Neuroendocrine,epigenetic, and intergenerational effects of general anesthetics

The progress of modern medicine would be impossible without the use of general anesthetics (GAs). Despite advancements in refining anesthesia approaches, the effects of GAs are not fully reversible upon GA withdrawal. Neurocognitive deficiencies attributed to GA exposure may persist in neonates or endure for weeks to years in the elderly. Human studies on the mechanisms of the long-term adverse effects of GAs are needed to improve the safety of general anesthesia but they are hampered not only by ethical limitations specific to human research, but also by a lack of specific biological markers that can be used in human studies to safely and objectively study such effects. The latter can primarily be attributed to an insufficient understanding of the full range of the biological effects induced by GAs and the molecular mechanisms mediating such effects even in rodents, which are far more extensively studied than any other species. Our most recent experimental findings in rodents suggest that GAs may adversely affect many more people than is currently anticipated. Specifically, we have shown that anesthesia with the commonly used GA sevoflurane induces in exposed animals not only neuroendocrine abnormalities (somatic effects), but also epigenetic reprogramming of germ cells (germ cell effects). The latter may pass the neurobehavioral effects of parental sevoflurane exposure to the offspring, who may be affected even at levels of anesthesia that are not harmful to the exposed parents. The large number of patients who require general anesthesia, the even larger number of their future unexposed offspring whose health may be affected, and a growing number of neurodevelopmental disorders of unknown etiology underscore the translational importance of investigating the intergenerational effects of GAs. In this mini review, we discuss emerging experimental findings on neuroendocrine, epigenetic, and intergenerational effects of GAs.     

Optimization of non-isotopic in situ hybridization on formalin-fixed, paraffin-embedded material using digoxigenin-labelled probes and transgenic tissues.

The sensitivity of non-isotopic in situ hybridization (NISH), particularly on formalin-fixed, paraffin-embedded (FFPE) clinical tissues, has been the subject of controversy. Generally, NISH has been regarded as being less sensitive than radiolabelled procedures, although some reports have contradicted this. Accordingly, tissues from mice which were transgenic for variable amounts of the human alpha-1-antitrypsin gene were used to optimize the NISH procedure and to estimate the sensitivity. This approach showed that prolonged incubation of slides in final substrate resulted in high sensitivity--about 13 kb of target DNA. However, this prolonged incubation crucially depended on achieving minimal non-specific background staining. Many factors affected the degree of background staining, but five were particularly important. First, the method of mounting cut sections onto slides. Second, the length of the probe (ideally less than 400 bp). Third, the procedure for proteolytic digestion. Fourth, the denaturation technique, and fifth, the quality of the dextran sulphate used in the hybridization mix. The optimized protocol showed variable patterns of mRNA distribution in the transgenic mouse livers, while DNA distribution appeared uniform.     

Isolation of a fastidious Bergeyella species associated with cellulitis after a cat bite and a phylogenetic comparison with Bergeyella zoohelcum strains

Bergeyella zoohelcum is an uncommon zoonotic pathogen typically associated with cat or dog bites. Previously, only five cases of B. zoohelcum infection have been reported. We report the isolation and characterization of a fastidious Bergeyella species from acute cellulitis in the upper extremity of a 60-year-old woman. The organism was too fastidious for identification and susceptibility testing with traditional culture methods. The isolate was characterized further by PCR amplification and sequencing of the 16S rRNA gene with broad-range eubacterial primers. Phylogenetic analysis of the 16S ribosomal DNA sequence indicated that this isolate was a member of the species B. zoohelcum (previously Weeksella zoohelcum), a gram-negative bacillus that is rarely associated with infections in humans. Despite sharing a close genetic relationship with other B. zoohelcum strains, this isolate was extremely fastidious in nature, raising the possibility that similar strains from cat or dog bite wound infections have been underreported.     

Non-isotopic in situ hybridisation and immunophenotyping of infected cells in the investigation of human fetal parvovirus infection.

AIMS: To compare the use of biotinylated and digoxigenin labelled probes for diagnosis of human fetal parvovirus B19 infection in formalin fixed, paraffin wax embedded tissues; and to assess the cellular distribution of the virus in positive cases. METHODS: Sections of lung tissue from 23 cases of anatomically normal non-immune fetal hydrops presenting between 1984 and 1989, and from 13 control cases of hydrops due to chromosomal abnormality were probed for B19 DNA by in situ hybridisation using both biotinylated and digoxigenin labelled probes. The distribution of the virus was then investigated in all cases of fetal B19 infection confirmed in this laboratory to date (n = 11) by combining in situ hybridisation for viral DNA (using the digoxigenin system) with immunohistological labelling for a range of cellular antigens. RESULTS: Five unequivocal cases of B19 infection were identified among the 23 fetuses with unexplained hydrops using both probe labels. When combined with data from previous studies of the period 1974-1983, the results indicate that B19 infection was responsible for 27% of cases of anatomically normal non-immune hydrops and 8% of all cases, of non-immune hydrops presenting to this hospital over 15 years. False positive signal was seen in an additional three cases, using biotinylated probes. Digoxigenin labelled probes gave greater specificity and permitted detailed investigation of tissues high in endogenous biotin. Though most cells containing B19 DNA colabelled as erythroid precursors, viral DNA was frequently detected within mononuclear-phagocytic cells. In three cases viral signal was also found within occasional myocardial cells labelled by antibody to desmin. CONCLUSIONS: A relatively high proportion of cases of anatomically normal, non-immune hydrops are caused by B19 infection. Digoxigenin is a more reliable probe label than biotin for in situ hybridisation in archival fetal tissues. Double labelling for cellular antigens and viral nucleic acid is a powerful technique for investigating virus-host cell interactions, and provides evidence that cell types other than those of erythroid lineage may have a role in human fetal parvovirus infection.     

Molecular epidemiologic evaluation of endocarditis due to Oerskovia turbata and CDC group A-3 associated with contaminated homograft valves

Oerskovia turbata is an unusual bacterial cause of endocarditis and septicemia in immunocompromised patients. In this study, we compared 12 isolates from a 1975 medical center cluster, 11 originally identified as O. turbata (four from the blood of a homograft aortic valve-associated endocarditis patient and seven from contaminated homograft valves) and one CDC group A-3 strain from the blood of a second endocarditis patient with fatal outcome, with eight control strains from unrelated locations. The control strains included type and reference strains of O. turbata, Cellulomonas hominis, and CDC group A-3. The four blood isolates from the first patient and six of the valve isolates shared identical biochemical, antimicrobial susceptibility, and BglI ribotype patterns that differed from the second patient's isolate and control strains. The blood isolate from the second patient and the remaining valve isolate shared a phenotypic and genotypic profile and were phenotypically identical to, but epidemiologically different from, the CDC group A-3 reference strain with the strain-specific enzyme. Also, these isolates differed from the type strain and the other reference strains of C. hominis and O. turbata. Our results indicate that the four blood isolates from the first patient and six of the homograft valve isolates represent a single clone of O. turbata associated with endocarditis. Additionally, our results indicate that the blood isolate from the second patient and one of the homograft valve isolates differ from O. turbata and C. hominis and represent a unique clone of CDC group A-3 associated with fatal endocarditis.     

Cortical dendritic pathology in human immunodeficiency virus encephalitis.

Previous neuropathological and morphometric studies of the cerebral cortex of patients with human immunodeficiency virus encephalitis (HIVE) have shown a decrease in the population of large neurons, moderate loss in synaptophysin immunoreactivity, and pathological changes in dendrites. To further characterize and quantify alterations in the dendritic tree of neocortical pyramidal neurons, we performed a modified Golgi impregnation technique on Formalin fixed blocks from the frontal cortex of 5 HIVE cases, 5 human immunodeficiency virus seropositive control cases without encephalitis, and 5 human immunodeficiency virus seronegative controls. Apical dendrites of HIVE cases were dilated, vacuolated, and tortuous with decreased length and branching. Basal and oblique dendrites also showed these alterations, but to a lesser extent. Some dendrites presented lacunae and filopodia consistent with remodeling. Computer aided quantification of HIVE cases showed a 40-60% decrease in spine density throughout the entire length of dendrites. Laser confocal imaging of Golgi impregnated sections displayed aberrant spines in regions of abnormal second order dendritic branches. These observations support the role of primary dendritic damage in HIVE in contrast to other neurodegenerative disorders where the primary pathology is presynaptic.     

Passive-aggressive personality disorder: the demise of a syndrome

This article presents an explanation and critique of the rationale for dropping passive-aggressive personality disorder (PAPD) from DSM-IV. The clinical and research literature on PAPD is reviewed along with the historical changes in definition, diagnostic criteria, and usage. PAPD can be reliably diagnosed, is fairly prevalent, and has good internal consistency. Because PAPD is no less valid than other personality disorders, and describes clinical phenomena that are unique among personality disorders, we recommend the reinstatement of PAPD in the official diagnostic nomenclature.     

Co-occurrence of mood and personality disorders: a report from the Collaborative Longitudinal Personality Disorders Study (CLPS)

The purpose of this study was to examine the relationship of subtypes and particular clinical features of mood disorders to co-occurrence with specific personality disorders. Five hundred and seventy-one subjects recruited for the Collaborative Longitudinal Personality Disorders Study (CLPS) were assessed with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and the Diagnostic Interview for DSM-IV Personality Disorders (DIPD-IV). Percent co-occurrence rates for current and lifetime mood disorders with personality disorders were calculated. Logistic regression analyses examined the effects of clinical characteristics of depressive disorders (e.g., age at onset, recurrence, symptom severity, double depression, and atypical features) on personality disorder co-occurrence. In comparison with other DSM-IV personality disorders, avoidant, borderline, and dependent personality disorders (PDs) were most specifically associated with mood disorders, particularly depressive disorders. Severity and recurrence of major depressive disorder and comorbid dysthymic disorder predicted co-occurrence with borderline and to a lesser extent research criteria depressive personality disorders. The results are consistent with the view that a mood disorder with an insidious onset and recurrence, chronicity, and progression in severity leads to a personality disorder diagnosis in young adults.