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Biomedical subjects

P Hauser

Publications and source records attributed to P Hauser.

At least 19 recordsLinked to original sources
PubMed2000

MRI-based measurements of temporal lobe and ventricular structures in patients with bipolar I and bipolar II disorders.

OBJECTIVE: There have been relatively few quantitative MRI studies of temporal lobe structures and the lateral ventricles in bipolar patients and a lack of agreement across studies as to whether these structures differ significantly in size from control subjects. Also there have been no quantitative MRI studies of bipolar II patients. The present study measured temporal lobe and ventricular structures in both bipolar I and bipolar II patients, as well as control subjects. METHOD: Twenty-five bipolar I patients, 22 bipolar II patients and 19 control subjects underwent MRI brain scans. The 5 mm coronal slices of each subject were coded and measured by a rater who was blind with respect to subject diagnosis. Volume estimates of the temporal lobe and hippocampus were calculated for each hemisphere by measuring the area of the structure in each slice in which it appears, multiplying by 5 mm and summing. In addition to these volume estimates, the area of the lateral ventricle and the inferior horn of the lateral ventricle, the lateral ventricle to cerebrum area ratio (LV/C) and the temporal lobe to cerebrum area ratio (TL/C), were calculated for each hemisphere in one reference slice only. The area of the third ventricle was also measured. Volume estimates and area ratios were then compared among diagnostic groups. RESULTS: There were no significant differences in temporal lobe or hippocampal volume estimates, in the third ventricle and inferior horn of the lateral ventricle area measurements, and in the TL/C area ratio among diagnostic groups. The lateral ventricle area and LV/C area ratio were significantly larger in bipolar I patients than either bipolar II patients or control subjects only in the left hemisphere. Furthermore, these measures were approximately twice as large in the bipolar I patients as the other groups. CONCLUSIONS: The current study adds to a growing literature that bipolar I disorder, particularly in males, may show different neurobiological alterations compared to bipolar II patients or control subjects. The pathophysiologic implications of this accumulating evidence of increased left ventricular size in bipolar I disorder remains to be further elucidated.

Adult↗
PubMed2000

Elevated sorbitol concentration in the cerebrospinal fluid of patients with mood disorders.

This study was undertaken to test the hypothesis that a specific pathophysiological mechanism of diabetic neuropathy, namely increased polyol pathway flux, could be operative in patients with bipolar and unipolar mood disorders. Numerous studies have shown abnormalities of carbohydrate metabolism, including high rates of diabetes mellitus, in patients with mood disorders. Several studies have found that peripheral neuropathy is a risk factor for depression in diabetics. Furthermore, increased polyol pathway flux results in elevated sorbitol concentrations in peripheral tissues and cerebrospinal fluid (CSF) of diabetics with neuropathy. The purpose of this study was to determine whether sorbitol concentration is elevated in the CSF of non-medically ill patients with mood disorders. Lumbar punctures were performed on 30 subjects - 10 with bipolar mood disorder, 10 with unipolar mood disorder, and 10 age-matched normal controls, and CSF sorbitol concentrations were measured, using a gas chromatographic-mass spectroscopic technique. The mean+/-standard deviation of CSF sorbitol concentrations differed among the three groups as follows: bipolar (22.9+/-4.6 micromoles/l) > unipolar (19.0+/-2.8 micromoles/l)>normal control (15. 6+/-1.9 micromoles/l). One-way ANOVA showed significant (P=0.0002) differences among the three groups. Post-hoc tests indicated a significant (P<0.05) difference between bipolars and normal controls, bipolars and unipolars, and unipolars and normal controls. Further investigation is needed to determine the pathophysiological significance of this novel finding of elevated sorbitol concentration in the CSF of patients with mood disorders.

Adult↗
PubMed2000

Study of chromosome rearrangements associated with the trpE26 mutation of Bacillus subtilis.

Chromosome rearrangements involved in the formation of merodiploid strains in the Bacillus subtilis 168-166 system were explained by postulating the existence of intrachromosomal homology regions. This working hypothesis was tested by analysing sequences and restriction patterns of the, as yet uncharacterized, junctions between chromosome segments undergoing rearrangements in parent, 168 trpC2 and 166 trpE26, as well as in derived merodiploid strains. Identification, at the Ia/Ib chromosome junction of both parent strains, of a 1.3 kb segment nearly identical to a segment of prophage SPbeta established the existence of one of the postulated homology sequences. Inspection of relevant junctions revealed that a set of different homology regions, derived from prophage SPbeta, plays a key role in the formation of so-called trpE30, trpE30+, as well as of new class I merodiploids. Analysis of junctions involved in the transfer of the trpE26 mutation, i.e. simultaneous translocation of chromosome segment C and rotation of the terminal relative to the origin moiety of the chromosome, did not confirm the presence of any sequence suitable for homologous recombination. We propose a model involving simultaneous introduction of four donor DNA molecules, each comprising a different relevant junction, and their pairing with the junction regions of the recipient chromosome. The resolution of this structure, resting on homologous recombination, would confer the donor chromosome structure to the recipient, achieving some kind of 'transstamping'. In addition, a rather regular pattern of inverse and direct short sequence repeats in regions flanking the breaking points could be correlated with the initial, X-ray-induced, rearrangement.

Bacillus subtilis↗
PubMed2000

Spontaneous apoptosis and retinoic acid receptor incidence in neuroblastomas and peripheral neuroectodermal tumors.

Twelve cases of neuroblastoma (NB) (7 boys and 5 girls) and 4 cases of primitive peripheral neuroectodermal tumor (PNET) (3 boys and 1 girl) were investigated for the presence of apoptosis and retinoic acid receptor (RAR) by immunhistochemical method. The apoptotic index in NB was zero or 1% in 8 children and relatively low (2-4.8%) in the other 4 cases, while it was higher (4.1-10.5%) in PNET. The RAR index determined by immunoperoxidase reaction in NB was zero or 3% in 5 cases and 9-34% in 7 children. RAR index in PNET was 16-68% in all the 4 cases. Good correlation (r = .47 according to Pearson-Bravis) was found between the number of RAR and spontaneous apoptosis. These results suggest that the RAR index in untreated NB and PNET shows great individual variation since its determination is necessary for the evaluation of the efficacy of retinoic acid treatment.

Apoptosis↗
PubMed2000

A preliminary study of the relation of neuropsychological performance to neuroanatomic structures in bipolar disorder.

OBJECTIVE: To investigate the relation between neuropsychological dysfunction and volumetric measures of neuroanatomic structures in patients with bipolar disorder. BACKGROUND: Previous research suggests that neuropsychological deficits are associated with neuroanatomic changes in patients with bipolar disorder. METHOD: Twenty-six outpatients who met Diagnostic and Statistical Manual, Third Edition-Revised criteria for bipolar disorder were administered a battery of neuropsychological tests that assessed memory, abstracting ability, psychomotor performance, sustained attention, and intelligence. Patients also received a magnetic resonance imaging scan, from which volumes of the temporal lobes, hippocampus, third ventricle, and areas of the lateral ventricles were calculated. Using multiple regression analyses, neuroanatomic structures were compared with neuropsychological test variables. RESULTS: Data suggest that a larger right hippocampal volume is associated with poorer neuropsychological functioning. CONCLUSIONS: Further studies are needed to both replicate and examine the relation between potential mechanisms of neuroanatomic alterations and neuropsychological dysfunction in patients with bipolar disorder.

Adult↗
PubMed1999

Intranasal murine model of Bordetella pertussis infection. I. Prediction of protection in human infants by acellular vaccines.

Bicomponent, tricomponent and pertactin DTPa vaccines were tested in sublethal aerosol, and lethal and sublethal intranasal murine Bordetella pertussis respiratory challenge models. Pertactin and bicomponent vaccines induced protective immunity against lethality but with little or no bacterial clearance. Intranasal challenge discriminated in a reproducible, statistically significant manner between the efficacies of bicomponent and tricomponent DTPa, in agreement with clinical trial data. This discrimination was not observed in the aerosol challenge. Pertactin had a synergistic effect with bicomponent DTPa. Intranasal challenge may be useful as part of the preclinical evaluation of new acellular pertussis formulations or DTPa-based combinations.

Administration, Inhalation↗
PubMed1999

Epithelial mesothelioma with deciduoid features.

A rare case of malignant mesothelioma in a 15-year-old girl is described. The patient presented with secondary amenorrhoea and clinical symptoms resembling those of an ovarian cyst. One large and multiple small peritoneal nodules were found at laparoscopy. Histologically the tumour was characterised by an unusual pattern with a superficial resemblance to decidual reaction, but because of significant mitotic activity the diagnosis of a malignant tumour, epithelial mesothelioma with deciduoid features, was made. The patient died 11 months after diagnosis. Post-mortem examination revealed extensive extraperitoneal spread.

Adolescent↗
PubMed1999

Screening methods for thyroid hormone disruptors.

The U.S. Congress has passed legislation requiring the EPA to implement screening tests for identifying endocrine-disrupting chemicals. A series of workshops was sponsored by the EPA, the Chemical Manufacturers Association, and the World Wildlife Fund; one workshop focused on screens for chemicals that alter thyroid hormone function and homeostasis. Participants at this meeting identified and examined methods to detect alterations in thyroid hormone synthesis, transport, and catabolism. In addition, some methods to detect chemicals that bind to the thyroid hormone receptors acting as either agonists or antagonists were also identified. Screening methods used in mammals as well as other vertebrate classes were examined. There was a general consensus that all known chemicals which interfere with thyroid hormone function and homeostasis act by either inhibiting synthesis, altering serum transport proteins, or by increasing catabolism of thyroid hormones. There are no direct data to support the assertion that certain environmental chemicals bind and activate the thyroid hormone receptors; further research is indicated. In light of this, screening methods should reflect known mechanisms of action. Most methods examined, albeit useful for mechanistic studies, were thought to be too specific and therefore would not be applicable for broad-based screening. Determination of serum thyroid hormone concentrations following chemical exposure in rodents was thought to be a reasonable initial screen. Concurrent histologic evaluation of the thyroid would strengthen this screen. Similar methods in teleosts may be useful as screens, but would require indicators of tissue production of thyroid hormones. The use of tadpole metamorphosis as a screen may also be useful; however, this method requires validation and standardization prior to use as a broad-based screen.

Animals↗
PubMed1998

Reliability and acceptability of psychiatric diagnosis via telecommunication and audiovisual technology.

The reliability of psychiatric diagnoses made remotely by telecommunication was examined. Two trained interviewers each interviewed the same 30 psychiatric inpatients using the Structured Clinical Interview for DSM-III-R. Fifteen subjects had two in-person interviews, and 15 subjects had one in-person and one remote interview via telecommunication. Interrater reliability was calculated for the four most common diagnoses: major depression, bipolar disorder, panic disorder, and alcohol dependence. For each diagnosis, interrater reliability (kappa statistic) was identical or almost identical for the patients who had two in-person interviews and those who had an in-person and a remote interview, suggesting that reliable psychiatric diagnoses can be made via telecommunication.

Alcoholism↗
PubMed1998

Cytokines and brain function: relevance to interferon-alpha-induced mood and cognitive changes.

Cytokines such as interferon-alpha (IFN-alpha) are increasingly being exploited as biologic response modifiers to treat cancer. However, treatment with IFN-alpha can adversely affect mood and cognition, causing depression, memory disturbances, and other signs of central nervous system (CNS) dysfunction. The genes encoding cytokines and their receptors are expressed in the CNS under both resting and stimulated conditions, and cytokines can affect key brain functions. The physiologic effects of IFN-alpha therapy on the CNS are probably a consequence of the activation of a complex cascade of secondary cytokines both in the periphery and within the CNS. We review the neurobiology of cytokines and outline some of the potential mechanisms by which alterations of cytokine expression in the CNS could contribute to cognitive dysfunction and mood disorders during IFN-alpha therapy.

Brain↗
PubMed1998

Mood and cognitive side effects of interferon-alpha therapy.

The central nervous system side effects associated with interferon-alpha (IFN-alpha) therapy, including depression and cognitive changes, can compromise otherwise effective immunotherapy. The term "depression" has multiple meanings ranging from a feeling of sadness to a neuropsychiatric disorder with defined diagnostic criteria. A syndrome of mood disturbance with memory impairment, cognitive slowing, and impaired executive function is common with IFN-alpha therapy and is consistent with mild subcortical dementia. Cognitive deficits and mood disorder may occur independently, and in some cases depression is a reactive phenomenon. Risk factors for development of IFN-alpha neurotoxicity include duration of treatment, high-dose therapy, and prior cranial irradiation or neurologic illness. Past or current psychiatric illness also may put the patient at risk. Subtypes of major depression are associated with neuroendocrine and neurochemical alterations that are consistent with the observed activities of IFN-alpha. This may provide insight into the etiology of IFN-alpha neurotoxicity, as well as possible interventions. Assessment of the neuropsychiatric status of patients treated with IFN-alpha should be a standard of care. Possible pharmacologic interventions to decrease the neurotoxicity associated with IFN-alpha therapy include antidepressants, psychostimulants, and opioid antagonists. Preliminary clinical and research experience suggests that it is possible to effectively palliate IFN-alpha toxicity.

Cognition Disorders↗
PubMed1998

Development and efficacy assessment of combination vaccines, with emphasis on acellular pertussis.

The number of vaccines suitable for infant immunization is increasing, leading to a need to co-administer them in combination or combos. The recent demonstration of high efficacy against whooping cough using DTPa vaccines makes it desirable to administer combos such as DTPaHBIPVHib. For all vaccines included, surrogate markers for protection exist, except for pertussis. The field efficacy studies performed with DTPa vaccines did not allow the establishment of a correlate for protection. We propose to use detailed serology and cell-mediated immunity markers obtained from infant immunization studies, as well as a mouse intranasal challenge model, to monitor the immune responses induced by DTPa-combos.

Animals↗
PubMed1997

Immunization with a polyvalent OspA vaccine protects mice against Ixodes ricinus tick bites infected by Borrelia burgdorferi ss, Borrelia garinii and Borrelia afzelii.

Sequence variability of the outer surface protein (Osp) A among Borrelia burgdorferi sl species suggests that a monovalent OspA vaccine may not protect against the various Borrelia present in Eurasia. Here, we confirmed that a monovalent recombinant OspA (rOspA) vaccine does not protect mice against Ixodes ricinus mediated infection with B. burgdorferi ss, Borrelia garinii and Borrelia afzelii. However, when mice were vaccinated with a cocktail of various rOspA from these three species, they were protected, and all challenge ticks that fed on them were cleared of their spirochetes. These results showed that a multiple OspA antigens vaccine, compatible with human use, was very efficient at protecting mice against B. burgdorferi ss, B. garinii, and B. afzelii.

Animals↗
PubMed1997

Vaccination of natural reservoir hosts with recombinant lipidated OspA induces a transmission-blocking immunity against Lyme disease spirochaetes associated with high levels of LA-2 equivalent antibodies.

As observed in humans, immune responses in naturally infected reservoir hosts of Borrelia burgdorferi sensu lato rarely target the outer surface proteins (Osp) A and B of Lyme disease spirochaetes. The absence of protective immunity in such hosts following tick-borne infection allows them to play an effective role in the maintenance of Lyme borreliosis in nature. Therefore, the question was addressed whether one of the most prominent natural reservoir host species of B. burgdorferi s.l. in Europe, the yellow-necked mouse (Apodemus flavicollis), may lack the ability to elicit transmission-blocking antibodies to Lyme borreliosis spirochaetes. Yellow-necked mice were immunized with a recombinant lipidated OspA from B. burgdorferi sensu stricto or with high numbers of UV-irradiated whole spirochaetes. All immunized mice, but not untreated controls, developed polyclonal humoral immune responses to OspA (31 kDa). Serum antibodies of animals vaccinated with the recombinant OspA contained high levels of antibody to an epitope of OspA, defined by the monoclonal antibody LA-2, whereas only low levels of LA-2 equivalent antibodies could be detected in sera from animals immunized with killed spirochaetes. Ixodes ricinus ticks infected with B. burgdorferi s.s. lost their spirochaete load after feeding on animals with high levels of LA-2 equivalent antibody; ticks feeding on animals which had only low or undetectable serum levels of LA-2 equivalent antibodies retained their spirochaete infection. Furthermore, animals with high levels of LA-2 equivalent antibody were protected against spirochaete infection. Our study shows that natural mouse reservoir hosts are highly competent to generate transmission-blocking antibodies after vaccination with a lipidated recombinant OspA and indicates that antibodies to the LA-2 epitope play a key role in the destruction of B. burgdorferi s.s. within feeding Ixodes ricinus ticks.

Animals↗