Tube-perilymph fistula. An experimental study

Before exploratory tympanotomy, it is difficult to diagnose an idiopathic perilymph fistula (PLF) because of its variable presentations. An animal model tube-PLF on guinea pigs was established to evaluate the change of the sensitivity of the cochlea function and the value of the postural audiometry in PLF. A fine polyethylene tube (O.D. 0.6mm) was inserted into the scala tympani of the basal turn through the incised round window membrane in 10 experimental guinea pigs, and another 5 as controls. The hearing threshold (HT), action potential (AP) latency for stimulus of 105 dB SPL, difference of HT and AP latency from the test ear down to up were measured by electrocochleography (ECoG) immediately after operation and one week later. The HT, AP latency and postural audiometry showed no significant changes immediately but a significant difference one week later in HT (P less than 0.01) and postural audiometry, the AP latency also presented a significant delay (P less than 0.01). The results showed that the tube-PLF model may be a valuable method for studying chronic PLF.

Differentiation of myoblasts and CNS cells grown either separately or as co-cultures on microcarriers

Dispersed neuronal and muscular elements from fetal or neonatal origin, can organize and mature in culture when grown on positively charged cylindrical microcarriers (MCS), to a stage which simulate in vivo maturation. Cells arrange themselves on the MCS to form aggregates which remain floating in the nutrient medium. In such a tridimensional organization, the neuronal tissue is capable of regenerating a network of nerve fibers which establish synapse interconnections and undergo myelination. Oligodendrocytes organize on MCS in a tridimensional pattern and produce extensive myelin-like membranes. Myoblasts in MC-cultures fuse into polynucleated myotubes which become striated and contract spontaneously. Creatine kinase and acetylcholine receptor (AChR) are formed during myogenesis in similar quantities in MC-cultures and in monolayers. When both neuronal and muscle tissues are prepared from the same fetus (autologous nerve-muscle co-cultures) and are cultured on MCS, they interconnect to form neuro-muscular junctions. Cells from both tissues, exhibit better differentiation, for longer periods in MC-cultures than they do in monolayers. The floating functional entities are easy to sample and can be harvested for ultrastructural, immunocytochemical and biochemical analysis. In addition, MC-cultures can be used as a good tool for the study of acute and chronic exposures to toxicological agents, as well as for implantation into demyelinated, injured or dystrophic tissues. In this case the MCS in the implanted entities will serve as identifiable markers.

Computer 3-dimensional reconstruction of intraglandular lymph vessels and ductal systems of the human submandibular gland

Computer three-dimensional reconstruction of serial sections is currently an active area of research. In this paper we combine computer graphics, image processing and biomedical techniques to reconstruct a stereo model of intraglandular lymphatic vessels, veins, arteries and ducts from serial microsections of the human submandibular gland.

Stroke in China (Sino-MONICA-Beijing study) 1984-1986

We present here the results of the Sino-MONICA-Beijing stroke study based on 700,000 Beijing residents in 1984-1986. To compare incidence rates for stroke with other communities and countries, we adopted the criteria of the WHO Collaborative Study of 17 centers which used the same definition and methodology as was used in this study. Over the 3-year period of the study, 2,593 stroke events were registered in the 25- to 74-year age-group. The incidence rate for all strokes was 189.5/100,000 and the incidence rate for first strokes was 133.6/100,000. Men had a significantly higher incidence rate than women (all strokes 219.7/100,000 for male vs. 160.5/100,000 for female, OR = 1.32, 99% limits 1.19-1.46; first strokes 151.6/100,000 for male vs. 116.4/100,000 for female, OR = 1.25, 99% limits 1.11-1.42). In comparison with other studies, age-adjusted incidence rate of stroke in Beijing was higher than in other countries, especially for hemorrhagic stroke. The proportion of hemorrhagic stroke related to other types of stroke was also higher in Beijing. Further analysis of the cases confirmed by computerized tomography also supported this finding. Unlike the incidence rates, the 4-week case fatality rate for women, 39.5%, was higher than for men, 32.8%. This finding was confirmed by a multiple logistic analysis controlling for age (p less than 0.001) and for previous stroke (p less than 0.001). The adjusted sex difference is also significant (OR = 1.37, p less than 0.001). In addition, results showed that men had a higher hospitalization rate than women. More women than men were treated at home, possibly indicating better medical care for men.

Mortality and incidence of bladder cancer in benzidine-exposed workers in China

We examined bladder cancer mortality and incidence to 1981 in 1,972 workers employed in benzidine-exposed jobs in Tianjin, Shanghai, and Jilin, China, between 1972 and 1977, and in 1,974 unexposed workers employed during the same time period. In comparison to general population rates, in the benzidine-exposed group the ratio of observed to expected deaths (SMR) was 17.5 (95% C.I.: 7.5-34.5) and the ratio of observed to expected incident cases (SIR) was 25.0 (95% C.I.: 16.9-35.7). No excess was noted in the unexposed group. The 25-fold increase in bladder cancer incidence in the exposed group was related to level of exposure, with the SIR rising from 4.8 for low exposure to 36.2 for medium exposure, and 158.4 for high exposure. Risks were elevated both for producers of benzidine (SIR = 45.7; 95% C.I.: 20.9-86.8) and for users (SIR = 20.9; 95% C.I.: 12.9-32.0) of benzidine dyes. Benzidine-exposed workers who smoked tobacco had a 31-fold risk (95% C.I.: 20.4-46.4), while non-smoking workers had an 11-fold risk (95% C.I.: 3.6-25.8), suggestive of a multiplicative relationship between these two carcinogens.

[Clinical pharmacokinetics of cis-diamminedichloroplatinum (DDP)]

We studied the pharmacokinetics of DDP in 9 cancer patients who received iv infusion of DDP (100-120 mg/m2). Platinum concentration was measured by high performance liquid chromatography (HPLC). Plasma clearance of platinum was biphasic. There was a short initial phase with a half life of 19.8 min and a long second phase with a half life of 41.13 hours. A small peak was noted in 5 hours after the end of DDP infusion in about 50% of patients. This suggested tissue reabsorption, release and entero-hepatic circulation. Plasma ultrafiltrable platinum concentration fell with a half life of 21 min. Nearly 75-96% of the platinum in the plasma was protein bound 24 minutes after DDP infusion. The urinary excretion of platinum was found to be 9.52-21.35% in 24 hours with 6.69-19.57% eliminated within the first three hours.

Hepatic artery ligation and infusion chemotherapy for unresectable primary liver cancer

During the period of 1958-1989, 356 patients with pathologically proven primary liver cancer (PLC) were determined by laparotomy to be unresectable. Of the 356 patients, 51 (14.3%) were of subclinical stage, 287 (80.6%) of moderate stage and 18 (5.1%) of late stage. The association of liver cirrhosis was present in 310 patients (87.1%). Treatment modalities in 356 patients were divided into 4 groups: hepatic artery ligation (HAL) (51), hepatic artery infusion (HAI) of chemotherapeutic agents (114), HAL + HAI (117), and HAL + HAI + radiotherapy (74). The 5-year survival rate was zero in the 4 groups in the period of 1958-1977. During 1978-1989, however, the 5-year survival rate was zero in HAL, 7.9% in HAI, 24.4% in HAL + HAI (with second look resection in 10 patients), and 36.5% in HAL + HAI + radiotherapy (with second look resection in 19). The marked improvement in survival in later period was attributable to the accurate site of hepatic artery catheter, longer infusion chemotherapy, and combination treatment, particularly second look resection in some of the patients. These results indicate that HAL + HAI + combination treatment might provide a possible prolongation of survival or even resection in some patients with original unresectable PLC.

[Textual research on luohuangzi]

By studying ancient and modern literatures and observing the material object, we have come to the conclusion that the fruit called "luohuangzi" in ancient times should be the seed of Sterculia nobilis rather than Tamarindus indica. We therefore suggest that "luohuangzi" be no longer used as another name for T. indica, and, in order to eliminate the confusion about the name and material object of "luohuangzi". Tamarindus should be called the "genus Shuandou" in Chinese instead of the "genus Luowangzi".

[Pharmacological studies on warming the middle-jiao to alleviate pain by Pericarpium Zanthoxyli]

The pharmacological effects of the ethereal extract and aqueous extract of Pericarpium Zanthoxyli on warming the middle-jiao to alleviate pain have been studied. It is suggested that the effects of Pericarpium Zanthoxyli on antagonizing ulcer, and inflammatory and functional diarrheas, protecting liver, and correcting gastrointestinal disorder are the connotation of its warming the middle-jiao to alleviate pain, its analgesic effect helps to relieve various abdominal pains.

[Comparison of several screening instruments for dementia]

Both evidences of cognitive and functional impairments are necessary for the diagnosis of dementia. Following instruments: Mini-Mental State Examination (MMSE), Blessed Dementia Scale (BDS) and Hasegawa Dementia Scale (HDS) for cognitive assessment, and Activity of Daily Living (ADL) and Pffefer's Social Function Questionnaire (POD) for function measurement, were used in a survey sample of 5055 aged persons. It was found that the scores of both categories of tests were significantly correlated. The scores of MMSE, BDS and HDS were highly education-related, thus the education-dependent cutoff point should be decided. Among the cognitive assessment scales, MMSE and HDS seems better than BDS, while in functional scales, POD was more suitable for community survey. Sensory and motor disturbances, emotional and health problem were also interfered with both cognitive and daily or social function, it should be taken account in the diagnostic process for dementia.

[A preliminary report of evoked potential marker study of pattern shift visual evoked potentials (PS-VEP) and auditory evoked potentials (AEP) on schizophrenic twins]

This paper reports the result of electroneurophysiological study of the pattern shift visual evoked potentials (PS-VEP) and auditory evoked potentials (AEP) on six pairs of schizophrenic twins. The result indicated that there were significant differences in the inter-pair variance between MZ and DZ in latency P2, amplitude P2-N2 and P2 of using PS-VEP. AEP was also used for this group cases, and the result showed the presence of statistical differences in the inter-pair variance of latency N2, amplitude N1-P2 and P2. The authors speculated upon that the above six electrophysiological markers may be related to genetic factors, which had been proved by the blood group, character, clinical symptoms and treatment response of those patients.

[Studies on warming the middle-jiao and analgesic effect of flos Caryophylli]

The effects of water extract and ether extract of Flos Caryophylli have been investigated by four experimental gastric ulcer models, choleresis in rats, two diarrhea models in mice, two pain stimulations in mice, and acute liver injury induced by CCl4 in rats. The results suggest that the action of Flos Caryophylli on dispelling the cold by warming the middle-jiao and curing abdominalgia is related to its anti-ulcer, choleresis increasing, anti-diarrhea and analgesic functions.

CG dinucleotide transitions in the factor IX gene account for about half of the point mutations in hemophilia B patients: a Seattle series

Hemophilia B is due to multiple molecular defects in the factor IX gene. Over 80% of mutations are single base substitutions. By amplification and direct sequencing, 51 single base substitutions were found in the transcribed sequence of the factor IX genes of patients from 50 distinct families with hemophilia B. These include 30 mutations in 29 families not previously reported by us; of these, 12 are novel, i.e., not previously published in other series. Of the 51 substitutions in our overall series 23 (45%) occurred as C-to-T or G-to-A transitions at 11 sites within CG dinucleotides. It is estimated that CG transitions occur from one to two orders of magnitude more frequently than mutations in nucleotides that are not within a CG pair. More than one family had identical defects for 6 of the CG mutations. At 4 of these sites, most patients had different haplotypes compatible with distinct mutations. Non-CG-type mutations occurred throughout the coding regions with only one mutation in more than one family. The latter included 7 families with a 397 Ile-to-Thr defect that all share a rare haplotype, suggesting a common ancestor.

Enhancement of the cytotoxicity of mistletoe lectin-1 (ML-1) by high pH or perturbation in Golgi functions

We have studied the cytotoxicity of Mistletoe lectin-1 (ML-1), a cytotoxic protein produced by Viscum album, in CHO and V79 cells and in mutant cell lines altered in Golgi functions or in endosomal acidification. In wild-type CHO cells, cytotoxicity of ML-1 was greatly enhanced by ammonium chloride or nigericin. A CHO mutant defective in endosomal acidification (DMPR-2), which is resistant to diphtheria toxin, modeccin and Pseudomonas aeruginosa exotoxin A and hypersensitive to ricin, showed increased sensitivity to ML-1. MonR-31 and MF-1 are monensin- and compactin-resistant mutants derived from CHO and V79 cell lines, respectively, and are presumably altered in Golgi functions. The cytotoxicity of ML-1 was found to be increased in both MonR-31 and MF-1 cells as compared with their parental cells. These results indicate that the effects of chemicals or mutations altering endosomal acidification and Golgi functions on the cytotoxicity of ML-1 are similar to those on ricin cytotoxicity. Our results suggest that the cytotoxicity of ML-1 is enhanced by an increase in endosomal pH, as well as by chemicals or mutations altering the structure/functions of the Golgi regions. Like ricin, the intoxication process of ML-1 may involve the Golgi regions.

Improved serodiagnosis of hepatitis C virus infection with synthetic peptide antigen from capsid protein

Cloning and expression of hepatitis C virus have allowed the development of immunoassays to detect hepatitis C virus infection. However, currently available recombinant fusion protein C100-3 assays, based on a nonstructural protein of the virus, are limited in sensitivity, particularly for detecting acute infection. In this report seroconversion panels showed that an assay based on synthetic peptides, derived from immunodominant regions of both capsid and nonstructural proteins, accelerated hepatitis C virus antibody detection by 4-10 weeks. In screening, this enzyme immunoassay increased detection from 47% to 64% in plasmapheresis donors with elevated alanine aminotransferase levels (greater than 100 international units per liter), from 15% to 24% in anti-hepatitis B core antigen-positive blood donors, and from 28% to 42% in renal dialysis patients when compared with nonstructural peptide-based assays. The screening assay was repeatedly reactive for 27 of 2902 volunteer blood donor samples (0.93%); four sera reacted only with the capsid antigen. The peptide test distinguished true from false positive results in agreement with recombinant immunoblot assay in 96% of blood donor samples repeatably reactive on a recombinant hepatitis C virus enzyme immunoassay.

Splice junction mutations in factor IX gene resulting in severe hemophilia B

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[Pharmakinetics of carboplatin in cancer patients]

Pharmakinetics of carboplatin was studied in 6 cancer patients who received carboplatin (300 mg/m2) by 30 minute intravenous infusion. Platinum plasma concentration was measured by reverse high performance liquid chromatography. The results showed that total platinum plasma clearance was biphasic in all patients with a short initial phase half-life of 1.27 hrs and a long second phase half-life of 6.92 hrs. The distribution volume of the drug was 57.78 L/m2 and area under the total platinum concentration curves was 84.71 mg/L.hr.

[Effect of rhizoma Zingiberis on anoxic or cooled mice]

The anti-anoxic experiments have indicated that the petroleum ether extract of Rhizoma Zingiberis can prolong the survival time in mice poisoned by KCN or under the condition of normobaric hypoxia, as well as decapitation-induced gasping duration in mice, but can not prolong the survival time in mice poisoned by NaNO4. The anti-anoxic action might be related to the reduction rate of O2 consumption of the body. The aqueous extract of Rhizoma Zingiberis does not possess the above-mentioned anti-anoxic action. Both extracts do not affect the survival time in cooled mice.

A yeast protein with homology to the beta-subunit of G proteins is involved in control of heme-regulated and catabolite-repressed genes

The product of the Saccharomyces cerevisiae AER2 gene is responsible for maintaining repression of at least two distinct regulatory pathways: heme activation/repression and catabolite repression. Mutations in the gene caused an eightfold increase in the expression of the heme-activated CYC1 gene in the absence of heme, a substantial increase in the expression of the heme-repressed ANB1 gene in the presence of heme, and a 13-fold increase in the expression of the catabolite-repressed GAL1 gene in the presence of glucose. Lesser or no increases in the expression of these genes were observed under derepressed or activation conditions. The aer2 mutations also caused a large increase in CYC7 gene expression under all conditions; this gene is subject to heme activation/repression, as well as catabolite repression. The AER2 gene was cloned and the sequence determined. The large open reading frame contiguous with the transcript from the complementing region encoded a 713-amino acid polypeptide chain with extensive homology to the beta-subunit of G proteins. The sequence revealed that AER2 is the TUP1 gene. A deletion mutation was constructed and the null phenotype was the same as the original mutants. The aer2 null mutant was shown to have increased aerobic and anaerobic levels of RNA encoding the ROX1 repressor, normally expressed only aerobically and responsible for the aerobic repression of ANB1 expression. The increase in both ROX1 and ANB1 RNAs aerobically in this mutant suggests that the repressor is nonfunctional in the mutant.

Coordinate occupancy of AP-1 sites in the vitamin D-responsive and CCAAT box elements by Fos-Jun in the osteocalcin gene: model for phenotype suppression of transcription

Osteocalcin, a bone-specific protein and marker of the mature osteoblast, is expressed only in nonproliferating osteoblasts in a mineralizing extracellular matrix, while type I collagen is expressed in proliferating cells. The nuclear proteins encoded by the c-fos and c-jun protooncogenes are expressed during the proliferation period of osteoblast phenotype development. We present evidence that AP-1 (HeLa cell-activating protein 1) sites residing within two promoter elements of the osteocalcin gene bind the Fos-Jun protein complex: the osteocalcin box (OC box; nucleotides -99 to -76), which contains a CCAAT motif as a central element and influences tissue-specific basal levels of osteocalcin gene transcription, and the vitamin D-responsive element (VDRE; nucleotides -462 to -440), which mediates enhancement of osteocalcin gene transcription. Gel electrophoretic mobility-shift analysis demonstrated high AP-1 binding activity in proliferating osteoblasts and dramatic changes in this activity after the down-regulation of proliferation and the initiation of extracellular-matrix mineralization in primary cultures of normal diploid osteoblasts. Methylation interference analysis established at single nucleotide resolution that purified recombinant Fos and Jun proteins bind in a sequence-specific manner to the AP-1 sites within the VDRE and OC box. Similarly, an AP-1 motif within a putative VDRE of the alkaline phosphatase gene, which is also expressed after the completion of proliferation, binds the Fos-Jun complex. These results support a model in which coordinate occupancy of the AP-1 sites in the VDRE and OC box in proliferating osteoblasts may suppress both basal level and vitamin D-enhanced osteocalcin gene transcription as well as transcription of other genes associated with osteoblast differentiation--a phenomenon we describe as phenotype suppression. This model is further supported by binding of the Fos-Jun complex at an AP-1 site in the type alpha I collagen promoter that is contiguous with, but not overlapping, the VDRE. Such a sequence organization in the collagen VDRE motif is compatible with vitamin D modulation of collagen but not with osteocalcin and alkaline phosphatase expression in proliferating osteoblasts.

Molecular characterization of immune inhibitor A, a secreted virulence protease from Bacillus thuringiensis

The gene for the secreted neutral metalloprotease, immune inhibitor A (InA), from Bacillus thuringiensis var. alesti has been cloned and sequenced. The deduced amino acid sequence has been confirmed by partial amino acid sequencing. The central part of the amino acid sequence showed similarity to the active site in thermolysin. Southern and Western blots show that InA-related sequences are common among other B. thuringiensis subspecies. In Western blots, 17 out of 25 tested species gave a positive signal. Culture filtrates from subspecies expressing InA were toxic when injected in Trichoplusia ni larvae, whereas filtrate from a strain negative in Western blot had no effect when injected. The LD50 dose of purified InA protein injected in T. ni larvae was 12.5 +/- 2.5 ng per mg of larval body weight.