Expression of a nonmuscle myosin heavy chain in glomerular cells differentiates various types of glomerular disease in rats

To characterize the phenotypic modulation of mesangial and glomerular epithelial cells, we investigated the expression of a nonmuscle type myosin heavy chain, SMemb, and alpha-smooth muscle actin (alpha-SM actin) in rat experimental glomerular diseases, which included anti-Thy 1 nephritis, 5/6 nephrectomy, diabetes, and anti-glomerular basement membrane nephritis. SMemb was only slightly expressed in normal glomerular epithelial cells but not in mesangial cells. In the anti-Thy 1 nephritis rats, both SMemb and alpha-SM actin were most conspicuously induced in mesangial cells. However, the expression profile was shifted from alpha-SM actin to SMemb dominant pattern over the course of glomerulonephritis. The expression of SMemb was also increased in epithelial cells in this model. In the other three models, glomerular cells did not express alpha-SM actin, but did so for SMemb. In the nephrectomized and the diabetic rats SMemb was newly expressed in mesangial cells at earlier stages, but at later stages was remarkably enhanced in epithelial cells when severe glomerular hypertrophy developed. In the anti-GBM nephritis rats, SMemb expression was increased in epithelial cells. In all models examined, mesangial and epithelial expression of SMemb was confirmed by immunoelectron microscopy, and enhanced expression of SMemb mRNA in glomeruli was verified by RNase protection assay. We conclude from these results that glomerular cells change their phenotypes differently depending on various types of glomerular diseases. These phenotypic changes in glomerular cells can be revealed by the combined immunostaining for SMemb and alpha-SM actin. SMemb is especially useful to detect both mesangial and glomerular epithelial cell activation in these glomerular disease models. Understanding the functional difference and regulatory mechanisms of these cytoskeletal proteins will provide insight into the pathogenesis and progression of glomerular diseases.

[Effectiveness of LH-RH agonist for bone metastases of breast cancer--report of a case]

A 44-year-old premenopausal woman with bone metastases of breast cancer was initially treated with systemic chemotherapy (CEF) and radiation therapy after standard mastectomy. However, progressive change of bone metastases with elevation of tumor markers (CEA, NCC-ST 439) was detected, so continuous administration of LH-RH agonist and combination chemotherapy (CEF) were conducted. Subsequently, complete objective regression was attained after 40 weeks.

Loss of heterozygosity at the DCC gene locus is not crucial for the acquisition of metastatic potential in oesophageal squamous cell carcinoma

Tumour specimens from 111 patients with oesophageal squamous cell carcinoma were screened for loss of heterozygosity (LOH) at the deleted colorectal carcinoma (DCC) gene locus. DCC-LOH occurred in 10 of 61 informative cases (16%). No statistically significant correlation was observed between DCC-LOH and lymph node metastasis, histopathological grade or tumour stage. The survival of patients exhibiting DCC-LOH was not statistically different from that of patients without LOH. These results suggest that LOH at the DCC locus is not related to the acquisition of metastatic potential or the state of tumour cell differentiation in oesophageal squamous cell carcinoma.

Mucopolysaccharidosis IVA: four new exonic mutations in patients with N-acetylgalactosamine-6-sulfate sulfatase deficiency

We report four new mutations in Japanese patients with mucopolysaccharidosis IVA (MPSIVA) who were heterozygous for a common double gene deletion. A nonsense mutation of CAG to TAG at codon 148 in exon 4 was identified, resulting in a change of Q to a stop codon and three missense mutations. V (GTC) to A (GCC) at codon 138 in exon 4, P (CCC) to S (TCC) at codon 151 in exon 5, and P (CCC) to L (CTC) at codon 151 in exon 5. Introduction of these mutations into the normal GALNS cDNA and transient expression in cultured fibroblasts resulted in a significant decrease in the enzyme activity. V138A and Q148X mutations result in changes of restriction site, which were analyzed by restriction-enzyme assay. P151S and P151L mutations that did not alter the restriction site were detected by direct sequencing or allele specific oligohybridization. Detection of the double gene deletion was initially done using Southern blots and was confirmed by PCR. Haplotypes were determined using seven polymorphisms to the GALNS locus in families with the double gene deletion. Haplotype analysis showed that the common double gene deletion occurred on a single haplotype, except for some variation in a VNTR-like polymorphism. This finding is consistent with a common founder for all individuals with this mutation.

Distinct responses of different populations of bone cells to mechanical stress

To explore lineage-dependent responses to mechanical stress in bone cells, newborn rat calvarial cells, exhibiting differential characteristics of osteoblastic and osteocytic cells, were compared in their immediate and late responses to stretching. Seven fractions of sequentially prepared cells were cultured on Matrigel to promote their differentiation. By cyclically stretching the flexible bottom of culture plates, cells were exposed to a physiological stress of approximately 4000 microstrain on Matrigel. Cells in fractions IV, V and VI exhibited striking responses; the levels of cAMP and insulin-like growth factor I, bone Gla protein, and mineral accumulation were significantly elevated in the stretched cells. Also, proliferation was significantly inhibited regardless of the presence of 10(-6)M indomethacin. In contrast, osteoblasts in fraction III and osteocyte-like cells in fraction VII exhibited no significant response. Thus, these intermediate cells, very mature osteoblasts to young osteocytes, are likely to serve as a mechanosensor in bone, controlling the metabolic aspects of physical stress. We conclude that the responses of these young osteocytes to low level, physiological strain are transmitted in a manner different from the responses of osteoblasts to higher magnitude of strain in which PGE2 induces cell proliferation, as reported by others.

Coexistence of gene mutations causing Fabry disease and Duchenne muscular dystrophy in a Japanese boy

Both Fabry disease and Duchenne muscular dystrophy were confirmed by gene analysis in a Japanese boy. He developed muscle weakness at 4 years of age. A muscle biopsy revealed lamellar inclusion bodies in vascular endothelial cells in addition to myopathic changes with negative dystrophin staining. The myopathic symptoms progressed, and he died of pneumonia at 24 years of age. No clinical manifestations of Fabry disease were observed except for hypohidrosis and angiokeratoma. However, glycolipid accumulation was found in biopsied renal tissue. Molecular analysis demonstrated two gene mutations; a novel single-base deletion in exon 3 of the alpha-galactosidase gene, and a dystrophin gene deletion extending from exon 46 to exon 50. His mother was confirmed to be heterozygous for both gene deletions.

Correction by gene expression of biochemical abnormalities in fibroblasts from Zellweger patients

Zellweger syndrome is a prototype of peroxisomal biogenesis disorders and a fatal autosomal recessive disease with no effective therapy. We identified nine genetic complementation groups of these disorders, and mutations in peroxisome assembly factor-1 (PAF-1) and the 70-kD peroxisomal membrane protein (PMP70) genes have been detected by our group F and Roscher's group 1, respectively. We now describe permanent recovery from generalized peroxisomal abnormalities in fibroblasts of a Zellweger patient from group F, such as biochemical defects of peroxisomal beta-oxidation, plasmalogen biosynthesis, and morphologic absence of peroxisomes, by stable transfection of human cDNA encoding PAF-1. In the light of these observations, we designed a gene expression system using fibroblasts from patients with peroxisomal biogenesis disorders. In Zellweger fibroblasts obtained from Roscher's group 1 and transfected with human cDNA encoding PMP70, peroxisomes were not morphologically identifiable, and peroxisomal function did not normalize.

Clinical significance of simultaneous determinations of alpha-fetoprotein and des-gamma-carboxy prothrombin in monitoring recurrence in patients with hepatocellular carcinoma

BACKGROUND

Measurements of serum alpha-fetoprotein (AFP) concentration and plasma concentration of des-gamma-carboxy prothrombin (DCP) have been widely used for the early diagnosis of hepatocellular carcinoma (HCC). The two markers generally run parallel to each other. However, in our study, they sometimes fluctuated independently in response to tumor regression or recurrence.

METHODS

A longitudinal series of concentrations of serum AFP and plasma DCP were determined simultaneously for 245 patients with HCC from the time of diagnosis to tumor recurrence after treatment.

RESULTS

Positive reactions for AFP were noted in 168 patients (69%) and for DCP in 126 patients (51%). One hundred and ten of 245 patients with HCC (45%) were positive for both AFP and DCP. In 35 patients (14%), these 2 tumor markers fluctuated independently in response to tumor regression and recurrence. These patients were categorized into four groups as follows: Group 1 had elevated AFP only at diagnosis; it then decreased after treatment, but DCP was elevated at the time of tumor recurrence without AFP elevation (3 patients); Group 2 had elevated DCP at diagnosis and elevated AFP at tumor recurrence (4 patients); Group 3 had elevated AFP and DCP at diagnosis, but only AFP (8 patients) or DCP (7 patients) was elevated at tumor recurrence; Group 4 had only elevated AFP (2 patients) or DCP (11 patients) at diagnosis, but both AFP and DCP were elevated at tumor recurrence.

CONCLUSIONS

The results of this study indicate that simultaneous determinations of AFP and DCP are useful for monitoring recurrence in patients with HCC after treatment, and that the decrease to normal levels of a single marker does not always indicate the absence of tumor recurrence.

Neurotensin-containing endocrine cells and neurotensin receptor mRNA-expressing epithelial cells in the chicken thymus

Distribution of neurotensin-containing cells and neurotensin receptor-expressing cells was examined in the chicken thymus using a combination of in situ hybridization histochemistry for neurotensin receptor mRNA and immunohistochemistry for neurotensin. Neurotensin receptor mRNA-expressing cells and neurotensin-immunoreactive cells were localized in the medulla. Neurotensin receptor mRNA-expressing cells showed a round or elongated shape, while neurotensin-immunoreactive cells revealed round, ovoid, spindle or reticular shapes. Neurotensin-immunoreactive cells were much more numerous than those displaying labeling for the neurotensin receptor mRNA in males and females. Furthermore, electron microscopic immunohistochemistry for neurotensin showed that immunoreactive cells contained a large number of round or spherical granules which were 250-350 nm in diameter. This evidence indicates that neurotensin is localized in endocrine cells, and that neurotensin receptor mRNA is expressed in epithelial cells. It further suggests the possibility of microenvironmental interaction of neurotensin between endocrine cells and epithelial cells within the chicken thymus.

[Two cases of the successful treatment of TAPVR with asplenia syndrome in neonates and infants]

Two patients of asplenia syndrome with pulmonary venous obstruction underwent TAPVR repair in the period of neonate (14 days) and infant (49 days). Associated procedures were necessary to adjust pulmonary blood flow (central shunt in 1, PA banding in 1). Both patients required subsequent surgical procedures; right modified BT shunt, due to kinking of central shunt in one patient and rePA banding for reduction of pulmonary blood flow in another patient. One patient died 4 months after the first operation of arrhythmia. Another patient is doing well in 7 months after the first operation. The TAPVR repair in the early period of infant or naonate is necessary to prevent progress of pulmonary venous obstruction. Adjustment of pulmonary blood flow is important for management of patients of asplenia syndrome after TAPVR repair.

A synthetic peptide corresponding to the Rab4 hypervariable carboxyl-terminal domain inhibits insulin action on glucose transport in rat adipocytes

The present study was conducted to examine the involvement of Rab4, a low molecular weight GTP-binding protein, in the action of insulin on glucose transport. A synthetic peptide corresponding to the Rab4 hypervariable carboxyl-terminal domain, Rab4-(191-210), was successfully transferred into rat adipocytes by electroporation and inhibited insulin-stimulated glucose transport by about 50% without affecting the basal transport activity. In contrast, synthetic peptides corresponding to the Rab3C and Rab3D carboxyl-terminal hypervariable domain had little effect on insulin action on glucose transport. The Rab4-(191-210) peptide also reduced insulin-induced GLUT4 translocation from the intracellular pool to the plasma membrane. Furthermore, the Rab4-(191-210) peptide reduced both insulin-induced glucose transport and GLUT4 translocation in the presence of a major histocompatibility complex class I antigen-derived peptide, D(k)-(62-85), which is a potent inhibitor of GLUT4 internalization, suggesting that the peptide inhibited exocytotic recruitment of GLUT4-containing vesicles. The Rab4-(191-210) peptide also inhibited GTP gamma S-stimulated glucose transport. In addition, insulin-stimulated glucose transport was inhibited by the addition of anti-Rab4 antibody. These results suggest that Rab4 protein plays a crucial role in insulin action on GLUT4 translocation, especially in exocytotic recruitment by the hormone of the glucose transporter to the plasma membrane from the intracellular retention pool.

Nephrosis aggravates HCl-ethanol-induced gastric lesions in rats

This study was performed to evaluate the effect of nephrosis on gastric lesions in the rats. A single i.v. injection of daunomycin (12 mg/kg) into rats produced severe proteinuria and hypercholesterolemia on the 20th and 40th days after the administration. The severity of HCl-ethanol-induced gastric lesions was significantly greater in nephrotic rats than in control animals on the 20th and 40th days. The gastric mucosal blood flow on the 40th day was significantly lower in nephrotic rats. Pretreatment of normal rats with N(ω)-nitro-l-arginine or N(ω)-nitro-l-arginine methyl ester, a nitric oxide (NO) synthase inhibitor, methylene blue, a guanylate cyclase inhibitor, or phenylephrine, a vasoconstrictor, significantly aggravated the HCl-ethanol-induced gastric lesions and reduced the blood flow. When N(ω)-nitro-l-arginine methyl ester was given to nephrotic rats on the 40th day, it further increased the aggravation of the gastric lesions caused by nephrosis. These results suggest that the aggravation of HCl-ethanol-induced gastric lesions observed in nephrotic rats may be, at least in part, related to the decrease in the release of NO from endothelial cells.

Cloning and characterization of a functional promoter of the rat pp120 gene, encoding a substrate of the insulin receptor tyrosine kinase

Cloning of the 5 -flanking region of the rat pp120 gene has indicated that it is a housekeeping gene: it lacks a functional TATA box and contains several Sp1 binding sites and multiple transcription initiation sites at nucleotides -101, -71, -41, and -27 spread over a GC-rich area. A fragment between nucleotides -21 and -1609 exhibited promoter activity when ligated in a sense orientation into a promoterless luciferase reporter plasmid and transiently transfected into rat H4-II-E hepatoma cells. 5' progressive deletion and block substitution analyses revealed that the three proximal Sp1 boxes (boxes 3, 5, and 6) are required for basal transcription of the pp120 gene. Promoter activity was stimulated 2-3-fold in response to insulin, dexamethasone, insulin plus dexamethasone, and cAMP. Although unaltered by phorbol esters alone, promoter activity was stimulated 4-5-fold in response to phorbol esters plus cAMP. Several motifs resembling response elements for insulin (in the rat phosphoenolpyruvate carboxykinase gene), glucocorticoids, cAMP, and phorbol esters as well as a number of putative binding sites for activating proteins-1 (Jun/Fos) and -2, and liver-specific factors were detected. The role of these sites in tissue-specific expression of pp120 remains to be investigated.

Does inhibition of coronary nitric oxide synthesis alter coronary vascular tone in normal dogs?

To examine whether endothelial nitric oxide formation contributes to the vascular tone of resistance coronary vessels in vivo, we administered NG-nitro-L-arginine methyl ester (L-NAME) (10 and 100 micrograms/kg/min), a nitric oxide synthase inhibitor, as well as D-enantiomer into the left circumflex artery in normal dogs. Intracoronary L-NAME, which was associated with dose-related reductions in acetylcholine-induced coronary vasodilation, significantly reduced the baseline left circumflex blood flow by 6% and increased coronary vascular resistance of the left circumflex artery by 6%. D-enantiomer was ineffective in altering baseline coronary blood flow and vascular resistance of the left circumflex artery. These results indicate that continuous nitric oxide formation in the vasculature is important in the regulation of the coronary vascular tone of resistance vessels in vivo, and serves to maintain the vessels in a dilated state.

Absence of down-regulation and translocation of the eta isoform of protein kinase C in normal human keratinocytes

Among 11 isoforms of protein kinase C (PKC), we previously reported that the eta isoform of PKC plays a crucial role in mediating differentiation of keratinocytes. Activation of PKC is associated with its intracellular translocation from the cytoplasm to the plasma membrane, followed by down-regulation through proteolytic cleavage of the PKC molecules. In the present study, we demonstrated that the eta isoform of PKC is unique in that it is not translocated nor down-regulated upon stimulation. The level of the eta isoform, assayed by immunoblotting, remained unchanged during the first 12 h and then increased slightly up to 24 h when treated with tumor promoters or activators of PKC in constitutively expressing normal human keratinocytes. The activity of the eta isoform also remained unchanged after the 12-O-tetradecanoyl-phorbol-13-acetate treatment, as judged by binding ATP analog, autophosphorylation, and phosphorylation of an exogenous substrate. The alpha isoform of PKC, however, was rapidly down-regulated and was undetectable by 6 h after the treatment. These observations were further confirmed by immunohistochemical staining of normal human keratinocytes and transiently expressing COS1 cells. In addition, although the alpha isoform rapidly translocated to the plasma membrane, the eta isoform remained in the cytoplasm.

Preservation of skin free-flap using trehalose

In this study, we looked for a solution able to preserve traumatically amputated tissues such as nose tip, ear, and scalp for at least 48 hr that was easy to handle and low in price. Trehalose is a nonreducing disaccharide that can protect many prokaryotes, fungi, and yeasts against adverse conditions by stabilizing cell membranes. In order to study its protective effect, 60 skin free-flaps of the ears of rabbits were preserved in Euro-Collins (EC) solution or in modified Euro-Collins solution in which 7% trehalose replaced glucose (EC + 7%T) for 24, 48, and 72 hr at 4 degrees C. After completion of preservation, these flaps were transferred to the other ear with microvascular anastomosis. After 7 days, we obtained a survival rate of 100% of flaps after preservation for 24 hr in both solutions. But, after preservation for 48 hr or longer, this decreased to 60% (6 of 10 preserved flaps survived) in EC solution and 90% (9 of 10 flaps) in EC + 7%T solution. This difference became clearer after 72 hr of preservation, when the survival rate was higher and light microscopic observation showed less damage for flaps preserved in EC + 7%T solution (20% in EC and 70% in EC + 7%T) (P < 0.05). Thus, EC + 7%T solution was superior to EC solution in the preservation of skin free-flaps of the ear of rabbits. Trehalose shows great promise in the preservation of many organs, including storage of traumatically amputated tissues such as nose tip, ear, and scalp.

Expression of neolactoglycolipids: sialosyl-, disialosyl-, O-acetyldisialosyl- and fucosyl- derivatives of neolactotetraosyl ceramide and neolactohexaosyl ceramide in the developing cerebral cortex and cerebellum

The following neolacto glycolipids were identified and their developmental expression was studied in the rat cerebral cortex and cerebellum: Fuc alpha 1-3IIInLcOse4Cer,Fuc alpha 1-3VnLcOse6Cer and (Fuc)2 alpha 1-3III,3VnLcOse6Cer, as well as acidic glycolipids, NeuAc alpha 2-3IVnLcOse4Cer [nLM1], (NeuAc)2 alpha 2-3IVnLcOse4Cer [nLD1], O-acetyl (NeuAc)2 alpha 2-3IVnLcOse4Cer [OAc-nLD1] and their higher neolactosaminyl homologues NeuAc alpha 2-3VlnLcOse6Cer [nHM1] and (NeuAc)2 alpha 2-3VlnLcOse6Cer [nHD1]. These glycolipids were expressed in the cerebral cortex only during embryonic stages and disappeared postnatally. This loss was ascribed to the down regulation of the synthesis of the key precursor LcOse3Cer which is synthesized by the enzyme lactosylceramide: N-acetylglucosaminyl transferase. On the other hand in the cerebellum, these glycolipids increased with postnatal development due to increasing availability of LcOse3Cer. In the cerebellum, only nLM1 and fucosyl-neolactoglycolipids declined after postnatal day 10-15, perhaps due to regulation by other glycosyltransferases. Also, in the cerebellum, nLD1 and nHD1 were shown to be specifically associated with Purkinje cells and their dendrites in the molecular layer and with their axon terminals in the deep cerebellar nuclei, similar to other neolactoglycolipids shown previously.

[Antimicrobial activities of meropenem against clinically isolated strains. The result against strains isolated from blood and cerebrospinal fluid]

In order to evaluate the antimicrobial activity of meropenem (MEPM), minimum inhibitory concentrations (MICs) of MEPM and control drugs were determined against clinical isolates from blood and cerebrospinal fluid that were obtained from January, 1993 to December, 1994. The results are summarized as follows; 1. The MIC-range, 50% MIC (MIC50) and 90% MIC (MIC90) of MEPM were equal to those of imipenem (IPM) and panipenem (PAPM) against Streptococcus pneumoniae including benzylpenicillin (PCG)-insensitive or -resistant S. pneumoniae, Streptococcus agalactiae and Listeria monocytogenes which are Gram-positive strains, and were stronger than those of ampicillin (ABPC) and cefotaxime (CTX). 2. The MIC-range, MIC50 and MIC90 of these 3 drugs of carbapenems (MEPM, IPM and PAPM) were different against Escherichia coli and Haemophilus influenzae which are Gram-negative strains. The MIC90 of MEPM was < or = 0.025 microgram/ml and those of IPM and PAPM were 0.2 microgram/ml against E. coli. The MIC90 of MEPM was 0.1 microgram/ml, that of IPM was 25 micrograms/ml and that of PAPM was 6.25 micrograms/ml against H. influenzae. Thus, the antimicrobial activity of MEPM was stronger than those of IPM and PAPM. The MIC90's of IPM and PAPM against H. influenzae were high with the MIC of IPM at 12.5 approximately 25 micrograms/ml and the MIC of PAPM at 3.13 approximately 12.5 micrograms/ml against 3 IPM-resistant strains among 17 isolates. 3. The MIC90 of ABPC was 0.39 microgram/ml and that of CTX was 0.1 microgram/ml against 20 strains of S. pneumoniae including 6 strains of PCG-insensitive or resistant S. pneumoniae. The MIC90 of ABPC and CTX were higher than those of 3 carbapenem drugs. There were E. coli of 8 strains with ABPC-high resistance (the MIC of ABPC was > 100 micrograms/ml) and 2 strains for which MIC of CTX were 0.39 microgram/ml and 3.13 micrograms/ml. It was found that 29.4% of H. influenzae were beta-lactamase producing strains. 4. It appeared that antimicrobial activities of carbapenems, particularly MEPM were strong against clinical isolates from blood and cerebrospinal fluid. MEPM will be first choice drug by empiric therapy in infections including sepsis and purulent meningitis.

Urinary excretion of pyridinoline and deoxypyridinoline measured by immunoassay in hypothyroidism

OBJECTIVE

We measured pyridinium cross-links, markers of bone resorption, by an enzyme-linked immunosorbent assay (ELISA) in hypothyroid patients to see whether bone resorption was reduced in hypothyroidism and whether it increased with T4 treatment.

DESIGN AND PATIENTS

Eight hypothyroid patients, whose initial TSH levels were 268.1 +/- 87.7 mU/l (mean +/- SE), were treated with T4 (100 micrograms/day). Urinary excretion of pyridinium cross-links was assayed before and after T4 treatment.

MEASUREMENTS

Pyrilinks and Pyrilinks-D kits were used. The Pyrilinks assay measures free forms of pyridinoline and deoxypyridinoline together (PYD), while the Pyrilinks-D assay measures deoxypyridinoline (DPD) alone. The Pyrilinks reference ranges for normal subjects are 8-24nmol/mmol creatinine in males and 10-28nmol/mmol creatinine in normal premenopausal females. The DPD reference ranges obtained from normal men and women aged 40-50 years were 3.20 +/- 0.75 (mean +/- SD) nmol/mmol creatinine and 4.55 +/- 1.22 nmol/mmol creatinine, respectively.

RESULTS

The sensitivity of the assay was enhanced by simply using less diluted urine samples. Concentrations of both compounds of the urinary pyridinium cross-links were low in untreated hypothyroid patients and increased gradually as thyroid hormone status improved from hypothyroidism to euthyroidism. One month after treatment when the TSH levels in the patients were still as high as 74.4 +/- 44.5 mU/l, urinary PYD excretion has increased to 2.6 times the pretreatment level. When the TSH levels of the patients decreased below 10 mU/l, both PYD and DPD increased significantly to 3.8 and 3.3 times pretreatment values, respectively.

CONCLUSIONS

Although hyperthyroidism or excess treatment with thyroid hormone has been known to induce bone resorption, this is the first report that urinary excretion of pyridinium cross-links is reduced in hypothyroidism and is normalized by physiological thyroid hormone replacement.

Sex differences in constitutive level of renal lauric acid hydroxylase activities and CYP4A-related proteins in mice

The constitutive level of renal fatty acid hydroxylase was examined in ddY mice by measuring the activities of lauric acid omega- and (omega-1)-hydroxylase, (LA12H and LA11H respectively). The activities of both LA12H and LA11H of male mice were significantly higher than those of female mice. This sex difference in renal lauric acid hydroxylase (LAH) activity exists in other strains of mice, including Balb/c, C57BL/6, C3H/HeN and C3H/HeJ. Renal LAH activities are at significantly low levels in both sexes of immature animals, but are sexually differentiated in the mature state. In male mice, orchiectomy caused a drastic decrease in renal LAH activities, and the activities were restored by testosterone treatment to above the level of the intact animal. In female mice, ovariectomy and estradiol treatment had no effect on the activities, but testosterone treatment caused an increase in the activities to the level of the intact male animal. These results suggested that testosterone is a key regulatory factor in the level of LAH activity in mouse kidney. The administration of dexamethasone and clofibrate affected the level of LAH activity. The above data are consistent with the level of CYP4A-related proteins (band H and L protein) measured by using anti-rat CYP4A1 antibodies.antibodies. The antibodies inhibited both LA12H and LA11H activities. The level of band H protein was regulated by testosterone and dexamethasone. On the other hand, the level of band L protein was regulated by clofibrate. These results suggest that distinct modes of regulation exist in the level between band H and L protein in mouse kidney.

Rapid enlargement of a syringomyelia cavity following syringo-subarachnoid shunt: case report

We describe a patient who presented with syringomyelia 20 years following an operation for foramen magnum meningioma. A syringo-subarachnoid shunt was placed, which connected the syrinx and the cerebello-pontine angle cistern. Following shunt placement, the patient's symptoms rapidly progressed, and magnetic resonance imaging (MRI) revealed enlargement of the syrinx. The symptoms improved with a decrease in syrinx size after placement of a syringo-peritoneal shunt in combination with revision of the syringo-subarachnoid shunt, changing the position of the subarachnoid tip to the caudal spinal subarachnoid space. The mechanism of rapid enlargement of the syrinx cavity following placement of the syringo-subarachnoid shunt is discussed.