In vitro and in vivo bioequivalence of commercial prednisone tablets

The purpose of the study was to examine the bioequivalence of five commercially available oral prednisone products. The in vivo study utilized 18 healthy males, each of whom was administered 20 mg of prednisone as a reference solution or as a tablet in a 6-week, six-way crossover design. Blood was collected and serum was assayed, using an HPLC procedure specific for prednisone and prednisolone. Mean pharmacokinetic parameters (t 1/2, ke, Cmax, tmax, and AUC) were determined. ANOVA was performed on the prednisone and prednisolone data (F-test, p less than 0.05) as well as Duncan's multiple range analysis. Dissolution tests were also performed on each of the five products in order to test the relationship between dissolution and bioequivalence among prednisone products. The in vitro study consisted of a standard USP dissolution test which included tablets from the same lots as the tablets used in the in vivo study. The data showed no statistical difference in any of the pharmacokinetic parameters among tableted products, subjects, or dosing periods in the study. There was also no statistical difference in the dissolution study among the five commercial tablet forms.

Pre-exposure rabies prophylaxis: efficacy of a new packaging and delivery system for intradermal administration of human diploid cell vaccine

The efficacy of a newly designed syringe prepacked with human diploid cell vaccine in a sufficient quantity to deliver individual 0.1 ml doses intradermally was tested by injecting 40 veterinary students with a single dose on each of days 0, 7 and 28. A second group of 20 students received the ordinary series of three 1.0 ml intramuscular vaccine doses by needle and syringe. All participants in both groups developed neutralizing antibodies to rabies above the suggested minimum of 0.5 international units per ml by day 49. The geometric mean titres were somewhat lower in the group receiving the 0.1 ml doses compared to the group given 1.0 ml doses; however, this was considered of no clinical significance since everyone achieved a titre above the suggested minimum. There was little difficulty in reconstituting the vaccine prepacked in the lumen of the syringe and the syringe was easy to manipulate.

Accumulation of coated vesicles bearing mannose 6-phosphate receptors for lysosomal enzymes in the Golgi region of I-cell fibroblasts

The distribution of mannose 6-phosphate (Man6P) receptors for lysosomal enzymes was investigated in human normal and mucolipidosis II (I-cell) disease fibroblasts by light and electron microscopic immunocytochemistry. In normal fibroblasts whose lysosomal enzymes contain Man6P recognition markers required for binding to the receptor, intracellular immunoreactive receptors were concentrated in one or two cisternae located on one side of the Golgi stack, in coated vesicles, and in lysosomes and endosomes. Presumably, this distribution delineates the Man6P-dependent transport pathway for newly synthesized lysosomal enzymes. In I-cell fibroblasts whose lysosomal enzymes lack the Man6P recognition marker, intracellular receptors were found almost exclusively in one or two Golgi cisternae and in numerous coated vesicles located near the immunoreactive cisternae but were rarely detected in lysosomes and endosomes. The results obtained on I-cell fibroblasts suggest that in the absence of endogenous ligands (lysosomal enzymes bearing Man6P residues), Man6P receptors do not constitutively shuttle-via coated vesicles-between the Golgi complex and lysosomes or endosomes. Rather, they accumulate in coated vesicles concentrated at the presumptive sorting site in the Golgi complex. The findings suggest that a specific subpopulation of coated vesicles (primary lysosomes) is involved in Man6P receptor transport of lysosomal enzymes from the Golgi complex to lysosomes and that their relocation is triggered by ligand binding.

Redistribution of mannose-6-phosphate receptors induced by tunicamycin and chloroquine

The distribution of Man-6-P receptors was determined by immunoperoxidase cytochemistry in Clone 9 hepatocytes cultured in the presence or absence of tunicamycin and chloroquine, agents that perturb lysosomal enzyme sorting and lead to their secretion. In control (untreated) cells, receptors were localized in cis Golgi cisternae, coated vesicles, and in endosomes or lysosomes. After tunicamycin treatment, receptors were found in coated vesicles lined up along the cis cisternae but were not detected in endosomes or lysosomes. After chloroquine treatment, receptors were localized in large vacuolated endosomes or lysosomes but were not usually detected in Golgi cisternae or in coated vesicles. These results demonstrate a redistribution of receptors along the normal Man-6-P-dependent sorting pathway after these treatments. In ligand-deficient (tunicamycin-treated) cells, immunoreactive receptors accumulate at the presumptive sorting site in the cis Golgi and are depleted from endosomes and lysosomes. When the intralysosomal pH is increased (by chloroquine treatment) preventing ligand-receptor dissociation, receptors accumulate at the presumptive delivery site (lysosomes and endosomes) and are depleted from the cis Golgi region. The findings also suggest that (a) ligand binding triggers movement of the receptor to endosomes or lysosomes, and (b) ligand dissociation triggers their movement back to the cis Golgi region.

Intracranial sparganosis: an uncommon infection. Case report

The first case of intracranial sparganosis to be reported from the United States is presented. The patient, a 27-year-old woman, complained of focal seizures involving the right lower extremity. A left parietal parasagittal craniotomy was performed, and a granuloma containing a sparganum was excised from the parietal lobe. The clinical and pathological features of sparganosis are reviewed. Only five cases of intracranial sparganosis have previously been described.

Lipomatous meningioma associated with cerebral vascular malformation

A unique epileptic patient with intracranial neoplasm is reported in which a meningioma with lipomatous and osseous components was found associated with cerebral arteriovenous malformation at the same location in the right frontal lobe. The development of the leptomeningeal neoplasm may have been influenced by the underlying vascular anomaly. The cerebral arteriovenous malformation and altered hemodynamics also could have induced the sudden onset of clinical seizures, hemiparesis, and unconsciousness.

Intracranial ultrasound diagnosis of neonatal periventricular leukomalacia

Periventricular leukomalacia (PVL) is characterized by focal areas of white matter necrosis adjacent to the external angles of the lateral ventricles. The diagnosis of PVL has hitherto been limited to autopsy findings. The authors discuss pertinent literature and report in vivo diagnosis of nonhemorrhagic PVL by real-time intracranial ultrasonography. They recommend further study of ultrasound as a diagnostic method for evaluating infants at risk for PVL.

An in vivo single- and multiple-dose study of several marketed brands of conventional and controlled-release theophylline

In a single-dose study, 18 healthy adult males consumed each of six dosage forms of theophylline. A conventional-release tablet, a syrup, and four competing brands of controlled-release theophylline were studied. Serial serum samples were obtained and analyzed via high pressure liquid chromatography (HPLC). After achieving steady state, 15 healthy adult males consumed each of five dosage forms of theophylline in a multiple-dose study. Serial blood samples were obtained between 0 and 72 hours and subjected to analysis with HPLC. The results indicated that the controlled-release products were not bioequivalent, although they achieved longer time-to-peak values than did the immediate-release syrup and the conventional-release tablet. A single sustained-release product was uniquely different on most pharmacokinetic parameters when compared with the remaining three controlled-release products. In general, the dosage form variation exceeded the individual subject variation on the single-dose study, but the opposite was true for the multiple-dose study.

The mannose-6-phosphate receptor for lysosomal enzymes is concentrated in cis Golgi cisternae

Mannose-6-phosphate (Man-6-P) receptors for lysosomal enzymes were localized by immunocytochemistry in several secretory and adsorptive cell types using monospecific antireceptor antibodies. By immunofluorescence, the receptors were found in the Golgi region of polarized cells. When localized by immunoperoxidase at the electron microscope level, they were detected in Golgi cisternae, coated vesicles, endosomes, and lysosomes of all cell types examined (hepatocytes, exocrine pancreatic and epididymal epithelia). Within the Golgi complex, immunoreactive receptors were restricted in their distribution to one or two cisternae on the cis side of the Golgi stacks. They were not detected in trans Golgi or GERL cisternae. Based on their high concentration of Man-6-P receptors, we propose that the cis Golgi cisternae represent the site where the secretory and lysosomal pathways diverge: lysosomal enzymes bearing the Man-6-P recognition marker bind to Man-6-P receptors in this location and are delivered to endosomes and lysosomes via coated vesicles.

Specific and azurophilic granules from rabbit polymorphonuclear leukocytes. I. Isolation and characterization of membrane and content subfractions

The specific and azurophilic granules of rabbit polymorphonuclear heterophils (PMNs) have been isolated and fractionated into membrane and extractable subfractions. Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) revealed several features of the protein composition of the two granules: (a) Whereas each type of granule had 40-60 proteins separable on one-dimensional gradient gels, few of the proteins were common to both granules. (b) The proteins of the extractable fractions (which comprised approximately 98% of the total granule protein) of each granule were distinct from the proteins of the membrane fractions (which comprised approximately 2% of the total granule protein). (c) The extractable proteins co-migrated with those collected from the medium of ionophore-treated, degranulating PMNs and therefore were defined as content proteins. These results were confirmed by radiolabeling studies. Lactoperoxidase-catalyzed iodination of intact granules did not label the content proteins but did label proteins that co-migrated with major granule membrane proteins. Moreover, disruption of the granules before iodination led to labeling of both content and membrane proteins. We conclude that the membranes of specific and azurophilic granules, which arise from different faces of the Golgi complex, are composed of unique sets of membrane proteins some of which are exposed on the cytoplasmic face of the granules.

Specific and azurophilic granules from rabbit polymorphonuclear leukocytes. II. Cell surface localization of granule membrane and content proteins before and after degranulation

The compositional relationship between the cell surface of rabbit polymorphonuclear leukocytes (PMNs) and the membranes of PMN cytoplasmic granules has been investigated. Heterophilic PMNs obtained from peritoneal exudates contained 13 cell surface polypeptides ranging in molecular weight from 220,000 to 12,000 daltons as determined by lactoperoxidase-catalyzed protein iodination and gel electrophoresis. Of these, four polypeptides co-migrated with proteins identified as the major constituents of specific (SpG) and azurophilic (AzG) granule membranes. The most notable of these were cell surface proteins of 145,000 and 96,000 daltons that co-migrated with proteins identified as granule content proteins released from PMNs during exocytosis. Extensive washing did not remove these proteins from the cell surface. Iodination of PMNs after the release of SpG and AzG contents by calcium ionophore- induced exocytosis revealed that there was not a dramatic quantitative change in the proteins on the cell surface. Instead, there were large, quantitative increases in the relative amounts of (125)I that were incorporated into several pre-existing cell surface proteins; all of these cell surface proteins co-migrated as a set with those polypeptides identified as either granule membrane or content proteins. Although nearly all of the major polypeptides of SpG and AzG had counterparts on the cell surface of freshly isolated peritoneal exudates PMNs, there were several polypeptides that were unique to the cell surface. Thus, the PMN has at least three membrane compartments with strikingly different protein compositions.

The effects of cholestyramine, colestipol, and ADR-132 on the rat prostate and dunning R-3327 adenocarcinoma

The effects of three compounds known to have hypocholesterolemic activity in several species were investigated on the rat prostate and the hormone-dependent R-3327 rat prostatic adenocarcinoma. Cholestyramine, colestipol, and ADR-132 are bile acid-sequestering anion exchange resins which were fed to separate groups of adult male Copenhagen X Fischer (F1) hybrid rats in doses of 0.25%, 1.00%, and 2.00% of diet. The results indicate that serum cholesterol levels in tumor-bearing rats and controls fed these compounds for 29 days were not reduced. The body and organ weights as well as the histological features of the prostate gland, seminal vesicles, and the R-3327 tumor were unaffected by these agents.

Failure of atractyloside to inhibit synaptosomal mitochondrial energy transduction

Studies on synaptosome mitochondrial respiration are complicated by "free" mitochondria. Veratridine stimulation of synaptosomal respiration was due to increased Na+ cycling at the synaptosome membrane associated with increased oxidative phosphorylation of intraterminal ADP and was inhibited by oligomycin, ouabain or Na+ free medium. Atractylate or carboxyatractyloside failed to block veratridine-stimulated respiration but inhibited exogenous-ADP-stimulated respiration. Protein synthesis in the synaptosome fraction was inhibited by oligomycin, valinomycin or 2,4-dinitrophenol but was unaffected by excess atractylate. No change in synaptosomal adenine nucleotide content was found in the presence of atractylate, although a significant decrease in the [ATP]/[ADP] was found with oligomycin, veratridine or valinomycin. These findings show that atractylate does not modify intraterminal mitochondrial energy transduction and indirectly suggest an impermeability of the synaptosome membrane to atractylate.

Pathological findings underlying focal temporal lobe hypometabolism in partial epilepsy

Histopathological studies were carried out on temporal lobe tissue from 25 patients with partial complex seizures who were studied by interictal positron computed tomography (PCT) with 18F-fluorodeoxyglucose and subsequently underwent anterior temporal lobe resection. Abnormalities were identified on x-ray computed tomographic scans in 7 patients, but none indicated the site of a pathologically confirmed structural lesion. Hypometabolic zones were observed on PCT scans of 22 patients and corresponded to focal pathological abnormalities in 19 (15 mesial temporal sclerosis, 2 small neoplasms, 1 angioma, 1 heterotopia). In 1 patient with a focally abnormal PCT scan and no pathological changes, the lesion may have been located posterior to the resection. In the remaining 2 patients, the hypometabolic zones later disappeared and may have represented a transient response induced by depth electrode implantation. Three patients with normal PCT scans had no pathological abnormalities in their resected tissue. The degree of relative hypometabolism measured by PCT correlated well with the severity of the pathological lesion, but the size of the hypometabolic zone was generally much larger than the area of pathological involvement. This discrepancy could not be considered an artifact of technique and must represent either structural abnormalities below the resolution of routine histopathological studies (e.g., loss of synapses) or functional inactivation of neuronal elements associated with the epileptogenic lesion.

Mesenchymal differentiation in trigeminal neurilemmoma

An unusual neurilemmoma of the trigeminal nerve in a 31-year-old woman is described. The neoplasm was roentgenographically calcified and contained various types of mesenchymal tissue, including a cavernous angioma, cartilage, bone, and adipose tissue. Angioma in combination with neurilemmoma occurs more frequently than other forms of mesenchymal tissue. Lipoma is an uncommon component of neoplasms affecting the cranial nerves. Cartilage and bone are rarely encountered in benign intracranial neurilemmomas. The histogenesis of this combined neoplasm is discussed in relation to the ectomesenchymal properties of the neural crest.

Thermo-magnetic surgery for experimental renal cancer

Thermo-magnetic surgery is an innovative modality in the treatment of malignancies. This unique combination can produce selectively controlled destruction of deep tumors. Heating of the magnetic metallic compounds of ferrosilicone by hysteresis produces temperatures which are incompatible with cancer cell survival. The intense focal heating causes a coagulation necrosis. Damage to surrounding normal tissue can be avoided by careful temperature monitoring and power control of the magnetic field. Cell destruction in the target tissue has been demonstrated by light and electron microscopy. Reproducible and predictable VX2 renal carcinomas in rabbits have been produced and used as the tumor model in the initial experiments of this research project. A clinical trial with selected cancer patients, performed with this technique of thermo-magnetic surgery, is now a reasonable and feasible procedure.

Community-acquired methicillin-resistant Staphylococcus aureus endocarditis in the Detroit Medical Center

Between June 1980 and September 1981 we evaluated 24 cases of endocarditis from methicillin-resistant Staphylococcus aureus. All of the cases occurred in drug addicts and all were community-acquired. The patients ranged in age from 21 to 59 years and represented an older population than that generally reported for bacterial endocarditis in addicts. Men and women were equally represented (one man presented twice). This unusually high proportion of women may reflect a difference in the rate and location of carriage of methicillin-resistant S. aureus compared with that of methicillin-sensitive staphylococci. Three patients died, one of whom had signed out of the hospital on the 14th day and returned moribund 27 days later. Vancomycin treatment for 28 days was adequate therapy for most patients.

Bioavailability of regular and controlled-release chlorpheniramine products

The bioavailability of chlorpheniramine regular-release versus controlled-release products was compared using 15 human subjects. The dosage forms evaluated were an 8-mg barrier coated-bead capsule, an 8-mg repeat action tablet, two 4-mg tablets, and 4- and 8-mg syrups. Single doses of each product were administered orally in a 5-way crossover study, plasma samples were collected at specific time intervals, and chlorpheniramine levels assayed by HPLC. Pharmacokinetic analysis was based on a two-compartment open model. The average plasma elimination half-life of chlorpheniramine was calculated to be approximately 18.3 hr. The controlled-release products gave a higher Cmax than the 4-mg syrup, but less than two 4-mg tablets. The controlled-release products also extended the time necessary to attain peak drug levels compared to the 4- and 8-mg syrups. The area under the curve (AUC) data for the controlled-release products was not equivalent to equal amounts of the regular-release products. The study indicated that while the controlled-release chlorpheniramine products were successful in prolonging the time course of absorption, this was at the expense of incomplete bioavailability of the drug.

Review article: mucolipidosis IV

We review all reported cases of Mucolipidosis IV, add a new one, and present evidence for a generalized phospholipid storage. All phospholipids were increased in the liver, skin fibroblasts and urine. Lysobisphosphatydic acid which was markedly elevated in these samples was the only lipid stored in muscle. A slowly progressive neurological disease with mental retardation and corneal opacities, but lacking mucopolysaccharide excretion, skeletal changes and organomegaly should raise the suspicion of this disease. At this time, the diagnosis is made by EM studies of skin or conjunctiva which should be done if results of tests on serum or bone marrow for lysosomal diseases are normal. We found some of the typical inclusions in skin fibroblasts from an obligate carrier, which suggests that distinction between the homozygote and heterozygote may be difficult. Despite this, two succeeding pregnancies with normal outcomes were successfully monitored.

Variations in the vaginal bacterial flora: a preliminary report

Fourteen women had specimens collected from their nares, hands, vaginal vestibule, and vagina. Samples were taken the week before, during, and the week after menstruation during three menstrual cycles for a total of nine specimens from each location. Qualitative and quantitative studies were done on the vaginal specimens; the other specimens were examined specifically for Staphylococcus aureus. The premenstrual specimens averaged the highest number of bacteria (approximately 10(9)/mL) but the lowest number of different species (approximately 11). The menstrual specimens averaged the lowest total number of bacteria (approximately 4.0 x 10(7)/mL) but the highest average of different species (approximately 14). The highest rate of positive cultures was for the nares, 34%; followed by vaginal vestibule, 20%; vagina, 19%; and hands, 4%. The nine sequential location samples showed the following percentages of S. aureus: nares, 57%; hands, 29%; vaginal vestibule, 57%; and vagina, 64%.