Routine minimally invasive aortic valve procedures

BACKGROUND

Due to the lack of objective evidence supporting the advantages and early technical difficulties, minimally invasive aortic valve procedures were performed on a highly selective rather than routine basis.

METHODS

From September 1997 to February 1999, one surgeon routinely used upper or transverse minimally invasive sternotomy to perform 46 consecutive cases of aortic valve procedures (M), whereas two other surgeons performed 40 aortic valve procedures through a conventional sternotomy (C).

RESULTS

More time consuming and technically demanding surgeries were done in M. There was one death in each group. Aortic clamp time was longer in M (93+/-40 vs 59+/-24 min, P=0.001). There were no differences in operating time, pump time, intubation duration, bleeding and intensive care unit stay. The advantages of minimally invasive aortic valve operation included better postoperative ejection fraction (58+/-17 vs 51+/-10%, P=0.04), decreased pain score (3+/-2 vs 5+/-2, P=0.004), less transfusion (19 vs 55%, P=0.02), shorter duration of chest tube drainage, and cosmetically more acceptable surgical wound (6.8+/-2.2 vs 5.2+/-2.0, P=0.018). From our series, we could not find any negative effects of minimal access surgery.

CONCLUSIONS

Our study demonstrated that aortic valve surgeries could be performed routinely by the minimally invasive approach with a high degree of effectiveness and safety.

Reconstruction of the Achilles tendon and overlying soft tissue using antero-lateral thigh free flap

Reconstruction of combined loss of the Achilles tendon and overlying soft tissue was performed using an antero-lateral thigh free flap in three patients. The cutaneous portion is used to cover the open wound, and a piece of fascia lata is utilised to replace the missing segment of the Achilles tendon. The skin defect ranged from 5 x 2.5 to 7 x 5 cm, and the tendon loss measured from 3.5 to 5.5 cm in length. All of the patients showed satisfactory functional results with a follow-up period from 3 to 9 months. The advantages of the procedure are that: it is a single-staged operation; it promotes rapid healing of the tendo Achilles since the tendon substitute is well vascularised; it is adaptable to a wide range of defect sizes and shapes; it can be performed in the supine position without the need for postural change; and it can restore good contour and causes minimal morbidity at the donor site.

SPACR in the interphotoreceptor matrix of the mouse retina: molecular, biochemical and immunohistochemical characterization

Mouse SPACR cDNA was cloned by screening a mouse retina cDNA library using a PCR probe derived from human SPACR cDNA. Mouse SPACR cDNA comprises 3675 bp containing an open reading frame coding for 742 amino acids. Multitissue Northern blot analysis and in situ hybridization studies indicate that SPACR expression is restricted to retinal photoreceptors. The SPACR core protein was identified with Western blotting following SDS-PAGE with a SPACR C-terminal peptide polyclonal antibody and a chondroitin-6-sulfate Deltadisaccharide monoclonal antibody. The 150 kD immunopositive band was isolated, digested with trypsin and the peptides analysed by MALDI mass spectroscopy. Peptide mass mapping confirmed the identity of the 150 kD immunopositive band to be mouse SPACR core protein. Alignment comparisons of the deduced amino acid sequence of mouse and human SPACR show 64% homology. Like SPACR in the human interphotoreceptor matrix, the mouse orthologue contains a large central mucin-like domain flanked by consensus sites for N-linked oligosaccharide attachment, one EGF-like domain and four hyaluronan-binding motifs. Unlike human SPACR, which contains no conventional consensus sites for glycosaminoglycan attachment, mouse SPACR contains three. Recent biochemical studies of human and mouse SPACR protein indicate that this novel interphotoreceptor matrix molecule is a glycoprotein in human and a proteoglycan in the mouse. The presence of consensus sites for glycosaminoglycan attachment in the deduced sequence of mouse SPACR and the absence of these sites in human SPACR provide molecular verification of our biochemical results, suggesting that differences in post-translational modifications of SPACR may be important in SPACR function in foveate and non-foveate retinas.

Necrotizing enterocolitis: experience of 27 cases from a single Korean institution

Necrotizing enterocolitis (NEC) can involve any site in the gastrointestinal tract and is a fatal complication of immunosuppression. To characterize NEC, clinical and radiological characteristics were analyzed. A total of 27 cases of NEC were identified from January 1993 to August 1998, and medical records were reviewed. NEC was diagnosed by clinical and radiological criteria, and other mimicking conditions were excluded. Of the NEC cases, 22 (81.5%) occurred in patients with underlying hematologic malignancy. All patients complained of abdominal pain and fever at the time of inclusion. Escherichia coli was the most common pathogen identified. The most common finding by computed tomography was single-layered diffuse bowel wall thickening with variable density. Other findings were ascites, fascial thickening, pneumatosis, and mesenteric lymphadenopathy. Of the patients, 25 were treated with antimicrobials with or without recombinant hematopoietic growth factors, and 2 were treated with surgery because of perforation and profound bleeding. Among the 12 patients who died, NEC was the direct cause of death in 7 patients. In conclusion, computed tomography is an effective tool for early diagnosis of NEC. Bowel rest, broad-spectrum antimicrobials, and recombinant hematopoietic growth factors are important aspects of treatment. Surgery should be reserved for complicated cases.

Phosphorylation of serine 43 is not required for inhibition of c-Raf kinase by the cAMP-dependent protein kinase

The activity of the serine/threonine kinase c-Raf (Raf) is inhibited by increased intracellular cAMP. This is believed to require phosphorylation with the cAMP-dependent protein kinase (PKA), although the mechanism by which PKA inhibits Raf is controversial. We investigated the requirement for PKA phosphorylation using Raf mutants expressed in HEK293 or NIH 3T3 cells. Phosphopeptide mapping of (32)P-labeled Raf (WT) or a mutant lacking a putative PKA phosphorylation site (serine to alanine, S43A) confirmed that serine 43 (Ser(43)) was the major cAMP (forskolin)-stimulated phosphorylation site in vivo. Interestingly, the EGF-stimulated Raf kinase activity of the S43A mutant was inhibited by forskolin equivalently to that of the WT Raf. Forskolin also inhibited the activation of an N-terminal deletion mutant Delta5-50 Raf completely lacking this phosphorylation site. Although WT Raf was phosphorylated by PKA, phosphorylation did not inhibit Raf catalytic activity in vitro, nor did forskolin treatment inhibit the activity of an N-terminally truncated Raf protein (Raf 22W) or a full-length Raf protein (Raf-CAAX) expressed in NIH 3T3 cells. In contrast, forskolin inhibited the EGF-dependent activation of a Raf isoform (B-Raf), lacking an analogous phosphorylation site to Ser(43). Thus, these results demonstrate that PKA exerts its inhibitory effects independently of direct Raf phosphorylation and suggests instead that PKA prevents an event required for the EGF-dependent activation of Raf.

Identification of cis site involved in nickel-responsive transcriptional repression of sodF gene coding for Fe- and Zn-containing superoxide dismutase of Streptomyces griseus

A sodF gene coding for iron- and zinc-containing superoxide dismutase (FeZnSOD) of Streptomyces griseus was cloned and sequenced. A 5' end of 0.8-kb sodF transcript was mapped at the 57 nucleotides upstream from an ATG initiation codon. Employing expressions of sodF::xylE fusions in trans in Streptomyces lividans, nickel-responsive transcriptional repression was found to be relieved if mutations were introduced into an operator sequence of inverted-repeat, TTGCAN(7)TGCAA, which traverses the 5' end (+1, G) of the sodF mRNA. Nickel-dependent interaction between cell extracts and sodF regulatory DNA, monitored through gel-mobility shift assay, was abolished when the operator was mutated. Recombinant sodF operon having operator mutations showed protein level and enzyme activity, which were no longer repressed by nickel, suggesting that nickel-responsive repression of FeZnSOD is regulated mainly at the level of transcription through the operator.

CT features of intraductal intrahepatic cholangiocarcinoma

OBJECTIVE

The objective of this report was to describe the CT features of intraductal intrahepatic cholangiocarcinoma.

CONCLUSION

Segmental or lobar dilatation of the intrahepatic bile ducts associated with or without intraductal polypoid mass, amorphous structures, or both with slight hyperattenuation are common CT findings of intraductal intrahepatic cholangiocarcinoma. The size of the intraductal mass determines the visibility on CT.

Diagnosis of vertebral metastasis, epidural metastasis, and malignant spinal cord compression: are T(1)-weighted sagittal images sufficient?

The objective of this study was to determine whether T(1)-weighted sagittal images alone are adequate in the diagnosis of vertebral metastasis, epidural metastasis, and malignant spinal cord compression. Ninety-four complete magnetic resonance (MR) studies of the spinal column (a complete study consisting of T(1)-weighted sagittal images, T(2)-weighted sagittal images, and T(1)- and/or T(2)-weighted axial images) and 94 T(1)-weighted sagittal images alone (a subset of the complete studies) from 57 consecutive cancer patients over the last 2 years with clinically suspected cord compression were blindly and independently evaluated by four radiologists. The complete MR studies were used as the standard. Overall, the sensitivity of T(1)-weighted sagittal images alone to vertebral metastasis (87%) was statistically greater than cord compression (70%) (p = 0.05), and statistically greater than epidural metastasis (46%) (p </= 0.02). The specificity for cord compression (97%) was greater than the specificity for epidural metastasis (89%) (p = 0.03), and greater than the specificity for vertebral metastasis (83%) (p </= 0.02). There was a strong trend for better detection of cord compression overall and better detection of vertebral metastasis in the cervical spine by the most experienced radiologist. Complete studies of the spine are necessary in the diagnosis of vertebral metastasis, epidural metastasis, and cord compression, particularly with less experienced radiologists.

Effect of Korea red ginseng on the blood pressure in conscious hypertensive rats

The change of blood pressure and heart rate after intravenous injection of Korea red ginseng (KRG) were studied in the conscious normotensive and one-kidney, one-clip Goldblatt hypertensive (1K, 1C-GBH) rats. Crude saponin (CS) of KRG (50, 100 mg/kg i.v.) induced a hypotensive effect and bradycardia in a dose-dependent manner in the anesthetized rats. On the other hand, CS of KRG (100 mg/kg) induced a hypotensive effect and reflex tachycardia in the conscious rats. Saponin-free fraction (SFF) of KRG did not affect them in the anesthetized normotensive rats (P>.05). The maximal hypotensive effect by CS of KRG in the conscious 1K, 1C-GBH hypertensive rats and L-nitroarginine methyl ester (L-NAME, 40 mg/kg)-treated conscious hypertensive rats was not different from that of conscious normotensive rats (Delta 31.6+/-6.3, Delta 27.5+/-5.8 vs. Delta 26.7+/-4.3 mmHg, P>.05). However, pretreatment of L-NAME significantly inhibited the reflex tachycardia by CS of KRG (70.8+/-7.0 vs. 30.6+/-15.0 bpm, P<.05). Hemolysate-sensitive nitric oxide (NO) current by the CS of KRG was greater than that of the SFF of KRG (651.9+/-128.2 pA for CS and 164.9+/-92.5 pA for SFF, P<.001). These findings suggest that KRG has a hypotensive effect and its effect may be due to saponin fraction of KRG in the conscious rats. The releasing effect of NO of KRG, like NO donor, may be partly contributed to the hypotensive effect of KRG.

Effects of biatrial pacing in prevention of postoperative atrial fibrillation after coronary artery bypass surgery

BACKGROUND

Atrial fibrillation (AF) is common after coronary artery bypass surgery (CABG) and results in prolonged hospitalization. The purpose of this study was to evaluate the efficacy of biatrial pacing in preventing post-CABG AF compared with single-site atrial pacing.

METHODS AND RESULTS

A total of 132 patients who had no history of AF and who underwent CABG were randomized to 1 of the following 4 groups: biatrial pacing (BiA), left atrial pacing (LA), right atrial pacing (RA), or no pacing (control) in postoperative period. Overdrive atrial pacing was performed for 5 days. The incidence of AF was significantly reduced in the BiA group (12.5%) compared with the other 3 groups (LA, 36.4%; RA, 33.3%; control, 41. 9%; P<0.05). The mean length of hospital stay was significantly reduced in the BiA group. At baseline, the mean P-wave duration (P(dur)) and dispersion (P(dis)) were not prolonged. BiA pacing resulted in the most significant percentage of reduction in P(dis) when compared with the LA or RA groups (BiA, 42+/-8%; LA, 13+/-6%; RA, 10+/-9%; P<0.05 for BiA versus LA or RA). No significant differences existed in mean P(dur) and P(dis) between patients who developed AF and those who remained in sinus rhythm at baseline. However, only those patients who remained in sinus rhythm had a significant reduction in mean P(dur) and P(dis) after pacing therapy.

CONCLUSIONS

Biatrial overdrive pacing is more effective in preventing post-CABG AF than single-site atrial pacing; this therapy also results in a shortened hospital stay. The overall reduction in atrial activation time with BiA pacing was reflected in the reduction in P(dis).

Dose-dependent pharmacokinetics of amphotericin B lipid complex in rabbits

Amphotericin B lipid complex (ABLC) was recently approved by the Food and Drug Administration for treatment of patients with invasive fungal infections who are intolerant of or refractory to conventional amphotericin B therapy. Little is known, however, about the pharmacokinetics of this new antifungal compound. We therefore investigated the pharmacokinetics of ABLC in comparison with those of conventional desoxycholate amphotericin B (DAmB) in rabbits. The pharmacokinetics of DAmB in a rabbit model were similar to those previously reported in humans. The pharmacokinetics of ABLC differed substantially from those of DAmB. Plasma amphotericin B levels following ABLC administration were 10 times lower than those following administration of an equal dosage of DAmB. The levels of ABLC in whole blood were approximately 40 times greater than those in plasma. The ABLC model differed from the DAmB model by (i) a dose- and time-dependent uptake and return between the plasma compartment and apparent cellular components of the blood-sediment compartment and (ii) time-dependent tissue uptake and return to plasma from serially connected compartments. Following infusion of ABLC, there was a nonlinear uptake into the apparent cellular components of the blood-sediment compartment. This uptake was related to the reciprocal of the integral of the total amount of drug infused (i.e., the more drug infused the greater the fractional uptake between 0.5 and 5 mg/kg of body weight for ABLC). The transfer of drug from plasma to the cellular components of the blood-sediment compartment resulted in initial uptake followed by rapid redistribution back to the plasma. The study describes a detailed model of the pharmacokinetics of ABLC and characterizes a potential role of the cellular components of the blood-sediment compartment in the distribution of this new antifungal compound in tissue.

Finite-size effects of two-particle diffusion-limited reactions

We have studied the finite-size effects of two-particle diffusion-limited reaction A+B-->0, on a one-dimensional lattice using the Monte Carlo method. The density at a finite lattice follows a power law, C(t) approximately t(-x) below the crossover time, and shows an exponential decay above the crossover time. The crossover time depends on the lattice size and the bias field. We found second-order correction terms of the density decay as C(t) approximately t(-1/4)[1+O(t(-1/8))] for the isotropic diffusion of particles and C(t) approximately t(-1/3)[1+O(t(-1/24))] for the maximum drift. We proposed the scaling function of the density given as C(t) approximately L(-1/2)f(o)(t/L(2))+L(-3/4)f(1)(t/L(2)) for the isotropic diffusion and C(t) approximately L(-1/2)f(o)(t/L(3/2))+L(-9/16)f(1)(t/L(3/2)) for the maximum drift where f(o) and f(1) are scaling functions.

Parameter estimates for number of lambs born at different ages and for 18-month body weight of Rambouillet sheep

Genetic parameters were estimated using REML with animal models for number of lambs born and 18-mo body weight in Rambouillet sheep. Number of lambs born was modeled either as repeated measurements on the same trait or as different traits at different ages. The original data for number of lambs born were separated according to age of the ewe into two classes: 2 and 3 yr, and older than 3 yr. Numbers of ewes with lambing records for the age classes were 653 and 466 with 1,106 and 1,118 records, respectively. For the data set that included all ages, the number of ewes was 684 with 2,224 records, and for 18-mo body weight the number of ewes measured was 557. For number of lambs born, the animal model included random genetic, permanent environmental, and residual environmental effects and fixed effects for age of ewe, year of lambing, and month of year of lambing. Lambing day within season was used as a covariate. For 18-mo body weight, year of birth of ewe was used as a fixed effect. Actual age in days when the ewe was weighed was used as a covariate. Estimates of heritability for number of lambs born by age group were .04, for 2- and 3-yr old ewes, and .06, for ewes greater than 3 yr old, from the two-trait (two age of ewe classes) analyses and .06 when all ages were included. Estimates of heritability for number of lambs born from the single-trait analyses were somewhat less than estimates from two-trait analyses. Estimate of genetic correlation between number of lambs born for the 2 and 3 yr and the >3 yr classes was near unity (1.00), which suggests that a repeated measures model for number of lambs born is adequate for making selection decisions. Estimate of genetic correlation between number of lambs born and 18-mo body weight was .35 with a heritability estimate of .48 for 18-mo body weight. The estimate of genetic correlation suggests that selection for increased number of lambs born would result in increased 18-mo body weight.

Parameter estimates for greasy fleece weight of Rambouillet sheep at different ages

Variance components for greasy fleece weight in Rambouillet sheep were estimated. Greasy fleece weight was modeled either as repeated measurements on the same trait or as different traits at different ages. The original data were separated according to the age of the ewe at shearing into three classes; 1 yr, 2 and 3 yr, and older than 3 yr. An animal model was used to obtain estimates of genetic parameters with a REML algorithm. Total numbers of animals in pedigrees for the different age classes were 696, 729, and 573, respectively, and 822 for the repeated measures model across ages. The animal model included direct genetic, permanent environmental, and residual environmental random effects and fixed effects for age of ewe, shearing date as contemporary group, and number of lambs born. Days between shearings was used as a covariate. Single-trait analyses were initially done to obtain starting values for multiple-trait analyses. A repeated measures model across ages was also used. Estimates of heritability by age group were .42, .50, and .58 from three-trait (age class) analyses and for the repeated measures model the estimate was .57. Estimates of genetic correlations between fleece yields for 1 yr and 2 and 3 yr, 1 yr and >3 yr, and 2 and 3 yr and >3 yr classes were .88, .89, and .97, respectively. These estimates of genetic correlations suggest that a repeated measures model for greasy fleece weight is adequate for making selection decisions.

The HslU ATPase acts as a molecular chaperone in prevention of aggregation of SulA, an inhibitor of cell division in Escherichia coli

HslVU is an ATP-dependent protease consisting of two multimeric components: the HslU ATPase and the HslV peptidase. SulA, which is an inhibitor of cell division and has high tendency of aggregation, is degraded by HslVU protease. Here we show that HslU plays a role not only as a regulatory component for the HslV-mediated proteolysis but also as a molecular chaperone. Purified HslU prevented aggregation of SulA in a concentration-dependent fashion. This chaperone activity required oligomerization of HslU subunits, which could be achieved by ATP-binding or in the presence of high HslU protein concentrations. hsl mutation reduced the SulA-mediated inhibition of cell growth and this effect could be reversed upon overproduction of HslU, suggesting that HslU promotes the ability of SulA to block cell growth through its chaperone function. Thus, HslU appears to have two antagonistic functions: one as a chaperone for promotion of the ability of SulA in cell growth inhibition by preventing SulA aggregation and the other as the regulatory component for elimination of SulA by supporting the HslV-mediated degradation.

Lack of integrative control of body temperature after capsaicin administration

BACKGROUND

Body temperature is usually regulated by opposing controls of heat production and heat loss. However, systemic administration of capsaicin, the pungent ingredient of hot peppers, facilitated heat production and heat loss simultaneously in rats. We recently found that the capsaicin-induced heat loss and heat production occur simultaneously and that the biphasic change in body temperature is a sum of transient heat loss and long-lasting heat production. Moreover, suppression of the heat loss response did not affect capsaicin-induced heat production and suppression of heat production did not affect capsaicin-induced heat loss. These observations suggest the independent peripheral mechanisms of capsaicin-induced thermal responses. Thus, the capsaicin-induced thermal responses apparently lack an integrated control.

METHODS

Male Wistar rats were maintained at an ambient temperature of 24 +/- 1 degrees C on a 12 h on-off lighting schedule at least for two weeks before the experiments. They were anesthetized with urethane (1.5 g/kg, i.p.) and placed on a heating pad, which was kept between 29 and 30 degrees C. Skin temperature(Ts) was measured with a small thermistor, which was taped to the dorsal surface of the rat's tail, to assess vasoactive changes indirectly. Colonic temperature(Tc) was measured with another thermistor inserted about 60 mm into the anus. O2 consumption was measured by the open-circuit method, and values were corrected for metabolic body size (kg0.75). Capsaicin (Sigma) was dissolved in a solution comprising 80% saline, 10% Tween 80, and 10% ethanol, and injected subcutaneously at a dose of 5 mg/kg. Each rat received a single injection of capsaicin because repeated administration of capsaicin renders an animal insensitive to the subsequent administration of capsaicin. Laminectomy was performed at the level of the first and second cervical vertebrae to expose the cervical spinal cord for sectioning. The brain was transected at 4-mm rostral from the interaural line with an L-shaped knife.

RESULTS

After administration of capsaicin, O2 consumption increased from 13.5 +/- 0.4 mL/min/kg0.75 at 0 min to a peak of 15.9 +/- 0.4 mL/min/kg0.75 at 71 min and gradually declined but remained higher than the basal value until the end of the 4-h observation period. Ts also immediately increased from 27.7 +/- 0.2 degrees C to 31.9 +/- 0.3 degrees C at 39 min, and it returned to the baseline level within 90 min after the capsaicin administration. Tc initially decreased from 37.1 +/- 0.1 degrees C to 36.8 +/- 0.2 degrees C at 43 min and then gradually increased over the baseline level and remained at 37.6 +/- 0.2 degrees C until the end of the experiment. In spinalized rats, the capsaicin-induced increases in O2 consumption was largely attenuated, while the basal O2 consumption was similar to that of control rats. The basal Ts of spinalized rats was 32.4 +/- 0.3 degrees C, which was higher than that of control rats. Capsaicin increased Ts by less than 1 degree C, and Tc did not change after the capsaicin administration. O2 consumption of decerebrated rats was statistically higher than that of control rats after the injection of capsaicin. However, capsaicin did not increase Ts, showing a lack of a vasodilatory response. Decerebration between the hypothalamus and midbrain prevented the capsaicin-induced heat loss but not the heat production response.

CONCLUSION

These results show that the capsaicin-induced heat production and heat loss are controlled separately by the brainstem and by the forebrain, respectively, and suggest that the body temperature regulation is performed without an integrative center.

Effects of gamma radiation on the conformational and antigenic properties of a heat-stable major allergen in brown shrimp

This study was performed to evaluate the application of food irradiation technology as a method for reducing shrimp allergy without adverse effects. Shrimp heat-stable protein (HSP) was isolated and gamma irradiated at 0, 1, 3, 5, 7, or 10 kGy in the condition of solution (1 mg/ml), and fresh shrimp was also irradiated. Conformational change of irradiated HSP was monitored by means of spectrometric measures, enzyme-linked immunosorbent assay with mouse monoclonal antibody, or human patients' sera and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The ability of the immunoglobulin E of patients allergic to shrimp to bind to irradiated HSP was dose dependently reduced. The amount of intact HSP in an irradiated solution was reduced by gamma irradiation, depending on the dose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the main band disappeared and the traces induced from coagulation appeared at a higher molecular weight zone. The binding ability of immunoglobulin E to allergens in the extracts from irradiated shrimp decreased, depending on the dose. The results provide a new method so that food irradiation technology can be applied to reduce allergenicity of shrimp.

Topotecan-based combination chemotherapy in patients with transformed chronic myelogenous leukemia and advanced myelodysplastic syndrome

BACKGROUND

Patients with transformed chronic myelogenous leukemia(CML) and advanced myelodysplastic syndrome(MDS) have poor prognosis. The aim of this study is to evaluate the feasibility of second chronic phase induction in accelerated phase(CML-AP) or blastic crisis of CML(CML-BC) and remission induction in advanced MDS by combining topoisomerase I inhibitor (topotecan) with topoisomerase II inhibitor(mitoxantrone).

METHODS

Twenty-four evaluable patients were entered on this study with a median age of 34 years. Eighteen patients with transformed CML(7 CML-AP, 11 CML-BC) and 6 patients with advanced MDS were treated. Topotecan was administered as 1.5 mg/m2/day by continuous infusion over 24 hours daily for 5 days every 4 to 8 weeks until remission. To enhance the tumoricidal effects, mitoxantrone(12 mg/m2/day, Days 1-3) was added.

RESULTS

Eight patients(33%) achieved a complete remission(CR). Four of 7 patients with CML-AP(57%), 2 of 4 patients with CML-lymphoid blastic crisis (-LBC)(50%) and 2 of 6 patients with advanced MDS(33%) had CR lasting more than 45 days(45 to 400 days). There was no CR in the patients with CML-myeloid blastic crisis(-MBC). The dose level of 1.5 mg/m2/day(7.5 mg/m2/course) of topotecan was well tolerated in all patients. Mucositis occurred in 69% of patients (severe in 5%) and diarrhea in 67%(severe in 8%). In addition, there were no new or unexpected toxicities in the patients who were treated at this dose(7.5 mg/m2/course). In patients who recovered their neutrophil count, the absolute neutrophil count(ANC) remained below 500/microL for a period of 13 to 58 days(median 21 days) and the time to ANC recovery was associated with pretreatment severity of bone marrow fibrosis(mainly CML patients). Likewise, in the patients who recovered unsupported platelets, the platelets remained below 20,000/microL for a period of 0 to 37 days (median 19 days).

CONCLUSION

The combination of topotecan-mitoxantrone has shown modest activity in CML-AP, CML-LBC and advanced MDS with acceptable toxicities.

Bioadhesive-based dosage forms: the next generation

Prolonged contact time of a drug with a body tissue, through the use of a bioadhesive polymer, can significantly improve the performance of many drugs. These improvements range from better treatment of local pathologies to improved drug bioavailability and controlled release to enhanced patient compliance. There are abundant examples in the literature over the past 15 years of these improvements using first generation or "off-the-shelf" bioadhesive polymers. The present mini-review will remind us of the success achieved with these first-generation polymers and focus on proposals for the next-generation polymers and attendant benefits likely to occur with these improved polymeric systems.

Genetically engineered fibroblasts with antigen-presenting capability: efficient induction of an antigen-specific cytotoxic T-lymphocyte response and protection against tumor development in vivo

BLK mouse fibroblasts (H-2b) were genetically engineered to express costimulatory B7.1 and interleukin-2 (BLK/IL2/B7.1). The BLK/IL2/B7.1 cells were then pulsed with an ovalbumin (OVA) epitope as a model antigen (Ag) (BLK/IL2/B7.1/OVA), and tested for the induction of OVA-specific cytotoxic T lymphocytes (CTLs) in C57BL/6 mice (H-2b). The genetically engineered fibroblasts lacking one or two of three factors (interleukin-2, B7.1, and OVA) were constructed and used as controls. Immunization with the BLK/IL2/B7.1/OVA cells induced strong cytotoxic activities against OVA-expressing EL4 (EG7) tumor cells, but not against other H-2b tumor cells, such as EL4, C1498 and B16F1 cells. The magnitude of the cytotoxic response in mice with the BLK/IL2/B7.1/OVA cells was significantly higher than the response in mice immunized with any other cell constructs. CD8+ T cells with OVA-specific cytotoxic activities were predominant in mice immunized with the BLK/IL2/B7.1/OVA cells. Furthermore, immunization with the BLK/IL2/B7.1/OVA cells significantly prolonged the survival of mice, compared with any other cell constructs, when the mice were challenged with EG7 tumor cells at 2 weeks postimmunization. Induction of antitumoral CTL immunity by the BLK/IL2/B7.1/OVA cells was independent of host Ag-presenting cells and of CD4+ T-cell and natural killer 1.1+ cell help. These results suggest that fibroblasts can be genetically modified to efficient Ag-presenting cells for the induction of an Ag-specific CTL response.

alpha5beta1 integrin protects intestinal epithelial cells from apoptosis through a phosphatidylinositol 3-kinase and protein kinase B-dependent pathway

Renewal of the gastrointestinal epithelium involves a coordinated process of terminal differentiation and programmed cell death. Integrins have been implicated in the control of apoptotic processes in various cell types. Here we examine the role of integrins in the regulation of apoptosis in gastrointestinal epithelial cells with the use of a rat small intestinal epithelial cell line (RIE1) as a model. Overexpression of the integrin alpha5 subunit in RIE1 cells conferred protection against several proapoptotic stimuli. In contrast, overexpression of the integrin alpha2 subunit had no effect on cell survival. The antiapoptotic effect of the alpha5 subunit was partially retained by a mutated version that had a truncation of the cytoplasmic domain. The antiapoptotic effects of the full-length or truncated alpha5 subunit were reversed upon treatment with inhibitors of phosphatidylinositol 3-kinase (PI-3-kinase), suggesting that the alpha5beta1 integrin might interact with the PI-3-kinase/Akt survival pathway. When cells overexpressing alpha5 were allowed to adhere to fibronectin, there was a moderate activation of protein kinase B (PKB)/Akt, whereas no such effect was seen in alpha2-overexpressing cells adhering to collagen. Furthermore, in cells overexpressing alpha5 and adhering to fibronectin, there was a dramatic enhancement of the ability of growth factors to stimulate PKB/Akt; again, this was not seen in cells overexpressing alpha2 subunit and adhering to collagen or fibronectin. Expression of a dominant negative version of PKB/Akt in RIE cells blocked to ability of alpha5 to enhance cell survival. Thus, the alpha5beta1 integrin seems to protect intestinal epithelial cells against proapoptotic stimuli by selectively enhancing the activity of the PI-3-kinase/Akt survival pathway.

Catatonia in a psychiatric intensive care facility: incidence and response to benzodiazepines

This study was performed to establish the incidence of catatonia in a psychiatric intensive care unit, to test the Bush-Francis Catatonia Screening Instrument (BFCSI) and to assess the response of catatonic signs to benzodiazepines. During a 12-month period all patients admitted to a psychiatric intensive care unit were screened for catatonic signs using the BFCSI. Patients with catatonia were further assessed with the Bush-Francis Catatonia Rating Scale (BFCRS), the Modified Rogers Scale (MRS), and scales for associated psychotic and parkinsonian symptoms. They were treated with oral lorazepam or parenteral clonazepam and their responses evaluated daily. Neuroleptics were stopped for at least 3 days. Twenty four patients met the DSM IV criteria for catatonia, giving an incidence of 15% with a significantly higher proportion of non-Europeans. The most common associated diagnosis was schizophrenia (54%). Twenty two patients completed the benzodiazepine trial. All showed significant responses after 3 days of treatment. Sixteen (16/22, 73%) had full remission within 6 days, most within 2 to 4 days. Partial responders (n = 6) all had schizophrenia and were more likely to have longer pre-trial catatonic episodes. We find the BFCSI a simple and reliable tool to screen for catatonia, and our data attest to the efficacy of benzodiazepines in the treatment of catatonia.

Activating protein-1, nuclear factor-kappaB, and serum response factor as novel target molecules of the cancer-amplified transcription coactivator ASC-2

ASC-2 was recently discovered as a cancer-amplified transcription coactivator molecule of nuclear receptors, which interacts with multifunctional transcription integrators steroid receptor coactivator-1 (SRC-1) and CREB-binding protein (CBP)/p300. Herein, we report the identification of three mitogenic transcription factors as novel target molecules of ASC-2. First, the C-terminal transactivation domain of serum response factor (SRF) was identified among a series of ASC-2-interacting proteins from the yeast two-hybrid screening. Second, ASC-2 specifically interacted with the activating protein-1 (AP-1) components c-Jun and c-Fos as well as the nuclear factor-kappaB (NFkappaB) components p50 and p65, as demonstrated by the glutathione S-transferase pull-down assays as well as the yeast two-hybrid tests. In cotransfection of mammalian cells, ASC-2 potentiated transactivations by SRF, AP-1, and NFkappaB in a dose-dependent manner, either alone or in conjunction with SRC-1 and p300. In addition, ASC-2 efficiently relieved the previously described transrepression between nuclear receptors and either AP-1 or NFkappaB. Overall, these results suggest that the nuclear receptor coactivator ASC-2 also mediates transactivations by SRF, AP-1, and NFkappaB, which may contribute to the putative, ASC-2-mediated tumorigenesis.