Circadian variation of DNA replication in hamster cheek pouch epithelium analysed by tritiated thymidine labelling, flow sorting and autoradiography: no resting S phase cells in the normal epithelium

In the normal hamster cheek pouch epithelium, cell proliferation takes place with a pronounced circadian rhythm. We tested our previous hypothesis that all cells having S phase DNA content are actively synthesizing DNA and thus participating in the daily cohort of proliferating cells. We found no evidence of resting S phase cells in the normal epithelium. Using labelling with tritiated thymidine followed by fluorescence activated cell sorting according to DNA content and by autoradiography of the sorted nuclei, it was demonstrated that during the 24 h period almost all cells with mid S phase DNA content were active in DNA synthesis.

Antioxidant enzymes in intramural nerves of the opossum esophagus

Superoxide radical (O2-.) combines with nitric oxide (NO) to form peroxynitrite, thereby nullifying the biological activity of NO. Superoxide dismutase (SOD) prevents this reaction by converting O2-. to H2O2. We tested the hypotheses that the antioxidant enzymes catalase (CAT), Mn SOD, and Cu/Zn SOD are present in enteric neurons of the opossum esophagus, and that O2-. alters esophageal motor function. Immunostaining demonstrated CAT, Mn SOD, and Cu/Zn SOD immunoreactivity in interganglionic nerve bundles and ganglia of the myenteric and submucosal plexuses. Western blot analysis confirmed the presence of these enzymes in homogenates of esophageal muscularis propria, and enzyme assays demonstrated Cu/Zn SOD and Mn SOD activities of 262 and 73 U/mg protein, respectively. Both diethyldithiocarbamic acid, an inhibitor of Cu/Zn SOD, and xanthine (X) with xanthine oxidase (XO), which generate O2-., shortened the latency of the nerve-mediated contraction of circular esophageal muscle, the off response, by 20.2 and 23.4%, respectively. SOD alone did not affect the latency, but it inhibited the effect of X with XO on the latency. Antioxidant enzymes found in intramural esophageal nerves may play a role in regulating NO-mediated neuromuscular communication in the esophagus.

Chronic intestinal pseudo-obstruction: diagnosis and treatment

Chronic intestinal pseudo-obstruction (CIP), a syndrome of disordered intestinal motility, is characterized by failure of the intestine to propel its contents through an unobstructed lumen. The symptoms and signs of CIP can be very similar to those of mechanical bowel obstruction. The two disease states differ in management, however; therefore, clinicians must differentiate the two. Abnormal propulsion can result from many causes. Cases can be classified as primary or secondary, and identifiable causes can be subdivided into those affecting neuronal control of motility and those directly affecting intestinal muscle function. Careful history, physical examination, and investigations help identify causative factors. The secondary forms of CIP are more common than the primary, and many cases are reversible by correction of the causative factor (e.g., drugs, metabolic abnormalities, or infection). Management of CIP depends on the cause of the disorder, the extent and location of intestine involved, and the severity of symptoms; general measures include dietary changes, prokinetic agents, and, rarely, surgical interventions. Some children with severe, refractory CIP who are wholly dependent on parenteral nutrition are candidates for consideration of intestinal transplantation.

Ultrasonographic in vitro examination of nonpalpable breast masses. A new method

Specimen radiology is necessary for ensuring successful surgical excision of nonpalpable, clinically occult breast masses discovered by mammography. However, occasionally nonpalpable lesions are only detected by sonography. A simple method of ultrasonographic in vitro identification of nonpalpable lesions invisible on specimen radiographs is presented.

Manganese superoxide dismutase and reduced nicotinamide adenine dinucleotide diaphorase colocalize in the rat gut

BACKGROUND & AIMS

Superoxide and other free radicals participate in inflammatory bowel disease and ischemia-reperfusion injury. Manganese superoxide dismutase (SOD) scavenges superoxide. Mn SOD is colocalized with reduced nicotinamide adenine dinucleotide (NADH) diaphorase in some tissues. NADH diaphorase histochemistry selectively stains enteric nerves. The aim of this study was to seek colocalization of Mn SOD with NADH diaphorase in the gut, especially in enteric nerves.

METHODS

Indirect immunofluorescent staining and histochemistry were used to localize Mn SOD and NADH diaphorase in rat gut.

RESULTS

Strong Mn SOD immunoreactivity was found in parietal cells, most intramural nerve cell bodies, the colonic interstitial cells of Cajal (at the submucosa-circular muscle layer interface), and intestinal epithelium cells. Weak to moderate Mn SOD immunoreactivity characterized smooth muscle cells, small submucosal arteries, esophageal striated muscle, esophageal epithelium, gastric epithelium, and intestinal glands. NADH diaphorase histochemistry (with Triton X-100) resulted in identical staining.

CONCLUSIONS

Mn SOD and NADH diaphorase are colocalized throughout rat gut with strong activity in enteric nerves and colonic interstitial cells of Cajal.

Effect of nitroblue tetrazolium on NO synthase and motor function of opossum esophagus

Nitric oxide mediates neuromuscular events in the opossum esophagus. The NADPH diaphorase stain is used to localize nitric oxide synthase-containing enteric neurons. Cells stain by the NADPH diaphorase technique because they reduce nitroblue tetrazolium to the visible formazan. The effects of nitroblue tetrazolium on neuromuscular function and nitric oxide synthase of esophageal muscle were studied. The NADPH diaphorase stain was performed. Nitroblue tetrazolium inhibited lower esophageal sphincter relaxation, abolished the latency gradient of the off response, and inhibited nitric oxide synthase. The NADPH diaphorase technique stained myenteric plexus nerve cell bodies and nerve processes. Nitroblue tetrazolium is not a nonspecific muscle or nerve toxin, as nerve-mediated cholinergic responses, responses to exogenous nitric oxide, and responses to myogenic stimulation were maintained after nitroblue tetrazolium abolished the off response and lower esophageal sphincter relaxation. Nitroblue tetrazolium inhibits nitric oxide-mediated events and nitric oxide synthase. It stains neurons in the esophageal myenteric plexus.

[Primary intracranial and intraspinal neoplasms in Denmark 1943-1987]

This is a descriptive study of primary intracranial and intraspinal tumours notified to the national Danish Cancer Registry during the years 1943-1987. A total of 19,317 cases of benign and malignant neoplasms were included over these 45 years with a doubling of the age-standardized incidence rates for both men and women from start till end of the registration period. The trend was mainly explained by markedly increasing rates in the age groups 60 years or above at diagnosis. Approximately some 74% of tumours were derived from the brain tissues and 19% from the intracranial and intraspinal meninges. Meningiomas predominate among women with a male:female ratio of 0.5, while tumours of the brain tissues predominate among men (ratio 1.3). Meningiomas are more frequently encountered as a chance finding at autopsy compared to other types of intracranial and intraspinal tumours. The above-mentioned increase in age-specific incidence is due mainly to improved diagnostic capabilities over the period and a subsequent decrease in the underreporting of these tumour types.

Minute virus of mice transcriptional activator protein NS1 binds directly to the transactivation region of the viral P38 promoter in a strictly ATP-dependent manner

The NS1 polypeptide of minute virus of mice (MVM) is a potent transcriptional activator of the MVM P38 promoter. The minimum region of this promoter required for transactivation has been identified and termed the transactivation region (tar). However, the function of tar and the biochemical steps involved in NS1-mediated transactivation are not well understood. Here we provide evidence that NS1 binds directly and specifically to tar in a strictly ATP-dependent manner. A DNA fragment containing tar was specifically coimmunoprecipitated with purified baculovirus-expressed MVM NS1, using antibodies directed against NS1 amino- or carboxy-terminal peptides. Using this immunoprecipitation assay, we found that the NS1-tar interaction was enhanced approximately 10-fold by ATP, but subsequent incubation at elevated temperatures in the presence, but not the absence, of MgCl2 caused rapid loss of tar binding. This finding suggests that the tar-NS1 complex has a short half-life under assay conditions which favor ATP hydrolysis. Specific binding was efficiently inhibited by self-ligated oligonucleotides containing the core DNA sequence (ACCA)3, but the same nonligated 20- and 21-mer oligonucleotides were unable to compete effectively, indicating that NS1 only binds to its cognate site when this site is presented on DNA fragments of sufficient size. DNase I footprinting experiments performed in the presence of gamma S-ATP revealed that NS1 protects a 43-bp sequence extending asymmetrically from the (ACCA)2 sequence toward the TATA box of the promoter. NS1 footprints obtained at other sites in the MVM genome were similarly large and asymmetric, all extending approximately 31 bp 5' from the core (ACCA)2-3 sequence. Surprisingly, no footprints were obtained in the absence of gamma S-ATP even under low-stringency binding conditions. However, ATP could be omitted from the reactions if NS1 was first incubated with antibodies directed against its 16-amino-acid carboxy-terminal peptide. Since these antibodies probably create intermolecular cross-links, this finding suggests that NS1 may only bind its cognate site efficiently, or perhaps at all, if the transactivator is first induced to form oligomers. From these data, we hypothesize that ATP binding may also induce NS1 to oligomerize and that such assembly is required before the protein can bind effectively to the tar sequence. The functional implications of the NS1-tar interaction will be discussed.

Co-localization of manganese superoxide dismutase and NADH diaphorase

Manganese superoxide dismutase (Mn SOD), mitochondrial enzyme, defends against the toxic effects of superoxide radical (O2.-) in pathological processes by catalyzing the conversion of O2.- to hydrogen peroxide (H2O2). The activity of another enzyme, NADH diaphorase, forms the basis for a histochemical method used commonly to demonstrate nerve cell bodies in the enteric plexuses. We found identical patterns of localization of Mn SOD immunoreactivity and NADH diaphorase activity in brain, esophagus, stomach, colon, liver, and kidney. NADH diaphorase enzymatic activity co-migrated with complexes of Mn SOD on a non-denaturing gel. This suggests that the NADH diaphorase may in some way be related to Mn SOD.

Ultrasound-guided renal biopsy with biopsy gun technique--efficacy and complications

One hundred and thirty-one ultrasound-guided renal biopsies performed in 127 patients with automated spring-loaded biopsy technique were evaluated. Adequate tissue for histologic diagnosis was obtained in 92% of the procedures (94% of the patients). The mean glomerular yield was 16.8 glomeruli. Complications were seen in 21% of the patients, 18% having minor and 3% having major complications. Patients with severe hypertension had significantly more complications than the rest of the patients. The rate of complications in patients who had 3 or 4 biopsy passes was not increased compared to patients who had one or 2 biopsy passes. Thus, this study indicates that the risk of complications and the safety of the procedure is not influenced by increasing the number of biopsy passes in order to obtain representative specimens.

NADPH-diaphorase-positive nerve fibers in smooth muscle layers of opossum esophagus: gradients in density

Nitric-oxide-releasing nerves regulate esophageal smooth muscle function. The density of such nerve fibers may differ in the different functional parts of the esophagus. We used both inspection and gray-scale analysis of digitized images to seek differences in density of such nerve fibers, stained for reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-diaphorase), between esophageal body and esophago-gastric sphincter and between smooth muscle layers in the opossum esophagus. Sections of Swiss roll preparations of the entire organ were stained for NADPH-diaphorase and for immunoreactivity to vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), galanin (GAL), substance P (SP) and constitutive nitric oxide synthase (cNOS). In the circular muscle layer, NADPH-diaphorase-positive fibers were most abundant at the cephalic end of the esophageal body with a significant decline toward and through the esophago-gastric sphincter. In the longitudinal muscle layer and the longitudinally-oriented muscularis mucosae, NADPH-diaphorase-positive nerve fibers were most abundant at the esophago-gastric sphincter with a significant decline toward and through the striated-smooth muscle junction. cNOS immunoreactivity co-localized with NADPH-diaphorase activity. Fibers stained for CGRP immunoreactivity were distributed like the NADPH-diaphorase-positive fibers. Fibers stained for immunoreactivity to the other peptides (VIP, GAL, SP) showed no clear differences in distribution along the esophagus in any of the muscle layers.

The NS1 polypeptide of the murine parvovirus minute virus of mice binds to DNA sequences containing the motif [ACCA]2-3

A DNA fragment containing the minute virus of mice 3' replication origin was specifically coprecipitated in immune complexes containing the virally coded NS1, but not the NS2, polypeptide. Antibodies directed against the amino- or carboxy-terminal regions of NS1 precipitated the NS1-origin complexes, but antibodies directed against NS1 amino acids 284 to 459 blocked complex formation. Using affinity-purified histidine-tagged NS1 preparations, we have shown that the specific protein-DNA interaction is of moderate affinity, being stable in 0.1 M salt but rapidly lost at higher salt concentrations. In contrast, generalized (or nonspecific) DNA binding by NS1 could be demonstrated only in low salt. Addition of ATP or gamma S-ATP enhanced specific DNA binding by wild-type NS1 severalfold, but binding was lost under conditions which favored ATP hydrolysis. NS1 molecules with mutations in a critical lysine residue (amino acid 405) in the consensus ATP-binding site bound to the origin, but this binding could not be enhanced by ATP addition. DNase I protection assays carried out with wild-type NS1 in the presence of gamma S-ATP gave footprints which extended over 43 nucleotides on both DNA strands, from the middle of the origin bubble sequence to a position some 14 bp beyond the nick site. The DNA-binding site for NS1 was mapped to a 22-bp fragment from the middle of the 3' replication origin which contains the sequence ACCAACCA. This conforms to a reiterated motif (ACCA)2-3, which occurs, in more or less degenerate form, at many sites throughout the minute virus of mice genome (J. W. Bodner, Virus Genes 2:167-182, 1989). Insertion of a single copy of the sequence (ACCA)3 was shown to be sufficient to confer NS1 binding on an otherwise unrecognized plasmid fragment. The functions of NS1 in the viral life cycle are reevaluated in the light of this result.

Purification and characterization of the major nonstructural protein (NS-1) of Aleutian mink disease parvovirus

We have previously described the expression of the major nonstructural protein (NS-1) of Aleutian mink disease parvovirus (ADV) in insect cells by using a baculovirus vector (J. Christensen, T. Storgaard, B. Bloch, S. Alexandersen, and B. Aasted, J. Virol. 67:229-238, 1993). To study its biochemical properties, ADV NS-1 was expressed in Sf9 insect cells and purified to apparent homogeneity with a combination of nuclear extraction, Zn2+ ion chromatography, and immunoaffinity chromatography on monoclonal antibodies. The purified protein showed ATP binding and ATPase- and ATP- or dATP-dependent helicase activity requiring either Mg2+ or Mn2+ as a cofactor. The ATPase activity of NS-1 was efficiently stimulated by single-stranded DNA and, to a lesser extent, double-stranded DNA. We also describe the expression, purification, and characterization of a mutant NS-1 protein, in which a lysine in the putative nucleotide binding consensus sequence of the molecule was replaced with serine. The mutated NS-1 was expressed at 10-fold higher levels than wild-type NS-1, but it exhibited no ATP binding. ATPase, or helicase activity. The availability of large amounts of purified functional NS-1 protein will facilitate studies of the biochemistry of ADV replication and gene regulation leading to disease in mink.

Clozapine serum levels and side effects during steady state treatment of schizophrenic patients: a cross-sectional study

Serum clozapine (S-Cloza) and serum desmethyl-clozapine concentrations (S-Descloza) were measured in 30 chronic schizophrenic in- and out-patients on a variable dose regimen. All patients were in steady state with respect to clozapine therapy and in a stable condition with respect to psychotic illness. The 24-h clozapine dose (median with interquartile range in parenthesis) was 350 (228-425) mg/24 h (range 100-700). There was a weak positive correlation between doses and the BPRS total score (r = 0.44, P < 0.05). The median S-Cloza was 1076 (706-1882) nmol/l (range 196-5581 corresponding to 64-1824 ng/ml). The S-Cloza was linearly correlated to dose but with a high interindividual variation at equal doses, e.g. a factor of 8 at 400 mg/24 h, but a low intraindividual variability of 20%. The S-Descloza averaged 77% of the S-Cloza and was highly correlated to S-Cloza (r = 0.90; P < 0.001). The S-Descloza/dose ratio increased with age and duration of treatment. The side effects registered were EEG abnormalities (83%), tachycardia (23%), increased liver enzyme activity (60%), orthostatic hypotension (17%), and moderate leucocytosis (17%). Only EEG changes were correlated to S-Cloza (r = 0.43; P < 0.05). The score values of the UKU Side Effect Scale were weakly (r = 0.36) correlated to S-Cloza. No side effects were correlated to S-Descloza, doses, or treatment duration. The frequency of side effects was higher than in studies using lower mean doses indicating a correlation between doses or S-Cloza and the frequency of side effects. It is concluded that clozapine fulfils the criteria for therapeutic drug monitoring. TDM may contribute to finding the lowest effective dose with the fewest possible side effects.

Measurement of monochromatic ocular aberrations of human eyes as a function of accommodation by the Howland aberroscope technique

Further development of the objective version of the Howland and Howland [(1976) Science, 193, 580-582; (1977) Journal of the Optical Society of America, 67, 1508-1518] aberroscope technique for measuring ocular aberrations is described. Compensation for refractive corrections and calibration is discussed. The technique was used to investigate the effect of accommodation upon the monochromatic aberrations of the right eyes of 15 subjects. Coma and coma-like aberrations were the dominant aberrations for most people at different accommodation levels, thus confirming previous findings. Variations in aberrations were considerable between subjects. About half the subjects showed the classical trend towards negative spherical aberration with accommodation. Changes in spherical aberration with accommodation in this study were less than found in previous studies where all monochromatic aberration was considered to be spherical aberration.

Iodide mumps after intravascular administration of a nonionic contrast medium. Case report and review of the literature

Swelling of the submandibular, sublingual and/or parotid glands ("iodide mumps") is an uncommon complication to intravascular administration of contrast material. The etiology remains unclear, but the reaction seems to be idiosyncratic or related to toxic accumulation of iodide in the ductal systems of the salivary glands. The introduction of nonionic contrast media has not eliminated the risk of developing iodide mumps. The first reported case of iodide mumps after intravascular administration of iopromide (Ultravist 300) is presented.

Hypocomplementemic urticarial vasculitis syndrome. Clinical and serologic findings in 18 patients

We identify and describe clinical findings in hypocomplementemic urticarial vasculitis syndrome (HUVS), an uncommon to rare illness related to systemic lupus erythematosus (SLE). A patient with recurrent, idiopathic urticaria-like lesions was diagnosed as having HUVS if a lesional biopsy showed leukocytoclastic vasculitis, the serum C1q was markedly decreased, and antibody to C1q was detected in the patient's serum. The clinical characteristics, serologic findings, and outcome of patients who met these criteria were determined from prospective and retrospective data, including hospital and office records, patient interviews, previously banked serum samples, and freshly drawn sera. Eighteen patients with HUVS were identified, and high incidences of angioedema, ocular inflammation, glomerulonephritis, and obstructive pulmonary disease were found. Renal and lung biopsies showed mesangial or membranoproliferative glomerulonephritis and severe pulmonary emphysema without vasculitis. Pulmonary function was measured in 17 patients, 11 of whom had dyspnea. All dyspneic patients had moderate to severe airflow obstruction, which progressed in all 11 and subsequently improved in only 1. Six of these 11 patients died of respiratory failure, 1 underwent lung transplantation, and 3 of the remaining 4 have moderately severe to life-threatening respiratory insufficiency. Treatment did not appear to alter the progression of obstructive lung disease. In contrast, renal insufficiency improved with treatment in 2 of 2 patients. Angioedema, ocular inflammation, obstructive lung disease, and glomerulonephritis appear to be common in HUVS, and lung disease causes substantial morbidity and mortality. The pathogenesis of HUVS may involve humoral autoimmunity, although it is not clear how autoimmunity would participate in development of obstructive lung disease. Cigarette smoking appears to be a risk factor for fatal lung disease in HUVS. All patients with HUVS should be made aware of this possibility and should be advised, encouraged, and helped to avoid tobacco smoke.