Season and suicide: recent findings from Italy

Seasonal asymmetry in yearly suicide occurrence is a long-observed phenomenon in psychiatric, suicidological, and sociological research, and the effects of seasonal factors on suicidal behavior have been the focus of a number of earlier studies. Taking into account limitations of data and methods, these studies have generally favored interpretations based on psychosocial factors. Recent studies have challenged the widely held notion that seasonal effects on suicide are a unitary phenomenon, not influenced by age, gender, or circumstances of the act. In particular, the seasonal occurrence of suicides has been found to differ significantly between the young and the elderly, and differences have also been found between male and female cycles of occurrence. Suicides using violent methods have been shown to follow clearer seasonal patterns than suicides by less violent methods (such as drug or gas poisoning), possibly reflecting the greater impulsive component involved in the choice of a violent lethal means. In this paper, findings from Italy are used to illustrate the clinical implications of studies into the topic of season and suicide, with the aim of developing more effective preventative strategies.

Risk for obstetric complications and schizophrenia

The goal of this study was to determine whether cases with schizophrenia or related disorders show a history of obstetric complications significantly more often than control subjects and, if so, whether the enhanced risk of a negative pregnancy outcome also extends to the non-schizophrenic offspring of cases. Data based on the obstetric birth case-notes of patients with diagnosed schizophrenia or related disorders were compared to those of normal 'healthy' control subjects; each case/control pair was individually matched by gender, time and parity of birth, maternal age and marital status. Forty-four case/control pairs born in Padova (Italy) between 1964 and 1978 were assessed for prenatal and perinatal complications, including abnormal gestational age or birthweight. No significant differences were observed between cases and control subjects in the general characteristics of birth; gestational age and birthweight in particular were strictly comparable between cases and control subjects. The schizophrenia spectrum patients (75%) were more likely than control subjects (59%) to have experienced at least one definite obstetric complication: odds ratio=2.07 (95% CI: 0.83-5. 15). Cases also suffered more complications per birth than control subjects (average 2:1). In particular, obstetric complications involving a clear damaging potential were seen significantly more often among cases than control subjects: 34% vs. 9%, Fisher's exact test, P=0.008 (odds ratio=5.17, 95% CI: 1.55-17.21). Moreover, severe obstetric complications were noted more often among males (n=13, 41%) than females (n=2, 15%). When any previous pregnancies of the mothers of patients were compared with those of the mothers of control subjects, mothers of cases were seen to have suffered unfavorable pregnancy outcomes significantly more often. In particular mothers of cases were seen to have had more miscarriages (OR=4.66), and pre-term births (OR=2.58) than control subects' mothers. Severe, brain-damaging obstetric complications would seem to be a possible antecedent to a diagnosis of schizophrenia or a related disorder in adulthood. Indeed, some early onset cases may be accounted for by prenatal brain lesions. This enhanced risk of negative pregnancy outcome may be under genetic control, contributing to the persistence of schizophrenia in the general population. The 'healthy' status of control subjects was ascertained indirectly, not by individual assessment of the subjects. The sample size limits the statistical power of calculations.

Vanoxerine National Institute on Drug Abuse

Vanoxerine (GBR-12909) is a high-affinity dopamine reuptake inhibitor that was synthesized in the late 1970s and was initially tested in Europe as a potential antidepressant. In 1989, it was suggested that GBR-12909 might be useful in the treatment of cocaine addiction [346980]. The drug has completed phase I clinical trials conducted by the US National Institute on Drug Abuse for the potential treatment of cocaine abuse [346245,376621]. A multidose, safety and pharmacokinetics, open-label, fixed-order dose-escalating study has been completed. Four doses of vanoxerine in healthy normal volunteers were administered, to assess the safety and tolerability of the drug at 25, 50, 75 and 100 mg. Further development is likely to continue, pending review of the data [376621]. Dopamine transporter occupancy has also been measured. After 2 weeks of dosing at either 50, 75 or 100 mg oral vanoxerine in 8 human subjects, preliminary results of subsequent PET scans show that occupancy increased with dose, reaching 25 to 35% at 100 mg [346245]. At these doses, the drug did not cause the behavioral symptoms such as those of cocaine, suggesting that the drug does not have abuse potential. If no safety issues arise, the compound will be evaluated in trials with cocaine-dependent subjects, along with its derivative, compound 5 [346980]. It is thought that prolonged treatment with vanoxerine could reverse the addiction process, following studies in rats showing that dopamine transporter levels returned to normal when animals were switched to vanoxerine therapy immediately after cocaine administration [346980]. Vanoxerine has an affinity constant (Ki), at the human dopamine transporter, of 9 nM [347021]. Gist-Brocades originally initiated studies of vanoxerine, along with another piperazine, GBR-12935, for the treatment of cocaine dependence. The company was also investigating vanoxerine as a potential antipsychotic therapeutic agent; development for this indication has been discontinued [190331]. In 1995, the NIDA began to fund studies into the potential of vanoxerine to reduce cocaine self-administration by rhesus monkeys. Early data showed that vanoxerine could decrease cocaine-maintained responding (CMR) in rhesus monkeys, without affecting similar levels of food-maintained responding (FMR). Furthermore, a decanoate ester of a hydroxylated analog of vanoxerine, DBL-583, could decrease CMR by 80% while leaving FMR unaffected; this effect lasted almost 30 days with a single injection [227488,346980]. Similar studies have shown that, by inhibiting the dopamine transporter, for which vanoxerine has a 500-fold increased affinity in comparison to cocaine, vanoxerine could selectively reduce(1 mg/kg i.v.) or eliminate (3 mg/kg i.v.) cocaine self-administration in primates. The drug was well tolerated with no changes in blood pressure or oxygen saturation. Oral administration of the drug in clinical trials was planned following this study [346990].

BP-897 Bioprojet

BP-897 is a dopamine D3 receptor agonist which is under development by Bioprojet for the potential treatment of drug craving and vulnerability to relapse that are elicited by drug-associated environmental stimuli; it is undergoing phase I trials [318397,334036,340721]. Preclinical investigations were carried out by Cambridge University and INSERM [295680]. BP-897 functions as a partial agonist in vitro and as either an agonist or an antagonist in vivo. It inhibits cocaine-seeking behavior that depends upon the presentation of drug-associated cues, without having any intrinsic, primary rewarding effects [334036]. In preclinical studies, BP-897 administration before testing reduced cocaine-seeking behavior in rats in a dose-dependent manner [304557,307758,334036]. In D3 receptor knockout mice, BP-897 has no effect [345710]. It does not reduce self-administration of cocaine in monkeys [318397].

Identification and expression of NEU3, a novel human sialidase associated to the plasma membrane

Several mammalian sialidases have been described so far, suggesting the existence of numerous polypeptides with different tissue distributions, subcellular localizations and substrate specificities. Among these enzymes, plasma-membrane-associated sialidase(s) have a pivotal role in modulating the ganglioside content of the lipid bilayer, suggesting their involvement in the complex mechanisms governing cell-surface biological functions. Here we describe the identification and expression of a human plasma-membrane-associated sialidase, NEU3, isolated starting from an expressed sequence tag (EST) clone. The cDNA for this sialidase encodes a 428-residue protein containing a putative transmembrane helix, a YRIP (single-letter amino acid codes) motif and three Asp boxes characteristic of sialidases. The polypeptide shows high sequence identity (78%) with the membrane-associated sialidase recently purified and cloned from Bos taurus. Northern blot analysis showed a wide pattern of expression of the gene, in both adult and fetal human tissues. Transient expression in COS7 cells permitted the detection of a sialidase activity with high activity towards ganglioside substrates at a pH optimum of 3.8. Immunofluorescence staining of the transfected COS7 cells demonstrated the protein's localization in the plasma membrane.

Death by homicide in Italy, 1980-94: age and gender differences among victims

To investigate the role of sociodemographic factors in the risk of death by homicide in Italy, official statistics from 1980 to 1994 concerning death by homicide have been studied. Homicide rates increase from 1980 to 1994 for males and, to a much lesser extent, for females. Clear differences exist by age and gender, with rates peaking in both genders at young adult age (25-34) and men having five times higher rates than women. Mean rate in the general population is 1.98 per 100,000, one of the highest rates in the civilized world. These findings are mostly influenced by higher homicide rates for both males and females in southern regions, where cultural attitudes towards violence, linked to the greater diffusion of criminal organizations, greatly influence the risk of death by homicide. About 75% of homicides involve firearms: clearly in Italy availability of lethal weapons is a key factor in homicide. Intervention aimed at increasing community awareness of the causes and methods of prevention of violence (including the roles of substance abuse and social inequality) are needed if adequate policies are to be developed to reduce the risk of death by homicide. Differences in homicide rates across countries clearly indicate that homicide is a preventable cause of death.

Increase in first admissions for schizophrenia and other major psychoses in Italy

Despite reports of falling first-admission rates for schizophrenia in some Western countries, methodological problems and bias preclude a definite conclusion about a genuine fall in the incidence of schizophrenia. This study set out to test the hypothesis that first admissions for schizophrenia in Italy have fallen in recent years. All admissions rated as 'first contact' in Italy from 1984 to 1994 for severe mental illnesses to general hospital psychiatric services, as reported in the Italian National Institute for Statistics Health-Care Yearbooks, were considered. Data were analyzed as rates per 100000 in the general population, and changes over time in incidence of schizophrenia, paranoia, affective psychoses and drug-induced psychoses (diagnosed according to ICD 9) were recorded. Changes in rates over time, with rates as the dependent variable and years as the independent variable, were the main outcome measure. First-admission rates for schizophrenia and paranoia increased progressively from 1984 to 1994, as did those for affective psychoses, mania and, to a lesser extent, major depression. In the same period, all admissions (both total and rated as 'first-contact') for mental disorders increased. Although linear regression tests for admission rates in most, but not all, cases indicate a significant ascending linear trend, quadratic model results show a significantly better fit than does the simple linear regression model for the majority of data. The change described by the quadratic model suggests an increase in admission rates more marked in the second half than in the first half of the period of the study. First-admission rates for schizophrenia and, to a lesser extent, paranoia seemed to increase concurrent to a decrease in first-admission rates for 'other' non-organic psychoses. Contrary to reports from other Western countries, hospital incidence in Italy for schizophrenia is on the increase, as is that for other severe psychoses. This increase is likely to be a reflection of changes in mental health-care organisation, in treatment and diagnostic patterns, and in cultural attitudes towards mental illness. Radical changes in the true incidence of psychoses, in particular of mood disorders, as described elsewhere, cannot be ruled out as contributing factors. Data bias and limitations preclude a generalisation of results, however.

Nerve growth factor induces sphingomyelin accumulation in pheochromocytoma cells

The pheochromocytoma cells are a well-known model for studying the nerve growth factor (NGF)-induced molecular changes during the differentiation process. The involvement of sphingomyelin (SM) was studied using the fluorescent analogue of ceramide, i.e. N-lissamine rhodaminyl-(12-aminododecanoyl) D-erythro-sphingosine (C12-LRh-Cer). This fluorescent analogue is metabolically active and can be used to follow the biosynthesis of SM in intact cells. NGF induces a 4-fold increase of fluorescent SM content in PC12 cells, when loaded with C12-LRh-Cer. Treatment of PC12 cells with actinomycin D or cycloheximide completely abolishes the NGF-induced elevation of SM. Inhibition of p140(trkA) receptor by AG-879 prevents extracellular signal-regulated kinase 1/2 phosphorylation and suppresses the increase of SM. Inhibition of protein kinase C (PKC), protein kinase A (PKA) and phosphatidylinositol 3-kinase does not have any effect on NGF-induced C12-LRh-SM accumulation. On the other hand, activation of PKA or PKC with simultaneous treatment with NGF has a synergistic effect on increase of SM content. The NGF-induced SM increase in PC12 cells is an effect promoted by other differentiating agents like dibutyryl cyclic AMP or fibroblast growth factor-2 but not by a mitogenic agent like epidermal growth factor.

Phase II study of paclitaxel in combination with mitoxantrone and ifosfamide/mesna for patients with relapsed or refractory non-Hodgkin's lymphoma after failure to cytarabine/cisplatin combination

PURPOSE

Evaluate response, duration of response, and toxicity of paclitaxel in combination with other drugs known to be effective in non-Hodgkin's lymphoma (NHL).

METHODS

Thirty-eight patients with relapsed/refractory NHL who had been exposed to doxorubicin as well as the cytarabine-cisplatin combinations received Mesna 1.33 gm/M2/D daily days 1, 2, 3 i.v. over 1 hour; ifosfamide 1.33 gm/M2/D daily days 1, 2, 3 i.v. over 1 hour (same bag); Novantrone 8 mg/M2/D i.v. day 1; and Taxol 27.5 mg/M2/D daily days 1, 2, 3, 4 by continuous 24-hour intravenous infusion. Premedication for Taxol included dexamethasone, diphenhydramine, and cimetidine on day 1.

RESULTS

Of 35 evaluable patients, 9 (26%) achieved a complete response and 7 (20%) a partial response for a total response rate of 46%. The median failure-free and overall survival times were 2 and 10 months, respectively. Major toxicity was hematologic with a median absolute neutrophil nadir of 196/mm3. Only 10% of the cycles were associated with a grade 3-4 infection.

CONCLUSION

MINT is an active and safe regimen for relapsed/refractory NHL that have failed both an Adriamycin-containing regimen and a cytarabine/cisplatin-containing regimen.

Influence of method on seasonal distribution of attempted suicides in italy

To verify if attempted suicides follow different seasonal distributions according to the method chosen, we studied the Italian monthly distribution of admissions for attempted suicide in the period 1984-1995 according to gender and age, distinguishing between non-violent (ICD 950-952) and violent (ICD 953-958) attempted suicides. The effect of temperature was also taken into account. A clear asymmetry in seasonal distribution of events can be observed in the oldest age groups in both genders, with a peak in warmer months. Only male attempted suicides by violent methods show a clear asymmetry in seasonal distribution, with a peak in spring months and a trough in autumn months. Spectral analysis, more accurate in detecting seasonal rhythms than analyses that only compare monthly seasonal means, identifies a circannual rhythm for violent suicides in both genders. The seasonal components of total variance in attempted suicides account for 16.5 and 12.4%, respectively, of violent male and female attempted suicides. Among males, a significant (p < 0.05) 4 cycles/year pattern is seen alongside the more relevant (89.4%, p < 0.01) 1 cycle/year distribution. Among females, aside from the 1 cycle/year distribution (63.3%, p < 0.01) noted, a 6 cycles/year pattern is found to contribute significantly (16.9%, p < 0.05) to the seasonal component of variance. A clear relationship with temperature indicators is noted among males: higher temperatures positively correlate with attempted suicides, whereas cooler temperatures seem to exert a protective action. Female attempts show a less evident correlation with indicators of temperature. Sample composition by age and gender and the lack of distinction between methods of attempted suicide may have obscured the seasonal component of some classes of attempted suicide in previous studies. The circannual rhythm found in this study of violent attempted suicide in relation to climate seasonal change confirms the importance of taking chronobiological variables into account in the evaluation of patients at risk of suicide.

Some social correlates of homicide rates in Italy

In Italy, as elsewhere, homicide rates are higher in poorer regions. Unemployment rates associated strongly and positively with homicide rates, explaining up to 54% of variance in regional distribution of homicide rates across the 20 Italian administrative regions.

Expression of a novel human sialidase encoded by the NEU2 gene

Sialidases (E.C.3.2.1.18) belong to a group of glycohydrolytic enzymes, widely distributed in nature, which remove sialic acid residues from glycoproteins and glycolipids. All of the sialidase so far characterized at the molecular level share an Asp block, repeated three to five times in the primary structure, and an F/YRIP sequence motif which is part of the active site. Using a sequence homology-based approach, we previously identified a human gene, named NEU2, mapping to chromosome 2q37. NEU2 encoded protein is a polypeptide of 380 amino acids with two Asp block consensuses and the YRIP sequence in the amino terminal part of the primary structure. Here we demonstrate that NEU2 encodes a functional sialidase. NEU2 was expressed in COS7 cells, giving rise to a dramatic increase in the sialidase activity measured in cell extracts with the artificial substrate 4-MU-NANA. Using a rabbit polyclonal antiserum, on Western blots a protein band with a molecular weight of about 42 kDa was detectable, and its cytosolic localization was demonstrated with cell fractionation experiments. These results were confirmed using immunohistochemical techniques. NEU2 expression in E.coli cells allowed purification of the recombinant protein. As already observed in the enzyme expressed in COS7 cells, NEU2 pH optimum corresponds to 5.6 and the polypeptide showed a K(m)for 4-MU-NANA of 0.07 mM. In addition, based on the detectable similarities between the NEU2 amino acid sequence and bacterial sialidases, a prediction of the three-dimensional structure of the enzyme was carried out using a protein homology modeling approach.

Suicide and unemployment in Italy, 1982-1994

OBJECTIVE

To investigate whether either the condition of being unemployed, or changes in unemployment rates are associated with suicide risk.

DESIGN

Administrative data for suicide according to occupational status have been analysed considering three employment categories: employed, seeking new job (unemployed), seeking first job (never employed). Comparison of suicide rates by economic position and correlation between suicide and unemployment rates have been made.

SUBJECTS AND SETTINGS

20,457 deaths by suicide registered in Italy among economically active people from 1982 to 1994.

MAIN OUTCOME MEASURES

Change over time in suicide rates by economic position; coefficient of aggravation according to occupational status.

RESULTS

Suicide rates among the unemployed are clearly and constantly higher than those among the employed: up to three times higher among men, and twice as high among women. Among the unemployed a clear and significant rise in suicide rates in both sexes took place over the study period; suicide rates among the employed showed a less marked increase. The rise in suicide rates was accompanied by a concurrent rise in unemployment rate percentage. Men seem to be affected most by this change in unemployment rate percentage; women are subject to less evident influences and variations.

CONCLUSION

Different suicidal behaviour trends among unemployed compared with employed people indicate that unemployment (and above all the prospect of not having access to a working role) acts as a contributing factor for suicide. Unemployment, even if symptomatic of a mental disorder, should therefore always be taken into consideration as a risk factor for suicide: the potentially lethal consequences of its negative influence on both self esteem and the ability to use supportive networks in a efficient way is an element to which great attention should be paid.

Cloning and characterization of NEU2, a human gene homologous to rodent soluble sialidases

Sialidases (EC 3.2.1.18) are a group of glycohydrolytic enzymes, widely distributed in nature, that cleave sialic acid residues from the oligosaccharide components of glycoconjugates. All of the sialidase enzymes thus far characterized share an Asp block, repeated three to five times in the primary structure, and an F/YRIP sequence motif that is part of the active site. Using a sequence homology-based approach, we have identified a novel human gene, named NEU2, mapping to chromosome 2q37. The nucleotide sequence analysis of the gene has shown that it contains only one intron of about 1.25 kb, and the longest open reading frame encodes a protein of 380 amino acids, with a two-Asp block consensus, and the YRIP sequence. In the putative promoter sequence there are a classical TATAA box and four E boxes, which are consensus binding sites for muscle-specific transcription factors. Northern blot analysis revealed expression of the NEU2 transcript only in skeletal muscle.

Interleukin-10 levels are often elevated in serum of adults with Hodgkin's disease and are associated with inferior failure-free survival

BACKGROUND

Interleukin-10 (IL-10) is a pleiotropic cytokine that protects B- or T-lymphocytes and hemopoietic progenitors from apoptosis induced by doxorubicin, glucocorticoids, or deprivation of growth factors. IL-10 is also immunosupressive, and tumor cells secreting IL-10 can grow in syngeneic or allogeneic hosts, and can inhibit the generation of tumor-specific cytotoxic T cells. Hodgkin-Reed-Sternberg cells are derived from follicular center B cells and they may be latently infected by EBV. When this occurs they often express IL-10. Based on these considerations we investigated the relationship between pretreatment serum IL-10 levels and failure-free survival (FFS) in Hodgkin's disease (HD).

PATIENTS AND METHODS

Untreated patients, older than 16 years, with biopsy-proven HD, were included if treated with ABVD or equivalent regimens, and if pretreatment serum was available. IL-10 levels were determined with a capture enzyme-linked immunoassay specific for cellular IL-10.

RESULTS

Among healthy adult volunteers serum IL-10 levels ranged from 4.8-9.8 pg/ml (mean 7.1, standard deviation 1.5 pg/ml). Therefore levels > or = 10 pg/ml were considered elevated. We identified 101 patients with available serum. Their median age was 32 years, and 60% had B-symptoms. Ann Arbor stage was I in 4, II in 21, III in 35, and IV in 41 patients. Histology was nodular sclerosis in 74, mixed cellularity in 12, lymphocyte predominance in six, lymphocyte depletion in one, and unclassified in eight patients. Pretreatment serum IL-10 levels were elevated in 51 patients, and were higher in those with serum albumin < 3.5 g/dl, B symptoms, serum beta 2-microglobulin > or = 2.5 mg/l, anemia, and AAS III or IV. After a median follow-up of 32 months for survivors, 20 patients have progressed, and the three-year FFS of those with high vs. normal serum IL-10 was 60% +/- 9 vs. 91 +/- 9% (50% vs. 50% of the population; P = 0.004 by log-rank). Among patients with Ann Arbor stage III or IV the three-year FFS for those with high vs. normal serum IL-10 (58 vs. 42% of the population) was 57 +/- 9% vs. 92 +/- 6% (P = 0.008 by log-rank). Multivariate analysis using Cox's proportional hazards model confirmed that IL-10 was an independent variable associated with inferior FFS in this population.

CONCLUSIONS

Elevation of serum IL-10 levels is frequent and is associated with inferior FFS in adults with ABVD-treated HD. This observation should be verified in other patient populations. In addition, the source and the role of IL-10 in the biology of HD should be further investigated.

Suicide among eminent artists

To evaluate suicide risk by profession among eminent artists data from Garzanti's Encyclopedia, a broad biographical repertory, were used. Six categories in the visual and literary arts were compared: architects, painters, sculptors, writers, poets, and playwrights. Only people whose deaths occurred in the 1800s or 1900s were included since it is likely that underestimation of suicide has been lower in the more recent centuries. A total of 59 suicides were observed in a sample of 3,093 people: this corresponds to a ratio of 1.90%. Suicides were 51 among men (ratio 1.75%) and 8 among women (ratio 4.30%). The comparison by profession indicates that poets and writers exceed the mean suicide ratio of the sample. Painters and architects, conversely, have a clearly lower risk than the mean. Mean age of suicides was 44 yr. (SD = 12), with writers being slightly older (48 yr., SD = 12) than other artists. Artists who died of causes other than suicide reach a mean of 65 yr. (SD = 10). Suicide among artists seems to have a peculiar pattern, clearly different from the pattern of the general population, wherein suicide risk is higher among men and older people. Adverse financial circumstances and the stress attributed to rejection of personal products may contribute to the specific risk of suicide among artists. The link between mental disorders, such as manic-depression, which imply a higher risk of suicide, and creativeness is discussed as a contributing factor.

Seasonality in suicides: the influence of suicide method, gender and age on suicide distribution in Italy

In order to ascertain if and how age, gender and choice of lethal means influence the seasonal distribution of suicide in Italy, data concerning all suicides registered in Italy from 1984 to 1995 have been analyzed, taking these variables into account. In the age group 14-65 years and over a total of 31771 male suicides (mean yearly rate, 12.6 per 100000) and 11984 female suicides (mean yearly rate, 4.4 per 100000) have been identified in Italy during the study period. Suicides in the younger age ranges, both among males and females, show a less marked asymmetrical seasonal distribution than those in the older age groups. Only suicides committed by violent methods (ICD 953-958) show clear evidence of seasonality, with a peak in spring and a low in late autumn. Suicides committed by non-violent methods (950-952) follow no seasonal trend in either sex. Spectral analysis reveals a circannual rhythm for violent suicides (ICD 953-958) in both genders. For male non-violent suicides (ICD 950-952), a period with a frequency of 0.0833 (12 months) has been identified, but with a polarity opposite to that of male violent suicides. For female non-violent suicides, no period of frequency of 0.0833 could be identified, but, as for female violent suicides, a period with frequency close to 0.2500 (4 months) has been found. Changes in climate, then, correlate with the monthly distribution of violent and non-violent suicides in opposite ways: male violent suicides show a significant positive relationship with indicators of temperature and exposure to the sun, and a significant negative relationship with indicators of humidity and rainfall. Female suicides show less significant relationships with climate indicators. Work aimed at suicide prevention should therefore take into account the complex influence of seasonal climate both on human biological rhythms (particularly on 5-HT related functions and their actions on mood and impulsivity) and on sociorelational habits.

Ganglioside GM2 is substrate for a sialidase in MDCK cells

GM1 ganglioside carrying a fluorescent fatty acid in substitution of the natural one, has been administered to cultured Madin-Darby canine kidney (MDCK) cells for different pulse times (0.5-24 h), and its metabolic fate was followed. The fluorescent GM2, asialo-GM2, asialo-GM1 and ceramide were the only detectable metabolites. The complete absence of fluorescent GM3 is consistent with the presence in these cells of a sialidase working on GM1 and GM2 gangliosides. After treatment of the cells with chloroquine the fluorescent GM1 remained essentially undegraded, indicating a catabolic processing at lysosomal level.

The influence of climate on suicidal behaviour in Italy

A growing number of studies report an asymmetry in the seasonal distribution of suicides, with a peak in the late spring months for both sexes. The aim of this study is to verify if the climate, apart from its seasonal change, exerts a direct influence on suicidal behaviour. To this end, deaths by suicide in 17 Italian towns which all have a meteorologic station have been analyzed, taking into account some climatic indicators. Results of analyses show an unequal distribution of suicides with respect to latitude, with a peak in the North. The distribution of deaths by suicide shows a negative relationship with mean yearly temperature values, max and min, and with sun exposure indicators, and a positive, but less significant relationship with rainfall values. As far as climatic variables considered as a whole are concerned, stepwise regression identifies three relevant factors with significant relationships to suicide rates: humidity grade, rainfall mean, and sunlight exposure. These three climatic indicators explain up to 63% (Adj R2) of the variance in the distribution of suicide rates for both genders, with sunlight exposure offering the most significant contribution, when regressed on suicide rates via a multiple regression model. Higher suicide rates, therefore, correspond to dry places which are less exposed to the sun. However, the variable which shows the most significant correlation with suicide rates for both sexes is not a climatic one, but the percentage of the population aged 65 and over. The distribution of people at greater biological risk for possible disruption of brain neurochemistry (i.e. older people), therefore, predicts the distribution of suicide rates. Climate contributes to this biological risk by modifying both the responsiveness of the circuits that control mood and behaviour, and also the frequency and intensity of social interaction.

High-dose chemotherapy for relapsed and refractory diffuse large B-cell lymphoma: mediastinal localization predicts for a favorable outcome

PURPOSE

This study was performed to evaluate the outcome of high-dose chemotherapy and autologous transplantation in patients with diffuse B-cell large-cell lymphoma, and, specifically, to evaluate the impact of primary mediastinal localization on the outcome of high-dose chemotherapy.

PATIENTS AND METHODS

A retrospective review was performed of all patients with diffuse large B-cell lymphoma who underwent autologous marrow or peripheral-blood stem-cell transplantation at our institution between January 1 986 and December 1995.

RESULTS

Ninety patients were identified, of whom 31 (34%) had a primary mediastinal B-cell large-cell lymphoma (PML). Cumulative probabilities of disease-free survival, overall survival, and disease progression are 40% (95% confidence interval [CI], 29 to 51), 42% (95% CI, 31 to 53), and 52% (95% CI, 40 to 64), respectively. By univariate analysis, low lactate dehydrogenase (LDH) level and low Ann Arbor stage at transplant were associated with improved survival and disease-free survival. There was a trend for improved disease-free survival and survival for patients with PML. Multivariate stepwise Cox regression analysis showed that LDH level, Ann Arbor stage, and primary mediastinal localization were independent favorable prognostic factors for disease-free survival and survival. LDH level and Ann Arbor stage were also predictive for the risk of disease progression.

CONCLUSION

Our results indicate that patients with PML may display an increased susceptibility to high-dose chemotherapy compared with other types of B-cell large-cell lymphoma. These findings, if confirmed, may have implications for the initial management of patients with PML.

Use of the international prognostic index and the tumor score to detect poor-risk patients with primary mediastinal large B-cell lymphoma: a study of 37 previously untreated patients

We tested two prognostic models devised for intermediate-grade lymphomas, the age-adjusted international prognostic index and the tumor score, in 37 consecutive untreated patients treated for a diagnosis of primary mediastinal large B-cell lymphoma (PMLCL). Neither model selected for a group of patients with statistically significant differences in rates of complete response, failure-free survival (FFS) and overall survival (OS). Because the level of beta microglobulin (beta2m) is consistently low in the serum of patients with PMLCL despite bulky disease, we tested the median value of this continuous variable in the 37 patients and found it to be statistically significant for predicting FFS. A hypothetical tumor score model using the adjusted value for beta2m improved the prognostic accuracy for achievement of complete response (93% vs. 60%; P = 0.02), FFS (73% vs. 35%; P = 0.02), and OS (80% vs. 55%; P = 0.05). This hypothetical model merits further testing in a larger population of patients with PMLCL.

The influence of seasonal change on suicidal behaviour in Italy

The seasonal variance of suicides and attempted suicides in Italy from 1974 to 1994 has been studied to determine the extent and the nature of the seasonal influence on suicidal behaviour. The relationship between some climatic factors and suicide and attempted suicide rates has also been analyzed. A significant effect of seasonal change on suicidal behavior, with a clear peak in spring has been detected (ANOVA: df = 3/248, F = 5.875, p = 0.0007 for suicide; df = 3/248, F = 6.198, p = 0.0004 for attempted suicide), with a greater seasonal effect on males than females. The monthly distribution of suicide deaths and of attempted suicides follows a significant direct relationship with exposure to sun, and an inverse relationship with rainfall levels. So, one of the possible explanations for the effect of seasonal change on suicidal behaviour could be the changing seasonal climate. The complex influence of seasonal climate on human biological rhythms, particularly on 5-HT (serotonin) related functions, together with its effects on sociorelational habits, should be considered for suicide prevention.

Phase I study of fludarabine and paclitaxel for the treatment of low-grade non-Hodgkin's lymphoma

We conducted a phase I clinical trial of a new combination of fludarabine and paclitaxel in which 19 patients with histologically confirmed recurrent low-grade non-Hodgkin's lymphoma (NHL) were treated at five dose levels. Fludarabine was administered intravenously by bolus for 5 days and paclitaxel was given by intravenous (I.V.) continuous infusion for 96 or 72 hours starting day 1. Courses were repeated every 4 weeks. Patients whose disease responded received a maximum of six courses. All 19 patients received at least one course and could be evaluated for toxic effects, and 18 patients could be evaluated for response. The maximum tolerated dose (MTD) was 20 mg/m2/day I.V. bolus for 5 days of fludarabine plus 60 mg/m2/day I.V. of paclitaxel given as a continuous infusion over 72 hours. The limiting toxic effect was neutropenic fever, which was observed in five of the seven patients treated at the highest dose level. Grade 3 non-hematologic toxic effects of stomatitis (14%), neuropathy (14%), and hypotension (14%) were also observed at the highest dose level. No grade 4 non-hematologic toxic effects or treatment-related deaths occurred. One patient had herpes zoster infection of the skin 1 year after the completion of therapy. The overall response rate was 50%, with the two patients whose disease completely responded remaining disease free at 22 and 17 months. Patients with no prior exposure to either paclitaxel or fludarabine had 62% response rate. We conclude that the combination of fludarabine and paclitaxel appears to have promising activity for the treatment of recurrent low-grade NHL.