Evans' syndrome associated with Graves' disease

A 36-year-old woman who had had Graves' disease for 6 years was admitted with severe thrombocytopenia. Evans' syndrome was diagnosed. The patient's family history showed multiple cases of Graves' disease but no cases of Evans' syndrome. Both conditions in this patient improved with corticosteroid and thiamazole therapy. Several autoimmune antibodies were found, but a common autoimmune mechanism was not clearly shown. Although the combination of Graves' disease and Evans' syndrome had not occurred previously in her family, genetic factors may play an important role in the pathogenesis of both conditions.

Relationship between pharmacokinetics of unchanged cisplatin and nephrotoxicity after intravenous infusions of cisplatin to cancer patients

PURPOSE

The relationships between pharmacokinetic parameters of unchanged cisplatin (CDDP) and several markers for nephrotoxicity after CDDP infusion (80 mg/m2) over 2 and 4 h were quantitated in patients with various cancers (lung, stomach and colon cancers and mediastinal tumor).

METHODS

Plasma and urinary levels of unchanged CDDP were measured using a specific high-performance liquid chromatography method. Pharmacokinetic parameters were calculated according to the model-independent method. The nephrotoxicity markers, blood urea nitrogen (BUN), serum creatinine (SCr), plasma and urinary beta2-microglobulin (BMGp and BMGu), urinary N-acetyl-beta-D-glucosaminidase (NAG) and creatinine clearance (CCR) were monitored for 30 days following CDDP administration.

RESULTS

The maximum plasma concentration (Cmax), maximum urinary excretion rate (dAe/dt(max)), area under the plasma concentration-time curve from time zero to infinity (AUC), cumulative amount excreted in urine from time zero to infinity (Ae), total clearance (Clt), renal clearance (Clr) and plasma half-life (t1/2) of unchanged CDDP were not significantly different between the 2-h and 4-h infusion schedules. The values of the nephrotoxicity markers changed significantly following CDDP administration, suggesting that CDDP chemotherapy (80 mg/m2) caused nephrotoxicity. The Cmax of unchanged CDDP was the most informative pharmacokinetic parameter for nephrotoxicity. Cmax was related to maximum BUN, maximum SCr and minimum CCR levels in 27 CDDP treatments according to an exponential model.

CONCLUSION

In order to attain more effective CDDP chemotherapy with minimum nephrotoxicity, the present pharmacokinetic and pharmacodynamic studies suggest that the Cmax or steady-state plasma level of unchanged CDDP should be maintained between 1.5 and 2 microg/ml in a standard continuous infusion schedule over 2 h and 4 h.

A lipid A analog inhibits LPS-induced cytokine expression and improves survival in endotoxemic mice

It has recently been shown that inactive disaccharidic analogs of lipid A, an essential structure of lipopolysaccharide (LPS), may act as LPS antagonists which would be effective against septic shock induced by gram-negative bacteria endotoxin. In the present study we examined the inhibitory effect of DY-9973, a synthetic monosaccharidic lipid A analog, on LPS-induced cytokine expression in macrophages and lethal toxicity in mice. DY-9973 inhibited TNF-alpha production induced by LPS in human monocytes and monoblastic U937 cells. Expression of cytokine mRNAs such as TNF-alpha and IL-1 beta induced by LPS was inhibited by treatment with DY-9973 in U937 cells. Meanwhile, DY-9973 did not inhibit IL-1 beta-induced TNF-alpha production in U937 cells. TNF-alpha production induced by LPS or IL-1 beta was similarly inhibited by treatment with herbimycin, a tyrosine kinase inhibitor. Pretreatment with DY-9973 inhibited the elevation of serum TNF-alpha activity induced by the injection of LPS and reduced the lethal toxicity of LPS in BCG-primed mice. These results suggest that monosaccharidic lipid A analog such as DY-9973 can inhibit LPS-induced activation of macrophages and that it reduces lethal toxicity of LPS.

Yersinia pseudotuberculosis in China

Thirty strains of Yersinia pseudotuberculosis were isolated from rabbits (17 strains), wild rats (9 strains) and house rats (4 strains) in China between 1990 and 1993. The biochemical properties of these isolates were identical with those of Y. pseudotuberculosis and no special characteristics were found in these strains. Serologically, serogroups 4b and 5b were identical to isolates found in Japan, and a new serogroup 1c and unclassified strains have also been detected. The existence of virulence-associated properties were different among strains. The pYV plasmid was detected from 6 strains of 30 isolates. This report documents the presence of Y. pseudotuberculosis in China, providing important epidemiological information.

In vitro and in vivo antifungal activities of DU-6859a, a fluoroquinolone, in combination with amphotericin B and fluconazole against pathogenic fungi

DU-6859a is an investigational fluoroquinolone agent with potent bactericidal activity, but by itself it has no antifungal activity. When combined with amphotericin B (AmB), however, DU-6859a clearly enhanced the in vitro antifungal activity of AmB against Candida albicans, Candida tropicalis, Candida krusei, Candida glabrata, and Cryptococcus neoformans in microdilution checkerboard studies. Positive interactions of DU-6859a with AmB against Aspergillus fumigatus were dependent on the medium used; yeast nitrogen base supplemented with amino acids, ammonium sulfate, and 1% glucose was better for demonstrating synergism, while in RPMI 1640 medium, unexpected antagonism between the drugs occurred against three of the strains tested. In combination with fluconazole (Flu), DU-6859a increased the activity of Flu against C. albicans both in synthetic amino acid medium fungal and in supplemented yeast nitrogen base. An in vitro time-kill study revealed that DU-6859a combined with AmB significantly suppressed the regrowth of C. albicans compared with the suppression brought about by AmB used alone in a concentration-dependent fashion. Furthermore, in a model of C. albicans infection in mice, the fungal load in infected kidneys was significantly less in mice given the combination treatment of DU-6859a plus either AmB or Flu, and thus, the combination treatment resulted in prolonged survival of infected mice compared with treatment with either antifungal alone. The prolonged survival in mice given the combined treatment was also observed in mice with A. fumigatus infection, indicating that DU-6859a potentiated the actions of the antifungal agents in vivo as well as in vitro.

[Induction of protective immune responses by a chimeric soluble protein from a recombinant BCG vector candidate vaccine to HIV-1]

We have been isolated HIV strains from blood specimens of HIV infected individuals in Japan for these 6 years. The number of specimens tested reached approximately 1,700 that ninety percent of them were from hemophiliacs repeatedly injected blood products from the United States. More than 300 of field HIV were successfully isolated from the samples. The isolation rates has decreased to 30 percent in 1993 from 40 percent in 1992, suggesting that treatment with anti-HIV drugs such as AZT and/or ddI may be effective to HIV-infected individuals. Further, both of the viral and genomic sequences of HIV were classified to be clade B virus. The clinical isolates that expressed IHIGPGRAFY sequence at the center of the HIV-V3 domain were found to be neutralized by an anti-clade B-V3 monoclonal antibody, mu 5.5. By individual levels, when asymptomatic seropositives have progressed to disease-states, neutralization core motif of GPGR in approximately 6% of the viruses has changed to GPGG and hydrophilic amino acid changed to hydrophobic amino acid, correlating the loss of binding activity to PND-peptide of Japanese Consensus virus. Further, rapid progressors to HIV-induced diseases showed decreased activity of the binding antibody. By using the Japanese consensus sequence of HIV-1, we successfully constructed chimeric protein secretion vectors by selecting an appropriate insertion site of a carrier protein, and established the PND-peptide secretion system in BCG. The recombinant BCG inoculated guinea pigs were initially screened by delayed-type hypersensitivity (DTH) skin reactions to the PND peptide followed by passive transfer of the DTH by the systemic route.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukocyte subpopulation changes in rats with autotransplanted endometrium and the effect of danazol

PROBLEM

This study examines immune cell populations in rats with autotransplanted endometrium and determines the effect of danazol on leukocyte subsets.

METHODS

As an experimental model of endometriosis, an autologous endometrial segment was implanted in the rat peritoneum. We used flow cytometry to analyze lymphocyte subsets in the peripheral blood (PB) and peritoneal fluid (PF) of the following groups of rats: no treatment, sham operation, endometrial implantation, endometrial implantation treated with danazol, and normal rats treated with danazol.

RESULTS

The natural killer (NK) cell population was decreased in both the PB and PF of rats with autotransplanted endometrium. Moreover, NK cells increased in a dose-dependent manner following danazol administration. Surgery itself increased the number of peritoneal macrophages as compared with the untreated group. This elevation was suppressed partially by endometrium-implantation and was attenuated by subsequent administration of danazol in a dose-dependent fashion.

CONCLUSIONS

These data suggest that ectopic endometrial cells may release immunosuppressive factors. This is the first documentation that rats with autotransplanted endometrium show the same immunologic changes as humans with endometriosis, and establishes the utility of this model for the study of endometriosis.

Production of tumor necrosis factor induced by synthetic low-toxicity lipid A analog, DT-5461a, is mediated by LPS receptor sites and tyrosine kinase-MAP kinase signaling pathway in murine macrophages

The synthetic low-toxicity lipid A analog DT-5461a induces endogenous TNF production in mice. The activity of TNF so induced is probably the main contributor to the antitumor effect of this compound. In the present study, we investigated the mechanism by which DT-5461a induces TNF production in murine macrophage RAW 264 cells. DT-5461a mimicked the ability of LPS to induce TNF production in a dose-dependent manner. DT-5461a at higher concentrations inhibited specific binding of [3H]LPS to the cells and reduced LPS-induced TNF production to the level induced by DT-5461a alone. In addition, DT-5461a, as well as LPS, induced tyrosine phosphorylation of MAP kinases, the early signal transduction pathway of this production. Herbimycin A, an inhibitor of tyrosine kinase, inhibited the LPS- and DT-5461a-induced tyrosine phosphorylation, expression of TNF mRNA, and subsequent TNF secretion. These results suggest that DT-5461a and LPS induce TNF production in murine macrophages through the common receptor sites and the similar early signaling pathway.

The antioxidant effect of palm fruit carotene on skin lipid peroxidation in guinea pigs as estimated by chemiluminescence-HPLC method

To study the antioxidant effect of palm fruit carotene on skin lipid peroxidation, the guinea pigs were orally fed ad libitum palm fruit carotene, beta-carotene, or vehicle emulsions, in which carotene (0.05%, w/w) was suspended in drinking water. After treatment of carotene for 12 weeks, animals were exposed to ultraviolet ray (UV), and squalene monohydroperoxide (SqOOH)/squalene (Sq) ratios in the skin lipid were analyzed using the chemiluminescence-HPLC method. Carotene accumulation was found in the skin of guinea pigs that were orally administered palm fruit carotene or beta-carotene. After UV irradiation, especially immediately after, the rise in the SqOOH/Sq ratio was effectively suppressed in both carotene-drinking groups in contrast with the control (carotene-untreated) group. An inverse correlation between the carotene content and the SqOOH/Sq ratio in the skin was also observed. The results suggested that palm fruit carotene intake prevents skin lipid peroxidation caused by UV irradiation.

The effect of natural carotenoid (palm fruit carotene) intake on skin lipid peroxidation in hairless mice

To study the effect of palm fruit carotene intake on skin lipid peroxidation, hairless mice were given ad libitum palm fruit carotene, beta-carotene, or vehicle emulsions for 15 weeks in which the carotene (0.005%, w/w) was suspended in drinking water, and then their dorsal skin was exposed to ultraviolet ray (UV). The carotene content of the skin was increased by the oral intake of palm fruit carotene or beta-carotene. In carotene-drinking mice, before the UV irradiation, the amount of thiobarbituric acid-reacting substances (TBARS) in the skin was lower than that of control (carotene untreated) mice. The skin TBARS immediately after the UV irradiation was lower in carotene-treated mice than in control mice. At 24 h after irradiation, the skin TBARS of mice that orally received palm fruit carotene was lower than that of beta-carotene mice. Immediately after the UV irradiation, the skin carotene content transiently decreased but gradual recovery was observed at 48 h. In palm fruit carotene-treated mice, the rate of carotene recovery after UV irradiation was higher than in beta-carotene-treated mice. Retinol found in the skin had also decreased after UV irradiation, and recovered gradually in both carotene-drinking groups within 48 h. These results suggested that the carotene intake, especially palm fruit carotene, prevented skin lipid peroxidation in hairless mice.

Antitumor synthetic lipid A analog DT-5461a upregulates cytokine expression in a murine macrophage cell line through LPS pathway

We previously showed that DT-5461a, a lipid A analog, has antitumor activity and relatively low toxicity in animals. To clarify its immunostimulatory effect we have studied the cytokine inducibility of DT-5461a and the mechanism involved in the cytokine expression in macrophages. While the activity is lower than that of LPS, DT-5461a enhanced production of TNF-alpha and GM-CSF in the murine macrophage cell line J774.1 in a dose-dependent fashion. Simultaneous addition of IL-4 inhibited DT-5461a and LPS-induced TNF-alpha production in a similar manner. Expression of cytokine mRNAs including TNF-alpha, IL-1 beta, IL-6, and GM-CSF was also enhanced by the treatment with DT-5461a. Treatment with cycloheximide indicated that the expression of TNF-alpha mRNA does not require new protein synthesis. Actinomycin D chase experiments revealed that cytokine mRNAs have rather long half-lives and we could not find significant changes in mRNA stability of cytokines in the J774.1 cells. The binding activity of a nuclear transcription factor NF-kappa B was enhanced by treatment with DT-5461a, suggesting enhanced transcription of cytokine genes. Specific binding of [3H]LPS to the cells was significantly inhibited by the addition of DT-5461a. These results indicate that DT-5461a enhances production of a variety of cytokines in macrophages through the LPS receptor sites and that this cytokine induction may occur primarily via transcriptional enhancement. These immunostimulatory effects may provide evidence for the mechanisms of the antitumor effect of this lipid A analog.

[Hematologic abnormalities in a patient with chronic myelogenous leukemia with advanced myelofibrosis were improved by G-CSF]

A 56-year-old woman was admitted with pyrexia, cough, and dyspnea on August 21, 1991. Physical examination revealed anemia in the palpebral conjunctivas and moist rales at the right lower lung field. Neither the Liver nor spleen was enlarged. Examination of the peripheral blood showed a hemoglobin level of 8.1 g/dl, a platelet count of 14.8 x 10(4)/microliters, and a white blood cell count of 2,800/microliters, with 7% blasts and 8% megakaryocytes. Tear drop-like erythrocytes, agranular neutrophils, and erythroblasts were also seen in the peripheral blood. Examination of the bone marrow showed 15% peroxidase positive blasts, and many micromegakaryocytes. Cytogenetic studies for bone marrow cells revealed the existence of the Philadelphia (Ph1) chromosome. Bone marrow biopsy showed normal cellularity with increase of megakaryocytes and advanced myelofibrosis. Breakpoint cluster region (bcr) rearrangement analysis using the peripheral blood mononuclear cells revealed M-bcr rearrangement. According to the Hannover classification for myeloproliferative disease, she was diagnosed as having CML with advanced myelofibrosis followed by CML with megakaryocytic increase. Since she had neutrocytopenia and severe infectious disease, she received a subcutaneous injection of 125 micrograms of G-CSF. Not only increase of the white blood cell count, but also disappearance of blasts, improvement of anemia, increase of the platelet count, and improvement of myelofibrosis were observed.

beta 2-GPI-dependent and independent binding of anticardiolipin antibodies in patients with recurrent spontaneous abortions

We measured anticardiolipin antibodies (aCL) in plasma samples from 214 women with a history of recurrent spontaneous abortions by an enzyme-linked immunosorbent assay (ELISA) utilizing solid phase cardiolipin (CL) and beta 2-glycoprotein I (beta 2-GPI). Sixteen patients (7.5%) were positive for beta 2-GPI-dependent aCL. Though beta 2-GPI appeared to enhance the binding of aCL, beta 2-GPI-independent aCL were also observed in these patients (4.7%). The patients were classified into three groups on the basis of their medical history, and analysis of data of individual groups revealed that the incidence of beta 2-GPI-dependent aCL was significantly higher in patients who had experienced at least one fetal loss in the second or third trimester.

Relative bioavailability of two disopyramide capsules in humans based on total, unbound, and unbound enantiomer concentrations

The relative bioavailability of two 100-mg disopyramide formulations which showed almost an 8- to 10-fold difference in their dissolution rates at pH 1.2 and 6.8 was determined in eight healthy subjects using a randomized block design. Although no significant differences in relative bioavailability were observed between the two formulations when based on the total disopyramide concentration, an almost 30 per cent difference in the extent of bioavailability was observed when assessed in terms of the unbound (+/-)- and (-)-disopyramide concentration, due probably to stereoselective nonlinear plasma protein binding. This suggests that unbound enantiomer parameters would be more sensitive to differences in bioavailability between two disopyramide formulations. Therefore, the type of concentration used would be an important factor for precise evaluation of the relative bioavailability of racemic drugs.

Characterization of Yersinia pseudotuberculosis serogroups O9, O10 and O11; subdivision of O1 serogroup into O1a, O1b, and O1c subgroups

In this study, three new antigens (O9, O10 and O11) of Yersinia pseudotuberculosis are described. The O1 antigen is further subdivided into O1a, O1b and O1c. The methods used to prepare specific antisera for O-antigen identification are also described. Furthermore, the H antigens of these new serogroups are determined and their biochemical characteristics analysed. The antigenic formulae of the known serogroups within the basic antigenic scheme introduced by the authors' laboratories are presented.

Dosing rate-dependent relationship between propranolol plasma concentration and beta-blockade

The effect of propranolol dosing rate on beta-blockade was studied in human volunteers after administration of a conventional tablet and a sustained release capsule. The slope of the plot of the percentage of reduction in the heart rate against log plasma propranolol concentration was significantly greater after administration of a sustained release capsule than after administration of a conventional tablet. A marked leftward shift of the plasma concentration-response curve was also observed in rabbits as the infusion rate was decreased over the same infusion period. This shift was not altered by pretreatment with 6-hydroxydopamine and plasma catecholamine levels were not affected by the rate of infusion, indicating that the contribution of sympathetic activation to the effect was minimal. By contrast to the anticlockwise hysteresis of the temporal response after propranolol, no such hysteresis was found with the more hydrophilic beta-adrenoceptor antagonist atenolol, or was there any leftward shift in the plasma concentration- response relationship. Data from the isolated guinea pig atrial preparation also showed anticlockwise hysteresis and a leftward shift of the concentration-response curve at a low propranolol input rate, whereas no shift was observed with more hydrophilic beta-blockers such as atenolol, pindolol and metoprolol.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of early syphilis presenting general paresis-like symptoms and bilateral tonic pupils]

A 40-year-old man was admitted after 8 months of speech disturbance and locomotive ataxia. He had no seizures, lightning pains, paresthesia, visual loss, bladder disturbance or rectal incontinence. He had never been neurologically or psychiatrically ill and had no history of syphilis. When the patient was admitted, his general physical examination including blood pressure and dermatologic examination was normal. His consciousness was alert. He was found to have a deterioration of mental status such as inability to concentrate, failing memory, amnesia and circumstantiality. His pupils were anisocoric and Achilles jerks were absent. No rigidity of the neck muscles, paralysis and sensory disturbance were recognized. Romberg's sign was absent. The right pupil was 7.0 mm and the left was 6.0 mm in room illumination. The pupils were nonreactive to bright light and both did not constricted to near stimuli. 0.125% pilocarpine eyedrops produced bilateral pupillary constriction. The results indicated bilateral tonic pupils. Laboratory data revealed white cell count of 12,600/mm3 and normal erythrocyte sedimentation rate of 8 mm/hr. Cerebrospinal fluid (CSF) examination revealed the following: opening pressure, 140 mm of water; cell counts, 76/mm2 (mononuclear cells); total protein, 116 mg/dl; glucose, 57 mg/dl. A serum venereal disease research laboratories (VDRL) test was positive in a 1:32 titer confirmed by positive treponema pallidum hemagglutination (TPHA) test in a 1:40,960 titer and positive fluorescent treponemal antibody-absorption (FTA-ABS) test. Serum TPHA-IgM was positive in a 1:320 titer but TPHA-IgG was negative. CSF examination revealed positive TPHA test (titer of 1:2,560) and positive FTA-ABS test.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of retroperitoneal teratoma showing high level of CA19-9]

We report a case retroperitoneal mature teratoma showing an abnormally high CA19-9 (carbohydrate antigen 19-9) serum level in a 30-year-old woman. She was hospitalized for an episode of left upper abdominal pain. High CA19-9 tissue level and immunohistochemical findings were found in removed tissue. This case is the third report of a CA19-9-producing teratoma and literature was reviewed and discussed.

[A case of significant, non-neoplastic, ovarian hypertestosteronism]

A 24-year-old female with significant ovarian hypertestosteronism, who responded well both to gonadotropin releasing hormone (GnRH) agonist and cyclic administration of estrogen and gestagens in terms of suppressing circulating testosterone levels is reported. The patient's menstrual periods had been regular since menarche at the age of 12 until she became amenorrheic at the age of 20. She visited our facility in November 1988 after receiving three cycles of estrogen and gestagen replacement therapy from a previous physician which caused withdrawal bleeding. Clomiphen citrate reportedly failed to induce apparent ovulation. On her first visit with us, she was 160 cm tall weighing 47 kg with apparent hoarseness but not with hirsutism. Pelvic examination revealed significant clitoromegaly but otherwise normal external and internal genitalia. Laparoscopic examination disclosed that her uterus appeared to be normal with bilateral ovaries relatively small (4 x 4 x 3 cm) without tumorous or polycystic appearance. Histological examination of her ovaries obtained at laparoscopy showed several primary follicles with mild infiltration of the stromal cells. No thickened tunica albuginea or cystic formation were observed. These findings did not support either polycystic ovary or hyperthecosis. Serum testosterone (T) levels were extremely high (7.1 ng/ml), while serum androstenedione levels were only slightly above normal range (3.1 ng/ml). Urine 17-KS excretion was slightly increased (6.1 mg/day), while 17-OHCS output was within normal range (4.0 mg/day). Basal serum LH and FSH levels were within normal range and LH pulse frequency was reduced to 1 in 4 hours. Administration of dexamethasone 1 mg/day for 2 days did not suppress circulating T and free T levels but lowered serum cortisol concentration and urine excretion of 17-OHCS. Blood glucose and insulin levels were within normal limits and their responses to oral glucose administration were normal. Abdominal and pelvic ultrasonography and computed tomography as well as adrenal scintigraphy did not reveal any tumorous lesions in bilateral adrenals and ovaries. Administration of GnRH agonist, Buserelin 900 micrograms/day, suppressed circulating T concentrations to 0.7 ng/ml in 8 days, while it had no significant effects on DHEA and DHEA-S levels. After 16 weeks of Buserelin administration, ovulation was successfully induced by hMG administration. Cyclic estrogen and gestagen replacement therapy by Kaufmann's schedule for 2 cycles also suppressed serum T levels to normal, female range. Thus, the present case represents non-neoplastic, non-PCO, ovarian hypertestosteronism which responded well both to GnRH agonist and estrogen and gestagen replacement therapy in terms of lowering circulating T levels.

The weak calcemic vitamin D3 analogue 22-oxacalcitriol suppresses the production of tumor necrosis factor-alpha by peripheral mononuclear cells

The effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and its analogue 22-oxacalcitriol (OCT), which was reported to have very weak bone resorbing activity, on the production of tumor necrosis factor (TNF)-alpha was investigated. Mononuclear cells (MNC; 10(6)/ml) were incubated in 5% FCS/RPMI-1640 medium containing 1 microgram/ml lipopolysaccharide (LPS) in the presence or absence of 10(-8) M 1,25(OH)2D3 or 10(-8) M OCT for up to 96 h. Both 1,25(OH)2D3 and OCT suppressed TNF-alpha release by LPS-stimulated mononuclear cells, from the early to late stage of the incubation period, while neither 1,25(OH)2D3 nor OCT shifted the peak time point of TNF-alpha release clearly. MNC (10(6)/ml) were incubated with 1 microgram of LPS in the presence of various concentrations of 1,25(OH)2D3 or 10(-8) M OCT for 48 h. 1,25(OH)2D3 reduced TNF-alpha levels of LPS-stimulated MNC culture supernatant at 48 h in a dose-dependent manner. The half-maximal dose (ED50) for this suppressive effect was 3.7 x 10(-9) M. OCT decreased TNF-alpha levels of culture supernatant at 48 h with a half-maximal dose of 7.8 x 10(-11) M, which indicates that it is approximately 50 times more potent than that of 1,25(OH)2D3. These results indicate that OCT may be applicable as an immunosuppressive agent with limited calcium metabolic activity.