Forebrain-specific ablation of phospholipase Cγ1 causes manic-like behavior.

Manic episodes are one of the major diagnostic symptoms in a spectrum of neuropsychiatric disorders that include schizophrenia, obsessive-compulsive disorder and bipolar disorder (BD). Despite a possible association between BD and the gene encoding phospholipase Cγ1 (PLCG1), its etiological basis remains unclear. Here, we report that mice lacking phospholipase Cγ1 (PLCγ1) in the forebrain (Plcg1f/f; CaMKII) exhibit hyperactivity, decreased anxiety-like behavior, reduced depressive-related behavior, hyperhedonia, hyperphagia, impaired learning and memory and exaggerated startle responses. Inhibitory transmission in hippocampal pyramidal neurons and striatal dopamine receptor D1-expressing neurons of Plcg1-deficient mice was significantly reduced. The decrease in inhibitory transmission is likely due to a reduced number of γ-aminobutyric acid (GABA)-ergic boutons, which may result from impaired localization and/or stabilization of postsynaptic CaMKII (Ca2+/calmodulin-dependent protein kinase II) at inhibitory synapses. Moreover, mutant mice display impaired brain-derived neurotrophic factor-tropomyosin receptor kinase B-dependent synaptic plasticity in the hippocampus, which could account for deficits of spatial memory. Lithium and valproate, the drugs presently used to treat mania associated with BD, rescued the hyperactive phenotypes of Plcg1f/f; CaMKII mice. These findings provide evidence that PLCγ1 is critical for synaptic function and plasticity and that the loss of PLCγ1 from the forebrain results in manic-like behavior.

Crystal structure of human annexin I at 2.5 A resolution.

cDNA coding for N-terminally truncated human annexin I, a member of the family of Ca(2+)-dependent phospholipid binding proteins, has been cloned and expressed in Escherichia coli. The expressed protein is biologically active, and has been purified and crystallized in space group P2(1)2(1)2(1) with cell dimensions a = 139.36 A, b = 67.50 A, and c = 42.11 A. The crystal structure has been determined by molecular replacement at 3.0 A resolution using the annexin V core structure as the search model. The average backbone deviation between these two structures is 2.34 A. The structure has been refined to an R-factor of 17.7% at 2.5 A resolution. Six calcium sites have been identified in the annexin I structure. Each is located in the loop region of the helix-loop-helix motif. Two of the six calcium sites in annexin I are not occupied in the annexin V structure. The superpositions of the corresponding loop regions in the four domains show that the calcium binding loops in annexin I can be divided into two classes: type II and type III. Both classes are different from the well-known EF-hand motif (type I).

Lichen planus pemphigoides with circulating autoantibodies against 200 and 180 kDa epidermal antigens.

We describe a case of lichen planus pemphigoides with circulating autoantibodies against 200 and 180 kDa epidermal antigens. A 24-year-old man presented pruritic erythematous patches with occasional central blister formation on the face, neck, and trunk and erythematous hyperkeratotic patches on the elbows and feet for 10 months. Histopathological findings of the neck and plantar lesions were consistent with lichen planus. Direct immunofluorescence studies from both lesions showed a linear deposition of IgG and C3 and cytoid bodies along the basement membrane zone. Indirect immunofluorescence studies demonstrated circulating IgG antibodies deposited on the epidermal side of salt-split skin. Immunoblot analysis using epidermal extract showed that the patient's serum reacted with 180 kDa bullous pemphigoid antigen (BPAG2) and a 200 kDa antigen. The cutaneous lesions almost cleared with a low dose of prednisolone and acitretin.

Contrast-enhanced magnetic resonance angiography: dose the test dose bolus represent the main dose bolus accurately?

OBJECTIVE: To determine whether the time-intensity curves acquired by test and main dose contrast injections for MR angiography are similar. MATERIALS AND METHODS: In 11 patients, repeated contrast-enhanced 2D-turbo-FLASH scans with 1-sec interval were obtained. Both test and main dose time intensity curves were acquired from the abdominal aorta, and the parameters of time-intensity curves for the test and main boluses were compared. The parameters used were arterial and venous enhancement times, arterial peak enhancement time, arteriovenous circulation time, enhancement duration and enhancement expansion ratio. RESULTS: Between the main and test boluses, arterial and venous enhancement times and arteriovenous circulation time showed statistically significant correlation (p < 0.01), with correlation coefficients of 0.95, 0.92 and 0.98 respectively. Although the enhancement duration was definitely greater than infusion time, reasonable measurement of the end enhancement point in the main bolus was impossible. CONCLUSION: Only arterial and venous enhancement times and arteriovenous circulation time of the main bolus could be predicted from the test-bolus results. The use of these reliable parameters would lead to improvements in the scan timing method for MR angiography.

The optimization of scan timing for contrast-enhanced magnetic resonance angiography.

OBJECTIVE: To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time. MATERIALS AND METHODS: Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods. RESULTS: Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method. CONCLUSION: The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method.

Transcaval TIPS in patients with failed revision of occluded previous TIPS.

OBJECTIVE: To determine the feasibility of transcaval transjugular intrahepatic portosystemic shunt (TIPS) in patients with occluded previous TIPS. MATERIALS AND METHODS: Between February 1996 and December 2000 we performed five transcaval TIPS procedures in four patients with recurrent gastric cardiac variceal bleeding. All four had occluded TIPS, which was between the hepatic and portal vein. The interval between initial TIPS placement and revisional procedures with transcaval TIPS varied between three and 31 months; one patient underwent transcaval TIPS twice, with a 31-month interval. After revision of the occluded shunt failed, direct cavoportal puncture at the retrohepatic segment of the IVC was attempted. RESULTS: Transcaval TIPS placement was technically successful in all cases. In three, tractography revealed slight leakage of contrast materials into hepatic subcapsular or subdiaphragmatic pericaval space. There was no evidence of propagation of extravasated contrast materials through the retroperitoneal space or spillage into the peritoneal space. After the tract was dilated by a bare stent, no patient experienced trans-stent bleeding and no serious procedure-related complications occurred. After successful shunt creation, variceal bleeding ceased in all patients. CONCLUSION: Transcaval TIPS placement is an effective and safe alternative treatment in patients with occluded previous TIPS and no hepatic veins suitable for new TIPS.

Regulation of type I collagen and interstitial collagenase mRNA expression in human dermal fibroblasts by colchicine and D-penicillamine.

Sclerosis is a disease process in which idiopathic hardening occurs in the skin and/or internal organs as a result of the accumulation of type I collagen, induced mainly by transforming growth factor-beta. Colchicine and D-penicillamine are widely used for its treatment. Their effects are known to be due to post-translational down-regulation of type I collagen synthesis, with colchicine also up-regulating interstitial collagenase. To determine whether or not they have any pre-translational effect on type I collagen and MMP-1, and also to observe their effects on the action of TGF-beta, cultured neonatal foreskin fibroblasts were treated with colchicine and D-penicillamine, singly and together. The amount of type I collagen and MMP-1 mRNA were quantitated by Northern blot hybridization. Colchicine suppresses the basal level of type I collagen mRNA but minimally stimulates the mRNA expression of MMP-1, whereas D-penicillamine does not have any significant effects on either. Colchicine was also able to significantly suppress the TGF-beta-induced up-regulation of type I collagen mRNA expression.

Deep hypothermic circulatory arrest in adults undergoing aortic surgery: local experience.

INTRODUCTION: The aim of our study was to evaluate the efficacy and safety of deep hypothermic circulatory arrest (DHCA) as a method of cerebral protection during aortic surgery. MATERIALS AND METHODS: We carried out a retrospective review of 59 consecutive patients (48 men, 11 women) undergoing elective or emergency aortic surgery requiring DHCA from January 1999 to April 2002 in 2 tertiary care hospitals. Data regarding demographics, clinical characteristics, operation type, duration of circulatory arrest, nasopharyngeal temperatures, use of retrograde cerebral perfusion and central nervous system (CNS) morbidity and perioperative mortality were collected and analysed. RESULTS: There were 47 (79.7 %) operations for aortic dissections and 12 (20.3 %) for aortic aneurysms. The mean duration of circulatory arrest was 42 +/- 23 minutes. The lowest nasopharyngeal temperature at the time of arrest was 16.5 degrees +/- 1.9 degrees C. Eight (13.6 %) patients had a new irreversible neurologic deficit postoperatively. These patients had a mean circulatory arrest time of 50 +/- 28 minutes. Temporary neurologic dysfunction occurred in 8 (13.6 %) patients. Intra-hospital mortality was 22 %. The mean circulatory arrest time for patients who died was 54 +/- 24 minutes. CONCLUSION: DHCA is a simple and effective method of CNS protection in aortic surgery with satisfactory outcomes. With increased surgical and anaesthetic experience, as well as selective use of adjuncts of cerebral protection, reductions in mortality and neurological morbidity will likely be achieved in the future.

B-Z DNA junctions contain few, if any, nonpaired bases at physiological superhelical densities.

The reactions of bromoacetaldehyde (BAA) with recombinant plasmids that contain sequences which can adopt left-handed Z structures or, at other locations, cruciforms were studied as a function of supercoil density. The sequence in pRW756 that undergoes a supercoil induced transition from a right to left-handed helix was (dC-dG)16 and regions near the replication origin of the pBR322 vector were converted from linearforms to cruciforms. The locations of the most nonpaired structural features were mapped by S1 nuclease cleavage of the "wedged open" duplexes after linearization of the DNAs. Three cruciforms in the pBR322 portions of the plasmids were specifically detected by BAA reaction at physiological supercoil densities (sigma = -0.067). However, the B-Z junctions did not react with BAA under these conditions although the junctions were present since the (dC-dG)16 was shown to be left-handed. Thus, the B-Z junctions have less single-stranded character than the pBR322 cruciforms (3-6 nonpaired bases) and may be fully paired. At much higher superhelical densities (sigma = -0.11-0.12), the B-Z junctions as well as the cruciforms react with BAA indicating a change in the nature of the junctions. Studies were also performed with pRW777 which harbors the mouse kappa immunoglobin sequence (dT-dG)32 . (dC-dA)32 that adopts a left-handed helix under appropriate conditions; the results were similar to those found with pRW756.

The cytochrome c peroxidase-catalyzed oxidation of ferrocytochrome c by hydrogen peroxide. Steady state kinetic mechanism.

Initial velocities for the cytochrome c peroxidase-catalyzed oxidation of ferrocytochrome c by hydrogen peroxide have been measured as functions of both the ferrocytochrome c (0.27-104 microM) and hydrogen peroxide (0.25-200 microM) concentrations at 25 degrees C, 0.01 M ionic strength, and pH 7 in a cacodylate/KNO3 buffer system Eadie-Hofstee plots of the initial velocity as a function of ferrocytochrome c concentration at constant hydrogen peroxide are nonlinear. A mechanism is proposed which includes random addition of the two substrates to the enzyme and a single catalytically active cytochrome c binding site. The mechanism is consistent with prior studies on cytochrome c peroxidase and fits the steady state kinetic data well.

Common blue naevus with satellite lesions: possible perivascular dissemination resulting in a clinical resemblance to malignant melanoma.

We report a case of common blue naevus with polymorphous guttate and linear satellite lesions, thereby mimicking peripherally spreading malignant melanoma. Histopathologic examination showed that the naevus cells are clustered around blood vessels in the primary as well as satellite lesions, suggestive of spreading of the naevus cells along the perivascular space. Such biological behaviour resulting in a clinical manifestation of a malignant melanoma-like lesion is a rarity in common blue naevus, a benign cutaneous disorder that is devoid of a malignant potential, and has not been described before.

Prevalence of malocclusion among Latino adolescents.

Although numerous studies have documented malocclusion in various ethnic groups in the United States, the prevalence of malocclusion in the Latino population is not well known. The Latino population may be the largest minority group in the United States by the year 2004. This study analyzes the occlusion of 507 Latino adolescents between the ages of 12 and 18 years. More than 93% of the subjects demonstrated some form of malocclusion. The distribution of malocclusion patterns is presented and contrasted with data published for other ethnic groups. Information about the prevalence and types of malocclusion in the Latino population should be of interest to general dental practitioners and specialists.

Hypereosinophilic syndrome: imaging findings in patients with hepatic involvement.

OBJECTIVE: Hypereosinophilic syndrome (eosinophilia without demonstrable cause) commonly involves eosinophilic infiltration of the liver and spleen, but few reports have described the imaging findings. Accordingly, we reviewed the imaging findings in five patients with this syndrome in whom the liver was involved. MATERIALS AND METHODS: Five patients who had hypereosinophilic syndrome with hepatic involvement were included in the study. The diagnosis of hepatic involvement was based on pathologic proof in two patients and on imaging and laboratory findings in the other three. Histologic examination of the hepatic lesions showed extensive eosinophilic infiltration in two patients and centrilobular necrosis in one. All patients had chest radiography, barium studies of the gastrointestinal tract, abdominal CT, and sonography. Four patients had hepatosplenic scintigraphy. All patients were followed up for 4-24 months. RESULTS: All patients had mild to marked hepatomegaly with multiple focal lesions. Focal lesions were detected on sonograms in three patients, on CT scans in four, and on scintigrams in three. On sonograms, the lesions were usually small (less than 2 cm in diameter), sharply or poorly defined nodules with varied echogenicity scattered throughout the liver. The lesions were hypodense with poorly defined margins on CT scans and appeared as variably sized areas of decreased radionuclide uptake on scintigrams. For each patient, the number, size, and shape of the lesions varied considerably from one imaging study to another. On follow-up studies 2-6 months after treatment, the appearance of the liver was normal. Other radiologic findings included transient pulmonary infiltrates (two patients), mild cardiomegaly (one patient), and mild lymphadenopathy (three patients). CONCLUSION: Hypereosinophilic syndrome is a cause of focal hepatic lesions seen on sonograms, CT scans, or scintigrams. The lesions are characterized by the varied appearance on the different types of images and the disappearance of the lesions with treatment.

Diepoxybutane forms a monoadduct with B-form (dG-dC)n.(dG-dC)n and a crosslinked diadduct with the left-handed Z-form.

The characteristics of the reactions of DL-diepoxybutane (DEB) with (dG-dC)n.(dG-dC)n in the right-handed B-form or the left-handed Z-form were investigated. DEB does react with right-handed B-DNA since less salt is required to convert the modified B-form to Z-form than for the unmodified DNA. However, the product appears to be a monoadduct rather than the crosslinked diadduct formed with the Z-form. The modified B-form can be isolated, converted to a Z-form with l mM MnCl2, and then this activated complex further reacts intramolecularly to give the crosslinked Z-product. This modified Z-form cannot be reverted to the B-form unless the crosslink is cleaved with periodate. Only MnCl2, and to a lesser extent ZnCl2, was effective in facilitating the intramolecular conversion of the B-DNA monoadduct to the Z-DNA diadduct; lmM MgCl2 and 4M NaCl were ineffective suggesting that somewhat different types of modified left-handed conformations were generated by the different salts. DEB also cleaves DNA under our reaction conditions thus precluding studies with supercoiled recombinant plasmids harboring segments that adopt Z-structures.

Osteoma cutis coexisting with cutis laxa-like pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is a heritable disorder of elastic fibers characterized by yellowish, coalescing papules on the loose and wrinkled flexural area. There have been no reports of osteoma cutis associated with PXE. A 17-year-old Korean girl presented cutis laxa-like marked wrinkling on the flexural area, and a skin biopsy specimen revealed multiple foci of ossification with irregularly clumped, basophilic-stained elastic fibers in the reticular dermis and calcium deposits along the elastic fibers. Ultrasonographic evaluation showed multiple tiny osteomas diffusely scattered along the entire abdominal wall, axillae, and medial aspect of the upper arms. We report the first case of osteoma cutis coexisting with cutis laxa-like PXE.

Unusual DNA structures in the adenovirus genome.

More than 80% (approximately 29 kilobase pairs) of the adenovirus serotype 2 genome was surveyed for the presence of unusual DNA conformations. Seven recombinant DNAs containing the largest HindIII fragments of AD2 DNA were analyzed for the presence of negative supercoil-dependent S1 nuclease-sensitive sites. Four plasmids each contained a specific site of S1 nuclease sensitivity whereas the other three showed no reaction. Further investigation was focused on a plasmid containing one of the positively reacting fragments (fragment C) which contained the major late promoter at coordinate 16.4 on the genome; three serotypes (Ad2, Ad7, Ad12) were studied. Fine mapping studies revealed the S1-sensitive sites to be a small region (approximately 6 base pairs) located at the TATA box of the major late promoter in all three cases. Other determinations (supercoil relaxation, T7 gene 3 product sensitivity, bromoacetaldehyde reactivity, anomalous gel mobility, the influence of negative superhelical density on nuclease sensitivity) led to the conclusion that the B-helix deformation was not due to a previously recognized DNA conformation (left-handed Z-DNA, cruciform, bent DNA), but may be accounted for by the homopurine X homopyrimidine nature of this region.

Thermodynamic parameters are sequence-dependent for the supercoil-induced B to Z transition in recombinant plasmids.

The entropy and enthalpy changes which contribute to the thermodynamics of the B to Z transition were determined for three recombinant plasmids containing a (dC-dG)16 tract and for a plasmid containing a pair of (dT-dG)20 regions. For each base pair which adopts a left-handed conformation in the plasmids with (dC-dG)16 sequences, the delta HBZ and delta SBZ are -2.1 kcal/mol bp and -8.8 cal/K-mol bp, respectively. In the plasmid containing the (dT-dG)20 tracts, however, the delta HBZ and delta SBZ values are 0.58 kcal/mol bp and -0.76 cal/K-mol bp, respectively. Also, these determinations show that for each B-Z junction that forms in the plasmids containing the (dC-dG), the enthalpy and entropy changes are 24 kcal/mol junction and 65 cal/K-mol junction, whereas for the (dT-dG) plasmid, the enthalpy and entropy changes are -1.8 kcal/mol junction and -22 cal/K-mol junction, respectively. Those values for the enthalpy and entropy changes for the formation of a BZ junction in (dC-dG) and (dT-dG) plasmids suggest that the properties and possibly the structures of the junctions are different. Calculations using the enthalpy and entropy changes determined in this study reveal that the B to Z transition in plasmids containing (dC-dG) blocks are more temperature-dependent than the transitions in plasmids with (dT-dG) blocks. Surprisingly, at temperatures above 60 degrees C, calculations indicate that the B to Z transitions in (dT-dG) plasmids should be energetically favored over that transition in (dC-dG) plasmids.