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Biomedical subjects

T C Huang

Publications and source records attributed to T C Huang.

At least 37 records · Page 2Linked to original sources

Control of the dehydration process in production of intermediate-moisture meat products: a review.

IM meat products are produced by lowering the aw to 0.90 to 0.60. Such products are stable at ambient temperature and humidity and are produced in nearly every country in the world, especially in developing areas where refrigeration is limited or unavailable. Traditionally IM meats use low cost sources of energy for drying, such as sun drying, addition of salt, or fermentation. Products produced by different processes are of interest since they do not require refrigeration during distribution and storage. Many different IM meat products can be produced by utilizing modern processing equipment and methods. Production can be achieved in a relatively short period of time and their advantages during marketing and distribution can be utilized. Nevertheless, a better understanding of the principles involved in heat transfer and efficiency of production are still needed to increase efficiency of processing. A basic understanding of the influence of water vapor pressure and sorption phenomena on water activity can materially improve the efficiency of drying of IM meats. Predrying treatments, such as fermentation and humidity control, can also be taken advantage of during the dehydration process. Such information can lead to process optimization and reduction of energy costs during production of IM meats. The development of sound science-based methods to assure the production of high-quality and nutritious IM meats is needed. Finally, such products also must be free of pathogenic microorganisms to assure their success in production and marketing.

Absorption↗

Transport and hydrolysis of urea in a reactor-separator combining an anion-exchange membrane and immobilized urease.

A membrane reactor-separator, in which an anion-exchange membrane and a urease-immobilized poly(vinyl alcohol) (PVA) membrane were clamped together to separate the feed solution and the stripping solution of a dialysis cell, was constructed. The urea in the feed solution passed through the anion-exchange membrane, water film, and then was hydrolyzed to ammonium carbamate in the urease-immobilized PVA membrane. The experimental results showed that no ammonium ion was found in the feed solution under either phosphate or citrate buffer systems at 0.05-0.2 mol dm-3 and pH 6-9, and various initial concentrations of urea in the feed solution (20-200 mmol dm-3). This indicates that the water film between two membranes allows the carbamate ions to decompose into ammonium and carbonate ions completely before entering the anion-exchange membrane. The device therefore can be used for the removal of urea from feed solution, while preventing the backflow of ammonium ions from the stripping solution or water film into feed solution. It has significant potential in the development of a wearable or portable artificial kidney. The properties of the urease-immobilized PVA membrane were examined. A kinetic model describing the transport-reaction behavior of urea in the membrane reactor-separator was developed, and the optimum values of the reactor parameters were obtained.

Biological Transport↗

Prevalence of larval helminths in freshwater snails of the Kinmen Islands.

A survey of larval helminths in freshwater snails of Kinmen was conducted from 1986 to 1987. Parasitological examinations of a total of 726 live snails collected from 25 loci revealed that 20 of 80 Bithynia fuchsiana were infected with metacercariae of Echinostoma gotoi and 36 with metacercariae of other echinostomes. Among 57 Radix auricularia swinhoei snails, 27 were infected with echinostomes and eight with metacercariae of other flukes. Of 20 Cipangopaludina chinensis, 18 were found with larvae of echinostomes. Larval trematodes were also found in three of 37 Austropeplea ollula and two of 87 Gyraulus spirillus. Third-stage larvae of Parastrongylus cantonensis were found in Ampullarius canaliculatus (5/103), Sinotaia quadrata (20/141), Hippeutis umbilicalis cantori (1/70) and Gyraulus spirillus (2/87). Segmentina hemisphaerula were not infected. Cercariae of Centrocestus formosanus, Haplorchis pumilio and a xiphidiocercaria were found in three, two and two specimens, respectively, of 37 Thiara tuberculata.

Animals↗

Fluconazole in the treatment of candida peritonitis in continuous ambulatory peritoneal dialysis: report of a case.

There are no generally accepted therapeutic regimens for the treatment of fungal peritonitis in patients with continuous ambulatory peritoneal dialysis (CAPD). We share our experience in the treatment of candida peritonitis using oral fluconazole. In CAPD patients with candida peritonitis, fluconazole seems to offer several advantages over other antifungal drugs.

Administration, Oral↗

[Clinical study of 78 cases of nontyphoid Salmonella bacteremia].

A total of 78 consecutive patients with nontyphoid salmonella bacteremia were selected by microbiological and chart reviewing in the past 18 months to study its epidemiology, treatment and prognosis at Chang Gung Memorial Hospital Linkou Medical Center. Children under 5 years of age had the highest incidence (28.2%) followed by patients between the ages of 50 to 79 years (16.2%). Nontyphoid salmonella bacteremia occurred with greatest frequency from June through October. Only 24 out of 78 patients (30%) had diarrhea associated with this disease. The concomitant focal infections with bacteremia included septic arthritis (5.1%), urinary tract infection (3.8%), peritonitis (2.6%), and empyema (1.3%). The overall curde fatality rate was 34.6%. Eighty nine point three percent of adult patients had underlying diseases. Hundred percent of blood isolates were sensitive to all available third generation antibiotics in the hospital (i.e. cefotaxime, moxalactam, ceftriaxone and ceftazidime). However, only 39.5%, 32.9%, and 68.3% were sensitive to ampicillin, chloramphenicol, and trimethoprim--sulfamethoxazole, respectively. According to the treatment results, the use of third generation cephalosporins compared with other antibiotics is not statistically significant.

Adolescent↗

Laser-assisted nerve repair. Laser-trimming of nerve ends with epineurial suture anastomosis.

Suture repair of cranial and peripheral nerves has reached a maximal level with the use of advanced microneurorrhaphy techniques; however, functional recovery of the repaired nerve is still often unsatisfactory due to misrouted axonal regrowth. Freeze-trimming the nerve ends prior to anastomosis has been shown to significantly improve fascicular alignment and subsequent functional recovery. This study assessed the feasibility of using laser energy to trim the nerve ends prior to suture anastomosis. The 302-nm excimer laser was used to trim the severed sciatic nerve ends prior to anastomosis in 28 rats. Scanning electron and light microscopy, horseradish peroxidase retrograde labeling, nerve conduction velocity, and functional recovery were assessed postoperatively. The excimer laser was able to trim the nerve ends flat thereby facilitating the coaptation and alignment of the nerve ends. Misrouting of axons occurred in both the laser-trim and control groups. Although this technique has theoretical advantages, no statistically significant improvement was demonstrated in this investigation. This may have been in part due to the small sample size, since a small increment of improvement was noted. It is possible, however, with continued refinements in technique that a functional improvement may be seen in subsequent studies.

Anastomosis, Surgical↗

A study on the removal of urea from aqueous solution with immobilized urease and electrodialysis.

A five-compartment electrodialyzer with immobilized urease was developed for the removal of urea from aqueous solution. The immobilized urease, supported on polyurethane foam, was placed in the central (dilute) compartment, where urea was hydrolyzed and the products NH4+ and CO3(2-)/HCO3- were removed simultaneously by electrodialysis. The system was studied both under constant current and under constant voltage. The effects of urea concentration and applied current or voltage on the removal of urea and ammonium ions from the dilute solution were investigated. The variations of the pH of dilute solution, the current or voltage of system, and current efficiency were also examined during reaction-electrodialysis. The removal of urea by enzymic reaction was not affected significantly by the applied electric field. The current efficiencies for removing ammonium ions from dilute solution were mostly within 40-80%, and the removal percentage of ammonium ions was dependent on current density and current efficiency.

Dialysis↗

Laser vs. suture nerve anastomosis.

The repair of injured or transected nerves is frequently encountered in head and neck surgery. Recently, CO2 lasers with milliwatt capability and micrometer spot sizes have been developed that may be used in nerve anastomosis. A comparative study was performed between microsuture and CO2 laser repair of transected sciatic nerves in rats. Nerve regeneration was measured in terms of morphology, electrophysiology, and function. Histologic studies revealed no difference in the size and number of regenerated axons, although there was less scar tissue formation at the anastomotic site with the laser repair. EMG and nerve conduction velocity were similar for the two repair methods. Functional recovery, as determined objectively using measurements of gait footprints, showed no difference between suture and laser repair. Laser-repaired nerves did have a higher dehiscence rate, although this problem can probably be prevented by splinting the rats postoperatively. However, laser repair was faster and simpler than suture repair and required less manipulation of the nerve. This study shows laser repair of peripheral nerves is possible with results comparable to conventional microsuture neurorrhaphy. Laser nerve anastomosis may be an effective alternative to suture nerve repair.

Anastomosis, Surgical↗

Setting of the Circadian N(2)-Fixing Rhythm of the Prokaryotic Synechococcus sp. RF-1 while Its nif Gene Is Repressed.

The N(2)-fixing activity of the prokaryotic Synechococcus sp. RF-1 was repressed in the presence of nitrate. When the cultures in nitrate-containing medium were exposed to diurnal light-dark cycles, an endogenous circadian N(2)-fixing rhythm developed after the cells were transferred to nitrate-free medium and incubated in continuous light. The N(2)-fixing phase of the rhythm coincided with the dark phase of the light-dark cycles that were imposed when the cells were in nitrate-containing medium. The results indicate that after the endogenous N(2)-fixing rhythm has been set, it can be kept latent for at least 38 hours before first manifesting itself.

Journal Article↗

Circadian Rhythm in Amino Acid Uptake by Synechococcus RF-1.

In the prokaryote Synechococcus RF-1, circadian changes in the uptake of l-leucine and 2-amino isobutyric acid were observed. Uptake rates in the light period were higher than in the dark period for cultures entrained by 12/12 hour light/dark cycles. The periodic changes in l-leucine uptake persisted for at least 72 hours into continuous light (L/L). The rhythm had a free-running period of about 24 hours in L/L at 29 degrees C. A single dark treatment of 12 hours could initiate rhythmic leucine uptake in an L/L culture. The phase of rhythm could be shifted by a pulse of low temperature (0 degrees C). The free-running periodicity was "temperature-compensated" from 21 to 37 degrees C. A 24 hour depletion of extracellular Ca(2+) before the free-running L/L condition reduced the variation in uptake rate but had little effect on the periodicity of the rhythm. The periodicity was also not affected by the introduction of 25 mm NaNO(3). The uptake rates for 20 natural amino acids were studied at 12 hour intervals in cultures exposed to 12/12 hour light/dark cycles. For eight of these amino acids (l-Val, l-Leu, l-Ile, l-Pro, l-Phe, l-Trp, l-Met, and l-Tyr), the light/dark uptake rate ratios had values greater than 3 and the rhythm persisted in L/L.

Journal Article↗

Age and alcohol, marijuana and hard drug use.

Developmental theories of adolescent alcohol, marijuana and hard drug use have emphasized the factor of age as an explanatory variable. However, studies have not attempted to examine the manner in which age interacts with other explanatory variables to predict usage. This article examines the interactive nature of age in predicting alcohol, marijuana and drug use based on a sample of 435 students from schools in a north-central county of Illinois. The results indicated statistically significant interaction terms for age with peer and social control factors for each type of usage. These findings suggest that many factors commonly associated with adolescent usage may be conditioned by age. The article also recommends that additional research examine the interactive nature of age, as well as other factors, when testing theories of alcohol, marijuana and drug use among adolescents.

Adolescent↗

Circadian Rhythm of the Prokaryote Synechococcus sp. RF-1.

The prokaryotic Synechococcus sp. RF-1 exhibited a nitrogen fixation circadian rhythm with characteristics remarkably similar to the circadian rhythm of eukaryotes. The rhythm had a free-running period of about 24 hours when the length of the preen-trained cycle did not differ too much from 24 hours, and it was insensitive to changes in temperature from 22 degrees C to 33 degrees C. Because the endogenous rhythm of nitrogen fixation was not affected by a phase-shift of its previous cycles, the circadian rhythm in Synechococcus sp. RF-1 was not considered to be controlled simply by a feedback mechanism.

Journal Article↗

Analyses of surface membrane carbohydrates in parasitic flagellates of the order kinetoplastida using lectins.

Crithidia fasciculata, Leishmania donovani, Leishmania major, Leishmania mexicana amazonensis, Leishmania tropica, Leishmania tarentolae, Trypanosoma sp. from Formosan bats (Tb), Trypanosoma lewisi, Trypanosoma musculi, and different strains of Trypanosoma cruzi (Tc) were cultivated at 27 degrees C in a liquid culture medium. Flagellates harvested from log phase culture were analyzed for their lectin agglutinating characteristics with concanavalin A (Con A), Peanut agglutinin, Ricinus communis agglutinin 120, soybean agglutinin (SBA), Ulex europeus agglutinin (UEA) and wheat germ agglutinin (WGA). Results indicated that all these flagellates might have D-galactose and methyl- alpha-D-manopyranoside on their surface. The presence of L-Fucose, which complexes specifically with UEA, could not be demonstrated on the surface of these flagellates. Results from quantitative comparison of surface molecules of Tb and the Tulahuen strain of Tc suggested that Tb may have more WGA-binding molecules while Tc may have more ConA-binding molecules. Pretreatment of the flagellates with 0.05% trypsin at 37 degrees C for 30 minutes caused some reduction of agglutination titers. Cell agglutination with lectins was completely inhibited or reversed in the presence of the specific lectin-binding monosaccharides.

Agglutination↗

Punctal occlusion and topical medications for glaucoma.

We studied the effects of punctal occlusion on the intraocular pressures of patients treated with topical medications for glaucoma. Silicone punctal plugs were used to occlude the inferior punctum of one eye in each of 19 patients treated with identical antiglaucoma eyedrops in both eyes. The intraocular pressures before and after punctal occlusion were compared. The eyes with the punctal plugs showed a statistically significant (P less than .0001) decrease in pressure of 1.32 mm Hg after punctal occlusion when compared to that of the fellow control unplugged eyes. The intraocular pressures in the plugged eyes decreased an average of 1.82 mm Hg after punctal occlusion when compared to before punctal occlusion (P = .001). The intraocular pressure in the unplugged control eyes did not change significantly after punctal occlusion of the fellow treated eye.

Administration, Topical↗

Pathology of Schistosoma haematobium infection in the capuchin monkey (Cebus apella).

Capuchin monkeys exposed to 500-2000 Schistosoma haematobium cercariae were followed for up to 6 1/2 years after infection. Worm burdens decreased as infections became more chronic and decreasing numbers of eggs and active circumoval lesions were found in the bladder and elsewhere. Nodular and hyperplastic epithelial lesions of the urinary bladder were not seen during the first year of infection but occurred in 30% of monkeys examined 1-2 years after infection and in 23% of those examined between the second and third years; they were present in only 3% of monkeys studied 3-6 1/2 years after infection. These epithelial proliferative lesions were located near foci of egg deposition and occurred in the monkeys with the most intense active lesions in the bladder. The lesions regressed in animals followed sequentially. The lesions thus appear not to be neoplastic. Obstructive lesions of the ureter accompanied by hydronephrosis were present in a few animals. The obstructive uropathy did not appear to cause significant morbidity. Mortality was substantial among infected monkeys at most intervals after infection but was rare among uninfected controls.

Animals↗

Resistance of capuchin monkeys to reinfection with Schistosoma haematobium.

Capuchin monkeys were resistant to reinfection with Schistosoma haematobium one year after exposure to 500 cercariae, but worms in these monkeys continued to produce normal numbers of eggs. Monkeys were apparently completely refractory to reinfection when challenged 2-5 years after an initial exposure of 1000 to 2000 cercariae.

Animals↗

Quality improvement of sweet-potato (Ipomoea batatas L. Lam.) roots as feed by ensilage.

1. Sweet-potato (Ipomoea batatas L. Lam.) strips (SPS) mixed with maize powder (CP) in proportions 10:0, 9:1, 8:2, and 7:3 were ensiled for 1, 2 or 3 months. 2. Trypsin inhibitor activity (TIA) decreased during ensilage in samples of all treatments while the SPS-CP mixture (7:3, w/w) ensiled for 3 months contained the lowest TIA. 3. SPS-CP (8:2, w/w) dried or ensiled for 2 months, or ensiled for 2 months and dried, were each mixed with twice the amount of control diet (1:2, w/w) to make three diets. These three diets together with the control diet were used for a feeding experiment with rats to evaluate the nutritive value. 4. General composition analysis (including metabolizable energy), fatty acid composition and amino acid analysis (including percentage of essential amino acids) of the samples did not change during ensilage to an extent which could explain the improved performance of rats fed on ensiled diets. 5. Rats fed on diets containing dried SPS-CP (8:2, w/w) showed significantly lower (P less than 0.05) body-weight gain than rats fed on the control diet or ensiled SPS diets, at the end of the 8th week. They also showed enlargement of the pancreas. The adverse effect of SPS was associated with TIA which seemed to be prevented to some extent by ensilage. 6. The possibility that the starch of SPS may also contribute to the adverse effect cannot be excluded at present.

Amino Acids↗

Quantification of intersegmental reactions during rapid swing motion.

A simple mathematical model was developed to quantify the non-muscular reactions between two adjacent segments undergoing rapid free-segment motion. Newtonian equations of motion were used to simulate the trajectories of the two segments using the input parameters of linear acceleration and muscular moment acting only about the proximal end of the proximal link. The intersegmental muscular force and moment were mathematically considered to be zero, and no constraints were placed on the motion of the two segments. The motion of the thigh and shank during the swing phase of running was simulated by the model and compared to the real motion obtained from cinematographic records. The simulation demonstrated that proximal thigh motion has a significant effect on the distal shank motion. Depending on the initial conditions, intersegmental reactions alone can produce large increases in distal segment speed. The role of the knee musculature in preventing these reactions during the swing phase of running was inferred.

Biomechanical Phenomena↗