Investigation of the DNA adducts formed in B6C3F1 mice treated with benzene: implications for molecular dosimetry

We have investigated the formation of DNA adducts in the bone marrow and white blood cells of male B6C3F1 mice treated with benzene using P1-enhanced 32P-postlabeling. No adducts were detected in the bone marrow of controls or mice treated with various doses of benzene once a day. After twice-daily treatment for 1 to 7 days with benzene, 440 mg/kg, one major (no. 1) and up to two minor DNA adducts were detected in both the bone marrow and white blood cells. The relative adduct levels in these cells ranged from 0.06 to 1.46 x 10(-7). a significant correlation (r2 = 0.95) between levels of adducts in bone marrow and white blood cells was observed. After a 7-day treatment with benzene, 440 mg/kg twice a day, the number of cells per femur decreased from 1.6 x 10(7) to 0.85 x 10(7), indicating myelotoxicity. In contrast, administration of benzene once a day produced only a small decrease in bone marrow cellularity. The observed induction of toxicity in bone marrow was paralleled by formation of DNA adducts. In vitro treatment of bone marrow with hydroquinone (HQ) for 24 hr produced the same DNA adducts as found after treatment of mice with benzene, suggesting that HQ is the principal metabolite of benzene leading to DNA adduct formation in vivo. Using P-postlabeling the principal DNA adduct formed in vivo was compared with N2-(4-hydroxyphenyl)-2'-deoxyguanosine-3'-phosphate. The results of this comparison demonstrated that the DNA adduct formed in vivo co-chromatographs with N2-(4-hydroxyphenyl)-2'-deoxyguanosine-3'-phosphate. These studies indicate that metabolic activation of benzene leads to the formation of DNA adducts in bone marrow and white blood cells and suggest that measurement of DNA adducts in white blood cells may be an indicator of biological effect following benzene exposure.

Three new adjacent bis-tetrahydrofuran acetogenins with four hydroxyl groups from Asimina triloba

Three new adjacent bis-tetrahydrofuran ring Annonaceous acetogenins with four hydroxy groups, bullatetrocin (1), 10-hydroxyasimicin (2), and 10-hydroxytrilobacin (3), were isolated by activity-directed fractionation from the stem bark of Asimina triloba. Their structures were established on the basis of chemical and spectral evidence. The absolute stereochemistry at the C-10 hydroxy position was determined by converting 2 and 3 to their ketolactone isomers, 2,4-cis/trans 10-hydroxyasimicinones and 2,4-cis/trans 10-hydroxytrilobacinones, respectively. The bioactivities of the new compounds against brine shrimp larvae and six human solid-tumor cell lines are reported, and structure-activity relationships between trihydroxylated and tetrahydroxylated acetogenins are discussed. In addition to 1-3, gigantetrocin A, 2,4-cis/trans-gigantetrocin A-ones, annonacin, and annonacin A were also isolated for the first time from this species.

Chlorinated annonaceous acetogenins and their bioactivities

4(S)-Chloro-4-deoxygigantetrocin A and 4(S), 18-dichloro-4,18-dideoxyasimilobin were obtained by treating gigantetrocin A with triphenylphosphine and CCl4. The structures were determined by spectroscopic methods. The chlorinated compounds show decreased bioactivities in the brine shrimp lethality test and against human tumor cell lines.

Effect of anticomplement agent K76 COOH on hamster-to-rat and guinea pig-to-rat heart xenotransplantation

In normal rats, the xenobiotic K76 inhibited the C5 and probably the C2 and C3 steps of complement and effectively depressed classical complement pathway activity, alternative complement pathway activity, and the C3 complement component during and well beyond the drug's 3-hr half-life. It was tested alone and with intramuscular tacrolimus (TAC) and/or intragastric cyclophosphamide (CP) in rat recipients of heterotopic hearts from guinea pig (discordant) and hamster (concordant) donors. Single prevascularization doses of 100 and 200 mg/kg increased the median survival time of guinea pig hearts from 0.17 hr in untreated controls to 1.7 hr and 10.2 hr, respectively; with repeated injections of the 200-mg dose every 9-12 hr, graft survival time was increased to 18.1 hr. Pretreatment of guinea pig heart recipients for 10 days with TAC and CP, with or without perioperative splenectomy or infusion of donor bone marrow, further increased median graft survival time to 24 hr. Among the guinea pig recipients, the majority of treated animals died with a beating heart from respiratory failure that was ascribed to anaphylatoxins. Hamster heart survival also was increased with monotherapy using 200 mg/kg b.i.d. i.v. K76 (limited by protocol to 6 days), but only from 3 to 4 days. Survival was prolonged to 7 days with the addition of K76 of intragastric CP at 5 mg/kg per day begun 1 day before operation (to a limit of 9 days); it was prolonged to 4.5 days with the addition of intramuscular TAC at 2 mg/kg per day beginning on the day of transplantation and continued indefinitely. In contrast to the limited efficacy of the single drugs, or any two drugs in combination, the three drugs together (K76, CP, and TAC) in the same dose schedules increased median graft survival time to 61 days. Antihamster antibodies rapidly increased during the first 5 days after transplantation, and plateaued at an abnormal level in animals with long graft survival times without immediate humoral rejection. However, rejection could not be reliably prevented, and was present even in most of the xenografts recovered from most of the animals dying (usually from infection) with a beating heart. Thus, although effective complement inhibition with K76 was achieved in both guinea pig- and hamster-to-rat heart transplant models, the results suggest that effective interruption of the complement cascade will have a limited role, if any, in the induction of xenograft acceptance.

Surgical treatment of spinal tumor (analysis of 32 cases)

With the advance of spinal surgery in the last decade, surgical treatment of spinal tumors has been no longer limited to simple laminectomy. The principles of surgical treatment of spinal tumors include: (1) anterior approach for the anterior lesion and posterior approach for the posterior lesion; (2) combined anterior and posterior approach for extensive lesions and (3) internal fixation for spinal stability. 32 cases of spinal tumors were treated on the basis of the above guiding principles and 84% (27/32) showed excellent or good results.

Production of 8-hydroxy-2'-deoxguanosine in DNA by microsomal activation of tamoxifen and 4-hydroxytamoxifen

Using rat liver microsomal preparations, we have investigated the activation of the anti-estrogen compound tamoxifen (TAM) and its metabolite 4-hydroxytamoxifen (4-OH-TAM) to form 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in DNA. When reduced nicotinamide adenine dinucleotide phosphate (NADPH) was used as a cofactor in microsomal activation of either TAM or 4-OH-TAM, the levels of 8-OH-dG were 3-fold higher than in microsomes plus cofactor only. In contrast, no significant increase in the level of 8-OH-dG was detected in DNA samples from microsomal activation of either TAM or 4-OH-TAM with cumene hydroperoxide as the cofactor. These results demonstrate that the microsomal activation of TAM and 4-OH-TAM to form 8-OH-dG is dependent upon the cofactor used. The addition of either EDTA or catalase to the activation system significantly decreased the formation of 8-OH-dG by TAM, but not by 4-OH-TAM. The presence of either sodium azide, superoxide dismutase or mannitol inhibited the formation of 8-OH-dG by both TAM and 4-OH-TAM. Taken together these findings indicate that microsomal activation of TAM and 4-OH-TAM with NADPH generates reactive oxygen species which result in the formation of 8-OH-dG. We propose that the formation of 8-OH-dG by TAM and its metabolites may contribute to the observed carcinogenic effects of TAM.

cis-gigantrionenin and 4-acetyl gigantetrocin A, two new bioactive annonaceous acetogenins from Goniothalamus giganteus, and the stereochemistries of acetogenin 1,2,5-triols

Using activity-directed fractionation, two new bioactive acetogenins, cis-gigantrionenin (1) and 4-acetyl gigantetrocin A (2), have been isolated from the bark of Goniothalamus giganteus (Annonaceae). Compound 1 has a cis-mono-THF ring with one flanking hydroxyl and possesses a cis-double bond at C-21/22 of the aliphatic chain; it represents only the second example of the cis-mono-THF ring annonaceous acetogenins having one flanking hydroxyl. Compound 2 has a trans-mono-THF ring with one flanking hydroxyl, but it possesses a mono-acetyl group at the 4-OH position; it represents only the second natural example of the acetylated annonaceous acetogenins; the first acetogenin reported, uvaricin, was mono-acetylated at the 24-OH. The stereochemistries of 1 and 2 were determined by the advanced Mosher ester method. In addition, the absolute stereochemistries of gigantriocin (3), gigantrionenin (4), and giganenin (5) were determined by the advanced Mosher ester method and by circular dichroism (CD). The stereochemistries of the 7,8-diols in murihexocins A (6) and B (7) were determined to have the S,S-configurations, respectively.

[Different techniques of internal fixation applied in lumbosacral fusion: 83 cases analysis]

Posterior lumbosacral fusion using bone graft without internal fixation requires long immobilization and has high rate of pseudoarthrosis. To overcome such limitation technique of spinal internal fixation has been developed and applied in past twenty years. Since 1982, the authors have done lumbosacral fusion with internal fixation and bone graft by using Harrington alar hook (32 cases), luque ring (26 cases), Galveston technique (7 cases), Steffee plate (10 cases), Dick pedicle screw (1 cases), RF instrumentation (3 cases) and CD technique (4 cases). Totally 83 cases have been treated, which include paralytic pelvic tilt (9 cases), spinal fracture (4 cases), lumbosacral tuberculosis (5 cases), degenerative stenosis (21 cases); L5-S1 spondylolisthesis (38 cases), L5-S1 disc protrusion (4 cases); L5 semivertebra (1 cases) and neurofibromatosis (1 cases). Patients have been follow-up for 63.7 months on average. Good fusion has been seen in 82 cases (98.8%). The procedure does not need long immobilization and has less complication.

Applying Mosher's method to acetogenins bearing vicinal diols. The absolute configurations of muricatetrocin C and rollidecins A and B, new bioactive acetogenins from Rollinia mucosa

Muricatetrocin C (1), rollidecin A (2), and rollidecin B (3), three new bioactive annonaceous acetogenins bearing vicinal diols, were isolated from the leaves of Rollinia mucosa (Annonaceae) using activity-directed fractionation. The total structural elucidations of 1-3, including the absolute stereochemistries of the vicinal diols, were achieved by analyzing their per-Mosher ester derivatives. All three compounds showed potent and selective inhibitory effects against several human cancer cell lines.

An alpha-mercaptoacrylic acid derivative is a selective nonpeptide cell-permeable calpain inhibitor and is neuroprotective

Overactivation of calcium-activated neutral protease (calpain) has been implicated in the pathophysiology of several degenerative conditions, including stroke, myocardial ischemia, neuromuscular degeneration, and cataract formation. Alpha-mercaptoacrylate derivatives (exemplified by PD150606), with potent and selective inhibitory actions against calpain, have been identified. PD150606 exhibits the following characteristics: (i) Ki values for mu- and m-calpains of 0.21 microM and 0.37 microM, respectively, (ii) high specificity for calpains relative to other proteases, (iii) uncompetitive inhibition with respect to substrate, and (iv) it does not shield calpain against inactivation by the active-site inhibitor trans-(epoxysuccinyl)-L-leucyl-amido-3-methylbutane, suggesting a nonactive site action for PD150606. The recombinant calcium-binding domain from each of the large or small subunits of mu-calpain was found to interact with PD150606. In low micromolar range, PD15O6O6 inhibited calpain activity in two intact cell systems. The neuroprotective effects of this class of compound were also demonstrated by the ability of PD150606 to attenuate hypoxic/hypoglycemic injury to cerebrocortical neurons in culture and excitotoxic injury to Purkinje cells in cerebellar slices.

Interaction between an integral protein of the nuclear envelope inner membrane and human chromodomain proteins homologous to Drosophila HP1

At the nuclear envelope in higher eukaryotic cells, the nuclear lamina and the heterochromatin are adjacent to the inner nuclear membrane, and their attachment is presumably mediated by integral membrane proteins. In a yeast two-hybrid screen, the nucleoplasmic domain of lamin B receptor (LBR), an integral protein of the inner nuclear membrane, associated with two human polypeptides homologous to Drosophila HP1, a heterochromatin protein involved in position-effect variegation. LBR fusion proteins bound to HP1 proteins synthesized by in vitro translation and present in cell lysates. Antibodies against LBR also co-immunoprecipitated HP1 proteins from cell extracts. LBR can interact with chromodomain proteins that are highly conserved in eukaryotic species and may function in the attachment of heterochromatin to the inner nuclear membrane in cells.

[Failure and complication following surgical treatment of scoliosis: analysis of 101 cases]

Complications occur frequently after surgical treatment of scoliosis. In order to prevent from them effectively, 101 cases with failure and postoperative complications were analysed. They included rod fracture in 22 cases (15 Harrington rods, 4 Zielke rods, and 3 Luque rods); recurrence of curve severity in 12 cases; broken or loossened luque wires in 15 cases; loss of thoracic kyphosis (flat back) in 6 cases; progressive kyphosis with or without paraplegia following incorrect posterior decompression in 5 cases; and increased unbalance of shoulders after instrumentation in 2 cases due to neglect of the tilting of the first thoracic vertebra. Infection occurred in 8 cases (incision infection 7 cases; deep wound infection in 1 case); and pneumothorax in 1 cases. They were induced by biomechanical factors in 23 cases (22.77%), incorrect selections of indications in 29 cases (28.71%), oprational mistakes in 37 cases (36.63%), internal fixation factors in 15 cases (14.85%). The authors hold that there are quite a lot of factors leading to occurrence of complications and the effective way for prevention from them is to understand the factors and main technical points related to internal fixation.

Rollinecins A and B: two new bioactive annonaceous acetogenins from Rollinia mucosa

Two new mono-THF ring acetogenins, rollinecins A (1) and B (2), were isolated from the partitioned ethanolic extracts of the leaves of Rollinia mucosa (Annonaceae) by activity-directed fractionation. 1 and 2 are epimeric at the C-14 carbinol stereocenter. Their absolute stereochemical structures were solved by preparing their respective per-Mosher ester derivatives. 1 and 2 showed equivalent and selective in vitro activities against several human solid tumor cell lines.

Longimicins A-D: novel bioactive acetogenins from Asimina longifolia (annonaceae) and structure-activity relationships of asimicin type of annonaceous acetogenins

Bioactivity-directed fractionation of the ethanol extract of Asimina longifolia led to the isolation of four novel bioactive annonaceous acetogenins: longimicins A-D (1-4). Compounds 1-4 represent the asimicin type of acetogenins; however, the locations of the adjacent bis-tetrahydrofuran (THF) ring moieties are shifted along the aliphatic chains compared to the known compounds of this type. They are the first examples among this type of acetogenins with the placements of the ring systems altered. Compounds 1-4 showed bioactivities in several bioassays, but they are less active than their structural isomers. Study of their structure-activity relationships (SAR) reveals that the position of the adjacent bis-THF ring moiety is essential for maximization of the bioactivities among these asimicin type annonaceous acetogenins.

[Selective training of the vastus medialis muscle using electrical stimulator for chondromalacia patella]

Chondromalacia patella is closely related with subluxation and tilt of patella, as well as with muscular atrophy of quadriceps, especially in vastus medialis muscle. 364 cases of chondromalacia patella were treated with selective training of the vastus medialis muscle using electrical stimulator in our hospital. 211 cases were followed up after treatment from 6 months to 3 years. Among them excellent and good results were seen in 130 cases (62%), fair results were seen in 69 cases (33%) and no change was seen in 12 cases (5%). Significant reduction of CA (P < 0.01) and LPA (P < 0.001) were observed in all these patients in comparison with their primary angle. We believe that the selective training of the vastus medialis muscle using electrical stimulator is one of the effective methods for the treatment of chondromalacia patella.

Longifolicin, longicoricin, and gigantetroneninone, three novel bioactive mono-tetrahydrofuran annonaceous acetogenins from Asimina longifolia (Annonaceae)

Longifolicin (1), longicoricin (2) and (2,4-cis and trans)-gigantetroneninone (3), three novel bioactive mono-tetra-hydrofuran (THF) gamma-lactone acetogenins, were isolated from the leaves and twigs of Asimina longifolia (Annonaceae) by directing the fractionation with the brine shrimp lethality test (BST). The structures were elucidated based on spectroscopic and chemical methods. Compounds 1-3 showed selective and potent cytotoxicities to certain human tumor cell lines.

[The pulmonary function in scoliotic patient]

This paper investigated preoperative pulmonary functions in 134 scoliotic patients, of whom 32 cases was followed up for their postoperative pulmonary functions. The results show that the bigger the Cobb of the scoliosis, the greater the damages of the pulmonary functions. Congenital scoliosis is more severely affected by pulmonary functions than idiopathic scoliosis. There was no significant difference among the different sections of scoliosis with regard to their effect on the pulmonary functions. The authors concluded that the Harrington Instrumentation improved pulmonary functions in scoliosis.

Channel catfish, Ictalurus punctatus rafinesque, neutrophil adhesion to selected extracellular matrix proteins, lipopolysaccharide, and catfish serum

Adhesion of leukocytes to endothelium and extracellular matrix proteins is an important step in the inflammatory process. Therefore, the adhesion of channel catfish neutrophils to a surface coated with extracellular matrix proteins, LPS, and non-immune catfish serum was evaluated. Stimulation of neutrophils with phorbol dibutyrate (PDBU) resulted in at least two-fold increases in cellular adhesion to all substrates tested except laminin. When EDTA was included during or after PDBU stimulation, neutrophil adhesion to fibrinogen and LPS coated surfaces was reduced to the level of unstimulated neutrophils or to 50-60% of that for stimulated neutrophils. Similarly, EDTA and Ca2+/Mg2+ deficient medium reduced homotypic aggregation of PDBU stimulated neutrophils to background levels. Adhesion of stimulated neutrophils to fibrinogen coated surfaces was inhibited 44, 33, and 50% when soluble fibrinogen, fibronectin, and serum, respectively, were used to block the adhesion assay. The tripeptide integrin adhesion recognition sequence, Arg-Gly-Asp (RGD), caused 83% reduction and the fibrinogen-binding inhibitor protein caused 10% reduction in binding of stimulated neutrophils to fibrinogen coated surfaces. Two hexapeptides tested did not reduce neutrophil adhesion to fibrinogen. The binding of channel catfish neutrophils to the matrices used in the present study is suggestive that integrin mediated adhesion occurs during biological and pathological processes of teleosts.

1H, 15N and 13C resonance assignments and secondary structure of group II phospholipase A2 from Agkistrodon piscivorus piscivorus: presence of an amino-terminal helix in solution

1H, 15N and 13C resonance assignments are presented for the group II phospholipase A2 (PLA2) from Agkistrodon piscivorus piscivorus. The secondary structure of the enzyme has been inferred from an analysis of coupling constants, interproton distances, chemical shifts, and kinetics of amide exchange. Overall, the secondary structure of this PLA2 is similar to the crystal structure of the homologous group II human nonpancreatic secretory phospholipase [Scott, D.L., White, S.P., Browning, J.L., Rosa, J.J., Gelb, M.H. and Sigler, P.B. (1991) Science, 254, 1007-1010]. In the group I enzyme from porcine pancreas, the amino-terminal helix becomes fully ordered in the ternary complex of enzyme, lipid micelles and inhibitor. The formation of this helix is thought to be important for the increase in activity of phospholipases on aggregated substrates [Van den Berg, B., Tessari, M., Boelens, R., Dijkman, R., De Haas, G. H., Kaptein, R. and Verheij, H.M. (1995) Nature Strct. Biol., 2, 402-406]. However, the group II enzyme from Agkistrodon piscivorus piscivorus possesses a defined and well-positioned amino-terminal helix in the absence of substrate. Therefore, there is a clear difference between the conformation group I and group II enzymes in solution. These conformational differences suggest that formation of the amino-terminal helix is a necessary, but not sufficient, step in interfacial activation of phospholipases.

[Selective embolization of coronary vein of the stomach--a new approach for the treatment of bleeding from esophageal varices]

Selective embolization of coronary vein of stomach was employed for the treatment of 222 patients with bleeding from esophageal varices due to portal hypertension. The coronary vein was separated at middle segment and tube was inserted and clamped 5 cm below and above the cardia. The gamma-octyl-cyanoacrylate was used for embolization. 19 patients received preventive operation, 106 was subject to emergency surgery and 98 patients was treated by elective operation. The bleeding of all patients receiving emergency procedure was stopped. 3 died of liver failure after operation. 219 survived. 189 cases were followed up for 1-2 years and on varices was found. 182 cases followed up for 6 years revealed no relapse of bleeding. This technique could achieve good curative effect, which provides a new approach for the treatment of bleeding from esophageal varices of portal hypertension.

Chimeric GABAA/glycine receptors: expression and barbiturate pharmacology

GABAA and glycine receptors are close relatives in the "gene superfamily" of ligand-gated ion channels, but have distinctly different pharmacology. For example, barbiturates have two effects on GABAA receptors (GABAA-R): at low micromolar concentrations (2-5 microM), the anesthetic barbiturate methohexital potentiates submaximal chloride current responses to GABA; at higher concentrations (20-50 microM), the barbiturate causes direct gating of the channel in the absence of agonist. Neither of these barbiturate effects is seen on the glycine receptor (Gly-R). In order to study the structural parts of the GABAA-R involved in this barbiturate pharmacology, two unique restriction sites were introduced into the cDNAs encoding the alpha 2 and beta 1 subunits of the human GABAA-R and the alpha 1 subunit of the human gly-R. The first site ('X') corresponded to the C-terminal end of the third transmembrane domain (M3) in each subunit and enabled exchange of C-terminal fragment of approximately 100 amino acids (which includes the large 'cytoplasmic loop' and M4 segment) between GABAA-R and Gly-R subunits. The second site ('S') was approximately 30 amino acids 3'- from the N-terminal end of each subunit and enabled exchange of a small N-terminal fragment between GABAA-R and Gly-R subunits. Several chimeric receptor subunit cDNAs were constructed and the resulting receptors tested for their ability to respond to GABA and glycine and for sensitivity to the barbiturate methohextial (MTX). The results show that neither the large C-terminal fragment nor the smaller N-terminal fragment is associated with the enhancement or direct activation of the GABAA-R by MTX. These results demonstrate the viability of chimeric GABAA/Gly-R and suggest that the method will be suitable for further investigation of the molecular basis of the barbiturate pharmacology of the GABA-R.

Autoantibodies from patients with primary biliary cirrhosis recognize a region within the nucleoplasmic domain of inner nuclear membrane protein LBR

Autoantibodies from rare patients with primary biliary cirrhosis (PBC) recognize LBR, or lamin B receptor, an integral membrane protein of the inner nuclear membrane. Human LBR has a nucleoplasmic, amino-terminal domain of 208 amino acids followed by a carboxyl-terminal domain with eight putative transmembrane segments. Autoantibodies against LBR from four patients with PBC recognized the nucleoplasmic, amino-terminal domain but not the carboxyl-terminal domain. Immunoblotting of smaller fusion proteins demonstrated that these autoantibodies recognized a conformational epitope(s) contained within the stretch of amino acids from 1 to 60. These results, combined with those of previous studies, show that autoepitopes of nuclear membrane proteins are located within their nucleocytoplasmic domains and that autoantibodies from patients with PBC predominantly react with one domain of a protein antigen. This work also provides further characterization of anti-LBR antibodies that have found utility as reagents in cell biology research.

Anatomy of vasculature of 850 spleen specimens and its application in partial splenectomy

BACKGROUND

Anatomic knowledge of vasculature of the splenic lobe and segment is of great clinical significance in partial resections and transplantation of the spleen.

METHODS

The methods of two-colored corrosion casting, roentgenography, and anatomic dissection were used to evaluate the vasculature of the splenic hilum and intraspleen. On this basis splenic lobectomy and segmentectomy were performed on 42 patients with traumatized spleens.

RESULTS

In the observation of 850 spleen specimens the spleen showed a single lobar artery in 7 cases (0.8%), two lobar arteries in 730 cases (86%), three lobar arteries in 104 cases (12.2%), and multiple lobar arteries (i.e., more than three lobar arteries) in 9 cases (1%). In a subgroup of 276 specimens 17%, 53%, 24%, 4%, 1%, and 1% of spleen specimens had three, four, five, six, seven, and eight segmental arteries, respectively. The result from a subgroup of 280 specimens indicated that mean percentages of the existence of the superior and inferior polar arteries and of the coexistence of both polar arteries were 31.3%, 38.8%, and 13.3%, respectively. Relative avascular planes between segments or lobes were seen. Basic steps of splenic lobectomy or segmentectomy include mobilization of the injured spleen, ligation of vessels in the lobe or segment, transection of the splenic parenchyma, and sutures of the cut surface of the remaining spleen. The postoperative courses of all 42 patients undergoing partial splenectomy were uneventful. No postoperative bleeding and necrosis of the remaining spleen or infectious complications were registered.

CONCLUSIONS

Anatomically the spleen is defined with two primary lobes (the superior lobe and inferior lobe), one accessory lobe, and three to five segments. This new classification facilitates surgeons to perform partial resections of the spleen and allotransplantation of the hemispleen from a living related donor in human beings.

Demonstrations of de-and remineralization mechanism as revealed in synthetic auditory ossicle (Apaceram) of rats by laser-Raman spectrometry

In investigations of the process of bone destruction caused by chronic otitis media complicated with cholesteatoma, we proposed previously a hypothesis to explain its mechanism. In the present study, we substitute a synthetic auditory ossicle (Apaceram) for the bone to simplify the model system of experiments for our hypothesis. Its process was studied on a model simulation in vitro, in vivo and clinically at molecular level, using laser-Raman spectrometry. An increase of conductivity in both the saline solution and double-distilled water immersed Apaceram indicated demineralization depending on time lapse. The process of demineralization was revealed by the Raman spectral profiles as shown by narrowing a half-peak breadth (p < 0.01) of v1 signal (PO4(3-), 960 cm-1) and the disappearance of the shoulder at circa 950 cm-1 on the Apaceram surface implanted for 6 months. On the other hand, the process of remineralization was revealed in vivo by the spectral profiles: 1) a broader half-peak breadth (p < 0.01) of v1 signal on the Apaceram surface implanted for 10 months than that implanted for 6 months; 2) a weak reappearance of the shoulder at ca. 950 cm-1 on the Apaceram surface after 10 months; 3) four signals (v1 through v4) of PO4(3-) on the HOAP observed for inside the Apaceram shaft and 4) a weak v1 signal on both the granular fluorescent substance in the clinical case and the high density area of subcutaneous tissue after contact with the Apaceram in rats for 3 months. Judging from these investigations, it is proposed that the mechanism of bone destruction associated with cholesteatoma is a form of de- and remineralization.

[Surgical treatment of spinal tumors: a report of 30 cases]

With the advance of spinal surgery in the last decade, surgical treatment of spinal tumors has been no longer limited to sole laminectomy. The principles of surgical treatment of spinal tumors include: (1) anterior approach for the anterior lesion and posterior approach for the posterior lesion, (2) combined anterior and posterior approach for extensive lesions and (3) internal fixation for spinal stability. 30 cases of spinal tumors were treated on the basis of the above guiding principles and 83.3% (25 of 30 cases) showed excellent or good outcomes.

Longicin and goniothalamicinone: novel bioactive monotetrahydrofuran acetogenins from Asimina longifolia

Longicin [1] and (2,4-cis and trans)-goniothalamicinone [2], two new monotetrahydrofuran Annonaceous acetogenins, have been isolated from the leaves and twigs of Asimina longifolia (the long leaf paw paw) by the use of the brine shrimp lethality test for bioactivity-directed fractionation. The structures were elucidated based on spectroscopic and chemical methods. Compound 1 was converted to its ketolactone isomer, (2,4-cis and trans)-longicinone [3], to aid the stereochemical elucidation of 1. Compounds 1-3 showed selective and potent cytotoxicities to certain human tumor cell lines, with the potency of 1 against pancreatic carcinoma (PaCa-2) over one million times that of adriamycin. Nine known cytotoxic acetogenins, annonacin, xylomaticin, isoannonacin, gigantetrocins A and B, muricatetrocins A and B, gigantetrocin-A-one and goniothalamicin, were also isolated for the first time from this species.

Variable chimerism, graft-versus-host disease, and tolerance after different kinds of cell and whole organ transplantation from Lewis to brown Norway rats

The bidirectional paradigm of tolerance involving reciprocal host vs. graft and graft vs. host reactions was examined after Lewis (LEW)-->Brown Norway (BN) transplantation of different whole organs (liver, intestine, heart, and kidney) or of 2.5 x 10(8) LEW leukocytes obtained from bone marrow, spleen, lymph nodes, and thymus. The experiments were performed without immunosuppression or under 14 daily doses of postoperative tacrolimus, which were continued in weekly doses to 100 days in a "continuous treatment" subgroup, and to 27 days in a short treatment group. Without immunosuppression, all organs and cell suspensions failed to engraft or were acutely rejected. GVHD (usually fatal) was always caused when either the long or short treatment was used for recipients of intestinal grafts and cell suspensions of spleen and lymph nodes. In contrast, both immunosuppressive protocols allowed engraftment of bone marrow cells, liver, heart, and kidney without clinical GVHD, whereas thymus cell suspensions and small doses of whole blood neither engrafted nor caused GVHD. At 100 days, now drug-free for 73 days, the liver, bone marrow, and heart recipients were tolerant in that they accepted all challenge LEW heart and/or liver grafts for 100 more days despite in vitro evidence of donor-specific reactivity (split tolerance). At 200 days, histopathologic studies of the challenge livers were normal no matter what the priming graft. However, the still-beating challenge hearts had a spectrum from normal to severe chronic rejection that defined the tolerogenicity of the original primary grafts: liver best-->bone marrow next-->heart least. Both the GVHD propensity and tolerogenicity in these experiments were closely associated with recipient tissue chimerism 30 and 100 days after the experiments began. The tissue chimerism was invariably multilineage, but the GVHD outcome was associated with T cell over-representation. These observations provide guidelines that should be considered in devising leukocyte augmentation protocols for human whole organ recipients. The results are discussed in relation to the historical tolerance studies of Billingham, Brent, and Medawar; Good; Monaco; and Calne.

Protein-protein interactions between human nuclear lamins expressed in yeast

Protein-protein interactions between the nuclear lamins are responsible for the assembly of the nuclear lamina, a meshwork of intermediate filaments associated with the nuclear envelope inner membrane. We have used the yeast two-hybrid system to examine the interactions between the predominant human nuclear lamins expressed as GAL4 fusion proteins in Saccharomyces cerevisiae. Lamin A, prelamin A, lamin B1, and lamin C were able to form homodimers as well as heterodimers. Analysis of the different structural domains of lamin B1 demonstrated that the second half of coil 2 of the rod domain was necessary for the formation of the most stable homodimers. The results show that the yeast two-hybrid system can be used to study the interactions between structural proteins and their domains.

Simple aromatics identified with a NFAT-lacZ transcription assay for the detection of immunosuppressants

Determination of the mechanism of action of FK506 and cyclosporin A has yielded new molecular targets involved in signal transduction during T cell activation. A common target of FK506 and cyclosporin A is inhibition of activation of the NFAT transcription factor, for which a specific binding region is present in the promoter of the IL-2 gene. A reporter gene assay has been used to screen for agents that interfere with this early step in T cell activation. Simple aromatic compounds that block NFAT-dependent transcription and show in vitro immunosuppressive activity were isolated from the broth and mycelia of two Streptomyces sp. fermentations. The compounds were active at concentrations that were not directly cytotoxic.

Hamster to rat kidney xenotransplantation. Effects of FK 506, cyclophosphamide, organ perfusion, and complement inhibition

Hamster to rat renal xenotransplantation was performed with recipient nephrectomies. Recipients were treated beginning on day 0 with continuous FK 506 monotherapy, a 7-day or open-ended monotherapeutic course of cyclophosphamide (CP), and the two drug regimens combined. CP alone (10 mg/kg/day) prevented a xenospecific antibody response and tripled median survival of the kidney (defined as recipient death) from 6 (control) to 18.5 days whereas FK 506 alone had no effect. The drugs in combination were no better than CP alone (15 days) unless the 5-day course of CP was given at a higher dose (15 mg/kg) and started 3 days preoperatively (79 days). In further experiments, adjuvant measures were added to the minimally effective FK 506/7-day CP regimen which gave a median survival of only 15 days. In the most successful modification, intraoperative antibody depletion by the temporary transplantation of third party hamster liver or en bloc kidneys increased median survival from 15 to 34 and 48 days, respectively. An intraoperative i.v. dose administration of the anticomplement drug K76 instead of antibody depletion increased survival to 26 days. Although the events of kidney rejection were similar to those of heart xenografts and partially forestalled by the antibody inhibiting CP treatment, or by antibody depletion, survival for > 100 days was accomplished in only 5 of 86 treated animals. The poorer survival previously reported with cardiac xenotransplantation is largely explained by the life support requirement of the kidneys. Renal failure was responsible for almost all deaths before 60 days, and subnormal renal failure was a pervasive adverse factor thereafter, frequently caused by pyelonephritis which is suspected to have had an immunologic etiology.

[Patella resurfacing and patellofemoral resurfacing]

Since 1983 isolated polyethylene patellar prosthesis was used for patella resurfacing of 19 patients with patellofemoral osteoarthritis. After an average of 44.9 months follow-up, the treatment was found to be not as satisfactory as earlier trials. The main reason was the wide erosion of femoral condyle caused by the polyethylene patella. To overcome this shortness, a new type of patellofemoral prosthesis was designed by the authors, which was named Y-L-Q. From January, 1991 to November, 1993, this prosthesis was used to treat 16 knees of 13 patients with patellofemoral osteoarthritis. Most of those patients improved both symptomatically and functionally. The good to excellent results rate was 87.5% (14/16 knees) at the time of an average 10 month follow-up. The early results of our experience with patellofemoral resurfacing are encouraging, and extended follow-ups are in progress.

Patella and patellofemoral resurfacing (37 cases report)

Chondromalacia and patellofemoral osteoarthritis are common diseases that cause pain and disablement of the knee. Conservative therapy is not always effective. Since 1983 we have used isolated polyethylene patellar prosthesis for patella resurfacing of 19 patients with patellofemoral osteoarthritis. After an average of 44.9 months follow-up, we found the treatment was not as satisfactory as earlier trials. The main reason is the wide erosion of femoral condyle caused by the polyethylene patella. To overcome this shortness, we designed a new type of patellofemoral prosthesis which is named Y-L-Q. From January, 1991 to November, 1993, we used this prosthesis to treat 16 knees of 13 patients with patellofemoral osteoarthritis. Most of those patients improved both symptomatically and functionally. The good to excellent results rate was 87.5% (14/16 knees) at the time of an average 16 months follow-up. The early results of our experience with patellofemoral resurfacing are encouraging, and extended follow-ups are in progress.

Effects of voltage perturbation of the lingual receptive field on chorda tympani responses to Na+ and K+ salts in the rat: implications for gustatory transduction

Taste sensory responses from the chorda tympani nerve of the rat were recorded with the lingual receptive field under current or voltage clamp. Consistent with previous results (Ye, Q., G. L. Heck, and J. A. DeSimone. 1993. Journal of Neurophysiology. 70:167-178), responses to NaCl were highly sensitive to lingual voltage clamp condition. This can be attributed to changes in the electrochemical driving force for Na+ ions through apical membrane transducer channels in taste cells. In contrast, responses to KCl over the concentration range 50-500 mM were insensitive to the voltage clamp condition of the receptive field. These results indicate the absence of K+ conductances comparable to those for Na+ in the apical membranes of taste cells. This was supported by the strong anion dependence of K salt responses. At zero current clamp, the potassium gluconate (KGlu) threshold was > 250 mM, and onset kinetics were slow (12 s to reach half-maximal response). Faster onset kinetics and larger responses to KGlu occurred at negative voltage clamp (-50 mV). This indicates that when K+ ion is transported as a current, and thereby uncoupled from gluconate mobility, its rate of delivery to the K+ taste transducer increases. Analysis of conductances shows that the paracellular pathway in the lingual epithelium is 28 times more permeable to KCl than to KGlu. Responses to KGlu under negative voltage clamp were not affected by agents that are K+ channel blockers in other systems. The results indicate that K salt taste transduction is under paracellular diffusion control, which limits chemoreception efficiency. We conclude that rat K salt taste occurs by means of a subtight junctional transducer for K+ ions with access limited by anion mobility. The data suggest that this transducer is not cation selective which also accounts for the voltage and amiloride insensitive part of the response to NaCl.

[Modified en bloc resection procedure for malignant tumor of the shoulder girdle]

En bloc resection of the shoulder girdle (Tikhoff-Linberg procedure) is a valuable limb-sparing surgical technique for bony and soft tissue malignant tumor in and around the proximal humerus and shoulder girdle. Significant amount of hand-elbow function is maintained with the procedure, and long time results in the treatment of neoplasms by this technique was found to be the same as by the method of a forequarter amputation or the shoulder disarticulation in the English literature. Four cases with malignant tumor in the shoulder girdle was treated with this modified method in our department. The average follow-up was 8 years. One case died due to another kind of tumor 6 years after operation, and other 3 cases are alive and disease free.

Application of internal fixation in the treatment for tuberculosis of the spine

This is a study of 18 patients who had surgical treatment for spinal tuberculosis. All patients were admitted with the spinal tuberculosis and treated with a combination of anterior debridement and bone graft with posterior internal fixation using the Luque or Dick technique. The patients were able to walk within a few days postoperation. Three to seven years follow-ups show no recurrence, kyphosis and/or solid fusion.

Intracellular Ca2+ and Ca(2+)-binding proteins in chemically transformed rat fibroblasts

Disturbed Ca2+ handling and altered levels of Ca(2+)-binding proteins (CaBPs) have been found in many transformed cells. To investigate whether there exists a correlation between expression of CaBPs and intracellular Ca2+ we analyzed three transformed rat fibroblast cell lines (T14, T10, and T43) exhibiting different levels of CaBPs. All three cell lines express calmodulin (CaM) at elevated levels compared to normal tissues. In addition, oncomodulin (OM) is expressed at high levels in T14 cells and at much lower levels in T10 cells, while T43 cells do not express OM. We demonstrate that CaBP levels are affected by changes of extracellular [Ca2+] ([Ca2+]o). In reduced [Ca2+]o, CaM levels were increased up to 60%, while OM levels were decreased up to 65% in T14 and T10 cells. Increase of [Ca2+]o, on the other hand, led to a decrease of CaM levels and an increase of OM levels, suggesting that [Ca2+]o exerts its effect on OM and CaM differently. Comparison of the growth rates in reduced [Ca2+]o revealed that T14 cells with the most pronounced CaM increase induced by low [Ca2+]o grew best under these conditions. These results indicate that elevated CaM expression but not the presence of OM reduces the Ca2+ requirement for growth. Intracellular [Ca2+] transients are not buffered by the high concentration of CaBPs in T14 cells. In contrast, [Ca2+]i transients induced by increase of [Ca2+]o or addition of serum were most pronounced in T14 cells compared to T10 and T43 cells.

[Long-term follow-up of patients with patella resurfacing]

Patellar resurfacing was performed by the authors. From 1983 to 1988, 19 cases (22 knees) with patello-femoral osteoarthritis were treated with this procedure in our hospital. Excellent and good results were recorded in 13 cases (59.1%) one year after operation, but were zero in the long-term follow-up (average 8.7 years) because of recurrent knee pain due to the wearing of the cortex of the femoral groove. Further operation was necessary for those cases, such as patellectomy or total knee replacement. Since 1991 Y-L-Q's type of patellofemoral replacement has been used in 11 cases in our department to alter the isolated resurfacing of the patella. The femoral groove was replaced with a metallic implant that allows sliding of a polyethylene patella to prevent the wearing of the femoral cortex. Preliminary results are good.