Gene organization and primary structure of a ribosomal RNA gene cluster from Streptomyces griseus subsp. griseus

The Streptomyces griseus subsp. griseus KCTC 9080 genome contains six rRNA-encoding gene (rDNA) clusters. One rDNA cluster (rrnE), contained in an 8.7-kb BamHI fragment, was cloned and sequenced. The rDNA were arranged in the order 16S-23S-5S, and separated by small intergenic spacers. No tRNA-encoding sequences were found in the spacer regions. The lengths of the mature 16S, 23S and 5S rRNAs were 1528, 3120 and 120 nucleotides (nt), respectively. The G + C content of the gene cluster was lower than that of the chromosomal DNA. In general, the primary and secondary structures of the three rRNAs showed good agreement with those from other Streptomyces species. However, in comparison with Escherichia coli, two noticeable changes (mismatches and deletions) and two large insertions were identified in the 16S and 23S rRNAs, respectively. On the other hand, regions showing considerable heterogeneity, even within the genus Streptomyces, were found in both rRNAs. Putative primers and processing signals showing high sequence similarity to those from other Streptomyces species were located in the region upstream from the 5' end of the mature 16S rRNA. A potential hairpin loop structure reminiscent of a Rho-independent terminator was located just downstream from the 5S rRNA. A considerable degree of sequence conservation and variation within rDNA gene clusters was revealed in this study, both at the infra- and suprageneric levels.

Patterns of vertebral ossification and pelvic abnormalities in paralysis: a study of 200 patients

To clarify the characteristics, extent, and frequency of spinal ossification and abnormalities of the sacroiliac joint, symphysis pubis, and hip in paralysis, routine radiographs of the lumbar spine, pelvis, and abdomen were retrospectively evaluated in 95 quadriplegic, 105 paraplegic, and 100 age-matched control patients, with attention to age and race and to spinal level and duration of paralysis. The spinal radiographs were evaluated for presence of osteophytes, syndesmophytes, paravertebral ossification, and flowing hyperostosis characteristic of diffuse idiopathic skeletal hyperostosis (DISH); the pelvic radiographs were used to measure the widths of the sacroiliac joint, hip, and symphysis pubis articulations and evaluate for presence of enthesopathy. Bone formation around vertebral bodies was often seen in quadriplegic (n = 41 [43%]) and paraplegic (n = 46 [44%]) patients. In quadriplegic patients, four distinct vertebral ossification patterns were evident: osteophytosis, paraspinal ossification resembling that found in psoriasis, syndesmophytosis, and flowing ossification similar to that in DISH. In paraplegic patients, osteophytosis was most frequent. Vertebral ossification in quadriplegic patients was significantly associated with age (P < .01) and increased in frequency and severity with increasing age.

[Effectiveness of dapsone on refractory immune thrombocytopenia in a patient with systemic lupus erythematosus associated with sarcoidosis]

A 57-year-old man was admitted with massive nasal bleeding and blurred vision in January, 1991. Laboratory examination showed a prominent decrease of platelet number (1,000/microliters) and a marked elevation of PAIgG (4,025 ng/10(7) cells). Serological test revealed positive antinuclear factor, low concentration of C3 and C4, high level of immune complex and polyclonal hypergammaglobulinemia. The patient had uveitis and bilateral hilar lymphadenopathy with a high level of serum lysozyme and negative PPD skin test. The diagnosis of SLE complicated with thrombocytopenia and sarcoidosis was made. In spite of the various trials of treatment, such as oral prednisolone (PSL), methyl-PSL pulse therapy, plasma exchange, high-dose intravenous gammaglobulin, cyclophosphamide, azathioprine, vincristine, colchicine, cyclosporine-A, mizoribine, danazol, ascorbic acid and interferon alpha 2b, the platelet number could not be raised enough to keep more than 10,000/microliters, though the level of PAIgG decreased to 200 ng/10(7) cells. Finally, the administration of 75 mg/day of dapsone brought about a significant rise in platelet number within 2 weeks. The maximum number of 6.2 x 10(4)/microliters was obtained after 2 months. Then the patient stopped himself to take the drug, but the platelet number remained around 4-5 x 10(4)/microliters. Same dose of the drug was again prescribed to confirm the effect of dapsone. The platelet number increased to 7.9 x 10(4)/microliters in 2 weeks, and gradually returned to 5 x 10(4)/microliters after cessation of the drug. Thus being certainly effective against thrombocytopenia, dapsone should be considered as one of the therapeutic choice for refractory autoimmune thrombocytopenia.

Cervical spine: comparison of 45 degrees and 55 degrees anteroposterior oblique radiographic projections

The orientation of the intervertebral foramina (IVF) at six cervical levels on transaxial images in 65 magnetic resonance (MR) studies was determined to explain variations in size and shape evident on the 45 degrees standard radiographic oblique view. Analysis of MR imaging data showed that substantial variations in the orientation of the cervical IVFs occurred throughout the cervical spine and that a 55 degrees anteroposterior (AP) oblique view with standard radiography probably would lead to better visualization of the lower cervical IVFs. These results were confirmed with a radiographic and anatomic study of two cadaveric specimens. In a prospective clinical study of 23 patients, 45 degrees and 55 degrees AP oblique views were compared by measuring the maximal transverse diameter of all the cervical IVFs. IVF size was substantially increased on the 55 degrees AP oblique projection at all lower cervical levels. The 55 degrees AP oblique view of the cervical spine is optimal for evaluating the lower cervical foramina and can be a routine alternative to the 45 degrees oblique view in the analysis of all cervical foramina.

Suprageneric classification of thermoactinomyces vulgaris by nucleotide sequencing of 5S ribosomal RNA

The 5S rRNA nucleotide sequence of Thermoactinomyces vulgaris was determined and compared with published sequences of representative Gram-positive bacteria. The primary and secondary structure of the sequence is of the type characteristic of Gram-positive bacteria that have DNA with a low proportion of guanine plus cytosine. It was evident from the phylogenetic trees that T. vulgaris has little in common with actinomycetes but is related to the genus Bacillus, showing a moderately high relationship with B. stearothermophilus. The taxonomic implications of these relationships are discussed and an emended description of the family Bacillaceae is given.

Identification and production of flavonoids in a cell suspension culture of Scutellaria baicalensis G

A high yielding cell line of Scutellaria baicalensis G. has successfully been developed to produce flavonoids. Major components of the flavonoids were identified as baicalin and wogonin-7-O-glucuronic acid by a series of instrumental analyses using UV, IR, MASS, and NMR. After 12 days in suspension culture, the cell growth reached 14 g (DW)/l, and baicalin and wogonin-7-O-glucuronic acid were obtained in concentrations of 2.9 g/l and 1.07 g/l, respectively. The culture temperature was found to be an important parameter for improving production yield of the flavonoids. The yield of baicalin was observed to increase to 4.2 g/l by shifting the temperature from 30 °C to 25 °C after 72 h of suspension culture.

Comparison of the pharmacokinetics and pharmacodynamics of the aldose reductase inhibitors, AL03152 (RS), AL03802 (R), and AL03803 (S)

The pharmacokinetics of AL03152 (RS) and its enantiomers, AL03802 (R) and AL03803 (S), were studied in the Sprague-Dawley rat following intravenous bolus administration. The enantiomers had differing pharmacokinetic profiles, while the racemic compound exhibited pharmacokinetic parameters approximating the mean values of the individual enantiomers. The total clearance (CLT) values of the two enantiomers were similar, but the intrinsic clearance (Cl(int)) was much greater for the S-enantiomer than for the R-enantiomer. The volume of distribution (Vss) for AL03802 (R) was threefold greater than that for AL03803 (S). The stereoselectivity in Vss could not be totally accounted for by the slight difference in serum protein binding of the isomers and resulted in a difference in the half-lives of the enantiomers. Only the R-isomer exhibited a persistent terminal elimination phase, consistent with more extensive tissue binding than the S-isomer. AL03152 enantiomers were equivalent in potency assessed from in vitro IC50 values toward rat lens aldose reductase and rat kidney L-hexonate dehydrogenase and lens EC50 values in diabetic rats.

Piezoelectric lithotripsy of radiopaque gallstones: results and six-month follow-up

Sixty-eight patients with radiopaque gallbladder stones (38 with a single stone, 30 with multiple stones) were treated with piezoelectric extracorporeal shock wave lithotripsy (ESWL) and results were compared with those of 69 patients with radiolucent stones (28 with a single stone, 41 with multiple stones). Stones were fragmented to 4 mm or less in 76.8% after 41,466 +/- 36,504 shock waves in the radiolucent stone group and 77.9% after 54,686 +/- 51,024 shock waves in the radiopaque stone group (p = 0.876 and 0.130, respectively). In 137 patients, ten patients were lost to follow-up. Average period of follow-up was 220 +/- 198 days. Six-month clearance rate of the radiolucent stone group was 43.5% and that of the radiopaque stone group was 16.4% (p less than 0.05) Figure 1. Six-month clearance rate of patients with single stones smaller than 2 cm was also significantly higher in the radiolucent stone group than in the radiopaque stone group (69.5% vs 18.6%; p less than 0.01). However, in patients with multiple stones, the presence of calcification did not affect rates of successful fragmentation or 6-month clearance. There was no statistically significant difference in incidence of complications between the radiolucent and radiopaque stone groups. Although the number of cases are small and the follow-up period is short, our results of ESWL on radiopaque gallstones are so far not satisfactory in terms of stone clearance. Strict patient selection is needed unless there is an improvement in the lithotripsy procedure or post-lithotripsy management.

Suppression of proliferative response of BoCD4+ T lymphocytes by activated BoCD8+ T lymphocytes in the mammary gland of cows with Staphylococcus aureus mastitis

Investigations were conducted to determine the mechanisms that account for differences in the responses of BoCD4+ lymphocytes from mammary gland secretions (MGS) in healthy cows and in cows with Staphylococcus aureus infection. The proliferative response to lectins and S. aureus antigens of mammary gland lymphocytes from healthy, S. aureus immunized cows was less than the response of peripheral blood lymphocytes. The lower responses of mammary gland lymphocytes were attributable both to less efficient antigen presentation by mammary gland antigen-presenting cells (APC) than by peripheral blood APC, and to lower responsiveness of mammary gland lymphocytes to lectins and antigen. In addition, the proliferative response of infected mammary gland lymphocytes was less than the response of uninfected mammary gland lymphocytes. This difference resulted from decreased proliferation of BoCD4+ lymphocytes in infected MGS. Flow cytometric analysis revealed that infected MGS contained increased numbers of BoCD8+ cells which coexpressed an activation molecule, ACT2, relative to BoCD8+ cells from uninfected MGS. Removal of BoCD8+, ACT2+ lymphocytes resulted in increased antigen responsiveness by lymphocytes from infected mammary glands. Also, when purified BoCD4+ lymphocytes were stimulated with antigen in the presence of varying numbers of ACT2+, BoCD8+ lymphocytes, antigen responsiveness was decreased in a dose-related manner. These data demonstrate that hyporesponsiveness of mammary gland lymphocytes to lectins and S. aureus antigen is, in part, mediated by activated BoCD8+ lymphocytes and suggest that this population enhances persistent intramammary infection by S. aureus.

Selection of BoCD25 monoclonal antibodies by screening mouse L cells transfected with the bovine p55-interleukin-2 (IL-2) receptor gene

The bovine interleukin-2 receptor-alpha (IL-2R alpha) gene has been isolated and a rabbit antiserum against a fusion protein of the gene has been produced. However, the antiserum does not inhibit IL-2-dependent proliferation. Since a panel of monoclonal antibodies (mAb) to bovine activation antigens was available, we transfected the gene into mouse L fibroblasts, selected stable transfectants with the rabbit antiserum, and screened for antibodies that bound the transfected cells but not the untransfected cells. Three mAb were selected and all three precipitated a molecule of M(r) 55,000 (under reducing conditions) from activated cells, as expected from homology with mouse and human IL-2R alpha (CD25, Tac). One of the three mAb was a strong inhibitor of IL-2-dependent proliferation of bovine lymphocytes. Thus, the availability of transfected cells allowed us to establish quickly and unequivocally the antigenic specificity of a number of antibodies.

Inoculum dynamics ofGliocladium virens associated with roots of cotton seedlings

A system was developed to evaluate the effects of root growth of cotton seedlings on the inoculum dynamics ofGliocladium virens in nonsterile soil. In soil infested withG. virens, inoculum densities of the fungus increased when plants remained alive. After 30 days, shoots were excised and the roots allowed to deteriorate. During this portion of the experiment (30-60 days) soil inoculum densities ofG. virens declined. In infested soil without a seedling, inoculum densities remained constant throughout the duration of the experiments. Colonization of roots byG. virens was found to increase throughout the duration of the experiments. At 60 daysG. virens was recovered from approximately 60% of the root pieces (1-cm) sampled. The percentage of primary, secondary, or tertiary roots colonized was different (P = 0.01), but the total colonization of roots at three depths (0-10, 10-20, and 20-30 cm) was not different (P = 0.64). In noninfested soil, colonization of roots by indigenous propagules ofG. virens was never greater than 3%.

Obstructive jaundice after laparoscopic cholecystectomy with electrocautery

The authors describe a special complication, bile duct stenosis, which occurred after a laparoscopic cholecystectomy using electrocautery. The preventive precautions that were taken and the remedial surgical procedures performed are stated.

Pharmacokinetics and efficacy of structurally related spirohydantoin and spirosuccinimide aldose reductase inhibitors

1. Six potent aldose reductase inhibitors (ARI), three spirohydantoin (I to III) and three spirosuccinimide (IV to VI) compounds, showed similar IC50 activities in vitro for the inhibition of rat lens aldose reductase, but their ED50 values in diabetic rats varied as much as 20-fold in the lens and 50-fold in the sciatic nerve tissue. Pharmacokinetic studies were undertaken to investigate these findings. Structure-pharmacokinetic relationships were studied following i.v. administration to cynomolgus monkeys. 2. The clearance (CL) of each spirosuccinimide ARI was faster (greater than 5 times) than that of the corresponding spirohydantoin compound. In both series the CL values of the C(4) methyl and methoxy analogues were 4-fold greater than those for the unsubstituted compounds, although the CL values of the methoxy and methyl derivatives in the same series were not significantly different. 3. The volumes of distribution (Vss) of the spirohydantoins were about one-half those of the corresponding spirosuccinimides, and the Vss values of the parent compounds of both ARI series did not differ dramatically from those of their methyl and methoxy analogues. 4. All six compounds were eliminated from plasma in a biexponential fashion. The half-lives (lambda 1 and lambda 2) of the spirohydantoin compounds were much longer than those of the corresponding spirosuccinimide compounds, and the unsubstituted compounds had longer half-lives than their methyl and methoxy derivatives. The longest lambda 1 and lambda 2 half-lives were observed for imirestat, while two of the spirosuccinimides had the shortest half-lives. 5. These results indicate that the relationships observed between the in vitro and in vivo activities of the six ARI can be attributed to structurally dependent differences in metabolic clearance.

Bovine mononuclear leukocyte subpopulations in peripheral blood and mammary gland secretions during lactation

Florescence flow cytometry and monoclonal antibodies were used to analyze the composition of leukocytes from peripheral blood and mammary gland secretions. Samples were obtained from Holstein dairy cows, free of IMI, at six time points during the lactation cycle. The percentage of monocytes in peripheral blood mononuclear cells varied from 15 to 31%; the lowest percentage occurred at the early nonlactation period. The percentage of T lymphocytes from mammary gland secretions varied from 16% during the periparturient period to 62% at late lactation. The B lymphocytes varied from 7% at late lactation to 25% during the periparturient period. Macrophages varied from 21 to 69%; the highest percentage occurred during the periparturient period. The mean ratio of CD4+:CD8+ T lymphocytes in the peripheral blood and mammary gland secretions was 1.53 and .85, respectively. A subpopulation of activated CD8+ T lymphocytes present in mammary gland secretions throughout the lactation cycle coexpressed a new activation molecule, ACT2. Increases in the proportion of CD8+ T lymphocytes were associated with an increase in the percentage of CD8+, ACT2+ T lymphocytes. Activated CD8+ T lymphocytes may play an important role in the regulation and expression of the local immune response to pathogens.

Classification of acidophilic, neutrotolerant and neutrophilic streptomycetes by nucleotide sequencing of 5S ribosomal RNA

Complete 5S ribosomal RNA sequences were obtained for four acidophilic actinomycetes, seven neutrophilic streptomycetes and a strain of Streptoverticillium baldaccii. All of the organisms contained RNAs belonging to the 120 nucleotide type. An evolutionary tree was generated after combining the test data with results from similar studies on representative Gram-positive bacteria. The acidophilic, neutrotolerant and neutrophilic actinomycetes were recovered in a distinct cluster that was equated with the genus Streptomyces. The sequence data support the view that the genera Chainia, Elytrosporangium, Kitasatoa and Microellobosporia should be considered as synonyms of the genus Streptomyces. The recovery of the Streptoverticillium baldaccii strain on the fringe of the Streptomyces cluster is also consistent with current trends in the taxonomy of these organisms. Further work is needed to determine the taxonomic status of the two streptomycete subgroups that comprised the streptomycete cluster.

Metabolism of the aldose reductase inhibitor ALO1567 in man

1. The metabolism of the aldose reductase inhibitor, ALO1567, was studied in man. The major biotransformation pathway was aromatic hydroxylation followed by glucuronide conjugation. 2. Hydroxylation occurred at several positions on the fluorene ring. The major metabolite was identified as the 7-hydroxy analogue of ALO1567 and three minor metabolites were characterized as positional isomers of the 7-hydroxy metabolite. 3. Oxidative defluorination and metabolism on the hydantoin ring were also indicated as minor pathways. 4. The capacity of normal subjects to oxidize ALO1567 was indicated by the urinary ratio of the parent drug to the 7-hydroxy metabolite after daily oral administration of 100 mg and 200 mg of ALO1567. Most subjects having higher ALO1567 plasma concentrations showed higher ratios.

Regulation of early precursor B cell proliferation in mouse bone marrow: stimulation by exogenous agents mediated by macrophages in the spleen

An increase in pre-B cell proliferation and B lymphocyte production in mouse bone marrow has previously been shown to follow the administration of various foreign agents in vivo. The responses of early precursor B cells before the expression of mu chains (pro-B cells) have now been examined, using double immunofluorescence labeling for terminal deoxynucleotidyl transferase (TdT) and B220 glycoprotein as detected by monoclonal antibody 14.8. A single injection of sheep red blood cells (SRBC) was followed by an increase in the number of cells in three defined populations of early precursor B cells lacking mu chains (TdT+ 14.8- cells, TdT+ 14.8+ cells, and 14.8+ mu- cells) as well as cytoplasmic mu-bearing pre-B cells and surface mu-bearing B lymphocytes. An accompanying increase in proliferative activity was indicated by the numbers of 14.8+ mu- cells and pre-B cells which accumulated in metaphase after inducing mitotic arrest with vincristine. These effects were all abrogated either by treating mice with silica to depress macrophage function or by splenectomy. In mice given multiple injections of SRBC for 4 weeks the elevated levels of early precursor B cell production and B cell genesis were sustained. The work demonstrates that the in vivo production of early precursor B cells, putatively including those at the stage of Ig heavy chain gene rearrangement, can be stimulated by exposure to external agents acting indirectly by a silica-sensitive, spleen-dependent mechanism. The findings suggest that the level of pro-B cell proliferation and primary B cell genesis normally taking place in mouse bone marrow may reflect the level of exposure to potential stimulants in the external environment mediated by activation of splenic macrophages. The possibility that abnormally high levels of macrophage activation could predispose to dysregulations of the B cell lineage is raised.

Embolic control of lumbar artery hemorrhage complicating percutaneous renal biopsy with a 3-F coaxial catheter system: case report

A case is presented in which massive retroperitoneal hemorrhage from the left first lumbar artery complicating a percutaneous renal biopsy was successfully controlled by superselective embolization with microcoils. An anterior radiculomedullary artery (artery of Adamkiewicz) originated from the lumbar artery. To minimize the risk of ischemic damage to the spinal cord from embolization, the extravasating branch of the lumbar artery had to be superselectively catheterized using a 3-F coaxial catheter system. Computed tomography (CT) scan localized the hematoma within the left posterior pararenal space in the retroperitoneal space.

Capillary gas chromatographic-electron-capture assay for the aldose reductase inhibitor imirestat in lens and plasma

A sensitive and selective gas chromatographic-electron-capture assay was developed for the determination of the aldose reductase inhibitor imirestat in lens and plasma. The method involves solid-phase extraction of drug and internal standard from the plasma specimen or lens sample homogenate using "Baker"-10 SPE extraction columns followed by derivatization with pentafluorobenzyl bromide and further purification. Derivatives of drug and internal standard were separated on a fused-silica capillary column and analyzed using a 63Ni electron-capture detector. The limit of detection was 2.5 ng per lens or ml of plasma. The method was used to evaluate the pharmacokinetics of imirestat in human subjects and to quantitate imirestat in animal lens tissue following topical ocular administration.

Mutagenicity of Maillard reaction products from D-glucose-amino acid mixtures and possible roles of active oxygens in the mutagenicity

The mutagenicity for Salmonella typhimurium TA100 without S9 mix of Maillard reaction products (MRP) obtained from equimolar amounts of glucose and amino acids under different pHs was investigated. MRP derived from arginine and lysine exhibited the strongest mutagenicity, and weaker mutagenicity was shown by the mixtures with alanine, serine, threonine and monosodium glutamate. MRP from proline and cysteine had no detectable mutagenicity. Furthermore, glucose-arginine and glucose-lysine reaction mixtures, which presented a marked mutagenicity, showed pH- and browning intensity-dependent expression of their mutagenic activities. The mutagenicity of MRP, especially glucose-arginine and glucose-lysine mixtures, was significantly suppressed by active oxygen scavengers such as cysteine, mannitol, alpha-tocopherol, catalase and superoxide dismutase (SOD) and reducing agents such as sodium bisulfite and glutathione. Among these desmutagenic factors tested, cysteine, catalase, sodium bisulfite and glutathione had higher desmutagenic activities than the others. Accordingly, it is assumed that the mutagenicity of MRP is due to the direct action of low-molecular-weight compounds such as carbonyls and heterocyclics produced by the Maillard reaction and is enhanced by active oxygens, especially singlet oxygen and hydrogen peroxide derived from their autoxidation.

Retained intrahepatic stones: treatment with piezoelectric lithotripsy combined with stone extraction

Extracorporeal shock wave lithotripsy (ESWL) was performed in 11 patients with oriental cholangiohepatitis and intrahepatic stones associated with segmented strictures of intrahepatic ducts. All patients had previously undergone biliary surgery and basket extraction via a T-tube tract at the time of lithotripsy. The indication for ESWL was failure of, or anticipated difficulty with, basket extraction of the stones via a T-tube tract. A piezoelectric lithotriptor was used in all procedures. The average total number of shock waves administered was 29,756 (range, 10,000-61,395). The average number of treatment sessions was 3.1 (range, 1-6); the number of shock waves used in a single session ranged from 10,000 to 15,000 with a frequency of five shots per second and 30%-50% power. In six patients, the stones were successfully fragmented and completely removed; in three of the others of the stones were fragmented and removed. The overall success rate, including complete (54%) and incomplete (27%) success, was 82%. Difficulty in targeting stones, and severe strictures and deformities of intrahepatic ducts, were the factors responsible for failure. No significant complications were observed.

Interspecies comparison of the pharmacokinetics of aldose reductase inhibitors

The pharmacokinetics of three aldose reductase inhibitors (ARIs) were evaluated in various species, including rat, dog, cynomolgus monkey, rhesus monkey, chimpanzee, and man. The three ARIs (AL01567, AL01576, and AL01750) were administered intravenously as a single dose to all species except rat, which was dosed orally with AL01750, and man, who was dosed orally with AL01567 and AL01576. Plasma drug concentrations were measured by HPLC or liquid scintillation spectrometry and various pharmacokinetic parameters (clearance, CL; Vd, volume of distribution; and t1/2) were calculated from the data. Overall the pharmacokinetics of the three compounds were quite similar, each being characterized by low CL, intermediate Vd, and long t1/2. For AL01576, mean CL ranged from 0.21 ml/min/kg in cynomolgus monkey to 0.91 ml/min/kg in dog, mean Vd from 0.66 liter/kg in cynomolgus monkey to 2.4 liters/kg in dog and man and mean t1/2 from 29 hr in dog to 72 hr in man. Mean CL of AL01567 ranged from 0.14 ml/min/kg in man to 1.4 ml/min/kg in dog, mean Vd from 0.45 liter/kg in rat to 3.5 liters/kg in dog and mean t1/2 from 22 hr in rhesus monkey to 63 hr in man. Mean CL of AL01750 ranged from 0.13 ml/min/kg in chimpanzee to 1.3 ml/min/kg in dog, mean Vd from 0.40 liter/kg in rat to 1.8 liters/kg in dog and mean t1/2 from 12 hr in rhesus monkey to 62 hr in chimpanzee. For all three drugs, CL and Vd corrected for body weight were quite similar in all species except dog, whose CL and Vd were two- to fourfold greater than the other animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative studies on FcR (FcRII, FcRIII, and FcR alpha) functions of murine B cells

Distribution of FcR II, FcRIII, and FcR alpha on murine splenic B cells was examined by using FITC-labeled heat-aggregated IgG of each subclass and IgA. Almost 60 to 80% of B cells expressed both FcRII and FcRIII. However, FcR alpha was expressed on only a small proportion (6%) of B cells that co-expressed FcRII. By inhibition assays with the use of cold IgG of each subclass and IgA in addition to anti-FcRII mAb (2.4G2), it was found that IgG1, IgG2a, and IgG2b utilized the same receptor (FcRII), whereas IgG3 and IgA bound only to their unique receptors, FcRIII and FcR alpha, respectively. Immune complexes IC prepared by IgG1, IgG2a, IgG2b, and IgA anti-TNP mAb with TNP-coupled SRBC inhibited the polyclonal Ig secretion and proliferative responses of B cells stimulated with either IL-4 or LPS. The inhibition of B cell activation was associated with the blockade of the membrane depolarization. Moreover, IC prepared by these antibodies caused production of suppressive B cell factor (SBF) as is the case with rabbit IgG antibody to SRBC, and SBF thus prepared regulated antibody responses in an isotype-nonspecific manner. In contrast, no inhibition for these responses or production of SBF was attained by the IC of IgG3 antibody. We concluded that FcRII and FcR alpha mediates a suppressive signal for B cells by acting on the initial step of activation, whereas FcRIII lacks this activity.