Bilateral aplasia of the anterior cerebral artery in the presence of its vascular source: a case report.

PURPOSE: Our goal was to investigate the cases of bilateral aplasia of the anterior cerebral artery (ACA). METHODS: The macro- and microdissection of the target human brain arteries of 388 cadaveric cases was applied under the magnifying glass. Each case was photographed and diagrammatically represented in the workbook. The length and the outer diameter of the corresponding arteries on the photos were measured using a computer software program. RESULTS: There was only one case (1/388 or 0.25%) of bilateral ACA aplasia that belonged to a male adult cadaver. Except for the variations of the posterior communicating artery on one side and the basilar artery, the instance of cerebral pathology was not recorded in this case. We compared the recent case with available literature cases. CONCLUSION: Summarizing small number of literature cases, the recent case of bilateral ACA aplasia as the fifth case discovered so far, represents a true morphological rarity.

Ultramorphological Characteristics of Podocyte Development in the Human Fetal Metanephros.

The aim of this study was to determine the developmental characteristics of podocytes in the human fetal metanephros using scanning electron microscopy, light microscopy, and transmission electron microscopy. Kidney samples of 15 human fetuses of both sexes (gestational age 10-22 weeks) were analyzed. At the S-shaped body stage, primitive podocytes were arranged in a layer of cuboidal cells beneath the vascular cleft. When observed from Bowman's space, the demarcation between adjacent podocytes was not clear, but mild depressions indicated cell boundaries. At the more advanced S-shaped body stage, podocytes were polygonal, with a flat apical surface. They were in close contact, but boundaries between adjacent cells were distinct. After initial separation of their apical parts, podocytes continued to separate from each other along their lateral sides. Their shape changed from polygonal to spherical, resembling clusters of grapes. Cytoplasmic buds could be seen at the base of some podocytes initially, when all podocytes were spherical. Parallel with the development of the first capillary loops, wider intercellular spaces were noted between elliptical-shaped podocytes. Podocytes then developed cytoplasmic processes and became flattened and star shaped. Their cell bodies separated from the glomerular basement membrane through the insertion of thick processes under the cell body. Thick primary processes ramified to form the foot processes, which interdigitated on the surface of capillary loops. During the capillary loop stage, the degree of differentiation of the podocytes varied among various glomerular regions, as well as within the same capillary loop.

Stereological study of developing glomerular forms during human fetal kidney development.

BACKGROUND: Human fetal kidney development is a complex and stepwise process. The number, shape, size and distribution of glomeruli provide important information on kidney organization. The aim of this study was to quantify glomerular developing forms during human fetal kidney development using stereological methods. METHODS: Kidney tissue specimens of 40 human fetuses with gestational ages ranging from 9 to 40 weeks were analyzed. Specimens were divided into eight groups based on gestational age, each corresponding to 1 lunar month. Stereological methods were used at the light microscopy level to estimate volume, surface and numerical density of the glomerular developing forms. RESULTS: During gestation, nephrogenesis continually advanced, and the number of nephrons increased. Volume, surface and numerical densities of vesicular forms and S-shaped bodies decreased gradually in parallel with gradual increases in estimated stereological parameters for vascularized glomeruli. Volume density and surface density of vascularized glomeruli increased gradually during fetal kidney development, and numerical density increased until the seventh lunar month. A relative decrease in vascularized glomeruli per unit volume of cortex occurred during the last 3 lunar months. Nephrogenesis began to taper off by 32 weeks and was completed by 36 weeks of gestation. The last sample in which we observed vesicles was from a fetus aged 32 weeks, and the last sample with S-shaped bodies was from a fetus aged 36 weeks. CONCLUSIONS: The present study is one of few quantitative studies conducted on human kidney development. Knowledge of normal human kidney morphogenesis during development could be important for future medical practice. Events occurring during fetal life may have significant consequences later in life.

Congenital absence of the bilateral internal carotid artery: a review of the associated (ab)normalities from a newborn status to the eighth decade of life.

PURPOSE: Due to the fact that the internal carotid artery (ICA) is responsible for nourishing two thirds of the brain volume, our aim was to inspect the morphofunctional consequences of the bilateral lack of this artery. METHODS: In order to examine this condition, we referred to both the library archive of our Faculty of Medicine and electronic databases of anatomical and clinical reports that included the following keywords: "absence," "aplasia," or "agenesis" in combination with "internal carotid artery," "common carotid artery," or only "carotid artery." RESULT: We found 60 recorded cases of the bilateral ICA absence in the subjects of newborn status to the eighth decade of life, which had been discovered in 20 countries. The following ten parameters were described: the embryological base, terminology, history, incidence, general data, differential diagnosis, collateral circulation, the associated vascular aplasia and/or other variants, pathophysiology, and the importance in praxis. CONCLUSION: This review noted all the cases of the bilateral ICA aplasia published for the past 104 years. Although there were 11.6% of cases of the associated cerebral aneurysms and 1-4 cases of 16 other diseases, approximately one quarter of the cases was without any pathology.

Variation of some arteries of the vertebrobasilar system: case report.

A specificity of the vertebrobasilar system (VBS) is a convergent junction of paired vertebral arteries (VAs) in the basilar artery (BA) usually at the level of bulbopontine sulcus on the ventral side of the rhombencephalon. We revealed multiple VBS variations (a high junction of both VAs, absence of posterior inferior cerebellar arteries, short and ectatic BA, hypoplasia and initial duplication of the left anterior inferior cerebellar artery, and bilateral common trunks of the posterior cerebral and superior cerebellar arteries) in a 52-year-old male that routinely autopsied at the Institute of Forensic Medicine. Embryological base and morphological status of presented VBS variations is highlighted according to the literature data. Summarized variations of VBS can be classified as morphological rarity, and may be of clinical importance during angiographic studies or neurosurgical procedures.

Fenestrations of the human posterior cerebral artery.

BACKGROUND: The posterior cerebral artery (PCA), as a paired terminal branch of the basilar artery, runs through four segments (P1 to P4) to the inferior and medial surfaces of the occipital and a part of the temporal lobes. There are many PCA variants in its course. The literature data indicated that a fenestration of the PCA was very rare and that its clinical significance is unknown. The purpose of this investigation was to present the frequency, location, and some morphological features of PCA fenestration in the prenatal and postnatal period. METHOD: Using brain bases of 468 (200 fetal and 268 adult) cadavers, we applied macroscopic and microscopic investigation. RESULTS: We found four (0.85 %) cases of PCA fenestrations-two at the left and right P1 segment of fetuses, respectively, then one adult at the left P2 segment, as well as one adult at one right PCA of the two existing arteries. There were associated multiple vascular abnormalities in one adult case. We did not find any case of PCA aneurysm originating from fenestration, as well as from PCA without fenestration. CONCLUSION: The frequency, segment, and side location, as well as the size and shape of PCA fenestrations in specimens of our population did not significantly differ from the same in other populations. PCA fenestrations in our adult specimens were not the bases of aneurysms.

Morphology of the cerebral arterial circle in the prenatal and postnatal period of Serbian population.

BACKGROUND: In the literature, there are descriptions of morphological types of the cerebral arterial circle (CAC) of different human populations around the world, but not the Serbian population. This additionally inspired the authors to present the results of previous and current researches of CAC's configuration in the prenatal, as well as in the postnatal period. METHOD: The study was performed on CACs of 190 human fetuses and 143 adult cadavers. The caliber and configuration of fetal vessels were examined under the operating microscope, while the same of adults were studied using the ImageJ. Statistical analysis of CACs vessels' calibers was performed. Classification into one of CAC morphological types was based on the presence of hypoplasia of corresponding vessel(s). RESULTS: There was not only significant difference of the three communicating arteries calibers before and beyond the 16th week of gestation. Calibers of the right pre-communicating part of the posterior cerebral artery and right cerebral part of the internal carotid artery were significantly higher in male than in female adults. There were 13 morphological types of CACs from the prenatal to the postnatal period. Most frequent CAC types were the type I (normal CAC) prenatally and type IV (unilateral hypoplasia of the posterior communicating artery) in the postnatal period. There were not relationships between the cerebral cause of death and a presence of aneurysm. CONCLUSION: Results of this study will be the basis for future investigation of CACs according to the same or different ages and causes of disease and/or death.

Trigeminal artery: a review of normal and pathological features.

OBJECTS: Carotid-vertebrobasilar anastomoses-the trigeminal, otic, hypoglossal, and proatlantal intersegmental arteries-serve as transitory channels between primitive internal carotid arteries and bilateral longitudinal neural arterial plexus, which is the precursor of future basilar artery, when the human embryo reaches about 4-mm length. MATERIAL AND METHODS: Normal and/or abnormal morphofunctional aspects of the prenatal and postnatal forms of the trigeminal artery are described according to personal and literature data. Many arteries of similar origin and course are also noted in the differential diagnosis of the trigeminal artery. CONCLUSIONS: The persistent primitive trigeminal artery, as the most commonly carotid-vertebrobasilar anastomosis, has a reported incidence of 0.03-2.2% in the literature. There is female sex predilection, and it may be discovered in patients of any age, on either side, and in association with many vascular variants. Although the significance of persistent primitive trigeminal artery regarding the development of an aneurysm or association with another pathological condition may not be clear, its (ab)normal morphology is the inspiration for anatomists, especially for neurosurgeons, before planning diagnostic and therapeutic procedures.

Vertebral and/or basilar dolichoectasia in human adult cadavers.

BACKGROUND: Intracranial arterial dolichoectasia is a condition in which arteries demonstrate an increase in length and diameter, with the vertebrobasilar system being the most commonly affected segment. Because the criteria for and degree of vertebrobasilar dolichoectasia are usually established on three-dimensional time-of-flight MR angiography, we presented the results of an anatomic study of vertebrobasilar dolichoectasia cadaveric specimens. METHOD: Examination was carried out on the brains of human adult cadavers, routinely dissected at the Institute of Forensic Medicine. Measurement of the outer diameter and length of vertebral and/or basilar arteries was performed using the ImageJ processing program. RESULTS: There were 14 cases (14/216) of vertebral and/or basilar (dolicho)ectasia. Their classification into special (sub)types is made according to the basilar and/or vertebral diameter. The basilar length ranged from 32.91-59.37 mm, and the basilar outer diameter ranged from 3.51-8.92 mm in relation to the corresponding point of its measurement. The outer diameter of the vertebral arteries ranged from 0.67-5.91 mm. The Games-Howell post hoc test additionally showed that a basilar outer diameter of grade III and IV was significantly larger than in grade II (p < 0.05). CONCLUSIONS: We noted a predisposition of males older than 40 years to arterial dolichoectasia in the vertebrobasilar system, independently from population group, as well as its asymptomatic appearance, independently from the presence of atherosclerotic plaques.

Possible therapeutic use of spermatogonial stem cells in the treatment of male infertility: a brief overview.

Development of germ cells is a process starting in fetus and completed only in puberty. Spermatogonial stem cells maintain spermatogenesis throughout the reproductive life of mammals. They are undifferentiated cells defined by their ability to both self-renew and differentiate into mature spermatozoa. This self-renewal and differentiation in turn is tightly regulated by a combination of intrinsic gene expression as well as the extrinsic gene signals from the local tissue microenvironment. The human testis is prone to damage, either for therapeutic reasons or because of toxic agents from the environment. For preservation of fertility, patients who will undergo radiotherapy and/or chemotherapy have an attractive possibility to keep in store and afterwards make a transfer of spermatogonial stem cells. Germ cell transplantation is not yet ready for the human fertility clinic, but it may be reasonable for young cancer patients, with no other options to preserve their fertility. Whereas this technique has become an important research tool in rodents, a clinical application must still be regarded as experimental, and many aspects of the procedure need to be optimized prior to a clinical application in men. In future, a range of options for the preservation of male fertility will get a new significance.

C-kit-immunopositive interstitial cells of Cajal in human embryonal and fetal oesophagus.

Interstitial cells of Cajal (ICC) are morphologically and functionally intercalated between the elements of the enteric nervous system and the smooth muscle cells (SMCs) in the musculature of the digestive tract. Kit immunohistochemistry reliably identifies the location of these cells and provides information on changes in ICC distribution and density. Human oesophagus specimens (7 embryos, 23 fetuses at 7-27 weeks gestational age; both sexes) were exposed to Kit antibodies to determine ICC differentiation. Enteric plexuses were examined immunohistochemically by using anti-neuron-specific enolase, whereas the differentiation of SMCs was studied with antibodies against alpha-smooth-muscle actin and desmin. By week 7, c-kit-immunopositive cells were present along the entire oesophagus in the form of an uninterrupted layer around the myenteric plexus (MP) elements. From the beginning of the 3rd month, the number of ICC progressively decreased around the MP ganglia but increased within the muscle layers. Concomitantly, differences in the number and distribution of ICC were established in the various portions of the oesophagus: specifically, ICC were abundant in the lower portion, less numerous in the middle region and rare in the upper part. By the 5th month of development, the relationship as found in later developmental stages had been established: C-kit IR ICC were present within the circular muscle layer, within the longitudinal layer and in the connective septa surrounding the muscle bundles but were completely missing around the MP ganglia.

Human bony jugular foramen: some additional morphological and morphometric features.

BACKGROUND: The jugular foramen, the bony opening on the basis of skull, is an opening through which pass the ninth, tenth, and eleventh cranial nerves, two dural sinuses, and the meningeal branches of the occipital and ascending pharyngeal arteries. The increasing use of modern diagnostic procedures and new surgical approaches has created a need for much more detailed anatomical studies and explanations. This article reveals some additional features. MATERIAL/METHODS: Fifty jugular foramina of skulls of persons of unknown age and gender were examined. The morphological characteristics of all the investigated jugular foramina were described, measured, and compared, taking into consideration their side. RESULTS: All quantitative mean values, except for the width of the anteromedial compartment, were greater on the right side; of these, the lengths and widths of the posterolateral compartment were significantly greater. The bipartite form of the jugular foramen dominated. Complete bony bridging of the jugular foramen was found in 24% of cases. There is no rule of simultaneous complete bony bridging of the jugular foramen and splitting of the hypoglossal canal. CONCLUSIONS: A detailed examination of the jugular foramen anatomy was performed. The main types of jugular foramina and the frequencies of bipartite or tripartite division were established. Several dimensions of the parts of the jugular foramen were measured. Some new data could provide important information about the anatomy of the jugular foramen for reliable surgical interventions in this area.

Otic artery: a review of normal and pathological features.

Three primitive arteries - the trigeminal, otic and hypoglossal take the names according to their close relation with the V, VIII and XII cranial nerves, while at the cervical level, the first segmental artery is named the primitive proatlantal intersegmental artery. When the human embryo is 4 mm long, these arteries serve as transitory anastomoses between primitive internal carotid arteries and bilateral longitudinal neural arterial plexus, which is the precursor of future basilar artery. Normal and/or abnormal morphofunctional aspects of the prenatal and postnatal forms of the otic artery are described according to the personal and literature data. Many (ab) normal arteries are also noted in differential diagnosis of the otic artery. Postnatally, individual incidence rates of the carotid-vertebrobasilar anastomoses have been found to be inversely related to their order of disappearance. The persistent trigeminal artery has a reported incidence from 0.06-0.6%, whereas the persistent primitive otic artery has been convincingly documented only in minor rates. Persistent carotid-vertebrobasilar anastomoses between the anterior and posterior cranial circulation are important to recognize during angiography for endovascular and surgical planning. Most frequently, the otic artery was an incidental finding.

Association of Two Primitive Carotid-Basilar Anastomoses and Cerebrovascular Abnormalities on the Brain Base: A Case Report.

Simultaneous presence of the persistent primitive trigeminal artery and so-called intermediate communicating artery was discovered in a 77-year-old cadaver autopsied due to the myocardial infarction. Many vascular variants and abnormalities such as aplasia of the right vertebral artery (VA), presence of two right posterior cerebral arteries (PCAs), partial duplication of the right superior cerebellar artery, hypoplasia of the pre-communicating part (A1) of the right anterior cerebral artery and the right PCA of basilar origin, a special configuration of the anterior communicating artery (ACoA), and a small aneurysm at the right A1-ACoA junction were associated. The finding of an incipient cerebral aneurysm at the junction of the hypoplastic A1 and embryonal configuration of the ACoA in the eight decade of life indicates that its development was caused by long-term pressure of blood flow at branching points of this artery independent from its caliber. However, it is not yet clear whether the persistence of the first and/or the second carotid-basilar anastomoses in this case was the condition for an aplasia of one VA or vice versa.

Proatlantal intersegmental artery: a review of normal and pathological features.

OBJECTS: Primitive carotid-vertebral and carotid-basilar anastomoses are formed early during human embryogenesis at approximately 24 days. From cephalic to caudal direction, these anastomoses are cranial extensions of the primitive internal carotid, trigeminal, otic, hypoglossal and proatlantal intersegmental arteries. MATERIALS AND METHODS: Normal and/or abnormal morphofunctional aspects of prenatal and postnatal forms of the proatlantal intersegmental artery, from the 24th day of gestation to postnatal eight decades, are described according to personal and literature data. Many (ab) normal carotid-vertebral anastomoses are also marked in differential diagnosis of the proatlantal intersegmental artery. CONCLUSIONS: The proatlantal intersegmental artery maintains the posterior circulation until the vertebral arteries are fully developed between the seventh and eighth gestational weeks. When this artery fails to obliterate, it becomes persistent one. The proatlantal intersegmental artery, most commonly, is an incidental finding or it may be of clinical significance in some patients.

Arterial abnormalities and associated variations of the vertebrobasilar system on the brain base: apropos of a rare case / Anomalías arteriales y variaciones asociadas del sistema vertebrobasilar en la base del cerebro: un caso raro

SUMMARY: The presented case characterizes an association of primitive and definitive arteries with variations on the cadaveric brain base of a very old man. This case is found by the retrospective review of the data archive obtained during many years of cooperation of the author and co-authors. Fenestration of the (ectatic) basilar artery, partial and total duplication of some cerebellar arteries was associated with other variations of the vertebrobasilar and carotid systems. Although this is a case autopsied because of the myocardial infarction, the peculiarity of the case lies in the absence of the aneurysm based on the fenestration or dissection of one of the cerebral arteries.

RESUMEN: El caso presentado caracteriza una asociación de arterias primitivas y definitivas con variaciones sobre la base cerebral cadavérica de un anciano. Este caso se encuentra mediante la revisión retrospectiva de datos obtenidos durante muchos años de un trabajo de cooperación del autor y coautores. La fenestración de la arteria basilar (ectásica), la duplicación parcial y total de algunas arterias cerebelosas se asoció con otras variaciones de los sistemas vertebrobasilar y carotídeo. Si bien se trata de un caso de autopsia a causa de un infarto del miocardio, la peculiaridad del caso radica en la ausencia del aneurisma en base a la fenestración o disección de una de las arterias cerebrales.

Fenestrations and Various Duplications of the Posterior Communicating Artery in the Prenatal and Postnatal Periods.

BACKGROUND: The 2 paired arteries-the posterior communicating arteries (PCoAs) and the precommunicating parts of the posterior cerebral arteries-form the so-called posterior segment of the cerebral arterial circle on the base of the brain. A number of (ab)normal morphologic features were described in the literature (e.g., unusual kinking, or extreme elongations, hypoplasia, duplications, fenestrations, the infundibular widening, or aplasia of the PCoA in the prenatal and/or postnatal periods). The aim of this study was to analyze an incidence of various fenestrations and duplications of the PCoA, and describe their general features and their association with other vascular abnormalities. METHODS: The research was performed on the brains of 200 human fetuses and 377 adult cadavers of both genders and different ages using microdissection and macrodissection methods. RESULTS: There were 0.34% cases with PCoA fenestrations and 3.12% cases with various PCoA duplications. Their morphologic features were described and compared with the similar PCoA abnormalities recorded in the scientific literature. There was no association between the PCoA and either duplication or aneurysm in adult cases. CONCLUSIONS: After thorough examination, the fenestrations and duplications of the PCoA are distinguished as 2 special forms of vascular abnormalities, and the PCoA duplications are characterized as partial and total. Furthermore, whereas the low incidence of a fenestration of the PCoA suggests it to be a sufficiently rare phenomenon, the duplications of the PCoA trunk are fairly frequent, especially concerning its terminal segment.

Infundibular dilatation of the posterior communicating artery in a defined population.

Unusual widening of the posterior communicating artery (PCoA) at its beginning from the cerebral portion of the internal carotid artery (ICA) was described as its infundibular dilatation (ID). A possibility of ID rupture or progression to aneurysm was the reason for an investigation of its frequency and morphologic features in specimens of the Serbian population. Cerebral arteries on the brain base of 267 adult cadavers of both genders and varying age and causes of death were dissected. The images of the PCoA in 190 fetuses were also reviewed. ID of the PCoA was defined as a funnel shaped beginning of different width from ICA, wherein PCoA continues from ID apex to the posterior cerebral artery. There were no cases of ID in fetuses. ID and aneurysms of the PCoA were found in 6/267 or 2.2% and 3/267 or 1.12% of adults, respectively. Unilaterally, they existed on the left side and, frequently, in male cases aging 70 years and older, that had died without cerebral cause. Bilaterally, ID was found in 2/6 cases. There was only one case of ID and aneurysm of the PCoA, but from the ID. We are of the opinion that ID of the PCoA only develops postnatally and probably is due to the influence of hemodynamic factors or hypertension.

Oxidant and antioxidant status in experimental rat testis after testicular torsion/detorsion.

BACKGROUND: The aim of this study was to determine oxidative stress (OS) parameters after testicular torsion/detorsion in adult rats. MATERIALS AND METHODS: In this experimental study, male adult Wistar rats were divided into four groups, each consisting of seven animals: group I-one hour right testicular torsion with subsequent orchiectomy, group II-one hour right testicular torsion followed by detorsion, group III-unilateral right-sided orchiectomy without previous torsion and group IV-control. After 30 days, bilateral orchiectomies were performed in rats with both testes and unilateral orchiectomies in rats with single testicles. Parameters of OS were determined in testicular tissue and in plasma. RESULTS: Plasma concentrations of advanced oxidation protein products (AOPP) and thiobarbituric acid reactive substances (TBARS) were higher (p<0.05 and p<0.01, respectively), whilst the plasma concentration of the total sulfhydryl (T-SH)-groups was lower (p<0.05) in group I compared to the control group. Group II had higher plasma concentrations of AOPP compared to group IV (p<0.05), as well as significantly increased TBARS and decreased T-SH-group levels compared to groups III (p<0.05 and p<0.01, respectively) and IV (p<0.01, for both parameters). There were significant differences in OS markers between the ipsilateral and contralateral testis, as well as significant correlations among levels of both plasma and tissue markers of OS. CONCLUSION: The increase in TBARS levels seen throughout the experimental period indicated that OS development was caused by ischemia/reperfusion in the testicular tissue. The oxidant-antioxidant system of the testicular tissue was altered during torsion as well as detorsion.