Drug-Tea Polyphenol Interaction (III) Incompatibility between Aripiprazole Oral Solution and Green Tea

The details of incompatibility between aripiprazole (ARIP) oral solution and green tea were examined. When the ARIP oral solution was mixed with a commercial PET bottled green tea beverage, the residual rate of ARIP in the mixed solution decreased to 15.7-17.6%. Mixing with ARIP reduced the content of gallate-type green tea polyphenols (GTPs) in the mixed solution but not the content of non-gallate-type GTPs. Furthermore, using pH 3.0 lactic acid buffer, 2.23 mM ARIP solution and 2.23 mM GTP solution were prepared, and the same volumes of ARIP solution and GTP solution were mixed. When the gallate-type GTP solution was mixed, the residual rate of ARIP in the mixed solution decreased. On the other hand, when the non-gallate-type GTP solution was mixed, the residual rate of ARIP in the mixed solution did not decrease. From the above results, it was found that the main reason for the incompatibility between ARIP oral solution and green tea was the formation of an insoluble substance composed of ARIP and gallate-type GTPs in green tea. Furthermore, experimental results using the continuous variation method revealed that ARIP and (-)-epigallocatechin gallate, which is the most representative gallate-type GTP, interact at a molar ratio of 3 : 2.

Preparation and Antiviral Activity of Some New C3- and CS-Symmetrical Tri-Substituted Triazine Derivatives Having Benzylamine Substituents

We report the preparation of new C₃- and C_S-symmetrical molecules constructed on a triazine (TAZ) template. Anti-herpes simplex virus type 1 (anti-HSV-1) and cytotoxic activities against Vero cells of synthesized TAZ derivatives were evaluated. The results suggested that the presence of an electron-donating group(s) on the benzene ring in benzylamine groups on the TAZ template is an important structural factor for expressing a high level of anti-HSV-1 activity and low cytotoxicity for these C₃ types of TAZ derivatives. Among the tested TAZ derivatives, compounds 4f and 7h showed the highest anti HSV-1 activities (EC₅₀=0.98 and 1.23 µM, respectively) and low cytotoxic activities to Vero cells (50% cytotoxic concentration (CC₅₀)=292.2 and >200 µM, respectively).

Synthesis of new 5-substituted hydantoins and symmetrical twin-drug type hydantoin derivatives

In connection with our studies on hydantoin derivatives, a conventional regioselective chemical transformation of 5-methylene hydantoins 4a-c to 5-aminomethyl-substituted hydantoins 5-10 or to 5-amino-5-methyl-disubstituted hydantoins 11-14 is described. Synthesis of bivalent twin-drug type hydantoin derivatives 19-24 and the binding property of a bivalent symmetrical hydantoin derivative 24b to sulfated glycosaminoglycans are also described.

Incompatibility between propericiazine oral solution and tea-based drink

Here, we studied the incompatibility between an oral solution of propericiazine (PCZ), an antipsychotic drug, and various commercially available bottled tea-based drinks. When 0.5 mL of the PCZ oral solution (10 mg/mL) was mixed with 16.5 mL of a tea-based drink (such as green tea, oolong tea, and black tea), the residual PCZ content declined to approximately 50% in some mixed solutions. After mixing with other tea-based drinks, the residual PCZ content declined to approximately 30%, while in others, it changed very little. The residual PCZ content declined immediately after mixing with tea-based drinks, but the rate remained almost unchanged for the next 24 h. Furthermore, the pH of the mixture increased to 4.5-5.1 after the oral solution of PCZ (original pH 3.8) was diluted with various tea-based drinks. Afterwards, the pH did not change for 24 h. The mixture became cloudy immediately after diluting PCZ oral solution with tea-based drinks, and the insoluble substance gradually precipitated. In order to elucidate factors responsible for the decline in the content of PCZ, a (-)-epigallocatechin gallate solution, which is a main ingredient of green tea polyphenol, was mixed with the PCZ oral solution. After mixing, the residual PCZ content declined to approximately 60-75%. On the other hand, the content of PCZ did not decline when a (-)-epigallocatechin solution was mixed with the PCZ oral solution. The results from this study demonstrated that PCZ content was reduced after dilution in tea-based drinks because of the interaction between PCZ and polyphenol with a galloyl group in tea-based drinks.

[Mechanism of interaction between risperidone and tea catechin (2) influence of presence of galloyl group in catechin on insoluble complex formation with risperidone]

The influence of the presence of a galloyl group in catechin on complexation with risperidone (RISP) was examined using (--)-epigallocatechin gallate (EGCg) and (--)-epigallocatechin (EGC), which are present in green tea as tea catechins. By quantitative analysis using HPLC, it was found that EGCg formed an insoluble complex with RISP for concentration dependence, whereas EGC did not. The large contribution of the galloyl group of catechin to form an insoluble complex with RISP was recognized in this study. In a molecular modeling study, it was found that the EGCg-R complex (EGCg with RISP) formed three hydrogen bonds between the hydroxyl groups of EGCg and the two N atoms and an O atom of RISP. The hydrogen bond between the hydroxyl group of the galloyl ring in EGCg and the N atom of the piperidine ring in RISP stabilized EGCg-R more energetically. The EGC-R complex (EGC with RISP) also formed three hydrogen bonds, but the N atom of the piperidine ring in RISP did not participate in hydrogen bond formation. According to the calculation using the COSMO-RS method, the water solubility of the EGCg-R complex was 1/26 that of the EGC-R complex. Therefore, the EGCg-R complex was difficult to dissolve in water. In the (1)H-NMR spectra of RISP in DMSO-d(6), although chemical shifts of protons near the N atom on the piperidine ring moved downfield on the addition of EGCg, no change in chemical shifts of these protons was observed on the addition of EGC. Therefore, based on these results, the galloyl group of EGCg contributes to the formation of an insoluble complex between tea catechin and RISP, and this insoluble complex is stabilized by the hydrogen bond between the hydroxyl group of the galloyl ring in EGCg and the N atom of the piperidine ring in RISP.

High-yield automated synthesis of [18F]fluoroazomycin arabinoside ([18F]FAZA) for hypoxia-specific tumor imaging

The aim of this study was to develop an efficient fully automated synthesis method to achieve a high radiochemical yield of [(18)F]FAZA with a small amount of precursor. A small cartridge containing 25mg of the QMA resin was prepared and evaluated to obtain [(18)F]F(-) in a small quantity of base (K(2)CO(3)), which might allow the use of a small amount of precursor. The labeling and hydrolyzing conditions for [(18)F]FAZA synthesis were also investigated manually. No-carrier-added [(18)F]F(-) was trapped on the small QMA cartridge and eluted with a mixture of Krytofix 222 (2.26 mg, 6.0 μmol) and K(2)CO(3) (0.69 mg, 5.0 μmol) in 70% MeCN (0.4 mL). The automated synthesis of [(18)F]FAZA was optimally performed with a modified NIRS original synthesis system for clinical use, by labeling 2.5mg (5.2 μmol) of the precursor in DMSO (0.4 mL) at 120°C for 10 min, and then by hydrolyzing the (18)F-labeled intermediate with 0.1M NaOH (0.5 mL) at room temperature for 3 min. Using the above condition, the [(18)F]FAZA injection was obtained with a high radiochemical yield of 52.4±5.3% (decay-corrected, n=8) within 50.5±1.5 min.

Population pharmacokinetics of phenobarbital by mixed effect modelling using routine clinical pharmacokinetic data in Japanese neonates and infants: an update

WHAT IS KNOWN AND OBJECTIVE

Optimal use of phenobarbital in the neonatal population requires information regarding the drug's pharmacokinetics and the influence of various factors, such as different routes of administration, on the drug's disposition. However, because of sampling restrictions, it is often difficult to perform traditional pharmacokinetic studies in neonates and infants. This study was conducted to establish the role of patient characteristics in estimating doses of phenobarbital for neonates and infants using routine therapeutic drug monitoring data.

METHODS

The population pharmacokinetics of phenobarbital was evaluated using 109 serum concentration measurements obtained from routine phenobarbital monitoring of 70 neonates and infants. The data were analysed using the non-linear mixed effects model. A one-compartment pharmacokinetic model with first-order elimination was used. Covariates screened were current total bodyweight (TBW), gestational age, postnatal age (PNA), post-conceptional age, gender and neonates-infants clearance factor (serum concentration of phenobarbital; Conc).

RESULTS AND DISCUSSION

The final pharmacokinetic parameters were CL/F (mL/h) = (5.95.TBW (kg) +1.41.PNA (weeks)) Conc (serum phenobarbital concentration >50 μg/mL)(-0.221),Vd/F(L) =1.01.TBW (kg), and F = 0.483 for oral administration and F = 1 was assumed for suppository. Conc(-0.221) is 1 for phenobarbital concentration <50 μg/mL. The important variables for predicting phenobarbital clearance in this study were TBW, PNA and Conc. Phenobarbital clearance increases proportionately with increasing TBW, and an older newborn was expected to have a higher rate of clearance than a younger newborn of equal bodyweight. Moreover, the clearance of phenobarbital decreased nonlinearly with increasing serum concentration of phenobarbital >50 μg/mL (Conc(-0.221) ).

WHAT IS NEW AND CONCLUSION

We developed a new model for neonate and infant dosing of phenobarbital with good predictive performance. Clinical application of our model should permit more accurate selection of initial and maintenance doses to achieve target phenobarbital concentrations in Japanese neonates and infants, thereby enabling the clinician to achieve the desired therapeutic effect. A similar approach can be used to validate our model for use in other neonate and infant populations.

The relationship between histomorphological characteristics and Ki-67 proliferation index in meningiomas

OBJECTIVES

This study had two aims. The first was to use the Ki 67 proliferation index (Ki-67 PI) to study the relationship between the proliferation potential and histopathological features such as mitosis, necrosis, loss of architecture, small cell change, hypercellularity, pleomorphism, brain invasion, dura invasion, bone invasion, and histological grade. The second aim was to compare primary and recurrent meningioma with respect to morphological characteristics and Ki-67 PI values.

BACKGROUND

Meningiomas are tumors whose histological features do not predict their biological behavior. Despite their slow growth and even after total resection, recurrence may occur

METHODS

A total of 245 meningioma cases in whom Ki-67 PI was studied were included in the study. The cases were assessed with respect to 10 morphological characteristics, and a possible significant relationship between these and Ki 67 PI was statistically tested.

RESULTS

We found a statistically significant relationship between Ki-67 PI and mitotic activity, necrosis, loss of architecture, small cell change, brain invasion. In contrast to brain invasion, no significant relationship was present between dura or bone invasion and Ki-67 PI. We identified asignificant increase in the histological grade, mitotic activity and Ki-67 PI value of recurrent tumors, as compared to primary ones

CONCLUSION

Ki-67 PI values overlap in different grades. This overlapping might be due to the heterogeneity of biological activity within the tumor tissue (Tab. 2, Fig. 7, Ref. 21).

Spontaneous remission of acute lymphoblastic leukemia with mediastinal mass

Spontaneous remission/regression of cancer is defined as partial or complete disappearance of malignant disease temporarily or permanently in the absence of medical treatment. This event is named as spontaneous regression for solid tumors and spontaneous remission for leukemia. The authors report the case of a girl aged 4 years and 3 months, who presented with mediastinal mass and leukemic findings in the bone marrow both of which reappeared after spontaneous regression and remission, respectively.

Interaction between catechol-O-methyltransferase (COMT) Val108/158Met and brain-derived neurotrophic factor (BDNF) Val66Met polymorphisms in age at onset and clinical symptoms in schizophrenia

Catechol-O-methyltransferase (COMT) gene is one of the candidate genes for schizophrenia because it codes an enzyme that participates in the metabolic inactivation of dopamine and noradrenaline and a limiting factor of dopamine metabolism in the prefrontal cortex. COMT gene lies on chromosome 22q11.2, which has been associated with schizophrenia susceptibility. A single-nucleotide polymorphism of COMT gene at position 108/158 results in an amino acid substitution from valine (val) to methionine (met), which modifies its enzymatic activity and may change the brain morphology and expressional behaviors. On the other hand, brain-derived neurotrophic factor (BDNF) plays a critical role in the development of mesolimbic dopaminergic- related systems. BDNF also contains a functional single-nucleotide polymorphism at codon 66 (Val66Met) of its prodomain and this polymorphism is responsible for schizophrenia susceptibility. In this study, we first investigated the relationship between COMT Val108/158Met polymorphism and age at onset as well as levels of clinical symptoms in 158 of chronic schizophrenia inpatients and then we investigated the gene-by-gene interaction between COMT Val108/158Met polymorphism and BDNF Val66Met polymorphism with age- and sex-matched control subjects (n = 318). We concluded that the COMT Val108/158Met polymorphism was not related to either the onset at age or the levels of clinical symptoms after long-term antipsychotic treatment in schizophrenia.

Permeation-enhancing effect of aloe-emodin anthrone on water-soluble and poorly permeable compounds in rat colonic mucosa

The aims of this study were to examine the enhancing effects of aloe-emodin anthrone (AEA) on the colonic membrane permeability of water-soluble and poorly permeable compounds and to clarify the mechanism of the permeation-enhancing activity of AEA. The permeation-enhancing activity of AEA was estimated from changes in the permeability coefficient of 5(6)-carboxyfluorescein (CF) in rat colonic mucosa using a Ussing-type chamber. Various inhibitors were used to investigate the mechanism of action of AEA. The structural change in the membrane and the cytotoxicity of AEA in the intestinal mucosa were evaluated by measuring the electrical resistance of the membrane (R(m)) and lactate dehydrogenase (LDH) activity, respectively. AEA significantly increased the permeation of CF in a dose-dependent manner. The enhanced permeability was significantly suppressed by a histamine H(1) receptor antagonist, pyrilamine, and a mast cell stabilizer, ketotifen, but not by a histamine H(2) receptor antagonist, cimetidine. The enhancing effect was also inhibited by an inhibitor of protein kinase C (PKC). Potential difference and short-circuit current values decreased, while R(m) values remained constant throughout the experiment. The addition of AEA to the mucosal solution decreased R(m) to 30%, but then remained constant. LDH activity with AEA was not significantly different from that of the control. In conclusion, AEA is a candidate for effective absorption enhancers without damage of the membrane and cytotoxicity. We propose that AEA stimulates mast cells within the colonic mucosa to release histamine, which probably bind to the H(1) receptor. The intracellular PKC route activated by H(1) receptor activation enhances the permeability of water-soluble and poorly permeable drugs via opening of tight junctions in rat colonic membrane.

[Enhancing effects of ion-pair complexes on skin permeation of cromolyn in vitro]

Lipophilic ion-pair complexes of 3-dl-alpha-tocopherylcarbonyl-1-n-alkyl-pyridinium-cromolyn (TAP-CG) were designed to enhance the percutaneous absorption of cromolyn (CG), and the effect of n-alkyl chainlength of the ion-pair complexes on the CG permeation through hairless mouse skin was evaluated in vitro. The permeation rates of CG were examined in isopropyl myristate (IPM) suspension using static Keshany-Chien type diffusion cells at 32 degrees C. The permeation parameters, steady-state flux, diffusion coefficient, partition coefficient between skin and IPM, and permeability coefficient were determined. Steady-state fluxes of CG increased linearly with the increasing n-alkyl chain-length of TAP-CG, and 3-dl-alpha-tocopherylcarbonyl-1-n-hexyl-pyridinium-cromolyn (THP-CG) produced the highest CG flux (0.62 +/- 0.11 nmol.cm-2.h-1), which was 14-fold greater than that of CG.Na in IPM suspension and more than 480-fold greater than that of CG.Na in aqueous solution due to increasing lipophilicity. In the case of TAP-CG with longer n-alkyl chainlength than THP-CG, however, the steady-state fluxes of CG decreased due to the high molecular weight and/or the high lipophilicity of the ion-pair complexes. It is suggested that lipophilic ion-pair complexes, especially THP-CG, are effective in absorption of cromoglicate through the skin. The results would be useful for studies on the role of each counterion in the lipophilic ion-pair complexes.

Anti-inflammatory effects of 5-aminosalicylic acid conjugates with chenodeoxycholic acid and ursodeoxycholic acid on carrageenan-induced colitis in guinea-pigs

Two epimeric bile acid conjugates, 5-aminosalicylic acid-chenodeoxycholic acid (5-ASA-CDCA) and 5-aminosalicylic acid-ursodeoxycholic acid (5-ASA-UDCA), were synthesized to deliver 5-ASA to the large intestine by oral administration. The movement of the conjugates down the gastrointestinal tract and the anti-inflammatory effects on ulcerative colitis were investigated by administering the conjugates to guinea-pigs with an inflammatory bowel disease induced by 2% degraded carrageenan solution. The conjugates were protected from deconjugation in stomach and small intestine and reached the caecum and the colon, where 5-ASA was more easily liberated from 5-ASA-CDCA than from 5-ASA-UDCA. The conjugates at doses equivalent to 50 or 150 mg kg(-1) 5-ASA were orally administered once a day for 4 weeks from the 15th day after starting carrageenan treatment. The body weights and the bleeding scores of occult blood in faeces were measured during the experiment. The number of ulcers in the caecum and the colon were counted after killing the guinea-pigs at the end of the experiment. Rapid onset of efficacy was shown by a significant reduction in bleeding scores within a week after administration of the conjugates. Treatment with the lower dose of 5-ASA-CDCA showed a recovery of body weight and a significantly decreased number of ulcers in the caecum, and the ulcers in the colon had completely disappeared bythe end of the experiment. There was a good correlation found between the number of ulcers in the caecum and the bleeding scores of occult blood in faeces. The findings indicate that both conjugates were sufficiently delivered to the large intestine without deconjugation and that the lower dose of 5-ASA-CDCA is enough for treatment of ulcerative colitis in colonic inflammatory bowel diseases.

Miliary tuberculosis: clinical manifestations, diagnosis and outcome in 38 adults

OBJECTIVE

The aim of the study was to determine the clinical, radiographic and laboratory characteristics, diagnostic methods, and prognostic variables in patients with miliary tuberculosis (TB).

METHODOLOGY

The records of 38 patients (15 male, 23 female; mean age 41 years, range 16-76 years) with miliary TB from 1978 to 1998 were analyzed. Patients were evaluated also as to whether they presented with a fever of unknown origin (FUO). Criteria for the diagnosis of miliary TB were (i) miliary pattern on chest X-ray or (ii) biopsy or autopsy evidence of miliary organ involvement. Paraffin-embedded tissues with granulomata (n = 15) were re-evaluated for the presence of Mycobacterium tuberculosis DNA by polymerase chain reaction (PCR).

RESULTS

Predisposing conditions were present in 24% of the patients. The findings were fever, weakness, night sweats, anorexia/weight loss (100% for each), hepatomegaly (37%), splenomegaly (32%), choroidal tubercles (13%), neck stiffness (11%), altered mental status (8%), anaemia (76%), leukopenia (26%), thrombocytopenia (16%), lymphopenia (76%), pancytopenia (8%) and hypertransaminasemia (55%). Eighteen patients (47%) met the criteria for a FUO. Miliary infiltrates were found on chest X-rays of 32 of 38 cases (84%). In six cases without miliary infiltrates, the diagnosis was made by laparotomy in four cases, and autopsy in two cases. Tuberculin skin test was positive in 32% of cases. Acid-fast bacilli were demonstrated in 37% (16/43), and cultures for M. tuberculosis were positive in 90% (9/10) of tested specimens (predominantly sputum and bronchial lavage). Granulomas were found in 85% (11/13) of lung, 100% (15/15) of liver, and 56% (9/16) of bone marrow tissue specimens. Acid-fast bacilli staining was negative in all (0/21), while PCR was positive in 47% (7/15) of specimens with granulomata. Mortality was 18%. Stepwise logistic regression identified male sex (P = 0.005), non-typical miliary pattern (P = 0.015), altered mental status (P = 0.002) and failure to treat for TB (P = 0.00001) as independent predictors of mortality.

CONCLUSIONS

Miliary infiltrates on chest X-ray or FUO should raise the possibility of miliary TB. Therapy should be administered urgently to prevent an otherwise fatal outcome.

Multimodal inclusion complexes between barbiturates and 2-hydroxypropyl-beta-cyclodextrin in aqueous solution: isothermal titration microcalorimetry, (13)C NMR spectrometry, and molecular dynamics simulation

Multiple types (structures) of inclusion complexes between barbiturates and 2-hydroxypropyl-beta-cyclodextrin (HPCD) were evaluated by isothermal titration microcalorimetry and (13)C NMR spectroscopy. The geometries of the inclusion complexes were suggested by molecular dynamics simulation. Barbituric acid (BA), barbital (B), amobarbital (AB), pentobarbital (PB), secobarbital (SB), cyclobarbital (CB), and phenobarbital (PHB) were used as barbiturates with different substituents on the barbituric acid ring and compared for inclusion types in aqueous solution. The association constants (K), stoichiometries, and thermodynamic parameters change in free energy (DeltaG) change in enthalpy (DeltaH), and change in entropy [DeltaS] for each type of complex were determined from the calorimetric data. The inclusion complexation was largely entropy driven because of hydrophobic interactions. The values of K increased in the order BA<B<AB<PB<SB<CB<PHB. Barbiturates, except B and BA, form two types of inclusion complex with a 1:1 stoichiometry in the un-ionized forms. The first type of inclusion complex with high affinity (K(1)) was characterized by small negative values of DeltaH(1) and large positive DeltaS(1), where the substituent R2 of the barbiturate was initially inserted into the cavity of HPCD through hydrophobic interactions. There was a good relationship between DeltaG(1) obtained from the calorimetric data for the first type of inclusion complex and DeltaG(R2) calculated from the changes in (13)C Nuclear Magnetic Resonance (NMR) chemical shifts for the substituent R2 of barbiturates. These types were very stable in aqueous solution at various pHs. The second type of complex, with low affinity (K(2)), was characterized by large negative values of DeltaH(2) and small positive DeltaS(2), reflecting van der Waals' interactions in the un-ionized forms of barbiturates at pH values less than pK(a). The values of K(2) were markedly decreased to <10(3) M(-1) as the barbiturates were ionized over pH 8. Thus, in the second type, the barbituric acid ring contributed to forming the complexes. The geometries were stabilized by hydrogen bond formation between the hetero atoms in the barbituric acid ring and the secondary hydroxyl groups on the rim of the cyclodextrin. The (13)C NMR chemical shifts of C4 and C6 carbons in the barbituric acid ring were moved upfield significantly by the inclusion complexation. On the other hand, B and BA could form only one type of complex, the lid-type supramolecular complex with small association constants.

Influence of pentoxifylline and interferon-alpha on prevention of stricture due to corrosive esophagitis. An experimental study in the rat

The effects of pentoxifylline (PTX) and interferon alpha (IFN-alpha) in the prevention of strictures due to corrosive esophagitis in rats were investigated. Forty rats were randomly divided into four equal groups. Corrosive esophagitis was induced in all groups by application of 37.5% NaOH to the distal esophagus for a period of 90 s followed by saline rinse. Histopathologic damage was significantly lower in the PTX and IFN-alpha-treated groups than in the untreated group. During the study period, PTX and INF-alpha-treated animals showed a significant increase in body weight when compared to controls. However, PTX provided more significant prevention of stricture formation than IFN-alpha. In the PTX-treated group, the wall thickness and quantity of hydroxyprolin were significantly lower than in the untreated and IFN-alpha-treated groups. Stenosis index in the PTX group was significantly reduced compared to the control group. PTX prevents the stricture formation due to corrosive esophagitis in this experimental model. IFN-alpha was also shown to prevent stricture formation when considering amelioration of histopathologic damage and increase in body weight.

Congenital dyserythropoietic anemia type I with ringed sideroblasts

A 25-year-old male with anemia, jaundice and liver dysfunction was admitted to our institution. Anisopoikilocytosis with tear-drop forms, polychromasia, basophilic stippling in peripheral blood smear, erythroid hyperplasia with megaloblastoid changes, binucleated cells and intranuclear bridging in bone marrow aspirate and spongy, unevenly condensed nuclear chromatin in electron microscopy studies indicated that he had congenital dyserythropoietic anemia (CDA) type I. As a rare finding in CDA, ringed sideroblasts were noted. It is proposed that this patient is an example for the designation 'variant congenital dyserythropoietic anemia with ringed sideroblasts'.

Detection of t(14;18) in turkish follicular lymphomas using the polymerase chain reaction

A t(14;18) translocation is closely associated with the follicular lymphoma but is also seen in diffuse B cell lymphomas with a previous history of a follicular lymphoma as well as de novo diffuse lymphomas. Estimation of the frequency of t(14;18) in follicular lymphoma vary widely from 33 to 89%. Furthermore, no extensive data have been published on the frequency of t(14;18) in Turkish cases of follicular lymphoma. Representative tissue blocks from 67 patients with follicular lymphoma, 12 cases of diffuse large B cell lymphomas and 11 cases of reactive hyperplasias were examined for the presence of this translocation using PCR. DNA probes capable of detecting rearrangement at both the major and minor break point regions were employed. We could detect t(14;18) in 46 out of 67 cases (68.7%) of follicular and 25% of diffuse large B cell lymphomas. In follicular lymphomas 64.2% of these break points were at mbr and 4.5% were at the mcr region. Review of the literature showed that comparable results have been obtained previously using molecular techniques. Our data showed that despite the relative infrequency of follicular lymphomas in the Turkish population these lymphomas share a common molecular pathogenesis with involvement of bcl-2 gene and background incidence of such rearrangement is similar in all populations, regardless the incidence of folicular lymphoma.

Magnetic resonance imaging of bone marrow versus bone marrow biopsy in malignant lymphoma

Bone marrow involvement is a frequent finding in malignant lymphoma. Bone marrow biopsy of the posterior iliac crest is routinely performed for staging. Abnormal magnetic resonance imaging (MRI) signals of bone marrow was also reported to be indicative of bone marrow involvement. This study included 60 patients with malignant lymphoma. Unilateral bone marrow biopsy of the posterior iliac crest was performed. MRI of lumbar spine was studied within 24 hours of bone marrow biopsy. 22 healthy controls were used for the detection of MRI objectivity during visual evaluation. In 83% of patients (50/60), biopsy and MRI results agreed completely. In two patients, histologic sections failed to show any evidence of bone marrow involvement despite abnormal MRI signals suggestive of involvement. In three patients, MRI was completely normal despite biopsy proven bone marrow infiltration. False negativity (3/60) and false positivity (2/60) rates were very low. Negative biopsy findings with positive or equivocal MRI results should not exclude bone marrow involvement and needs further evaluation with bilateral or guided biopsy. Thus, we conclude that MRI of bone marrow is a fairly sensitive, noninvasive modality and might be of potential value in detecting bone marrow infiltration in malignant lymphoid neoplasms which can be utilized as a useful adjunct to standard staging procedures.

Primary splenic tuberculosis in a patient with nasal angiocentric lymphoma: mimicking metastatic tumor on abdominal CT

Tuberculosis may be difficult to diagnose when it presents in an uncommon extrapulmonary site. The authors report a case of splenic tuberculosis mimicking metastatic tumor on computed tomography in a 60-year-old woman who had been treated with combination chemotherapy for nasal angiocentric lymphoma. Diagnostic splenectomy revealed multiple necrotic masses in the spleen, which were consistent with caseating granulomas microscopically. Diagnosis was confirmed by positive cultures in Lowenstein medium, which grew typical Mycobacterium tuberculosis organisms. Following splenectomy, the patient was also treated with a triple-drug antituberculosis regimen with no recurrence of her symptoms.

Calciphylaxis: a condition mimicking necrotizing vasculitis

A patient with end stage renal disease developed ischaemic skin necrosis and digital gangrene. He had diffuse arterial calcification associated with hyperparathyroidism secondary to renal failure. The patient received inappropriate cyclophosphamide therapy as he had been misdiagnosed as having an inflammatory vasculitis. This clinical picture, previously named "calciphylaxis" should come into the differential diagnosis of systemic vasculitis in a uraemic patient with hyperparathyroidism.

Thermodynamic characterization of drug binding to human serum albumin by isothermal titration microcalorimetry

Binding sites on human serum albumin (HSA) for anionic drugs and fatty acids have been thermodynamically characterized by microcalorimetry. The binding and the thermodynamic parameters were directly computed from the calorimetric titration data at 37 degrees C in a phosphate buffer (pH 7.4) using one- and two-class binding models. From compensation analyses plotting the molar enthalpy change (delta Hm,i) versus those of the molar free energy (delta Gm,i) and molar entropy (delta Sm,i) for each class of binding sites, HSA binding sites were classified into groups S1, S2, and S3. Group S1 included high-affinity binding sites for site II-bound drugs, such as ibuprofen, flufenamic acid, and ethacrynic acid, and short- or medium-length alkyl-chain fatty acids; group S2 included low-affinity binding sites of site II-bound drugs and long-length alkyl-chain fatty acids; and group S3 contained the high-affinity binding sites for site I-bound drugs, such as phenylbutazone, oxphenbutazone, and warfarin, and long-length alkyl-chain fatty acids. High- and low-affinity bindings sites for salicylic acid and acetylaslicylic acid agreed with the regions of groups S3 and S2, respectively. Groups S1 and S2 were characterized by large negative values of delta Hm,i and delta Sm,i, reflecting van der Waals interaction and hydrogen-bonding formation in low dielectric media, and the main force to stabilize the binding complex in group S3 was a hydrophobic interaction, characterized by a small negative delta Hm,i and minor or positive values of delta Sm,i (entropy-driven).

Biothermodynamic characterization of monocarboxylic and dicarboxylic aliphatic acids binding to human serum albumin: a flow microcalorimetric study

Thermodynamic parameters have been evaluated for the binding of unbranched monocarboyxlic aliphatic acids (MCAs) of 4 to 16 carbons (MC4 to MC16) and dicarboxylic aliphatic acids (DCAs) of 4 to 16 carbons (DC4 to DC16) to human serum albumin (HSA) on the basis of microcalorimetric measurement at pH 7.4 and 37 degrees C by computer-fitting to single- and two-class binding models. Long-chain MCAs (MC10 to MC16) and DCAs (DC14 and DC16) had the first class of binding sites with high affinity (large binding constant) of 10(5) to 10(6) M-1 and the second class with lower affinity and high capacity (large numbers of binding sites). Short- or medium-chain MCAs and DCAs bound to HSA at some low affinity binding sites. The binding constants of MCAs were ten times larger than those of DCAs. All the relationships between the thermodynamic parameters and alkyl-chain length of the acids showed clear-cut inflections in their plots around eight or nine methylene units. The free energy change of the first class of binding sites (- delta G1) became more negative with an increment of -1.0 kJ mol-1 CH2(-1) as the alkyl-chain length increased, but there were steep rises between MC9 and MC11 with -2.90 kJ mol-1 CH2(-1) and between DC9 and DC12 with -2.02 kJ mol-1 CH2(-1). The enthalpy change (- delta H) increased at the rate of -7.4 kJ mol-1 CH2(-1) to the maximum at MC9 and DC10, then decreased due to hydrophobicity of the alkyl-chains. From compensation analyses (delta H vs. delta S and delta G), HSA binding sites were characterized into three groups.

Thermodynamic aspects of fatty acids binding to human serum albumin: a microcalorimetric investigation

Thermodynamic parameters have been evaluated for the binding interaction between human serum albumin (HSA) and unbranched fatty acids (FFA) on the basis of a flow microcalorimetric measurement at pH 7.4 and 37 degrees C by computer-fitting to single- and two-class binding models. The heat of binding increased exothermically with increasing alkyl chain length. FFA with nine or less carbons bound to only one class of binding sites (n = 2) with a binding constant (K) of 10(4) M-1. FFA with ten or more carbons bound to the first class of binding sites with high affinity K in the older of 10(5) to 10(6) M-1, and to the second class with a lower affinity and high capacity. The free energy change of the first class of binding sites (delta G1) became more negative as the chain length of FFA was increased. The enthalpy change per mol of FFA (delta H) decreased at the rate of -7.47 kJ.mol-1.CH-1(2) to a minimum at C9 and then increased due to the hydrophobicity of alkyl chains. Compensation analysis for the i th class of HSA molecule by plotting molar changes of enthalpy (delta Hmi) against entropy (delta Smi) and free energy (delta Gmi) indicates two distinct binding sites. The first class (i = 1) of the long-chain FFA on HSA is an entropy-driven reaction associated with nearly constant values of delta Hm1 (-43.0 +/- 4.8 kJ.mol-1), slightly negative values of delta Sm1 (-47.4 less than or equal to delta Sm1 less than or equal to -8.1 J.mol-1.K-1) and -delta Gm1 values, increasing with increasing alkyl chain length. The second class (i = 2) of the long-chain FFA may lie in the same region as the binding sites of the short- and medium-chain FFA with a linear relationship between delta Hmi-delta Smi.

Drug binding to human erythrocytes in the process of ionic drug-induced hemolysis. Flow microcalorimetric approaches

Erythrocyte hemolysis induced by cationic phenothiazine derivatives and anionic non-steroidal anti-inflammatory drugs was compared, by flow microcalorimetry, with respect to thermodynamic characteristics for drug binding to intact human erythrocytes. Phenothiazines having high hemolytic activities bound strongly to erythrocyte cells, inducing an immediate hemolytic action characterized by an endothermic heat effect prior to saturating available binding sites. The thermodynamic observable delta H and delta S fell within the ranges of -119 to -65.1 kJ/mol and -308 to -128 J/mol/K, respectively, for these cationic species. There was a linear relationship between the hemolytic activity and the degree of exothermicity of delta H which was enhanced significantly by the presence of a halogen atom(s) at the C-2 position of the phenothiazine nucleus in the order of H less than Cl less than CF3. Anti-inflammatory drugs, however, bound to quite different sites in the erythrocytes with lower affinities and higher capacities than cationic drugs. The latter was characterized by small negative delta H (-17.3 to -7.1 kJ/mol) and positive delta S (10 to 41 J/mol/K). In the calorimetric profiles observed during hemolysis by anionic drugs, two stages were seen: the first, an exothermic process, arising from drug binding to the erythrocytes; the second, an endothermic process, corresponding to the heat of dilution of hemoglobin released from erythrocytes. Hemolysis occurred after the binding sites on the erythrocytes were saturated with drugs. Our data suggest that the binding activities of ionic drugs, such as the amounts of the bound drug and their binding energies to erythrocytes, contribute to the hemolysis.

Inhibitory effect of beta-cyclodextrin on ampicillin polymerization in aqueous solution

Ampicillin polymerizes in aqueous solution to produce antigenic polymers; the polymers were separated by anion-exchange chromatography and shown to consist of a dimer, trimer, tetramer and pentamer of ampicillin by the masses found in fast atom bombardment mass spectroscopy. The presence of an intact beta-lactam ring in each of the polymers was revealed by the characteristic positive Cotton effect near 230 nm in their circular dichroism spectra. beta-Cyclodextrin was found to inhibit this polymerization by complex formation involving equimolar quantities of the constituents. Formation of this complex was complete in 10% aqueous solution within 6 hr at 24 degrees C. The positive Cotton effect arising from the beta-lactam ring decreased as the degree of polymerization increased, but was unchanged by the complex formation with beta-cyclodextrin.

Microcalorimetric study for the binding of ionic drugs to human erythrocytes and the ghost membranes

The binding of phenothiazine derivatives (as cationic drugs) and non-steroidal anti-inflammatory drugs (as anionic drugs) to human erythrocytes and ghost membranes has been compared with respect to their thermodynamic characteristics, by flow microcalorimetry at pH 7.4 and 37 C. From enthalpyentropy correlation, it was shown that anionic and cationic drugs are bound to different binding sites on the membranes. Phenothiazines bind to a single common site of the erythrocyte membranes with relatively high binding affinities (K = 10(4)-10(5) M-1). The binding is entropy-driven and characterized by a small negative enthalpy (delta H) and a positive entropy change (delta S), reflecting hydrophobic interactions. However, the binding reaction for the intact erythrocytes shows large negative values for both delta H and delta S. The values of K for the membranes and delta H for the intact erythrocytes increased with the increase of the hydrophobic character of the substituent group at the C-2 position of the phenothiazine nucleus (H less than Cl less than CF3). The results indicate that phenothiazines bind and or penetrate to the inner membranes of the erythrocytes and react with intracellular components such as haemoglobin, while anti-inflammatory drugs bind to the surface protein on the membranes with a lower affinity (K = 10(3) M-1) than phenothiazines, reflecting the small negative delta H and positive delta S for the interaction with intact erythrocytes.

Thermodynamics of the binding of phenothiazines to human plasma, human serum albumin and alpha 1-acid glycoprotein: a calorimetric study

A flow microcalorimetric study has been carried out to investigate the interactions between phenothiazine derivatives and human plasma, human serum albumin (HSA) and alpha 1-acid glycoprotein (AGP) at pH 7.4 and 37 degrees C. The direct analyses of enthalpic titration curves allowed the determination of the binding enthalpy change (delta H), the apparent binding constant (K), and the number of the binding sites (n), as well as the evaluation of the apparent free energy (delta G), and entropy (delta S) changes. The overall binding of phenothiazines was exothermic with negative delta H, which was compensated for by changes in delta S. The values of delta G were relatively insensitive to variation in the molecular details of the binding reaction. HSA possessed two classes of binding sites for phenothiazines. The first (n1 = 1), with high affinity (K1 = 10(5)-10(6) M-1) was characterized by small negative delta H and positive delta S values due to hydrophobic interaction. The second class of sites had a low affinity (K2 = 10(3)-10(4) M-1) and high capacity (n2 = 3-8) and contributed to the negative delta H and delta S values. The binding and thermodynamic parameters were influenced by the aliphatic side chain moieties on the phenothiazine nucleus. On the other hand, the drugs were bound to AGP at a single common binding site with a binding affinity of the order of 10(4)M-1, characterized by negative delta H and delta S values, which partially reflected the effect of a van der Waals' interaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Application of differential flow microcalorimetry for study of drug interactions in the blood system

A compact differential flow microcalorimeter has been developed to investigate biomolecular reactions, especially drug interactions in the blood system. The calorimeter is an adiabatic type and consists of a twin-cell structure, each mixing part having a volume of 60 microliters. Both the precision and accuracy of the instrument have been evaluated by dilution of sucrose solutions to be 0.1-0.5% at a heat effect of 100-10 microW. The resolution is approximately 0.5 microW (less than 10(-3) Torr). The heat produced in erythrocyte hemolysis induced by chlorpromazine hydrochloride (CPZ) and the binding heat of CPZ to human blood components viz., intact erythrocytes, erythrocyte membranes, serum albumin and plasma were measured. The heat effect of hemolysis was endothermic and related to the quantity of free hemoglobin released from erythrocytes. The overall binding of CPZ to blood components was, however, an exothermic process. The thermodynamic and binding parameters were computed directly from the calorimetric data by use of a nonlinear least squares regression method, assuming a one-class binding model, and the stoichiometry of the binding reaction was determined.