Blood levels following multiple oral dosing of chlorpheniramine conventional and controlled release preparations

An examination of steady-state performance of chlorpheniramine conventional versus controlled release products was conducted using 15 male subjects in a 3-way crossover study with a 2-week washout period between studies. The study was designed to determine if chlorpheniramine formulations provide consistent pharmacokinetic performance between individual units upon going from single dose to multiple dose therapy. In addition, the validity of predicting steady-state levels for these kinds of products using only single oral dose data was examined. The dosage forms evaluated were a conventional 4 mg tablet, and 8 mg barrier coated-bead capsule, and an 8 mg repeat action tablet. Multiple doses of each product were orally administered to each subject for 6 days prior to the study day to achieve steady-state levels and on the actual study day. Serum samples were collected at specific time intervals on the study day, and chlorpheniramine levels assayed by HPLC. Pharmacokinetic analysis was based on a two-compartment open model. The mean plasma elimination half-lives of the various dosage forms were in the range 24.5-25.4 h. There was no rapid release of drug from the controlled release products nor did they have drug release problems during the dosing interval. Good agreement was obtained between predicted average drug concentration at steady-state and drug concentration actually present for all the formulations studied. Based upon comparative examination of AUC, Cmax, and fraction of dose absorbed data, the controlled release products administered every 12 h were comparable in performance to a conventional release tablet administered every 6 h. Since the half-life of chlorpheniramine is approximately 1 day, therapeutic management may possibly be gained with dosing the patient once daily with a controlled release product or twice daily with a conventional tablet.

Changes in intelligence following temporal lobectomy: relationship to EEG activity, seizure relief, and pathology

Pre- and posttemporal lobectomy measures of intelligence and memory in 36 patients with medically refractory complex partial seizures were compared with (1) various aspects of presurgical ictal and interictal EEG activity derived from surface and deep electrodes, (2) postlobectomy seizure relief, and (3) pathological findings in the resected lobe. With respect to interictal EEG data, bilaterally synchronous surface spikes (accompanied or unaccompanied by simultaneous deep spikes) and sharp waves were significantly correlated with lower prelobectomy intelligence scores and a drop in these scores following lobectomy. With respect to ictal EEG data, bilaterally synchronous and multifocal onsets were significantly correlated with a postlobectomy drop in intelligence scores. Patients with poor postlobectomy seizure relief tended to have lower presurgical intelligence scores and a drop in intelligence scores following lobectomy. The patients most likely to show a postlobectomy drop in intelligence were those demonstrating some combination of poor seizure relief, an absence of pathology in the resected specimen, or EEG signs indicative of poor seizure relief. Postlobectomy changes in intellectual status are therefore not necessarily exclusively attributable to the amount of postlobectomy seizure relief experienced by these patients, but might be due to a combination of factors.

Intracerebral neurilemmoma

Two examples of intracerebral neurilemmoma occurred in the absence of von Recklinghausen's disease. The first case was unique because the patient was clinically asymptomatic, and the second case was unusual with a combination of oligodendroglioma and neurilemmoma in the same mass. The latter lesion arising in persons without stigmata of neurofibromatosis has not been described. The nature of nerve sheath neoplasms in both instances has been verified by electron-microscopy. Clinical features of this rare neoplasm differ from those of acoustic or other cranial nerve tumour, particularly in relation to age and sex. Intracerebral neurilemmoma has been found most often in the first two decades of life and more often in males. Seizures and paresis, although non-specific are common signs and symptoms. Probable histogenesis of this neoplasm from perivascular elements in brain has been suggested.

Neuropathological findings following temporal lobectomy related to surface and deep EEG patterns

Interictal and ictal characteristics of preoperative EEG recordings, derived from limited surface montages, and medial temporal lobe sites, were compared with the results of pathological studies done on resected lobes obtained from 44 patients with complex partial seizures. Pathological material was divided into four groups: (a) sclerosis (mesial temporal or restricted to pes hippocampi); (b) neoplasia (mainly hamartomas); (c) miscellaneous lesions; and (d) no significant lesions. Interictal EEG correlates of no pathology included bilaterally synchronous surface spikes (with or without simultaneous deep spikes) and independent surface spikes (with or without simultaneous deep spikes) on the sides of lobectomy. Ictal EEG correlates of no pathology included unilateral surface or surface/deep onsets, bilaterally synchronous surface onsets, more than one onset location, and suppression at onset. Focal onsets correlated with sclerosis. Frequent interictal spike activity in the nonlobectomized lobe and fast buildup at onset of ictus suggested neoplasia. Many of the EEG correlates of no pathology are known to correlate with poor postsurgical seizure relief, due probably in part to the fact that absence of pathology in the resected specimen is a negative prognostic sign. Patients with sclerosis could be distinguished from patients with no demonstrable pathology with 81% cross-validation classification accuracy using a distribution-independent, nonlinear classifier. Both interictal and ictal EEG measures were used by the classifier, and one may conclude that ictal and interictal EEG recordings contain nonredundant information for predicting the presence and type of underlying pathology.

Ultrastructure of capillaries in acoustic neurilemmoma

The microvasculature of normal acoustic nerve tissue and small intracanalicular and large extracanalicular neurilemmomas was analyzed by electron microscopy. The capillaries of normal acoustic nerve were nonfenestrated, but the microvasculature in nerve-sheath neoplasms was fenestrated. Hypertrophy and hyperplasia of endothelial cells were observed only in the small lesions. The proliferated and enlarge endothelial cells often partially occluded the vascular lumen and formed multichannel vascular lumina. Many fenestrae of capillaries were found in small neoplasms, but these were rarely identified in the large extracanalicular lesions. The gap junctions of endothelium in small nerve-sheath neoplasms were long, wavy, and convoluted, had no openings, and differed from those of large lesions in which the tight junctions were short, straight, and occasionally patent. Additionally, heavy vascularization and erythrocytes within basement membranes were observed only in large neurilemmomas. These ultrastructural features may constitute a basis for differences between large and small acoustic neurilemmomas noted in cerebrospinal fluid findings.

Perinatal methylmercury intoxication: behavioral effects in rats

Sprague-Dawley rats were subjected to perinatal (4th gestational day until Postnatal Day 21) methylmercury intoxication to determine the long-term behavioral effect of the mercury poisoning. Experimental and control animals were evaluated at 110-140 days of age. Compared to controls, the methylmercury animals demonstrated significant behavioral deficits characterized by hypoactivity and by reduced appetitive, escape, and avoidance learning.

Studies on valinomycin inhibition of synaptosome-fraction protein synthesis

The ionophore valinomycin inhibited adult and neonatal synaptosome fraction protein synthesis with half-maximal inhibition at approximately 10nM. Valinomycin had no effect on [3H]leucine uptake into synaptosomes at high or low external [K+]. Synaptosome-fraction protein synthesis was dependent on [K+]e reaching a maximum at 25mM-K+. Valinomycin inhibition of protein synthesis was not reversed at high [K+]e. Valinomycin failed to influence the intrasynaptosomal [K+] even at zero [K+]e. A significant increase in State-4 respiration of synaptosomal fractions was found at 5nM-valinomycin with a decrease in the respiratory control index. At these concentrations of valinomycin there was no inhibition of the ADP-stimulated (State 3) respiration rate. Valinomycin had no effect on cerebral microsomal protein synthesis in vitro, which was inhibited by puromycin (100 micrograms/ml) or the absence of ATP. Valinomycin, 2,4-dinitrophenol and KCN inhibition of protein synthesis was not reversed by added ATP, suggesting impermeability of the membrane to ATP. Valinomycin induced a rapid fall in synaptosome ATP content not observed with atractylate or ouabain. Valinomycin inhibition of protein synthesis under these conditions is secondary to uncoupling of mitochondrial oxidative phosphorylation with a subsequent decrease in intraterminal ATP necessary for translation.

Congenital hydrocephalus in two pregnancies following the birth of a child with a neural tube defect: aetiology and management

A family is described with congenital hydrocephalus occurring in two pregnancies following the birth of a child with a neural tube defect (NTD). Prenatal diagnosis of hydrocephalus at mid-gestation was achieved by ultrasonography. The increased frequency of hydrocephalus among sibs of probands with a NTD and vice versa suggests that, following the birth of a child with either malformations, subsequent pregnancies should be monitored at mid-gestation by amniotic fluid AFP and serial ultrasound examination.

Estrogen receptors in acoustic neurilemmomas

Acoustic neurilemmomas are more frequent, larger, and more vascular in women, and such lesions have a rapidly progressive clinical course in pregnant women; these findings suggest that the growth of these neoplasms may bear a relationship to certain hormone levels. Tissues from 8 patients with acoustic neurilemmoma (3 men and 5 women) were studied by a new fluorescent steroid histochemical technique to detect the presence of estrogen receptors in or on neoplastic cells. Estrogen receptor protein has also been found in meningioma cells in women. Neurilemmoma of the acoustic nerve is the second neoplasm of the central nervous system in which such receptors have been demonstrated.

Meningioangiomatosis in the absence of von Recklinghausen's disease

Two patients who had been having seizures for 10 years or longer were found to have a peculiar neoplastic alteration in the cerebral cortex. The lesion in both instances consisted of a combined proliferation of meningothelial and endothelial cells; and are best described as meningioangiomatosis. The tissues were surgically excised and the frequency and severity of the patients' seizures decreased. In neither instance were there stigmata of von Recklinghausen's disease. In one example, as long as 8 years after craniotomy, no evidence of any disorder of the peripheral nerve was found. A review showed that such lesions have always been associated with multiple intracranial and spinal neoplasms; therefore, these two patients appear to be unique.

Development of capping ability during differentiation of HL-60 human promyelocytic leukemia cells

Developmental changes in cell surface and cytoskeletal elements have been studied in human promyelocytic leukemia cels (line HL-60) which differentiate into functionally mature myeloid cells when grown in dimethyl sulfoxide (DMSO)-supplemented medium. Both differentiated and undifferentiated HL-60 cells bind fluorescent concanavalin A (F-Con A) in a diffuse pattern over the entire cell surface. As with normal neutrophils, pretreatment of the differentiated HL-60 cells with colchicine before incubation with Con A causes the formation of large cytoplasmic protrusions over which the lectin associates into a cap. On the other hand, similarly treated undifferentiated HL-60 cells do not form the cytoplasmic protuberances and are unable to cap the Con A. Transmission electron microscopy reveals that the number and distribution of microtubules and microfilaments change during differentiation. Thus, developing myeloid cells undergo important alterations in the structure and function of the cytoskeleton as they differentiate into mature phagocytes.

Systemic carnitine deficiency--a treatable inherited lipid-storage disease presenting as Reye's syndrome

A 3 1/2-year-old boy presented at three months of age with an acute episode of lethargy, somnolence, hypoglycemia, hepatomegaly, and cardiomegaly, which responded poorly to restoration of the blood sugar level to normal. The absence of ketonuria during subsequent episodes of severe hypoglycemia prompted a search for a defect in fatty acid oxidation. Plasma carnitine (2.0 to 5.0 mumol per liter), muscle carnitine (0.01 to 0.02 mumol per gram, wet weight) and liver carnitine (0.021 to 0.065 mumol per gram, wet weight) were all less than 5 per cent of the normal mean. During a 36-hour fast, ketones were barely detectable. Prolonged treatment with oral carnitine over a six-month period resulted in increased muscle strength, a dramatic reduction in cardiac size, relief of cardiomyopathy, partial repletion of carnitine levels in plasma and muscle, and complete repletion in the liver. Systemic carnitine deficiency is an easily treatable cause of recurrent Reye's-like syndrome. Its diagnosis requires measurement of carnitine levels.

Use of the rapid fermentation test in determining carbohydrate reactions of fastidious bacteria in clinical laboratories

The rapid fermentation test was used to determine the carbohydrate reactions of some of the fastidious bacteria encountered in clinical laboratories, such as: Haemophilus species, including Haemophilus vaginalis; Actinobacillus actinomycetemcomitans; Cardiobacterium hominis; Kingella species; Corynebacterium species; Propionibacterium species; and Erysipelothrix rhusiopathiae. Results were usually obtained within 4 h by using inocula from 24- or 48-h blood or chocolate agar media.

Effects of long-term raphe nucleus stimulation on chronic limbic seizures in monkeys

Long-term electrical stimulation of the raphe nuclei was performed in two monkeys with chronic psychomotor seizures. The daily seizure rate was significantly reduced in one monkey when a stimulus charge of 0.1 microC was used, but not during a subsequent experiment using a 0.4 microC charge. A charge of 0.4 microC also failed to alter the frequency of limbic seizures in a second monkey. The raphe stimulation caused neural damage to the brain stems of both animals. The possible effect this damage may have had on the repeatability of the results suggests that long-term raphe stimulation, like some other neural prostheses, may have diminishing effectiveness over time.

Pyrogenic reactions after inadvertent infusion of endotoxin during cardiac catheterizations

In April 1976 the attack rate of chills and fever with or without falls in blood pressure increased in association with cardiac catheterizations. Fevers were associated with coronary angiography and right and left heart catheterizations. Blood cultures were negative, and reactions did not correlate with amounts of contrast materials infused or with procedures done by a single operator. Significant numbers of Acinetobacter calcoaceticus (var. anitratus) and a Pseudomonas species were cultured from hospital-reservoir distilled water when it was flushed through a catheter before gas sterilization. This same water after ethylene oxide sterilization contained 2 x 10(5) ng/mL of endotoxin by limulus lysate test and was positive by rabbit pyrogen test. When washed reusable cardiac catheters were sterilized daily or when disposable catheters were substituted, febrile reactions ended. Pyrogenic reactions in patients undergoing cardiac catheterizations correlated with emptying retained endotoxin with injected contrast material from reused washed-sterilized catheters.

Plasma levels of clobazam after 10-, 20-, and 40-mg tablet doses in healthy subjects

It is evident that substantial intersubject and intrasubject varition in the bioavailability of clobazam exists following ingestion of 10, 20 and 40 mg doses in these 12 volunteers. Peak concentrations and area under the plasma level-time curve were directly proportional to the dose of clobazam and the mean plasma half-life of clobazam was about 18 hours regardless of dose administered. The t1/2 value was less than that previously reported, as the current results allow differentiation of parent drug from metabolites. This 18 hr t1/2 compares favorably with the half-life of other benzodiazepines.

Epithelial melanosis of the gingiva possibly resulting from the use of oral contraceptives

This case is typical of others we have seen. All cases have been those of female patients who were taking oral contraceptives. A relationship is suggested between use of oral contraceptives and gingival melanosis in individuals with light complexions. It would be appropriate, therefore, to question such patients about the use of oral contraceptives and to consider this relationship in a differential diagnosis.

Sequential vaginal cultures from normal young women

Vaginal specimens were collected two to three times a week for 1 month from seven nurses. A total of 65 specimens were collected. Each sample consisted of three swabs and a saline wash. Semiquantitation of anaerobic and aerobic bacteria, mycoplasma and ureaplasma, and yeast was performed. Numerous species were recovered in each specimen; at least 37 species were isolated. Lactobacilli, Corynebacterium, Ureaplasma, Mycoplasma, Bacteroides melaninogenicus, and Candida albicans, when present, tended to remain throughout the entire month. Other organisms were present on a more sporadic basis. The number of organisms varied greatly during the sampling for each individual, whereas the types of organisms isolated from a particular subject remained relatively constant.

Susceptibility testing of clinically isolated anaerobic bacteria by an agar dilution technique

Agar dilution minimal inhibitory concentrations (MICs) of penicillin, tetracycline, chloramphenicol, and clindamycin were determined using Wilkens-Chalgren agar for 1,266 clinical isolates of anaerobic bacteria. In addition, a reference strain of Bacteroides fragilis was repeatedly tested and demonstrated the precision of the technique. Fifty-six percent of our Bacteroides melaninogenicus strains were resistant (MIC greater than or equal to 4.0 microgram/ml) to penicillin. Resistance to this antibiotic was also seen among other anaerobes, but the results are more in accord with previous reports. Resistance to tetracycline (MIC greater than or equal to 4.0 microgram/ml) was found in 60% of our isolates. Chloramphenicol proved to be the most effective agent in vitro with only 2.0% of strains resistant (MIC less than or equal to 16 microgram/ml). Only 5% of strains were resistant to clindamycin (MIC greater than or equal to 8.0 microgram/ml), and this included 10 isolates of B. fragilis and 4 of B. melaninogenicus. The incidence of resistance of anaerobic bacteria to these frequently used antibiotics is greater than previous reports and indicates the need for reliable susceptibility testing of anaerobic bacteria.

Purification of rat liver lysosomal cholesteryl ester hydrolase

An acidic cholesteryl ester hydrolase (EC 3.1.1.13) from rat liver lysosomes was purified approximately 120-fold with 5% recovery of the original homogenate activity. The sequential steps were: digitonin solubilization, agarose gel filtration, DEAE-agarose and CM-agarose column chromatography. The enzyme was at least 90% pure as judged by polyacrylamide gel electrophoresis and sodium dodecyl sulfate polyacrylamide gel electrophoresis. It exhibited a molecular weight of about 60 000 as determined by sodium dodecyl sulfate polyacrylamide electrophoresis and gel filtration. The soluble enzyme required substrate which was incorporated into phospholipid vehicles for optimal activity. On the contrary, aggregates of the enzyme required a substrate preparation that involved the direct addition of cholesteryl ester in acetone. The enzyme also catalyzed the hydrolysis of emulsions of triacylglycerol. The ratio of the two activities remained almost constant during purification suggesting that the two activities (EC 3.1.1.13 and EC 3.1.1.3, respectively) may be the result of the broad specificity of one enzyme. The effects of some inhibitors and some properties of the enzyme have been studied and discussed.

Isolation of ribosome containing synaptosome subpopulation with active in vitro protein synthesis

Subpopulations of synaptosomes harvested from neonatal rat brain cortices revealed a differential ability to synthesize protein in vitro. Incubation of synaptosomes with radiolabeled leucine, followed by continuous sucrose gradient centrifugation produced an asymmetric shift in the radioactivity toward the higher density sucrose fractions. The bulk of the mitochondrial cytochrome c-oxidase activity was also found in these fractions, however, subfractionation studies of osmotically-lysed synaptosomes suggested that the newly-synthesized proteins reside in an osmotically sensitive, non-mitochondrial compartment. The ability of each subpopulation of synaptosomes to synthesize protein in vitro was assessed after their isolation from linear continuous sucrose gradients. There was an enrichment of highly active protein synthesizing particles in the "heavy" subpopulations of neonatal synaptosomes. The inhibitory effects of chloramphenicol and cycloheximide on the protein synthesis in these particles were similar to those of the original synaptosome fraction. Electron microscopic analysis revealed an increase in the numbers of ribosome-containing structures resembling dendritic and axonal growth cones.

Ultrastructural differentiation and synaptogenesis in aggregating rotation cultures of rat cerebral cells

Cerebral cortices from fetal rats were dissociated into single cells by either trypsinization or mechanical sieving. Then the cells were allowed to form aggregates in rotation cultures. At 7, 14, 21, 28, and 35 days, aggregates were processed for electron microscopic study of morphological differentiation with special emphasis on synaptogenesis. Whether the tissue was initially dissociated by trypsin treatment or by mechanical sieving, the aggregating cultures did not exhibit any apparent differences in ultrastructural differentiation and synaptogenesis. At day 7, most neurons were immature and the extracellular space was large. Cell processes had not yet branched extensively but did contain numerous microtubules. A few immature synapses were observed. Astrocytes and oligodendrocytes displayed many of their typical cytological features. At day 14, dendritic spines had developed, some of which formed axodendritic spinous synapses. Multilayered myelin sheaths were tightly wrapped around axons. At day 21, synapses appeared mature and their number per unit area was maximal. The extracellular space had greatly decreased. At this age, asymmetrical synapses had increased approximately sixfold, whereas symmetrical synapses increased only fourfold when compared with the 7-day-old aggregates. Multifocal degeneration became apparent at 28 days and was accompanied by a significant decline in the number of synapses.

Orbital embryonal rhabdomyosarcoma and intracranial schwannoma

A 39-year-old woman had a large benign intracranial schwannoma of the Gasserian ganglion. Thirty-two years previously, she had an embryonal rhabdomyosarcoma of the orbit. She had been treated by enucleation, local excision, and low-dose supplemental irradiation (1,400 rads). This is the longest survival of which we are aware following any treatment modality in such tumors. No correlation between the two tumors has been established.