IA-2 antibody prevalence and risk assessment of early insulin requirement in subjects presenting with type 2 diabetes (UKPDS 71)

AIMS/HYPOTHESIS

Established autoimmune markers of type 1 diabetes, including islet cell autoantibodies (ICA) and autoantibodies to glutamic acid decarboxylase (GADA) have been used to screen people presenting with type 2 diabetes for latent autoimmune diabetes in adults. We have examined the prevalence of autoantibodies to protein tyrosine phosphatase isoforms IA-2 (IA-2A) and IA-2beta/phogrin (IA-2betaA) in a cohort of adult UKPDS patients thought to have type 2 diabetes, and investigated the possible role of these autoantibodies in predicting requirement for insulin therapy.

METHODS

IA-2A and IA-2betaA were measured by a validated radioimmunoassay with human recombinant autoantigens in 4,169 white Caucasian patients aged 25-65 years and newly diagnosed with type 2 diabetes. The clinical requirement for insulin therapy within 6 years was examined in 2,556 patients not randomised to insulin.

RESULTS

IA-2A and IA-2betaA were present in 2.2 and 1.4%, respectively, of these patients. IA-2A were more prevalent in younger patients (p for trend <0.00001), more often associated with the HLA-DR4 allele (26.3 vs 8.0%, p<0.0001), and their presence increased the likelihood of insulin therapy requirement within 6 years from diagnosis [relative risk (95%CI) 12.2 (9.8-15.3)]. The presence of IA-2A together with GADA increased the relative risk of requiring insulin therapy from 5.4 (4.1-7.1) for GADA alone to 8.3 (3.7-18.8) and the corresponding positive predictive value from 33 to 50%.

CONCLUSIONS/INTERPRETATION

In type 2 diabetes, the presence of IA-2A is infrequent, associated with the HLA-DR4 haplotype, and highly predictive of future need for insulin therapy. The measurement of IA-2betaA does not provide additional information.

Loss of heterozygosity at the SS receptor type 5 locus in human GH- and TSH-secreting pituitary adenomas

SS receptor types 2 and 5 (sst2 and sst5) are involved in the control of secretion and proliferation of normal and tumoral somatotrophs and thyrotrophs. The mechanisms leading to reduced responsiveness to SS analogues in patients with pituitary tumors are poorly understood. The aim of the study was to verify the possible loss of heterozygosity (LOH) at the sst5 gene locus in somatotroph and thyrotroph adenomas by screening leukocyte and tumor DNA for two single nucleotide polymorphisms, i.e. C1004T leading to P335L change and T-461C in the 5'-upstream region. Among the 13 informative samples, 1 GH- and 1 TSH-secreting adenoma showed LOH at sst5 gene locus with the retention of Leu335 variant. By analyzing other polymorphic markers spanning from telomere to 16p13.3-13.2 boundaries, DNA deletion of at least 1 megabase was found in both tumors. LOH in thyrotroph adenoma was associated with unusual tumor aggressiveness that required a second surgery and resistance to SS analogs, while no obvious phenotype was identified in the case of the somatotroph adenoma. In conclusions, LOH at the sst5 gene locus is a rare phenomenon, occurring in about 10% of pituitary tumors, that seems to be associated with an aggressive phenotype, at least in thyrotroph adenomas. Further studies are required to confirm this association and to identify the genes, in addition to sst5, lost in these tumors.

Rhythm-specific pharmacological modulation of subthalamic activity in Parkinson's disease

The subthalamic nucleus (STN) has a key role in the pathophysiology of Parkinson's disease and is the primary target for high-frequency deep brain stimulation (DBS). The STN rest electrical activity in Parkinson's disease, however, is still unclear. Here we tested the hypothesis that pharmacological modulation of STN activity has rhythm-specific effects in the classical range of EEG frequencies, below 50 Hz. We recorded local field potentials (LFPs) through electrodes implanted in the STN of patients with Parkinson's disease (20 nuclei from 13 patients). After overnight withdrawal of antiparkinsonian therapy, LFPs were recorded at rest both before (off) and after (on) acute administration of different antiparkinsonian drugs: levodopa, apomorphine, or orphenadrine. In the off-state, STN LFPs showed clearly defined peaks of oscillatory activity below 50 Hz: at low frequencies (2-7 Hz), in the alpha (7-13 Hz), low-beta (13-20 Hz), and high-beta range (20-30 Hz). In the on-state after levodopa and apomorphine administration, low-beta activity significantly decreased and low-frequency activity increased. In contrast, orphenadrine increased beta activity. Power changes elicited by levodopa and apomorphine at low frequencies and in the beta range were not correlated, whereas changes in the alpha band, which were globally not significant, correlated with the beta rhythm (namely, low beta: 13-20 Hz). In conclusion, in the human STN, there are at least two rhythms below 50 Hz that are separately modulated by antiparkinsonian medication: one at low frequencies and one in the beta range. Multiple rhythms are consistent with the hypothesis of multiple oscillating systems, each possibly correlating with specific aspects of human STN function and dysfunction.

The genetic basis of immune and autoimmune responses

HLA class I and class II molecules play a major role in the presentation of short, pathogen-derived peptides to T cells, a process that initiates the adaptive cellular and humoral immune responses. However, the factors governing a cell's ability to respond or not to particular peptides are still not completely understood. Taking the example of a viral infection, in tissues infected with a virus, viral particles are taken up by antigen-presenting cells and uncoated. The viral DNA or RNA enters the nucleus, where it replicates. mRNA enters the cytosol and is transcribed into proteins. These proteins are degraded in proteasomes and the resulting peptides (8-10 residues) are loaded onto class I molecules for export to the surface of the cells. In the meantime, the groove of the class II molecules is also preparing to accommodate peptides (12-24 residues) generated by the endocytic protein-processing pathway. The surface of the infected cell then becomes adorned with peptide-loaded human leukocyte antigen (HLA) molecules. CD4+ T helper lymphocytes engage class II molecules and elicit responses from B cells, which will ultimately lead to antibody production, whereas CD8+ T lymphocytes become cytotoxic T cells. As a consequence, the virus is eliminated from the body. However, certain mysteries and challenges remain. How can, as an exception to this rule, an autoimmune response be the escape from the perfect machinery? This review offers some hypotheses on how to see the problem through to its solution.

Gonadotropin-releasing hormone initiates multiple signaling pathways in human GH-secreting adenomas

Abnormal GH responses to GnRH test, observed in about 15% of patients with acromegaly, have been reported exclusively in patients bearing tumors without gsp mutation. The absence of responsiveness to GnRH in gsp+ tumors was not predicted on the basis of the mechanism of GnRH action that mainly involves the activation of calcium and protein kinase C dependent pathways. The aim of the present study was to investigate in detail the transduction of GnRH signaling in these tumors. GH-secreting adenomas removed from patients in vivo responsive to GnRH test were studied. Tumor DNA was screened for Gsalpha and GnRH receptor gene sequences. Intracellular calcium ([Ca2+]i) and cAMP levels were measured in dispersed cells and adenylyl cyclase (AC) activity in membrane preparations. DNA analysis showed wild sequence of both Gsalpha and GnRH receptor genes. GnRH caused a significant increase in intracellular Ca2+ that was associated with a significant stimulation of cAMP accumulation. In these cells neither TRH nor GHRP-6 were effective in causing significant modifications of cAMP levels, despite their ability to increase [Ca2+]i. Finally, GnRH was able to directly stimulate AC from 11.1 +/- 3.3 pmol/mg prot/min to 26.9 +/- 5.4 (p<0.005). We report that GnRH was effective in increasing both [Ca2+]i and AC in GH-secreting adenomas removed from responsive patients. The ability of GnRH to signal through Gsalpha protein may account for the lack of GH responses to GnRH observed in acromegalic patients with tumors carrying gsp mutation.

Area under the curve of methotrexate and creatinine clearance are outcome-determining factors in primary CNS lymphomas

Although high-dose methotrexate (HD-MTX) is the most effective drug against primary CNS lymphomas (PCNSL), outcome-determining variables related to its administration schedule have not been defined. The impact on toxicity and outcome of the area under the curve (AUC(MTX)), dose intensity (DI(MTX)) and infusion rate (IR(MTX)) of MTX and plasmatic creatinine clearance (CL(crea)) was investigated in a retrospective series of 45 PCNSL patients treated with three different HD-MTX-based combinations. Anticonvulsants were administered in 31 pts (69%). Age >60 years, anticonvulsant therapy, slow IR(MTX) (</=800 mgm(-2)h(-1)), and reduced DI(MTX) (</=1000 mgm(-2)wk(-1)) were significantly correlated with low AUC(MTX) values. Seven patients (16%) experienced severe toxicity, which was independently associated with slow CL(crea). A total of 18 (40%) patients achieved complete remission after chemotherapy, which was independently associated with slow CL(crea). In all, 22 patients were alive at a median follow-up of 31 months, with a 3-year OS of 40+/-9%; slow CL(crea) and AUC(MTX) >1100 micromol hl(-1) were independently associated with a better survival. Slow CL(crea) and high AUC(MTX) are favourable outcome-determining factors in PCNSL, while slow CL(crea) is significantly related to higher toxicity. AUC(MTX) significantly correlates with age, anticonvulsant therapy, IR(MTX), and DI(MTX). These findings, which seem to support the choice of an MTX dose >/=3 gm(-2) in a 4-6-h infusion, every 3-4 weeks, deserve to be assessed prospectively in future trials. MTX dose adjustments in patients with fast CL(crea) should be investigated.

Genetic prediction of type 1 diabetes in a population with low frequency of HLA risk genotypes and low incidence of the disease (the DIABFIN study)

BACKGROUND

To develop a sensitive, specific screening strategy for predicting genetic risk for type 1 diabetes mellitus (T1DM) in the low-incidence continental Italian population, and to define with this tool, a cohort of high-to-moderate risk infants for an immunological follow-up study aimed at identifying environmental risk factors for T1DM.

METHODS

4855 newborns in three regions of continental Italy were screened for T1DM HLA-DRB1-DQB1 risk genotypes using a reverse line blot typing method. Risk classification was based on odds ratios (OR) found in a preliminary case-control study (356 T1DM patients, 412 controls). Screening efficiency was optimized by allele subtyping.

RESULTS

Screening for well-known T1DM susceptibility genotypes [DRB1*03/*04-DQB1*0302; DRB1*03/*03; DRB1*04/*04-DQB1*0302; DRB1*04-DQB1*0302/X where X is not equal to DRB1*03, DRB1*04-DQB1*0302, DQB1*0602 or DQB1*0603] was associated with <60% sensitivity due to their low frequencies in the general Italian population. Inclusion of an additional genotype from which protective DRB1 and DQB1 alleles had been excluded [DRB1*03/X degrees where DQB1 is not equal to *0301, *0503, *0602, or *0603 and X degrees not equal DRB1*03, DRB1*04-DQB1*0302 or DRB1*07] increased screening sensitivity to 75% (specificity: 85%). Among 4855 newborns, we have found the high-risk genotype [DRB1*03/*04-DQB1*0302; estimated absolute risk (AR) 1/23] to be present in only 0.9%. The moderate-risk genotypes were found in 13.8% of newborns (estimated AR 1/177).

CONCLUSIONS

Risk classification must be tailored to the characteristics of the individual population, in particular, the allelic frequencies in the background population and T1DM prevalence. We have developed a screening strategy with good levels of sensitivity that should prove effective for use throughout the Italian peninsula.

The subthalamic nucleus in Parkinson?s disease: power spectral density analysis of neural intraoperative signals

To test a new tool for the neurophysiological identification of the human subthalamic nucleus (STN) during stereotactic surgery for the implantation of deep-brain-stimulation (DBS) electrodes, we analysed off-line the intraoperative signals recorded from patients with Parkinson's disease. We estimated the power spectral density (PSD) along each penetration track (8 patients, 13 sides) and determined the spatial correlation of the PSD with the target location estimated from neuroimaging procedures ("anatomical target"), and with the final target location derived from standard intraoperative neurophysiological procedures for STN localization ("clinical target"). At each step we recorded the 'on-line' signal for 120 seconds; because the PSD was estimated by calculating the periodogram for 6-second epochs of neural signal, we had 20 epochs at each step. When the electrode track crossed the STN, the PSD in the 0.25-2.5 kHz band increased, peaking on average <0.5 mm cranial to the clinical target and 1.00+/-1.51 mm caudal to the anatomical target. When the track was outside the nucleus, the PSD remained unchanged. Even on recordings with low signal-to-noise ratio, off-line PSD analysis of neural signals showed a good correspondence with the target indicated by the surgical team. On-line intraoperative estimation of the PSD may be a simple, reliable, rapid and complementary approach to electrophysiological monitoring during STN surgery for Parkinson's disease.

Intracranial metastasis of testicular seminoma in an HIV-positive. Case report and review

We present what appears to be the first case of an intracranial metastasis from testicular seminoma in an HIV-positive patient. The computed tomography and magnetic resonance imaging appearance of the lesion mimicked meningioma or lymphoma. A significant increase in the risk of testicular seminoma has been reported in AIDS patients. Whenever there is lymph-node involvement upon diagnosis of testicular seminoma, intracranial metastases may appear. After surgical removal of an intracranial metastasis from testicular seminoma, radiotherapy should be considered. Chemotherapy is to be included in the treatment of intracranial metastases from testicular seminoma with systemic involvement.

Deep brain stimulation for Parkinson's disease: the experience of the Policlinico-San Paolo Group in Milan

Thirty patients with idiopathic Parkinson's disease were treated with deep brain stimulation electrode in the subthalamic nucleus. After surgery, the patients' best mean Unified Parkinson's Disease Rating Scale (UPDRS III) scores (medictionOFF-stimulatorON versus preoperative medicationOFF) were 77+/-14% at 3 months ( n=20 patients) and 72+/-14% at 12 months follow-up ( n=16). The mean reduction in therapy (expressed in levodopa dose equivalents in mg) was 68+/-25% at 12 months. Postoperative complications were rare, mostly mild, and reversible. Therapeutic success depends on a multidisciplinary team approach, meticulous patient selection, including patients' cognitive, psychic, and behavioral status, and patient and family lifestyles.

Do intraoperative microrecordings improve subthalamic nucleus targeting in stereotactic neurosurgery for Parkinson's disease?

AIM

The clinical importance of intraoperative microrecordings for subthalamic nucleus (STN) localization in neurosurgical practice remains a matter of debate in the various groups.

METHODS

To investigate their usefulness in localizing the STN, we retrospectively evaluated how intraoperative microelectrode recordings changed the targeting of the STN estimated only on intraoperative stimulation and neuroanatomic targeting procedures. For neuroradiologic targeting of the nucleus we used a TC-MRI fusion algorithm and direct visualization of the STN. Besides standard microrecordings we also analyzed the power spectral density (PSD) pattern of physiological signals along the track and its neuroanatomic and clinical correlations.

RESULTS

In our series of 12 patients with Parkinson's disease undergoing surgery for implantation of deep-brain stimulation (DBS) electrodes in the STN we found that in 25% (1/4) of patients, microrecordings determined the choice of the optimal track. In all the tracks analyzed the PSD peak coincided with the point selected for the final electrode implantation on the basis of the standard procedure for intraoperative monitoring based on both microstimulation and recordings.

CONCLUSION

Intraoperative microrecordings are of determinant importance for accurate STN localization and are essential for optimal results in neurosurgical practice. PSD analysis is a simple and quick quantitative signal descriptor that will probably provide even more precise, simple and rapid tool for intraoperative neurophysiological localization of the STN.

Multiple sequential image-fusion and direct MRI localisation of the subthalamic nucleus for deep brain stimulation

AIM

Deep brain stimulation (DBS) is the treatment of choice for advanced Parkinson's disease. The target co-ordinates are traditionally calculated in relation to the intercommissural distance. Anterior (AC) and posterior commissures (PC) may be visualised by the means of ventriculography, CT or MRI.

METHODS

We have studied the efficacy of direct visualisation of the subthalamic-red nucleus complex on MRI, the advantage of fusion of stereotactic CT and MR images (Multiple Sequences Image Fusion - MuSIF). These methods are combined with double check of indirect calculation of the target co-ordinates based on AC-PC line, as well as the corrispondence to the stereotactic electronic atlas.

RESULTS

Subthalamic nucleus (STN) was well recognisable in fused images in all 22 sides. At 3 months from surgery it was possible to reduce 76% of L-dopa equivalent daily dose. Dyskine-sias reduced to 50% and motor fluctuation up to 45%.

CONCLUSION

In our experience MuSIF offers very high rate of accuracy in calculation of target co-ordinates. Direct visualisation of STN in MR and MuSIF are reliable and facilitate the accuracy of identification of target co-ordinates. Intraoperative neurophysiological recording increases the accuracy of microelectrode position.

Visualisation of the subthalamic nucleus: a multiple sequential image fusion (MuSIF) technique for direct stereotaxic localisation and postoperative control

A novel multiple, sequential image fusion (MuSIF) procedure merging stereotaxic CT with frameless magnetic resonance imaging (MRI) is used since June 2000 to visualise and directly localise the subthalamic nucleus (STN) on T2 images. In 13 consecutive Parkinson's cases, intraoperative recording and stimulation verified bilateral electrode implantation guided by fused T2 images. In 85% of sides, final implantation opted for visualised target track. Implanted electrode position on postoperative T2 images matched planned target. Clinical follow-up reproduces literature's best results. This MuSIF technique, effective for direct STN targeting, has practical advantages: MRI can be performed regardless of surgery time; regular MR scanning to correct real image distortion is unneeded; and the need for multiple localising tracks is reduced by enabling us to account for each patient's STN anatomy.

Anatomo-clinical correlation of intraoperative stimulation-induced side-effects during HF-DBS of the subthalamic nucleus

The efficacy of deep brain stimulation of the subthalamic nucleus (STN) is dependent on the accuracy of targeting. In order to reduce the number of passes and, consequently, the duration of surgery and risk of bleeding, we have set up a new method based on direct magnetic resonance imaging (MRI) localisation of the STN. This procedure allows a short duration of the neurophysiological session (one or two initial tracks). Whenever a supplementary track is needed, the stimulation-induced side effects are analysed to choose from one of the remaining holes in Ben's gun. A good knowledge of anatomical structures surrounding the STN is mandatory to relate side effects to the actual position of the track. In our series of 11 patients (22 sides, 37 tracks), the most common and reproducible side effects were those characterised by motor, sensorial, oculomotor and vegetative signs and symptoms. Moreover, the therapeutic window (distance between the current intensity needed to obtain the best clinical effect and the intensity capable to induce side effects) predicted clinical efficacy in the long-term, and contributed to the choice of which among the examined tracks had to be implanted with the chronic macroelectrode.

Movement-related modulation of neural activity in human basal ganglia and its L-DOPA dependency: recordings from deep brain stimulation electrodes in patients with Parkinson's disease

Through electrodes implanted for deep brain stimulation in three patients (5 sides) with Parkinson's disease, we recorded the electrical activity from the human basal ganglia before, during and after voluntary contralateral finger movements, before and after L-DOPA. We analysed the movement-related spectral changes in the electroencephalographic signal from the subthalamic nucleus (STN) and from the internal globus pallidus (GPi). Before, during and after voluntary movements, signals arising from the human basal ganglia contained two main frequencies: a high beta (around 26 Hz), and a low beta (around 18 Hz). The high beta (around 26 Hz) power decreased in the STN and GPi, whereas the low beta (around 18 Hz) power decrease was consistently found only in the GPi. Both frequencies changed their power with a specific temporal modulation related to the different movement phases. L-DOPA specifically and selectively influenced the spectral power changes in these two signal bands.

Renal angiomyolipoma: typical and atypical features

Renal angiomyolipoma is an uncommon lesion, well-known to the radiologists as one of the few lesions for which a specific diagnosis can be achieved on the basis of radiological findings. It contains variable amounts of adipose tissue, smooth muscle and vessels. It usually grows as single lesion, and it can be isolated or associated with tuberous sclerosis or with the more rare lymphangioleiomyomatosis. From a radiological point of view there are typical aspects that allow a confident diagnosis, whereas more rarely there are atypical aspects that make the diagnosis more controversial. In this review the clinical, macro and microscopic morphological aspects of angiomyolipoma are presented as well as the therapeutic approaches that can be adopted in different circumstances. The most frequent and the atypical characteristics that can be appreciated with diagnostic imaging are described as well.

Cerebellar mature teratoma in adulthood

Mature teratoma of the posterior cranial fossa in adults is extremely rare. We report a particularly rare case of medio-lateral cerebellar mature teratoma that became symptomatic in a middle-aged man. The CT revealed the lesion of heterogeneous density with calcifications in the solid medial portion. Only the MRI could reliably define the borders of the cystic component extending into the left cerebellar lobe. Histologically the presence of fully matured representative tissues of the 3 germ layers ensured the diagnosis of mature teratoma. We suggest that the cyst formation from progressive latent hemorrhage and/or secretion from the gland cells of the tumor, may be responsible for the clinical decompensation even in adulthood.

Assessment of cure and recurrence after pituitary surgery for Cushing's disease

BACKGROUND

The treatment of choice in Cushing's disease is transsphenoidal adenomectomy with a recurrence rate ranging 9-23%. We investigated whether abnormal hormonal responses may predict the relapse in "operated" patients followed-up for a long period.

METHOD

Sixty-eight surgically treated patients with Cushing's disease were followed-up for 12-252 months. Forty-eight patients underwent selective adenomectomy, 17 enlarged adenomectomy and 3 underwent total hypophysectomy. After surgery ACTH and cortisol levels were measured after stimulatory (desmopressin and CRH) and inhibitory tests (dexamethasone and loperamide).

FINDINGS

After operation 46 patients were cured (group A), 15 patients only normalized cortisol levels (group B), 7 patients were surgical failures. During the follow-up, a disease-free condition was maintained in 48 of 61 cases (79%), while a recurrence occurred in 13 patients (21%, 5 of group A and 8 of group B). In 5/13 patients who relapsed an absent inhibition after dexamethasone and an exaggerated response to CRH test preceded the recurrence. In 5 other patients the relapse was suspected by loperamide test. In the 3 remaining cases, positive responses to desmopressin preceded the recurrence. In 7/13 patients who relapsed the pituitary tumour was visualized by MRI/CT imaging.

INTERPRETATION

During the follow-up a careful assessment of ACTH dynamics is needed. Although no single test can reliably predict the late outcome, individual patients at risk for relapse may be identified by abnormal responses to desmopressin, CRH and loperamide tests; particularly, the persistent responsiveness to desmopressin may be a criterion of risk for recurrence in patients who only normalized cortisol levels after surgery.

Clinical predictors of drug response in obsessive-compulsive disorder

The aim of this study was to evaluate which clinical variables might influence the antiobsessional response to proserotonergic drugs in a sample of patients with obsessive-compulsive disorder (OCD). One hundred fifty-nine patients with DSM-IV OCD underwent a 12-week standardized treatment with fluvoxamine, clomipramine, citalopram, or paroxetine. According to treatment response, defined as a reduction of the Yale-Brown Obsessive Compulsive Scale total score >35%, patients were divided into two groups. Ninety patients (56.6%) responded to treatment and 69 (43.4%) did not. Responders had a significantly higher frequency of positive family history for OCD (FH-OCD) in their first-degree relatives, whereas nonresponders had an earlier onset and a higher frequency of "poor insight" subtype and somatic obsessions. The predictive value of all these variables was tested by a stepwise logistic regression analysis that confirmed poor insight and FH-OCD to be the best predictors of poor and good drug treatment response, respectively. These preliminary findings need additional investigations toward a better definition of the genetic and biological heterogeneity of patients with OCD, and they underlie the importance of collecting the insight score and family history for psychiatric disorders in the pretreatment assessment.

Multiple intracranial lesions in head injury: clinical considerations, prognostic factors, management, and results in 95 patients

BACKGROUND

The goal of this study was to identify clinical and radiological predictors of prognosis in patients with multiple post-traumatic intracranial lesions.

METHODS

We reviewed 95 patients (75 male and 20 female) between the ages of 18 and 70 (average 38) admitted between 1993 and 2000 with multiple post-traumatic intracranial lesions. Intracranial pressure (ICP) monitoring was carried out in 67 patients (70%); 77 received intensive care unit (ICU) treatment. Since in all cases it was possible to identify a clearly predominant lesion, 3 groups of patients emerged from the data: the first with extradural hematoma (EDH), the second with a combination of homolateral subdural (SDH) and intracerebral hematoma (ICH), and the third with pure focal intracerebral hematoma (ICH).

RESULTS

Twenty-seven patients were treated conservatively, 2 of whom died (7.4%); both had bilateral ICH and compression of the basal cisterns. Sixty-eight patients underwent one or more surgeries; 8 died (11.7%). In the group with EDH-predominant lesions (27 cases) all patients were operated (16 for multiple lesions); no one died. In the group with SDH+ICH-predominant lesions, 26 of 32 patients were operated (10 had multiple procedures); 6 died (18.7%), 3 were vegetative. In the group with ICH-predominant lesion, 15 of 36 patients were operated (7 bilaterally); 4 died (11%). Decompressive craniectomy proved to be a useful means to control ICP. Bilateral lobectomy is not recommended because of poor results. Immediate postoperative computed tomography (CT) scan proved to be mandatory to detect additional surgically treatable lesions (16 cases). Statistical analysis was performed by means of chi(2) analysis and multiple linear regression model. The multiple linear regression model was used to ascertain risk factors independently associated with the outcome. The type of lesion (presence of SDH+ICH predominant lesion), the worst recorded Glasgow Coma Scale (GCS) score, the presence of prolonged increased ICP, and the absence of pupillary reflexes were all statistically significant predictors of a bad outcome (dead or vegetative state).

CONCLUSIONS

Multiple lesions have the same prognosis as the corresponding single lesions; therefore, their management should be guided by the predominant pathology.

[Spiral-CT with multiplanar reconstructions (MPRS) in the evaluation of ureteral neoplasms: preliminary results]

PURPOSE

Urothelial tumors of the upper urinary tract (renal pelvis and ureters) are rare: the most common of these are Transitional Cell Carcinomas (TCC), usually localized in the bladder (75% of cases), whereas only 7-10% arise in the renal pelvis and 2,5-5% in the ureter. Multicentricity is not infrequent and synchronous or metachronous tumors have been reported to develop in 11-13% of patients with upper urinary tract cancer and 2-4% of those with bladder cancer. The presence of additional lesions can change patient management. Clinically these tumors may present with hematuria or flank pain, but sometimes there are no specific clinical findings. Radiological studies play an important role in tumor detection and staging and in follow up. The diagnosis is usually performed by IVU and US, while CT is generally employed in the staging. Our purpose was to verify the role of Spiral CT with Multiplanar Reconstructions (MPRs) in the evaluation of ureteral tumors.

MATERIAL AND METHODS

Nine patients with ureteral neoplasms were examined with a single detector spiral-CT, using the following parameters: 120 kV, 200 mA; 5 mm collimation, pitch 1.4, slice reconstruction every 5 mm; image acquisition 2-5 minutes after injection of 120 cc of contrast medium (300 mgI/ml). All the exams were transferred to a separate workstation to obtain curvilinear MPRs.

RESULTS

Spiral CT on the axial plane visualized 4 urothelial tumors as concentric ureteral wall thickening; 3 as intraluminal soft tissue masses, with involvement of almost the entire urinary tract, as far as the bladder in 1 case. In other 2 patients there were synchronous lesions which presented both patterns (wall thickening and intraluminal mass). In all cases the lesions exhibited moderate enhancement after c.m. injection. Medium- to high-grade hydronephrosis above the tumors was always present. On MPRs both ureteral involvement and dilated, urine-filled upper urinary tract were clearly represented on coronal and sagittal oblique planes; these images allowed to visualize the craniocaudal extension of short or long lesions, and to detect multicentricity.

DISCUSSION

The radiological diagnosis of ureteral tumors is usually performed by IVU, US and CT. IVU allows to visualize the tumors as filling defects or irregular narrowing of the ureteral lumen. IVU however is unable to show the real extent of the tumor in obstructive disease or in nonfunctioning kidney. US visualizes the lesion as an echoic mass in the lumen, although it is sometimes difficult to differentiate neoplastic lesions from other filling defects and to visualize the entire ureteral tract. CT is generally employed in the staging of ureteral tumors. CT findings are usually very useful for distinguishing ureteral neoplasms from other filling defects based on their attenuation and enhancement characteristics. Spiral CT with MPRs allows to obtain panoramic views of the urinary tract; these images are more effective than those of IVU, because of their capability to show the longitudinal extension of the lesion and the presence of multicentric tumors. Furthermore with MPRs it is possible to visualize the ureteral tract distal to the lesion, overcoming the limitations of IVU in nonfunctioning kidney or obstructive disease.

CONCLUSIONS

Spiral CT with MPRs is useful in the evaluation of ureteral tumors as it is capable of visualizing the whole extension of the lesion and the presence or absence of multicentric lesions, which can change patient management.

Characterization of unifocal liver lesions with pulse inversion harmonic imaging after Levovist injection: preliminary results

The aim of this study was to evaluate capabilities of pulse inversion harmonic imaging (PIHI) in characterization of unifocal liver lesions. We evaluated with PIHI (HDI5000, ATL, Bothell, Wash.) and spiral CT 46 consecutive patients with a single liver lesion identified by fundamental US [7 hepatocellular carcinomas (HCC), 2 cholangiocarcinomas, 7 focal nodular hyperplasias (FNH), 17 hemangiomas and 13 metastases]. The PIHI was performed before and 30 s, 2 and 4 min after bolus administration of Levovist (2.5 g, 300 mg/ml). Scans were digitally stored and reviewed using a dedicated software. Hepatocellular carcinoma was hyperechoic on 30-s scan, and hypoechoic (n = 5) or isoechoic (n = 2) on 2-min scan. Cholangiocarcinoma had inhomogeneous persistent enhancement. Focal nodular hyperplasia was hyperechoic (n = 5) or isoechoic (n = 2) on 30-s scan, hyperechoic (n = 4), isoechoic (n = 2) or slightly hypoechoic (n = 1) on 2-min scan. Large hemangioma revealed peripheral enhancement on 30-s scan which extended centripetally on 2-min scan. Small hemangioma appeared isoechoic on 2-min scan in all but two cases in which they were hypoechoic on 2-min scans and hyperechoic on 4-min scan. Metastasis was hypoechoic on all scans, 70% with rim enhancement. Similar changes in enhancement pattern have been observed at spiral CT. The 30-s and the 2-min scans revealed a conclusive importance in characterization of HCC, cholangiocarcinoma, and large hemangioma. The 2-min scan often furnished enough information for characterization of small hemangioma and metastasis. The 4-min scan allowed characterization of two hemangiomas which appeared hypoechoic on 2-min scans. In the other cases it did not provide further information. Diagnosis of FNH is usually reached with Colour Doppler US; PIHI should be used when colour Doppler is biased by artefacts or when colour Doppler findings are not characteristic. Our results seem to show that PIHI could be a valuable alternative diagnostic approach to spiral CT for unifocal liver lesion characterization. This hypothesis needs to be confirmed with an increased number of lesions.

Abnormal pattern of cortical activation associated with voluntary movement in obsessive-compulsive disorder: an EEG study

OBJECTIVE

Converging evidence in patients with obsessive-compulsive disorder (OCD) shows abnormalities of prefrontal areas and basal ganglia, which are also involved in motor control. Event-related desynchronization of mu and beta EEG rhythms is considered a correlate of motor activation during motor preparation and execution, followed by cortical idling or inhibition indicated by event-related synchronization. The authors investigated the circuits involved in motor behavior in OCD by using event-related desynchronization/synchronization.

METHOD

Data on alpha and beta event-related desynchronization/synchronization with self-paced movement of the right thumb were obtained by using 29-channel EEG in 10 untreated OCD patients and 10 normal subjects.

RESULTS

OCD patients showed delayed onset of mu event-related desynchronization with movement preparation and less postmovement beta synchronization, compared to normal subjects.

CONCLUSIONS

Delayed event-related desynchronization in OCD is consistent with involvement of structures related to motor programming, such as basal ganglia. Lower levels of postmovement beta synchronization suggest impairment of the inhibitory system in OCD.

The importance of substance P and calcitonin gene related peptide as vasodilator neuropeptide during acute phase of experimental posthemorrhagic vasospasm

BACKGROUND

Several immunohistochemical studies conducted in the acute phase following SAH have demonstrated a marked depletion of certain peptides like Substance P (SP), Calcitonin Gene Related Peptide (CGRP) from the adventitia of perivascular nerves. The present experimental study was carried out with the aim of determining whether the depletion of these peptides could be a protection mechanism against the factors which sustain the vasospasm.

METHODS

To accomplish this goal, we administered specific antiserum to block the potential effect of neuropeptides (SP and CGRP) prior to SAH. Our study tried also to realize whether difference can be demonstrated between endothelium-dependent (SP) and endothelium-independent vasodilatory mechanisms (CGRP) during the acute phase ofvasospasm. Twenty-three rabbits were divided in 5 experimental groups: Group A included normal control animals, Group B included rabbits who received saline injection prior to SAH, Group C included animals who received preimmune serum, groups D and E included animals who received respectively antiserum against CGRP and against SP prior to SAH. The antisera were administered into the cisterna magna by means of percutaneous suboccipital puncture. After 15 minutes 1 ml of autologous non-heparinized blood was injected in the same way. After 20 minutes the animals were sacrificed by cardiac perfusion. The basilar artery was removed by means of transclival approach and it was included in Epon 812. Mean diameters and luminal areas of the arteries were measured with morphometric method on sections of 2-3 microm of thickness.

RESULTS

The results showed a reduced mean diameter and luminal areas in the group B comparing to normal controls of the group A. A marked vasospasm is mainly evident in group D and E. In group C the vasospasm is not significantly different from that of group B. No significant difference was demonstrated between group D and group E.

CONCLUSIONS

We can conclude that: 1) the marked depletion of neuropeptides in the early phases of vasospasm represents a functional phenomenon in order to reduce the effectiveness of spasmogenic stimula. In fact the inhibition of the activity of these neuropeptides worses the entity of the vasospasm. 2) During the acute phase of vasospasm the endothelium-dependent vasodilatory mechanism is still functioning. No significant difference in the entity of vasospasm has been demonstrated between inhibition of SP (endothelium-dependent) and CGRP (endothelium-independent). Inactivation of such a mechanism occurs during late phases.

Color Doppler sonographic appearance of renal perforating vessels in subjects with normal and impaired renal function

PURPOSE

The purpose of this study was to assess the prevalence and color Doppler sonographic characteristics of perforating vessels-small arteries and veins connecting the intrarenal vasculature with the capsular plexus-in healthy subjects, in hypertensive patients, and in patients with renal failure due to hypertensive nephroangiosclerosis or ischemic nephropathy.

METHODS

Fifteen healthy subjects 24-34 years old, 15 healthy subjects 68-80 years old, 25 hypertensive patients, 25 patients with hypertension and chronic renal failure (15 mild, 10 severe), and 12 patients with hypertension and chronic renal failure and acute renal insufficiency due to ischemic nephropathy underwent color Doppler sonography of both kidneys.

RESULTS

The few perforating arteries in healthy and hypertensive patients had various resistance indices and flow toward the capsule. Perforating veins in these patients were much more common than perforating arteries. Perforating arteries with a lower mean resistance index than the mean interlobar resistance index and flow toward the capsule were detected in 76% of kidneys in the patients with mild chronic renal failure and in 20% of those in patients with severe chronic renal failure. Only a few perforating veins were seen in patients with chronic renal failure. In 64% of the kidneys with renal artery stenosis detected in the patients with chronic renal failure complicated by acute renal insufficiency, there were perforating arteries with flow toward the kidney and a mean resistance index higher than the mean interlobar resistance index.

CONCLUSIONS

Perforating vessels are recognizable using color Doppler sonography both in healthy subjects and in patients with renal failure. The prevalence and flow characteristics of perforating vessels differ between healthy subjects, patients with mild and with severe chronic renal failure, and patients with chronic renal failure complicated by acute renal insufficiency caused by renal artery stenosis.

Serum liver enzymes in Turner syndrome

Increased serum concentrations of liver enzymes are sometimes observed, in the absence of clinical symptoms of liver disease, in patients with Turner syndrome. The purpose of this study was to evaluate, in our Turner patients, serum liver enzyme levels and to find a cause for their increase. In 70 Turner patients, serum AST, ALT, GGT levels were evaluated every 6 months during a period of 0. 8-21.9 years. In patients in whom increased values of liver enzymes were found, serological markers for infectious hepatitis, serum hepatitis C virus RNA and virus genotype, IgG and IgA antibodies to gliadin and endomysium, coeruloplasmin, copper, alpha(1)-antitrypsin, total proteins and electrophoresis, IgG, IgA, IgM, fibrinogen, prothrombin, alkaline phosphatase, creatine kinase and total and direct bilirubin were also determined. Antinuclear, anti-smooth muscle and anti-liver-kidney microsome antibodies together with antithyroglobulin and anti-thyroid peroxidase antibodies were determined in all patients and in 166 age-matched female controls. In 22 patients, increased liver enzymes were observed, not related to karyotype. Follow-up showed that the hepatic disorder did not worsen with the time. Serological markers of hepatitis C virus were positive in three patients. When the serum liver enzyme increase was first observed in the other 19 patients with high enzyme levels (group A), 14 patients had never been submitted to hormonal treatment, 4 were on oestrogen/gestagen treatment and 1 was being treated with both growth hormone and oestrogen. Coeliac disease, alpha(1)-antitrypsin deficiency and Wilson disease were ruled out by appropriate investigations. In 8/19 group A patients, antinuclear and/or anti-smooth muscle antibodies were present versus 6/48 of patients with normal liver enzymes (group B). Thyroid antibodies were found in 8/19 patients in group A and in 13/48 in group B. Weight excess SDS was significantly higher in Turner girls with liver enzyme increase. Ultrasonography, performed in 17 patients of group A, showed mild hepatomegaly in 4 and increased echogenicity with fatty infiltration in 6.

CONCLUSION

Hepatic abnormalities in Turner syndrome are not progressive. Oestrogen should not be considered the main cause of increased liver enzymes in Turner syndrome since most of our patients with this finding had not been previously treated with oestrogens. An auto-immune pathogenesis might be considered in some cases, whereas the association with weight excess seems the most frequent cause of liver disorder in Turner syndrome.

[IDDM-Sardinia Project: a study model on the etiopathogenesis of insulin-dependent diabetes mellitus and other autoimmune pathologies. Gruppi di studio IDDM-Sardegna]

The "IDDM-Sardinia project" started in the beginning '90s and this main objective was, and still is, to clarify the epidemiological aspects of insulin-dependent diabetes mellitus in Sardinia, an island with a high incidence of the disease. Initially, the project included three main aims: 1) to continue monitoring the incidence of the disease and to design maps of geographical distribution of it in the island; 2) to study the pre-diabetes period, by assaying islet-related autoantibodies (ICA, GADA and IA-2icA), and to design models of prediction in a general population from a large cohort of 10,000 schoolchildren, and 3) to investigate the natural history of the disease by monitoring the appearance of islet-related autoantibodies in a cohort of 19,000 newborn. Most recently, new research lines branched from these main topics, and now the project is also investigating other autoimmune diseases, in particular coeliac disease and autoimmune thyroiditis. In this paper we still summarise and discuss the state-of-the-art of the whole project.

Detection of liver metastases with pulse inversion harmonic imaging: preliminary results

The aim of this study is to evaluate capability of contrast enhanced ultrasonography (US) using pulse inversion harmonic imaging (PIHI) to detect liver metastases in comparison to fundamental B-mode ultrasound and spiral CT. Thirty-six consecutive patients with known malignancies and sonographically proved or suspicious liver metastases have been examined with fundamental B-mode US, with PIHI 2', 4' and 6' after Levovist injection and with four phase spiral-CT. Presence, conspicuity and number of lesions have been evaluated comparing PIHI with fundamental B-mode US and spiral-CT. A strong grey-scale enhancement of the liver parenchyma has been observed 2' and 4' after Levovist injection. The optimum parenchymal enhancement and contrast difference between liver and metastases was observed during the 2' measurements. PIHI revealed more lesions than fundamental B-mode US in 56 % of patients, while in 39 % and in 5 % revealed respectively the same number and fewer lesions. PIHI and spiral-CT were in agreement in 67 % of patients, while in 22 % and 11 % PIHI revealed respectively more and fewer lesions. PIHI accurancy presents restrictions in anterior superficial and in deep liver areas, whereas it may be superior to spiral-CT in studying sub-diaphragmatic liver regions.

fMRI changes in the brain associated with the carotid compression test

PURPOSE

The purpose of our investigation was to study in normal volunteers the response to a unilateral common carotid (CC) compression test using dynamic MRI sensitive to variations in blood magnetic susceptibility.

METHOD

Nine volunteers, positioned in a 1.5 T MR scanner, performed a unilateral 40 to 45 s CC self-compression during the acquisition of single slice axial T2*-weighted FLASH images.

RESULTS

In three subjects, the signal showed a significant 2% drop from baseline in the ipsilateral frontal temporal cortex during the compression. In another three subjects, a significant 1.5-2% signal decrease was observed in both hemispheres. In two subjects whose MR angiography showed abnormalities of the circle of Willis, the bilateral signal drop was more remarkable (3%). In one volunteer, the signal did not change.

CONCLUSION

Increased deoxyhemoglobin within the brain microcirculation is the probable explanation for the signal drop. This method could be further tested in view of the widespread use of open interventional MR units.

Comparative measurements between a new logging tool and a reference instrument

Measurements were performed on reference samples (D2O-H2O mixtures) and on highly heterogeneous rocks (Vosges sandstone) with a new logging tool designed to give access to a high spatial resolution, below 1.5 cm on the vertical scale, for a toroidal sensitive volume of 20 cm3. The results were compared to measurements obtained on a clinical magnetic resonance imaging (MRI) equipment working at the same frequency (4.3 MHz). T2 differences as high as 30% were observed for the reference samples; the shortest values were obtained with the logging tool. Porosity profiles of the rock samples were also compared to reference profiles obtained with a conventional computed tomography (CT) scanner. Both nuclear magnetic resonance (NMR) measurements underevaluate porosity by 2-4% for short T2 values (< 10 ms).

Differential effects of selective beta-adrenergic blockade on insulin sensitivity and release in control subjects and in patients with angina and normal coronary arteries (syndrome X)

AIMS

Betablockers are very effective in patients with angina and angiographically smooth coronary arteries (syndrome X), but may exacerbate the state of insulin resistance that is known to be present in such patients. The aim of the study was to evaluate the effects of short-term treatment with atenolol on carbohydrate metabolism in syndrome X patients, as compared to normal subjects.

METHODS AND RESULTS

Seventeen patients (15 females, 55 +/- 8 years, BMI 23.4 +/- 2.7 kg/m2) and 11 controls (5 females, 50 +/- 7 years, BMI 23.1 +/- 2.0 kg/m2) were studied twice by an intravenous glucose tolerance test (IVGTT, 0.5 g/kg) after ten days of both placebo and atenolol (100 mg o.d.), given in random order. Metabolic indices measuring glucose effectiveness and insulin sensitivity were derived from minimal model analysis of the glucose and insulin profiles measured during the IVGTT. Indices of first- and second-phase insulin release were also calculated from the IVGTT insulin response. Atenolol had different metabolic effects on normal subjects and syndrome X patients. Despite the fact that the drug was found to be effective in relieving symptoms of chest pain, it induced a significant (p < 0.05) worsening of insulin resistance in syndrome X patients. No such effect was observed in control subjects. On the other hand, atenolol produced a marked reduction (40%, p < 0.05) of first-phase insulin release in control subjects, but no significant change of the same index in syndrome X patients.

CONCLUSION

These results show that betablockers are very effective for controlling symptoms and improving quality of life in syndrome X patients. However, they appear to further impair the ability to dispose glucose. Long-term studies on the net effects of beta-blockade administration for the treatment of such patients are warranted.

Commutability of control materials in glycohemoglobin determinations

The intermethod variabilities of control materials and patient blood samples for the measurement of glycohemoglobin were compared. Sets of 50 blood samples and 15 control materials were analyzed by HPLC and affinity and immunochemical methods. For each pair of methods, the distances of the materials from the regression line of patient blood results (expressed as normalized residuals) were calculated. Only two of 15 controls had normalized residuals exceeding 3 standard deviations from the regression line. Total hemoglobin (Hb) content, Hb derivatives, and cellulose acetate electrophoresis demonstrated that only a minority of controls could be considered similar to patients' blood samples. We selected Menarini's and our home-prepared controls to simulate calibration of the different techniques by these materials. Intermethod calibration succeeded mostly in harmonizing results obtained by HPLC methods. On the contrary, calibration of the immunochemical techniques (Boehringer and Roche) did not improve intermethod agreement to a clinically useful level.

Circadian secretory pattern of growth hormone, insulin-like growth factor type I, cortisol, adrenocorticotropic hormone, thyroid-stimulating hormone, and prolactin during HIV infection

The circadian rhythms of plasma growth hormone (GH), insulin-like growth factor type I (IGF-I), cortisol, adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), and prolactin (PRL) were evaluated in 13 HIV-seropositive patients (8 males and 5 females; mean age [+/-SD], 30 +/- 5 years), classified as CDC C2. Sixteen clinically healthy subjects (9 males and 7 females; mean age [+/-SD], 32 +/- 8 years) were chosen as control group. Samples were taken every 4 hr from 04:00 to 20:00 and every 2 hr from 20:00 to 04:00. Plasma GH was evaluated by IRMA procedure, plasma IGF-I by RIA (after separation of soluble IGF-I from IGF-I-binding proteins, using acid-ethanol extraction), plasma cortisol by a solid-phase RIA, plasma ACTH by double-antibody RIA, and serum TSH and serum PRL by a solid-phase two-site fluoroimmunometric assay. Rhythmometric data were analyzed by single and population mean cosinor analysis; the comparison of the parameters of the rhythm between patients and controls was carried out by the mesor test and the amplitude-acrophase Hotelling test. Alterations of the circadian pattern of GH, IGF-I, cortisol, ACTH, TSH, and PRL were demonstrated in HIV-seropositive patients. In fact, the circadian profiles of these hormones were clearly flattened and no statistically significant 24-hr rhythm was detectable (with the exception of cortisol). These results are consistent with the hypothesis that alterations of the circadian temporal structure may already be present in HIV-seropositive patients without wasting and infectious complications.

Excitatory pattern of gamma-interferon on natural killer cell activity in senile dementia of the Alzheimer type

Spontaneous natural killer (NK) cell activity and NK-induced cytotoxicity after interferon-gamma (IFN-gamma) were measured in healthy elderly subjects and in patients with senile dementia of Alzheimer type (SDAT) and multi-infarct dementia (MID). Normal basal and IFN-gamma-stimulated NK cytotoxicity were found in healthy old subjects and in patients with MID. On the contrary higher NK cytotoxicity after IFN-gamma (650 IU) was demonstrated in SDAT patients than in MID and healthy subjects (p < 0.001). A significant inverse correlation between the percent increase of NK cytotoxicity after IFN-gamma and the Mini Mental State Examination score (p < 0.001) was also demonstrated in patients with SDAT. Our data might suggest a cytokine-dependent mechanism of NK activation in SDAT associated with the neuroimmune hypothesis of the disease.

Nephelometry in the clinical assessment of glomerular proteinuria and tubular function in diabetic nephropathy

Urinary excretion rate and total clearances of albumin, IgG, IgA and alpha 1-microglobulin, together with selectivity index and proteinuria, were determined by computerized nephelometry in 187 IDDM and NIDDM diabetic out-patients and in 39 healthy subjects in order to perform a prompt clinical assessment of diabetic nephropathy. Significant correlations between nephelometric and RIA procedures were demonstrated for the urinary excretion of albumin (p < 0.001) and total IgG (p < 0.001) in diabetic patients and healthy subjects. Nephelometry allowed us to classify diabetic patients in different stages of nephropathy: non nephropathic, normoalbuminuric with hyperfiltration, with incipient (microalbuminuric) and overt nephropathy (macroalbuminuric). Thirty consecutive subjects were analyzed within 1 h from the beginning of the procedure. A normal tubular function was demonstrated in non nephropathic, hyperfiltering and in 34% of microalbuminuric diabetic patients. On the contrary, in 66% of microalbuminuric and in 93% of macroalbuminuric patients alpha 1-microglobulin urinary levels were found above the upper normal limit. Urinary excretion of IgA was significantly increased only in macroalbuminuric diabetic patients (p < 0.001); this marker might therefore characterise the stage of overt nephropathy. Computerized nephelometry can be considered as a prompt, reproducible and high sensitive approach in the clinical evaluation of proteinuria and tubular function in diabetic renal disease.

Retrospective analysis of long-term hemorheologic effects of pentoxifylline in diabetic patients with angiopathic complications

Blood rheology alterations have often been reported in diabetic patients and may be associated with an increased risk for diabetic vascular disease. In this light a hemorheologic approach with pentoxifylline has been suggested in diabetic patients with hemorheological changes in order to improve the hemorheology approach and to evaluate the long-term effects of this treatment on the other clinical and metabolic variables. The study concerned a 10-year retrospective analysis of diabetic patients with hemorheologic alterations and angiopathic complications. Pentoxifylline (Trental 400) significantly reduced blood and plasma viscosity (at high and low shear-rates), fibrinogen and erythrocyte aggregation, and increased erythrocyte filterability throughout the study. The improvement of the hemorheologic pattern was obtained independently of the variation in glycometabolic control and body weight changes, whereas concomitant reductions of arterial blood pressure levels and of urinary excretion of albumin and total proteins was observed during the treatment. Pentoxifylline might therefore be successfully employed for long-term periods in the treatment of hemorheologic disorders in diabetic patients without effects on the metabolic pattern.

Changes in endocrine circadian rhythms as markers of physiological and pathological brain aging

We studied the circadian rhythm of plasma melatonin, growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH), and cortisol in 52 mentally healthy old subjects, 35 old demented patients, and 22 clinically healthy young controls. When compared to young controls, the circadian profile of plasma melatonin of old subjects, both demented or not, was clearly flattened, particularly during the night. The selective impairment of nocturnal melatonin secretion was significantly related to both the age and the severity of mental impairment (Mini Mental State Examination [MMSE] score). The PRL and GH circadian profiles were similar in the three groups during the day, but a significant lowering of the values recorded during the night occurred with aging. The impairment of the nocturnal secretion was related to the subjects' age and, for the GH secretory pattern only, also to the MMSE score. The ACTH circadian profile was similar in the three groups studied, even when old subjects exhibited higher ACTH levels throughout the 24 h cycle, compared to young controls. Significantly higher cortisol values at evening- and nighttime occurred in elderly subjects and particularly in the demented group. Both the mean levels and the nadir values of plasma cortisol were positively related to age and negatively to MMSE score. In order to verify the sensitivity of the hypothalamo-pituitary-adrenal (HPA) axis to the steroid feedback, the circadian profile of plasma cortisol was evaluated also after dexamethasone (DXM) administration (1 mg at 23:00 h); the sensitivity of the HPA axis was significantly impaired in old subjects and particularly in the demented ones. These findings suggest that the neuroendocrine alterations already present in physiological aging, due to both anatomical damages and unbalanced central neurotransmitters, are enhanced in senile dementia.

Hyperviscosity and microproteinuria in central obesity: relevance to cardiovascular risk

OBJECTIVES

To investigate the role of blood rheology changes in the occurrence of glomerular proteinuria in obese patients with central fat distribution.

SUBJECTS

Fifty-nine obese out-patients (31 with central and 28 with peripheral body fat distribution) and 24 healthy subjects.

MEASUREMENTS

Blood and plasma viscosity (Rotational viscometer CV100 HAAKE), erythrocyte deformability (whole-blood filtration time), fibrinogen (nephelometry), urinary excretion rates of albumin, IgG, transferrin and IgA (nephelometry).

RESULTS

Higher blood viscosity (at low and high shear-rates), plasma viscosity, fibrinogen, erythrocyte aggregability and lower erythrocyte deformability were found in patients with central obesity than in patients with peripheral obesity (P < 0.01) and in healthy subjects (P < 0.001). Furthermore an increased urinary excretion rate of albumin (P < 0.001), IgG (P < 0.001), transferrin (P < 0.01) and IgA (P < 0.05) was found in patients with central obesity than in the other two groups. Blood hyperviscosity (at shear-rate 1 s-1 and 1/200 ratio) significantly correlated with the amount of urinary excretion of proteins independently of the other clinical and metabolic variables.

CONCLUSIONS

The data demonstrated haemorheologic disorders related to pathologic proteinuria in patients with central obesity. The interaction between these two components may increase the risk of widespread cardiovascular disease.