Paraoxonase active site required for protection against LDL oxidation involves its free sulfhydryl group and is different from that required for its arylesterase/paraoxonase activities: selective action of human paraoxonase allozymes Q and R

Human serum paraoxonase (PON 1) exists in 2 major polymorphic forms (Q and R), which differ in the amino acid at position 191 (glutamine and arginine, respectively). These PON allozymes hydrolyze organophosphates and aromatic esters, and both also protect LDL from copper ion-induced oxidation. We have compared purified serum PONs of both forms and evaluated their effects on LDL oxidation, in respect to their arylesterase/paraoxonase activities. Copper ion-induced LDL oxidation, measured by the production of peroxides and aldehydes after 4 hours of incubation, were reduced up to 61% and 58%, respectively, by PON Q, but only up to 46% and 38%, respectively, by an equivalent concentration of PON R. These phenomena were PON-concentration dependent. Recombinant PON Q and PON R demonstrated similar patterns to that shown for the purified serum allozymes. PON Q and PON R differences in protection of LDL against oxidation were further evaluated in the presence of glutathione peroxidase (GPx). GPx (0.1 U/mL) alone reduced copper ion-induced LDL oxidation by 20% after 4 hours of incubation. The addition of PON R to the above system resulted in an additive inhibitory effect on LDL oxidation, whereas PON Q had no such additive effect. The 2 PON allozymes also differed by their ability to inhibit initiation, as well as propagation, of LDL oxidation. PON Q was more efficient in blocking LDL oxidation if added when oxidation was initiated, whereas PON R was more potent when added 1 hour after the initiation of LDL oxidation. These data suggest that the 2 allozymes act on different substrates. Both PON allozymes were also able to reduce the oxidation of phospholipids and cholesteryl ester. PON Q arylesterase activity was reduced after 4 hours of LDL oxidation by only 28%, whereas the arylesterase activity of PON R was reduced by up to 55%. Inactivation of the calcium-dependent PON arylesterase activity by using the metal chelator EDTA, or by calcium ion removal on a Chelex column, did not alter PON's ability to inhibit LDL oxidation. However, blockage of the PON free sulfhydryl group at position 283 with p-hydroxymercuribenzoate inhibited both its arylesterase activity and its protection of LDL from oxidation. Recombinant PON mutants in which the PON free sulfhydryl group was replaced by either alanine or serine were no longer able to protect against LDL oxidation, even though they retained paraoxonase and arylesterase activities. Overall, these studies demonstrate that PON's arylesterase/paraoxonase activities and the protection against LDL oxidation do not involve the active site on the enzyme in exactly the same way, and PON's ability to protect LDL from oxidation requires the cysteine residue at position 283.

Endoscopic sinus surgery and postoperative intravenous aminoglycosides in the treatment of atrophic rhinitis

A total of 29 atrophic rhinitis patients were treated by endoscopic sinus surgery between 1990 and 1995. After the surgery, a 7 to 10-day course of systematic aminoglycoside was administered. Two cases were excluded, due to later occurrence of nasal lymphoma in one patient and incompleteness of postoperative antibiotic therapy in the other. Among those included, atrophic rhinitis occurred in the absence of prior surgery in 24 patients, and the condition was secondary to a previous intranasal surgery in the other three patients. After a 1 to 6-year follow-up (mean: 63.4 months), seven patients were successfully managed without any characteristic symptom or sign of atrophic rhinitis. Another 18 patients felt improved. Only two patients did not have any improvement. The rate of improvement was 92.6%. Overall, one patient suffered from a left retrobulbar hematoma after operation. Exposed orbital fat was observed in the other patient. The orbital complication rate was therefore 7.4%. No other major complication occurred in this series. The bacteriologic, radiological, antroscopic, and pathologic findings are also included here. It is concluded that endoscopic sinus surgery in combination with adequate postoperative antibiotic therapy can significantly treat atrophic rhinitis.

Japanese encephalitis virus is transported across the cerebral blood vessels by endocytosis in mouse brain

Japanese encephalitis (JE) virus principally infects neuron systems of animals and causes severe encephalitis. The mechanism by which the virus enters the central nervous system (CNS) from the circulatory system remains elusive. In this study, electron-microscopic techniques have been used to determine these sequential events in the suckling mouse brain. The results indicate that (1) endocytosis is employed when JE virus is transported across the cerebral blood vessels (CBV) and breaches the blood-brain barrier (BBB). (2) Uncoated vesicles, which may be caveolae, and coated vesicles are involved in the endocytic and transcytotic vesicles of capillary endothelium and pericytes. (3) The JE virus is transported in endocytic vesicles across the endothelial cells and pericytes. (4) Endocytosis and transportation of JE virus in pericytes seems to be the same as that in endothelial cells. (5) The interaction of the viral envelope and cell membrane of endothelial cells and pericytes plays an important role in the endocytosis. This study elucidates the infectious processes of JE virus entering the CNS from the circulatory system in the mouse brain.

Accuracy of auscultation in the detection of haemopneumothorax

OBJECTIVE

To assess the accuracy of auscultation in the detection of haemopneumothorax.

DESIGN

Prospective study.

SETTING

University hospital, Taiwan.

PATIENTS

148 patients with chest injuries admitted between July 1994 and August 1996.

MAIN OUTCOME MEASURES

Correlation between the results of auscultation and radiographic findings in 148 patients with injuries to the chest. 83 (56%) had internal injuries, of whom 38 had pneumothoraces, 24 haemothoraces, and 21 haemopneumothoraces.

RESULTS

Auscultation had a sensitivity of 84%, a specificity of 97%, an accuracy of 89% and a positive predictive value of 97% in the detection of these injuries.

CONCLUSIONS

Auscultation is not as accurate as chest radiography. Chest tubes can be inserted before chest radiography in patients in whom auscultation has indicated an injury. A chest radiograph is essential in those patients with normal breath sounds to exclude a haemopneumothorax that had been missed by auscultation.

Experimental hypoxemic hypoxia: effects of variation in hematocrit on magnetic resonance T2*-weighted brain images

T2*-weighted gradient echo magnetic resonance images of rat brain were obtained dynamically during acute hypoxemic hypoxia to investigate the relations between changes in cerebral blood oxygen saturation (deltaYb), blood hematocrit (Hct), and R2* (deltaR2*). Images from hypoxemic rats with normal Hct (42.8%+/-2.33%; n=12) were compared with those from hypoxemic rats with mild (33.4%+/-1.88%; n=8) or moderate (27.14%+/-2.7%; n=10) reduction of Hct. A linear relation between deltaYb and deltaR2* was obtained for all three groups. However, the slopes of the linear regressions were statistically different from one another (P < 0.001), with the slopes of the regression lines increasing inversely with Hct; that is, the slope for normal Hct is less than the slope for mildly reduced Hct, which is less than the slope for moderately reduced Hct. These data suggest that for any given reduction in the oxygen saturation of cerebral blood, the deltaR2* will be of a lesser magnitude when the hemoglobin concentration is reduced; the data are consistent with existing theoretical models of deoxyhemoglobin content-dependent effects in T2*-weighted magnetic resonance imaging.

Bacteriology of the maxillary and ethmoid sinuses in chronic sinusitis

The bacteriology of chronic sinusitis was studied by using swab and mucosal specimens from both the maxillary and ethmoid sinuses. The specimens of the maxillary sinus were taken through translabial antroscopy. The specimens of the ethmoid sinus were taken after removing the ethmoid bulla during functional endoscopic sinus surgery (FESS). Eighty-six samples of each type of specimen were collected. Among the maxillary sinus samples, the culture rate was 60.5 per cent from the swab specimens and 36 per cent from the mucosal specimens. Among the ethmoid sinus samples, the culture rate was 58.1 per cent from the swab specimens and 75.6 per cent from the mucosal. The p-value by the Chi-Square test is higher than 0.01 (p = 0.015). As there were more isolates of Staphylococcus epidermidis from the mucosal specimens, they are not a better choice of specimen for sampling the ethmoid sinus than a swab specimen.

Methylprednisolone inhibition of TNF-alpha expression and NF-kB activation after spinal cord injury in rats

Post-traumatic inflammatory reaction has been implicated in the secondary injury after SCI. TNF-alpha is a key inflammatory mediator, which plays a pathogenetic role in cell death in inflammatory disorders and traumatic brain injury. TNF-alpha exerts its effector actions, at least partially, through the activation of a pro-inflammatory transcription factor, NF-kB, which in turn upregulates such genes as iNOS, cytokines, adhesive molecules, and others. Consistent with a post-traumatic inflammatory reaction after SCI, we noted an increase in TNF-alpha expression by Western blotting (4.5-fold increase at 1 day after SCI, P<0.01) and immunohistochemistry in a rat SCI model. Post-traumatic TNF-alpha expression was accompanied by an increase in NF-kB binding activity in nuclear proteins isolated from the injured cord (3.9-fold increase, P<0.01). MP is the only drug proven effective in improving neurological function in patients with acute SCI. The mechanism of action of MP is not fully understood, but is thought to be related to its antioxidant effects. MP is also a potent anti-inflammatory agent, which has been recently shown to inhibit NF-kB binding activity. MP (30 mg/kg, i.v.) given immediately after SCI reduced TNF-alpha expression by 55% (P<0.01) and NF-kB binding activity. These findings suggest that post-traumatic inflammatory activity that is mediated by the TNF-alpha-NF-kB cascade can be suppressed by MP.

Outpatient weekly chemotherapy in patients with nasopharyngeal carcinoma and distant metastasis

BACKGROUND

Distant metastasis is a more common pattern of failure than locoregional recurrence after adequate radiotherapy in patients with nasopharyngeal carcinoma (NPC). The objective of this Phase II study was to assess the efficacy and toxicity of weekly chemotherapy in NPC patients with distant metastasis.

METHODS

Patients with a histologic diagnosis of NPC and documented distant metastasis were eligible, including those who 1) had metastatic disease at presentation; 2) had developed metastatic disease during or at any time after local radiotherapy; or 3) had developed progressive disease or recurrence of metastasis after prior chemotherapy. The weekly chemotherapy regimen was comprised of 5-fluorouracil (5-FU), 1250 mg/m2, plus cisplatin, 25 mg/m2, as a 24-hour continuous intravenous infusion via a subcutaneous implanted port, using an ambulatory pump in an outpatient setting for the first 19 patients. Because of the low incidence and reduced severity of toxicity, the dosage of chemotherapy was escalated to 5-FU, 1667 mg/m2, plus cisplatin, 33.3 mg/m2, for the subsequent 25 patients.

RESULTS

Between October 1992 and June 1996, a total of 44 patients with metastatic NPC were studied. They were 36 males and 8 females with a median age of 48 years (range, 30-72 years). Poorly differentiated epidermoid carcinoma or undifferentiated carcinoma were the major pathologic types. Twenty-six patients had single organ metastasis, whereas 18 patients had multiple organ involvement. Locoregional disease existed simultaneously in 16 patients. The majority of patients had received previous radiotherapy (33 patients) and chemotherapy (23 patients: 16 as concurrent therapy for localized disease, 6 as salvage therapy for metastatic disease, and 1 for a postradiation adjuvant purpose). Among 38 patients with measurable disease, 8 obtained a complete response (CR) (21.1%), 12 obtained a partial response (PR) (31.6%), 17 had stable disease (SD) (44.7%), and 1 had progressive disease (2.6%). The median duration of CR, PR, and SD were 6.5 months, (range, 2-12 months), 5.5 months (range, 2-9 months), and 2.5 months (range, 1-6 months), respectively. Toxicity was found to be very mild. Only one patient developed a World Health Organization (WHO) Grade 1 mucositis. No visible alopecia and no treatment-related deaths occurred. WHO Grade 3-4 hematologic toxicities occurred in 1.0% of patients for leukopenia, 4.1% for anemia, and 2.9% for thrombocytopenia.

CONCLUSIONS

Data from the current study indicate that 24-hour weekly infusion of 5-FU plus cisplatin has moderate activity but very low toxicity for NPC patients with distant metastasis. Further study is necessary to find more effective therapy.

Involvement of de novo ceramide biosynthesis in tumor necrosis factor-alpha/cycloheximide-induced cerebral endothelial cell death

Cytokines, including tumor necrosis factor-alpha (TNF-alpha), may elicit cytotoxic response through the sphingomyelin-ceramide signal transduction pathway by activation of sphingomyelinases and the subsequent release of ceramide: the universal lipid second messenger. Treatment of bovine cerebral endothelial cells (BCECs) with TNF-alpha for 16 h followed by cycloheximide (CHX) for 6 h resulted in an increase in ceramide accumulation, DNA fragmentation, and cell death. Application of a cell permeable ceramide analogue C2 ceramide, but not the biologically inactive C2 dihydroceramide, also induced DNA laddering and BCEC death in a concentration- and time-dependent manner. TNF-alpha/CHX-mediated ceramide production apparently is not a result of sphingomyelin hydrolysis because sphingomyelin content does not decrease in this death paradigm. In addition, an acidic sphingomyelinase inhibitor, desipramine, had no effect on TNF-alpha/CHX-induced cell death. However, addition of fumonisin B1, a selective ceramide synthase inhibitor, attenuated TNF-alpha/CHX-induced intracellular ceramide elevation and BCEC death. Together, these findings suggest that ceramide plays at least a partial role in this paradigm of BCEC death. Our results show, for the first time, that ceramide derived from de novo synthesis is an alternative mechanism to sphingomyelin hydrolysis in the BCEC death process initiated by TNF-alpha/CHX.

Aging and cerebrovascular disease

Aging influences cerebrovascular disease expression by a variety of mechanisms. Age-related changes in cerebral autoregulation, cellular metabolism, the blood-brain barrier, and autonomic function may leave the cerebrovascular system vulnerable to injury. Certain cerebrovascular disease, such as atrial fibrillation, watershed infarctions, carotid artery atherosclerosis, cerebral hemorrhages, subdural hematomas, and transient global amnesia manifest in the elderly. Vascular dementia and white matter disease are better understood with newer neuroimaging studies, careful neuropsychological and histopathologic examinations. Atherosclerosis and cerebral amyloid angiopathy may have larger roles than previously understood in Alzheimer's disease.

Comparison of effects of surfactants with other MDR reversing agents on intracellular uptake of epirubicin in Caco-2 cell line

P-glycoprotein (P-gp) actively pumps out a number of anticancer drugs, such as epirubicin, from tumor cells. P-gp is also expressed in the small intestine under normal physiological conditions. Inhibition of intestinal P-gp function using MDR reversing agents may enhance the oral bioavailability of some chemotherapeutic agents. Human colon adenocarcinoma (Caco-2) cell line expresses many characteristics of differentiated cells of the normal small intestine. Using Caco-2 as an in vitro intestinal model, the overall goal of the present study was to evaluate the MDR-reversing effects of some commonly used nonabsorptive pharmaceutical surfactants, such as Tween 20, Tween 80 and acacia on the intracellular accumulation of epirubicin by flow cytometry. Tween 20, Tween 80 or acacia all significantly increased intracellular accumulation of epirubicin with the highest enhancing effect for acacia and the lowest for Tween 20. Apart from progesterone, the enhancing effects of surfactants were better than those of non-surfactant MDR reversing agents such as verapamil, trifluoperazine and reserpine. In conclusion, our results demonstrate that progesterone, acacia, Tween 20 and Tween 80 are potent MDR modifiers of epirubicin in Caco-2 at concentrations that could be achieved in vivo. Use of surfactants in excipients may increase the intestinal absorption of some drugs through P-gp inhibition and thus improve drug bioavailability for P-gp substrate.

Involvement of de novo ceramide biosynthesis in tumor necrosis factor-alpha/cycloheximide-induced cerebral endothelial cell death

Cytokines, including tumor necrosis factor-alpha (TNF-alpha), may elicit cytotoxic response through the sphingomyelin-ceramide signal transduction pathway by activation of sphingomyelinases and the subsequent release of ceramide: the universal lipid second messenger. Treatment of bovine cerebral endothelial cells (BCECs) with TNF-alpha for 16 h followed by cycloheximide (CHX) for 6 h resulted in an increase in ceramide accumulation, DNA fragmentation, and cell death. Application of a cell permeable ceramide analogue C2 ceramide, but not the biologically inactive C2 dihydroceramide, also induced DNA laddering and BCEC death in a concentration- and time-dependent manner. TNF-alpha/CHX-mediated ceramide production apparently is not a result of sphingomyelin hydrolysis because sphingomyelin content does not decrease in this death paradigm. In addition, an acidic sphingomyelinase inhibitor, desipramine, had no effect on TNF-alpha/CHX-induced cell death. However, addition of fumonisin B1, a selective ceramide synthase inhibitor, attenuated TNF-alpha/CHX-induced intracellular ceramide elevation and BCEC death. Together, these findings suggest that ceramide plays at least a partial role in this paradigm of BCEC death. Our results show, for the first time, that ceramide derived from de novo synthesis is an alternative mechanism to sphingomyelin hydrolysis in the BCEC death process initiated by TNF-alpha/CHX.

MIB-1 labeling index in nonpilocytic astrocytoma of childhood: a study of 101 cases

BACKGROUND

The prognosis of pediatric patients with nonpilocytic astrocytoma, and in particular those with anaplastic astrocytoma, is somewhat unpredictable. This study used MIB-1 monoclonal antibody, a proliferative marker that can be used in formalin fixed paraffin embedded tissues, to study nonpilocytic pediatric astrocytoma.

METHODS

Astrocytoma, anaplastic astrocytoma, and glioblastoma specimens excised from a total of 101 pediatric patients during the period from January 1975 to September 1996 were retrieved from the authors' surgical pathology file. Histologic grading of the specimens was performed based on a modified Ringertz system. The proliferative potential of the tumors was estimated by using the MIB-1 labeling index (LI), which was evaluated with morphologic grades of tumors and survival of the patients.

RESULTS

Of the 101 patients, 34 had astrocytoma, 33 had anaplastic astrocytoma, and 34 had glioblastoma. Their mean survival times were 165.2+/-14.9 months (mean+/-standard error; SE), 46.1+/-9.9 months, and 21.8+/-5.6 months, respectively. The mean MIB-1 LI of different tumor grades were as follows: astrocytoma, 3.9+/-4.3 (mean+/-standard deviation; range, 0.0-21.6); anaplastic astrocytoma, 24.3+/-15.6 (range, 1.7-62.8); and glioblastoma, 35.9+/-16.4 (range, 7.36-63.3). The mean survival of the entire group of patients with LIs < or = 11 was 173.2+/-12.2 months (mean+/-SE), and the mean survival of those with LIs > 11 was 20.3+/-4.1 months. The survival of anaplastic astrocytoma patients with LIs < or = 11 was similar to that of astrocytoma patients, whereas the survival of anaplastic astrocytoma patients with LI > 11 was similar to that of patients with glioblastoma.

CONCLUSIONS

The results of the current study show that histopathologic grading can predict the outcome for patients with astrocytomas and glioblastomas, whereas MIB-1 LI can separate better and worse prognostic groups in patients with anaplastic astrocytoma.

Condensing osteitis of the clavicle: case report and review of the literature

Osteitis condensans of the clavicle is a rare condition characterized by pain in the shoulder and often limitation of motion of the shoulder. The medical history and results of the physical examination, laboratory data, and radiographic studies (including computed tomography and magnetic resonance imaging), often establish the diagnosis. Patients who have slight or no pain usually require no treatment. Varying results have been reported for many different methods of treatment, including surgical excision, chemotherapy, antibiotics, nonsteroidal anti-inflammatory medications, radiation, local corticosteroid injection, and physical therapy. A typical case report and the differential diagnosis for condensing osteitis of the clavicle are presented.

Effects of Chinese herbal prescriptions on copulatory activity in aged male rats: a preliminary study

Four herbal prescription medicines, Chi-Pao-Mei-Jan-Tan, Gui-Fu-Ba-Wei-Wan, Huan-Shao-Tan; and San Tsai-Feng-Sui-Tan, were tested for their effects on sexual behavior in aged rats. Crude liquid extracts of these herbs were administered to the rats daily through oral tubing for 14 days. All four herbal prescriptions showed some effects in restoration of mount and intromission behaviors, but there was no effect on restoration of ejaculation in 26 month old rats that had exhibited no copulatory activity (no mount, intromission and ejaculation) previously. The effects of Chi-Pao-Mei-Jan-Tan were further tested in 26 month old rats with low mount and intromission activities but without ejaculation behavior, and in 15 month old rats (middle-age group) that showed normal mount and intromission behavior but no ejaculation activity. Chi-Pao-Mei-Jan-Tan was effective in improving the frequency of both mount and intromission, but failed to restore the ejaculation activity of the old rats with low mount and intromission behaviors. It was, however, very effective in restoration of ejaculation activity in middle-aged rats that exhibited normal mount and intromission behaviors. Serum testosterone (T) levels of Chi-Pao-Mei-Jan-Tan in tested old and middle-aged rats were determined by radioimmunoassay, and showed no difference before and after treatment. Our findings demonstrated that the four herbal prescriptions had some effects in restoration of mount and intromission behaviors, but not ejaculation activity in old rats, and that Chi-Pao-Mei-Jan-Tan was very effective in restoration of ejaculation activity in middle-aged rats. The promotional effect of Chi-Pao-Mei-Jan-Tan on copulatory behavior was not correlated with serum T levels.

The diazoxide derivative IDRA 21 enhances ischemic hippocampal neuron injury

The diazoxide derivative IDRA 21 and other positive modulators of (AMPA)-type glutamate receptors are considered potential memory-enhancing agents. However, AMPA receptor activation contributes to CA1 hippocampal neuron damage from global ischemia in rodents, raising the possibility that 7-chloro-3-methyl-3-4-dihydro-2H-1,2,4 benzothiadiazine S,S-dioxide (IDRA 21) or drugs with similar actions may worsen ischemic neuronal injury. Here we demonstrate that glutamate plus IDRA 21 kills cultured rat hippocampal neurons by AMPA receptor activation, and, in vivo, 12 and 24 mg/kg of IDRA 21 given orally increases CA1 neuron loss produced by 10 minutes of global ischemia. Treating patients with drugs that potentiate AMPA receptor activation will have to consider these potential effects, particularly when coexistent with conditions in which excessive activation of AMPA receptors may occur (eg, stroke, seizures).

Primary ethmoid sinus craniopharyngioma: a case report

A seven-year-old boy complained of intermittent epistaxis for several months. Computerized tomography (CT) scans showed increased soft tissue density over the left ethmoid sinus. Endoscopic sinus surgery was used to remove the mass completely. The pathological report was craniopharyngioma. No other focus of lesion was found, and he continues to do well.

Inactivation of protein kinase C in rat liver during late hypoglycemic phase of sepsis

Changes in protein kinase C (PKC) (calcium- and phospholipid-dependent protein kinase) activity in rat liver during different metabolic phases of sepsis were studied. Sepsis was induced by cecal ligation and puncture (CLP). Experiments were divided into three groups: control, early sepsis, and late sepsis. Early and late sepsis refers to those animals sacrificed at 9 and 18 h, respectively, after CLP. Hepatic PKC was extracted and partially purified by ammonium sulfate fractionation and DEAE-cellulose chromatography. PKC activity was assayed based on the rate of incorporation of 32p from [gamma-32P]ATP into histone. The results show that during early sepsis, both membrane-associated and cytosolic PKC activities remained relatively unaltered. During late sepsis, membrane-associated PKC was unaffected while cytosolic PKC activity was decreased by 19.5-34.4%. Kinetic analysis of the data on cytosolic PKC during late phase of sepsis reveals that the Vmax values for ATP, histone, Ca2+, phosphatidylserine, and diacylglycerol were decreased by 23.4, 22.1, 19.5, 25, and 34.4%, respectively, with no changes in their Km values. These data indicate that cytosolic PKC activity was inactivated in rat liver during late hypoglycemic phase of sepsis. Since PKC-mediated phosphorylation plays an important role in regulating hepatic glucose metabolism, an inactivation of cytosolic PKC may contribute to the development of hypoglycemia during late phase of sepsis.

Protein kinase C activity is increased in rat heart during the early hyperdynamic phase of sepsis

Changes in protein kinase C (PKC) (calcium- and phospholipid-dependent protein kinase) activity in rat heart during different cardiodynamic phases of sepsis were studied in an attempt to understand the pathophysiology of altered myocardial function during sepsis. Sepsis was induced by cecal ligation and puncture. Experiments were divided into three groups: control, early sepsis, and late sepsis. Early and late sepsis refers to those animals sacrificed at 9 and 18 h, respectively, after cecal ligation and puncture. Cardiac PKC was extracted and partially purified by ammonium sulfate fractionation and diethylaminoethyl-cellulose chromatography. PKC activity was assayed on the basis of the rate of incorporation of 32P from [gamma-32P]adenosine triphosphate into histone. The results show that during early sepsis, cytosolic PKC activity was increased by 42-73%, whereas membrane associated PKC activity was unchanged. During late sepsis, both cytosolic and membrane associated PKC activities remained unchanged. Kinetic analysis of the data on cytosolic PKC during the early phase of sepsis reveals that the Vmax (maximal velocity) values for Ca2+, phosphatidylserine, and diacylglycerol were increased by 58, 42, and 50%, respectively, with no changes in their Km (substrate concentration required for half-maximal enzyme activity) values. These data indicate that cytosolic PKC activity was activated in rat heart during the early hyperdynamic phase of sepsis. Because PKC mediated phosphorylation plays an important role in regulating myocardial contractility, an activation in cytosolic PKC may contribute to the development of a hypercardiodynamic state during the early phase of sepsis.

Experimental hypoxemic hypoxia: changes in R2* of brain parenchyma accurately reflect the combined effects of changes in arterial and cerebral venous oxygen saturation

A two-dimensional T2*-weighted gradient-echo sequence was used to image the rat brain before and during graded hypoxemia. Changes in R2* (deltaR2*) with respect to the control state were calculated for brain parenchyma and were compared with changes in hemoglobin saturation measured from both arterial and jugular venous blood samples. DeltaR2* was first correlated with the changes in arterial (deltaYa) and venous (deltaYv) hemoglobin saturations individually. Although a general trend toward a linear relationship with deltaR2* was observed for both deltaYa and deltaYv, neither alone was strong (correlation coefficients r=0.71 and 0.75 for deltaYa and deltaYv, respectively, and standard errors of the regression (SER)=0.52 and 0.48 for deltaYa and deltaYv, respectively). However, when an "effective" cerebral blood hemoglobin saturation change (deltaYb) was constructed that takes into account the approximate weighting of the contributions from the arterial and venous phases of the circulation (deltaYb = 0.75 x deltaYv + 0.25 x deltaYa), a stronger correlation with deltaR2* was obtained and there was less variance (r=0.87 and SER=0.35). It is concluded that an appropriate weighting of the contributions of arterial and venous phases of the circulation must be taken into account in modeling the volume susceptibility effects of deoxyhemoglobin on R2* of brain parenchyma. In this way, a more accurate relationship between deltaR2* and deltaYb can be obtained.

Cisplatin, etoposide, and weekly high-dose 5-fluorouracil and leucovorin infusion (PE-HDFL)--a very effective regimen with good patients' compliance for advanced gastric cancer

We have previously shown that weekly 24-hour infusion of high-dose 5-fluorouracil and leucovorin (HDFL), a regimen initially designed for the treatment of advanced colorectal cancer, is also effective in the treatment of gastric cancer. This HDFL regimen is unique in that it is virtually non-myelosuppressive, and thus provides a comerstone on which ideal protocols may be developed. In this prospective phase II study, we examined the efficacy and toxicity of PE (cisplatin, etoposide)-HDFL, a HDFL-based combination chemotherapy, in the treatment of advanced-gastric cancer. This regimen consisted of cisplatin 60 mg/m2, i.v., D1; etoposide 65 mg/m2, i.v., D1-3; and 5-fluorouracil 2600 mg/m2 plus leucovorin 300 mg/m2, 24-hour i.v. infusion by an ambulatory infusion pump, D2,9,16; repeated every 4 weeks. The major eligibility criteria of the patients included: a) a histologically confirmed, objectively measurable, recurrent or primary inoperable gastric adenocarcinoma; b) age > or = 75 years; c) a Karnofsky performance status > or = 50%; d) an absolute granulocyte count (AGC) > or = 2000/mm3, and a platelet count > or = 100,000/mm3; e) a serum bilirubin concentration < or = 2.0 mg/dl; f) a serum creatinine concentration < or = 1.5 mg/dl; and g) a signed informed consent. Between March 1992 and June 1996, a total of 42 patients were enrolled onto the study. There were 31 men and 11 women with a median age of 54 (24-75) years; these included 16 primary metastatic, 3 locally advanced and inoperable, and 23 postgastrectomy recurrent gastric cancer patients. ECOG (Eastern Cooperative Oncology Group) grade III/IV leukopenia and thrombocytopenia developed in 34.0% and 11.0% of a total of 229 courses given, respectively. There was no treatment-related death. Four patients developed a reversible neurotoxicity; and two of them refused further chemotherapy. Among the 40 patients evaluable for responses, 9 [22.5%; 12-38%, 95% confidence interval (C.I.)] patients achieved complete remission, and 20 [50.0%; 33-67%, 95% C.I.] patients achieved partial remission. The overall response rate was 72.5% [56-86%, 95% C.I.]. The overall median survival and median time to progression of the responders were 10 and 7 months, respectively. The overall median survival of the whole group was 9 months. We concluded that PE-HDFL is a highly effective treatment for advanced gastric cancer. The treatment-related toxicity was mild and the patients' compliance was satisfactory.

Down-regulation of nucleophosmin/B23 during retinoic acid-induced differentiation of human promyelocytic leukemia HL-60 cells

Human promyelocytic leukemia HL-60 cells were induced to undergo granulocytic differentiation by treatment with retinoic acid (RA, 10 microM, 1-5 days). The steady-state level of nucleophosmin/B23 mRNA decreased during the RA-induced differentiation. There was also decrease in the level of total cellular nucleophosmin/B23 protein during the RA-induced differentiation. Stabilization and nuclear run-on assays indicate that the decrease in nucleophosmin/B23 mRNA in RA-treated HL-60 cells was transcriptionally regulated. Unlike c-myc mRNA, there was virtually no decline of nucleophosmin/B23 mRNA during the growth arrest by serum-starvation. The decrease in nucleophosmin/B23 mRNA expression in HL-60 cells subsequent to retinoic acid treatment can thus be attributed to cellular differentiation rather than the growth arrest induced by RA. Nucleophosmin/B23 antisense oligomer treatment significantly potentiated RA-induced cellular differentiation. Results of this study suggest that nucleophosmin/B23 is one of the key elements in the down-regulation of nucleolar function for cellular differentiation.

Periurethral fat injection in the treatment of recurrent genuine stress incontinence

PURPOSE

We evaluated the efficacy, safety and mechanism of periurethral fat injection in the treatment of recurrent genuine stress incontinence.

MATERIALS AND METHODS

Periurethral fat injections were performed in 26 patients for the treatment of recurrent genuine stress incontinence. A complete urogynecological study, including a 1-hour pad test, urodynamic studies and chain urethrocystography were done in each case and were repeated at least 3 months after operation. Each patient was followed for at least 12 months.

RESULTS

Of 26 patients 13 (50%) were dry after operation and 4 (15.4%) showed improvement and were satisfied with the results of the operation, giving a total success rate of 65.4%. There were 6 cases of immediate postoperative minor complications (23%). Average volume of injected fat was 14.8 +/- 4.8 cc, which did not affect the success rate. Preoperative and postoperative chain urethrocystographic values for bladder neck descent in reference to the pubosacral tip line showed no statistical difference between successfully and unsuccessfully treated groups. Urodynamic studies in all cases showed no differences relating to operation. However, minimal urethral resistance increased from 0.122 +/- 0.061 to 0.205 +/- 0.134 (p = 0.023) in the treatment success group. This change was not demonstrated in the treatment failure group.

CONCLUSIONS

Periurethral fat injection for the treatment of recurrent genuine stress incontinence is a simple technique that works by the increment of urethral resistance. It has an acceptable success rate without financial outlay for the injected material.

Effects of aged fluoride-containing restorative materials on recurrent root caries

Accumulated evidence has illustrated that secondary caries is the major reason for the failure of amalgam and resin composite restorations. The purpose of this study was to assess the cariostatic effects of aged fluoride-containing restorative materials on the formation of secondary root caries. Fifty sound human molars were selected and randomly assigned to five material groups: non-fluoride-containing amalgam (NA), fluoride-containing amalgam (FA), non-fluoride-containing composite (NC), fluoride-containing composite (FC), and glass-ionomer cement (GIC). After standardized class V cavity preparations and placement of restorations, teeth within each group were randomly divided into two subgroups, "non-aged" and "aged". The aged subgroup was immersed in an inorganic buffer solution for 2 wks before being thermocycled. After being thermocycled and subjected to four cycles of caries formation in a bacterial model system, the teeth were sectioned. Depths of outer lesions and areas of lesions on the cavity walls were measured by polarized light microscopy. The results showed that the FA and GIC groups, whether aged or not, had significantly smaller outer lesion depth than the non-fluoride-containing NA and NC groups. After aging, the FA group demonstrated significantly greater lesion depth (p = 0.0002), while the GIC group exhibited no significant changes in lesion depths. The NA group had a greater wall lesion area than the NC group, while both demonstrated no significant changes following 2 weeks of aging. The FA and GIC groups had similar inhibition areas along the cavity walls, whereas both inhibition areas increased significantly after the aging process. It is concluded that the fluoride-containing amalgam and the glass-ionomer cement, even after a two-week aging process, can still elicit a significant preventive effect on recurrent root caries in an in vitro bacterial model system.