Ultrastable Free-Space Laser Links for a Global Network of Optical Atomic Clocks.

A global network of optical atomic clocks will enable unprecedented measurement precision in fields including tests of fundamental physics, dark matter searches, geodesy, and navigation. Free-space laser links through the turbulent atmosphere are needed to fully exploit this global network, by enabling comparisons to airborne and spaceborne clocks. We demonstrate frequency transfer over a 2.4 km atmospheric link with turbulence comparable to that of a ground-to-space link, achieving a fractional frequency stability of 6.1×10^{-21} in 300 s of integration time. We also show that clock comparison between ground and low Earth orbit will be limited by the stability of the clocks themselves after only a few seconds of integration. This significantly advances the technologies needed to realize a global timescale network of optical atomic clocks.

Postanginal septicaemia (Lemmiere's disease) complicated by haemophagocytosis.

We report a case of postanginal septicaemia complicated by bronchopneumonia and haemophagocytosis in a 19-year old male, presenting with severe thrombocytopenia. We believe that this is the first reported case of thrombocytopenia due to haemophagocytosis in this unusual condition.

A pragmatist's approach to pathology costing: the Welsh Datatree project.

The Datatree costing project in Wales has provided the Welsh pathology laboratories with a standard costing package that allows pathologists to understand how their own laboratory's test costs are compiled. The software provides answers to the question "what if? ..." and shows instantly the effect of salary or consumable cost alterations. Resource management at a laboratory level is enhanced by a greater knowledge of costs, particularly in relation to volumes of work. Perhaps this is one of the stepping-stones across the river to the "open market." In the United Kingdom NHS any information of this kind must be regarded as invaluable.

Continuous intravenous infusion of high-dose recombinant interleukin-2 for acute myeloid leukaemia--a phase II study.

A group of 13 patients with acute myeloid leukaemia of differing disease status were treated with continuous intravenous infusion of high-dose recombinant interleukin-2 (rIL-2). There was up-regulation of the cellular cytotoxic functions in all these patients following the rIL-2 therapy, with increase in the natural killer (NK) activity, lectin-dependent cellular cytotoxicity, induction of cytotoxicity-linked cytoplasmic serine esterase and lymphocyte activation. However, the clinical response to rIL-2 in these patients was disappointing, especially in patients treated in frank relapse. Although 1 patient treated in early second relapse achieved a third complete remission, the duration of the remission was brief and lasted only 6 months. Adverse reactions among these patients were common. Whether or not lymphokine-activated killer cells are needed to improve the response rate over rIL-2 alone in these patients deserves further investigation.

Experiences with dual protein bound aqueous vitamin B12 absorption test in subjects with low serum vitamin B12 concentrations.

A dual isotope vitamin B12 absorption test in which vitamin B12 is given both in aqueous solution and bound to protein (chicken serum), was evaluated in 26 controls and 68 patients with subnormal serum vitamin B12 concentrations (19 with pernicious anaemia, 13 with iron deficiency, seven after partial gastrectomy, seven with malabsorptive states, five with folate deficiency, four with chronic alcoholism and 13 in whom no cause was apparent). In control patients protein bound absorption decreased with age; isotope excretion was 1.0% or over in those aged under 60 and 0.5% or over in those aged 60 and above. Malabsorption of protein bound vitamin B12 with normal aqueous absorption occurred in five patients with iron deficiency, three with alcoholism, two after partial gastrectomy, two with folate deficiency and in one with a malabsorptive state. In alcoholics abstinence produced an improvement in protein bound absorption. All patients in the group for whom no cause could be found for the subnormal serum vitamin B12 concentration had normal aqueous absorption but four had malabsorption of protein bound vitamin. Although the dual isotope test gave reproducible results and was consistent with the standard Schilling test some anomalies were detected; nine patients had reduced aqueous absorption with normal protein bound absorption. Despite this the dual test may prove useful in determining the importance of a subnormal vitamin B12 concentration where the cause is not clinically apparent. Further development is needed before it can be considered for routine use.

Hypomagnesaemia: an underdiagnosed interaction between gentamicin and cytotoxic chemotherapy for acute non-lymphoblastic leukaemia.

Hypomagnesaemia occurred in 6 of 11 leukaemic patients who received gentamicin. This problem has been reported relatively infrequently when gentamicin is used alone. Our hypomagnesaemic patients received concurrent courses of gentamicin with cytotoxic therapy significantly more often but it is not clear whether this represents a true drug interaction or an interaction between gentamicin and the products of cell lysis produced by cytotoxic treatment. The incidence of this problem has been underestimated previously because hypocalcaemia was used as an indicator. Renal wasting of magnesium is well documented as the mechanism by which the hypomagnesaemia is sustained but further investigation is required to see whether other factors are involved in its initiation.

Pleomorphic T-cell leukaemia in a Caucasian adult: clinical phenotypic and functional characteristics.

Pleomorphic T-cell leukaemia occurring in an adult Caucasian patient is described. The leukaemia cells expressed both antigenic determinants (T4 and T8) normally detected separately on either helper or suppressor cells. They functioned as helper cells and there was evidence of unbridled antibody production. It is possible that a distinctive subtype of pleomorphic T-cell leukaemia occurs in Caucasian patients.

C-reactive protein levels in neutropenic patients with pyrexia.

This study describes the experience of a clinical haematology unit in dealing with pyrexial episodes in 62 patients. Serum C-reactive protein levels were serially estimated and proved to be useful in following the course of the illness. No significant difference could be demonstrated in the C-reactive protein levels of those patients with bacteriologically proven illnesses, those in whom a clinically evident infection was present, and those with a 'pyrexia of unknown origin'. However, those patients in whom disease activity was thought to be responsible for the pyrexia had significantly lower C-reactive protein levels compared with those patients who had a septicaemic illness.

C-reactive protein concentration as a guide to antibiotic therapy in acute leukaemia.

Serial monitoring of the serum C-reactive protein (CRP) concentration was performed, using a one-hour laser-immunonephelometric assay, during 29 episodes of infection in 22 neutropenic patients with acute leukaemia. Serum CRP increased to above a diagnostic level of 100 mg/l in all 29 episodes and continued to rise progressively until appropriate antibiotics, or granulocytes, were given when it fell with a half-life of approximately three days. Serial study of the serum concentration was of value in detecting occult or unresolved bacterial infection and provided an objective means of monitoring the response to antibiotic and granulocyte therapy.

Ceftazidime--a new extended-spectrum cephalosporin.

65 patients with serious infections, including 25 with septicaemia, were treated with ceftazidime, a new extended-spectrum cephalosporin. 80% of the infection were cured by the antibiotic. 11 of 12 infected patients who had malignant disease or were otherwise immunocompromised responded satisfactorily to ceftazidime; 7 of these 12 had infections caused by Pseudomonas aeruginosa. The serum half-life of ceftazidime was 1.9 h in a patient with normal renal function. After a 1 g intravenous dose the antibiotic was present in pus, sputum, and bile in therapeutic concentrations. The antibiotics should prove a useful and non-toxic alternative to the aminoglycosides.

Cardiac involvement in secondary haemochromatosis: a catheter biopsy study and analysis of myocardium.

Although high blood transfusion regimens have improved the life expectancy of the patient with Thalassemia Major, cardiac failure and arrhythmias remain a cause of early death. It is not certain whether the massive myocardial iron deposition found in such patients is preventable by intensive chelation therapy. This study evaluates endomyocardial biopsy as a method of assessing myocardial iron deposition. Of four patients with clinical and biochemical evidence of severe haemochromatosis, only one had a myocardial iron content comparable to that found in severe haemochromatotic myocardium. The one patient with cardiac failure had an endomyocardial iron content within the normal range. Studies of the iron distribution in haemochromatotic myocardium demonstrate that the subendocardial myocardium contains only half the iron content of the subepicardial layer, and there is a large sampling variation. It is concluded that catheter endomyocardial biopsy is an insensitive method of determining early myocardial deposition because of the location of iron and the variability of the sampling. Studies of the nature of the myocardial iron protein with CM32 cation exchange resin chromatography show that there is a large increase in the haemosiderin: ferritin ratio (5:1) in iron overload myocardium as compared with the normal heart (2:1). Similar results have been observed in the liver with iron overload, where the increase in hepatic haemosiderin was associated with greater lysosomal fragility. It is possible that myocardial cell damage may also occur by the rupture of iron engorged lysosomes.