Adequacy in pre-dilution haemofiltration: Kt/V or infusion volume? The Sardinian Collaborative Study Group on Haemofiltration On-line

Kt/V is the main index of adequacy for diffusive and diffusive convective methods of extracorporeal depuration, yet there exists no universally acceptable validation of an adequacy index for the solely convective methods such as haemofiltration (HF). The aim of the present study is to analyse which of the parameters of adequacy used in two multicentre HF studies, Kt/V for urea or infusion volume, correlate best with nutritional parameters and can therefore be utilized for the evaluation of treatment dose in on-line pre-dilution HF. Twenty-three clinically stable patients were enrolled in the first study [3 months of haemodialysis (HD)+ 3 months of HF]. In the second study, 24 stable patients were studied in three phases: 6 months in HF, 6 months in HD and a further 6 months in HF; in this study, a target of Kt/V= 1.2 in all three periods was preestablished: 15 patients completed the full study. In both studies, we utilized the same monitor (AK 100/200 Ultra, Gambro), the same membrane (polyamide) and the same on-line prepared ultrapure dialysis fluid and sterile infusion solution. In both studies, we ensured that HF fulfilled the following parameters of adequacy: urea kinetics, cardiovascular and blood pressure stability (better in HF than in HD), common haematochemical and nutritional parameters, reduction in beta2-microglobulin levels, a good intra- and extra-session clinical outcome, and a good quality of life with morbidity and mortality rates no different from those of HD. HF proved to be an efficacious method of ensuring adequate depuration and a good quality of life for uraemic patients. We have shown that in longer periods of HF, a notable correlation between Kt/V and normalized protein catabolic rate (nPCR) and an equally good correlation between total ultrafiltration (UF)/dry weight ratio and nPCR could be achieved. In both studies, the patients showed a good level of epuration adequacy when total UF per session was at least 1.3 times the dry body weight. The total UF/body weight ratio thus seems to be an easy method in HF because of its greater ease of predictability and measurement, also when it is used independently of the Kt/V index.

[Cost of ICU in Italy. Results from an empirical study on a sample of 12 hospitals]

BACKGROUND

The Italian hospital payment system based on DRG doesn t properly include Intensive Care Units (ICU) costs. Since great emphasis has been recently given to rationing health care resources, assessing ICU costs seems to be dramatically relevant. Aim of the study was to assess the average yearly cost and the cost per diem of a sample of Italian multispecialistic ICU wards.

METHODS

In September 1995, a questionnaire concerning data on variable and fixed cost was sent to 25 Italian ICU wards, 11 NHS hospital-based (Northern Italy: 5; Central Italy: 4; Southern Italy: 2) and 14 school of medicine-based (Northern Italy: 7; Central Italy: 5; Southern Italy: 2). Variable cost data included: disposable, drugs, blood and blood-derived products, physical tests, chemical and microbiological routines, instrumental diagnostic procedures and physiotherapy. Concerning fixed costs, data on personnel and equipment were requested. In addition, some hospital overheads data (utilities; power; heating; maintenance; cleaning; laundry; accounting; waste disposal; cafeteria) were collected.

RESULTS

On the basis of the 12 questionnaires returned (Northern Italy: 9; Central Italy: 3; Southern Italy: 0), the yearly cost of an ICU ward is Liras 4,580,032,000 (range 2,739,277,000-7,704,292,000), whereas the average cost per diem is Liras 1,802,000 (range 1,234,000-3,179,000). Cost of personnel is about 61% of the above mentioned costs.

CONCLUSIONS

Despite the lack of questionnaires from Southern Italy and the unavailability of some data concerning both the cost of equipment and the overheads, the remarkable average cost values obtained could support further research.

Early exposure to restraint stress enhances chemical carcinogenesis in rat liver

This study examines the effect of a stress-associated condition on chemical hepatocarcinogenesis in the rat. Rats were given diethylnitrosamine (200 mg/kg. b.w., i.p.), followed, 1 week later, by three cycles of immobilization at room temperature. Two weeks after the last cycle they were treated according to the resistant hepatocyte protocol. At 4 weeks after selection, mean size of glutathione-S-transferase 7-7 positive foci/nodules was increased in the immobilized group (0.82+/-0.22 vs. 0.25+/-0.04 mm(2) in controls). Furthermore, at the end of 1 year 10/13 animals (77%) developed hepatocellular carcinoma in the former group, while only 6/14 (43%) incidence of cancer was found in controls. These results indicate that exposure to restraint stress early during carcinogenesis enhances the development of chemically-induced hepatocellular carcinoma in the rat.

The role of dopamine in the mechanism of action of antidepressant drugs

The present paper reviews evidence on the effect of antidepressant treatments on dopamine transmission. Chronic treatment with antidepressant drugs potentiates the behavioural stimulant responses elicited by the stimulation of dopamine receptors, including reward-related behaviours. Moreover, antidepressants affect dopamine release in several brain areas. The reviewed literature is discussed in terms of the possible mechanisms underlying antidepressant-induced supersensitivity to dopamine-mediated behavioural responses, and of the possible implications for the therapeutic effect of these drugs. It is concluded that the potentiation of dopaminergic neurotransmission induced by chronic antidepressant treatments might contribute to their therapeutic effect.

A prospective naturalistic study of 326 panic-agoraphobic patients treated with antidepressants

OBJECTIVE

How far the results of randomized controlled studies apply to everyday care cannot be judged without regular measurements of outcomes in daily practice. We report on systematic data from a 3-year naturalistic prospective study on panic disorder-agoraphobic (PDA) patients treated with antidepressants in a setting of routine clinical practice. Our aim is to describe the evolution of PDA in relation to the treatments employed, and to explore demographic and clinical characteristics that might be predictive of outcome.

METHODS

326 DSM-III-R PDA patients treated with antidepressants in a setting of routine clinical practice were included in a 3-year naturalistic prospective study. We utilized structured and semi-structures instruments, including the Structured Clinical Interview for Diagnosis and the Longitudinal Interview Follow-up Examination. The main antidepressants used were imipramine (39%), clomipramine (28.5%) and paroxetine (23.3%); only 9% of patients received other antidepressants.

RESULTS

147 patients (45.1%) stayed on medication throughout the entire period of the follow-up. Of those who interrupted the treatment, 38% stayed in remission. The probability of achieving at least one remission during the 3-year follow-up period was 96.5% for PD and 95.9% for Agoraphobia. Relapses after a period of at least 2 months of complete remission were also common, and the probability of presenting at least one relapse during the 3-years follow-up period was 67.1% for PD and 39% for Agoraphobia. The longest period of remission of PD is associated with low severity, medium-lasting course in patients with an onset of the illness in young adulthood. Less severe agoraphobia associated with moderately severe panic attacks appears to confer a better control of phobic behavior. All three major drugs were reasonably well tolerated (only 9% dropped out because of side effects), with sexual dysfunction and increased appetite being the most common side effects at the last evaluation; in the first phase of the treatment anticholinergic effects and jitteriness were more common with TCAs.

CONCLUSION

Both classical antidepressants and paroxetine emerge as a useful treatment in the long-term management of PDA; paroxetine appears particularly useful in PDA patients because it was significantly less likely to induce jitteriness, thereby reducing barriers to compliance.

Activation of olfactory cortex in newborn infants after odor stimulation: a functional near-infrared spectroscopy study

In mammals, perception of smells during the first hours of life is an essential prerequisite for adaptation of the newborn to the new extrauterine world. Functional magnetic resonance studies have shown that olfactory impression is processed in the lateral and anterior orbito-frontal gyri of the frontal lobe. Near-infrared spectroscopy (NIRS) can detect changes in oxygenated [Hb O2], and deoxygenated [Hb H] Hb during cortical activation. The aim of this study was to assess by NIRS olfactory cortex activity in newborn infants receiving olfactory stimuli. Twelve males and 11 females were studied when awake at 6 h to 8 d after birth. NIRS monitoring was carried out using two optodes placed above the left anterior orbito-frontal gyri. Each newborn was exposed for 30 s to two different smell stimuli-mother's colostrum and vanilla-and to a negative control, distilled water. Changes in Hb concentration were measured over the orbitofrontal region. During exposure to vanilla, [Hb O2] increased significantly over the left orbito-frontal area in all babies. The magnitude of the [Hb O2] increase over the illuminated region during colostrum exposure was inversely related to postnatal age. We conclude that monitoring Hb changes by NIRS can be valuable in assessing olfactory responsiveness in infants.

Exploratory behaviour and grooming after repeated restraint and chronic mild stress: effect of desipramine

In a previous study, we have recently shown that chronic treatment with desipramine either reduced or potentiated the locomotor response to the dopamine D(2)-like receptor agonist quinpirole, a behavioural response mediated by the mesolimbic dopamine system, depending on whether the animals were subjected, respectively, to repeated restraint or to chronic mild stress (different stressors randomly presented). In this study, we examined the interaction between prolonged exposure to either repeated restraint stress or chronic mild stress with the chronic administration of the antidepressant desipramine on two spontaneous behaviours, in which an involvement of the mesolimbic dopamine system has been suggested: novelty-induced exploratory activity and grooming. Exploratory activity in the open field was reduced by chronic mild stress regardless of the drug treatment, while it was not influenced by restraint stress. Desipramine reduced exploratory activity in rats subjected to restraint stress. Restraint stress increased grooming and desipramine reversed this effect, while increasing grooming in the chronic mild stress group. These findings suggest that antidepressants exert their effect by opposing the modifications induced by stress. The available experimental evidence is consistent with the hypothesis that an important role in the observed behavioural changes is played by the mesolimbic dopamine system.

Chronic lithium chloride fails to prevent imipramine-induced sensitization to the dopamine D(2)-like receptor agonist quinpirole

Lithium salts, an effective antimanic treatment, are able to prevent the development of the dopaminergic behavioural supersensitivity induced by chronic treatment with neuroleptics, by denervation of the dopaminergic terminal fields and by rapid eye movements (REM) sleep deprivation, which is considered a model of mania. We have studied the effect of a lithium (LiCl) diet, inducing a lithium serum level in the range of therapeutic efficacy, on the development of the supersensitivity to the locomotor effect of the dopamine D(2)-like receptor agonist, quinpirole, induced by chronic treatment with the antidepressant drug, imipramine. The results show that lithium is not able to prevent the development of such behavioural supersensitivity. The present data suggest that antidepressant-induced dopaminergic supersensitivity might provide a useful model of those manic states induced by (or subsequent to) antidepressant treatments. Moreover, the finding is consistent with the view that antidepressant-induced dopaminergic supersensitivity might play a role in the therapeutic effect of these drugs (which is known to be augmented by lithium, and not antagonised). Finally, the results show that the dopaminergic supersensitivity induced by imipramine is qualitatively different from that induced by neuroleptics or denervation of the dopaminergic terminal fields.

The costs of pharmacological treatment for major depression. The Italian Prospective Multicentre Observational Incidence-Based Study

OBJECTIVE

To describe the pharmacological treatment for major depression under the conditions of routine Italian public mental health facilities, assess its costs, and study its main predictors according to a societal perspective.

DESIGN

This was a prospective multicentre observational study designed to evaluate the economics of treatment of major depression using a specifically designed 65-item questionnaire. Data on drug consumption were collected in a section of the questionnaire and are presented here.

PATIENTS AND PARTICIPANTS

60 mental health facilities were selected and 556 patients were enrolled and followed up for 15 months.

RESULTS

Pharmacological treatment appears to be the most common treatment for major depression. 98% of patients were prescribed an antidepressant. Selective serotonin reuptake inhibitors (SSRIs) were the most prescribed antidepressants. Patients treated with SSRIs suffered from less severe depression than those treated with tricyclic antidepressants. Benzodiazepines were prescribed for 84% of patients enrolled. The total drug cost was 1,120,000 Italian lire ($US707) per patient (1995 values). Less than 20% of this cost was borne by the Italian National Health Service, as the majority of drugs used were not reimbursed.

CONCLUSIONS

The costs of the most widespread approach to treating major depression (pharmacological treatment) are not currently covered by the Italian National Health Service. Prescribing of drugs seems to diverge from the standards of treatment indicated by the Italian Drug Committee.

Diagnosis of neonatal hemochromatosis with MR imaging and duplex Doppler sonography

Neonatal hemochromatosis is a rare congenital disorder which affects both fetuses and newborns. It is characterized by hepatocellular failure, often appearing on the first day of life in the form of coagulopathy, hypoalbuminemia, hypoglycemia, and jaundice. Most of the affected infants die early in life, and definitive diagnosis has often been made only by post-mortem evaluation. With the help of MRI, plus increasing awareness of the disorder, diagnosis is now often made early, even in utero. Duplex Doppler sonography does not provide information on siderosis but shows abnormalities in the liver or blood-flow patterns associated with liver disease.

Elevated S100 blood level as an early indicator of intraventricular hemorrhage in preterm infants. Correlation with cerebral Doppler velocimetry

The aim of this study was to assess the use of S100 protein in blood as a means of identifying preterm infants at risk of intraventricular hemorrhage. In 25 preterm newborns, S100 blood concentrations were measured by an immunoradiometric assay during the first 48 h. Cerebral Doppler velocimetry waveform patterns were also tested at the time the blood sample was taken, when clinical and cerebral ultrasound scanning were still normal. Of the 25 newborns studied, 14 were controls and 11 developed intraventricular hemorrhage as revealed by ultrasound scanning more than 72 h after birth, and clinically confirmed by neurological examination on the seventh day of follow-up. S100 blood concentrations were significantly higher (P<0.002) in infants with intraventricular hemorrhage than in control infants and also correlated significantly (r=0.81, P<0.003) with the grade of hemorrhage. A significant correlation (r=0.70, P<0.05) between the S100 blood concentration and the middle cerebral artery pulsatility index was also observed. The present data show that S100 blood concentrations offer a measurable parameter of brain lesion in preterm infants before a radiological assessment of hemorrhage can be performed, when clinical symptoms may be silent and preventive/therapeutic action could be especially useful.

Visuospatial attention in myopia

Four experiments were conducted to ascertain whether myopia is associated with deficits of visuospatial attention. In myopic and emmetropic control subjects, we studied: (1) automatic and voluntary orienting of attention, (2) focusing of attention and (3) performance on a visual search task. The results indicated that automatic orienting was defective in myopics and their performance in visual search was less efficient than that of controls. By contrast, myopics showed no deficits in voluntary orienting and in focusing.

Complex phase tracing method for fringe pattern analysis

We present what we believe to be a novel complex phase tracing method for fringe pattern analysis related to the phase-locked loop idea. The image with deformed complex fringes is analyzed with lexicographic scansion that leads directly to the investigated phase without unwrapping. Robustness of the procedure is ensured by the delay mechanism in the process of calculating the reference value. A numerical model and examples of application of the presented method are given.

Cerebral blood-flow monitor for use in neonatal intensive care units

The implementation of a real-time multichannel system for monitoring cerebral blood-flow is described. The instrument relies on a completely modular architecture and is based on the principle of measuring the electrical impedance between a number of periodically sensed electrode pairs positioned around the subject's head. The whole setup is controlled by a host computer that performs several functions, such as real-time acquisition, analysis, display and data logging. Two operating options can be chosen by the user: a normal mode that allows continuous monitoring and a triggered mode in which the measurement cycle is automatically started by the occurrence of a preset condition in some other circulatory signal, e.g. the permanently available ECG signal. The design is considerably user-friendly and embodies a number of special safety precautions to take account of the peculiar condition of patients, usually newborn infants hospitalized in intensive care units.

[Diagnostic imaging of current pulmonary tuberculosis. Clinical significance of the presentation patterns and particular aspects in HIV-positive and HIV-negative subjects]

PURPOSE

We compared two groups of risk patients to try to identify different radiologic patterns in pulmonary tuberculosis.

MATERIALS AND METHODS

74 subjects, divided into two groups (HIV+:27; HIV-:47) were included since 1993. The patients were examined with chest X-ray (CXR) and CT.

RESULTS

In the HIV+ group we observed 40 radiologic alterations, with 6 cases of bilateral lung involvement and 9 of atypical localizations; particularly: 11 consolidations, 8 cavitations, 5 miliary diseases, 9 hilar or mediastinal adenopathies, 3 extrapulmonary localizations and 4 negative CXRs. In the HIV- group we found 53 radiologic alterations, with 6 cases of bilateral lung involvement and 3 of atypical localizations; particularly: 12 consolidations, 25 cavitations, 5 nodular patterns, 1 miliary disease, 5 nodal disease, 4 pleural diseases and 1 negative CRX.

DISCUSSION AND CONCLUSIONS

In HIV- patients lung consolidations and tysiogen patterns are significantly prevalent, while miliary diseases, mediastinal diseases and atypical localizations and negative CRXs are more frequent in HIV+ patients. We found miliary diseases, mediastinal diseases and extrapulmonary localizations also in HIV- patients with heavily impaired social, economic and sanitary conditions. This alterations indicate compromised host resistance, independent of the causes and modalities of immunodeficiency. The distinction between primary and secondary tuberculosis is currently not mandatory.

Fatty acid composition of human milk in Italy

The fatty acid composition of breast milk from 20 Italian women, delivering at term and on ad libitum diets, was analyzed with high-resolution gas chromatography. Milk samples were collected twice a day, on the 1st, 4th, 7th, 14th, 21st and 28th day after colostrum appearance. No significant differences were detected between the two daily samples. During the maturation process a significant reduction in long-chain polyunsaturated fatty acids of the n-6 series (p = 0.002) and n-3 series (p = 0.005) was recorded, particularly in arachidonic acid (p = 0.035), docosatetraenoic acid (p = 0.035) and docosahexaenoic acid (p = 0.032). The linoleic acid/n-6 and alpha-linolenic acid/n-3 ratios increased (p = 0.024 and p = 0.037), while the docosatetraenoic/docosahexaenoic acid ratio decreased (p = 0.032). The fatty acid composition of mature milk was the following: saturated 45.50%; unsaturated 54.51%; monounsaturated 42.69%; polyunsaturated 11.82%; long-chain polyunsaturated 1.27%; linoleic acid 9.79%, and alpha-linolenic acid 0.36%. The fatty acid composition of milk collected from Italian women appears similar to that of women in other southern European countries and, therefore, could reflect dietary habits.

Dizocilpine prevents the enhanced locomotor response to quinpirole induced by repeated electroconvulsive shock

Repeated administration of electroconvulsive shock, as expected, potentiated the locomotor stimulant response to quinpirole (0.3 mg/kg s.c.), a dopamine D2-like receptor agonist. Chronic, but not acute, treatment with the NMDA receptor non-competitive antagonist dizocilpine (0.3 mg/kg i.p.) prevented electroconvulsive shock-induced potentiation of quinpirole locomotor response. These results suggest that NMDA receptor activation is necessary for the development of supersensitivity to dopamine receptor agonists produced by repeated electroconvulsive shock. The relevance of this observation in regard to the mechanism of electroconvulsive shock therapeutic effect is discussed.

Behavioural sensitization of mesolimbic dopamine D2 receptors in chronic fluoxetine-treated rats

A common action of chronic antidepressant treatments is the potentiation of dopaminergic transmission in the limbic system. We now report that chronic, but not acute, treatment with fluoxetine (2.5 mg/kg by intragastric gavage once a day for 21 days) potentiates the locomotor stimulant effect of quinpirole, a selective dopamine D2/D3 receptor agonist. However, neither quinpirole-induced stereotypies nor the sedative effects elicited by low doses of this dopamine receptor agonist are influenced by chronic fluoxetine. These results suggest that fluoxetine, as well as classical antidepressants, sensitize postsynaptic dopamine D2/D3 receptors in the mesolimbic system.