1989年 · 第102卷第01期

Acute pulmonary hypertension was caused by inhalation of 5% O2 in rats. Pulmonary vascular re-sistance (PVR) increased, but heart rate (HR), cardiac output (CO) and carotid arterial pressure (CAP) were not obviously changed. After an intravenous admini-stration of Radix Angelicae sinensis, the acute pulmonary hypertension induced by inhalation of 5% O2 could be attenuated, but this effect disappeared if propranolol was given before Radix Angelicae sinensis. In chronic experiments, the same results were obtained, but the protective effect of Radix Angelicae sinensis on heart function was not influenced by propranolol. It is suggested that Radix Angelicae sinensis rmght play a role by stimulating the β2-receptor in the prevention of acute and chronic hypoxic pulmonary hypertension. However, prevention of hypertrophy of the right ventricle and enhancement of heart function in chronic hypoxic rats might not be attributed to the β1 receptor in the heart.

The fate of human cartilage allografts and the mechanism of its kinetical development were studied histopathologically and immunohistologically. After transplantation, the grafts underwent necrosis, cakification and were partially invaded by osteoplastic tissue of the host and eventually replaced by bone tissue. Thus, the contour of the transplanted cartilage was kept partially by the living cartilage and the newly-formed osseous tissue. The grafts were surrounded initially by granular tissue and then by scar tissue, in which numerous T cells and a few macrophage infiltrates were noted. In T cells, T4+ lymphocytes predominated but T8+ cells accounted for a small number. B cells were not found within the infiltrates. Most of the infiltrating cells expressed l2 antigens, indicating that the majority of T cells were activated. It was concluded that T lymphocytes mediated cellular immunity played an important role. The chondrocytes of the cartilage did not express HLA I and II antigens before transplantation, but one month later, the living chondrocytes became HLA I and II antigens positive, and the antigen expression became stronger with the elapse of time; this might be induced by lymphokins, especially by interferon produced by the infiltrating lymphocytes. Such an expression of MHC antigens on chondrocytes might contribute to the further enhancement of immunorejection.

To clarify the rule of monoamine in cerebral ischemia, 3-methoxy-4-hydroxyhenylglycol (MHPG), 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) in cerebrospinal fluid (CSF) of 33 patients and 18 controls were measured with high performance liquid chromatography. Results showed all the three metabolites increased in patients with severe ischemia but only MHPG and 5-HIAA increased significantly. MHPG changed more quickly and regularly in cerebral ischemia than the other two. A positive correlation between any couple of the metabolites was found in both the controls and patients in the first week after stroke, but it was disturbed at the end of the second week. Computer-assisted multivariate analysis indicated that 5-HIAA and MHPG are more closely related to the state of illness in the acute stage while HVA the least. Possible explanations for the changes of CSF levels of amine metabolites were discussed.

Intraventricular injection of iron causes seizures and lipid peroxidation in brain tissue. To determine the effects of iron-induced lipid peroxidation on GABA uptake and release, synaptosomal fraction was prepared from 30-day-old iron-treated and control Wister rats. Our data demonstrated that GABA release was more severely damaged than GABA uptake by lipid peroxidation. This imbalance between release and uptake may reduce GABA inhibition, which could contribute to the neurochemical pathogenesis of iron-induced seizures.

Local spinal cord ischemia model was established in 11 adult dogs. The anterior spinal artery, posterior spinal artery and radicular artery were cauterized with bipolar cautery. Ischemia of this segment of spinal cord was thus produced followed by paraplegia. The pathological findings of this spinal cord segment were softening and necrosis. The establishment of this animal model of segmental spinal cord ischemia is beneficial to scientific research in basic medicine and clinical practice.

The vascular pedicled periosteum was used in II cases in our hospital for the treatment of femoral neck fracture with good result. The follow-up period ranged from 2 to 6 years, with an average of 4 years. Animal experiment was made to elucidate the repairing process. It demonstrated that the pedicled periosteum played double roles, namely, blood supply and osteogenesis. The clinical and experimental results are presented.

It is well known that growth hormone (GE) secretion and regulation in diabetics are abnormal. In order to evaluate the response of GH to nonphysiological stimuli in diabetics, a thyrotropin-releasing hormone (TRH) test (500 μg by IV bolus injection) was carried out in 12 patients with insulin-dependent diabetes (IDD, 6 males and 6 females). 11 noninsulin-dependent diabetes (NIDD, 5 males and 6 females), and 10 normal controls (6 males and 4 females). The results showed that the basal serum GH levels in diabetics were higher than that in normal controls and it was even higher in IDD than in NIDD. Following the TRH stimulus, the mean peak level of GH in IDD was the highest among the three groups, the differences being statistically significant (F=9.323, P<0.01). It was concluded that a nonspecific response to TRH of GH did occur in IDD, and the peak values were even higher in female than in male subjects. A negative correlation existed between the GH peak values and the age of the patients as well as in the controls. This supported the view that GH responsiveness to TRH has a tendency of progressive decline with age. However, no significant correlation was found between the peak value of GH and the blood glucose level or the microangiopathic complications. The mechanism of TRH stimutation on GH release in diabetics is discussed.

Growth hormone (GH) secretion is mediated by hypothalamic factors, mainly growth hormone releasing factor (GRF) and somatostatin (SS). The hypothalamic hormones, under direct neurotransmitter control, stimulate GH secretion through different central mechanisms. Atropine, an anticholinergic agent, can cross the blood-brain barrier and inhibit GH secretion stimulated by exercise and sleep in normal persons. In order to study the inhibiting effect of atropine on GH release and whether glucose can be replaced by stropine, normal persons and acromegaly patients were observed during exercise, after stropine, and 100 g glucose loading. The results confirmed that GH secretion increases after exercise and that this GH elevation can be inhibited by stropine in normal subjects. But in acromegaly patients high basal GH levels can not be inhibited by 100 g glucose loading or 0.6 mg atropine during the active phase of the disease. Blood sugar levels remained unchanged during the atropine test. It is suggested that the atropine test can be used as a GH inhibitory test in acromegaly patients with overt diabetes.

NBT-PABA test was performed in 72 subjects with simultaneous determination of the plasma PABA time-concentration curve. The curve in 25 controls after oral administration of N-benzoyl-L-tyrosyl-P-aminobenzoic acid (NBT-PABA) peaked (3.88±0.78µg/ml, M±SD) at the third hour. In patients with chronic pancreatitis (24) and pancreatic carcinoma (6), the curves were flattened, and peaked at the fifth hour (2.7±1.4pg/ml, M±SD), and fourth hour (3.14±2.26pg/ml, M±SD), respectively. The discrimination between the controls and patients with chronic pancreatitis was most significant in the third-hour plasma PABA concentration (P<0.0001). This study shows that determination of the third-hour plasma PABA concentration is better in sensitivity and specificity than the 6-hour urinary excretion of PABA, suggesting that the third-hour plasma PABA concentration after oral administration of NBT-PABA might be a sensitive index of exocrine pancreatic function test.

The cytoplasm of human bile ductule epithelia was found to be Type V collagen positive, demonstrating that the epithelia were able to generate this type of collagen. The ductules proliferated greatly with Type V collagen positive cytoplasm in piece-meal necrosis of chronic active hepatitis (CAH). The capillary-like bile ductules inside human hepatic lobules were identified. Our findings might explain the mechanism of fibroplasia in CAH.