Absolute measurements of water content using magnetic resonance imaging: preliminary findings in an in vivo focal ischemic rat model

Using a magnetic resonance (MR) imaging method, absolute measurements of in vivo brain water content were obtained in 15 male Long Evans rats that underwent a 90-min focal cerebral ischemia. A strong linear relationship (r = 0.80) with a slope of 1 was observed when correlating MR-measured water content to that obtained with the ex vivo wet/dry measurements. This effective spin-density-based method is the first-reported in vivo absolute quantification of brain tissue water content associated with a pathophysiological state and preliminary findings suggest that a noninvasive measurement of brain water content can be obtained with MRI.

MIB-1 labeling index as a prognostic indicator for survival in patients with FIGO stage IB squamous cell carcinoma of the cervix

OBJECTIVE

The goal of this study was to assess whether the MIB-1 labeling index (LI) and conventional parameters could distinguish between a good and a poor prognosis in patients with squamous cell cervical carcinoma of the same FIGO stage.

METHODS

The study included 97 cases of stage IB squamous cell cervical carcinoma which were treated with radical hysterectomy between 1989 and 1991. The relation of the MIB-1 LI, conventional clinicopathologic parameters, and survival was evaluated.

RESULTS

The MIB-1 LI of the entire group of tumors was 57.1 +/- 15.9 (mean +/- SD). The MIB-1 LI was significantly different only in living and dead patients, while it was not related to conventional clinicopathologic prognostic parameters. The 5- and 10-year survival rates of patients with an MIB-1 LI </=55 were 90.0 and 88.6%, respectively, which were significantly better than the survival rates of patients with LI >55, which were 73.1 and 66%, respectively. Multivariate analyses showed that MIB-1 LI >55, lymph node metastasis, and tumor size >/=40 mm were powerful predictors of shorter survival.

CONCLUSIONS

Lymph node metastasis, tumor size, and MIB-1 LI were significant prognostic markers in patients with stage IB squamous cell cervical carcinoma.

Nucleophosmin/B23 regulates the susceptibility of human leukemia HL-60 cells to sodium butyrate-induced apoptosis and inhibition of telomerase activity

Stable clones of HL-60 cells in which nucleophosmin/B23 was over-expressed or down-regulated were established. The nucleophosmin/B23 protein levels in nucleophosmin/B23 over-expressed (pCR3-B23) or down-regulated (pCR3-32B) cells during BuONa/vanadate-induced apoptosis were characterized as compared with control vector-transfected (pCR3) cells. Over-expression of nucleophosmin/B23 resulted in decreased susceptibility of the cells to BuONa/vanadate-induced apoptosis. The response to inhibition of telomerase activity under BuONa/vanadate treatment also decreased in nucleophosmin/B23 over-expressed (pCR3-B23) cells. On the other hand, down-regulation of nucleophosmin/B23 made the cells more susceptible to BuONa-induced apoptosis or inhibition of telomerase activity. More precisely, by serial dilutions of each extract, the telomerase activity of the cells without drug treatment was determined and was found to be higher in nucleophosmin/B23 over-expressed (pCR3-B23) cells and lower in nucleophosmin/B23 down-regulated (pCR3-32B) cells as compared with the control vector-transfected (pCR3) cells. Our results indicate that nucleophosmin/B23 plays a functional role in the control of cellular apoptosis and immortalization.

Glucocorticoid receptor expression in the spinal cord after traumatic injury in adult rats

Methylprednisolone (MP), a glucocorticoid, is the only effective therapeutic agent used in the clinical treatment of acute spinal cord injury (SCI). MP given within 8 hr after SCI significantly improves neurological function. Although the glucocorticoid receptor (GR) is suggested to mediate MP actions, limited knowledge is available on its expression and possible function after SCI. Presently, the expression of GR was studied in a weight-drop SCI model in adult rats. Immunohistochemistry and Western blot analysis revealed an increase in GR protein expression as early as 15 min after injury. GR expression sharply increased at 4 hr (22-fold), peaked at 8 hr (56-fold), rapidly declined at 1 d, and returned to the baseline level at and after 3 d. During its peak expression, GR was localized in neural somata and dendrites but not in axons and their terminals. GR immunoreactivity was also found in oligodendrocytes and astrocytes. Interestingly, other cell types, such as endothelial cells, were GR-negative. An increase in the binding activity of nuclear proteins to the glucocorticoid responsive element was also observed after SCI, demonstrating a functional element of GR activation. Finally, colocalization of GR and tumor necrosis factor alpha (TNF-alpha), an inflammatory cytokine, was observed in neurons and glial cells, consistent with MP regulation of TNF-alpha in this model. Thus, the transient expression of high levels of GR after SCI may provide new insights into the anti-inflammatory action of MP.

Tuberculous meningitis in a Filipino maid

Tuberculous meningitis, while not uncommon in Taiwan, has not been reported among foreign workers. We report the first case of tuberculous meningitis in a 37-year-old Filipino maid in Taiwan, who presented with headache, fever and vomiting. She had been well before this episode and the small screening films of the chest radiograph obtained on her arrival in Taiwan 15 months previously, and every 6 months thereafter showed no evidence of tuberculosis. The suspicion of tuberculous meningitis was delayed until disturbance of consciousness manifested and a standard chest radiograph showed a diffuse miliary pattern in both lung fields. A cerebrospinal fluid sample that was sent for a polymerase chain reaction-based assay specific for Mycobacterium tuberculosis showed a positive result. The patient recovered with sequelae of mildly incoherent speech and urinary incontinence after antituberculous medication and short-course steroid treatment. Clinicians should be aware of the possibility of tuberculous meningitis in foreign workers with complaints of fever and headache. Because high-quality chest radiographs are a prerequisite for early detection of pulmonary tuberculosis, we recommended that standard posterior-anterior chest radiographs should be obtained as part of the routine health examination for foreign workers.

Internal impingement of the shoulder: a clinical and arthroscopic analysis

Internal impingement was first described by Walch in 1992 and defined as contact between the supraspinatus tendon and posterior-superior glenoid rim with the shoulder in the cocked, throwing position of 90 degrees of abduction and maximum external rotation. The hypothesis of the study was that this contact may be seen in patients who are not throwing athletes nor in those who have instability. One hundred five consecutive patients who underwent shoulder arthroscopy were prospectively studied with preoperative history and physical examination. All patients underwent general anesthesia and arthroscopy with a standard posterior portal. With the patient under arthroscopy the arm was placed in abduction and external rotation until contact was made or until full elevation was reached. Eighty-five percent (N = 90) of the patients made contact between the rotator cuff and glenoid rim at an average of 95 degrees of abduction and 74 degrees of external rotation. No statistically significant relationship was seen (P > .05) between the position of contact at internal impingement and mechanism of injury, throwing versus nonthrowing, instability, rotator cuff tear, preoperative external rotation, or preoperative impingement signs. The intraoperative finding of contact of the rotator cuff to the posterosuperior glenoid with the arm in abduction and external rotation can occur in a wide spectrum of shoulder disease and is not limited to the throwing athlete. Not all patients with increased laxity and instability demonstrate this contact, suggesting that these factors may not be essential for internal impingement.

Bacteriology of endoscopically normal maxillary sinuses

The bacteriology of maxillary sinuses with normal endoscopic findings is reported in this study. When transantral sinoscopy was used to examine the maxillary sinuses, the whole maxillary sinus was inspected with different-angle endoscopes. If no lesion was seen over the whole maxillary sinus mucosa, no secretion existed in the maxillary sinus cavity, and the maxillary sinus ostium was wide open, the maxillary sinus was considered endoscopically normal. The bacteriology of these endoscopically normal maxillary sinuses was studied by passing cotton-tipped sticks through the cannula to collect swab specimens. In some cases, a biopsy forceps was also passed to obtain mucosal specimens. The specimens were sent to the laboratory for aerobic and anaerobic cultures. Between July 1990 and May 1998, 83 swab and 31 mucosal specimens were collected from 69 patients who had not taken any antibiotic within 10 days before endoscopy. The culture rates were 62.3 per cent (35/53) from swab specimens and 57.1 per cent (eight out of 14) from mucosal specimens in patients with the diagnosis of chronic paranasal sinusitis, and were 46.7 per cent (14/30) from swab specimens and 41.2 per cent (seven out of 17) from mucosal specimens in patients without this diagnosis. This study shows that endoscopically normal maxillary sinuses are not sterile.

Injection therapy for stress incontinence in women

Periurethral bulking agents have been used to treat intrinsic sphincter deficiency for decades. Currently available agents include polytetrafluoroethylene, glutaraldehyde cross-linked collagen, autologous fat and silicone microimplants. Polytetrafluoroethylene has never been approved by the United States Food and Drug Administration for periurethral injection because of the risk of particle migration. Early results have reported subjective cure rates of up to 95% with collagen injections. However, collagen may cause allergic reactions and long-term results are still awaited. Periurethral fat injection has a reported success rate ranging from 23% to 65%. It is simple and avoids the use of foreign materials, but the main disadvantage relates to the variability of resorption and connective tissue replacement. Silicone microimplants need further study to evaluate their efficacy and safety. The best material has not yet been defined. Long-term studies are still necessary to define the optimal injectable agent.

Quantitative magnetic resonance imaging in experimental hypercapnia: improvement in the relation between changes in brain R2 and the oxygen saturation of venous blood after correction for changes in cerebral blood volume

Acute hypercapnia simultaneously induces increases in regional cerebral blood volume (rCBV) and the oxygen saturation of cerebral venous blood (Yv). Changes in both physiologic parameters may influence the changes in R2 (deltaR2) that can be measured in the brain with gradient echo magnetic resonance imaging. The authors examined the effect of incorporating independent measurements of the change in rCBV (deltarCBV) on the fidelity of the relation between deltaR2 and deltaYv in the setting of experimental hypercapnia. A two-dimensional T2-weighted gradient echo sequence was used to measure deltaR2 in the brain parenchyma of anesthetized rats in response to hypercapnia with respect to the control state. In parallel, estimates of rCBV were obtained using a three-dimensional steady-state approach in conjunction with a paramagnetic contrast agent during both control and hypercapnic states so that a deltarCBV could be calculated. Regional CBV values of 2.96 +/- 0.82% and 5.74 +/- 1.21% were obtained during the control and hypercapnic states, respectively, and linear relations between rCBV and CO2 tension in both arterial (r = 0.80) and jugular venous (r = 0.76) blood samples were obtained. When correlating deltaR2 directly with deltaYv, no clear relation was apparent, but a strong linear relation (r = 0.76) was observed when correction for deltarCBV was incorporated into the data analysis. These results are consistent with the current understanding of the mechanisms of blood oxygen level-dependent (BOLD) contrast and underscore the potential importance of taking into account deltarCBV when quantitative estimates of deltaYv from the "BOLD effect" are intended.

Post-functional endoscopic sinus surgery methicillin-resistant Staphylococcus aureus sinusitis

Methicillin-resistant Staphylococcus aureus (MRSA) is a highly virulent bacterium that is difficult to eradicate. It has become a common nosocomial pathogen, but it also causes sporadic infections in some outpatients. Among 358 chronic sinusitis patients who received functional endoscopic sinus surgery (FESS) for treatment between July 1995 and June 1997 in our department, 18 were infected postoperatively by MRSA by the end of August 1997. One patient was excluded because she received another nasal surgery, partial turbinectomy, and submucous resection of the nasal septum, after FESS. Most of 17 MRSA infected patients presented themselves with mucopurulent nasal discharge and/or nasal crust. The treatment was generally difficult because MRSAs were resistant to multiple antibiotics. When quinolone antibiotics were used to treat most patients, the improvement rate was 76.5%. We conclude that MRSA infections in post-FESS patients might affect the outcome of FESS.

Pyrithione, a zinc ionophore, inhibits NF-kappaB activation

Pyrrolidine dithiocarbamate (PDTC) suppresses NF-kappaB activity and exhibits cytotoxic effects in bovine cerebral endothelial cells (BCECs), and we have previously reported that these PDTC effects were accompanied by an increase in intracellular zinc levels. To further explore the role of zinc in the modulation of NF-kappaB activation, we studied the effect of pyrithione, a zinc ionophore, on NF-kappaB activation in BCECs. Pyrithione inhibited NF-kappaB activity in a time- and dose-dependent manner. Ca-EDTA, but not Zn-EDTA, prevented pyrithione inhibition of NF-kappaB activity. Pyrithione increased the intracellular zinc level within 15 min. This effect was also abolished by Ca-EDTA, but not by Zn-EDTA. The potency of pyrithione on NF-kappaB inhibition and zinc influx was approximately one order of magnitude more potent than PDTC. These findings establish the regulatory role of intracellular zinc levels on NF-kappaB activity in BCECs.

Berberine-induced apoptosis of human leukemia HL-60 cells is associated with down-regulation of nucleophosmin/B23 and telomerase activity

The steady-state level of nucleophosmin/B23 mRNA decreased during berberine-induced (25 microg/ml, 24 to 96 hr) apoptosis of human leukemia HL-60 cells. A decline in telomerase activity was also observed in HL-60 cells treated with berberine. A stable clone of nucleophosmin/B23 overexpressed in HL-60 cells was selected and found to be less responsive to berberine-induced apoptosis. About 35% to 63% of control vector-transfected cells (pCR3) exhibited morphological characteristics of apoptosis, while about 8% to 45% of nucleophosmin/B23-over-expressed cells (pCR3-B23) became apoptotic after incubation with 15 microg/ml berberine for 48 to 96 hr. DNA extracted from pCR3 cells contained more fragmented DNA than pCR3-B23 cells during treatment with 15 microg/ml berberine for 24 to 48 hr. Our results indicate that berberine-induced apoptosis is associated with down-regulation of nucleophosmin/B23 and telomerase activity. We also suggest that nucleophosmin/B23 may play an important role in the control of the cellular response to apoptosis induction.

Zinc is required in pyrrolidine dithiocarbamate inhibition of NF-kappaB activation

Pyrrolidine dithiocarbamate (PDTC) is a potent inhibitor of nuclear factor kappa B (NF-kappaB) activation. PDTC inhibited basal NF-kappaB activity of endothelial cells. PDTC, however, failed to inhibit basal NF-kappaB activity after withdrawal of serum in the media, and the inhibitory effect of PDTC could be restored by addition of zinc. When various preparations of metal ion-EDTA were tested with PDTC in serum-containing media, only Zn-EDTA failed to block the inhibitory effect of PDTC. The dependence on zinc was also noted in PDTC inhibition of NF-kappaB stimulated by TNF alpha. These facts suggest that zinc is required for PDTC inhibition of NF-kappaB activation.

Predictors of acute hospital costs for treatment of ischemic stroke in an academic center

BACKGROUND AND PURPOSE

We sought to determine predictors of acute hospital costs in patients presenting with acute ischemic stroke to an academic center using a stroke management team to coordinate care.

METHODS

Demographic and clinical data were prospectively collected on 191 patients consecutively admitted with acute ischemic stroke. Patients were classified by insurance status, premorbid modified Rankin scale, stroke location, stroke severity (National Institutes of Health Stroke Scale score), and presence of comorbidities. Detailed hospital charge data were converted to cost by application of department-specific cost-to-charge ratios. Physician's fees were not included. A stepwise multiple regression analysis was computed to determine the predictors of total hospital cost.

RESULTS

Median length of stay was 6 days (range, 1 to 63 days), and mortality was 3%. Median hospital cost per discharge was $4408 (range, $1199 to $59 799). Fifty percent of costs were for room charges, 19% for stroke evaluation, 21% for medical management, and 7% for acute rehabilitation therapies. Sixteen percent were admitted to an intensive care unit. Length of stay accounted for 43% of the variance in total cost. Other independent predictors of cost included stroke severity, heparin treatment, atrial fibrillation, male sex, ischemic cardiac disease, and premorbid functional status.

CONCLUSIONS

We conclude that the major predictors of acute hospital costs of stroke in this environment are length of stay, stroke severity, cardiac disease, male sex, and use of heparin. Room charges accounted for the majority of costs, and attempts to reduce the cost of stroke evaluation would be of marginal value. Efforts to reduce acute costs should be monitored for potential cost shifting or a negative impact on quality of care.

High rate of clinical complete response to weekly outpatient neoadjuvant chemotherapy in oral carcinoma patients using a new regimen of cisplatin, 5-fluorouracil, and bleomycin alternating with methotrexate and epirubicin

BACKGROUND

A Phase II trial was initiated to evaluate the response to and toxicity of a new regimen of weekly outpatient neoadjuvant chemotherapy in patients with oral carcinoma.

METHODS

Patients with previously untreated squamous cell carcinoma of the oral cavity were eligible for this trial. The neoadjuvant chemotherapy was comprised of cisplatin, 25 mg/m2, 5-fluorouracil, 1000 mg/m2, and bleomycin, 10 mg/m2, mixed in normal saline as a 24-hour intravenous (i.v.) infusion, alternating with methotrexate, 30 mg/m2, and epirubicin, 30 mg/m2, as an i.v. bolus (PFB/ME) on a weekly schedule for 8-12 weeks. In patients with American Joint Committee on Cancer Stage IV disease who completed neoadjuvant chemotherapy, surgery was preferred to radiotherapy, unless patients refused surgery.

RESULTS

A total of 40 patients (82.5% with Stage IV disease) with previously untreated oral carcinoma were enrolled. The median size of the primary tumor was 7 cm (range, 3-13 cm). Fifty percent of patients had tumor penetrating through the oral mucosa to the cheek skin and 62.5% had bony destruction. Detectable cervical lymph nodes were noted in 77.5% of patients. After neoadjuvant weekly chemotherapy, 22 patients (55%) showed complete response (CR) and 15 patients (37.5%) showed partial response, for an overall response rate of 92.5%. World Health Organization Grade 3/4 toxicity included mucositis (7.5%), leukopenia (25%), anemia (10%), and thrombocytopenia (2.5%). Eleven of 33 patients with Stage IV disease underwent surgery, and pathologic CR (2 patients) or microscopic residual tumor (4 patients) was noted (54.5%).

CONCLUSIONS

The results of the current study indicate that a weekly PFB/ME neoadjuvant chemotherapy regimen is highly effective for the treatment of patients with oral carcinoma. In addition, this regimen has low toxicity. The authors believe that implementation of this regimen into a multimodality therapy protocol deserves further study.

Pyrrolidine dithiocarbamate induces bovine cerebral endothelial cell death by increasing the intracellular zinc level

The antioxidant and metal-chelating effects of pyrrolidine dithiocarbamate (PDTC) have been extensively studied. PDTC prevents cell death induced by various insults. However, PDTC itself may cause cell death in selected experimental paradigms. PDTC induced bovine cerebral endothelial cell death. However, in serum-depleted medium, PDTC did not affect the cell viability, suggesting that certain factors in serum may mediate the cytotoxic effect of PDTC. The metal chelators bathocuproine disulfonic acid, o-phenanthroline, bathophenanthroline disulfonic acid, and N,N,N',N'-tetrakis(2-pyridyl-methyl)ethylenediamine (TPEN) prevented the cell death induced by PDTC. In a serum-deprived condition, addition of exogenous metals, copper or zinc, restored the cytotoxic effect of PDTC. These data indicate that metals such as copper or zinc in serum may mediate the cytotoxic effect of PDTC. The potency of zinc for PDTC-induced endothelial cell death was greater than that of copper. Zn-EDTA did not block PDTC-induced cell death, whereas Ca-EDTA and Cu-EDTA were able to prevent this PDTC effect. PDTC increased the intracellular fluorescence of the zinc probe dye N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide, which was quenched by TPEN or various EDTA preparations but not by Zn-EDTA. Results suggest that an increase in intracellular zinc concentration is required in PDTC-induced cerebral endothelial cell death.

Endoscopic sinus surgery for rhinocerebral mucormycosis

Rhinocerebral mucormycosis is a fulminant, often fatal, disease. Aggressive surgical debridement has been considered an important part of treatment. Traditionally, an external or transantral approach has been the classic method. Recently, endoscopic sinus surgery (ESS) has been tried on several occasions to reach the goal of radical resection. Since 1991, ESS has been used to treat 9 rhinocerebral mucormycosis patients in our department. Among them, ESS was the only surgical procedure in six patients. The other three patients were treated by ESS combined with a transantral procedure. As a result, eight patients (88.9%) have survived the disease. One patient died 5 days after ESS because of an internal carotid artery occlusion. We conclude that ESS can be used to treat rhinocerebral mucormycosis alone or in combination with the traditional surgical procedures. It has the advantage of less operative morbidity and greater operative accuracy.

Suppression of postischemic hippocampal nerve growth factor expression by a c-fos antisense oligodeoxynucleotide

We examined the uptake and distribution of an antisense phosphorothioated oligodeoxynucleotide (s-ODN) to c-fos, rncfosr115, infused into the left cerebral ventricle of male Long-Evans rats and the effect of this s-ODN on subsequent Fos, NGF, neurotrophin-3 (NT-3), and actin expression. To establish the uptake and turnover of s-ODN in the brain, we studied the copurification of the immunoreactivity of biotin with biotinylated s-ODN that was recovered from different regions of the brain. A time-dependent diffusion and the localization of s-ODN were further demonstrated by labeling the 3'-OH terminus of s-ODN in situ with digoxigenin-dUTP using terminal transferase and detection using anti-digoxigenin IgG-FITC. Cellular uptake of the s-ODN was evident in both the hippocampal and cortical regions, consistent with a gradient originating at the ventricular surface. Degradation of the s-ODN was observed beginning 48 hr after delivery. The effectiveness of c-fos antisense s-ODN was demonstrated by its suppression of postischemic Fos expression, which was accompanied by an inhibition of ischemia-induced NGF mRNA expression in the dentate gyrus. Infusion of saline, the sense s-ODN, or a mismatch antisense s-ODN did not suppress Fos expression. That this effect of c-fos antisense s-ODN was specific to NGF was demonstrated by its lack of effect on the postischemic expression of the NT-3 and beta-actin genes. Our results demonstrate that c-fos antisense s-ODN blocks selected downstream events and support the contention that postischemic Fos regulates the subsequent expression of the NGF gene and that Fos expression may have a functional component in neuroregeneration after focal cerebral ischemia-reperfusion.

Renal cell carcinoma: unusual pediatric renal tumors

Renal cell carcinoma (RCC), the most common renal tumor in adults, is rare in childhood, with an incidence much lower than that of Wilms' tumor. It is initially asymptomatic, but clinically overt symptoms such as an abdominal mass or hematuria may indicate late-stage disease and a poor prognosis. In this report, we describe the imaging features of pediatric RCC and emphasize the value of early diagnosis offered by ultrasonographic screening. From 1989 through 1997, we encountered five children (aged 7-15 yr) with RCC. Of these, two presented with symptoms, while the other three were asymptomatic and were identified in a large, school-based urologic ultrasonographic survey, in which more than 800,000 children were screened by our team. Reviewing the imaging features, we found that four tumors exhibited a heterogeneous nature. One patient had bilateral well-defined homogeneous tumors, which proved to be bilateral low-grade RCC. The three asymptomatic patients had smaller tumors than the other two patients. These three were treated with nephrectomy and were well after at least 15 months of follow-up. The two patients who presented with symptoms eventually died of tumor recurrence and pulmonary metastasis, respectively. The findings in these five cases of pediatric RCC add knowledge regarding the imaging features of this disease and highlight the value of ultrasonographic screening for early diagnosis.

Congenital choanal atresia: computed tomographic and clinical findings

Congenital choanal atresia is a rare developmental anomaly characterized by failure of communication of the posterior nasal cavity with the nasopharynx. It may present as a component of the CHARGE association (C, coloboma; H, heart disease; A, atresia choanae; R, retarded growth and development; G, genital hypoplasia; and E, ear anomalies and/or deafness). The purpose of this study is to evaluate the computed tomographic (CT) appearance of membranous or bony type congenital choanal atresia. Six patients (4 females, 2 males; age range, 1 day to 8 weeks; mean, 13.8 days) with choanal atresia were included in this study and evaluated by CT scan. The CT clearly delineated the full anatomic abnormalities of choanal atresia. Among the 6 patients, three (50%) had bilateral membranous atresia, two (33%) had bilateral bony atresia, and one (17%) had unilateral (left) membranous atresia. Additionally, two (33%) patients (1 bilateral membranous atresia, 1 bilateral bony atresia) fit at least four of the six criteria in the CHARGE association. The CT plays a significant role in the diagnostic and therapeutic approach to congenital choanal atresia and should be the examination method of choice to evaluate neonates with nasal obstruction.

Switching transient analysis of a metal/ferroelectric/semiconductor switch diode with high speed response to infrared light

A thin PbTiO(3)-n-p(+) silicon switch diode has been developed, in which the switching voltage (the turned-on voltage) changes in proportion to the infrared light power. The diode has a rapid response time of 0.65 mus compared with other conventional infrared sensors. It is attributed to the rapid switching device structure and the smaller pyroelectric layer thickness, 50 nm. In this paper, we have analyzed the rapid switching transient response by using heat conduction and switching theory successfully. The experimental results are in agreement with the theoretical analysis.

Sensitive determination of a new antiarrhythmic agent, trecetilide, in plasma by high-performance liquid chromatography with fluorescence detection

Two high-performance liquid chromatography (HPLC) methods were developed for the determination of trecetilide in plasma samples. Differing only in the addition of a derivatization step and different detection wavelengths, the two methods encompassed a wide concentration range. In both methods, plasma samples (0.1 ml) with added internal standard were applied to solid-phase extraction discs containing a non-polar/strong cation mixed-phase, washed and eluted with an acetone-acetonitrile triethylamine mixture. The eluate was evaporated to dryness, and either reconstituted and directly injected onto an HPLC column or first derivatized with 1-naphthyl isocyanate before HPLC analysis. In both methods, the separation was performed isocratically on a cyano analytical column utilizing a mobile phase composed of acetonitrile-pH 7.9 phosphate buffer (70:30, v/v). The column effluent was monitored by fluorescence detection at 290/345 nm (with derivatization) or 235/320 nm (without derivatization). The limits of detection and quantitation of the assay were 0.57 and 1.9 ng/ml, respectively, when derivatization was used, or 4.3 and 14 ng/ml, respectively, without derivatization.

Effects of acute normovolemic hemodilution on T2*-weighted images of rat brain

Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-2.2% to 33.4+/-2.1%) and moderate (Hct reduced from 44.6+/-2.7% to 26.2+/-1.7%). A two-dimensional gradient-echo sequence was used to monitor signal changes with high temporal resolution before, during, and after HD protocols. The time course of signal intensity change was closely related to that of changes in Hct. Corresponding changes in R2* (deltaR2*) with respect to the pre-HD state were calculated for the brain parenchyma. Average deltaR2* values of -0.24+/-0.06 s(-1) and -0.40+/-0.07 s(-1) were obtained for the mild and moderate HD groups, respectively, during the final 2 min of MR imaging (proximal to correlative measurements of Hct). MR measured deltaR2* values were in close agreement with the expected changes in R2* predicted from theory when the measured changes in Hct were used as independent variables. These data are in good agreement with the current understanding of the effects of changes in the intravascular concentration of deoxyhemoglobin on induced magnetic susceptibility and hold promise for quantitative measurement of brain oxygenation in vivo.

Amyloid beta-peptide possesses a transforming growth factor-beta activity

Amyloid beta-peptide (Abeta) of 39-42 amino acid residues is a major constituent of Alzheimer's disease neurite plaques. Abeta aggregates (fibrils) are believed to be responsible for neuronal damage and dysfunction, as well as microglia and astrocyte activation in disease lesions by multiple mechanisms. Since Abeta aggregates possess the multiple valencies of an FAED motif (20th to 23rd amino acid residues), which resembles the putative transforming growth factor-beta (TGF-beta) active site motif, we hypothesize that Abeta monomers and Abeta aggregates may function as TGF-beta antagonists and partial agonists, analogous to previously described monovalent and multivalent TGF-beta peptide antagonists and agonists (Huang, S. S., Liu, Q., Johnson, F. E., Konish, Y., and Huang, J. S. (1997) J. Biol. Chem. 272, 27155-27159). Here, we report that the Abeta monomer, Abeta-(1-40) and its fragment, containing the motif inhibit radiolabeled TGF-beta binding to cell-surface TGF-beta receptors in mink lung epithelial cells (Mv1Lu cells). Abeta-(1-40)-bovine serum albumin conjugate (Abeta-(1-40)-BSA), a multivalent synthetic analogue of Abeta aggregates, exhibited cytotoxicity toward bovine cerebral endothelial cells and rat post-mitotic differentiated hippocampal neuronal cells (H19-7 cells) and inhibitory activities of radiolabeled TGF-beta binding to TGF-beta receptors and TGF-beta-induced plasminogen activator inhibitor-1 expression, that were approximately 100-670 times more potent than those of Abeta-(1-40) monomers. At less than micromolar concentrations, Abeta-(1-40)-BSA but not Abeta-(1-40) monomers inhibited proliferation of Mv1Lu cells. Since TGF-beta is an organizer of responses to neurodegeneration and is also found in neurite plaques, the TGF-beta antagonist and partial agonist activities of Abeta monomers and aggregates may play an important role in the pathogenesis of the disease.

Effect of acetic acid on telomerase activity in cervical intraepithelial neoplasia

OBJECTIVE

To evaluate whether the telomerase activity in CIN lesions can be affected by a chemical solution of acetic acid, which is required to apply to the cervix prior to colposcopy-directed biopsy.

MATERIALS AND METHODS

Thirty-five patients with histologically confirmed high-grade squamous intraepithelial lesions of the cervix entered the study. Two specimens were collected from each patient, one before and one after the cervix was swabbed with 5% acetic acid. The standard telomeric repeat assay protocol (TRAP) was used to examine telomerase activity in these fresh frozen tissue samples. Normal cervical tissues from 10 control individuals were also examined for the presence of telomerase activity. A total of 80 specimens was analyzed.

RESULTS

Telomerase activity was detectable in 27 of 35 (77.1%) fresh tissue samples, 15 of 35 (42.9%) tissue samples swabbed with 5% acetic acid, and 0 of 10 (0%) normal cervical tissue samples, respectively. Twelve samples became telomerase negative after 5% acetic acid applied. Among the 15 telomerase-positive tissue samples swabbed with 5% acetic acid, 12 had relative weak telomerase activity compared to corresponding fresh tissue samples, the other 3 remained the same. Therefore, it is concluded that telomerase activity was affected by 5% acetic acid in 24 of 27 (88.9%) samples. Telomerase activity in HeLa cell line was also inhibited by 5% acetic acid.

CONCLUSION

We reported a relative high percentage of telomerase expression in high-grade CIN lesions when compared with previous reports. If detection of telomerase activity is to become a tool for diagnosis and prognosis of cervical neoplasias, applying acetic acid prior to colposcopy-directed biopsy that is submitted for telomerase assay should be avoided in order to increase the detection rate.

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.

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.

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.

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.

Surgical treatment for pilon fracture of the ankle-open reduction and internal fixation

From 1991 to 1994, 39 ankles of 38 patients underwent surgical open reduction and internal fixation for pilon fractures. These patients included 29 males and 9 females with an average age of 38.6 y/o (range 28 y/o-58 y/o). The follow up and evaluation period averaged 31.7 months (range 22Ms-44Ms), during which time a standing x-ray for arthrosis grading and functional scale was used for clinical evaluation. Complications included 1 case of infection, 1 case of loss reduction, 2 cases of partial skin necrosis and 2 cases of delayed union. Post-traumatic arthritis occurred in 23 ankles (59%) but only 4 ankles of grade 4 arthrosis resulted in poor functional scale and the overall satisfactory rate was 82%. It was found that anatomic reduction, rigid fixation and early motion exercise are important to successful treatment of ankle fractures. Regarding pilon fracture, specifically the severity of fracture pattern and delay of reduction are important problems to overcome to ensure successful results. Therefore, adequate surgical approach for entire view of ankle joint, reduction and fixation of fibula, sufficient bone graft for articular support, intraoperative x-ray check and postoperative immobilization are essential for the achievement of better clinical results.

Endogenous repair after spinal cord contusion injuries in the rat

Contusion injuries of the rat thoracic spinal cord were made using a standardized device developed for the Multicenter Animal Spinal Cord Injury Study (MASCIS). Lesions of different severity were studied for signs of endogenous repair at times up to 6 weeks following injury. Contusion injuries produced a typical picture of secondary damage resulting in the destruction of the cord center and the chronic sparing of a peripheral rim of fibers which varied in amount depending upon the injury magnitude. It was noted that the cavities often developed a dense cellular matrix that became partially filled with nerve fibers and associated Schwann cells. The amount of fiber and Schwann cell ingrowth was inversely related to the severity of injury and amount of peripheral fiber sparing. The source of the ingrowing fibers was not determined, but many of them clearly originated in the dorsal roots. In addition to signs of regeneration, we noted evidence for the proliferation of cells located in the ependymal zone surrounding the central canal at early times following contusion injuries. These cells may contribute to the development of cellular trabeculae that provide a scaffolding within the lesion cavity that provides the substrates for cellular infiltration and regeneration of axons. Together, these observations suggest that the endogenous reparative response to spinal contusion injury is substantial. Understanding the regulation and restrictions on the repair processes might lead to better ways in which to encourage spontaneous recovery after CNS injury.

Neuronal apoptosis and necrosis following spinal cord ischemia in the rat

We examined the characteristics of neuronal death induced by ischemia in the spinal cord. Spinal cord ischemia was induced in Long-Evans rats by occlusion of the descending aorta with a 2F Fogarty catheter for 20 min (model 1) or more limited aortic occlusion (15 min) coupled with blood volume reduction (model 2); rats were sacrificed 6 h-7 days later. The animals developed variable paraparesis in model 1 and reliable paraplegia in model 2. The extent of histopathological spinal cord damage, being maximal in the lumbar cord, correlated well with the severity of paraparesis. Two distinct types of spinal cord neuronal death were observed, consistent with necrosis and apoptosis. Neuronal necrosis was seen in gray matter laminae 3-7, characterized by the rapid (6 h) onset of eosinophilia on hematoxylin/eosin-stained sections, and gradual (1-7 days) development of eosinophilic ghosting. Although TUNEL positivity was present, disintegration of membranes and cytoplasmic organelles was seen under electron microscopy. Neuronal apoptosis was seen after 1-2 days in dorsal horn laminae 1-3, characterized by both TUNEL positivity and electron microscopic appearance of nuclear chromatin aggregation and the formation of apoptotic bodies. DNA extracted from the ischemic lumbar cord showed internucleosomal fragmentation (laddering) on gel electrophoresis. These data suggest that distinct spinal cord neuronal populations may undergo necrosis and apoptosis following transient ischemic insults.