Genetic polymorphism in the human UGT1A6 (planar phenol) UDP-glucuronosyltransferase: pharmacological implications

Two missense mutations were uncovered in the UGT1A6 (HLUG P1) cDNA which codes for a human phenol-metabolizing UDP-glucuronosyltransferase. The mutant and a wild-type UGT1A6 cDNAs were isolated from a custom synthesized human liver lambda Zap cDNA library. Both an A to G transition at nucleotide 541 (T181 A) and an A to C transversion at nucleotide 552 (R184S) occurred in exon 1 of the UGT1A6 (UGT1F) gene at the UGT1 locus. The two mutations on a single allele created a heterozygous genotype. Newly created BsmI and BsoFI sites at the T181 A and R184S locations, respectively, were confirmed by endonuclease treatment of PCR-generated DNA using the donor-liver genomic DNA as template. Screens with endonuclease treatment showed that 33/98 DNA samples were heterozygous with both mutations on one allele. One other individual also carried the R184S mutation on the second allele. Wild-type UGT1A6 generated a broad plateau of activity from pH 5.0 to pH 8.0 with certain experimental phenols, while activity was 1.3-2.5-fold higher at pH 6.4 than at pH 7.2 for others. UGT1A6*2 (181 A+ and 184S+) metabolized 4-nitrophenol, 4-tert-butylphenol, 3-ethylphenol/4-ethylphenol, 4-hydroxycoumarin, butylated hydroxy anisole and butylated hydroxy toluene, with the pH 6.4 preference, at only 27-75% of the rate of the wild-type isozyme whereas 1-naphthol, 3-iodophenol, 7-hydroxycoumarin, and 7-hydroxy-4-methylcoumarin were metabolized at essentially the normal level. Furthermore, UGT1A6*2 metabolized 3-O-methyl-dopa and methyl salicylate at 41-74% of that of the wild-type, and a series of beta-blockers at 28-69% of the normal level. This evidence suggests that the UGT1A6 enzyme activity is affected by different amino acids depending upon the substrate selection.

No effect of timing of biopsy in the menstrual cycle on incidence of bone marrow micrometastasis in patients with breast cancer

BACKGROUND

The timing of breast cancer excision relative to the menstrual cycle has been debated to be of significant prognostic value. The differences in survival relative to the timing in the menstrual cycle have been attributed to the incidence of micrometastasis.

METHODS

All patients underwent bone marrow aspiration after the diagnostic surgical biopsy, immediately before definitive surgery. The timing of the diagnostic surgical biopsy in the menstrual cycle was calculated according to Senie. Monoclonal antibodies to epithelium-specific antigens were used to detect bone marrow micrometastasis (BMM).

RESULTS

This study reports on the effect of the phase of the menstrual cycle on incidence of BMM after surgical biopsy. Ninety-two patients with regular cycles underwent bone marrow aspiration an average of 12 days (range 0-32 days) after biopsy. Thirty-nine patients had undergone biopsy during the follicular phase and 53 patients during the luteal phase. BMM were detected in 31% of patients (29 of 92). We observed BMM in 33% of patients (13 of 39) in the follicular phase and in 30% of patients (16 of 53) in the luteal phase. This difference is not significant (p > 0.70). The mean number of cells detected and the presence of clumps of cells is similar in the two groups.

CONCLUSIONS

The incidence and characteristics of bone marrow micrometastases are independent of the timing of diagnostic excision biopsy in the menstrual cycle.

Activated protein C resistance in a neonate with venous thrombosis

A term infant had a life-threatening inferior venal caval thrombosis during the first 24 hours of life. The plasma from the infant and his mother was found to be resistant to activated protein C and to be heterozygous for the factor V mutation (FV Leiden) associated with this disorder. The presence of this hereditary disorder should be considered in infants with thrombosis and in infants with conditions predisposing them to thrombosis.

Cytokine response to respiratory syncytial virus stimulation of human peripheral blood mononuclear cells

A key impediment to developing respiratory syncytial virus (RSV) vaccines is a lack of understanding of enhanced disease that occurred in children who received a formalin-inactivated RSV (FI-RSV) vaccine. Studies in mice have suggested that the FI-RSV vaccine induces a TH2 and live RSV induces a TH1 memory T cell response. In this study, the cytokine mRNA response of peripheral blood mononuclear cells (PBMC) from adults and children with and without previous RSV infection was characterized using a semiquantitative polymerase chain reaction (PCR). PBMC from 22 subjects previously infected with RSV usually had RSV-specific increases in TH1 cytokine-specific mRNA (interferon-gamma [IFN-gamma] mRNA, 20; interleukin [IL]-2 mRNA, 12; IL-5 mRNA, 6; and IL-4 mRNA, 0). PBMC from RSV antibody-negative children had no RSV-specific increases in IFN-gamma, IL-2, or IL-4 mRNA; 1 of 7 had an increase in IL-5 mRNA. These data indicate that naturally acquired RSV induces a TH1 memory T cell response.

Sedation with meperidine and midazolam in pediatric patients undergoing endoscopy

We conducted a randomized, double-blind trial evaluating the efficacy and safety of meperidine 2 mg.kg-1 (M) and meperidine 2 mg.kg-1 plus midazolam 0.05 mg.kg-1 (M + M) in 40 pediatric outpatients (age 1 to 17 years) undergoing upper endoscopy procedures. The physician and nurse performing the procedure were asked to rate cooperation, emotional status, drowsiness, and overall efficacy. A blinded observer recorded the frequency of negative behaviors indicating distress, vital signs, and oxygen saturation before, during, and after the procedure. No significant differences were noted in the overall efficacy of the regimens. Good or excellent efficacy was noted in 15 of 21 children (71%) in the M group and 15 of 19 children (79%) in the M + M group by physicians; nurses assigned a good or excellent rating for 14 of 21 (67%) and 13 of 19 (68%) in the M and M + M groups, respectively. Immediately following the procedure, amnesia was noted in 4 of 17 (23%) patients who received M versus 14 of 18 (78%) patients who received M + M (P = 0.002). Of the children who received M + M, the amnesia tended to occur more frequently in older children (> 11 years, 8 children, rate of amnesia 100%) than in younger children (< or = 11 years, 6 of 10 evaluable children, rate of amnesia 60%). There was no significant difference between the frequency of negative behaviors, rate of adverse effects, or changes in vital signs or oxygen saturation noted with the two drug regimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Deficiency of the human mitochondrial transcription factor h-mtTFA in infantile mitochondrial myopathy is associated with mtDNA depletion

Recent studies show that patients presenting with cytochrome oxidase (COX) deficiency in infancy may have reduced mitochondrial DNA (mtDNA) in muscle. The human mitochondrial transcription factor A (h-mtTFA) may be an important regulator of both transcription and replication of mtDNA. h-mtTFA levels were investigated in cell lines which were either free of mtDNA (rho 0) or temporarily depleted by treatment with dideoxycytidine (ddC), and in tissue from three patients with mtDNA depletion and cytochrome oxidase deficiency. h-mtTFA was compared with other mitochondrial proteins such as pyruvate dehydrogenase and porin by Western blotting. The ratio of mtDNA and h-mtTFA mRNA to reference nuclear probes was measured by dual labelling of dot blots. The ratio of mtDNA to nuclear DNA in skeletal muscle was low in muscle in the three patients and in other tissues in one. h-mtTFA was low in cells depleted either permanently or transiently of mtDNA, and this reduction in h-mtTFA roughly paralleled mtDNA levels. Similarly, treatment of rho 0 cell lines with ddC induced a reduction in mtDNA as well as h-mtTFA protein. The relationship between h-mtTFA and mtDNA levels suggests that they may be causally linked. MtDNA depletion was accompanied by an increase in the level of h-mtTFA RNA in the cell lines but low levels in the patient. This suggests that either h-mtTFA regulates mtDNA levels, or that h-mtTFA expression may be regulated by a feedback mechanism initiated by MtDNA Depletion.

Continuous quality improvement in an acute hospital: a report of an action research project in three hospital departments

Describes an action research project to improve quality in three hospital departments including operating theatres, X-ray, and medical records. The approach combined quality assurance (QA) or audit methods with those of continuous quality improvement (CQI) or TQM. The intention was to bring about improved organizational performance through an emphasis on bottom-up rather than top-down methodology, and to assess the relative effectiveness of different quality strategies being used within the hospital. Baseline studies of organizational climate and of patient perceptions enabled evaluation of effectiveness. Provides a description of the background to various health-care quality strategies, and argues that several perspectives are required if all stakeholders (e.g. policy makers, professionals, patients, and managers) are to be satisfied. Describes the responses of staff, superiors and professionals and recommendations offered for more effective quality strategy implementation.

Left ventricular mass index and coronary artery disease in hypertensive black males

Thallium-201 stress scintigraphy (TSS) and echocardiography were performed on 60 consecutive black male hypertensives and compared to 60 sex-, race-, and age-matched controls. We found a higher prevalence of left ventricular hypertrophy with repolarization abnormality in the hypertensive group; 32 of 60 (53%), compared to 10 of 60 (17%) of the controls, P < .05. Echocardiographically determined left ventricular mass index revealed a significantly higher mean value in the hypertensive group of 147 +/- 57 compared to 124 +/- 34 in the control group, P < .001. Thirty-one of 60 (52%) of the hypertensive group had a normal TSS compared to 22 of 60 (37%) of the controls. A total of 68 (38 fixed and 30 reversible) perfusion defects were noted in the hypertensive group compared to 74 (55 fixed and 19 reversible) in the controls. The severity of clinical syndromes associated with myocardial ischemia were noted in increased incidence in the presence of left ventricular hypertrophy and left ventricular mass index was noted to be predictive of severity of coronary disease independent of the standard risk factors.

A method to quantify binding of unlabeled peptides to class I MHC molecules and detect their allele specificity

A general method has been developed for measuring the stabilization of class I MHC molecules in extracts of the mutant cell lines .174/T2 and RMA-S. 35S-Met-labeled class I molecules which have been stabilized by peptides in vitro are immunoprecipitated with conformation dependent monoclonal antibodies and electrophoresed on polyacrylamide gels. The heavy and light chains are excised from the dried gel and quantified on a flat bed scintillation counter. The stabilizing effect of peptides on class I molecules in vitro correlates well with peptide binding measured by direct methods and can be therefore used to assess peptide binding affinity. We show that a peptide from HIV-1 gag (which has a high affinity for Db) is a CTL epitope restricted through Db, and also use the assay to analyse the effects of amino acid substitution on peptide affinity. In addition, the effect of a given peptide on a class I molecule within a mixture of human class I molecules can be distinguished by immunoprecipitation with the monomorphic antibody W6/32 and separation by 1-D isoelectric focussing. The technique therefore requires neither labeled peptide ligands nor allele-specific antibodies. It can be used to identify the peptide ligand of any human class I molecule, and gives a measure of peptide binding affinity. The technique should be of value in identifying epitopes recognized by CTL since we have found that these tend to bind with the highest affinities.

Heparin-induced thrombocytopenia in a child

We describe a case of thrombocytopenia and deep venous thrombosis in a boy who received heparin to maintain patency of a central venous catheter. Measurement of the release of serotonin labeled with carbon 14 confirmed the presence of heparin-induced thrombocytopenia. Children receiving heparin therapy should be monitored for the possibility of heparin-induced thrombocytopenia.

Primary and secondary amenorrhea associated with spironolactone therapy in chronic liver disease

Women with severe liver disease often have amenorrhea that resolves as liver disease abates. We describe three patients with mild to moderate chronic liver disease and amenorrhea. In each case amenorrhea resolved when spironolactone therapy was discontinued. We suggest that spironolactone, an androgen inhibitor, may also cause reversible amenorrhea.

Current management of male breast cancer. A review of 104 cases

Between 1975 and 1990, 104 male patients with a total of 106 breast cancers were treated at Memorial Hospital or the Ochsner Clinic and their records reviewed. The patients were followed for a median of 67 months (range, 0.5 to 14.4 years). Analysis of the frequency distribution by stage showed that 16 (17%) patients were stage 0 and 26 (27%) patients were stage I. The median duration of symptoms before diagnosis was 18 weeks (mean, 5 weeks; range, 1 to 156 weeks). Modified radical mastectomy was undertaken in 71 (67%) patients. The actuarial 5-year relapse-free survival for the entire group was 68% and the actuarial 5-year overall survival was 85%. Relapse-free survival at 5 years for axillary node-negative patients was 87% and for node-positive patients was 30% (p less than 0.001). Overall survival figures for the same subsets showed a 5-year survival of 100% for the node-negative subset and 60% for the node-positive subset. On multivariate analysis, the most powerful predictor of outcome in men was the status of the axillary lymph nodes, and the only prognostic factor that added significantly to this predictive power was the duration of symptoms. Patients who sought treatment less than 6 months after the onset of symptoms experienced a significant survival advantage when compared with patients whose symptoms were present for more than 6 months (p = 0.03). The profile of the stages at diagnosis, the treatment approach, and the survival rates approximate those reported in series of female breast cancers, and overall, the two diseases are remarkably similar.

High-performance liquid chromatographic analysis of trilostane and ketotrilostane in rat plasma

A simple high-performance liquid chromatographic (HPLC) method for assaying trilostane, a synthetic steroid, and one of its metabolites, ketotrilostane, in small volumes of rat plasma has been developed. A single liquid-liquid extraction was used to isolate the two compounds from acidified plasma prior to the quantitative analysis. The HPLC conditions involved the use of a Spherisorb ODS column (250 mm x 4.6 mm I.D.) and a mobile phase of 1,4-dioxan-Sorenson's buffer at pH 5.0 (52:48, v/v). Ethisterone was used as an internal standard. Trilostane and ketotrilostane were detected by their ultraviolet absorbance at 255 nm. Recoveries greater than 80% and detection limits of 50 ng/ml were obtained for both compounds. Inter-day coefficients of variation were less than 10%.

[Tracheal injury caused by intubation for compressive endothoracic goiter]

The tube cannot pass along the marked curve of the trachea, which is displaced by a large goiter extending into the posterior mediastinum. The trachea is perforated in a low thoracic location. Tracheal suture and exeresis of the goiter are performed through sternotomia. This serious accident seems to be exceptional. Can it be predicted?

Acute epididymitis: why patient and consort must be investigated

In this prospective study of 49 patients under 35 years of age with clinically diagnosed epididymitis, detailed microbiological investigation identified an infective cause in 67%. Chlamydia trachomatis was the commonest agent, present in 25 patients, but in 12 of these detection was based solely on raised antibody titres; 20 of the 28 female consorts screened were partners of men with chlamydial epididymitis and 80% of them were also positive for this infection. Isolating the micro-organism from 14 of 16 consorts indicated active infection despite the negative swabs from the men. If this important infection is to be adequately treated we recommend that all patients in this age group with epididymitis and their partners should be referred to a specialist unit with access to full chlamydia laboratory facilities.

Gait comparison of subjects with hemiplegia walking unbraced, with ankle-foot orthosis, and with Air-Stirrup brace

The effects of the Air-Stirrup (AS) standard ankle brace on the gait of 19 subjects with hemiplegia resulting from a cerebrovascular accident who exhibited excessive subtalar joint motion were studied. Videotaped trials and footprint analyses were used to measure subjects' hip, knee, and ankle sagittal plane angles; inversion and eversion of the calcaneus; and time-distance gait characteristics. A one-way analysis of variance for repeated measures was used to compare the gait of 19 subjects with the AS brace and unbraced and 11 subjects with the AS brace, unbraced, and with an ankle-foot orthosis. The AS brace was associated with more calcaneal stability during standing than the unbraced condition. The ankle-foot orthosis was associated with less plantar flexion at foot-strike than either the AS brace or unbraced condition. Both the AS brace and the ankle-foot orthosis were associated with less mid-swing plantar flexion and increased step length on the paretic side compared with no brace. These results support the effectiveness of the AS brace in controlling inversion and eversion instability in patients with hemiplegia.

Thermal entrainment methods for studying Raynaud's phenomenon

Entrainment occurs when an externally applied periodic temperature stimulus forces the peripheral bloodflow component of thermoregulation to oscillate at the same frequency. This phenomenon can be demonstrated using frequency transforms to analyse the spectral content of the bloodflow, and can be used as a diagnostic test for Raynaud's phenomenon. Correlations were performed between the clinical diagnosis and the objective tests. The average inter-clinical correlation coefficient was r = 0.66. When the average clinical diagnosis was compared with a combination of thermal entrainment and digital patency testing the correlation coefficient rose to r = 0.68. These results highlight the difficulties encountered when assessing patients with Raynaud's phenomenon and the necessity of applying both physiological and clinical techniques.

Reflex vascular responses in the finger to contralateral thermal stimuli during the normal menstrual cycle: a hormonal basis to Raynaud's phenomenon?

1. Raynaud's phenomenon is a condition which primarily affects women and it must be assumed that hormonal influences are responsible. 2. To further investigate this assumption the effect of cyclic sex hormone fluctuations on the digital vascular reactivity of ten normal young women was studied by the diagnostic techniques of thermal entrainment of finger blood flow and Doppler ultrasound mapping of the digital arteries. 3. In the immediate pre-ovulatory period the results obtained were comparable with those found in patients with established Raynaud's phenomenon, suggesting that oestrogen has an important modulating effect in vivo on reflex peripheral vasomotor responses to thermal stimuli. 4. 'Primary' Raynaud's phenomenon may represent an exaggerated response to oestrogen.

Thermal entrainment and human ovulation

The changes in the peripheral vascular response to temperature have been studied for ten menstrual cycles by calculating thermal entertainment levels. The entrainment levels exhibited peaks at around the time of ovulation, a result which we believe is due to the fluctuating levels of the hormones oestrogen and progesterone in the blood. An attempt has been made to explain the influence of these hormones on the vasomotor control system and where interactions may occur.

Benign osteoblastoma of the temporal bone

Benign osteoblastoma is an uncommon tumor in the skull and particularly rare in the temporal bone. This article presents the clinical, radiologic, and pathologic findings of the fifth case known to involve the temporal bone, and only th second case limited to the temporal bone itself. Subtotal removal was performed following embolization of the tumor. The patient currently has no evidence of disease eighteen months following therapy. Benign osteoblastoma is rarely synchronously or metachronously associated with its malignant counterpart, osteosarcoma. Treatment should be conservative. Subtotal curettage is acceptable and often results in long-term resolution. Radiotherapy is not recommended unless the removal is incomplete and the consequences of local recurrence are serious, as in vertebral lesions. This lesion may be highly vascular, and preoperative embolization should be considered to minimize blood loss at surgery.

Allopurinol treatment and its effect on renal function in gout: a controlled study

Fifty-nine patients with primary gout were treated with either a combination of colchicine and allopurinol or colchicine alone. Assessments of renal function over 2 years revealed a statistically significant fall of glomerular filtration rate an urine concentrating ability in those receiving only colchicine. The renal function of patients given allopurinol did not change. Treatment with allopurinol resulted ina significant reduction of ammonium excretion, a phenomenon which could not be readily explained. Urate clearance also declined during allopurinol treatment, and the impaired urate clearance associated with gout became more evident. The most important observation was that allopurinol retarded an apparent decline of renal function. Presumably this was achieved through its hypouricaemic effect and implies that the hyperuricaemia of gouty patients is deleterious to the kidneys.

Renal impairment and gout

A study of renal function of 51 patients with gout and an equal number of normouricaemic controls revealed significant differences. A relative impairment of the glomerular filtration rate and urine concentrating ability in the gouty subjects could not be wholly explained on the basis of aging or hypertension. Renal dysfunction was generally mild and was not associated with specific clinical characteristics higher levels of uric acid excretion, or hypertriglyceridaemia. Gout patients excreted urine with a significantly lower pH. This was associated with a relatively high excretion of titratable acid and a deficit of ammonium excretion, which was accentuated by ingestion of an acid load. Urate clearance was significantly reduced in gout, even when expressed as a fraction of the glomerular filtration rate.

Effects of stimulation and rest on the ultrastructure of the excitatory neuromuscular junctions of Locusta migratoria L

The terminals of the fast axon on extensor tibiae muscle fibres of Locusta were examined in untreated nerve-muscle preparations and in preparations stimulated electrically at frequencies varying from 0.5 to 100 Hz. The ultrastructure of the terminals in preparations stimulated at the lower range of these frequencies, which induce twitch contractions of the muscles, is similar to that of the controls. Stimulation at the higher frequencies induced tetanic muscle responses and rapid fatigue of the muscles after which they would not respond again to high frequency stimulation for about 1 h. This loss and recovery of the responses of the muscles is correlated with changes in the ultrastructural appearance of the terminals, in particular in the number and shape of the synaptic vesicles. The ultrastructure of these "recovering" axon terminals closely resembles that of the controls.

Glutamate uptake after stimulation-induced depletion of vesicle numbers in neuromuscular junctions of Locusta migratoria L

The distribution of radioactivity at branches and terminals of the fast axon in extensor tibiae muscle incubated in the radiolabelled putative neurotransmitter L-glutamate was determined by electron microscopic autoradiography. Quantitative analysis of the distribution of silver grains at the axon branches and terminals in preparations stimulated at a low frequency shows that most of the radioactivity is present in the glial cells. In preparations stimulated to the point of fatigue substantial radioactivity is present in both the glial cells and the axoplasm of the terminals. It is suggested that the uptake of L-glutamate into the axoplasm of the terminals is correlated with the depletion and recovery of vesicle numbers after stimulation.

Changes in the distribution and size of synaptic vesicles in neuromuscular junctions of Locusta migratoria after stimulation and rest

The distribution and size of synaptic vesicles in excitatory terminals of the extensor tibiae muscle were determined after stimulation at frequencies varying from 0.5 to 100 Hz and after subsequent rest. Only in preparations stimulated at the higher frequencies do these parameters differ from those in the controls. The synaptic vesicles in the nonsynaptic areas of these terminals are depleted in number, and the remaining vesicles are reduced in size. These effects are reversed after a 1 h rest.

Pharmacokinetics of cytosine arabinoside in patients with acute myeloid leukaemia

1 The pharmacokinetics of cytosine arabinoside were studied after a single i.v. bolus of 2 mg/kg ara-C in patients with newly diagnosed untreated AML, using a bioassay and GC-MS method to measure the plasma concentrations. 2 Most patients showed a bi- or tri-phasic decline in plasma concentrations with time. Plasma clearance was 3.9 to 18.1 l/min as measured by the GC-MS method, and terminal half-lives varied from 7--107 min. 3 There was poor correlation of the GC-MS assay with the bioassay, probably because the latter was interfered with by the release of endogenous nucleosides from blasts after after ara-C. 4 Plasma concentrations were measured by GC-MS during continuous infusions in 14 patients. Plasma clearances were much lower than after a bolus, 0.39 to 5.25 l/min. 5 There was no correlation of response (remission or fall in peripheral blast count) with exposure to ara-C calculated from infusion dose, clearance and duration of infusion. 6 This study shows that ara-C pharmacokinetics varies markedly from patient to patient and that there is a wide range in the plasma concentrations associated with therapeutic response.