Phosphorus Acquisition Efficiency and Transcriptomic Changes in Maize Plants Treated with Two Lignohumates

Lignohumates are increasing in popularity in agriculture, but their chemistry and effects on plants vary based on the source and processing. The present study evaluated the ability of two humates (H1 and H2) to boost maize plant performance under different phosphorus (P) availability (25 and 250 μM) conditions in hydroponics, while understanding the underlying mechanisms. Humates differed in chemical composition, as revealed via elemental analysis, phenol and phytohormone content, and thermal and spectroscopic analyses. H1 outperformed H2 in triggering plant responses to low phosphorus by enhancing phosphatase and phytase enzymes, P acquisition efficiency, and biomass production. It contained higher levels of endogenous auxins, cytokinins, and abscisic acid, likely acting together to stimulate plant growth. H1 also improved the plant antioxidant capacity, thus potentially increasing plant resilience to external stresses. Both humates increased the nitrogen (N) content and acted as biostimulants for P and N acquisition. Consistent with the physiological and biochemical data, H1 upregulated genes involved in growth, hormone signaling and defense in all plants, and in P recycling particularly under low-P conditions. In conclusion, H1 showed promising potential for effective plant growth and nutrient utilization, especially in low-P plants, involving hormonal modulation, antioxidant enhancement, the stimulation of P uptake and P-recycling mechanisms.

Transcriptomic and physiological approaches to decipher cold stress mitigation exerted by brown-seaweed extract application in tomato

Chilling temperatures represent a challenge for crop species originating from warm geographical areas. In this situation, biostimulants serve as an eco-friendly resource to mitigate cold stress in crops. Tomato (Solanum lycopersicum L.) is an economically important vegetable crop, but quite sensitive to cold stress, which it encounters in both open field and greenhouse settings. In this study, the biostimulant effect of a brown-seaweed extract (BSE) has been evaluated in tomato exposed to low temperature. To assess the product effects, physiological and molecular characterizations were conducted. Under cold stress conditions, stomatal conductance, net photosynthesis, and yield were significantly (p ≤ 0.05) higher in BSE-treated plants compared to the untreated ones. A global transcriptomic survey after BSE application revealed the impact of the BSE treatment on genes leading to key responses to cold stress. This was highlighted by the significantly enriched GO categories relative to proline (GO:0006560), flavonoids (GO:0009812, GO:0009813), and chlorophyll (GO:0015994). Molecular data were integrated by biochemical analysis showing that the BSE treatment causes greater proline, polyphenols, flavonoids, tannins, and carotenoids contents.The study highlighted the role of antioxidant molecules to enhance tomato tolerance to low temperature mediated by BSE-based biostimulant.

Brown Seaweed Extract (BSE) Application Influences Auxin- and ABA-Related Gene Expression, Root Development, and Sugar Yield in Beta vulgaris L

The molecular and phenotypic effects of a brown seaweed extract (BSE) were assessed in sugar beet (Beta vulgaris L.). Transcript levels of BSE-treated and untreated plants were studied by RNA-seq and validated by quantitative real-time PCR analysis (RT-qPCR). Root morphology, sugar yield, and processing quality traits were also analyzed to better elucidate the treatment effects. RNA-seq revealed 1019 differentially expressed genes (DEGs) between the BSE-treated and untreated plants. An adjusted p-value < 0.1 and an absolute value of log2 (fold change) greater than one was used as criteria to select the DEGs. Gene ontology (GO) identified hormone pathways as an enriched biological process. Six DEGs involved in auxin and ABA pathways were validated using RT-qPCR. The phenotypic characterization indicated that BSE treatment led to a significant increase (p < 0.05) in total root length and the length of fine roots of plants grown under hydroponics conditions. The sugar yield of plants grown under field conditions was higher (p < 0.05) in the treated field plots compared with the control treatment, without impacting the processing quality. Our study unveiled the relevant effects of BSE application in regulating auxin- and ABA-related gene expression and critical traits related to sugar beet development and yield.

A dual-omics approach for profiling plant responses to biostimulant applications under controlled and field conditions

A comprehensive approach using phenomics and global transcriptomics for dissecting plant response to biostimulants is illustrated with tomato (Solanum lycopersicum cv. Micro-Tom and Rio Grande) plants cultivated in the laboratory, greenhouse, and open field conditions. Biostimulant treatment based on an Ascophyllum nodosum extract (ANE) was applied as a foliar spray with two doses (1 or 2 l ha^-1) at three different phenological stages (BBCH51, BBCH61, and BBCH65) during the flowering phase. Both ANE doses resulted in greater net photosynthesis rate, stomatal conductance, and fruit yield across all culture conditions. A global transcriptomic analysis of leaves from plants grown in the climate chamber, revealed a greater number of differentially expressed genes (DEGs) with the low ANE dose compared to the greater one. The second and third applications induced broader transcriptome changes compared to the first one, indicating a cumulative treatment effect. The functional enrichment analysis of DEGs highlighted pathways related to stimulus-response and photosynthesis, consistent with the morpho-physiological observations. This study is the first comprehensive dual-omics approach for profiling plant responses to biostimulants across three different culture conditions.

PsiNorm: a scalable normalization for single-cell RNA-seq data

MOTIVATION

Single-cell RNA sequencing (scRNA-seq) enables transcriptome-wide gene expression measurements at single-cell resolution providing a comprehensive view of the compositions and dynamics of tissue and organism development. The evolution of scRNA-seq protocols has led to a dramatic increase of cells throughput, exacerbating many of the computational and statistical issues that previously arose for bulk sequencing. In particular, with scRNA-seq data all the analyses steps, including normalization, have become computationally intensive, both in terms of memory usage and computational time. In this perspective, new accurate methods able to scale efficiently are desirable.

RESULTS

Here, we propose PsiNorm, a between-sample normalization method based on the power-law Pareto distribution parameter estimate. Here, we show that the Pareto distribution well resembles scRNA-seq data, especially those coming from platforms that use unique molecular identifiers. Motivated by this result, we implement PsiNorm, a simple and highly scalable normalization method. We benchmark PsiNorm against seven other methods in terms of cluster identification, concordance and computational resources required. We demonstrate that PsiNorm is among the top performing methods showing a good trade-off between accuracy and scalability. Moreover, PsiNorm does not need a reference, a characteristic that makes it useful in supervised classification settings, in which new out-of-sample data need to be normalized.

AVAILABILITY AND IMPLEMENTATION

PsiNorm is implemented in the scone Bioconductor package and available at https://bioconductor.org/packages/scone/.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

The outcomes of surgical management of failed two-stage revision knee arthroplasty

Background:

Joint infection following total knee arthroplasty has significant consequences on both the patient and healthcare system. Two stage revision arthroplasty is viewed as the gold standard in management. However, recurrence of infection following this procedure is a growing clinical problem for a multitude of reasons. Despite a variety of surgical options for management of failure of two-stage revision arthroplasty, the potential for complications and functional limitation remains high, and the optimal strategy is yet to be determined.

Methods:

We performed a systematic review of all papers reporting on the outcomes of the surgical management of failure of two-stage revision arthroplasty published up to and including January 2020. Data was extracted on patient demographics, study design, methodological quality, indication for surgery, surgical technique, clinical and functional outcomes, and complications.

Results:

Nine papers with a total of 273 patients were found and analysed. All surgical techniques had mixed results in term of clinical and functional outcomes, and the rate of complications was high in all studies. Knee arthrodesis had the lower risk of failure than repeat 2 stage revision. Poor patient immunological status and limb status were weakly associated with increased risk of failure.

Conclusion:

Despite failure of two-stage revision arthroplasty being a growing clinical issue, we were not able to identify any consistently superior surgical technique for the management of this scenario. Knee arthrodesis appears to provide the best results for improving quality of life and reducing infection recurrence, although the complication rate is high, and the functional outcomes appear to be worse. Further larger and prospective studies are needed to elucidate optimal surgical management in different patient subsets.

Transcriptional and Physiological Analyses to Assess the Effects of a Novel Biostimulant in Tomato

This work aimed to study the effects in tomato (Solanum lycopersicum L.) of foliar applications of a novel calcium-based biostimulant (SOB01) using an omics approach involving transcriptomics and physiological profiling. A calcium-chloride fertilizer (SOB02) was used as a product reference standard. Plants were grown under well-watered (WW) and water stress (WS) conditions in a growth chamber. We firstly compared the transcriptome profile of treated and untreated tomato plants using the software RStudio. Totally, 968 and 1,657 differentially expressed genes (DEGs) (adj-p-value < 0.1 and |log2(fold change)| ≥ 1) were identified after SOB01 and SOB02 leaf treatments, respectively. Expression patterns of 9 DEGs involved in nutrient metabolism and osmotic stress tolerance were validated by real-time quantitative reverse transcription PCR (RT-qPCR) analysis. Principal component analysis (PCA) on RT-qPCR results highlighted that the gene expression profiles after SOB01 treatment in different water regimes were clustering together, suggesting that the expression pattern of the analyzed genes in well water and water stress plants was similar in the presence of SOB01 treatment. Physiological analyses demonstrated that the biostimulant application increased the photosynthetic rate and the chlorophyll content under water deficiency compared to the standard fertilizer and led to a higher yield in terms of fruit dry matter and a reduction in the number of cracked fruits. In conclusion, transcriptome and physiological profiling provided comprehensive information on the biostimulant effects highlighting that SOB01 applications improved the ability of the tomato plants to mitigate the negative effects of water stress.

Clinical outcome and failure analysis of medial meniscus bucket-handle tear repair: a series of 96 patients with a minimum 2 year follow-up

INTRODUCTION

The failure rate of meniscal repair remains significant, especially for bucket-handle tears. This study aimed to evaluate the clinical outcomes, failure rate and risk factors for failure of bucket-handle medial meniscal tear repairs performed during ACL reconstruction.

MATERIALS AND METHODS

A retrospective analysis of prospectively collected data was performed on a consecutive series of 96 ACL reconstructions with meniscal arthroscopic suture of a bucket-handle tear of the medial meniscus with a minimum 2 year follow-up. Preoperative and postoperative evaluation at last follow-up included objective IKDC rating, instrumented differential laxity and Tegner activity level. Functional outcome was evaluated with Lysholm score at last follow-up. Failure rate, survival curves and risk factor analysis using Cox proportional hazard ratio models were performed to analyze suture repair failure.

RESULTS

At IKDC rating, all patients were C or D preoperatively, whereas they where all A or B at last follow-up. Instrumented differential laxity improved from 6.77 mm (1.57) to 1.02 mm (1.15) mm at last follow-up (p = 1.9 E^-18). The mean Tegner score before injury was 6.79 (± 1.47) and 6.11 (± 1.75) at last follow-up (p = 0.0011). Mean Lyholm score at last follow-up was 91.53 (± 11.6). The average entire cohort failure rate was 19% at final follow-up of 35.2 ± 9.8 months. Kaplan-Meier survival analysis demonstrated that the probability of the absence of failure decreased constantly over time. No significant difference in the objective IKDC, Lysholm or Tegner scores was observed between the failure group and the success group. Multivariate analysis revealed that younger patients and a procedure of ACL revision are more at risk for suture repair failure. In the majority of cases, the meniscal lesion observed at revision was equivalent or less extensive than the initial lesion.

CONCLUSION

Despite the fact that failure rate remains high for medial meniscus bucket-handle tears, suture repair of bucket-handle tears should be encouraged taking into account the long-term consequences of menisectomy.

The challenging surgical treatment of closed distal humerus fractures in elderly and octogenarian patients: radiographic and functional outcomes with a minimum follow-up of 24 months

INTRODUCTION

The main purpose of this retrospective, non-randomized, case series study was to evaluate the clinical and radiographic outcomes of distal humerus fractures (DHFs) in a consecutive series of elderly patients operatively treated by two surgeons, and second, to identify proper indications for two elderly age ranges and two fracture pattern groups.

MATERIALS AND METHODS

From January 2009 to June 2014, 51 patients (pts) underwent open reduction and internal fixation (ORIF) using the locking compression plate (LCP) distal humerus plate (DHP) system at our institution. Medical records and radiographs were retrospectively assessed. Patients were divided into 3 groups according to gender, age (pts <85 years, pts ≥85 years) and AO classification (13-B1-B2-C1-C2 or 13-C3). All subjects completed MEPS, Quick-DASH and SF-36 PCS/MCS scores at final follow-up, and statistical analysis was performed.

RESULTS

36 patients (20 women, 16 men), mean age 80.3 years, with AO type 13-B and 13-C DHFs were included with a mean follow-up of 56 months (range 24-92). The most common mechanism of trauma was a fall from ground level (55.6%). The mean MEPS was 78.9 points, Quick-DASH 28.4, SF-36 PCS 48.3 and MCS 48.9. There was statistically significant evidence that having a 13-C3 fracture leads to worse results in MEPS, Quick-DASH and SF-36. The female gender correlates with worse results in SF-36. The patients ≥85 years had a worse prognosis according to Quick-DASH and SF-36, while the AO 13-C3 pattern obtained the worst ROM outcomes versus AO 13 B1-B2-C1-C2 (normal ROM 0°-140°): mean ROM 24°-114° vs 10°-130°, mean flexion deficit 26° vs 10°, mean extension deficit 24° vs 10°, respectively). Complications were presents in 36.1% of patients, overall belonging to the AO type 13-C fracture pattern and to the group ≥85 years.

CONCLUSION

These study data seem to confirm our hypothesis that plate fixation for DHFs guarantees adequate fracture osteosynthesis and satisfactory functional outcomes at medium to long-term follow-up, not only in elderly patients, but also in octogenarian osteoporotic patients (≥85 years) with 13-C1 and 13-C2 fracture patterns, while an alternative solution should be considered for type C3 fractures, even in a primary trauma setting.

[Syncope and occupational risk survey: the role of continuing education and multidisciplinary approach]

Syncope is a common disorder characterized most of the times by a positive clinical outcome. However, it may turn to a life threatening event even for working colleagues and third party when occurring during an high risk job. We have recently found that, out of 670 patients admitted to the Emergency Department (ED) for syncope, about 50% were potential workers, being their age between 18 and 65 years. Also, we found that in this group of patients syncope recurrence was as high as 11% at 6 months. It is unknown how physicians address the problem of the occupational risk in patients suffering from syncope and how occupational aspects are taken into account in the clinical judgment before work readmission. One hundred eighty five doctors (149 occupational physicians, OP), participating in a work-shop on syncope, were asked to fulfill a questionnaire about their clinical experience and their attention to the occupational aspects in patients after syncope. Despite long lasting clinical experience, 41% of OP did not scrutinize syncope as a relevant symptom in their daily activity. 65% of the other specialists were used to address the occupational risk aspects in their syncope patients. A multidisciplinary approach involving continuing education on safety at work might reduce work accidents due to syncope relapse and promote a safe and suitable re-employment of patients with syncope. scrutinize syncope as a relevant symptom in their daily activity. 65% of the other specialists were used to address the occupational risk aspects in their syncope patients. A multidisciplinary approach involving continuing education on safety at work might reduce work accidents due to syncope relapse and promote a safe and suitable re-employment of patients with syncope.

[Syncope and work: role of the occupational physician and global risk stratification]

Safety risk for subjects suffering from syncope while working has not been as yet addressed by occupational medicine. The present study was aimed at evaluating a new developed methodology for job tasks risk stratification in patients with syncope. During a work-shop on syncope and occupational risk, 149 occupational physicians (OP) with about 10 years of clinical experience were asked to fulfil a Visual Analogue Scale (VAS) concerning the doctor's estimated potential damage (D) to the worker and the probability of a damage to occur (P) should syncope take place during the job task. Five job tasks characterized by different risk for safety (1, driving; 2, toxic products handling; 3, job performed closed to hot surfaces o free flames; 4, surgical activity; 5, office job) were identified. OP correctly stratified the risk associated to the different job tasks in patients with syncope. Unexpectedly, task #3 was given a risk similar to that obtained in drivers. This might be of paramount clinical and social importance when patients with syncope have to return to their job tasks.

[Syncope and work. STePS study (Short Term Prognosis of Syncope)]

BACKGROUND

Recurrent syncope is a common medical problem responsible for 3-5% of emergency department (ED) accesses and 1-6% of hospital admissions. If syncope occurs in a subject working in a critical safety task, the consequences of this event might be very dangerous for the worker, colleagues, others or for the environment. Therefore, syncope management is a major problem for occupational medicine, converning the general safety at work.

AIMS

To evaluate the syncope events in a group of potential workers aged 18 to 65 years; to evaluate the symptoms preceding syncope and the presence of associated illnesses and recurrent events.

POPULATION AND RESULTS

This study is part of the prospective study STePS (Short Term Prognosis of Syncope), and included 305 consecutive patients (aged 18-65 years, female 56%) who had syncope as a main symptom and presented at ED of four general hospitals in the Milan area, Italy, between the 23rd of January and 30th of June 2004. The 24% of subjects were hospitalized. In 21% the syncope occurs suddenly without any preceding symptom. The 67% of subjects didn't have any important illness at the time. 50% of subjects had recurrent syncope. In four subjects another syncope occurred in a 10 day follow-up.

CONCLUSIONS

occupational medicine should consider syncope scrupulously. Proper diagnostic management is important to permit a correct evaluation of work safety issues.

Clinical aspects of the AIDS dementia complex in relation to histopathological and immunohistochemical variables

To correlate cerebral histopathological and immunohistochemical changes in the neuroclinical features of the AIDS dementia complex (ADC), autopsy results of 28 ADC patients were related, in a retrospective analysis, to scores on a standardised neurological examination performed at neurologic onset. From a histopathological point of view, the cases were classified as follows: 9 cases of HIV leucoencephalopathy (HIVL; diffuse myelin damage and rare microglial nodules), 7 cases of HIV encephalitis (HIVE; several microglial nodules and no myelin damage) and 12 cases of mixed HIVL and HIVE (HIVL-E). The groups differed significantly with respect to symptoms and CD4 count at neurologic onset, survival and neurological impairment. Immunohistochemically, the interstitial component (p24-positive cells scattered singly within the white matter) was significantly more prevalent in HIVL, and the micronodular component (p24-positive cells confined within microglial nodules) in HIVE. Neurological damage was worse in cases with a high prevalence of interstitial component or a low prevalence of micronodular component. HIVE, HIVL and HIVL-E are distinct clinical forms of ADC. Neurological impairment is related to white matter damage.

Tubular segment-specific biomarkers of nephrotoxicity in the rat

Segment-specific localization of p-aminohippuric acid accumulation and glutamine synthetase activity along the proximal tubule was investigated in kidneys of rats treated with segment-specific nephrotoxicants such as potassium dichromate (pars convoluta) and hexachloro-1:3-butadiene (pars recta). Potassium dichromate and the highest dose (200 mg/kg b.w.) of hexachloro-1:3-butadiene caused a significant, dose-dependent decrease of p-aminohippuric acid uptake in the renal cortical slices 24 and 48 h after the treatment. In contrast, hexachloro-1:3-butadiene and only the highest dose (40 mg/kg b.w.) of potassium dichromate, caused a significant dose-dependent decrease of glutamine synthetase activity in the kidney beginning 24 h after treatment. Finally, potassium dichromate and the highest dose (200 mg/kg b.w.) of hexachloro-1:3-butadiene (48 h after the treatment) caused a significant dose-dependent loss of kidney protein content. The results suggest that p-aminohippuric acid accumulation is localized in the pars convoluta and confirm that glutamine synthetase is in the pars recta of the rat proximal tubule. p-Aminohippuric acid uptake impairment and glutamine synthetase activity loss caused by the highest doses of hexachloro-1:3-butadiene and potassium dichromate, respectively, suggests that high doses of segment-specific chemicals may involve other portions of the proximal tubule; in addition, the decrease of glutamine synthetase activity caused by potassium dichromate may be related to the protein content loss.

Historical control data on urinary and renal tissue biomarkers in naive male Wistar rats

Total proteins, angiotensin-converting enzyme, N-acetyl-beta-D-glucosaminidase, glutamine transaminase K and glutamine synthetase were determined in urine collected overnight (14 h: 6:00 p.m.-8:00 a.m.) from naive male Wistar rats; glutamine transaminase K and glutamine synthetase in the kidney 10,000 g supernatant and p-aminohippurate uptake in renal cortical slices also were measured. Urinary parameters were related both to urinary creatinine concentration and urinary flow rate; kidney parameters were related to protein concentration (enzymes) or slice/medium (S/M) ratio (p-aminohippurate uptake). The following reference ranges (1.0 and 99.0 percentiles) were obtained: urine: total urinary proteins (195 samples) 0.03-0.29 g mmol(-1) creatinine and 0.13-1.77 mg h(-1); angiotensin-converting enzyme (115 samples) 8.9-63.7 micromol mmol(-1) creatinine and 59.4-282.7 nmol h(-1); glutamine transaminase K (115 samples) 0-1.7 micromol mmol(-1) creatinine and 0-8.5 nmol h(-1); N-acetyl-beta-D-glucosaminidase (72 samples) 0.7-5.0 micromol mmol(-1) creatinine and 4.9-28.4 nmol h(-1) (naive male rats did not excrete glutamine synthetase); kidney: glutamine transaminase K (36 samples) 14.5-32.8 nmol mg(-1) protein; glutamine synthetase (22 samples) 13.9-48.6 nmol mg(-1) protein and p-aminohippurate (54 samples) 4.77-17.89 S/M. Urinary creatinine (r = -0.780), total urinary proteins (r = -0.521), angiotensin-converting enzyme (r = -0.650) and N-acetyl-beta-D-glucosaminidase (r = -0.796) but not glutamine transaminase K were well correlated with diuresis. In addition, the same parameters, but not glutamine transaminase K, were well correlated with creatinine (r = 0.604,0.701 and 0.747, respectively). Significant correlation also was observed between urinary indices adjusted to creatinine or urinary flow rate (total urinary proteins: r = 0.813; angiotensin-converting enzyme: r = 0.677; glutamine transaminase K: r = 0.939; N-acetyl-beta-D-glucosaminidase: r = 0.657). Finally, a low but significant correlation was found between total urinary proteins and angiotensin-converting enzyme (r = 0.293) and N-acetyl-beta-D-glucosaminidase (r = 0.471).

Assessment of cognitive function in asymptomatic HIV-positive subjects

This retrospective study aims to assess cognitive involvement in pre-AIDS, not drug abuser subjects and to determine whether CD4 status or disease stage best correlates with cognitive changes that may portend development of ADC. 328 cases were analyzed. No differences in psychometric performance in relation to CDC stage were found. Instead, patients with CD4 < 200/microl performed worse overall, with a statistically significant difference for Digit Symbol, Corsi Test, Block Design and HIVDA Scale. Even if cognitive decline is not evident in the early phase of HIV infection, CD4 count seems the more sensitive early indicator of cognitive changes adequately pointed out by the HIVDA Scale, which could be considered a useful screening tool for cognitive deficit.

Microglial nodular encephalitis and ventriculoencephalitis due to cytomegalovirus infection in patients with AIDS: two distinct clinical patterns

In patients with AIDS, cerebral infection due to cytomegalovirus (CMV) results in two distinct neuropathological patterns: microglial nodular encephalitis (MGNE) and ventriculoencephalitis (VE). In order to identify clinical features to facilitate the differential diagnosis of these two forms of CMV encephalopathy in living patients, we retrospectively reviewed the clinical records of 18 patients with MGNE or VE diagnosed at autopsy. We identified the following clinical features as distinguishing the two encephalopathies: (1) MGNE manifests earlier than VE; (2) the onset of MGNE is acute, whereas the onset of VE is insidious; (3) the onset of MGNE is marked by confusion and delirium, which do not occur in VE; (4) VE is frequently associated with radiculopathy, which is absent in MGNE; and (5) VE is associated with more marked alterations in cerebrospinal fluid (high protein levels and pleocytosis). The early neurological manifestations of MGNE should prompt a search for systemic CMV infection, which may lead to earlier treatment.

Light chain deposition disease neuropathy resembling amyloid neuropathy in a multiple myeloma patient

A 65-year-old man with IgG lambda multiple myeloma developed severe polyneuropathy with prominent thermal-pain sensory impairment and autonomic failure. Although the clinical presentation suggested amyloid neuropathy, nerve biopsy showed the immunohistochemical and ultrastructural features typical of light chain deposition disease (LCDD). A precise morphologic and clinical description of LCDD neuropathy is given for the first time in the present report.

Effects of HIV seropositivity and drug abuse on cognitive function

Fifty-eight HIV-positive drug abusers and 22 HIV-positive nondrug abusers at stages II-III and IV of the Centers for Disease Control classification were evaluated neuropsychologically. The study confirmed previous findings that drug abuse has a negative influence on cognitive function. It also emerges that seropositivity affects cognitive function, although the poor performance of group II-III patients compared to group IV may be explained by factors related to seropositivity (anxiety and panic) rather than the disease itself. It is concluded that disease-related factors probably determine cognitive performance in the earlier stages of HIV infection.

HIV infection and drug use: influence on cognitive function

OBJECTIVE

To examine the involvement of cognitive function in HIV-seropositive drug users (DU) in a pre-AIDS state.

DESIGN

Fifty-six HIV-positive DU were prospectively evaluated. They belonged to groups II, III and IV (subgroups A, C2 and E) of the 1987 Centers for Disease Control and Prevention classification, with anamnesis negative for neurological pathology. HIV-negative DU (n = 19) and non-DU (n = 27) were used as controls. Infection with HIV and use of toxic drugs were considered variables of influence on cognitive function.

METHOD

Subjects underwent neuropsychological evaluation by tests designed to explore cortical and subcortical function.

RESULTS

HIV-positive DU showed worse performance scores at the psychometric tests than HIV-negative non-DU, but there was no difference when compared with HIV-negative DU. Ex-DU showed better performance than active DU. No difference with regard to degree of disease evolution was observed among HIV-positive individuals (i.e., groups II and III versus group IV).

CONCLUSIONS

There was no evidence of cognitive deficits in HIV-positive individuals in non-AIDS phases to indicate early involvement by HIV at the cerebral level. Progression of the disease, prior to the AIDS phase, did not determine a worsening of intellectual performance. Instead, cognitive function was affected by the chronic and current use of toxic substances. In HIV-positive DU, a decline in cognitive function was found to be attributable to the chronic use of toxic substances rather than HIV infection.

Reversible bilateral opercular syndrome secondary to AIDS-associated cerebral toxoplasmosis

A case of reversible anterior bilateral opercular syndrome (Foix-Chavany-Marie syndrome) secondary to cerebral toxoplasma abscesses is described in a patient with AIDS. The symptoms regressed following antitoxoplasma and antiedema drug therapy. Although this is the first reported AIDS-related case, the syndrome is likely to recur in AIDS sufferers in whom multifocal cerebral lesions are common.