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Biomedical subjects

A Wallin

Publications and source records attributed to A Wallin.

At least 127 records · Page 7Linked to original sources
PubMed1991

Hypothalamic monoamines and neuropeptides in dementia.

The concentrations of monoamines and various neuropeptides were determined in the hypothalamus of brains from patients with Alzheimer's disease and vascular dementia (n = 26) and compared with control values (n = 21). Decreased concentrations of 5-hydroxyindoleacetic acid (P less than 0.05) and homovanillic acid (P less than 0.01) were found, and increased arginine vasopressin- (P less than 0.01), galanin- (P less than 0.05) and somatostatin- (P less than 0.01) like immunoreactivity. It is proposed that this disequilibrium may be important for certain circadian symptoms, e.g. the changes in sleep/wake rhythms that are rather often observed in dementia.

Aged↗
PubMed1991

Use of orthopantomographs in forensic identification.

Radiographs of the head region were used for identification of 17 victims during an 11-year period in the Department of Forensic Medicine, University of Turku, Finland. Examinations resulted in positive identification of 10 victims. Proof of identity of four people was based on exclusion identifications. In one case, comparable information supporting the identity was achieved. Due to insufficient ante- and postmortem material, two individuals remained unidentified by radiological methods. The use of orthopantomography in identification is recommended because it enables visualization of the structures of the jaws and related areas on a single radiograph.

Accidents↗
PubMed1991

Pathogenetic basis of vascular dementia.

Vascular dementia (VAD) was studied with reference to pathogenetic aspects, especially the importance of brain infarcts. A VAD diagnosis was chosen when the patients showed dementia in combination with transitory ischemic attacks (TIA), stroke episodes, or other pronounced vascular diseases judged to be causally related to the dementia. Computed tomography (CT) white matter lesions were shown to occur frequently (85%); a pronounced decrease in myelin lipids was common in subcortical white matter; a fronto-subcortical symptom complex was the prevailing clinical pattern; and an overall increased albumin ratio without relation to TIA/stroke was noted, indicating blood-brain barrier (BBB) dysfunction. When infarcts were present, they appeared to be endpoint manifestations of the vascular pathology rather than the cause of the disease. Today, thromboembolism with multiple cerebral infarcts is considered more or less the only pathogenetic substrate of VAD, with multi-infarct dementia (MID) as its clinical counterpart. Our findings suggest that subcortical white matter changes are another important VAD substrate.

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PubMed1991

White-matter lesions on CT in Alzheimer patients: relation to clinical symptomatology and vascular factors.

Fifty-four patients with Alzheimer's disease (AD) were examined for white-matter lesions (WMLs) using computerized tomography. WMLs were more frequent in late-onset AD (LAD) (26/34-76%) than in early-onset AD (EAD) (5/20-25%) (p less than 0.0001), in AD without parietal predominance (10/11-91%) (p less than 0.005) than in AD with parietal predominance (5/15-33%), and in AD with confusional symptoms (11/12-92%) than in AD without confusional symptoms (4/14-29%) (p less than 0.001). The supine systolic blood pressure was higher in AD with WMLs (151 +/- 20) than in AD without WML (139 +/- 22) (p less than 0.05). AD patients with WMLs, but not those without WMLs, had a higher mean albumin ratio (7.5 +/- 2.7) than healthy controls (5.7 +/- 2.1) (p +/- 0.005). The finding of less focal (= less parietal) symptomatology in AD with WMLs than without WMLs suggests clinical significance of WMLs in AD, while the relations between blood pressure, BBB function and WMLs support the hypothesis of a vascular pathogenesis.

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PubMed1990

Intrathecal synthesis of immunoglobulins in patients with Alzheimer's disease.

Serum and cerebrospinal fluid (CSF) of 45 patients with Alzheimer's disease (AD) and 24 healthy controls were examined in order to investigate the possibility of an intrathecal synthesis of immunoglobulins in AD. The group of AD patients showed higher IgG and IgM indices than the control group. Five (11%) AD patients had an intrathecal IgG synthesis and 7 (15%) an intrathecal IgM synthesis. In total, 12 (26%) AD patients had an intrathecal immunoglobulin synthesis, while there was none among the controls. This finding supports the hypothesis that immunological mechanisms may play a role in the etiology and/or pathogenesis of Alzheimer's disease, at least in a subgroup of patients.

Aged↗
PubMed1990

Biochemical substrates in normal aging and Alzheimer's disease.

In individuals above 60 years of age, an age-related decrease in the concentrations of dopamine, noradrenaline, and 5-hydroxytryptamine has been found. This may indicate a neuron loss. As the metabolites are not simultaneously reduced, a compensatory mechanism would seem to exist. In the hypothalamus there are significant positive correlations between the neuropeptides galanin and corticotropin-releasing factor on the one hand, and age over 60 on the other. In brains from patients with dementia of Alzheimer type there are reduced concentrations of cholineacetyl transferase. However, in some brain areas reduced concentrations of 5-hydroxytryptamine, dopamine, and noradrenaline have also been found. The metabolites homovanillic acid and 5-hydroxyindolacetic acid are also reduced. These findings indicate that there is not only a neuron loss in these brains but also a dysfunction of the remaining neurons, reducing the compensatory capacity of the brain. Postmortem investigations of hypothalamus from Alzheimer brains have shown reduced concentrations of 5-hydroxytryptamine. However, the concentrations of galanin, arginin, vasopressin, and somatostatin were significantly increased. The latter may be the result of a disturbed higher control over the hypothalamus. Hypothalamic dysfunction is of interest with regard to the neuroendocrine disturbances seen in Alzheimer-demented patients. Investigations of patients with vascular dementia have suggested the same type of neurotransmitter disturbances as in Alzheimer's disease.

Aging↗
PubMed1990

Neurochemical substrates of human aging and dementia.

Further development of clinical models of dementia to augment present unsatisfactory animal models, is of central importance to the understanding of the neurochemistry of dementia. Furthermore, present definitions of the neurotoxic processes underlying dementing disorders will need to be improved. Routine clinical markers will be necessary for the development of any therapy beyond present attempts for symptomatic treatment with neurotransmitter replacement.

Aging↗
PubMed1990

Single progesterone assay for early recognition of abnormal pregnancy.

Serum progesterone and human chorionic gonadotrophin (HCG) were analysed using a time-resolved fluoroimmunoassay in an unselected group made up of 158 women with clinical suspicions of abnormal early gestation. Only cases in which endovaginal sonography had failed to localize the pregnancy were included. A single HCG determination had no diagnostic value. On the other hand, a critical progesterone level of 30 nM was determined below which no viable intrauterine pregnancies were found. Eighty-eight per cent of the ectopic pregnancies (n = 97) and 83% of the spontaneous abortions had progesterone levels below this limit. The discriminatory efficacy of one single progesterone determination was independent of the actual HCG level and serial determinations of progesterone did not increase the discriminatory power.

Abortion, Spontaneous↗
PubMed1990

Parenteral administration of GM1 ganglioside to presenile Alzheimer patients.

The pharmacokinetic parameters of GM1 ganglioside were examined in 16 patients (mean age 64 +/- 5 years) with Alzheimer's disease. The ganglioside was given intramuscularly and subcutaneously. The maximum GM1 blood level was reached after 48-72 h, the subcutaneous route leading to the highest blood levels, but the individual variability was relatively large. When 100 mg GM1 ganglioside was given daily for a week, maximum serum values of 15 to 20 mumol/l were found in 3 patients. The elimination half-life from serum was 60-75 h.

Aged↗
PubMed1990

Intrathecal synthesis of immunoglobulin G in vascular dementia.

Serum and CSF from 53 vascular dementia (VD) patients and 50 controls were analysed to investigate the possibility of an intrathecal synthesis of IgG, defined as an elevated IgG index (greater than or equal to 7) and/or presence of oligoclonal IgG in cerebrospinal fluid (CSF), but not in serum. Five (9%) patients and no controls exhibited an intrathecal synthesis of IgG. The IgG index increased with the degree of dementia (p less than 0.05). It was positively related to presence/absence of hypertension (p less than 0.05) and correlated positively with diastolic blood pressure (p less than 0.05). The findings suggest that immunological factors might be involved in the pathogenesis of VD.

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PubMed1990

Blood brain barrier function in vascular dementia.

To investigate blood-brain barrier (BBB) function measured as an albumin ratio (cerebrospinal fluid/serum) in vascular dementia (VD) samples from 53 patients and 30 healthy controls were analysed. The VD group showed a higher mean albumin ratio than controls (8.5 +/- 3.8 and 5.7 +/- 2.1, respectively). The albumin ratio did not correlate significantly with age, nor with individual clinical vascular factors. The results of the present study suggest that the altered BBB might be a consequence of small vessel disorder rather than evidence of infarcts.

Aged↗
PubMed1990

Blood-brain barrier disturbance in patients with Alzheimer's disease is related to vascular factors.

To investigate the blood-brain barrier (BBB function), serum and cerebrospinal fluid (CSF) from 118 patients with Alzheimer's disease (AD) and 50 healthy controls was analyzed with regard to albumin concentrations. For the AD group, clinical vascular factors were also recorded. The CSF/serum albumin ratio was used as a measure of BBB function. When compared with controls, the AD group showed a higher mean albumin ratio, indicating a decline in BBB function. However, no significant reduction in BBB function was found in AD patients without vascular factors. These findings support the hypothesis that BBB disturbance is related to vascular factors, coexisting with AD. In the control group, no significant correlation between age and albumin ratio was found, which suggests that aging per se is not primarily associated with a decline in BBB function. The present study provides evidence in favour of the conclusion that a reduced BBB function is related neither to AD nor to aging, but to clinical vascular factors.

Aged↗
PubMed1990

Formoterol, a new long acting beta 2 agonist for inhalation twice daily, compared with salbutamol in the treatment of asthma.

Sixteen patients with stable chronic asthma participated in a double blind crossover study comparing the new inhaled long acting beta 2 agonist formoterol with salbutamol. Inhaled (n = 15) and oral steroid (n = 1) treatment were maintained at the same daily dose throughout the study. For four weeks the patients received either formoterol 24 micrograms twice daily or salbutamol 400 micrograms twice daily, plus additional puffs (with the same drug) when needed. Asthma symptoms, additional puffs of beta 2 agonist, peak expiratory flow (PEF), and side effects were recorded daily. During treatment with formoterol the patients used fewer additional puffs of beta 2 agonist, had better symptom scores, less disturbed sleep, more days without additional aerosol, and higher PEF both morning and evening than during salbutamol treatment. Thus formoterol 24 micrograms twice daily gave long lasting bronchodilatation and asthma symptoms were well controlled with regular twice daily administration.

Administration, Inhalation↗
PubMed1990

Is the toxicity of cysteine conjugates formed during mercapturic acid biosynthesis relevant to the toxicity of covalently bound drug residues?

In this brief review, we have focused on the relevance of the data on cysteine conjugate toxicity to the potential hazard of bound drug residues. A resonable scenario, based on assumptions as well as literature data, has been presented for the release of cysteine conjugates of drug residues from protein. Furthermore, we have presented evidence that should this occur, the conjugate would be bioavailable. Finally, the mechanisms which could lead to cysteine conjugate-induced toxicity have been discussed. The question which must be answered is, how realistic is the treat of toxicity to the consumer from cysteine-bound drug residues in food products? Based on the data presented here, the danger is minimal, though it cannot be excluded. This is particularly true of the potential for renal complications. However, an important caveat which must not be overlooked is the marked species differences in cysteine conjugate toxicity. Though S-(1,2LD50-dichlorovinyl)-L-cysteine (DCVC) is a renal toxin in rodent models (LD50 = 66-83 mg/kg) [88], a single dose of 4-5 mg/kg causes fatal aplastic anemia in calves [44,59]. Though such a response has never been reported for any other cysteine conjugate, these data must be reckoned with if attempts are made to place acceptable limits on the amount of residues allowable in food products.

Acetylcysteine↗
PubMed1990

Confusional symptomatology distinguishes early- and late-onset Alzheimer's disease.

Symptoms of confusion were examined in 75 patients with Alzheimer's disease (AD). Mild confusion was found in 20, and mode-rate/severe confusion in 8 patients. Confusion was more frequent in the late-onset (26/44-59%) than in the early-onset AD group (2/31-6%) (p less than 0.0001), and patients with confusion were older (p less than 0.0001) than those without confusion. The frequency of confusion was higher in patients with ischemic heart disease (13/28-46%) than in patients without this vascular factor (10/47-21%) (p less than 0.05). An inverse relation was found between confusional symptomatology and parietal-lobe symptoms. The findings in this study suggest that a subgroup of AD patients, fulfilling the NINCDS-ADRDA criteria for probable AD, is characterized by a clinical picture of mild confusional symptomatology together with no or mild parietal-lobe symptomatology, higher age and higher frequency of ischemic heart disease. This group contrasts with the other subgroup of pure AD, which is characterized by a clinical picture of marked parietal-lobe symptomatology, almost no confusional symptomatology, lower age and lower frequency of ischemic heart disease.

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