Current spectrum of cardiogenic shock and effect of early revascularization on mortality. Results of an International Registry. SHOCK Registry Investigators

BACKGROUND

Cardiogenic shock remains the leading cause of death of patients hospitalized with acute myocardial infarction (MI). This study was conducted to examine (1) the current spectrum of cardiogenic shock, (2) the proportion of patients who are potential candidates for a trial of early revascularization, and (3) the apparent impact of early revascularization on mortality.

METHODS AND RESULTS

Nineteen participating centers in the United States and Belgium prospectively registered all patients diagnosed with cardiogenic shock. Two hundred fifty-one patients were registered. The mean age was 67.5 +/- 11.7 years, and 43% were women. Acute mitral regurgitation or ventricular septal rupture was the cause of shock in 8%. Concurrent conditions contributing to the development of shock were noted in 5%, and 2% had isolated right ventricular shock. Among the remaining 214 patients, nonspecific findings on the ECG associated with "nontransmural" MI were seen in 14%. The median time to shock diagnosis after MI was 8 hours. The overall in-hospital mortality was 66%. Patients clinically selected to undergo cardiac catheterization were significantly younger and had a lower mortality than those not selected (51% versus 85%, P < .0001) even if they were not revascularized (58%). Mortality for patients undergoing percutaneous transluminal coronary angioplasty (PTCA) was 60% (n = 55) and 19% (n = 16) for coronary artery bypass graft surgery (CABG). Sixty percent (n = 150) of registered patients were judged eligible for a trial of early revascularization. Trial-eligible patients were significantly younger (65.4 +/- 11.0 versus 70.6 +/- 11.9 years, P < .001), had an earlier median time to shock onset after MI (6.5 versus 17.5 hours, P = .003), and had lower mortality (62% versus 73%, P = .077) than ineligible patients.

CONCLUSIONS

Patients diagnosed with cardiogenic shock complicating acute MI are a heterogeneous group. Those eligible for a trial of early revascularization tended to have lower mortality. Patients selected to undergo cardiac catheterization had lower mortality whether or not they were revascularized. Emergent PTCA and CABG are promising treatment modalities for cardiogenic shock, but biased case selection for treatment may confound the data. Whether PTCA and CABG reduce mortality and which patient subgroups benefit most remain to be determined in a randomized clinical trial.

Occupational and environmental exposures and myelodysplasia: a case-control study

A case-control study of newly diagnosed myelodysplastic syndrome patients investigated lifetime exposures through occupation, environment or hobby by questionnaire, structured and semi-structured interview. The exposure histories of 400 individually matched pairs were compared. Increased or possibly increased odds ratios were observed for radiation (2.05, 95% confidence interval 1.16-3.76), halogenated organics (1.57, 0.97-2.57), metals (1.40, 0.99-2.00), several specific radiation exposures and individual chemicals and for childlessness (1.46, 1.01-2.11). Since myelodysplasia generally carries a poor prognosis, whether or not individuals convert to leukaemia or to other cancer, these findings add to previous reports of exposures implicated in the aetiology of leukaemia and add to the case for minimizing exposures to radiation and halogenated organics.

Regional cerebral hypoperfusion in long-term type 1 (insulin-dependent) diabetic patients: relation to hypoglycaemic events

Regional distribution of cerebral blood flow was determined semi-quantitatively with 99Tcm-HMPAO brain SPET under basal conditions in Type 1 (insulin-dependent) diabetic patients of recent onset and longer disease duration, and related to metabolic control and history of hypoglycaemic events. Long-term diabetic patients showed significantly more alterations in regional cerebral blood flow than diabetics of recent onset and healthy controls. Regional hypoperfusion, predominantly localized in the fronto-temporal cortex, was almost exclusively observed in patients with long-term diabetes. The latter finding was related to lower HbA1c levels (i.e. better metabolic control) and to the frequency of impending hypoglycaemia, but not to age of the patient, duration of diabetes or to chronic diabetes complications. The incidence of hypoperfusion was comparable in patient groups with or without a medical history of hypoglycaemic coma. However, regions of hypoperfusion were larger in the patients who had experienced hypoglycaemic coma. It is concluded that regional cerebral hypoperfusion in long-term Type 1 (insulin-dependent) diabetics, as evidenced by HMPAO-SPET can be related to the frequency and degree of hypoglycaemic events and to tight metabolic control, which is however at the expense of an increased risk of recurrent hypoglycaemia.

Quality assurance in general practice: the state of the art in Europe

Quality assurance' (QA) is an important new development in general practice. In order to describe the state of the art in this field a preliminary survey was performed by the WONCA European Working Party on Quality in General Practice (EQuiP) in 17 European countries. The results revealed considerable differences in the systems and organization of general practice care [such as practice form, list size, the role of the general practitioner (GP), remuneration], which will have an impact on setting up QA. The preliminary findings demonstrated that most countries are only just beginning the implementation of QA. Nevertheless, there are many valuable developments and experiments concerned with the methodology, procedures and structures for it. In order to accelerate the speed of adoption of QA and to avoid the repetition of mistakes, policy makers and GPs from different parts of Europe should study examples in their fellow countries. A clearing house of QA projects in general practice can help to inform them on valuable developments.

An interactive technique for three-dimensional image registration: validation for PET, SPECT, MRI and CT brain studies

A multipurpose three-dimensional registration technique was validated with PET, SPECT, CT and MRI scans, which had been obtained under normal clinical conditions. In contrast to fully automated procedures, this coregistration method is highly interactive, which has the advantage that it does not impose rigid restrictions by data type and by alterations in normal anatomy or brain function resulting from disease.

METHODS

Basically, a computer program provides a variety of tools to examine the accuracy of coregistration visually and to specify necessary translations and rotations in all three dimensions. Tools and criteria to accept coregistration were applied according to a standardized protocol. Reproducibility was assessed with five independent users on nine pairs of image sets. In two pairs of these image sets, coregistration was repeated three times by each user.

RESULTS

Depending on the resolution of the images involved, the reproducibility of translation distances ranged from 0.32 to 2.22 mm (s.d.) and of rotation angles from 0.32 to 1.70 degrees. It was always much smaller than the point-spread full-width half maximum of the device with the lower resolution. The accuracy of coregistration was examined using two arbitrarily misplaced image sets. Interindividual and intraindividual variance were similar, which suggested that the influence of subjectivity was not significant. Average displacements after coregistration were 0.43 and 0.29 mm or less for PET and MRI data, respectively, which indicated the absence of a systematic bias.

CONCLUSION

The results indicate the high reproducibility and accuracy of this three-dimensional coregistration technique, which is comparable or superior to those of automated techniques and methods based on external artificial landmarks.

HMPAO SPET and FDG PET in Alzheimer's disease and vascular dementia: comparison of perfusion and metabolic pattern

Positron emission tomography (PET) of 18F-2-fluoro-2-deoxy-D-glucose (FDG) and single-photon emission tomography (SPET) of 99mTc-hexamethylpropylene amine oxime (HMPAO) were performed under identical resting conditions within 3 h in 20 patients with probable Alzheimer's disease (AD), 12 patients with vascular dementia (VD) and 13 normal persons. In the temporoparietal association cortex similar impairment of relative regional cerebral glucose metabolism (rCMRGl) and relative HMPAO uptake (rCBF) was found. In addition PET showed hypometabolism in the occipital association cortex. The functional pattern was condensed to a ratio of regional values of association areas divided by regional values of structures that are typically less affected by AD. In normals this ratio was significantly related to age for PET metabolic data (r = -0.66, P = 0.01). The ratio was significantly lower in AD than in VD and controls for both rCMRGl and rCBF. In AD only, the metabolic ratio was related to severity of dementia (r = 0.54, P = 0.003) and age (r = 0.64, P = 0.003). Metabolic differences between normals and AD patients were less obvious in old age. In contrast, there were no significant correlations between the perfusion ratio and severity of dementia or age. Comparing the metabolic and perfusion ratio by receiver operating characteristic curves, PET differentiated AD from normals only marginally better than SPET. Differentiation between AD and VD was much better achieved by PET. Our results suggest that both PET and SPET can distinguish AD patients from controls, whereas for differentiation between AD and VD SPET is of little value.

The activation of Escherichia coli aspartate transcarbamylase by ATP. Specific involvement of helix H2' at the hydrophobic interface between the two domains of the regulatory chains

The regulatory chain of E. coli aspartate transcarbamylase (E.C. 2.1.3.2) is folded into two domains. The allosteric domain harbours the regulatory site where the activator ATP and the inhibitors CTP and UTP bind competitively. The zinc domain ensures the contact with the catalytic chains. The interface between these two domains is hydrophobic, and involves the carboxy-terminal part of the helix H2' of the allosteric domain and several residues of the zinc domain. This structural feature mediates the transmission of the ATP regulatory signal. In the present work, site-directed mutagenesis and molecular modelling were used to investigate the role of specific amino acid residues in this process. The modifications of the hydrophobic core which are expected to alter the position of helix H2' reduce or abolish the sensitivity of the enzyme to ATP. The properties of the mutants and the results of modelling are fully consistent and suggest that a movement of helix H2' is part of the mechanism of activation by ATP. A model is proposed to account for the transmission of the ATP signal from the regulatory site to the interface between the regulatory and catalytic chains.

Prospective evaluation of technetium-99m-HMPAO SPECT in mild and moderate traumatic brain injury

We prospectively evaluated the contribution of 99mTc-HMPAO SPECT in patients who have sustained acute, mild or moderate head trauma.

METHODS

Forty-two patients formed the first subgroup of moderate trauma (ModTr) and 25 patients formed the second subgroup of mild trauma (MilTr). All 67 patients underwent an initial SPECT (Tinit) within 4 wk after a closed cranial trauma. After a mean interval of 3 mo from the time of Tinit, all patients were clinically re-evaluated; those with an abnormal Tinit underwent a repeat SPECT (Trpt) as well. All SPECT studies were visually graded by agreement of three observers adjudging a score ranging from 0 (no lesions) to 4.

RESULTS

For the group as a whole (ModTr + MilTr), the following results could be derived: (1) in 32/33 Tinit negative cases, clinical symptoms had resolved; (2) the positive predictive value of Tinit was only 20/34 (59%); (3) the sensitivity for the repeat SPECT was 19/20 (95%).

CONCLUSION

Our results show that: (1) SPECT alterations correlate well with the severity of the trauma; (2) a negative initial SPECT study is a reliable predictor of a favorable clinical outcome; (3) in cases with a positive initial SPECT, a follow-up consisting of a combination of SPECT and clinical data is necessary; (4) in patients suffering from postconclusive symptoms, SPECT offers an instrument to objective sequelae.

Non-dysplastic myelodysplasia?

Patients successfully treated for a malignancy with cytotoxic therapy have an increased risk of developing secondary myelodysplasia (MDS) and acute myeloid leukemia (AML). We report a patient in remission from Hodgkin's disease (HD) who remains hematologically normal 4 years after combination chemotherapy, but who has biological and genetic abnormalities characteristic of myelodysplasia. X-inactivation analysis using a 5' phosphoglycerate kinase (PGK) probe demonstrates polyclonal hematopoiesis, but cytogenetic analysis reveals a clonal population with a minority of metaphases having a 7q-deletion. NRAS mutations are not detectable 1 year after treatment, but are present in two separate clones (at codons 12 and 15) analyzed by single-stranded conformational polymorphism (SSCP), followed by cloning and sequencing 4 years after treatment. The presence of an activated NRAS with the same codon 12 mutation was independently confirmed by the nude mouse tumorigenicity assay. In vitro peripheral blood granulocyte-macrophage colony-forming units (CFU-GM) have changed from normal to undetectable levels while erythroid burst forming units (BFU-E) were significantly reduced on two occasions during the period of observation. These abnormalities are characteristic of MDS. Continued clinical follow-up will determine whether these evolving genetic and biological abnormalities pre-date the onset of clinical and morphological features of MDS.

Atypical progression of multiple myeloma with extensive extramedullary disease

Multiple myeloma is a neoplastic disorder caused by the proliferation of a transformed B lymphoid progenitor cell that gives rise to a clone of immunoglobulin-secreting cells. Other plasma cell tumours include solitary plasmacytoma of bone (SPB) and extramedullary plasmacytomas (EMP). Despite an apparent common origin there exist pathological and clinical differences between these neoplasms and the association between them is not completely understood. A case of IgG multiple myeloma that presented with typical clinical and laboratory features, including a bone marrow infiltrated by well differentiated plasma cells, is reported. The tumour had an unusual evolution, with the development of extensive extramedullary disease while maintaining mature histological features.

Extended cytogenetic follow-up and clinical progress in patients with myelodysplastic syndromes (MDS)

198 patients with MDS were followed cytogenetically for up to 90 months. There were significant differences in survival between patients with a normal karyotype, single abnormalities (p < 0.05) and multiple abnormalities (p < 0.0001). Survival differences were also seen in each of the FAB sub-types but were only significant in RAEB/RAEB-t and CMML (p = 0.001) where a normal karyotype was associated with prolonged survival. Single and multiple abnormalities of chromosomes 7 and 8 but only multiple abnormalities of chromosome 5 were also associated with reduced survival. 126 patients were successfully investigated on more than one occasion. Karyotype evolution occurred in 15 and was associated with reduced overall survival in those patients who had previously been karyotypically normal (p < 0.05). Median survival following evolution was only 10 months. 29 patients developed leukaemia. The incidence of transformation was significantly higher in patients with multiple abnormalities than in those with a normal karyotype (p < 0.05) or single abnormalities (p < 0.05).

A randomized phase II study of low-dose cytosine arabinoside (LD-AraC) plus granulocyte-macrophage colony-stimulating factor (rhGM-CSF) in myelodysplastic syndromes (MDS) with a high risk of developing leukemia. EORTC Leukemia Cooperative Group

In a randomized phase II study, patients with myelodysplastic syndromes (MDS) with 10-30% blasts in the bone marrow and hematopoietic failure were treated with low-dose Ara C (2 x 10 mg/m2 subcutaneously (s.c.) days 1-14) and rhGM-CSF (fully glycosylated, Sandoz/Schering-Plough, 2 x 150 micrograms protein/day s.c.) given either following Ara C (days 15-21) or simultaneously (days 8-14) for 1-5 cycles. 108 patients with a median age of 65 years, range 17-80 years and refractory anemia with an excess of blasts (RAEB, n = 54), RAEB with transformation (RAEBt, n = 50) or with chronic myelomonocytic leukemia (CMML, n = 4) were evaluable. Complete remission was achieved in 15 cases (14%), 11 had a partial response (10%), and 16 a minor response (15%). Stable disease was reached in 35 cases (32%). There were 16 cases of toxic death (15%), progression occurred in 15 patients (14%). No differences existed between the two treatment arms with respect to response and duration of response. Prognostic factors for poor response included the presence of cytogenetic abnormalities and a history of previous blood transfusions. Major adverse events during treatment were hemorrhage (55%), infections (54%), and fever associated with GM-CSF administration (40%). The overall response rate ws 39%, median duration was 12.5 months from start of treatment which allowed responding patients to lead good quality life without further therapy. The question whether the combination is indeed superior to LD-Ara C alone is not settled but will be evaluated in an ongoing clinical trial.

Semiquantitative analysis of cerebral blood flow by means of 99Tcm-HMPAO SPECT in individuals before and after a high altitude Himalayan expedition

Nine members of the 'Belgian Tibet Expedition 1991' underwent a 99Tcm-hexamethylpropyleneamine oxime (HMPAO) brain single photon emission computed tomographic study before and after their stay at high altitude. Cerebral and cerebellar activity were analysed in three circumference profiles, representing the lower, middle and upper transaxial sections of the brain. The count value of each volume element (VE) was normalized to the maximum cerebellar value. In order to compare individual regional cerebral blood flow (rCBF) before and after the expedition, the relative differences in rCBF were calculated for each VE as: rel delta (%) = 100 x (value after expedition - value before expedition)/value before expedition. In 4/9 cases regional rel delta values were negative in most cortical regions; in 3/9 individuals nonsignificant changes were found and 2/9 climbers showed a positive rel delta value in most cortical regions. For the group as a whole there was (1) a mean decrease of 1.7% in global cortical CBF and (2) a significantly (P < 0.01) diminished rCBF was observed in both temporal and the left frontotemporal areas.

Assembly of an antibody and its derived antibody fragment in Nicotiana and Arabidopsis

The yield and assembly of an IgG1 antibody and its derived F(ab) fragment were compared in Nicotiana and Arabidopsis. The results obtained showed a lot of interclonal variability. For 45% of the primary transgenic calluses, antigen-binding entities represented less than 0.1% of the total soluble protein (TSP). Only two of the 103 analysed transformants contained more than 1% of antigen-binding protein, with 1.26% being the highest yield. Analogous amounts of complete antibody and F(ab) accumulated in primary callus tissue. Moreover, yields were in the same range for both species as far as primary callus tissue is concerned. However, the accumulation of the F(ab) fragment in leaf tissue of regenerated plants differed significantly between Nicotiana and Arabidopsis. The F(ab) fragment accumulated to only 0.044% of TSP in Nicotiana leaves but up to 1.3% in Arabidopsis leaves. Furthermore, both species showed differences in the assembly pattern of the complete antibody. Whereas Arabidopsis contained primarily fully assembled antibodies of 150 kDa, Nicotiana showed an abundance of fragments in the 50 kDa range.

Haematological disorders and occupational hazards: a British Society for Haematology/Health and Safety Executive study

During a 3-year period 229 patients in the U.K. with haematological disorders thought to be associated with occupational hazards were notified to the British Society for Haematology/Health and Safety Executive office. Most were suffering from malignant or premalignant states or aplastic anaemia. Benzene and ionizing radiation were the most common agents recorded. While no estimate can be made of the incidence of chemical or radiation induced disease at the present time, the data suggests that routine documentation of exposure at work is an important step in allowing more specifically focused studies.

Clonal haemopoiesis following cytotoxic therapy for lymphoma

Patients successfully treated for lymphoma by conventional cytotoxic therapy are at increased risk of developing treatment-related myelodysplasia and acute myeloid leukaemia. In this study we have investigated a group of haematologically normal females in remission from lymphoma for evidence of clonal haemopoiesis as a possible marker for the development of clonal haemopoietic disorders. Unilateral X-inactivation, and hence clonality, can be determined in females heterozygous for X-linked restriction fragment length polymorphisms by differences in methylation between active and inactive X-chromosomes. We have studied methylation patterns at the DXS255 locus and the phosphoglycerate kinase (PGK) gene in 25 females in remission from lymphoma and compared them to 35 normal females. Unilateral X-inactivation was detected in 4/15 patients in remission from lymphoma versus 2/27 normals at the DXS255 locus and in 4/13 treated lymphoma patients versus 0/11 normals at the PGK locus. Six individuals were analysed by both techniques with complete concordance. Unilateral X-inactivation was more common following cytotoxic therapy for lymphoma (7/25) than in normals (2/35) (p < 0.025) and in the lymphoma cohort was associated with increasing time from the end of therapy (p = 0.03). Patients in remission from lymphoma have an increased incidence of clonal haemopoiesis compared to normal individuals. This may be due to either the clonal expansion of an abnormal genetically damaged stem cell or a variation of normal haemopoiesis. Prospective studies will establish whether this finding is associated with an increased risk of developing treatment-related myelodysplasia and acute myeloid leukaemia.

Expression of the colony-stimulating factor 1 receptor in B lymphocytes

The FMS proto-oncogene encodes for the colony-stimulating factor 1 receptor (CSF-1R), whose expression within the haematopoietic system has previously been thought to be restricted to cells of the mononuclear phagocyte lineage. We have studied the expression of the CSF-1R in peripheral blood mononuclear cells by indirect immunofluorescence and flow cytometry. FMS expression was detected on both monocytes and B lymphocytes from all samples analysed, including 14 haematologically normal individuals and 31 patients (23 in remission following cytotoxic therapy for lymphoma, six with B-cell chronic lymphocytic leukaemia and two with chronic myelomonocytic leukaemia). The level of FMS expression on B lymphocytes was lower than the level of expression detected on monocytes isolated from the same sample. FMS mRNA expression in B lymphocytes has been confirmed by a reverse transcription-polymerase chain reaction (RT-PCR)-based technique and Northern blot analysis. Thus, FMS may play a role in the normal function of B lymphocytes and, because of its potential oncogenic activity, may contribute to the pathogenesis of malignancies of this cell type.

Effect of T-DNA configuration on transgene expression

T-DNA vectors were constructed which carry a beta-glucuronidase (gusA) gene fused to the promoter of the nopaline synthase (nos) gene and the 3' end of the octopine synthase (ocs) gene. This reporter gene was cloned at different locations and orientations towards the right T-DNA border. For each construct, between 30 and 60 stably transformed calli were analysed for beta-glucuronidase activity. Depending on the T-DNA configuration, distinct populations of gusA-expressing calli were obtained. Placing the reporter gene in the middle of the T-DNA results in relatively low expression levels and a limited inter-transformant variability. Placing the gene with its promoter next to the right border led to an increase in both the mean activity and the variability level. With this construct, some of the calli expressed the gusA gene at levels four to five times higher than the mean. In all these series, at least 30% of the calli contained reporter gene activities that were less than half of the mean expression level. Separating the gusA gene from the right T-DNA border by an additional 3'-untranslated region, derived from the nos gene, resulted in an increase in the mean expression to a level almost four times higher than that of constructions carrying the reporter gene in the middle of the T-DNA. Moreover, the number of transformants with extremely low activities decreased by at least 50% and this resulted in significantly lower inter-transformant variability independently of the orientation of the reporter gene on the T-DNA.

Methylation of the DXS255 hypervariable locus 5′ CCGG site may be affected by factors other than X-chromosome activation status

Differences in the methylation status of certain cytosine residues between active and inactive X chromosomes can be used to determine X-inactivation in females heterozygous for X-linked restriction fragment length polymorphisms. We have studied methylation patterns in 105 females heterozygous at the DXS255 locus by Southern blotting of PstI and MspI or HpaII double digests and hybridization with the probe M27B. Unequivocal patterns of unilateral or bilateral X-inactivation were obtained in 15/64 and 49/64 cases, respectively. In the remaining 41 cases the results were unclear due to the absence of HpaII digestion of one or both PstI fragments. In 7 samples an unequivocal digestion pattern was demonstrated on repeat analysis, suggesting that the initial ambiguous pattern was due to incomplete HpaII digestion. In certain individuals, methylation at the 5' CCGG DXS255 locus may be affected by factors other than X-inactivation, making analysis of clonality with the M27B probe impossible. These individuals should be clearly identified in studies of clonality.