High resilience of campos rupestres plants to the interaction of drought and fire

The concurrent impacts of multiple disturbances have the potential to modify ecosystem functioning by diminishing recovery capacity and resilience. Nevertheless, it remains uncertain how plant species from tropical communities respond to the cumulative effects of drought and fire. In this study, we evaluated the responses of six plant species from campos rupestres subjected to a mild drought followed by fire and tested if plants subjected to simulated drought show reductions in carbon uptake and depletion of non-structural carbohydrate (NSC) reserves, thus constraining their resprouting. We monitored monthly variations in leaf gas exchange and aboveground biomass over 18 months. Subsequently, an accidental fire occurred in the study area, leading us to collect samples of belowground structures for NSC analyses on the day of the burn. There were no differences in the frequency of resprouting between the above two conditions. Additionally, gas exchange in most species either remained stable or increased after the fire. Drought had no adverse effects on NSC reserves in the belowground structures and may have contributed to species resprouting after fire. The impact of drought pre-conditions on post-fire aboveground biomass was generally minor for most species, except Vellozia nivea, which displayed roughly a 5% reduction in biomass following the drought. Our findings highlight the remarkable resilience of campos rupestres species, even after enduring 18 months of reduced water availability and an unintended fire event. These species demonstrated the capacity to maintain their physiological functions and resprouting capacities after a fire event, underscoring their strong recovery potential.

Safety and Effectiveness of Cladribine in Multiple Sclerosis: Real-World Clinical Experience From 5 Tertiary Hospitals in Portugal

OBJECTIVES

Cladribine is a selective and oral immunological reconstitution treatment, approved in Europe for very active multiple sclerosis (MS) with relapses. Aims were to assess the safety and effectiveness of cladribine in real-world setting, during treatment follow-up.

METHODS

This was a multicentric, longitudinal, observational study with retrospective and prospective data collection of clinical, laboratory, and imaging data. This interim analysis reports data from July 1, 2018 (study onset), to March 31, 2021.

RESULTS

A total of 182 patients were enrolled: 68.7% were female; mean age at onset was 30.1 ± 10.0 years, and mean age at first cycle of cladribine treatment was 41.1 ± 12.1; 88.5% were diagnosed with relapse-remitting MS and 11.5% with secondary progressive MS. Mean disease duration at cladribine start was 8.9 ± 7.7 years. Most patients (86.1%) were not naive, and median number of previous disease-modifying therapies was 2 (interquartile range, 1-3). At 12 months, we observed no significant Expanded Disability Status Scale score worsening (P = 0.843, Mann-Whitney U test) and a significantly lower annualized relapse rate (0.9 at baseline to 0.2; 78% reduction). Cladribine treatment discontinuation was registered in 8% of patients, mainly (69.2%) due to disease activity persistence. Most frequent adverse reactions were lymphocytopenia (55%), infections (25.2%), and fatigue (10.7%). Serious adverse effects were reported in 3.3%. No patient has discontinued cladribine treatment because of adverse effects.

CONCLUSION

Our study confirms the clinical efficacy and the safety profile of cladribine for treating MS patients with a long-term active disease in the real-world setting. Our data contribute to the body of knowledge of the clinical management of MS patients and the improvement of related clinical outcomes.

HBV and VZV seroprotection loss in MS patients under DMT

BACKGROUND

Strategies recommended to decrease the risk of infection associated with the use of multiple sclerosis disease-modifying treatments include screening and immunization against common viral infections such as varicella-zoster (VZV) and hepatitis B (HBV). However, the data concerning the durability of those vaccine responses and the need for re-test is scarce.

OBJECTIVES

We aimed to evaluate HBV and VZV seroprotection loss in MS patients under DMT.

METHODS

We conducted a cohort study including patients with basal seroprotective titers against HBV/VZV viruses and a subsequent serology performed at least 3 months apart. We evaluated predictors of seroprotection loss through a binary regression.

RESULTS

HBV seroprotection loss occurred in one-fifth of patients in a median interval of 21.3 months. Anti-CD20 treatment (OR 8.559 95%CI 3.467- 21.130, p < 000.1), age at last serology higher or equal to 55 years (OR 7.506, 95% CI 2.473-22.786, p < 0.001) and basal HBsAb titer (OR 0.992, 95%CI 0.987 -0.996, p=0.001) increase the risk of seroprotection loss. VZV seroprotection loss occurred rarely in a median interval of 21.3 months. We could not identify any factor associated with an increased risk of VZV seroprotection loss.

CONCLUSIONS

Anti-CD20 drugs are associated with a loss of seroprotection against HBV in a short-interval follow-up.

Seroconversion rate following HBV vaccination in clinical practice: The role of age and DMT treatment

HBV screening and immunization is recommended in all MS patients and is mandatory before the start of some DMT. However, studies evaluating the immune response to HBV vaccine in MS patients are scarce. We aimed to evaluate the seroprotection rate following HBV immunization in MS patients and to assess if older age and DMT-treatment influenced seroprotection. We conducted a cohort study between 2016 and 2020 and compared the immune response to HBV vaccine in MS patients under different DMTs and in patients 50 years old or younger and older than 50. We found that patients under non-injectable DMT presented lower rates of seroprotection comparing to patients under injectable DMT's or without treatment. In patients older than 50, although the seroprotection rate was similar to the remaining patients, the antibody anti-HBV surface antigen titers following HBV immunization were lower and patients were more likely to require a 4th dose of the vaccine to achieve seroprotection. Our findings highlight to need to consider HBV immunization in MS patients early in the disease course, in order to ensure a proper immune response to the vaccine.

Motor excitability measurements in early stage familial amyloid polyneuropathy: The influence of tafamidis treatment

OBJECTIVE

To test motor fiber excitability in early affected patients with transthyretin (TTR)-type familial amyloid polyneuropathy (TTR-FAP) before and during tafamidis treatment.

METHODS

We examined the left median nerve of 21 healthy-matched controls and 10 early affected TTR-FAP patients using the automated threshold-tracking program, QTRAC. TTR-FAP patients were tested one day before the initiation of tafamidis treatment, 3 and 6 months later.

RESULTS

The drug was well-tolerated in all patients; there was no drop-out. No statistical difference was found between healthy controls and TTR-FAP patients at study entry. On treatment, both stimulus intensity for 50% of the maximal motor response and rheobase increased significantly from entry to the last evaluation at 6 months (P<0.05). Strength duration time constant decreased significantly from the 3rd to the 6th month of evaluation (P<0.05). There was also a "fanning-out" effect on the late depolarization phase (TEd 90-100ms) as well as a shortened relative refractory period from study entry to the 6th month of evaluation.

CONCLUSIONS

Threshold-tracking of median nerve motor fibers is not a helpful technique for the early diagnosis of TTR-FAP patients. Tafamidis was well-tolerated. We observed possible membrane hyperpolarization during treatment. Threshold tracking can contribute to documenting the action of new drugs to treat neuropathies. Tafamidis may change nerve electrical properties by reducing the burden of amyloid fibrils.

Solitary Fibrous Tumors of the Orbit and Central Nervous System: A Case Series Analysis

Introduction:

Solitary fibrous tumor (SFT) is rarely diagnosed in clinical practice. Since its initial descriptions in the central nervous system (CNS) and the orbits, very few case reports and small case series have expanded their clinical and pathological characterization. We sought to describe a cases series of SFT from a single laboratory of neuropathology belonging to a tertiary university hospital.

Methods:

Retrospective clinical and histopathological description of eight cases of CNS and orbital SFT diagnosed over a 21-year period of time.

Results:

Median age was 47.3 years and four were males. Clinical presentation was related to local mass effect in all. Tumors occurred in the orbits (5/62.5%), intracranial dura attached (2), and the spinal medulla (1). The neuropathology showed the presence of hemangiopericytoma type (2), classic type (3), and mixed type (3). Histological anaplasia was present in two cases. Widespread/total immunoreactivity for vimentin, CD34, and Bcl-2 was present in all. Gross total removal was conducted in the majority (6/75%) and subtotal removal in 2 (25%). Three patients were submitted to adjuvant treatment (radiosurgery and radiotherapy). Recurrence occurred in four patients, 13–120 months after surgical intervention. Anaplasia was present in one case of recurrence.

Conclusion:

Our case series confirms the clinical and neuropathological diversity of CNS and orbital SFTs. Studies with longer follow-up periods are necessary to better understand the clinical behavior and prognosis of the SFT in the CNS and orbits.

Spinal Cord Lesion by Minor Trauma as an Early Sign of Multiple System Atrophy

Multiple system atrophy (MSA) is characterized clinically by parkinsonism, cerebellar, autonomic, and corticospinal features of variable severity. When the presentation is only parkinsonism, the disease might be difficult to differentiate from Parkinson's disease (PD). We present a case of an 80-year-old man with previous diagnosis of PD. One year after the diagnosis, he had a whiplash cervical trauma due to a tricycle accident caused by a hole in the road. This low-energy trauma caused an unstable C4-C5 cervical fracture with spinal cord injury, which required surgical decompression and stabilization. Neurological examination showed marked postural instability, no rest and postural tremor, finger tapping slowed on the right, spastic tetraparesis (ASIA D) - predominantly on the left side, brisk deep tendon reflexes in the upper and lower extremities, and bilateral extensor plantar response. He also presented with vertical gaze restriction, mild hypometria in horizontal saccades, moderate dysphagia, and dysphonia. As atypical parkinsonism was suspected, he underwent an MRI that revealed conjunction of findings suggestive of parkinsonian-type MSA. In our case, we hypothesize that the loss of postural reflexes, as an early manifestation of MSA, did not allow the patient to have an effective reaction response to a low-energy trauma, resulting in a more severe injury. With this case report, we speculate that the severe spinal lesions caused by minor accidents can be an early sign of postural instability, which may lead to clinical suspicion of neurodegenerative disorder manifested by postural reflexes impairment.

Clinical Value of the Assessment of Changes in MEP Duration with Voluntary Contraction

Transcranial magnetic stimulation (TMS) gives rise to muscle responses, known as motor evoked potentials (MEP), through activation of the motor pathways. Voluntary contraction causes facilitation of MEPs, which consists of shortening MEP latency, increasing MEP amplitude and widening MEP duration. While an increase in excitability of alpha motorneurons and the corticospinal tract can easily explain latency shortening and amplitude increase, other mechanisms have to be accounted for to explain the increase in duration. We measured the increase in duration of the MEP during contraction with respect to rest in a group of healthy volunteers and retrospectively assessed this parameter in patients who were examined in a standardized fashion during the past 5 years. We included 25 healthy subjects, 21 patients with multiple sclerosis, 33 patients with acute stroke, 5 patients with hereditary spastic paraparesis, and 5 patients with signs suggesting psychogenic paresis. We found already significant differences among groups in the MEP duration at rest, patients with MS had a significantly longer duration, and patients with stroke had significantly shorter duration, than the other two groups. The increase in MEP duration during voluntary contraction was different in patients and in healthy subjects. It was significantly shorter in MS and significantly longer in stroke patients. It was absent in the five patients with suspected psychogenic weakness. In patients with HSP, an abnormally increase in duration occurred only in leg muscles. Our results suggest that the increase in duration of the MEP during contraction may reveal the contribution of propriospinal interneurons to the activation of alpha motorneurons. This mechanism may be altered in some diseases and, therefore, the assessment proposed in this work may have clinical applicability for the differential diagnosis of weakness.

Modified surgical approach for removal of an ivory osteoma in the paranasal sinus. A case report

Osteomas are benign tumors that consist mainly of mature compact or cancellous bone. The most common site in maxillofacial complex is the mandible, particularly the angle, followed by sinuses. The authors report a case of an ivory osteoma of the paranasal sinus in a 16 year-old male patient. The lesion was located in the left paranasal sinus (frontal, ethmoidal and maxillary), obstructing the nasolacrimal duct, resulting in dacryocystitis and frontal mucocele. The ethmoid and orbital portions were approached and excised through a Weber-Ferguson incision and maxillary osteotomy was carried out to remove the ivory osteoma, considering its location in the central and deep region of the face. After tumor removal and drainage of frontal and ethmoidal sinuses, the bone flap was repositioned using titanium microplates and screws. Soft tissue was then sutured. The patient was seen again at 3 weeks, 3 months and 2 years after surgery. Overall, he showed a good recovery and wound healing. A multispeciality team approach is advisable in such cases if radical excision is necessary. A craniofacial approach made radical single stage excision of this multicompartmental ivory osteoma possible with an uneventful postoperative period.