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Biomedical subjects

C Hong

Publications and source records attributed to C Hong.

At least 127 records · Page 7Linked to original sources
PubMed1987

Rapid elongation of arteries and veins in rats with a tissue expander.

The saphenous arteries and veins of 40 rats were elongated with 20-cc tissue expanders underlying the leg adductor muscles. The mean rate of successful elongation of the vessels was 84 +/- 47 percent SD, with a maximum gain of 140 percent. The fastest mean elongation velocity reached 45 percent per day. Thrombosis occurred only with stretching velocities of more than 10 percent per day, which seemed to be a safe margin. Distribution of the volume into many intervals was safer than infrequent high-volume injections. Histology showed no reduction in vessel wall diameter or loss intimal integrity. Subendothelial cellular proliferation was an indicator of this rapid regeneration. Microvascular anastomoses performed in elongated arteries and veins had the same patency rate (90 percent) as in controls.

Animals↗
PubMed1987

Enhanced neovascularization of rat tubed pedicle flaps with low perfusion of the wound margin.

To study the role of ischemia due to low perfusion as the inciter of neovascularization, caudally based 3 X 9 cm skin flaps were created on the dorsum of 50 Sprague-Dawley rats. After injection of 0.2 ml 10% fluorescein, the animals were divided into two groups. In group I (n = 25), the distal margin of the flap tip was 1 cm proximal to the border of the fluorescence (good perfusion). In group II (n = 25), the flap was cut 1 cm distally in the nonfluorescent part (poor perfusion). The tips of the tubed flaps were transferred to a wound bed on the right flank. After 10 days, the pedicles were ligated, so that flap survival depended totally on the new vascular supply from the inset area of the flap. The flaps in group I showed a significantly higher rate of necrosis of 52.4 +/- 15.1 percent versus 1.7 +/- 1.4 percent in group II (p less than 0.0001), although the flap length in group I (5.85 +/- 1.16 cm) was less than in group II (7.15 +/- 0.95 cm; p = 0.0001). A nearly three times larger amount of tissue based on the new blood supply survived in group II compared to group I. Xerograms after injection of PbO2-gelatine on day 10 showed an increased ingrowth of blood vessels in group II. After excluding the delay phenomenon as the cause for the difference in necrosis rate, it is concluded that the only possible explanation is an enhancement of neovascularization by a perfusion gradient between the wound margins.

Angiography↗
PubMed1987

Rickettsial and serologic evidence for prevalent spotted fever rickettsiosis in inner Mongolia.

A field study in northeastern Inner Mongolia, People's Republic of China, in June of 1985 demonstrated a spotted fever group rickettsiosis. Two strains of spotted fever group rickettsiae were isolated. One strain was obtained from the blood of a patient with an eschar, regional lymphadenopathy, and history of a recent tick bite. The other strain originated from ova of ticks, Dermacentor nuttalli. These represent the second isolate of a spotted fever group rickettsia from a human and the first isolate from tick ova in the People's Republic of China. Antibodies to these rickettsiae were demonstrated by indirect immunofluorescence in the sera of 4% of healthy children and 34% of healthy human adults, in 58% of sheep, and in 76% of cattle in the same location. Hemolymph test revealed rickettsiae in 6 of 36 D. nuttalli examined.

Adolescent↗
PubMed1987

Elongation of axial blood vessels with a tissue expander.

The authors present a rat model and a surgical technique for the study of elongation of axial blood vessels using a tissue expander. The successful demonstration of elongation of axial vessels while maintaining patency further encourages use of the concept in other organ systems such as bowel, ureter, and so on.

Animals↗
PubMed1987

Apple-coring technique for severe gynecomastia.

In evaluating cases of gynecomastia it is important to differentiate between physiologic and pathologic forms. The authors review gynecomastia with reference to its occurrence in various age groups, the pathologic features and etiology, and the differentiation and classification of the two types. If the gynecomastia is large or longstanding, surgical treatment may be necessary. The authors review the various surgical techniques used from the early descriptions up to the present. The apple-coring technique has the advantages of leaving an inconspicuous scar, allowing correction of the hypertrophic areola and good chest-wall contour, maintaining the viability of the nipple and decreasing the common complications of inverted nipples and a doughnut-shaped deformity. The results and outcome in four patients treated by the apple-coring technique are reported. Although the method is not perfect, the results are encouraging and the technique is an addition to the armamentarium of surgeons treating large gynecomastia.

Adolescent↗
PubMed1986

Effects of thyroid hormone on cardiac size and myosin content of the heterotopically transplanted rat heart.

Infrarenal heterotopic cardiac isografts maintain structural and functional integrity. We have used this transplantation model to further explore the mechanisms of thyroid hormone-induced cardiac hypertrophy. Thyroid hormone administration, 1-thyroxine (T4) 10 micrograms/animal per d, led to a significant 30% increase in total heart weight and a 40% increase in the myosin content of the in situ heart when compared with control. In contrast, T4 treatment was without effect on the heart weight, protein content, rate of protein synthesis, or calculated myosin content of the heterotopic, nonworking heart. Heterotopic hearts demonstrated a significant decrease in the percentage of the V1 myosin isoenzyme from 95% to 61%. This shift occurred in euthyroid animals but was prevented by T4 treatment. These results suggest that thyroxine-induced cardiac hypertrophy is mediated indirectly via changes in cardiac work. Myosin isoenzyme expression can be altered by changes in work load but is still responsive to increased levels of thyroid hormone.

Adenosine Triphosphatases↗
PubMed1983

Influence of argon laser treatment of glaucoma on corneal endothelium.

The morphometric study of the corneal endothelium was carried out by means of specular microscopy prior to and for one year following laser trabeculoplasty (LTP) or laser iridotomy. A significant increase in the endothelial cell size was demonstrated in 6 months after trabeculoplasty and in 3 months following iridotomy. The magnitude of increase in cell size following laser iridotomy was significantly correlated with the amount of laser energy delivered to the eye. However, such correlation was not demonstrated following LTP where the applied energy was kept fairly constant among the present treated cases. The increase in cell size failed to correlate with clinical factors including IOP before and after laser therapy, age and the presence or absence of endothelial burn. The treatment protocols using reduced energy are indicated to minimize endothelial damage induced by LTP or laser iridotomy.

Adult↗
PubMed1982

Use of Fieldmaster automated perimeter for the detection of early visual field changes in glaucoma.

The efficacy of automated suprathreshold perimetry with Fieldmaster automated perimeter (model 101 PR and 200) was evaluated in the screening for very early glaucomatous visual field defects which failed to be detected with kinetic perimetry using a Goldman perimeter. Evaluation of 117 eyes with elevated intraocular pressure revealed a small, relative defect in the central field in 14 eyes which was confirmed by static perimetry with a Tübinger perimeter. Although Fieldmaster model 200 is equipped with more target positions than model 101 PR, detectability of early defects was almost identical between two models. Automated suprathreshold perimetry with either model of Fieldmaster perimeter is useful in detecting the early changes which may be missed by kinetic perimetry with a Goldman perimeter. Based on the difference in the false positive rate (45.6% with model 200 vs 26.7% with model 101 PR) the screening with 101 PR seems to be more rewarding.

Adult↗
PubMed1982

The corneal endothelial cells in ocular hypertension.

In order to evaluate the effect of the intraocular pressure (IOP) on the corneal endothelial cells, we investigated the endothelial cells of 37 untreated ocular hypertensive patients (72 eyes) and 40 normotensive individuals (65 eyes) by means of the contact type specular microscope, both groups being in the similar age range. The IOP was measured with a Goldmann applanation tonometer and the corneal thickness was determined with a pachymeter of Haag-Streit modified by Mishima & Hedbys. Endothelial photographs were taken in the central area of the cornea and the individual cell area was computed using a computerized image analyzer. The correlation among the IOP, the corneal thickness and the corneal endothelial cell size was analyzed. The mean cell size of corneal endothelial cells failed to be significantly correlated with either the IOP or the corneal thickness and did not show a significant difference between the right and left eyes in ocular hypertensive patients. The mean cell size of central corneal endothelial cells in ocular hypertensives was noted to be larger than that of the normotensives in each age group. The difference was of statistical significance in the subjects younger than 49 years old, and the mean difference in the cell size was the greatest in the patient group younger than 30 years old.

Adolescent↗
PubMed1981

Worm burdens of dairy heifers in England and Wales.

The size and composition of abomasal worm burdens from 143 casualty and cull dairy heifers were estimated. Over 60 per cent had totals of less than 10,000, only four exceeded 100,000 and the overall mean was 16,285. Ostertagia ostertagi was almost always present and usually formed the major proportion of the total. Trichostrongylus axei was recorded in 83 heifers and was the most common species on 17 occasions. The numbers of arrested early fourth stage worms were highest in winter and declined rapidly during spring. O lyrata was only found when O ostertagi was present and always as a small percentage of the total. Similarly in the case of two of the minor species, Skrjabinagia kolchida (= Grosspiculagia podjapolskyi) was never found independently of O leptospicularis (= O crimensis). These relationships are regarded as suggestive of polymorphism.

Animals↗
PubMed1981

Further observations on the action of fenbendazole against inhibited fourth stage larvae of Ostertagia ostertagi.

Two further trials are reported on the effect of fenbendazole on inhibited Ostertagia ostertagi larvae. In the first trial fenbendazole successfully eliminated inhibited burdens of O ostertagi, while in the second trial the effect was variable. As a result of these trials and previous reports it is concluded that a single oral dose of fenbendazole cannot be relied upon to prevent winter (type 2) ostertagiasis.

Animals↗
PubMed1981

The temperamental characteristics of Chinese babies.

This paper investigates the usefulness of Carey's Revised Infant Temperament Questionnaire in the Chinese culture and uses the questionnaire to assess the temperamental characteristics of Chinese babies. The revised questionnaire was administered to the mothers of 349 4--8-year-old infants in Taipei, Taiwan. The face validity of the questionnaire was supported within the different context: the distribution of scores was normal, and the mothers had no trouble in answering the questions. While the general pattern of results was similar to those found in Carey's American sample, differences were found, which may be interpreted in terms of response biases, racial differences, or a combination of these 2 factors. The data are analyzed for possible effects of sex and socioeconomic status, and these findings are in turn compared to results of American studies. Observational studies are seen as necessary in the future to understand the nature of cultural differences in temperament. Follow-up studies will examine the different ways a given temperamental characteristic may be responded to by different cultural environments.

Cross-Cultural Comparison↗
PubMed1979

The effect of age, acquired resistance, pregnancy and lactation on some reactions of cattle to infection with Ostertagia ostertagi.

An experiment is described in which the effects of age, previous infection, pregnancy and lactation on some reactions of cattle to infection with Ostertagia ostertagi were studied. It was found that an acquired resistance to the establishment of worms developed more rapidly in 20-month-old heifers than in calves, that it was unaffected by pregnancy of the host but that it was largely lost by heifers in early lactation. The rate at which populations were turned over, i.e. the mean life-span of worms through the late 4th and 5th stages was unaffected by the factors studied. Although, in the conditions of the experiment, development of the worms was not arrested in susceptible calves, both age of the host and its previous experience of infection were significant causes of arrest, and in previously infected 20-month-old cattle 86% of the worms of a challenge infection were arrested. Pregnancy did not affect the proportion of worms that was arrested but in lactating heifers only marginally more worms were arrested than in calves. Worms that were not arrested grew more rapidly in calves and in lactating heifers than in empty heifers or those in mid-pregnancy.

Age Factors↗