Fanconi syndrome with karyomegalic interstitial nephritis after ifosfamide treatment for osteosarcoma: a case report.

Patients with ifosfamide-induced renal damage present with Fanconi syndrome. Karyomegalic nephropathy/interstitial nephritis (KNIN) is a rare form of chronic tubulo-interstitial nephritis that was initially considered a type of familial nephropathy. However, several reports of drug-induced KNIN, i.e., KNIN-like nephropathy, have been reported in recent years. We present the case of an 18-year-old man who presented with Fanconi syndrome and progressive renal dysfunction after receiving chemotherapy including ifosfamide and cisplatin for right femoral osteosarcoma. Renal biopsy revealed numerous atrophied tubular epithelial cells with large, polymorphic nuclei, and the definitive diagnosis was KNIN. Most patients with KNIN-like nephropathy who receive ifosfamide are concomitantly treated with cisplatin, indicating that ifosfamide and cisplatin might act synergistically to increase the risk for KNIN-like nephropathy. Further investigation in case series is warranted to reveal potential treatment approaches and to evaluate prognosis.

Hypouricemia in the emergency department: A retrospective, single-center study.

Backgrounds: Few studies have reported the prevalence and characteristics of hypouricemia in the emergency department (ED). We investigated the prevalence and characteristics of hypouricemia in the ED of a university-affiliated hospital in Japan. Methods: This is a retrospective cross-sectional single-center study. All adult patients (18 years old or older) who had their serum uric acid (SUA) measured at the ED between 2011 and 2021 were included. Information collected included age, sex, SUA, and serum creatinine. Hypouricemia was defined as an SUA level ≦2.0 mg/dL. Results: A total of 10,551 patients were included in the study. Fifty-one percent were male. The median SUA levels were significantly higher in men than in women (6.0 [4.8-7.4] vs. 4.7 [3.7-6.1], p < 0.001). The prevalence of hypouricemia was higher in women than in men (2.0% vs. 0.9%, p < 0.001). A possible cause of hypouricemia was identified in 88 patients. Malignancy and diabetes were the major possible cause of hypouricemia (p < 0.001). Conclusion: The distribution of SUA levels and prevalence of hypouricemia differed significantly by sex and age in the ED. Malignancy was the leading cause of hypouricemia in the ED.

Seasonal Changes in the Prevalence of Hyperkalemia in the Emergency Department: A Single Center Study.

Background: Hyperkalemia is an electrolyte disorder frequently encountered in the emergency department. There are few studies on seasonal variation in the prevalence of hyperkalemia. The aim of this study was to investigate the seasonal changes in the prevalence of hyperkalemia in the emergency department. Materials and Methods: We retrospectively reviewed a total of 24,085 patients presented to the emergency department between January 2012 and December 2020. Age, gender, serum potassium level, and serum creatinine level were recorded. The definition used for hyperkalemia was a serum potassium level of ≥ 5.5 mEq/L. Renal function was divided into two categories: preserved (eGFR ≥ 60 mL/min/1.73 m2) or reduced (eGFR < 60 mL/min/1.73 m2). Results: The prevalence of hyperkalemia was 2.1% in patients with preserved renal function and was 11.9% in patients with reduced renal function (p < 0.001). The prevalence of hyperkalemia was highest in winter, followed by spring, autumn, and summer in patients with preserved renal function (p < 0.001) and those with reduced renal function (p < 0.001). There was a linear correlation between monthly weather temperature and the prevalence of hyperkalemia in patients with preserved renal function (r = -0.392; p < 0.001) and those with reduced renal function (r = -0.487; p < 0.001). Conclusions: we found that the prevalence of hyperkalemia was significantly higher in winter for both patients with preserved renal function and those with reduced renal function.

Various associations of aging and long-term HIV infection with different neurocognitive functions: detailed analysis of a Japanese nationwide multicenter study.

Detailed information of the effects of age and long-term HIV infection on various neurocognitive function have not been fully evaluated yet. In a prospective Japanese nationwide multicenter study of 17 facilities (J-HAND study), 728 HIV-infected individuals completed 14 neuropsychological (NP) tests; Verbal Fluency (VF; category and letter), Digit Span (DS; forward and backward), Trail Making Test (TMT) A-B, Rey-Osterrieth Complex Figure Test (ROCFT; copy, immediate and delayed recall), Story Memory Test (SMT; immediate and delayed recall), Digit Symbol Subset (DSS), and the Grooved Pegboard (GP; dominant and non-dominant). Multivariate analysis identified older age (≥ 50 years) to be associated with lower scores in all three ROCFT and GP dominant [odds ratio (OR) [95% confidence interval (CI)] 1.801 (1.217-2.664), 2402 (1.366-3.055), 2.691 (1.720-4.211), and 2.302 (1.145-4.628), respectively], whereas longer time since diagnosis was associated with a lower score in ROCFT (delayed recall) (OR 1.224, 95%CI 1.045-1.434). In VF letter, older age and longer time since diagnosis were associated with a better score [OR (95%CI) 0.449 (0.234-0.861) and 0.831 (0.692-0.997)]. In DSS and TMT-A, longer time since diagnosis was associated with a better score [OR (95%CI): 0.808 (0.670-0.973) and 0.795 (0.665-0.949), respectively]. Older patients in later years since diagnosis are at higher risk of visuospatial and motor impairments despite ART, whereas they are less likely to develop verbal impairment, suggesting that verbal function is relatively resistant to aging and long history of HIV infection under ART. These findings suggest that customtailored supports should be established based on the individual background.

7α-Hydroxypregnenolone, a key neuronal modulator of locomotion, stimulates upstream migration by means of the dopaminergic system in salmon.

Salmon migrate upstream against an opposing current in their natal river. However, the molecular mechanisms that stimulate upstream migratory behavior are poorly understood. Here, we show that 7α-hydroxypregnenolone (7α-OH PREG), a newly identified neuronal modulator of locomotion, acts as a key factor for upstream migration in salmon. We first identified 7α-OH PREG and cytochrome P450 7α-hydroxylase (P4507α), a steroidogenic enzyme producing 7α-OH PREG, in the salmon brain and then found that 7α-OH PREG synthesis in the brain increases during upstream migration. Subsequently, we demonstrated that 7α-OH PREG increases upstream migratory behavior of salmon. We further found that 7α-OH PREG acts on dopamine neurons in the magnocellular preoptic nucleus during upstream migration. Thus, 7α-OH PREG stimulates upstream migratory behavior through the dopaminergic system in salmon. These findings provide new insights into the molecular mechanisms of fish upstream migration.

Acute stress increases the synthesis of 7α-hydroxypregnenolone, a new key neurosteroid stimulating locomotor activity, through corticosterone action in newts.

7α-Hydroxypregnenolone (7α-OH PREG) is a newly identified bioactive neurosteroid stimulating locomotor activity in the brain of newt, a wild animal, which serves as an excellent model to investigate the biosynthesis and biological action of neurosteroids. Here, we show that acute stress increases 7α-OH PREG synthesis in the dorsomedial hypothalamus (DMH) through corticosterone (CORT) action in newts. A 30-min restraint stress increased 7α-OH PREG synthesis in the brain tissue concomitant with the increase in plasma CORT concentrations. A 30-min restraint stress also increased the expression of cytochrome P450(7α) (CYP7B), the steroidogenic enzyme of 7α-OH PREG formation, in the DMH. Decreasing plasma CORT concentrations by hypophysectomy or trilostane administration decreased 7α-OH PREG synthesis in the diencephalon, whereas administration of CORT to these animals increased 7α-OH PREG synthesis. Glucocorticoid receptor was present in DMH neurons expressing CYP7B. Thus, CORT appears to act directly on DMH neurons to increase 7α-OH PREG synthesis. We further investigated the biological action of 7α-OH PREG in the brain under stress. A 30-min restraint stress or central administration of 7α-OH PREG increased serotonin concentrations in the diencephalon. Double immunolabeling further showed colocalization of CYP7B and serotonin in the DMH. These results indicate that acute stress increases the synthesis of 7α-OH PREG via CORT action in the DMH, and 7α-OH PREG activates serotonergic neurons in the DMH that may coordinate behavioral responses to stress. This is the first demonstration of neurosteroid biosynthesis regulated by peripheral steroid hormone and of neurosteroid action in the brain under stress in any vertebrate class.

7α-Hydroxypregnenolone, a new key regulator of amphibian locomotion: discovery, progress and prospect.

Seasonally-breeding amphibians have served as excellent animal models to investigate the biosynthesis and biological actions of neurosteroids. Previous studies have demonstrated that the brain of amphibians possesses key steroidogenic enzymes and produces pregnenolone, a precursor of steroid hormones, and other various neurosteroids. We recently found that the brain of seasonally-breeding newts actively produces 7α-hydroxypregnenolone, a previously undescribed amphibian neurosteroid. This novel amphibian neurosteroid acts as a neuronal modulator to stimulate locomotor activity in newts. Subsequently, the mode of action of 7α-hydroxypregnenolone has been demonstrated in the newt brain. 7α-Hydroxypregnenolone stimulates locomotor activity through activation of the dopaminergic system. To understand the functional significance of 7α-hydroxypregnenolone in the regulation of locomotor activity, diurnal and seasonal changes in synthesis of 7α-hydroxypregnenolone have also been demonstrated in the newt brain. Melatonin derived from the pineal gland and eyes regulates 7α-hydroxypregnenolone synthesis in the brain, thus inducing diurnal locomotor changes. Prolactin, an adenohypophyseal hormone, regulates 7α-hydroxypregnenolone synthesis in the brain, and also induces seasonal locomotor changes. In addition, 7α-hydroxypregnenolone mediates corticosterone action to increase locomotor activity under stress. This review summarizes the discovery, progress and prospect of 7α-hydroxypregnenolone, a new key regulator of amphibian locomotion.

Prolactin increases the synthesis of 7alpha-hydroxypregnenolone, a key factor for induction of locomotor activity, in breeding male Newts.

We recently found that the Japanese red-bellied newt, Cynops pyrrhogaster, actively produces 7alpha-hydroxypregnenolone, a previously undescribed amphibian neurosteroid. 7alpha-Hydroxypregnenolone stimulates locomotor activity of male newts. Locomotor activity of male newts increases during the breeding period as in other wild animals, but the molecular mechanism for such a change in locomotor activity is poorly understood. Here we show that the adenohypophyseal hormone prolactin (PRL) stimulates 7alpha-hydroxypregnenolone synthesis in the brain, thus increasing locomotor activity of breeding male newts. In this study, cytochrome P450(7alpha) (CYP7B), a steroidogenic enzyme catalyzing the formation of 7alpha-hydroxypregnenolone, was first identified to analyze seasonal changes in 7alpha-hydroxypregnenolone synthesis. Only males exhibited marked seasonal changes in 7alpha-hydroxypregnenolone synthesis and CYP7B expression in the brain, with a maximum level in the spring breeding period when locomotor activity of males increases. Subsequently we identified PRL as a key component of the mechanism regulating 7alpha-hydroxypregnenolone synthesis. Hypophysectomy decreased 7alpha-hydroxypregnenolone synthesis in the male brain, whereas administration of PRL but not gonadotropins to hypophysectomized males caused a dose-dependent increase in 7alpha-hydroxypregnenolone synthesis. To analyze the mode of PRL action, CYP7B and the receptor for PRL were localized in the male brain. PRL receptor was expressed in the neurons expressing CYP7B in the magnocellular preoptic nucleus. Thus, PRL appears to act directly on neurosteroidogenic magnocellular preoptic nucleus neurons to regulate 7alpha-hydroxypregnenolone synthesis, thus inducing seasonal locomotor changes in male newts. This is the first report describing the regulation of neurosteroidogenesis in the brain by an adenohypophyseal hormone in any vertebrate.

Identification of 7alpha-hydroxypregnenolone, a novel bioactive amphibian neurosteroid stimulating locomotor activity, and its physiological roles in the regulation of locomotion.

We now know that steroids can be synthesized de novo by the brain and the peripheral nervous system. Such steroids are called neurosteroids and de novo neurosteroidogenesis from cholesterol is a conserved property of vertebrate brains. Our studies over the past decade have demonstrated that the brain expresses several kinds of steroidogenic enzymes and produces a variety of neurosteroids in sub-mammalian species. However, neurosteroid biosynthetic pathways in amphibians, as well as other vertebrates may still not be fully mapped. We first found that the newt brain actively produces 7alpha-hydroxypregnenolone, a previously undescribed amphibian neurosteroid. We then demonstrated that 7alpha-hydroxypregnenolone acts as a novel bioactive neurosteroid to stimulate locomotor activity of newt by means of the dopaminergic system. Subsequently, we analyzed the physiological roles of 7alpha-hydroxypregnenolone in the regulation of locomotor activity of newt. This paper summarizes the advances made in our understanding of 7alpha-hydroxypregnenolone, a newly discovered bioactive amphibian neurosteroid stimulating locomotor activity, and its physiological roles in the regulation of locomotion in newt.

Identification, biosynthesis, and function of 7alpha-hydroxypregnenolone, a new key neurosteroid controlling locomotor activity, in nonmammalian vertebrates.

It is now clearly established that steroids can be synthesized de novo by the brain and the peripheral nervous systems. Such steroids are called neurosteroids, and de novo neurosteroidogenesis from cholesterol is a conserved property of vertebrate brains. Our studies over the past decade have demonstrated that the brain expresses several kinds of steroidogenic enzymes and produces a variety of neurosteroids in submammalian species. However, the biosynthetic pathway of neurosteroids in nonmammalian vertebrates as well as in mammals may be still incompletely mapped out. We recently found that the brain of newts and quail actively produces 7alpha-hydroxypregnenolone, a novel bioactive neurosteroid, from pregnenolone. Interestingly, 7alpha-hydroxypregnenolone stimulates locomotor activity by means of the dopaminergic system. Subsequently, we demonstrated that melatonin regulates synthesis of 7alpha-hydroxypregnenolone, a key factor for induction of locomotor activity, thus inducing diurnal locomotor changes.

Seasonal changes in the synthesis of the neurosteroid 7alpha-hydroxypregnenolone stimulating locomotor activity in newts.

We recently found that the newt brain actively produces 7alpha-hydroxypregnenolone, a novel amphibian neurosteroid stimulating locomotor activity. It is well known that locomotor activity of male newts increases during the breeding period. To understand the physiological role of 7alpha-hydroxypregnenolone, we investigated seasonal changes in 7alpha-hydroxypregnenolone synthesis in the brain of male newts. Interestingly, 7alpha-hydroxypregnenolone synthesis in the brain showed marked changes during the annual breeding cycle, with a maximal level in the breeding period when locomotor activity of male newts increases. These results suggest that 7alpha-hydroxypregnenolone induces seasonal locomotor changes in male newts.

Diurnal changes in the synthesis of the neurosteroid 7alpha-hydroxypregnenolone stimulating locomotor activity in newts.

We recently identified 7alpha-hydroxypregnenolone as a novel amphibian neurosteroid stimulating locomotor activity in newts. Because male newts show marked diurnal changes in locomotor activity, we hypothesized that 7alpha-hydroxypregnenolone may be a key factor for the induction of diurnal changes in locomotor activity in male newts. In this study, we found diurnal changes in 7alpha-hydroxypregnenolone synthesis in the brain of male newts, which paralleled locomotor activity. Interestingly, the production of 7alpha-hydroxypregnenolone in the male newt brain increased during the dark phase when locomotor activity of males was high.