Cortical neuronal apoptosis in CADASIL.

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by mutations of the NOTCH3 gene and is a model of pure vascular dementia. Cortical atrophy has been reported to be associated with cognitive decline in the disease, although the underlying mechanism is unknown. We postulated that apoptosis may be involved in this process. METHODS: We report the clinical history, magnetic resonance imaging findings, and pathologic examinations of 4 patients (2 of whom were demented) who died from complications of the disease. Apoptosis was evaluated in brain tissue using antibodies against activated caspase3 and in situ end labeling assays for DNA fragmentation. RESULTS: Widespread neuronal apoptosis in the cerebral cortex (predominantly in layers 3 and 5) was observed in all patients. This was not seen in 3 non-CADASIL controls. Semiquantitative analysis suggested that apoptosis was more extensive in the presence of larger load of subcortical ischemic lesions and smaller brain volumes. CONCLUSIONS: Neuronal apoptosis may be involved in cortical atrophy in CADASIL and appears related to the burden of subcortical ischemic lesions. These findings may have important implications in other small vessel diseases and may provide a potential target for future therapeutic interventions.

Capsule structure changes associated with Cryptococcus neoformans crossing of the blood-brain barrier.

Cryptococcus neoformans is a yeast responsible for disseminated meningoencephalitis in patients with cellular immune defects. The major virulence factor is the polysaccharide capsule. We took advantage of a relevant murine model of disseminated meningoencephalitis to study the early events associated with blood-brain barrier (BBB) crossing. Mice were sacrificed at 1, 6, 24, and 48 hours post-intravenous inoculation, and classical histology, electron microscopy, and double immunofluorescence were used to study tissues and yeasts. Crossing of the BBB occurred early after inoculation, did not involve the choroid plexus but instead occurred at the level of the cortical capillaries, and caused early and severe damage to the structure of the microvessels. Seeding of the leptomeninges was not the primary event but occurred secondary to leakage of cortical pseudocysts. Organ invasion was associated with changes in cryptococcal capsule structure and cell size, which differed in terms of magnitude and kinetics, depending on both the organs involved, and potentially, on the bed structure of the local capillary. The rapid changes in capsule structure could contribute to inability of the host immune response to control cryptococcal infection in extrapulmonary spaces.

Altered fat differentiation and adipocytokine expression are inter-related and linked to morphological changes and insulin resistance in HIV-1-infected lipodystrophic patients.

OBJECTIVE: To achieve a better understand of the pathophysiology of HIV-related lipoatrophy, we compared the mRNA expression of adipocytokines in fat samples from patients and healthy HIV-seronegative controls together with fat morphology and we studied the relationship between changes in fat morphology, adipocytokine expression, markers of adipose tissue differentiation and whole body insulin sensitivity. DESIGN: Cross-sectional analytical study. SUBJECTS AND METHODS: The mRNA expression of adipocytokines and transcriptional factors in fat samples from 26 patients with peripheral lipoatrophy (all under anti-retroviral therapy associating protease inhibitor and nucleoside-analogue reverse transcriptase inhibitors) and from 16 non-HIV-infected controls was measured by real time quantitative RT-PCR. Fat morphology was assessed histologically on a subgroup of 10 patients and six controls: collagen fibres by Sirius Red staining, apoptosis by the TUNEL technique, vessels by smooth muscle alpha-actin staining and macrophages by CD68 staining. Insulin resistance was assessed by using the homeostasis model assessment. RESULTS: The patients' fat showed higher values of apoptosis (P=0.005), fibrosis (P<0.05), vessel density (P=0.001) and macrophage infiltration (P<0.05) than the controls' fat, together with lower adiponectin and leptin mRNA levels and higher interleukin (IL)-6 and tumour necrosis factor (TNF)alpha mRNA levels. TNFa and IL-6 expression correlated positively with the level of apoptosis (P=0.05 and P<0.05, respectively) and negatively with CCAAT-enhancer binding protein (C/EBP)alpha (P<0.001 and P<0.05, respectively). Apoptosis correlated negatively with the expression level of sterol-regulatory-element-binding-protein-1c (SREBP1c) (P=0.01) and C/EBPalpha (P=0.01) whilst the vessel density correlated negatively with SREBP1c (P<0.005), C/EBPalpha (P=0.001) and beta (P=0.001). Adiponectin and leptin expression correlated positively with each other, and also with adipogenic marker expression and overall insulin sensitivity. These relationships were also present when the patient group was studied separately. Finally, fat morphological abnormalities correlated positively with whole body insulin resistance. CONCLUSIONS: Adipose tissue from patients with HIV-1-related lipoatrophy shows increased apoptosis, together with decreased adipocyte differentiation. Increased TNFalpha and IL-6 expression could be a major phenomenon linking these alterations. Decreased adiponectin and leptin expression, which may result from decreased adipocyte differentiation, could be involved in the observed whole body insulin resistance.

Culture-proven herpetic keratitis after penetrating keratoplasty in patients with no previous history of herpes disease.

OBJECTIVE: To report three cases of herpetic infection in recipients of organ-cultured donor corneas among 586 consecutive corneal transplantation procedures. METHODS: Three patients with no history of symptomatic herpes infection underwent corneal transplantation for keratoconus (2 patients) and Fuchs dystrophy (1 patient). Two patients developed keratouveitis and primary graft failure. The third patient developed dendritic keratitis in the graft. Culture of corneal scrapings and the patient's bandage contact lens were positive for herpes simplex virus type 1 (HSV-1). Donor and recipient sera were tested for HSV serology by EIA. Recipient corneal buttons were studied by means of transmission electron microscopy and immunohistochemistry. The three HSV-1 strains were genotyped by sequencing part of a variable antigenic domain of glycoprotein B (gB). RESULTS: None of the donor corneas showed endothelial cell necrosis after organ culture. All keratoplasties performed with the three mate donor corneas had an uncomplicated course. All three donor sera were positive for HSV. Preoperative recipient sera were positive for HSV. Analysis of the recipient corneal buttons showed no evidence of herpetic infection. Sequence analysis revealed three different gB genotypes. CONCLUSION: Ascertaining that a postoperative herpetic infection in a corneal transplant originates from the donor tissue is still difficult. Although some features of the reported cases suggest donor-to-host transmission of herpes simplex virus, the recipients could have been the source of the virus.

Insulin-like growth factor binding protein-6 transgenic mice: postnatal growth, brain development, and reproduction abnormalities.

In biological fluids, IGFs bind to six distinct binding proteins (IGFBP-1 to -6). IGFBP-6 is of particular interest because it has been shown to inhibit proliferation in many cell types and to be synthesized in the central nervous system (CNS). It also has the strongest affinity for IGF-II among the IGFBPs. To study IGFBP-6 function in vivo, we established IGFBP-6 transgenic mice in which human IGFBP-6 (hIGFBP-6) cDNA is expressed under the control of the glial fibrillary acidic protein (GFAP) promoter. Northern and Western blot analysis revealed strong transgene expression in the CNS. With histological examination of the CNS, cerebellum size and weight proved to be reduced by about 25% and 35%, respectively, and there were smaller numbers of differentiated, GFAP-expressing astrocytes than in wild-type mice. Between birth and 1 month of age, transgenic mice had high levels of circulating hIGFBP-6 and reduced plasma IGF-I, and, as a result, body weight was significantly reduced. Reproductive physiology was also affected. Litter size was reduced by 27% when wild-type males were mated with 3-month-old transgenic females and by 66% when mated with 6-month-old transgenic females. Histological examination of ovaries of transgenic mice revealed a marked decrease in weight and in the number of corpora lutea, suggesting altered ovulation, and circulating LH levels were reduced by 50%. Our results indicate that this new model of transgenic mouse may prove to be a useful tool in elucidating the in vivo role of IGFBP-6 in the brain, especially in regard to hypothalamic control, and in reproductive physiology.

Intrathecal ropivacaine in rabbits: pharmacodynamic and neurotoxicologic study.

BACKGROUND: Ropivacaine is available for spinal or intrathecal use in humans, although data on neurotoxicity after spinal injection are not yet available. The authors experimentally determined the relationship between doses of intrathecal ropivacaine and spinal effects and local neurotoxic effects. METHODS: Eighty rabbits equipped with an intrathecal lumbar catheter were studied. Sixty were randomly assigned to receive 0.2 ml of intrathecal solutions as a sole injection of: 0.2%, 0.75%, 1.0%, and 2.0% ropivacaine (doses from 0.4-4.0 mg; groups R0.2 to R2.0), 5.0% lidocaine (10 mg; group L), or 0.9% NaCl as control (group C). Twenty other rabbits received either repeated injections of 0.2 ml of 0.2% ropivacaine every 2 days during 2 weeks (total dose of 2.8 mg; group RINT); or a continuous intrathecal infusion of 0.2% ropivacaine at the rate of 1.8 ml/h over 45 min (2.7 mg; group RCONT). Injection rate was 30 s in all groups except Rcont. Time to onset, duration and extent of motor block, and variations of mean arterial blood pressure were recorded in all groups. Somatosensory evoked potentials were also recorded in group RCONT and RINT. Seven days after the last intrathecal injection spinal cord and nerves were sampled for histopathologic study. RESULTS: In groups R0.2 and RINT, the lowest dose of ropivacaine induced a clinically visible spinal block in only 50% of rabbits, but SEPs recorded in group RINT were decreased by 70% in the lumbar dermatome. Complete motor block was observed with doses greater than 1.5 mg of ropivacaine (group RCONT and R0.75 to R2.0). Onset time was shorter and duration of block increased as doses of ropivacaine increased. Significant hypotension was observed only with 4.0 mg of ropivacaine (concentration of 2.0%). Complete paralysis and hypotension were observed with 5.0% lidocaine. No neurologic clinical lesion was observed in rabbits receiving saline or ropivacaine within the 7 days after the last intrathecal injection, and histopathologic study revealed no sign of neurotoxicity in these groups. In contrast, intrathecal lidocaine induced clinical and histopathologic changes. CONCLUSION: Ropivacaine induced dose-dependent spinal anesthesia, and did not induce any neurotoxicologic lesion in this experimental animal model.

Unilocular acinar cell cystadenoma of the pancreas an unusual acinar cell tumor.

We report an unusual case of acinar cell cystadenoma of the pancreas in a 52-year-old man treated for pulmonary adenocarcinoma. The lesion, located in the body of the pancreas, was revealed incidentally by abdominal computed tomography during follow-up for a pulmonary neoplasm. A left pancreatectomy was performed. The unilocular cystic lesion measured 5 cm and was lined by a single layer of columnar acinar cells with eosinophilic granular cytoplasm, faintly stained by periodic acid-Schiff. Immunohistochemical analysis showed the lining cells were positive for cytokeratin and trypsin, and electronic microscopy showed that they contained zymogen granules. Acinar cell tumors of the pancreas are rare and include acinar cell carcinomas, acinar cell cystadenocarcinomas, and acinar cell adenomas. We report a case of cystic acinar cell tumor of the pancreas with benign gross and histologic features that could be added to the list of cystic neoplasms of the pancreas as acinar cell cystadenoma.