Dentate-nucleus gadolinium deposition on magnetic resonance imaging: ultrasonographic and clinical correlates in multiple sclerosis patients

Objective

The objective of this study is to find out whether gadolinium accumulation in the dentate nucleus (DN) after repeated gadolinium-based contrast agent (GBCA) administration in multiple sclerosis (MS) patients is related to tissue alteration detectable on transcranial ultrasound.

Methods

In this case–control study, 34 patients (17 with, and 17 age-, sex-, MS severity-, and duration-matched participants without visually rated DN T1-hyperintensity) who had received 2–28 (mean, 11 ± 7) consecutive 1.5-Tesla MRI examinations with application of linear GBCA were included. Real-time MRI-ultrasound fusion imaging was applied, exactly superimposing the DN identified on MRI to calculate its corresponding echo-intensity on digitized ultrasound image analysis. In addition, cerebellar ataxia and cognitive performance were assessed. Correlation analyses were adjusted for age, MS duration, MS severity, and time between MRI scans.

Results

DN-to-pons T1-signal intensity-ratios (DPSIR) were larger in patients with visually rated DN T1-hyperintensity compared to those without (1.16 ± 0.10 vs 1.09 ± 0.06; p = 0.01). In the combined group, DPSIR correlated with the cumulative linear-GBCA dose (r = 0.49, p = 0.003), as did the DPSIR change on last versus first MRI (r = 0.59, p = 0.003). Neither DPSIR nor globus pallidus internus-to-thalamus T1-signal intensity-ratios were related to echo-intensity of corresponding ROI’s. DPSIR correlated with the dysarthria (r = 0.57, p = 0.001), but no other, subscore of the International Cooperative Ataxia Rating Scale, and no other clinical score.

Conclusions

DN gadolinium accumulation is not associated with trace metal accumulation, calcification, or other tissue alteration detectable on ultrasound. A possible mild effect of DN gadolinium accumulation on cerebellar speech function in MS patients, suggested by present data, needs to be validated in larger study samples.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05702-4.

A case report: Numb Chin Syndrome due to thalamic infarction: a rare case

BACKGROUND

Numb Chin Syndrome (NCS), which is also characterized as sensory neuropathy of the mental nerve, describes a mostly unilateral numbness of the chin and lower lip. Benign and malignant diseases are known to cause this circumscribed symptom, which can easily be overlooked or misdiagnosed. In this article we present the very rare case of a clinical NCS caused by thalamic lacunar infarction. As a pure sensory stroke it is a rare variant of the Cheiro-Oral Syndrome (COS).

CASE PRESENTATION

A 63-year-old male patient received an emergency referral to our department after the patient had noticed a feeling of numbness of the left lower lip and chin on the previous day. The neurological examination revealed an approximately 2 × 3 cm area of hypoesthesia in the area of the chin and left lower lip and the cranial MRI an acute ischemia in the right thalamus.

CONCLUSIONS

In this case report we introduce a patient who clinically shows an NCS. Various diseases may be responsible for NCS, including malignancies or even central neurological disorders such as multiple sclerosis. A lacunar thalamic ischemia as a cause of NCS is very rare and to our knowledge described in the literature only in the contex of a COS in three cases. We wish to remind the reader, through this case, of the purely descriptive and syndromal character of the NCS and the importance for detecting underlying diseases. Furthermore we give a brief overview of the NCS and causative disorders.

Modified DALI LDL-apheresis using trisodium citrate anticoagulation plus bicarbonate or lactate-buffered hemofiltration substitution fluids as primers

BACKGROUND

DALI (direct adsorption of lipids) is the first LDL-apheresis technique able to adsorb low-density lipoprotein (LDL) and lipoproteina) directly from whole blood. In the standard procedure, acid citrate dextrose (ACD-A) is used as anticoagulation and the adsorber is rinsed with a specially manufactured priming solution (PS). Using neutral trisodium citrate (TSC) instead of ACD-A might improve the acid-base homeostasis during DALI apheresis; moreover, applying wholesale hemofiltration solutions instead of the special PS might avoid the use of two separate solutions for both priming before and reinfusion after the treatment, thus simplifiying the procedure.

AIM

The present study was performed to test the effect of neutral (TSC) anticoagulation and of two different commercially available hemofiltration (HF) priming solutions on the efficacy and biocompatibility of DALI apheresis.

MATERIALS AND METHODS

Five hypercholesterolemic chronic DALI patients were treated prospectively, on a weekly or biweekly basis, 3 times each by standard DALI-apheresis (A). by DALI using 4% TSC and bicarbonate-buffered HF BIC35-210 priming (B). as well as by DALI using 4% TSC and lactate-buffered HF 23 priming (C). After the sessions, the extracorporeal circuit (ECC) was rinsed with saline in study arm A and with the corresponding HF solutions in study arms B and C, respectively.

RESULTS

Acute LDL-cholesterol reductions in the study arms A/B/C averaged 64/64/63%, for Lp(a) 62/64/62%, respectively (n=15). Clinically, all sessions were essentially uneventful and no clots were observed in the ECC. No major differences were found between the 3 study arms with respect to biocompatibility (elastase, C3a, thrombin-antithrombin, beta-thromboglobulin, bradykinin).

CONCLUSION

DALI apheresis using TSC anticoagulation and HF solutions for both priming and reinfusion proved to be as safe and effective as the standard DALI apheresis. These modifications, however, further simplify the procedure.

DNA binding specificity of the EcoRV restriction endonuclease is increased by Mg2+ binding to a metal ion binding site distinct from the catalytic center of the enzyme

In contrast to many other type II restriction endonucleases, EcoRV binds specifically to DNA only in the presence Mg2+. According to the co-crystal structure of an EcoRV-DNA complex, Mg2+ ion(s) bind to the active site of EcoRV liganded by Glu45, Asp74, and Asp90. Here we present experimental evidence suggesting that the EcoRV-DNA complex also interacts with Mg2+ ions at other sites: (i) We have prepared an EcoRV triple mutant, in which all acidic amino acids in the catalytic center are replaced by alanine. This mutant is catalytically inactive. It binds nonspecifically to DNA in the absence of Mg2+, whereas it binds specifically to DNA in the presence of Mg2+. This means that Mg2+ induces specific DNA binding in this mutant, although all Mg2+ ligands in the catalytic center are removed. Therefore, additional interactions between Mg2+ and the EcoRV-DNA complex probably occur at sites distinct from the catalytic center. (ii) We have measured the specific and nonspecific DNA binding constants of EcoRV and of the triple mutant in the presence and absence of Mg2+. Mg2+ reduces nonspecific binding by 3-4 orders of magnitude, presumably because Mg2+ ions bound to the DNA have to be released upon complex formation. In contrast, the specific binding of the wild-type enzyme and the triple mutant is increased in the presence of Mg2+. This result can only be explained if a Mg2+ ion binds to the specific EcoRV-DNA complex probably at a site distinct from the catalytic center.(ABSTRACT TRUNCATED AT 250 WORDS)

Two FIA-based biosensor systems studied for bioprocess monitoring

In this paper, two different FIA-based biosensor systems are described for application to different biotechnologically relevant purposes. In the first system, single fiber optodes were used to determine the pH, urea and penicillin V concentrations. A two-channel system was developed for the simultaneous monitoring of different variables to increase the analysis accuracy. This system was used for monitoring the penicillin V concentration during a cultivation of Penicillium chrysogenum. The second system described is a calorimetric immunoassay based on the use of an enzyme thermistor. A sandwich assay with protein A immobilized on a solid support for the determination of various IgGs was established. A fusion protein of protein A and beta-galactosidase obtained from a recombinant E. coli strain was used in the labelling and detection reaction. This system is designed for future application in bioprocess monitoring.

Direct in vivo biotinylation of erythrocytes as an assay for red cell survival studies

Direct in vivo labeling of erythrocytes with biotin is shown as a method for estimation of red cell survival as well as of enrichment of young or aged erythrocytes. Two succinimide esters (biotin-N-hydroxysuccinimide ester [BNHS], caproylamidobiotin-N-hydroxysuccinimide ester [C-BNHS] were used for biotin labeling of erythrocytes. With improved syntheses, pure BNHS (mp, 212 degrees-214 degrees C) and the spacered intermediate for C-BNHS, 6-(biotinylamide) hexanoate (mp, 225 degrees-226 degrees C) were obtained in an overall yield of 86%; the yield of C-BNHS (mp, 167 degrees-169 degrees C) was 68%. When three doses of 1 mg C-BNHS are injected intravenously into mice at 24-h intervals, all the red cells are biotin labeled. The rate of red cell production as well as the life span of red cells can be measured without any effect on erythropoiesis or damage by red cells in vitro. The survival curve seems to be linear, with 2.5%-3.3% disappearance of biotin-labeled red cells daily. In mice, in vivo biotin labeling avoids damaging red cells by in vitro procedures and does not influence the steady state of erythropoiesis by hypertransfusion. Therefore, in vivo biotin labeling is a very useful method for determining red cell survival time in small animals.