Bulb Area Research Articles

Assessment of predictive factors in endoscopic internal urethrotomy for bulbar urethral strictures

IntroductionDirect vision internal urethrotomy (DVIU) is usually the first treatment offered to patients with bulbar urethral strictures (US). Advances in devices and surgical techniques have contributed to reducing associated complications. Despite the favorable success rate of DVIU, various factors predicting better outcomes have been studied, including patient characteristics, stricture features, and procedural aspects. The main aim of our study is to assess predictive factors for success. MethodsWe conducted a retrospective descriptive study of patients who underwent endoscopic internal urethrotomy at our hospital over a 30 year period. Out of 788 DVIU performed, we selected 491 (62.3%) conducted for bulbar US with a minimum follow-up of 12 months. We examined clinical outcomes obtained, and assessed the relationship between different patient characteristics, stricture-related factors and procedural aspects related with clinical success -considered as the avoidance of further interventions for stricture recurrence-. Descriptive statistics were calculated and parametrical and non-parametrical comparative tests were applied. Kaplan-Meier survival analysis was used for evaluating time until recurrence. ResultsMean stricture length was 1.2 cm (SD 0.5), with only 12 patients presenting with more than 1 US in the bulbar area during DVIU. After a median follow-up of 170 months, 67.4% of patients did not experience clinical recurrence. Severe postoperative complications appear in 0.4% of cases, and need for overnight admission was 4.5%. A positive association was observed between clinical recurrence and a history of prior pelvic radiotherapy (OR 2.8, 95%IC 1.3-22.2), active smoking (OR 2.1, 95%IC 1.6-2.4), infectious etiology of stricture (OR 2.3, 95%IC 1.6-8), history of previous urethroplasty (OR 2.5, 95%IC 1.7-3.2), and higher postoperative urinary catheter sizes (OR 1.8 95%IC 1.1-2.9). Median time until recurrence after the first DVIU was 65 months, after the second was 60 months, after the third was 32 months, and after the fourth was 6 months. ConclusionsBulbar US could be safely managed with DVIU. The best clinical success is achieved in non-irradiated, non-smoker patients, without prior urethroplasties. The repetition of the procedure is significantly associated with a shorter time to clinical recurrence.

Evaluación de los factores predictivos tras uretrotomía interna endoscópica para estenosis de uretra bulbar

Introduction: Direct vision internal urethrotomy (DVIU) is usually the first treatment offered to patients with bulbar urethral strictures (US). Advances in devices and surgical techniques have contributed to reducing associated complications. Despite the favorable success rate of DVIU, various factors predicting better outcomes have been studied, including patient characteristics, stricture features, and procedural aspects. The main aim of our study is to assess predictive factors for success.Methods: We conducted a retrospective descriptive study of patients who underwent endoscopic internal urethrotomy at our hospital over a 30 year period. Out of 788 DVIU performed, we selected 491 (62.3%) conducted for bulbar US with a minimum follow-up of 12 months. We examined clinical outcomes obtained, and assessed the relationship between different patient characteristics, stricture-related factors and procedural aspects related with clinical success -considered as the avoidance of further interventions for stricture recurrence-. Descriptive statistics were calculated and parametrical and non-parametrical comparative tests were applied. Kaplan-Meier survival analysis was used for evaluating time until recurrence.Results: Mean stricture length was 1.2 cm (SD 0.5), with only 12 patients presenting with more than 1 US in the bulbar area during DVIU. After a median follow-up of 170 months, 67.4% of patients did not experience clinical recurrence. Severe postoperative complications appear in 0.4% of cases, and need for overnight admission was 4.5%. A positive association was observed between clinical recurrence and a history of prior pelvic radiotherapy (OR 2.8, 95%IC 1.3-22.2), active smoking (OR 2.1, 95%IC 1.6-2.4), infectious etiology of stricture (OR 2.3, 95%IC 1.6-8), history of previous urethroplasty (OR 2.5, 95%IC 1.7-3.2), and higher postoperative urinary catheter sizes (OR 1.8 95%IC 1.1-2.9). Median time until recurrence after the first DVIU was 65 months, after the second was 60 months, after the third was 32 months, and after the fourth was 6 months.Conclusions: Bulbar US could be safely managed with DVIU. The best clinical success is achieved in non-irradiated, non-smoker patients, without prior urethroplasties. The repetition of the procedure is significantly associated with a shorter time to clinical recurrence.

Differential functional change in olfactory bulb and olfactory eloquent areas in Parkinson's disease.

Olfactory dysfunction, or hyposmia, frequently occurs as a prodromal symptom and ongoing sign of Parkinson's disease. Functional MRI is a powerful tool for studying functional changes in the olfactory brain regions in patients with Parkinson's disease. However, existing studies show inconsistent results and no study has measured olfactory functional MRI abnormalities in the human olfactory bulb directly. This is mainly due to the well-known susceptibility artefacts in conventional functional MRI images that affect several key olfactory-eloquent brain regions, and especially the olfactory bulb. In this study, olfactory functional MRI was performed using a recently developed functional MRI approach that can minimize susceptibility artefacts and measure robust functional MRI signals in the human olfactory bulb during olfactory stimulation. Experiments were performed on high magnetic field (7 T) in 24 early (<5 years of parkinsonian symptoms) Parkinson's disease patients and 31 matched healthy controls. Our data showed increased functional MRI signal changes (ΔS/S) in the olfactory bulb in patients with early Parkinson's disease, which correlated with behavioural olfactory measures. Temporally, functional MRI signals in the olfactory bulb returned to the pre-stimulus state earlier after reaching peak amplitude in patients with early Parkinson's disease, implicating a faster olfactory habituation effect. The piriform cortex showed reduced numbers of activated voxels in patients with early Parkinson's disease, which correlated with behavioural olfactory assessment. Several secondary olfactory regions including the orbitofrontal cortex, temporal pole and amygdala exhibited reduced numbers of activated voxels and increased functional MRI signal changes in patients with early Parkinson's disease. Our data also showed that functional MRI results are highly dependent on voxel selection in the functional analysis. In summary, we demonstrate differential spatial and temporal characteristics of olfactory functional MRI signals between the primary and secondary olfactory regions in patients with early Parkinson's disease. These results may assist the development of novel quantitative biomarkers (especially in the early stages of Parkinson's disease) to track and predict disease progression, as well as potential treatment targets for early intervention.

Postsurgical tactile-evoked pain: a role for brain-derived neurotrophic factor-tropomyosin receptor kinase B-dependent novel tactile corpuscles.

Millions of people undergo surgical procedures each year with many developing postsurgical pain. Dynamic allodynia can arise when, for example, clothing brushing close to the surgical site elicits pain. The allodynia circuits that enable crosstalk between afferent tactile inputs and central pain circuits have been studied, but the peripheral tactile drive has not been explored. Investigate the innervation of the skin in the rat plantar hindpaw skin-muscle incision model. Incision increased epidermal thickness and cell layers and reduced intraepidermal nerve fibre density, identified with PGP9.5 immunostaining. Strikingly, Collagen IV immunostaining revealed the development of dermal protrusions, oriented towards the incision site, that were reminiscent of the dermal papillae that exist in glabrous footpads. S100 immunostaining for lamellar Schwann cells revealed the presence of novel tactile corpuscles (S100-positive bulb) within incision-induced putative dermal papillae. The occurrence of these novel tactile corpuscles coincided with behavioural observations of dynamic allodynia. Tactile corpuscles require brain-derived neurotrophic factor- tropomyosin receptor kinase B (BDNF-TrkB) signalling to form during development, and an increase in BDNF-immunostaining intensity was observed close to the incision site. Local acute administration of TrkB-Fc, to block BDNF-TrkB signalling, reduced, by approximately 50%, both tactile corpuscle size (S100+ bulb area) and dynamic allodynia. Surgery induces the development of novel tactile corpuscles in the incision surround, in a BDNF-TrKB-dependent manner, that contributes to postsurgical tactile-evoked pain.

Usefulness of Olfactory Bulb Measurement in 3D-FIESTA in Differentiating Parkinson Disease from Atypical Parkinsonism.

Parkinson disease is a prevalent disease, with olfactory dysfunction recognized as an early nonmotor manifestation. It is sometimes difficult to differentiate Parkinson disease from atypical parkinsonism using conventional MR imaging and motor symptoms. It is also known that olfactory loss occurs to a lesser extent or is absent in atypical parkinsonism. To the best of our knowledge, no study has examined olfactory bulb changes to differentiate Parkinson disease from atypical parkinsonism, even in an early diagnosis, and its association with conventional MR imaging findings. Hence, we aimed to assess the utility of olfactory bulb measurements in differentiating Parkinson disease from atypical parkinsonism even in the early stage. In this retrospective study, we enrolled 108 patients with Parkinson disease, 13 with corticobasal syndrome, 15 with multiple system atrophy, and 17 with progressive supranuclear palsy who developed parkinsonism. Thirty-nine age-matched healthy subjects served as controls. All subjects underwent conventional MR imaging and 3D FIESTA for olfactory bulb measurements using manual ROI quantification of the cross-sectional olfactory bulb area using the coronal plane. Bilateral olfactory bulb measurements were averaged. For group comparisons, we used the Welch t test, and we assessed diagnostic accuracy using receiver operating characteristic analysis. Patients with Parkinson disease had a mean olfactory bulb area of 4.2 (SD, 1.0 mm2), significantly smaller than in age-matched healthy subjects (6.6 [SD, 1.7 mm2], P < .001), and those with corticobasal syndrome (5.4 [SD, 1.2 mm2], P < .001), multiple system atrophy (6.5 [SD, 1.2 mm2], P < .001), and progressive supranuclear palsy (5.4 [SD, 1.2 mm2], P < .001). The receiver operating characteristic analysis for the olfactory bulb area measurements showed good diagnostic performance in differentiating Parkinson disease from atypical parkinsonism, with an area under the curve of 0.87, an optimal cutoff value of 5.1 mm2, and a false-positive rate of 18%. When we compared within 2 years of symptom onset, the olfactory bulb in Parkinson disease (4.2 [SD, 1.1 mm2]) remained significantly smaller than in atypical parkinsonism (versus corticobasal syndrome (6.1 [SD, 0.7 mm2]), P < .001; multiple system atrophy (6.3 [SD, 1.4 mm2]), P < .001; and progressive supranuclear palsy (5.2 [1.3 mm2], P = .003, respectively). 3D FIESTA-based olfactory bulb measurement holds promise for distinguishing Parkinson disease from atypical parkinsonism, especially in the early stage.

Factors associated with Edinburgh Cognitive and Behavioural ALS Screen (ECAS) alteration at time of diagnosis, in amyotrophic lateral sclerosis

BackgroundEdinburgh Cognitive and Behavioral ALS Screen (ECAS) is a validated assessment designed to screen cognitive functions and behavioral disorders in amyotrophic lateral sclerosis (ALS). Objective of this study is to determine the factors associated with ECAS impairment in a cohort of ALS patients without a co-morbid diagnosis of dementia, at the time of diagnosis. MethodsWe enrolled 71 non-demented ALS patient. We collected clinical and demographic data, ALS familiarity, analysis of the most commonly mutated genes in ALS, ALS Milano Torino Staging System and ALS Functional Rate Scale revised scores, progression rate; finally, we recorded whether symptoms onset involved spinal or bulbar area. The alteration of the ECAS was estimated based on age and education-adjusted-validated cut off for each of the items included in ECAS. A multivariable regression analysis was done. ResultsThe significant determinants of ECAS alterations were: bulbar onset in both ALS-specific test and total ECAS score; bulbar onset and familiarity in ALS-non-specific test; finally, familiarity and diagnosis delay in ALS-behavioral test. All the subjects carrying C9orf72 mutations had alteration of both total ECAS score and ALS-specific tests. DiscussionAt diagnosis, bulbar-onset ALS, family history, diagnosis delay and C9orf72 hexanucleotide repeat expansion may contribute to impairment of ECAS.

Stimulation of hair regrowth in an animal model of androgenic alopecia using 2-deoxy-D-ribose.

Androgenic alopecia (AGA) affects both men and women worldwide. New blood vessel formation can restore blood supply and stimulate the hair regrowth cycle. Recently, our group reported that 2-deoxy-D-ribose (2dDR) is 80%-90% as effective as VEGF in the stimulation of neovascularization in in vitro models and in a chick bioassay. In this study, we aimed to assess the effect of 2dDR on hair growth. We prepared an alginate gel containing 2dDR, polypropylene glycol, and phenoxyethanol. AGA was developed in C57BL6 mice by intraperitoneally injecting testosterone (TE). A dihydrotestosterone (DHT)-treated group was used as a negative control, a minoxidil group was used as a positive control, and we included groups treated with 2dDR gel and a combination of 2dDR and minoxidil. Each treatment was applied for 20 days. Both groups treated with 2dDR gel and minoxidil stimulated the morphogenesis of hair follicles. H&E-stained skin sections of C57BL/6 mice demonstrated an increase in length, diameter, hair follicle density, anagen/telogen ratio, diameter of hair follicles, area of the hair bulb covered in melanin, and an increase in the number of blood vessels. Masson's trichrome staining showed an increase in the area of the hair bulb covered in melanin. The effects of the FDA-approved drug (minoxidil) on hair growth were similar to those of 2dDR (80%-90%). No significant benefit were observed by applying a combination of minoxidil with 2dDR. We conclude that 2dDR gel has potential for the treatment of androgenic alopecia and possibly other alopecia conditions where stimulation of hair regrowth is desirable, such as after chemotherapy. The mechanism of activity of 2dDR remains to be established.

Circuit dynamics of the olfactory pathway during olfactory learning.

The olfactory system plays crucial roles in perceiving and interacting with their surroundings. Previous studies have deciphered basic odor perceptions, but how information processing in the olfactory system is associated with learning and memory is poorly understood. In this review, we summarize recent studies on the anatomy and functional dynamics of the mouse olfactory learning pathway, focusing on how neuronal circuits in the olfactory bulb (OB) and olfactory cortical areas integrate odor information in learning. We also highlight in vivo evidence for the role of the lateral entorhinal cortex (LEC) in olfactory learning. Altogether, these studies demonstrate that brain regions throughout the olfactory system are critically involved in forming and representing learned knowledge. The role of olfactory areas in learning and memory, and their susceptibility to dysfunction in neurodegenerative diseases, necessitate further research.

Superior versus inferior conjunctival rotational flap in primary pterygium surgery

Background Conjunctival rotational flap is one of the surgical treatment options for pterygium with variable recurrence rates. Taking a conjunctival flap from the superior bulbar area is sometimes unfeasible due to scarring, ocular surface disease, or previous trabeculectomy. Aim This study aimed to compare the superior versus the inferior conjunctival rotational flap results following primary pterygium excision. Patients and methods This is a retrospective, interventional, comparative study that enrolled 120 patients having primary pterygium. The patients were recruited from the Ophthalmology Department, Beni Suef University Hospital, Beni Suef, Egypt during the period from June 2020 to June 2022. The patients were classified into two groups: group I that included 73 (60.8%) patients who underwent the superior conjunctival flap technique, and group II that included 47 (39.2%) patients who underwent the inferior flap technique. Slit-lamp findings were reported during the scheduled appointments, with a focus on pterygium recurrence and other complications. Postoperative follow-up was performed for 6–18 months. Results The recurrence rate among the inferior conjunctival flap group (12.8%) was higher than in the superior conjunctival flap group (9.6%), with no statistically significant difference (P=0.585). No additional postoperative complications, such as flap separation, dullen formation, or granulomas occurred in either group. Conclusion There was no statistically significant difference in the outcome of the superior and inferior conjunctival rotational flaps in primary pterygium excision. We propose that inferior conjunctival flap preference can result in favorable outcomes in circumstances where the superior bulbar conjunctiva is required for protection or cannot be used.

Measurement of sucrose concentration using Imbibition length on paper: A device for equipment-free and environmentally-friendly detection

The Lucas-Washburn equation is commonly used to predict the distance (L) that a liquid travels through paper. This equation establishes that L2 is linear with time and inversely proportional to the viscosity of the liquid. However, there is currently no theoretical equation connecting the viscosity of a solution to its concentration. In this study, the imbibition flow of a sucrose solution was measured along the length of a horizontal strip of filter paper, featuring a printed, thermometer-shaped hydrophobic boundary. A sample (38 μL) was dispensed onto the bulb area, and the solution's flow was visually tracked using a red dye added to the sample. The imbibition length (L) was measured by a vernier caliper at 10.0 min after the sample addition. An empirical equation, based on literature values of the viscosity (η) and concentration (C) of sucrose solutions, was proposed. By integrating this empirical equation with the Lucas-Washburn equation, the following equation was derived: L = a⋅exp{-(bC + cC2)}, where ‘a’, ‘b’ and ‘c’ are parameters. This equation was fitted to the dataset of L and C, covering C values from 0 to 60 % w/w standard sucrose solutions, resulting in a coefficient of determination of 0.9987. The plot of L against C was observed to closely follow a linear line, with a fitting providing a coefficient of determination of 0.9986. The sucrose contents in samples, such as soft drinks, syrups, and sugarcanes, determined using the imbibition length method and conventional refractometry, were in statistical agreement via the paired t-test at the 95 % confidence level. This method is simple, instrument-free, requiring only a small amount of safe red food dye, and can be conducted on-site.

A cavity expansion theory-based hyperbolic model for the pull-out force of a compaction-grouted soil nail

Compared with conventional soil nails, the soil nail with grout bulbs (compaction-grouted soil nail) exhibits better performance in soil. In this study, a hyperbolic relationship was used to describe the relationship between pull-out stress (pull-out force divided by the cross-sectional area of a grout bulb) and displacement, in which the initial compressive modulus and ultimate compressive strength are the key factors that need to be determined in advance. In this case, the stress-strain behaviour of the soil around the grout bulb was investigated based on cavity expansion theory during compaction grouting and pull-out processes, and the initial compressive modulus with a compaction effect and the ultimate compressive strength were then quantified. Therefore, a cavity expansion theory-based hyperbolic model for the pull-out force of a compaction-grouted soil nail was proposed, in which the contribution of compaction grouting to the pull-out force was theoretically quantified. The proposed pull-out force model that combines the hyperbolic relationship and cavity expansion theory is simple and has high accuracy and will be useful for the design of the new soil nail with grout bulbs.

Mechanical epilation exerts complex biological effects on human hair follicles and perifollicular skin: An exvivo study approach.

Electrical epilation of unwanted hair is a widely used hair removal method, but it is largely unknown how this affects the biology of human hair follicles (HF) and perifollicular skin. Here, we have begun to explore how mechanical epilation changes selected key biological read-out parameters exvivo within and around the pilosebaceous unit. Human full-thickness scalp skin samples were epilated exvivo using an electro-mechanical device, organ-cultured for up to 6 days in serum-free, supplemented medium, and assessed at different time points by quantitative (immuno-)histomorphometry for selected relevant read-out parameters in epilated and sham-epilated control samples. Epilation removed most of the hair shafts, often together with fragments of the outer and inner root sheath and hair matrix. This was associated with persistent focal thinning of the HF basal membrane, decreased melanin content of the residual HF epithelium, and increased HF keratinocyte apoptosis, including in the bulge, yet without affecting the number of cytokeratin 15+ HF epithelial stem cells. Sebocyte apoptosis in the peripheral zone was increased, albeit without visibly altering sebum production. Epilation transiently perturbed HF immune privilege, and increased the expression of ICAM-1 in the bulge and bulb mesenchyme, and the number of perifollicular MHC class II+ cells as well as mast cells around the distal epithelium and promoted mast cell degranulation around the suprabulbar and bulbar area. Moreover, compared to controls, several key players of neurogenic skin inflammation, itch, and/or thermosensation (TRPV1, TRPA1, NGF, and NKR1) were differentially expressed in post-epilation skin. These data generated in denervated, organ-cultured human scalp skin demonstrate that epilation-induced mechanical HF trauma elicits surprisingly complex biological responses. These may contribute to the delayed re-growth of thinner and lighter hair shafts post-epilation and temporary post-epilation discomfort. Our findings also provide pointers regarding the development of topically applicable agents that minimize undesirable sequelae of epilation.

A comparison of intima media thickness in the common carotid artery, the bulb and plaque area as predictions of incident atherosclerotic events.

There is a debate on how to evaluate carotid artery intima-media thickness (IMT). We here compared IMT of the common carotid artery (CCA) and bulb with plaque area regarding incident atherosclerotic disease. In the PIVUS study (age 70 at baseline, 53% women, n = 856), IMT-CCA, IMT-bulb and plaque area were measured at ages 70, 75 and 80 years and these three measurements were used in updated Cox proportional hazard analysis. Over 15 years follow-up, 135 individuals experienced a first-time atherosclerotic disease (myocardial infarction or ischemic stroke). IMT-CCA was not significantly related to this composite endpoint (p = 0.10). IMT-bulb was significantly related to the endpoint (p = 0.003), but this relationship was attenuated following adjustment for CVD risk factors (p = 0.02). On the contrary, plaque area was consistently related to incident atherosclerotic disease also following adjustment for CVD risk factors (p<0.001). When added on top of traditional risk factors, both IMT-bulb and plaque area, but not IMT-CCA, improved the discrimination compared to the traditional risk factors (+5.2%, p = 0.0026 for IMT-bulb, +3.8%, p = 0.013 for plaque area and 0.0% for IMT-CCA). In elderly subjects, both IMT-bulb and plaque area improved the discrimination regarding incident atherosclerotic disease when added to traditional risk factors. This was not seen for IMT-CCA. IMT-CCA was therefore inferior compared to the other two carotid artery ultrasonographic measurements in this sample of elderly subjects.

Bilateral ablation of the vomeronasal organs produces dramatic changes in the EEG of the main olfactory system during paradoxical sleep

Background: The vomeronasal organ (VNO) plays an important role in reproductive physiology, behavior, sexual behavior and aggression. Objective: The aim is to report a surprising effect of the removal of the VNO on the cortical electrical activity of the olfactory bulb, piriform lobe and frontal cortex exclusively during paradoxical sleep (PS). Methodology: Seventeen adult armadillos chronically prepared for electrographic recordings were employed. Some animals were subjected to VNO bilateral remove. They were studied during wakefulness and sleep phases. Results: An outstanding phenomenon occurs during PS of armadillos submitted to bilateral ablation of the VNO. There is a dramatic change in the oscillations of the olfactory bulb electrical activity strictly confined to PS. The change consists of the sudden appearance, as soon as PS initiates, of high amplitude gamma oscillations during the whole duration of each PS episode. They disappear as soon as PS comes to an end. The oscillations are also seen in the paleocortex and the frontal neocortex. They disappear after the transverse section of the olfactory peduncles. Conclusions: Our results show the absence of VNO deeply modifies the electrophysiological expression of PS in the olfactory bulb and other extensive brain areas. They are elicited by the centrifugal input to the olfactory bulb. From there they propagate to the piriform and frontal neocortex. These results show a new and subtle role for the organs. Some hypotheses related to the effects of bilateral removal of the VNO are presented.

Effect of shoeing horses with eggbar shoes and shoes with wedge pads on blood flow parameters in the lateral digital artery in the Doppler ultrasound.

A sound knowledge of horseshoe impact on blood flow parameters is required for making shoeing decisions and selecting the most appropriate types of shoes. The aim of this study was to determine the effect of horse shoeing with egg bar shoes and shoes with wedge pads on blood flow parameters in the lateral palmar digital artery measured by Doppler ultrasound. The study was conducted on 16 horses divided into two groups. Horses from group 1 were shod with egg bar shoes. Horses from group 2 were shod with shoes with wedge pads. Doppler ultrasound parameters of the lateral palmar digital artery at the level of the metacarpophalangeal joint were evaluated. Doppler tests were performed before and after shoeing within a monthly interval. The results of the study indicate that egg bar shoes have a greater impact on blood circulation in the distal part of the equine limb than shoes with wedge pads. However, the only parameters to have changed substantially after shoeing with egg bar shoes were end-diastolic velocity (EDV) and mean velocity (Vmn) in the lateral palmar digital artery. A low-resistance blood flow pattern was noted before shoeing. After shoeing in group 1, it remained unchanged in 5 horses, whereas a high-resistance pattern was observed in 3 animals. A low-resistance blood flow pattern was noted in all group 2 horses after shoeing. The difference between the analyzed shoeing techniques could be attributed to increased pressure in the heel bulb area in horses shod with egg bar shoes. Wedge pads shift the load away from the heel bulbs, which might reduce the pressure on the palmar digital vessels and exert a smaller influence on the parameters measured in the Doppler ultrasound test.

CT evaluation of unilateral pulsatile tinnitus with jugular bulb wall dehiscence.

To investigate the imaging features of unilateral pulsatile tinnitus (PT) with jugular bulb wall dehiscence (JBWD). Computerized tomography angiography images of unilateral PT patients were reviewed between 2019 and 2021. Thirty-one symptomatic JBWD patients without sigmoid sinus wall dehiscence (SSWD) were included. Thirty-eight patients with SSWD were used as the control group. The prevalence of JBWD was calculated. The area and height of the jugular bulb, the extent of dehiscence, the presence of jugular bulb diverticulum, posterior condylar emissary vein (PCEV), oblique occipital sinus (OOS), venous outflow laterality (VOL), the degree of transverse sinus stenosis (TSS), and the pituitary height to sella turcica ratio were compared between the two groups. The prevalence of JBWD was 12.1%, and JBWD was established as a causative diagnosis in 5.0% of unilateral PT patients. There were no statistical differences in the gender, symptomatic side, or VOL between the two groups. The area of the jugular bulb was larger and the height was higher (parea < 0.001, pheight = 0.005). The prevalence of jugular bulb diverticulum was higher in the JBWD group (p = 0.002). The degree of symptomatic TSS was less severe (p < 0.001), and the prevalence of bilateral TSS was lower in the JBWD group (p < 0.001). The pituitary height to sella turcica ratio was greater (p = 0.004), the prevalence of PCEV (p = 0.014) was lower, and OOS (p = 0.015) was greater in the JBWD group. The correlating factors of PT with JBWD and PT with SSWD are significantly different. These findings can further facilitate early and efficient PT treatment. • The incidence of jugular bulb dehiscence (JBWD) accounted for approximately 12.1% in pulsatile tinnitus (PT) patients, and JBWD was established as a causative diagnosis in 5.0% of PT patients. • PT required large blood flows and abnormal flow patterns, whether in JBWD or sigmoid sinus wall dehiscence groups. • JBWD causing PT has some unique characteristic findings on CT.

Hair follicle associated pluripotent (HAP) stem cells jump from transplanted whiskers to pelage follicles and stimulate hair growth

Stimulation of hair growth in hair loss has been a difficult goal to achieve. Hair follicle-associated pluripotent (HAP) stem cells express nestin and have been shown to differentiate to multiple cell types including keratinocytes, neurons, beating cardiac muscles and numerous other cell types. HAP stem cells originate in the bulge area of the hair follicle and have been shown to migrate within and outside the hair follicle. In the present study, the upper part of vibrissa follicles from nestin-driven green-fluorescent protein (GFP) transgenic mice, containing GFP-expressing HAP stem cells, were transplanted in the dorsal area of athymic nude mice. Fluorescence microscopy and immunostaining showed the transplanted HAP stem cells jumped and targeted the bulge and hair bulb and other areas of the resident nude mouse pelage follicles where they differentiated to keratinocytes. These results indicate that transplanted nestin-GFP expressing HAP stem cells jumped from the upper part of the whisker follicles and targeted nude-mouse hair follicles, which are genetically deficient to grow normal hair shafts, and differentiated to keratinocytes to produce normal mature hair shafts. The resident nude-mouse pelage follicles targeted by jumping whisker HAP stem cells produced long hair shafts from numerous hair follicles for least 2 hair cycles during 36 days, demonstrations that HAP stem cells can stimulate hair growth. The present results for hair loss therapy are discussed.

Effects of COVID-19 on the Human Central Olfactory System: A Natural Pre-Post Experiment.

Reduced olfactory function is the symptom with the highest prevalence in coronavirus disease 2019 (COVID-19) with nearly 70% of infected individuals experiencing partial or total loss of their sense of smell at some point during the disease. The exact cause is not known, but beyond peripheral damage, studies have demonstrated insults to both the olfactory bulb and central olfactory brain areas. However, these studies often lack both baseline pre-COVID-19 assessments and control groups, and the effects could, therefore, simply reflect pre-existing risk factors. Shortly before the COVID-19 outbreak, we completed an olfactory-focused study, which included structural MR brain images and a full clinical olfactory test. Opportunistically, we invited participants back 1 year later, including 9 participants who had experienced mild-to-moderate COVID-19 (C19+) and 12 who had not (C19-), creating a natural pre-post experiment with a control group. Despite C19+ participants reporting subjective olfactory dysfunction, few showed signs of objectively altered function. Critically, all except 1 individual in the C19+ group had reduced olfactory bulb volume (average reduction, 14.3%), but this did not amount to a significant statistical difference compared with the control group (2.3%) using inference statistics. We found no morphologic differences in olfactory brain areas but stronger functional connectivity between olfactory brain areas in the C19+ group at the postmeasure. Our data suggest that COVID-19 might cause long-term reduction in olfactory bulb volume and altered functional connectivity but with no discernible morphologic differences in cerebral olfactory regions.

Insulin/IGF signaling regulates presynaptic glutamate release in aversive olfactory learning.

Insulin/insulin-like growth factor (IGF) receptor signaling (IIS) supports context-dependent learning in vertebrates and invertebrates. Here, we identify cell-specific mechanisms of IIS that integrate sensory information with food context to drive synaptic plasticity and learning. In the nematode Caenorhabditis elegans, pairing food deprivation with an odor such as butanone suppresses attraction to that odor. We find that aversive olfactory learning requires the insulin receptor substrate (IRS) protein IST-1 and atypical signaling through the insulin/IGF-1 receptor DAF-2. Cell-specific knockout and rescue demonstrate that DAF-2 acts in the AWCON sensory neuron, which detects butanone, and that learning preferentially depends upon the axonally localized DAF-2c isoform. Acute food deprivation increases DAF-2 levels in AWCON post-transcriptionally through an insulin- and insulin receptor substrate-1 (ist-1)-dependent process. Aversive learning alters the synaptic output of AWCON by suppressing odor-regulated glutamate release in wild-type animals, but not in ist-1 mutants, suggesting that axonal insulin signaling regulates synaptic transmission to support aversive memory.

SARS-CoV-2 Brain Regional Detection, Histopathology, Gene Expression, and Immunomodulatory Changes in Decedents with COVID-19.

Brains of 42 COVID-19 decedents and 107 non-COVID-19 controls were studied. RT-PCR screening of 16 regions from 20 COVID-19 autopsies found SARS-CoV-2 E gene viral sequences in 7 regions (2.5% of 320 samples), concentrated in 4/20 subjects (20%). Additional screening of olfactory bulb (OB), amygdala (AMY) and entorhinal area for E, N1, N2, RNA-dependent RNA polymerase, and S gene sequences detected one or more of these in OB in 8/21 subjects (38%). It is uncertain whether these RNA sequences represent viable virus. Significant histopathology was limited to 2/42 cases (4.8%), one with a large acute cerebral infarct and one with hemorrhagic encephalitis. Case-control RNAseq in OB and AMY found more than 5000 and 700 differentially expressed genes, respectively, unrelated to RT-PCR results; these involved immune response, neuronal constituents, and olfactory/taste receptor genes. Olfactory marker protein-1 reduction indicated COVID-19-related loss of OB olfactory mucosa afferents. Iba-1-immunoreactive microglia had reduced area fractions in cerebellar cortex and AMY, and cytokine arrays showed generalized downregulation in AMY and upregulation in blood serum in COVID-19 cases. Although OB is a major brain portal for SARS-CoV-2, COVID-19 brain changes are more likely due to blood-borne immune mediators and trans-synaptic gene expression changes arising from OB deafferentation.