Chronic toxicity of thiabendazole (TBZ) in CD-1 mice

Male and female CD-1 mice (50 mice per group) were administered thiabendazole (TBZ) in diet at levels of 0 (control), 0.031, 0.125 and 0.5% for 78 weeks. A life time study was terminated after 78 weeks due to enhanced strain specific mortality. There were no significant differences in mortality between the control and treated groups. Mean body weights of high-dose groups showed significant decreases compared with the controls. The bladder weights of male and female mice of the 0.5% group were significantly higher than those of the control mice. Gross findings in treated mice included the renal atrophy, hydronephrosis, calculi in renal pelvis and/or bladder and ovarian atrophy. Microscopic findings in the kidneys of treated mice included the nephrosis, hydronephrosis or hyperplasia of transitional epithelium of renal pelvis or papilla. In the bladder of treated mice, hyperplasia or squamous metaplasia of transitional epithelium and one transitional cell papilloma were observed. Dose-dependent decreases in the incidence of spontaneous lesion in the male or female reproductive system were recognized. It is concluded that TBZ is not carcinogenic to CD-1 mice of both sexes. However, caution should be exercised in the long-term application of high TBZ doses.

Goitrogenic effects of green tea extract catechins by dietary administration in rats

The effects of green tea extract catechins on the rat thyroid were examined in a 13-week feeding study and subsequent 2-,4- and 8-week studies. Commercially available polyphenon-60 (P-60) which contains green tea extract catechins at 66.2% was used as a source of catechins. A basic diet containing different concentrations of P-60 was used for experiments. In the 13-week study, 10 rats of each sex were administered diets containing P-60 at 0 (control), 0.625, 1.25, 2.5 and 5.0%. Goiters were observed in the 13-week test. The mean thyroid weight of rats fed a diet containing 5.0% of P-60 (5.0% group) significantly increased to 444% of the control in males and to 304% of the control in females. Histological examinations of the thyroid of the 5.0% group revealed marked hypertrophy and/or hyperplasia of the follicles, some with depletion of colloid and some with rich colloid, and formation of a fibrous capsule. Slight hypertrophy of follicular cells was observed in male rats fed a diet containing 1.25% of P-60 (1.25% group) and female rats fed a diet containing 2.5% of P-60 (2.5% group). Degree and incidence of thyroid lesions were higher in males than in females in the 1.25, 2.5 and 5.0% groups. In the 2-8-week studies, five rats of each sex were given diets containing 0 (control) and 5.0% of P-60. In the 5.0% group, the mean thyroid weight in males significantly increased to 161% of the control as early as 2 weeks and increased to 357% of the control at 8 weeks. Histologically, these goiters were also associated with follicular cell hypertrophy/hyperplasia as in the 13-week study. The degree and incidence of thyroid lesions were higher in males than in females. These results indicate that dietary administration of the green tea extract catechins at high doses induced goiters in rats, and this may be due to antithyroid effects of catechins. In the 13-week study, the no-observed effect level (NOEL) of green tea extract catechins for F344 rats based on histological changes of the thyroid was considered to be 0.625% in males and 1.25% in females in the diet, respectively.

Thiabendazole induces urinary tract toxicity in male ICR mice

Male ICR mice were administered thiabendazole (TBZ) in the diet at concentration of 0 (control), 0.8, 1.2 and 1.6% for 44 weeks. The mortality was 10, 6, 40 or 90% in control, 0.8, 1.2 or 1.6% TBZ group, respectively. In dead mice, the gross findings included the abnormalities of kidney such as atrophy, hydronephrosis or swelling in 2, 67, 95 or 96% of the 0, 0.8, 1.2 or 1.6% TBZ group, respectively. In surviving mice at the end of study, the right kidney weight of treated groups was significantly lower than that of control group. The urinary bladder weight of treated groups was significantly higher than that of control group. Gross findings in treated mice included the renal atrophy, hydronephrosis, calculi in renal pelvis or urinary bladder and thickening of the bladder wall. Microscopic findings in the kidneys of treated mice included nephrosis, hydronephrosis and hyperplasia of transitional epithelium of renal pelvis and/or papilla. In the urinary bladder, hyperplasia or squamous metaplasia of transitional epithelium were found in treated mice. Administration of TBZ in the diet for 44 weeks results in nephrosis and calculus formation in the renal pelvis and urinary bladder of male ICR mice, and is associated with hyperplasia of transitional epithelium of renal pelvis or urinary bladder.

Teratogenicity of thujaplicin in ICR mice

Beta-thujaplicin (TP) was studied by in vitro and in vivo tests for teratogenicity using ICR mice. In the in vitro study, TP (0, 3.125, 6.25, 12.5 microg/ml medium) dissolved in dimethyl sulfoxide (DMSO) was administered to cultured embryos on 9 day of gestation. After 24 hr of exposure to TP, the embryos were examined for developmental parameters and external anomalies. Growth retardation and embryos with facial dysplasia or hydrocyst of the tail tip were observed among the embryos given 12.5 microg/ml. In the in vivo study, TP (0, 420, 560, 750 or 1000 mg/kg) dissolved in olive oil was administered orally to pregnant mice on day 9 of gestation. All foetuses were removed from the uterus on day 18 of gestation, and were examined for external and skeletal anomalies. Various types of malformations were observed in the mice given 560 mg/kg or more. The number of litters having foetuses with external or skeletal anomalies increased in proportion to the dose of TP. The regression lines of Y (probit response) on X (log dose) for external anomalies was Y = 4.87X-8.43 . The 1% effective dose (ED1) for the malformation was 190 mg/kg. The present study shows that TP has teratogenic effects on mice.

Human and mouse ISLR (immunoglobulin superfamily containing leucine-rich repeat) genes: genomic structure and tissue expression

We have previously reported a transcript of the novel gene for human immunoglobulin superfamily containing leucine-rich repeat (ISLR). By additional screening of a human retina cDNA library, we isolated another type of transcript with a 5' UTR different from that of the previously reported type. Genomic sequencing of the ISLR gene revealed that these two types of transcripts, ISLR-1 and ISLR-2, originated from the same gene but are composed of different first exons. Because the entire open reading frame is contained in the second exon, these two transcripts produce the same protein. Radiation hybrid mapping linked the ISLR gene to AFM248yh1, which is in the critical region of Bardet-Biedl syndrome type 4 (BBS4) on chromosome 15. Sequence analysis of the ISLR gene in five BBS4 patients, however, showed no mutations, although a few polymorphic changes were detected. Cloning of the mouse homolog of ISLR (Islr) revealed that the predicted protein consists of 428 amino acids, 86% of which are identical to those of ISLR. The Islr gene was expressed in various mouse tissues, including retina, in which Islr mRNA was detected in the ganglion cell layer, the inner nuclear layer, and the inner segment of the photoreceptor.

[Efficacy of mupirocin in eradicating methicillin-resistant Staphylococcus aureus from nasal discharge in carrying cardiovascular surgical patients]

Methicillin-resistant Staphylococcus aureus from nasal discharge was identified in 37 (2.5%) cardiovascular patients operated between 1995 and 1997; 25 male and 12 female, ranging from 1 to 83 years (mean 63); 2 were excluded because of Arbekacin or Isodine-gel treatment. The first 17 were treated with Vancomycin inhalation (V group) and eradication was considered to have been achieved when 3 consecutive negative cultures were obtained; the subsequent 18 were treated with Mupirocin (M group) and eradication was determined by 1 negative culture. In post-eradication electively operated 13 V and 15 M, postoperative MRSA infection was observed in one M (wound infection); the interval from the first nasal culture to the operation was 68 +/- 58 in V and 32 +/- 12 days in M, respectively (p < 0.05). In the remaining 7 who had to undergo emergency surgery while waiting for eradication because of progression of symptoms (2 V) or prior to instituting treatment (2 V, and 3 M), postoperative MRSA infection was observed in 2 M (both pneumonia). No deaths from infection were observed. Though the time required for conversion of the nasal culture was longer in V (13 +/- 20) than in M (7 +/- 1 days) differences were not significant. Mupirocin is easier to use, eradication can be achieved generally within a week.

Plastic surgical reconstruction of left main coronary artery

OBJECTIVE(S)

To report the early and mid-term results of surgical plasty of the left main coronary artery in 12 patients operated upon between 1993 and 1997.

METHODS

The anterior approach was used in all patients. Saphenous vein (n = 4) of glutaraldehyde treated autologous pericardium (n = 8) were used as patch material. Additional coronary artery bypass grafting was performed in 7 patients, the first 3 as a safety back up, and for coexisting stenosis of other coronary branches not revascularized by the plastic procedure in the remaining 4.

RESULTS

Pathologic specimens of the left main coronary artery in 5 revealed atheroma in 3 and myxomatous intimal thickening in 2. The left main coronary artery was widely patent angiographically in all patients prior to discharge. Six patients consented to angiographic restudy 5-40 months after the procedure and revealed excellent results in 5. One patient upon whom autologous pericardial patch had been used underwent percutaneous coronary angioplasty for restenosis of the left main coronary artery and a new lesion of the proximal left anterior descending branch 5 months after the operation. There were no late deaths nor other cardiac events. All patients were in CCS class 1 at their last follow-up.

CONCLUSIONS

Surgical angioplasty of the left main coronary artery could be used to revascularize the left heart safely in patients with a discrete localized lesion of the left main coronary artery and is particularly useful in the face of unavailability of other conduits.

Cyanoglycosylation products of 17-O-acetyl-testosterone

17-O-Acetyl testosterone, which has no susceptible hydroxyl or carboxyl group for glycosylation, was glycosylated with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide in the presence of a mixed catalyst, Hg(CN)2 and HgBr2, in benzene-nitromethane. Reaction occurred on the alpha, beta-unsaturated ketone on the six-membered A-ring to give six 3-O-glycosides, each bearing a cyano group at the 3- or 5-position of the aglycon, and a 3-O-glycoside bearing a CONH2 group at the 3-position. Structural analyses of these products were carried out by various NMR (1H, 13C NMR, 1H-1H and 1H-13C COSY, HMBC, and DEPT), FABMS and X-ray analyses. The mechanisms of the formations of the products are discussed. It was determined that mercuric cyanide was essential as a catalyst for the progress of the cyanoglycosylation.

Mouse myocilin (Myoc) gene expression in ocular tissues

Human myocilin is identical to TIGR (trabecular meshwork inducible glucocorticoid response) which is responsible for the pathogenesis of juvenile-onset primary open angle glaucoma (GLCIA). We have isolated cDNA for mouse myocilin (Myoc) and investigated mouse myocilin gene expression in ocular tissues with in situ RNA hybridization. Hybridization signals were observed in the iris, ciliary body, trabecular meshwork, sclera, and retina in the mouse eye. The marked signals were seen in trabecular meshwork cells and the anterior portion of sclera. These findings suggest that myocilin mutation could affect the capacity of aqueous outflow and cause elevation of the intraocular pressure which is involved in the pathogenesis of glaucoma.

Homogeneity of kerato-epithelin codon 124 mutations in Japanese patients with either of two types of corneal stromal dystrophy

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[Emergent operation after percutaneous transluminal coronary rotational atherectomy (ROTABLATOR)]

Emergent operations were performed in seven patients after percutaneous transluminal coronary rotational atherectomy (PTCRA). The causes of the emergent operations were coronary rupture in three patients, acute coronary occlusion in two patients, perforation of the ascending aorta in one patient and impossible weaning from IABP in one patient. IABP was used preoperatively in all patients. Coronary artery bypass grafting was performed in all patients. Ruptured sites of the coronary arteries were closed and perforated site of the ascending aorta was repaired. Two patients died due to cardiac failure but five patients were recovered. Coronary artery rupture was main complication after PTCRA. It is important to recognize the difference between the complication after PTCRA and that after conventional PTCA.

Cloning of the cDNA for a new member of the immunoglobulin superfamily (ISLR) containing leucine-rich repeat (LRR)

We isolated cDNAs for a novel protein with a calculated molecular mass of 46 kDa, containing a leucine-rich repeat (LRR) with conserved flanking sequences and a C2-type immunoglobulin (Ig)-like domain. This novel protein was considered to be a new member of the Ig superfamily and was named ISLR (immunoglobulin superfamily containing LRR). These domains are known to be important for protein-protein interaction or cell adhesion, and therefore it is possible that the novel protein ISLR may also interact with other proteins or cells. Northern blot analysis showed the presence of a 2.4-kb transcript in various human tissues including retina, heart, skeletal muscle, prostate, ovary, small intestine, thyroid, adrenal cortex, testis, stomach, and spinal cord as well as fetal lung and fetal kidney. The ISLR gene was mapped on human chromosome 15q23-q24 by fluorescence in situ hybridization.

[Coronary artery bypass surgery in aged patients]

From January 1993 through December 1996, 749 patients underwent isolated coronary artery bypass grafting. Of these patients, 578 patients were older than 60 years old. We classified them into three groups; Group A were the 60 to 69 year age group (337 patients), Group B were the 70 to 79 year age group (224 patients) and Group C were over 80 years age group (17 patients). Emergency cases and preoperative LV dysfunction cases were more frequently in Group C, but mortality did not differ among three groups. Duration of intubation, ICU stay and hospital stay were longer in Group C than other groups and complications (PMI, arrhythmia and reoperation for bleeding) were more frequently in Group C. Coronary artery bypass surgery can be performed in aged patients, especially for patients over 80 years old, with acceptably low mortality and significant functional benefit but a high incidence of complications necessitates careful postoperative management in aged patients.

Positive and negative cis-regulatory regions in the soybean glycinin promoter identified by quantitative transient gene expression

The 5' and 3' flanking regions of the soybean glycinin gene, Gy1, responsible for expression in seeds, were analyzed by quantitative transient expression assay. The construct containing the β-glucuronidase (uidA) reporter gene under the control of the 1.12 kb Gy1 promoter and 0.74 kb Gy1 terminator was introduced into immature soybean seeds and leaves by particle bombardment. To normalize the variability of introduction efficiency, a second reporter gene, firefly luciferase, was cobombarded as an internal standard, and relative activities (GUS/luciferase) were measured. There was a seed-specific β-glucuronidase (GUS) expression, as observed by X-Gluc staining. Compared with the nopaline synthase gene (nos) terminator, the Gy1 terminator enhanced the level of expression in immature seeds, indicating that the terminator region of the glycinin gene is involved in the activation of the gene expression in these seeds. To identify cis-regulatory elements in the glycinin gene upstream sequence, deleted derivatives of the promoter were fused to the luciferase reporter gene. The expression could be measured with a higher accuracy, and constructs were introduced with the internal reporter uidA gene into immature seeds. The results suggest the presence of a positive regulatory element in the -620 to --380 region of the Gy1 promoter. A deletion which eliminates the legumin box with its RY element led to increased relative activity, suggesting that this box is negatively regulating expression of the seed storage protein gene. Analysis of mutant promoters also suggest that the RY element involves negative regulation in seeds. This quantitative transient expression assay using particle bombardment provides a reliable system for the study of seed-specific gene expression in soybeans.

Herbicide-resistant tobacco plants expressing the fused enzyme between rat cytochrome P4501A1 (CYP1A1) and yeast NADPH-cytochrome P450 oxidoreductase

Transgenic tobacco (Nicotiana tabacum cv Xanthi) plants expressing a genetically engineered fused enzyme between rat cytochrome P4501A1 (CYP1A1) and yeast NADPH-cytochrome P450 oxidoreductase were produced. The expression plasmid pGFC2 for the fused enzyme was constructed by insertion of the corresponding cDNA into the expression vector pNG01 under the control of the cauliflower mosaic virus 35S promoter and nopaline synthase gene terminator. The fused enzyme cDNA was integrated into tobacco genomes by Agrobacterium infection techniques. In transgenic tobacco plants, the fused enzyme protein was localized primarily in the microsomal fraction. The microsomal monooxygenase activities were approximately 10 times higher toward both 7-ethoxycoumarin and benzo[a]pyrene than in the control plant. The transgenic plants also showed resistance to the herbicide chlortoluron.

A case of vascular leiomyoma of the larynx

We present a 68-year-old woman with a vascular leiomyoma of the larynx, a benign tumour that rarely involves that organ. Chief complaints were a feeling of a narrowing of the pharynx and difficulty in breathing in the supine position. A spherical tumour measuring 1.5 cm and covered with normal mucosa was found at the margin of her epiglottis. The patient was administered a general anaesthetic and the tumour was successfully removed via direct laryngoscopy. Histological examination revealed that the tumour lay beneath a layer of stratified squamous epithelium and was encased in a well-defined fibrous capsule. The tumour parenchyma was composed of proliferated fibres that consisted of elongated cells, surrounded by an abundance of blood vessels. Its complete removal is the treatment of choice with care taken to avoid profuse bleeding. Recurrence is rare.

Three-dimensional cytoskeletal structures of the chinchilla organ of Corti: scanning electron microscopy application of the polyethylene glycol method

We describe the application of a polyethylene glycol (PEG) embedding technique to examine the sensory and supporting structures of the inner ear. The chinchilla organ of Corti was exposed by cracking PEG embedded cochleas. A range of PEG molecular weights (2000-8000) were utilized; PEG 2000, with a melting point of 57 degrees C was preferred. After removal of the PEG, the three-dimensional aspects of intracellular structures were observed using scanning electron microscopy. Filamentous elements in the hair cell cuticular plate and in the supporting cells were clearly observed, as was the meshwork of cross-linked actin filaments in the cuticular portion of sensory hair cells. Microtubule and microfilament alignment patterns in pillar and Deiters cells were also clearly demonstrated. Characteristic structures in the outer hair cell synaptic region, such as the post-synaptic cistern and synaptic body, were well preserved using the PEG method.

Neonatal cochlear hearing loss results in developmental abnormalities of the central auditory pathways

We have used animal models of long term neonatal cochlear hearing loss to study developmental plasticity of the central auditory pathways. Newborn chinchilla pups and feline kittens were treated with the ototoxic drug amikacin, so as to induce basal lesions in the cochlea. At maturity these animals were used in single unit electrophysiological mapping studies, in which the cochleotopic organization of primary auditory cortex (of the cat) and the inferior colliculus of the midbrain (in the chinchilla) were mapped. We have observed, both in the midbrain and auditory cortex, massive reorganization of frequency representation. Most striking were the presence of large monotonic regions (i.e. large areas in which all neurons have similar tuning properties). Cochlear lesions which involve inner hair cells clearly modify the normal development of cochleotopic representation in the midbrain and cortical regions. We suggest that similar abnormal patterns of frequency representation will exist in human subjects with long term neonatal hearing loss.

The effects of long-term cochlear hearing loss on the functional organization of central auditory pathways

We have developed an animal model of neonatal high-frequency cochlear hearing loss to investigate the long-term effects on the central auditory pathways. Specifically, we have induced basal cochlear lesions in newborn kittens using the ototoxic aminoglycoside, amikacin. We have monitored the consequent auditory threshold elevations using auditory brainstem evoked responses (ABR) to tone pip stimuli. In the mature animal we have mapped tonotopic (cochleotopic) representation in primary auditory cortex (AI) using standard micro-electrode recording techniques, and we show that this map becomes massively re-organized. In particular, one frequency area that corresponds to the high frequency cut-off slope of the subject's audiogram appears to become greatly expanded, in some cases to take up 75% of AI surface. In general, the development of normal cochleotopic or tonotopic representation in cortex appears to depend upon the integrity of ascending sensory input from the cochlea particularly during early stages of development. With the clinician in mind, we discuss our findings in relation to practical issues.

Roentgenographic findings of the cervical spine in tension-type headache

Roentgenographic studies were carried out on 372 patients with tension-type headache and 225 normal control subjects to determine relationships between straightened cervical spines, low-set shoulders, and cervical spine instability. A great majority of the patients with tension-type headache were found also to have straightened cervical spine. Patients with tension-type headache may have a restricted progression of the cervical spinal lordosis, which results in a straightened cervical spine. The flexor muscles of the head and neck prevent physiological lordosis of the cervical spine, and their sustained chronic contraction may be a principal cause of a straightened neck. The low-set shoulder was frequently seen in patients with tension-type headache, and it may result in traction of the brachial plexus, which gives rise to pain in the neck and shoulders. Cervical spine instability, on the other hand, was rather infrequent in patients with tension-type headache. Its relationship to tension-type headache is unclear and warrants further study. Our results suggest that both a straightened cervical spine and low-set shoulders may play an important role in the pathogenesis of tension-type headache and its accessory symptoms.

Auditory evoked potentials in cats with neonatal high frequency hearing loss. Evidence of abnormal frequency representation in the midbrain

We have recorded auditory evoked potentials, of both neurogenic and myogenic origin, in cats having neonatal high frequency cochlear hearing loss. Using frequency specific stimuli (tone pips) and by measuring responses near to threshold, we have probed tonotopic (or cochleotopic) representation within the brainstem-midbrain auditory pathway. At stimulus frequencies corresponding to the high frequency cut-off of the cats' audiograms we have observed enhanced amplitudes of both auditory brainstem evoked responses (ABR) and postauricular myogenic (PAM) potentials. We interpret our findings as evidence of a larger than normal population of neurons tuned to this frequency region. We suggest that such abnormal frequency representation results from a long-term sensory deficit caused by lesions to the basal, high frequency region of the cochleas.

Correlation of cochlear pathology with auditory brainstem and cortical responses in cats with high frequency hearing loss

Newborn kittens were treated with the aminoglycoside amikacin to produce a bilateral high frequency cochlear hearing loss. The degree and stability of hearing loss were confirmed by recording auditory brainstem evoked potentials (ABR audiograms). After maturation, cochleotopic frequency representation within primary auditory cortex (AI) was mapped using standard microelectrode recording techniques. The cochlear sensory epithelium was assessed with SEM and the pattern of damage compared with the ABR audiograms and cortical frequency maps. Amikacin treatment resulted in various patterns of haircell damage towards the base of the cochlea. A relatively abrupt transition between damaged and undamaged haircell regions resulted in an ABR audiogram with normal threshold to low frequencies and a high frequency elevation with a steep cut-off slope. In the cortical map, low frequency representation was normal, but anterior areas contained only neurons tuned to a common frequency which corresponded to the frequency-place position of the boundary of the haircell lesion and to the cut-off frequency of the audiogram. A large transitional zone of the cochlear lesion correlated with a gradual cut-off slope to the audiogram and again a remapping of the anterior and normally high frequency area to a common lower frequency. Haircell loss or damage (i.e. disarray of stereocilia) in lower frequency regions of the cochlea correlated with a significant reorganization of the lower frequency bands in the cortical map. We conclude from this study that the pattern of cochleotopic organization of the cortex is dependent on the pattern of activity in the ascending sensory pathway during early stages of development.