Global and fine information coded by single neurons in the temporal visual cortex

When we see a person's face, we can easily recognize their species, individual identity and emotional state. How does the brain represent such complex information? A substantial number of neurons in the macaque temporal cortex respond to faces. However, the neuronal mechanisms underlying the processing of complex information are not yet clear. Here we recorded the activity of single neurons in the temporal cortex of macaque monkeys while presenting visual stimuli consisting of geometric shapes, and monkey and human faces with various expressions. Information theory was used to investigate how well the neuronal responses could categorize the stimuli. We found that single neurons conveyed two different scales of facial information in their firing patterns, starting at different latencies. Global information, categorizing stimuli as monkey faces, human faces or shapes, was conveyed in the earliest part of the responses. Fine information about identity or expression was conveyed later, beginning on average 51 ms after global information. We speculate that global information could be used as a 'header' to prepare destination areas for receiving more detailed information.

The human serotonin transporter gene linked polymorphism (5-HTTLPR) shows ten novel allelic variants

The serotonin transporter (5-HTT) gene is a promising candidate for introducing the heritability of interindividual variation in personality and the genetic susceptibility for various psychiatric diseases. Transcription of the gene is modulated by a common polymorphism in its upstream regulatory region (5-HTT gene-linked polymorphic region: 5-HTTLPR). The 5-HTTLPR consists of variation of the repetitive sequence containing GC-rich, 20-23-bp-long repeat elements. A deletion/insertion in the 5-HTTLPR was first reported to create a short (S) allele and a long (L) allele (14- and 16-repeats, respectively). Three other kinds of alleles (18-, 19- and 20-repeats) in addition to the S and L alleles in 5-HTTLPR have been reported. In the present study, we examined the 5-HTTLPR polymorphism in detail and identified ten novel sequence variants, concluding that the alleles reported as S and L are divided into four and six kinds of allelic variant, respectively. Subsequently, we developed a method for genotyping. The total number of alleles (14-A, 14-B, 14-C, 14-D, 15, 16-A, 16-B, 16-C, 16-D, 16-E, 16-F, 19, 20 and 22) in the 5-HTTLPR was 14 in our populations (Japanese: n = 131; Caucasian: n = 74) in the present study. In addition, a significant ethnic difference between Japanese and Caucasian populations was observed for distributions of alleles and genotypes (P < 0.0001 and P < 0.0001, respectively). Our results suggest that the analyses of the 5-HTTLPR should be revised by genotyping with a more complete subdivision of alleles. Molecular Psychiatry (2000) 5, 32-38.

Discrimination value of the new western prognostic system (CLIP score) for hepatocellular carcinoma in 662 Japanese patients. Cancer of the Liver Italian Program

To reliably estimate the prognoses of patients with hepatocellular carcinoma (HCC), both liver function and tumor-related factors should be accounted for. However, there are few worldwide staging systems that assess prognostic value in the context of selecting individual patients for randomized stratification in therapeutic and clinical trials. We investigated the value of known prognostic systems and verified the usefulness of the new scoring system proposed by the Cancer of the Liver Italian Program (CLIP), as determined from 662 Japanese patients. A retrospective analysis of the HCC diagnoses at 4 Japanese institutions from 1990 and 1998 was performed. Overall survival was the only end point used in the analysis. Discriminatory ability and predictive power of the CLIP score were compared with those of Okuda stage and AJCC TNM stage. Compared with the Okuda and AJCC staging systems, the CLIP score's enhanced discriminatory capacity, which was tested by the linear trend test and Harrels' c-index, revealed a class of patients with an impressively more favorable prognosis and another class with a relatively shorter life expectancy. Moreover, the likelihood ratio test showed that the CLIP score had additional homogeneity of survival within each score above that of the Okuda stage or the AJCC stage. This was true for 3 subgroups of patients who received surgery, transcatheter arterial chemoembolizations, and percutaneous ethanol injections. Collectively, these findings indicate that the CLIP score has the highest stratification ability with regard to prognosis in patients with HCC. The CLIP score could be used internationally to stratify randomization groups in therapeutic and clinical trials.

Mutations of gamma-aminobutyric acid and glycine receptors change alcohol cutoff: evidence for an alcohol receptor?

Alcohols in the homologous series of n-alcohols increase in central nervous system depressant potency with increasing chain length until a "cutoff" is reached, after which further increases in molecular size no longer increase alcohol potency. A similar phenomenon has been observed in the regulation of ligand-gated ion channels by alcohols. Different ligand-gated ion channels exhibit radically different cutoff points, suggesting the existence of discrete alcohol binding pockets of variable size on these membrane proteins. The identification of amino acid residues that determine the alcohol cutoff may, therefore, provide information about the location of alcohol binding sites. Alcohol regulation of the glycine receptor is critically dependent on specific amino acid residues in transmembrane domains 2 and 3 of the alpha subunit. We now demonstrate that these residues in the glycine alpha1 and the gamma-aminobutyric acid rho1 receptors also control alcohol cutoff. By mutation of Ser-267 to Gln, it was possible to decrease the cutoff in the glycine alpha1 receptor, whereas mutation of Ile-307 and/or Trp-328 in the gamma-aminobutyric acid rho1 receptor to smaller residues increased the cutoff. These results support the existence of alcohol binding pockets in these membrane proteins and suggest that the amino acid residues present at these positions can control the size of the alcohol binding cavity.

Cell type-specific ATP-activated responses in rat dorsal root ganglion neurons

1. The aim of our study is to clarify the relationship between expression pattern of P2X receptors and the cell type of male adult rat (Wistar) dorsal root ganglion (DRG) neurons. We identified the nociceptive cells of acutely dissociated DRG neurons from adult rats type using capsaicin sensitivity. 2. Two types of ATP-activated currents, one with fast, the other with slow desensitization, were found under voltage-clamp conditions. In addition, cells with fast but not slow desensitization responded to capsaicin, indicating that there was a relationship between current kinetics and capsaicin-sensitivity. 3. Both types of neurons were responsive to ATP and alpha, beta methylene-ATP (alpha,betameATP). The concentration of alpha,(beta)meATP producing half-maximal activation (EC50) of neurons with fast desensitization was less (11 microM) than that of neurons with slow desensitization (63 microM), while the Hill coefficients were similar. Suramin and pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid tetrasodium (PPADS) antagonized alpha,betameATP-induced currents in both types of neurons. 4. In situ hybridization revealed that small cells of the DRG predominantly expressed mRNAs of P2X3 and medium-sized cells expressed mRNAs of P2X2 and P2X3. In contrast, both of mRNAs were not detected in large cells of the DRG. 5. These results suggest that capsaicin-sensitive, small-sized DRG neurons expressed mainly the homomeric P2X3 subunit and that capsaicin-insensitive, medium-sized DRG neurons expressed the heteromultimeric receptor with P2X2 and P2X3.

Identification of myelodysplastic syndrome-specific genes by DNA microarray analysis with purified hematopoietic stem cell fraction

Myelodysplastic syndrome (MDS) is a slowly progressing hematologic malignancy associated with a poor outcome. Despite the relatively high incidence of MDS in the elderly, differentiation of MDS from de novo acute myeloid leukemia (AML) still remains problematic. Identification of genes expressed in an MDS-specific manner would allow the molecular diagnosis of MDS. Toward this goal, AC133 surface marker-positive hematopoietic stem cell (HSC)-like fractions have been collected from a variety of leukemias in a large-scale and long-term genomics project, referred to as "Blast Bank," and transcriptome of these purified blasts from the patients with MDS were then compared with those from AML through the use of oligonucleotide microarrays. A number of genes were shown to be expressed in a disease-specific manner either to MDS or AML. Among the former found was the gene encoding the protein Delta-like (Dlk) that is distantly related to the Delta-Notch family of signaling proteins. Because overexpression of Dlk may play a role in the pathogenesis of MDS, the disease specificity of Dlk expression was tested by a quantitative "real-time" polymerase chain reaction analysis. Examination of the Blast Bank samples from 22 patients with MDS, 31 with AML, and 8 with chronic myeloid leukemia confirmed the highly selective expression of the Dlk gene in the individuals with MDS. Dlk could be the first candidate molecule to differentiate MDS from AML. The proposal is made that microarray analysis with the Blast Bank samples is an efficient approach to extract transcriptome data of clinical relevance for a wide range of hematologic disorders.

Molecular interactions and kinetic properties of fats

This article has reviewed the recent work on the molecular interactions and kinetic properties of the polymorphic transformations of the TAGs in the single and mixed states. Progress has recently been made in the molecular-level understanding of the polymorphic transformations of the TAGs. Particularly, the use of the time-resolved X-ray diffraction with Synchrotron radiation (SR-XRD) has provided precise information of the structural changes of the fat crystals at a time scale of 10 sec. Therefore, fruitful information was obtained on the kinetic and molecular aspects of crystallization and mixing processes of the various types of mixed-acid TAGs, which were not obtained with the traditional thermal and structural techniques because of their complicated structural properties. One may anticipate that, although the experimental sites and machine times are limited, the SR-XRD techniques will be more applied to the fat systems involving the following materials and systems; (a) multicomponent natural fats with and without additives of emulsifiers, proteins and carbohydrates, (b) fats in dispersed phases such as oil-in-water (O/W) and water-in-oil (W/O) emulsions, (c) crystallization and transformation processes under external influences of hydrostatic pressure and shear stress [68].

Suncus murinus: a new experimental model in emesis research

Effects of various emetic and antiemetic drugs were studied using Suncus murinus for its potential use as an experimental model in emetic research. Subcutaneous injection of nicotine bitartrate (10-15 mg/kg), veratrine sulfate (0.5-1.0 mg/kg), emetine dihydrochloride (40-80 mg/kg) and oral administration of copper sulfate (20-100 mg/kg) caused dose-dependent emesis in suncus. The ED50 of nicotine, veratrine, emetine and copper sulfate were 7.9, 0.4, 47.6 and 21.4 mg/kg, respectively. However, subcutaneously injected apomorphine hydrochloride (0.1-100 mg/kg), digitoxin (0.5-1.0 mg/kg) and orally administered emetine dihydrochloride (10-80 mg/kg) did not induce the vomiting. Chlorpromazine and promethazine decreased the emetic effect of nicotine, veratrine and copper sulfate, but scopolamine hydrobromide was not effective. These results indicate that the Suncus murinus is sensitive to various emetic and antiemetic drugs and can be used as a new experimental animal model for the emesis. Emetic behavior of suncus was discussed in comparison with other animals.

The effect of cortical bone thickness on the stability of orthodontic mini-implants and on the stress distribution in surrounding bone

Cortical bone thickness (CBT) was evaluated at mini-implant placement sites in 65 orthodontic patients and was found to be directly proportional to the success rate of the mini-implant. The success rate of the mini-implant was significantly greater at sites with CBT> or =1.0mm. To examine the biomechanical effects of CBT, finite element models were made for CBT from 0.5 to 1.5mm, at 0.25-mm intervals. Cortical bone models without cancellous bone were constructed to examine the biomechanical influence on cortical bone after cancellous bone resorption. CBT influenced the stresses in the cancellous bone, but could not directly influence the stresses in the cortical bone. For CBT<1mm, the cancellous bone models exhibited von Mises stresses exceeding 6MPa, and the cortical bone models without cancellous bone showed von Mises stresses exceeding 28MPa. Greater CBT values were associated with higher mini-implant success rates. This morphometric study and mathematical simulation verify that a clinical CBT threshold of 1mm improves the success rate of mini-implants.

Expression of vascular endothelial growth factor in patients with acute myocardial infarction

OBJECTIVE

The purpose of this study was to investigate the clinical significance of vascular endothelial growth factor (VEGF) in acute myocardial infarction (AMI). We also examined the involvement of peripheral blood mononuclear cells (PBMCs), which are a possible source of VEGF in AMI.

BACKGROUND

VEGF is a potent endothelial cell-specific mitogen and could affect the outcome of AMI.

METHODS

Thirty patients with AMI were used for this study. Serum and PBMCs were isolated from peripheral blood on days 1, 7, 14 and 21 after the onset of AMI. PBMCs were cultured at a density of 5 x 10(6) cells/ml for 24 h. VEGF levels in serum and the culture media were measured by enzyme-linked immunosorbent assay using a specific anti-human VEGF antibody.

RESULTS

Serum VEGF levels elevated gradually after the onset of AMI and reached a peak on day 14. VEGF levels in the culture medium of PBMCs after incubation for 24 h (PBMC-VEGF) were maximally elevated 7 days after the onset. Maximum serum VEGF levels showed significant positive correlations with maximum creatine phosphokinase (CPK) levels (r = +0.70, p < 0.001), but maximum PBMC-VEGF levels did not correlate with maximum CPK levels. Patients showing improvement in left ventricular systolic function during the course of AMI showed significantly higher PBMC-VEGF levels than patients without improvement.

CONCLUSIONS

The extent of myocardial damage contributes to the elevation of serum VEGF levels in AMI. VEGF produced by PBMCs may play an important role in the improvement of left ventricular function by promoting angiogenesis and reendothelialization after AMI.

Decrease of the D3 dopamine receptor mRNA expression in lymphocytes from patients with Parkinson's disease

We investigated the dopamine receptor (DAR) mRNA expression in peripheral blood lymphocytes from 45 patients with Parkinson's disease (PD) and 21 age-matched controls using the quantitative reverse transcription and polymerase chain reaction method. Beta-actin mRNA was used as an internal control to evaluate the relative expression level of the DAR mRNA. There was a statistically significant decrease of the D3 dopamine receptor (D3R) mRNA expression in PD patients compared with that in controls. There was no change in expression of the D5 dopamine reception mRNA in PD patients. A further binding study showed reduction of the D3R binding sites in PD lymphocytes. The decrease of the D3R mRNA expression correlated with the degree of clinical severity in PD patients.

Mullerian inhibiting substance in the adult rat ovary during various stages of the estrous cycle

Mullerian inhibiting substance (MIS) in the adult rat ovary can be detected by immunohistochemistry in the granulosa cells of growing preantral follicles and in the cumulus oophorus and periluminal granulosa cells of antral follicles in estrus, metestrus, diestrus, and proestrus. Neither the corpus luteum nor atreitic follicles stained for MIS. During proestrus, dramatic changes occurred in the large preovulatory antral follicles, which early in the day manifest intense MIS-specific staining in the granulosa cells located close to the oocyte, however, at 2300 h, just before ovulation when the germinal vesicle was extruded to indicate resumed meiotic division, MIS staining waned. When the morphology of the late preovulatory stage was created experimentally in 26-day-old immature ovaries by stimulating 48 h earlier with hCG, the intense staining of the granulosa cells surrounding the oocytes from untreated ovaries was lost in the cumulus cells of such hCG-treated animals. This temporal pattern of MIS staining and the prior demonstration that MIS could inhibit in vitro meiosis of oocytes from untreated immature rats suggest that this regressor, well characterized in the fetal testis, might function in the ovary as a regulator of oocyte maturation and follicular development during the adult reproductive cycle.

Localization of a gene for benign adult familial myoclonic epilepsy to chromosome 8q23.3-q24.1

Benign adult familial myoclonic epilepsy is an autosomal dominant idiopathic epileptic syndrome characterized by adult-onset tremulous finger movement, myoclonus, epileptic seizures, and nonprogressive course. It was recently recognized in Japanese families. In this study, we report that the gene locus is assigned to the distal long arm of chromosome 8, by linkage analysis in a large Japanese kindred with a maximum two-point LOD score of 4.31 for D8S555 at recombination fraction of 0 (maximum multipoint LOD score of 5.42 for the interval between D8S555 and D8S1779). Analyses of recombinations place the locus within an 8-cM interval, between D8S1784 and D8S1694, in which three markers, D8S1830, D8S555, and D8S1779, show no recombination with the phenotypes. Although three other epilepsy-related loci on chromosome 8q have been recognized-one on chromosome 8q13-21 (familial febrile convulsion) and two others on chromosome 8q24 (KCNQ3 and childhood absence epilepsy)-the locus assigned here is distinct from these three epilepsy-related loci. This study establishes the presence of a new epilepsy-related locus on 8q23.3-q24.11.

DNA analysis in hereditary dentatorubral-pallidoluysian atrophy: correlation between CAG repeat length and phenotypic variation and the molecular basis of anticipation

Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disease with variable clinical phenotypes. Progressive ataxia, choreoathetosis, and dementia are the main clinical features of adult-onset cases, whereas the main feature in juvenile-onset DRPLA is progressive myoclonus epilepsy. Earlier onset is apparent in successive generations (anticipation). The molecular abnormality underlying DRPLA is an expanded, unstable CAG trinucleotide repeat on chromosome 12p. We analyzed 71 DNA samples obtained from 12 Japanese DRPLA pedigrees that included 38 affected individuals. Normal alleles had 7 to 23 repeats, DRPLA alleles 53 to 88 repeats. DRPLA alleles also were detected in five asymptomatic family members. Patients with juvenile onset had significantly larger repeats than did those with adult onset, and there was a significant negative correlation between CAG repeat length and age at onset. In 80% of the paternal transmissions, there was an increase of more than five repeats, whereas all the maternal transmissions showed either a decrease or an increase of fewer than five repeats. There was a significant correlation between father-child differences in repeat length and differences in age at onset. The analysis of CAG repeat length is a reliable diagnostic test for DRPLA and is of value for the presymptomatic detection of individuals at risk. The expansion of CAG repeats is important in phenotypic variation and anticipation. In addition, the sex of the transmitting parent has a significant effect on the molecular mechanism of anticipation.

Secretion of sphingolipid hydrolase activator precursor, prosaposin

Sphingolipid hydrolases are activated by activator proteins or saposins. The precursor protein has been expected from the studies on the cDNA for saposins. Here we demonstrate that prosaposin occurs in various kinds of human secretory fluids such as cerebrospinal fluid, semen, milk, pancreatic juice, and bile. However, mature type saposins were not detected in these fluids. In human milk the amount of prosaposin changed during the lactating period; it became high in concentration within a few days after delivery, decreased during the transitional milk lactating stage, and then increased again toward the mature milk lactating stage. Prosaposin was released from human platelets in response to stimulation by thrombin, but mature saposins were not. From the time course of the release of prosaposin induced by thrombin and from the fact that weak platelet agonists, ADP, epinephrine, and collagen, did not cause the release of prosaposin, prosaposin secretion from platelets seemed to be from lysosome like granules. We postulate that some prosaposin works as a precursor for saposins in the lysosomes and the other serves as an extracellular protein with other specific roles.

Potent protective effect of melatonin on chromium(VI)-induced DNA single-strand breaks, cytotoxicity, and lipid peroxidation in primary cultures of rat hepatocytes

Incubation of primary cultures of rat hepatocytes with K2Cr2O7 plus the pineal hormone melatonin resulted in a marked decrease in cellular levels of DNA single-strand breaks caused by K2Cr2O7. Cellular treatment with melatonin also suppressed both dichromate-induced cytotoxicity, as evaluated by the leakage of lactate dehydrogenase, and lipid peroxidation, as monitored by malondialdehyde formation. In addition, treatment with melatonin attenuated the suppression of the levels of vitamins E and C as well as the inhibition of catalase activity attributed to K2Cr2O7. However, melatonin had no influence on cellular level of glutathione and the activity of glutathione reductase, glutathione peroxidase, superoxide dismutase, and alkaline phosphatase suppressed by dichromate. Under the same experimental conditions, cellular uptake and distribution of Cr were not affected by melatonin. Electron spin resonance (ESR) studies showed that melatonin did not affect the formation of Cr(V) complexes in the reaction of K2Cr2O7 with reduced glutathione; however, melatonin caused a 25% decrease in the levels of Cr(V)-related hydroxyl radicals in vitro. These results indicate that melatonin protects cells from Cr(VI)-induced DNA strand breaks, cytotoxicity, and lipid peroxidation, possibly through its ability to increase cellular levels of vitamins E and C as well as catalase activity and/or to directly scavenge toxic hydroxyl radicals in cells.

Acceleration of primary liver tumor growth rate in embolized hepatic lobe after portal vein embolization

BACKGROUND

Portal vein embolization (PVE) is now widely accepted as a useful preoperative procedure in selected patients undergoing extended hepatectomy. However, the effect of PVE on the growth of liver tumors has not been fully elucidated.

PURPOSE

To retrospectively evaluate the effects of PVE on the growth of liver tumors in the embolized lobes.

MATERIAL AND METHODS

Eight patients with a primary liver tumor, six hepatocellular carcinomas (HCC) and two cholangiocellular carcinomas (CCC), were studied. The growth rates of the tumors in the embolized lobes and non-embolized liver parenchyma were calculated using the computed tomography (CT) volume values at the time of tumor identification, and before and after PVE.

RESULT

The median tumor growth rate was 0.59 cm(3)/day (range 0.22-6.01 cm(3)/day) before PVE and 2.37 cm(3)/day (range 0.29-13.97 cm(3)/day) after PVE (P = 0.018). The tumor growth acceleration ratios ranged from 1.50 to 7.46 (median 2.65) in the six HCCs, and were 1.00 and 1.32 in the two CCCs. There was no apparent correlation between the tumor growth rate after PVE and the growth rate of non-embolized liver parenchyma (median 6.00 cm(3)/day, range 1.24-11.0 cm(3)/day).

CONCLUSION

Liver tumor growth in an embolized lobe accelerates after PVE, in patients with HCC.

A clinicopathologic study of ameloblastoma

One hundred four ameloblastomas, 97 in the mandible, five in the maxilla, and two in peripheral locations, were studied. A consistent correlation between the age of the patient and the radiographic or histologic type of mandibular ameloblastoma was observed. There was a tendency for ameloblastomas of the follicular type to show a multilocular or soap bubble appearance and for those of the plexiform type to show a unilocular appearance. Recurrent ameloblastomas had a predominantly multilocular appearance. Histologically, the ameloblastomas in the maxilla were of the follicular type.

Protection by prosaposin against ischemia-induced learning disability and neuronal loss

Prosaposin, the protein precursor of saposins A, B, C, and D which activate sphingolipid hydrolases, is abundant in several brain regions including the hippocampus. We infused prosaposin continuously for 7 days into the lateral ventricle of gerbils starting 3 hours before 3-min of forebrain ischemia. Using the step-down passive avoidance task, we demonstrated that ischemia-induced learning disability is prevented almost completely by prosaposin infusion. Subsequent light and electron microscopic examinations showed that pyramidal neurons in the CA1 field of the hippocampus as well as synapses within the strata moleculare, lacunosum/radiatum and oriens of the field were significantly more numerous in gerbils infused with prosaposin infusion than in those receiving saline infusion. These findings suggest that prosaposin possesses neurotrotrophic activity to protect hippocampal CA1 neurons from lethal ischemic damage.

Long-term coenzyme Q10 therapy for a mitochondrial encephalomyopathy with cytochrome c oxidase deficiency: a 31P NMR study

For 2 years we administered high doses of coenzyme Q10 (CoQ) to a patient having mitochondrial encephalomyopathy with cytochrome c oxidase deficiency. Abnormal elevation of the serum lactate per pyruvate ratio and the increased concentration of serum lactate plus pyruvate induced by exercise decreased with CoQ treatment. This therapeutic effect continued for 2 years. 31P nuclear magnetic resonance spectroscopy showed acceleration of the postexercise recovery of the ratio of phosphocreatine to inorganic phosphate in muscle during CoQ treatment. These observations support the beneficial effect of CoQ on the impaired mitochondrial oxidative metabolism in muscle. Also, impaired central and peripheral nerve conductivities consistently improved during CoQ treatment. These results indicate that CoQ has clinical value in the long-term management of patients with mitochondrial encephalomyopathies, even though there are clinical limitations to the effects of this therapy.

Prosaposin facilitates sciatic nerve regeneration in vivo

Prosaposin, a multifunctional protein, is the precursor of saposins, which activate sphingolipid hydrolases. In addition to acting as a precursor for saposins, prosaposin has been shown to rescue hippocampal CA1 neurons from lethal ischemic damage in vivo and to promote neurite extension of neuroblastoma cells in vitro. Here we show that prosaposin, when added to a collagen-filled nerve guide after sciatic nerve transection in guinea pigs, increased dramatically the number of regenerating nerve fibers within the guide. To identify the target neurons of prosaposin during peripheral nerve regeneration, we determined the degree of atrophy and chromatolysis of neurons in the spinal anterior horn and dorsal root ganglia on the prosaposin-treated and untreated side. The effect of prosaposin on large spinal neurons and small neurons of the dorsal root ganglion was more conspicuous. Subsequent immunohistochemistry demonstrated that the atrophy of cholinergic large neurons in the anterior horn is prevented to significant extent by prosaposin treatment. These findings suggest that prosaposin promotes peripheral nerve regeneration by acting on alpha-motor neurons in the anterior horn and on small sensory neurons in the dorsal root ganglion. The present study raises the possibility of using prosaposin as a tool for the treatment of peripheral nerve injuries.

Cellular localization of müllerian inhibiting substance in the developing rat ovary

The ontogeny of Müllerian Inhibiting Substance (MIS) production was studied in the immature developing rat ovary using immunohistochemistry and bioassay. In a graded organ culture assay, in which regression of the Müllerian duct of the 14 1/2-day rat fetus was used as a measure of bioactivity, MIS could not be detected in ovarian fragments from fetal rats. After birth, however, MIS bioactivity first became detectable at 4 days of age. Fragments from ovaries of rats 7 days of age and older contained moderate levels of MIS activity which remained detectable throughout the prepubertal period, although extreme individual variability was characteristic. A rabbit polyclonal antibody against human recombinant MIS was used to localize MIS in rat ovarian tissue. Avidin-biotin enhanced immunoperoxidase staining could not detect MIS in the 15-day fetal or 1 day postnatal ovary, where no follicular growth was noticed. In ovaries from rats 1 week or older, where follicular growth was apparent, MIS could be localized specifically and exclusively in the cytoplasm of granulosa cells. MIS was found more in the innermost layers of granulosa cells than in the peripheral layers in preantral follicles. In antral follicles, MIS was found predominantly in the cumulus oophorus cells and periantral cells. In these developing ovaries, MIS could not be found in follicles with features of atresia.

Macrophage migration inhibitory factor as a redox-sensitive cytokine in cardiac myocytes

OBJECTIVE

Macrophage migration inhibitory factor (MIF), which plays a pivotal role in the control of inflammatory responses, was first characterized as a T-cell cytokine, but later was also found as a pituitary peptide released in response to infection and stress. However, MIF's role and expression in the myocardium has never been reported. The goal of this study is to examine MIF in the myocardium.

METHODS AND RESULTS

MIF protein and mRNA levels were assayed using enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR), respectively. Increased MIF concentrations were detected in the sera of patients with acute myocardial infarction (AMI). In cultured rat cardiac myocytes, significant amounts of MIF were produced in response to hypoxia and hydrogen peroxide (H(2)O(2)), but not to angiotensin II, endothelin-1, interleukin-1beta (IL-1beta) or tumor necrosis factor alpha (TNFalpha). H(2)O(2)-induced MIF production increased in a time- and dose-dependent manner and was completely abolished in the presence of catalase. H(2)O(2) also induced MIF mRNA expression. The H(2)O(2)-induced MIF production was completely inhibited by the protein kinase C (PKC) inhibitor GF109203X, partially inhibited by the tyrosine kinase inhibitor herbimycin A, and uninhibited by calcium chelation or phorbol ester-sensitive PKC down-regulation. This suggests that H(2)O(2)-induced MIF production is mediated by an atypical PKC isoform. DNA microarray analysis revealed that 52 genes were preferentially expressed in response to MIF. Of these, the MIF-induced expression of both glutathione S-transferase (GST) and lipopolysaccharide-induced CXC chemokine (LIX) mRNAs was confirmed using RT-PCR analysis.

CONCLUSION

The present results suggest that MIF is expressed by the myocardium in response to redox stress and may play a role in the pathogenesis of myocardial ischemia.