bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of a totally implantable blood flow, blood pressure and temperature biotelemetry system
Authors: Pitsillides Koullis , Axelsson Michael
Published: June 2021

The EndoGear totally implantable multichannel biotelemetry system was validated using standard bench‐top instruments. Although this biotelemetry system has already been used in a variety of animal models, it had not been validated over a wider range of heart rates, blood flow velocities, blood pressures and temperatures.

Positive displacement pulsatile waveforms were generated using a bellows‐type pump and reference blood flow velocity was measured with a bench‐top Doppler flowmeter (Indus Instruments, 20MHz Doppler flowmeter module), while reference blood pressure was measured with a solid‐state blood pressure catheter (Millar Instruments, model SPR524). Similarly, reference temperature was measured with a calibrated temperature sensor. The pump rate, stroke volume and pressure‐chamber pressure were adjusted to simulate various physiological levels and were recorded on a computer. Temperature was varied separately, in a temperature controlled water bath, and the transmitted temperature data were recorded.

The results show that the EndoGear implant is capable of accurately measure flow velocity, pressure and rate waveforms in a large physiological range. This makes it useful in studies where blood flow velocities are in the range of 5‐100 cm/s, blood pressures are in the range of 0 to 300 mmHg, heart rates are up to 250 bpm and temperatures are in the range of 0 to 50°C. The size and weight of this implant allow it to be used in animals with body weights = 2 kg.

This research was supported by the Swedish Science Research Council Grants B‐DR 09856‐304 and 621‐2005‐2588
ACTIVE REGULATION OF LIPID TRANSPORT AND METABOLISM BY LYMPHATICS: COMPLIMENTARY IN VIVO AND IN VITRO STUDIES
Authors: Dixon J. Brandon , Rutkowski Joseph M. , Randolph Gwendalyn , Swartz Melody A.
Published: June 2021

Lipid uptake and transport by lymphatic vessels are critically important functions, but the active regulation of lipid uptake by lymphatic vessels has not been described, and the potential for lymphatic vessels to affect not only lipid transport, but also lipid metabolism, remains unexplored. We examined these phenomena in complementary in vivo and in vitro models. First, we demonstrate that dysfunctional lymphatic transport leads to significant tissue lipid accumulation as well as altered lipid metabolism and increased cholesterol, suggesting that lymphatic dysfunction may have systemic consequences. To explore active mechanisms, we developed an in vitro model to recreate the intestinal lacteal microenvironment and quantitate chylomicron transport through enterocyte‐ECM‐lymphatic cocultures. We use this to show the importance of lymphatic endothelium on regulating chylomicron secretion and to explore mediators of this crosstalk. This work highlights the potentially far‐reaching implications of the interplay of lymphatic function and lipid metabolism.
Increased arterial pressure response to angiotensin II in mice with mutation in the Lysosomal Trafficking Regulator gene
Authors: beyer andreas Meredith , Morgan Donald , Anderson Michael G , Rahmouni Kamal
Published: June 2021

Exfoliation syndrome (XFS) is commonly associated with disturbance in elasticity, oxidative stress and increased risk for aortic aneurism. Mice carrying a mutation in the lysosomal trafficking regulator (Lyst) gene recapitulate many of the phenotypes of human XFS. Therefore, these mice are used to understand the pathophysiological mechanisms of XFS. We previously showed that Lyst mice have endothelial dysfunction. Here, we tested whether the vascular defects alter arterial pressure in these mice. For this, we used radiotelemetry to examine the arterial pressure (AP) of Lyst mice, which are on a C57BL/6J genetic background, as compared to C57BL/6J control mice, at baseline (during 6 days) and in response to a slow acting dose of angiotensin II (ANG II, 600 ng/kg/h, sc) for 14 days. At baseline, Lyst mice exhibited lower heart rate (528±17 vs. 584±7 bpm, P<0.05) and increased daytime mean AP (109±3 vs. 104±1 mmHg). ANG II caused a significant increase in mean AP in C57/BL6J mice (23±2 mmHg). Interestingly, ANG II‐induced mean AP increase was significantly enhance in Lyst mice (36±4 mmHg, P<0.05 vs. controls). These data indicates that endothelial dysfunction found in the Lyst mice is associated with higher baseline AP and increased response to ANG II.
Role of rat urinary bladder interstitial cells in neurogenic detrusor overactivity
Authors: Ikeda Youko , Kanai Anthony
Published: June 2021

We have previously identified an increase in number and gap junction connectivity (connexin 43) of interstitial cells (ICs) in the urinary bladders of spinal cord transected (SCT) rats. Our data suggest that these ICs drive the enhanced spontaneous contractions responsible for neurogenic detrusor overactivity. In this study, we further characterized the changes in ICs that may contribute to this overactivity. ICs were identified through immunohistochemistry using vimentin and CD34 as IC‐markers. ICs form an extensive network throughout the bladder wall with a dense plexus in the suburothelium. In bladders from SCT rats, there was also a significant increase in the expression of P2Y6 and c‐kit receptors on ICs, particularly in the suburothelium. The amplitude of spontaneous contractions from in vitro tension recordings of SCT rat whole bladders sheet preparations (1.3±0.9 g/mm2, n=9) were decreased by the addition of 30 μM Gleevec (c‐kit receptor inhibitor, 52.5±16.0% reduction, n=6) and 10 μM MRS2578 (P2Y6‐antagonist, 34.8±18.6% reduction, n=4) to the superfusion solution. However, no effect on spontaneous contractions of normal adult bladder preparations was seen with these compounds (0.3±0.2 g/mm2, n=6). These functional results correlated with immunohistochemical data showing increased number of ICs and the involvement of P2Y6 and c‐kit receptors in detrusor overactivity following SCT. In summary, increased functionality of ICs has a contributory role in neurogenic detrusor overactivity and may represent a potential therapeutic target. This research was sponsored by awards from Pfizer Ltd.
Solid‐phase tissue electrophoresis enhances sodium dodecyl sulfate‐based decellularization of xenogeneic bioscaffolds
Authors: Arai Shiori , Orton Christopher
Published: June 2021

Treatment of xenogeneic bioscaffolds with ionic detergents does not completely remove soluble protein antigens from candidate xenogeneic scaffolds for tissue engineering. The study objective was to determine if solid‐phase tissue electrophoresis enhances removal of antigenic proteins from candidate bioscaffolds.

METHODS

Porcine aortic valve conduit (PAV) was subjected to hypotonic lysis and then treated with 0.25% or 1% sodium dodecyl sulfate (SDS) overnight Tissues were mounted in 2% agarose gel and subjected 0 (sham), 60, or 120 V for 4 h. After treatment, soluble proteins were extracted from tissues and assayed for antigenicity by immunoblot analysis with rabbit immune serum.

RESULTS

Solid‐phase tissue electrophoresis enhanced removal of protein antigens from PAV compared to untreated (UT) or sham treated controls (figure).

CONCLUSION

Solid‐phase tissue electrophoresis enhances SDS‐based bioscaffold decellularization. Supported by NIH HL081107.
Unexpected Severe Calcification After Myocardial Infarction Is Not Caused By Amniotic Fluid‐derived Stem Cells
Authors: Guan Xuan , Delo Dawn , Wang Zhan , Groban Leanne , Callahan Michael , Smith Tom , D'Agostino Ralph B. , Atala Anthony , Soker Shay
Published: June 2021

Introduction

Recent data by Chiavegato et al. has suggested that amniotic fluid derived stem (AFS) cells cause chondro‐osteogenic masses in the infarcted heart. The purpose of this study was to further investigate the consequence of transplantation of human AFS cells in infracted rat heart.

Materials and Methods

8‐10 week old male nude and Sprague Dawley rats were used. 3 groups were examined: ligation only, ligation plus injection of AFS cells and injection of AFS without injury. At 3 months, hearts were analyzed by various histological methods.

Results

Echocardiography revealed regions of infarction and presence of echogenic structures in the left ventricular wall in rats of all groups. Histology analysis demonstrated regions of osteogenic and chondrogenic morphology by Hematoxylin and Eosin, Alizarin Red, Von‐Kossa, and Movat's Pentachrome stain. Immunostaining confirmed expression of osteocalcin, collagen II and Matrix‐Gla‐Protein. Based on the histological finding rats were divided into two groups: with chondro‐osteogenic masses and without. The former group had larger infracted tissue and worse heart function (p=0.01).

Conclusions

Our study contradicts the study by Chiavegato et al. and indicates that chondro‐osteogenic masses can be found in the infarcted rat heart independent of cell transplantation.
Simultaneous integration of biosensor and EEG measurements in freely moving rodents
Authors: Johnson David A. , Aillon Daniel V. , Naylor Erik , Harmon Hans , Wilson George S.
Published: June 2021

Second by second measurement of neurochemicals such as glutamate, glucose and lactate in the brain using electrochemical biosensors is a powerful tool that has been used to profile concentration changes due to pharmacological and behavioral interactions. Now this ability to measure metabolic changes in targeted regions of the brain has been integrated with a very low‐noise, turn‐key electroencephalograph (EEG) recording system.

As an example of this system's strength, male C57 mice were simultaneously implanted with an intracerebral guide cannula targeting the prefrontal cortex and electrodes to measure cortical EEG. Real‐time, second by second measurements of glucose levels and EEG activity were recorded over a 24 hour period. Results showed that glucose levels in mice transitioning from waking to slow‐wave sleep rose an average of 116 ± 27.0 uM (n =57 episodes). Conversely, glucose levels in mice transitioning from sleep to wakefulness resulted in an average decrease of 121 ± 27.0 uM glucose. (n=54 episodes). Additional data will be presented demonstrating the system being used to monitor changes of neurotransmitters during normal sleep and periods of sleep deprivation.

Funding through NIH SBIR Grant #5R44MH076318‐03.
A statistical methodology for computational models of hepatic metabolism and sensitivity analysis
Authors: Kuceyeski Amy , Somersalo Erkki , Calvetti Daniela
Published: June 2021

The computational kinetic models of liver metabolism that we consider follow the changes in time of the profiles of metabolites in tissue and blood. A major challenge of complex kinetic models is the assignment of values to the large number of parameters in the kinetic expressions for reaction fluxes and transport rates, as well as the determination of initial concentrations of metabolites and intermediates. The novelty of our approach is that, by modeling the unknowns as random variables, we look not for single numerical estimates but for distributions of values. This approach, which follows the paradigm of Bayesian statistical inference, can account for uncertainty in the experimental data utilized and takes advantage of any type of a priori information available about the parameters and the system. The ensemble of models thus obtained is used to predict time courses of metabolites and fluxes of interest. The collection of model predictions can be further analyzed to identify hidden dependencies among metabolic pathways.
A shunted model of renal inner medulla with pre‐bend transitions: Comparison with multi‐nephron models.
Authors: Gonzalez Maria , Thomas S. Randall , Hegarty Alan
Published: June 2021

Mathematical models of the renal medulla face the problem of representing water and solute transfer among tens of thousands of nephrons and blood vessels of various lengths, arranged in countercurrent fashion. Published models fall into two broad categories with respect to this issue: multi‐nephron models, which explicitly represent a large number of individual nephrons, or lumped models with virtual shunts that represent the turning back of nephrons and vessels at varying depths. Shunt‐models have the advantage of a compact description and relatively rapid execution time but are ill‐suited to faithfully represent features such as pre‐bend transitions of epithelial permeabilities in nephrons of different lengths. Multi‐nephron models can explicitly represent such changes in individual nephrons at various medullary depths, but require greater resources of computer memory and more CPU time. We present a new shunt‐model approach that can accommodate pre‐bend transitions of nephrons at all medullary depths. The results of simulations with this model and a comparable multi‐nephron model are compared on the basis of model results (predicted flows and concentrations) and the required computer resources.
Anatomic investigation of the origin and distribution of the internal pudendal artery in female cadavers
Authors: Beech Sarah , Adams Michael
Published: June 2021

A formal understanding of female sexual anatomy is crucial for the evaluation and treatment of sexual dysfunction. Despite the higher prevalence of female compared to male dysfunction, there are limited investigations concerning the anatomy of female genital vasculature. In fact, a literature search on the internal pudendal artery (IPA), a vessel supplying the erectile tissue, found only 3 of 15 papers discussed female anatomy; and these focused on uterine arteries. A study of the IPA in female cadavers is long overdue and is lagging 30 years behind comparable male studies. The purpose of this study is to dissect and compare the architecture of the IPA bilaterally, with respect to vessel origin and distribution. Cadavers were selected based on quality of fixation and cause of death (COD); ie: vascular COD omitted. In most (4/5), the IPA was a branch of the anterior trunk of the internal iliac within the true pelvis. In one, a gluteopudendal trunk arose directly from the common iliac and the IPA did not start until the gluteopudendal trunk exited the true pelvis at the sacrotuberous ligament in another female. No consistent branching pattern was observed between or within subjects and there was substantial bilateral heterogeneity to the vasculature. These results indicate that the origin and distribution of the IPA is highly variable both within and between subjects. Research support source: Schulich Research Scholarship.

Grant Funding Source

Schulich Graduate Scholarship
The anatomical basis of Z‐musculoplasty of the triceps brachii for longstanding dislocated elbows treated by open reduction
Authors: Gashegu Julien
Published: June 2021

Patients presenting late with an unreduced posterior dislocation of the elbow are still a problem in developing countries and a challenge for surgeons. In developing countries, socio‐economical and cultural factors may affect the medical care of traumatic injuries.

Due to misconception, ignorance and poverty, patients go to local bonesetters to tradition treatment such as massage and manipulation which only aggravate the situation. Unreduced is defined as those posterior dislocated elbow not treated within 3 weeks after injury. These elbows are often fixed in extension and have no sufficient ranges of movements which allow activities of daily living.

Between January 2008 and June 2008, 15 cases of late‐presenting unreduced posterior dislocation of elbow were treated in the department of Surgery at Butare Teaching Hospital. They were 7 males and 8 were female, the age from 12 years to 72 years (mean, 31), the dislocated elbows were right for 7 patients and left for 8 patients. The time since the injury range 4 to 8 (mean, 5) months. All patients had no‐functional movements for the daily activities as the elbows were fixed in 10° to 50° (mean, 25°) of flexion.

All patients were operated and open reduction were performed using the posterior approach of the elbow. The triceps was lengthened using a Z musculoplasty technique which, for our best of knowledge, is not yet described. In our previous cases we find difficulty to repair the triceps muscle when applying the common V‐Y musculoplasty technique. In this poster we present the anatomical basis of the Z musculoplasty of the triceps<
The vectorial decomposition in the skeletal striated muscle: a tool for muscular function learning in two planes
Authors: Duque Parra Jorge Eduardo , Moscoso Ariza Oscar Hernán , Morales Parra Genaro , Barco Rios John Jairo
Published: June 2021

A method of vectorial decomposition for skeletal striated muscles is presented to allow providing and deducing the understanding of a given muscle function in two spatial planes.

Grant Funding Source

No
The impact of breast reduction surgery on the low back compressive forces and function in individuals with macromastia
Authors: Foreman K. Bo , Dibble Leland E. , Droge John , Carson Randy , Hawker Heather , Rockwell W. Bradford
Published: June 2021

Macromastia can be a morbid condition causing shoulder pain, back pain, intertrigo, and bra strap grooving. Subjective symptoms are effectively relieved by reduction mammaplasty. However, objective validations of efficacy for breast reduction are scarce and primarily rely on standardized patient reported data. Therefore, this pilot study was conducted to determine the extent to which reduction mammaplasty surgery produces a change in biomechanical stress of the spine and level of disability in women with macromastia. Eleven women were evaluated prior to surgery and 3 months post surgery. Evaluation measured maximal compressive forces at the low back (LB) during a lifting task and the subjective level of disability using the Functional Rating Index (FRI). The results demonstrated that the average maximum LB compressive forces decreased 35% for the lifting task. Furthermore, the FRI scores improved 76% following surgery. Greatest improvement was reported for the frequency of pain. The results from this study combined with previous research demonstrate that women who undergo medically necessary reduction mammaplasty surgery may be at a decreased risk for disc degeneration and LB disorders. These results warrant additional research to prospectively investigate these individuals. This research was supported by a grant from the Center for Contemporary Rehabilitation Research, University of Utah.
Use of cadaveric dissection for the exploration of anatomical and pathological structures as the primary learning tool in an undergraduate gross anatomy course: student perspectives
Authors: Wickenhauser Keith , Beamer Stephanie , Dorough Andrew , Winter Emily
Published: June 2021

At Westminster College, an undergraduate gross anatomy dissection was performed as part of a human gross anatomy program, with the objective of exploring anatomical and pathological structures in the cadaver. The course of dissection followed the 13th edition of Grant's Dissector and was completed by five undergraduates. The order of dissection led to ever‐evolving hypotheses as to indicated pathologies, as students worked through the scientific method in their dissections. As the dissection proceeded abnormalities were noted. These included, an intramuscular cyst found within the deltoid (length = 4.5 cm, width = 1.5cm), left ventricular wall hypertrophy (1.8 cm), surgical evidence of a shortened colon (by 47cm), and renal abnormalities. As each anatomical variation was dissected, students formed hypotheses and integrated observations from individual systems into an overall evaluation of indicated pathologies. Preliminary observations led to the likelihood of a long‐standing renal infection which may have materialized into xanthogranulomatous pyelonephritis. Students documented their experiences throughout the project.
The anatomical role of Scarpa's fascia in the manifestation of clinical signs associated with retroperitoneal haemorrhage and bile leakage
Authors: Ullah Shahnoor Mohammed , Grant Robert , McAlister Vivian
Published: June 2021

While the aetiology of eponymous surface signs of pancreatitis, retroperitoneal haemorrhage and bile leakage is known, it is unclear what causes their characteristic appearance. The location of Scarpa's fascia, the membranous layer of superficial fascia, makes it a potential candidate in understanding the pattern of these signs. The goal of this study was to assess the distribution of Scarpa's with respect to each sign. Dissections were performed on 7 embalmed cadavers, 3 males and 4 females, aged 63 to 92. Our results indicate that Scarpa's attaches where the umbilicus emerges from the external oblique aponeurosis providing a deficiency that can cause the bruising in Cullen's sign. As the membranous layer continues into the flanks, it creates a potential space which contributes to the pattern in Turner's sign. The continuation of the membranous layer into the axilla and chest forms another potential space for bile to form the pattern in Icterus Marginatus (demarcated truncal jaundice with retroperitoneal bile leakage). The anatomical characteristics of Scarpa's fascia described by this study support the hypothesis that it is involved in delineating the physical patterns seen in these clinical signs.

Grant Funding Source

Western Graduate Research
A Forensic Investigation of Human Cranial Remains Recovered From New York City via CT Imaging and Morphometric Analysis
Authors: Maciasz Rachael Maria , Delman Bradley N , Hong Simon , Lee Rosanna , Caceres Noel , Sawyer GJ , Márquez Samuel
Published: June 2021

Cranial remains were discovered during construction activity in NYC. A forensic workup was undertaken to determine sex, race, age and manner of death. Cranial elements identified included a partial calvaria with spanchnocranium, a left zygoma, and a broken mandible. An almost complete neurocranium with missing portions of the cranial base and left segments of parietal and temporal bones was documented. Quantitative measures were taken using available craniometric points. Various methods used to assess skeletal elements permitted skull reconstruction followed by CT imaging performed at Mount Sinai Hospital. Size and overall rugose expression of cranial features (pronounced mastoid process, strong browridge) suggest a male identification. Calvaria shows excellent ectocranial and endocranial preservation with no distinctly noticeable taphonomic deformities, although three‐dimensional CT reconstructions revealed evident warping on the right side of the cranial vault suggesting the skull lied flat on that side. Race was determined to be Caucasian though a cranial index of 71 fell within the dolicocephalic range indicative of an African phenotype. Caucasoid affinities exhibited by skull included marked projection of nasal bones, narrow nasal breadth, and lack of facial prognathism. Craniodental analysis suggests an adult age at the time of death. Manner of death, however, remains undetermined.

Grant Funding Source

None
ANATOMICAL METHOD FOR IN SITU STUDYING OF THE RENAL VASCULO‐DUCTAL ELEMENTS. PRELIMINARY REPORT
Authors: MATUSZ Petru L
Published: June 2021

In situ studying of the renal vasculo‐ductal elements is required in order to determine the real morphologic parameters of the vasculo‐ductal anatomical elements involved in performing renal transplant. Preparation of this method was done on laboratory animals (pigs of 25‐30 kg). The animals were euthanized before starting the experiment, based on the experiment protocol and observing the existing legislation regarding the ethics of animal experimentation. We made a posterior abdominal anatomical block (preserving the retroperitoneal abdominal plane), with the upper limit at diaphragm level (excluding liver, spleen and stomach) and the lower limit at lumbar‐sacral level. The intestines were excluded. Methyl metacrilate paste (TECHNOVIT 7143) was injected into the renal vasculo‐ductal system, into the origin of: reno‐urinary ductal system at the level of the abdominal portion of the urether (retrograde), arterial system, from the level of the abdominal aorta to the iliac arteries (antegrade), and venous system from the level of retrohepatic portion of inferior vena cava to the iliac veins (retrograde). After 24 hours the macroscopic vasculo‐ductal parietal dissection was performed, eliminating the vasculo‐ductal walls. It was subsequently followed by the chemical fixation of the anatomical structures. The realized specimen allows in situ study of extraparenchymal vasculo‐ductal elements. (Supported by CNMP 42097/2008).
Comparison of hindlimb muscle attachment sites of Smilodon fatalis, Neofelis nebulosa, and Felis catus
Authors: Carlon Burcu , Hubbard C J
Published: June 2021

Smilodon fatalis is the Rancho La Brea saber‐tooth cat with robust extremities and a short tail, and is believed to be an ambush predator. In this study, select pelvic, femoral, and tibial muscle attachment sites were determined for Smilodon fatalis based on osteological muscle scars and comparisons with muscle attachment site maps developed for Neofelis nebulosa (clouded leopard) and Felis catus (domesticated cat). Following careful dissection of several specimens of the cat and clouded leopard, the results showed that a comparison of the muscle attachment sites, proportional muscle weights, and muscle attachment site surface areas were remarkably similar. Comparison of Smilodon muscle scar locations and muscle scar surface areas with those of the cat and clouded leopard showed that all three species were also similar. Given these similarities, we are confident that our estimated recreation of the muscle attachment sites in Smilodon is reasonably accurate. In addition, we found that the attachment sites of the quadriceps femoris muscles in Smilodon had increased levels of rugosity compared to the clouded leopard and cat, supporting the concept that this animal may have been an ambush predator that required more robust muscles to leap at and grapple with prey.

Grant Funding Source

None
The Gaping Truth: A New Rationale for the Reconstruction of the Face of Smilodon fatalis
Authors: Koper Lindsey L , Naples Virginia L
Published: June 2021

Smilodon fatalis is the best known saber‐toothed cat. It has often been reconstructed by artists and anatomists who presume that this animal closely resembled a modern conical‐toothed felid, with the addition of elongated canine teeth. However, saber‐toothed canines do more than affect the distance to which this animal must gape to clear these teeth to make a bite. Greater gape means that there must be an increased soft tissue mass of lip and mucosa surrounding the oral opening. These tissues would be stretched to their maximum at full gape; however when relaxed, with the mouth closed, or open to less than full gape, these features would still be of greater volume than in conical‐toothed felids. It is likely that the upper lip in Smilodon would show a greater degree of sag than is typical for modern cats. The soft tissues of the nose are not preserved in Smilodon, although past reconstructions assumed that the nasal profile is nearly vertical, as is the case in modern cats. We suggest, instead, that the nasal soft tissues in Smilodon are retracted to a degree commensurate with the retraction of the nasal bones. The lower incisor row of Smilodon is strikingly larger than in comparable‐sized modern Panthera tigris, and would therefore need to be more voluminous to stretch over such teeth It is also likely that the lower lip in Smilodon sagged; perhaps causing this felid to resemble a bloodhound more than a conical‐toothed felid.

Grant Funding Source

American Association of Anatomists
Study of morphometry of ovarian follicles under DMPA treated adult female albino rats
Authors: Sivakumar Girija , Venugopal Kamakshi
Published: June 2021

The main aim of the present work is to study the effect of Demedroxyprogesteroneacetate (DMPA) in adult female albino rats. The long term usage of DMPA leads to irregularity in the menstrual cycle and subsequently disturbs the maturation of ovarian follicles. Adult female albino rats (150‐170gms) were selected and divided into two groups ‐ Control and Experimental (each group containing 20 adult female albino rats). Both were maintained under laboratory condition with the same feed and water. Control group were given ad.libitum throughout the experimental period. Estrous cycle was studied in both the groups for two consecutive cycles to see the different stages of estrous cycle. After two weeks, the experimental group was given DMPA at a dose of .3mg/day/Kg. body weight for one complete estrous cycle. 6 hrs after the treatment of DMPA, vaginal smear study was done at regular intervals (once in 4hrs) in both the control and experimental group to confirm the estrous cycle. Different stages of the estrous cycle was monitored during the experimental period in both control and experimental. After 48 hrs, both groups were sacrificed by euthanisation, and ovaries were removed. The tissues were stained with H&E stain. Morphological, histological and morphometrical studies were done. Control group of rats showed normal estrous cycle, normal follicular growth with follicles of different stages. The DMPA treated ovaries showed irregular estrous cycle, follicles remained atretic and some remained in primary or secondary stage. More of corpus luteum was found in the DMPA treated group.
Modeling of schizophrenia in mice: implications for white matter abnormalities in the pathophysiology of schizophrenia
Authors: Xu Haiyun , Yang Hong‐Ju , Clough Rich
Published: June 2021

Cuprizone (CPZ) is a copper‐chelating agent that causes central demyelination and behavioral characteristics in C57BL/6 mice that are reminiscent of human schizophrenia (impaired spatial working memory, social interaction, and auditory prepulse inhibition). Based on behavioral observations, we hypothesized that CPZ induces regionally specific damage to white matter, particularly in the forebrain. We examined the forebrains of C57BL/6 mice given 0.2% CPZ‐containing diet and compared with those of normal fed controls. We assessed: demyelination in white matter tracts of the forebrain; myelin breakdown in the main olfactory bulbs (MOB), cerebral cortices (CTX), caudate/putamen (CP), hippocampi (HP), thalamus (TH), and hypothalamus (HY); and, numbers of oligodendrocytes (OLs) in CTX, CP, TH, and HY. Obvious demyelination was observed in the corpus callosum, external capsule, CP, and dorsal hippocampal commisure whereas other tracts seemed to be unaffected. The neuropil of CTX, HP and MOB showed significant myelin breakdown whereas breakdown was mild in TH and HY. The CTX and CP, but not TH and HY, showed dramatic decrease in OL numbers. The data support a notion that abnormal behaviors of CPZ treated mice result from demyelination in the forebrain and suggest a putative role for oligodendrocyte abnormalities in the pathophysiology of schizophrenia. Supported by SIUSOM.
Development of Layered Structures of Normal Fetal Cerebral Cortex: A Study Using MR Imaging
Authors: zhonghe zhang , Sun Bo , Fan Lingzhong , Lin Xiangtao , Yu Taifei , Liu Shuwei
Published: June 2021

Purpose

To analyze the developmental changes of the layered structures of normal fetal cerebral cortex using 3.0T MRI. Materials and Methods: Head of 30 fetal specimens of 14‐35 weeks gestational (GA) were scanned, and developmental changes of the layered structures were observed.

Results

Coronal T1 images of parieto‐occipital part of the brain are chosen to analyze. At 14 GA, 3 layers can be recognized. During 18‐23 GA, when the layered structures are typical, 7 layers of different signals including continuing periventricular fiber‐rich zone and external capsule fibers can be differentiated, which correspond to 5 zones in the histological staining slices. During 24‐27 GA, layered structures remains the same appearance as 18‐23 GA, but the borderlines among them become obscured and periventricular fiber‐rich zone and the external capsule fibers become discontinuous. After 30 GA, layered structures disappear and turn into mature‐like. The migrating thalamocortical fibers appeare as a high signal layer located at the lower, middle, and upper part of the subplate zone respectively at different GA.

Conclusion

The development of layered structures of normal fetal cerebral cortex follows a specific spatio‐temporal law, and T1 images of parieto‐occipital part of the fetal brain obtained using 3.0T MRI are the best to show the developmental changes of layered structures of normal fetal cerebral cortex.
Directed evolution of ionizing radiation resistance in Escherichia coli
Authors: Hamilton Lindsay L. , Harris Dennis R. , Pollock Steve V. , Wood Elizabeth A. , Goiffon Reece J. , Klingele Audrey J. , Eggington Julie , Nguyen Trang D. , Middle Christina M. , Norton Jason E. , Cabot Eric L. , Popelars Michael C. , Li Hao , Klugman Sarit A. , Bane Lukas B. , Jenson Cassandra , Perna Nicole T. , Albert Thomas J. , Cox Michael M. , Battista John R.
Published: June 2021

Four extremely radioresistant strains of Escherichia coli K12 were independently derived from MG1655 following repeated exposure to high dose ionizing radiation. D37 values for two of the strains approached that exhibited by Deinococcus radiodurans. Complete genome re‐sequencing using two different methods revealed that each strain acquired its radioresistance through very different sets of genetic changes. Nearly 70 different genetic alterations were present in each strain. The results do not reinforce any current idea about the mechanisms underlying the radiation resistance of species such as Deinococcus radiodurans. One mutation, a deletion of the e14 prophage, provides a partial explanation for the acquired phenotype. This is the only genome alteration that is common to all of the evolved strains. Additional mutations common to most cells in particular evolved populations were documented, but did not contribute measurably to radiation resistance when isolated in an otherwise wild type genetic background. Additional and different contributions to radiation resistance are represented in the genomic alterations in each of the three strains. In nature, multiple paths of evolutionary innovation can give rise to radioresistance even within a single species.
Replication versus Repair Pathways for E. coli and T. aquaticus Pol I DNA Polymerases
Authors: Yang Yanling , LiCata Vince J.
Published: June 2021

Pol I DNA polymerases from different organisms may partition differently between replication and repair pathways. Non‐homologous DNA end joining (NHEJ) is a type of illegitimate recombination characterized by the joining of two DNA ends that lack homology. Pol I polymerases working with ligases can repair ds‐DNA breaks via NHEJ. We have identified several differences in the abilities of E. coli and Taq Pol I DNA polymerases to affect NHEJ with DNAs having non‐complementary or partially complementary ends. Both proteins enhance NHEJ, but Taq is relatively insensitive to the presence of magnesium or to 5'phosphorylation of the DNA, while NHEJ activity of E. coli Pol I is modulated by both these components. Gapped DNAs are intermediates in base excision repair. Gaps can be filled by Pol I and closed by ligase. The magnesium and 5'phosphorylation effects on Taq Pol I binding to gapped DNA differ depending on the length of the ssDNA gap. In the presence of magnesium, long (10nt) gap binding is preferred; while 5'phosphorylation enhances short (2nt) gap binding. Relative partitioning of E. coli and Taq Pol I enzymes between gaps and primed‐templates is also discussed.
Structure of the Thermus thermophilus 16 S rRNA methyltransferase KsgA
Authors: Jogl Gerwald , Demirci Hasan , Belardinelli Riccardo , Seri Emilia , Gregory Steven T , Gualerzi Claudio , Dahlberg Albert E
Published: June 2021

Post‐transcriptional modification of ribosomal RNA occurs in all kingdoms of life. The S‐adenosyl‐L‐methionine‐dependent methyltransferase KsgA introduces the most highly conserved ribosomal RNA modification, the dimethylation of A1518 and A1519 of 16S rRNA. Loss of this dimethylation confers resistance to the antibiotic kasugamycin. Here, we report biochemical studies and high‐resolution crystal structures of KsgA from Thermus thermophilus in complex with 5′‐methylthioadenosine. A structural comparison with related methyltransferases reveals the presence of a novel N‐terminal extension. Several mobile structure elements are observed that restrict access to the active site. A comparison with other rRNA modifying enzymes shows significantly different modes for substrate recognition.
Selective Decrease in Regulatory Iron Response Protein 1 (IRP1) binding to mRNA Iron Response Element (IRE)
Authors: KHAN MATEEN AHMAD , WALDEN WILLIAM E , THEIL ELIZABETH C , GOSS DIXIE J
Published: June 2021

In mRNA a family of 5' noncoding structures, iron response elements (IRE), control mRNA translation and protein biosynthesis rates by regulatory protein (IRP) binding when iron concentrations decrease. IRP protein represses translation by binding to the IRE and inhibiting formation of polysomes. We explored the extent to which the phylogentically conserved sequence differences among members of the IRE mRNA family related to differences in signal responses observed in vivo, since the regulatory proteins are the same for each mRNA. We selected two members of the IRE‐RNA family, ferritin and mitochondrial (mt‐) aconitase, to study effects on the 5' UTR IRE‐RNA sequence and IRP1 protein binding because of extensive structural information available, and because the iron responses in vivo range from 4‐fold for mt‐acontitase to more than 100‐fold for ferritin. We report here the binding affinity of IRP1 protein to ferritin and mt‐aconitase mRNA. The relative binding affinities varied dramatically depending on experimental conditions. Selective destabilization of ferritin and mt‐aconitase RNA/protein complexes as reported here explain in part the quantitative differences in signal response to iron in vivo and indicate possible new regulatory interactions.
Biochemical and immunohistochemical analysis of an unusual rat brain agmatinase
Authors: Uribe Elena Amparo , Mella Claudia , Castro Victor , Martinez Fernando , García María de los Angeles , Bustos Paula , Carvajal Nelson
Published: June 2021

Agmatine plays neurotransmitter/neuromodulatory actions in the brain. It result from decarboxylation of arginine by arginine decarboxylase and it is hydrolysed by agmatinase. Recently, we have cloned an unusual rat brain protein with agmatinase activity, although their deduced sequences greatly differ from all known agmatinases. However, in spite of only 12% identity with E. coli agmatinase, the rat brain protein is recognized by a polyclonal antibody raised against the bacterial enzyme. Like E. coli agmatinase, the rat brain enzyme exhibits an absolute requirement for Mn2+, not related to a metal‐binding LIM domain detected in its sequence. As shown here, the Mn2+ requirement is retained by a variant lacking the domain. We, therefore, associate Mn2+ to the hydrolytic reaction in the enzyme active site. Also described here is the generation of a polyclonal antibody against the brain agmatinase, which also reacts with the E. coli enzyme. We conclude that, although not sequence‐related, the rat brain agmatinase is structurally related to all known agmatinases. By immunohistochemical analysis, the enzyme was detected in arquate nucleus, ciliated ependymal cells and tanycytes hypothalamic. Since this coincide with that for agmatine, the enzyme would play a central role in regulating the levels and thus, the neurotransmitter/neumoregulatory actions of the primary amine in the brain. Grant FONDECYT 11070069
Enzymatic and mass spectral analysis of mutant and wild‐type selenomethionyl‐dihydrofolate reductase
Authors: Broderick Molly Eirinn , Broderick Kathleen Marie , Boles Jeffrey Oakley
Published: June 2021

The site‐specific incorporation of unnatural amino acids, namely selenomethionine, have been incorporated into proteins to facilitate structural studies for over a decade. At times, the stability of selenoproteins is limited due to this biosynthetic incorporation. Wild type and Selenomethionyl dihydrofolate reductase have been prepared and compared for stability and catalytic properties. The sensitivity of wild type and selenomethionyl DHFR to cyanogen bromide and the serine protease trypsin have also been determined to illustrate the application of mass spectral analysis to the study of selenoproteins.
Detection, Quantitation, and Distribution of the T9861C mtDNA Mutation in the Alzheimer's Disease Brain
Authors: Castora Frank J , Simsek‐Duran Fatma
Published: June 2021

Deficits in oxidative phosphorylation have been observed in brain and platelet samples from patients with Alzheimer's Disease. A reduction of approximately 30% in cytochrome c oxidase activity is routinely reported in these patients. Using an electrophoretic approach (single strand conformation polymorphism) to screen multiple AD and control brain samples, we have recently identified a point mutation at np 9861 in AD brain mtDNA that alters amino acid 219 of subunit III of cytochrome c oxidase from a phenylalanine to a leucine. We have developed a mismatched PCR‐RFLP assay to rapidly screen multiple samples and combined this with a modification of the single nucleotide primer extension assay to allow quantitation of low levels of this heteroplasmic mutation. In addition, we have begun to use an allele‐specific PCR amplification assay to both detect and quantify the mutation. Of forty AD brain samples tested, six were found to possess the T9861C mutation to varying degrees. None of 40 age‐matched control brains contained the mutation. This 15% frequency occurrence rate in AD brain samples is 63‐fold higher than the frequency (0.24%) of this polymorphism reported in mtDNA databases comprised of sequence information from 2,104 human samples. The T9861C mutation is heteroplasmic. The T9861C mutation is not localized to a single region but is also found in both the parietal and temporal cortex and in the caudate but not in the hippocampus. The presence of the T9861C mutation reduces cytochrome oxidase activity by 60% compared to wild type enzyme from age‐matched controls.
In PDE3B KO mice, White Adipose Tissue (WAT) Exhibits Characteristics of “Good Fat,” i.e., Brown Adipose Tissue (BAT): II. Alterations in Angiogenesis and cAMP‐and AMP Kinase‐signaling
Authors: Khan Faiyaz Ahmad , tang Yan , Chung Youn Wook , Zmuda‐Trzebiatowska Emilia , Hockman Steve , Gavrilova Oksana , Berger Karin , Degerman Eva , Manganiello Vincent
Published: June 2021

Obesity is a major risk factor for type 2 diabetes and cardiovascular disease. WAT affects body fat and energy utilization via storage and turnover/hydrolysis of triglycerides. In addition, WAT regulates and integrates physiological pathways, including energy utilization, glucose, insulin sensitivity, and inflammation. WAT also contributes to metabolic dysregulation that characterizes insulin resistance and obesity‐related metabolic and cardiovascular complications. Aquirement of BAT characteristics by WAT, with enhanced intra‐adipocyte FAO (fatty acid oxidation), represents a potential new strategy in treatment of obesity and diabetes. In PDE3B KO mice, epididymal WAT (EWAT) exhibits characteristics of BAT, including increased mitochondrial biogenesis, increased vascularization and expression of angiogenic genes, modification of proteins regulating cAMP signaling and lipolysis, and alterations in AMP kinase signaling, resulting in increased fatty acid oxidation. Compared to WT mice, O2 consumption was increased in vitro in BAT and EWAT isolated from KO mice, and in intact KO mice treated with B‐3 adrenergic receptor agonist. Although PDE3B KO mice show signs of insulin resistance, most likely due to dysregulation of hepatic glucose production, they are lean and not diabetic, perhaps because, in PDE3B KO mice, "good fat" compensates for insulin resistance.
TGF‐β/Smad3 signaling regulates pancreatic islet β cell function
Authors: Rane Sushil G , Lin Huei‐Min , Lee Ji‐Hyeon , Yadav Hariom , Matschinsky Franz , Harlan David M
Published: June 2021

Pancreatic islet β cell dysfunction is a signature feature of Type 2 diabetes pathogenesis. TGF‐ β signaling plays a critical role in pancreatic development although its role in the adult pancreas is obscure. Here, we define an important role of the TGF‐β pathway in regulation of β cell function. We show that the TGF‐β signaling effector Smad3 occupies the insulin gene promoter and represses insulin gene transcription. In contrast, Smad3 siRNAs relieve insulin transcriptional repression and enhance insulin synthesis. Transduction of adenoviral Smad3 into primary human and non‐human primate islets suppresses insulin synthesis, whereas, dominant negative Smad3 enhances insulin synthesis. Consistent with this, Smad3 deficient mice exhibit moderately elevated insulin levels and mild hypoglycemia. Moreover, Smad3 deficiency results in improved glucose tolerance and enhanced glucose‐stimulated insulin secretion in vivo. In ex vivo perifusion assays, Smad3‐deficient islets exhibit improved glucose‐stimulated insulin release; and interestingly, Smad3‐deficient islets harbor an activated insulin‐receptor signaling pathway. Finally, Smad3 loss confers protection from streptozotocin‐induced experimental diabetes. Together, these studies emphasize TGF‐β /Smad3 signaling as an important regulator of insulin gene transcription and islet β cell function.
Pyruvate dehydrogenase kinase 4 (PDK4) deficiency attenuates the long‐term negative effects of a high‐saturated fat diet
Authors: Hwang Byounghoon , Harris Robert A
Published: June 2021

The purpose was to determine the effects of PDK4 deficiency on the long‐term consequences (hyperglycemia, glucose intolerance, hepatic steatosis, and obesity) of feeding mice a high‐saturated fat diet. PDK4 deficiency might attenuate the negative effects of saturated fat by lowering blood glucose and improving insulin sensitivity, or it might promote fat accumulation in tissues and worsen insulin sensitivity by inhibiting fatty acid oxidation. This was examined by feeding mice a 60% saturated fat diet for 7 months. Hyperglycemia was induced in the wild type mice but attenuated in the PDK4 knockout mice. PDK4 knockout mice gained less weight. Glucose tolerance was improved and insulin sensitivity was greater in PDK4 knockout mice. Accumulation of fat in the liver of PDK4 knockout mice was reduced compared to wild type mice. PGC‐1α was reduced while ACC and FAS were increased in the liver of wild type mice fed the saturated fat diet compared to wild type mice fed a chow diet. PGC‐1α was not reduced and ACC and FAS were not increased in PDK4 knockout mice fed the saturated fat diet. These findings suggest that knocking out PDK4 creates conditions that prevent reduction of fatty acid oxidation and induction of fatty acid synthesis. This suggests that PDK4 deficiency exerts beneficial effects in saturated fat fed mice by altering upstream signaling components involved in regulation of fat metabolism. Supported by DK 47844.