Pseudorhodobacter psychrotolerans sp. nov., a psychrotolerant bacterium isolated from terrestrial soil, and emended description of the genus Pseudorhodobacter.

A Gram-stain-negative, facultatively aerobic, cream-coloured, ovoid-shaped, non-motile and psychrotolerant bacterial strain, PAMC 27389T, was isolated from terrestrial soil collected on King George Island, Antarctica. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain PAMC 27389T belongs to the genus Pseudorhodobacter, sharing highest similarities with the type strains of Pseudorhodobacter wandonensis (96.9 %), Pseudorhodobacter antarcticus (96.8 %), Pseudorhodobacter ferrugineus (96.5 %) and Pseudorhodobacter aquimaris (95.4 %). Average nucleotide identity values between strain PAMC 27389T and the type strains of P. wandonensis, P. antarcticus, P. ferrugineus and P. aquimaris were 70.8, 70.9, 71.0 and 70.5 %, respectively and the genome-to-genome distances were 18.4-19.1 %, indicating PAMC 27389T is clearly distinguished from the most closely related Pseudorhodobacter species. The genomic DNA G+C content was 60.1 mol%. Strain PAMC 27389T grew at 0-37 °C (optimally at 15-20 °C), at pH 5.5-9.0 (optimally at pH 6.5-7.0) and in the presence of 0.5-3.0 % (w/v) sea salt (optimally with 0.5 %). It lacked bacteriochlorophyll a. The major fatty acids (>5 %) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C18 : 1ω7c 11-methyl. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, an unidentified phospholipid, an unidentified aminolipid, an unidentified lipid and three unidentified aminophospholipids. The major respiratory quinone was Q-10. Based on the phenotypic, chemotaxonomic and genomic data presented, we propose the name Pseudorhodobacter psychrotolerans sp. nov. with the type strain PAMC 27389T ( = KCTC 42640T = JCM 30764T).

Rhodococcus aerolatus sp. nov., isolated from subarctic rainwater.

A Gram-stain-positive, rod-shaped and non-motile strain, designated PAMC 27367(T), was isolated from rainwater collected on the Bering Sea. Analysis of the 16S rRNA gene sequence of the strain showed an affiliation with the genus Rhodococcus. Phylogenetic analyses revealed that strain PAMC 27367(T) formed a robust clade with the type strains of Rhodococcus rhodnii, Rhodococcus aetherivorans and Rhodococcus ruber with 16S rRNA gene sequence similarities of 96.3 %, 95.8 % and 95.5 %, respectively. Cells of the strain grew optimally at 25 °C and at pH 6.5-7.0 in the presence of 0-2 % (w/v) sea salts. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and three unknown phospholipids. The major cellular fatty acids (>10 %) were iso-C16 : 0, C17 : 1ω8c and 10-methyl C17 : 0. Cell wall analysis showed that strain PAMC 27367(T) contained meso-diaminopimelic acid. The genomic DNA G+C content was 77.1 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic data presented here, we propose a novel species with the name Rhodococcus aerolatus sp. nov., with PAMC 27367(T) ( = KCTC 29240(T) = JCM 19485(T)) as the type strain.

Comorbidity profiles in association with vitiligo: a nationwide population-based study in Taiwan.

BACKGROUND: The previous literature has demonstrated the association of autoimmune and atopic diseases with vitiligo, but there has been no large-scale nationwide study conducted to confirm this. OBJECTIVES: The present study was conducted to clarify the comorbid profiles in vitiligo patients and thereby better understand their clinical scenarios and underlying pathogenesis. METHODS: This was a retrospective population-based study conducted from 1996 to 2011 via the National Health Insurance Research Database in Taiwan. The differences in the prevalence of multiple autoimmune and atopic diseases between case subjects and controls were analysed by multiple logistic regression method. RESULTS: A total of 14883 vitiligo patients and 59532 controls were enroled. The prevalence of vitiligo was 0.064% and the peak of onset age was 40-59 years old. The non-stratified analysis evidenced a significant association between vitiligo and several comorbid diseases, including alopecia areata, Hashimoto thyroiditis, myasthenia gravis, psoriasis, Graves' disease, Sjögren's syndrome, systemic lupus erythematosus and atopic dermatitis. Vitiligo patients also had higher prevalence of multiple comorbidities than controls. In the age- and gender-stratified analysis, increased risks of systemic lupus erythematosus and Sjögren's syndrome were observed only in subjects aged 60-79. The association of vitiligo with myasthenia gravis and rheumatoid arthritis was identified only in the subgroup aged 20-39 and in females aged 60-79 respectively. CONCLUSION: Our study not only confirmed the significant association of vitiligo with multiple autoimmune and atopic diseases in Taiwan but also disclosed several unique findings, including the much lower prevalence of vitiligo, delayed onset of vitiligo by three decades, different associated comorbidity profiles comparing to westerners and the age- and gender-specific approach for the vitiligo-associated comorbidities.

Autoimmune comorbid diseases associated with lichen planus: a nationwide case-control study.

BACKGROUND: Lichen planus (LP) is a chronic inflammatory disorder with unknown aetiology. The association between LP and various autoimmune diseases has been reported, but nationwide study of the relationship of LP with associated diseases is quite limited. OBJECTIVE: Our study aims to clarify the association between LP and a variety of autoimmune diseases in Taiwanese. METHODS: Data were obtained from the National Health Insurance Research Database (NHIRD) of Taiwan from 1997 to 2011. In total, 12,427 patients with LP and 49,708 age- and gender-matched controls were enrolled. RESULTS: Among patients with LP, there were significant associations with systemic lupus erythematosus (SLE) (multivariate odds ratio [mOR]: 2.87; 95% CI: 1.97-4.17), Sjögren's syndrome (mOR: 3.75; 95% CI: 2.66-5.28), dermatomyositis (mOR: 6.34; 95% CI: 1.82-22.16), vitiligo (mOR: 2.09; 95% CI: 1.31-3.32) and alopecia areata (mOR: 2.82; 95% CI: 2.20-3.62). On gender-stratified analyses, SLE and alopecia areata were significantly associated with LP in both genders. The association with Sjögren's syndrome was significant only in female patients. The associations with dermatomyositis and vitiligo became insignificant in both genders. CONCLUSION: Lichen planus is associated with various autoimmune diseases. Further study is required to elucidate the possible underlying mechanisms and roles of autoimmunity in the aetiology of LP.

The natural course of early-onset atopic dermatitis in Taiwan: a population-based cohort study.

BACKGROUND: Atopic dermatitis (AD) often manifests in early childhood and has variable disease course among individual patients. Previous studies regarding the natural course of AD have usually been of small sample size and were not based on nationwide populations. OBJECTIVES: We aimed to find out the disease duration and remission rate of children with early-onset AD (onset in the first 2 years of life) in Taiwan, and to determine whether the presence of allergic rhinitis (AR) or asthma affects the disease course. METHODS: The patients with early-onset AD in a nationally representative cohort were selected using the National Health Insurance Research Database of Taiwan and were followed from birth to 10 years of age. Kaplan-Meier survival analysis was carried out to analyse the disease duration and remission of AD. Between-group analysis using the log-rank test was carried out to analyse the influence of risk factors on the disease course. RESULTS: Of the 1404 children with early-onset AD, 19.4% had disease duration < 1 year and 48.7% had disease duration < 4 years. During the follow-up, 69.8% of the patients went into remission. Sex, onset age, presence of AR, presence of asthma and presence of respiratory atopy (either AR or asthma) did not show statistically significant influence on disease course. CONCLUSIONS: Children in Taiwan with early-onset AD had disease of variable natural course, and the median disease duration was 4.2 years. About 70% of the patients went into remission eventually. The presence of AR or asthma did not affect the disease course of AD.

HLA polymorphism among Chinese patients with chronic plaque psoriasis: subgroup analysis.

BACKGROUND: HLA-Cw*06 has a strong influence on the clinical features and the susceptibility to psoriasis in different ethnicities. It is also used as a biomarker to predict the therapeutic efficacy of biologics, with inconsistent results. Additionally, most Asian patients with psoriasis do not carry HLA-Cw*06. OBJECTIVES: To determine additional HLA alleles which confer susceptibility or affect the severity of psoriasis in Chinese Han individuals. In addition, the potential of using HLA to predict treatment outcomes was also investigated. METHODS: We conducted a case-control association study in 199 Chinese patients with psoriasis and 200 unrelated healthy controls. HLA-B and HLA-C genotyping was performed and correlated with the therapeutic efficacy of the biologics, including alefacept, efalizumab, etanercept and ustekinumab. Patients with psoriasis were divided into group A (high-need patients with moderate to severe psoriasis) and B (general patients with psoriasis). RESULTS: The frequencies of HLA-B*60, HLA-B*75, HLA-Cw*06 and HLA-Cw*10 were significantly increased in patients with psoriasis compared with the healthy controls. However, the prevalence of HLA-Cw*06 was lower in group A compared with group B (6% vs. 17%, Pc=0·04). HLA-B*46 was found to be strongly associated with group A but not with group B patients with psoriasis. HLA-Cw*01/HLA-B*46 was also identified as a risk haplotype for Chinese patients with psoriasis, compatible with the results in Thais. Significant differences in response to biologics were observed between HLA-Cw*01+ and HLA-Cw*01- individuals in the alefacept treatment group, and between HLA-B*37+ and HLA-B*37-, and HLA-B*58+ and HLA-B*58- individuals in the efalizumab treatment group. CONCLUSIONS: In addition to HLA-Cw*06, the HLA-Cw*01/HLA-B*46 haplotype was also increased in Chinese patients with psoriasis. High-need patients with psoriasis had a lower frequency of HLA-Cw*06 but a higher prevalence of HLA-B*46 compared with general patients with psoriasis in our population.

Psychiatric comorbidities in patients with alopecia areata in Taiwan: a case-control study.

BACKGROUND: Alopecia areata (AA) may be related to stress and has been reported to be associated with psychiatric disorders. Nevertheless, a nationwide study of the relationship between AA and comorbid psychiatric diseases has not been conducted, and the effect of onset age has rarely been reported. OBJECTIVES: To analyse the associations between AA and various psychiatric disorders using a nationwide database in Taiwan. METHODS: Data were obtained from the National Health Insurance Research Database of Taiwan from 2000 to 2009. In total, 5117 patients with AA and 20 468 age- and gender-matched controls were enrolled. RESULTS: Patients with AA tended to have more coexisting anxiety and less comorbid schizophrenia. Differences in ages of onset revealed differences in comorbidities. An increased risk of depression [odds ratio (OR) 2·23; 95% confidence interval (CI) 1·09-4·54] was found in patients with AA aged < 20years. An increased rate of anxiety (OR 1·43; CI 1·15-1·77) was observed with AA onset between the ages of 20 and 39years. The highest odds of obsessive-compulsive disorder (OR 3·00; CI 1·11-8·12) and anxiety (OR 2·05; CI 1·56-2·68) were observed in patients with AA aged 40-59years. Moreover, about 50% of psychiatric disorders occurred earlier than AA. CONCLUSIONS: AA is related to various psychiatric disorders. Onset age of AA is an important factor in the association with different comorbid psychiatric diseases. In addition to cosmetic impact, which may bring about anxiety or depression, stress neuroendocrine immunology may play an important role in the pathogenesis of both AA and psychiatric disorders.

Comorbidity profiles among patients with bullous pemphigoid: a nationwide population-based study.

BACKGROUND: Bullous pemphigoid (BP) has been associated with neurological and psychiatric diseases; however, large-scale population-based study of different comorbid diseases in patients with BP is quite limited. OBJECTIVES: We sought to analyse the prevalence of neurological, psychiatric, autoimmune and inflammatory skin diseases prior to the diagnosis of BP and their associations with BP among patients with BP from a nationwide database in Taiwan. METHODS: A total of 3485 patients with BP and 17,425 matching controls were identified from the National Health Insurance Database in Taiwan from 1997 to 2008. Conditional logistic regression analyses for a nested case-control study were performed to examine the prevalence of comorbidities prior to the diagnosis of BP between these two groups. RESULTS: Overall, our results showed that stroke [odds ratio (OR) 3·30; 95% confidence interval (95% CI) 3·03-3·60], dementia (OR 4·81; 95% CI 4·26-5·42), Parkinson disease (OR 3·49; 95% CI 3·05-3·98), epilepsy (OR 3·97; 95% CI 3·28-4·81), schizophrenia (OR 2·56; 95% CI 1·52-4·30) and psoriasis (OR 2·02; 95% CI 1·54-2·66) were significantly associated with BP. Among them, the association with schizophrenia and psoriasis was predominant in female and male patients, respectively, with BP. It remains for all these comorbid diseases to be independently associated with BP by multivariate analysis. CONCLUSIONS: Patients with BP are more likely to have various neurological diseases, schizophrenia and psoriasis prior to the diagnosis of BP, supporting associations found in other studies. Further research is required to elucidate the tentative causal association with BP.

A rapid molecular method for diagnosing epidemic dermatophytosis in a racehorse facility.

REASONS FOR PERFORMING STUDY: Identification of the species and strain of dermatophyte can play an effective role in control of disease outbreaks by establishing the source of infection. Current methods of identification are based on cultural and microscopic methods, often involving weeks before a positive identification are made. A rapid molecular diagnostic method would therefore be an important laboratory technique, but requires confirmation in equine clinical practice. OBJECTIVES: To test the sensitivity and specificity of molecular diagnostic methods applied to a racehorse herd from the Korean Racehorse Authority (KRA). METHODS: A total of 57 DNA samples were collected from hairs and crusts of skin lesions in KRA racehorses with histories and clinical signs suggestive of dermatophytosis, which was confirmed by dermatophyte-specific PCR amplification analysis using the primer pair for the chitin synthase 1 (CHS1) gene. RESULTS: Thirty-eight racehorses were definitively diagnosed with dermatophytosis using molecular and traditional diagnostic methods. PCR fingerprinting profiles using simple repetitive (GACA)4 primers showed that all diagnosed horses had the same pattern profile. Oligonucleotide sequencing of CHS1 gene PCR products confirmed Trichophyton mentagrophytes as the infectious agent. CONCLUSIONS: This study demonstrates that the PCR-based molecular diagnostic method is sensitive and specific and offers fast precise diagnosis of dermatophytosis in horses.

Is a 2-week steroid trial after initial negative investigation for malignancy useful in differentiating autoimmune pancreatitis from pancreatic cancer? A prospective outcome study.

BACKGROUND: Autoimmune pancreatitis (AIP) is a peculiar type of chronic pancreatitis that responds dramatically to steroid therapy. To date, there are no worldwide consensus criteria for AIP. Different criteria with institutional preference (HISORt, revised Kim and the revised Japanese criteria) are being used to diagnose AIP, and there is controversy regarding the inclusion of steroid responsiveness in the diagnostic criteria. In contrast to the HISORt and revised Kim criteria, the revised Japanese criteria do not include steroid responsiveness as a diagnostic component. AIMS: This study was performed to evaluate whether "a 2-week steroid trial and subsequent assessment of its response" is a useful diagnostic tool for the differentiation of AIP from pancreatic cancer. A further aim was to discover the surgical and clinical outcome for a patient who followed the treatment algorithm based on the steroid responsiveness. PATIENTS AND METHODS: From January 2004 to June 2007, in the setting of clinically suspected AIP, 22 consecutive patients with atypical imaging for AIP, while not meeting the classic imaging criteria for pancreatic cancer, were challenged to undergo 2 weeks of steroid therapy (0.5 mg/kg of oral prednisolone per day). After the 2-week steroid trial, steroid responsiveness was assessed based on a marked improvement of narrowing of the main pancreatic duct and a reduction of the pancreatic mass. The steroid trial was continued in the case of positive steroid responsiveness, whereas surgical exploration was conducted in the case of negative steroid responsiveness. The final diagnosis was made by surgical exploration or long-term clinical and radiological follow-up. RESULTS: All patients (n = 15) who responded to steroids were diagnosed as having AIP, whereas all patients (n = 7) who did not show a response to steroids were confirmed as having pancreatic cancer. Complete resection was possible in all (6/6; 100%), except one individual who refused surgery. CONCLUSION: In the clinical setting of suspected AIP with the continued need for differentiation from pancreatic cancer due to atypical imaging for AIP, "a 2-week steroid trial and subsequent assessment of its response" may be helpful in confirming the diagnosis of AIP without negative consequences for resectable pancreatic cancer. However, a steroid trial should be performed carefully only by specialists in pancreatology.

Kennicutt-Schmidt Law in the Central Region of NGC 4321 as Seen by ALMA.

We present the Atacama Large Millimeter/Sub-millimeter Array (ALMA) cycle-0 science verification data of the CO(1-0) line emission in the central region of NGC 4321 (also known as M100) at the distance of 17.1 Mpc and VLA, L-band data of HI of the same galaxy. We have drawn the center area of M100 in the (12)CO(J = 1-0) line with the resolution of (3.87″ × 2.53″) as viewed by ALMA, along with HI and Spitzer 8 and 3.6 µm data. The relationship between the surface density of molecular gas mass ∑H2 and that of star formation rate ∑SFR has been investigated, in addition to the relationship between the surface density of the neutral atomic hydrogen mass and that of ∑SFR (Kennicutt-Schmidt law) in this galaxy with a high spatial resolution. The results indicate that a significant correlation exists between the SFR surface density and the molecular gas mass density in the ~2 kpc region. The power-law index has been determined for three regions: center, upper and lower arms. The value of this index in the center region is 1.13, which follows the traditional (K-S) law and indicates that the molecular gas is affected by star formation.

Alterations with age of the T3-stimulated release of atrial natriuretic peptide and its effect on water and sodium metabolism in rats.

The influence of age on urinary excretion of sodium and water and in vitro release of atrial natriuretic peptide (ANP) were studied in rats. Older rats had increased daily water intake and urine output. They also had increased plasma ANP, decreased right atrial contents of ANP and increased ANP release in response to 10 nM T3. The ageing process may have altered the regulatory mechanisms of water metabolism and secretion of ANP.

Cu2+-induced blue shift of the pyrene excimer emission: a new signal transduction mode of pyrene probes.

A pentiptycene-bispyrenyl system (1) has been synthesized and investigated as a fluorescent chemosensor for metal ions. A novel blue shift along with an intensity enhancement of the pyrene excimer emission is observed for 1 in the presence of Cu(2+). Such a new signal transduction mode of pyrene probes results from the formation of a static pyrene excimer that has very different characteristics from its dynamic counterpart.

Regulation of thyroid hormones in the secretion of insulin and gastric inhibitory polypeptide in male rats.

The effect of thyroid hormones on glucose-induced secretion of gastric inhibitory polypeptide (GIP) and insulin was studied. Male rats were thyroidectomized (Tx) or sham Tx. Sham Tx rats were injected with either propylthiouracil ([PTU] 20 mg/kg intraperitoneally) or saline for 2 weeks. In addition, thyroid-intact rats were injected intravenously with triiodothyronine ([T3]5 microg/kg) or saline 10 minutes before an oral glucose load (3.2 g/kg). Blood samples were collected from each animal via a jugular catheter at 0, 10, 20, 30,45, 60, and 90 minutes following glucose ingestion. Plasma levels of GIP and insulin were measured by specific radioimmunoassays (RIAs). Thyroidectomy-induced hypothyroidism increased the basal level of plasma GIP, but decreased that of insulin. Insulin levels at 10, 20, and 30 minutes following oral glucose were lower in hypothyroid rats than in euthyroid rats. Conversely, GIP levels at 60 and 90 minutes following glucose ingestion in PTU-induced hypothyroid rats were higher than those in euthyroid rats. Furthermore, glucose-stimulated insulin secretion was unaltered by pretreatment with T3, whereas the glucose-induced increase in plasma GIP was completely abolished by preinjection of T3 in thyroid-intact rats. These results suggest that thyroid functions are involved in the regulation of insulin and GIP secretion in rats.

Novel findings in inhibition of mast cell-dependent immediate-type cutaneous reactions by Gahmi-Shini-San.

This report describes an inhibitory effect of Gahmi-Shini-San (GSS) on mast cell-mediated immediate-type allergic reactions. GSS is an Oriental herbal medication, which has been successfully used in Korea for the treatment of allergic disorders, mainly skin anaphylactic diseases. GSS inhibited the ear swelling response induced by intradermal injection of compound 48/80 in a mouse model on a concentration-dependent basis. The mast cells in mouse ear tissue were stained by alcian blue/nuclear fast red. GSS significantly inhibited the compound 48/80-induced degranulation from mast cells in ear tissue. GSS dose-dependently inhibited the histamine release from the rat peritoneal mast cells by compound 48/80. We also studied the effect of GSS on mast cell-dependent passive cutaneous anaphylaxis activated by dinitrophenyl IgE antibody. GSS showed inhibition of passive cutaneous anaphylaxis following oral administration. These results indicated that GSS has inhibitory effect on mast cell-dependent immediate type cutaneous reactions.

Activation of inducible nitric oxide synthase by Yongdam-Sagan-Tang in mouse peritoneal macrophages.

The objective of the current study was to determine the effect of Yongdam-Sagan-Tang (YS-Tang) on the production of nitric oxide (NO). Stimulation of mouse peritoneal macrophages with YS-Tang after the treatment of recombinant interferon-gamma (rIFN-gamma) resulted in increased NO synthesis. YS-Tang had no effect on NO synthesis by itself. When YS-Tang was used in combination with rIFN-gamma, there was a marked co-operative induction of NO synthesis in a dose-dependent manner. The optimal effect of YS-Tang on NO synthesis was shown 6 h after treatment with rIFN-gamma. This increase in NO synthesis was reflected as an increased amount of inducible NO synthase (iNOS) protein. NO production was inhibited by NG-monomethyl-L-arginine. The increased production of NO from rIFN-gamma plus YS-Tang-stimulated cells was decreased by the treatment with staurosporin. In addition, synergy between rIFN-gamma and YS-Tang was mainly dependent on YS-Tang-induced tumor necrosis factor-alpha (TNF-alpha) secretion. All the preparations of YS-Tang were endotoxin free. These results suggest that the capacity of YS-Tang to increase NO production from rIFN-gamma-primed mouse peritoneal macrophages is the result of YS-Tang-induced TNF-alpha secretion.

The nitric oxide-producing properties of Solanum lyratum.

We examined the effect of Solanum lyratum Thunb. (Solanaceae) (SL) on the production of nitric oxide (NO). Stimulation of mouse peritoneal macrophages with SL after the treatment of recombinant interferon-gamma (rIFN-gamma) resulted in increased NO synthesis. SL had no effect on NO synthesis by itself. When SL was used in combination with rIFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of SL on NO synthesis was shown 6 h after treatment with rIFN-gamma. The increased production of NO from rIFN-gamma plus SL-stimulated cells was decreased by the treatment with staurosporin. In addition, synergy between rIFN-gamma and SL was mainly dependent on SL-induced tumor necrosis factor-alpha (TNF-alpha) secretion. All the preparations of SL were endotoxin free. The present results indicate that the capacity of SL to increase NO production from rIFN-gamma-primed mouse peritoneal macrophages is the result of SL-induced TNF-alpha secretion via the signal transduction pathway of PKC activation.

Effects of autogenous toxoid-bacterin in lactating cows with Staphylococcus aureus subclinical mastitis.

To evaluate clinical effects of autogenous toxoid-bacterin treatment for Staphylococcus aureus subclinical mastitis in lactating cows, 22 cows which had at least one S. aureus infected quarter were selected from among cows at a S. aureus prevalent dairy farm. Eleven cows were injected with their own autogenous toxoid-bacterin and the others were maintained as non-injected control. In the toxoid-bacterin injected group, 27% of infected quarters were cured during the 12-week trial, compared to 5% in the control group. New intramammary infections with S. aureus were only detected in 3 quarters of the control group. Mean IgG antibody titer against S. aureus somatic antigens and alpha-toxin in serum and milk were significantly increased in the toxoid-bacterin injected group (p<0.05) and remained higher than those of the control group which showed no significant changes (p<0.05). In contrast to the control group, from 3 weeks after the second injection of the toxoid-bacterin injected group, mean S. aureus cfu/ml in milk samples from injected quarters with S. aureus was significantly decreased until the end of the study (p<0.05). In the toxoid-bacterin injected group, significant decreases of mean SCC were detected from milk samples from infected quarters with S. aureus from week 7 to week 10 (p<0.05). These data show that autogenous toxoid-bacterin treatment against S. aureus subclinical mastitis in lactating cows may increase the cure rate of the infections, reduce the severity of the infections and also prevent occurrence of the new infections.

Effect of hypothyroidism on the in vitro release of atrial natriuretic peptide in response to sodium challenge in rats.

The release of atrial natriuretic peptide (ANP) in vitro in response to the challenge of sodium chloride was investigated in hypothyroid rats. Male rats were injected with propylthiouracil (PTU, 20mg/kg BW, intraperitoneally), or PTU and thyroxine (T4, 20 micrograms/kg BW, subcutaneously) once daily for 14 days before decapitation. Rats injected with saline were used as control. The plasma samples were collected and extracted by Sep-Pak C18 cartridge. The concentrations of ANP in extracted plasma were measured by a radioimmunoassay (RIA). PTU-induced hypothyroidism resulted in decreased concentrations of plasma ANP. Replacement of T4 in PTU-treated hypothyroid rats restored the plasma concentrations of ANP to normal levels. Furthermore, we examined the right atrial ANP contents and the in vitro release of ANP in PTU-treated rats and control animals. The right atrium was excised and divided into 5 equal pieces, one was homogenized with 0.1 N HCl and extracted by Sep-Pak C18 immediately, and the others were incubated with Locke's solution at 37 degrees C. After basal incubation for 30 min, rat atrial tissues were then incubated with 154, 160, or 165 mM NaCl for 30 min. The concentrations of ANP in extracted atrial tissue and medium samples were also measured by RIA. Decreased atrial contents of ANP were noted in hypothyroid rats. The in vitro release of ANP in response to 165 mM sodium ion was significantly lower in PTU than in saline-injected animals. These results suggest that lower concentration of plasma ANP in hypothyroid rats is at least in part due to impairment of stimulation-secretion responses of right atria during thyroid hypofunction in rats.