[Relationship between distortion product otoacoustic emissions and frequency discrimination in normal-hearing and hearing-impaired ears]

Distortion product otoacoustic emissions (DPOAEs) and frequency difference limens (FDLs) were recorded in each of 10 ears with a sensorineural hearing loss of the dip-type and with sharp-cut high frequency hearing loss. DPOAEs were recorded with an Otodynamic Analyser ILO92 (ver. 1.35) at a f2/f1 frequency ratio 1.2. The distortion-product level (DP level) at 2f1-f2 was measured at 11 points at f2 frequencies between 696 Hz and 6348 Hz and at 26 points at f2 frequencies between 708 Hz and 6165 Hz in the dip-typed and the sharp-cut high frequency hearing loss patients, respectively. The stimulus intensity of primaries was fixed at 70 dBSPL at L and 60 dBSPL at L2. Graphs of DP levels versus f2 frequency (DP-gram) were plotted. FDLs were measured to use "same" or "different" method. Estimates of FDL were obtained at the same frequencies at 11 points from 696 Hz to 6348 Hz as f2 of DPOAE and at sensation levels from 25 dB to 35 dB. As a control, DPOAEs and FDLs were measured in 30 and 50 normal young adults, respectively. The following results ane conclusions were obtained: 1. The DP-gram obtained from 30 normal-hearing ears showed two peaks, at around 1.5 kHz and 5 kHz. 2. DP-grams were similar to Békésy audiograms in frequency specificity in 20 hearing-impaired ears. 3. DP-grams with a f2 abscissa were more similar in shape to Békésy audiograms than DP-grams with a (f1 x f2)1/2 abscissa. 4. The FDLs obtained in 50 normal-hearing ears showed an approximately linear increase in log delta F versus logarithmic frequency of stimuli up to 5 kHz. 5. FDLs at the DPOAE frequencies below the noise level in 20 hearing-impaired ears were greater than two standard deviations from the value for normal-hearing ears. 6. A significant correlation between DPOAEs and hearing threshold levels (HTLs) was found in the 20 ears of the hearing impaired. 7. Significant correlations between DPOAEs and FDL ratios (FDLs in hearing-impaired ears divided by FDLs in normal-hearing ears) were found in these 20 ears, although the correlation coefficient was not as high in the 10 ears with a sharp-cut high frequency hearing loss as in the 10 ears with the dip-typed hearing loss. These results suggested that DPOAEs might serve as an objective indicator of frequency discrimination. Care should be taken, however not to generalize this suggestion to all kinds of hearing loss patients.

[Invasive amebiasis at an institution for the mentally retarded in Shizuoka Prefecture]

Amebiasis caused by Entamoeba histolytica at an institution for mentally retarded in Shizuoka Prefecture is reported. Five of the 50 patients showed E. histolytica cysts in their stools and 4 were positive serologically. The polymerase chain reaction and restriction fragment length polymorphism revealed that the isolates were pathogenic-type E. histolytica. Epidemiological analysis revealed that the amebic infection was caused by the abnormal behavior of mentally retarded patients. Administration of diloxanide furoate and metronidazole for cyst-carriers eliminated cysts from the stool and lowered the antibody titer.

Intramural metastases from thoracic esophageal cancer: local indicators of advanced disease

The patterns of tumor spread and long-term survival of patients with (n = 54) and without (n = 270) intramural metastasis from esophageal cancer were investigated after either extended radical (n = 155) or less radical (n = 169) esophagectomy. The purpose was to evaluate whether extended radical esophagectomy has an impact on the long-term survival of patients with intramural metastases from the disease. The patients with intramural metastasis had significantly larger primary tumors (p < 0.01) and more frequent T4 tumors (p < 0.001), stage IV disease (p < 0.05), lymphatic invasion (p < 0.05), and lymph node metastasis (p < 0.01) than did those without intramural metastasis. The survival rates of patients with intramural metastases were significantly worse than those of patients without intramural metastases after resection (p < 0.001). No patient with intramural metastases survived more than 4 years after either extended or less radical esophagectomy, and there was no significant difference between the two survival curves. Therefore intramural metastases should be considered local indicators of advanced esophageal cancer, and radical esophagectomy may not be indicated for patients with intramural metastasis from the disease.

Electromagnetic interference of an external temporary pacemaker during maxillofacial and neck surgery

Indirect inhibition of an external temporary pacemaker by electrocautery is reported. Before induction of general anesthesia for a hemimaxillectomy and radical neck dissection, a temporary transvenous demand pacemaker was inserted into a patient with a first-degree atrioventricular block and complete left bundle-branch block. Although we provided common precautions to prevent electromagnetic interference by electrocautery, pacing failure still occurred. It was thought to be caused by current dispersing from the active electrocautery electrode. This case suggests that occipital placement of the electrocautery ground plate should be considered during neck surgery in a patient requiring a temporary pacemaker.

Different rifampicin inactivation mechanisms in Nocardia and related taxa

Mycolic acid-containing bacteria inactivate rifampicin in a variety of ways such as glucosylation, ribosylation, phosphorylation and decolorization. These inactivations were found to be a species-specific phenomena in Nocardia and related taxa. Gordona, Tsukamurella and fast-growing Mycobacterium modified rifampicin by ribosylation of the 23-OH group of the antibiotic. Such ribosylation was not observed in Rhodococcus and Corynebacterium, but phosphorylation of the 21-OH group of rifampicin was observed in one strain of Rhodococcus. Nocardia modified the antibiotic by glucosylation (23-OH group) and phosphorylation, but ribosylation was not observed.

Impaired synaptic functions with aging as characterized by decreased calcium influx and acetylcholine release

Age-related alterations of presynaptic functions were studied in terms of acetylcholine (ACh) synthesis and release using synaptosomes isolated from mouse brain cortices. The following three findings were obtained: 1) Choline acetyltransferase activity and ACh production rate remained constant throughout all ages tested. This observation, obtained with synaptosomes, was not consistent with data reported for brain slices (Gibson GE, Peterson C: J Neurochem 37:978-984, 1981). Various conditions, such as low glucose or membrane depolarization, modulated ACh synthesis to similar extents in young and aged synaptosomes. 2) Depolarization-induced release of ACh from synaptosomes significantly decreased in the senescent stage. The fraction of ACh released from aged synaptosomes was less than that released from young synaptosomes, although the ACh contents in the synaptosomes did not change with age. 3) Calcium influx induced by depolarization was lower in the synaptosomal preparations from aged mice than in those from young mice. A strong positive correlation was observed between the amounts of ACh released and the increased calcium levels when the data for all preparations, both from young and aged mice, were plotted. This indicates that diminished calcium influx may cause the reduced ACh release by aged synapses. The present study provides evidence for an age-related decrease in presynaptic functions, that is, a reduction in calcium influx via voltage-dependent calcium channels followed by a decreased ACh release from synapses despite an abundance of ACh within the synapses.

[Serial magnetic resonance imaging of acute disseminated encephalomyelitis, including evaluation of the contrast-enhancing effect of lesions by Gd-DTPA]

Many papers on the MR features of acute disseminated encephalomyelitis (ADEM) have been published, but only a few described contrast-enhanced MRI for this disease. In this study, we analyzed serial changes in MR features and the contrast-enhancing effect on lesions in five patients (5 men, 4-19 years old) discharged with the final diagnosis of ADEM. Hyperintense lesions in brain/spinal cord were demonstrated on T2-weighted MR images in all cases, but not all lesions were enhanced by Gd-DTPA. In the follow-up study many lesions disappeared, but some lesions were enlarged and some new lesions were found. These findings suggest that, although ADEM is clinically monophasic, some cases may progress with the coexistence of reducing, vanishing, and new lesions. Some clinically acute lesions were not enhanced. This might be explained by the following reasons ; lesions on various phases coexist ; the damage to the blood-brain barrier in the lesions is of different degrees even if it is on the same phase ; the duration of acute phase activity is short. Additionally, some hyperintense lesions remained for a long time on T2-weighted images in spite of the absence of clinical manifestation. That hyperintense area might reflect edema caused by incomplete repair of the blood-brain barrier. From our evaluation of these five cases, MRI is not useful for the diagnosis and follow-up study of ADEM.

Disposition of CS-670, a novel nonsteroidal anit-inflammatory drug, and its metabolites in healthy human volunteers

CS-670, a novel nonsteroidal anti-inflammatory drug, is a racemic prodrug. Plasma concentrations and urinary excretion of CS-670 and its metabolites were determined in experimental subjects after oral administration at a single 120 mg dose. CS-670 and four metabolites, the saturated ketone (M-A), unsaturated-alcohol (M-B), cis-alcohol (M-C), and trans-alcohol (M-D), were quantitated by GC-MS. The major metabolites in human plasma were M-B, M-C, and M-D and their terminal half-lives (t1/2) were 0.9, 2.6, and 1.2 h, respectively. The total recovery in the urine was 26% of the dose, but unchanged CS-670 accounted for less than 2% over a 48 h period. In addition, the absolute configurations of the metabolites were examined by HPLC after derivatization with chiral reagents. It was found that the configuration of the propionic acid moiety of the metabolites, M-B, M-C, and M-D, in human plasma, was rapidly inverted from (-)-(R) to the (+)-(S) configuration in stereoselective biotransformation. Furthermore, the configurations of the 1'- and 2'-carbons of M-C and M-D, were found to be (1'R, 2'S) and (1'R, 2'S), respectively. These results show that CS-670 is readily biotransformed by chiral inversion of the 2-arylpropionic acid moiety and stereoselective reduction of the alpha, beta-unsaturated ketone moiety in humans.

Different sensitivity to streptolysin-O of cells in macrophage lineage

We have surveyed the sensitivity of cells in macrophage lineage to Streptolysin-O (SLO). SLO had cytotoxic activity on immature myeloid cell lines such as M1 and WEHI-3BD+. SLO was toxic to the cells after a 2-hr incubation. However, mature macrophage cell lines such as A640-BB-2, J774, and P388D1 were not sensitive to the same dose of SLO. After M1 cells were treated with leukemia inhibitory factor (LIF), a differentiation-inducer to macrophage, these cells became insensitive to SLO in one day. This cytotoxic action of SLO was inhibited by pretreatment with anti-Streptolysin-O antibody or cholesterol. These results indicate that SLO has different effects on macrophage lineage.

Structure-activity relationships of synthetic saponins

The haemolytic and antifungal activities of synthetic diosgenyl, tigogenyl, hecogenyl, methyl oleanolate, methyl ursolate and methyl glycyrrhetinate glycosides were compared with each other. Both activities of the steroid glycosides were generally parallel to each other, while almost all haemolytic triterpenoid glycosides showed no antifungal activity.

Structure-activity relationships of synthetic cardiac glycosides

The antiviral, cytotoxic and anti-ATPase activities of 14 synthetic bufalyl glycosides were compared with each other. Among these glycosides, the activities of the gentiobioside and the melibioside were much weaker than those of the others. On the other hand, these three activities were found to be highly correlated with each other. These were parallel to the case of the digitoxigenyl glycosides in our previous paper.

[Role of MR imaging in the differentiation of benign and nonbenign intracranial meningiomas: the utility of contrast-enhanced T1-weighted images]

The purpose of this study was to develop useful criteria for distinguishing nonbenign (atypical and malignant) primary intracranial meningiomas from their benign counterparts by using magnetic resonance imaging (MRI). To determine useful MRI findings for this purpose, 12 benign and five nonbenign meningiomas were retrospectively evaluated according to the following items: 1) tumor signal intensity on plain T1-, T2- and proton density-weighted images, 2) degree of perifocal edema on T2-weighted images, 3) morphology of the tumor margin on contrast-enhanced T1-weighted images, 4) presence of irregular nodule and/or mushrooming pattern on contrast-enhanced T1-weighted images, 5) homogeneity of the tumor on contrast-enhanced T1-weighted images and 6) presence of marked skull destruction. Markedly irregular tumor margin, presence of irregular nodule and/or mushrooming pattern and markedly inhomogeneous enhancing pattern were significantly more frequent in nonbenign meningiomas. We defined these three MRI findings as nonbenign findings, and tried to categorize meningiomas by the number of nonbenign findings. It was found that 10 meningiomas with no or one nonbenign finding were benign lesions, of four meningiomas with two nonbenign findings two were benign lesions and two were nonbenign lesions, and three meningiomas with three nonbenign findings were nonbenign lesions. The two benign meningiomas with two nonbenign findings were accompanied by increased mitotic activity or brain invasion. Contrast-enhanced T1-weighted images were considered very useful in distinguishing benign and nonbenign meningiomas.

Platelet-activating factor acetylhydrolase activity in human follicular fluid

Platelet-activating factor (PAF) has been implicated in a number of reproductive processes ranging from ovulation to parturition. To examine the role of PAF in the human periovulatory processes, the PAF-acetylhydrolase (PAF-AH) activity was assayed in the follicular fluid (FF) obtained in conjunction with the in vitro fertilization and embryo transfer (IVF-ET) procedure and the activity related to oocyte maturation. The PAF-AH activity was also related to the concentrations of estradiol (E2) and progesterone (P) in FF. PAF-AH activity was significantly lower in the FFs obtained from follicles of more than 20 mm in diameter. The enzyme activity was significantly lower in the FFs of patients with a successful outcome of their pregnancies. E2 concentrations were negatively correlated with PAF-AH activities in the FFs. No correlation was found between the PAF-AH activity and concentration of P in the FF. Significantly more mature oocytes were recovered in the group who subsequently become pregnant compared to the non-pregnant group. It is suggested that PAF may be increased following follicular maturation. The increase in PAF may contribute to oocyte maturation and to the successful outcome of pregnancy following fertilization. An additional function of the increased PAF in FF may also be the stimulation of the contraction of smooth muscle in the ovary, thereby assisting the extrusion of the oocyte cumulus cell mass and signaling the completion of ovulation.

Involvement of neurohumoral factors in the pressor mechanism of NG-nitro-L-arginine

The mechanism of the NG-nitro-L-arginine (L-NNA)-induced pressor response was examined in pentobarbital-anesthetized dogs. The pressor effect of L-NNA (50 mg/kg, i.v.) was significantly and equally diminished by pretreatment with either hexamethonium (25 mg/kg, i.v.) or phentolamine (5 mg/kg, i.v.). The intracisternal administration of L-NNA (1 mg/kg), which did not cause changes in cardiovascular parameters when administered systemically, produced a significant pressor response and tachycardia. Furthermore, significant suppression of L-NNA-induced pressor responses was observed after treatment of dogs with captopril (5 mg/kg, i.v.) or a non-peptide angiotensin II receptor antagonist, losartan (10 mg/kg, i.v.), or bilateral occlusion of renal veins. The inhibitory effects of hexamethonium and losartan were additive. These results suggest that, in addition to vasoconstriction due to the inhibition of endothelial nitric oxide production, increased activity of the sympathetic nervous and renin-angiotensin systems contributes significantly to the development of pressor responses produced by the intravenous injection of L-NNA in anesthetized dogs.

Induction of apoptosis in cultured retinoblastoma cells by the protein phosphatase inhibitor, okadaic acid

The induction of apoptosis in cultured retinoblastoma cells by diverse drugs was examined by analyzing DNA fragmentation, a hallmark of apoptosis. First, the ability of six retinoblastoma cell lines to undergo apoptosis was surveyed using etoposide (30 micrograms/ml, 20 h exposure). The NCC-RbC-60 cell line, established in this laboratory showed DNA fragmentation clearly, whereas the other cell lines tested, including the representative retinoblastoma cell line, Y-79, did not show distinct DNA fragmentation. Biochemical modulators, such as A23187, forskolin, retinoic acid, phorbol 12-myristate 13-acetate and okadaic acid, were examined to ascertain whether they could induce apoptosis in NCC-RbC-60 and Y-79 cells after exposure for 20 h. Only okadaic acid induced DNA fragmentation in all the retinoblastoma cell lines tested and it induced DNA fragmentation in Y-79 cells in a time- and concentration-dependent manner. Flow-cytometric analysis and microscopic examination revealed that Y-79 cells treated with okadaic acid for 24-48 h accumulated at the G2/M, especially M, phases, before undergoing DNA fragmentation. Other mitotic poisons, nocodazole, colcemid and taxol, also induced apoptosis in Y-79 cells. In the K1034 cell line, established from non-malignant retinal pigmented epithelium, okadaic acid failed to induce both G2/M arrest and DNA fragmentation. These findings suggest that okadaic-acid-induced apoptosis occurs as a result of metaphase arrest.

[Evaluation of sexual function in adults with myelomeningocele]

In the present study, sexual function in 46 patients (22 males and 24 females) with myelomeningocele was assessed by a questionnaire study. The mean age of the patients was 24.0 +/- 9.6 years (with an age range of 18 to 50) for male patients and 25.2 +/- 6.2 years (with an age range of 18 to 42) for female patients. Having interest in the opposite sex and sexual desire were evident in 95% and 100% of male patients, and 83% and 75% of female patients, respectively. In male patients, erection was achieved in 95% by visual stimulation and in 86% by tactile stimulation. However, only 27% of the patients with erectility were satisfied with penile rigidity. Ejaculation and orgasm was noted in 67%. Orgasm was frequently seen in patients whose external sphincter activity was maintained. The age and the degree of lower extremity paralysis according to Sharrard classification were not significantly correlated with sexual function. In female patients, menstruation was regular in 95%, vaginal secrete was adequate in 88%, but only 19% of the patients felt ecstacy around perineal lesion at coital movements. In female patients, sexual function was not correlated with the age, the degree of lower extremity paralysis and detrusor activity-sphincter activity. Although most patients had sexual desire, only 18% of the males, and 33% of the females, had sexual intercourse activities. It appears, therefore, that these patients need to be given appropriate advice.

Detection of hepatitis C virus RNA in hepatocellular carcinoma by in situ hybridization

BACKGROUND

Hepatocellular carcinoma frequently is associated with chronic hepatitis C virus (HCV) infection. The presence of HCV in hepatocellular carcinoma has been detected by reverse-transcription polymerase chain reaction of antigenomic HCV RNA, a tissue-specific replicative form of the virus. Now, however, this method of detecting the presence of HCV has been invalidated by reports of antigenomic RNA in the blood or in peripheral blood mononuclear cells.

METHODS

In situ hybridization of HCV RNA was conducted with digoxigenin-labeled cDNA from the core region on surgical specimens of noncancerous and cancerous areas from 12 patients with chronic hepatitis C with or without cirrhosis associated with hepatocellular carcinoma. Several control experiments were also performed, including RNase digestion before hybridization, hybridization with the use of a negative control, and immunohistochemical staining of HCV-core protein.

RESULTS

The in situ hybridization showed positive signals both in noncancerous and cancerous areas of the liver tissue in eight cases. Positive signals were confined to neoplastic cells and nonneoplastic hepatocytes. There were fewer HCV-positive cells in the cancerous area than in the surrounding noncancerous area.

CONCLUSIONS

In situ detection of HCV presents direct evidence of HCV infection in the neoplastic cells of hepatocellular carcinoma and suggests that neoplastic cells may lose their affinity for HCV in the course of malignant transformation.

How to fashion a TRAM flap in the presence of a lower midline laparotomy scar. An experimental study in rats

The transverse rectus abdominis musculocutaneous (TRAM) flap cannot be used successfully in a patient with a pre-existing midline abdominal scar because the area distal to the scar undergoes circulatory failure leading to necrosis. To investigate the usefulness of various procedures to improve the circulation in such a flap, we studied the percentage area survival of experimental abdominal island flaps in five groups of rats with pre-existing midline scar treated by different procedures which depended on the source of blood used to supply the flap (control, arterial, venous, arteriovenous shunt, and delayed, n = 5 in each group). All flaps in the arterial group survived completely. The mean (SEM) percentages of the flaps that survived in the control (17(2)%) and venous (17(1)%) groups were significantly lower than those in the delayed (31(2)%) and arteriovenous shunt (67(6)%) groups (all, p < 0.01). These results indicate that preservation of arterial inflow by arterial anastomosis or arteriovenous shunt on the opposite side is important if the flap is to survive across the midline scar. Preservation of the vein in the opposite flap is not essential, because venous outflow is supposed to drain through the midline scar into the epigastric vein of the pedicle without any signs of congestion.

Platelet-activating factor-acetylhydrolase activity in follicular fluid of patients undergoing in vitro fertilization and embryo transfer

OBJECTIVE

To examine the role of platelet-activating factor (PAF) metabolism in the periovulatory processes.

DESIGN

The PAF-acetylhydrolase activity in the follicular fluid (FF) obtained in conjunction with IVF-ET procedure was assayed and its activity was related to oocyte maturation. The PAF-acetylhydrolase activity also was related to the concentration of various ovarian hormones.

SETTING

All patients were managed and treated at Oita Medical University Hospital, Oita, Japan.

PATIENTS

The study concerned 30 women between 28 and 36 years of age with tubal infertility.

MAIN OUTCOME MEASURE

The activity of PAF-acetylhydrolase in FF was assayed as well as E2 and P. Oocyte maturation also was evaluated.

RESULTS

Platelet-activating factor-acetylhydrolase activity was decreased significantly in the FFs of patients with a successful outcome of their pregnancies compared with the nonsuccessful group. Estradiol levels were negatively correlated with PAF-acetylhydrolase activities in the FFs. No correlation was found between the PAF-acetylhydrolase activity and P concentration in the FF. Significantly more mature and less immature oocytes were recovered in the group who subsequently became pregnant compared with the nonpregnant group.

CONCLUSIONS

It is suggested that the decrease in PAF-acetylhydrolase activity may result in an increase of PAF in the FFs, which in turn may contribute to a successful pregnancy. The determination of PAF-acetylhydrolase activity in FF may serve as a prognostic marker for the evaluation of oocytes that are utilized in IVF-ET procedure.

[Lysosomal hydrolases have specific conformational domains for acquisition of mannose-6-phosphate]

In many mammalian cells, the transport of newly synthesized or externally added lysosomal enzymes to lysosomes is depend on their specific recognition by receptors for mannose 6-phosphate (Man-6-P). The physiological importance of this pathway was confirmed by the finding that fibroblasts from patients with mucolipidosis type II (ML-II ; I - cell disease) fail to phosphorylate mannose residues on their newly synthesized lysosomal enzymes, which results in the secretion of a large percentage of their acid hydrolases into the culture medium. However, lysosomal enzymes themselves do not contain the any consensus amino acid sequences for acquiring the Man-6-P recognition marker. Kornfeld et al revealed using cathepsin D-pepsinogen chimera proteins that UDP-N-acetylglucosamine: lysosomal enzyme N-acetylglucosamine-1-phosphotransferase recognizes not only oligosaccharides but also the three-dimensional structure of the lysosomal enzymes when transfers N-acetylglucosamine-1-phosphate to lysosomal acid hydrolases.

Synchronous cancers of the esophagus and the ampulla of Vater after distal gastrectomy: successful removal of the esophagus, gastric remnant, duodenum, and pancreatic head

A case of synchronous squamous cell carcinoma of the esophagus and adenocarcinoma of the ampulla of Vater after previous gastrectomy is presented. The coexistence of these two lesions has never been reported in the English literature. We performed a subtotal esophagectomy, total residual gastrectomy, and pancreaticoduodenectomy with lymph node dissection in a one-stage procedure. An operation of this magnitude could be safely performed with attention to meticulous surgical technique and intensive postoperative care. Histological examination of the ampulla lesion showed adenocarcinoma with Paneth-cell differentiation. This is a rare lesion, and a review of the literature revealed only one other case. Neoplastic Paneth cells were also found in lymph node metastasis that originated from the ampulla tumor. This case confirms that cells with Paneth-cell differentiation can be a significant component in invasive carcinoma.