Effects of L-dopa and bromocriptine on haloperidol-induced motor deficits in mice

L-3,4-Dihydroxyphenylalanine (L-DOPA), the precursor of dopamine, and bromocriptine, a dopamine D2 receptor agonist, were investigated in haloperidol-induced motor impairments in mice using both catalepsy and pole tests. In catalepsy test, subcutaneous treatment with haloperidol (0.125, 0.25 and 0.5 mg/kg) caused a cataleptic effect in mice in a dose-dependent manner. This cataleptic effect was evident upto 7 hr after haloperidol treatment. In pole test, haloperidol (0.125, 0.25 and 0.5 mg/kg) produced the prolongation of Tturn and TLA as a marker of bradykinesia in mice and the prolongation lasted at least 7 hr after haloperidol treatment. Intraperitoneal co-pretreatment with L-DOPA (400 mg/kg) + carbidopa (10 mg/kg) in mice decreased the catalepsy induced by haloperidol at a dose of 0.125 mg/kg, while co-pretreatment with L-DOPA (200 and 400 mg/kg) + carbidopa (10 mg/kg) dose-dependently decreased the haloperidol (0.125 mg/kg)-induced bradykinesia. The effect of LDOPA + carbidopa in pole test was more pronounced than that in catalepsy test. Intraperitoneal pretreatment with bromocriptine (2 and 4 mg/kg) in mice reduced the catalepsy and bradykinesia produced by haloperidol at a dose of 0.125 mg/kg. The effect of bromocriptine in pole test was relatively similar to that in catalepsy test. Also, co-pretreatment with LDOPA (400 mg/kg) + carbidopa (10 mg/kg) and pretreatment with bromocriptine (2 and 4 mg/kg) significantly decreased the catalepsy induced by haloperidol at a higher dose of 0.5 mg/kg. These results indicate that co-administration with L-DOPA + carbidopa and single treatment with bromocriptine can decrease haloperidol-induced catalepsy and bradykinesia in mice. Furthermore, our study suggests that pole test as well as catalepsy test is of value in the screening of drugs against neuroleptic-induced motor deficits.

Inhibitory effect of soybean hypocotyls on Epstein-Barr virus early antigen induction and skin tumor promotion

The in vitro anti-tumor promoting effect of hypocotyls from fresh soybeans was evaluated. The dimethyl sulfoxide extracts of hypocotyls showed a stronger inhibitory effect than that of soybeans on Epstein-Barr virus early antigen activation induced by 12-O-tetradecanoylphorbol-13-acetate. Daidzin, an isoflavone with the highest content of hypocotyls, was also inhibitory. An in vivo evaluation of anti-tumor promoting activity of hypocotyls against the skin of mice also revealed a significant inhibitory effect on tumor formation.

Current treatment of brain abscess in patients with congenital cyanotic heart disease

OBJECTIVE

The goal of this study was to define clearly the role of management in patients with cyanotic heart disease and brain abscesses by evaluating retrospectively the factors influencing poor outcome in these patients.

METHODS

This study included 62 patients with cyanotic heart disease and brain abscesses diagnosed in the computed tomography era. Basic characteristic parameters (number, size, location, computed tomographic classification and organism type of abscess, convulsion, type of cyanotic heart disease, age distribution, immunocompromised status, pretreatment neurological state, and intraventricular rupture of brain abscess [IVROBA]) and therapeutic parameters (type of antibiotics and duration of administration, steroid medication and therapeutic modalities, aspiration with or without cerebrospinal fluid drainage, total extirpation after aspiration, or primary extirpation and medical treatment) were evaluated as independent predictors of poor outcome (totally disabled state or death) by using univariate and multivariate logistic regression analysis. We also statistically estimated the possible causes of IVROBA and the multiplicity of brain abscess.

RESULTS

Although there were no statistically significant correlations between patients with good and poor outcomes in regard to other basic characteristic and therapeutic parameters, patients with poor outcomes were older (P < 0.02), more frequently had IVROBA (P < 0.005), and had a higher frequency of neurological deterioration (P < 0.01) than those with good outcomes. Multiple logistic regression analysis predicted that poor outcome increased the relative risk of IVROBA by a factor of 18.9 (odds rate, 18.9; 95% confidence interval, 1.7-211.6; P < 0.02). More patients with multiple abscesses had positive immunocompromised states than those with single abscesses (P < 0.01). Deep-located abscesses also more frequently had IVROBA (P < 0.005) and abscesses located in the parieto-occipital region ruptured into the occipital horn of the lateral ventricle in a short period (P < 0.02).

CONCLUSIONS

Our findings suggest that IVROBA strongly influences poor outcome in patients with cyanotic heart disease. The key to decreasing poor outcomes may be the prevention and management of IVROBA. To reduce operative and anesthetic risk in these patients, abscesses should be managed by less invasive aspiration methods guided by computed tomography. Abscesses larger than 2 cm in diameter, in deep-located or parieto-occipital regions, should be aspirated immediately and repeatedly, mainly using computed tomography-guided methods to decrease intracranial pressure and avoid IVROBA. IVROBA should be aggressively treated by aspiration methods for the abscess coupled with the appropriate intravenous and intrathecal administration of antibiotics while evaluating intracranial pressure pathophysiology.

[The effects of caffeine on the respiratory depression by morphine]

The effects of intravenous administration of caffeine on the discharge of the phrenic nerve were studied following vagotomy in 7 pentobarbital anesthetized mechanically ventilated rats. Morphine (0.4 mg.kg-1.min-1) was administered until the respiratory rate decreased to about half of the baseline respiratory rate. In those state, we first administered caffeine (20 mg.kg-1), intravenously and then administered naloxone (0.02 mg) intravenously. The increase of inspiratory time from 0.49 +/- 0.16 to 2.01 +/- 0.47 s by morphine recovered to 0.86 +/- 0.38 s by caffeine and 0.50 +/- 0.22 s by naloxone. Expiratory time did not change during each drug administration. The decrease of respiratory rate from 46.6 +/- 5.9 to 20.6 +/- 4.1 breaths.min-1 by morphine recovered to 39.6 +/- 6.1 breaths.min-1 by caffeine and 47.6 +/- 4.6 breaths.min-1 by naloxone. Amplitude of integrated phrenic nerve discharge increased to 117 +/- 32% by caffeine and 156 +/- 39% by naloxone compared to the baseline. These results suggest that caffeine acts as a respiratory stimulant on the respiratory depression by morphine.

Synthesis and cataleptic effects of optically active dihydrohaloperidols and dihydrobromoperidols

Optically active dihydrohaloperidols and dihydrobromoperidols, the major metabolites of haloperidol and bromoperidol, clinically used as neuroleptic drugs in humans, were asymmetrically synthesized by Jaen's method. The motor effects of all the reduced haloperidol and bromoperidol metabolites were evaluated by the mouse catalepsy test. The results indicate that administration of the optically active dihydrohaloperidols and dihydrobromoperidols as well as haloperidol and bromoperidol can cause significant motor deficits in mice.

Sinus node function after mitral valve surgery via the transseptal superior approach

OBJECTIVE

The transseptal superior approach can offer an excellent view of the mitral valve but the incision almost always transects the sinus node artery. The purpose of this study was to evaluate the sinus node function after mitral operation by this approach.

PATIENTS AND METHODS

We reviewed the electrocardiograms of 76 patients who underwent mitral valve operations either via transseptal superior approach or via right lateral atriotomy. Nine patients who maintained the sinus rhythm for more than one year after surgery via the transseptal superior approach were selected for electrophysiological study to evaluate the sinus node function.

RESULTS AND CONCLUSIONS

Postoperative electrocardiographic and electrophysiological studies revealed that the sinus node function after the transseptal superior approach was relatively well maintained for more than one year after the operation. The influence of the transseptal superior approach on the sinus node function in the mid-term postoperative period was apparently mild and did not cause a serious problem. However, some of the patients did show abnormal data in terms of sino-atrial conduction time and intrinsic heart rate. Therefore, further follow-up of the sinus node function is necessary in patients who underwent mitral surgery through the transseptal superior approach.

[Improvement of cardiac function by aortic valve replacement for chronic aortic regurgitation with carbomedics heart valve]

Cardiac function after aortic valve replacement for chronic aortic regurgitation with CarboMedics heart valve was evaluated repeatedly by echocardiography and some examinations in 27 cases. There was no late death and all patients belonged to NYHA I functional class postoperatively. Systolic and diastolic dimensions of left ventricle, left ventricular mass index, cardiothoracic ratio and SV1+RV5 on electrocardiography improved significantly within half a year and those improved results remained thereafter. Fractional shortening of left ventricle also improved gradually and the difference reached statistical significance one year later. This investigation revealed reduced systolic function or eccentric myocardial hypertrophy were often reversible. Average values of systolic diameter and fractional shortening late after operation were within normal range even in cases whose preoperative systolic function were severely depressed. Left ventricular mass index decreased markedly although postoperative values were still out of normal range in most cases. These results suggest that aortic valve replacement can be indicated even in cases of aortic regurgitation with severely impaired preoperative cardiac function.

T-stem cell leukemia/lymphoma with both myeloid lineage conversion and T-specific delta recombination

We evaluated retrospectively the clinical and biological characteristics of six patients with CD7+ early T-acute lymphoblastic leukemia and lymphoma (T-ALL/LBL) originating from prothymocyte stage I (pro-T I) or II cells. Patients exhibited mediastinal mass (five of six) and lymphoadenopathy (five of six) but without leukocytosis and circulating blast cells (six of six). All patients achieved a complete remission. All but one had a relapse with a transformation to the mixed type (triphenotype--three cases, biphenotype-two cases) including myeloid features in three patients. The altered phenotypes were myeloperoxidase (MPO)+ (three of five), CD13+ (four of five), CD33+ (three of five) and CD19+ (three of five). The difference for MPO-positivity were observed between the bone marrow (BM)- and lymph node (LN)-blast cells (three of three). On cytogenetic analysis, there is no common abnormality in these patients. Immunomolecular analysis revealed T-cell lineage specific delta gene rearrangements [D delta 2-J delta 1 (five of six) and V delta 1-J delta 1 (one of six)] in all cases. Furthermore, D delta 2-J delta 1 occurred even in the cases with the pro-T I phenotype. Rearrangements of TCR beta, gamma or immunoglobulin heavy chain genes occurred in three patients. The same rearranged band(s) appeared at both diagnosis and relapse, indicating the same originality of the pro-T leukemic cell clone (three of three). We suggest that this type of CD7+ early T-ALL/LBL was transformed from a pro-T I or II cell, such as T-stem cell leukemia/lymphoma, which is a subtype of CD7+ stem cell leukemia as defined by Kurtzberg et al. This study reveals that pro-T I and II cells might be capable of myeloid, T- and B-lymphoid differentiation, and T-cell lineage specific TCR delta recombination occurs.

Identification of alternative first exons of NADH-cytochrome b5 reductase gene expressed ubiquitously in human cells

Two forms of NADH-cytochrome b5 reductase (b5R), soluble and membrane-bound, are known. A hypothesis that the human soluble form b5R is generated through post-translational processing of the membrane-bound form was previously proposed. In this study, the 5'-rapid amplification of cDNA ends for human reticulocyte, liver, brain, and HL-60 cell mRNAs revealed the ubiquitous presence of an alternative type of human b5R mRNA which can probably be translated into the soluble form b5R directly; however, the erythroid-specific transcript of the b5R gene was not found. This type of b5R mRNA initiating from at least two sites contains a non-coding new first exon located between the first two exons of the human b5R gene identified before. In addition, this new first exon shares 62% homology with the first exon and its 3'-flanking intron sequences of rat erythroid-specific b5R mRNA, whereas the 5'-flanking region of the new first exon possesses features of house-keeping gene. These results might be important to understand the regulation mechanism of human b5R biosynthesis and divergent evolution of the gene regulation.

Fibrous tissue overgrowth and prosthetic valve endocarditis: report of a case

Mechanical valve stenosis without restricted occluder motion and paravaluvular leakage developed in a patient who had undergone patch closure of partial atrioventricular septal defect and replacement of the left atrioventricular valve 13 years previously. Dense calcification of the supravalvular region was shown in a cineradiogram, whereas transthoracic and transesophageal echocardiography failed to reveal any obstructive mechanism. Elevated transprosthetic pressure gradient with unrestricted occluder motion suggested prosthetic valve stenosis resulting from fibrous tissue overgrowth, although this was not visualized by the modern diagnostic imaging tools. Reoperation confirmed calcified fibrous tissue overgrowth obstructing the mechanical valve inflow. Examination of resected tissue revealed prosthetic valve endocarditis due to alpha-streptococcus. Paravalvular leakage accompanying fibrous tissue overgrowth may indicate the presence of prosthetic valve infection even if the clinical manifestations are scarce.

Translesional synthesis on DNA templates containing a single abasic site. A mechanistic study of the "A rule"

Site-specifically modified oligodeoxynucleotides containing a single natural abasic site or a chemically synthesized (tetrahydrofuran or deoxyribitol) model abasic site were used as templates for primer extension reactions catalyzed by the Klenow fragment of Escherichia coli DNA polymerase I or by calf thymus DNA polymerase alpha. Analysis of the fully extended products of these reactions indicated that both polymerases preferentially incorporate dAMP opposite the natural abasic site and tetrahydrofuran, while DNA templates containing the ring-opened deoxyribitol moiety block translesional synthesis, promoting sequence context-dependent deletions. The frequency of nucleotide insertion opposite the three types of abasic sites follows the order dAMP > dGMP > dCMP > dTMP. The frequency of chain extension was highest when dAMP was positioned opposite a natural abasic site. The frequency of translesional synthesis past abasic sites follows the order tetrahydrofuran > deoxyribose > deoxyribitol. The Klenow fragment promotes blunt end addition of dAMP; this reaction was much less efficient than insertion of dAMP opposite an abasic site. We conclude that the miscoding potential of a natural abasic site in vitro closely resembles that of its tetrahydrofuran analog. Ring-opened abasic sites favor deletions. Studies with polymerase alpha in vitro predict preferential incorporation of dAMP at abasic sites in mammalian cells.

Terminal deoxynucleotidyl transferase staining of malignant lymphomas in paraffin sections: a useful method for the diagnosis of lymphoblastic lymphoma

Terminal deoxynucleotidyl transferase (TdT) is a DNA polymerase located in the cell nucleus which catalyses the polymerization of deoxynucleotides at the 3'hydroxyl ends of oligo- or polydeoxynucleotide initiators without a template. TdT is known as a useful marker for the diagnosis of acute lymphoblastic leukaemia/lymphoma, but its detection usually requires fresh tissue specimens or cell suspensions, using either an enzyme analysis or immuno-fluorescence or -peroxidase staining. Until the recent development of the use of microwave-treated paraffin sections for immunoperoxidase staining, detection of TdT in paraffin sections required rather complicated processes. This new simple technique was applied to paraffin sections from the tumour tissue specimens of 16 patients with lymphoblastic lymphoma and of seven patients with non-endemic Burkitt's lymphoma, which is sometimes difficult to differentiate from lymphoblastic lymphoma because of their similar clinicopathological characteristics. In addition, as a control, ten cases each were examined of adult T-cell leukaemia/lymphoma (ATLL) and angioimmunoblastic lymphoma (AILD), which are both peripheral T-cell lymphomas. The tumour cells from 15 of the 16 (94 per cent) patients with lymphoblastic lymphoma were found to be TdT-positive. The specificity of the anti-TdT antibody used was confirmed by immunoblot and the specific 60 kD band was detected only in a specimen of lymphoblastic lymphoma. These results show that the immunostaining of TdT on paraffin-embedded sections is a useful method for differentiating lymphoblastic lymphoma from other lymphomas. This method is applicable to a routine diagnostic service.

Synthesis and dual antagonistic activity against thromboxane A2 and leukotriene D4 of [4-[1-(benzenesulfonamido)alkyl]phenyl]alkanoic acid derivatives

In order to find new antiasthmatic agents with dual antagonistic activity against thromboxane A2 (TXA2) and leukotriene D4 (LTD4) receptors, synthesis and pharmacological evaluation of various [4-[1-(benzenesulfonamido)-alkyl]phenyl]alkanoic acid derivatives were undertaken. TXA2 and LTD4 antagonistic activities in vitro were evaluated by measuring the inhibitory effects on L-46619-induced contraction of guinea-pig trachea and LTD4-induced contraction of guinea-pig ileum and trachea. Several compounds showed satisfactory dual antagonistic activities, and their effect (after oral administration) on LTD4-induced bronchoconstriction in guinea-pig in vivo was examined. The results demonstrated that both 4-[4-[1-(4-chlorobenzenesulfonamido)hexyl]phenyl]butyric acid (12e) and 4-[4-[1-(4-chlorobenzenesulfonamido)-5-methylhexyl]phenyl]bu tyric acid (12m) possessed good anti-LTD4 activities. Compounds 12e and 12m were then evaluated for other related pharmacological effects involving the arachidonic acid cascade. These compounds appear to be hybrid eicosanoids antagonists having antagonistic activity against contraction of guinea-pig trachea induced by prostaglandin D2 (PGD2) and PGF2 sigma, as well as TXA2 and LTD4 antagonistic activities.

Lack of promotion of colon carcinogenesis by high-oleic safflower oil

BACKGROUND

The nonpromoting effect of olive oil on colon carcinogenesis has been attributed to its high oleic acid content, whereas a positive association of monounsaturated fat in beef tallow with colon tumors has been reported. The effect of constituents other than fatty acids could not be neglected in these experiments. In order to minimize the effects of minor constituents in the oils, the authors compared conventional safflower oil with oil from a mutant strain of safflower that is rich in oleic acid.

METHODS

ICR mice were treated with 1,2-dimethylhydrazine (DMH, 20 mg/kg body weight every week for 12 weeks) and then were fed either a high-fat diet (23.5% by weight), containing safflower oil (HF-LA) or high-oleic safflower oil (HF-OA), or a low-fat diet (5% by weight), containing safflower oil (LF-LA) or high-oleic safflower oil (LF-OA). The test diets were continued until termination of the experiment at 30 weeks after the first administration of DMH. Fatty acid composition of colon phospholipids was determined by gas-liquid chromatography-mass spectrometry.

RESULTS

Tumor multiplicity in animals fed the HF-OA diet was indistinguishable from that in animals fed LF-LA or LF-OA. In contrast, animals fed the HF-LA diet had a significantly higher incidence of colon tumors (mostly adenocarcinomas) than the other groups. Fatty acid profiles of colon phospholipids reflected those of the diet. Animals fed a HF-LA diet showed a marked decrease of nervonic acid (C24:1, n-9) in the colon sphingomyelin.

CONCLUSIONS

These data indicate that oleic acid does not enhance DMH-induced colon carcinogenesis in mice, even when they are fed a high-fat diet.

Pathological evaluation of effect of anti-rheumatic drugs on type II collagen-induced arthritis in Lewis rats

The effects of anti-rheumatic drugs (dexamethasone 0.1 mg/kg and naproxen 5 mg/kg) were evaluated immunologically and histopathologically on type II collagen-induced arthritis in Lewis rats. Increased paw volume in the hind limbs was significantly suppressed in the groups treated with dexamethasone or naproxen, but noticeable retardation of body weight gain was observed in the group treated with dexamethasone. Serum anti-type II collagen IgG was significantly suppressed in the group treated with dexamethasone but not naproxen. Histopathological evaluation by our grading system, classification of the stages in arthritic lesion development, revealed suppression of the inflammatory changes in the tarsal joints of the animals treated with dexamethasone or naproxen. From our results, histopathological evaluation is considered to be more suitable for assessment of the efficacy of anti-rheumatic drugs on type II collagen-induced arthritis, an animal model for human rheumatoid arthritis.

Functional changes of rat brain microsomal membrane surface after learning task depending on dietary fatty acids

Biochemical characteristics of brain microsomal membranes were examined before and after the brightness-discrimination learning tasks in rats that were fed either safflower oil (alpha-linolenate-deficient) or perilla oil (alpha-linolenate-sufficient) diets. We detected small changes in the chain elongation system for polyunsaturated fatty acids in microsomes, whereas no significant difference was detected in the inositol trisphosphate-induced calcium release and ATP-induced calcium uptake profiles of microsomes between the two dietary groups. The calcium ion-induced aggregation rate of microsomes was determined in both groups. We found that the aggregation rate of microsomes in the safflower oil group was significantly greater than that in the perilla oil group. The difference in susceptibility of microsomal membrane phospholipids to phospholipase A2 between the groups was obvious, and the amount of released fatty acids by phospholipase A2 from the perilla oil group microsomes was nearly half of that from the safflower oil group microsomes after the learning task. Susceptibility of sialic acids on the brain microsomal membranes to exogenous sialidase was different only after the learning task in the safflower and perilla oil groups. These results suggest that the biochemical characteristics of membrane surfaces of brain microsomes are affected significantly by the learning task itself in a dietary oil-dependent manner.

Abasic site binding by the human apurinic endonuclease, Ape, and determination of the DNA contact sites

The mutagenic and lethal effects of abasic sites in DNA are averted by repair initiated by 'class II' apurinic (AP) endonucleases, which cleave immediately 5'to abasic sites. We examined substrate binding by the human AP endonuclease, Ape protein (also called Hap1, Apex or Ref-1). In electrophoretic mobility-shift experiments, Ape bound synthetic DNA substrates containing single AP sites or tetrahydrofuran (F) residues. No complexes were detected with single-stranded substrates or unmodified duplex DNA. In EDTA, the concentration of Ape required to shift 50% of duplex F-DNA was approximately 50 nM, while the addition of 10 mM MgCl2 nearly eliminated detectable F-DNA@Ape complexes. Filter-binding studies demonstrated a half-life of approximately 50 s at 0 degrees C for F-DNA@Ape complexes in the presence of EDTA, and <15 s after the addition of Mg2+. The DNA recovered from F-DNA@Ape complexes was intact but was rapidly cleaved upon addition of Mg2+, which suggests that these protein-DNA complexes are on the catalytic pathway for incision. Methylation and ethylation interference experiments identified DNA contacts critical for Ape binding, and Cu-1, 10-phenanthroline footprinting suggested an Ape-induced structural distortion at the abasic site prior to cleavage.

Cutaneous infiltration by leukemic cells in acute promyelocytic leukemia of a child after treatment with all-trans retinoic acid

We describe here the first case of childhood acute promyelocytic leukemia (APL) with cutaneous infiltration of leukemic cells following treatment with all-trans retinoic acid (ATRA) confirmed by immunostaining and polymerase chain reaction for PML/RAR alpha. An 11-year-old girl was diagnosed as having APL. Chromosomal analysis demonstrated the characteristic karyotype of t(15;17). ATRA therapy was begun at a dose of 45 mg/m2 daily. During ATRA therapy, leukocytosis and retinoic acid syndrome were observed but were resolved by dexamethasone. Two months after commencement of ATRA therapy, complete remission was achieved. During the course of consolidation chemotherapy, however, multiple cutaneous nodules developed in her trunk, the size and number of which increased despite intensive chemotherapy. Histological and immunological studies of the cutaneous nodules showed infiltration of leukemic cells. PML/RAR alpha mRNA was detected in both the cutaneous nodules and bone marrow by means of polymerase chain reaction. ATRA treatment for APL may be associated with an increased incidence of extramedullary disease such as cutaneous lesions. The best available therapy for APL may be a combination of ATRA and chemotherapy, especially when a marked leukocytosis occurs during ATRA therapy.

Synaptic vesicle ultrastructural changes in the rat hippocampus induced by a combination of alpha-linolenate deficiency and a learning task

Rats fed either a safflower oil (alpha-linolenate-deficient) or a perilla oil (alpha-linolenate-sufficient) diet through two generations (F1) showed significant differences in the brightness-discrimination learning task. In this task, correct responses were lever-pressing responses, which were reinforced with dietary pellets, and incorrect responses were those with no reinforcement. The inferior learning performance in the safflower oil group was caused mainly by the inferior ability to rectify the incorrect responses through the learning sessions. In the safflower oil group after the learning task, the average densities of synaptic vesicles in the terminals of the hippocampus CA1 region were decreased by nearly 30% as compared with those in the perilla oil group, and it is notable that this difference was not detected without the learning task. These results suggest that dietary oil-induced morphological changes in synapses in the hippocampus of rats are related to the differential learning performance and that the turnover rate of synaptic vesicles in the hippocampus may be an important factor affecting learning performance.

Mechanism of bypass synthesis through an abasic site analog by DNA polymerase I

Bypass synthesis by DNA polymerase I was studied using synthetic 40-nucleotide-long gapped duplex DNAs each containing a site-specific abasic site analog, as a model system for mutagenesis associated with DNA lesions. Bypass synthesis proceeded in two general stages: a fast polymerization stage that terminated opposite the abasic site analog, followed by a slow bypass stage and polymerization down to the end of the template. The position of the 3'-terminus of the primer relative to the absic site analog did not affect bypass synthesis in the range of -1 to -5. In contrast, bypass synthesis increased with the distance of the 5'-boundary of the gap from the lesion for up to 3-fold in the range of +1 to +9. Bypass synthesis was severely inhibited by moderate concentrations of salts, and under conditions that were optimal for the synthetic activity of DNA polymerase I (100 mM K+), bypass synthesis was completely inhibited (< 0.02% bypass). Elimination of the 3'-->5' proofreading exonuclease activity of the polymerase, by using a mutant DNA polymerase, caused a dramatic 10-60-fold increase in bypass synthesis. Determination of the kinetic parameters for insertion opposite the abasic site analog revealed a strong preference for the insertion of dAMP, dictated by a lower Km and a higher kcat as compared to the other nucleotides. The rate of bypass was increased by omitting one or two dNTPs, most likely due to the facilitation of the polymerization past the lesion.

Lymphoblastic lymphoma expressing natural killer cell phenotype with involvement of the mediastinum and nasal cavity

Most CD56+ lymphomas display polymorphic and angiocentric/angiodestructive histologic features and are closely related to Epstein-Barr virus (EBV) infection. We report a 47-year-old Japanese man with CD56+ lymphoma that showed histologic features of lymphoblastic lymphoma with mediastinal and nasal involvement and an aggressive course. A sample specimen showed the histology of lymphoblastic lymphoma with a positive reaction for terminal deoxynucleotidyl transferase (TdT) but no angiocentric/angiodestructive features. Transmission electron microscopy revealed a few membrane-bound electron-dense granules in their cytoplasm. Immunohistochemically, lymphoma cells exhibited CD56+ cytoplasmic CD3 (cCD3)+ TdT+. A Southern blot analysis showed no integration of EBV and human T-lymphotrophic virus 1 (HTLV-1) and no rearrangement of the T-cell receptors or immunoglobulin heavy chain genes. This unusual lymphoblastic lymphoma exhibiting cCD3 + CD56 + TdT + TCR- is assumed as an immature or progenitor natural killer cell lineage.

Clonal identification of trisomies 3, 5 and X in angioimmunoblastic lymphadenopathy with dysproteinemia by fluorescence in situ hybridization

Trisomies 3, 5 and X in six Japanese patients with AILD were detected by fluorescence in situ hybridization (FISH). Trisomies 3 and X were detected using centromeric probes. Cosmid probes locating on 5q31.1, the commonly deleted region, was used to detect trisomy 5. FISH detected three patients with trisomy 3 alone, one with trisomy 5 alone and one with all the three trisomies analysed. The sample that showed all three aberrations was further analysed by dual color FISH. The three trisomies were present on different cells. The AILD cells with trisomy 5 tended to replicate slowly, whereas those with trisomy 3 seem to have a proliferative advantage. An increase in the histopathological stage was reflected in the increase in the percentage of trisomy 3 cells in one patient.

No evidence of HTLV-I proviral integration in lymphoproliferative disorders associated with cutaneous T-cell lymphoma

Several recent studies have reported detection of HTLV-I genetic sequences in patients with cutaneous T-cell lymphoma (CTCL) including mycosis fungoides and Sezary syndrome. The purpose of this study was to determine whether HTLV-I was detectable in lesional tissues of patients suffering from diseases known to be associated with CTCL. Thirty-five cases were obtained from diverse geographical locations including Ohio, California, Switzerland, and Japan. Six of them had concurrent CTCL. Cases were analyzed using a combination of genomic polymerase chain reaction (PCR)/ Southern blot, dot blot, and Southern blot analyses. All assays were specific for HTLV-I provirus. Sensitivity ranged from approximately 10(-6) for PCR-based studies to 10(-2) for unamplified genomic blotting. Lesional DNA from patients with lymphomatoid papulosis (fourteen cases), Hodgkin's disease (twelve cases), and CD30+ large-cell lymphoma (nine cases) was tested for the HTLV-I proviral pX region using a genomic PCR assay followed by confirmatory Southern blot analysis with a nested oligonucleotide pX probe. All cases were uniformly negative. All of the Hodgkin's disease cases, eight of the large-cell lymphoma cases, and six of the lymphomatoid papulosis cases were then subjected to dot blot analysis of genomic DNA using a full-length HTLV-I proviral DNA probe that spans all regions of the HTLV-I genome. Again, all cases were negative. Finally, eleven of the Hodgkin's disease cases were also subjected to Southern blot analysis of EcoRI-digested genomic DNA using the same full-length HTLV-I probe. Once again, all cases were negative. These findings indicated that, despite utilization of a variety of sensitive and specific molecular biological methods, HTLV-I genetic sequences were not detectable in patients with CTCL-associated lymphoproliferative disorders. These results strongly suggest that the HTLV-I retrovirus is not involved in the pathogenesis of these diseases.

Ultrastructural study of capillary and myocytic changes in the masseter and heart of KK-Ay mice

We studied the capillaries and myocytes of masseter and cardiac muscles of diabetic KK-Ay mice, using light microscopy, transmission electron microscopy and scanning electron microscopy. The following changes were observed for diabetic masseters: capillary tortuosity, diversity of capillary caliber, endothelial cell swelling accompanied by luminal narrowing, widening of the pericapillary space and pericapillary fibrosis, and subsarcolemmal accumulation of myocytic mitochondria in areas adjacent to capillaries. In addition, attenuated capillary segments were largely covered by pericytes with profuse processes. In contrast, cardiac muscles of KK-Ay mice exhibited subsarcolemmal accumulation of myocytic mitochondria in areas contiguous to capillaries, and degenerative changes of myocytes such as disarrangement of myofilaments, disappearance of Z-bands and clustering of lipid-like vacuoles, although conspicuous changes of capillaries were not noted. Microvascular and myocytic changes described above may suggest the presence of microangiopathy and myopathy in the masseter and heart of KK-Ay mice.