Haemoglobin Pierre-Benite--a high affinity variant associated with relative polycythaemia.

This is the second reported example of Hb Pierre--Benite (beta90 Glu-->Asp). This mutation is associated with increased oxygen affinity and polycythaemia. No instability was found and there was no charge shift detected by cellulose acetate electrophoresis at pH 8.3. The mutation was however, clearly indicated by electrospray ionization mass spectrometry (ESI MS), which showed an abnormal beta chain with a 14 Da decrease in mass. Blood volume studies documented a relative rather than a true polycythaemia and this finding has been reported in at least two other high affinity haemoglobin variants--Hb Heathrow and Hb Rahere. This finding led to delay in diagnosis because high oxygen affinity variants are conventionally considered to cause a true polycythaemia.

Methanol poisoning.

AIMS: This study examines clinical experience with methanol poisoning during a one-year period. METHODS: All admissions with the diagnosis of suspected methanol toxicity were analysed and the current guidelines for the management of this problem were reviewed. RESULTS: Twenty-four subjects were identified. Most had a history of chronic use of methylated spirits. Four died before admission to hospital and the other 20 patients had 26 admissions to hospital and form the basis for this report. Four patients died in the Intensive Care Unit. In total 11 patients were admitted to the Intensive Care Unit. Seven patients received haemodialysis. There was no correlation between the methanol level and the outcome. The strongest predictor of death or a poor outcome was a blood pH < 7.0. Some patients, in spite of potentially lethal methanol levels of up to 160 mmol/L, did not develop signs of toxicity. CONCLUSIONS: The overall mortality was high and ethanol was given to most of the patients for up to several days. Some patients did not show any toxicity and some of those were not given ethanol. It is recommended that chronic meths drinkers, who are not acidaemic and are generally well, do not require ethanol treatment. Only the complete removal of methanol from methylated spirits will reduce the morbidity of this condition.

Cerebrovascular disease as a general medicine discharge diagnosis: assessment of diagnostic agreement on case note review.

BACKGROUND: Accurate clerical coding of discharge diagnoses is important partly because results may be used to derive a recommended costing for hospital length of stays (LOS). Some authors think that discharge coding undertaken by clinicians will result in less diagnostic misclassification than clerical coding. This presupposes a high degree of between-observer diagnostic agreement between clinicians. AIMS: To compare discharge coding undertaken by two general physicians, for patients receiving a clerical discharge code of cerebrovascular disease. The recommended LOS was then calculated from each observer's discharge codes using the Physicians Diagnosis Related Group Working Guidebook. RESULTS: Eighty-two cases were coded as stroke by the clerical coder. Both medical coders agreed with this diagnosis in 68 (83%) of these cases. The corresponding figure for cases coded by the clerical coder as transient cerebral ischaemia was 47% (32/68) agreement between all three observers. Correcting for chance agreement between medical observers using the kappa statistic, a value of 0.64 was obtained for the combined stroke and transient cerebral ischaemia discharges, suggesting moderate diagnostic agreement. Using the clerical coder's results, the mean recommended LOS for all cases of cerebrovascular disease over the study period was calculated at 6.68 days. The corresponding values for the two medical coders were 6.68 days and 6.75 days. CONCLUSIONS: Diagnostic agreement between clinicians was moderate. Consideration of alternative diagnostic possibilities and the difficulty in determining the duration of neurological deficit were the main reasons for diagnostic disagreement. The mean recommended LOS was similar, however, when comparing results from all three observers.

Invasive aspergillosis in severely neutropenic patients over 18 years: impact of intranasal amphotericin B and HEPA filtration.

The impact of intranasal amphotericin B and high-efficiency particulate air (HEPA) filtration on the incidence of invasive aspergillosis was reviewed in patients from 1977 to 1994 undergoing intensive chemotherapy. Overall, the incidence of proven invasive aspergillosis was reduced from 24.4% (1977-1984) to 7.1% (1985-1991) (P < 0.001) following the introduction of intranasal prophylaxis, but when probable cases of aspergillosis were included and lymphoma cases excluded, there was no change in incidence. Following the introduction of HEPA filtration, patient exposure to aspergillus spores as measured by air sampling was markedly reduced and there were no new cases of invasive aspergillosis. HEPA filtration proved effective in reducing invasive aspergillosis and has allowed increasingly aggressive treatment regimens to be introduced.

Usefulness of D-dimer, blood gas, and respiratory rate measurements for excluding pulmonary embolism.

BACKGROUND: A study was undertaken to assess the usefulness of the SimpliRED D-dimer test, arterial oxygen tension, and respiratory rate measurement for excluding pulmonary embolism (PE) and venous thromboembolism (VTE). METHODS: Lung scans were performed in 517 consecutive medical inpatients with suspected acute PE over a one year period. Predetermined end points for objectively diagnosed PE in order of precedence were (1) a post mortem diagnosis, (2) a positive pulmonary angiogram, (3) a high probability ventilation perfusion lung scan when the pretest probability was also high, and (4) the unanimous opinion of an adjudication committee. Deep vein thrombosis (DVT) was diagnosed by standard ultrasound and venography. RESULTS: A total of 40 cases of PE and 37 cases of DVT were objectively diagnosed. The predictive value of a negative SimpliRED test for excluding objectively diagnosed PE was 0.99 (error rate 2/249), that of PaO2 of > or = 80 mm Hg (10.7 kPa) was 0.97 (error rate 5/160), and that of a respiratory rate of < or = 20/min was 0.95 (error rate 14/308). The best combination of findings for excluding PE was a negative SimpliRED test and PaO2 > or = 80 mm Hg, which gave a predictive value of 1.0 (error rate 0/93). The predictive value of a negative SimpliRED test for excluding VTE was 0.98 (error rate 5/249). CONCLUSIONS: All three of these observations are helpful in excluding PE. When any two parameters were normal, PE was very unlikely. In patients with a negative SimpliRED test and PaO2 of > or = 80 mm Hg a lung scan is usually unnecessary. Application of this approach for triage in the preliminary assessment of suspected PE could lead to a reduced rate of false positive diagnoses and considerable resource savings.

An audit of the assessment and management of adults admitted to Christchurch Hospital with community acquired pneumonia.

AIMS: To audit the management of adult patients admitted with community acquired pneumonia including the standards of clinical assessment, use of modified British Thoracic Society prognostic criteria and antibiotic therapy. METHODS: A prospective, 16 week, study of consecutive patients admitted to Christchurch Hospital with community acquired pneumonia. RESULTS: Ninety-six patients met the inclusion criteria. The median age was 70 years. A pathogen was identified in 28 (26%) patients. Forty two patients fulfilled the modified British Thoracic Society criteria for severe disease and all 9 deaths occurred in that subgroup. The management guidelines were followed without exception in only 15% of cases. Documentation of the prognostic criteria was often incomplete and therefore only 33% of those patients with severe disease were correctly identified. Seventy one percent of those with severe disease were treated with only one antibiotic and there was significant delay in administering the first dose in 44% of cases. A follow up chest radiograph was performed in 43 (51%) of those discharged. CONCLUSIONS: There was poor compliance with the management guidelines. There was a lack of awareness of the severity criteria leading to inadequate treatment in many cases. Further educational initiatives are indicated.

Asthma management at Christchurch Hospital: compliance with guidelines.

AIM: To audit compliance with guidelines for the assessment and management of adult patients admitted to Christchurch Hospital with acute asthma. METHODS: An asthma admission form and management guidelines, based on international consensus statements, were designed for use by resident staff at Christchurch Hospital. Compliance with these guidelines was audited during the winter of 1994 by means of retrospective case record review. RESULTS: One hundred and forty three admissions were screened. The form was used in 99 patients (69%), of which 97 had records available for audit. Sixty two patients were admitted under general medical services and 35 under respiratory specialist services. The median age was 34 years (range 14-84) and 77% were female. The history including interval status was adequately documented in over 95% of cases. Peak flow rate was recorded on admission in 93 patients (96%) and spirometry in 62 (64%). During the acute phase of treatment 528 items were prescribed, of which 382 (72%) were appropriate according to the guidelines. The major area (55%) of nonguideline prescribing was the use of nebulised ipratropium in addition to salbutamol for mild or moderate asthma. Written evidence of asthma education was present in 42 (43%). In 34 patients (35%) there was specific reference to the introduction of an asthma action plan. Of the 33 smokers only 17 appeared to have been given smoking cessation advice. Discharge prescribing complied with the guidelines in 71%. The most common variation from the guidelines for discharge therapy related to the manner of prednisone dose reduction. The readmission rate at 1 month was 11%. CONCLUSIONS: The introduction of an asthma admission form enhanced the quality of clinical data gathering by junior staff. Compliance with management guidelines was adequate. Specific sections pertaining to the use of chest radiographs, arterial blood gases and the prescribing of ipratropium and prednisone will be reviewed in updated guidelines.

Acute adrenal insufficiency: a new presentation of Castleman's disease.

We report the case of a 35-year-old patient who presented with acute adrenal insufficiency, then developed fever, hypoalbuminuria, anasarca, thrombocytopaenia and anaemia. Lymphadenopathy appeared later with microscopic features typical of Castleman's disease. Clinical remission followed treatment with intravenous immunoglobulin. Circulating interleukin-6 levels were elevated initially but were normal after immunoglobulin therapy. We surmise that high circulating levels of interleukin-6 (and ACTH) may have induced haemorrhagic necrosis of the adrenal glands and accounted for the constitutional symptoms.

Oligoclonal B-cell leukemia characterized by spontaneous cell division and telomere association.

Cytogenetic analysis of unstimulated cultures from a female patient with chronic B-cell leukemia (CLL) revealed three cytogenetically distinct clones, suggesting that the patient's leukemia was oligoclonal. Immunoglobulin heavy chain gene rearrangement studies revealed 1 germline and 4 rearranged bands, indicative of an oligoclonal leukemic population. Further evidence of oligoclonality was provided by X-linked RFLP studies. This is the first report of oligoclonality in CLL demonstrated by cytogenetic, immunoglobulin gene rearrangement, and X-chromosome inactivation studies. In addition to oligoclonality, the patient's leukemic cells exhibited telomere association, a Robertsonian translocation, and clonal evolution, suggesting an underlying genomic instability.

Identification of potent mixed leukocyte reaction-stimulatory cells in human bone marrow. Putative differentiation stage of human blood dendritic cells.

Dendritic cells (DC) have been isolated from blood, lymphoid tissue, and other tissues, as potential members of a hemopoietic lineage of specialist APC for naive T lymphocyte activation. To define human bone marrow (BM) DC we have attempted to identify allostimulatory cells with DC-like characteristics among human BM mononuclear cells (BMMC) by FACS cell sorting and immunophenotyping, monitoring the APC function of different cell lineages in the human primary MLR. We show that fresh human BM stimulates allogeneic T lymphocytes with an activity equal to or greater than that of peripheral blood. As with DC from other tissue sources, the most potent stimulatory activity was found in the low density BMMC, and these cells, like peripheral blood, stimulated a maximal allogeneic MLR response at days 5 to 6. FACS purification of the allostimulatory population in fresh human BMMC was undertaken by using a wide range of mAb directed against lineage-associated molecules of mature and immature lymphoid, erythroid, and myeloid cells. The most potent constitutive BMMC stimulatory activity was located in the CD3-, CD11b-, CD14-, CD15-, CD16-, CD19-, CD57-, and glycophorin A- population. A mixture of antibodies to these Ag was used to isolate a "mix-negative" BMMC population, which contained the most highly potent MLR-stimulatory cells. Further cytologic and immunophenotypic analysis of this population revealed an enriched population of HLA-DP+, HLA-DQ+, HLA-DR+, and CD45+ cells, with morphologic similarities to the human tonsil and blood DC. These cells were CD4- and CD1a- and were weakly CD33+ (but CD15-), suggesting a possible early myeloid origin distinct from both the committed granulocytic and monocytic lineages. In addition, they lacked both CD10 and CD20, making a lymphoid origin unlikely. Further identification of these putative DC precursors will allow analysis of the early phases of DC hemopoiesis, whereas the characterization of the MLR-stimulatory cells in human BM will be of major importance in the understanding of BM transplant failure and graft-vs-host disease.

Geographical distribution of acute lymphoblastic leukaemia subtypes: second report of the collaborative group study.

Childhood acute lymphoblastic leukemia (ALL) T and B precursor subtypes have been identified by standardised immunophenotyping in different geographic and ethnic settings. Comparison of the relative frequencies and estimated incidence rates of the major subtypes indicates very similar values, with the striking exception of black childhood populations in Africa in which there appears to be a significant and selective deficit in the incidence of the common (B-cell precursor) subset of ALL. There is suggestive evidence for a similar bias in ALL subtypes in South Africans of mixed ethnic origin and in Mapuche Indians from Chile. Several interpretations of these data are possible but the one favoured attributes these differences primarily to socio-economic factors and patterns of infection in infancy.

Isolation and characterization of periaxolemmal and axolemmal enriched membrane fractions from the rat central nervous system.

In this report, we describe the fractionation of crude axolemmal fractions from rat lower brainstem into subfractions enriched in markers for either periaxolemmal myelin or axolemma. These subfractions were isolated on density gradients as bands layering on 0.8M and 1.0M sucrose. Both subfractions consisted of unilamellar vesicles. Relative to myelin purified from the same starting material, the 0.8M subfraction was enriched in MAG, CNPase, carbonic anhydrase and Na+, K+ ATPase but was extremely low in PLP and MBP. In addition, this fraction exhibited a protein profile distinct from myelin. The 1.0M fraction was also highly enriched in Na+, K+ ATPase and had an overall composition similar to the 0.8M subfraction. However, it differed from the 0.8M subfraction by being low in MAG, CNPase, and carbonic anhydrase, but enriched in voltage-dependent Na+ channel, axon-specific fodrin, and MAP-1B. Based on these characteristics we concluded that the 0.8M and 1.0M subfractions were highly enriched in periaxolemmal myelin and axolemmal membrane, respectively. Plasmolipin10 was unique with equally high levels in myelin and in the 0.8M and 1.0M subfractions. Both subfractions were enriched, relative to myelin, in the alpha subunit of the GTP binding protein, Go, and the alpha subunit common to all G proteins, GA/1. Electrophysiology with membrane subfractions fused to lipid bilayers showed that both membranes contained sets of K+ and Cl- channels, which based on channel sizes and open times, are largely distinct from one another.

Identification of plasmolipin as a major constituent of white matter clathrin-coated vesicles.

We have isolated and characterized coated vesicles from bovine white matter and compared them to those isolated from gray matter. The virtual absence of synaptic vesicle antigens in the white matter coated vesicles indicates they are distinct from those found in gray matter and from vesicles derived from synaptic membranes. The white matter coated vesicles also lack compact myelin components, e.g., the myelin proteolipid, galactocerebroside, and sulfatides, as well as the periaxolemmal myelin marker myelin-associated glycoprotein. On the other hand, these vesicles contain 2',3'-cyclic nucleotide phosphohydrolase. The vesicles also contain high levels of plasmolipin, a protein present in myelin and oligodendrocytes. Plasmolipin was found to be four to five times higher in white matter coated vesicles than in gray matter coated vesicles. Based on western blot quantitation, the concentration of plasmolipin in white matter coated vesicles is 3-4% of the vesicle bilayer protein. These studies indicate that a significant proportion of coated vesicles from white matter may be derived from unique membrane domains of the myelin complex or oligodendroglial membrane, which are enriched in plasmolipin.

Epstein-Barr viral DNA in acute large granular lymphocyte (natural killer) leukemic cells.

Serologic studies in a male Caucasian presenting with an acute hepatitis-like illness, associated with an increase in peripheral blood large granular lymphocytes (LGLs), suggested a chronic or reactived Epstein-Barr virus (EBV) infection. The LGL were shown to have a natural killer (NK) cell, CD3- CD16- CD56+ CD57- phenotype and mediated strong nonspecific major histocompatability complex-unrestricted (NK) cytotoxic activity. A progressive increase in the peripheral blood LGL count was associated with a rapid deterioration, hepatic necrosis, and death. Widespread organ infiltration with LGLs suggested a malignant lymphoproliferative condition, but no lymphoid (T-cell receptor or IgH) gene rearrangement or cytogenetic marker was detected. However, molecular analysis identified EBV genomic DNA present in a single episomal form within the LGL, establishing the clonal nature of the LGL proliferation. Confirmation that the EBV had infected the leukemic LGL was obtained by in situ hybridization studies that showed EBV RNA within the LGLs. Immunoblotting of LGL protein extracts established that, of the EBV gene products, EBV nuclear antigen-1 (EBNA-1) was expressed but EBNA-2 and the latent membrane protein (LMP-1) were not detectable in the leukemic cells. These results suggest that EBV may be involved directly in LGL cell transformation, in a manner similar to EBV-associated B-cell lymphomas, although other molecular changes probably contribute to the evolution of a fully malignant leukemic clone.

A community study of vitamin B12 and folate levels in the elderly.

OBJECTIVE: To measure the prevalence of low serum vitamin B12, folate, and red cell folate levels and their relationship with other nutritional indices. DESIGN: Prospective survey of elderly subjects using radioisotope dilution assays. SETTING: Primary care medical center, Christchurch, New Zealand. PATIENTS: 257 elderly subjects (age 65 years and over), residing in their own homes or in residential homes, were randomly selected. Of these, 204 (79%) participated. The study population was comparable to the elderly population of New Zealand. MAIN OUTCOME MEASURES: Vitamin B12, serum, and red cell folate levels. RESULTS: The prevalence rates for low levels of serum vitamin B12, folate, and red cell folate were 7.3%, 1%, and 3.3%, respectively. The elderly cohort had lower vitamin B12 (P less than 0.001) but higher serum and red cell folate levels (P less than 0.001) than our normal reference range (age 18-65 years). Red blood cell folate levels showed positive correlations with nutritional indices and mental test scores. No correlations were found between vitamin B12 levels and diet or other nutritional indices. CONCLUSIONS: Low folate levels in older people living at home are infrequent findings. In contrast low vitamin B12 levels are more common. Poor diet and undernutrition may contribute to low folate levels, but these factors are less important for the low B12 levels found.

Aplastic anaemia in Christchurch Hospital 1979-89.

We have reviewed the records of all patients referred to our departments with aplastic anaemia during the 11 years from 1979 to 1989. Of the 22 patients identified, 19 fulfilled the standard criteria for severe aplastic anaemia. There were 11 females and 11 males. Their mean age was 35 (range 2-85 years). Five cases followed exposure to drugs known to cause aplastic anaemia and one had a recent history of viral hepatitis. A variety of treatments were used. Four patients received an allogeneic bone marrow transplant (BMT) from matched sibling donors and two of these were alive and well 65 and 120 months post BMT. Antithymocyte globulin (ATG) treatment has been followed by lasting complete remission in two of the six patients treated and a partial response was seen in one other patient. Cyclosporin therapy was associated with unmaintained complete remission in one of the three patients given this drug after ATG had failed. The remaining 13 patients received only supportive care with or without androgens and six (46%) had early recovery of bone marrow function with lasting complete remission. These patients illustrate some of the therapeutic options available for aplastic anaemia.

The costs and benefits of bone marrow transplantation.

The average direct costs of performing a bone marrow transplant (BMT), including the subsequent year, was found to be NZ$27,074 for 43 consecutive transplants. In 29 BMTs a full two year period of follow up was available and a quality of life analysis was carried out on these patients. It was calculated that 59 quality adjusted life years (QALYs) had been gained by the BMT procedure at the time of analysis. By combining these two analyses the cost of each QALY gained by BMT is NZ$13,272. The relatively low cost of BMT is partly due to the extremely low annual costs in second and subsequent years post BMT. In our patients this cost amounted to $195 per year. The costs and benefits of BMT compare very favourably with other complex medical procedures.