P-glycoprotein expression on acute myeloid leukaemia blast cells at diagnosis predicts response to chemotherapy and survival

P-glycoprotein (Pgp) expression, which is associated with the multi-drug resistance (MDR) phenotype, has been reported to be a useful predictor of treatment outcome in acute leukaemia. We have examined the expression of Pgp on acute myeloid leukaemia (AML) cells in 54 newly diagnosed patients, using a novel streptavidin-biotin complex (ABC) technique. 55% of patients at diagnosis were positive for Pgp with JSB-1, a monoclonal antibody that binds to an internal epitope of Pgp. All patients received intensive induction chemotherapy. Post-remission treatment consisted of further chemotherapy +/- bone marrow transplantation. Complete remission (CR) rates were significantly lower in the Pgp positive group than in the Pgp negative group (60% v 92%; P = 0.02). The overall survival for Pgp-positive patients was significantly shorter (329 v 534d, P = 0.004), disease-free survival was also reduced but the difference was not statistically significant (median 277 v 522d, P = 0.16). In this study CD34 expression was not predictive of response to chemotherapy nor was it associated with Pgp expression. Our results confirm the prognostic value of Pgp expression in AML at diagnosis and we suggest that Pgp could be a useful therapeutic target for reversing multi-drug resistance. Furthermore, our simple and sensitive method of detecting Pgp should enable widespread testing to be performed.

Flumecinol for the treatment of pruritus associated with primary biliary cirrhosis

OBJECTIVE

To determine whether flumecinol (3-trifluoromethyl-alpha-ethylbenzhydrol, Zixoryn) is effective in ameliorating pruritus of cholestasis, particularly in primary bilary cirrhosis.

METHODS AND RESULTS

50 patients (46 with primary biliary cirrhosis, PBC) took oral flumecinol 600 mg or identical placebo once weekly for 3 weeks. Patients assessed pruritus by scoring a daily 100 mm visual analogue scale (VAS; 0 = no itch, 100 = severe, continuous, day and night intolerable itch). Quality of life was similarly measured. Patients scored the VAS daily for a 7-day baseline and for a further 21 days. Subjectively, pruritus improved in 13 of 24 on flumecinol and 10 of 26 on placebo (chi 2 = 1.24, P = 0.27). Median difference in fall in VAS pruritus score between baseline week (mean score for each individual used) and the last week was 8.0 [95% confidence interval (CI) -2.1 to 20.8] and for VAS quality of life was 5.0 (95% Cl 0.4 to 13.0) both in favour of flumecinol over placebo. Later, 19 patients (all PBC) were randomised to flumecinol 300 mg or placebo daily for 3 weeks. Subjectively, pruritus improved in 7 of 10 on flumecinol and 1 of 9 on placebo (Fisher's exact test, P = 0.02). Median difference in fall in VAS pruritus score was 19.8 mm (95% CI 3.3 to 40.7 mm) in favour of flumecinol over placebo and for quality of life was 3.5 mm (95% Cl -5.9 to 24.9 mm). Flumecinol did not significantly affect liver function tests, antipyrine clearance or serum total bile acids, and was not associated with any significant side-effects.

CONCLUSION

Flumecinol was safe at the above doses and short term treatment with 300 mg daily, significantly ameliorated pruritus in primary biliary cirrhosis.

The development of functional ovarian cysts during pituitary down-regulation

This study investigated the development of functional ovarian cysts during pituitary down-regulation prior to in-vitro fertilization (IVF), and identified 16 cases of cysts in 288 IVF cycles studied. Comparing the patients with functional ovarian cysts to the other 272 IVF cycles, there was no significant difference in age or incidence of endometriosis but significantly (P < 0.01) more patients with cysts had ovulatory dysfunction. The serum progesterone was < 5.7 nmol/l in all 16 patients with cysts on day 4 of the IVF cycle, and in eight of these patients the serum progesterone was < 5.7 nmol/l on the day buserelin was commenced. In 10 of the 16 patients with cysts, serum oestradiol concentrations remained elevated despite the prolonged use of buserelin, and the cysts were aspirated. The aspirate in all cases was clear without any suggestion of endometriosis. The cyst aspirates had significantly lower progesterone (P < 0.001), higher androstenedione (P < 0.01) and similar oestradiol concentrations to 10 follicular fluid samples collected at the time of oocyte retrieval. This study suggests that functional ovarian cysts may develop during pituitary down-regulation, and these cysts are follicular cysts rather than persistent corpora lutea or endometriomata.

[Use of fluorine-19 nuclear resonance spectroscopy for the measurement of changes induced in blood perfusion volume in experimental tumors in vivo]

The biological response of some anti-cancer therapeutic agents is probably mediated via the tumour vasculature. A novel approach using 19F NMR spectroscopy in vivo has been developed to directly measure changes in vascular perfusion volume in experimental tumours. A 100% w/v perfluorooctylebromide (PFOB) emulsion was used as a tracer. For a fixed position of a 7 mm surface coil placed over the tumour, the signal from the PFOB rapidly reached an equilibrium value remaining unchanged for at least 2 hours. Since the strength of the fluorine signal is directly proportional to the perfusion volume of the tumour vasculature, reduction of signal intensity should correspond directly to any reduction in volume which may be a manifestation of a change in the tumour blood flow. This hypothesis was investigated using hydralazine as a physiological modifier of tumour blood flow. Administration of 5 mg/kg of hydralazine following dosing with the PFOB emulsion reduced the 19F signal intensity from the murine tumors RIF-1 and KHT and from the human tumour HT29 with no or little reduction in the SCCVII/Ha murine and HX118 human tumours. Changes in blood volume in KHT tumour accompanied local changes in tumour blood flow rate as measured by the Xe-133 clearance rate technique. Thus, these data demonstrate the potential of the PFOB emulsion as a 19F NMR tracer of the vasculature to measure changes induced by therapeutic agents on blood volume in accessible tumours. This method may also be useful to detect early changes in blood volume produced during angiogenesis of solid tumours or angiostatic activity of anti-cancer drugs.

Overnight urine growth hormone, cortisol and adenosine 3' 5' cyclic monophosphate excretion in children with chronic asthma treated with inhaled beclomethasone dipropionate

Overnight urine samples were obtained from 34 asthmatic children, 24 of whom were receiving inhaled beclomethasone dipropionate (BDP), and 30 controls. The urine volume of the children receiving inhaled steroids was significantly greater than that of the other asthmatic children and of the controls (P < 0.05). Urine growth hormone was within the normal range for all of the subjects and there was no demonstrable relationship between urine growth hormone and height or height standard deviation score. Urine steroid output was significantly reduced in the BDP receiving group when the results were expressed in U l-1 but there was no difference between the groups when the results were expressed per specimen. Urine adenosine 3' 5' cyclic monophosphate (cAMP) results were similar for all groups. We conclude that use of BDP increases overnight urine volume but, in our study, does not appear to influence the output of urine cortisol. Urine free cortisol measurements may not be a very sensitive tool for the detection of small changes in endogenous steroid production. The use of BDP does not adversely affect the output of urine growth hormone.

An economic appraisal of alternative pre-natal screening programmes for Down's syndrome

The objective of this study was to evaluate economically a screening programme within the Oxford Regional Health Authority for Down's syndrome, based on maternal serum alpha fetoprotein, unconjugated oestriol and human chorionic gonadotrophin as well as maternal age (the triple test) against maternal age alone. The design of the study involved cost-effectiveness analysis of the triple test relative to the maternal age screening programme, and the main outcome measure was the cost per Down's birth avoided. It was found that the triple test is more cost-effective over a wide range of assumptions concerning detection rates and procedure costs. Indirect costs are important in considering the cost-effectiveness of the screening programmes. The most efficient detection rate is around 58 per cent for which the cost per Down's birth avoided is approximately 29,600 pounds if only direct costs are evaluated, 20,100 pounds if all NHS costs are considered and -49,800 pounds if all resource consequences are analysed. It may be concluded that screening for Down's syndrome using the triple test is cost-effective over a wide range of assumptions concerning detection rate and procedure costs. If all resource costs are considered, the programme is highly cost-effective in comparison with other health care interventions.

Controversies in cross-infection control

The following article is intended to question certain procedures designed to prevent cross-infection. It is the first of a series of occasional articles describing new techniques, research, and new products, which it is hoped, may enable dental practitioners to update their knowledge of this rapidly changing subject.

A genetic map of chromosome 20q12-q13.1: multiple highly polymorphic microsatellite and RFLP markers linked to the maturity-onset diabetes of the young (MODY) locus

Multiple highly polymorphic markers have been used to construct a genetic map of the q12-q13.1 region of chromosome 20 and to map the location of the maturity-onset diabetes of the young (MODY) locus. The genetic map encompasses 23 cM and includes 11 loci with PIC values > .50, seven of which have PICs > .70. New dinucleotide repeat polymorphisms associated with the D20S17, PPGB, and ADA loci have been identified and mapped. The dinucleotide repeat polymorphisms have increased the PIC of the ADA locus to .89 and, with an additional RFLP at the D20S17 locus, the PIC of the D20S17 locus to .88. The order of the D20S17 and ADA loci determined genetically (cen-ADA-D20S17-qter) was confirmed by multicolor fluorescence in situ hybridization. The previously unmapped PPGB marker is closely linked to D20S17, with a two-point lod score of 50.53 at theta = .005. These markers and dinucleotide repeat markers associated with the D20S43, D20S46, D20S55, D20S75, and PLC1 loci and RFLPs at the D20S16, D20S17, D20S22, and D20S33 have been used to map the MODY locus on chromosome 20 to a 13-cM (sex averaged) interval encompassing ADA, D20S17, PPGB, D20S16, and D20S75 on the long arm of chromosome 20 and to create a genetic framework for additional genetic and physical mapping studies of the region. With these multiple highly polymorphic loci, any MODY family of appropriate size can be tested for the chromosome 20 linkage.

Dependency, quality and staffing of institutions for elderly people

There have been dramatic changes in residential and nursing care of elderly people in the community over the last decade. Despite this, little is known about how these institutions compare in terms of: the quality of care they provide to residents; the dependency of the residents; or the manpower levels and qualifications of the staff employed. This study was undertaken with the aim of comparing the public and private sectors providing care to elderly people. A random selection of institutions was invited to participate, including private residential and nursing homes, Social Services homes and National Health Services long-term care wards. The findings show that the dependency of residents in the public sector was greater than in the private sector, with more mentally confused, incontinent and socially disengaged residents in the public sector. The staff to resident ratio in public institutions did not differ significantly from the private sector. Overall scores of quality of care were similar. Nevertheless, these scores masked important differences between the sectors, eg poorer buildings and facilities characterised the National Health Service units. Fewer activities and therapies, but a better ambience, was noted in the private nursing homes. These results suggest that the outcome of a policy to transfer the most heavily dependent patients from the care of the public sector could increasingly burden the private sector. This would result increase the proportion of highly dependent residents, with no clear provision for improved staff ratios, quality of care or training of staff.

The association of age with the activity of alcohol dehydrogenase in human liver

Ethanol is principally oxidized in the liver by the cytosolic enzyme alcohol dehydrogenase (ADH). We have examined the effect of age and sex on alcohol dehydrogenase activities in human liver obtained from 16 healthy subjects, age range 45-88 years. There was no correlation between ADH activity, whether expressed as activity per mg cytosolic protein or per gram wet weight liver, and age. Activities were similar in men and women. These results suggest that, in common with activities of other hepatic drug metabolizing enzymes, age has no effect upon the activity of ADH in human liver.

Expression of CD7 on normal human myeloid progenitors

Existence of biphenotypic leukemias co-expressing CD7 and CD34 has prompted the question of whether a similar population of cells is present in normal human bone marrow. As CD7 is considered to be a T cell-restricted Ag, the co-expression of CD7 with the "human stem cell Ag" CD34 may identify a bipotent stage within hemopoietic differentiation. Cells with this phenotype have previously been isolated from human thymus. In this report we provide evidence that human marrow mononuclear cells also contain a minor subpopulation of cells co-expressing CD7 and CD34. The CD7+/CD34+ cells were found to contain committed myeloid progenitors assayed both as CFU in semi-solid media and by their ability to produce granulocytes in long term marrow cultures. Expression of CD7 on myeloid committed progenitors was further confirmed in a C-mediated cytotoxic assay. We conclude that CD7 expression is not restricted to T cells but is also expressed during early stages of myeloid differentiation.

Expression of CD7 on normal human myeloid progenitors

Existence of biphenotypic leukemias co-expressing CD7 and CD34 has prompted the question of whether a similar population of cells is present in normal human bone marrow. As CD7 is considered to be a T cell-restricted Ag, the co-expression of CD7 with the "human stem cell Ag" CD34 may identify a bipotent stage within hemopoietic differentiation. Cells with this phenotype have previously been isolated from human thymus. In this report we provide evidence that human marrow mononuclear cells also contain a minor subpopulation of cells co-expressing CD7 and CD34. The CD7+/CD34+ cells were found to contain committed myeloid progenitors assayed both as CFU in semi-solid media and by their ability to produce granulocytes in long term marrow cultures. Expression of CD7 on myeloid committed progenitors was further confirmed in a C-mediated cytotoxic assay. We conclude that CD7 expression is not restricted to T cells but is also expressed during early stages of myeloid differentiation.

Effects of agents which inhibit the regulation of intracellular pH on murine solid tumours

Cell killing can be achieved in an acidic environment in tissue culture (medium pH less than 7.0) by agents (nigericin, carbonylcyanide-3-chlorophenylhydrazone (CCCP)) which transport protons from the extracellular space into the cytoplasm. Cell killing is enhanced when these agents are used in combination with compounds (amiloride, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS)) which inhibit the membrane-based exchangers responsible for the regulation of intracellular pH (pHi). We describe experiments which assess the ability of these agents to kill tumour cells in spheroids and in vivo. Both nigericin and CCCP were observed to penetrate tissue based on their ability to kill tumour cells in spheroids. The mean extracellular pH (pHe) of the KHT fibrosarcoma and the EMT-6 sarcoma were observed to be 0.21 and 0.32 pH units more acidic than the mean pHe in muscle tissue. Intraperitoneal (i.p.) administration of the vasodilator hydralazine (10 mg kg-1) caused a reduction of the mean pHe of the KHT but not the EMT-6 tumour. Nigericin (2.5 mg kg-1, i.p.) plus amiloride (10 mg kg-1, i.p.) followed 30 min later by hydralazine (10 mg kg-1, i.p.) reduced the surviving fraction of cells in the KHT and EMT-6 tumours, but had minimal effects on growth delay. When KHT tumours were treated with 15 Gy X-rays followed immediately by nigericin plus amiloride and hydralazine a reduced surviving fraction as well as an increase in tumour growth delay was observed compared to radiation alone. The administration of nigericin (2.5 mg kg-1, i.p.) or the combination of nigericin (2.5 mg kg-1, i.p.) followed by hydralazine (10 mg kg-1, intravenous (i.v.)) resulted in reductions of tumour pHi of 0.27 and 0.29 pH units respectively as determined by 31P magnetic resonance spectroscopy (MRS). Our results show that the combination of nigericin and hydralazine (with or without amiloride) can kill cells in rodent solid tumours and that cell killing is associated with a reduction in the mean pHi of tumour cells.

The detrimental influence of functional ovarian cysts during in-vitro fertilization cycles

Reviewing 780 in-vitro fertilization (IVF) cycles, where buserelin was commenced in the preceding luteal phase and human menopausal gonadotrophin on day 4 of the ensuing menses, 53 cycles were identified with sonolucent cysts (30-50 mm diameter). Of the latter 53 cycles, the serum oestradiol was significantly greater on day 4 in 22 cycles abandoned for poor follicular development than in 31 cycles which proceeded to oocyte retrieval (P less than 0.05). Of the 31 cycles proceeding to oocyte retrieval, nine had a day 4 serum oestradiol greater than 200 pmol/l (95th centile for day 4 oestradiol in patients without apparent cysts), and these cycles produced significantly fewer grade 1 embryos than the cycles with day 4 oestradiol levels less than or equal to 200 pmol/l (P less than 0.05). Six of the 53 cycles with cysts resulted in conception, and all of these cycles had a day 4 serum oestradiol less than 200 pmol/l. Among the 53 cycles with ovarian cysts, the serum progesterone on the day of abandonment in four cycles and on the day of human chorionic gonadotrophin administration in one non-abandoned cycle, was above the range established for 104 cycles without cysts. No significant difference was seen in day 4 serum androstenedione levels, and the day 4 serum progesterone was less than 5 nmol/l in all but one patient. Functional activity of ovarian cysts is associated with an adverse influence on IVF cycles.

Use of fluorine-19 nuclear magnetic resonance spectroscopy and hydralazine for measuring dynamic changes in blood perfusion volume in tumors in mice

BACKGROUND

One method of evaluating the mechanism of action of agents which alter tumor oxygenation is to determine their effects on tumor blood flow.

PURPOSE

This study tests applicability of a new approach using an emulsion of the inert fluorocarbon perfluorooctylbromide (PFOB) at nontoxic doses as a tracer in fluorine-19 (19F) nuclear magnetic resonance (NMR) spectroscopy to evaluate dynamic changes in vascular perfusion volume in transplanted tumors.

METHODS

The PFOB emulsion (100% wt/vol) was injected into the tail vein in tumor-bearing C3H/He or nu/nu mice immobilized in a magnet interfaced to a spectrometer, either as a single bolus injection of 8 mL/kg body weight or in multiple injections to a total dose of 24 mL/kg. A 7-mm external surface coil was placed over the tumor. Signal from the PFOB in the tumor volume seen by the coil rapidly reached equilibrium and was maintained for at least 2 hours, and multiple doses of PFOB emulsion resulted in a linear increase in 19F signal strength. Since the 19F signal strength was directly proportional to the perfusion volume of the tumor vasculature, reduction of signal intensity should correspond directly to any reduction in volume caused by a change in the tumor blood flow. To investigate this hypothesis, the vasoactive agent hydralazine (5 mg/kg) was injected intravenously after administering the PFOB emulsion to induce changes in tumor blood supply. KHT and RIF-1 murine sarcomas, the HT29 human colon carcinoma, and the HX118 human melanoma tumors were studied. In a comparative analysis of changes in blood flow induced by hydralazine, we studied Xe-133 clearance in KHT murine sarcoma and SCCVII/Ha (SCCVII) murine squamous cell carcinoma.

RESULTS

Hydralazine significantly reduced the 19F signal intensity in the murine tumors RIF-1 and KHT and in the HT29 human tumor, with little reduction in the SCCVII/Ha murine and HX118 human tumors. Hydralazine induced a statistically significant 64% decrease in mean clearance rate in the KHT tumor, while SCCVII/Ha tumors showed no significant change, indicating that hydralazine restricted blood flow to a greater extent in the tumor type that showed reduced 19F signal from the PFOB emulsion.

CONCLUSION

These data demonstrate the potential of PFOB emulsion as a tracer in NMR spectroscopy for studying tumor vasculature.

Generation and Objective Rotation of Generalized Learning Curves Using Matrix Language Products

Two SAS macros are presented which perform Tucker's (1966) modified principal components approach to modeling generalized learning curves analysis up to a rotation of the components. The problem of rotation to a psychologically meaningful solution is considered. For example, when analyzing learning data, one may wish to rotate the components to satisfy Tucker's criteria for learning curves. For the modeling of other kinds of change, different rotational criteria may be appropriate. Graphical or hand rotation is often difficult for researchers. By using matrix manipulation languages currently available, it is possible for a researcher to develop a small number of candidate rotated solutions. Three SAS macros are described which determine whether dimensions should be reflected or rotated, perform objective rotations of the factor pattern matrix in line with Tucker's desiderata, and generate corresponding factor scores.