Treatment of cobalamin deficiency in dementia, evaluated clinically and with cerebral blood flow measurements.

We investigated the relation between cobalamin deficiency, clinical changes and brain function in dementia patients. On admittance to the clinic, 24 patients had cobalamin deficiency, and dementia with additional symptoms of delirium. During cobalamin supplementation, the patients underwent repeated regional cerebral blood flow (rCBF) studies, psychiatric evaluations, and in some cases assessment with MMSE and the Organic Brain Syndrome scale. Fifteen patients who showed mild to moderate dementia improved clinically, and also showed a concomitant increase in their general CBF after treatment. In contrast, 9 patients who were severely demented showed no obvious clinical improvement, and no general blood flow change, although some regional flow increases were seen in sensory motor areas. We conclude that symptoms which probably indicated superimposed delirium such as clouding of consciousness, disorientation and clinical fluctuation, responded to the vitamin B12 supplementation, while the underlying dementia condition remained basically unchanged. The clinical improvement was also mirrored in general and focal rCBF changes.

Plasma methylmalonic acid in relation to serum cobalamin and plasma homocysteine in a psychogeriatric population and the effect of cobalamin treatment.

Cobalamin deficiency seems to be a relatively common condition in psychogeriatric patients. To elucidate the diagnostic possibility of cobalamin deficiency we have in this study analysed three markers for cobalamin deficiency, plasma methylmalonic acid, plasma homocysteine and serum cobalamin, in 96 psychogeriatric patients. Patients were divided into four groups according to serum cobalamins above or below 150 pmol/l and normal (< 19.9 mumol/l) or increased plasma homocysteine. The upper reference limit (95th percentile) for plasma methylmalonic acid in 100 healthy subjects was established to 0.42 mumol/l. The mean value of methylmalonic acid was increased only in the group of patients with serum cobalamin below 150 pmol/l and increased plasma homocysteine compared to the other groups. In this group six (46%) out of 13 patients exhibited increased plasma methylmalonic acid, whereas in the other groups the frequency of increased plasma methylmalonic acid only varied from 10 to 13%. During cobalamin supplementation the most pronounced decrease of plasma methylmalonic acid also occurred in the group of patients with low serum cobalamin levels and increased plasma homocysteine. Only 39% of the initial mean value for plasma methylmalonic acid was noted after 7-10 days of cobalamin administration.

Hyperhomocysteinaemia--a common finding in a psychogeriatric population.

Plasma homocysteine concentration is a sensitive marker for cobalamin and folate deficiency. The previously reported high incidence of increased plasma homocysteine in psychogeriatric patients and the association between reduced concentrations of cobalamin, folate and neuropsychiatric symptoms led to the present study on 741 consecutive psychogeriatric patients. The concentrations of plasma homocysteine correlated significantly with blood folate, serum cobalamin and serum creatinine both in demented (n = 295) and in non-demented patients with other psychiatric disorders (n = 215). Plasma homocysteine concentrations were significantly increased in both the demented and the non-demented patients, whereas only the demented patients had lower blood folate and serum creatinine concentrations than 163 control subjects. Almost all of the different diagnostic groups of demented and non-demented patients exhibited significantly increased plasma homocysteine concentrations compared with control subjects. Significantly decreased blood folate concentrations were mainly found in the different diagnosis groups of demented patients. Plasma homocysteine concentrations in both demented and non-demented patients with serum cobalamin and blood folate above the lower 20th percentile of these vitamins in the control subjects were also studied. Despite these vitamin concentrations, both groups of patients still exhibited significantly higher plasma homocysteine concentrations than the control subjects, which may indicate an increased frequency of impaired genetic capacity to metabolize homocysteine in these patients. Patients with either dementia of vascular cause or a history of other occlusive arterial disease had a significantly higher plasma homocysteine concentration than those without a history of vascular disease.

Prevalence of thyroid hormone abnormalities in elderly patients with symptoms of organic brain disease.

Analysis of the serum concentrations of free thyroid hormones (fT3, fT4) and thyrotropin (TSH) in 173 psychogeriatric patients (94 females and 79 males, mean age 79 +/- 8 years) disclosed that the hormone levels were related to sex, psychiatric diagnosis, medication and the presence of nonthyroid illness (NTI). Subnormal concentrations of thyroid hormones and/or TSH were found in 25% of the patients. In addition, fT3 and fT4 concentrations were significantly lower (p < 0.05 and p < 0.001, respectively) in demented males compared with demented females although the levels were within the reference limits. Strongly negative correlations between fT3 and age (p < 0.001), and between fT3 and the sedimentation rate (SR) (p < 0.01) were found in demented but not in non-demented patients. These correlations were most pronounced in (age) or restricted to (SR) demented males. In addition, the correlation between fT3 and Hb was strongly positive (p < 0.001) in demented as well as in nondemented patients, particularly in males. The concentration of fT4 was positively correlated to Hb in demented males (p < 0.001), whereas TSH concentration was positively correlated to Hb in demented females (p < 0.05). The results show that TSH is not sufficient as the sole screening assay for evaluation of possible thyroid dysfunction in psychogeriatric patients. In addition, central (hypothalamic?) hypothyroidism may be present in a substantial amount of psychogeriatric patients, as we found an adequate TSH response to exogenous thyrotropin-releasing hormone (TRH) also in patients with decreased fT3/fT4 and no signs of non thyroid diseases. Furthermore, there was an apparent lack of correlation between thyroid hormone levels and dementia (or subgroups of dementia), even though thyroid hormone abnormalities seemed to be rather common in frontotemporal dementia (38%) and non specified dementia (36%).

Plasma homocysteine in relation to serum cobalamin and blood folate in a psychogeriatric population.

Plasma homocysteine, serum cobalamin and blood folate were analysed in 296 consecutive patients referred to a psychogeriatric department for diagnosis of mental disease. Plasma homocysteine correlated with positive significance with age and serum creatinine, and with negative significance with serum cobalamin and blood folate. Approximately 35-40% of the patients with low serum cobalamin (< 150 pmol l-1) or low blood folates (< 150 nmol l-1) exhibited normal values of plasma homocysteine (< 19.9 mumol l-1). Possibly, these patients do not have a deficiency of the vitamins in the tissue. At least 7.5% of the patients with serum cobalamin levels (> 150 pmol l-1) showed an inexplicably increased level of plasma homocysteine. These patients might have a deficiency of tissue cobalamin despite the normal serum cobalamin levels. The effect of cobalamin supplementation for 7-10 days on plasma homocysteine was tested in 62 patients with different levels of serum cobalamins. We found the most pronounced decrease of plasma homocysteine in the patients with lowest serum cobalamin levels and in the patients with highest plasma homocysteine, indicating that the percentage decrease of the initial concentration of plasma homocysteine could reflect the degree of cobalamin deficiency. Folate supplementation for 7-10 days reduced plasma homocysteine not only in patients with folate deficiency but also in those with a normal folate status, and even in patients with cobalamin deficiency. The latter patients further reduced their plasma homocysteine after additional cobalamin treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Cortical blood flow during head-up postural change in subjects with orthostatic hypotension.

Regional cerebral blood flow was measured with the 133-Xenon inhalation method in seven healthy subjects with orthostatic hypotension not due to autonomic failure (i.e. non-neurogenic clinical disorder). Measurements were performed during supine rest and during head-up tilt (70 degrees). All subjects had a consistent drop in systolic blood pressure and the typical symptomatology of orthostatic hypotension. The results showed lower mean hemispheric blood flow during head-up tilt than during supine rest. In addition, a consistent and significant redistribution of the regional flow values was seen, with a reduction in frontal and an increase in postcentral areas. The frontal flow decrease during tilt was more marked than in subjects without orthostatic hypotension and was not related to variations in the level of PCO2 or to respiration. In contrast to the clinical symptoms of orthostatic hypotension (dizziness, nausea, visual disturbances, and in some cases syncope), the cortical blood flow reduction was, however, relatively moderate.

Redistribution of blood flow in the cerebral cortex of normal subjects during head-up postural change.

Regional cerebral blood flow was measured in 21 normotensive subjects during supine rest and during head-up tilt to 70 degrees. The results showed significant and consistent regional cerebral blood flow changes in the frontal areas with lower relative flow distribution values (percentage of mean flow) during head-up tilt than during supine rest. The lower frontal flow distribution values during tilt were not related to habituation, to repeated measurements, or to the estimated level of arterial CO2 which was derived from expired end-tidal CO2 levels. None of the subjects had orthostatic hypotension and there was no significant difference in mean hemispheric blood flow between lying down and standing up. There was no significant gender difference in regional cerebral blood flow, although female subjects tended to have higher mean hemispheric flow than males in both postures. It remains to be established whether the flow decreases in the frontal cortex are caused by cerebral functional factors or by haemodynamic mechanisms.

Inhibition of platelet aggregation by granulocytes stimulated during experimental trauma.

The effect of granulocytes, stimulated in vivo by standardized soft tissue trauma, on the aggregation of autologous platelets in vitro, was studied in the pig. Platelet aggregation induced by ADP and arachidonic acid was inhibited when platelets harvested before trauma were incubated with granulocytes obtained 5 min after trauma. The granulocytes were separated from the platelets during the incubation by enclosure in dialysis tubes. Platelet inhibition was evident when the cell cohorts were suspended in cell-free medium as well as in autologous plasma extracted before trauma. In addition, incubation of platelets harvested before trauma with plasma obtained after trauma decreased platelet aggregation. In conclusion, granulocytes stimulated in vivo inhibited platelet function in vitro. Platelet inhibitory activity was shown to be related with the granulocytes per se, but also with factors present in plasma after trauma.

Inhibition of platelet aggregation by myeloid leukaemic cells demonstrated in vitro.

The effect of myeloid leukaemic cells, cells of the promyelocytic cell line HL-60 and normal polymorphonuclear granulocytes (PMN), enclosed in dialysis tubes, on the aggregation of allogeneic normal platelets after induction with arachidonic acid (AA) and with adenosine diphosphate (ADP) was investigated in vitro. Inhibition of aggregation was seen after preincubation of the platelets with leukaemic blood or bone marrow cells from 7/14 patients belonging to various FAB groups and with HL-60 cells, but not with normal PMN (14/14 cases). A dose-dependent inhibition was seen after lysis of some leukaemic cells with anti-human rabbit antiserum and active complement. Lysis of normal PMN inhibited platelet aggregation slightly and inconstantly and only at higher cell concentrations. Platelet inhibitory activity was not related to a higher rate of metabolism of the leukaemic cells which inhibited platelet aggregation since they did not differ from the cells not inhibiting aggregation with respect to heat production. Neither was a non-specifically increased cell membrane permeability the cause of the release of platelet inhibitory factor(s) since the release of 51Cr-labelled leukaemic cells was not related to the inhibition of platelet aggregation.

Abnormal granulocyte functions in autoimmune disorders demonstrated by microcalorimetry.

Heat production by polymorphonuclear granulocytes (PMN) was assayed in 14 patients suffering from diseases known to be associated with circulating immune complexes (CIC) and in 10 healthy blood donors. The patients' PMN produced significantly more heat than the normal PMN when the cells were suspended in autologous plasma (23.8 +/- 3.9 pW/cell vs. 18.1 +/- 1.9 pW/cell, p less than 0.0005), but not when the cells were suspended in tissue culture medium (5.6 +/- 1.2 pW/cell vs. 5.6 +/- 0.8 pW/cell, p greater than 0.05). After mixing with IgG-coated latex particles the heat production by patients' PMN were significantly less stimulated than that of normal PMN when the cells were suspended in autologous plasma (42 +/- 13% vs. 75 +/- 22%, p less than 0.0005), but not when the cells were suspended in tissue culture medium (82 +/- 24% vs. 83 +/- 22%, p greater than 0.05). The increase of heat production by normal PMN after stimulation with IgG-coated latex particles was significantly lower when the cells were preincubated with heat aggregated human gammaglobulin compared to that obtained when the cells were preincubated in saline (11 +/- 10% vs. 51 +/- 11%, p less than 0.001). This finding shows that the increased PMN heat production which occurs after binding of the IgG-coated particles is mediated via Fc receptors. A plasma factor(s), possibly circulating immune complexes, can explain the abnormal PMN functions in the patients.

Differential pattern of oncogene and beta-actin expression in leukaemic cells from AML patients.

The presence of mRNA hybridizing to five oncogene (fos, mos, myc, sis, abl) and a beta-actin probe(s) was studied with a semiquantitative dot-blot procedure in eight AML patients. Around 10(7) leucocytes, corresponding to 1-10 ml blood, sufficed for the analysis. Each patient, regardless of the FAB group, exhibited a distinct pattern of oncogene or beta-actin expression. Especially strong signals were obtained with the beta-actin probe in two patients and with the fos probe in three patients. The findings underscore the heterogeneity of AML, either present from the first step towards malignancy or arising during the progression of the disease. The pattern of oncogene expression in leukaemic cells studied in routine blood samples may become an additional means for classification and follow-up of AML patients.

Demonstration of antibodies binding to autologous and allogeneic leukemic cells in childhood ALL. Evidence for a common ALL antigen(s).

The humoral immune response to autologous leukemic cells was investigated in childhood ALL using a 125I protein A binding assay. In 5/7 patients antibodies were demonstrated at diagnosis and in 3/7 cases also after chemotherapy. Sera from 2/3 patients, which bound significantly to autologous leukemic cells, did not bind significantly to autologous remission cells. In allogeneic experiments sera bound significantly to ALL leukemic cells (6/7 positive combinations), but not to AML leukemic cells (8/8 negative combinations). We propose that ALL sera contain antibodies binding to autologous leukemic cells and that they are directed against a common ALL antigen(s).

Use of microcalorimetry in analysing the kinetics of ADCC.

Microcalorimetry was found to be a useful technique for the demonstration of antibody-dependent cellular cytotoxicity (ADCC) against human melanoma cells mediated by a heterologous rabbit antiserum and two monoclonal antibodies in combination with human peripheral blood lymphocytes as effector cells. The rabbit antiserum and the monoclonal IgG3 antibody 2B2 directed against the GD3 ganglioside expressed cell-inhibitory effects resulting in a decreased heat production rate over 2-18 h of incubation. The 4.2 monoclonal IgM antibody to GD3 had no similar cell-inhibitory effect. In contrast, the 4.2 antibody expressed a much stronger effect than 2B2 in tests for complement-dependent cytotoxicity. The kinetics of these effects were quite reproducible. It is concluded that microcalorimetry is a sensitive and particularly suitable method for the analysis of cytotoxicity kinetics.

Differentiation of myeloid leukemic cells in vitro demonstrated by microcalorimetry: stimulation of leukemic and remission cells by IgG-binding Fc receptors.

Interaction of immunoglobulin G (IgG)-coated latex particles with Fc receptors on myeloid leukemic blood cells and on polymorphonuclear granulocytes (PMN) from remission patients and healthy blood donors was investigated using microcalorimetry. The induced heat production by leukemic cells from 13 patients with the M2, M4 and M5 FAB groups (French-American-British classification) of acute myeloid leukemia (AML) was significantly higher than that of leukemic cells from 7 patients with the M1 FAB group (p less than 0.005) and mononuclear blood cells from 10 healthy individuals (p less than 0.005). The values were similar for PMN from 10 remission patients and 10 healthy blood donors. After incubation of M1 cells in vitro for 24-30 h at 37 degrees C the heat production induced by IgG-coated latex particles by the cells increased significantly, indicating the appearance of Fc receptors for IgG. In addition, the heat production by unstimulated M2, M4 and M5 cells was significantly higher than that by unstimulated M1 cells (p less than 0.005) and normal mononuclear cells (p less than 0.0005). The heat production by unstimulated PMN suspended in tissue culture medium was similar in remission patients and healthy blood donors.

Antibodies to human adult T cell leukaemia virus type I associated antigens in Swedish leukaemia patients and blood donors.

Antibodies to antigens associated with human T cell leukaemia virus type I (HTLV I) in Swedish adult leukaemia patients and blood donors were sought with a sensitive screening test using membrane antigen prepared from virus producing cells (MA-ELISA). Four persons (one ALL, one AML and two healthy blood donors) out of 483 persons tested reacted in the test. However, they were negative in the more specific anti-p19 and anti-whole virion ELISA tests. The prevalence of sera with definite anti-HTLV I activity seems to be very low in Sweden. The finding of four MA-ELISA positive persons needs further investigation.

Microcalorimetry as a tool for the detection of complement-dependent cytotoxicity.

Microcalorimetry using a 4-channel static ampoule microcalorimeter of thermopile type has been evaluated as a tool for the detection of complement-dependent cytotoxicity against the surface antigens of living cells. Cytotoxic reactions mediated by a rabbit antiserum against human white blood cells and by 2 different monoclonal antibodies recognizing a melanoma-associated antigen on a human melanoma cell line were studied. The cytotoxic reactions were registered as a decrease of the heat production rate when the cells were exposed to antibodies in the presence of active complement as compared to the heat production rate of the cells exposed to the same antibodies in the presence of inactive complement. This investigation shows that microcalorimetry can be used as a highly sensitive method for the detection of complement-dependent immune reactions, detecting antibody dilutions higher than 10(-5). It also indicates that microcalorimetry may become a particularly important technique in the analysis of the kinetics of cytotoxic immune reactions in vitro.

Effect of latex-stimulated granulocytes on platelet aggregation in man.

The effect of granulocytes on human platelet aggregation was investigated in vitro. Platelet function was assayed by photometric technique. Incubation of platelets with latex-stimulated granulocytes for 1 h at room temperature resulted in total inhibition of arachidonic acid-induced platelet aggregation. ADP-induced platelet aggregation was suppressed, lacked secondary wave and was pursued by swift disaggregation. Platelet aggregates induced by collagen dispersed faster under the influence of stimulated granulocytes. The present results indicate that granulocytes may play a role in the hemostatic mechanism in man.

Immunoglobulin G antibodies binding to a synthetic peptide deduced from the nucleotide sequence of the env gene of HTLV I in patients with leukemia and rheumatoid arthritis, HLA sensitized persons and blood donors.

A synthetic pentadecapeptide preparation, env 406-420, with an amino acid sequence deduced from the envelope glycoprotein gene of human T cell leukemia virus type I (HTLV I), was used as the antigen in an enzyme immunoassay for immunoglobulin G antibodies, exploring its usefulness for seroepidemiological purposes. The frequency of reactivity in the test groups, presented in decreasing order was: patients with rheumatoid arthritis; multitransfused nonleukemic patients; Japanese cases of adult T cell leukemia (ATL); HLA sensitized persons; Swedish cases of adult acute leukemia; and Swedish blood donors. Three American cases of ATL and 12 HTLV I seropositive monkeys did not react. In RF positive sera from patients with rheumatoid arthritis, no quantitative correlation between RF activity and anti-env 406-420 activity was seen. Anti-env 406-420 positive sera did not react or reacted only weakly with four control peptide preparations with different amino acid sequences. The experience with oligopeptide serology still is limited. Our results illustrate that unexpected cross-reactions which are hard to interpret can occur. Although absorption experiments indicated an HTLV I specific component of the reactivity, antibodies against epitopes of allo- and auto-immune specificity may also have participated.