[Myasthenia gravis: an analysis of patients with postoperative crisis after thymectomy]

Five patients with myasthenia gravis whose condition declined during the postoperative unstable period were studied. The Osserman's type, age at the time of onset, duration of illness, sex, age at the time of surgery, preoperative steroid therapy, thymoma and acetyl choline receptor antibody titers were compared with those of 21 patients (control) with myasthenia gravis who had an uneventful postoperative course. In comparison, the study group's Osserman's type was slight, age at the time of onset was older (p < 0.05) and duration of illness was shorter (p < 0.05). There was no significant difference between the groups in sex, age at the time of surgery, thymoma and acetyl choline receptor antibody titers. None of them had preoperative steroid therapy. Intensive postoperative management and careful follow-up at the postoperative unstable period are necessary particularly for patients who have slight Osserman's type, old age at the time of onset, short duration of illness and no preoperative steroid therapy.

Detection of Salmonella gallinarum and S. typhimurium DNA in experimentally infected chicks by polymerase chain reaction

DNA detection with polymerase chain reaction (PCR) as a mean of identifying Salmonella infection in chickens was compared with the conventional culture procedure. DNA was extracted from organs of experimentally infected chicks with either S. Gallinarum or S. Typhimurium. The pair of primers used were those directed at the InvA gene. Bacteria isolation was done by inoculating the pre-enrichment media with samples. As was expected a 284 bp fragment DNA was amplified from extracted DNA of infected organs by PCR. The results of our studies indicate that the PCR method is more sensitive than the conventional culture procedure since we were able to detect both S. Gallinarum and S. Typhimurium DNA not only in samples positive for bacteria isolation but also in negative samples. It was possible to detect Salmonella DNA in 15 out of 20 organ samples from chicks infected with S. Gallinarum 21 hr after infection, but, only five were positive for bacteria isolation. Salmonella DNA was detected throughout the entire test period. The results of this study confirm that PCR is a useful tool for the detection of Salmonella infection in poultry.

Evaluation of binding equation method for prediction of unbound serum valproic acid concentration in pediatric patients with epilepsy

We retrospectively evaluated the ability of Scatchard binding equation method to predict the unbound serum valproic acid (VPA) concentration in 37 pediatric patients with epilepsy receiving VPA monotherapy. The correlation between predicted and observed unbound serum concentrations was high and significant (r = 0.873, p < 0.001). Mean prediction error (ME), mean absolute prediction error (MAE), and root mean squared error (RMSE) were calculated, and served as a measure of prediction bias and precision. The 95% confidence intervals of ME did not include 0, showing a bias to overpredict unbound concentration. The MAE and RMSE were not small in magnitude (MAE 17.4 mumol/l, RMSE 22.8 mumol/l). The current method using the in vivo population mean binding parameters from healthy young adults may be limited in the predictive performance of unbound serum VPA concentration.

Identification of N-acetyl-S-(3-oxo-3-carboxy-n-propyl)cysteine in the urine of a patient with cystathioninuria using LC/APCI-MS

A new cystathionine metabolite has been identified in the urine of a patient with cystathioninuria using liquid chromatography-mass spectrometry with an atmospheric pressure chemical ionization interface system (LC/APCI-MS). By this method a very intense quasi-molecular ion was observed as a base peak of synthetic N-acetyl-S-(3-oxo-3-carboxy-n-propyl)cysteine (NAc-OCPC). The quasimolecular ion [M + H]+ of NAc-OCPC observed in the urine of a patient with cystathioninuria was the same as that of the authentic compound (m/z 264). The retention time and Rf value on paper chromatography of the synthetic compound were the same as those of the urinary compound from the patient with cystathioninuria. From these results, this new cystathionine metabolite was identified as N-acetyl-S-(3-oxo-3-carboxy-n-propyl)cysteine.

Is long-protocol gonadotropin releasing hormone agonist administration superior to the short protocol in ovarian stimulation for in vitro fertilization?

OBJECTIVE

To compare the long and short protocols of gonadotropin releasing hormone agonist (GnRH-a) administration for ovarian stimulation.

SETTING

University hospital.

SUBJECTS

90 patients on their first attempt at in vitro fertilization and embryo transfer (IVF-ET).

METHOD

The results of two stimulation protocols were compared with respect to number of follicles greater than 17 mm, peak serum estradiol level, number of oocytes retrieved and fertilized, fertilization rate per oocyte, number of embryos transferred, and pregnancy rate per initiated cycle.

RESULTS

The number of follicles greater than 17 mm and the peak estradiol level were significantly (P < .05) higher in the long protocol than those in the short protocol. The number of oocytes retrieved and fertilized, the number of embryos transferred, and the pregnancy rate per initiated cycle were also significantly (P < .001) higher in the long protocol than those in the short protocol. The fertilization rates per oocyte retrieved did not differ significantly between groups.

CONCLUSION

The long protocol of gonadotropin releasing hormone agonist administration for ovarian stimulation in IVF-ET may be the preferred method when GnRH-a is used.

Simultaneous determination of cystathionine and NAc-cystathionine using liquid chromatography atmospheric pressure chemical ionization mass spectrometry

A method for simultaneous determination of cystathionine and NAc-cystathionine in biological samples has been developed by using column liquid chromatography-mass spectrometry. The concentrations of cystathionine and NAc-cystathionine in urine, several tissues, and serum of propargylglycine-treated rats with experimental cystathioninuria were determined by scanning the [M + H]+ ions of each compound. The recoveries of authentic compounds were 95.69 +/- 4.44% (n = 10) for cystathionine and 91.59 +/- 5.26% (n = 10) for NAc-cystathionine after ion-exchange resin treatment. The contents of cystathionine and NAc-cystathionine in the urine of a patient with cystathioninuria were also measured. The results coincided well with those obtained using an amino acid analyzer.

Iminodipeptides containing proline with C-terminal and N-terminal residues prime the stimulation of human neutrophil superoxide generation by fMLP

Preincubation of human peripheral blood polymophonuclear leukocytes with an iminodipeptide containing proline at the C-terminus and/or N-terminus, Pro-Pro, Gly-Pro, Pro-Gly, Ala-Pro and Pro-Ala, significantly enhanced N-formyl-methionyl-leucyl-phenylalanine-induced superoxide generation in a concentration-dependent manner. The iminodipeptide with C-terminal proline showed higher effect than that of the counterpart with N-terminal proline. These iminodipeptides also enhanced the superoxide generation induced by opsonized zymosan but not that induced by arachidonic acid or phorbol myristate acetate. Tyrosyl phosphorylation of the 45-kDa protein occurred in parallel with the iminodipeptide-dependent enhancement of superoxide generation in neutrophil.

Differential hypoglycemic effect of 2,5-anhydro-D-mannitol, a putative gluconeogenesis inhibitor, in genetically diabetic (db/db) and streptozotocin-induced diabetic mice

2,5-Anhydro-D-mannitol (AM), a putative gluconeogenesis inhibitor, completely reversed the hyperglycemia in genetically diabetic (db/db) mice that exhibited hyperinsulinemia and enhanced hepatic gluconeogenic enzyme (glucose-6-phosphatase (G-6-Pase) and fructose-1,6-diphosphatase (F-1,6-DPase)) activities compared with the control +/+ mice. In contrast, AM only partially reversed the hyperglycemia of streptozotocin (STZ)-treated +/+ mice in which the hepatic gluconeogenic enzyme activities were enhanced to the same degree as in the db/db mice, whereas the blood insulin level was depressed. In the db/db mice, the STZ-treatment attenuated the hyperinsulinemia and exaggerated the hyperglycemia as well as the hepatic gluconeogenic enzyme activities, and it greatly reduced the hypoglycemic action of AM. Not only the dose-response curve of AM but also the time-course of the blood glucose level (expressed as % of pre-treatment value) following 320 mg/kg of AM were almost identical between +/+, STZ-treated +/+ and STZ-treated db/db mice. In the STZ-treated +/+ mice, a combination treatment of insulin (320 micrograms/kg) with AM (320 mg/kg) caused hypoglycemia that was greater than that induced by AM or insulin alone. On the other hand, in vitro studies with purified F-1,6-DPase revealed that phosphorylated AM (AM-1,6-diphosphate) but not AM itself inhibited the gluconeogenic enzyme activities. These results suggest that inhibition of gluconeogenesis is responsible, at least in part, for the hypoglycemic activity of AM. AM appears to inhibit hepatic gluconeogenic enzyme activities after being phosphorylated by an insulin-dependent mechanism.

The differential roles of sympathetic nerve activity in the pathogenesis of antral and corpus lesions induced by indomethacin in rats

A s.c. dose (32 mg/kg) of indomethacin induced antral ulcers and corpus erosions in refed rats, but almost exclusively corpus erosions in fasted rats. In the refed rats the antral ulcers were not affected by a preganglionic splanchnicectomy, but were significantly attenuated by 6-hydroxydopamine (80 mg/kg i.p.), prazosin (32 mg/kg p.o.), yohimbine (32 mg/kg p.o.) or streptozotocin (80 mg/kg i.v.), whereas the corpus erosions were exaggerated by the latter three treatments. Blood analysis revealed that refeeding of fasted rats caused instant increases in plasma glucose and insulin levels and a subsequent gradual increase in plasma norepinephrine (NE). These plasma parameter changes were hardly affected by an indomethacin treatment. The NE response to refeeding was reversed by 6-hydroxydopamine which minimally affected the glucose and insulin responses. Splanchnicectomy changed none of these responses, although it almost completely depleted plasma epinephrine levels. The NE response was enhanced by yohimbine and prazosin, and the insulin response was enhanced by the former. Streptozotocin abolished the insulin response and reversed the NE response. It is concluded that hyperinsulinemia in response to refeeding induces NE release and results in an activation of alpha-1 and/or alpha-2 adrenergic receptors which plays a permissive role in the indomethacin-induced antral ulcer formation. Conversely, this series of events may play a protective role against the corpus erosion formation.

The possible role of age-related increase in the plasma glucagon/insulin ratio in the enhanced hepatic gluconeogenesis and hyperglycemia in genetically diabetic (C57BL/KsJ-db/db) mice

Genetically diabetic db/db mice and their normoglycemic littermates (+/+ mice) were studied to determine plasma levels of glucose, glucagon and insulin and hepatic gluconeogenic enzyme activities. Plasma glucose levels did not differ significantly between the 5-week-old db/db and +/+ mice, but increased with age in the former until the animals were 16-week-old. Similar age-associated changes were observed in the activities of the gluconeogenic enzymes, glucose-6-phosphatase (G-6-Pase) and fructose-1,6-diphosphatase (F-1,6-DPase). While the plasma levels of insulin and glucagon that peaked at 7 weeks of age did not parallel the hyperglycemia, the plasma glucagon/insulin (G/I) ratio roughly paralleled the hyperglycemia. Analysis of individual values for the db/db mice revealed statistically significant (P < 0.001) correlations between plasma glucose levels and hepatic G-6-Pase (r = 0.78) or F-1,6-DPase (r = 0.74) activity. There were also significant correlations between the G/I ratio and plasma glucose levels (P < 0.001, r = 0.66), hepatic G-6-Pase (P < 0.01, r = 0.48) or F-1,6-DPase (P < 0.01, r = 0.57) activity. It is thus concluded that the relative predominance of glucagon over insulin action plays an important role in the age-associated development of hyperglycemia in db/db mice. Glucagon presumably activates the hepatic gluconeogenic enzymes to enhance hepatic glucose output.

Purification and characterization of a novel enzyme, alpha-neoagarooligosaccharide hydrolase (alpha-NAOS hydrolase), from a marine bacterium, Vibrio sp. strain JT0107

A novel enzyme, alpha-neoagarooligosaccharide hydrolase (EC 3.2.1.-), which hydrolyzes the alpha-1,3 linkage of neoagarooligosaccharides to yield agaropentaose (O-beta-D-galactopyranosyl(1-->4)-O-3,6-anhydro-alpha-L-galactopyranosyl (1-->3)-D-galactose], agarotriose [O-beta-D-galactopyranosyl(1-->4)-O-3,6-anhydro- alpha-L-galactopyranosyl (1-->3)-D-galactose], agarobiose [O-beta-D-galactopyranosyl(1-->4)-3,6-anhydro-L-galactose], 3,6-anhydro-L-galactose, and D-galactose was isolated from the marine bacterium Vibrio sp. strain JT0107 and characterized. This enzyme was purified 383-fold from cultured cells by using a combination of ammonium sulfate precipitation, successive anion-exchange column chromatography, gel filtration, and hydroxyapatite chromatography, gel filtration, and hydroxyapatite chromatography. The purified protein gave a single band (M(r), 42,000) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Estimation of the M(r) by the gel filtration method gave a value of 84,000, indicating that the enzyme is dimeric. Amino acid sequence analysis revealed it to have a single N-terminal sequence that has no sequence homology to any other known agarases. The optimum temperature and pH were 30 degrees C and 7.7, respectively. The Km and maximum rate of metabolism for neoagarobiose were 5.37 mM and 92 U/mg of protein, respectively.

In vivo binding characteristics of carbamazepine and carbamazepine 10, 11-epoxide to serum proteins in monotherapy adult patients

The in vivo serum protein binding characteristics of carbamazepine and carbamazepine 10, 11-epoxide, which was the main metabolite of carbamazepine in plasma, were assessed in sera from 30 adult patients with epilepsy on carbamazepine monotherapy. The binding characteristics of each compound were analyzed according to the two-site binding model. Association constants to the high-affinity binding site on alpha 1-acid glycoprotein (AAG) were 0.053 l/mumol for carbamazepine and 0.013 l/mumol for carbamazepine 10, 11-epoxide. The maximum binding capacities for drug-AAG binding were 49.2 mumol/l for carbamazepine and 48.1 mumol/l for carbamazepine-10, 11-epoxide. The products of the association constant and binding capacity for the lower-affinity site (i.e., the linear component of albumin binding site) were 1.273 for carbamazepine and 0.525 for carbamazepine 10, 11-epoxide. Within the total concentration range of each compound investigated, the contribution of drug-AAG binding to the total serum binding was relatively larger than that of drug-albumin binding.

Determination of D,L-propargylglycine and N-acetylpropargylglycine in urine and several tissues of D,L-propargylglycine-treated rats using liquid chromatography-mass spectrometry

An experimental animal model with cystathioninuria was obtained by the injection of D,L-propargylglycine into rats. The concentrations of D,L-propargylglycine in urine, several tissues and serum at different times after the injection were measured by liquid chromatography-mass spectrometry. The propargylglycine accumulated rapidly in several tissues and serum of the rats, and reached its maximum level at about 2 h after the injection. Approximately 21.2% of the administered propargylglycine was excreted in urine. N-Acetylpropargylglycine was identified as a new metabolite of propargylglycine in urine. The concentration of propargylglycine was 100 times that of N-acetylpropargylglycine in urine.

Cloning of a cDNA encoding tobacco omega-3 fatty acid desaturase

A cDNA was isolated from a tobacco (Nicotiana tabacum cv. SR1) leaf cDNA library using, as a hybridization probe, a cDNA fragment from the gene (fad7) encoding Arabidopsis thaliana chloroplast omega-3 fatty acid (FA) desaturase. The deduced 379-amino-acid (aa) sequence has 67-71% identity to those deduced from the previously described genes encoding the omega-3 FA desaturases of A. thaliana. The absence of an N-terminal extension transit peptide in the deduced aa sequence of the cDNA clone and the accumulation pattern of the mRNA corresponding to this cDNA in leaf and root tissues indicate that the isolated cDNA encodes a tobacco microsomal omega-3 FA desaturase.

Specific sequences from the carboxyl terminus of human p53 gene product form anti-parallel tetramers in solution

Human p53 is a tumor-suppressor gene product associated with control of the cell cycle and with growth suppression, and it is known to form homotetramers in solution. To investigate the relationship of structure to tetramerization, nine peptides corresponding to carboxyl-terminal sequences in human p53 were chemically synthesized, and their equilibrium associative properties were determined by analytical ultracentrifugation. Secondary structure, as determined by circular dichroism measurements, was correlated with oligomerization properties of each peptide. The sedimentation profiles of peptides 319-393 and 319-360 fit a two-state model of peptide monomers in equilibrium with peptide tetramers. Successive deletion of amino- and carboxyl-terminal residues from 319-360 reduced tetramer formation. Further, substitution of alanine for Leu-323, Tyr-327, and Leu-330 abolished tetramerization. Circular dichroism studies showed that peptide 319-351 had the highest alpha-helix content, while the other peptides that did not form tetramers had low helical structure. These studies define a minimal region and identify certain critical residues involved in tetramerization. Cross-linking studies between monomer units in the tetramer suggest that the helices adopt an anti-parallel arrangement. We propose that conformational shifts in the helical structure of the p53 tetramerization domain result in a repositioning of subunits relative to one another. This repositioning provides an explanation relating conformational changes at the carboxyl terminus with changes in sequence-specific DNA binding by the highly conserved central domain.

Immunohistochemical demonstration of intestinal-type alkaline phosphatase in stomach tumors induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats

A polyclonal antibody against rat intestinal-type alkaline phosphatase (I-ALP) was generated and proven to be applicable immunohistochemically to paraffin-embedded sections. Expression of I-ALP in normal tissues, intestinal metaplasia and stomach tumors induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was then investigated in five different strains of rats. Male SD (Crj:CD), Lewis (LEW/Crj), WKY (WKY/NCrj), Wistar (Crj:Wistar) and F344 (F344/DuCrj) animals were given drinking water containing 100 micrograms/ml of MNNG for 30 weeks and were killed at week 50. Among the 5 strains, stomach adenocarcinomas were found most frequently in the SD case. The susceptibility of rats to induction of stomach carcinoma did not correlate with the development of intestinal metaplasias in each strain. Histochemical staining for mucin demonstrated all stomach tumors (adenomatous hyperplasias and well-differentiated adenocarcinomas) to consist mainly of gastric type cells (pyloric gland cell and surface mucous cell types), with intestinal-type tumor cells (goblet cell and intestinal absorptive cell types) being only occasional findings. Immunohistochemically, I-ALP was strongly positive on the striated cell borders of small intestinal absorptive cells of the villus and on brush borders of epithelial cells of kidney proximal tubules. I-ALP was also detected in the normal stomach, limited to the striated cell borders of absorptive cells of the upper one-fourth of intestinal metaplastic glands. I-ALP may thus be a useful marker for stomach tumor cells of intestinal absorptive cell type, indicative of maturation and differentiation. No stomach tumors consisting mainly of intestinal-type cells were found, and therefore there was no suggestion of any derivation from intestinal metaplasias.

Inhibition of phagocytosis by rainbow trout (Oncorhynchus mykiss) macrophages by botulinum C2 toxin and its trypsinized component II

Botulinum C2 toxin (C2T) is composed of two nonlinked protein components, components I and II. The toxin reconstituted with component I and trypsinized component II inhibited phagocytosis of rainbow trout (Oncorhynchus mykiss) and mouse macrophages. Inhibition in both cell types was observed over a range of toxin concentrations that were not toxic to the cells. Because cytoplasmic action of rainbow trout macrophages is ADP-ribosylated by component I, the inhibition of phagocytosis in trout cells by C2T is probably due to inactivation of cytoplasmic actin. Moreover, phagocytosis by trout cells was also inhibited in a dose-dependent manner by trypsinized component II alone, and did not cause cell death. The present results show that the macrophages of aquatic vertebrates are susceptible to C2T, and that trypsinized component II elicits a novel biological activity by binding to the cell membrane of the macrophages.