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Biomedical subjects

C Y Lin

Publications and source records attributed to C Y Lin.

At least 199 records · Page 11Linked to original sources
PubMed1995

In vitro effects of interleukins on human mesangial cells: implications for glomerulonephritis.

Intrinsic glomerular cells, especially mesangial cells, are considered to be actively involved in the pathogenesis of glomerulonephritis (GN), but the precise mechanism(s) remains elusive. We have previously demonstrated that nephritogenic IgA immune complex can stimulate human mesangial cells (HMCs) to increase their production of interleukin-1 (IL-1) and interleukin-6 (IL-6). In order to evaluate the roles of cytokines such as IL-1 and/or IL-6 and mesangial cells as mediators of renal injury in GN, we have now examined the changes of HMCs and their secreted products in vitro, after stimulation with various concentrations of IL-1 and IL-6. Cytokine-activated HMCs showed the following changes: (1) increased cell size, with intracytoplasmic vacuoles, dilated endoplasmic reticulum, increased free ribosomes and polysomes, and mitochondrial swelling; (2) increased cell proliferation, reflected in thymidine incorporation and an increased proportion of S and G2/M phase cells by cell cycle analysis; (3) enhancement of IL-6 mRNA expression in HMCs with stimulation of IL-6 alone or IL-1 plus IL-6; and (4) release of large amounts of platelet activating factor (PAF), thromboxane B2 (TxB2), and superoxide anion. Taken together, these results strongly suggest that mesangial cell proliferation and increased production of immune/chemical mediators and superoxide anion can be directly induced by IL-1 plus IL-6. These changes may lead to ongoing renal injury.

Adolescent↗
PubMed1995

Obstructive sleep apnea syndrome and bronchial hyperreactivity.

This study was designed to investigate the prevalence of bronchial hyperreactivity (BH) in patients with obstructive sleep apnea syndrome (OSAS), heavy snorers, and light snorers; its correlation with OSAS severity; and its response to nasal CPAP therapy. Forty-eight age- and sex-matched subjects were selected on the basis of preentry sleep studies: Group I consisted of 16 patients with OSAS (hypopnea-apnea index (HAI) = 35 +/- 9); group II consisted of 16 cases of heavy snorers without OSAS; and group III, a control group, consisted of 16 subjects with only mild snoring. All 48 patients had normal pulmonary function (simple spirometry) prior to study entry and had no history of asthma or allergies. The prevalence of BH was prospectively assessed by giving each subject a methacholine challenge test (MCT). Patients with a positive MCT were treated with 2-3 months of nasal CPAP treatment, after which they had a second MCT. Four of 16 patients in group I had BH on MCT (PD20 = 88, 103, 109, 162 D.U.), whereas none of the group II or III subjects demonstrated BH. There was no correlation between BH and the severity of the OSAS. The 4 patients with BH in group I showed an increase in PD20M after 2-3 months of nasal CPAP treatment. In conclusion, BH may occur in patients with OSAS. It is unrelated to the severity of the OSAS, and nasal constant positive airway pressure (CPAP) therapy can decrease the hyperreactivity to methacholine in these patients.

Adult↗
PubMed1995

Endoscopic variceal ligation versus conservative treatment for patients with hepatocellular carcinoma and bleeding esophageal varices.

BACKGROUND: Endoscopic variceal ligation (EVL) is currently a favored treatment for control of bleeding from esophageal varices. However, little is known about the treatment of bleeding varices in hepatocellular carcinoma. METHODS: EVL was performed in 16 patients with bleeding esophageal varices due to concomitant hepatocellular carcinoma. Treatment results were compared with those of another 23 patients who were conservatively treated. RESULTS: Comparing the two groups, ligation significantly reduced the risk of fatal bleeding (44% vs 70%; P < 0.05). Significantly fewer patients in the ligation group died at the time of the index hemorrhage (11% vs 52%; P < 0.05). Rebleeding occurred in 44% of the ligation group and 73% in the control group (P > 0.05). The mean days of survival were 40 +/- 20 (range, 7 to 103) in the ligation group and 20 +/- 30 (range, 1 to 136) in the control group (P = 0.08). In the absence of portal vein thrombosis, ligation significantly reduced the rebleeding rate (17% vs 50%, P < 0.05) and the mortality rate (0% vs 100%, P < 0.05). CONCLUSION: EVL is a good choice for palliation in patients with esophageal variceal bleeding and hepatocellular carcinoma. Aggressive use of EVL may be tried in those patients without portal venous thrombosis.

Adult↗
PubMed1995

Helicobacter pylori in cirrhotic patients with peptic ulcer disease: a prospective, case controlled study.

BACKGROUND: There is an increased prevalence of peptic ulcer disease in patients with liver cirrhosis, but the role of Helicobacter pylori is unclear. METHODS: lgG antibodies against H. pylori were measured in 60 patients with compensated liver cirrhosis, in 60 sex- and age-matched patients with compensated liver cirrhosis, and in 60 normal controls. All patients received panendoscopic examinations to search for the evidence of esophageal varices, congestive gastropathy, and peptic ulcers. RESULTS: Duodenal ulcers were more common in compensated and decompensated cirrhotic patients (16.7% and 13.3%, respectively) than in normal controls (3.3%, p < 0.05). Gastric ulcers were more frequent in decompensated (15.0%) than compensated cirrhotic patients and normal controls (3.3% and 1.7%, respectively, p < 0.05). The prevalence of H. pylori was not statistically different among the three groups (normal 60.0%, compensated 61.7%, and decompensated, 75.0%; p > 0.05). The prevalence of H. pylori also showed no statistical differences in respect to duodenal ulceration (100%, 80%, and 87.5%, respectively, p > 0.05). The prevalence of H. pylori did not differ significantly in relation to the presence or absence of esophageal varices (68.4% vs 100% if no varices, p = 0.04) and in the presence of congestive gastropathy (50.0 vs 94.7%, p = 0.03). CONCLUSIONS: The prevalence of peptic ulcer was increased in cirrhotic patients, but the prevalence of H. pylori was similar in compensated cirrhotic patients, decompensated cirrhotic patients, and normal controls. The frequency of non-H. pylori-associated peptic ulcers in cirrhotic patients was increased in the presence of esophageal varices or congestive gastropathy.

Case-Control Studies↗
PubMed1995

Morphological description of Taenia saginata asiatica (Cyclophyllidea: Taeniidae) from man in Asia.

In order to clarify the taxonomic status of the Taenia saginata-like tapeworm in East Asia, the morphological characteristics of the adult and cysticercus of classical T. saginata (American, Swiss and Poland strains) and the Taiwan Taenia were compared in the present study. The morphologic characteristics of these two parasites are very similar. The protoscolex of cysticercus of the Taiwan Taenia has a sunken rostellum while that of classical T. saginata has only an apical pit. In addition, the rostellum of the Taiwan Taenia cysticercus is usually surrounded by two rows of rudimentary hooklets. However, this structure is rarely found in classical T. saginata. Based on the results of molecular studies and morphological characteristics, the T. saginata-like tapeworm in East Asia represents a subspecies of T. saginata, named T. saginata asiatica.

Animals↗
PubMed1995

Treatment of hepatitis B virus-associated membranous nephropathy with recombinant alpha-interferon.

An open, randomized trial study on the therapeutic effect of recombinant alpha-interferon (IFN alpha) in 40 patients with hepatitis B virus membranous nephropathy (HBVMN) was conducted. All were pathologically proven to have HBVMN which showed no response to corticosteroid treatment represented by persistent heavy proteinuria. Both HBeAg and HBsAg were positive in all. Group 1 was composed of 20 patients who were treated with recombinant IFN alpha (5 subjects, body wt < 20 kg; 8 subjects, body weight > or = 20 kg) by subcutaneous (s.c.) injection three times a week for 12 months. In group 2 there were 20 patients who received supportive treatment only. At the end of the third month of treatment, all patients in Group 1 were free of proteinuria. In contrast, 10 patients (50%) in Group 2 had persistent heavy proteinuria and another 10 patients (50%) had light proteinuria with exacerbation during respiratory tract infection. At the end of the twelfth month, 8 patients (40%) in Group 2 still had persistent heavy proteinuria and 12 patients (60%) had light proteinuria with frequent relapses. Eight patients (40%) in Group 1 had HBeAg seroconversion between the fourth and sixth months and HBsAg seroconversion between the tenth and twelfth months. HBe seroconversion only [HBeAg (-)/HBsAg (+)] was found in four patients. Four patients had no change in HBV serological markers [HBeAg (+)/HBsAg (+)]. The remaining 4 patients had HBeAg (-)/HBeAb (+) HBsAg (-)/HBsAb (-) at the end of the twelfth month. In contrast, there was no seroconversion of HBeAg (+)/HBsAg (+) in Group 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1995

Cerebral metabolic consequences of hypotensive challenges in hemodiluted pigs with and without cardiopulmonary bypass.

We tested the hypothesis that progressive aortic hypotension with bicarotid occlusion produces greater reductions in cerebral blood flow (CBF) and more flow-metabolism mismatching with hemodilution during cardiopulmonary bypass (CPB) than with hemodilution alone. In Yorkshire pigs randomized to hemodilution with CPB (n = 10) or hemodilution without CPB (control; n = 9), the effects of bicarotid ligation and graded hypotension on CBF (microspheres), the electroencephalogram (EEG), and cortical energy metabolites were examined. After bicarotid ligation, systemic flow was reduced for 15-min intervals of 80, 60, and 40 mm Hg aortic pressure, followed by a cortical brain biopsy. At baseline, CBF was lower in CPB (58 +/- 3 mL.100g-1.min-1) than control (90 +/- 3 mL.100 g-1.min-1., P < 0.05) animals, as was cerebral oxygen metabolism (3.1 +/- 0.1 vs 4.2 +/- 0.2 mL.min-1.100g-1; P < 0.05). Although CBF remained 40% lower at each level of hypotension in CPB than control animals (P < 0.05), EEG scores showed no intergroup differences, indicating similar flow-metabolism matching. Brain metabolites were similar between CPB and control groups (adenosine triphosphate, 9.6 +/- 2.4 vs 12.4 +/- 1.9 mumol/g; adenosine diphosphate, 6.0 +/- 0.7 vs 6.3 +/- 0.4 mumol/g; adenosine monophosphate, 4.8 +/- 0.9 vs 3.8 +/- 0.8 mumol/g; creatine phosphate, 8.3 +/- 1.8 vs 7.9 +/- 1.0 mumol/g; and lactate, 178.4 +/- 20.2 vs 150.8 +/- 13.9 mumol/g). Thus, despite significantly lower CBF during hypotension with bicarotid occlusion in hemodiluted animals during normothermic CPB, cortical electrical activity and the balance between flow and metabolism did not differ from those in control animals without CPB.

Adenine Nucleotides↗
PubMed1995

Loss of alveolar macrophages during anesthesia and operation in humans.

Pulmonary macrophages play an important role in the host defense against infection, and the importance of this role is probably enhanced when the upper airway defenses are circumvented by endotracheal intubation. Studies in animals suggest that exposure to volatile anesthetics compromises the viability and function of alveolar macrophages. We studied the effect of surgery and anesthesia on the alveolar macrophages of 41 human subjects undergoing lower abdominal procedures of varying lengths during nitrous oxide-isoflurane anesthesia. Alveolar macrophages were harvested from bronchoalveolar lavage fluid obtained before incision and compared to those recovered just before emergence from anesthesia. Macrophages were analyzed for aggregation and viability, assessed by the ability of viable cells to exclude trypan blue dye. Operations lasting 2 h or less led to little aggregation and had little effect on viability. However, there was a strong correlation between loss of macrophages and the duration of surgery and anesthesia. Aggregation increased and viability decreased as a function of procedure length. Studies are needed to determine whether prolonged surgery contributes to the incidence of postoperative pulmonary complications by disturbing the function and survival of alveolar macrophages in humans.

Adolescent↗
PubMed1995

Hyperglycemia during hypothermic canine cardiopulmonary bypass increases cerebral lactate.

BACKGROUND: Hyperglycemia frequently occurs during cardiopulmonary bypass (CPB), although its direct effects on cerebral perfusion and metabolism are not known. Using a canine model of hypothermic CPB, we tested whether hyperglycemia alters cerebral blood flow and metabolism and cerebral energy charge. METHODS: Twenty anesthetized dogs were randomized into hyperglycemic (n = 10) and normoglycemic (n = 10) groups. The hyperglycemic group received an infusion of D50W, and the normoglycemic animals received an equal volume of 0.9% NaCl. Both groups underwent 120 min of hypothermic (28 degrees C) CPB using membrane oxygenators, followed by rewarming and termination of CPB. Cerebral blood flow (radioactive microspheres) and the cerebral metabolic rate for oxygen were measured intermittently during the experiment and brain tissue metabolites were obtained after bypass. RESULTS: Before CPB, the glucose-treated animals had higher serum glucose levels (534 +/- 12 mg/dL; mean +/- SE) than controls (103 +/- 4 mg/dL; P < 0.05), and this difference was maintained throughout the study. Cerebral blood flow and metabolism did not differ between groups at any time during the experiment. Sagittal sinus pressure was comparable between groups throughout CPB. Tissue high-energy phosphates and water contents were similar after CPB, although cerebral lactate levels were greater in hyperglycemic (37.2 +/- 5.7 mumol/g) than normoglycemic animals (19.7 +/- 3.7 mumol/g; P < 0.05). After CPB, pH values of cerebrospinal fluid for normoglycemic (7.33 +/- 0.01) and hyperglycemic (7.34 +/- 0.01) groups were similar. CONCLUSIONS: Hyperglycemia during CPB significantly increases cerebral lactate levels without adversely affecting cerebral blood flow and metabolism, cerebrospinal fluid pH, or cerebral energy charge.

Adenine Nucleotides↗
PubMed1995

Increasing organ blood flow during cardiopulmonary bypass in pigs: comparison of dopamine and perfusion pressure.

OBJECTIVE: To determine whether low-dose dopamine infusion (5 micrograms/kg/min) during cardiopulmonary bypass selectively increases perfusion to the kidney, splanchnic organs, and brain at low (45 mm Hg) as well as high (90 mm Hg) perfusion pressures. DESIGN: Randomized crossover trial. SETTING: Animal research laboratory in a university medical center. SUBJECTS: Ten female Yorkshire pigs (weight 29.9 +/- 1.2 kg). INTERVENTION: Anesthetized pigs were placed on normothermic cardiopulmonary bypass at a 100-mL/kg/min flow rate. After baseline measurements, the animal was subjected, in random sequence, to 15-min periods of low perfusion pressure (45 mm Hg), low perfusion pressure with dopamine (5 micrograms/kg/min), high perfusion pressure (90 mm Hg), and high perfusion pressure with dopamine. Regional perfusion (radioactive microspheres) was measured in tissue samples (2 to 10 g) from the renal cortex (outer two-third and inner one-third segments), stomach, duodenum, jejunum, ileum, colon, pancreas, and cerebral hemispheres. MEASUREMENTS AND MAIN RESULTS: Systemic perfusion pressure was altered by adjusting pump flow rate (r2 = .61; p < .05). In the kidney, cortical perfusion pressure increased from 178 +/- 16 mL/min/100 g at the low perfusion pressure to 399 +/- 23 mL/min/100 g at the high perfusion pressure (p < .05). Perfusion pressure augmentation increased the ratio of outer/inner renal cortical blood flow from 0.9 +/- 0.1 to 1.2 +/- 0.1 (p < .05). At each perfusion pressure, low-dose dopamine had no beneficial effect on renal perfusion or flow distribution. Similar results were found in the splanchnic organs, where regional perfusion was altered by perfusion pressure but not by dopamine. In contrast, neither changing perfusion pressure nor adding low-dose dopamine altered blood flow to the cerebral cortex. CONCLUSIONS: These data indicate that the lower autoregulatory limits of perfusion to the kidneys and splanchnic organs differ from those limits to the brain during normothermic bypass. Selective vasodilation from low-dose dopamine was not found in renal, splanchnic, or cerebral vascular beds. Increasing the perfusion pressure by pump flow, rather than by the addition of low-dose dopamine, enhanced renal and splanchnic but not cerebral blood flows during cardiopulmonary bypass.

Animals↗
PubMed1995

Intraperitoneal recombinant human erythropoietin therapy: influence of the duration of continuous ambulatory peritoneal dialysis treatment and peritonitis.

This study was performed to investigate the factors that influence intraperitoneal absorption of recombinant human erythropoietin (rHuEPO) and to evaluate the differences of the pharmacokinetics of intraperitoneally administered rHuEPO before peritonitis and after recovery. First, the pharmacokinetics in different groups of continuous ambulatory peritoneal dialysis (CAPD) patients was studied. Thirty-six CAPD patients were enrolled and divided into four groups. Group 1 included 20 patients who were either just placed on CAPD therapy or had been on CAPD for < 1 year, but with a low frequency of peritonitis episodes. Group 1 was divided into four subgroups by body weight (20-30, 31-45, 46-55, and > 55 kg). Group 2, patients who had received CAPD treatment for more than 1 year, was further divided into group 2a and group 2b according to a low or a high frequency of peritonitis episodes, respectively. rHuEPO (100 U/kg) was administered as a single bolus of intravenous, subcutaneous, or intraperitoneal injection. Intraperitoneal rHuEPO was retained for 10 h. The results showed no significant differences between subcutaneous and intraperitoneal administration in group 1 patients. However, peak concentration, time to reach peak serum level, area under the curves, and bioavailability were substantially lower after intraperitoneal than after subcutaneous administration in group 2a and group 2b patients. There was no influence of body size on peak concentration and area under the curve in group 1 patients. Second, comparison of the pharmacokinetics of intraperitoneal administration before and after recovery from peritonitis in group 1 patients revealed that the serum levels of rHuEPO became lower after the occurrence of peritonitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

A clinicopathological study of idiopathic nephrotic syndrome in children.

This paper retrospectively examines the association of outcome with histological and clinical manifestations in 107 pediatric patients with idiopathic nephrotic syndrome (INS). At the time of renal biopsy, the patients were between 2 and 15 years of age. The interval from the onset of the disease to renal biopsy ranged from 1 to 156 months with a mean of 21 months. Continuous clinical follow-up was successfully conducted in 96 patients. The average duration of INS in these patients was 86.6 months (31 to 208 months). IgM deposition in the mesangium may play an important role in the pathogenesis of INS and our data showed that even in a minor glomerular abnormality (MCNS) subgroup, nearly half of the cases (42.9%) showed mesangial IgM deposition. However, the severity of hematuria, response to drug therapy with either steroids or cyclophosphamide, and the outcome, were not related to the presence or absence of IgM deposition, but were more closely associated with the type of histological category. The subgroup of patients with focal segmental glomerulosclerosis (FSGS) and diffuse mesangial proliferation (FSGS + DP) showed the most significant ultrastructural changes with positive mesangial IgM deposition (73.6%). The presence of IgM deposition in most of the patients in the subgroups with diffuse mesangial proliferative glomerulonephritis (DPGN) and FSGS + DP closely corresponded to the presence of electron-dense mesangial deposition. The FSGS + DP subgroup had a high incidence of denudation, vacuolization and detachment of podocytes, partial collapse of the glomerular basement membrane, and a very high incidence of resistance to steroid therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Histomorphometric study in children with idiopathic nephrotic syndrome.

From 1981 to 1987, renal specimens obtained from 91 children with idiopathic nephrotic syndrome were categorized into 5 histologic subgroups, according to the WHO classification. We analyzed differences in the ratios of the size of the mesangial stalks and attached capillary, including the Bowman's space between the capillary tufts (E), mesangial matrix (Mx), and approximate capillary lumens (E-Mx) to the whole glomerular area of these subgroups using the histomorphometer-IBAS. Focal segmental glomerulosclerosis with diffuse mesangial proliferation (FSGS + DP) had the largest matrix area (Mx/G > 0.5), and smallest capillary lumen size (E/G-Mx/G) (0.3474 +/- 0.0702). On the contrary, FSGS with minimal change (FSGS + MC) had the smallest mesangial matrix (Mx/G), 0.2834 +/- 0.07726, but preserved a larger capillary lumen (0.427 +/- 0.1215). The approximate size of capillary lumens, from the smallest to the largest, was in the following order: FSGS + DP, diffuse mesangial proliferative glomerulonephritis (DPGN), focal segmental proliferative glomerulonephritis (FSPGN), FSGS + MC and minimal change nephrotic syndrome (MCNS). The ratio of the total number of mesangial cells to the area of the whole glomerulus (MCN/G) derived from the light microscopic examination was parallel to the value of Mx/G obtained by the histomorphometric technique. In summary, we introduced the histomorphometric technique using the histomorphometer-IBAS for quantitative measurement of various areas in the glomeruli. The data derived from the system is compatible with those obtained by experienced nephrologists, suggesting that the histomorphometric technique is helpful in histopathology. It is hoped that this new methodology will be used more extensively in the near future.

Adolescent↗
PubMed1995

Power spectral analysis of systemic arterial pressure signals during open heart surgery.

BACKGROUND: The close relationship between the balance of sympathetic and parasympathetic tones and the results of power spectral analysis (PSA) of systemic arterial pressure (SAP) has been suggested recently. The purpose of this study was to further describe the changes of balance between the two autonomic nervous components during open heart surgery for coronary arterial disease (CAD) or valvular heart disease (VHD) with the PSA technique of SAP. METHODS: By relaying the SAP signals to a personal computer utilizing a power spectral analysis algorithm, radial arterial pressure signals of 27 patients (11 with CAD for coronary artrial bypass graft, as CAD groups; 16 with VHD, as VHD group, including 8 for aortic valve replacement and 8 for mitral valve replacement) during open heart surgery were monitored in a continuous, on-line and real-time manner. On-line power spectral analysis was performed according to the five different stages of the operation. RESULTS: Power density tended to increase in the high frequency (HF) band during the ventilator-supported stages of the open heart procedures, i.e., the pre-cardiopulmonary bypass (CPB) and the off-CPB periods. The power density in other frequency bands during the whole course of general anesthesia otherwise decreased significantly, with the lowest values occurring during CPB. The power density in very low frequency (VLF) band was much higher than in other bands during CPB, and became the major component of total power density in this period. CONCLUSIONS: The balance between sympathetic and parasympathetic components of autonomic nervous system changes rapidly during open heart surgery and needs careful monitoring. By utilizing PSA of SAP, mathematical error might be an obstacle of using LF:HF ratio as an index of autonomic balance during the CPB period when the HF density approaches zero.

Aged↗