Biomedical subjects
Publications and source records attributed to C C Chu.
One course of intravenous immunoglobulin was tried on a patient with the syndrome of polyneuropathy, organomegaly, endocrinopathy, M-protein and skin lesions and Castleman's disease. No effect was noted.
In Flaveria pringlei, a C3 plant, P protein of the glycine-cleavage system is encoded by a small gene family consisting of at least five transcriptionally active genes. We have cloned and sequenced two of these genes, gdcsPA and gdcsPB, and provide the first detailed report on the complete structure of eukaryotic gdcsP genes. Based on the lengths of exons and intervening sequences, the P-protein genes can be subdivided into two parts. In both cases the N-terminal region consists of one very long exon followed by a long intron. In contrast, the C-terminal parts show a complex mosaic structure of relatively small exons and introns. A highly conserved leucine-zipper motif was identified, which is supposed to participate in the assembly of the glycine decarboxylase multienzyme complex. The transcript derived from the gdcsPA sequence corresponds perfectly to a leaf cDNA isolated earlier. Reverse-transcriptase PCR experiments show that both genes are preferentially active in leaves. Stems contain distinctly less P protein mRNA and the relative level in roots is very low but still clearly detectable. In all three organs, but most significantly in roots, the gdcsPA transcript level is distinctly higher than that of gdcsPB. Analysis of promoter-beta-glucuronidase fusions in transgenic tobacco suggests that far-upstream elements enhance the transcriptional activity of both genes in leaves relative to stems. The analysis of distal gdcsPA promoter deletions reveals the presence of regulatory elements acting with a distinct organ preference and indicates their approximate location.
Although only five isotoxins of the beta-bungarotoxin family had been claimed, this work indicated the existence of more than sixteen isotoxins. Crude snake (Bungarus multicinctus) venom was divided into four main fractions by gel filtration on a Sephadex G-50 column. beta-Bungarotoxin appeared in a major fraction that contained mainly the M(r) 20,000 protein components. The fraction could be further resolved into eighteen peaks designated P1-P18 by HPLC on a Protein Pak SP 5PW column that was eluted with a linear gradient of 0.1-0.6 M CH3COONa in 20 mM NaH2PO4-Na2HPO4 at pH 7.4 P3-P18 were demonstrated to be isotoxins of the beta-bungarotoxin family. Results of protein sequencing for P8, P9 and P11, the three main isotoxins, confirmed that they shared a common phospholipase A2 subunit, which was very similar to although not completely identical with the A1 chain reported previously.
This case report concerns a girl with spindle cell lipoma of the neck. Spindle cell lipoma is a variant of lipomas and was first described by Enzinger and Harvey in 1975. It occurs chiefly in males between 40 and 70 years of age. It is a benign lesion that can be cured by excision, and local recurrence is rare. Spindle cell lipoma is composed of adipocytes and non-fat-storing immature mesenchymal cells. The condition is uncommon in adults and had not been reported to occur in children.
A 14-month-old girl had purulent discharge from a sinus over the subpubic region for 2 weeks. Radiography and voiding cystourethrography revealed a 4.5 cm. long fistula extending to the retropubic region without any connection to the lower urinary tract. The fistula was excised. Histological findings revealed that the fistula had 3 different types of epithelium: stratified squamous, transitional and columnar. Clinical and pathological findings indicated that the sinus was most likely a remnant of the cloaca.
Nippostrongylus brasiliensis (Nb) infection of mice induces IL-4 producing CD4+ T cells which stimulate polyclonal IgE and IgG1 production, providing a model system to study IL-4 action on B cells in vivo. B cell Ia expression and the proportion of IL-2R beta positive B cells were increased in Nb-inoculated mice, and B cells from these mice responded to IL-2 by prompt and marked cell growth. Injection of anti-IL-4 1 day after Nb inoculation substantially inhibited these responses, indicating that they were largely IL-4 dependent. Thus IL-4 acted as a polyclonal B cell activator in vivo and caused B cells to develop into IL-2 responsive cells. Furthermore, injection of IL-2 inhibited IgG1 and IgE production by Nb-inoculated mice. To understand the mechanism of this IL-2-mediated inhibition, we used an in vitro IgG1 and IgE induction system. B cells from Nb-inoculated mice displayed an increase in the capacity of IL-2 to inhibit lipopolysaccharide (LPS) plus IL-4-driven IgE and IgG1 production, indicating that B cells expressing IL-2R beta are highly sensitive to IL-2. This inhibition was principally dependent upon the direct action of IL-2 on B cells. However, partial abolition of IL-2 inhibitory action by anti-IFN-gamma treatment suggested that endogenous IFN-gamma released from IL-2-stimulated cells was also involved in this IL-2-mediated IgE and IgG1 inhibition. Northern blot analysis demonstrated that IL-2 inhibited IL-4 induction of germline and productive C epsilon transcripts in LPS-stimulated B cells. Digestion-circularization polymerase chain reaction analysis revealed IL-2 inhibited IL-4 induction of s mu-s gamma 1 rearrangement in LPS-stimulated B cells.
OBJECTIVES: To understand the prevalence of polyneuropathy and correlations among the clinical manifestations, electrophysiological findings, and degree of exposure to carbon disulphide (CS2) in workers who were exposed to variable concentrations of CS2 in a viscose rayon factory. METHODS: All the 163 workers received a detailed physical and neurological evaluation. Fixed point air samples were analysed for CS2. Nerve conduction velocity was studied in 26 workers with symptoms similar to neuropathy. RESULTS: Nine workers (53%) with overt polyneuropathy from the fibre cutting department and 19 workers (13%) with oligosymptoms similar to polyneuropathy from various jobs were noted. The fixed point air concentrations of CS2 were 150-300 ppm in the cutting areas and 15 to 100 ppm in the spinning areas. The estimated eight hour time weighted averages in the fibre cutting areas were 40-67 ppm. The occurrence of polyneuropathy was generally correlated with the degree of exposure to CS2. Nerve conduction velocities (NCVs) were significantly different in the overt polyneuropathy and subclinical polyneuropathy groups from the normal controls. The sensitive indicators for CS2 polyneuropathy were distal latency, motor NCV, and amplitude of sensory nerve action potentials in sensory NCVs. CONCLUSION: The outbreak of polyneuropathy was attributed to higher concentrations of CS2 in fibre cutting areas. Even in other jobs with relatively lower concentrations of CS2, the hazard of subclinical polyneuropathy cannot be overlooked.
BACKGROUND: The use of neuraxial opioids has gained popularity over the last few years; they may augment the analgesia produced by the local anesthetic through direct binding with the specific spinal receptors. Morphine, a lipophobic opioid, may not be optimal as an intrathecal drug for intraoperative analgesia because of its slow onset. The lipophilic opioid, fentanyl for instance, if administered intrathecally, its onset is fast and many of its merits by virtue of its lipophilic property may be seen intraoperatively. METHODS: Seventy five healthy pregnant women who sustained cesarean section under spinal anesthesia were assessed in a randomized fashion. The spinal anesthetic used was 0.5% hyperbaric bupivacaine. Patients were divided into 5 groups, 15 in each group. Fentanyl 0 (Group I), 7.5 (Group II), 10 (Group III), 12.5 (Group IV) and 15 (Group V) micrograms was respectively added to normal saline to make a total volume of 0.3 ml, which was then added to bupivacaine and administered to patients in a randomized fashion. The effect of analgesia, vital signs and side effects were observed every 5 min during operation and every 30 min after operation. RESULTS: It was disclosed that all patients in group V and IV had excellent analgesia intraoperatively, while only 33.3% patients in the control group had an analgesia which was qualified as excellent. Complete analgesia (time from injection to first report of pain) also lasted longer in group IV (201.3 +/- 16.4 min, mean +/- SEM) and group V (210.3 +/- 18.6 min) compared with group I (118.9 +/- 10.4 min). The duration of effective analgesia (time from injection to first parental opioid) was increased with the dose of intrathecal fentanyl above 12.5 micrograms (293 +/- 22.4 min). Both complete analgesia and effective analgesia were not significantly different between group IV and group V. Pruritus was the most common side effect. The incidence of shivering decreased significantly in group IV & V as compared with control group. CONCLUSIONS: The combination of bupivacaine with a dose of fentanyl as low as 7.5 micrograms did not produce actual clinical effects. As the dose of fentanyl was increased to 12.5 micrograms or 15 micrograms the quality of surgical analgesia was better and the postoperative analgesia lasted longer. It seemed that the clinical effect might reach its ceiling at the dose of 12.5 micrograms. Pruritus was the most common side effect, but it was mild.
BACKGROUND: The physiological effect of CO2 pneumoperitoneum during laparoscopy is a great concern of the anesthesiologists. Its effect in pediatric laparoscopy has not been previously reported. The purpose of this study was to examine the physiological alteration of pediatric patients during CO2 pneumoperitoneum. METHODS: One hundred and twenty six children aged from 11 mon to 13 yr undergoing laparoscopic inguinal exploration were divided into three groups based on age orientation: group I comprising 40 children with age from 11 mon to 2 yr; group II 46 children with age between 2 to 5 yr; and group III 40 children aged from 5 to 13 yr. All patients received endotracheal anesthesia with halothane-N2O in 50% O2 and atracurium for muscle relaxation. Respiration was controlled by an Ohmeda 7000 ventilator with constant minute ventilation to maintain baseline end-tidal CO2 tension (PETCO2) between 32-33 mmHg. After anesthesia, CO2 was insufflated into the peritoneal cavity via the opened hernia sac. The intraabdominal pressure exerted by CO2 was 10 mmHg and the duration of pneumoperitoneum and laparoscopy was 15 min. We recorded airway pressure, PETCO2, body temperature, blood pressure, heart rate, heart rhythm, and oxygen saturation simultaneously at 1 min interval before, during, and after laparoscopy. RESULTS: The airway pressure and PETCO2 showed significant increases during laparoscopy (15-18% and 18-20% respectively) in all cases, but the percentage of increases were not significantly different among groups. However, the PETCO2 change in terms of time lag were different between groups: (1) the time lag from CO2 insufflation to the emergence of PETCO2 change (latent period) was respectively 0.7 +/- 0.1 (mean +/- SD) min in group I, 0.9 +/- 0.2 min in group II and 1.5 +/- 0.2 min in group III (p < 0.05); (2) the PETCO2 change from baseline to a plateau (ascending period) was respectively 4.2 +/- 0.6 min in group I, 6.3 +/- 1.0 min in group II and 9.1 +/- 1.1 min in group III (p < 0.05); (3) the PETCO2 decline from plateau to baseline after CO2 deflation (descending period) was respectively 6.2 +/- 0.5 min in group I, 8.3 +/- 0.8 min in group II and 12.0 +/- 1.3 min in group III (p < 0.05). The body temperature and hemodynamics including blood pressure, heart rate, heart rhythm, oxygen saturation were not significantly changed during laparoscopy in all groups. CONCLUSIONS: The changes of PETCO2 during laparoscopy did not influence the hemodynamic stability in our study. The younger children give a faster reaction time of PETCO2 change after CO2 insufflation than do the older children which may be related to the variation of physiological exhibition at different state of development.
Three isotoxins (SP I-III) of the beta-bungarotoxin family were purified to homogeneity via a series of isolation procedures including a final step of h.p.l.c. on an SP column washed with a linear gradient of 0.2-0.6 M sodium acetate at pH 7.4. Their proportions varied greatly with the batch of venom. Each isotoxin was demonstrated by SDS/PAGE to contain a phospholipase A2 subunit and a non-phospholipase A2 subunit. The three proteins were reductively alkylated with 4-vinylpyridine and the alkylated derivatives of the two subunits of each isotoxin were separated. N-Terminal sequence analysis of the alkylated derivatives revealed that the three isotoxins probably share a common phospholipase A2 subunit but differ in their non-phospholipase A2 subunits. The non-phospholipase A2 subunits of SP II and SP III were identical with those of beta 2- and beta 1-toxin respectively, except that there was an additional valine inserted between Thr-18 and Val-19 in beta 2-toxin and Pro-18 and Val-19 in beta 1-toxin. The non-phospholipase A2 subunit of SP I differed greatly from that of SP III but was almost identical with that of SP II, except that Lys-14 and Ala-29 in SP II were replaced by Arg-14 and Glu-29 in SP I. Analysis of the effect of CaCl2 on protein fluorescence showed the existence of a low- and a high-affinity site on the different domains of each isotoxin for Ca2+ binding. The three isotoxins showed no great difference in their ability to bind Ca2+ on both the high- and low-affinity site. They had slightly different phospholipase A2 activities but differed to a great extent with respect to their neurotoxic effects. LD50 values increased in the order SP I > SP II > SP III. In contrast, the ability to inhibit the indirectly evoked contraction of chick biventer cervicis muscle was in the order SP III > SP II > SP I.
The purpose of this work was threefold: to enhance the adhesion between the reinforced absorbable calcium phosphate (CaP) fibers and the absorbable polyglycolide acid (PGA) matrix, to improve the hydrolytic degradation of the CaP fibers, and preliminarily to evaluate the cytotoxicity of the plasma treated surface of CaP fibers. A CH4 plasma treatment was used to achieve these goals. The microbond method was used to evaluate the effects of the plasma treatment on the interfacial shear strength between the PGA matrix and CaP fibers. The treatment increased the mean interfacial shear strength of the CaP/PGA composite system by 30%. AFM data showed that CH4-treated CaP fibers had considerable microscopic surface roughness, which facilitated mechanical interlocking between the reinforced CaP fibers and PGA matrix. The untreated and plasma-treated fibers were also subjected to in vitro hydrolytic degradation in a phosphate buffer solution of pH 7.44 at 37 degrees C for up to 15 h. CH4 plasma treatment resulted in a considerable lower polar term of the surface energy and a significantly higher disperse term in water media. This change in the proportion of surface energy terms may reduce the capillary wicking phenomena of water through the CaP fiber/PGA matrix interface. The CaP fiber dissolution studies revealed that both CH4 and Parylene plasma polymer coatings appeared to reduce the solubility of CaP fibers, and that the magnitude of reduction was higher in an acidic than a physiologic pH environment. A preliminary cytotoxicity test revealed that both CH4 and Parylene plasma-treated CaP fibers were noncytotoxic. Additional research should be done to determine the optimum plasma conditions and the possible use of other plasma gases to improve the interfacial shear stress of the composite and the dissolution properties of CaP fibers.
The purpose of this study was to derive new mathemtic formulae that could be used reliably to predict water permeability of surgical fabrics before they are made and tested for water permeability. Such a theoretical prediction of water permeability, Qprd, of surgical fabrics is needed for not only timely characterization but also for assisting in more efficient future design and development of better surgical fabrics. Two mathematic formulae, Qw and Qk, were derived from the Buckingham Pi Theorem, in which relevant fiber and fabric parameters were placed into dimensionless pi groups and computed for 25 commercial and experimental vascular fabrics. Linear regression analysis of the relationship between these pi groups with water permeability on the woven and knitted grafts yielded coefficients for the corresponding pi groups that were required for constructing appropriate mathematic formulae to predict water permeability of vascular fabrics. When proper sources of the experimentally determined water permeability, Qexp, were chosen for comparison, we found that 86% of woven fabrics (6 of 7) and 77% of knitted fabrics (14 of 18) had their Qprd within 10% of their Qexp. This high percentage of close matching (within 10%) between Qprd and Qexp should be considered satisfactory because the experimental error for obtaining Qexp is generally higher than 10%. The difference between Qprd and Qexp ranged from as small as 0.27% to as high as 74.2%, depending on the type of fabrics and source of Qexp.(ABSTRACT TRUNCATED AT 250 WORDS)
In vivo occipital asymmetry (OA) measurements have been used to infer functional asymmetries such as language dominance. We investigated the degree of correlation between OA measurements derived by the same rater from different scans of the same subject. We used magnetic resonance (MR) and computerized axial tomography (CT) to study correlations between MR:MR, CT:CT and CT:MR. The highest intrasubject correlation was for MR:MR (r = 0.79). The CT:CT value was similar (r = 0.78) and the CT:MR correlation was slightly lower (r = 0.72). The findings indicate that the reliability of occipital asymmetry measurements is modest at best, setting a low ceiling on the valid use of this variable to infer other indexes.
A 3-year-old girl presented with a prolapsed cutaneous vesicostomy, and symptoms and signs of acute intestinal obstruction. The vesicostomy had been performed when she was 19 months old for bilateral vesicoureteral reflux. Postoperatively, prolapse of the bladder from the stoma occurred almost daily. The prolapsed part retracted naturally when the patient was relaxed and reclining. Intestinal obstruction was due to strangulated herniation of the bowel into the prolapsed bladder via the stoma of vesicostomy. Treatment consisted of manual reduction and the stoma of the vesicostomy was revised with the patient under general anesthesia.
Fractal analysis has recently been suggested [Med. Phys. 20, 1611-1619 (1993)] as a means to characterize the structure of cancellous bone by measuring the fractal dimension using a box counting algorithm. This work re-examines the possible fractal nature of such structures on nuclear magnetic resonance (NMR) images of cancellous bone by estimating the trabecular boundary length as a function of box size under various experimental conditions. On high-resolution images (pixel sizes on the order of 50 microns) and signal-to-noise ratios of 30, the trabecular boundary turns out to be a smooth surface relative to the achievable resolution and is thus nonfractal. The fractal dimension of the trabecular structure is undefined and can vary significantly as a function of image signal-to-noise ratio. The present work further indicates the "apparent" fractal dimension obtained by box counting to be a reflection of marrow pore size. In conclusion, the results indicate that, at the currently achievable resolution, the box counting algorithm is not suitable for fractal analysis on images of cancellous bone and that the fractal appearance of the trabecular network reported previously is artifactual.
Six sbc::Tn5 insertions and one sbc::IS50 insertion, which cause recE expression in Escherichia coli, have been cloned, and their DNA sequences have been determined. The sites of insertion are found at three positions in a 10-bp region: 58, 63, and 68 bp upstream of recE. Primer extension experiments with the cloned Tn5 insertions demonstrate that recE transcripts start adjacent to the insertion elements of five of these mutations and both adjacent and one nucleotide within the insertion element for the sixth mutation. This supports the hypothesis that these mutations have inserted a promoter, and PCR analysis reveals an outward promoter within the distal 69 nucleotides of Tn5. Primer extension analysis of RNA from the uncloned Tn5 and IS50 mutants reveals three additional insertion sites close to the others. Because all the insertions lie in the spacer region between racC and recE, transcribed in sbcA6 and sbc-23 strains, we propose that these insertions be renamed recEs::Tn5 and recEs::IS50.
A case of Kluver-Bucy syndrome associated with delayed cerebral necrosis after radiation therapy and chemotherapy is reported. The patient--a 51-year-old man who was a victim of nasopharyngeal cancer--developed a complex behavioral disturbance consisting of visual agnosia, alteration of sexual behavior, strong oral tendency, placidity, memory deficit and speech disturbance one year after two courses of irradiation and chemotherapy. Brain computed tomography disclosed bilateral temporal hypodensity with edema. The patient expired from cachexia three months later. The clinical picture fulfilled the criteria of Kluver-Bucy syndrome. It should be emphasized that this syndrome may occur after irradiation and chemotherapy in patients with nasopharyngeal cancer.
beta 1-Bungarotoxin consists of a phospholipase A2 subunit and a non-phospholipase A2 subunit. The toxin was oxidized with a 100-fold molar excess of chloramine T with respect to the methionine content of the protein in 0.1 M Tris/HCl at pH 8.5 and at room temperature. Reactivities of the two methionine (Met-6 and Met-8 of the phospholipase A2 subunit), five histidine, 14 tyrosine and one tryptophan residues of one toxin molecule with chloramine T were assessed from the change in intrinsic fluorescence and amino acid composition of the protein. Met-8 and one tyrosine on the phospholipase A2 subunit and less than one histidine were oxidized, while Met-6 remained intact after 30 min of reaction. One histidine and approx. two tyrosine residues were oxidized when both methionine residues were oxidized after 90 min of reaction. The sole tryptophan was oxidized slightly throughout the reaction. The chloramine T oxidation did not destroy the two Ca(2+)-binding domains, though it modified the toxin to become less effective at binding Ca2+. The modified toxin obtained after 30 or 90 min reaction time retained 65% or 40% of the phospholipase A2 activity of the parent toxin, but both were not lethal to mice and showed a very weak ability to induce the indirectly evoked contraction of chick biventer cervicis muscle. It is suggested that Met-8 may play an important role in the phospholipase A2-independent interaction with the nerve terminal membrane during the neurotoxic effect of beta 1-bungarotoxin.