One of the pre-requisites for forensic DNA analysis is the fact that all nucleated cells of a person carry the same genetic information. However, this is not the case for individuals who have received an allogeneic hematopoietic stem cell or bone marrow transplantation, as all new cells formed by the bone marrow no longer show the genetic information of the recipient but that of the donor, while all other cells still carry the original information before transplantation. Thus, STR typing of a blood sample after successful transplantation yields a DNA profile that differs from the recipient’s original profile and corresponds to the donor genotype instead. Evidence from a routine case suggests that transplanted individuals may show donor alleles in skin swabs, as well. In order to examine this issue more closely, various skin swabs from 28 patients who have received an allogeneic hematopoietic stem cell transplantation were examined in this study. Swabs from the right and left palm, the back of the hand, one of the two upper arms, and the neck were collected from each person. Ninety-one of the 140 resulting swabs delivered useful results. All of those samples showed mixtures of recipient and donor DNA with different mixture ratios and the proportions of donor and recipient alleles revealed inter- and intra-individual differences. Those results were discussed with respect to graft versus host disease. The most important basis for a molecular genetic investigation is that the genetic information in every nucleated cell of a person’s body is identical. If a person leaves cell material such as skin cells and blood or mucosal cells behind on objects or at location, STR typing yields identical DNA profiles that can usually be assigned to that person.People, who in addition to their own hereditary traits carry the genetic information of another person, are an exception. Whereas a so-called chimerism can occur after every allogeneic organ transplantation, it is rarely found after transplantation of solid organs. A bone marrow or allogeneic hematopoietic stem cell transplantation  aims to completely substitute the recipient’s endogenous bone marrow with that of the donor. Accordingly, all blood and immune cells built from the new bone marrow show the donor’s characteristics (complete chimerism). Allogeneic hematopoietic stem cell transplantation has become increasingly important in recent years due to a significantly expanded indication for both malignant and none-malignant bone marrow diseases . The European Society for Blood and Marrow Transplantation (EBMT) registered 19.630 patients with a first-time alloHSCT within their area of competence in 2018 [A swab from a person’s hand who had previously received bone marrow transplantation was examined as part of a molecular genetic trace investigation in a sexual offense case. STR typing revealed a DNA mixture of recipient and donor DNA alleles . At thisIn order to clarify the issue, swabs from different skin areas were collected from 28 transplanted patients in this study. All swabs were pre-tested for the presence of blood. Subsequently, STR profiles were created and, as far as possible, used to determine the proportion of recipient to donor alleles.2O, were used to collect swabs from the following skin areas of 28 individuals who had received an alloHSCT at least 6 months in advance: the right and left palm, the back of either the right or left hand, the right or left upper arm, and the neck. Swabs were then left to air-dry. Additionally, a buccal swab and a blood sample  were taken from each person and left to air-dry in order to determine recipient and donor alleles.Cotton swabs (Sarstedt Forensic Swab in transport tubes with ventilation membranes), moistened with HPrior to sampling, each person was informed about both scope and aim of the study and gave their written consent. Samples were completely anonymized immediately after sampling and could therefore not be assigned to the respective patient subsequently. Due to the principle of data avoidance and data economy, subsequent patient survey was limited. Neither data regarding a patient’s medical history with special regard to the donor (family/unrelated donor), intensity of prior therapy or pre-transplantation conditioning treatment, and the question of skin reactions as an indication of an immune clearance or graft versus host disease nor data regarding a patient’s personal environment and habits  were collected. Hair was not collected either. Samples were collected at Klinikum Rechts der Isar, Technische Universität München, and München Klinik Schwabing usually by the same doctor under identical conditions. Sampling and sample analysis were performed by different individuals.3Test®E .All body swabs and oral swabs were tested for blood in advance using the ComburAfter external lysis, DNA was isolated semi-automatically with the Maxwell®16 robotic system and the Maxwell® Blood DNA Kit , according to the manufacturer’s instructions. The amount of human DNA per sample was determined using the Quantifiler® Trio DNA Quantification Kit (Thermo Fisher Scientific) and a real-time PCR instrument 7500 , according to the manufacturer’s instructions. Samples with DNA amounts of less than 0.5 pg/µl were not submitted for subsequent analysis. PCR was conducted for samples with DNA amounts of ≥ 0.5 pg/µl using the PowerPlex® ESX 17 Fast System  on a 2720 Thermal Cycler  in a volume of 12.5 µl . A maximum DNA amount of 300 pg was set per run. Samples ranging from 100 to 300 pg of DNA went through 30 PCR cycles. All samples that contained less than 100 pg of DNA went through 32 PCR cycles. Single DNA fragment analysis was carried out per sample on a 3500xL Genetic Analyzer  with the GeneMapper® ID-X Software v1.4  according to the manufacturer’s instructions. Positive and negative controls were included at each step.Since cells newly produced by the bone marrow after successful transplantation should exclusively show donor alleles, each patient’s blood sample was used as a reference for the corresponding donor’s DNA profile. Buccal swabs were used as the recipient’s reference sample because usually a high proportion of buccal mucosa cells can be expected in those samples.For evaluation, results were divided into three categories: Samples that yielded either no or no useful STR typing results, specifically profiles with less than 15 fully typed systems and non-interpretable DNA mixtures, were assigned to category A. All samples from patients whose recipient and donor alleles could be completely or partially derived and which yielded results in 15 or 16 autosomal systems, respectively, were grouped in category B. Finally, category C included all samples that were suitable for calculating the recipient and donor proportion. These were samples from category B in which all recipient and/or donor DNA alleles were present that either did not show any additional alleles from other individuals or, if alleles from other individuals were present, these occurred only sporadically or their intensity was so low that they could be distinguished from the recipient and donor alleles.The proportion of recipient and donor alleles was calculated based on the peak area ratios across all systems.Statistical calculations were performed using IBM® SPSS® Statistics Version 25 software.Pre-testing for blood was positive or weakly positive for 11 out of 28 buccal swabs. For all remaining buccal swabs and all skin swabs, the test was negative.Since cells newly produced by the bone marrow after successful transplantation should exclusively show the donor’s alleles, blood samples were taken from the patients in order to determine them. For 18 tested persons, STR typing of such blood samples revealed single person profiles that differed from the respective buccal swab results (complete chimerism). Eight blood samples showed mixtures (mixed chimerism), which indicate a possible recurrence. In seven samples, isolated recipient alleles were detected, whereas one sample showed the complete recipient’s DNA profile as a minor component . Two blood samples resulted in balanced two-person-mixtures, whereby the donor characteristics could be derived for one of the samples based on the alleles obtained for the corresponding buccal swab. The donor alleles could not be derived for the other sample (patient 15).Only two buccal swabs (reference sample for the recipient’s DNA profile) yielded individual profiles that did not match the blood samples’ alleles, including one sample with a weakly positive preliminary blood test. However, this person showed a complete chimerism in the blood sample. Thus, the presence of the patient’s blood on the according buccal swab, e.g., due to bleeding gums, would have resulted in a mixture of recipient and donor alleles. Consequently, the Combur test result may have been falsely positive, possibly triggered by other substances on the swab, such as food residues. All other buccal swabs showed mixtures in STR typing. For 16 of these samples, however, clearly definable main components could be derived, which in turn did not correspond to the respective alleles of the blood samples. Analysis of the buccal swabs of the remaining ten persons examined resulted in more or less balanced allele mixtures, whereby partial recipient DNA profiles could be derived regarding the donor alleles obtained from the corresponding blood samples. For one individual (patient 15), the recipient alleles could not be deduced due to the mixed genotype in the corresponding blood sample. In all ten buccal swabs that tested positive for blood and showed mixtures, the admixture of donor alleles can be explained by the additional blood cells. For the remaining 16 swabs with visible allele mixtures, the preliminary blood test was negative. This means that either the test showed false negative results or that cells with donor alleles were found on the swabs lacking the admixture of erythrocytes . These samples were not further examined. Fourteen percent of the samples contained DNA amounts of 0.5–1 pg/μl, 53% amounts of 1–10 pg/µl, and 22% contained a DNA amount of 10–100 pg/µl. Four samples (3%) contained an amount greater than 100 pg/µl DNA  showed no significant differences between samples taken from the right or left hand, the back of the hand, and the upper arm (data not shown). Only the swabs taken from the neck showed a significant difference compared to the samples from the right palm , left palm , back of the hand , and upper arm . Thus, as already described by Kamphausen et al. [The results also show that some persons shed widely varying amounts of DNA from different parts of the body. Swabs from the neck showed DNA amounts greater than 0.5 pg/µl for all patients and provided the greatest DNA yield in 19 of 28 tested individuals. Three of the remaining nine patients left the greatest DNA amount on swabs of each, the right or left hand, two on swabs of the back of their hand and one on the swab taken from the upper arm  and consequently gives a very low negative, but non-significant correlation. This, together with the fact that no additional features were found on the four swabs with a DNA amount greater than 100 pg/μl, provides at least an indication that less foreign material can be detected on swabs with a higher DNA yield. It is well known that as the amount of DNA decreases, the number of drop-in events increases, which could explain at least part of these results. Moreover, this fact was also previously described by Goray et al. [In 76 of the total of 91 (83%) samples assigned to category B, alleles of other persons could be detected in addition to the recipient and donor alleles. The affected samples showed between two and 31 additional alleles in the 16 autosomal STR systems examined. Most frequently, one to ten additional signals were found (data not shown). No extraneous material was detectable on the remaining 15 swabs. All four swabs with DNA amounts greater than 100 pg/µl were among those samples. The remaining samples in this group showed a DNA amount of 1–10 pg/µl (four samples) and 10–100 pg/µl (seven samples), respectively. A correlation of the DNA amounts in all samples and the results regarding the number of additionally obtained alleles shows a Spearman-Rho correlation coefficient of − 0.202 with a y et al. , where gy et al. , this coAll 91 samples assigned to category B showed both recipient and donor alleles in different proportions or mixture ratios. For nine of the skin swabs, mixtures could be obtained in which all recipient alleles were detectable. The donor’s alleles were detected almost completely or only partially . On the other hand, in 22 samples, donor’s alleles were completely present in the mixtures and those of the recipient only incompletely . Donor’s as well as recipient’s complete DNA profiles were found in the mixtures of 34 samples in total. In the remaining 26 samples, neither the recipient nor the donor alleles could be completely detected.Twenty-one skin swabs with complete profiles of the recipient and/or donor  showed admixtures caused by additional persons, observable either due to too many alleles per locus or unusually high signal intensities. These samples as well as the 26 samples in which neither the recipient’s nor the donor’s alleles could be completely detected were not further evaluated. The remaining 44 skin swabs were assigned to category C and the ratio of recipient to donor alleles was determined.The 44 samples assigned to category C consisted of eight swabs from the right palm, ten from the left palm, seven from the back of the hand, four swabs from the upper arm, and 15 samples from the neck from a total of 18 different patients. Sixteen of these samples contained a DNA amount of 1–10 pg/µl, 24 between 10 and 100 pg/µl, and four of the swabs more than 100 pg/µl. The proportion of recipient’s to donor’s alleles of these samples was determined considering the peak areas. This showed a range of variation from 12–81% for recipient alleles and consequently from 19–88% for donor alleles  located in the lower stratum spinosum and first described by Paul Langerhans in 1868 should be mentioned as cells of the epidermis with a myeloid background while dermal dendritic cells are located beyond the basal membrane, in the dermis , 15. WhiThe wide range of variation between 19–88% of donor alleles and 81–12% of recipient alleles obtained in samples collected at least 180 days after alloHSCT and examined here shows that different amounts of recipient’s cells and cells with donor’s alleles were found on the prepared swabs. Assuming that after this time all LC have been replaced by donor cells , 34, theHowever, the wide variation can also be explained by an incomplete chimerism of these cells. Divergent observations regarding a chimerism of the skin were made based on different models. Thus, complete donor chimerism of the LC was described after 84–100 days after dose-reduced conditioning, whereas a study by Perreault et al.  showed tp-value of 0.167 (significance level 5%), thus yielding only a very slight negative  and positive , non-significant correlation. Consequently, the recipient and donor proportion has no significant effect on the DNA quantity. There is only a slight tendency suggesting that a higher DNA amount could be yielded when the proportion of donor cells is larger.When comparing the DNA quantities of all 44 samples assigned to category C with the respective proportions of recipient and donor alleles, a Spearman-Rho correlation coefficient of –0.212  and 0.212  was obtained with a In only three cases , all skin swabs could be assigned to category C and the calculation of recipient to donor allele ratio could subsequently be carried out  and the complexity of the examination have so far prevented a broad data collection in clinical studies regarding skin chimerism of the LC after an alloHSCT. STR typing of easy to collect, non-invasive skin swabs could provide the basis for a broader data collection at least for those who shed sufficient amounts of cell material. For example, one could investigate to what extent the exchange of recipient LC with donor LC correlates with the post transplantation time span and whether other factors, such as the presence or absence of donor T-cells, play a role. The method applied in this study could also help investigate a possible correlation of the exchange of LC with the occurring of GvHD. A better understanding of dermal processes leading to GvHD is of great clinical interest. Insights as to whether the exchange of recipient LC with donor LC can be interpreted as a harbinger or as a result of an inflammation could contribute to a prognosis regarding both occurrence and course of an acute or chronic GvHD of the skin as well as to monitor the response to therapy.


Alligator mississippiensis). The results demonstrate that body movements have a significant influence on CSF pressure, often orders of magnitude beyond the influence of arterial pressure.The cerebrospinal fluid (CSF) supports, nourishes, and cleans the brain and spinal cord. Fulfilling these functions requires a certain dynamic of the CSF, it is constantly being produced , circulates around and through the brain and spinal cord, then is constantly being lost (primarily to the venous and lymphatic systems). The dynamics of the CSF are greatly influenced, if not driven, by the fluid pressure of the CSF, but the origins and magnitude of the CSF fluid pressure are poorly understood. Earlier experimental and clinical studies documented how arterial pressure and the ventilatory cycle influence CSF pressure; recent studies, mainly using telemetric recordings, have shown that movement increases the magnitude and variation of CSF pressure. The present study was designed to explore the relative contributions of specific body movements to CSF fluid pressure; these movements include physiological (as occurs during ventilation), postural, or physical displacements (bending or locomotion). The study was performed by taking direct CSF pressure recordings from anesthetized and freely moving American alligators (Alligator mississippiensis) under anesthesia and post-recovery. Pressures were recorded during physiological activities ; manual manipulation of the anesthetized animals ; as well as voluntary movements post-recovery . The CSF pulsations associated with the cardiac cycle had the lowest mean amplitude (3.7 mm Hg); during active ventilation and defensive strikes; the alligators routinely generated CSF pressure spikes in excess of 100 mm Hg. The recorded CSF pressures appear to be caused by a variety of mechanisms including vascular pressure; fluid inertia; and possible physical displacement of the spinal cord. The results of the study suggest that any model of CSF dynamics or perfusion should incorporate the episodic high-pressure CSF pulsations associated with movementThis study was undertaken to document how the cerebrospinal fluid (CSF) pressure varied during movements and physiological activities. Using surgically implanted pressure catheters; the CSF pressure was recorded from sub-adult American alligators ( The cerebrospinal fluid (CSF) functions in the development  and metaRecordings of CSF pressure pulsations generally include a higher-frequency component corresponding to the cardiac cycle , and a lThe majority of the data on CSF fluid dynamics has been collected from animal or human subjects using magnetic resonance imaging (MRI) , or via Recent telemetric studies of human movement ,18,19 anAlligator mississippiensis). Recent studies have shown that A. mississippiensis has a well-developed myodural bridge, the contraction of which is capable of altering CSF pressure [The goal of the present study was to document the influence of movements, both fictive and natural, on CSF pressure, in the American alligator  were obtained from the Louisiana Department of Wildlife and Fisheries. The animals were housed communally in a 29 m2 facility that featured three submerging ponds, natural light, and artificial lights on a 12:12 cycle. The facility was maintained at 30–33 °C, warm water rain showers were provided every 20 min, which helped maintain the facility at >75% relative humidity. The alligators were maintained on a diet of previously frozen adult rats. When the individual animals were removed from the enclosure, they were caught by noosing, then their jaws were taped using vinyl tape. The husbandry and use of the live alligators followed all applicable federal guidelines, and were approved by the IACUC of A.T. Still University .Seven live sub-adult  American alligators (A treadmill (270 cm long × 61 deep × 46 wide) was fabricated out of steel beams, lined with stainless steel sheeting, and fitted with a custom (538 cm long × 41 cm wide) tread . The two ends of the treadmill had sliding gates. Each alligator was trained twice weekly to locomote along the length of the treadmill, initially with the treadmill off, subsequently with it moving in the range of experimental velocities (0.1–0.25 m/s). All training sessions were recorded using two digital video cameras , one providing a dorsal view and the other a head-on view. Once all of the alligators demonstrated stable locomotor patterns on the moving treadmill, the surgical experiments were initiated. One terminal surgical experiment was performed each week; the training schedule was maintained for all of the remaining animals.When the individual alligator was noosed for the surgical experiment it was induced to bite a bite pad, and the animal’s mouth was taped shut around the bite pad. Each individual alligator was placed on a stiff board (244 × 28 × 3.8 cm thick), which exceeded the maximum width and length of the alligators used for this study. Six 2.5 cm wide heavy duty straps  were used to secure the alligator to the board; the straps were tight enough to minimize movement of the animal but not tight enough to impede ventilation or circulation. With the alligator’s mouth held open by the bite pad, a laryngoscope was used to depress the gular valve  and expoA surgical drill  was used to bore a 4.0 mm diameter hole through the dorsum of the alligator’s skull to expose the dura. A small incision was made in the dura to allow the passage of a pressure catheter. Surgical adhesive  was used to seal the dura around the catheter, then epoxy cement was added to fill the bored hole and secure the catheter to the skull. A fluid pressure transducer  was rested upon, and sutured to, the large osteoderm that covers the dorsum of the alligator’s neck. The pressure transducer, and the attached pressure catheter, were filled with a reptilian Ringers solution . The leaThe experimental sequence for each alligator was identical and involved 10 stages or steps. Once the alligator reached a surgical plane of anesthesia: (1) the pressure catheter was implanted into the cranial sub-dural space and a series of baseline CSF, EKG, and (forced) ventilatory cycles were recorded. (2) the ventilator was turned off for 30 s intervals to document CSF pressure during apnea. (3) with the animal still under anesthesia it was tilted 30° head-up and 30° head-down (separately), each over a 90 s duration divided into 30 s baseline, 30 s tilt, then 30 s recovery. (4) the animal was allowed to recover from anesthesia, this is a slow (hours-long) process in alligators ; the aniTypically 3–4 locomotor sequences were recorded from each alligator (see below). Immediately after the last locomotor sequence the treadmill was turned off and the alligator allowed to remain (stationary) on the treadmill while post-locomotor CSF pressures were recorded. The animal was then returned to the surgical board, re-anesthetized, then euthanized through cardiac excision and exsanguination . ImmediaThe surgery and locomotor experiment were performed in the same small room which was maintained at >30 °C to prevent metabolic disruption to the alligators . An LED The video records were analyzed using Kinovea (kinovea.org). The majority of the locomotor sequences recorded were not used for data analysis . These sequences were excluded because the alligator failed to perform at least 3 complete footfall (step) sequences, collided with the end or sides of the treadmill, was physically contacted by either researcher, or exhibited locomotor kinematics  that differed from those recorded during the final training sessions. Ultimately, 11 locomotor sequences were analyzed; these had a mean duration of 13.12 s (s.e. = 4.87). The physiological data was quantified with Midas, was exported to SpectraPlus  for Power Spectral Analysis, or was exported to EXCEL for statistical analysis.The final data set consisted of an equal number of baseline, apnea, head-up and head-down rotations, manual tail oscillations, manual limb displacements, and manual body bends collected from all seven of the specimens. Baseline treadmill recordings were taken from all seven specimens. Nine defensive strikes were recorded (from four different specimens), and 11 locomotor sequences were quantified from 6 of the alligators .EKG traces were recorded once the animal was at a surgical plane of anesthesia; power spectral analysis of these records A reveal 2 record yielded a mean dominant frequency of 0.8 Hz  tilted to 30° head-down for 30 s . The 30°t-test; t = 40.49, p < 0.00001, df = 13) higher in frequency than the heart rate (or cardiac-related CSF pulsation) recorded in the same trial. The individual CSF pulsations recorded during tail oscillation had a mean amplitude of 4.9 mm Hg (s.d. = 1.17).With the alligators under anesthesia, and the pelvic girdle and the body rostral to it mechanically restrained, the distal tip of the tail was wiggled manually to generate sinusoidal waves in the tail. Video analysis revealed that the sinusoidal tail waves had a mean frequency of 4.56 Hz (s.d. = 0.79), and that they propagated the length of the tail, which is roughly half the total length of the alligator. The CSF pressure traces show high-frequency pulses coincidental to the manual oscillations of the tail; these pulses are concurrent with the cardiac- and ventilatory-related pulses A,B. WhenImmediately following the tail oscillation trials, while the alligator was still under anesthesia, the left hind limb was manually moved through a step-cycle. That is, the pes was first slightly elevated and protracted, then moved caudally while maintaining a constant distance from the body. Every effort was taken to make the foot sweeps as smooth and repeatable as possible. Protraction of the hind limb caused a marked increase in cranial sub-dural CSF pressure , this prThe restraining straps on the body were removed, so only those securing the head and neck remained. Then, using the pelvis and mid-tail at contact points, the body of the anesthetized alligator was manually deflected to one side see . Each deAlligator . During this recovery period data were recorded periodically. Near mid-recovery, the cardiac frequency was 0.39 Hz (s.d. = 0.07) corresponding to a heart rate of 23.5 bpm. The cardiac-related CSF pulsations recorded mid-recovery had amplitudes that were not significantly different from the baseline values . During the recovery period the animal would start performing spontaneous breaths, herein defined as movement of the thoracic and/or abdominal body wall that altered the ventilatory airflow pattern. These breaths varied widely in duration  from the cardiac-linked pulsations recorded while the animal was under anesthesia  which seemed to be related to postural shifts and associated changes in body tone . The animal was left undisturbed until it began independent sustained locomotion along the treadmill. CSF pulsations recorded during these non-locomotor periods A had a mesthesia B. Duringesthesia . Since tody tone . The aniody tone A or woulody tone A. The teOnce fully recovered the alligators would frequently exhibit defensive behaviors, particularly hissing, tail whips, and defensive strikes. During the “typical” defensive strike the body is bent sharply to one side as both the tail and head are elevated and rapidly turned in the same direction A,B. Thesp = 0.00005, df = 1, R = 0.92) relationship between increasing oscillatory frequency of the head and the frequency of the CSF pulsations. In addition to these sinusoidal pulses, locomotor activity caused a general increase in CSF pressure with a mean pressure increase of approximately 20 mm Hg  sinusoidal changes A with me20 mm Hg A,C.The cardiac-related CSF pressure pulsations were the smallest pulsations recorded that could be clearly linked to a physiological feature or activity . Some ofAlligator mississippiensis was used in this study, all seven animals were trained to locomote on the same treadmill, the same surgical approach was used on each animal, and the sequence of data collection was held constant. The CSF pressure pulsations linked to the cardiac cycle had the lowest amplitudes recorded. Changes in body tone, ventilatory movements, and passive (under anesthesia) or active (after recovery) movements all generated shifts in the CSF pressure baseline, or CSF pulse amplitudes, that were larger, in some cases more than an order of magnitude larger, than those attributed to the cardiac cycle.The present study was undertaken to document the influence of movement, including locomotion, on CSF pressure. To minimize variation, a restricted size range of This study used surgical implantation of a pressure catheter to record CSF pressure in the subdural space; this is a well-established technique  that is Alligator mississippiensis. Accordingly, our emphasis is not on the absolute value of the CSF pressure  since this would change over the enormous size range of A. mississippiensis [The present study was designed to explore the influence of movement on CSF pressure, not the CSF fluid dynamics of ppiensis  and woulppiensis . Insteadppiensis ,49, and Alligator mississippiensis was recorded while the animals were under anesthesia. The pooled heart rates: immediately post-surgery (mean = 22 bpm), mid-recovery (mean = 23.5 bpm), and immediately upon full recovery (mean 23.9 bpm); did not significantly change over the course of the experiment and are comparable with earlier studies of anesthesia and heart rate in Alligator [The heart rate of the seven lligator . Like thThe change in CSF pressure observed when the animal is exposed to an orthostatic gradient  was used, in part, to check the integrity of the experimental preparation. Every animal exhibited a similar magnitude of CSF pressure change upon rotation , these mA. mississippiensis. Secondly, this species has some of the most variable ventilatory mechanics of any vertebrate. Crocodilians have the ability to switch between thoracic, abdominal, and pelvic aspiration [The ventilatory-related CSF pressure pulsations, though easily identified , were hipiration ,55, actipiration , and a hpiration  which mapiration . The traA. mississippiensis has a functional diaphragm [Since iaphragm , the aniAlligator mississippiensis) by the vertebrae, physical displacement of the spinal cord, or a mechanical impingement on the peritoneal or thoracic cavity. These four causal mechanisms may not be discrete, nor need they be exclusive.The other changes in CSF pressure documented in this study are likely the product of changes in fluid momentum of the CSF (an impulse), a mechanical impingement on the sub-dural space . Accordingly, the spikes in CSF that were produced by moving the limb  are diffAlligator mississippiensis, which was done manually  acting on the CSF. These two oscillatory movements were quite different  . Though pressure , though Post-surgery, while the animals were still under anesthesia, cardiac and (passive) ventilatory-associated pulses in the CSF pressure were recorded, which, at 3.7 and 9.2 mm Hg, respectively, were among the smallest influences recorded. Once the animals were recovered from anesthesia, as evidenced in part from their independent and sustained movements, statistically similar cardiac-related CSF pressure pulses were recorded , but nowEvidence for a more dynamic system, capable of coping with high-pressure pulses of CSF pressure, can be found in the literature from studies that recorded from human subjects which had recovered from anesthesia. A study of coughing  noted thTelemetric studies of human CSF pressure typically publish data records over longer intervals which obscure the cardiac pulsations, but do show clear variation and marked increases in CSF pressure often attributed to movement or postural changes ,71,72. TWhile moving on the treadmill the alligators used variable speeds and a mix of “low walk” and “high walk” postures , which wThe consistent findings of the present study, and the general similarity between these results and the literature on telemetrized CSF recordings from humans and other mammals, suggests that the dynamics of the CSF in freely-moving organisms have likely been under-estimated.This study was performed to document the influence specific body movements have on the cerebrospinal fluid (CSF) pressure in the American alligator. Surgically implanted pressure catheters were used to record the CSF pressure; simultaneous recordings of the EKG, exhalatory gases, and video recordings of the animals, established a quantitative relationship between movement and changes in CSF pressure. The cardiac related pulsations had the lowest amplitude of all the CSF pressures. Physical displacement of the body, as during locomotion or defensive strikes, produced pulses of CSF pressure orders of magnitude greater than the cardiac-related pulsation; the more of the body that moved, and the faster it moved, the greater the recorded CSF pressures. Physiological movements, as during active ventilation, or active changes in body cavity pressure, were quite variable (producing both positive and negative CSF pressure changes); coughing produced some of the largest CSF pulse amplitudes recorded. The link between body movement and CSF pressure/flow warrants additional analyses as we work to understand the role of CSF dynamics in maintaining the health of the brain and spinal cord.


The choroid plexus is a tissue located in the lateral ventricles of the brain and is composed mainly of choroid plexus epithelium cells. The main function is currently thought to be the secretion of cerebrospinal fluid and the regulation of its pH, and more functions are gradually being demonstrated. Assistance in the removal of metabolic waste and participation in the apoptotic pathway are also the functions of choroid plexus. Besides, it helps to repair the brain by regulating the secretion of neuropeptides and the delivery of drugs. It is involved in the immune response to assist in the clearance of infections in the central nervous system. It is now believed that the choroid plexus is in an inflammatory state after damage to the brain. This state, along with changes in the cilia, is thought to be an abnormal physiological state of the choroid plexus, which in turn leads to abnormal conditions in cerebrospinal fluid and triggers hydrocephalus. This review describes the pathophysiological mechanism of hydrocephalus following choroid plexus epithelium cell abnormalities based on the normal physiological functions of choroid plexus epithelium cells, and analyzes the attempts and future developments of using choroid plexus epithelium cells as a therapeutic target for hydrocephalus. Hydrocephalus is a common neurological disease with complex etiology and frequently unsatisfactory outcome. It can develop at all ages, with infants and the elderly as the most frequent groups, with congenital hydrocephalus in infants and idiopathic normal pressure hydrocephalus (iNPH) in the elderly .It is believed that under the action of multiple factors, cerebrospinal fluid (CSF) circulation becomes impaired and CSF accumulates excessively , causingIn the past perception, it was believed that the lymphatic system did not exist in the brain. However, a study in 2000 found the existence of a system of intracranial material removal in the brain similar to the lymphatic system, and named it the glymphatic system . Its essThrough the efforts of many researchers, the pathogenesis of hydrocephalus is being completed, but it has not been fully explained . The widExisting studies have found that brain parenchyma can be permeable to water through water channel proteins and ion channels , which sThe application of these theories can solve part of the problems in clinical treatment but not all of them, indicating that these theories have some limitations. Thus, we go to explore the relationship between CPE cells and hydrocephalus, and provide new targets for clinical treatment.CPE have a relatively simple structure. They consist of a single layer of cuboidal epithelial cells that reside on a basement membrane. Beneath the basement membrane is a network of fenestrated capillaries that are surrounded by connective tissue composed of fibroblasts and immune cells . By virtIn short, either intrinsic genetic factors or external environmental factors  that subWhether it is based on the classical hypothesis of cerebrospinal fluid production or a newly proposed hypothesis, the current literature lacks a review of the relationship between the CPE and hydrocephalus formation. Understanding the relationship between the CPE and hydrocephalus is more conducive to our exploration of the pathogenesis of hydrocephalus and thus to the treatment of hydrocephalus.In the ventricles of the human brain, there are four CPE located in the bilateral lateral ventricles, the third ventricle and the fourth ventricle. Together, they form the main component of BCSFB. During early embryonic development (fourth week) , cells o+-K+-ATPase, sodium potassium chloride co-transporter 1 (NKCC1) [The inner and outer surfaces of multicellular organisms are covered with epithelium, which keeps out most invasive substances. In addition, there are a number of important functions, as described below. And all these functions are based on the same basis of cell biology. In order to regulate selective transport processes to maintain a proper internal environment, membrane proteins appear asymmetrically distributed. This requires the expression of specific transport proteins by cells according to their functional needs and the proper sorting and transport of these membrane proteins. This is known as cell polarization . The CPE (NKCC1)  and Na/H (NKCC1) . These p (NKCC1) .The CPE is composed of a single layer of cuboidal epithelial cells whose most important function is to produce CSF. In order to secrete CSF, it is mediated by a variety of membrane proteins that allow water and solutes to be transported across the epithelium, across the BCSFB, and from the blood side to the CSF side. The relevant biophysical principles have not yet been unified regarding the study of this situation, and among many relevant opinions, isotonic transport is currently widely recognized and studied with emphasis. To explain how water transport in the CPE is coupled with solute transport, resulting in near-isotonic transport, several models have been proposed to study the molecular mechanisms and have been continuously refined. Among these are three-compartment model , standinWater transport in the CPE is associated with AQP, a transmembrane water transport protein. AQP1, AQP3, AQP4 , AQP5, A+ is the most important ion that powers the secretion of CSF. The most important of these transporter proteins is Na+–K+-ATPase, which, in addition to transporting Na+ into the CSF, forms electrochemical gradients to help other ion transporters [+ channel (ENaC) is a channel for Na+ to enter via the basolateral membrane [+–HCO3− cotransporter. It is located in the luminal membrane and in addition to transporting Na+ according to the ratio of one to three of Na+ and HCO3− [3− [+–borate cotransporter can transport Na+ and borate into cells, but its specific mechanism of action is not known.Nasporters . The epimembrane . The NKCmembrane . The elend HCO3− , and it CO3− [3− . NHE1 isCO3− [3− . Na+–bor+ transport by the CP is very complex and relies on transport proteins in addition to paracellular pathways. K+ channels in the luminal membrane recirculate K+ [+–K+-ATPase [+ from the CSF to the CPE. KCNQ1 and KCNE2, expressed in the luminal membrane, are also involved in the formation of K+ channels [+–Cl− cotransporters (KCC), expressed in the basolateral membrane as KCC3a and in the luminal membrane as KCC4 [The mechanism of Kulate K+ , which culate K+ , and als+-ATPase  and NKCCchannels . The K+– as KCC4 , their e as KCC4 .2+ plays many important roles within the central nervous system, regulating many physiological processes and is a key factor in maintaining the stability of various signaling pathways [2+ in CPE is involved in transporter proteins and not by simple diffusion through paracellular pathway [2+ is taken into cells by transient receptor potential vanilloid 5 (TRPV5) and transient receptor potential vanilloid 6 (TRPV6) from the basement membrane, bound to calcium-binding proteins, transferred to the luminal membrane, and released into the CSF via Ca2+-ATPase (PMCA) and Na+/Ca2+ exchanger (NCX), but this model lacks experimental evidence [2c receptor agonists can promote spontaneous calcium activity [2+ to flow into cells and stimulates calcium-sensitive potassium in a tissue-specific manner channels that can be inhibited by two different specific antagonists, which are named HC067047 and RN1734 [+. It serves to protect the brain from cationic neurotoxins by removing the corresponding substances from the CSF [− and HCO3−, and trans-cellular transport for Cl−has been demonstrated in several experiments [−. Just for example, arginine pressor (AVP) activates receptor V1, which inhibits the ability of the CPE to transport Cl−, thereby reducing CSF formation [− efflux and HCO3− uptake, and the gene encoding it belongs to the Slc4 family. The Slc4a10 gene, also in the Slc4 family, encodes an Na+-dependent Cl−/HCO3− exchanger (NCBE) involved in Cl− and HCO3− transport, and CPE lacking NCBE appears to omit molecular mechanisms involving CSF secretion rather than compensating for the loss of sodium load. The reason that knocking out this gene is more harmful than knocking out the AQP gene is that the former contains more than one signaling pathway [− channels and HCO3− channels located in the luminal membrane, which are responsible for the transport of Cl− and HCO3−, the NKCC1 and the KCC are also involved [Capathways . It has  pathway . There ievidence . 5-HT2c activity . GSK1016 the CSF . The traeriments . Therefoormation . AE2, lo pathway . The lac pathway . In addiinvolved .+ co-transporter (SNAT3) and large neutral amino acid transporter type 2 (LAT2). To maintain the amino acid concentration gradient between plasma and CSF, the CPE drives CSF reuptake of essential amino acid substrates for this retrotransport protein via efflux of LAT2. However, other amino acid transporter proteins have only been detected at the level of mRNA and have not been localized at the protein level [+, Cl−, and HCO3− [In addition to the transport of water and ions, the CPE has been shown to be involved in the transport of albumin and some amino acids. The soluble and cell surface albumin-binding glycoproteins secreted protein acidic and rich in cysteine (SPARC) is thought to be involved in the transport of albumin into the brain and is the docking site for albumin, mediating the uptake of albumin from the blood by the CPE, crossing the blood–CSF barrier from the basement membrane and transferring it to the CSF . Sodium-in level . The atynd HCO3− .To study the problems related to CSF clearly, it is necessary to study these transporter proteins first. As far as we can see from the review, some of the transporter proteins have been discovered and their role were confirmed, others have only been discovered but their role has not yet been confirmed, and we presume that there are still some that have not been discovered . Among tThe concentration of inorganic phosphorus in the CSF is lower than in plasma, and how and why it is controlled is not known. However, some studies have found that Pi transporter2 (PIT2) in the CPE may be part of the phosphorus sensory or regulatory pathway. The active clearance of phosphatidylinositol from the CSF has been linked to the sodium-dependent transporter protein PIT2 . Protein+ effector memory cells that retain a TCR (T cell receptor) profile against CNS antigens. T cell-mediated immunity affects the CP and attenuates the secretion of IL-4 (interleukin 4) [Leukocytosis in the CSF is widely used clinically to assess inflammatory conditions in the central nervous system. This suggests that the CP, located at the junction of blood and CSF, is a multifunctional organ that serves as a gateway for immune cells to enter the CSF and plays an important role in immune surveillance and regulation of immune cell transport. However, studies on the principles of BCSFB control of immune cells are limited, and only some features of the CPE have been identified . Epitheleukin 4) , which heukin 4) .+-dependent Cl−/HCO3− exchanger that, together with HCO3−, absorbs Na+ from the blood side [3− [+/HCO3− co-transporter and exports Na+ and HCO3− to the CSF in a one-to-three ratio at high CO2 concentrations [+/H+ exchangers, importing Na+ into cells and exporting H+ into the CSF. NHE6 is located in the structural domain of the luminal membrane and regulates pH in concert with V-ATPase. The CLC-3, CLC-4, CLC-5, and CLC-7 are all Cl−/H+ exchangers that export Cl− outward. In addition to this, there is V-ATP [Controlling the pH of the CSF is very important because it directly affects the pH of the BIF closest to the ventricular system, which in turn causes the onset of certain diseases . It was ood side . The aniside [3− . NBCe2, trations . The NHEis V-ATP  involvedIn the CSF secreted by CPE, neuropeptides are regulated by an endocrine-like mechanism that uses the bulk flow of CSF to aggregate neuropeptides, including brain-derived neurotrophic factor (BDNF), epidermal growth factor (EGF), fibroblast growth factor (FGF), glial cell line-derived neurotrophic factor (GDNF), insulin-like growth factor (IGF), nerve growth factor (NGF), pituitary adenylate cyclase activating polypeptide (PACAP) and vascular endothelial growth factor (VEGF) . They arThe tightly connected CPE is involved in constituting the BCSFB , which iThe CPE is a highly vascularized tissue that provides an important interface between the blood and the CNS . HoweverThe p75 neurotrophin receptor (p75NTR) is expressed in the CP and is localized to the luminal membrane of epithelial cells. In neurons, p75NTR receptor has a dual function: promoting survival together with TrkA in response to NGF, and inducing apoptotic signaling through p75NTR. which in turn alters antibody clearance and inhibits neuronal growth by inducing apoptosis through p75NTR. The role of p75NTR in antibody-induced cell death was confirmed by blocking the biological activity of p75NTR .The CP, a component of the blood–CSF barrier interface, is an epithelium that can be used to sparingly deliver drugs to the brain. Drugs delivered from the blood to the lateral ventricles are delivered through the CSF to targets within the ventricles and are used to regulate secretion and help treat disease . The undorpk mutants can lead to cilia dysfunction, which in turn interferes with signaling pathways, disrupts CSF flow, resulting in increased transcytosis activity in the CPE, increasing CSF secretion and decreasing its pH. Ciliary dysfunction leads to increased cAMP content and activation of PKA, which allows phosphorylation of extracellular signal-regulated kinases (ERKs), which in turn regulates related ion channels and ion transport proteins, resulting in increased secretion of Cl− and HCO3−, ultimately manifesting as increased CSF secretion [Cilia (kinocilia) play an important role in the normal physiological regulation of the CPE, and treatment with hydantoin or Tg737ecretion .IVH causes the rupture of blood vessels, leading to a hemolytic phenomenon that releases extracellular hemoglobin (Hb) into the CSF and activates an inflammatory response . IVH stiCSF is produced by the epithelium of the CP, travels through a certain pathway, and is finally absorbed by the venous sinuses. Injury to any part of this process can lead to abnormal CSF levels and result in hydrocephalus.The inflammatory response induces an increase in CSF secretion by the CPE to affect directly, or induces ciliary dysfunction to affect indirectly. In the animal model of microbial infection, the CP exhibited distinct histological features altered by focal leukocyte infiltration and lamellar loss of epithelial cells, in addition to the reduction of epithelial cell microvilli observed by electron microscopy . ObesityImpaired transport of water molecules and ions is the most important cause of abnormal CSF secretion, which will be described specifically below.The accumulation of hypertonic substances in the CSF alters the osmotic pressure of the CSF and affects the transport of substances.− channels to release Cl− [+, Cl−, K+, and HCO3− ions, all of which could be the molecular basis for the generation of hydrocephalus.The main and most important cause is a series of transporter proteins for water molecules and ions, either missing or malfunctioning, or in the wrong place, which may cause abnormal secretion. The functional transcription factor p73 regulates the production and reabsorption of CSF by regulating the water channel protein AQP3. This then leads to non-obstructive hydrocephalus . When inease Cl− . Higher ease Cl− . In addiThe presence of large amounts of hypertonic substances in the CSF will produce a higher osmotic pressure that acts as a driving force to affect water transport. In thrombin-derived hydrocephalus, part of the cause can be attributed to the degradation of the blood–CSF barrier by VE-cadherin through activation of signaling pathways such as PAR1/p-SRC/p-PAK1, which increases its permeability and leads to leakage of CSF . Toxic sIn conclusion, whether the process of hydrocephalus formation is understood with the help of the circulatory theory or the osmolarity theory, any disruption of either of these components may be a factor in the pathogenesis, the difference only lies in whether it is common and whether the underlying molecular mechanisms are understood. Only some of the possible etiologies have been mentioned above, and in an abbreviated manner, without addressing too many of the deeper mechanisms. Researchers are still required to speculate boldly and seek proof carefully Fig. .Fig. 3HyThere are neither drugs that are exclusively effective in treating hydrocephalus, nor is there a surgical procedure that can solve the problem once and for all. The lack of in-depth basic research on hydrocephalus  and the Surgical destruction of the CP, CP cautery using the electric knife has been used clinically, and the results of the treatment, although not perfect, are still considerable. In contrast to traditional surgical methods, immunotoxin-mediated CP ablation  is now aAlthough the CPE has many types of transporter proteins, only a few have been used as targets for the treatment of hydrocephalus, and almost all have been studied in animal models and have not been applied in human studies. A brief description of the relevant studies is presented.The water channel protein AQP family is an important class of transporter proteins responsible for the transport of water molecules, and therefore studies using them as targets are widespread. Upregulation of AQP has been found in several types of hydrocephalus or other related diseases, for example, upregulation of AQP1 and AQP4 in SAH, suggesting that we may be able to inhibit CSF secretion and alleviate hydrocephalus by downregulating AQP symptoms. There may also be a mechanism for endocytosis of AQP1 in the CPE to slow down CSF secretion during hydrocephalus. Although the CSF production in mice with knockout AQP1 was reduced by only thirty percent, this was sufficient to affect the formation of hydrocephalus , suggestIVH activates the STE20-type stress kinase SPAK via TLR4 , which b+–K+-ATPase is an important transporter protein responsible for the transport of Na+ and K+ and plays a very important role in the secretion of CSF. It has been found that ANP [+–K+-ATPase and helps regulate CSF production. The use of ouabain inhibits Na+–K+-ATPase, leading to a decrease in CSF production [Nathat ANP  binds tothat ANP , the maioduction .The blood–brain barrier is the key issue, which limits the entry of therapeutic compounds or systemically transplanted cells into the brain. The intended application of cell therapy is to regenerate the disrupted VE and drug delivery to improve brain microcirculation and neurological function. CPE cell transplantation  for hydrThe methods mentioned above, both those already applied and those still under investigation, are based on the theory of CSF circulation flow associated with the CPE. The newly proposed theory of CSF osmolarity, on the other hand, offers the possibility of new treatment options. Removal of substances accumulated in the ventricles, such as hemoglobin and its degradation products, platelets, and leukocytes, reduces osmotic pressure, attenuates damage to CPE cells, and decreases CSF secretion. Upregulation of efflux molecular transport proteins also removes substances accumulated within the ventricles and relieves hydrocephalus.It is worth noting that these two theories are not completely separated, but are mutually corroborative. A certain causative factor or a certain treatment, interpreted from different perspectives, may belong to different theories, but in the final analysis, the two are essentially related. We need to continue our research to deepen our understanding of both theories in order to identify the correct and comprehensive theories to explain hydrocephalus and to provide new and reliable ideas for its treatment Fig. .Fig. 4ThAs a disease with diverse etiologies, complex conditions, and imperfect underlying theories, hydrocephalus requires more attention from researchers. The widely accepted theories are the CSF circulation flow theory and the osmolarity theory. These theories demonstrate the causative factors from different perspectives and are somewhat different, but not completely disconnected. The same pathogenic factors can be divided into different theories, which to some extent indicates that these theories interpenetrate and interdepend on each other, only that deeper research is needed to integrate them.At present, the clinical treatment of hydrocephalus mainly uses some dehydrating drugs to reduce edema, and surgery is roughly divided into shunt surgery and ventriculostomy (such as endoscopic third ventriculostomy). Although they have been used clinically with some success, they are not considered to be specific and there should be a more focused approach to solve hydrocephalus efficiently.This article provides a comprehensive overview of the role of the CP in hydrocephalus formation, and although some of the mechanisms remain unclear, it has provided new targets, with multiple transport proteins located in the parietal and luminal membranes of the CPE being a hot topic of study. In addition, it would be extremely valuable to clarify the unknown molecular mechanisms, both to deepen the understanding of the mechanisms of hydrocephalus formation and to provide new targets for possible therapeutic modalities.In conclusion, the study of the CP, at any level, has its unique significance. Although studies have denied that the CP acts as a power pump in the circulatory flow of CSF, it is undeniable that the CP has a crucial role in the secretion of CSF. In pathological states, excessive secretion of CSF by the CPE, or other dysfunctions mentioned above, leads to abnormal accumulation of CSF in the ventricles or subarachnoid space, and eventually to hydrocephalus. We describe the functional role of the CPE with the aim of suggesting its role in the formation of hydrocephalus and ultimately providing researchers with ideas to target the CPE as a therapeutic tool for hydrocephalus, in order to discover more effective means to alleviate or even cure hydrocephalus.


Similar to other South American regions, Tierra del Fuego has an admixed population characterized by distinct ancestors: Native Americans who first occupied the continent, European settlers who arrived from the late 15th century onwards, and Sub-Saharan Africans who were brought to the Americas for slave labor. To disclose the paternal lineages in the current population from Tierra del Fuego, 196 unrelated males were genotyped for 23 Y-STRs and 52 Y-SNPs. Haplotype and haplogroup diversities were high, indicating the absence of strong founder or drift events. A high frequency of Eurasian haplogroups was detected (94.4%), followed by Native American (5.1%) and African (0.5%) ones. The haplogroup R was the most abundant (48.5%), with the sub-haplogroup R-S116* taking up a quarter of the total dataset. Comparative analyses with other Latin American populations showed similarities with other admixed populations from Argentina. Regarding Eurasian populations, Tierra del Fuego presented similarities with Italian and Iberian populations. In an in-depth analysis of the haplogroup R-M269 and its subtypes, Tierra del Fuego displayed a close proximity to the Iberian Peninsula. The results from this study are in line with the historical records and reflect the severe demographic change led mainly by male newcomers with paternal European origin. Tierra del Fuego is a Patagonian archipelago located in the southernmost part of the American continent. It is formed by a main island (Isla Grande of Tierra del Fuego) and a group of smaller islands shared by Argentina and Chile .Archaeological evidence places the arrival of Native Americans in the archipelago between 12,770 and 12,400 YBP ,4.Upon the European arrival in the Strait of Magellan in 1520, numerous contacts were forged with the Fuegian natives, but the earliest establishment of European settlers in Tierra del Fuego only occurred in 1869 when an Anglican mission was stationed in the present-day city of Ushuaia. After the border treaty between Argentina and Chile was signed, in 1881, the Argentine state handed over enormous extensions of land, and several new settlers moved into Tierra del Fuego, engaging mainly in sheep farming and gold mining .Some of these newcomers were immigrants, mainly from Europe, who moved overseas during the late 19th and early 20th centuries. Throughout this period, Argentina was the South American country that welcomed the largest number of immigrants who inherently impacted the Argentine demography. The bulk of these immigrants who settled in the country were from Italy and Spain, and to a lesser extent from other regions such as France, Germany, Russia, Croatia, the British Isles, and the Ottoman Empire .Until the 1970s, the main migratory flows to Argentine Tierra del Fuego stemmed from Chile, probably due to its geographical proximity and labor shortage in the archipelago. To reverse this situation, Argentina launched a financial promotion regime to encourage Argentine citizens to move to the extreme south. As a result, thousands of migrants, mainly from central Argentina, settled in the archipelago between 1980 and 2010, leading to an increase in Tierra del Fuego population from 27,463 to 127,205 [Previous studies on the genetic composition of urban populations show a heterogeneity in the migratory flows in the different regions of Argentina. Regarding mtDNA, Native American lineages reach the highest frequencies in the northern provinces ,11,12,13Argentine Patagonia follows the same trend. Studies in central Patagonia reported a conspicuous predominance of Native American maternal lineages in different populations ,22,23,24To evaluate the impact of migratory flows and the admixture processes, we investigated the origin of the paternal lineages present in the current population from Tierra del Fuego, through the analysis of Y-STRs and Y-SNPs. The results were interpreted considering the genealogical, historical, and demographic information available, to understand the impacts of the influx from other regions of Argentina, South America, Europe, and the Middle East, to the archipelago that was once exclusively inhabited by Native Americans. Furthermore, due to the large-scale Eurasian immigration to Argentina, the R-M269 lineages were analyzed in finer detail to estimate contributions from different European and Middle Eastern regions to the Tierra del Fuego paternal genetic background.A total of 196 samples were collected from unrelated males living in the cities of Río Grande and Ushuaia, Tierra del Fuego province, Argentina . The samParticipants were informed of the scopes of the study and filled out a questionnaire to obtain information about their birthplace and from the three preceding generations , accompanied by a written informed consent. A summary of the information collected is available in the The project and sample collection were approved by the Ethics Committee of the Investigações Biomédicas (IMBICE) under resolution number RENISCE000023 Resol/120618 and by the Teaching and Research Committees of the Regional Hospital of Río Grande and the Regional Hospital of Ushuaia.® Y23 System . Amplification was performed according to the manufacturer’s recommended protocol, and PCR products were separated and detected on an ABI3500 Genetic Analyzer . Genotyping was performed using the GeneMapper™ Software v5.0 (Applied Biosystems), and alleles were assigned based on the allelic ladder provided with the kit.The samples were genotyped for 23 Y-STR loci using the PowerPlexhttps://www.nevgen.org/, accessed on 30 October 2020).A total of 52 Y-SNPs were selected to discriminate the most frequent Eurasian, Native American, and Sub-Saharan African haplogroups . These YThe multiplexes were carried out through PCR and single-base extension (SBE) reaction using the SNaPshot™ Multiplex kit (Applied Biosystems), as previously described by Brion et al.   and the results were analyzed using the GeneMapper™ Software v5.0 (Applied Biosystems).The V88 was genotyped via Sanger sequencing method using the BigDye™ Terminator v3.1 Cycle Sequencing Kit (Applied Biosystems), as previously described in González et al. . The proSTR and STF genetic distances between samples from Tierra del Fuego and other Latin American, African, and Eurasian populations were performed using the Arlequin 3.5.2.2 software [Haplogroup frequencies were calculated by direct counting. Genetic diversities and pairwise software . PairwisNetworks were constructed using the Network 10.0 software . The reduced median  and the −10 [The Eurasian contribution in Tierra del Fuego was estimated for R-M269 and its sub-haplogroups using the ADMIX 2.0 software . This so−10 . All theA total of 193 different haplotypes were identified in the 196 samples analyzed . Out of Haplogroups inside the clade R are the most widely represented in the Tierra del Fuego, accounting for nearly half of the dataset. The remaining haplogroups belong to clades J, E, I, G, Q, and T, and to the paragroup KL.The most likely continental provenance of each of these haplogroups was traced to Eurasia, Native America, and Africa, based on the distribution of the Y-chromosomal haplogroups across different populations and considering the history of Tierra del Fuego as well as Argentina.While some haplogroups in our sample are common on a single continent, others have a wider distribution, being present in both Eurasia and Africa. According to the history of Tierra del Fuego, the Eurasian component is thought to have been contributed by Spanish colonizers and immigrants with European and Middle Eastern ancestry. The African component is likely the result of the transatlantic slave trade that brought a significant number of enslaved people from West and Central Africa and, to a lesser extent, from Mozambique, to the ports of Buenos Aires ,48.The haplogroups whose geographic distribution is in both Eurasia and Africa are as follows: E-M35*, E-M78, E-M81, E-M123, J-12f2a*, J-M172, R-V88, T-M70, and KL-M9*. However, some of these haplogroups on the African continent are constrained to North and East Africa. A gene influx coming directly from those regions is rather unlikely and, consequently, haplogroups E-M78, E-M81, E-M123, J-12f2a*, J-M172, T-M70, and KL-M9* were regarded as being brought to South America by Eurasians.For haplogroups E-M35* and R-V88, which are present in African regions involved in the slave trade, networks were set up using haplotypes from African and Eurasian populations.Although at low frequencies ,50,51, tHaplogroup R-V88, found in two individuals from Tierra del Fuego, is chiefly reported in Africa, more precisely in the Sahel region ,60,61,62The Eurasian lineages found in the Fuegian pool are included into the clades E (except for one sample belonging to haplogroup E-U290), G, I, J, K, T, and R . These lOnly two Native American haplogroups were reported in the present study, Q-M3*  and Q-Z19483, both present at low frequency . The Q-M3* is the founder of most lineages in the Americas that fall under the haplogroup Q. Its presence can be detected all over the double-continent ,70,71,72It is worth noting that 8 of the 10 chromosomes carrying native haplogroups  were calculated between our dataset and other admixed Latin American populations  with Argentina , and 26 in northern Argentina see . Furthern = 11; 5.6%), followed by Bolivia  and Paraguay . Most of these lineages originating elsewhere in Latin America present a Eurasian origin. As addressed in the introduction, these three countries bordering Argentina were the main ones from where the immigrants in Tierra del Fuego had moved in the recent decades.Tierra del Fuego shares connections with the rest of Latin America, and some of the lineages in our dataset trace back to other Latin American countries. Out of the 196 sample donors, 21 indicated a Latin American origin, accounting for 10.7%, of which slightly more than half were from Chile  were calculated between Tierra del Fuego and the Eurasian populations (Pairwise ulations .p > 0.05) values with the populations from northern Italy , central Italy , and Galicia , and the pairwise analysis using Y-STRs revealed nonsignificant values with northern Italy , Portugal , and Tyrol .The comparative analysis using Y-SNPs revealed that Tierra del Fuego presents statistically nonsignificant  influxes in Argentina were notorious. It is estimated that roughly 2 million Italians and 1.4 million Spanish immigrants moved to Argentina between 1881 and 1914 ,101, keeel Fuego  is not un = 29; 14.8%) and Spain   who have a known European paternal heritage trace their origins mainly to Italy  . The res; 12.8%) . As we aThe haplogroup R is the most frequent in Tierra del Fuego, accounting for around half of the Eurasian lineages. The overriding bulk of these R lineages are subtypes of the haplogroup R-M269. These subtypes are broadly spread in both Europe and the Middle East, presenting a clinal distribution with increasing frequencies in Western Europe . Unlike A PC analysis was performed to inquire which sub-haplogroups have the most weight in the differentiation of Tierra del Fuego, European, and Middle Eastern populations . In the In order to estimate the contribution of Eurasian populations in Tierra del Fuego and other South American regions regarding R-M269 and its sub-haplogroups, admixture coefficients were computed using the ADMIX 2.0 software. For the analysis, populations from the Iberian Peninsula  , Italy , GermanyThe results illustrated in Compared with the other South American populations under analysis, Tierra del Fuego stands out at a continental level, presenting the lowest Iberian and the highest Italian and Irish contributions. Since it was not possible to include other samples from Argentina in the analysis (due to lack of data), the pattern found may be present in other regions of the country. Because Tierra del Fuego reflects the overall Argentinian genetic background, the results obtained could also imply lower Spanish and higher Italian and Irish contributions in Argentina compared to the rest of South America, regarding R-M269 and its sub-lineages.The paternal lineages of the current population from Tierra del Fuego present high haplotype and haplogroup diversities, pointing to the absence of strong founder or drift events. This paternal genetic legacy reflects the influence of the European gene flow into the Americas during the colonial period and large-scale immigrations, tallying one of the highest percentages of Eurasian lineages in Latin America. Furthermore, according to genealogical data, the fathers and grandfathers of the sample donors were mainly from central Argentina, where the Eurasian lineages score high frequencies. Therefore, Native American haplogroups are underrepresented in our sample, contrasting with central and northern Patagonia and northwestern Argentina, which feature higher frequencies of native lineages. Moreover, most of the Native American lineages found in Tierra del Fuego should be a result of influxes from other parts of Argentina, Bolivia, and Peru, denoting a lack of native Fuegian lineages in the modern population.It is worth noting that this study aimed to assess the impact of migratory flows and admixture processes on the current population, and therefore samples were randomly selected, and genealogical information was used only to interpret the results, and not as a selection criterion. However, communities that descend from Fuegian ancestral populations still persist in Tierra del Fuego, in which a greater preservation of the native genetic pool is expected.Typical Sub-Saharan African haplogroups score a scant percentage in Tierra del Fuego, a very similar result to that found in other Argentinian regions. This bolsters that the African influx left little trace on the paternal component of the Argentinian population, unlike what occurred in other Latin American regions, such as northeastern Brazil, Colombia, and Ecuador.Pairwise genetic distances using haplotype data show that Tierra del Fuego has proximity to populations from northern Italy and the Iberian Peninsula, with the gap for the Italian population being perceptibly smaller. This indicates that Italian and Spanish inflows during the colonial period and large-scale immigrations markedly shaped the Y-chromosomal landscape of Tierra del Fuego. Analyses focused on the haplogroup R-M269 and its subtypes suggest a major Iberian contribution, followed by smaller inputs from Italy and the British Isles. Furthermore, the PC analysis shows a high influence of the sub-haplogroup R-S116* in Tierra del Fuego and Spain, meanwhile Italy and the British Isles are mainly influenced by R-U152 and R-M529, respectively. This is in line with the genealogical data, which shows that the individuals who trace back their paternal ancestry to Spain carry, mainly, the sub-haplogroup R-S116*, and the individuals with Italian ancestry bear mainly the sub-haplogroup R-U152.


The asymmetry of paravertebral muscle (PVM) degeneration in degenerative lumbar scoliosis (DLS) patients has been extensively studied by imaging and histological examination and has not yet been verified by surface electromyography (sEMG) techniques. To study the relationship between the surface electromyography (sEMG) and degenerative characteristics of paravertebral muscles (PVMs) in patients with degenerative lumbar scoliosis (DLS). In twenty DLS patients and fifteen healthy subjects, sEMG activity of the PVMs at the level of the upper end vertebra (UEV), apical vertebra (AV) and lower end vertebra (LEV) was measured during static standing and dynamic standing forward flexion and backward extension tasks. Action segmentation was achieved according to inertial measurement unit (IMU) data. The sEMG characteristics of the PVMs on the convex and concave sides were compared, and the relationship of these data with the Cobb angle and lumbar lordotic angle (LL) was analyzed. In the DLS group, there was no difference in sEMG activity between the convex and concave sides at the UEV or AV level, but in the motion and return phases of the standing forward flexion task  and the maintenance and return phases of the standing backward extension task , there was a significant difference in sEMG activity between the convex and concave sides at the LEV level. Asymmetrical sEMG activity at the LEV level was negatively correlated with the Cobb angle  and LL angle . In the DLS group, asymmetrical sEMG activity of the PVMs appeared at the LEV level, with the concave side being more active than the convex side. This sEMG characteristics were consistent with their imaging and histological degenerative features and correlated with bone structural parameters. Degenerative lumbar scoliosis (DLS) is a spinal deformity in which the lumbar spine degenerates after skeletal maturity, resulting in scoliosis with a Cobb angle > 10° on the coronal plane that is often accompanied by a change in sagittal balance. It has a complex pathogenesis, a long course, and a progressive trend.2. Therefore, the study of PVMs in the lumbar spine, especially asymmetry in PVM degeneration, is important to further understand the occurrence and development of lumbar degenerative diseases. In this regard, domestic and foreign scholars have conducted a large number of verification studies through imaging and histological examinations5.Previous studies have demonstrated the association between paravertebral muscle (PVM) degeneration and spinal disorders and the prevalence of PVM degeneration in DLS patients6. The surface EMG (sEMG) characteristics of PVMs in the dynamic state are valuable in clinical evaluations, and EMG changes in subjects during dynamic movements can reflect the function of the neuromuscular system8.Electromyography (EMG) is a recording of neuromuscular activity, and its characteristics represent changes in muscle function and can be used to analyze the relationship between PVMs and scoliosisAt present, most sEMG studies have focused on AIS patients, and there have been few related studies on degenerative scoliosis. In this study, sEMG was used in combination with inertial measurement units (IMUs) to examine sEMG changes in PVMs in DLS patients during static standing and dynamic standing forward flexion and backward extension movement tasks. By measuring the sEMG data of PVMs at multiple levels (upper end vertebra (UEV), apical vertebra (AV), and lower end vertebra (LEV)), we were able to compare the convex and concave sides and analyze correlations between these data and bone structural parameters. The purpose was to summarize the relationship between the sEMG characteristics of PVMs and the degree of PVM degeneration in DLS patients.To the best of our knowledge, this is the first study to combine sEMG with the use of IMUs to record the sEMG activity of multiple PVMs simultaneously during motion in DLS patients, verify asymmetry in activity and analyze degenerative characteristics by convex-concave side comparisons.The subjects included twenty DLS patients diagnosed in Tianjin Hospital from March 2021 to September 2021. The inclusion criteria were as follows: (1) no history of lumbar scoliosis, diagnosis of lumbar scoliosis upon examination, and Cobb angle > 10°; (2) age > 50 years; (3) routine imaging examination, including full-length spine view; and (4) no nerve root lesions in untreated patients. The control group consisted of fifteen healthy persons who underwent a comprehensive physical examination at Tianjin Hospital from March 2021 to September 2021. The inclusion criteria were as follows: (1) age > 50 years; (2) no degenerative lumbar spine disease; and (3) no radiculopathy or treatment.The medical ethics committee of the hospital approved the study, and informed consent was obtained from the patients themselves and their families in all cases. All experiments were performed in accordance with the relevant guidelines and regulations, i.e. the reports in the manuscript follow the recommendations in the Declaration of Helsinki.There were no significant differences in sex, age, height, weight, or body mass index (BMI) between the two groups Table .Table 1DThe exclusion criteria were as follows: (1) significant limitation of standing and lumbar extension and flexion activities; (2) manifestation of lower limb neuralgia; (3) abnormal vertebral development, spinal fracture and spinal instability seen in imaging data; and (4) spine, pelvis, and lower limb surgery history.In the DLS group, the Cobb angle between the upper endplate of the UEV and the lower endplate of the LEV on the coronal plane view of the lumbar spine was measured with standard full-length anteroposterior radiography, and the lumbar lordotic (LL) angle between the L1 upper endplate and the S1 upper endplate was measured in standard lateral radiography. All data were analyzed using Surgimap software . The measurement results were as follows: In the DLS group, fourteen samples had left-sided convexity, six samples had right-sided convexity, the average Cobb angle was 17.6° ± 5.20°, and the average LL angle was 32.84° ± 8.96°  bipolar circular surface electrodes  prepared with conductive gel were placed on the abdomen of bilateral PVMs at the level of the UEV, AV and LEV  was used to record sEMG signals at a sampling frequency of 2000 Hz. According to the European sEMG recommendationsMovement tasks included maximum standing forward flexion and maximum standing backward extension. Under the guidance of the metronome, subjects were instructed to (a) static standing for 5 s, (b) perform maximum forward flexion/backward extension of the trunk at a self-selected speed for 5 s, (c) remain in forward flexion/backward extension for 5 s, and (d) return to the initial static standing position for another 5 s Fig. . Each mosEMG signals during trunk forward flexion and backward extension movements were analyzed, and the sEMG signals from phase (a) were used as the static standing phase. Each patient was tested three times, and the average of the three tests was used for further analysis.Before the formal measurements, participants had a practice session to familiarize themselves with the experimental procedure, and patients were instructed to perform lumbar extension and flexion activities, avoiding pelvic and lower limb involvement as much as possible. To prevent fatigue, there was a 1-min break between any two consecutive tests.15 and fixed to the L1, L3, and L5 horizontal spinous processes using double-sided adhesive, allowing measurement of the angular velocity of lumbar spine motion. Motion signals from three IMUs were collected: acceleration along the vertical axis (x-axis), along the horizontal axis (y-axis), and along the anterior–posterior axis (z-axis)  Fig. . sEMG an16.The original sEMG signals were processed with a Butterworth bandpass filter 30–500 Hz), and the baseline noise was removed . A simple linear regression model was used to analyze the influence of Cobb angle and LL angle on the convex/concave sEMG ratio at the LEV level. By drawing the scatter plot, we can judge whether there is a linear relationship between them. P < 0.05 was considered a statistically significant difference.Statistical analysis was performed using SPSS 25.0 . The measurement data are described by the mean ± SD. All data were analyzed by descriptive analysis and normality tests. A nonparametric test was used to compare the demographic data of the two groups. Paired The study protocol was approved by the ethical review committee of Tianjin Hospital, and all participants and their legal representatives gave informed consent to participate in the study.The study was approved by the Ethical Committee of Tianjin Hospital (2020088). The participants provided written informed consent.In the static standing phase, there was no difference in the sEMG activity of the PVMs between the left and right sides in the control group, and there was no difference in the sEMG activity of the PVMs between the convex and concave sides in the DLS group Fig. .In the standing forward flexion task, there was no difference in sEMG activity between the left and right sides in the control group, no difference in sEMG activity between the convex and concave sides in the DLS group at the UEV or AV level, and a significant difference in sEMG activity between the convex and concave sides in the DLS group at the LEV level during the motion phase of the standing forward flexion task  and the return phase of the standing forward flexion task  Fig. .In the standing backward extension task, there was no difference in sEMG activity between the left and right sides in the control group, no difference in sEMG activity between the convex and concave sides in the DLS group at the UEV or AV level, and a significant difference in sEMG activity between the convex and concave sides in the DLS group at the LEV level during the maintenance phase of the standing backward extension task  and the return phase of the standing backward extension task  , there was a negative correlation between the convex/concave sEMG ratio at the LEV level and the Cobb angle Fig.  and LL aThe sEMG values (mean ± SD) and statistical analysis results for the three levels of PVMs (L1/L3/L5 or UEV/AV/LEV) during the three movement tasks  for the DLS and control groups are presented in Table 2 = 52.2%). The regression equation is: the sEMG ratio at the LEV level = 1.572 + (− 0.046 × Cobb angle), which is a negative correlation.The Cobb angle has a statistically significant effect on the convex/concave sEMG ratio (sEMG activity on the convex side divided by sEMG activity on the concave side) at the LEV level, F = 93.791, P < 0.001; the Cobb angle can explain 52.8% of the sEMG ratio, with a moderate degree of influence (Adjust R2 = 43.2%). The regression equation is: the sEMG ratio at the LEV level = 1.563 + (− 0.024 × LL angle), which is a negative correlation.The LL angle has a statistically significant effect on the convex/concave sEMG ratio (sEMG activity on the convex side divided by sEMG activity on the concave side) at the LEV level, F = 65.564, P < 0.001; the LL angle can explain 43.8% of the sEMG ratio, with a moderate degree of influence  of PVMs at the lower intervertebral disc level was more serious than that at the upper intervertebral disc level. Xia19 found that the relative cross-sectional area (CSA) of PVMs decreased gradually from top to bottom, which was consistent with the results reported by Park20. Compared with the upper lumbar level, the lower lumbar level had a higher degree of PVM degeneration.Imaging and histological studies have shown that the rate of muscle degeneration varies in different regions of the lumbar spine, and the degree of PVM degeneration varies between the convex and concave sides at the same level. The degeneration of PVMs was more obvious in the dorsal extensor group, which began at the level of the lower lumbar vertebra and gradually developed upward21.The appearance of this degeneration pattern has been suggested to be a result of biomechanical compensation. The closer the PVM is to the lower intervertebral disc, the greater the forces it is subjected to, and the more likely the muscle is to degenerate, as evidenced by a gradual increase in muscle FI and muscle degeneration along with the level of the paravertebral extensors from top to bottom24. Compared with AIS patients, DLS patients exhibit asymmetrical sEMG activity at the LEV level, demonstrating that the asymmetry is caused by muscle degeneration, whereas the abnormal activity of PVMs on the convex side in AIS patients is considered to be a secondary compensatory response to the scoliosis deformity and therefore appears at the AV level.Our findings are consistent with this degenerative pattern. But in AIS patients, sEMG asymmetry between the convex and concave sides is obvious at the AV level2. In DLS patients, the sEMG activity of PVMs on the concave side is more active than that on the convex side at the LEV level.25. In DLS patients, the degeneration of PVMs at the same level is asymmetrical, and the degeneration on the concave side is greater than that on the convex side, which manifests on imaging and histology. The CSA of PVMs on the convex side is larger than that on the concave side, indicating hyperplasia and hypertrophy; the CSA of PVMs on the concave side is decreased and accompanied by an increased FI4, whereas in normal subjects, there is no such asymmetry.At present, domestic and foreign scholars believe that the degeneration of PVMs is characterized by a decrease in muscle volume and an increase in fat infiltration26 found that the FI on the concave side multifidus muscle was significantly higher than that on the convex side multifidus muscle in patients with degenerative scoliosis, while the muscle CSA was smaller than that on the convex side. This is similar to the research results reported by Ding27. Shafaq3 studied histological changes in PVMs in DLS patients and found that the diameter of muscle fibers and the number of nuclei in the multifidus muscle were decreased on the concave side, suggesting that the degeneration of PVMs is more common and severe on the convex side.Xie28. The high load on the convex side causes compensatory hyperplasia and hypertrophy and inhibits adipocyte differentiation25, while the concave side shows atrophy and steatosis. Thus, compensatory hypertrophy of the PVMs on the convex side occurs to compensate and maintain the imbalance in the coronal position of the spine and reduce the inclination of the spine to the concave side, while muscle atrophy on the concave side may be associated with increased FI.The appearance of this asymmetry in degeneration is thought to be the result of biomechanical compensation. Due to the large load carried by the lumbar dorsal extensor group, scoliosis leads to different forces on each side, and the tension load on the convex side is greater than that on the concave side30. The results of this study show that the sEMG activity is greater on the concave side than on the convex side in DLS patients, which is consistent with imaging and histological studies. That is, the degree of degeneration is greater on the concave side than the convex side, which also supports the view that biomechanical compensation leads to asymmetrical degeneration on the convex and concave sides.We chose RMS/MVC as an indicator of sEMG activation, which produced a higher value in atrophied or hypertrophic muscles, followed by fatigued muscles and a minimum in normal muscles. In PVMs at the same level, weak or heavily degenerated muscles produce greater sEMG activity3. Relationship between sEMG asymmetry on the convex and concave sides and bone structural parameters.23. However, for DLS patients, there have been no reports on the correlation of sEMG asymmetry with bone structural parameters.In the sEMG study of AIS patients, the convex/concave sEMG ratio was positively correlated with the Cobb angle; that is, the larger the Cobb angle was, the greater the difference in sEMG activity between the convex and concave sides5 found that asymmetry in the CSA between the convex and concave sides in DLS patients was correlated with the Cobb angle in lumbar scoliosis. This is similar to the findings reported by Tang25, Ding27, and Xia19. Xie26 found that the asymmetry of PVM imaging indexes between the convex and concave sides was not only related to the Cobb angle but also had a weak negative correlation with the LL angle. Therefore, the asymmetry of PVMs in DLS patients reflects the severity of coronal and sagittal imbalance in the lumbar spine27.Yagi26. Our results showed that the convex/concave sEMG ratio in DLS patients was negatively correlated with the Cobb angle and LL angle; that is, the convex/concave sEMG ratio decreased as the Cobb angle and LL angle increased. The reason for this analysis is that the degeneration of PVMs on the convex and concave sides increases with increasing Cobb angle and LL angle in DLS patients, with greater degeneration on the concave side than on the convex side. Muscle activation on the concave side requires higher EMG activity, and the convex/concave sEMG ratio decreases. PVM asymmetry between the convex and concave sides in DLS patients is mainly due to serious degeneration of the concave side. This is different from what occurs in AIS patients, where asymmetry results from excessive muscle loading on the convex side, and more active muscle activity is needed on the convex side to correct the deformity31. This correlation explains why dynamic soft tissue stabilization plays a key role in maintaining spinal alignment and PVM misalignment is related to coronal/sagittal imbalance in DLS patients.The larger the Cobb angle is, the greater the asymmetric mechanical load on the concave and convex sides and the worse the stability of the spine, which is the main reason for the aggravation in PVM asymmetryConsidering the presence of EMG crosstalk, changes in the sEMG activity of specific muscles were not measured according to the anatomical structure, and the sEMG characteristics of scoliosis were measured at only three levels .There were differences in sEMG activity among individuals in the groups, which may have been caused by variations in muscle mass, body posture, and electrodeposition.The asymmetry of sEMG activity at the LEV level does not appear in all phases of movement tasks, which may due to the large variation in movement amplitude from one movement task to another and the different degrees of mobilization of the PVMs.In DLS patients, asymmetrical sEMG activity between the convex and concave sides appears at the LEV level, with more sEMG activity on the concave side than on the convex side, which is significantly different from that observed in healthy controls and AIS patients. This asymmetrical sEMG activity in PVMs is consistent with the findings of imaging and histological studies.In DLS patients, the main reason for the asymmetrical sEMG activity between the convex and concave sides is muscle degeneration, which is predominant on the concave side; this is significantly different from the findings in AIS patients.Asymmetrical sEMG activity between the convex and concave sides in DLS patients is related to the Cobb angle and LL angle.