Neopallavicinin from the Taiwanese liverwort Pallavicinia subciliata

Neopallavicinin (2), a diastereomer of pallavicinin (1), was identified from the Taiwanese liverwort Pallavicinia subciliata. The structure of neopallavicinin was deduced by spectroscopic analysis. Three chemotypes may be classified for the species Pallavicinia subciliata.

Clinical and electrophysiologic attributes as predictors of results of autonomic function tests

Autonomic dysfunction is a feature of some neuropathies and not others. It has been suggested that some clinical and electrophysiologic attributes are predictable of autonomic impairment detected using laboratory testing; however, dear guidelines are unavailable. We evaluated 138 relatively unselected patients with peripheral neuropathy who underwent neurologic evaluation, electromyography (EMG), nerve conduction studies, and autonomic function tests to determine which variables were predictive of laboratory findings of autonomic failure. The variables evaluated were 1) clinical somatic neuropathic findings, 2) clinical autonomic symptoms, and 3) electrophysiologic findings. Autonomic symptoms were strongly predictive (Rs = 0.40, p < 0.001) of autonomic failure. Among the non-autonomic indices, absent ankle reflexes were mildly predictive (Rs = 0.19, p = 0.022) of autonomic impairment, but all others were not (duration, clinical pattern, severity, weakness, sensory loss). Electrophysiologic changes of an axonal neuropathy predicted autonomic impairment while demyelinating neuropathy did not. We conclude that autonomic studies will most likely be abnormal in patients who have symptoms of autonomic involvement and those who have an axonal neuropathy.

Differential diagnosis of type 2 neurofibromatosis: molecular discrimination of NF2 and sporadic vestibular schwannomas

Patients who present with unilateral vestibular schwannomas either at a young age or with additional features of type 2 neurofibromatosis (NF2) are at risk of developing bilateral disease and transmitting a risk of neurogenic tumours to their offspring. We have identified 15 patients from a series of 537 with unilateral vestibular schwannomas who also had one or more of the following: other tumours (10/15), features of NF2 (3/15), or a family history of neurogenic tumours (5/15). No germline NF2 mutations were detected and in 7/9 cases where tumour material was available for analysis a germline mutation in the NF2 gene has been excluded. Although a possibility of gonosomal mosaicism still exists, exclusion tests for the offspring are now possible. We suggest a general strategy, based on analysis of tumour DNA, for distinguishing sporadic and familial cases of tumours caused by two hit mechanisms. Application of this strategy suggests that most instances of unilateral vestibular schwannoma which do not fulfil criteria for NF2 represent chance occurrences.

Provision of positive and negative selections in retroviral vectors containing the cytosine deaminase gene

The E. coli cytosine deaminase (CD) provides a negative selection system for suicide gene therapy as CD transfectants are eliminated following 5-fluorocytosine (5FC) treatment. Here we report a positive selection system for the CD gene using 5-fluorouracil (5FU) and cytosine in selection medium to screen for CD-positive transfectants. It is based on the relief of 5FU toxicity by uracil which is converted from cytosine via CD catalysis, as uracil competes with the toxic 5FU in subsequent pyrimidine metabolism. Hence, a retroviral vector containing the CD gene may provide both positive and negative selections after gene transfer. The CD transfectants selected with the positive selection system showed susceptibility to 5FC in subsequent negative selection in vitro and in vivo. Therefore, this dual selection system is useful not only for combination therapy with transgene and CD gene, but can also act to eliminate selectively transduced cells after the transgene has furnished its effects or upon undesired conditions if 5FC is applied for negative selection in vivo.

Two-dimensional crystallization and projection structure of KcsA potassium channel

Potassium channels are integral membrane proteins that play a crucial role in regulating diverse cell functions in both electrically excitable and non-excitable cells. Molecular cloning has revealed a diverse family of genes that encode these proteins, and a variety of experimental strategies have defined functional domains. We have cloned, over-expressed and purified the KcsA potassium channel to homogeneity and reconstituted this channel protein with phospholipids to form two-dimensional crystals. The crystals belong to plane group p4 and have unit cell dimensions of a=b=48 A. A projection map at 6 A resolution has been obtained by electron crystallography. The map shows that the protein is a homotetramer, having a low-density region on the 4-fold axis that is the site of the ion conduction pathway. Each monomer contains density features that are consistent with the molecular model of a truncated form of KcsA recently determined by X-ray crystallography.

Modulating the antitumor immunity of MBT-2 murine bladder tumor bearing mice by postoperative administration of interferon-alpha

This study was conducted mainly to investigate the effect of interferon-alpha (IFN-alpha) on the antitumor immunity of a tumor bearing host (TBH) when postoperatively administrated with or without lethally irradiated autologous tumor cells. Using the C3H/He-MBT-2 murine bladder tumor model, a status of postoperative residual tumor was mimicked by rechallenging tumor cells 24 hours after resecting the day-17 tumor. Using immunohistochemical analysis we demonstrated that after treating with lethally irradiated MBT-2 tumor cells (IRMBT-2) + IL-2 cells of CD4+, CD8+, CD44+ and CD11b+ phenotypes prominently infiltrate the subcutaneous local injection sites. In contrast, only scanty immune responding cells could be seen locally if treated with IRMBT-2 + IFN-alpha 2b, albeit in the presence of interleukin-2 (IL-2). However, the spleens of D17TBM treated with IRMBT-2 + IFN-alpha 2b contained the highest percentage of CD44+ memory T cells and cells of the CD11b+ phenotype; moreover, their natural killer (NK), lymphokine activated killer (LAK) and cytotoxic T lymphocytes (CTL) activities were significantly augmented. The results of in vivo tumor rechallenge revealed that administration of IFN-alpha, either alone or combined with IRMBT-2, could both effectively suppress the outgrowth of perioperative rechallenged tumor cells as well as prolong the survival of TBH. We conclude that despite the presence of autologous tumor vaccine, postoperative administration of IFN-alpha can further enhance the antitumor immunity of TBH and therefore can be an effective adjuvant therapy to improve the therapeutic results of surgery on a tumor bearing host.

Somatic mosaicism: a common cause of classic disease in tumor-prone syndromes? Lessons from type 2 neurofibromatosis

Blood samples from 125 families with classic type 2 neurofibromatosis with bilateral vestibular schwannomas were analyzed for mutations in the NF2 gene. Causative mutations were identified in 52 families. In five families, the first affected individual in the family (the index case) was a mosaic for a disease-causing mutation. Only one of nine children from the three mosaic cases with children are affected. Four of these nine children inherited the allele associated with the disease-causing mutation yet did not inherit the mutation. NF2 mutations were identified in only 27/79 (34%) of sporadic cases, compared with 25/46 (54%) of familial cases (P<.05). In 48 families in which a mutation has not been identified, the index cases have had 125 children, of whom only 29 are affected with NF2 and of whom only a further 21 cases would be predicted to be affected by use of life curves. The 50/125 (40%) of cases is significantly less than the 50% expected eventually to develop NF2 (P<.05). Somatic mosaicism is likely to be a common cause of classic NF2 and may well account for a low detection rate for mutations in sporadic cases. Degrees of gonosomal mosaicism mean that recurrence risks may well be <50% in the index case when a mutation is not identified in lymphocyte DNA.

Clinical evaluation of C7 spinal nerve transection: 21 patients with at least 2 years' follow-up

We have performed C7 spinal nerve transfer to treat root injury of the brachial plexus since 1989. Out of a total of 43 patients, 21 have been followed up for at least 2 years. Evaluation of the effect of C7 transection included clinical examination, intraoperative C7 stimulation, LIDO Workset machine and electrophysiological studies to test C7 innervated muscles, and histochemical analysis of the anterior and posterior division of the upper trunk using acetylcholinesterase stain. Nearly half of the study group (48%) reported no significant sensory changes and most patients (81%) did not notice any weakness of the limb following C7 transection. Some patients did experience sensory and motor abnormalities which were most frequent during the first postoperative month, improved during the 2nd month and in most cases resolved in the 3rd postoperative month. The only longer persistent abnormality was the triceps reflex, which becomes weak or absent. We also found that intraoperative C7 stimulation was a useful predictor of possible post-transection morbidity. Subclinical deficits, detected by the LIDO workset machine and by electro-physiological studies, were quite common. Histochemical analysis revealed that the posterior division of C7 had more motor fibres than the anterior division.

Antisense oligonucleotide specific for transforming growth factor-beta 1 inhibit both in vitro and in vivo growth of MBT-2 murine bladder cancer

INTRODUCTION AND OBJECTIVES

TGF-beta is a potent immunosuppressive cytokine produced by many tumor cells. Secretion of TGF-beta by malignant cells may be a mechanism by which tumor cells escape destruction by tumor-specific T lymphocytes. In this study, we used a TGF-beta producing C3H/He-MBT-2 murine bladder tumor model to investigate the feasibility of antisense oligonucleotide (ODN) gene therapy strategy to block the production of TGF-beta from tumor cells and evaluate its influence on both in vitro tumor growth and in vivo tumor formation.

MATERIALS AND METHODS

Using a plasmid, pRUFCD, we constructed a recombinant plasmid pRUFCD/TGF-beta 1(-) containing antisense TGF-beta ODN and then transfected in into MBT-2 cells by electroporation. Three transfectant clones were successfully obtained by their resistance to 5-fluorouracil and cytosine.

RESULTS

The secretion of TGF-beta from the three obtained TGF-beta antisense-blocked MBT-2 cell clones, as assessed by ELISA, were all decreased. Moreover, they all exhibited smaller colony size in the in vitro anchorage-independent soft agar colony forming assay. Tumor growths in mice injected with these three clones were all inhibited compared with those injected with parental tumor cells.

CONCLUSION

This study demonstrates that after reducing the secretion of TGF-beta 1 on tumor cells by TGF-beta 1 antisense, ODN can inhibit their in vitro growth and in vivo tumor formation suggesting that this approach can be a potentially useful strategy to abolish the adverse immunosuppression effect of TGF-beta 1 producing autologous tumor vaccine and therefore to enhance host antitumor immune response.

The inhibitory effect of Staphylococcus epidermidis slime on the phagocytosis of murine peritoneal macrophages is interferon-independent

The extracellular slime produced by Staphylococcus epidermidis has been shown to interfere with several human neutrophil functions in vitro, such as chemotaxis, degranulation and phagocytosis. Slime production has been suggested as a useful marker for clinically significant infections with coagulase-negative Staphylococcus. Since the main role of macrophages in defense mechanisms is phagocytosis, the effect of slime on the phagocytic activity of macrophages was investigated. The phagocytic activity of murine peritoneal macrophages treated with slime in vitro decreased in a dose-dependent fashion. A similar decrease was also observed in macrophages isolated from mice that had previously received intraperitoneal injection of slime. To investigate whether interferon also plays a role in this process, mice were treated with interferon or an interferon inducer, polyinosinic-polycytidylic acid (poly I:C), together with slime before macrophage isolation. The slime-suppressed phagocytic activity of macrophages was partially relieved by both agents, and the recovery effect of poly I:C in slime-suppressed phagocytosis of macrophages in vivo might be attributed to the increased interferon level in peritoneal fluid and sera. However, when slime was given to poly I:C-pretreated mice, the phagocytic activity remained suppressed. Thus, it appears that slime is able to suppress the phagocytic activity of macrophages regardless of the state of macrophage activation by poly I:C. The results suggest that the inhibition of phagocytosis by S. epidermidis slime may be independent from the activation of interferon.

Hirayama disease: MR diagnosis

We report the MR findings in two cases of Hirayama disease, a kind of cervical myelopathy related to flexion movements of the neck. In flexion MR studies, we can see the striking and pathognomonic picture of anterior shifting of posterior dura at the lower cervical spinal canal. In nonflexion studies, we find that asymmetric cord atrophy, especially at the lower cervical cord, though subtle, is highly suggestive of Hirayama disease. When it is seen, a flexion MR study is warranted to prove this diagnosis.

The effect of large-dose prednisolone on patients with obstructive lung disease associated with consuming sauropus androgynus

BACKGROUND

In 1995, the consumption of the vegetable Sauropus androgynus in order to reduce weight led to an outbreak of patients with obstructive ventilatory impairment. The pathologic findings showed bronchiolitis obliterans with or without organized pneumonia. Steroid therapy was used in an attempt to reverse the pulmonary dysfunction even though the pathogenesis was unknown.

METHODS

In this retrospective study, we reviewed the response of seven non-smoking female patients who were consuming Sauropus androgynus to large-dose prednisolone therapy (prednisolone > 0.5 mg/kg/day, > 30 days). Conventional pulmonary function testing (PFT) was used to assess patient lung function.

RESULTS

All patients had greatly reduced forced expiratory volume in one second (FEV1) before and after steroid treatment. There was no significant change in the parameters of PFT, such as FEV1, forced vital capacity (FVC), FEV1/FVC, and carbon monoxide diffusion capacity (DLco) after prednisolone therapy.

CONCLUSIONS

Large-dose steroid therapy was unable to relieve the obstructive ventilatory impairment present in patients after consuming Sauropus androgynus.

Prothymosin alpha promotes cell proliferation in NIH3T3 cells

Thymic hormones have immunomodulatory effects on T cells and hence have been used clinically to restore the immunity of immunodeficient patients as well as to enhance the cellular immunity of cancer patients. Prothymosin alpha, which is a member of the thymic hormone family, has recently been suggested to act as a nuclear protein participating in the stimulation of cell proliferation. To characterize the biological activities ofprothymosin alpha in vitro, we established NIH3T3 cell transformants that constitutively express higher prothymosin alpha protein and its mRNA compared with the wild-type counterpart. Cells that overexpressed prothymosin alpha increased the proliferative activity assayed by the [3H]-thymidine incorporation or by the cell cycle analysis with the fluorescent-activated cell sorter. The results provide direct evidence that prothymosin alpha plays a role in cell proliferation by shortening the duration of the G1 phase.

Deletion mapping defines three discrete areas of allelic imbalance on chromosome arm 8p in oral and oropharyngeal squamous cell carcinomas

Deletions on chromosome arm 8p, as defined by allelic imbalance, are a frequent event in many different types of malignant tumors, including those of the head and neck. These regions are thought to harbor tumor suppressor genes. In order to define a high-density deletion map of this chromosomal arm in oral and oropharyngeal squamous cell carcinomas, we have tested for allelic imbalance in 35 such tumors with 22 short tandem-repeat polymorphisms. Overall, 21 (60%) of the 35 tumors showed allelic imbalance at one or more loci on chromosome arm 8p. Interstitial deletions defined three discrete areas of deletion: at 8p23, 8p22, and 8p12-p21. Tumors of TNM stages II-IV showed a significantly higher frequency of allelic imbalance on 8p than did TNM stage I tumors. Our data suggest that there are least three tumor suppressor loci on chromosome arm 8p that may be implicated in oral carcinogenesis. Furthermore, inactivation of such genes may be associated with high-grade tumors.

Low concentration of inducer favors production of active form of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in Escherichia coli

Expression of chicken and rat liver bifunctional enzyme, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, in Escherichia coli encountered two common problems: the chicken enzyme was liable to proteolysis and the rat enzyme was prone to form inclusion bodies. Reducing the rate of protein synthesis by lowering either growth temperature or isopropyl-beta-D-thiogalactopyranoside (IPTG) concentration alleviated these two problems. Growth at 22 degrees C was optimum for expression of both enzymes. The optimum range of IPTG concentration for expression was 0.1-1 microM for the chicken liver bifunctional enzyme and 10 microM for rat liver enzyme. The components of growth medium also influenced the production. Compared with Luria-Bertani medium, an enriched medium-tryptone-phosphate medium-tripled the production of the active enzymes. Addition of glucose (0.2%) doubled the expression level of active chicken liver enzyme, but reduced the production of active rat liver enzyme to half the maximal level, while the phosphate in tryptone-phosphate medium had no effect on the production of the two enzymes.

Midazolam premedication increases sedation but does not prolong discharge times after brief outpatient general anesthesia for laparoscopic tubal sterilization

Preoperatively administered midazolam may contribute to postoperative sedation and delayed recovery from brief outpatient general anesthesia, particularly in patients who receive significant postoperative opioid analgesics. We evaluated the effects of midazolam premedication (0.04 mg/kg) on postoperative sedation and recovery times after laparoscopic tubal sterilization (Falope rings) in 30 healthy women in a randomized, double-blind, placebo-controlled study. Patients received midazolam or saline-placebo intravenously 10 min before anesthesia. General anesthesia was induced with fentanyl, propofol, and mivacurium and was maintained with N2O and isoflurane. Sedation was quantified before and after premedication and 15, 30, and 60 min after emergence from anesthesia, using the digit-symbol substitution (DSST) and Trieger dot (TDT) tests. Management of postoperative pain and nausea and discharge criteria were standardized. Groups were similar with respect to age, weight, and duration of surgery and anesthesia. Midazolam was associated with impairment of performance on the TDT and DSST after premedication administration and 15 (TDT and DSST) and 30 (DSST) min after postanesthesia care unit (PACU) arrival. There were no differences in PACU time and time to discharge-readiness. In conclusion, midazolam premedication augments postoperative sedation in this population but does not prolong recovery times.

[Study model for isolated heart perfusion combined with NMR technique]

Some improvements made to overcome the difficulty in the long distance perfusion, temperature maintenance, oxygen supply and the recollection of perfused fluid were described in our Langendorff perfusion in combination of NMR technique with which the rhythmic activity of isolated rat heart can be measured as long as 90 min.

Modulation of the immunostimulating effect of autologous tumor vaccine by anti-TGF-beta antibody and interferon-alpha on murine MBT-2 bladder cancer

Our aims were to: a) elucidate whether MBT-2 cells, lethally irradiated or nonirradiated, express TGF-beta 1 mRNA and secrete TGF-beta 1 protein, and b) to investigate whether the adverse effects from IRMBT-2-secreting TGF-beta 1 in the tumor vaccine can be abrogated by exogenous addition of monoclonal anti-TGF-beta 1 antibody and/or IFN-alpha.

MATERIALS AND METHODS

using the Northern hybridization analysis and the two-antibody sandwich ELISA, we demonstrate that both irradiated IRMBT-2 and nonirradiated MBT-2 cells secrete TGF-beta 1. The effect of anti-TGF-beta and/or IFN-alpha were studied by an in vitro splenocyte proliferation assay and in vivo tumor rechallenge study on day 17-TBM.

RESULTS

Both IRMBT-2 and splenocytes from day 17-TBM secrete TGF-beta 1 which can express suppression of the proliferation of the splenocytes from day 17-TBM. This suppression can be partially reversed by the simultaneous addition of both anti-TGF-beta and IFN-alpha, either alone being insufficient. The result of the in vivo tumor rechallenge study on day 17-TBM reveals that a lower tumor outgrowth incidence can be obtained in groups of mice treated with postoperative vaccination with anti-TGF-beta modified tumor vaccine with or without an additional administration of IFN-alpha.

CONCLUSION

Apart from TGF-beta, MBT-2 cells, both irradiated and nonirradiated, may also secrete other suppressive factors that adversely downregulate the immune response of TBM which can not then be adequately reversed by IFN-alpha.

Accumulation of E2F-4.DP-1 DNA binding complexes correlates with induction of dhfr gene expression during the G1 to S phase transition

Previously genomic DNase I footprinting showed changes in protein binding to two overlapping E2F sites correlates with activation of dhfr gene expression at the G1/S boundary of the Chinese hamster cell cycle (Wells, J., Held, P., Illenye, S., and Heintz, N. H. (1996) Mol. Cell. Biol. 16, 634-647). Here gel mobility and antibody supershift assays were used to relate changes in the components of E2F DNA binding complexes in cell extracts to repression and induction of dhfr gene expression. In extracts from log phase cells, E2F complexes contained predominantly E2F-4 and E2F-2 in association with DP-1, and DNA binding assays showed complexes containing E2F-2 preferentially interact with only one of the two overlapping E2F sites. In serum starvation-stimulation experiments, arrest in G1 by low serum was accompanied by decreased levels of dhfr mRNA and the appearance of an E2F-4.DP-1.p130 complex. After serum stimulation, induction of dhfr gene expression was preceded by loss of the p130 complex in mid G1 and coincided with marked increases in two free E2F.DP-1 complexes in late G1, one of which contained E2F-4 and a second which contained an unidentified E2F. We suggest activation of dhfr gene expression after serum stimulation requires at least two temporally distinct processes, relief of p130-mediated repression and subsequent activation of transcription by free E2F.

Epidural hematoma in an ambulatory surgical patient

Epidural hematoma is a rare but potentially devastating complication of epidural anesthesia. We report a case of an epidural hematoma in an ambulatory surgical patient who received epidural anesthesia in the presence of nonsteroidal antiinflammatory drugs and low molecular weight heparin. The patient developed symptoms of an epidural hematoma after hospital discharge. An emergency decompressive laminectomy was performed, and the patient regained full motor and sensory function.

Lung injury related to consuming Sauropus androgynus vegetable

BACKGROUND

Taking Sauropus androgynus, a Malaysian food, to reduce weight began as a fad in Taiwan in 1994. Some advocates of this fad developed pulmonary dysfunction. The aim of this study is to report the lung injury in patients taking Sauropus androgynus.

METHODS

From July 1995 to November 1995, we investigated 104 nonsmoking patients (one male and 103 females) with chest roentgenography, pulmonary function, test, and Technetium 99m-labeled diethylene triamine penta-acetate (Tc-99m DTPA) radioaerosol inhalation lung scintigraphy.

RESULTS

Among the 90 patients receiving Tc-99m DTPA inhalation lung scan, 46 (51.1%) patients had increased clearance of Tc-99m DTPA from lung and 20 (22.2%) patients had inhomogeneous deposition of the submicronic radioaerosol. Eighteen (18/100) patients had obstructive ventilatory impairment in pulmonary function test. Analyzing the results, we found that the patients with respiratory symptoms (n = 42) took more vegetables (p = 0.016), had increased clearance of Tc-99m DTPA (p = 0.010) and had lower FEV1 (p = 0.001), FEV1/FVC (p < 0.001), FEF25-75 (p = 0.001), VC (p = 0.002) and DLCO (p = 0.009) than the patients without respiratory symptoms (n = 62). FEV1 and FEV1/FVC were significantly reduced in patients with severe impairment of alveolar permeability. The cumulative dosage and duration of exposure were significantly associated with the reduction of FEV1 and FEV1/FVC.

CONCLUSION

The lung injury after taking Sauropus androgynus involves alveoli and/or small airways and is manifest as obstructive ventilatory impairment with inhomogeneous aerosol distribution and increased lung epithelial permeability.

[Methicillin-resistant Staphylococcus aureus: an alarming problem in Chang Gung Memorial Hospital]

Strains of methicillin-resistant Staphylococcus aureus (MRSA) have become increasingly common in the United States and in many other countries since 1975. The prevalence of MRSA colonization and infection has increased in acute-care and chronic-care facilities, outpatient clinics, and in the community. We reviewed the sensitivity test of antibiotics in Chang Gung Memorial Hospital system, and revealed a steady decrease in sensitivity to Cephalothin, Oxacillin and Clindamycin during the past 10 years. It is still sensitive to Vancomycin. However, the amount of Vancomycin prescribed in the hospital system has increased three-folds during the recent 4 years. The purpose of this article is to review the MRSA in this hospital and to describe measures used to control MRSA transmission.

Oral anticoagulant prophylaxis and epidural catheter removal

BACKGROUND AND OBJECTIVES

The use of regional anesthesia in patients receiving anticoagulants is controversial. The purpose of this review is to document the incidence of neurologic complications with insertion and removal of an epidural catheter in patients receiving oral anticoagulants and antiplatelet medication.

METHODS

A retrospective review was made of the charts of 459 patients who underwent hip pinning or hip or knee replacement under regional anesthesia and received postoperative epidural analgesia and warfarin thromboembolism prophylaxis. The number of patients receiving preoperative antiplatelet therapy and warfarin, as well as baseline coagulation parameters, was documented. For patients who had postoperative epidural analgesia, the prothrombin time on the day of epidural catheter removal was obtained. Neurologic complications during the hospital stay were noted.

RESULTS

Spinal anesthesia was administered to 47 patients and epidural anesthesia and postoperative analgesia to 412. Before surgery, antiplatelet therapy was given to 270 and warfarin to 180 patients, with some patients receiving both. The mean +/- SD preoperative prothrombin and partial thromboplastin times were 10.8 +/- 1.2 seconds (normal, 9.6-11.1 seconds) and 27.5 +/- 3.5 seconds (normal, 24.6-33.2 seconds), respectively. Blood on needle or catheter insertion was noted in 21 patients, all of whom were taking antiplatelet medication and/or warfarin. Epidural catheters remained postoperatively for a mean of 43.6 +/- 12.5 hours (range 5-118 hours). The mean prothrombin time on the day of epidural catheter removal was 14.1 +/- 3.2 seconds. Four postoperative peripheral neuropathies were detected. There was no clinical evidence of spinal hematoma in any patient.

CONCLUSIONS

Epidural catheter placement and removal in patients taking oral anticoagulants appears to be safe. Careful monitoring of the patient for evidence of spinal hematoma after epidural catheter removal is recommended.

Purification and biochemical characterization of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate-sensitive L-glutamate receptors of pig brain

Two preparations of glutamate receptors were purified from the synaptic junctions of pig brain by a combination of detergent solubilization, anion-exchange chromatography, wheat-germ agglutinin affinity chromatography and sedimentation through sucrose gradients. These preparations were enriched in specific L-[3H]glutamate binding activity (> 5000 pmol of glutamate binding sites/mg of protein), and the rank order of ligand affinity for binding to these preparations was: quisqualate > 6-cyano-7- nitroquinoxaline-2,3-dione > alpha-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid (AMPA) > L-glutamate > kainate > > N-methyl-D-aspartate approximately L-2-amino-4-phosphonobutyrate. SDS/PAGE analysis revealed that more than 80% of the protein in either of these preparations appeared as a single protein band of 106 kDa. Two-dimensional gel electrophoresis further revealed that these 106 kDa proteins consisted of a series of acidic proteins which were recognized by antibodies against rat AMPA receptor subunits. These 106 kDa proteins were also recognized by wheatgerm agglutinin and concanavalin A; in addition, peptide N-glycosidase F treatment of these preparations decreased their size to 99 kDa. Our results suggest that the putative glutamate receptors isolated here are likely to belong to the AMPA subtype of glutamate receptors in pig brain. Using the purification procedure reported here, 5 micrograms of AMPA receptor proteins can be isolated from 250 g of pig brain tissue.

Marchantin H as a natural antioxidant and free radical scavenger

The antioxidant activity of marchantin H was investigated using various experimental models. Marchantin H inhibited nonenzymatic iron-induced lipid peroxidation in rat brain homogenates with an IC50 value of 0.51 +/- 0.03 microM. It was more potent than desferrioxamine or other classical antioxidants. Marchantin H also suppressed NADPH-dependent microsomal lipid peroxidation with an IC50 value of 0.32 +/- 0.01 microM without affecting microsomal electron transport of NADPH-cytochrome P450 reductase. Marchantin H could scavenge the stable free radical 1,1-diphenyl-2-picrylhydrazyl and peroxyl radical derived from 2,2 '-azobis(2-amidinopropane) dihydrochloride in aqueous phase, but not the peroxyl radical derived from 2,2 '-azobis(2,4-dimethylvaleronitrile) in hexane. The oxygen consumption during peroxyl radical-induced human erythrocyte ghost oxidation was decreased in a concentration-dependent manner by marchantin H. Furthermore, it was reactive toward superoxide anion generated by the xanthine/xanthine oxidase system. On the other hand, marchantin H inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity, thiobarbituric acid-reactive substance formation, and electrophoretic mobility in a concentration-dependent manner. Our results indicate that marchantin H is a potentially effective and versatile antioxidant and can be used as a chaperone protecting biomacromolecules against peroxidative damage.

Molecular characterization of a plasmid-borne (pTC82) chloramphenicol resistance determinant (cat-TC) from Lactobacillus reuteri G4

Lactobacillus reuteri G4 contains a 7.0-kb plasmid (pTC82) encoding resistance to chloramphenicol (Cm). Determination of the nucleotide sequence of the genetic determinant (cat-TC) encoding resistance to Cm on pTC82 revealed an open reading frame for a 238-amino-acid Cm acetyltransferase (CAT) monomer. This structural cat gene, 714 bp in length, was highly related (ca. 95% nucleotide and ca. 81% amino acid identity) to the 648-bp cat gene from Staphylococcus aureus plasmid pC194. A total of 6 bp transversions and 4 bp deletions was observed along the whole DNA sequence of cat-TC compared to that of cat-pC194. To determine the activity of the putative cat-TC gene, recombinant plasmid pUC8217 containing the cat determinant from pTC82 was subjected to a maxicell analysis. The observed molecular mass of the synthesized protein, based on electrophoretic mobility, was in reasonable agreement with the 27.3 kDa predicted from the DNA sequence. This is the first reported nucleotide sequence of a Cm-resistance determinant from L. reuteri and also the first evidence of adding Lactobacillus to the list of versatile bacterial genera which naturally acquire the cat-pC194 gene in the microbial ecological system.

Mice with adenine phosphoribosyltransferase deficiency develop fatal 2,8-dihydroxyadenine lithiasis

Deficiencies in different steps of purine metabolism give rise to a number of human inherited disorders. Lesch-Nyhan syndrome is a severe neurological disorder, caused by a deficiency in the purine salvage enzyme hypoxanthine phosphoribosyltransferase (HPRT). HPRT-deficient mice have been generated, but have proved to be an unsuccessful model of the human disease. We have suggested that this may be due to a greater dependency in rodents on the other purine salvage enzyme, adenine phosphoribosyltransferase (APRT). We have generated an APRT-deficient mouse line by gene targeting, with a phenotype that closely resembled the symptoms of APRT deficiency in man. APRT null mice were viable, but 90% died prematurely before 6 months of age, displaying highly abnormal kidney morphology, with pathology characteristic of tubule obstruction. These mice have elevated urinary levels of adenine and 2,8-dihydroxyadenine, a highly insoluble adenine derivative, plus birefringent crystalline deposits and calculi within tubules throughout the kidney. A standard therapy for APRT-deficient human patients is the administration of the xanthine oxidase inhibitor, allopurinol. This has proved an effective therapy for APRT null mice, preventing accumulation of 2,8-dihydroxyadenine and much of the resultant renal obstruction, allowing us to establish a breeding line. We believe that these mice should provide a useful model for further study of APRT deficiency in humans. Furthermore, by generating APRT and HPRT double mutants, we will be able to test our hypothesis that both genes must be inactivated in mice before a model for Lesch-Nyhan syndrome can be obtained.

Expression of dominant-negative mutant DP-1 blocks cell cycle progression in G1

Unregulated expression of the transcription factor E2F promotes the G1-to-S phase transition in cultured mammalian cells. However, there has been no direct evidence for an E2F requirement in this process. To demonstrate that E2F is obligatory for cell cycle progression, we attempted to inactivate E2F by overexpressing dominant-negative forms of one of its heterodimeric partners, DP-1. We dissected the functional domains of DP-1 and separated the region that facilitate heterodimer DNA binding from the E2F dimerization domain. Various DP-1 mutants were introduced into cells via transfection, and the cell cycle profile of the transfected cells was analyzed by flow cytometry. Expression of wild-type DP-1 or DP-1 mutants that bind to both DNA and E2F drove cells into S phase. In contrast, DP-1 mutants that retained E2F binding but lost DNA binding arrested cells in the G1 phase of the cell cycle. The DP-1 mutants that were unable to bind DNA resulted in transcriptionally inactive E2F complexes, suggesting that the G1 arrest is caused by formation of defective E2F heterodimers. Furthermore, the G1 arrest instigated by these DP-1 mutants could be rescued by coexpression of wild-type E2F or DP protein. These experiments define functional domains of DP and demonstrate a requirement for active E2F complexes in cell cycle progression.

Nuclear localization of DP and E2F transcription factors by heterodimeric partners and retinoblastoma protein family members

E2F is a family of transcription factors implicated in the regulation of genes required for progression through G1 and entry into the S phase. The transcriptionally active forms of E2F are heterodimers composed of one polypeptide encoded by the E2F gene family and one polypeptide encoded by the DP gene family. The transcriptional activity of E2F/DP heterodimers is influenced by association with the members of the retinoblastoma tumor suppressor protein family (pRb, p107, and p130). Here the intracellular distribution of E2F and DP proteins was investigated in transiently transfected Chinese hamster and human cells. In transfected cells, DP-1 did not accumulate in the nucleus unless it was coexpressed with the heterodimeric partners E2F-1, E2F-2, or E2F-3. Domain mapping experiments showed that regions of E2F-1 and DP-1 that are required for stable association of the two proteins were also required for nuclear localization of DP-1. Unlike E2F-1, -2, and -3, E2F-4 did not accumulate in the nucleus unless it was coexpressed with DP-2, p107 and p130, but not pRb, stimulated nuclear localization of E2F-4, either alone or in combination with DP-2. These results indicate that DP proteins preferentially associate with specific E2F partners, and suggest that the ability of specific E2F/DP heterodimers to localize in the nucleus contributes to the regulation of E2F activity.

The use of fiberoptic endoscopy in anesthesia

The fiberoptic bronchoscope has contributed greatly to the practice of anesthesiology over the past 30 years. It has become an indispensable tool in the approach to the difficult airway, as well as the placement and positioning of double-lumen tubes for thoracic surgery. The equipment, preparation, and methods for using the endoscope in anesthesia, are presented here.

Allelic imbalance on chromosome 3p in oral dysplastic lesions: an early event in oral carcinogenesis

We have demonstrated previously a loss of constitutional heterozygosity on the short arm of chromosome 3 in approximately 50% of oral squamous cell carcinomas. In the present study, we have investigated 30 oral dysplastic lesions (DLs), presenting clinically as either erythroplakias or leukoplakias with histopathological features of either severe epithelial dysplasia or carcinoma in situ, for LOH on chromosome 3p using 15 microsatellite markers. Thirteen of the 30 LDs (approximately 43%) showed allelic imbalance at one or more loci. The pattern of loss in these lesions defined three noncontiguous regions of interstitial deletions that overlap with those defined for oral squamous cell carcinomas. These data indicate that the alteration of tumor suppressor genes on chromosome 3p is probably an early event in oral carcinogenesis. Additionally, 7 of the 30 DLs showed microsatellite instability. However, the frequency of loci showing microsatellite instability per lesion was low.

Education, age, and the cumulative advantage in health

The positive association between educational attainment and health is well established, but the way in which the education-based gap in health varies with age is not. Do the health advantages of high educational attainment and disadvantages of low educational attainment diverge or converge with age? The cumulative advantage perspective predicts a diverging SES gap in health with age, but past evidence does not allow us to accept or reject the hypothesis. We address this issue in two samples, cross-sectionally and over time, with three health measures. The first data set consists of a 1990 telephone interview of a national probability sample of U.S. households. There are 2,031 respondents, aged 18 to 90. The second is a national probability sample of U.S. households in which 2,436 respondents aged 20 to 64 were interviewed by telephone in 1979 and reinterviewed in 1980. We find that the gap in self-reported health, in physical functioning, and in physical well-being among people with high and low educational attainment increases with age. The health advantage of the well educated is larger in older age groups than in younger. Health advantages of high income and disadvantages of low income also diverge with age, but household income does not explain education's positive effect.

Marchantinquinone, isolated from Reboulia hemisphaerica, as inhibitor of lipid peroxidation and as free radical scavenger

The antioxidant effect of marchantinquinone was studied using various models. Marchantinquinone inhibited Fe(2+)-induced lipid peroxidation in rat brain homogenate in a concentration-dependent manner with an IC50 15.3 +/- 2.9 microM. Marchantinquinone was less effective than alpha-tocopherol and BHT in reducing the stable free radical diphenyl-2-picrylhydrazyl (DPPH). The IC0.200 were 37.5 +/- 2.5, 9.2 +/- 1.6 and 14.5 +/- 2.5 microM, respectively. Marchantinquinone also scavenged peroxyl radical derived from 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) in aqueous system with a stoichiometric factor of 0.9 +/- 0.1. Furthermore, it prevented conjugated-diene formation and apolipoprotein B (apo B) oxidation of LDL. However, marchantinquinone did not chelate Fe2+ or possess superoxide anion and hydroxyl radical scavenging activity. It also did not scavenge 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN)-derived peroxyl radical in hexane. These results indicate that marchantinquinone may be an effective antioxidant and can protect rat brain homogenate and LDL against oxidation.

Stiff-man syndrome: report of a case

A 40-year-old Taiwanese farmer developed progressive stiffness and pain in the lower back with intermittent cramps over a 3-year period. The cramps were extremely painful and the patient was sensitive to any sudden movement or external stimulation. His lower back was so stiff that the patient had great difficulty performing daily activities and walked with a rigid and straight back. The stiffness of the muscles subsided during normal sleep. Except for a left S1 radiculopathy, no other neurologic abnormalities were noted. Electromyography showed spontaneous continuous muscle fiber activity which was markedly suppressed after a trial with 20 mg intravenous diazepam. The muscular stiffness disappeared during treatment with oral diazepam 80 mg daily, which was tapered to 15 mg daily without any recurrence of spasm for 20 months. This is the first report of stiff-man syndrome in a Taiwanese patient and emphasizes the importance of recognizing this treatable disease.

In vivo association of E2F and DP family proteins

The mammalian transcription factor E2F plays an important role in regulating the expression of genes that are required for passage through the cell cycle. This transcriptional activity is inhibited by association with the retinoblastoma tumor suppressor protein (pRB) or its relatives p107 and p103. The first cDNA from the E2F family to be cloned was designated E2F-1, and multiple E2F family members have now been identified. They bind to DNA as heterodimers, interacting with proteins known as DP. Here we demonstrate that DP is also a family of polypeptides with at least two members (hDP-1 and hDP-2). Both hDP-1 and hDP-2 bind to all E2F family members in vivo, and each complex is capable of activating transcription. However, the various E2F/DP complexes display strong differences in the ability to bind to either pRB or p107 in vivo, and the specificity of pRB or p107 binding is mediated by the E2F subunit.

Prevention of emesis after strabismus repair in children: a prospective, double-blinded, randomized comparison of droperidol versus ondansetron

STUDY OBJECTIVE

To compare the effectiveness of ondansetron with droperidol in preventing postoperative emesis in children after strabismus repair.

DESIGN

Randomized, double-blind study.

PATIENTS AND SETTING

57 ASA physical status I and II children aged 3 to 14 years, undergoing outpatient strabismus repair in two separate study centers.

INTERVENTIONS

Patients were randomized to receive either 0.15 mg/kg intravenous (i.v.) ondansetron or 0.075 mg/kg i.v. droperidol shortly after induction of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Number of episodes of emesis and times to discharge from the recovery room and ambulatory center were assessed. Twenty-nine (94%) of 31 children who received ondansetron and 21 (81%) of 26 children who received droperidol were emesis-free (p = NS). There were no significant differences in the number of episodes of emesis on the day after surgery or times to discharge.

CONCLUSIONS

Ondansetron is at least as effective as droperidol in reducing the frequency of emesis in children after strabismus repair, and it did not shorten times to discharge home. The low number of patients in our study may have masked a difference in effect between the two groups. The clinician should decide whether the increased cost of ondansetron justifies its use over other antiemetics.

Deletion mapping on the short arm of chromosome 3 in squamous cell carcinoma of the oral cavity

Loss of heterozygosity indicative of the presence of tumor suppressor genes on chromosome 3p is commonly observed in carcinomas of various tissues. We have examined loss of heterozygosity on chromosome 3p in 27 oral squamous cell carcinomas using 15 highly informative microsatellite polymorphisms and constructed a deletion map of chromosome 3p. Overall, loss of heterozygosity at one or more loci was observed in 14 tumors (approximately 52%). A majority of these tumors (86%) show loss in more than one area. Three distinct regions were identified: 3p13-3p21.1, 3p21.3-3p23, and 3p25. These data suggest a role for at least three tumor suppressor genes on chromosome 3p in oral squamous carcinomas. The regions of deletions overlap with those described for carcinomas of other tissues and parallel those observed in lung carcinomas. This may reflect the common etiology of the two cancers.

Histologic changes of doxycycline pleurodesis in rabbits. Effect of concentration and pH

The effects of doxycycline hyclate (DOXY) pleurodesis were compared with those of tetracycline hydrochloride (TCN) in 25 healthy New Zealand White rabbits. One group of rabbits received TCN (pH 2.0) in the left pleural space at a concentration of 35 mg/kg in 3.0 ml of saline solution. Four other groups of rabbits received DOXY in two concentrations (35 mg/kg or 10 mg/kg) and at two pHs (an acid of 2.0 and a NaOH neutralized pH of 7.6). No attempt was made to drain the pleural space after pleurodesis. At autopsy 2 weeks later, bloody fluid filled the pleural cavity and extensive intrapleural adhesions compressed the underlying lung. Microscopically, fibrin and collagen were diffusely deposited in the pleural connective tissue and in the intrapleural adhesions. The visceral pleural thickness increased from its normal value of 0.01 mm to values of 0.5 to 0.9 mm in the TCN and DOXY groups. Fibroblasts were the predominant inflammatory cell in the pleural connective tissue with few neutrophils or lymphocytes. No significant differences of histologic characteristics were observed between the TCN and DOXY groups. Alterations in pH or concentration in the DOXY groups produced similar changes in the gross and microscopic appearance of the pleural space. We conclude that DOXY is as effective as TCN in producing chemical pleurodesis. Doxycycline concentrations of 10 mg/kg were sufficient to substantially sclerose the pleural space in these healthy rabbits. Doxycycline pleurodesis was effective at neutral pH suggesting a mechanism of action independent of acid injury to the mesothelium.

Gastric volume and pH in infants fed clear liquids and breast milk prior to surgery

Recommendations for fasting intervals prior to anesthesia in pediatric patients have changed in recent years. There are few data concerning infants less than 1 yr of age fed clear liquids or breast milk before surgery. We performed a prospective, blinded study to determine residual gastric volumes and pH in this population. Approximately 2 h prior to surgery, 46 formula-fed infants ingested up to 8 oz of clear liquids and 24 breast-fed infants nursed as usual. After induction of general anesthesia and tracheal intubation, gastric fluid samples were aspirated by a blinded researcher who measured gastric volume and pH. Sufficient gastric fluid for analysis was obtained from 10 (22%) of the infants fed clear liquids and 8 (33%) of the breast-fed infants. For the group fed clear liquids, the residual gastric volume was 0.3 +/- 0.9 mL/kg and the pH was 2.1 +/- 1.4. Eight (17%) had gastric volumes > or = 0.4 mL/kg, 2 (4%) had gastric volumes > or = 1 mL/kg, and 9 (90%) of 10 measured had pH < or = 2.5. In the breast-fed group the residual gastric volume was 0.71 +/- 1.1 mL/kg (P = not significant [NS]) and the pH was 2.6 +/- 1 (P = NS). All eight (33%) breast-fed infants had gastric volumes > or = 0.4 mL/kg (P = NS), seven (29%) had gastric volumes > or = 1 mL/kg (P = 0.03), and four (50%) of eight measured had pH < or = 2.5 (P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Ondansetron decreases emesis after tonsillectomy in children

We performed a double-blind, randomized, placebo-controlled trial to investigate the efficacy and safety of ondansetron in preventing vomiting after tonsillectomy with or without adenoidectomy in children. Sixty children were premedicated with 0.5 mg/kg of oral midazolam and underwent inhaled induction and maintenance of anesthesia with halothane and nitrous oxide. Intravenous morphine 0.075 mg/kg, vecuronium 0.1 mg/kg, and either ondansetron 0.15 mg/kg (maximum = 8 mg), or saline placebo were administered after intravenous catheter placement. All episodes of postoperative vomiting on the day of surgery and the following day were recorded. There were no significant differences between the two groups with regard to age, weight, sex, time to endotracheal intubation, duration of surgery, duration of anesthesia, or number of patients having adenoidectomy. More patients in the ondansetron group received dexamethasone as part of the surgeon's routine protocol (P = 0.03). Twenty-three children (77%) who received ondansetron were emesis-free as opposed to only eight (27%) in the placebo group (P < 0.001). This was especially evident in the number of children who had two or more episodes of vomiting; 17 children (57%) who received placebo had two or more episodes of vomiting as opposed to only two children (7%) who received ondansetron. The incidence of emesis on the day after the surgery did not differ between the two groups. Three children who received ondansetron and one who received placebo complained of abdominal cramping on the night of the surgery. There were no other complaints or complications. Analysis of the 51 children who did not receive dexamethasone revealed similar results.(ABSTRACT TRUNCATED AT 250 WORDS)

Subarachnoid glioependymal cyst: a case report

A case of subarachnoid glioependymal cyst in a newborn baby is reported. An intracranial cystic lesion was found at 32 weeks of gestation by ultrasonography. The infant was born with an enlarged head and impaired auditory evoked potential (AEP). Computed tomography and magnetic resonance imaging revealed a large homogeneous cystic lesion over the left cerebral convexity with displacement of the left hemisphere to the right. Craniotomy was performed, with removal of the cystic wall and insertion of a cystoperitoneal shunt. Postoperatively, improvement was noted on clinical examination and ultrasonography. Previously, only one such case, treated perinatally, has been reported.

Comparison of techniques for measurement of gelatinases/type IV collagenases: enzyme-linked immunoassays versus substrate degradation assays

Radiolabeled substrate degradation assays and gelatin zymography are routinely employed to assay 72 kDa gelatinase A (MMP-2) and 92 kDa gelatinase B (MMP-9) in biological fluids. Enzyme-linked immunosorbent assays (ELISA) have recently been developed for the quantitation of these matrix metalloproteinases (MMP). In this study, we have compared ELISA to standard substrate degradation assays for measurement of MMP-2 and MMP-9 in human plasma and tumor-conditioned media. Gelatin Sepharose chromatography and gel filtration chromatography were employed as partial purification procedures for MMP-2 and MMP-9. The ELISA data for MMP-2 and MMP-9 are linear on a log:log regression curve over a wide range of MMP concentrations and are specific for the designated gelatinase, with no overlap detected with related metalloproteinases. The minimum detectable concentrations of MMP-2 and MMP-9 were approximately 0.5 ng/ml and 0.2 ng/ml, respectively, in the ELISA as compared to 4 ng/ml and 3 ng/ml, respectively, in gelatin zymography. The [3H]gelatin degradation assay required a combination of > 50 ng/ml of MMP-2 and MMP-9 for detection. Although gelatin zymography was less sensitive than ELISA (primarily due to the smaller sample volume employed) and was more difficult to quantitate, this procedure offers the important advantage of being able to distinguish between latent and activated gelatinases.