Chronological changes of auditory brainstem responses in Cockayne's syndrome

Cockayne's syndrome (CS) is a rare autosomal recessive premature-aging disorder which is clinically characterized by physical and mental retardation, retinal pigmentation, sensorineural deafness and other neurological abnormalities. Auditory brainstem responses (ABRs) and behavioral audiometry were studied in 4 cases of confirmed CS chronologically. In one case, ABRs were normal at first but became abnormal. Initially, ABRs revealed only wave I with prolonged latency and thereafter no response. In another case, ABRs revealed the absence of all waves beyond wave III and then revealed the disappearance of all waves. In 2 other cases, ABRs were absent from the first testing. Behavioral levels were elevated in all 4 cases. In 2 cases, behavioral levels did not change in spite of partial disappearance of ABR waves, but they had elevated severely since all waves including wave I disappeared. Our findings suggest that the disease spreads from the upper brainstem to the cochlear nerve and that the site of the lesion causing hearing loss in CS is in the brainstem lesion as well as the peripheral one.

Enhancement of phorbol ester-induced production of tumor necrosis factor-alpha by 2,6-dimethylphenylphthalimide

The effect of phenyl- and benzylphthalimide analogs on tumor necrosis factor (TNF)-alpha production by a human leukemia cell line, HL-60, stimulated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) was investigated. Though non-substituted phenyl- and benzyl-phthalimide had no effect on TNF-alpha production after TPA-induction, introduction of methyl group(s) onto the phenyl group resulted in the appearance of potent enhancing activity on TNF-alpha production.

Changes in the basal ganglia and thalamus following reperfusion after complete cerebral ischaemia

We report specific changes bilaterally in the basal ganglia and thalamus following reperfusion after complete cerebral ischaemia. A 69-year-old man, resuscitated after cardiac arrest, showed symmetrical low-density lesions in the head of the caudate nucleus and lentiform nucleus on CT. MRI revealed methaemoglobin derived from minor haemorrhage in the basal ganglia and thalamus, not evident on CT. We suggest that this haemorrhage results from diapedesis of red blood cells through the damaged capillary endothelium following reperfusion.

Prevalence of HCV genotype among patients with chronic liver diseases in the Tokyo metropolitan area

We examined 613 Toranomon Hospital patients with HCV RNA-positive chronic liver disease to elucidate the viral genotype in the Tokyo metropolitan area. An epidemiological and clinical study was conducted in the 565 patients whose HCV genotype could be determined. The HCV genotypes found were type II, in 414 patients (67.5%); type III, in 103 (16.8%); type IV, in 37 (6.0%); type V, in 4 (0.7%); mixed genotype II and III, in 5 (0.8%); and mixed genotype II and IV, in 2 (0.3%). The HCV genotype could not be determined in 48 patients. Type II was most prevalent. The HCV genotype I was not found at all. There were no significant differences between genotypes in relation to sex, age, history of blood transfusion, or the progression of the disease. It was uncommon to find a history of blood transfusion in the patients with mixed genotypes; however, a high incidence of hepatic disorders was noted among the family members of these patients. Ninety-two percent of the patients with HCV genotype II tested positive for C100-3, while 70.9% of those with type III, and 43.2% of those with type IV tested positive for this antibody. HCV genotype II was most prevalent, and the positivity rate for anti C100-3 in patients with this HCV genotype was significantly higher (P < 0.00001) than that in patients with the other genotypes.

An ultrastructural study of the dorsal lingual epithelium of the rat snake, Elaphe quadrivirgata

The histological characteristics and ultrastructure of the dorsal lingual epithelium of the rat snake, Elaphe quadrivirgata, were investigated by light microscopy and scanning and transmission electron microscopy. Most of the surface of the bifurcated part of the tongue was relatively smooth. Dome-shaped, hemispherical bulges were compactly arranged on the epithelial cell surface of the basal area of this region. Intercellular borders were clearly recognizable as striations. Microridges were densely distributed on the epithelial cell surface of the lingual body. Intercellular borders were thickened. A keratinized layer was clearly visible in the epithelium of the anterior bifurcated area, namely, at the apex of the tongue. Although keratohyalin granules were not found in any layer of the epithelium in this area, the cells of the surface layer were filled with keratin filaments. The dorsal lingual epithelium of the posterior area, namely, the lingual body, did not show any evidence of keratinization. Each cell on the surface side still had a large, oval nucleus and intact organelles, such as mitochondria, rough endoplasmic reticulum, ribosomes, tonofibrils, and tonofilaments. Cellular interdigitation was evident between adjacent cells and clear microridges or microvilli were observed on the cell membranes on the free-surface side of cells located in the surface layer. The phylogenetic relevance of these findings is discussed.

Specific changes in human brain following reperfusion after cardiac arrest

BACKGROUND AND PURPOSE

Very few reports are available on serial changes in human brain after cardiac arrest. The primary objective of this study is to investigate sequential neuroradiological changes in patients remaining in a persistent vegetative state following resuscitation after cardiac arrest.

METHODS

We repeatedly studied eight vegetative patients resuscitated from unexpected out-of-hospital cardiac arrest using computed tomographic (CT) scanning and high-field magnetic resonance (MR) imaging at 1.5 T.

RESULTS

In seven of the eight patients, CT scans obtained between days 2 and 6 features symmetrical low-density lesions in the bilateral caudate, lenticular, and/or thalamic nuclei. These ischemic lesions were persistently of low density on serial CT scans. In these seven patients, MR images demonstrated what were thought to be hemoglobin degradation products derived from minor hemorrhages localized in the bilateral basal ganglia, thalami, and/or substantia nigra. Diffuse brain edema in the acute stage and diffuse brain atrophy in the chronic stage were consistent neuroradiological findings. No abnormal enhanced lesions were demonstrated by CT scans.

CONCLUSIONS

The most characteristic findings on high-field MR images were symmetrical lesions in the bilateral basal ganglia, thalami, and/or substantia nigra with specific changes suggestive of minor hemorrhages that were not evident on CT scans. We speculate that these minor hemorrhages result from diapedesis of red blood cells in these regions during the reperfusion period through the endothelium disrupted by ischemia-reperfusion insult.

[A case of pontine hemorrhage presenting with abnormal vertical ocular movements]

A 52-year-old woman was admitted to hospital because of sudden loss of consciousness. Neurological examination on admission revealed a comatose consciousness level, horizontal and upward palsies of both eyes and quadriparesis. The diagnosis of pontine hemorrhage was confirmed based on a brain CT scan, which showed a high density area involving the bilateral pontine tegmentum and right midbrain tegmentum at the inferior collicular level. The left eye moved downward below its primary position, and the movements usually comprised rapid downward and slow upward excursions and, on occasion, slow downward and rapid upward excursions, and were arrhythmical with irregular amplitudes. Oculocephalic maneuver did not modify the ocular movements. No horizontal movements were seen with ice-cold water irrigation into the ear canal on either side. Sixty days after hemorrhage onset, her right eye began to assume the same abnormal vertical movements as the left one, and 90 days after their onset, the ocular movements became oscillations. The abnormal vertical ocular movements in our patient were characterized by irregularities of phase, rhythm and amplitude. Accordingly, they were easily differentiated from ocular bobbing and ocular dipping. As these abnormal ocular movements resembled those of a float pulled by a fish, we propose they be termed ocular floating. The paramedian pontine reticular formation (PPRF) is believed to excite the burst neurons of the rosral interstitial nucleus of medial longitudinal fasciculus (riMLF) responsible for upward gaze and inhibit those for downward gaze. This role was suggested by the clinical observation that a pontine tegmental lesion causes upward gaze palsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Bilateral organized chronic subdural haematomas: high field magnetic resonance images and histological considerations

The authors describe a 66-year-old man with progressive gait disturbance caused by bilateral organized chronic subdural haematomas. The characteristics of these lesions on magnetic resonance (MR) images have not yet been clarified. The organized haematoma in our patient exhibited slight hypo-intensity on T 1-weighted MR images and marked hypo-intensity on T 2-weighted MR images obtained at 1.5T. Preoperative MR imaging may give us useful information about surgical strategy in the case of chronic subdural haematoma with an unusual appearance on computed tomographic (CT) scans.

Enhancement of 12-O-tetradecanoylphorbol-13-acetate-induced tumor necrosis factor alpha production by phenethylphthalimide analogs

Effects of phenyl-, benzyl-, phenethyl-, and phenylpropylphthalimides on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor necrosis factor (TNF)-alpha production by human leukemia cell line HL-60 were examined. Among the four phthalimide derivatives, only phenethylphthalimide showed potent enhancing effect on TNF-alpha production.

Inactivation of the macrolide antibiotics erythromycin, midecamycin, and rokitamycin by pathogenic Nocardia species

A survey of five Nocardia spp. with respect to susceptibility towards three macrolides (erythromycin, rokitamycin, and midecamycin) showed that the Nocardia spp. have different susceptibility profiles. Most of the resistance was due to the inactivation of the macrolides by phosphorylation, glycosylation, reduction, deacylation, or a combination thereof.

Specific binding of 12-O-tetradecanoylphorbol-13-acetate to histone H1

12-O-Tetradecanoylphorbol-13-acetate (TPA) binds specifically to histone H1 prepared from HeLa cells and to calf histone H1 with dissociation constants of 4.3 x 10(-7) and 9.3 x 10(-7) M, respectively. The TPA-binding to histone H1 was confirmed immunologically using a monoclonal antibody directed against an evolutionally conserved epitope of histone H1. This binding would influence DNA structure and the basal level of transcription, and may, in turn, account for the cell growth-regulatory activity of TPA.

Ustiloxins, antimitotic cyclic peptides from false smut balls on rice panicles caused by Ustilaginoidea virens

Ustiloxins A (1a), B (1b), C (1c), D (1d) and E (1e), antimitotic peptides, have been isolated from the water extract of false smut balls caused on the panicles of rice plant by a fungus Ustilaginoidea virens. The structure of 1b was assigned from its spectral property and its amino acid analysis in relation to 1a whose structure was determined previously by a combination of X-ray crystallographic and amino acid analyses. Structures of 1c and 1d were elucidated by their spectroscopic data, specially based on their 1H and 13C NMR spectra. Bioactivities of these compounds against microtubule assembly as well as mammal, plant and fungal cells have been studied.

Phosphorylative inactivation of rifampicin by Nocardia otitidiscaviarum

Rifampicin was inactivated by Nocardia otitidiscaviarum to yield two products designated RIP-3 and RIP-4. The full structures of RIP-3 and RIP-4 were determined to be 21-(O-phosphoryl) rifampicin and 3-formyl-21-(O-phosphoryl) rifamycin SV, respectively, but neither product had any antimicrobial activity.

Increase in the chemically-induced differentiation of human leukemia cell lines by tubulin disruptors

The effect of various structural/functional tubulin disruptors (including colchicine-type disruptors, vinblastine, rhizoxin, maytansine, peptide-type disruptors, and taxol) on the chemically induced differentiation of human leukemia cell lines (HL-60 and K562) was examined. As differentiation-inducing agents, 12-O-tetradecanoylphorbol-13-acetate (TPA) was used for the differentiation of both HL-60 and K562 to monocyte/macrophages, retinoids were used for the differentiation of HL-60 to mature granulocytes, and hemin was used for the erythroid differentiation of K562. All the tubulin disruptors investigated increased the chemically-induced differentiation of HL-60 and K562 cell lines to the cognate mature cell types, regardless of the nature of the differentiation.

(S)-form of alpha-methyl-N(alpha)-phthalimidoglutarimide, but not its (R)-form, enhanced phorbol ester-induced tumor necrosis factor-alpha production by human leukemia cell HL-60: implication of optical resolution of thalidomidal effects

The rate of racemization of N(alpha)-phthalimidoglutarimide (thalidomide) was determined as its half life to be 566 min at pH 7.4/37 degrees C. This fast racemization of thalidomide resulted in no apparent difference between (S)- and (R)-forms of the compound on enhancing activity of phorbol ester-induced tumor necrosis factor (TNF)-alpha production by human leukemia HL-60 cells. Optically pure forms of structurally related analog of thalidomide, (S)- and (R)-alpha-methyl-N(alpha)-phthalimidoglutarimides (methylthalidomides), which do not racemize under the physiological condition, were prepared. Only (S)-form of methylthalidomide, but not its (R)-form, elicited TNF-alpha production-enhancing effect, suggesting that the (S)-isomer of thalidomide would be the active form in terms of thalidomidal biological response modifying effects.

Factors predictive of response to interferon-alpha therapy in hepatitis C virus infection

To determine the patient-dependent and virus-related factors that may predict sustained response to interferon-alpha therapy, we prospectively evaluated 60 consecutive patients with chronic hepatitis C who received a standardized treatment schedule of interferon-alpha. Twenty-eight patients achieved a long-term sustained remission, 14 patients had temporary responses during treatment but relapsed after completing it and 14 patients did not respond. Four patients dropped out because of severe side effects and were excluded from evaluation of efficacy. Twenty-one variables were chosen as possible predictors of sustained response and were analyzed by means of multivariate analysis. Variables related to the hepatitis C virus included genotype and concentration in serum before treatment. The former was determined by means of the polymerase chain reaction with genotype-specific primers for genotypes PT, K1, K2a and K2b, which were deduced from nonstructural region 5 of the hepatitis C virus genome. The latter was measured with a competitive polymerase chain reaction technique. Three variables were statistically significant (p < 0.05) on univariate analysis: viral genotype, pretreatment level of viremia and Knodell's fibrosis score. In multivariate analysis viral genotype and Knodell's fibrosis score were correlated independently with a sustained response (p < 0.05 for both). Incidence of sustained response was 40% and 91% in patients with genotypes K1 and K2a, respectively. We conclude that with the treatment schedule used, viral genotype was the most useful predictor of a sustained response to treatment with interferon-alpha.

Interaction of ustiloxin A with bovine brain tubulin

Ustiloxin A is a modified peptide derived from false smut balls on rice panicles, caused by the fungus Ustilaginoidea virens; structurally, it resembles phomopsin A. Ustiloxin A is cytotoxic and is an inhibitor of microtubule assembly in vitro. Because of its resemblance to phomopsin A, we examined its interaction with tubulin and compared the results with those obtained with phomopsin A and dolastatin 10, both of which were found previously to have very similar effects. We determined that ustiloxin A inhibited the formation of a particular intra-chain cross-link in beta-tubulin, as do vinblastine, maytansine, rhizoxin, phomopsin A, dolastatin 10, halichondrin B and homohalichondrin B; this is in contrast to colchicine and podophyllotoxin which do not inhibit formation of this cross-link. Ustiloxin A also inhibited the alkylation of tubulin by iodo[14C]acetamide, as do phomopsin A and dolastatin 10; vinblastine was almost as potent as inhibitor of alkylation as ustiloxin A, whereas maytansine, halichondrin B and homohalichondrin B have little or no effect. In addition, ustiloxin A inhibited exposure of hydrophobic areas on the surface of the tubulin molecule. In this respect, ustiloxin A was indistinguishable from phomopsin A but slightly more effective than dolastatin 10 and considerably more effective than vinblastine; this provides a strong contrast to maytansine, rhizoxin, and homohalichondrin B which have no effect on exposure of hydrophobic areas and to halichondrin B which enhances exposure. Lastly, ustiloxin A strongly stabilized the binding of [3H]colchicine to tubulin. The combination of ustiloxin A with cholchicine stabilized tubulin with a half-life of over 8 days, comparable with results obtained with phomopsin A and colchicine. A comparison of the structures of ustiloxin A, phomopsin A and dolastatin 10 raised the possibility that the strong stabilization of the tubulin structure may require a short segment of hydrophobic amino acids such as the modified valine-isoleucine sequence present in all three compounds. The rest of the structure, specifically the large ring of ustiloxin A and phomopsin A, may serve to place this sequence in an appropriate conformation to interact with tubulin.

Effects of testosterone, dihydrotestosterone and estrogen on 3,2'-dimethyl-4-aminobiphenyl-induced rat prostate carcinogenesis

Post-initiation effects of testosterone propionate (TP), alpha-dihydrotestosterone (DHT) and ethinyl estradiol (EE) on 3,2'-dimethyl-4-aminobiphenyl (DMAB)-prostate carcinogenesis in F344 rats have been investigated by administration of each hormone individually or either androgen in combination with EE. DMAB plus TP resulted in induction of invasive adenocarcinomas in the lateral and anterior prostate and seminal vesicles, as shown in a previous study, whereas DHT did not exhibit any positive modulation potential. Administration of EE together with TP produced increased carcinoma incidence in the lateral and anterior prostate, from 17 and 28% to 70% and 80%, respectively. Dorsal prostate tumors, all of the non-invasive in situ type, were also evident in 30% of animals receiving both TP and EE. Rats treated with DHT plus EE, however, did not develop tumors. Our experiment thus provides evidence that estrogen may play an important role in prostate carcinogenesis.

Enhancement of phorbol ester-induced production of tumor necrosis factor alpha by thalidomide

The effect of thalidomide [racemic (DL-) form and optically pure (D- and L-) forms] on tumor necrosis factor (TNF) alpha production by human leukemia cell lines (HL-60, K562 and U937) stimulated with 12-O-tetradecanoylphorbol-13-acetate (TPA) was investigated. Though thalidomide has been regarded as a specific inhibitor of TNF-alpha production, our study indicated that all forms of thalidomide enhanced (but did not inhibit) the TPA-induced TNF-alpha production by the human leukemia cell lines investigated. The effects of thalidomide on TNF-alpha production might be cell type-specific.

Tumor necrosis factor is markedly synergistic with interleukin 1 and interferon-gamma in stimulating the production of nerve growth factor in fibroblasts

A possible interaction between tumor necrosis factor-alpha (TNF) and other cytokines/growth factors in stimulating the production of nerve growth factor (NGF) in Swiss 3T3 cells was studied. TNF's stimulatory activity on fibroblast NGF production was synergized by interleukin-1 alpha (IL-1 alpha), IL-1 beta and interferon-gamma (IFN-gamma), but was antagonized by transforming growth factor-beta (TGF-beta). The most remarkable synergistic effect was observed between TNF and IL-1 alpha/beta; as little as 0.003 ng/ml of IL-1 beta markedly enhanced TNF's stimulatory activity on NGF production in the cells. These findings reinforce the idea that TNF, in concert with IL-1 alpha/beta, plays an essential role in regulating the regeneration of peripheral nerves following injury through an indirect mechanism by which it stimulates NGF production in fibroblasts.

Antiviral effect of lymphoblastoid interferon-alpha on hepatitis C virus in patients with chronic hepatitis type C

To study the antiviral effect of lymphoblastoid alpha interferon (IFN) on hepatitis C virus (HCV) we conducted a randomized, controlled trial on 80 patients with chronic hepatitis C using three different doses. Patients were randomly assigned to treatment with 1, 3 or 6 million units of lymphoblastoid IFN-alpha daily for 2 weeks. To assess the antiviral effect of IFN, the amount of HCV present in the serum was estimated by competitive nested polymerase chain reaction (PCR) before and after 2 weeks of treatment. The multiple logistic analysis was used to evaluate factors associated with virus clearance, adjusting the imbalance in predictive factors among patients. Hepatitis C virus became negative as assessed by nested PCR after therapy in 26, 50 and 63% of patients receiving 1, 3 and 6 mega units, respectively. Hepatitis C virus was cleared more often in patients having initially low (< 10(5)/mL) amounts of virus. No significant decrease in the amount of virus was observed in the untreated, control group. Patients without bridging fibrosis in liver histology and with HCV genotypes other than K1 (type II) tended to respond well. These results indicate that lymphoblastoid IFN-alpha suppresses HCV in a dose dependent manner. Higher initial virus amounts, bridging fibrosis and genotype K1 were factors associated with poor response.

Divergent expression of EtA and EtB receptors in response to cyclosporine in mesangial cells

We examined the effects of cyclosporine (Cy) on preproendothelin-1 (prepro Et-1) and both Et receptors, A-type (EtA) and B-type (EtB), in rat glomerular mesangial cells. Cy at 10(-5) mol/L, the concentration relevant to tissue levels in vivo, increased mRNA for prepro Et-1 after both 1 and 3 hours to 183 +/- 14% (n = 8) and 147 +/- 12% (n = 9) of levels seen in control cells. A similar pattern was observed at a lower dose of Cy (10(-6) mol/L, the concentration relevant to plasma levels in vivo): at 1 hour, expression increased to 146 +/- 15% (n = 5); at 3 hours, expression was 159 +/- 25% (n = 8). Concomitant with these changes in expression of prepro Et-1 mRNA, the Et-1 protein nearly doubled at 3 hours. Both EtA and EtB mRNA were expressed in unstimulated mesangial cells and were affected differently by Cy. Little change was observed in the EtA mRNA. In contrast, EtB mRNA increased with Cy (10(-5) mol/L) up to 129 +/- 8% (n = 6) at 1 hour and 265 +/- 62% (n = 3) at 3 hours. A similar effect was seen with the lower dose of Cy: EtB expression increased to 129 +/- 9% (n = 6) of control value at 1 hour and 253 +/- 74% (n = 4) at 3 hours. These results indicate that Cy enhances expression of mRNA for prepro Et-1 and production of mature Et-1 by glomerular mesangial cells. Further, Cy has differential effects on EtA and EtB, affecting EtA minimally while markedly increasing the expression of EtB. These results constitute the first demonstration that Et receptor subtypes are modulated in a pathophysiological setting. The divergent modulation of EtA and EtB raises the possibility that there are differences in contribution of each of the receptor subtypes to pathophysiological mechanisms of Cy toxicity.

Effects of freezing of bovine preimplantation embryos derived from oocytes fertilized in vitro on survival of their inner cell mass cells

The morphology of the inner cell mass (ICM) cells and the proportion of dead ICM cells in frozen-thawed bovine preimplantation embryos were investigated by differential fluorochrome staining. Embryos at the blastocyst stage of development were frozen and thawed by two different techniques (three-step and one-step) in two different basic salt solutions (PBS and TCM 199) containing 1.36M glycerol. After thawing and glycerol removal, embryos were co-cultured in a cumulus cells monolayer in TCM 199 for 48 hr (morula) or 24 hr (blastocysts). Differential cell counts of the ICM and trophectoderm were then done using differential fluorochrome staining. Overall, there was no significant difference in the viability of embryos frozen in the two basic salt solutions. Low proportions of dead ICM cells were observed in embryos frozen at the morula stage in both PBS (19.1%) or TCM 199 (18.0%). However, blastocyst stage embryos frozen by the three-step technique had a higher (P < 0.05) proportion of dead ICM cells in TCM 199 (37.7%) than in PBS (18.2%). Blastocysts frozen by the one-step technique had a higher (P < 0.05) proportion of dead ICM cells (42.2%) than those frozen by the three-step technique (18.2%), regardless of basic salt solutions. Results indicate that freezing and thawing damages ICM cells in morphologically normal embryos and that the degree of damage depended on the basic salt solution and the freezing method.

Site specific regulation in the kidney of endothelin and its receptor subtypes by cyclosporine

Endothelin (Et) has been suggested by us and others to play a role in glomerular dysfunction that characterizes cyclosporine (Cs)-associated nephrotoxicity. Since Et exerts its actions through at least two receptor subtypes, and because these receptor subtypes have particular distributions in the renal parenchyma, we investigated changes in mRNA expression for Et and its receptor subtypes in glomeruli and medulla of rats treated with Cs. Polymerase chain reaction coupled with reverse transcription (RT-PCR) method was used to assess prepro-Et-1, type A (EtA) and type B (EtB) receptor mRNA at 1, 3, 6, and 24 hours after Cs (20 mg/kg body wt i.v.). Results were normalized to the expression of beta-actin as an internal standard. Compared with control rats, glomerular mRNA expression for prepro-Et-1 was not affected by Cs. Similarly, Cs did not significantly change the glomerular mRNA expression of either EtA or EtB receptor subtypes. By contrast, in the medulla there was a marked and persistent increase in the expression for prepro-Et-1 and the EtB receptor subtype: prepro-Et-1 at 1, 3, 6, and 24 hours was 336 +/- 61, 295 +/- 65, 339 +/- 73, 440 +/- 123% of controls, respectively (P < 0.05 compared with controls at each time point). The EtB receptor mRNA at 1, 3, 6, 24 hours was 164 +/- 22, 157 +/- 15, 148 +/- 14, 116 +/- 18% (compared with controls, P < 0.01 at 3 hr and P < 0.05 at 1 and 6 hr), while the mRNA expression for EtA was not affected by Cs treatment.(ABSTRACT TRUNCATED AT 250 WORDS)