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Biomedical subjects

W C Huang

Publications and source records attributed to W C Huang.

At least 91 records · Page 5Linked to original sources
PubMed1988

Angiotensin influences on tubuloglomerular feedback mechanism in hypertensive rats.

The tubuloglomerular feedback (TGF) mechanism was evaluated in the nonclipped kidney of Goldblatt hypertensive rats from both stop flow pressure (SFP) and single nephron glomerular filtration rate (SNGFR) responses to step increases in late proximal perfusion rate from 0 to 40 nl/min. During control conditions, increases in late proximal perfusion rate produced flow dependent decreases in SFP and SNGFR with maximal values of 10.2 +/- 1.0 mm Hg and 12.9 +/- 2.5 nl/min, values similar to those obtained in normal rats. During ACE inhibition (MK 422; 0.6 mg/kg/hr), arterial pressure decreased from 168 +/- 8 to 137 +/- 7 mm Hg and there was a marked attenuation in the magnitude of SFP feedback responses (delta = 2.5 +/- 0.3 mm Hg). SNGFR feedback responses, however, were not significantly impaired. Direct decreases in renal arterial pressure reduced control SFP but SFP feedback responses were maintained, indicating that the attenuated SFP feedback responses during ACE inhibition were not due to decreased arterial pressure. Superimposed infusion of angiotensin II during ACE inhibition partially restored SFP feedback responses. In contrast, norepinephrine infusion did not result in a similar restoration of SFP feedback sensitivity. These results indicate that the nonclipped kidney of Goldblatt hypertensive rats has an intact TGF mechanism as assessed from SFP and SNGFR feedback responses. Furthermore, ACE inhibition attenuates SFP but not SNGFR feedback responses, and systemic angiotensin II infusions can restore SFP feedback responsiveness towards normal.

Angiotensin II↗
PubMed1988

Antihypertensive and renal effects of cilazapril and their reversal by angiotensin in renovascular hypertensive rats.

1. The antihypertensive and renal effects of cilazapril, a new angiotensin converting enzyme inhibitor, were evaluated in both two-kidney, one-clip Goldblatt hypertensive rats (n = 11) and normotensive rats (n = 6). 2. Intravenous infusion of cilazapril (1 mg/kg followed by 25 micrograms min-1 kg-1) caused significant reductions of blood pressure from 163 +/- 3 to 122 +/- 4 mmHg and from 157 +/- 2 to 113 +/- 3 mmHg in two separate groups of hypertensive rats and from 124 +/- 1 to 105 +/- 2 mmHg in normotensive rats. The hypotensive effect in terms of absolute value of percentage change was greater in hypertensive rats than in normotensive rats (41 +/- 6 vs 20 +/- 3 mmHg or 25 +/- 4% vs 16 +/- 2%, respectively). 3. Cilazapril increased glomerular filtration rate, urine flow, and absolute and fractional excretion rates of sodium and potassium in the non-clipped kidney of hypertensive rats. In contrast, the clipped kidney exhibited a depressed renal function during cilazapril infusion. 4. In normotensive rats, the hypotensive and enhanced renal function responses to cilazapril were much less than those of the non-clipped kidney of hypertensive rats. 5. Superimposed administration of either angiotensin II or angiotensin III during cilazapril infusion completely reversed the blood pressure and bilateral renal responses of cilazapril in both hypertensive and normotensive rats. 6. These results indicate that cilazapril reduces arterial pressure and enhances renal excretion mainly via inhibition of angiotensin II and angiotensin III formation.

Angiotensin II↗
PubMed1988

Pulmonary function in normal subjects after bronchoalveolar lavage.

Twenty seven healthy individuals were divided randomly into three groups. The first group of nine subjects received only a routine bronchoscopic examination. The second group of nine subjects was examined with the bronchoscope followed by bronchoalveolar lavage (BAL) with 200 ml of 25 degrees C normal saline solution. The third group of nine subjects received a bronchoscopic examination followed by BAL, but with 200 ml of 37 degrees C normal saline solution. Examination in all groups included arterial blood gas (ABG) analysis and pulmonary function test (PFT), both pre- and post-procedure. In group 1 there was no statistical difference in the pulmonary function test result after routine bronchoscopic examination except for decrease in PaO2. The results in group 2 showed a statistical difference in both ABG and PFT data, especially PaO2, FEF 200-1200, FEF25%-75%, FEF25%, FEF50%, and FEF75%. In group 3, there was a significant decrease of PaO2 and no significant difference in PFT before and after BAL. From these data we conclude that BAL is a safe examination. However, the administration BAL fluid (BALF) with 25 degrees C normal saline solution can affect the results of the PFT significantly. Much of this adverse reaction can be minimized by using body temperature (37 degrees C) saline solution. At 37 degrees C, the ABG data showed a decrease in PaO2, but pulmonary function was not affected significantly.

Adult↗
PubMed1988

Tubuloglomerular feedback-dependent influence of angiotensin II on the kidney in rats.

To examine the modulatory role of angiotensin II on the tubuloglomerular feedback (TGF) mechanism, TGF responses were assessed during control conditions, converting enzyme inhibition (CEI; MK 422, 0.6 mg/kg.hr) and during continued CEI with the replacement of angiotensin II. TGF responses were assessed from stop flow pressure (SFP) feedback responses obtained during step increases in the late proximal perfusion rate from 0-40 nl/min. SFP values in the absence of perfusion were used to estimate glomerular pressure (GP) under conditions where the influence of the TGF mechanism should be at a minimum. During CEI, the arterial pressure decreased from 124 +/- 3 to 106 +/- 3 mmHg and the estimated GP decreased from 53 +/- 1.4 to 49 +/- 0.8 mmHg. There was a marked attenuation in the magnitude of SFP feedback responses from 11.0 +/- 1.3 to 2.7 +/- 0.6 mmHg. TGF feedback responses, however, were restored towards normal during superimposed angiotensin II infusion (7.7 +/- 0.9 mmHg). These results indicate that converting enzyme inhibition decreases the effects of angiotensin II on the kidney through TGF dependent mechanism.

Angiotensin II↗
PubMed1988

Effect of angiotensin converting enzyme inhibition on renal response to atrial natriuretic factor in rats.

Previous studies have shown that atrial natriuretic factor (ANF) inhibits renin secretion whereas cilazapril blocks angiotensin II generation via converting enzyme inhibition. Both agents enhance renal excretory function. The present study was conducted to test whether the renin-angiotension system is involved in the ANF-induced renal effects. ANF was administered to anesthetized normal rats (n = 16) with or without a simultaneous infusion of cilazapril. Single bolus injections of ANF at doses of 2.5 micrograms/kg and 5.0 micrograms/kg significantly decreased mean arterial blood pressure by 6.8 +/- 2.3% and 9.4 +/- 2.2%, respectively. The corresponding increases in glomerular filtration rate were 5.6 +/- 3.7% and 8.4 +/- 2.8%, in absolute sodium excretion were 55.0 +/- 18.5% and 105.2 +/- 39.9%, and in urine flow were 24.8 +/- 9.3% and 35.6 +/- 14.6%. Intravenous infusion of cilazapril (33 micrograms/kg.min) reduced the arterial blood pressure, elevated the glomerular filtration rate and increased sodium and water excretion. The corresponding doses of ANF administration during continuous infusion of cilazapril further decreased blood pressure by 8.3 +/- 1.9% and 10.9 +/- 5.4%, respectively. However, there were no significant changes in the glomerular filtration rate and sodium and water excretion. The failure of ANF to exhibit a renal effect was irrelevant to the lowering blood pressure induced by cilazapril. These results suggest that reduced endogenous angiotensin II generation contributes to the renal, but not the hypotensive, effect of ANF.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1988

[A preliminary study for cellular, albumin and immunoglobulin components of bronchoalveolar lavage fluid in normal control, pulmonary T.B. and malignant lung diseases].

Bronchoalveolar lavage (BAL) is a new diagnostic tool which could be applied repeatedly to investigate the nature of lesion in pulmonary diseases. To evaluate the clinical significance of the difference in immunoglobulin content for the differential diagnosis between benign and malignant pulmonary diseases, we performed bronchoalveolar lavage for 64 patients. They included 12 patients with bronchogenic carcinoma, 12 patients with pulmonary tuberculosis, 20 patients with benign non-specific bronchopulmonary diseases (these including 6 patients with pneumoconiosis, 6 patients with bronchietasis, 2 patients with paraquate intoxication, 6 patients with pneumonia) and 20 healthy persons as of the control group. We analyzed the following items: (1) cell count (2) differential count (3) protein content (4) immunoglobulin content. The results showed that there were increase in PMN cells in paraquate intoxication, pnuenmonia and bronchiectasis. While there was lymphocytosis in pulmonary tuberculosis. In comparison with the control group, there was elevation of statistical significance in the IgA/Albumin ratio in bronchogenic carcinoma and pulmonary tuberculosis. Although the IgG/Albumin ratio would be elevated with statistical significance among a variety of pulmonary diseases, it was particularly high in pulmonary tuberculosis. In contrast, the IgA/IgG ratio was significantly increased only in bronchogenic carcinoma. In conclusion, there were differences in the cell number, differential cell count, protein content and immunoglobulin content among various pulmonary diseases. It may be useful in making differential diagnosis between benign and malignant pulmonary disease and the prediction of prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[T-cell subpopulation of bronchoalveolar lavage fluid in patients of sarcoidosis and hypersensitivity pneumonitis--2 cases report].

Diffuse interstitial lung diseases include more than 100 varieties. Even for a chest specialist differential diagnosis is difficult; accurate diagnosis without transbronchial lung biopsy or open lung biopsy was particularly hard. Bronchoalveolar Lavage (BAL) is a new diagnostic procedure which is relatively safe and repeatable. It takes about 30 minutes more, during the usual bronchoscopic examination, to obtain fluid and cells from the lower respiratory tract. These specimens aid differential diagnosis and an understanding of pathogenesis in the early stage of diffuse interstitial lung disease. Two cases are reported. One was sarcoidosis, as proved by mediastinoscopic lymph node biopsy; the other one was hypersensitivity pneumonitis by clinical impression. Both patients received bronchoscopic examination with bronchoalveolar lavage. The bronchoalveolar lavage fluid showed an increase in total cell count, lymphocyte count and lymphocyte percentage. In sarcoidosis, the main T-lymphocyte subpopulation was helper T-lymphocytes while, in hypersensitivity pneumonitis, the main T-lymphocyte subpopulation was suppressor T-lymphocytes. We concluded that, if the patients of diffuse interstitial lung diseases had increased lymphocyte count and percentage in bronchoalveolar Lavage fluid, examination of the lymphocyte subpopulation would help differential diagnosis.

Adult↗
PubMed1987

Early third-stage larvae of Gnathostoma hispidum in cyclops. Surface topography revealed by scanning electron microscopy.

Surface structures of the early third-stage larvae were examined by scanning electron microscopy. There were hemispherical head-bulbs at the apical ends. These bulbs could be clearly distinguished from the bodies. The head-bulbs (52 X 29 micron) had four transverse rows of sharp hooklets. The number of hooklets in each row was 37, 36, 38, and 43, posteriorly. The larvae posessed a pair of lateral lips in the head-bulb. Each of the lips had two labial papillae and an amphid between the papillae. Small unidentate cuticular spines were present along the entire length of larvae on their transverse striations. The number of these cuticular striations was 175-217. A pair of cervical papillae and an excretory pore were present on the anterior part of the body. Another pair of papillae was detected laterally on the posterior one-third of the body. The shape of the posterior body papillae resembled that of cervical papillae. The cuticular spines were absent around the anus.

Animals↗
PubMed1987

A new disposable microvascular double clip.

A new disposable microvascular double clip made of polycarbonate has been designed. In order to investigate whether or not the clip causes vascular damage, experiments were conducted with scanning electron microscopy and light microscopy, using the common carotid arteries of Fischer rats. The study revealed that the new clip did not produce any damage to the arterial wall. The clip has also been used in 30 clinical cases, with generally good results. The new microvascular clip is economical, atraumatic to the vascular wall, and is always in the best condition, because of its disposability. The device is very useful for both laboratory and clinical microvascular surgery.

Animals↗
PubMed1987

Natural killer cell activity in lung cancer patients.

A total of 50 lung cancer (CA) patients and 20 normal persons as controls were included in our study. We obtained lymphocytes from heparinized blood by Ficoll-Hypaque gradient method, and after the macrophages were removed, they were incubated with 51Cr-labelled K562 cells at concentrations of 100:1, 50:1, 12.5:1 for four hours. We calculated the cytotoxicity activity and lytic unit (LU) of natural killer (NK) cells. Significant impairment was noted in the comparison of NK cytotoxicity and LU between stage III-M1 lung CA patients (n = 28) and the control group. However, significant impairment was also noted in stage III-M1 and III-M0 patients. Four cases in stage I underwent surgery, and the NK cytotoxicity before the operation was noted to be low. After the operation, the NK cytotoxicity increased. These results indicate that NK cytotoxicity assay was impaired in stage III-M1 lung CA and also suggest that it may act as a therapeutic guide in determining the results of the operation.

Adult↗
PubMed1987

Antihypertensive and bilateral renal responses to diuretics in 2-kidney, 1-clip Goldblatt hypertensive rats.

Experiments were conducted to assess the effect of furosemide or amiloride alone and a combination of both agents on each kidney in anesthetized 2-kidney, 1 clip Goldblatt hypertensive rats (n = 25). Intravenous infusion of furosemide alone (1.02 mg/kg.hr) significantly reduced the blood pressure by 14 +/- 5 mmHg. There were 6- to 10-fold increases in water, absolute sodium and fractional sodium excretions and a 2-fold increase in potassium excretion in the nonclipped kidney. A smaller but significant increase in the excretory function was also observed in the clipped kidney. There was no significant change in GFR of both kidneys. Indomethacin pretreatment (2 mg/kg) failed to significantly alter the vasodepressor and renal responses to furosemide in both hypertensive and normal rats. Removal of the renal artery clip from the hypertensive rats reduced the blood pressure by 12 +/- 3 mmHg and enhanced the function of the ipsilateral, unclipped kidney. Subsequent administration of furosemide further increased the excretory response. Administration of amiloride alone (2.4 mg/kg.hr) or with furosemide into hypertensive rats reduced the arterial pressure and increased excretion rates of urine flow and urinary sodium. Potassium excretion rate decreased bilaterally in amiloride treated rats but did not alter significantly in rats which received a combination of amiloride and furosemide. These results indicate that diuretics ameliorate the excretory function of both the stenotic kidney and the nonstenotic kidney and that the improvement of the kidney function is independent of prostaglandin. Furthermore, removal of the stenosis accentuates the beneficial effect of diuretics on the kidney.

Amiloride↗
PubMed1987

Plasmacytoma of pleural origin associated with Bence Jones proteinuria.

A 33-year-old male presented with right side pleural plasmacytoma with secretion of Bence Jones (BJ) protein and deposition of amyloid. The pleural effusion contained a prominent peak of kappa-type BJ protein on the background of polyclonal gammopathy. Pleural biopsy disclosed features of plasmacytoma with amyloid deposition. A small peak of BJ protein was also present in serum electrophoretogram on the background of increased polyclonal IgG and IgA. Kidney function was impaired and urine protein ranged from 7.8 to 19.1 g/day with 92.5% bimodal BJ protein. There were no bone lesions by systemic bone survey, and repeated bone biopsies and marrow aspirations showed plasma cells of less than 5%. The clinical course worsened progressively; over the next five months the pleurisy became bilateral and peritoneal involvement supervened. This is believed to be the first report of primary plasmacytoma involving successively pleurae and peritoneum.

Adult↗
PubMed1987

[Study of the natural killer cell activity in lung cancer patients].

A total of 50 lung CA patients and 20 normal persons as control were included in our study. We obtained lymphocytes from heparinized blood by Ficoll-Hypaque gradient method and after incubation with Cr51 labelled K562 cells at concentrations of 100: 1, 50:1, 12.5:1 for four hours, we calculated the cytotoxicity activity of NK cells. Significant impairment was noted in the comparison of NK cytotoxicity between stage III-M1 lung CA patients (n = 28) and the control group (n = 20) (E/T; 50:1, 29.55 +/- 24.20% vs 49.83 +/- 14.46%, p less than 0.001; E/T: 25:1, 10.23 +/- 7.19% vs 27.66 +/- 6.06%, p less than 0.001). 4 cases in stage I underwent surgery, the NK cytotoxicity before the operation was noted to be low, E/T: 25:1, 9%, 11%, 14% and 19% respectively. After the operation, the NK cytotoxicity was increased to 33%, 35%, 42% and 44% respectively. 3 stage I lung CA patients has continuously followed up, 2 relapsed cases had decreased NK cytotoxicity to 22% and 25%. These results indicated that the NK cytotoxicity assay was impaired in stage III-M1 lung CA and also suggested that it may act as a therapeutic guide for the results of the operation.

Adult↗