was characterized. The cDNA [2,395 bp plus additional poly(A) residues] contained an open reading frame from an initiator methionine at nucleotide 240 to an opal stop codon at nucleotide 1,286 (GenBank accession number UO7559), encoding a predicted protein of 349 amino acids (39 kDa). From their ends, 23 additional clones were sequenced, revealing 15 incomplete cDNAs and 8 intron-containing partially processed precursors. As determined by Northern blotting and reverse transcriptase-polymerase chain reaction analysis, Isl-1 was most abundantly expressed as a 2.4-kb mRNA in human islets, with a restricted pattern of expression in other adult human tissues. Analysis of genomic clones revealed that Isl-1 is encoded by six exons, varying in size from 168 bp (exon 5) to 1,230 bp (exon 6). Exons 2 and 3 each encode a LIM domain, while the homeodomain is completely contained within exon 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Dichloroacetate--its in vivo effects on carbohydrate metabolism in the conscious dog.

The effects of sodium dichloroacetate (DCA) on carbohydrate metabolism in conscious, 48-h-fasted dogs were examined using the hepatic A-V difference technique and a double isotope infusion technique (3H-glucose to measure glucose production and 14C-alanine to assess gluconeogenesis). DCA infusion (0.4 mg/kg-min) resulted in an 82 +/- 1% fall in the arterial plasma alanine level and a 53 +/- 8% fall in the arterial whole blood lactate level. Hepatic uptake of alanine and lactate fell 67 +/- 5% and 59 +/- 15%, respectively, although the fractional extraction of these intermediates was not altered. DCA decreased the conversion of circulating alanine and lactate to glucose but by only 41 +/- 7%, suggesting that a slight increase in the efficiency of the intrahepatic gluconeogenic process took place. This may be explained by the decrease in the plasma insulin level (39 +/- 9%) that occurred in the presence of an unchanged plasma glucagon concentration. Despite the substantial fall in the levels of gluconeogenic precursors in blood and the considerable decrease in their rate of conversion to glucose, the overall rates of glucose production and the blood glucose concentration were not altered by DCA. These data indicate that the alanine and lactate supplied by the periphery after a 48 h fast in the dog are not essential for the acute maintenance of glucose production or euglycemia. They suggest, further, that a compensatory increase in glucose production can occur by drawing on an alternate intrahepatic carbon source, the nature of which and signal for which remain unclear.

Inhibition of tyrosine aminotransferase gene expression by retinoic acid.

Regulation of tyrosine aminotransferase (TAT) gene expression was examined in RALA255-10G, a simian virus-40 tsA mutant-immortalized adult rat hepatocyte line. At the nonpermissive temperature (40 C), these hepatocytes exhibited a differentiated phenotype and actively expressed the TAT gene, but only in the presence of dexamethasone (DEX). The glucocorticoid-mediated TAT expression was inhibited by cycloheximide, a protein synthesis inhibitor, and by RU486, a glucocorticoid antagonist, suggesting that glucocorticoid induction requires protein synthesis and may be mediated through hormone receptors. (Bu)2cAMP (Bt2cAMP) or retinoic acid, individually or in combination, failed to increase TAT mRNA levels. However, Bt2cAMP greatly potentiated the induction by DEX, whereas retinoic acid inhibited the induction by DEX or DEX/Bt2cAMP. Nuclear run-on assays demonstrated that the induction of TAT expression by DEX or DEX/Bt2cAMP in RALA255-10G cells is regulated primarily at the transcriptional level. In contrast, retinoic acid antagonized the DEX- or DEX/Bt2cAMP-mediated induction without affecting the rate of TAT gene transcription. Instead, retinoic acid destabilized TAT mRNA. The half-life values of TAT mRNA in DEX/Bt2cAMP- and DEX/Bt2cAMP/retinoic acid-treated cells were approximately 235-270 min and 90-100 min, respectively. Our results indicate that inhibition of TAT expression by retinoic acid was regulated primarily at the posttranscriptional level.

Autonomous hyperprolactinemia in tuberous sclerosis.

Amenorrhea and galactorrhea developed in a female patient with tuberous sclerosis. There was no evidence of a pituitary tumor; she had an abnormal EEG, and computed tomographic scan showed multiple intracerebral calcifications but no lesions in the pituitary gland or hypothalamus. She had fixed hyperprolactinemia that was unresponsive to protirelin, chlorpromazine, levodopa, bromocriptine mesylate, or estrogen. The circulating prolactin may be of pituitary origin or may possibly be secreted ectopically by a hamartoma.

An acquired hemorrhagic disorder from long-acting rodenticide ingestion.

A 62-year-old man who presented with gross hematuria was found to have a severe and prolonged coagulopathy. The workup involved mixing studies, which suggested an acquired factor deficiency, and specific factor assays, which demonstrated isolated defects in vitamin K-dependent factors. With vitamin K deficiency excluded, and serum warfarin levels undetectable, so-called superwarfarin ingestion was suspected. This diagnosis was subsequently proved by biochemical evidence (an increase in the serum vitamin K epoxide-vitamin K ratio) and compatible history. This case illustrates how a logical workup can lead to a diagnosis of superwarfarin ingestion, even without a history of such an ingestion. New serum assays for specific superwarfarins are also mentioned. This case report should increase clinicians' awareness of long-acting rodenticide ingestions.

The effect of educational preparation on physician performance with a sexually transmitted disease-simulated patient.

BACKGROUND: Simulated patients are used with increased frequency for medical students and residents, but have not been used very often with practicing physicians. We hypothesized that educational materials could improve primary care physicians sexual practices history taking and counseling as assessed by a simulated patient in the physician's office. METHODS: Simulated patient (SP) visits were made to 232 (75% of eligible) primary care physicians. The patient simulated was a sexually active young woman with vaginitis and sexually transmitted disease/human immunodeficiency virus risk behaviors. In advance of the visit, physicians were provided educational materials (monograph, pamphlet, and audiotape) developed for the study, including a risk assessment questionnaire that could be used with patients. RESULTS: Most physicians randomly allocated to the intervention participated. Twenty-one percent of physicians refused to schedule an SP visit. Physicians who received an SP rated the experience highly. Physicians who prepared for the visit with the educational materials performed significantly better than those who did not. About two thirds of physicians reviewed the materials, many for the second time, after the SP visit. Physicians who used the study risk assessment questionnaire performed better. Many physicians (24.9% to 39.8%) did not meet each of the four goals for the visit, as assessed subjectively by the SP. Physician performance was better for measures of general patient interaction than for measures of sexual practices history taking and counseling techniques. CONCLUSION: The SP visit was acceptable to most physicians practicing in a community and was evaluated by them as an appealing and an effective educational experience. The SP, however, has limited feasibility because of cost. The SP led to review of materials by nearly all physicians either before or after the visit. Physicians who prepared before the visit performed better on every dimension, eliciting more information, displaying better patient interaction skills, and meeting more of the educational goals. Even with educational preparation, however, many physicians were not perceived as being effective counselors.

Papilledema in two patients with acromegaly and intrasellar pituitary tumors.

Two patients had bilateral papilledema complicating acromegaly. Both patients had enlarged blind spots, but otherwise visual fields were normal. Suprasellar extension of the pituitary tumors was diligently sought with the use of visual field examination, pneumoencephalography, internal carotid arteriography, and computed axial tomography, and tumor extension did not exist. Transphenoidal and transethmoidal routes were used to perform partial hypophysectomies in these patients. The procedure was completely successful in one patient and partially successful in the other patient. After hypophysectomy, papilledema resolved in both patients. This beneficial effect may be the result of anatomical changes, the reduction in growth hormone levels, or both. These observations suggest that the acromegaly may be different from papilledema that occurs secondary to suprasellar expansion of pituitary tumors.

Epidermal growth factor stimulates production of progesterone in cultured human choriocarcinoma cells.

Epidermal growth factor (EGF) stimulates the production of progesterone by JEG-3, a clonal strain of human choriocarcinoma cells. Stimulation occurs in a time and dose-dependent manner. In addition, EGF increases [14C]-acetate incorporation into [14C]-cholesterol in JEG-3 cells, and this may constitute its mechanism of action in enhancing progesterone synthesis.

Cloning and functional expression of the human glucagon-like peptide-1 (GLP-1) receptor.

Truncated forms of glucagon-like peptide-1 are the most potent endogenous stimuli of insulin secretion and have powerful antidiabetogenic effects. To determine the structure and coupling mechanisms of the human GLP-1 receptor we have isolated two pancreatic islet cDNAs, encoding the 463 amino acid receptor and differing mainly in their 3' untranslated regions. The deduced amino acid sequence is 90% homologous with the rat GLP-1 receptor. Northern blot analysis shows expression of a single 2.7 kb transcript in pancreatic tissue. When expressed in COS-7 cells the recombinant receptor conferred specific, high affinity GLP-1(7-37) binding. GLP-1(7-37) increased intracellular cAMP in a concentration dependent manner and caused an increase in the free cytosolic calcium ([Ca2+]i) from an intracellular pool, characteristic of phospholipase C (PLC) activation. Thus, like the structurally related glucagon and parathyroid hormone receptors, the human GLP-1 receptor can activate multiple intracellular signaling pathways including adenylyl cyclase and PLC. Knowledge of the GLP-1 receptor structure will facilitate the development of receptor agonists and elucidation of the important role of GLP-1 in normal physiology and disease states.

Lack of a role for glucagon in the disposal of an oral glucose load in normal man.

The present study was undertaken to determine the role of glucagon in determining the disposition of an oral glucose load in normal man. To accomplish this, the plasma glucose response to an oral glucose load was determined in four normal men who were studied on two occasions. During one study, glucagon (3 ng/kg.min) was administered to prevent the fall in plasma glucagon noted after oral glucose ingestion. Despite elevation of plasma glucagon levels to 350 pg/ml in this protocol, the plasma insulin and glucose levels achieved were virtually identical to those obtained after oral glucose alone. These results indicate that neither physiological elevations of plasma glucagon nor the suppression of plasma glucagon seen during oral glucose administration alter glucose tolerance in normal man. Thus, in a normal man capable of secreting appropriate amounts of insulin in response to the ingestion of glucose, glucagon plays no appreciable role in the disposition of this glucose load.

Long term therapy with luteinizing hormone-releasing hormone in isolated gonadotropin deficiency: failure of therapeutic response.

We have evaluated the therapeutic response to exogenous LRH (1 mg, sc, either twice daily or three times daily) in six subjects with isolated gonadotropin deficiency. Four males were treated for 6 months, of whom two showed a transient rise in serum testosterone. However, testosterone levels subsequently remained at pretreatment levels in each of the four subjects during LRH therapy. One of the two female subjects displayed a transient rise in 17 beta-estradiol levels. All four males showed a notable rise in testosterone after hCG, and the one female tested responded to menotropins, while receiving LRH. We propose that the number of quanta of gonadotropins released per day with our therapeutic regimen was inadequate to generate a normal gonadal response.

Pituitary and gonadal desensitization after continuous luteinizing hormone-releasing hormone infusion in normal females.

Three normal females were studied during the early follicular phase of the menstrual cycle employing a continuous infusion of LHRH (1.4 micrograms/min) for 72 h. Blood samples were taken every 4 h. LH concentrations climbed from 9.3 mIU/ml basally to peak values of 120 mIU/ml at 12 h, then fell to a plateau between 23-31 mIU/ml from 36-72 h. FSH levels rose from 5.4 to 36 mIU/ml at 4 h of infusion and then returned to baseline. 17 beta-Estradiol increased from 48 to 184 pg/ml at 32 h, but subsequently fell toward basal concentrations. 17-Hydroxyprogesterone increased from 0.5 to 1.23 ng/ml at 12 h and remained elevated for the remainder of the infusion period. Serum progesterone levels remained constant. Three females with premature ovarian failure were studied, and the pattern of gonadotropin release was similar to that of normal subjects. Studies demonstrate that continuous LHRH infusion in normal females causes pituitary and gonadal desensitization. The desensitization of the pituitary is independent of gonadal activity.

Corticotropin-releasing hormone is not the sole factor mediating exercise-induced adrenocorticotropin release in humans.

To determine whether CRH is the sole mediator of ACTH release during exercise, five men and five women were given, in a subject-blinded random manner at separate visits, both a 6-h infusion of ovine CRH (1 microgram/kg.h) and a saline infusion as a placebo. After the fourth hour of each infusion, when plasma concentrations of ovine CRH were sufficiently elevated to saturate the capacity of the corticotroph to respond further to CRH, each subject completed a high intensity intermittent run. Plasma ACTH and cortisol levels increased significantly during the CRH infusion from 4.6 +/- 0.8 (mean +/- SE) to 8.6 +/- 1.6 pmol/L and from 361 +/- 39 to 662 +/- 70 nmol/L, respectively (P less than 0.05). Despite elevated preexercise cortisol levels during the CRH infusion, plasma ACTH rose to 32.0 +/- 8.5 pmol/L after exercise. During the saline infusion, plasma ACTH rose from 3.4 +/- 0.6 pmol/L before exercise to 18.1 +/- 4.2 after exercise. Time-integrated responses for postexercise values of ACTH and cortisol were higher during the CRH infusion than during the saline infusion (P less than 0.05). No significant exercise-induced differences in heart rate or plasma concentrations of lactate, epinephrine, and norepinephrine were observed between the two tests. The findings suggest that some factor(s) in addition to CRH causes ACTH release during exercise. Vasopressin, produced by the magnocellular and/or parvocellular neurons of the hypothalamus, is a likely candidate.