Improvement of chemical analysis of antibiotics. Part XIX: Determination of tetracycline antibiotics in milk by liquid chromatography and thin-layer chromatography/fast atom bombardment mass spectrometry

A precise liquid chromatographic (LC) determination with high sensitivity and a reliable mass spectrometric (MS) confirmation were established for the determination of tetracycline antibiotics (TCs) in milk. The determination of the TCs was based on C18 cartridge cleanup followed by LC separation. Recoveries of TCs from milk fortified at 20 ppb were 73.0-81.8%, and coefficients of variation were 2.6-4.6%. With this method, concentrations of oxytetracycline and tetracycline as low as 10 ppb and chlortetracycline and doxycycline as low as 20 ppb were determined readily. Thin-layer chromatography (TLC)/fast atom bombardment (FAB) MS with a condensation technique was used to confirm TCs in milk. After the C18 cartridge cleanup, separation on a C8 TLC plate, and application of the sample condensation technique, FAB mass spectra were measured. TCs in milk at 50 ppb were reliably confirmed by TLC/FABMS.

Glutamine repeats as polar zippers: their possible role in inherited neurodegenerative diseases

Four inherited neurodegenerative diseases are linked to abnormally expanded repeats of glutamine residues in the affected proteins. Molecular modeling followed by optical, electron, and x-ray diffraction studies of a synthetic poly(L-glutamine) shows that it forms beta-sheets strongly held together by hydrogen bonds. Glutamine repeats may function as polar zippers, for example, by joining specific transcription factors bound to separate DNA segments. Their extension may cause disease either by increased, nonspecific affinity between such factors or by gradual precipitation of the affected proteins in neurons.

[Antigen-induced pulmonary arterial responses in the isolated perfused lung of sensitized rabbits]

To investigate whether blood components, such as complements, antibody, platelets and leukocytes, can play important roles in increasing pulmonary arterial and airway pressures after antigen challenge in sensitized rabbits, we measured the time course of pulmonary arterial pressure, airway pressure and lung weight gain after antigen challenge in isolated perfused rabbit lungs. Nineteen rabbits were divided into 3 groups; S group (n = 9), which was sensitized rabbit lung with antigen added into perfusate; NS group (n = 5), which was nonsensitized rabbit lung with antigen added into perfusate; S+R group (n = 5), which was sensitized rabbit lung with autologous erythrocytes added into perfusate. Although agglutinin titer in sensitized rabbits was more than 1: 10,000, that in the perfusate was less than 1:16. Pulmonary arterial and airway pressures significantly increased after antigen challenge in S group, while those in NS and S+R groups did not show any change. Also there were no significant changes in pulmonary arterial and airway pressures and lung weight gain in nonsensitized rabbit lungs of the same agglutinin titer as S group. Lung weight gain in S group was 2-4 times higher than that in S+R group after antigen challenge. We conclude that blood components, such as complements, antibody, platelets and leukocytes, do not play important roles on antigen induced pulmonary responses in sensitized rabbit lungs.

[Changes in and factors related to fatigue of in-home caregivers who utilize temporary nursing home assistance]

In order to understand the fatigue of in-home caregivers of the elderly and the remedical effects of temporary nursing home assistance (i.e., "respite care service"), pre- and post-service surveys were conducted on the Cumulative Fatigue Symptoms Index (CFSI) of 34 in-home caregivers who use the respite care service offered by a nursing home in Shizuoka, Japan. The results of these two surveys are as follows: 1) The physical fatigue of caregivers before using the respite service is higher, and caregiver's free time is related to their feelings of fatigue. 2) According to CFSI figures, chronic fatigue, general fatigue, anxiety, depression (p < 0.01), and irritability caused by excessive workload and reduced vitality (p < 0.05) were significantly reduced by the services given. 3) Twenty-seven caregivers, or 79% of the sample, showed some improvement, while the remaining 7 caregivers (21%) showed none. 4) Factors which may have affected the degree of fatigue recovery were shown, including reasons and days for using the respite service.

[Muscular sarcoidosis]

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology presenting with bilateral hilar lymphadenopathy, pulmonary, skin, and eye lesion. Sarcoidosis involving skeletal muscle is not uncommon because non caseating granuloma have been demonstrated in as much as 50 to 80% of sarcoidosis cases. Symptomatic muscle involvement, however, is rare. Chronic and acute myopathy and palpable nodular lesions due to sarcoidosis involving skeletal muscle have been reported. Chronic myopathy is progressive muscle disease with muscle weakness and wasting. Because this syndrome is rare, its natural history and responsiveness to corticosteroid have not been defined well. We review the medical literature of previously reported cases of muscular sarcoidosis.

An improved method for detecting cytostatic toxin (emetic toxin) of Bacillus cereus and its application to food samples

We developed an improved HEp-2 cell assay method for the detection of Bacillus cereus toxin, which affects the proliferation of HEp-2 cells. The cytostatic toxin was stable upon exposure to heat, pH 2, pH 11 and trypsin, which suggests it is an emetic. Using the HEp-2 cell assay, we examined the distribution and contamination of B. cereus strains that produced an emetic toxin in various foods. Although there were 228 enterotoxin producers among 310 B. cereus strains obtained from foods, 16 of them produced the cytostatic type (emetic toxin). All of the strains that produced the cytostatic toxin were of the H.1 serotype.

[An evaluation study on arbekacin for MRSA-infectious diseases including pneumonia, septicemia and others]

Availability of arbekacin (ABK) was analyzed in the chemotherapy of 24 MRSA-infected patients with symptoms of pneumonia (12), sepsis (6) and others (6). Most patients had background diseases such as malignant tumors or cerebrovascular disorders. 47% (7/15) of them were immunologically abnormal. 17 of them had been previously treated with cephems, imipenem, minocycline or fosfomycin. The ABK therapy was performed with doses ranging 50-400 mg a day, divided into 1-3 times (mostly 100 mg x 2), and for 5-24 days. (18 patients were treated between 5 and 14 days). 14 patients (58%) received combined therapy with other antibiotics (mostly with beta-lactams, 12). The clinical efficacy rate of the ABK therapy was 62% (good, 13; fair, 4; ineffective, 4; unknown, 3). The bacteriological efficacies were: eradicated, 7 (44%); decreased, 4; no change, 5; unknown, 8. Side effects were found in 3 patients (oliguria, 2; eruption due to drug, 1) and one case resulted in serious renal disorder. Abnormal laboratory data were found in 7 cases. Above results have indicated that ABK is a useful antibiotic in chemotherapy of MRSA-infections.

Isolation and characterization of two tightly linked catalase genes from castor bean that are differentially regulated

Two catalase genes, cat1 and cat2, have been isolated from the castor bean genome. They were located in the same direction on a chromosome at a distance of 2.4 kb, cat1 being on the downstream side of cat2. The two genes contained introns at the same positions except that one of the 7 introns in cat1 is missing in cat2 and the corresponding introns differed in size and sequence between the two genes. The translated regions of the two genes had the same number of nucleotides and exhibited 81.3% nucleotide sequence identity. In addition to introns, the nucleotide sequences of the 5'- and 3'-flanking regions are highly divergent between the two genes. In etiolated seedlings, cat1 mRNA was present abundantly in endosperms and cotyledons and only in a small amount in roots. The cat1 mRNA could not be detected in hypocotyls. By contrast, cat2 mRNA is most abundant in hypocotyls and roots, while endosperms and cotyledons contained only low levels of cat2 mRNA. Although neither cat1 nor cat2 mRNA could be detected in dry seeds, both mRNAs showed temporal accumulation in the endosperm in response to germination. These results suggest that expression of two tightly linked catalase genes of castor bean, cat1 and cat2, are differentially regulated during development.

Single- and double-strand breaks in pBR322 DNA by vacuum-UV from 8.3 to 20.7 eV

Solid pBR322 DNA was irradiated in a vacuum by monochromatic photons from 8.3 eV (150 nm) to 20.7 eV (60 nm), and the formation of single- and double-strand breaks (ssb and dsb) was determined using agarose gel electrophoresis. The action cross sections increased 20 times (ssb) and 43 times (dsb) from 8.3 eV to 20.7 eV; the quantum yields increased 5.4 times (ssb) and 12 times (dsb). The cross sections for dsb were 0.0059 at 8.3 eV and 0.013 at 20.7 eV of those of ssb; these values were smaller than about 0.04 for 2.1 keV photons, or about 0.18 for 60Co gamma-rays. Although vacuum UV photons were proved to induce dsb, they had a lower efficiency than when using soft X-rays or gamma-rays.

Relationship between force and electromyographic activity during rapid isometric contraction in power grip

Force response and surface electromyographic (EMG) activity of extrinsic extensors and flexors of the hand were measured under 6 target force conditions during rapid pulse isometric contractions (power grip) targeted using an oscilloscope display of exerted and target forces. For target forces ranging from 16.7% to 50% of maximum voluntary contraction (MVC), the rate of force rise increased with the peak force, while the time to peak force remained almost constant. However, at target forces between 66.7% and 100.0% MVC, the rate of force rise leveled off and the time to peak force was prolonged. In association with these changes in force trajectories, modulation of the EMG activity of the flexor digitorum superficialis muscle was observed. At the lowest target force (16.7 MVC), the EMG of this muscle showed a single initial activity; the activity increased linearly up to the 50% MVC target force, while the duration was relatively constant. However, at target forces above 50% MVC, no further increase of the initial activity was observed, while the amplitude and duration of an additional activity progressively increased. These results indicate that the neural control of rapid isometric contraction at target forces at and below 50% MVC differs from that operating at larger target force levels.

Isolation of complementary DNA encoding K-cadherin, a novel rat cadherin preferentially expressed in fetal kidney and kidney carcinoma

Complementary DNA for a novel member of the cadherin family, designated K-cadherin, was isolated from a rat renal cell carcinoma complementary DNA library by screening it with a short complementary DNA probe which was initially obtained from the RNA of day 16 fetal Wistar rat stomach mucosa by the polymerase chain reaction. The deduced primary structure of K-cadherin is 789 amino acid residues, which contain five internal repeats in its extracellular domain, a single putative transmembrane domain, and a cytoplasmic tail characteristic of those of classic type cadherins. K-cadherin exhibits low homology with mature proteins of mouse N- (38%), E- (35%), and P-cadherin (32%), and high homology with a partially identified human cadherin-6 protein (95%) at the amino acid level. Northern blot analysis revealed a high level of expression of K-cadherin mRNA in fetal rat kidney and brain, and rat kidney carcinoma with two major transcripts, 4.1 and 8.0 kilobases in size, whereas there was very weak or no expression in any organ of adult rats. The level of K-cadherin expression was also elevated in some human kidney cancer tissues. In the developing kidney, in situ hybridization showed localization of K-cadherin mRNA in the nephroblastic epithelial cells of comma bodies coinciding with those in the process of polarization during glomeruloneogenesis. These results demonstrate that K-cadherin must have important functions in both the process of kidney development and tumorigenesis of some types of kidney cancer.

Benign schwannoma of the esophagus: report of two cases with immunohistochemical and ultrastructural studies

Two cases of benign schwannoma of the esophagus are presented. The tumors were found in the thoracic esophagus of women of 56 and 64 years of age, respectively, who had complained of dysphagia and back pain. Tumorectomies were performed and the tumors were found to be located within the esophageal wall arising from the muscularis propria. The tumors were examined immunohistochemically and ultrastructurally. These tumors were identical in gross, histological and electron microscopic features. Grossly, the tumors showed yellowish-white cut surfaces without hemorrhage or necrosis. Microscopically, they were composed of spindle-shaped cells showing moderate variation in size and shape, and nuclear palisading. Lymphoid aggregates with germinal centers surrounded the tumors. Immunohistochemically, strong reactions for S-100 protein and neuron-specific enolase were observed in the cytoplasm of spindle cells, whereas reactions for muscle actin and desmin were negative. These findings, together with electron microscopic observations, supported the Schwann cell origin of these tumors.

[Breast sarcoidosis: 2 case reports and a review of 19 literature]

Case 1. A 40-year-old Japanese female with a 11 years history of sarcoidosis. Biopsy of a 0.5 cm-sized right breast nodule showed sarcoid granuloma. About two years later she had had bloody galactorrhoea and biopsy of an apparently normal site of the breast revealed periductal sarcoid granuloma and duct papillomatosis. Case 2. A 63-year-old Japanese female in whom biopsy of a 1 cm-sized right breast nodule revealed sarcoid granuloma. BHL, lung, eyes, muscle, lymph nodes and skin lesions were subsequently detected and the last two were histologically confirmed as sarcoidosis. After nine months all lesions disappeared. Some problems presented in the literature such as periductal sarcoid granuloma formation, latent sarcoidosis in the grossly normal breast and coexistent breast cancer are discussed briefly.

A 28 kDa-protein with disintegrin-like structure (jararhagin-C) purified from Bothrops jararaca venom inhibits collagen- and ADP-induced platelet aggregation

A 28 kDa-protein with inhibitory activity on collagen- and ADP-induced platelet aggregation was purified from the venom of the snake Bothrops jararaca. Its complete amino acid sequence corresponded to the carboxyl-terminal region consisting of disintegrin-like and cysteine-rich domains of jararhagin, a high molecular weight hemorrhagic metalloprotease. Sequence homology of the protein to other disintegrins and disintegrin-like proteins from various snake venoms is also presented.

Archaebacterial ether-linked lipid biosynthetic gene. Expression cloning, sequencing, and characterization of geranylgeranyl-diphosphate synthase

Archaebacterial Sulfolobus acidocaldarius geranylgeranyl-diphosphate (GGPP) synthase (EC 2.5.1.29) catalyzes consecutive condensations of isopentenyl diphosphate with allylic diphosphates to produce GGPP which is the important precursor of archaebacterial ether-linked lipids. We developed an expression screening method for cloning the GGPP synthase gene, which utilizes the carotenoid biosynthesis genes of Erwinia uredovora to visualize a clone expressing GGPP synthase, and then screened a genomic DNA library from S. acidocaldarius for the GGPP synthase gene by using this method. Positive clones were shown to contain GGPP synthase gene by the use of an in vitro assay. Extracts from Escherichia coli transformants catalyzed the condensation of isopentenyl diphosphate with farnesyl diphosphate (FPP) to produce (all-E)-GGPP. The nucleotide sequence of the 2.3-kilobase HindIII fragment of the cloned fragment was determined. This sequence specifies two open reading frames, ORF-1 and ORF-2. ORF-1 encodes GGPP synthase with the expected molecular weight of 36,873, and ORF-2 encodes a protein with homology for UDP-N-acetylglucosaminedolichyl phosphate N-acetylglucosaminephosphotransferase. The cloned GGPP synthase was partially purified with several chromatographies after heat treatment of cell free extract. This enzyme is extremely thermostable and has an optimal pH at 5.8. Dimethylallyl diphosphate, geranyl diphosphate, and (all-E)-FPP are, in decreasing order of activity, acceptable as allylic substrates to produce (all-E)-GGPP. When dimethylallyl diphosphate or geranyl diphosphate are the allylic substrates, a significant amount of mixture of the products is shorter than GGPP. (2Z,6E)-FPP is not a substrate. This enzyme recognizes the E-configuration of allylic substrate.

Growth-inhibition by hemin in K562 human leukemic cells is related to hemoglobin-producing activity

To determine the mechanism of the growth inhibition associated with the induction of erythroid differentiation in K562 cells by hemin, we used two K562 subclones with different hemoglobin (Hb)-producing activity. Hemin strongly inhibited the growth of K562-L, which had a low Hb-producing activity, but not that of K562-H, which had a high Hb-producing activity. When the cell growth of K562-L was inhibited by hemin, the S phase of the cell cycle decreased and the G2/M phase increased. In contrast, hemin had no effect on the cell cycle of K562-H. Without hemin treatment, the alpha-globin mRNA level was related to the degree of Hb production in K562-L and -H but the gamma-globin mRNA level was not. With hemin treatment, there was no increase in the alpha-globin mRNA level in K562-L but there was an increase in K562-H. The difference in alpha-globin mRNA levels correlated with the Hb production in K562-L and -H induced by hemin. The levels of c-myc and c-myb mRNAs in K562-L decreased when cell growth was strongly inhibited by hemin. These findings indicate that the growth inhibition of K562 cells by hemin is due to a suppression of the progression from the G0/G1 phase to the S phase and a delay in the G2/M phase, caused by the inhibition of c-myc and c-myb transcription. It is also affected by the Hb production, reflected in alpha-globin transcription.

Effects of intravenous infusion of dopamine on tumor blood flow in rat subcutis

To determine the effects of intravenous administration of dopamine hydrochloride (DA) on tumor blood flow (TBF), we measured the blood flow of normal subcutaneous tissue and subcutaneous tumor (LY-80, a variant of Yoshida sarcoma) in enflurane-anesthetized male Donryu rats using a hydrogen clearance method. Measurements were made before and during intravenous infusion of DA at a rate of 5 micrograms/kg/min, while recording the mean arterial blood pressure of the rats. Under mild hypertension induced by DA, the blood flow of normal subcutis decreased and TBF increased significantly. SCH-23390, an antagonist of the DA1 receptor, inhibited the enhancement of TBF by DA; while domperidone, an antagonist of the DA2 receptor, did not modify the effects of DA. In experimental chemotherapy against the tumor using adriamycin (ADM) 5 mg/kg i.v., only the combination of DA and ADM significantly inhibited the tumor growth. Moreover, DA reduced the weight loss caused by ADM. These results indicate that DA could have a role in increasing TBF and possibly enhance drug delivery to tumors. Moreover, it appears that the DA1 receptor contributes, at least in part, to the enhanced blood flow in rat subcutaneous tumor following DA administration.

Impaired hepatic copper homeostasis in Long-Evans Cinnamon rats: reduced biliary excretion of copper

To explain the pathogenesis of excessive copper accumulation in Long-Evans Cinnamon (LEC) rats, regarded as one of the animal models for hepatic-type Wilson's disease, we measured copper contents in liver tissue and bile, serum total copper concentration, and ceruloplamin oxidase activity in LEC rats before and after the onset of spontaneous hepatitis. The copper contents in liver tissue of both 11-wk-old and 18-mo-old LEC rats were about 60 times the amounts in age-matched Wistar and Long-Evans Agouti rats. The biliary copper excretion in 11-wk-old LEC rats was significantly lower than that of the Long-Evans Agouti and Wistar rats that were the same age (27.9 and 41.4%, respectively). In 18-mo-old LEC rats, biliary copper excretion was lower than that in the Long-Evans Agouti rats that were the same age, but the finding was statistically not significant. Serum copper and ceruloplasmin levels were markedly reduced in LEC rats of both ages. These findings suggest that LEC rats have similar defects of biliary copper excretion as observed in patients with Wilson's disease.

Assignment of disulfide bridges in the fusion glycoprotein of Sendai virus

The mature fusion (F) glycoprotein of the paramyxovirus family consists of two disulfide-linked subunits, the N-terminal F2 and the C-terminal F1 subunits, and contains 10 cysteine residues which are highly conserved at specific positions. The high level of conservation strongly suggests that they are indeed disulfide linked and play important roles in the folding and functioning of the molecule. However, it has not even been clarified which cysteine residues link the F2 and F1 subunits. This report describes our assignment of the disulfide bridges in purified Sendai virus F glycoprotein by fragmentation of the polypeptide and isolation of cystine-containing peptides and determination of their N-terminal sequences. The data demonstrate that all of the 10 cysteine residues participate in disulfide bridges and that Cys-70, the only cysteine in F2, and Cys-199, the most upstream cysteine in F1, form the interchain bond. Of the remaining eight cysteine residues clustered near the transmembrane domain of F1, the specific bridges identified are Cys-338 to Cys-347 and Cys-362 to Cys-370. Although no exact pairings between the subsequent four residues were defined, it seems likely that the most downstream, Cys-424, is linked to Cys-394, Cys-399, or Cys-401. Thus, we conclude that the cysteine-rich domain indeed contributes to the formation of a bunched structure containing at least two tandem cystine loops.

Antitumor and immunological activity of lentinan in comparison with LPS

Lentinan manifests marked antitumor and antimetastatic activity in numerous tumor/host systems, and prevents chemical and viral carcinogenesis. Modulation of immune or vascular functions by lentinan is involved in its antitumor effects. The impact of lentinan on the functions of macrophages is distinct from that of LPS. One of the effects of lentinan on the vascular system is the vascular dilatation and hemorrhage (VDH) reaction, and the effect can be monitored as augmented skin reactions to vasoactive mediators. Lentinan induces the VDH-like reaction at the tumor site, resulting in the induction of hemorrhagic necrosis and complete regression of the tumor. In contrast to LPS-induced tumor necrosis (Shwartzman's-like reaction), lentinan-induced tumor necrosis is T-cell dependent.

MR diagnosis of myelofibrosis

We present a case of secondary myelofibrosis in which magnetic resonance imaging (MRI) contributed to the diagnosis. On both T1- and T2-weighted images, bone marrow showed hypointensity. However, since blood transfusion therapy was performed prior to MRI, it was necessary to differentiate fibrosis from siderotic marrow. On gradient echo (GRASS) images, bone marrow also showed hypointensity, but not as prominent as that seen in siderotic marrow. After intravenous administration of gadolinium-dimethylene triaminepentaacetic acid (Gd-DTPA), enhancement of the marrow space may be induced by a fibrous change of the marrow. MR findings were confirmed by histological examination of the biopsy specimen.

Polyclonal B cell activation, endotoxin tolerance, and limulus tests of endotoxin preparations of some periodontopathogens

Potencies of polyclonal B-cell activation in C3H/HeN mice of Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis endotoxins were 0.36, 0.13 and 0.04, taking Salmonella abortusequi as 1.0. F. nucleatum and P. gingivalis endotoxins showed positive reactions in C3H/HeJ mice. Most activities in C3H/HeN other than that of F. nucleatum were suppressed by polymyxin B. In C3H/HeJ mice, similar inhibitions were only 60% for P. gingivalis and hardly observed with F. nucleatum. The resistances to polymyxin B could be due to protein in the endotoxins. A promoting effect of T cells added to B cells was observed only in the activity of F. nucleatum endotoxin in C3H/HeJ mice; there was no influence in other groups. Test endotoxins had nearly the same ability to produce colony stimulating factor as did references and could not produce the factor in tolerant mice. The clinical significance of tolerance is discussed. Regression lines of endotoxin doses and limulus activities of test endotoxins and Salmonella were parallel, either in specific or non-specific tests. The lines of two test groups were also parallel; values obtained by two tests were very close. These data indicate that the test endotoxins did not contain (1-3)-beta-D-glucan and elicited qualitatively similar limulus reactions to that of the reference, despite their different chemical natures. In conclusion, these test preparations had an endotoxicity similar to that of the reference and contribute to produce periodontitis through polyclonal B cell activation.