Intraneuronal Aβ, non-amyloid aggregates and neurodegeneration in a Drosophila model of Alzheimer’s disease

We have developed models of Alzheimer's disease in Drosophila melanogaster by expressing the Abeta peptides that accumulate in human disease. Expression of wild-type and Arctic mutant (Glu22Gly) Abeta(1-42) peptides in Drosophila neural tissue results in intracellular Abeta accumulation followed by non-amyloid aggregates that resemble diffuse plaques. These histological changes are associated with progressive locomotor deficits and vacuolation of the brain and premature death of the flies. The severity of the neurodegeneration is proportional to the propensity of the expressed Abeta peptide to form oligomers. The fly phenotype is rescued by treatment with Congo Red that reduces Abeta aggregation in vitro. Our model demonstrates that intracellular accumulation and non-amyloid aggregates of Abeta are sufficient to cause the neurodegeneration of Alzheimer's disease. Moreover it provides a platform to dissect the pathways of neurodegeneration in Alzheimer's disease and to develop novel therapeutic interventions.

Open versus closed day-case haemorrhoidectomy: is there any difference? Results of a prospective randomised study

BACKGROUND AND AIMS

Nowadays there is still controversy as to whether open or closed haemorrhoidectomy is the surgical treatment of choice for haemorrhoidal pathology.

PATIENTS AND METHODS

We carried out a randomised prospective study in the Day Surgery Unit comparing 100 patients undergoing Milligan-Morgan haemorrhoidectomy (group A) versus 100 patients undergoing Ferguson haemorrhoidectomy (group B) for symptomatic haemorrhoids, in whom medical treatment or rubber band ligation had failed.

RESULTS

Characteristics of the population were: mean age 43.5 years, with predominance of males, 123 vs. 77; 88% ASA I-II.

CLINICAL PRESENTATION

95% rectal bleeding; 87.5% third-fourth degree. The anaesthetic technique of choice was local anaesthesia plus sedation in 180 patients (90%). Length of surgery: 24 min (group A) and 30 min (group B) (p=n.s.). Resection of three haemorrhoidal cushions was done in 87.5% of cases. There were no re-operations or re-admissions after discharge. Symptomatic recurrence, stenosis and incontinence were not found during the follow-up of the first year. Postoperative pain during the first postoperative week was greater in the open haemorrhoidectomy group, but the difference was statistically significant (p<0.05) only during bowel movements. There was complete healing in 40% of the patients in group A and 90% of those in group B (p<0.05) after 1 month. After 1 year, the results and complications were similar in both groups (p=n.s.).

CONCLUSIONS

Closed haemorrhoidectomy gives better results in terms of pain and healing than open haemorrhoidectomy, whereas recurrence and complications are similar after 1 year.

Phenylisothiocyanate and dansyl chloride precolumn derivatizations for the high-performance liquid chromatography analysis of the antitumoral agent ES-285 in dog plasma

Chromophor and fluorophor addition reactions involving phenylisothiocyanate (PITC) and dansyl chloride (DC) were optimized to adapt two high-performance liquid chromatography (HPLC) procedures designed for the accurate determination of the novel antitumoral agent ES-285 in Beagle dog plasma. ES-285 was reacted with PITC at 60 degrees C for 15 min in the presence of triethylamine. The dansyl derivative was obtained by reaction of ES-285 with dansyl chloride in a basic medium at 80 degrees C for 20 min. Both reactions also worked for ES-299, a compound structurally related to ES-285 which was used as internal standard. The treatment of ES-285 and ES-299 spiked plasma samples with a basic phosphate buffer and MeOH permitted the extraction of the drug from the matrix. The purification of the analytes was carried out by solid-phase extraction followed by precolumn derivatization with PITC and DC. The phenylisothiocyanate adducts were analyzed by isocratic HPLC with UV detection at 254 nm. The ES-285 and ES-299 derivatives were eluted from a C(18) column at approximately 6.9 and approximately 8.1 min, respectively. The eluent ACN-water (95:5, v/v) was delivered to the column at a flow-rate of 1 ml/min and the analysis was completed in 15 min. The dansyl derivatives were analysed by a two-HPLC column system with fluorescence detection and gradient elution. The column temperature was maintained at 40 degrees C. The analysis lasted 55 min with the elution of ES-285 and ES-299 derivatives at approximately 35.2 and approximately 37.9 min, respectively. The PITC- and DC-based procedures were characterized by limits of quantification of 20 and 15 ng/ml, respectively. Both procedures were validated according to the ICH and FDA guidelines. They were selective for ES-285 and provided accurate, precise and reproducible results. ES-299 was shown to be a suitable internal standard. The HPLC procedure involving derivatization with DC was more sensitive and permitted to process plasma sample volumes as low as 100 microl. On the other hand, the PITC-based procedure characterised by a quite similar LOQ permitted a higher throughput but implied the processing of a 500-microl plasma volume.

Dimerization induced by the RKKY interaction

We report the presence of spin dimerization in the ground state of the one-dimensional Kondo lattice model at quarter filling. The emergence of this new phase of the Kondo lattice can be traced to the form of the RKKY interaction between the localized moments and provides the first example of dimerization induced indirectly by itinerant electrons. We propose this dimer ordering as the driving mechanism of the spin-Peierls phase observed in the quasi-one-dimensional organic compounds (Per)2M(mnt)(2) (M=Pt, Pd). Moreover, this suggests that a richer phase diagram than the Doniach paradigm may be needed to accommodate the physics of heavy fermion materials.

Quantitative analysis of ES-285, an investigational marine anticancer drug, in human, mouse, rat, and dog plasma using coupled liquid chromatography and tandem mass spectrometry

A method was developed for the quantitative analysis of the novel anticancer agent ES-285 (spisulosine; free base) in human, mouse, rat, and dog plasma using high-performance liquid chromatography/electrospray ionization tandem mass spectrometry in order to support pre-clinical and clinical studies with the drug. Sample preparation was carried out by protein precipitation with acetonitrile, containing isotopically labeled (d(3)) ES-285 as internal standard. Aliquots of 10 micro l of the supernatant were injected directly on to an Inertsil ODS-3 column (50 x 2.0 mm i.d., 5 micro m). Elution was carried out using methanol-10 mM ammonium formate (pH 4) in water (80 : 20, v/v) pumped at a flow-rate of 0.2 ml min(-1) with a run time of 8 min. Multiple reaction monitoring chromatograms obtained on an API365 triple-quadrupole mass spectrometer were used for quantification. The lower limit of quantitation (LLOQ) was 10 ng ml(-1) in human, mouse, rat, and dog plasma and the linear dynamic range extended to 500 ng ml(-1). A full validation of the method was performed in human plasma, and partial validations were performed in mouse, rat and dog plasma. Accuracies and precisions were <20% at the LLOQ concentration and <15% for all other concentrations in all matrices. ES-285 was stable during all steps of the assay. Thus far this method has been used successfully to analyze over 500 samples in pre-clinical trials, and will be implemented in the planned clinical phase I studies.

[Per and early postoperative use of low molecular weight heparin in carotid surgery]

The goal of this study was to evaluate per and postoperative use of nadroparin during carotid surgery with mortality and neurologic morbidity as primary end points. From January 1995 to December 1999, 237 procedures were performed on 215 patients for isolated carotid surgery; 57% were symptomatic. Surgery was performed under general anesthesia. Before clamping, patients received an intravenous bolus of 70 UI/kg of nadroparin. Shunting was used in 40% of patients. Postoperatively, from the 6(th) hour, nadroparin was given subcutaneously, 2,850 UI or 3,800 UI every 12 hours depending on the patient weight (less or more than 70 kg). The only biologic surveillance was platelet count twice a week. Antiplatelet drugs were given at day 2. Completion Duplex scan was performed before day 30. Seven postoperative ischemic strokes (3 non disabling) occurred including one fatal stroke. Another patient died at day 25 from inaugural duodenal bleeding due to pancreas cancer. The 30 days stroke or death rate was 3.37% (5.92% in symptomatic; 0% in asymptomatic). No hemorrhagic stroke occurred. Four patients were reoperated for cervical hematoma (1.68%). No thrombocytopenia occurred. Duplex scan, performed on 235 operated carotid arteries, showed 2 asymptomatic carotid thromboses. No other cardiovascular complication was found on clinical data. These results are comparable to published literature data in prospective as well as retrospective studies. Per and postoperative use of nadroparin in carotid surgery gave results similar to previously published reports in terms of mortality, neurologic morbidity and hematoma. Its easy use, needing only 2 injections a day and platelet count, with a reduction of the risk of heparin-induced thrombocytopenia make the use of nadroparin very attractive during the perioperative period.

Phase diagram of the anisotropic Kondo chain

We establish the phase diagram of the one-dimensional anisotropic Kondo lattice model at T = 0 using a generalized two-dimensional classical Coulomb gas description. We analyze the problem by means of a renormalization group treatment. We find that the phase diagram contains regions of paramagnetism, partial and full ferromagnetic order.

[Clinical and psychometric diagnosis of depression in patients in general medicine]

BACKGROUND

The Hamilton scale, applied by an external evaluator and the self rating Beck inventory for depression, can give discrepant results in psychiatric patients with depression.

AIM

To compare depression scores obtained with the Hamilton scale and the Beck inventory in general medical patients.

PATIENTS AND METHODS

Patients attending an outpatient clinic of a University Hospital were studied. Clinical psychiatric diagnoses were based on DSM-III. Hamilton scale was applied to 100 patients and 80 answered the Beck depression inventory.

RESULTS

Patients with major depression obtained the higher scores with both scales. However, Beck inventory had false positive and false negative results. Moreover, some patients overstated their depressive symptoms.

CONCLUSIONS

Self assessment of depression can be distorted by anxiety and somatic symptoms.

Analysis and quantification of the secretory products of the subcommissural organ by use of monoclonal antibodies

Bovine Reissner's fiber (RF) glycoproteins were used as antigen for the production of polyclonal and monoclonal antibodies (Mabs). We also produced Mabs against intracellular secretory glycoproteins of the bovine subcommissural organ (SCO). These Mabs were used for immunodetection of secretory proteins in situ (structural and ultrastructural immunocytochemistry), in blots, and in solutions. Three different antigen-mediated ELISA were designed to evaluate the affinity of the Mabs, to study the nature of the epitopes, and for competition test among Mabs. Two double antibody sandwich ELISA were designed to detect and quantify soluble secretory materials in different samples, to study coexistence of epitopes, and to elucidate whether epitopes for Mabs are repeated or not in the RF-glycoproteins. Twenty-three Mabs recognizing the bovine RF- and SCO-glycoproteins in solutions (ELISA) as well as in tissue sections, were obtained. Nineteen of these Mabs also recognized the pig SCO, 11 the rabbit SCO, 6 the dog SCO, and 5 the rat SCO. None of the Mabs recognized the SCO of non-mammalian species. The different types of ELISA demonstrated that: (1) the epitopes reside in the proteinaceous moiety of the secretion, (2) they coexist in the same molecular forms and, with few exceptions, they did not overlap, (3) they were not repeated in the secretory molecule(s). Three Mabs were used for immunoblotting of RF; one of them revealed the same band pattern as that shown by an anti-RF serum. It is concluded that all Mabs raised in our laboratory are directed against non-repeated sequences of RF-glycoproteins that have not been conserved in vertebrate phylogeny.

Searching for specific binding sites of the secretory glycoproteins of the subcommissural organ

The molecular organization of Reissner's fiber (RF), the structure of its proteins, and the permanent turnover of these proteins are all facts supporting the possibility that RF may perform multiple functions. There is evidence that CSF-soluble RF-glycoproteins may occur under physiological conditions. The present investigation was designed to investigate the probable existence within the CNS of specific binding sites for RF-glycoproteins. Three experimental protocols were used: (1) immunocytochemistry of the CNS of bovine fetuses using anti-idiotypic antibodies, raised against monoclonal antibodies developed against bovine RF-glycoproteins; (2) in vivo binding of the RF glycoproteins, perfusing into the rat CSF 125I-labeled RF-glycoproteins, or grafting SCO into a lateral ventricle of the rat; (3) in vitro binding of unlabeled RF-glycoproteins to rat and bovine choroid plexuses maintained in culture. One of the anti-idiotypic antibody generated by a Mab raised against RF-glycoproteins binds to choroidal cells. Furthermore, binding of RF-glycoproteins to the rat choroid plexus was obtained when: (1) the choroid plexus was cultured in the presence of unlabeled RF-glycoproteins; (2) the concentration of soluble RF-glycoproteins in the CSF was increased by isografting SCOs into a lateral ventricle; (3) radiolabeled glycoproteins were perfused into the ventricular CSF. This evidence suggests that the apical plasma membrane of the ependymal cells of the choroid plexus has specific binding sites for RF-glycoproteins, of unknown functional significance. The radiolabeled RF-glycoproteins perfused into the rat CSF also bound to the paraventricular thalamic nucleus, the floor of the Sylvian aqueduct and of the rostral half of the fourth ventricle, and the meninges of the brain and spinal cord. The labeling of the paraventricular thalamic nucleus points to a functional relationship between this nucleus and the SCO. The possibility that the SCO may be a component of the circadian timing system is discussed.

Localization-induced Griffiths phase of disordered Anderson lattices

We demonstrate that local density of states fluctuations in disordered Anderson lattice models universally lead to the emergence of non-Fermi liquid (NFL) behavior. The NFL regime appears at moderate disorder ( W = Wc) and is characterized by power-law anomalies, e.g., C/T approximately 1/T((1-alpha)), where the exponent alpha varies continuously with disorder, as in other Griffiths phases. This Griffiths phase is not associated with the proximity to any magnetic ordering, but reflects the approach to a disorder-driven metal-insulator transition (MIT). Remarkably, the MIT takes place only at much larger disorder W(MIT) approximately 12Wc, resulting in an extraordinarily robust NFL metallic phase.

Tumor antigen presentation by dermal antigen-presenting cells

Several phenotypes of antigen-presenting cells are present in the dermis, where they presumably function to present encountered antigens for immune responses. This study examined the ability of dermal antigen-presenting cells to present tumor-associated antigens for the induction of in vivo antitumor immunity. Total murine dermal cells were exposed either to medium alone or to medium containing tumor-associated antigens from S1509a tumor cells. Subsequently, dermal cells were injected subcutaneously at weekly intervals into naïve mice for a total of three immunizations. One week following the final immunization, mice were challenged with living tumor cells. In these experiments, dermal cells pulsed with tumor-associated antigens induced protective immunity to tumor growth. Dermal cells exposed to tumor-associated antigens were also able to elicit delayed-type hypersensitivity after footpad injection into mice previously immunized against S1509a tumor cells. The ability to present tumor-associated antigens for both induction of antitumor immunity and elicitation of delayed-type hypersensitivity was dependent on I-A+ cells and was genetically restricted. Finally, dermal cells tended towards eliciting a greater antitumor delayed-type hypersensitivity response than epidermal cells. These results show that the murine dermis contains antigen-presenting cells capable of processing S1509a tumor antigens for the generation of protective antitumor immunity in vivo.

Relationship between sex differences in onset of schizophrenia and puberty

Some neurodevelopmental hypotheses of schizophrenia have postulated that sex differences in onset of illness could be explained by sexual dimorphism in onset of puberty, suggesting that early maturation accounts for the later onset of illness in women. The objective of this study was to analyse the relationship between age of menarche and age of onset of schizophrenia in a sample of Chilean patients. The medical records of 105 schizophrenic women diagnosed according to DSM-III-R criteria were studied. In all cases age of onset (first psychotic symptoms) and age of menarche were obtained. Pearson's correlation and student's t-test were used to analyse the data. The mean age of menarche in the sample of female patients (12. 98 years, S.D.=1.49) was significantly different from that of the general population of Santiago, Chile (12.53 years, S.D.=1.32) (t=2. 38; P<0.05). The mean age of onset of schizophrenia in female patients (19.92 years, S.D.=5.13) was significantly earlier in the Chilean sample than that reported in European and North American samples (P<0.05). No differences were observed when comparing the mean age at menarche. The subtypes with the earliest onset presented the earliest age of menarche and the subtypes with the latest onsets showed the latest ages at menarche. However, no correlation was observed between the age at onset of illness and the age at menarche, both in the total sample and in the analysis by subtype. The results of this study do not support a correlation between puberty and age of onset of illness.

Identification of Reissner's fiber-like glycoproteins in two species of freshwater planarians (Tricladida), by use of specific polyclonal and monoclonal antibodies

By using one polyclonal antiserum raised against bovine Reissner's fiber and seven monoclonal antibodies raised against bovine Reissner's fiber and against immunopurified bovine subcommissural organ glycoproteins, we have investigated two freshwater planarian species (Girardia tigrina, Schmidtea mediterranea) by light- and electron-microscopic immunocytochemistry. ELISA probes showed that the monoclonal antibodies recognized different, nonoverlapping, unrepeated, proteinaceous epitopes present in the same compounds of bovine Reissner's fiber. Cells immunoreactive to the polyclonal and monoclonal antibodies were found in the dorsal and ventral integument of both planarian species. Labeled cuboid epidermal cells bore cilia and displayed several types of secretory granules; they were covered by a film of immunoreactive material. Studies on adjacent thin and semithin sections revealed coexistence of label in the same regions and in the same cells when two different monoclonal antibodies were used. These results indicate that a secretory substance immunologically similar to the secretion of the vertebrate subcommissural organ is present in primitive tripoblasts such as planarians, suggesting that these secretions are ancient and well conserved in phylogeny.

Immunogenicity and effectiveness of post-exposure rabies prophylaxis with a new chromatographically purified Vero-cell rabies vaccine (CPRV): a two-stage randomised clinical trial in the Philippines

Recent improvements in chromatographic purification procedures have made it possible to develop a new chromatographically purified rabies vaccine (CPRV) by further purifying the current rabies vaccine prepared from Vero-cell culture (PVRV) (Verorab; Pasteur Merieux Connaught). The immunogenicity and effectiveness of post-exposure rabies prophylaxis with this new vaccine were evaluated in a two-stage clinical trial conducted in the Philippines. In both study stages. post-exposure treatment consisted of five injections of vaccine [(D)ays 0, 3, 7, 14, 28], together with a dose of rabies immunoglobulin (RIG) of equine or human origin on D0. In stage 1, 231 subjects with low-risk rabies exposure (WHO category I or II), and who had a negative ERIG skin test, were treated with either CPRV (n = 114) or PVRV (n = 117). By D14, all subjects in each group had achieved rabies antibody titres over ten times that recommended by the WHO as indicating seroconversion (> or = 0.5 IU/ml). The kinetics of the immune response to vaccination were very similar in the two groups, and at D28, the immunogenicity of CPRV was equivalent to that of PVRV (one-sided equivalence test). Following these positive results, 132 subjects with severe rabies exposure were included in the second stage of this trial. All were scheduled to receive four vaccine doses with CPRV. After D14, only those 57 patients with confirmed rabies exposure (animal with positive FA test) and seven patients for whom rabies exposure could not be excluded (animal lost or not tested) completed the treatment and were followed for one year to assess survival. After 1 year, 62 patients treated for confirmed or possible severe rabies exposure had been examined and were still alive. Two patients contacted by letter and telephone confirmed good health 7 and 16 months after exposure. No severe local or systemic reactions were reported in either stage of the study, and no treatment-related serious adverse event occurred. This two-stage clinical trial attests to the safety and satisfactory immunogenicity of CPRV in post-exposure rabies treatment, and confirms the effectiveness of a new rabies vaccine in patients with severe confirmed exposure.

Comparative evaluation of the in vitro activity of three combinations of beta-lactams with beta-lactamase inhibitors: piperacillin/tazobactam, ticarcillin/clavulanic acid and ampicillin/sulbactam

Recently, two new combinations of Beta-lactam antibiotics with Beta-lactamase inhibitors became commercially available in Brazil: piperacillin/tazobactam and ampicillin/sulbactam. This study was designed to assess and compare the in-vitro activity of these new compounds, as well as that of ticarcillin/clavulanic acid, against bacteria isolated in our environment. A total of 749 bacteria isolated at São Paulo Hospital were tested using the disk diffusion method, in compliance with NCCLS standardization, using strict quality control. Only one sample per patient was included in the study. Oxacillin-resistant staphylococcus samples were not included in this study. Of the total samples tested, 84.5% were susceptible to piperacillin/tazobactam, 81.2% to ticarcillin/clavulanic acid, and 77.6% to ampicillin/sulbactam. Piperacillin/tazobactam was also found to be the most active combination of the three against Enterobacteriaceae ( n = 312), inhibiting 91.7% of the bacteria tested. Ticarcillin/clavulanic acid was active against 85.8% of the Enterobacteriaceae, while ampicillin/sulbactam inhibited 83.2% of the samples. This order of the spectrum of action (piperacillin/tazobactam > ticarcillin/clavulanic acid >ampicillin/sulbactam )was maintained for the majority of Enterobacteriaceae species analyzed. Pseudomonas aeruginosa ( n = 117) showed extremely high resistance to the three combinations. Piperacillin/tazobactam was active against 61.5% of the samples, while ticarcillin/clavulanic acid was active against 56.4% of the samples of this species. The activity of ampicillin/sulbactam against P. aeruginosa was extremely low; however, this was the most active combination against Acinetobacter baumannii ( 87.0% susceptibility). Piperacillin/tazobactam was the most active combination against Stenotrophomonas (Xanthomonas )maltophilia (100% susceptibility) and Burkholderia cepacia (90.9% susceptibility). The three combinations showed excellent activity against the Gram-positive cocci tested (97.3% to 98.2% susceptibility). In sum, piperacillin/tazobactam was more active against all Gram-negative species than the other two combinations, with the exception of A. baumannii, and showed similar activity against Gram-positive cocci.

A multicenter, double-blind, randomized comparison of oral ondansetron 8 mg b.i.d., 24 mg q.d., and 32 mg q.d. in the prevention of nausea and vomiting associated with highly emetogenic chemotherapy. S3AA3012 Study Group

The objectives of this study were to compare the efficacy and safety of orally administered ondansetron 8 mg b.i.d., 24 mg q.d., and 32 mg q.d. in the prevention of nausea and vomiting associated with high-dose cisplatin-based chemotherapy (cisplatin > or = 50 mg/m2). This was a randomized, parallel-group, double-blind study conducted in North America. It was planned that all patients would receive one of the following orally administered ondansetron treatments 30 min before starting cisplatin dosing (administered over < or = 3 h): 8 mg b.i.d. with 8 h between doses (124 patients), 24 mg q.d. (116 patients), and 32 mg q.d. (117 patients). Use of prophylactic corticosteroids was not permitted. During the 24-h study period, the highest complete response rate (no emesis, rescue antiemetic therapy, or withdrawal) occurred in patients who received ondansetron 24 mg q.d.: 76/115 or 66%, as against 68/124 (55%) after ondansetron 8 mg b.i.d. and 64/117 (55%) after ondansetron 32 mg q.d. Complete control of nausea (no nausea, no rescue, no withdrawal) occurred in more patients in the ondansetron 24 mg q.d. group (64/114, 56%) than in the ondansetron 8 mg b.i.d. group (43/121, 36%) or in the ondansetron 32 mg group (55/117, 50%). These results demonstrate that following highly emetogenic cisplatin-based chemotherapy (> or =2 50 mg/m2), oral ondansetron 24 mg q.d. is more effective than 8 mg b.i.d. for overall control of nausea, and at least as effective if not more effective in the control of acute vomiting than 8 mg b.i.d. or 32 mg q.d. Ondansetron 24 mg q.d. was well tolerated, and no new or unexpected adverse events were identified.

A randomized blinded clinical trial of two antivenoms, prepared by caprylic acid or ammonium sulphate fractionation of IgG, in Bothrops and Porthidium snake bites in Colombia: correlation between safety and biochemical characteristics of antivenoms

A randomized blinded clinical trial was performed in 53 patients bitten by Bothrops sp. and Porthidium sp. in Antioquia and Chocó, Colombia, in order to compare the efficacy and safety of two antivenoms made of whole IgG obtained by either ammonium sulphate (monovalent anti-B. atrox) or caprylic acid (polyvalent) fractionation. Additionally, antivenoms were compared by electrophoretic and chromatographic analyses and anticomplementary activity in vitro. With a protocol of 2, 4 and 6 antivenom vials for the treatment of mild, moderate and severe envenomings, respectively, both antivenoms were equally efficient to neutralize the most relevant signs of envenoming and to clear serum venom levels in patients from the first hour and later on. Three patients with severe envenoming and initially treated with less than six vials on admission had persistent or recurrent venom antigenemia within 12-48 h. Monovalent antivenom fractionated by ammonium sulphate precipitation had higher amounts of protein aggregates and nonimmunoglobulin proteins than polyvalent antivenom fractionated by caprylic acid precipitation. Both antivenoms presented anticomplementary activity in vitro, being higher in the monovalent product. In agreement, monovalent antivenom induced a significantly higher incidence of early antivenom reactions (52%) than polyvalent antivenom (25%).

mRNA and protein expression of SSA/Ro and SSB/La in human fetal cardiac myocytes cultured using a novel application of the Langendorff procedure

Irreversible congenital heart block (CHB) and the transient rash of neonatal lupus are strongly associated with maternal antibodies to SSA/Ro and SSB/La proteins; however, the precise mechanism by which these antibodies mediate organ-specific injury is not yet defined. Culturing of keratinocytes has provided critical insights. Accordingly, successful culturing of human fetal cardiac myocytes at high yield would constitute a powerful tool to directly examine conditions that promote expression of the target autoantigens. To accomplish this aim, fetal cardiac myocytes from 18- to 22-wk abortuses were established in culture using a novel technique in which cells were isolated after perfusion of the aorta with collagenase in a Langendorff apparatus. After preplating to decrease fibroblast contamination, cardiocytes were grown in flasks and slide chambers. Staining with monoclonal anti-sarcomeric alpha-actinin revealed the expected striations typical of cardiac myocytes in 70-90% of the cells after 4 d in culture. Furthermore, the cells were observed to beat at rates varying between 25-75 beats per minute (bpm) after the addition of 1.8 mM CaCl2. An average yield of 45-60 x 10(6) cells was obtained from a 3- to 5-g heart. Cellular localization of SSA/Ro and SSB/La by indirect immunofluorescence and demonstration of mRNA expression by reverse transcriptase polymerase chain reaction supports the feasibility of cultured cardiac myocytes for the study of congenital heart block. In contrast to the increased expression of SSA/Ro reported for keratinocytes, incubation of cultured human cardiac myocytes with either 17beta-estradiol or progesterone did not alter mRNA expression or cellular localization of 48 kD SSB/La, 52 kD SSA/Ro, or 60 kD SSA/Ro. In summary, we describe a novel method to successfully culture human fetal cardiac myocytes that should provide a valuable resource for investigation of the molecular mechanism(s) contributing to the development of congenital heart block. Differential constitutive and estradiol-induced expression of 52 and 60 kD SSA/Ro in human cardiac myocytes compared with keratinocytes may be a factor contributing to the marked discordance of clinically detectable injury in these two target tissues.

Quantification of the secretory glycoproteins of the subcommissural organ by a sensitive sandwich ELISA with a polyclonal antibody and a set of monoclonal antibodies against the bovine Reissner's fiber

The subcommissural organ (SCO) is an ependymal brain gland that releases glycoproteins into the ventricular cerebrospinal fluid where they condense to form the Reissner's fiber (RF). We have developed a highly sensitive and specific two-antibody sandwich enzyme-linked immunosorbent assay (ELISA) for the quantification of the bovine SCO secretory material. The assay was based on the use of the IgG fraction of a polyclonal antiserum against the bovine RF as capture antibody and a pool of three peroxidase-labeled monoclonal antibodies that recognize non-overlapping epitopes of the RF glycoproteins as detection antibody. The detection limit was 1 ng/ml and the working range extended from 1 to 4000 ng/ml. The calibration curve, generated with RF glycoproteins, showed two linear segments: one of low sensitivity, ranging from 1 to 125 ng/ml, and the other of high sensitivity between 125 and 4000 ng/ml. This assay was highly reproducible (mean intra- and interassay coefficient of variation 2.2% and 5.3%, respectively) and its detectability and sensitivity were higher than those of ELISAs using exclusively either polyclonal or monoclonal antibodies against RF glycoproteins. The assay succeeded in detecting and measuring secretory material in crude extracts of bovine SCO, culture medium supernatant of SCO explants and incubation medium of bovine RF; however, soluble secretory material was not detected in bovine cerebrospinal fluid.

Bioequivalence evaluation of 2 different oral formulations of ciprofloxacin in healthy volunteers

A bioequivalence study of 2 oral formulations of 500 mg tablets of ciprofloxacin was carried out in 24 healthy volunteers according to a single dose, two-sequence, crossover randomized design. Blood samples were taken prior to each administration and at 13 points within 32 hours after the dose, and plasma concentrations of ciprofloxacin were determined by HPLC. The pharmacokinetic parameters Cmax and tmax were obtained directly from plasma data, ke was estimated by log-linear regression, and AUC was calculated by the trapezoidal rule. The pharmacokinetic parameters AUC and Cmax were tested for bioequivalence after log-transformation of data, differences of tmax were evaluated nonparametrically. The 90% standard confidence intervals of the mean values for the test/reference ratios were 0.87-0.97 for AUC and 0.91-1.05 for Cmax, within the bioequivalence acceptable range of 0.80-1.25 limits. So, we conclude that both formulations were found bioequivalent and, therefore, interchangeable.