[The observation of changes in plasma PGI2 and TXA2 levels and the therapeutic effect of tetramethylpyrazine in E. coli induced acute lung injury in rabbits]

Thirty two rabbits were equally divided at random into 4 groups: A. control; B. E.coli; C. E.coli + ibuprofen; D. E.coli + tetramethylpyrazine. The plasma concentration of 6-keto-PGF1 alpha and TXB2, arterial blood gas as well as platelet aggregability were measured and the pathological changes of lung tissue were observed. The results suggest that TXA2 and PGI2 do take part in the pathogenesis of acute lung injury; that PGI2 may serve as an indicator in the evaluation of the degree of injury in the pulmonary endothelial cells and may also contribute to septic shock; and that both tetramethylpyrazine and ibuprofen possess therapeutic effects on the amelioration of acute lung injury, and the former is rather stronger than the latter in the inhibitory effect on granulocytic sequestration within the lung.

[Clinical study of superoxide dismutase in recurrent aphthous ulceration]

Activity of superoxide dismutase (SOD) was determined in erythrocytes obtained from 74 patients with recurrent aphthous ulcerations (RAU) and 100 healthy individuals. The results showed that activity level of SOD in RAU was significantly lower as compared with that in the controls (P less than 0.01). The activity of SOD in 30 cases of RAU at interval period was elevated on reexamination, but it was still lower than that in the controls (P less than 0.01). There is evidence that damage of superoxide radicals (O.2) and decrease of activity of SOD may play important roles in the pathogenesis of RAU. A random double-blind, placebo-controlled, cross-over trial on membrane SOD was carried out in 40 patients with RAU. The results demonstrated that the effective rate of SOD was 90%, being markedly higher than that of placebo. It is suggested that membrane SOD, as a topical medicine, could increase the concentration of SOD on the ulcerous surfaces, prevent O.2-induced injury, decrease capillary permeability, relieve inflammation and improve cure of ulcer.

[The in vitro inhibitory effect of sodium selenite on complement activation]

Sodium selenite exerts a marked inhibiting effect on the hemolysis induced by complement fixation. The results of rocket immunoelectrophoresis tests for the activated fragments C3d and C4d show that sodium selenite inhibits complement activation through the alternative pathway.

Competitive control of myosin expression: hypertrophy vs. hyperthyroidism

The competition between two opposing influences on the phenotypic expression of skeletal muscle myosin were studied to determine which was the dominant regulator. Experimental hyperthyroidism, which induces fast myosin expression, was produced by subcutaneous implantation of a 40-day constant-time-release triiodothyronine pellet. Compensatory hypertrophy, which induces slow myosin expression, was produced by surgical removal of a synergistic hindlimb muscle. Hyperthyroidism increased the percentage of type II fibers and the fast myosin isoforms in both the plantaris and soleus muscles. Hypertrophy significantly increased the percentage of type I fibers and the slow myosin type in the plantaris and soleus muscles. However, with the simultaneous introduction of hyperthyroidism and hypertrophy, only the hyperthyroid effects were observed. Hyperthyroidism and not physiological demand was found to be the dominant regulator of skeletal muscle myosin expression.

Empyema of the gallbladder treated by laparoscopic cholecystectomy

PATIENT

A 52-year-old woman with an eight-year history of gallstones who had twice declined to have a cholecystectomy.

CLINICAL FEATURES

The patient presented as an emergency with severe abdominal pain, hectic fevers and rigors. Results of examination showed an enlarged, tender and easily palpable gallbladder. A diagnosis of empyema of the gallbladder was made.

INTERVENTIONS

Intravenous administration of antibiotics was started immediately and a laparoscopic cholecystectomy was performed 36 hours after admission.

OUTCOME

Postoperative recovery was uncomplicated. The patient was discharged after 72 hours and returned to normal activities within one week.

CONCLUSION

Laparoscopic cholecystectomy seems a useful technique to treat gallbladder disease in emergency as well as elective situations.

Gastric antral patch esophagoplasty for extensive corrosive stricture of the esophagus

A case is reported of a patient with a 9-cm stricture of the esophagus caused by ingestion of sodium hydroxide, who was treated by gastric antral patch esophagoplasty. In this procedure, a full-thickness pedicled patch of gastric antrum, based on the left gastroepiploic artery, was used to enlarge the esophageal lumen, thus allowing preservation of esophageal continuity and utilization of a functioning lower esophageal sphincter. The patient ate normally after the operation, and radiological, manometric, and esophageal pH monitoring studies indicated satisfactory esophageal function. Gastric antral patch esophagoplasty avoids the complications associated with esophageal bypass or resection. Previous long-term results of this procedure in patients with reflux-induced esophageal stricture have been good, and the technique merits consideration in the treatment of severe corrosive strictures.

The molecular basis for the synergism between the CD3/alpha beta T cell receptor and the CD2 antigen-derived signals in promoting T-cell proliferation

Northern blot analysis and a highly sensitive methodology for mRNA phenotyping, polymerase chain reaction (PCR), were used to explore the basis for the synergism between CD3/alpha beta T cell receptor (TCR) and the CD2 antigen-derived signals in promoting proliferation of T cells. Northern blotting of RNA isolated from highly purified normal human T cells revealed that crosslinking of anti-TCR-1 (a mAb directed at a framework determinant of the TCR) and OKT11 (a mAb directed at the SRBC-binding epitope of the CD2 antigen) induced the expression of the interleukin-2 gene and the gene for IL-2 receptor alpha, mRNA phenotyping by PCR revealed that crosslinkage of TCR with the CD2 antigen, and not independent crosslinking of TCR or the CD2 antigen, results in the induction of IL-2, IL-2 receptors alpha and beta, and IL-4-specific transcripts. Highly purified CD4+ T cells, as well as CD8+ T cells proliferated by crosslinking TCR with CD2 antigen. Moreover, crosslinkage of TCR with the CD2 antigen and not of either antigen with the CD4 antigen (on the surface of CD4+ T cells) or the CD8 antigen (on the surface of CD8+ T cells) resulted in marked proliferation. Our demonstration that the CD2 antigen-derived signal(s) contribute to the expression of growth promoting genes elicited via the TCR, and that the CD2 antigen is more efficient compared with the CD4 or CD8 antigen in evoking T cell proliferation, suggests that autoimmunity as well as alloimmunity might be regulated by targeting the CD2 antigen.

Endoscopic management of gallstone pancreatitis

The use of minimally invasive techniques of removing gallstones, and the gall-bladder, is an attractive option for patients who may be severely ill with pancreatitis. We describe here a patient with gallstone pancreatitis who was managed completely by endoscopic techniques consisting of endoscopic retrograde cholangiopancreatography (ERCP) followed by laparoscopic cholecystectomy.

[Analysis of prognostic factors in malignant melanoma of the uveal tract]

106 patients with malignant melanoma of the uveal tract, confirmed by histopathology, were analysed statistically for prognostic factors. It was found that older age, larger dimension of the tumor base, and more anteriorly advanced margin of the tumor were clinical factors for poor prognosis, and the inclusion of epithelioid cells was pathological factor for poor prognosis.

Orbital rhabdomyosarcoma. Immunohistochemical studies of seven cases

An immunohistochemical analysis using a series of mono- and polyclonal antibodies against myoglobin, desmin, vimentin, actin, NSE, S-100 protein and keratin was done on alveolar rhabdomyosarcoma (3 cases), embryonal (3) and pleomorphic rhabdomyosarcoma of the orbit (1). All tumors were stained by monoclonal antibodies to desmin and vimentin, whereas 6 of the 7 cases were stained by myoglobin. The results indicate that desmin and vimentin are highly sensitive immunohistochemical markers for the diagnosis of rhabdomyosarcoma, especially in poorly differentiated ones.

Is closure of the peritoneal layer necessary in the repair of midline surgical abdominal wounds?

This study describes a prospective randomized controlled trial to evaluate whether suture of the peritoneal layer is necessary as a separate step in the closure of midline abdominal surgical wounds. Consecutive patients undergoing abdominal operation--elective and emergency surgery--through a midline abdominal wound were randomized to have the peritoneal layer closed with continuous catgut, or to have this step omitted. The linea alba was closed with interrupted stainless steel sutures, and the skin approximated with staples. Patients were evaluated for wound sepsis, wound dehiscence, and subsequent incisional hernia development. Postoperative pain was assessed by a self-administered visual analogue score, and by measuring narcotic requirements. There was no significant difference in narcotic requirements, pain scores, or wound complications between the 2 groups. Single-layer closure of the abdominal wall is quicker, less costly, and theoretically safer than layered closure, and it is recommended that separate suture of the peritoneum be abandoned.

Inhibition of Escherichia coli glutamine synthetase by alpha- and gamma-substituted phosphinothricins

We have investigated the inhibition of Escherichia coli glutamine synthetase (GS) with alpha- and gamma-substituted analogues of phosphinothricin [L-2-amino-4-(hydroxymethylphosphinyl)butanoic acid (PPT)], a naturally occurring inhibitor of GS. These compounds display inhibition of bacterial GS that is competitive vs L-glutamate, with Ki values in the low micromolar range. At concentrations greater than Ki the phosphinothricins caused time-dependent loss of enzyme activity, while dilution after enzyme inactivation resulted in recovery of enzyme activity. ATP was required for inactivation; the nonhydrolyzable ATP analogue AMP-PCP failed to support inhibition of GS by the phosphinothricins. The binding of these inhibitors to the enzyme was also characterized by measurement of changes in protein fluorescence, which provided similar inactivation rate constants k1 and k2 for the entire series of compounds. Rate constants koff for recovery were also determined by fluorescence measurement and were comparable for both PPT and the gamma-hydroxylated analogue GHPPT and significantly greater for the alpha- and gamma-alkyl-substituted compounds. Electron paramagnetic resonance spectra provided information on the interaction of the phosphinothricins with the manganese form of the enzyme in the absence of ATP, and significant binding was observed for PPT and GHPPT. 31P NMR experiments confirmed that enzyme inactivation is accompanied by hydrolysis of ATP, although phosphorylated phosphinothricins could not be detected in solution. The kinetic behavior of these compounds is consistent with a mechanism involving inhibitor phosphorylation, followed by release from the active site and simultaneous hydrolysis to form Pi and free inhibitor.

Attenuated induction of heat shock gene expression in aging diploid fibroblasts

We examined the effects of cellular aging on the regulation of heat shock gene expression in IMR-90 human diploid fibroblasts. Heat shock (42-43 degrees C) and canavanine (200-400 micrograms/ml) were used to evoke the heat shock response in these cells. We showed that heat shock induced the synthesis of proteins with apparent molecular weights of 98,000, 89,000, 78,000, 72,000, 64,000, 50,000 and 25,000, with heat shock protein (HSP) 89 and 72 being most prominent. Canavanine induced the synthesis of the four high molecular weight HSPs, particularly HSP 89 and HSP 78, without noticeably enhancing synthesis of the low molecular weight HSPs. We found that, while a similar series of HSPs were induced in the young and old cells, there was a marked decrease in the magnitude of this induction in the old cells. Using cells with defined population doubling levels, we observed a direct correlation of the inducibility of HSP synthesis and the replicative potential of the cells used. Analysis of the amount of translatable and hybridizable mRNA, by the methods of in vitro translation and Northern blot hybridization, demonstrated that the induction of HSPs synthesis can be accounted for by increases in their mRNA. Nuclear runoff transcription provided evidence that the decrease in inducible expression of the HSPs in aging IMR-90 cells was attributable to a transcriptional mechanism. This conclusion was substantiated by analysis of the hsp 70 promoter activity in transient expression assay of the hsp 70 promoter-chloramphenicol acetyltransferase construct. We propose that there is an age-associated dysfunction in the signaling mechanism of the heat shock response.

Sources of Carbon for Export from Spinach Leaves throughout the Day

Rates of net carbon exchange, export, starch, and sucrose synthesis were measured in leaves of spinach (Spinacia oleracea L.) throughout a 14-hour period of sinusoidal light to determine the sources of carbon contributing to export. Net carbon exchange rate closely followed light level, but export remained relatively constant throughout the day. In the morning when photosynthesis was low, starch degradation provided most of the carbon for export, while accumulated sucrose was exported during the evening. At high photosynthesis rate, the regulatory metabolite fructose 2,6-bisphosphate was low, allowing more of the newly fixed carbon to flow to sucrose through cytosolic fructose bisphosphatase. When the rate of sucrose synthesis exceeded the rate of export from the leaf, sucrose accumulated and soon thereafter sucrose synthesis declined. A decreasing sucrose synthesis rate resulted in additional carbon moving to the synthesis of starch, which was maintained throughout the remainder of the day. The declining sucrose synthesis rate coincided with decreasing activity of sucrose phosphate synthase present in gel-filtered leaf extracts. A rise in the leaf levels of uridine diphosphoglucose and fructose 6-phosphate throughout the day was consistent with this declining activity.

A case-control study of cancer of the esophagus and gastric cardia in Linxian

A case-control study involving interviews with 1,244 patients (758 males and 486 females) with cancer of the esophagus or gastric cardia and 1,314 population-based controls (789 males, 525 females) was carried out in Linxian, a rural county in North Central China with one of the world's highest mortality rates for these tumors. Cancer risks tended to rise with increasing intake of wheat and corn, but no association was found with adult intake of pickled vegetables, the leading a priori suspect, and risks were not elevated among those consuming low quantities of fresh vegetables or fruits. Few differences in preparation or storage of food or water were detected, although cancer patients reported less fluid intake than controls. Few persons reported drinking alcoholic beverages. Smoking was reported by 61% of the male cases and was a mild risk factor, related more to cancer of the cardia than of the esophagus. The risk was increased by 70% among those whose parents had esophageal or stomach cancer, but only slightly among those whose spouses had such cancers, suggesting that exposure early in life and/or genetic effects may be involved.

[En-bloc resection with immediate reconstruction of malignant tumor of the humerus--report of 9 patients]

From March 1966 to June 1985, 9 patients with humerus malignant tumor were treated by en-bloc resection and immediate reconstruction. There were 5 males and 4 females. The ages ranged from 18 to 74 with an average of 38.3 years. These 9 lesions were diagnosed by pathology as malignant giant cell tumor of the bone (2), chondrosarcoma (2), reticulum cell sarcoma (1), osteoblastoma (osteosarcomatous) (1), osteogenic sarcoma (1) and metastatic cancer (1) clear cell cancer and 1 thyroid cancer), located either in the upper or lower end of the humerus. Cutting margin was 4-7 cm from the tumor. The length of resected humerus was 10-18 cm. Simple excision without reconstruction was done only in 1 patient. The bone defect after resection was reconstructed with autogenous fibular graft in 3 patients, replantation of the limb in 2, one of whom was added with prosthesis for reconstruction of the elbow function, humerus prosthesis in 2 and elbow prosthesis in 1. All the patients were followed. Only two had died and 7 are still alive without evidence of disease. The longest survival was 20.5 years and the shortest, 18 months with an average of 10.1 years. The causes of death (1 osteoblastoma and 1 osteogenic sarcoma) were recurrence and lung metastasis. The indication, extent of excision and causes of recurrence are discussed.

[Establishment of human glioma cell line--nude mice solid tumor model NHG-1 and its characteristics]

Establishment and its characteristics of a nude mice solid tumor model NHG-1 from human glioma cell line are reported. 5-8 week old NC nude mice of both sexes and SHG-44 cell line used in this experiment were from our laboratory. The initial successful transplantation rate was 7/11 (64%) and that of 30 passages in the subsequent 4 years was 100%. After subcutaneous inoculation, growth curve showed a latent period in week 1-2, slow growing period in week 3-4, rapid growing period in week 5-6 and a final plateau period in week 7. The doubling time was 7 days and cell cycle time was 2.5 days. The cells in G1, S and G2M phases comprised 56%, 27% and 17%, respectively. The survival time of the host was 54 +/- 15 days. The tumor tissues showed a tendency towards invading the surrounding soft tissues. By morphological observation with light and electron microscopes, LDH isozyme assay, PAP immuno-histochemistry labelling GFAP and chromosome analysis, it is confirmed that the transplantable tumor possesses the characteristics of human malignant glioma. The estrogen receptor in the transplantable tumors demonstrated by cytochemical assay indicates that the glioma carcinogenesis is related to endocrine factor of the host. The therapeutic effects of anticancer drugs, such as ACNU, BCNU and 10-hydroxy-2-decenoic acid from the royal jelly on NHG-1 model are evaluated.

Induction of resistance to alkylating agents in E. coli: the ada+ gene product serves both as a regulatory protein and as an enzyme for repair of mutagenic damage

The expression of several inducible enzymes for repair of alkylated DNA in Escherichia coli is controlled by the ada+ gene. This regulatory gene has been cloned into a multicopy plasmid and shown to code for a 37-kd protein. Antibodies raised against homogeneous O6-methylguanine-DNA methyltransferase (the main repair activity for mutagenic damage in alkylated DNA) were found to cross-react with this 37-kd protein. Cell extracts from several independently derived ada mutants contain variable amounts of an altered 37-kd protein after an inducing alkylation treatment. In addition, an 18-kd protein identical with the previously isolated O6-methyl-guanine-DNA methyltransferase has been identified as a product of the ada+ gene. The smaller polypeptide is derived from the 37-kd protein by proteolytic processing.