Prevalence and features of delirium in older patients admitted to rehabilitation facilities: a multicenter study

BACKGROUND

Delirium is thought to be common across various settings of care; however, still little research has been conducted in rehabilitation.

AIM

We investigated the prevalence of delirium, its features and motor subtypes in older patients admitted to rehabilitation facilities during the three editions of the "Delirium Day project".

METHODS

We conducted a cross-sectional study in which 1237 older patients (age ≥ 65 years old) admitted to 50 Italian rehabilitation wards during the three editions of the "Delirium Day project" (2015 to 2017) were included. Delirium was evaluated through the 4AT and its motor subtype with the Delirium Motor Subtype Scale.

RESULTS

Delirium was detected in 226 patients (18%), and the most recurrent motor subtype was mixed (37%), followed by hypoactive (26%), hyperactive (21%) and non-motor one (16%). In a multivariate Poisson regression model with robust variance, factors associated with delirium were: disability in basic (PR 1.48, 95%CI: 1.17-1.9, p value 0.001) and instrumental activities of daily living (PR 1.58, 95%CI: 1.08-2.32, p value 0.018), dementia (PR 2.10, 95%CI: 1.62-2.73, p value < 0.0001), typical antipsychotics (PR 1.47, 95%CI: 1.10-1.95, p value 0.008), antidepressants other than selective serotonin reuptake inhibitors (PR 1.3, 95%CI: 1.02-1.66, p value 0.035), and physical restraints (PR 2.37, 95%CI: 1.68-3.36, p value < 0.0001).

CONCLUSION

This multicenter study reports that 2 out 10 patients admitted to rehabilitations had delirium on the index day. Mixed delirium was the most prevalent subtype. Delirium was associated with unmodifiable (dementia, disability) and modifiable (physical restraints, medications) factors. Identification of these factors should prompt specific interventions aimed to prevent or mitigate delirium.

The association between low skeletal muscle mass and delirium: results from the nationwide multi-centre Italian Delirium Day 2017

Introduction

Delirium and sarcopenia are common, although underdiagnosed, geriatric syndromes. Several pathological mechanisms can link delirium and low skeletal muscle mass, but few studies have investigated their association. We aimed to investigate (1) the association between delirium and low skeletal muscle mass and (2) the possible role of calf circumference mass in finding cases with delirium.

Methods

The analyses were conducted employing the cross-sectional “Delirium Day” initiative, on patient 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes and hospices in Italy in 2017. Delirium was diagnosed as a 4 + score at the 4-AT scale. Low skeletal muscle mass was operationally defined as calf circumference ≤ 34 cm in males and ≤ 33 cm in females. Logistic regression models were used to investigate the association between low skeletal muscle mass and delirium. The discriminative ability of calf circumference was evaluated using non-parametric ROC analyses.

Results

A sample of 1675 patients was analyzed. In total, 73.6% of participants had low skeletal muscle mass and 24.1% exhibited delirium. Low skeletal muscle mass and delirium showed an independent association (OR: 1.50; 95% CI 1.09–2.08). In the subsample of patients without a diagnosis of dementia, the inclusion of calf circumference in a model based on age and sex significantly improved its discriminative accuracy [area under the curve (AUC) 0.69 vs 0.57, p < 0.001].

Discussion and conclusion

Low muscle mass is independently associated with delirium. In patients without a previous diagnosis of dementia, calf circumference may help to better identify those who develop delirium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01950-8.

New experimental Oximes in the management of organophosphorus pesticides poisoning

Organophosphorus compounds (OPCs) are widely used in agriculture as pesticides and occasionally in industrial settings. They have also been developed as warfare nerve agents. OPCs poisoning from intentional, accidental, and occupational exposure is a major public health problem, especially across the rural developing world. The main toxic mechanism of OPCs is the inhibition of the enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), resulting in accumulation of acetylcholine (ACh) at the synapse with cholinergic crisis and possible death. Exposure to even small amounts of an OPC can be fatal and death is usually caused by respiratory failure. Standard treatment involves the administration of intravenous atropine and an oxime to counteract acetylcholinesterase inhibition at the synapse, but the usefulness of oximes is still debated. During more than five decades, pyridinium oximes have been developed as therapeutic agents used in the medical treatment of poisoning with OPCs. They act by reactivation of AChE inhibited by OPCs. However, their activity in poisonings with pesticides and warfare nerve agents is different, and there is still no universal oxime sufficiently effective against all known OPCs. The aim of this article was to review the most recent findings in this field and compare the protection conferred by the new K-oximes and sugar oximes with the effect of the four recommended pyridinium oximes (pralidoxime, obidoxime, trimedoxime, and HI-6), in the search for a broad-spectrum AChE reactivator.

[Consultations at the Poison Center of Rome on pesticide poisoning referrals]

From 1 January 1998 to 31 October 1999 the two Poison Control Centres active in Rome provided 923 telephone consultations for individuals and health care providers on suspected poisonings involving pesticides. Exposures more frequently reported in association with suspected cases were insecticides (n. 636), including organophosphates (n. 300), carbamates (n. 155), pyrethroids (n. 102), and organochlorines (n. 79). Children aged 1-4 years accounted for 22% of all suspected poisonings (n. 200). Each case was classified as to the likelihood of a relationship between the reported pesticide exposure and the occurrence of health effects. Around 18% of suspected pesticide poisonings (n. 168) were subsequently classified as definite, around 43% (n. 390) as possible, and around 37% were considered unlikely (n. 344).

Interferon alpha-2B and ribavirin in combination for patients with chronic hepatitis C who failed to respond to, or relapsed after, interferon alpha therapy: a randomized trial

PURPOSE

To assess the efficacy of interferon alpha-2b and ribavirin in combination in the treatment of patients with chronic hepatitis C who had either failed to respond to therapy with interferon alpha (nonresponders), or who had relapsed after interferon therapy (relapsers).

SUBJECTS AND METHODS

Four hundred patients with chronic hepatitis C (200 nonresponders and 200 relapsers) were randomly assigned in equal numbers to receive either subcutaneous administration of recombinant interferon alpha-2b (3 million units three times per week) and ribavirin (1,000 to 1,200 mg/daily orally) or interferon alpha-2b alone (6 million units three times per week). Both ribavirin and interferon alpha-2b were given for 24 weeks. The patients were then followed for an additional 24 weeks.

RESULTS

At the end of the treatment period, normalization of serum alanine aminotransferase levels and absence of hepatitis C virus RNA were seen in 21% of nonresponders and in 39% of relapsers who were treated with interferon alpha-2b and ribavirin, compared with 5% of nonresponders (P = 0.001) and 9% of relapsers treated with interferon alpha-2b alone (P <0.001). At the end of follow-up, 14% of nonresponders and 30% of relapsers treated with the combination therapy had a sustained response, compared with 1% of nonresponders (P = 0.001) and 5% of relapsers treated with interferon alpha alone (P <0.001).

CONCLUSIONS

A 24-week course of treatment with interferon alpha-2b and ribavirin offers a chance of sustained response, whereas retreatment with interferon alpha-2b alone does not give satisfactory results. The role of long-term therapy in inducing prolonged remission remains to be explored.

Emergency therapeutical approach simulating ultrarapid opioid detoxification in methadone withdrawal precipitated by erroneous administration of naltrexone

We report the case of a 30-year-old male, heroin dependent, receiving methadone treatment, who, while staying at home, ingested 50 mg of naltrexone. He immediately developed serious withdrawal symptoms and was admitted to the hospital. In the emergency department the drugs given to counteract the agitation were ineffective, and the patient developed respiratory distress. Anaesthesia with propofol was then started and the patient was intubated, ventilated and hospitalized in the intensive care unit. He was then sedated for 48 hours due to persistent withdrawal signs. When medically stable the patient was transferred to the medical ward where daily treatment with naltrexone and psychological support where started. After 4 days the patient was discharged. Afterwards he did not attend his scheduled outpatient follow-up visits. Treatment with propofol is effective in the case of a patient with a serious withdrawal syndrome secondary to naltrexone overdose during methadone therapy. Despite the actual possibility of getting through the withdrawal symptoms the patient failed to return for follow-up visits, which might be related to a lack of motivation.

TCR expression and clonality analysis in peripheral blood and lymph nodes of HIV-infected patients

We compared the T cell receptor (TCR) V beta gene family repertoire in peripheral blood mononuclear cells (PBMC) and lymph node (LN) cells from 7 human immunodeficiency virus (HIV)-infected patients and 3 seronegative healthy controls. Virtually all the V beta family specificities were represented in patient PBMC and LN cells, and mean values for each specificity were comparable to figures in seronegative controls. In 4 patients, however, some V beta gene segment transcripts were overrepresented in the LN compartment, compared to the peripheral blood counterpart. To ascertain whether this phenomenon was due to polyclonal or oligoclonal expansion of T cells bearing the relevant V beta gene product, we sequenced the entire CDR3 region of a panel of 238 PCR clones corresponding to the V beta transcripts expanded in LN; as control, the same regions were cloned and sequenced in patient's PBMC, and in PBMC and LN cells from seronegative individuals. This analysis disclosed preferential usage of J beta 2 genes in PBMC and LN cells from both seropositive patients and controls, regardless of the V beta gene segment considered, thus indicating that this skewness in the V beta-J beta repertoire could be a consistent feature of at least a part of the V beta repertoire in different lymphoid compartments, regardless of the pathologic conditions. In addition, in LN from HIV seropositive patients we found the presence of recurrent TCR rearrangements, accounting for 8-23% of the generated clones, in each of the 4 V beta specificities analyzed; recurrent sequences were not found in PBMC from patients nor in PBMC and LN cells from seronegative controls. These findings suggest that antigen-driven oligoclonal T cell expansions may occur in vivo in lymphoid organs of HIV seropositive patients.

Quantitative cerebral blood flow and metabolism determination in the first 48 hours after severe head injury with a new dynamic SPECT device

OBJECTIVE

To determine cerebral blood flow (CBF) and metabolism in the acute phase after severe head injury by a new dynamic SPECT device using 133Xenon and to evaluate a possible role of CBF and metabolism in the determination of prognosis.

DESIGN

Prospective study.

SETTING

General intensive care unit in a universitary teaching hospital.

SUBJECTS

23 severely head injured patients having CT scan and CBF determination, intracranial pressure (ICP) and jugular bulb oxygen saturation monitoring in the first 48 hours.

MEASUREMENTS AND MAIN RESULTS

CBF varied from 18.0 to 60.0 ml/100 g/min. No correlation was found between early CBF and severity of trauma evaluated with the Glasgow Coma Score (GCS) (F = 2.151, p = 0.142) and between CBF and prognosis at 6 months evaluated with Glasgow outcome score (GOS) (F = 0.491, p = 0.622: rs = 0.251, p = 0.246). CMRO2 was depressed in relation to the severity of injury, specifically ranging from 0.9 +/- 0.5 ml/100 g/min in patients with GCS 3 to 1.7 +/- 0.8 ml/100 g/min in patients with GCS 6-7. In no patient with CMRO2 less than 0.8 ml/100 g/min was a good outcome observed. A significant correlation was found between GCS and GOS (rs = 0.699, p = 0.0002), between CMRO2 and GOS (F = 4.303, p = 0.031; rs = 0.525, p = 0.013) and between AJDO2 and GOS (F = 3.602, p = 0.046; rs = 0.491, p = 0.017). Fronto-occipital ratio (F/O) of CBF distribution was significantly lower than normal values (chi 2 = 18.658, p = 0.001) but did not correlate either with prognosis (chi 2 = 1.626, p = 0.443) or with severity (chi 2 = 1.913, p = 0.384).

CONCLUSIONS

CBF in the first 48 hours after trauma varies within a large range of values and is not correlated with severity and prognosis. Clinical evaluation with GCS and CMRO2 are much more reliable indicators of severity of head trauma and have a significant role in the determination of prognosis. F/O ration is significantly altered from normal values confirming "post-traumatic hypofrontalism" but does not correlate with severity and prognosis.

[Computerized multiple-choice questions: an efficacious method of evaluation in medical instruction?]

To evaluate the efficacy of Multiple Choice Questions (MCQ) as an evaluation tool in medical education, were analyzed the responses to 80 MCQ delivered by 300 physicians working in emergency departments and following a course on Basic and Advanced Life Support. Pre- and post-test were administered using a dedicated computer application running on PC. Students' scores were high and demonstrated both course and test validity. More than 95% of the students used the computer application without interface difficulties. However, some limits of MCQ were individuated: first, misinterpretation of some questions, especially when two or more similar answers were presented; from the other side, the student's personal experiences during the course practice could influence student's responses bringing him to different conclusions on respect to the instructor. These difficulties should be kept in mind in the development of a MCQ session, and students should have the possibility to give to the instructor a feedback of problems encountered during the course. This is especially important when MCQ are the sole evaluation technique.

Reactivation of oral-lingual herpes by chlorinated swimming pool water: a case report

The authors describe the case of a highly stressed 36-year-old man who experienced ten or more painful episodes per year of recurrent oral-lingual herpes simplex virus 1, which were only partially responsive to acyclovir therapy for three years. A three-year diary of activities, personal stresses, concurrent infections, local trauma, and other possible psychogenic, somatogenic, and environmental events was used systematically to attempt to pair the stresses with the recurrent herpes episodes. Chlorinated swimming pool water seems to have been the triggering agent of the recurrent herpes simplex virus 1 episodes due to its temporal correlation and the greater than twenty-four-month asymptomatic period after the patient discontinued swimming in chlorinated water, but continued to swim in fresh and salt water, along with his normal pursuit of all other activities and habits.

What is the best test to predict outcome after prolonged cardiac arrest?

Multimodality evoked potentials (EPs), linear electroencephalograms and Glasgow Coma Scale (GCS) scores were recorded within 24 h of cardiac arrest in 62 patients who were comatose following cardiopulmonary resuscitation. The cardiac arrest had a cardiac cause in 35 patients and a non-cardiac cause in 27 patients. The Glasgow Outcome Scale (GOS) scores were established 6 months after resuscitation. The prognostic value of all the recorded variables was calculated in terms of sensitivity, specificity and accuracy. Spearman's rank test was also used for the determination of the correlation coefficients with GOS. EP recordings furnished no falsely pessimistic predictions, with a specificity of 100%. In other words, when EPs were altered, the prognosis was always poor. However, while all patients who regained consciousness had normal EPs, not all patients in whom EPs were recordable survived. The GCS score showed a higher sensitivity and correlation with GOS score than EPs, but it was associated with a high percentage of false positive results, and its specificity was only 67%. The combination of the GCS score with EPs may be a promising strategy to counterbalance the respective limits of these methods and to reduce the loss of information due to sedation and myorelaxation, which impede clinical examination but not EP results.

B and T cell function parameters during zidovudine treatment of human immunodeficiency virus-infected patients

The aim of this study was to assess the effects of zidovudine on B cell dysregulation in human immunodeficiency virus (HIV)-infected patients and the phenomenon of gp 120/anti-gp 120 antibody complex adhesion to CD4+ cells. Compared with pretherapy figures, zidovudine treatment was not associated with a change in spontaneous in vitro synthesis of anti-HIV antibodies but was related to restoration of lymphocyte ability to produce Epstein-Barr virus-specific antibodies in 43% of previously unresponsive patients. After 30 days of therapy, the percentage of circulating CD4+/IgG+ lymphocytes decreased; the number of available CD4 receptors per cell increased, and antibodies to gp 120, evident in CD4+ cell eluates from most untreated patients, were no longer detectable. These results indicate that zidovudine partly restores in vitro humoral responsiveness but does not substantially influence the overall activation of the B cell compartment. The findings also suggest that zidovudine may down-regulate some immunopathologic phenomena that amplify direct viral damage.

B cell activation and human immunodeficiency virus infection. V. Phenotypic and functional alterations in CD5+ and CD5- B cell subsets

B cell dysregulation is a hallmark of human immunodeficiency virus infection. Since B lymphocytes comprise two distinct subpopulations, CD5+ and CD5- cells, we addressed their individual phenotypic and functional behavior. Seropositive patients with both limited and advanced disease progression had an increased percentage of peripheral blood CD5+ B cells, compared to seronegative controls (20.1 +/- 2.1 and 22.7 +/- 5.7, respectively, vs 17.0 +/- 3.4 in controls); however, due to the lymphopenia and reduced number of circulating B cells in infected individuals, the absolute number of CD19+CD5+ lymphocytes was actually reduced. Although HIV-specific antibodies were synthesized spontaneously in vitro only by CD5- B cells, a 10-fold lower degree of spontaneous, non-HIV-specific activation was also displayed by unstimulated CD5+ B cells. These findings indicate that B cell dysregulation during HIV infection involves both the CD5- and the CD5+ B cell compartments; moreover, in view of the putative role of CD5+ B cells in autoimmune phenomena and IL-10 production, these data reinforce the possibility that B cell dysfunction might be causally involved in AIDS pathogenesis.

Persistent polyclonal lymphocytosis in human immunodeficiency virus-1-infected patients

In this study we describe the clinical, morphologic, immunologic, and genetic features of a chronic peripheral blood lymphocytosis associated with posttraumatic splenectomy in patients with human immunodeficiency virus-1 (HIV-1) infection. Among a series of 2,365 consecutive HIV-1 seropositive cases investigated, eight patients were selected for the presence of more than 4,000 lymphocytes/mm3. All cases were characterized by a lymphocytosis with cytoplasmic azurophilic granules; in three patients the hematologic picture was superimposable with that of lymphoproliferative disease of granular lymphocytes. Phenotypic analysis of lymphocytes showed a prevalent CD3+CD8+ pattern. In vitro evaluations, including the response to mitogens and interleukin-2 and the cytotoxic assays, showed an unimpaired lymphocyte function in the majority of our patients, even in those with advanced stages of the syndrome. The analysis of the configuration of the T-cell receptor (TCR) beta and gamma genes showed a polyclonal pattern of rearrangement. At the mean follow-up time of 45 +/- 8 months, one patient died of overdose when the clinical conditions were stable; all the other patients are alive, although disease progression was documented in two. Our results indicate that a chronic polyclonal lymphocytosis may be associated with HIV-1 infection; this finding seems to be restricted to patients who have undergone splenectomy. The demonstration of a still uncompromised immune system together with a silent clinical course in the patients under study also suggest that splenectomy per se does not favor an aggressive clinical behavior of HIV-1 infection.

Standardization of in vitro synthesis and detection of HIV-1-specific antibodies

Optimal conditions for in vitro anti-human immunodeficiency virus type 1 (HIV-1) antibody (Ab) synthesis and detection were re-appraised. Western blot (WB) and radioimmunoassay (RIA) could detect about 1 and 10 ng, respectively, of HIV-1-specific Ab (HIV-Ab), while the sensitivity of an enzyme-linked immunosorbent assay (ELISA) was much lower. Optimal HIV-Ab recovery was obtained by culturing 2.5 x 10(6) peripheral blood mononuclear cells (PBMC)/ml from seropositive subjects for 16 days in the absence of mitogens; at higher cell concentrations, background levels were unacceptably high. The background of non-de novo synthesized HIV-Ab was due to insufficient PBMC washing and/or cytophilic immunoglobulin (Ig); a particular washing procedure, as well as 24 h peripheral blood mononuclear cells (PBMC) pre-culture, might help in limiting this phenomenon. However, results should be compared with those obtained in cultures containing puromycin especially in infants, where a higher CD16 antigen expression in lymphocytes is likely responsible for increased amounts of cytophilic Ig released in culture supernatants, compared to adults.

AZT-induced mitochondrial myopathy

Histochemical, electron microscopy and biochemical studies were performed on muscle biopsy specimens from 11 AIDS patients treated with zidovudine. A peculiar association of structural abnormalities and mitochondrial dysfunction was found. Focal cytochrome c oxidase (COX) deficiency was evident in muscle sections from 9 patients, 8 of whom had received long-term treatment while one had been treated for 1 month only. Electron microscopy showed changes in number, size and structure of mitochondria. Biochemical studies proved partial COX and succinate cytochrome c reductase (SCR) deficiency in 4 patients; one patient had only reduced SCR activity. Our data confirm that AZT therapy can cause toxic myopathy with mitochondrial dysfunction.

Serial multimodality-evoked potentials in severely head-injured patients: diagnostic and prognostic implications

OBJECTIVES

To assess the prognostic reliability of multimodality-evoked potentials and to evaluate the diagnostic implications and define the limits of these evoked potentials.

SETTING

An ICU in a university hospital.

DESIGN

Prospective clinical study.

PATIENTS

Seventy-three severely head-injured patients aged 10 to 75 yrs.

METHODS

Serial recording of brainstem auditory-evoked potentials and somatosensory-evoked potentials between days 1 and 21 after trauma. Comparison between evoked potential findings and prognosis, along with clinical data.

RESULTS

Considering the single recordings of both brainstem auditory-evoked potentials and somatosensory-evoked potentials, the accuracy of prognostication in predicting a bad outcome was good only for severely abnormal brainstem auditory-evoked potentials. Serial brainstem auditory-evoked potential recordings and simultaneous recordings of brainstem auditory-evoked potentials and somatosensory-evoked potentials proved to be good prognostic indices in predicting a favorable outcome. Brainstem auditory-evoked potentials correlated well with brainstem reflexes and with pupil asymmetries but did not correlate with Glasgow Coma Scale scores.

CONCLUSIONS

Serial recording and the use of a multimodality approach provided the best prognostic capabilities. The main diagnostic implications were: a) the possibility of detecting brainstem compression by means of brainstem auditory-evoked potentials before the appearance of pupil abnormalities; b) the usefulness of brainstem auditory-evoked potentials in monitoring brainstem function in patients undergoing high-dose barbiturate therapy. The main limitations of evoked potentials were the occurrence of peripheral acoustic damage, the electromagnetic sources of artifacts in the ICU, and the administration of ototoxic drugs.

B-cell activation during HIV-1 infection. III. Down-regulating effect of mitogens

Spontaneous in vitro production of HIV-1-specific antibodies, a hallmark of infected subjects, is often down-regulated by the addition of pokeweed mitogen. We observed that a decrease in such ongoing anti-HIV-1 antibody synthesis could also be induced in cultures from most patients by addition of phytohemagglutinin and Concanavalin A, but not by Epstein-Barr virus, a selective B-cell mitogen. In most cases, this down-regulatory effect of mitogens was evident within the first 24 h of culture. The observed mitogen-associated decrease in spontaneous antibody synthesis was prevented by treating peripheral blood mononuclear cells with agents inhibiting non-major histocompatibility complex-restricted cytotoxic activity or by adding third-party cells to the cultures. In most cases, the mitogen-induced effect was also counteracted by removal of T lymphocytes or CD8+ T-cell sub-population. These findings recall a similar phenomenon observed in normal subjects following intentional immunization, and indicate that mitogen-induced down-regulation of spontaneous in vitro anti-HIV-1-antibody production most probably occurs through a lectin-dependent cytotoxic effect on activated B cells.

[Brain mapping of middle latency auditory potentials in normal subjects]

The MLRs of 20 normal hearing adults were recorded by cerebral mapping. In regard to the Pa and Na waves, it is suggested that two different generation sites exist because of the different spatio-temporal distribution of the waves over the scalp. It is demonstrated that amplitudes measured by the "grand average" technique are constantly lower than those obtained with the manual determination, and they conclude that manual determination represents the most reliable method in order to calculate waves amplitude. Finally, it is suggested that, due to the different generation sites for Pa and Na waves and to the uneven distribution of the Na wave over the scalp, Pa amplitude should be measured from the baseline and not from the Na negative deflection. Moreover, in 14 cases, when one ear was stimulated the Pa wave obtained at most recording points was significantly larger than the one recorded contralaterally.

B cell activation during HIV-1 infection. II. Cell-to-cell interactions and cytokine requirement

This study examined the mechanisms underlying the intense activation of HIV-1-specific B cells observed in peripheral blood of HIV-1-infected subjects. Spontaneous in vitro synthesis of anti-HIV-1 antibodies, as well as total Ig production, were dramatically reduced by accessory cell, but not T cell removal. This fall was counteracted by addition of rIL-6, but not other cytokines, to monocyte-depleted cultures; moreover, antisera against IL-6 suppressed spontaneous anti-HIV-1 antibody synthesis in a dose-dependent manner. Although IL-6 apparently sustained HIV-1-specific B cell activation, no increase in serum IL-6 levels was observed; PBMC from seropositive subjects did not produce increased amounts of IL-6 in vitro, compared to seronegative controls, both spontaneously and in the presence of LPS stimulation; finally, no constitutive expression of IL-6 gene could be documented in freshly isolated PBMC. These findings indicate that IL-6 may play a central role in HIV-1-specific B cell activation in seropositive patients, and further stress the importance of this cytokine during HIV-1 infection.

B cell activation during HIV-1 infection. II. Cell-to-cell interactions and cytokine requirement

This study examined the mechanisms underlying the intense activation of HIV-1-specific B cells observed in peripheral blood of HIV-1-infected subjects. Spontaneous in vitro synthesis of anti-HIV-1 antibodies, as well as total Ig production, were dramatically reduced by accessory cell, but not T cell removal. This fall was counteracted by addition of rIL-6, but not other cytokines, to monocyte-depleted cultures; moreover, antisera against IL-6 suppressed spontaneous anti-HIV-1 antibody synthesis in a dose-dependent manner. Although IL-6 apparently sustained HIV-1-specific B cell activation, no increase in serum IL-6 levels was observed; PBMC from seropositive subjects did not produce increased amounts of IL-6 in vitro, compared to seronegative controls, both spontaneously and in the presence of LPS stimulation; finally, no constitutive expression of IL-6 gene could be documented in freshly isolated PBMC. These findings indicate that IL-6 may play a central role in HIV-1-specific B cell activation in seropositive patients, and further stress the importance of this cytokine during HIV-1 infection.

[Bile salts, copper, ceruloplasmin in meal test]

Biliary salts determination after meal test is an useful liver function test. We evaluated both biliary salts and copper-ceruloplasmin after meal test in different liver diseases. Copper-ceruloplasmin determination does not seem to be useful in the diagnosis of liver diseases because copper has only partial hepatic clearance.