Biomedical subjects
Publications and source records attributed to Z Lin.
24 cases (25 thumbs) of thumb reconstruction and 14 cases (10 fingers) of finger reconstruction by second toe transplantation, 11 cases of thumb reconstruction by the big toe-nail flap, and 1 case of "hand" reconstruction by both second toes are presented. 48 cases (52 fingers and thumbs) are successful. Functions and aesthetic results are satisfactory.
We have successfully performed chondrolaryngoplasty in 6 cases. The results are satisfactory. Of the patients, five have previously undergone male to female transsexual operation and one with pseudohermaphroditism. Chondrolaryngoplasty is performed under local anesthesia. The amount of excised thyroid cartilage is 2.0 to 2.4 cm in length and 0.6 to 1.2 cm in width on each side. In 3 cases, mild hoarseness is observed postoperatively and it is very transient, lasting less than 20 days. This paper introduces the applied anatomy, operative technique and key points for a successful chondrolaryngoplasty.
Methamphetamine (MA) was analyzed using formalin-fixed organ tissues from experimental animals and an autopsied cadaver. The brain, lung, liver, kidney and skeletal muscles of rabbits that had been administered MA were collected, and then fixed with a non-buffered 10% formalin solution at room temperature (10-20 degrees C) for five different fixation periods (1, 3, 7, 14 and 28 days). After the Extrelut column extraction, MA was derivatized using anhydrous trifluoroacetic acid (TFA) and analyzed by GC-MS using a DB-17 column. MA-TFA in the eluates from the organ tissues after the formalin-fixation could be identified by GC-MS. Even one day after the formalin-fixation, concentrations of MA in the fixed organ tissues already significantly decreased to 1.3-3.1% when compared with those of MA in the non-fixed tissues, and to 0.04-0.4% in all of the fixed organ tissues at 28 days after the fixation. Moreover, MA in the organ eluates from the autopsied male cadaver after one-month formalin-fixation was qualitatively detected. These results obviously show the usefulness of MA detection using formalin-fixed organs in the practice of forensic medicine and police science.
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The mouse alcohol dehydrogenase gene, Adh-1, is expressed in a tissue-specific manner. We examined the promoter activity of a series of 5' deletions extending from bp -473 to -47 and demonstrated that there are positive regulatory elements between bp -229 and +54 and a negative regulatory element between bp -323 and -229. To identify the sequence of the negative regulatory element, gel retardation and DNase I footprint assays were performed using nuclear proteins from mouse liver and from a hepatoma cell line, H4IIE-C3. A specific protein-binding site covered bp -324 and -297. Within this region, we identified sites of close protein-DNA contact by methylation interference assays, located in the sequence TGGAAGTTTCAGGTT (nt -316 to -302). Site-directed mutagenesis of four protein-DNA contact sites within this sequence eliminated the specific protein-DNA binding, assayed by gel retardation, and restored expression of Adh-1 in transient transfection assays to the levels seen when the entire region containing the negative element was deleted. Thus, we have identified a negative regulatory element within the Adh-1 promoter. No homology was found between this negative element and other regulatory elements, suggesting that this is a novel negative element.
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A medico-legal autopsy case of hydranencephaly in a male infant which was first suspected of maternal infanticide is reported. The infant was 48 cm in height, weighed 2.86 kg and the circumference of the head, the chest and the abdomen was 32.2 cm, 31.0 cm and 30.4 cm, respectively, with no deformities of the head or body. Autopsy examination, however, revealed a severe defect in the central nervous system. The cranial cavity was filled with a cloudy dark red fluid (ca. 310 ml) instead of the cerebral hemispheres. The residual central nervous tissues were mostly subtentorial structures from the midbrain to the spinal cord namely, corpus mamillare, corpora quadrigemina, corpus pineale, crus cerebri, pons, cerebellum, medulla oblongata and spinal cord. The basal ganglia, thalamus, hypothalamus and chiasma opticum could not be found, although atrophic hypophysis, eyeballs and optic nerves were present. The usual distribution of cerebral blood vessels, especially the branches of the anterior and middle cerebral arteries and Willis' ring, was absent despite the presence of the internal and external carotid arteries. Other organs were, in general, congestive. The marked cortical atrophy of the adrenal glands (left 0.5 g, right 0.6 g), especially the zona fasciculata, was characteristic. The hydrostatic lung test gave partially positive results, but this was considered to be due to artificial respiration by an ambulance man because amniotic fluid components were microscopically noted and fully expanded alveoli were not found. In conclusion, the cause of the infant's death was diagnosed as stillbirth due to aspiration of amniotic fluid caused by the severe defect of vegetative hypothalamic function through hydranencephaly.
In the human small intestine there is omnipresent electrical activity with a frequency of 0.15-0.2 Hz. The electrical activity of the small intestine can be measured by surface electrodes placed on the abdominal skin. The most annoying problem in the surface electrical recording is the respiratory artifact which is not discernible from the small intestinal signal. The frequency of the respiration is about 0.2-0.4 Hz, which is very close to that of small intestinal activity, making the use of the conventional bandpass filtering impractical. In this paper a selective frequency domain adaptive filter was proposed for the cancellation of the respiratory artifact. The basic principle of the selective frequency domain adaptive filter is that only selected filter weights are adapted based on the frequency characteristics of the respiratory artifact. Therefore, a substantial reduction of computation is achieved. A series of computer simulations was conducted for the optimization of the system parameters and for the investigation of the system performance. It was demonstrated in this paper that the selective frequency domain adaptive filter is as effective as, but more efficient than, the conventional frequency domain adaptive filter. The adaptive system for the cancellation of the respiratory artifact based on the selective frequency domain adaptive filter is very efficient in computation, has a fast convergence (about 100 adaptations), substantial reduction of the respiratory artifact and little effect (or distortion) on the small intestinal electrical signal.
A monoclonal antibody (mAb) to infectious bursal disease virus (IBDV) was bound to polystyrene latex microspheres. The microspheres agglutinated with extracts of bursae and sera from chickens infected with all strains or isolates of IBDV tested. Agglutination appeared within a 10-min reaction time. The assay could detect a 10(3.7) to 10(4.5) mean embryo infective dose (EID50) of the virus in 0.01 ml and the titer of the assay was 10- to 40-times higher than that of the agar gel precipitin test.
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We constructed common primers for the polymerase chain reaction to detect the genes for various Verotoxins reported, that is, VT1 (or SLT-I), VT2 (or SLT-II), VT2vha, VT2vhb, SLT-IIv (or VT2vp1, VTe) and SLT-IIva (or VT2vp2). A total of 80 Verocytotoxin-producing Escherichia coli strains isolated from humans, domestic animals and meats gave a positive result by PCR with the designed common primers. Digestion by restriction endonucleases BglII and EcoT14I of the amplicon of the VT2vp2 gene gave specific bands of the expected sizes, but not of the amplicons of other VT genes, suggesting a possible method for identification of the VT2vp2 gene. Application of the PCR with the designed primers in diagnostic and epidemiological studies on VTEC infection is also discussed.
We cloned and sequenced two new Verotoxin 2 (VT2) variant genes: one from an Escherichia coli strain from a case of bovine diarrhea and the other from an E. coli strain from a patient with diarrhea. The nucleotide and amino acid sequences of these two genes were highly homologous with, but distinct from those of the VT2, VT2vha, VT2vhb, SLT-IIv (VT2vp1) and SLT-IIva (VT2vp2) genes. Their nucleotide sequences were much more closely homologous to that of VT2vh than to that of VT2vp. Search for these two new genes in other Verocytotoxin-producing E. coli strains resulted in the isolation of 2 strains carrying one of the new VT2 variant genes, one strain from Tokyo and the other from Canada.
In an effort to identify the regulatory gene controlling the expression of the tdh gene, encoding the thermostable direct hemolysin of Vibrio parahaemolyticus, we examined total DNA of AQ3815 (a Kanagawa phenomenon-positive strain) for sequences homologous to that of the toxR gene of Vibrio cholerae. The extracted DNA gave a weak hybridization signal under reduced-stringency conditions with a toxR-specific DNA probe. Cloning and sequence analysis of the probe-positive sequence revealed an operon (Vp-toxRS) which was highly similar to the toxRS operon of V. cholerae (Vc-toxRS) (52 and 62% similarities in the two genes, respectively). The deduced amino acid sequences of the Vp-toxRS gene products (Vp-ToxRS) contained regions similar to the proposed transmembrane and activity domains of the Vc-toxRS gene products (Vc-ToxRS). All clinical and environmental strains of V. parahaemolyticus examined possessed the Vp-toxRS genes. In the presence of Vp-ToxS, Vp-ToxR promoted expression of the tdh2 gene, one of two tdh genes (tdh1 and tdh2) carried by Kanagawa phenomenon-positive strains. The DNA sequence located 144 bp upstream of the tdh2 coding region was shown to be important for the Vp-ToxR-stimulated expression of the tdh2 gene in an Escherichia coli background. Comparative analysis of AQ3815 and its isogenic Vp-toxR null mutant gave the following results: (i) Vp-ToxR promoted, in an AQ3815 background, expression of the tdh gene to different degrees in various culture media, with KP broth (2% peptone, 0.5% NaCl, 0.03 M KH2PO4, pH 6.2) being most effective (12-fold); (ii) the promotion of tdh gene expression in KP broth was at the level of transcription; and (iii) Vp-ToxR was essential for demonstration of enterotoxic activity of AQ3815 in the rabbit ileal loop, a model previously used to demonstrate thermostable direct hemolysin-mediated enterotoxic activity of AQ3815. These results demonstrate that Vp-ToxR and Vc-ToxR share a strikingly similar function, i.e., direct stimulation at the transcriptional level of the gene encoding a major virulence determinant (enterotoxin) of a Vibrio species.
The metabolism of (5-15N)glutamine and (2-15N) glutamine has been studied by isolated hepatocytes obtained from either control, chronically acidotic, or alkalotic rats. The main goal was to elucidate the mechanism(s) by which altered acid-base state affects hepatic ureagenesis from glutamine. Isolated hepatocytes were incubated in Krebs buffer (pH 7.4) supplemented with 0.1 mM ornithine plus either 1 mM (5-15N)glutamine or (2-15N)glutamine. To elucidate the role of glutamine cycling in net ammonia metabolism, a separate series of experiments were performed with 1 mM unlabeled glutamine plus 1 mM (15N)H4Cl. Net glutamine utilization was significantly lower in hepatocytes obtained from chronically acidotic rats compared with control or alkalotic rats. The sum of the rates of 15NH3 and (15N)urea production from (5-15N)glutamine was decreased in acidosis compared with alkalosis. After incubations of 50 min, approximately 75, 65, or 90% of the N in carbamoyl-phosphate was derived from the 5-N of glutamine in control, acidosis, or alkalosis respectively. In experiments with (2-15N)glutamine, the production of singly and doubly labeled (15N)urea as well as (15N)aspartate and (15N)H3 was significantly smaller in acidosis compared with alkalosis. Furthermore, a correlation was observed between production rates of (15N)aspartate and (15N)urea, suggesting that alterations in urea production may depend on aspartate formed from glutamine. However, the production of (15N)alanine was higher in acidosis compared with alkalosis with apparent correlation between the production of (15N)alanine and 2-oxoglutaramate, a product of the glutamine aminotransferase pathway. In addition, the rate of glutamine recycling was significantly higher in acidosis compared with control or alkalosis, indicating that both flux through glutamine aminotransferase and flux through glutamine synthetase were elevated in acidosis compared with alkalosis. These data suggest that decreased formation of aspartate from glutamine may limit ureagenesis in chronic metabolic acidosis. The formation of aspartate may depend on the availability of oxaloacetate rather than diminished flux through transaminase reaction. The enhancement of alanine production and glutamine synthesis may provide an alternate route of N disposal in cases of diminished urea formation.
OBJECTIVES: To guide development of a hepatitis B control program in China, we investigated village doctors' sterilization practices, injection use, vaccination levels, and knowledge and counseling skills. METHODS: The head doctor from each village health station in a rural county (n = 260) completed a self-administered questionnaire. RESULTS: Of the respondents, 94.2% reported adequate sterilization of needles; however, inadequate sterilization of syringes and acupuncture needles was common. Injections were found to be frequent and profitable. Of head doctors, 16.2% reported that most infants in their villages are vaccinated against hepatitis B. There was very high knowledge of modes of hepatitis B transmission, but it was not used to formulate advice for a hypothetical carrier. Knowledge of the consequences, prevalence, and use of condoms to prevent sexual transmission was lower. CONCLUSIONS: The sterilization of acupuncture needles, reuse of syringes, and frequent injections are practices that may transmit the hepatitis B virus. Research into issues of vaccine acceptance is needed to expand immunization. A review of treatment practices and better training in counseling for village doctors is suggested.
The Cooperative Medical System (CMS) in China is an established medical system that serves the rural areas and provides treatment and prevention of disease, immunization, family planning, and maternal and child health care services. Past experience suggests that the CMS benefited the peasants in rural China. During the 1980s, following reform of China's economic system, the CMS underwent major changes. In some places, CMS stations evolved into various other types of medical and health care systems; in other places, CMS stations ceased operation altogether. This article attempts to analyze the causes and meaning of these changes, and examines the conditions for continuation of this system.