JPH203, a newly developed anti-cancer drug, shows a preincubation inhibitory effect on L-type amino acid transporter 1 function.

JPH203 is a novel anti-cancer drug targeting L-type amino acid transporter 1 (LAT1), which plays a primary role in the uptake of essential amino acids in tumor cells. Although a co-incubation inhibitory effect of JPH203 has been shown in a conventional uptake assay, its preincubation inhibitory effects have remained undetermined. Therefore, we aimed to characterize the preincubation inhibitory effects of JPH203 on LAT1 function using leucine uptake assays in LAT1-positive human colon cancer HT-29 cells. Preincubation of the cells with JPH203 (0.3 µM for 120 min) decreased the activity level to 30% of that in dimethylsulfoxide-treated cells. Similarly, in time-dependency analysis, preincubation of HT-29 cells with 10 µM JPH203 for 30, 60, and 120 min decreased the leucine uptake activity (42%, 32%, and 28% of that in control cells, respectively). Furthermore, the IC50 value of the combination of preincubation and co-incubation effects was lower than that of co-incubation inhibition alone (34.2 ± 3.6 nM vs. 99.2 ± 11.0 nM). In conclusion, we revealed that JPH203 has the capability to inhibit LAT1 function through preincubation effects. Moreover, preincubation synergistically enhances the co-incubation inhibitory effects. These findings provide a novel insight into the anti-cancer effects of JPH203 in cancer therapy.

Sodium-coupled monocarboxylate transporter 1 interacts with the RING finger- and PDZ domain-containing protein PDZRN3.

Sodium-coupled monocarboxylate transporter SMCT1 (SLC5A8) mediates monocarboxylate transport in the proximal tubule of the kidney. We have identified PDZK1 and PDZ domain-containing RING finger 3 (PDZRN3) as potent binding partners of SMCT1, which has a PDZ motif (Thr-Arg-Leu), by yeast two-hybrid screening and revealed that PDZK1 enhances the transport activity of SMCT1. In this study, we aimed to characterize the interaction between SMCT1 and PDZRN3 as well as to examine how PDZRN3 regulates SMCT1 function. An interaction between SMCT1 and PDZRN3 through the PDZ motif was observed in a co-immunoprecipitation assay and yeast two-hybrid assay. A transport assay showed that PDZRN3 abolished the enhancing effect of PDZK1 on nicotinate uptake via SMCT1. Our results suggest that SMCT1 interacts with PDZRN3 and that PDZRN3 may regulate SMCT1 function by interfering with the interaction between SMCT1 and PDZK1.

Identification of the multivalent PDZ protein PDZK1 as a binding partner of sodium-coupled monocarboxylate transporter SMCT1 (SLC5A8) and SMCT2 (SLC5A12).

Sodium-coupled monocarboxylate transporters SMCT1 (SLC5A8) and SMCT2 (SLC5A12) mediate the high- and low-affinity transport of lactate in the kidney, but their regulatory mechanism is still unknown. Since these two transporters have the PDZ-motif at their C-terminus, the function of SMCTs may be modulated by a protein-protein interaction. To investigate the binding partner(s) of SMCTs in the kidney, we performed yeast two-hybrid (Y2H) screenings of a human kidney cDNA library with the C-terminus of SMCT1 (SMCT1-CT) and SMCT2 (SMCT2-CT) as bait. PDZK1 was identified as a partner for SMCTs. PDZK1 coexpression in SMCT1-expressing HEK293 cells enhanced their nicotinate transport activity. PDZK1, SMCT1, and URAT1 in vitro assembled into a single tri-molecular complex and their colocalization was confirmed in the renal proximal tubule in vivo by immunohistochemistry. These results indicate that the SMCT1-PDZK1 interaction thus plays an important role in both lactate handling as well as urate reabsorption in the human kidney.

Uncommon Human Telomerase Reverse Transcriptase Promoter Mutations Are Associated With Poor Survival in Ovarian Clear Cell Carcinoma.

OBJECTIVES: The present study assessed whether human telomerase reverse transcriptase (TERT) promoter mutations mediate the increased mortality risk observed in patients with ovarian clear cell carcinoma (CCC) and characterized the pathologic features of TERT promoter mutation-associated ovarian CCC. METHODS: The TERT promoter region in genomic DNA extracted from paraffin-embedded ovarian CCC specimens (n = 93) was bidirectionally sequenced. RESULTS: A total of 24 TERT promoter mutations were identified among the analyzed CCC cases, of which 11 were known "hotspot" mutations whose frequency was increased in CCC cases with compared to without coexistent adenofibroma (P < .05). In contrast, the 14 (including three novel) identified uncommon site mutations were shown to be associated with a poor progression-free survival rate (P < .01). CONCLUSIONS: The identified uncommon TERT promoter mutations exacerbate the poor prognosis characteristic of ovarian CCC cases, and the hotspot mutations appear to be a molecular feature of the adenofibroma-associated form of the disease.

Influence of self-phase modulation effect on waveform degradation and spectral broadening in optical BPSK-SSB fiber transmission.

Self-phase modulation (SPM) effect is analyzed in a dispersion-compensated transmission using optical BPSK single sideband (SSB) modulation. The effect was evaluated numerically using both waveform degradation and spectral degradation, clarifying that waveform degradation is induced dominantly by peak power of the quadrature component of a Hilbert-transformed signal. Eye-opening degradation of BPSK-SSB is induced by lower fiber input power than the conventional double sideband (DSB) case because the SSB-homodyne system is sensitive to phase error resulting from SPM. Spectral degradation from SPM has two phases with increasing fiber input power. In the first phase, the sideband in the suppressive frequency region expands with increasing optical power. In the second phase, the spectral envelope in the non-suppressive frequency region becomes broad, and its shape is somewhat varied.

Effect of diet on the cardiovascular system in healthy beagles.

In management of canine cardiac disorders, cardiac drugs are commonly administered with food, although the cardiovascular effects of feeding and frequency of feeding are unknown. This study investigated the cardiovascular effect of feeding and frequency of feeding using a telemetry monitoring system in unanesthetized and unrestrained dogs. Systolic and diastolic blood pressure, heart rate and double product were steeply elevated during the five minutes immediately before feeding. They showed a sharp fall within 60 min after feeding time, especially the systolic and diastolic blood pressure, which showed lower values than from before feeding time. There were no significant differences in the means of preprandial elevation, postprandial fall or 24-hr averages in the once- and twice-daily feeding periods.

Influence of preemptive analgesia with meloxicam before resection of the unilateral mammary gland on postoperative cardiovascular parameters in dogs.

Preemptive analgesia is recommended in small animal medicine. However, many studies have evaluated the response to analgesic treatment by behavioral observation. Therefore, the influence of preemptive analgesia with meloxicam on postoperative cardiovascular and renal parameters remains to be clarified. The present study examined the changes in blood pressure, heart rate, double product and heart rate variability for 14 days and the changes in glomerular filtration rate (GFR) and serum cortisol level for 24 hr after resection of the unilateral mammary gland in meloxicam and control groups consisting of 5 healthy dogs. All data were collected under unanesthetized and unrestrained conditions using a radio telemetry system. Blood pressure, heart rate and double product were significantly lower in the meloxicam compared with the control group, and the meloxicam group's diurnal changes became stable more than 36 hr earlier than those of the control group. The systolic, diastolic and mean blood pressure values of the meloxicam group were 5- to 20-mm Hg lower than those of the control group until 5 days after surgery. The maximum difference between the two groups in terms of the double product values 14 days after surgery was 2,000 bpm x mmHg. Autonomic activity inhibition was prolonged in the control group. There were no significant differences in the 24-hr changes in GFR or serum cortisol level. This study showed that perioperative administration of meloxicam reduced unfavorable postoperative changes in the cardiovascular system without influencing renal function.

Salt-sensitive hypertension is associated with dysfunctional Cyp4a10 gene and kidney epithelial sodium channel.

Functional and biochemical data have suggested a role for the cytochrome P450 arachidonate monooxygenases in the pathophysiology of hypertension, a leading cause of cardiovascular, cerebral, and renal morbidity and mortality. We show here that disruption of the murine cytochrome P450, family 4, subfamily a, polypeptide 10 (Cyp4a10) gene causes a type of hypertension that is, like most human hypertension, dietary salt sensitive. Cyp4a10-/- mice fed low-salt diets were normotensive but became hypertensive when fed normal or high-salt diets. Hypertensive Cyp4a10-/- mice had a dysfunctional kidney epithelial sodium channel and became normotensive when administered amiloride, a selective inhibitor of this sodium channel. These studies (a) establish a physiological role for the arachidonate monooxygenases in renal sodium reabsorption and blood pressure regulation, (b) demonstrate that a dysfunctional Cyp4a10 gene causes alterations in the gating activity of the kidney epithelial sodium channel, and (c) identify a conceptually novel approach for studies of the molecular basis of human hypertension. It is expected that these results could lead to new strategies for the early diagnosis and clinical management of this devastating disease.

Influence of optical filters on pulse circulation in fiber rings with a frequency shifter and EDFA.

Optical fiber ring circuits constructed with frequency shifters and EDFAs are applicable to pulsed lightwave frequency sweepers, wavelength converters, and optical packet buffers. The salient criterion for those applications is how many times the optical pulse can circle the ring. Optical band-pass filters in the ring can serve an important role for pulse circulation because the filter determines the gain bandwidth at every circulation under the condition of signal wavelength shift. This paper clarifies the effects of optical filter response on pulse circulation in the ring through numerical simulation of the EDFA dynamic model, considering the gain spectrum.

Hepatocellular toxicosis associated with the alternate administration of carprofen and meloxicam in a siberian husky.

A 4-year-old female Siberian Husky was diagnosed with pyogranulomatous steatitis at the site of a recurrence of left anal sac rupture (day 1). Carprofen and orbifloxacin were given for 13 days without improvement. A single dose of meloxicam was administered prior to surgical resection of the anal sac, and based on elevated liver enzyme activity, liver supportive therapy was initiated. The dog received carprofen and orbifloxacin orally on the evening of day 14. The dog became anorectic the following morning, and began vomiting. Despite supportive therapy, the dog was unresponsive to treatment and died on day 16. Postmortem examination revealed severe vacuolar change and acute necrosis of hepatocytes consistent with carprofen and meloxicam induced-toxicosis.

Thermal tuning of mechanically induced long-period fiber grating.

We have developed a wideband tunable optical filter that uses a long-period fiber grating (LPFG) in which both resonance wavelength and its signal attenuation can be adjusted. We create the grating mechanically by pressing a spring coil to an optical fiber. We achieve continuous fine tuning of wavelength and attenuation by varying the temperature of the LPFG. The adjustable ranges of the LPFG are more than 200 nm in resonance wavelength and more than 10 dB in signal attenuation.

Breeding season in female cats acclimated under a natural photoperiod and interval until puberty.

The breeding season was investigated in 174 female cats that were acclimated under a natural photoperiod, and determined the interval between birth and initial estrus (puberty) was determined in 125 cats. Although the breeding season differed noticeably among individual animals, the mean was 180.4 +/- 3.0 (SE) days between the end of January and the end of July. The interval between birth and first estrus ranged from 181 to 560 days, with a mean of 345.0 +/- 0.9 days. With respect to month of birth, the mean interval was 343.0 +/- 9.5 days in cats born between March and June. Among cats that were born between July and October, the mean intervals were 242.0 +/- 6.3 days in cats that exhibited estrus the year after birth and 519.2 +/- 5.8 days in those that exhibited estrus 2 years after birth.

Acquired mitral stenosis in a cat with hypertrophic cardiomyopathy.

A seven-year-old castrated male domestic shorthair cat was diagnosed with hypertrophic cardiomyopathy (HCM) and suspected mitral stenosis (MS) based on electrocardiography, thoracic radiographs and echocardiographic findings. Post-mortem examination of the heart revealed morphological features consistent with HCM. In addition, there was marked fibrous deposition on the surfaces of the chordae tendineae extending to both mitral valve leaflets, which caused total chordal fusion into pillars of fibrous tissue and fusion of the commissures. The present case indicates that acquired MS can occur in association with HCM in the cat.

Ebstein's anomaly in a beagle dog.

An intact male beagle dog aged 1 year was referred because of shortness of breath, exercise intolerance and cardiac murmur. Based on the results from electrocardiography, thoracic radiography and echocardiography, the dog was diagnosed as Ebstein's anomaly. Although the orally administered digoxin, vasodilators and diuretics partially improved congestive signs, the dog became to be refractory and died 20 months after the diagnosis. Necropsy confirmed malformation and apical displacement of the basal attachment of tricuspid valve leaflets.

Androgen-mediated induction of the kidney arachidonate hydroxylases is associated with the development of hypertension.

Hypertension is a leading cause of cardiovascular, cerebral, and renal disease morbidity and mortality, and epidemiological evidence suggests a role for sex-dependent mechanisms in the pathophysiology of hypertension. We show here that treatment of rats with 5alpha-dihydrotestosterone increases the activity of the kidney arachidonate omega/omega-1 hydroxylase and the biosynthesis of 20-HETE (165 and 177% of control untreated male and female rats, respectively) and raises the systolic blood pressures of male and females rats by 46 and 57 mmHg, respectively. These androgen effects are associated with an upregulation in the kidney levels of CYP 4A8 mRNA and a decrease in CYP 4A1 transcripts. Dissected renal microvessels, the target tissue for most of the prohypertensive actions of 20-HETE, show an androgen-dependent upregulation of vascular CYP 4A8 mRNA and a fourfold increase in 20-HETE synthase activity. We propose that androgens regulate renal function and systemic blood pressure through a combination of transcriptional and hemodynamic mechanisms that are ultimately responsible for the regulation of renovascular tone and function.

Lone atrial fibrillation in a dog.

An intact male Pointer aged 9 year was found to have atrial fibrillation (AF). Thoracic radiography and echocardiography as well as routine blood work revealed no cardiac disease. Thus, the dog was diagnosed as lone AF. The arrhythmia disappeared 6 hr after the initiation of the supportive therapy, and relapse was not observed.

Hypertrophic cardiomyopathy in a mixed breed cat family.

A spayed female mixed cat (case 1) and its female offspring, the result of a pairing between case 1 and its male sibling, were diagnosed with hypertrophic cardiomyopathy (HCM). A pedigree survey revealed that the prevalence of HCM was at least 12.5% in the family, which was considered to be significantly higher than that in a hospital-based population (approximately 1.6%). Thus, this finding seems to support the suspected occurrence of familial HCM in this group of related cats.

Hyperzincemia with systemic inflammation: a heritable disorder of calprotectin metabolism with rheumatic manifestations?

A boy had infantile-onset systemic inflammation, growth failure, hepatosplenomegaly, anemia, leukocytopenia, progressive muscular dystrophy, and hypercalprotectinemia, resulting in marked hyperzincemia. His mother had a history of chronic arthritis since childhood and also showed hypercalprotectinemia/hyperzincemia. We postulate an inherent defect in calprotectin metabolism.