The identification of pathological subtypes of Alzheimer's disease using cluster analysis

A cluster analysis was performed on 78 cases of Alzheimer's disease (AD) to identify possible pathological subtypes of the disease. Data on 47 neuropathological variables, including features of the gross brain and the density and distribution of senile plaques (SP) and neurofibrillary tangles (NFT) were used to describe each case. Cluster analysis is a multivariate statistical method which combines together in groups, AD cases with the most similar neuropathological characteristics. The majority of cases (83%) were clustered into five such groups. The analysis suggested that an initial division of the 78 cases could be made into two major groups: (1) a large group (68%) in which the distribution of SP and NFT was restricted to a relatively small number of brain regions, and (2) a smaller group (15%) in which the lesions were more widely disseminated throughout the neocortex. Each of these groups could be subdivided on the degree of capillary amyloid angiopathy (CAA) present. In addition, those cases with a restricted development of SP/NFT and CAA could be divided further into an early and a late onset form. Familial AD cases did not cluster as a separate group but were either distributed between four of the five groups or were cases with unique combinations of pathological features not closely related to any of the groups. It was concluded that multivariate statistical methods may be of value in the classification of AD into subtypes.

Intravenous gammaglobulin has no advantages over oral corticosteroids as primary therapy for adults with immune thrombocytopenia: a prospective randomized clinical trial

Symptomatic immune thrombocytopenia in adults is potentially lethal, and, when conventionally treated with oral corticosteroid agents, approximately two thirds of patients will have some response in platelet count, but this is seldom durable. Since cytotoxic drugs are of limited benefit at this stage, splenectomy becomes necessary in 70% of patients. Intravenous gammaglobulin has been advocated as an alternative to prednisone as the primary form of treatment. A prospective, randomized comparison was carried out between oral prednisone (1 mg/kg/day; group 1; n = 17), high-dose intravenous gammaglobulin (400 mg/kg on days 1 through 5; group 2; n = 13), or a combination of both agents given on the same schedule (group 3; n = 13). The groups were well matched clinically and hematologically. No mortality occurred after initiating therapy, but one patient experienced a cerebrovascular accident. Response, defined as a platelet count greater than 50 x 10(9)/L, was achieved in 82%, 54%, and 92% of patients in groups 1, 2, and 3, respectively, but was only significant between groups 2 and 3 (P = 0.0365). The median times to peak platelet counts were 8.5 days (range 7 to 21 days), 7 (range 5 to 10 days), and 7 (range 3 to 23 days), respectively. Although there was a trend in favor of the steroid-administered groups, relapse was not significantly different, which occurred at a median of 184, 32, and 76 days, respectively, nor was the average time to splenectomy different at 339, 59, and 98 days, respectively. At a minimum of 2 years of follow-up, 5 of 17 in group 1, 2 of 13 in group 2, and 1 of 13 in group 3 had achieved platelet counts of greater than 100 x 10(9)/L and, therefore, did not require splenectomy. In contrast, where this indication was present for failure to respond, 8 of 12 (67%) in group 1, 4 of 8 (50%) in group 2, and 9 of 12 (75%) in group 3 remain in complete remission. Significantly more patients in group 2 than group 3 experienced a relapse (P = 0.0365). It is concluded that in previously untreated adults with symptomatic immune thrombocytopenia, gammaglobulin offers no advantage over conventional corticosteroid administration as the primary form of therapy. Additionally, more intense immunosuppression, resulting from the use of both agents combined, is no better than single agent corticosteroid agents and appears to be an unnecessary and unwarranted expense.

T cell depletion by exposure to Campath-1G in vitro prevents graft-versus-host disease

Campath-1G is an immunosuppressive monoclonal antibody directed against human lymphocytes. Its effectiveness in preventing graft-versus-host disease (GVHD) by simple opsonisation of bone marrow T-cells has been studied in 36 consecutive allografts: in 17 for leukaemia, one for essential thrombocytosis and four for myeloma this was the sole means of GVHD prophylaxis. A further eight patients with aplastic anaemia received 3 months post-transplantation cyclosporin A (CsA) for this purpose whereas in the ninth and tenth the preparative regimen has been modified with this immunosuppressive agent now discontinued. Nucleated cells were harvested and after quantitative recovery of the mononuclear population on the Cobe 2997 separator they were exposed to 20 mg Campath-1G for 30 min at room temperature and then infused. Following standard conditioning, which included total lymphoid irradiation, the median days to reach 0.5 and 1.0 x 10(9)/l neutrophils were respectively 18 (range 9-34) and 28 (range 10-59); to 25 and 100 x 10(9)/l platelets the corresponding times were 17 days (range 5-32 days) and 27 days (range 13-127 days). In all, the day 14 trephine biopsy showed engraftment. At median follow-up of 20 months (range 5-44 months) only one patient has developed possible grade I cutaneous GVHD that responded promptly to corticosteroids: no chronic GVHD or CMV pneumonitis has been encountered. Of those with haematological malignancy transplanted in remission only two with acute leukaemia have relapsed. In aplastic anaemia graft loss initially occurred but this has been overcome by adding Campath-1G in vivo and omitting CsA.(ABSTRACT TRUNCATED AT 250 WORDS)

Construction and features of lambda EMBL3cosW, a lambda replacement vector for detailed analysis of large regions of genomic DNA

A phage lambda replacement vector, lambda EMBL3cosW, is described which expedites detailed analysis of large regions of chromosomal DNA. Two features of the vector aid this process. Firstly, the replaceable stuffer in lambda EMBL3cosW is flanked by SP6 and T7 promoters so that end-specific hybridisation probes can be rapidly generated from cloned inserts for identification of sequentially overlapping clones in genomic libraries. Secondly, because all the phage coding sequences in the vector (which are placed to the right of the replaceable stuffer) can be removed from cloned inserts by cleavage with NotI, restriction mapping of cloned inserts using partial digest strategies is greatly facilitated. Other features of the vector are: (1) strategically placed BamHI and XhoI sites for the cloning of genomic DNA partially digested with MboI or Sau3AI by two different methods; (2) SalI and SfiI sites for the isolation of intact cloned inserts; and (3) transcription terminators to insulate vector genes from transcriptional interference from cloned insert DNAs.

Mapping of 386 kb of genomic DNA in the human dystrophin-encoding gene (DYS) using an ordered phage lambda sublibrary of a YAC clone containing the DYS region

An integrated restriction map for HindIII and EcoRI has been constructed for 386 kb of the human dystrophin-encoding gene by partial digest mapping of 35 overlapping lambda EMBL3cosW phage clones derived from a yeast artificial chromosome containing this region. Map construction was simplified in two ways. Firstly, the sequence arrangement of lambda EMBL3cosW is such that only map data from cloned inserts are generated using partial digests of lambda phage DNA asymmetrically labelled at the left cos end with a complementary 32P-labelled oligodeoxyribonucleotide. Secondly, the degree of partial digestion was standardised for each restriction enzyme by using ultraviolet light-induced formation of thymine dimers in the recognition sequence to partially block the cleavage reaction. The map provides the basis for work on the analysis of chromosomal rearrangements in this region which give rise to Duchenne muscular dystrophy, and for studies of chromosome structure and function.

Detection of Epstein-Barr virus and cytomegalovirus in patients with chronic fatigue

Patients with chronic fatigue as a major complaint frequently present with recurrent sore throat, and on physical examination they have hyperemia and lymphoid hyperplasia of the pharyngeal area. Pharyngeal scrapings were obtained from 41 such patients and analyzed for Epstein-Barr virus or cytomegalovirus DNA by colorimetric in situ hybridization. Results were compared with healthy control subjects matched for age and sex. Epstein-Barr virus-DNA was detected more frequently in male patients, 5/9 (55.6%), than controls, 0/6 (0%), but there was no difference in frequency in female patients, 4/32 (12.5%), than control subjects, 1/29 (3.4%). Cytomegalovirus-DNA was detected infrequently in patients and controls, 13% versus 22% respectively. The presence of EBV-DNA did not correlate with antibody titers nor with the complaint of sore throat. Four of the five males who had positive EBV-DNA in the pharyngeal smears have now recovered.

Plasma exchange for homozygous familial hypercholesterolaemia: the Cape Town experience

Homozygous familial hypercholesterolaemia (FH) is a rare disorder having a greater frequency in populations with founder effects for the mutations in low density lipoprotein (LDL) receptors. It is characterized by early signs of cholesterol infiltrates with premature coronary artery disease and does not respond to conventional lipid-lowering therapy. Plasma exchange is an established mode of treatment which improves the biochemical abnormality and may allow reversal of the physical manifestations as well as favourably influencing the clinical course of the disease. The efficacy, safety and tolerability of this procedure is confirmed by our experience over the 15 years following the previous report. In a subset of these patients who have residual LDL receptor activity, further lowering of the plasma cholesterol concentration was achieved by adding simvastatin, an hydroxy-methylglutaryl coenzyme A reductase inhibitor. It is concluded that this combined approach may be of benefit in selected cases of homozygous FH undergoing regular plasmapheresis.

Generation of ordered phage sublibraries of YAC clones: construction of a 400-kb phage contig in the human dystrophin gene

A phage contig of 400 kb that extends from the brain-specific promoter at the 5'-end of the human dystrophin gene, through the muscle-specific promoter over 100 kb further downstream, and across most of intron 1 has been assembled. To achieve this, a yeast artificial chromosome (YAC) subcloning approach was used. Total DNA from a yeast strain containing a 400-kb YAC from the dystrophin gene was cloned using a lambda phage vector containing RNA polymerase promoters flanking the cloning sites. Phage containing human DNA inserts were then ordered into an overlapping set by hybridization of end-specific RNA probes from individual clones back to plaque lifts of gridded phage subclones. The clones generated will be useful as reagents for detailed structural and functional analyses of this region of the dystrophin gene.

Cloning, sequencing and expression of a cDNA encoding mammalian valyl-tRNA synthetase

A fragment of the cDNA encoding a rat valyl-tRNA synthetase (TrsVal)-like protein was cloned from a rat cDNA library in lambda gt11 using an oligodeoxyribonucleotide (oligo) probe. Three independent plaque clones containing the human TrsVal cDNA were then isolated from a lambda gt10 human erythroleukemia cDNA library using the rat cDNA fragment as the hybridization probe. Sequence analyses of the cDNA fragments provided a 3.2-kb sequence with an open reading frame that contained the 'HIGH' synthetase signature sequence and the tRNA 3'-end-binding motif, KMSKS, and putative Val-binding motif, EWCISRQ. The sequence was extended to the 3' end of the cDNA by the polymerase chain reaction using an internal primer and an oligo(dT) adapter. The deduced 1051-amino-acid sequence shares 65% identity with yeast TrsVal, and contains a highly basic N-terminal region, a newly evolved protease-sensitive region in sequence close to the C terminus, and several sites for protein kinase C phosphorylation. A 3-kb cDNA fragment was sub-cloned into plasmid pSVL and expressed in COS-7 cells; up to a sevenfold increase in TrsVal activity was obtained. These results confirm the cloning and sequencing of a human TrsVal-encoding cDNA.

Changes in social support and quality of life: a case study of a man with an enduring psychotic illness

The Government's White Paper on community care has drawn attention to the importance of assessing changes in a person's well-being which occur as a consequence of clinical and social interventions. In the UK the evaluation of the quality of life of people with chronic mental illness is relatively new. This case study demonstrates the use of the 'Lancashire Quality of Life Profile' in routine clinical practice with reference to residential changes in the 'care programme' of a person with a long history of a severely disabling psychotic illness. The formulation and review of his care plan were determined by a network of agencies involved in his long term care.

Treatment of acute lymphoblastic leukaemia (ALL)

Forty-six consecutive patients with acute lymphoblastic leukaemia (ALL), having a median age of 23 years (range 14 to 64), underwent induction and consolidation chemotherapy with weekly parenteral vincristine, adriamycin, l-asparaginase and daily oral prednisone (VAAP), followed by standard central nervous system (CNS) prophylaxis. Maintenance therapy was given for 3 years and consisted of daily 6-mercaptopurine, weekly methotrexate, and monthly intrathecal chemotherapy, with drug intensification comprising either vincristine, adriamycin and l-asparaginase (VAA) or cyclophosphamide, vincristine, cytosine arabinoside and prednisone (COAP). Complete remission (CR) was achieved in 36 patients (78%) and only the FAB L1 morphology was a significant predictive factor (Chi-squared = 3.91: p < 0.05). Eight of the 10 non-responders had significant drug resistance and 3 deaths were associated with marrow hypoplasia. Median follow-up is 52 months. Median duration of CR is 28 months, median survival of all patients is 16 months, and for those who achieved CR is 44 months. There was no difference between the two maintenance arms. Significant prognostic factors for survival are French-American-British (FAB) subtype, in which the L1 is better than L2 (p = 0.05), and age (p = 0.035). Nineteen patients have experienced medullary relapse and 7 (37%) achieved subsequent CR; this is durable in a single patient who underwent allogeneic bone marrow transplantation. Eight patients (17%) had CNS disease at diagnosis; 5 achieved CR and 1 is alive and disease-free at 65+ months. There has been 1 CNS relapse. These results demonstrate that prolonged remissions and survival can be achieved with this protocol and many patients possibly cured. The level of toxicity is acceptable and the pattern of induction failure indicates that a margin exists for intensifying chemotherapy and thereby possibly further improving results.

Splenectomy in the chronic myeloproliferative syndromes. A retrospective risk-versus-benefit analysis

The effect of splenectomy on the course of the chronic myeloproliferative syndromes was retrospectively analysed and compared in 96 patients who underwent this procedure and 195 who did not. The operation had a 4% mortality and a 47% morbidity rate, mainly attributable to haemorrhage, infection and respiratory complications. While splenectomy conferred benefit in certain selected cases with hypersplenism, there was no significant overall improvement in the postoperative haematological values and no influence on the rate of blastic transformation. Splenectomy did not improve survival in the group as a whole, or in any subset (P greater than 0.5). In the non-splenectomy group, only a minority of patients experienced massive progressive splenomegaly and in most individuals the spleen size varied little from the time of presentation to death. Splenectomy in patients with the chronic myeloproliferative syndrome carries a significant mortality and has a high morbidity, does not reduce the rate of blastic transformation and has no influence on survival. The majority of patients on conventional therapy do not experience the discomfort of massive splenomegaly during the course of their disease and the routine use of this operation is inappropriate.