Automated PET-only quantification of amyloid deposition with adaptive template and empirically pre-defined ROI.

Amyloid PET is useful for early and/or differential diagnosis of Alzheimer's disease (AD). Quantification of amyloid deposition using PET has been employed to improve diagnosis and to monitor AD therapy, particularly in research. Although MRI is often used for segmentation of gray matter and for spatial normalization into standard Montreal Neurological Institute (MNI) space where region-of-interest (ROI) template is defined, 3D MRI is not always available in clinical practice. The purpose of this study was to examine the feasibility of PET-only amyloid quantification with an adaptive template and a pre-defined standard ROI template that has been empirically generated from typical cases. A total of 68 subjects who underwent brain (11)C-PiB PET were examined. The (11)C-PiB images were non-linearly spatially normalized to the standard MNI T1 atlas using the same transformation parameters of MRI-based normalization. The automatic-anatomical-labeling-ROI (AAL-ROI) template was applied to the PET images. All voxel values were normalized by the mean value of cerebellar cortex to generate the SUVR-scaled images. Eleven typical positive images and eight typical negative images were normalized and averaged, respectively, and were used as the positive and negative template. Positive and negative masks which consist of voxels with SUVR ⩾1.7 were extracted from both templates. Empirical PiB-prone ROI (EPP-ROI) was generated by subtracting the negative mask from the positive mask. The (11)C-PiB image of each subject was non-rigidly normalized to the positive and negative template, respectively, and the one with higher cross-correlation was adopted. The EPP-ROI was then inversely transformed to individual PET images. We evaluated differences of SUVR between standard MRI-based method and PET-only method. We additionally evaluated whether the PET-only method would correctly categorize (11)C-PiB scans as positive or negative. Significant correlation was observed between the SUVRs obtained with AAL-ROI and those with EPP-ROI when MRI-based normalization was used, the latter providing higher SUVR. When EPP-ROI was used, MRI-based method and PET-only method provided almost identical SUVR. All (11)C-PiB scans were correctly categorized into positive and negative using a cutoff value of 1.7 as compared to visual interpretation. The (11)C-PiB SUVR were 2.30 ± 0.24 and 1.25 ± 0.11 for the positive and negative images. PET-only amyloid quantification method with adaptive templates and EPP-ROI can provide accurate, robust and simple amyloid quantification without MRI.

16th IHIW: a website for antibody-defined HLA epitope Registry.

The concept that HLA antibodies are specific for epitopes rather than HLA antigens is important not only for the determination of mismatch acceptability for sensitized patients but also for a better understanding of the antibody response to an HLA mismatch. Numerous publications describe epitope-specific antibodies, but there is no standardized information about the repertoire of clinically relevant HLA epitopes. Under auspices of the 16th IHIW, we have developed a website-based registry of antibody-verified HLA epitopes. Epitope notations are based on HLA molecular modelling of amino acid residues in polymorphic sequence positions. Informative epitope-specific antibodies had been induced by a transplant, transfusion or pregnancy and were monoclonal antibodies or eluates of sera absorbed with single HLA alleles. Antibody reactivity was determined in binding assays with single-allele panels. Antibody producer/immunizer HLA types enhanced the characterization of specific epitopes. The Registry also includes epitopes described in original research publications. Based on the extent of antibody reactivity information, we assigned epitope status as confirmed (well documented) or provisional (more data are needed). At present, the Registry has 69 HLA-ABC, 53 DRB1/3/4/5, 17 DQ, 8 DP and 22 MICA antibody-verified epitopes and will be updated on a quarterly basis. Laboratories worldwide continue to submit data about previously unreported antibody-specific epitopes. For each epitope, the website shows its amino acid composition and HLA alleles that share the epitope. Links show antibody reactivity patterns, sensitization information and references. Other links show molecular modelling of corresponding structural epitopes and polymorphic residue information for epitope-carrying alleles. The website will also have a link to epitope frequency information in different populations. Search functions will list mismatched epitopes on mismatched alleles for selected HLA types. The HLA Epitope Registry will become a valuable resource for researchers interested in HLA compatibility at the epitope level and investigating antibody responses to HLA mismatches.

Caveolin-1 expression is a distinct feature of chronic rejection-induced transplant capillaropathy.

Peritubular capillary basement membrane multilayering (PTCBMML) is a pathological landmark of chronic rejection-induced transplant capillaropathy (TC), but its cellular mechanisms are not fully understood. We observed de novo caveolae formation in endothelial cells in TC under electron microscopy. To examine the role of caveolae and their structural components in TC, biopsy samples from cases of chronic rejection were double-immunostained for Caveolin-1 (Cav-1) and Pathologische Anatomie Leiden-endothelium (PAL-E; a marker of peritubular capillary [PC]). Thirty-two cases of chronic rejection (group I) were compared with 18 cases of interstitial fibrosis and tubular atrophy with no evidence of any specific etiology (IF/TA; group II) and eight cases of peritubular capillaritis (group III). The Cav-1/PAL-E immunoreactivities in groups I-III (%Cav-1/PAL-E) were 41.8+/-23.1%, 8.1+/-7.3% (p < 0.01 vs. group I) and 12.7+/-7.4% (p < 0.01 vs. group I), respectively. Furthermore, multiple linear regression models demonstrated that %Cav-1/PAL-E was independently associated with the PTCBMML grade and reduced PC number. No correlation was observed between %Cav-1/PAL-E and PC C4d deposition in group I. We conclude that de novo caveolae formation in PC endothelia is involved in TC in chronic rejection.

Thickening of the peritubular capillary basement membrane is a useful diagnostic marker of chronic rejection in renal allografts.

In kidney transplantation, the multilayering of the peritubular capillary basement membrane (MLPTC) in electron microscopy (EM) has been recognized as a feature of chronic rejection (CR). In this study, thickening of the peritubular capillary (PTC) basement membrane was evaluated by light microscopy (LM) to determine whether it corresponds to the MLPTC in EM and whether it can be used as a diagnostic marker of CR. Forty-eight patients with late renal allograft were divided into chronic allograft nephropathy (CAN) with CR (Group 1, n = 23), CAN without CR (Group 2, n = 19) and CAN-free (Group 3, n = 6). The thickening of the PTC basement membrane (ptcbm) was scored from grades 0 to 2 (ptcbm score), and the MLPTC thickness was measured in EM. Interobserver agreement on ptcbm scores was statistically significant (Kappa coefficient = 0.63). LM and EM lesions corresponded very well. The ptcbm score was highest in Group 1, and ptcbm2 corresponded closely with CR. Group 1 showed significantly thicker MLPTC than Groups 2 and 3. The results validated the usefulness of the ptcbm score and suggested that the thickening of the PTC basement membrane can be a novel diagnostic marker of CR.

[Surgical fixation for flail chest].

Flail chest occurs by blunt chest trauma and is associated with pulmonary contusion, atelectasis, pneumothorax, hemothorax, and respiratory failure. Because of its severity, it may need internal pneumatic stabilization or surgical fixation. Some patients do not need the internal stabilization and are observed conservatively. Some of these patients, however, increase the flail after palliating the pain and getting up. These patients show inefficient ventilation and surgical fixation is needed. The operation should be performed after the improvement of pulmonary contusion. In this paper, we presented 2 patients who showed such course and clarified the surgical methodology.

Herpes simplex virus types 1 and 2 infect the mouse pituitary gland and induce apoptotic cell death.

Herpes simplex virus (HSV) infected the anterior lobe of the pituitary gland resulting in cytopathic changes following intravenous (i.v.) inoculation of male mice. Both HSV type 1 (HSV-1) and type 2 (HSV-2) were isolated from pituitary gland following i.v. infection, but not after intraperitoneal inoculation. HSV-infected pituitary cells were microscopically visible beginning at 24 h or 48 h following i.v. inoculation and were localized in the anterior pituitary. In both HSV-1 and -2 infections the pituitary lesions were apoptotic, as determined by light and electron microscopy, TUNEL, and DNA gel electrophoresis. However, the pituitary infection does not appear to be life-threatening since pituitary lesions were also observed following i.v. infection with HSV-1 strain -GC which possesses low virulence. These results suggest that the pituitary gland is one of the target organs of HSV infection.

Histological analysis of late renal allografts of antidonor antibody positive patients with C4d deposits in peritubular capillaries.

The association of humoral immunity with late renal allograft dysfunction has recently been recognized, and many reports have revealed C4d deposits in peritubular capillaries (C4d in PTC), and the presence of serum antidonor HLA antibody in patients suffering from graft dysfunction, long time after transplantation. In this study, morphological changes in renal allograft biopsies more than 1 year after transplantation in 14 patients with C4d in PTC and serum antidonor antibody were investigated for the presence of chronic rejection (CR). In addition to the light microscope study, an electron microscope study was done to evaluate the multilayering of the peritubular capillary basement membrane (MLPTC). Histologically, only seven of 14 patients met the criteria of CR, and 71.4% (5/7) of CR patients had episodes of acute humoral rejection (AHR), coexisting with acute tubulointerstitial rejection. Peritubular capillaritis was observed in all patients, although it differed in severity. Transplant glomerulitis and interstitial inflammation were also observed in many patients: 71.4% (10/14) and 92.9% (13/14) respectively. MLPTC was observed in 12 patients (85.7%), but the severity of the MLPTC did not reflect the severity of peritubular capillaritis or any other histological features. The long-term outcomes of the patients CR, especially those with episodes of AHR, were poor, and two of them lost their graft functions. On the other hand, patients without CR had relatively favourable outcomes. In conclusion, we confirmed the diverse morphological changes of late renal allografts, which cannot be categorized as chronic humoral rejection (CHR), and such patients who do not have typical morphological changes such as CHR, should be followed-up on a long-term basis in order to clarify the significance of C4d on PTC in late renal allografts.

Acute adrenal infection by HSV-1: role of apoptosis in viral replication.

Replication of herpes simplex virus type 1 (HSV-1) in the adrenal gland of mice was observed 12 h after intravenous inoculation, peaked at 48 h (7 x 10(7) PFU/tissue), and was maintained until death. Virus spread to the bilateral intermediolateral column of the thoracic spinal cord. Infected cells appeared in the fascicular zone of the adrenal cortex 12 h after infection, and cell death was evident in lesions found in the adrenal cortex. Lesions involved the medulla 48 h after inoculation. In cortical lesions, cell nuclei were fragmented or shrunken with little damage to the cytoplasm. DNA fragmentation appeared 12 h after inoculation and increased mainly in cortical lesions, which were characterized by apoptosis induced by HSV-1 infection. In the adrenal medulla, cells were fused and formed multinucleated giant cells but rarely displayed cell death. Macrophages, which serve as a frontal barrier to viral infection in the adrenal gland, especially the cortex, were fewer in number than those found in the liver or spleen. It is likely that HSV-1 easily infects the adrenal gland, resulting in suppression of local immunity, and that adrenal cell apoptosis serves as a primitive type of immunity to limit viral replication.

Are there histopathologic characteristics particular to fulminant hepatic failure caused by human herpesvirus-6 infection? A case report and discussion.

An 8-month-old boy was admitted to a neighboring hospital for severe liver dysfunction and drowsiness 4 days after a diagnosis of exanthem subitum. A diagnosis of fulminant hepatic failure was made, and liver biopsy was performed during the acute stage. The presence of human herpesvirus-6 variant B (HHV-6B) DNA was shown in liver tissue by polymerase chain reaction (PCR) and in the endothelium of the portal vein by in situ hybridization (ISH). Histologic examination showed microvesicular steatosis resembling that of Reye's syndrome, even though aspirin had not been prescribed. We considered HHV-6 to be the causative agent in this case and report what is perhaps the first precise histologic description of fulminant hepatic failure caused by HHV-6.

Quantitative analysis of pulmonary neuroendocrine cell distribution of the fetal small airways using double-labeled immunohistochemistry.

Pulmonary neuroendocrine cells (PNECs) are supposed to play an essential role in development of fetal lung and neonatal respiratory adaptation. Some previous studies have suggested the close relation between PNECs and sudden infant death syndrome (SIDS). To investigate how PNECs distribute to the thermal bronchioli of fetal lung may be a clue to clarify this relation. Since it is difficult to distinguish bronchiole from alveolus in fetal lung, we performed double immunostaining with antibody against chromogranin A (CGA) and alpha-smooth muscle actin (SMA) which can make clear distinction between them. In this study, formalin-fixed, paraffin-embedded lung tissues from 18 autopsy cases from 16 to 28 weeks of gestation were assessed. CGA immunopositive cells were counted and the length of basement membranes of terminal bronchioli was measured with computed image analyzer. Density of PNECs was expressed as the number of immunopositive cells per millimeter of basement membrane. Terminal bronchiole stained with SMA was clearly distinguished from alveolus at 16 weeks. With gestational age, CGA immunopositive PNECs were gradually increased in 2 folds by the 25th week. After that, their density wasn't changed significantly until termination. It is suggested that PNECs in terminal bronchiole was playing an important role in morphogenesis of alveolar ducts and alveolar sacks.

[Role of apoptosis induced by acute herpes simplex virus].

Apoptosis is induced by acute herpes simplex viral infection in the adrenal cortex, myenteric plexus of the gut, ovary, and liver of mice. Viral replication is closely related to apoptosis. This apoptosis is increased in immunosuppressive regions like the adrenal cortex and liver of macrophag-depleted mice. However, the herpes simplex virus is known to possess US3 gene, which interferes with cell apoptosis. In the liver of macrophage-depleted mice infected with US3 gene-deficient mutant herpes, the apoptosis is confined to within the narrow limits of inflammatory cell infiltration, mainly of neutrophils, and it plays a part in the restriction of virus multiplication. Thus, a possibility exists that apoptosis works as a primitive immunity in herpes simplex virus infection.

Patterns and mechanisms of pedestrian injuries induced by vehicles with flat-front shape.

To clarify the difference between flat-front vehicles and bonnet-front vehicles with regard to the patterns and mechanisms of vehicle-induced pedestrian injuries, we investigated 101 cases of pedestrians who were struck by the front of a vehicle. There were 33 flat-front vehicle collision cases and 68 bonnet-front vehicle collision cases. The frequency of chest injuries in flat-front vehicle collisions (30.3%) was significantly higher than that in bonnet-front vehicle collisions (11.8%). Lower leg fractures were more common in bonnet-front vehicle collisions than in flat-front vehicle collisions. Although head injuries were common in both cases, the mechanisms of these injuries differed. The pedestrians who were struck by flat-front vehicles tended to sustain more severe injuries at lower impact speeds. All of these results stem from the difference in the front shape of the two types of vehicle. Pedestrians who are struck by the front of flat-front vehicles receive the impact force to the trunk, particularly the chest, at the initial impact and are thrown out forward after the impact, because the front of these vehicles is perpendicular to the road.

Pulmonary neuroendocrine cell distribution in sudden infant death syndrome.

The density of pulmonary neuroendocrine cells (PNECs) in 21 sudden infant death syndrome (SIDS) cases, 19 controls, and 25 fetuses was studied morphometrically. Formalin-fixed, paraffin-embedded lung samples were immunostained with antibody against chromogranin A (CGA). The percentage of PNEC-positive airways and the density of PNECs in each airway were calculated in all cases. The density of PNECs was expressed as the number of cells per millimeter of basement membrane. The percentage of PNEC-positive airways reached nearly 100% by term and did not change significantly until 12 months of age in both the SIDS cases and the controls. The density of PNECs also showed a rapid increase in the saccular stage fetus and had its peak of about 4 cells/mm around birth. The density of PNECs, including the standard deviation, was higher in SIDS cases than in controls. The uneven distribution of PNECs may affect respiratory control in SIDS victims.

Herpes simplex virus hepatitis in macrophage-depleted mice: the role of massive, apoptotic cell death in pathogenesis.

Infection with herpes simplex virus or hepatitis viruses can lead to fulminant hepatitis, but there is controversy about the underlying conditions needed for such disease. To investigate how the impairment of host defences might be involved, macrophages were depleted by administration of silica to mice before intravenous injection with herpes simplex virus type 1 (HSV-1). Such mice died rapidly and their livers were yellowish and shrunken (acute yellow atrophy), and occasionally grossly haemorrhagic. Small foci of apoptotic cells developed in the liver lobules; these rapidly became confluent and zonal over time. The overall lesion pattern was similar to massive hepatic necrosis, and there was extensive HSV replication in the liver lesions. In the liver, DNA fragmentation characteristic of apoptosis followed the time course of HSV-1 propagation. These findings suggest that one of the underlying conditions for fulminant viral hepatitis may be inadequate macrophage response, and that the massive hepatic damage, often defined as cell necrosis, may actually be apoptosis of liver cells subsequent to virus infection.

Streptococcal and staphylococcal superantigen-induced lymphocytic arteritis in a local type experimental model: comparison with acute vasculitis in the Arthus reaction.

Many pathogenic bacteria produce superantigenic exotoxins. To study their pathogenetic role, in particular to test whether these toxins are able to induce vasculitis, we developed a local-type experimental model in rabbits. Toxins were injected along the intermediate auricular artery of the ear. The histology of ear skin, including the artery, was examined after single or repeated injections. Repeated injections of streptococcal erythrogenic toxins produced chronic-type arteritis characteristic of lymphocytic infiltration, whereas single injection induced no acute-type vasculitis. Staphylococcal enterotoxin B and toxic shock syndrome toxin-1 also induced the same type of arteritis, although weaker in degree. In human patients these lesions are similar to those of Kawasaki disease, a systemic vasculitis with unknown etiology. The Arthus reaction to human serum albumin in immunized rabbits included acute-type vasculitis similar to polyarteritis nodosa when examined in this model. Microvasculitis lesions similar to leukoclastic vasculitis were combined in the Arthus reaction but not in the superantigen-induced lesions. Our experimental model described here is widely applicable to the study of the etiology and pathogenesis of human diseases involving vasculitis lesions.

Erythrogenic toxin-induced arteritis in a rabbit ear model. Comparison with Arthus reaction angiitis.

We have developed a local type experimental model of angiitisin rabbits. Repeated intracutaneous injections of erythrogenic toxins types A and C (ETA, ETC) along the intermediate auricular artery of the rabbit ear produced subacute type arteritis, characteristic of lymphocyticinfiltration, simulating Kawasaki disease angiitis. Staphylococcal enterotoxin B (SEB) and toxic shock syndrome toxin 1 (TSST) also induced similar lesions, indicating superantigens as inflammogens in vivo. Conversely, the Arthus reaction included acute type angiitis when tested similarly in rabbits immunized to human serum albumin. The ear artery was infiltrated by heterophil leukocytes, often together with venules and capillaries affected, resembling periarteritis nodosa and leukoclastic vasculitis in human disease.

Identification of regions of bovine factor VII essential for binding to tissue factor.

Initiation of the extrinsic blood coagulation pathway is mediated by a complex formed between plasma-derived factor VII/VIIa and cell-derived tissue factor (TF). To identify the site(s) of interaction, zymogen VII and VIIa were enzymatically and chemically modified, and their affinities for TF were estimated by measuring their inhibitory effects on the amidolytic activity enhanced after formation of the VIIa-TF complex. We found that the VIIa-light chain (Ki = 3.5 x 10(-7) M) and its fragment consisting of the gamma-carboxyglutamic acid (Gla)-domain and the first epidermal growth factor (EGF)-like domain (Gla-EGF1 peptide; Ki = 1.0 x 10(-6) M) have an affinity for TF. Therefore, one of the binding sites of VII with TF is probably located in the Gla-EGF1 region. On the other hand, a dansyl-Glu-Gly-Arg chloromethyl ketone-treated Gla-domainless VIIa (Ki = 0.7 x 10(-7) M) showed a high affinity for TF, whereas the corresponding Gla-domainless VII similarly treated showed no binding potential, thereby indicating that binding site(s) other than in the Gla-EGF1 region are present in VIIa but not in VII. Acetylation or carbamylation of the alpha-amino group of the NH2-terminal Ile-153 of VIIa resulted in the loss of binding affinity for TF; such modifications convert VIIa into a zymogen-like inactive form by destroying the salt bridge between Ile-153 and Asp-343 in VIIa. The rate of carbamylation of VIIa was reduced in the presence of TF. Protection of the alpha-amino group of Ile-153 from carbamylation after complex formation was consistent with salt bridge formation between Ile-153 and Asp-343 in the VIIa-TF complex. Therefore, binding of TF with the heavy chain of VIIa may induce a conformational change that brings the alpha-amino group of Ile-153 close to the beta-carboxyl group of Asp-343 to make a stable salt bridge.

[Prolonged action preparation of cefaclor].

This study was conducted to develop a prolonged action preparation of cefaclor (CCL) which can offer, with the twice-a-day administration, as much effectiveness as its conventional preparation (Kefral capsule) with the 3 times-a-day administration. Absorption site of CCL in gastrointestinal tract, preparation form (enteric coated granules) which slowly release CCL, dissolution property of the form, and mixed ratio of the form and rapid release form (nonenteric coated granules) were studied and complex granules consisting of 40% of nonenteric coated granules and 60% of enteric coated granules which dissolve at pH 6 were chosen as a prolonged action preparation of CCL. Bactericidal activity of the prolonged action preparation (S6472) was confirmed to be the same as that of the conventional preparation by comparative viable cell count study in which concentrations of CCL simulated to plasma concentrations following the administration of S6472 at the dosage of 375 mg b.i.d. and the conventional preparation at the dosage of 250 mg t.i.d. were used. From the above, S6472 is considered to be a prolonged action preparation of CCL which serve our purpose. Since S6472 can be given with the twice-a-day administration, its daytime administration is not necessary. Therefore, S6472 is considered to be much useful preparation for the patients.