Attachment representations, patterns of emotion regulation, and social exclusion in patients with chronic and episodic depression and healthy controls

BACKGROUND

The experience of social exclusion (ostracism) is linked to the etiology and maintenance of depression. Most individuals experience emotional stress in states of social exclusion. Insecurely attached individuals, especially with an unresolved trauma, show maladaptive coping in response to social stress. The present study examines (a) the differences with regards to attachment representations in episodic (ED) and chronic depressive (CD) inpatients and (b) how ostracism affects their emotional reactions.

METHODS

Patients with CD (n=29) and ED (n=23) and healthy control subjects (n=29) were interviewed using the Adult Attachment Projective Picture System (AAP), a valid measure to assess attachment representation; and played a virtual ball tossing game simulating social exclusion (Cyberball). Multiple depression-related risk and protective factors were considered. We hypothesized that CD patients show the most severe attachment disorganization and are emotionally most affected by the social exclusion situation. Moreover, we explored the interaction between ostracism and attachment.

RESULTS

Contradicting our hypotheses, ED and CD individuals were almost akin with regards to their attachment insecurity/disorganization and reactions to Cyberball. An emotionally altered reaction to social exclusion was identified in the insecure-disorganized depressive subgroup.

LIMITATIONS

Small sample size hampering further subgroup analyses. The ED sample may include single CD subjects with recent manifestation.

CONCLUSIONS

The pattern of emotion regulation in the depressive groups matches with findings from clinical studies, including attachment research. The relationship between attachment representations and ostracism should be further investigated in larger samples of depressive individuals.

Current and future developments in the use of temozolomide for the treatment of brain tumours

Brain tumours comprise only 2% of all adult cancers, but they are among the most debilitating malignant diseases. Temozolomide, an alkylating agent that can be administered orally, has been approved for the treatment of recurrent malignant glioma on a daily schedule for 5-day cycles. Continuous administration schedules with a higher dose intensity are being explored, but an improvement in efficiency remains to be shown. The benefit from temozolomide given as a single agent in recurrent disease will be several weeks at best. This drug is therefore now undergoing clinical testing as neoadjuvant chemotherapy or with concomitant radiotherapy in patients with newly diagnosed glioma. Several phase I trials are investigating the combination of temozolomide with other agents active against brain tumours. This review briefly summarises the pharmacological background and clinical development of temozolomide and focuses on current and future clinical exploration of this drug for the treatment of brain tumours.

Sequential administration of temozolomide and fotemustine: depletion of O6-alkyl guanine-DNA transferase in blood lymphocytes and in tumours

BACKGROUND

The DNA repair protein O6-alkylguanine-DNA alkyl transferase (AT) mediates resistance to chloroethylnitrosoureas. Agents depleting AT such as DTIC and its new analogue temozolomide (TMZ) can reverse resistance to chloroethylnitrosoureas. We report the results of a dose finding study of TMZ in association with fotemustine.

PATIENTS AND METHODS

Twenty-four patients with metastatic melanoma or recurrent glioma were treated with escalating dose of oral or intravenous TMZ ranging from 300 to 700 mg/m2, divided over two days. Fotemustine 100 mg/m2 was given intravenously on day 2, 4 hours after TMZ. AT depletion was measured in peripheral blood mononuclear cells (PBMCs) and in selected cases in melanoma metastases and was compared to TMZ pharmacokinetics.

RESULTS

The maximum tolerated dose (MTD) of TMZ was 400 mg/m2 (200 mg/m2/d) when associated with fotemustine the 2nd day with myelosuppression as dose limiting toxicity. The decrease of AT level in PBMCs was progressive and reached 34% of pretreatment values on day 2. There was however wide interindividual variability. AT reduction was neither dose nor route dependent and did not appear to be related to TMZ systemic exposure (AUC). In the same patients, AT depletion in tumour did not correlate with the decrease of AT observed in PBMCs.

CONCLUSIONS

PBMCs may not be used as a surrogate of tumour for AT depletion. Further study should concentrate on the pharmacokinetic pharmacodynamic relationship in tumour to provide the basis for individually tailored therapy.

Measurement of DNA cross-linking in patients on ifosfamide therapy using the single cell gel electrophoresis (comet) assay

The single cell gel electrophoresis comet assay has become established as a sensitive technique for measuring DNA strand breaks. The technique has been modified to allow the sensitive detection and quantitation of DNA interstrand cross-linking at the single cell level. Cells are irradiated immediately before analysis to deliver a fixed level of random strand breakage. After embedding of cells in agarose and lysis, the presence of cross-links retards the electrophoretic mobility of the alkaline denatured cellular DNA. Cross-links are, therefore, quantitated as the decrease in the comet tail moment compared with irradiated controls. Using this method, a linear response of cross-linking versus dose of chlorambucil over a wide dose range was demonstrated in human lymphocytes after drug treatment ex vivo. The method was also sensitive enough to determine cross-linking in clinical samples after chemotherapy. For example, crosslinking was observed in the lymphocytes of patients receiving ifosfamide (3 g/m2/day) as a continuous infusion for 3-5 days or as a 3-h infusion daily for 3 days. Cross-links were detected in all patients within 3 h, with no evidence of DNA single strand break formation. In patients receiving continuous infusion, a plateau of cross-linking was reached by 24 h. In the patients receiving ifosfamide over 3 h, a clear decrease in the peak level of cross-linking was observed before subsequent infusions.

Pharmacokinetics of temozolomide in association with fotemustine in malignant melanoma and malignant glioma patients: comparison of oral, intravenous, and hepatic intra-arterial administration

PURPOSE

Depletion of the DNA repair enzyme O6-alkylguanine-DNA alkyltransferase (AT) has been shown to increase tumor sensitivity to chloroethylnitrosoureas. Temozolomide (TMZ), an analogue of dacarbazine, can deplete AT, suggesting that it may be used to sensitize tumors to chloroethylnitrosoureas. However, the influence of nitrosoureas on the pharmacokinetics of TMZ is unknown, and a pilot study was performed to assess the pharmacokinetics of TMZ given via, various routes to 29 patients (27 malignant melanomas, 2 gliomas) with or without sequential administration of i.v. fotemustine.

METHODS

On day 1, TMZ was given intravenously (i.v.), orally (p.o.), or by intra-hepatic arterial infusion (h.i.a.) at four ascending dose levels (150 to 350 mg/m2 per day). On day 2 the same dose of TMZ was given by the same route (or by another route in six patients for determination of its bioavailability), followed 4 h later by fotemustine infusion at 100 mg/m2. Plasma and urinary levels of TMZ were determined on days 1 and 2 by high-performance liquid chromatography after solid-phase extraction.

RESULTS

The pharmacokinetics of i.v. TMZ appeared linear, with the area under the curve (AUC) increasing in proportion to the dose expressed in milligrams per square meter (r = 0.86 and 0.91 for days 1 and 2, respectively). The clearance after i.v. administration was 220 +/- 48 and 241 +/- 39 ml/min on days 1 and 2, respectively. The apparent clearance after p.o. and h.i.a. administration was 290 +/- 86 and 344 +/- 77 ml/min, respectively. The volume of distribution of TMZ after i.v., p.o., and h.i.a. administration was 0.4, 0.6, and 0.6 l/kg on day 1 and 0.5, 0.5, and 0.6 l/kg on day 2, respectively. The absolute bioavailability of TMZ was 0.96 +/- 0.1, regardless of the sequence of the i.v.-p.o. or p.o.-i.v. administration, confirming that TMZ is not subject to a marked first-pass effect. A comparison of TMZ pharmacokinetics after i.v. and h.i.a. treatment at the same infusion rate revealed little evidence of hepatic extraction of TMZ. However, the systemic exposure to TMZ (AUC) appeared to decrease at a lower infusion rate. TMZ excreted unchanged in the urine accounted for 5.9 +/- 3.4% of the dose, with low within-patient and high interpatient variability. TMZ crosses the blood-brain barrier and the concentration detected in CSF amounted to 9%, 28%, and 29% of the corresponding plasma levels (three patients). The equilibrium between plasma and ascitic fluid was reached after 2 h (assessed in one patient).

CONCLUSION

The sequential administration of fotemustine at 4 h after TMZ treatment had no clinically relevant influence on the pharmacokinetics of TMZ. The potential clinical effect of TMZ given by h.i.a. or by locoregional administration has yet to be established, as has the impact of the infusion duration on patients' tolerance and response rate.

Intracellular Localization and intercellular heterogeneity of the human DNA repair protein O(6)-methylguanine-DNA methyltransferase

O(6)-Methylguanine-DNA methyltransferase (MGMT) is a DNA repair protein that removes alkyl adducts from DNA and may be important in tumor resistance to alkylation chemotherapy. MGMT was visualized in human cells and tumor tissues with monoclonal antibodies against MGMT and immunofluorescence microscopy, and fluorescent signals were quantified by digital image analysis. MGMT was found both in the cytoplasm and the nucleus, and in either locale the protein reacts with alkylated DNA bases and becomes inactivated and lost from the cell. Cell lines in culture and xenografts showed a broad normal distribution of nuclear MGMT levels, but human brain tumors often showed a skewed distribution, with a significant fraction of cells with high levels of MGMT. O(6)-Benzylguanine, a suicide substrate inactivator for MGMT activity, reduced MGMT in human cells and in a mouse xenograft to levels undetectable by antibody assay 1 h post-treatment. In melanoma specimens taken from a patient 3 h post-treatment with temozolomide, MGMT levels were reduced by 70%. This quantitative immunofluorescence assay can be used to monitor MGMT and it depletion in human tumors to improve the use of alkylating agents in cancer chemotherapy.

Determination of temozolomide in human plasma and urine by high-performance liquid chromatography after solid-phase extraction

As a part of a pilot clinical study, a high-performance reversed-phase liquid chromatography analysis was developed to quantify temozolomide in plasma and urine of patients undergoing a chemotherapy cycle with temozolomide. All samples were immediately stabilized with 1 M HCl (1 + 10 of biological sample), frozen and stored at -20 degrees C prior to analysis. The clean-up procedure involved a solid-phase extraction (SPE) of clinical sample (100 microliters) on a 100-mg C18-endcapped cartridge. Matrix components were eliminated with 750 microliters of 0.5% acetic acid (AcOH). Temozolomide was subsequently eluted with 1250 microliters of methanol (MeOH). The resulting eluate was evaporated under nitrogen at RT and reconstituted in 200 microliters of 0.5% AcOH and subjected to HPLC analysis on an ODS-column (MeOH-0.5% AcOH, 10:90) with UV detection at 330 nm. The calibration curves were linear over the concentration range 0.4-20 micrograms/ml and 2-150 micrograms/ml for plasma and urine, respectively. The extraction recovery of temozolomide was 86-90% from plasma and 103-105% from urine over the range of concentrations considered. The stability of temozolomide was studied in vitro in buffered solutions at RT, and in plasma and urine at 37 degrees C. An acidic pH (< 5-6) should be maintained throughout the collection, the processing and the analysis of the sample to preserve the integrity of the drug. The method reported here was validated for use in a clinical study of temozolomide for the treatment of metastatic melanoma and high grade glioma.

[Lipoma of the left ventricle and insulinoma of the pancreas]

In a 59-year-old woman with cerebral attacks a left ventricular tumor was detected by two-dimensional echocardiography and confirmed by angiocardiography. The tumor was considered a source of embolism and resected. It proved to be a lipoma. Recurrent cerebral attacks finally led to the diagnosis of an insulinoma of the pancreas. After resection the cerebral attacks ceased.

[The exercise test in cardiomyopathy]

The exercise test in 30 patients with hypertrophic (HCM) and 29 patients with dilatative cardiomoyopathy (DCM) showed a positive test with significant ST depression in half of each group. In 12 out of 30 patients with HCM and 7 out of 29 patients with DCM, exercise testing caused angina. Rhythm disturbances surprisingly did not occur in HCM but where unexpectedly frequent in DCM: in 4 cases exercise testing provoked frequent supraventricular premature beats, in 3 patients paroxysmal atrial fibrillation, and in 11 patients ventricular ectopic beats (Lown class II-IVb). Nine patients exhibited an exacerbation by at least one Lown class as compared with the electrocardiogram at rest. In patients with atypical angina pectoris and a pathological exercise test the possibility of cardiomyopathy - apart from coronary artery disease - should be increasingly considered. With provocation of arrhythmias the possibility of DCM should especially be borne in mind.

[Pregnancy and labor in a mother with Silver-Russel syndrome]

A 23-year-old primigravida admitted to the labor room one week prior to term because of bleeding was known to have a congenital asymmetry, but a heart defect, which decisively affected the course of delivery, had been undiagnosed up to that time. Secondary caesarean section was necessary for fetal and maternal indications. In women with congenital hemihypertrophy or hemihypotrophy (Silver-Russel syndrome), any associated malformations should be ruled out prior to pregnancy.

Two successful pregnancies in a patient with single ventricle and transposition of the great arteries

A 29-year-old female with transposition of the great arteries, single ventricle, a small open ductus arteriosus and a mild aortic incompetence experienced two successful pregnancies without major complications. The benign course of pregnancy is attributed to the relatively low pulmonary vascular resistance and to the fact that the patient has not yet developed an Eisenmenger syndrome.

[Correlation the laevocardiogram and plain chest films in the presence of myocardial insufficiency (author's transl)]

A correlation was attempted in 106 patients with myocardial insufficiency between linear and volume parameters of the laevocardiogram and the corresponding parameters on plain chest films, as well as between pressure measurements and the degree of pulmonary congestion. Measurements on the plain radiograph provide only limited information on the function of the myocardium and the severity of myocardial lesion respectively. Nevertheless, they are of some value during the course of the disease.

Atriogenic diastoliceflux in patients with atrioventricular block

In five patients with total A-V block studied by thermodilution, infusion of 10 to 25 ml of cold saline into the right ventricle over a period of several seconds resulted in lowering right atrial temperature usually 0.25 to 0.7 second after P waves not followed in normal temporal sequence by QRS complexes. In three of these patients, in whom left heart catheterization was performed, the same phenomenon could be detected during and after infusion of cold saline into the left ventricle while temperature was measured by a thermistor introduced by transseptal route into the left atrium. Isolated atrial contractions, although capable of partially closing the A-V valves as indicated by the higher ventricular than atrial pressure, lead to atriogenic reflux from the ventricle. Ventricular contraction, however, whether normal or extrasystolic, produced efficient closure of the A-V valves.