Primary intraosseous carcinoma in the pediatric and adolescent mandible

BACKGROUND

Primary intraosseous carcinoma (PIOC) is a rare malignant odontogenic tumor that predominantly occurs in males older than 50 years. PIOC can be misdiagnosed as odontogenic cyst because it occasionally shows a well-defined border on radiography. In this study, related literatures of pediatric and adolescent PIOC cases were analyzed under strict PRISMA guidelines along with an adolescent case who was provisionally misdiagnosed as an odontogenic cyst.

METHODS

All case reports for PIOC published in English from 1966 to 2021 were collected. Cases under the age of 20 were classified as pediatric and adolescent populations in this study. A total of 12 pediatric and adolescent cases including 11 PIOCs from the literature and one new case of a 14-year-old female were analyzed. Clinical and radiographic features, diagnosis and treatment approaches, and prognosis were investigated.

RESULTS

Ages ranged from 4 to 18 years. The female to male ratio was 1.4:1. Seven cases occurred in the mandible. Swelling was observed in 11 patients. The radiologic borders were well-defined in six cases and corticated in four cases. Tooth displacement and root resorption were observed in four and six cases, respectively. The provisional diagnosis for seven patients was odontogenic cyst and enucleation was performed in six cases including the new case. During the follow-up period, local recurrence occurred in three patients. The pediatric and adolescent PIOC cases with local recurrence showed poor prognosis. The locally recurred lesion in the new case did not decrease in size despite concurrent chemo-radiation therapy.

CONCLUSIONS

Three-dimensional imaging modalities and incisional biopsy with multiple specimens are necessary to rule out PIOC in the lesions with atypical radiographic findings. PIOC should be diagnosed differentially from odontogenic cyst even in pediatric and adolescent populations to properly manage the disease with poor prognosis.

Female reproductive factors and risk of joint replacement arthroplasty of the knee and hip due to osteoarthritis in postmenopausal women: a nationwide cohort study of 1.13 million women

OBJECTIVES

Previous studies of the relationships between female reproductive factors and osteoarthritis (OA) have shown conflicting results. In this study, we aimed to explore the relationships between reproductive factors and joint replacement arthroplasty of the knee (TKRA) and hip (THRA) in a large nationwide population-based cohort of postmenopausal Korean women.

METHODS

We included 1,134,680 subjects who participated in national health examinations in 2009 in the study. The study outcomes were incident THRA or TKRA due to severe hip or knee OA. The relationships between reproductive factors and THRA or TKRA were evaluated using a multivariable-adjusted proportional hazards model.

RESULTS

During a mean follow-up duration of 8.2 years, 1,610 incident THRA cases and 60,670 incident TKRA cases were observed. Later age at menarche, longer breastfeeding, HRT and OC use were associated with increased risk of TKRA for severe knee OA, while later age at menopause and longer reproductive span were associated with decreased risk. With regard to THRA for severe hip OA, later menarche, longer breastfeeding, HRT more than 5 years, and OC use more than 1 year were associated with higher risk. The associations between reproductive factors and severe OA were more pronounced in underweight and younger subjects.

CONCLUSION

We found that shorter estrogen exposure was associated with higher risk of TKRA due to severe knee OA, and such associations were more pronounced in underweight and younger subjects. The association between shorter estrogen exposure and THRA was not robust.

Female reproductive factors and the risk of dementia: a nationwide cohort study

BACKGROUND AND PURPOSE

The aim was to investigate whether female reproductive factors are associated with dementia.

METHODS

In all, 4 696 633 post-menopausal women without dementia were identified using the Korean National Health Insurance System database. Data on reproductive factors were collected using a self-administered questionnaire. Dementia was determined using dementia diagnosis codes and anti-dementia drug prescription. Cox proportional hazards regression was conducted to assess the hazard ratio (HR) for dementia according to reproductive factors.

RESULTS

During a median follow-up of 5.74 years, there were 212 227 new cases of all-cause dementia (4.5%), 162 901 cases of Alzheimer's disease (3.5%) and 24 029 cases of vascular dementia (0.5%). The HR of dementia was 1.15 [95% confidence interval (CI) 1.03-1.16] for menarcheal age ≥17 years compared with menarcheal age 13-14 years, 0.79 (0.77-0.81) for menopausal age ≥55 years compared with menopausal age <40 years, and 0.81 (0.79-0.82) for fertility duration ≥40 years compared with fertility duration <30 years. Whilst being of parity one (HR 0.89, 95% CI 0.85-0.94) and breastfeeding <6 months (HR 0.92, 95% CI 0.88-0.95) was associated with lower risk of dementia, being of parity two or more (HR 1.04, 95% CI 0.99-1.05) and breastfeeding ≥12 months (HR 1.14, 95% CI 1.01-1.07) was associated with a higher risk of dementia than women without parity or breastfeeding history. Use of hormone replacement therapy and oral contraceptives independently reduced the dementia risk by 15% and 10%, respectively.

CONCLUSIONS

Female reproductive factors are independent risk factors for dementia incidence, with higher risk associated with shorter lifetime endogenous estrogen exposure.

Oxytocin alleviates cellular senescence through oxytocin receptor-mediated extracellular signal-regulated kinase/Nrf2 signalling

BACKGROUND

Oxytocin (OT) is a neuropeptide hormone that has many beneficial biological effects, including protection against age-related disorders. However, less is known about its role in intrinsic skin ageing, which is accelerated by an increase in senescent cell fraction in skin tissue.

OBJECTIVES

To investigate the novel function and the underlying mechanism of OT in preventing cellular senescence in normal human dermal fibroblasts (NHDFs) isolated from the skin of female donors of different ages.

METHODS

NHDFs from young and old donors were exposed to conditioned medium from senescent or control NHDFs in the presence or absence of 10 nmol L^-1 OT for 3 days, and were continuously subcultured for 12 days. Subsequently, various age-associated signs of senescence including decreased proliferation rate, elevated p16 and p21 levels, and positivity for senescence-associated β-galactosidase expression were examined.

RESULTS

We found that OT suppressed senescence-associated secretory phenotype-induced senescence in NHDFs, and its effect depended on the age of the donor's NHDFs. The inhibitory effects of OT required signalling by OT receptor-mediated extracellular signal-regulated kinase/Nrf2 (nuclear factor erythroid 2-related factor 2). The age-dependent antisenescence effects of OT are closely related to hypermethylation of the OT receptor gene (OXTR).

CONCLUSIONS

Our findings bring to light the role of OT in the prevention of skin ageing, which might allow development of new clinical strategies. What's already known about this topic? Senescent keratinocytes and fibroblasts accumulate with age in the skin and contribute to the loss of skin function and integrity during ageing. Senescent cells secrete senescence-associated secretory phenotype (SASP), which includes the release of proinflammatory cytokines such as interleukin (IL)-6 and IL-1, chemokines, extracellular matrix-remodelling proteases and growth factors. The neuropeptide oxytocin (OT) and its receptor (OXTR) have protective effects against various age-related disorders. What does this study add? OT suppressed SASP-induced cellular senescence in normal human dermal fibroblasts (NHDFs), depending on the age of the NHDFs' donor. The inhibitory effects of OT on cellular senescence required OXTR-mediated phosphorylation of extracellular signal-regulated kinase, which enhanced nuclear localization of Nrf2, a vital factor in the antioxidant defence system. The age-specific antisenescent effects of OT were closely related to hypermethylation of OXTR. What is the translational message? Our results suggest that OT and OXTR agonists could be clinically promising agents for the improvement of age-associated skin ageing, especially in women.

Underestimated caregiver burden by cancer patients and its association with quality of life, depression and anxiety among caregivers

This study examined how patients with cancer estimate caregiver burden (CB) and the association between their underestimation of CB and their caregivers' self-ratings of their quality of life (CQOLC-K; Korean version of the Caregiver Quality of Life Index-Cancer), depression and anxiety (Korean version of the Hospital Anxiety and Depression Scale). Participants consisted of 990 patient-caregiver dyads recruited from a nationwide cross-sectional survey conducted in South Korea. Medical baseline data were retrieved from the hospital information systems of the participating centres. The patients with cancer who underestimated CB ranged from 18.62% (for physical CB) to 23.33% (for social CB). They had less advanced cancer, a lower income, were the caregiver's spouse, reported higher levels of family avoidance of communication about cancer, and had female caregivers. The patients' underestimation of CB was significantly related to lower CQoL and higher levels of caregiver depression and anxiety. The current study provides empirical evidence for the link between the underestimation of CB by patients with cancer and compromised caregiving experiences of cancer caregivers. Open family communication about cancer was discussed as one of several practical strategies for decreasing patients' underestimation of CB.

Comparison of the Analgesic Effect of an Ice Cube versus 4% Lidocaine Cream in Intradermal Antibiotic Skin Testing

Objective

This study was performed to compare the analgesic effect of an ice cube with that of 4% lidocaine cream (L.M.X.4®) for intradermal skin testing.

Methods

In this prospective randomised study, healthy adult volunteers were divided into ice cube and lidocaine analgesic pretreatment groups. Randomisation was performed using a randomisation table in blocks of four. Intradermal skin testing was performed after applying ice in the ice cube group and 5 mg of lidocaine cream in the lidocaine group. After the intradermal skin test, the pain intensity was investigated using the visual analog scale (VAS) on questionnaires. We calculated that a minimum of 24 subjects were required for statistical power of 80% at a significance level of 0.05 (two-sided). The groups' VAS scores were compared using the Mann-Whitney U-test.

Results

The study population consisted of 35 volunteers: 17 in the ice cube group and 18 in the lidocaine group. There were no differences in demographic characteristics between the two groups. The median VAS score was 20 (interquartile range: 0-35) in the ice cube group and 70 (interquartile range: 50-80) in the lidocaine group (p<0.001).

Conclusions

The results suggested the utility of an ice cube as analgesic pretreatment for intradermal skin testing in the emergency department.

Low albumin-to-globulin ratio associated with cancer incidence and mortality in generally healthy adults

BACKGROUND

Chronic inflammation is known to be one of the main steps in carcinogenesis. Identification of those with chronic inflammation may help identify subjects at risk of cancer. Previous studies have reported low albumin-to-globulin ratio (AGR) to be associated with increased cancer mortality in cancer patients, but there has been no study based on healthy populations.

PATIENTS AND METHODS

Our retrospective cohort study involved 26 974 generally healthy adults aged 30 or older who visited Seoul National University Hospital Health Promotion Center for self-referred health checkup. National medical service claims data were used to determine cancer incidence, and Korean death registry data was used to determine mortality. Median follow-up time for survival was 5.9 years (interquartile range 4.1 years).

RESULTS

Compared with subjects with AGR ≥ 1.5, subjects with 1.1 > AGR ≥ 1.0 and 1.0 > AGR showed adjusted hazard ratio (aHR) 2.69 (95% confidence interval, CI, 1.54-4.72) and aHR 6.71 (95% CI 3.56-12.66) for all-cause mortality, aHR 2.95 (95% CI 1.42-6.11) and aHR 4.38 (95% CI 1.57-12.25) for cancer mortality, and aHR 2.07 (95% CI 1.28-3.36) and aHR 3.99 (95% CI 2.10-7.58) for cancer incidence, respectively. When cancer incidence events after 2 years from baseline were separately analyzed, subjects with 1.1 > AGR ≥ 1.0 and 1.0 > AGR were associated with aHR 1.88 (95% CI 1.01-3.48) and aHR 2.55 (95% CI 1.03-7.11) for cancer incidence, respectively. Cancer events were increased in all types of cancer, but especially in liver and hematologic malignancies.

CONCLUSIONS

Low AGR is a risk factor for cancer incidence and mortality, both short- and long terms, in a generally healthy screened population. The results of this study need to be replicated in larger studies, along with the determination of the sensitivity and other diagnostic values of low AGR.

Attitudinal concordance toward uptake and disclosure of genetic testing for cancer susceptibility in patient-family member dyads

Decisions for cancer susceptibility genetic testing (CSGT) uptake and dissemination of results occur within the family context. A national survey was performed with 990 patient-family member dyads (participation rate:76.2%), with paired questionnaires examining attitudes toward CSGT uptake and disclosure of results in response to a hypothetical scenario in which a reliable CSGT was available for the specific cancer a patient was being treated. While most patients and family members responded they would uptake or recommend CSGT if available, concordance between the dyads was poor for both patient's testing (agreement rate 77.5%, weighted κ=0.09) and first-degree relatives' testing(agreement rate 78.0%, weighted κ=0.09). Most patients (93.2%) and family members (92.9%) indicated that patients should disclose positive CSGT results to family members, with dyadic agreement of 89.1% (κ=0.15). However, there were substantial disagreement regarding when disclosure should take place, who should make the disclosure (the patient or the health care professionals), and to whom the results should be disclosed. Patients and family members may hold different attitudes toward CSGT uptake of and disclosure of results within the family. Our findings reinforce the need for a family system approach to incorporate perspectives of patients as well as their family members.

Anti-inflammatory effect of sinomenine by inhibition of pro-inflammatory mediators in PMA plus A23187-stimulated HMC-1 Cells

BACKGROUND AND OBJECTIVES

Sinomenine is an alkaloid compound and a prominent anti-inflammatory agent found in the root of the climbing plant Sinomenium acutum. However, its effects on the mechanism of human mast cell line (HMC)-1-mediated inflammation remained unknown.

MATERIALS AND METHODS

To provide insight into the biological effects of sinomenine, we examined its influence on the pro-inflammatory cytokine production in HMC-1 cells stimulated by phorbol 12-myristate-13-acetate (PMA) plus A23187 by evaluating the stimulated cells in the presence or absence of sinomenine. In the present study, the pro-inflammatory cytokine production was measured using ELISA, Reverse Transcription-polymerase chain reaction (RT-PCR) and nuclear factor (NF)-kappaB, mitogen-activated protein kinases (MAPKs) pathway activation, as determined by Western blot analysis. Also, cyclooxygenase (COX)-2 expression was measured through Western blot and RT-PCR analysis.

RESULTS

Sinomenine inhibited the pro-inflammatory cytokine production induced by PMA plus A23187 in a dose-dependent manner. Furthermore, sinomenine inhibited the phosphorylations of extracellular signal-regulated kinase (ERK) and p38 MAPKs as well as the translocation of NF-kappaB p65 through reduced IkappaBalpha degradation. In addition, sinomenine suppressed COX-2 protein and mRNA expression dose-dependently.

CONCLUSIONS

Taken together, the results of this study indicate that the anti-inflammatory effects of sinomenine may occur via the inhibition of pro-inflammatory cytokine and COX-2 production through the inhibition of MAPKs and NF-kappaB pathway activation by PMA plus A23187 stimulation in HMC-1 cells.

Anti-inflammatory effects of Hylomecon hylomeconoides in RAW 264.7 cells

BACKGROUND AND OBJECTIVES

Papaveraceae serve as a rich source of various alkaloids which have anti-inflammatory effect.

MATERIALS AND METHODS

In this study, we investigated the effect of Hylomecon hylomeconoides ethanol extract (HHE) on lipopolysaccharide (LPS)-induced NO and interleukin-6 (IL-6) production in RAW 264.7 cells.

RESULTS

HHE inhibited LPS-induced NO and IL-6 production. Moreover, HHE suppressed the phosphorylation of ERK1/2 and p38 in LPS-induced RAW 264.7 in a dose-dependent manner. Furthermore, major constituents, dihydrosanguinarine and 6-methoxydihydrosanguinarine, of the chloroform-soluble extract were analyzed.

CONCLUSIONS

Taken together, the results of this study indicate that the anti-inflammatory effects of HHE may occur via the inhibition of NO and IL-6 expression through the down-regulation of MAP kinase (ERK1/2, p38) phosphorylation in RAW 264.7 cells.

Antibacterial activity of bark of Alnus pendula against methicillin-resistant Staphylococcus aureus

BACKGROUND AND OBJECTIVES

Methicillin-resistant Staphylococcus aureus (MRSA) infections are a rapidly growing health problem around the globe. Recently, there has been considerable interest in the use of plant materials as an alternative method to control pathogenic microorganisms. In this study we evaluated the antibacterial activity of bark of Alnus pendula against MRSA.

MATERIALS AND METHODS

The MIC determination was done using the microdilution broth method and bacterial growth was determined by measuring optical density using spectrophotometer.

RESULTS

Alnus pendula bark EtOH extract and fractions (F-1, -2, -3 and -4) were investigated against MRSA. The most active fractions (F-3 and F-4) led to the isolation of oregonin (ORE) and hirsutanone (HIR). These compounds were active against MRSA strains with minimum inhibitory concentrations (MICs) ranging from 31.25 to 250 microg/ml MIC and 2 MIC of HIR completely inhibited the growth of MRSA.

CONCLUSIONS

The bark EtOH extract of Alnus Pendula has potent antibacterial activity against MRSA.

Antimicrobial activity of the constituents of Smallanthus sonchifolius leaves against methicillin-resistant Staphylococcus aureus

BACKGROUND AND OBJECTIVES

Methicillin-resistant Staphylococcus aureus (MRSA) has been a serious problem as its infection is associated with higher mortality and increase cost worldwide. In the present study, the antibacterial activity of enhydrin, polymatin B, allo-schkuhriolide from the leaves of Smallanthus sonchifolius was investigated.

MATERIAL AND METHODS

Enhydrin, polymatin B, allo-schkuhriolide from the leaves of Smallanthus sonchifolius were tested for antimicrobial activity using micro dilution broth method against 2 strains of ATCC 33591, ATCC 25923 and 15 strains of clinical isolates MRSA.

RESULTS

The antibacterial activity of Smallanthus sonchifolius can safely be attributed to enhydrin as polymatin B, and allo-schkuhriolide are not showing any activity against Staphylococcus aureus strains. The enhydrin showed good antibacterial activity against all tested strains (MIC = 125-500 microg/ml).

DISCUSSION

These results suggest that only enhydrin can be considered as an antibacterial drug against MRSA.

Receptor activator of nuclear factor kappa B ligand-mediated osteoclastogenesis is elevated in ankylosing spondylitis

OBJECTIVE

Ankylosing spondylitis (AS) is an inflammatory arthritis involving the axial skeleton. Decreased bone mineral density has also been reported in AS patients. This study sought to determine whether osteoclastogenesis and osteoclast activity are increased in AS.

METHODS

Twenty patients with AS were evaluated using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and other clinical parameters. Mononuclear cells were separated out from peripheral blood samples taken from AS patients and normal healthy controls and cultured with monocyte colony stimulating factor and receptor activator of the nuclear factor kappa B ligand (RANKL). Multi-nucleated, tartrate-resistant acid phosphatase stain-positive osteoclasts were counted after 9 days, and the areas of calcium absorption on calcium-coated plates were determined.

RESULTS

Osteoclastogenesis was significantly greater in AS patients than in normal controls (number of osteoclasts/1106 mononuclear cells, median, 518.0 vs. 362.5, p=0.036). No differences were observed between AS patients and controls in terms of calcium absorption areas or the serum concentrations of tumor necrosis factor and RANKL. Osteoclastogenesis was greater in AS patients with sacroiliac joint ankylosis than in those without. Osteoclastogenesis and the calcium absorption area were not found to be correlated with BASDAI nor with other clinical parameters including age, erythrocyte sedimentation rate, and C-reactive protein levels.

CONCLUSION

Osteoclastogenesis is elevated in AS patients, especially in those with sacroiliac joint ankylosis. Increased osteoclastogenesis may be related to osteopenia in AS patients.

Impact of perception of socioeconomic burden on advocacy for patient autonomy in end-of-life decision making: a study of societal attitudes

We investigated the impact of perception of socioeconomic burden on beliefs regarding a patient's autonomy in end-of-life (EOL) decision making. We also sought to identify the characteristics of individuals who advocate patient autonomy and their attitudes toward other EOL issues. A total of 1055 individuals from the Korean general population were interviewed through a telephone survey using a structured questionnaire that was designed to investigate public attitudes toward various EOL issues. Of 1019 individuals included in the analysis, 635 (62.3%) specified the patient and 221 (21.7%) the family, when asked who is the appropriate decision maker in terms of EOL decisions in the absence of perception of socioeconomic burden. In contrast, the numbers were 458 (44.9%) and 500 (49.1%), respectively, if substantial burden was assumed. Respondents who favoured the patient's right to make decisions regardless of perception of socioeconomic burden numbered only 312 (30.6%) and were likely to be younger and have knowledge of hospice than who favoured family decision. Former group also favoured the disclosure of terminal illness to patients, withholding life-sustaining treatment, and preparation of advanced directives. Societal attitudes toward patient autonomy were significantly influenced by perception of socioeconomic burden. Open and balanced discussion about burden to family and adequate welfare support are thus suggested.

Blunted hypothalamo-pituitary-adrenal axis reactivity is associated with the poor intelligence performance in children with attention-deficit/hyperactivity disorder

The aim of the present study was to examine the effects of hypothalamo-pituitary-adrenal (HPA) axis reactivity on intelligence test performance in subjects with attention-deficit/hyperactivity disorder (ADHD). We investigated the extent to which an increase or decrease in cortisol after stress was associated with the intelligence test performance in 68 clinic-referred children with ADHD. The mean age of the participants was 8.8 years; 54 of the 68 participants were boys and 14 were girls. ADHD was diagnosed using the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version (K-SADS-PL). Psychological tests, including the Wechsler Intelligence Scale for Children-III and the ADHD diagnostic system (ADS), were administered as a stressor. A saliva sample was collected from each subject before and after psychological testing in order to measure the level of cortisol in the saliva. The cortisol level was measured using a solid-phase radioimmunoassay. Fifty-one of the 68 subjects showed no increase in the level of cortisol after the test. Decreases in the level of cortisol after the test were correlated with poor intelligence performance and the decrease of cortisol in respect to baseline significantly affected the verbal, performance and total IQ (effect sizes, 7.4-9.5%) in subjects who showed blunted responses to stress.

Effects of specific monoclonal antibodies to dense granular proteins on the invasion of Toxoplasma gondii in vitro and in vivo

Although some reports have been published on the protective effect of antibodies to Toxoplasma gondii surface membrane proteins, few address the inhibitory activity of antibodies to dense granular proteins (GRA proteins). Therefore, we performed a series of experiments to evaluate the inhibitory effects of monoclonal antibodies (mAbs) to GRA proteins (GRA2, 28 kDa; GRA6, 32 kDa) and surface membrane protein (SAG1, 30 kDa) on the invasion of T. gondii tachyzoites. Passive immunization of mice with one of three mAbs following challenge with a lethal dose of tachyzoites significantly increased survival compared with results for mice treated with control ascites. The survival times of mice challenged with tachyzoites pretreated with anti-GRA6 or anti-SAG1 mAb were significantly increased. Mice that received tachyzoites pretreated with both mAb and complement had longer survival times than those that received tachyzoites pretreated with mAb alone. Invasion of tachyzoites into fibroblasts and macrophages was significantly inhibited in the anti-GRA2, anti-GRA6 or anti-SAG1 mAb pretreated group. Pretreatment with mAb and complement inhibited invasion of tachyzoites in both fibroblasts and macrophages. These results suggest that specific antibodies to dense-granule molecules may be useful for controlling infection with T. gondii.

Early postoperative intraperitoneal chemotherapy with mitomycin C, 5-fluorouracil and cisplatin for advanced gastric cancer

OBJECTIVE

The long-term survival of patients who undergo surgery for stage IV gastric cancer is poor, due to metastatic spread of the tumor. Intraperitoneal chemotherapy (IPT) as a possible treatment for peritoneal dissemination has been investigated in a number of different tumors. The aim of this study was to investigate the toxicity and impact of early postoperative IPT on the survival of patients with advanced gastric cancer.

METHODS

Between 1993 and 1997, a total of 91 patients with stage IV gastric cancer who underwent potentially curative or palliative resection received intraperitoneal mitomycin C before closure of the abdominal wound. 5-Fluorouracil and cisplatin were administered intraperitoneally on postoperative days 1-4, and this was repeated at 4-week intervals.

RESULTS

All patients received a median of 3 IPT perfusions. There were 24 (26.4%) postoperative complications and 1 (1.1%) mortality. The most frequent hematologic toxicity (grade 3-4) was leukopenia. The major nonhematologic toxicities (grade 3-4) were emesis and nephrotoxicity. After a median follow-up period of 26 months, 14 patients remain alive without evidence of recurrence, whereas 75 patients died due to recurrence or progression of disease. The median survival period for all 91 patients was 15.4 months. When survival according to the residual tumor was analyzed, median survival was 36.0 months in the R0 (curative resection) group, 20.6 months in the R1 group (margins of resected specimens showing microscopic residual tumor or diameter of each residual tumor less than 3 mm) and 9.0 months in the R2 group (macroscopic residual tumor larger than 3 mm) (p < 0.001).

CONCLUSIONS

IPT was found to be safe, and it appears to improve the prognosis in patients with minimal residual tumors. However, complete cytoreductive surgery is mandatory for achieving the beneficial effect of IPT.

The asp-rich region at the carboxyl-terminus of calsequestrin binds to Ca(2+) and interacts with triadin

Calsequestrin (CSQ) is a high capacity Ca(2+) binding protein in the junctional sarcoplasmic reticulum of striated muscles, and has been shown to regulate the ryanodine receptor (RyR) through triadin and junctin. In order to identify the functional roles of specific regions on CSQ, several CSQ deletion mutants were prepared by molecular cloning and Escherichia coli expression. 45Ca(2+) overlay assay using a native gel system revealed that the major Ca(2+) binding motif of CSQ resides in the asp-rich region (amino acids 354-367). In an in vitro binding assay using a glutathione-S-transferase affinity column, the interaction between CSQ and triadin was found to be Ca(2+)-dependent, and the site of interaction was confined to the asp-rich region of CSQ. Our results suggest that the asp-rich region of CSQ could participate in the RyR-mediated Ca(2+) release process by offering a direct binding site to luminal Ca(2+) as well as triadin.

Seroepidemiological study of Toxoplasma gondii infection in the rural area Okcheon-gun, Korea

There have been some reports about the prevalence of anti-Toxoplasma gondii antibody among Koreans, and most of all data were taken from patients visiting hospitals. However, the epidemiological data of the community-based study in Korea are rare. This study was performed to evaluate the seroprevalence of toxoplasmosis among the inhabitants of the rural area Okcheon-gun, Korea. A total of 1,109 serum samples (499 males, 610 females) were examined for the IgG antibodies by ELISA. To set up the cut-off point for ELISA, we used a commercial latex agglutination (LA) kit. The sensitivity and specificity of ELISA against LA test were 89.5%, and 98.6% respectively. Among 1,109 sera, 6.9% showed seropositivity by ELISA. The positive rates of males and females were 6.0% and 7.2%, respectively. However, there were no significant differences between sexes. Comparing the age groups, the highest seropositive rate showed in the seventies or higher, and their rates had a tendency to increase with age (0.05 < p < 0.3). These results revealed that the seroprevalence of toxoplasmosis in rural inhabitants is similar to previous reports in Korea; however we need further investigation to clarify the prevalence of toxoplasmosis in the general population.

[History of medical ethics in Korea: focused on analysis of medical codes and covenants]

This article deals with the emergence of the codes of medical ethics and their change in Korean history. The modernized medical codes or covenants by the group of medical doctors has been made from the mid-twentieth century, although Korea has a long tradition of medical ethics, so called the Confucian medical ethics, Insul or Uido which were taken on very strong paternalistic characters. The history of the codes of medical ethics in contemporary Korea showed several revisions in 1961, 1965, 1979, and 1997 since the first establishment in 1955. Changes of political circumstances, the cultural level of the people, medical care system, and medical power leaded to the revisions. Throughout the revisions the codes or covenants of medical ethics in Korea has changed from simple translations of the codes by the World Medical Association and the American Medical Association to the reflexes of domestic medical situations; from the ones based on paternalistic doctor-patient relationship to more democratic ones; from the ones that only medical ethics were expressed to the ones that bioethics was expressed too.

Calcineurin regulates ryanodine receptor/Ca(2+)-release channels in rat heart

The present study was undertaken to examine the physical and physiological interaction of protein phosphatase 2B, calcineurin, with the ryanodine receptor (RyR) in rat cardiac tissue and neonatal cardiomyocytes. The presence of calcineurin, the RyR and FK506-binding protein (FKBP)12.6 in rat cardiac sarcoplasmic reticulum (SR) was identified by Western blot analysis. The possible interactions between calcineurin, the RyR and FKBP12.6 were further studied by co-immunoprecipitation using CHAPS-solubilized cardiac-membrane fractions (CSMFs) or SR preparations. Physical interactions between the RyR and calcineurin were found in the CSMF in the presence of added 100 microM Ca(2+); however, the interactions were interrupted in the presence of 20 mM EGTA, 1 microM rapamycin or 1 microM FK506, suggesting that the interaction is Ca(2+)-dependent, and is mediated by FKBP12.6. The Ca(2+)-dependent interaction between FKBP12.6 and the RyR was also found by co-immunoprecipitation. Effects of calcineurin inhibitors were tested on neonatal-rat-heart cardiomyocytes. Treatment of neonatal cardiomyocytes with 20 microM deltamethrin, 10 microM cyclosporin A (CsA), or 10 mciroM FK506 led to Ca(2+) oscillations in originally quiescent cardiomyocytes. Preincubation of cardiomyocytes with 20 microM rapamycin which dissociates FKBP12.6 from the RyR, evoked Ca(2+) oscillations, probably due to the leakiness of the RyR. However, Ca(2+) oscillations by rapamycin were not further affected by 10 microM CsA or 10 mciroM deltamethrin, suggesting that only RyR-associated calcineurin could regulate the channel activities. In spontaneously Ca(2+)-oscillating cardiomyocytes, CsA or FK506 treatments increased the frequency of oscillations. In 10 microM ryanodine-treated cardiomyocytes, CsA failed to induce Ca(2+) oscillations. These data show evidence that calcineurin associated with the RyR could modulate Ca(2+) release in rat heart.

Sequential analysis of cell differentials and IFN-gamma production of splenocytes from mice infected with Toxoplasma gondii

To assess the relationship between the changes of cellular components and the production of Th1 cytokine in the immune tissue, inbred C57BL/6 mice were orally infected with 40 cysts of 76K strain of Toxoplasma gondii. The sequential change of cell differentials and IFN-gamma production of splenocytes were analyzed by Diff-Quik stain and RT-PCR. There were no significant proportional changes of cellular components of splenocytes until day 4 postinfection (PI) as compared to those of day 0, and the relative percentage of macrophages and neutrophils/eosinophils increased significantly (p < 0.01) thereafter. The expression of IFN-gamma mRNA of CD3- cells was observed from day 1 PI at a low level. However, IFN-gamma production of CD3+ cells increased significantly from day 4 PI (p < 0.01) which progressively increased thereafter. These findings provide the relative percentages of granulocytes and macrophages were increased in conjunction with increase of total number of splenocytes after oral infection with T. gondii in the susceptible murine hosts, and lymphocytes were the major cellular components and the important source of IFN-gamma.

Regulation of ATP-induced calcium release in COS-7 cells by calcineurin

Experiments were conducted to examine the role of calcineurin in regulating Ca(2+) fluxes in mammalian cells. In COS-7 cells, increasing concentrations (1-10 microM) of ATP triggered intracellular Ca(2+) release in a dose-dependent manner. Treatment of the cells with calcineurin inhibitors such as cyclosporin A (CsA), deltamethrin and FK506 resulted in an enhancement of ATP-induced intracellular Ca(2+) release. Measurement of calcineurin-specific phosphatase activity in vitro demonstrated a high level of endogenous calcineurin activities in COS-7 cells, which was effectively inhibited by the addition of deltamethrin or CsA. The expression of constitutively active calcineurin (CnADeltaCaMAI) inhibited the ATP-induced increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), in both the presence and the absence of extracellular Ca(2+). These results suggest that the constitutively active calcineurin prevented Ca(2+) release from the intracellular stores. In the calcineurin-transfected cells, treatment with CsA restored the calcineurin-mediated inhibition of intracellular Ca(2+) release. Protein kinase C-mediated phosphorylation of Ins(1,4,5)P(3) receptor [Ins(1,4,5)P(3)R] was partly inhibited by the extracts prepared from the vector-transfected cells and completely inhibited by those from cells co-transfected with CnADeltaCaMAI and calcineurin B. On the addition of 10 microM CsA, the inhibited phosphorylation of Ins(1,4,5)P(3)R was restored in both the vector-transfected cells and the calcineurin-transfected cells. These results show direct evidence that Ca(2+) release through Ins(1, 4,5)P(3)R in COS-7 cells is regulated by calcineurin-mediated dephosphorylation.

Recurrence following curative resection for gastric carcinoma

BACKGROUND

The diagnosis and treatment of recurrent gastric cancer remains difficult. The aim of this study was to determine the risk factors for recurrence of gastric cancer and the prognosis for these patients.

METHODS

Of 2328 patients who underwent curative resection for gastric cancer from 1987 to 1995, 508 whose recurrence was confirmed by clinical examination or reoperation were studied retrospectively. The risk factors that determined the recurrence patterns and timing were investigated by univariate and multivariate analysis.

RESULTS

The mean time to recurrence was 21.8 months and peritoneal recurrence was the most frequent (45.9 per cent). Logistic regression analysis showed that serosal invasion and lymph node metastasis were risk factors for all recurrence patterns and early recurrence (at 24 months or less). In addition, independent risk factors involved in each recurrence pattern included younger age, infiltrative or diffuse type, undifferentiated tumour and total gastrectomy for peritoneal recurrence; older age and larger tumour size for disseminated, haematogenous recurrence; and older age, larger tumour size, infiltrative or diffuse type, proximally located tumour and subtotal gastrectomy for locoregional recurrence. Other risk factors for early recurrence were infiltrative or diffuse type and total gastrectomy. Reoperation for cure was possible in only 19 patients and the mean survival time after conservative treatment or palliative operation was less than 12 months.

CONCLUSION

The risk factors for each recurrence pattern and timing of gastric cancer can be predicted by the clinicopathological features of the primary tumour. Since the results of treatment remain dismal, studies of perioperative adjuvant therapy in an attempt to reduce recurrence are warranted.

Identification of cytoskeletal markers for the different microvilli and cell types of the rat vomeronasal sensory epithelium

The vomeronasal organ (VNO) of the mammal nose is specialized to detect pheromones. The presumed site of the chemosensory signal transduction of pheromones is the vomeronasal brush border of the VNO sensory epithelium, which has been shown to contain two different sets of microvilli: (i) the tall microvilli of supporting cells and (ii) the short microvilli of the chemoreceptive VNO neurons that branch and intermingle with the basal portions of the longer supporting cell microvilli. A key problem when studying the subcellular distribution of possible VNO signal transduction molecules at the light microscope level is the clear discrimination of immunosignals derived from dendritic microvilli of the VNO neurons and surrounding supporting cell structures. In the present study we therefore looked for cytoskeletal marker proteins, that might help to distinguish at the light microscope level between the two sets of microvilli. By immunostaining we found that the VNO dendritic microvilli can be selectively labelled with antibodies to the calcium-sensitive actin filament-bundling protein villin, whereas supporting cell microvilli contain the actin filament cross-linking protein fimbrin, but not villin. Useful cytoplasmic marker molecules for cellular discrimination were cytokeratin 18 for supporting cells and beta-tubulin for dendrites of VNO neurons. A further finding was that the non-sensory epithelium of the rat VNO contains brush cells, a cell type that appears to be involved in certain aspects of chemoreception in the gut. Brush cells or other structures of the vomeronasal brush border did not contain alpha-gustducin.

Recurrence following curative resection for gastric carcinoma

BACKGROUND

The diagnosis and treatment of recurrent gastric cancer remains difficult. The aim of this study was to determine the risk factors for recurrence of gastric cancer and the prognosis for these patients.

METHODS

Of 2328 patients who underwent curative resection for gastric cancer from 1987 to 1995, 508 whose recurrence was confirmed by clinical examination or reoperation were studied retrospectively. The risk factors that determined the recurrence patterns and timing were investigated by univariate and multivariate analysis.

RESULTS

The mean time to recurrence was 21.8 months and peritoneal recurrence was the most frequent (45.9 per cent). Logistic regression analysis showed that serosal invasion and lymph node metastasis were risk factors for all recurrence patterns and early recurrence (at 24 months or less). In addition, independent risk factors involved in each recurrence pattern included younger age, infiltrative or diffuse type, undifferentiated tumour and total gastrectomy for peritoneal recurrence; older age and larger tumour size for disseminated, haematogenous recurrence; and older age, larger tumour size, infiltrative or diffuse type, proximally located tumour and subtotal gastrectomy for locoregional recurrence. Other risk factors for early recurrence were infiltrative or diffuse type and total gastrectomy. Reoperation for cure was possible in only 19 patients and the mean survival time after conservative treatment or palliative operation was less than 12 months.

CONCLUSION

The risk factors for each recurrence pattern and timing of gastric cancer can be predicted by the clinicopathological features of the primary tumour. Since the results of treatment remain dismal, studies of perioperative adjuvant therapy in an attempt to reduce recurrence are warranted.

Crystallization and preliminary X-ray crystallographic studies of the D2 region of the skeletal muscle ryanodine receptor

The N-terminal portion (amino acids 1303-1367) of the type 1 ryanodine receptor D2 region is thought to be critical for excitation-contraction coupling in skeletal muscle. A segment of the D2 region (amino acids 1317-1355) was expressed as a glutathione S-transferase fusion protein (GST-D2) and then crystallized at room temperature using ammonium sulfate as precipitant. Using a newly developed cryo-soaking method, complete native data sets were measured to a resolution of 2.2 A using synchrotron radiation. The crystal was found to be hexagonal, belonging to space group P6(3)22, with unit-cell parameters a = b = 116.1, c = 77.9 A.

Clinicopathologic characteristics of mucinous gastric adenocarcinoma

There has been considerable controversy over the prognosis of mucinous gastric adenocarcinoma (MGC). In this study we analyzed the clinicopathologic differences between MGC and non-mucinous gastric carcinoma (NMGC). In addition, the relationship between mucin content and other clinicopathologic variables, including prognosis in MGC, was also investigated. We reviewed 2118 patients with pathologically-confirmed gastric cancer who underwent gastrectomy at the Department of Surgery, Yonsei University College of Medicine, during the period between Jan. 1987 and Dec. 1993. Among them, 130 patients had gastric carcinoma with extracellular mucin (MGC) and 1988 patients had gastric carcinoma without extracellular mucin (NMGC). We placed the MGC patients into two groups according to mucin content: mucin content involving over 50% of the tumor (dominant type, n = 94) and mucin content involving less than 50% of the tumor area (partial type, n = 36). The results were as follows: MGC was more common in males than NMGC. The size of the tumor in MGC (mean 5.3 cm) was larger than that of NMGC (mean 4.4 cm). The patients with MGC had a higher incidence of Borrmann type IV (MGC: 16.1%, NMGC: 9.9%), more frequent serosal invasion (MGC: 75.4%, NMGC: 48.6%), lymph-node metastasis (MGC: 75.4%, NMGC: 50.7%), and peritoneal metastasis (MGC: 10.0%, NMGC: 3.5%) than patients with NMGC. The patients with MGC were more advanced in stage at the time of diagnosis and had a worse overall 10-year survival rate (44.9%) than patients with NMGC (54.7%). However, the 10-year survival rate according to the stage of MGC was similar to that of NMGC. There were no significant differences between the mucin content and other pathologic variables, including prognosis, i.e. similar biologic behavior between dominant type MGC and partial type MGC. In conclusion, we suggest that MGC was more frequently diagnosed in advanced stage than NMGC with a poorer prognosis and that it is reasonable to consider the carcinoma with mucin content involving more than 30% of the tumor area as MGC.

Functional and quantitative analysis of splenic T cell immune responses following oral toxoplasma gondii infection in mice

Functional and quantitative analysis of splenic T cell immune responses following oral Toxoplasma gondii infection in mice. Experimental Parasitology 91, 212-221. Immunity to Toxoplasma gondii is mediated primarily by the host T cell response. Although there is considerable information regarding host immunity following intraperitoneal infection with tachyzoites, little information is available regarding naturally acquired infection following peroral infection with bradyzoites. In this study, a sequential quantitative analysis of the cell-mediated immune response was performed at the single cell level. To assess the kinetics of this response and parasitic loads, inbred mice were orally infected with the 76K strain bradyzoites of T. gondii. Within 24 h of infection, follicular hyperplasia followed by infiltration with histiocytes, macrophages, and apoptotic bodies was observed in the spleens of infected mice. T. gondii were detected from day 1, and counts increased gradually during the experimental period. Splenocyte DNA synthesis to antigen and mitogen was severely suppressed at days 7 and 10. The percentages of NK1.1(+) or delta gamma T cells were increased from day 1, whereas CD4(+) and CD8alpha+ T cells were signficantly increased after day 7 postinfection. CD25 expression and intracellular IFN-gamma production increased in NK1.1(+) cells on day 1 and by all other T cell subsets after day 4. Intracellular IL-4 did not increase until day 7, and IL-10 production was increased in all T cell subsets after day 4. Together, these findings indicate that oral infection with T. gondii stimulates a strong cellular immune response that appears to polarize toward an early Th1 response. However, within 7 days, a strong immune Th2 regulatory response as well as high parasitic loads can be observed, with a reduction in lymphoproliferation to mitogen stimulation, increased production of IL-4 and IL-10, and evidence of T cell apoptosis in the splenic immune compartment.

A generalized estimating equations approach for testing ordered group effects with repeated measurements

In repeated measures studies, we are often interested in comparing group effects in which groups are associated with a certain order relation. We propose testing procedures for ordered group effects using the generalized estimating equations (GEE) approach of Liang and Zeger (1986, Biometrika 73, 13-22). The order-constrained GEE estimators of group effects are approximated by the isotonic regression of the unconstrained GEE estimators. Based on these constrained estimators, we construct test statistics for detecting ordered group effects. The limiting distributions of the test statistics are mixtures of chi-square distributions. A Monte Carlo experiment shows improved performances of the proposed tests over the usual chi-square tests in detecting ordered group effects. The proposed test procedures are illustrated by familial polyposis supplementation trial data.

Cerebral perfusion impairment in a patient with toluene abuse

We report the case of a 17-yr-old man diagnosed as a toluene abuser. He had an 8-mo history of toluene inhalation exposure and was admitted to this hospital with symptoms of auditory and visual hallucination. Magnetic resonance imaging (MRI) revealed no structural abnormalities both on T1- and T2-weighted images, whereas SPECT using 99mTc-ethyl cysteinate dimer (ECD) showed multifocally decreased perfusion in the cerebral cortex, basal ganglia and thalami. Our case indicates that SPECT detects early central nervous system injury from toluene inhalation even when neurological examination and neuroanatomic imaging such as MRI are normal.

Extralobar pulmonary sequestration with an associated cyst of mixed bronchogenic and esophageal type--a case report

We report an unusual case of extralobar pulmonary sequestration (ELS) with an associated cyst of mixed bronchogenic and esophageal type. A 58-year-old woman was incidentally found to have a 6 x 6 x 5 cm sized mass in the right superior mediastinum. The mass consisted of sequestrated pulmonary tissue and an unilocular cyst with a direct communication. The cyst could not be easily classified because it was lined by squamous or respiratory epithelium with two distinct muscle layers and bronchial glands. Bronchial cartilage was present in close proximity to the ELS. This unusual combination of ELS with a foregut cyst might be a part of bronchopulmonary foregut malformation, attributed to a common embryologic pathogenesis.

[Immunological properties of the 30 kDa antigen of toxoplasma gondii]

The molecular weight 30 kDa membrane protein of Toxoplasma gondii (Toxoplasma 30 kDa) apparently conserved in most strains of T. gondii and sera of infected hosts. The present study aimed to elucidate Toxoplasma 30 kDa as a useful diagnostic antigen for serodiagnosis of toxoplasmosis by ELISA and for induction of protective immunity. Murine spleen cells immunized with the membrane antigen of T. gondii were fused with mouse Sp2/O-Ag14 myeloma cells. Out of 8 clones selected, five were IgG2b, the others belonged to IgG1 and IgG2a. The 30 kDa antigen was distributed mainly on the surface membrane of tachyzoites by indirect fluorescence method. Murine peritoneal macrophages which were activated by 30 kDa antigen produced more amounts of NO2 compared with crude antigen-treated group, however there were no significant differences in toxoplamacidal activity between the two groups. Higher specificity of Toxoplasma 30 kDa antigen was recognized for serodiagnosis of toxoplasmosis than the crude antigen. From these results, Toxoplasma 30 kDa antigen enhances the cytotoxic effect of macrophages as well as a more reliable means for the serodiagnosis of toxoplasmosis by ELISA.

[Detection of Toxoplasma antigens and antibodies in mice infected with different strains of Toxoplasma gondii]

This study aims to assess the possible strain-dependent variations in detection of Toxoplasma antigens and antibodies. The virulent RH strain or avirulent Beverley strain of T. gondii were injected into mice, intraperitoneally, and their antigens, antibodies and parasites were identified from the blood or tissues; liver, brain and spleen by ELISA, Western blot and PCR. In mice infected with RH strain, circulating antigens and parasitemia were first detected from 2 days after infection, and Toxoplasma DNA were found in the blood, liver, brain and spleen from 3 days after infection. It was impossible to detect specific IgM and IgG antibodies to T. gondii, and any specific band was not found by Western blot. In mice infected with Beverley strain, circulating antigens were detected between day 10 and day 35. The Toxoplasma DNA was found in the blood and liver from day 15 until day 60, and in the brain from day 20. But Toxoplasma DNA in the spleen were mainly detected between day 10 and day 30. The IgM antibodies were first appeared on day 10 post-infection, and were noted obviously increased between day 15 and 25. The IgG antibodies were first detected on day 15, and showed progressively increased titers. The antibody binding bands were specific according to infection period. Sera from mice infected with Beverley strain reacted mainly with the antigen of 27.5-kDa and 32.5-kDa. In conclusion, mice infected with RH strain revealed Toxoplasma antigens strongly, but not antibodies. However, mice infected with Beverley strain revealed both the Toxoplasma antigens and antibodies. The present results showed that immune responses are different between avirulent and virulent T. gondii.

[Intestinal parasite and Clonorchis sinensis infection among the inhabitants in the upper stream of Taechong Dam, Kumgang (River)]

The prevalence of intestinal parasites and Clonorchis sinensis infection was observed among inhabitants in the upper stream of Kumgang (River) from January to October 1991. A total of 743 fecal specimens was examined by cellophane thick smear and formalin-ether concentration technique. The parasite positive rate including helminth eggs and protozoan cysts was 40.8%, the positive rates for every species were: Clonorchis sinensis 30.8%, Metagonimus spp. 14.5%, Fasciola spp. 0.7%, Taenia spp. 1.5%, Ascaris lumbricoides 0.4%, Enterobius vermicularis 0.1%, Hookworm 0.1%, Trichuris trichiura 1.6%, Entamoeba coli 0.7%, E. histolytica 0.3%, Endolimax nana 0.3%, Giardia lamblia 0.3% and Iodamoeba buetschlii 0.1%, respectively. The cumulative positive rate in Okchon-gun showed 51.1%, in the Kumsan-gun 50.8% and in the Muju-gun 28.6%. Through this survey, it was concluded that the soil transmitted intestinal parasites including helminthseggs and protozoan cysts have been decreased remarkably among the inhabitants along the upper stream of Taechong Dam, Kum-gang (River), on the other side, Clonorchis sinensis, Metagonimus spp. and Taenia spp. are still morderate prevalent.

Effects of cytokines in the activation of peritoneal macrophages from mice infected with Toxoplasma gondii

The present study was undertaken to assess the role of cytokines in the activation of peritoneal macrophages from Toxoplasma-infected mice. Peritoneal macrophages from Toxoplasma-infected mice (10 cysts of Beverley strain/mouse) were harvested 8 weeks after infection, and incubated with the mitogen-induced lymphokine, recombinant mouse interferon-gamma (IFN-gamma), recombinant mouse tumor necrosis factor-alpha (TNF-alpha) alone or in combination with IFN-gamma (IFN-gamma/TNF-alpha) for 24 hr at 37 degrees C, 5% CO2. Macrophage activation was measured by the amount of H2O2 and NO2- production, and anti-Toxoplasma activities of macrophages. IFN-gamma or IFN-gamma/TNF-alpha-treated macrophages from Toxoplasma-infected mice revealed significantly higher H2O2 production than resident macrophages from Toxoplasma-infected mice. The production of NO2- by TNF-alpha-, IFN-gamma- or IFN-gamma/TNF-alpha-treated macrophages from Toxoplasma-infected mice were significantly higher than that by resident macrophages, whereas lymphokine-treated group produced similar amount as that produced by resident macrophages. Anti-Toxoplasma activities of cytokine-treated macrophages from Toxoplasma-infected mice were significantly higher than those of resident macrophages. IFN-gamma-treated macrophages were significantly increased production of H2O2 and NO2-, and anti-Toxoplasma activities of macrophages between normal and Toxoplasma-infected mice, whereas the other cytokine-treated groups were not significant differences between them. These data suggested that IFN-gamma was the only one of cytokines capable of significantly activating the peritoneal macrophages from Toxoplasma-infected mice.

[Prophylactic effects of trimethoprim-sulfamethoxazole in Toxoplasma-infected mice]

This study was performed to evaluate the prophylactic effects of trimethoprim-sulfamethoxazole (TMP-SMZ) in mice experimentally infected with virulent RH strain and avirulent Beverley strain of T. gondii. The mice infected with 1 x 10(5) tachyzoites were used in the measurement of mean survival days, and the mice infected with 10 cysts were used in the titrations of specific antibodies and enumeration of brain cysts. Mean survival days of mice were significantly increased in mice treated with TMP-SMZ as compared with spiramycin-treated and untreated control group. Mean survival days and survival rates of mice were increased according to the increment of dosages, and TMP-SMZ protected 100% of mice after fifteen daily dose of 24 mg/mouse or more administered orally. Toxoplasma-specific serum IgG and IgM antibody titers were significantly lower in mice treated with TMP-SMZ than those of spiramycin-treated and untreated control group. Toxoplasma cysts were not found in mice treated with TMP-SMZ at a dose of 24 mg/mouse or more per day, but the group of spiramycin treatment and untreated controls were found in the brain from 20 days after infection. The present results revealed that TMP-SMZ can be used as a prophylactic agent against murine toxoplasmosis after intraperitoneally challenges with the virulent or avirulent strain of T. gondii.

[Effects of interferon-gamma in T cell subsets of mice infected with Toxoplasma gondii]

This study was performed to evaluate differences of T cell subsets according to the injection period of recombinant mouse interferon-gamma (IFN-gamma) in acute Toxoplasma gondii infection. Each mouse was infected intraperitoneally with 100 cysts of Beverley strain T. gondii, and injected with 5 x 10(4) units of IFN-gamma every other day two tmres. The percentage of Thy-1,2 cells and L3T4/Ly-2 cell ratio were significantly increased in the mice that received two doses of IFN-gamma on days 2 and 0 before infection, or days 0 and 2 after infection. The percentage of Ly-2 cells decreased in the IFN-gamma injected groups at the 3rd and 4th week after infection. The results suggest that administration of IFN-gamma to T. gondii-infected mice improves the changed population of T cell subsets to a normal state, especially when IFN-gamma was injected just after the infection.

[Study on the therapeutic effects of interferon and gamma-globulin in experimental Pneumocystis carinii pneumonia]

This study was performed to observe the therapeutic effects of interferon-gamma(IFN-gamma) and gamma-globulin(gamma-globulin) in experimental Pneumocystis carinii pneumonia of immune suppressed mice. After 9 weeks, trimethoprim-sulfamethoxazole(TMP-SMZ; 10-50 mg/mouse/day), mouse IFN-gamma(5 x 10(4) units/mouse/day) and mouse gamma-globulin(20 mg/mouse/day) were administered to the mice for 3 weeks by the experimental group. The therapeutic efficacy was evaluated by body weights, histopathologic and electron microscopic findings of the lungs, and number of P. carinii cysts by Gomori's methenamine silver stain. Body weights of the mice were significantly increased in the group of combination therapy of TMP-SMZ with IFN-gamma or gamma-globulin, and in the group of TMP-SMZ treatment (p < 0.05), however, little effect was found in the group of gamma-globulin alone. Histopathologic findings of P. carinii pneumonia were much improved in the group of combination therapy of TMP-SMZ with IFN-gamma. Treatment with either TMP-SMZ or IFN-gamma significantly reduced the number of cysts in the P. carinii pneumonia, but gamma-globulin alone was ineffective. In electron microscopic findings of P. carinii pneumonia, the number of trophozoites and cysts were reduced by treatment with either TMP-SMZ or IFN-gamma, and most of the cysts were empty or containing one or two intracystic bodies. The present results suggested, that combination therapy of TMP-SMZ with IFN-gamma had synergistic effects in treatment of P. carinii pneumonia in experimental mice.

[Changes in blastogenic responses and antibody titers of mice infected with Toxoplasma gondii]

This study was performed to observe the cell-mediated and humoral immune responses in mice which were infected with Beverley, Fukaya and ME49 strain of Toxoplasma gondii, respectively. The blastogenic responses of splenocytes using [3H]-thymidine and serum antibody titers were measured weekly up to 10 weeks after infection. The blastogenic responses of splenocytes treated with concanavalin A and Toxoplasma lysate were significantly declined in the 3 strain groups as compared with the non-infected group (p less than 0.05), however lipopolysaccharide-treated blastogenic responses were not significantly different between infected and non-infected groups. The serum IgG antibody titers in the three infected groups increased from 2 weeks after infection, and the serum IgM antibody titers increased until 4 weeks after infection. No significant differences were revealed in blastogenic responses and serum antibody titers among the 3 groups. The present study suggested that cell-mediated immune responses were involved in T. gondii infected mice and blastogenic responses of T lymphocytes were inhibited in acute T. gondii infection.

[An experimental study on prednisolone-induced interstitial pneumonia caused by Pneumocystis carinii]

This study was performed to observe the role of Pneumocystis carinii as an etiologic agent of interstitial pneumonia in immunocompromised hosts. Total 90 male Sprague-Dawley rats, approximately 150-180 g, were used. Fifteen of them were used as control group and remaining 75 (5 groups) were as immunosuppression groups; group 1 received prednisolone (25 mg/kg twice weekly) only; group 2 prednisolone and tetracycline (75 mk/kg/day); group 3 prednisolone, tetracycline and trimethoprim-sulfamethoxazole (50-250 mg/kg/day); group 4 prednisolone and trimethoprimsulfamethoxazole; and group 5 prednisolone and griseofulvin (300 mg/kg/day) until death. The survival days of each group rat were calculated, and upon death their lungs were removed immediately and then stamp smears were prepared and stained by Giemsa or toluidine blue O. For histopathologic observation, lungs were fixed in 10% formalin, cut into sections and stained with Gomori's methenamine silver, hematoxylin-eosin, and Brown & Brenn stain. The results obtained were as follows: 1. The mean survival time of each group rat was 19.3 +/- 5.2 days (group 1), 41.1 +/- 14.0 days (group 2), 50.5 +/- 18.4 days (group 3), 43.0 +/- 22.9 days (group 4) or 21.8 +/- 5.1 days (group 5). Significant differences were noted between group 1 and group 2(p less than 0.01), group 1 and group 3 (p less than 0.01), and group 1 and group 4 (p less than 0.01), which represented bacterial infections were most fatal in immunocompromised rats.(ABSTRACT TRUNCATED AT 250 WORDS)