Volume 111  ·   Issue 09  ·  1998

OBJECTIVE To investigate the tumor-suppressive activity of polyactin B (PB) and the life-span of tumor bearing mice treated with PB and the anti-tumor mechanisms of PB by blockage of macrophage in vivo. METHODS Thirty-two S180 sarcoma-bearing (s.c.) BALB/c inbred mice were divided into 4 groups, i.e., control group (8 mice), PB group (8), Trypan blue (TrB) group (8) and PB + TrB group (8). Five days after PB injection (i.p.), the tumor size of the mice was measured, and the ratio of TNA to TTA in HE section of the tumor maximal area was calculated and the pathological features of the tumors were observed. Forty S180 sarcoma-bearing (i.p.) ICR mice, which were randomly divided into 4 groups as above, were used for observation of the life-span. RESULTS PB could strongly inhibit the growth of S180 sarcoma with the tumors regressing completely in 3 of 8 mice, prolong the life-span of mice bearing S180 sarcoma, increase the infiltration of macrophages and lymphocytes in the periphery and inside of the tumors. In addition, there were more prominent hemorrhagic necrosis, neutrophil infiltration and microthrombi in small vessels around the necrotic areas in the tumors of PB treated group. The tumor-suppressive effect of PB disappeared after macrophage system blockage with TrB. In PB + TrB, TrB, control and PB groups, the size of tumors reduced, and the life-span of mice increased in successive order. CONCLUSIONS (1) PB is a strong activator of macrophage. (2) In vivo the tumor-suppressive effect of PB is initially mediated by PB activated macrophage system. Then other immunocompetent cells, e.g., T-cells, NK-cells, etc, activated directly and/or indirectly by PB, may play a very important role in tumor suppression. (3) PB-activated macrophages are more sensitive to TrB blockage. Therefore, using TrB + PB to block macrophage system is more effective than TrB alone. (4) Blockage of macrophage function might influence the life-span of the mice.

OBJECTIVE To investigate the therapeutic effects of dl-3-n-butylphthalide (dl-NBP) on regional cerebral blood flow impairment and blood-brain barrier damage induced by subarachnoid hemorrhage (SAH) in rats. METHODS SAH was induced by an injection of 0.35 ml autologous blood into the lateral ventricle. The regional cerebral blood flow in caudate nucleus was determined by hydrogen clearance method. Permeability of blood-brain barrier was measured by extravasation of the protein bound Evans blue dye to brain tissue. RESULTS SAH produced a marked decrease in both caudate blood flow and blood-brain barrier damage which showed increased extravasation of protein bound Evans blue dye to brain tissue. dl-NBP (5-20 mg/kg, given 5 min after the onset of SAH) and nimodipine (0.25 mg/kg) significantly increased the regional cerebral blood flow in caudate nucleus within 3 hours of SAH. Moreover, dl-NBP (10 mg/kg) and nimodipine (0.25 mg/kg, given 5 min and 3 h after SAH) significantly reduced the brain extravasation of Evans blue dye which increased after 6 hours of SAH. CONCLUSIONS By improving the regional cerebral blood flow and blood-brain barrier, dl-NBP has therapeutic effects on experimental SAH.

OBJECTIVE To examine the relationship between selenium (Se)- and vitamin E(VE)-deficiency and thyroid hormone (TH) metabolic disturbance, especially type I iodothyronine 5'-deiodinase (ID-I) activity. METHODS We observed the metabolic changes of TH-3, 3',5-triidothyronine (T3) and thyroxin (T4) and their free radicals-glutathione peroxidase (GSH-Px) and lipid peroxides (LPO) in the peripheral tissues (liver, kidney and blood) of Wistar rats maintained on Se- and VE-deficient artificial semi-synthetic diet for 8 weeks. RESULTS In the Se- and VE-deficient rats (compared with Se- and VE-supplement rats): 1). Hepatic and renal ID-I activities decreased by 60% and 50% respectively, serum levels of T3 reduced 36%, and T4 increased by 32%. Hepatic ID-I activity and serum T3 concentration in Se- and VE-supplement rats were significantly higher than those in the Se-supplement and VE-deficient rats. 2). GSH-Px activities in the whole blood and liver decreased by 61% and 82% respectively. LPO concentrations in serum and liver increased by 53% and 40% respectively. When Se content remained the same, changes of VE content did not significantly affect GSH-Px activity, but the combined supplement of Se and VE decreased significantly the LPO concentration. CONCLUSIONS The data suggests that GSH-Px activity is influenced mainly by Se level, but ID-I activity is influenced by VE concentration in addition to Se level. VE seemed to play a protective role on ID-I and its mechanism might be related to the fact that VE protects the stability of microsomal membrane in which ID-I exists, avoiding from free radical damage as well as the coordinated action and mutual sparing effect of Se and VE.

OBJECTIVE To study the expression of epidermal growth factor receptor (EGFR) on cochlear hair cells of normal and explosion-stricken guinea pigs and the effects of epidermal growth factor (EGF) and dexamethasone (DXM) treatment for blast hearing loss. METHODS Immunohistochemical technique and auditory brainstem response (ABR) test were used. RESULTS Scattered expression of EGFR was seen in inner hair cells (IHCs) and outer hair cells (OHCs) in normal guinea pigs. Segmentally distributing positive reaction was also located in stereocilia of hair cells. Distribution of EGFR reaction was seen in the cytoplasm of IHC 24 hours after exposure to blasts, and in the stereocilia of IHC and the cuticular plate of OHC 72 hours postexposure. At one week EGFR reaction in hair cells increased obviously and part of OHC stereocilia also showed positive reaction. EGFR reaction reduced at two weeks, though positive reaction could still be found in the stereocilia of hair cells at one month. Combination of EGF and DXM administrations promoted hearing recovery significantly. CONCLUSIONS The healing of injured hair cells may be related to EGF.

OBJECTIVE To evaluate the effect of gynostemma pentaphyllum mak (GP) on carcinomatous conversions of leukoplasia of the golden hamster cheek pouch induced by dimethylbenzanthracene (DMBA). METHODS 284 golden hamsters, ranging from 4 to 8 weeks of age, 80 to 100 grams in weight were randomly divided into three groups: control, model and experimental groups. Control group (8 hamsters) were sacrificed at week 0 and week 12 for control. Model group (123 hamsters) were pasted in bilateral cheek pouches with 0.5% DMBA, 3 times a week for establishment of experimental leukoplasia, and sacrificed at week 2 to week 9 (12-22 hamsters were sacrificed a week). Experimental group (153 hamsters) were divided into three subgroups. Subgroup A underwent simultaneous DMBA pasting and oral taking of GP, and were sacrificed at week 6 and week 9. Subgroup B underwent oral taking of GP for 12 weeks after completion of DMBA pasting. Subgroup C underwent DMBA pasting after completion of oral taking of GP for 12 weeks. RESULTS The earliest epithelial dysplasia and carcinoma in situ occurred at week 3 and week 6 after DMBA pasting. There were significant differences between subgroup B and model group for 3 weeks' administration of DMBA (P<0.05), and between subgroup C and model group (P<0.01), while there was no difference between subgroup B and model group for 6 week's administration of DMBA (P>0.05). CONCLUSIONS GP could inhibit and reverse the carcinomatous conversions of leukoplasia of golden hamster cheek pouches, indicating its positive anticarcinogenic effect.

OBJECTIVE To demonstrate that heme oxygenase (HO) isoforms exist in rat spleen treated with hematin and phenylhydrazine and to confirm that the isolated cDNA actually encodes HO-1 by expressing cDNA in monkey kidney cells (COS-1 cells) in order to prepare HO-1 mutant for inhibiting the natural enzyme. METHODS The rat spleen microsomal fractions were first purified by diethylaminoethyl (DEAE)-Sephacel and hydroxylapatite. The activity of two isoforms (HO-1 and HO-2) of enzyme and their apparent molecular weight on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (SDS-PAGE) were measured. Secondly, using the isolated HO-1 cDNA clone, the expression plasmid pcDNA3HO1 was constructed and transfected into cultured COS-1 cells. The transfected cells were collected and disrupted by sonication, and the microsomes were prepared by ultracentrifugation. The activity of HO-1 was measured. RESULTS Two isoforms were purified and identified in treated rat spleen and HO-1 was the predominant form. The ratio of HO-1 to HO-2 was 3.2:1. The apparent molecular weights of HO-1 and HO-2 were about 30 kD and 36 kD under reducing conditions, respectively. The HO-1 was highly expressed in endoplasmic reticulum of transfected cells. The specific band was located in molecular weight of 30 kD. The specific activity was five times higher than that of the control. CONCLUSIONS The activity of expressed HO-1 in COS-1 cells is higher than that of purified enzyme from rat spleen tissue. It is suggested that this clone having an insert of 1030 base-pairs encodes HO-1 and that we can prepare HO-1 mutant by site-directed mutagenesis of HO-1 cDNA to prevent and treat hyperbilirubinemia.

OBJECTIVE To study the antioxidant and antiapoptotic effects of U-74389G on ischemic brain in rats. METHODS Right focal cerebral ischemia and reperfusion was induced by suturing in 103 male SD rats weighing 280-310 g. To determine LPO in the cortex and striatum, we randomly divided 78 rats into 5 groups: group 1, sham-operative group (6 rats); group 2, control (18); group 3, U-74389G administration before ischemia (18); group 4, U-74389G administration before reperfusion; group 5, CS-4 vehicle as negative control. Groups 2-5 were further divided into 3 subgroups according to the duration of reperfusion. Another 25 rats were similarly grouped (5) to detect apoptosis with TUNEL stain. RESULTS The concentrations of MDA in groups 3 and 4 were reduced and the activities of SOD and concentrations of GSH were partially restored as compared with the control group. These effects were more significant in group 3 than in group 4. Otherwise, CS-4 can not provide protective effects. The number of apoptotic cells in groups 3 (P<0.01) and 4 (P<0.05) was significantly reduced as compared with the control group. CONCLUSIONS U-74389G has antioxidant and antiapoptotic effects on ischemic brain in rats. The administration of U-74389G before the onset of ischemia was more useful than that before the onset of reperfusion.

OBJECTIVE To provide baseline data on an animal model in which collecting and voiding can be accurately characterized urodynamically in the conscious state and natural posture. METHODS Thirty-one female Yucatan microswines (age 4-8 months, weight 11-43 kg) were used. Portcatheters were placed in the bladder and peritoneal cavity, and reservoirs were implanted under the back skin for easy access. For urodynamic study, conscious pigs were restrained in specially designed adjustable cages. The portcatheter reservoirs were connected by 20-gauge needles and tubings to a UDS-120 digital computer polygraph to measure the total bladder pressure (pves) and abdominal pressure (pabd). A flow meter was placed behind and underneath the animal to measure the uroflow. Diuresis was induced with furosemide, and 2-4 voiding cycles were monitored. Isovolumetric detrusor pressure (pdet, isv) was obtained in the last cycle by manual interruption of flow per vagina. Urodynamic investigations were performed satisfactorily in all animals. RESULTS The voided volume was 102-340 ml (mean 181.7±11.9 ml). Seven pigs had residual urine (4-39 ml, mean 14.3±4.7 ml). The initial opening pressure at the start of voiding was 19.9±1.5 cmH2O; detrusor pressure at maximum flow rate was 15.7±1.3 cmH2O; average flow was 12.6±0.7 ml/s; maximum flow rate was 20.7±1.1 ml/s; pdet, isv was 51.6±2.4 cmH2O; flow time was 15.9±1.2 seconds; mean resistance factor (R) was 0.06±0.01 cmH2O ml-2s2; mean urethral resistance factor (URA) was 7.10±0.51 cmH2O; and mean strength of voiding detrusor contraction was 3.91±0.20 W/m2. CONCLUSIONS The above model allows reliable measurement of pressure-flow parameters in the conscious state and natural posture, permitting in-vivo urodynamic characterization of obstructive voiding dysfunction and correlation with detrusor structure.

OBJECTIVE To investigate the effectiveness of selective superior mesentery arteriography and a guide wire as an intraoperative locating mark on diagnosing, locating the bleeding sites in the small intestines caused by arteriovenous malformations (AVMs). METHODS The selective superior mesentery arteriography was done in seven patients with AVMs of the intestines, and a segment of guide wire was placed simultaneously as a locating mark. RESULTS All the resected intestines were marked by sutures for pathological examination and confirmed as AVMs of the small intestines. The patients were followed up for an average of 25 months (17-35 months). During this period, all patients had no recurrence of hemorrhage. CONCLUSIONS The selective superior mesentery arteriography and placement of a guide wire as an intraoperative locating mark in AVMs of the intestines can help surgeons successfully in finding and resecting the lesions without complications. It is a new method and has a perspective to be widely spread.

OBJECTIVE To probe ultrastructurally into the mechanism why hip region is the predilected site of fracture in aged people, yet with femoral head exempted. METHODS Proximal femoral ends were collected from 14 aged people, who had undergone endoprosthetic replacement for intra-capsular fracture of the femoral neck, and from 7 young men died of brain injury. These specimens were processed and subjected to scanning electron microscopic and transmission electron microscopic observation for bone resorption. RESULTS As compared with the specimens from young men, there were three types of bone resorption in the proximal femoral ends of aged people, i.e. osteoclastic resorption and osteocytic resorption of the trabeculae of cancellous bone, and osteoclastic resorption of Haversian systems of the cortical bone. In the proximal femoral ends of the young men, the arch structures composed of trabeculae in the femoral head showed a round or roundish configuration, while those at the femoral head-neck junction revealed an oval profile and those in the femoral neck exhibited a narrow oval contour. In the proximal femoral ends of the aged people, the morphological characteristics of the trabecular arch remained unchanged despite overt bone resorption. CONCLUSIONS Vulnerability of hip region to fracture in aged people is due to a decline in the structural strength of bone tissues of the proximal femoral ends resulting from osteoclastic and osteocytic resorption. The round and roundish trabecular arch of the femoral head can bear external forces from different directions, so that no fracture occurs here, while the oval and narrow oval arches at the head-neck junction and in the neck region fail to stand the horizontal external forces (abduction and adduction injuries), thereby fracture easily happens.

Diffuse panbronchiopitis (DPB) is a disease characterized by chronic inflammation of bronchioles and terminal bronchioles. Most DPB cases have been found in Japan in the past three decades. We report the first typical DPB in the mainland of China diagnosed by open lung biopsy.