Morphometric multislice computed tomography examination of the craniovertebral junction in neck flexion and extension

BACKGROUND

Detailed study of the craniovertebral junction (CVJ) is necessary to completely understand the mechanism of its flexion and extension.

MATERIALS AND METHODS

One cadaver head was sectioned in the sagittal plane. Also, in 22 volunteers, examined using the multislice computed tomography (MSCT), 14 parameters and 2 angles were measured in the neutral position, flexion and extension.

RESULTS

The obtained measurements showed the anterior part of the occiput to move inferiorly in flexion, and the anterior atlas arch and the tip of the dens to get closer to the basion. At the same time, the opisthion moves superiorly, but the cervical spine bends anteriorly. Consequently, the dens-opisthion diameter and the opisthion-posterior atlas arch distance slightly decrease in length, whilst the arches of the atlas (C1), axis (C2) and C3 vertebra become more distant. Following extension, the posterior part of the occiput moves inferiorly, so that the basion-dens tip, the basion-axis arch, and the basion-posterior atlas arch distances increase in length. In contrast, the distances of the C1-C3 arches decrease in length. The angle between the foramen magnum and the dens tip decreases 1.620 on average in flexion, but increases 3.230 on average in extension. The angle between the axis body and the opisthion also decreases in flexion (mean, 3.360) and increases in extension (mean, 6.570). Among the congenital anomalies, a partial agenesis of the posterior atlas arch was revealed (4.5%), as well as an anterior dehiscence of the C1 foramen transversarium (13.6%).

CONCLUSIONS

The mentioned measurements improved our understanding of the CVJ biomechanics. The obtained data can be useful in the evaluation of the CVJ instability caused by trauma, congenital anomalies and certain spine diseases.

A 3 tesla magnetic resonance imaging volumetric analysis of the hippocampal formation: dependence on handedness and age

BACKGROUND

The hippocampal formation (HF) is one of the most important parts of the brain in the magnetic resonance imaging (MRI) volumetric analysis in various domains, but not completely from all aspects, including the handedness. The aim of our study was to evaluate the possible differences in the volume of the right and left HF among the healthy right-handed and left-handed subjects, and to determine whether the volume differences are age related.

MATERIALS AND METHODS

The MRI of this prospective study was performed using T1 fast field echo (FFE) sequence. The 124 subsequent coronal slices (thickness 1.5 mm) were performed in each participant. The obtained HF volumes were normalised and statistically compared. Volunteers comprised 30 persons aged 22.0 years, 12 of whom were the left-handed, and 30 persons aged 75.2 years on average, 9 of whom were the left-handed.

RESULTS

The right and left HF volumes averaged 2.986 cm3 and 2.858 cm3 in the right-handed, and 2.879 cm³ and 3.020 cm³ in the left-handed young volunteers, as well as 2.728 cm³ and 2.650 cm³ in the right-handed, and 2.617 cm³ and 2.780 cm³ in the left-handed elderly persons. The HF volume ratios in the young left-handed participants showed a significant left-greater-than-right asymmetry. A significant difference was also noticed within the right-to-left volume ratios of the right- and left-handed young and elderly participants. The latter reduction in the HF volume within the aged group can be interpreted as a slight atrophy of the HF.

CONCLUSIONS

There is a significant difference in the volumes of the left and right HF of the left-handed young participants. The age related HF volume differences were proven between the groups of the young and elderly volunteers. The obtained data should be included into the future MRI studies of the HF volumes in various clinical domains.

Brain and art: illustrations of the cerebral convolutions. A review

BACKGROUND

Aesthetics and functional significance of the cerebral cortical relief gave us the idea to find out how often the convolutions are presented in fine art, and in which techniques, conceptual meaning and pathophysiological aspect.

MATERIALS AND METHODS

We examined 27,614 art works created by 2,856 authors and presented in art literature, and in Google images search.

RESULTS

The cerebral gyri were shown in 0.85% of the art works created by 2.35% of the authors. The concept of the brain was first mentioned in ancient Egypt some 3,700 years ago. The first artistic drawing of the convolutions was made by Leonardo da Vinci, and the first colour picture by an unknown Italian author. Rembrandt van Rijn was the first to paint the gyri. Dozens of modern authors, who are professional artists, medical experts or designers, presented the cerebralc onvolutions in drawings, paintings, digital works or sculptures, with various aesthetic, symbolic and metaphorical connotation. Some artistic compositions and natural forms show a gyral pattern. The convolutions, whose cortical layers enable the cognitive functions, can be affected by various disorders. Some artists suffered from those disorders, and some others presented them in their artworks.

CONCLUSIONS

The cerebral convolutions or gyri, thanks to their extensive cortical mantle, are the specific morphological basis for the human mind, but also the structures with their own aesthetics. Contemporary authors relatively often depictor model the cerebral convolutions, either from the aesthetic or conceptual aspect. In this way, they make a connection between the neuroscience and fineart.

MR imaging of subcallosal artery infarct causing amnesia after surgery for anterior communicating artery aneurysm

BACKGROUND AND PURPOSE

During surgery to treat an aneurysm in the anterior communicating artery, injury to the subcallosal artery, a perforator of the anterior communicating artery, may lead to infarction that produces basal forebrain amnesia after surgery. Our purpose was to examine whether 3D MR imaging can detect subcallosal artery infarction in patients with amnesia after surgery for an anterior communicating artery aneurysm.

MATERIALS AND METHODS

We evaluated 3D-T2-weighted MR images obtained a median of 4 months after treatment of anterior communicating artery aneurysm for the presence of infarcted foci in 10 consecutive patients with postoperative amnesia. Because the subcallosal artery and its neighboring perforator, the recurrent artery of Heubner, were considered the most easily affected vessels during that surgery, we focused mainly on 8 regions of the subcallosal artery territory per hemisphere and 5 regions of the recurrent artery of Heubner territory per hemisphere.

RESULTS

All 10 patients had infarcts in the territory of the subcallosal artery (median, 9 regions per patient), and most were bilateral (9 of 10 patients). Five patients had additional infarcted foci in the territory of the recurrent artery of Heubner (median, 1 region per patient), all unilateral. Among the regions perfused by the subcallosal artery, the column of the fornix was involved in all patients; the anterior commissure, in 9; and the paraterminal gyrus, in 8 patients.

CONCLUSIONS

3D MR imaging revealed subcallosal artery infarction, the distribution of which was mostly bilateral, presumably owing to the unpairedness of that artery, in patients with postoperative amnesia after anterior communicating artery aneurysm repair.

Structure and immunohistochemistry of the human lenticulostriate arteries

BACKGROUND

Data about the structure and immunohistochemistry of the lenticulostriate arteries (LSAs), although very important for medical research and clinical practice, have been rarely reported in literature.

MATERIALS AND METHODS

Fourty serially sectioned LSAs were stained with hematoxilin and eosin, and prepared for immunohistochemistry.

RESULTS

Our examination revealed a typical endothelial lining and a narrow subendothelial space with subintimal smooth muscle cells occasionally. The internal elastic lamina was fragmented or absent in the smallest LSAs branches. The mediacoat, with a mean diameter of 148.5 μm, contained typical smooth muscle cells which formed 14.2 layers on average and showed a positive immune reactions for alfa-actin, desmine, laminin and collagen IV. The thin adventitial coat contained fibroblasts, collagen fibers, and nerve bundles, with the strongest immunopositivity to thyrosin hydroxilase. The immune reactions against CD31 and CD34 proteins,endothelial nitric oxide synthase, S 100 protein, neurofilament protein and synaptophysin,seem to be performed in the LSAs wall for the first time. Similarly,the thickness of the LSAs wall and its coats have never been reported, nor the number of the smooth muscle cell layers.

CONCLUSIONS

Our results related to the structure and immunohistochemistry of the LSAs could be important in cerebrovascular pathology, neurology and neurosurgery.

Surgical treatment of neonatal ovarian cysts

Medical experts are still at issue over the most suitable management of simple neonatal ovarian cysts exceeding 40mm and complex cysts of any size. The authors present surgical treatment of these cysts by classical laparotomy and laparoscopy. The study included 13 newborn babies surgically treated for 6 simple and 7 complex ovarian cysts. The diameter of the cysts ranged from 29 to 102mm. The age of children was from 2 days to 10 months. The open classical laparotomic approach was performed in 8 babies. In the laparotomy group, cystectomy was done in 3 infants with simple cysts. The other 5, presented with ovarian torsion, required salpingo-oophorectomy. Video-assisted cystectomy was the procedure for 3 simplex and one complex cyst with torsion. Laparoscopic adnexectomy was applied in one case with auto-amputated cyst. Our small study demonstrates that laparoscopy is as safe and effective as classical laparotomy in managing neonatal ovarian cysts, but with better cosmetic results.

Comparative environmental assessment of natural and recycled aggregate concrete

Constant and rapid increase in construction and demolition (C&D) waste generation and consumption of natural aggregate for concrete production became one of the biggest environmental problems in the construction industry. Recycling of C&D waste represents one way to convert a waste product into a resource but the environment benefits through energy consumption, emissions and fallouts reductions are not certain. The main purpose of this study is to determine the potentials of recycled aggregate concrete (concrete made with recycled concrete aggregate) for structural applications and to compare the environmental impact of the production of two types of ready-mixed concrete: natural aggregate concrete (NAC) made entirely with river aggregate and recycled aggregate concrete (RAC) made with natural fine and recycled coarse aggregate. Based on the analysis of up-to-date experimental evidence, including own tests results, it is concluded that utilization of RAC for low-to-middle strength structural concrete and non-aggressive exposure conditions is technically feasible. The Life Cycle Assessment (LCA) is performed for raw material extraction and material production part of the concrete life cycle including transport. Assessment is based on local LCI data and on typical conditions in Serbia. Results of this specific case study show that impacts of aggregate and cement production phases are slightly larger for RAC than for NAC but the total environmental impacts depend on the natural and recycled aggregates transport distances and on transport types. Limit natural aggregate transport distances above which the environmental impacts of RAC can be equal or even lower than the impacts of NAC are calculated for the specific case study.

[Ultrasound-guided water enema for reduction of childhood intussusception]

INTRODUCTION

Intussusception is a common abdominal emergency in infants and children. Ultrasonography and barium enema are very useful in diagnosis and treatment of this condition. The aim of the study was to assess the accuracy of ultrasound-guided saline enema for intussusception and to determine if some factors may improve the outcome of this technique.

MATERIAL AND METHODS

Intussusception was diagnosed in 63 patients at the Clinic of Pediatric Surgery in Novi Sad. The study period was divided into two 2-year phases: phase I, from 2001 through 2002, and phase II, from 2003 through 2004. During phase I, besides barium enema and fluoroscopy, we started using ultrasonography and ultrasound-guided hydrostatic saline enema in the diagnosis and reduction of intussusception. In phase II, this method of reduction was routinely used in all cases. Our technique of ultrasonic reduction was similar to the conventional hydrostatic barium reduction, except the reservoir was higher than that of barium, analgosedation of patients was performed and in case of difficult and prolonged reduction, gentle manual pressure to the abdomen at right lower quadrant was used.

RESULTS

In phase I the diagnostic accuracy of ultrasonography in detecting intussusception was 53.8%, and 100% in phase II. The success rate of ultrasound-guided saline enema was 55.5% in phase I, and 83.8% in phase II. Only 6 patients (16.2%) underwent operative manual reduction of intussusception in phase II. There were no cases with boewl gangrene or perforations in both groups.

CONCLUSIONS

Ultrasonography is a useful screening tool in the diagnosis of intussusception. Tme main advantage of hydrostatic reduction with ultrasound guidance is avoidance of ionizing radiation. The success rate of this method of reduction may be increased with an integrated team approach to the management and with modifications of the technique.

Esophageal atresia and situs inversus--an unusual association of abnormalities--a case report

We present a case report of a neonate with esophageal atresia and tracheoesophageal fistula. In the 31st week of gestation, maternal polyhydramnions was observed by prenatal ultrasonography. Postnatal insertion of an orogastric tube into the stomach was unsuccessful. On auscultation, the apex of the heart was heard at the right side of the thorax, while the liver was palpable 1 cm below the left rib cage. Esophageal atresia with tracheoesphageal fistula and situs inversus of the thoracic and abdominal organs was diagnosed During the first day of life, left transpleural thoracotomy was performed. The fistula was closed and esophageal anastomosis performed. One year after the operation the child had no difficulties when eating solid and liquid foods. More than 50% of infants with esophageal atresia have associated anomalies and the esophagogram showed good passage of contrast with anastomotic stricture. This was the first report of esophageal atresia with tracheoesophageal fistula repair in a patient with situs inversus treated in our Clinic.

[Constipation--a common problem in childhood]

INTRODUCTION

Constipation in children is defined as the infrequent and difficult passage of hard stool, not necessarily associated with in-frequent stools. All healthy newborns have their first stool within the first 24 to 48 hours after birth. Intestinal transit time increases with age, therapy decreasing the frequency of stooling. ANATOMY AND PHYSIOLOGY OF ANUS AND RECTUM: Acquisition of fecal continence requires: normal internal and external anal sphincters, puborectal muscle as well as intact sensory input from both the rectal vault and anal canal. ETIOLOGY AND DIFFERENTIAL DIAGNOSIS: During the first year of life, failure to have bowel movement every other day warrants evaluation. During infancy, constipation is usually due to dietary manipulations, malnutrition or some other functional abnormalities. Anatomic causes are found only in 5% of patients.

DIAGNOSIS AND THERAPY

Diagnosis relies on history and physical examination. Digital rectal examination usually reveals a shorter anal canal with decreased sphincter tone. The rectal ampulla is dilated and filled with stool. Anorectal manometry is helpful in differentiating functional constipation from aganglionosis or other neurologic problems. Treatment varies depending on the underlying cause. Bowel retraining, aimed at establishing regular daily bowel movement, is of utmost importance in children. The response to treatment is usually dramatic.

CONCLUSION

Constipation in children causes anxiety in the family and successful treatment requires persistent reassurance and repeted reevaluation.

[Urogenital abnormalities and atresia of the gastrointestinal tract]

INTRODUCTION

The goal of the study was to ivestigate the frequency of urogenital congenital abnormalities among atresias of the digestive system and analyze fetal maldevelopment. The study also deals with gastrointestinal and urogenital embryology.

MATERIAL AND METHODS

This retrospektive study analyzed the clinical status of 55 newborns admitted to the Pediatric Surgery Clinic in Novi Sad due to atresia of the gastrointestinal tract during 1995-2003. All atresias were classified at primordial gut levels (foregut, midgut and hindgut). The incidence of associated abnormalities, especially urogenital, was analyzed. Diagnostic procedures included standard methods: clinical investigation, ultrasound, native and contrast medium radiography, etc.

RESULTS

Results showed that urogenital anomalies were present in 21 (38.18%) newborns with gastrointestinal atresia. Foregut atresia was diagnosed in 14 newborns and it was associated with urogenital congenital anomalies in 9 (64.28%) newborns. Midgut atresias were found in 15 patients and in 4 (22.22/%) they were associated with urogenital anomalies. Hindgut atresias were established in 23 and in 8 (34. 78%) cases they were associated with urogenital anomalies.

DISCUSSION AND CONCLUSIONS

It was confirmed that foregut atresias ara commonly accompanied by associated abnormalities. That is why the fourth gestational week is important when both gastrointestinal and urogenital systems are developed. When midgut differentiates into its own derivates, the frequency of congenital anomalies decreases for a short period, and then increases again during foregut development (seventh and eighth gestational weeks). There were no information on environmental teratogenic factors in maternal history. These abnormalities may be explained by complex urorectal development and separation of two systems.

Associated congenital anomalies: vestibular fistula, duodenal atresia and obstructive refluxing megaureter

Congenital gastrointestinal anomalies include spectrum of malformations, simple ones as well as complex, which are associated with anomalies of other organs and systems of organs. Most infants (50-60%) with imperlbrate anus also have genitourinary, cardiovascular, gastrointestinal and vertebral anomalies. This case report is of a female newborn with prenatally diagnosed duodenal atresia and right hydronephrosis. Clinical investigation revealed an imperforate anus with vestibular fistula. A plain abdominal X-ray showed a "double-bubble" sign, characteristic for duodenal atresia. Intraluminal membrane was excised and sigmoid colostomy was performed in general anesthesia on the first day of life. Ultrasound and intravenous pyelography confirmed a hydronephrotic right kidney and obstructive megaureter after Pena. In the fifth month of life, the ureter was tapered and reimplanted. Six months later, posterior sagittal anorectoplasty was performed. In the seventeenth month of life the colostomy was closed This child attained normal growth and development, normal bowel control, fecal continence without soiling, obstipation and urinary infections.

Clinical evaluation of fecal continence after posterior sagittal anorectoplasty in anorectal abnormalities

Introduction Posterior sagittal anorectoplasty (PSAKP) was introduced in 1982, by Repa and de Vries, as a new surgical procedure for patients with anorectal malformations. It was supposed to provide better chance for normal fecal continence. Meterial and methods Between 1991 and 2000, 50 patients with anorectal abnormalities underwent PSARP. In 43 patients PSARP was primary operation and in 7 it was a secondary procedure. At the time of study patients were not younger than 3, and not older than 13 years. Patients and their parents were interviewed, and fecal continence was graded as follows: voluntary bowel contractions, soiling less than once a week, soiling more than once a week, daily soiling and constipation. Results Amongst patients who underwent primary surgical correction, 74% had voluntary bowel contractions. Babies with perineal fistula, rectal atresia and stenosis presented with best results in term of voluntary bowel contractions (100%), as with vestibular fistula, ten of eleven patients. Only 18% of patients (atresia without fistula, vestibular fistula and bulbourethral fistula) had soiling. Patients with perineal fistula and rectal atresia and stenosis 40% were totally continent (voluntary bowel movements without soiling). The most frequent sequel was constipation, which appeared in 48%, without coincidence with frequency of soiling. The problem of constipation was surprisingly more frequent in patients with expected better prognosis in fecal continence. Conclusion Although PSARP offers a good esthetic result, only two third of patients have voluntary bowel movements and in about half there exists a problem with constipation, with necessary further treatment.

Umbilical hernia in children

Introduction Umbilical hernia is a common condition in the pediatric population. Embryology Umbilical hernia is a consequence of incomplete closure or weakness at the umbilical ring, where protrusion of intraabdominal contents may occur. Anatomy Fascia posterior to the canal is thinner creating an area of weakness. Congenital or direct hernia occurs in this area, while herniation in the umbilical canal leads to indirect or acquired hernia. Incidence The incidence of umbilical hernia is 1.9% to l8.5% in white population. Clinical manifestations The great majority of pediatric umbilical hernias are asymptomatic. Incarceration and strangulation are uncommon Rupture of umbilical hernia with resultant evisceration is extremely rare Umbilical hernia may also be the source of intermittent umbilical or abdominal pain. Treatment Treatment options for umbilical hernias range from simple observation to surgical repair. The great majority close spontaneously and observation with periodic follow-up is appropriate in most cases. There are no available data to suggest that strapping improves or accelerates closure. Operation would be recommended for defects greater than 1cm, by the age 3 to 4. Persistence or enlargement of fascial defect during the period of observation are reasons to consider repair, whatever the age. Complications Complications of operative repair of umbilical hernias include those related to anesthesia and local wound infections. Conclusion Umbilical hernia is a common condition among infants and children. In the great majority of cases the natural history is one of eventual closure without treatment. If spontaneous closure does not occur until the age of 3-4 years, operative correction is recommended.

Efficient radical addition of tertiary amines to electron-deficient alkenes using semiconductors as photochemical sensitisers

Tertiary amines can be added to electron-deficient alkenes with yields up to 98% in a radical chain reaction initiated by a photochemical electron transfer using inorganic semiconductors like TiO2 as sensitiser.

Etiology, diagnostics and therapeutic procedures in renal trauma in children: 1995-1997

A retrospective study analyses diagnostic and therapeutic procedures in children with renal trauma. The most prominent symptom among the history data was pain in the injured area and macroscopic hematuria in clinical examination. Ultrasound examination was made systematically and if necessary intravenous pyelography and CT scan of the kidneys. Clinical experience based on 18 patients with kidney injury shows that the injury classified according to Guerrier et all as minor renal injury was presented in 11 patients (61.11%), and major renal injury in 7 patients (38.89%). In 4 patients surgical procedure was indicated, and 2 nephrectomies were performed. Conservative treatment is preferable in the small children with renal trauma.

The surgical anatomy of the perforating branches of the anterior choroidal artery

BACKGROUND

The available information about certain microanatomic features of the AChA perforators is incomplete. Precise knowledge of these vessels is necessary to understand the consequences of their occlusion and to safely operate in their region.

METHODS

The AChA perforators were microdissected and examined under the stereoscopic microscope in 10 vascular casts and in 20 hemispheres injected with india ink or radiopaque substance.

RESULTS

The perforating branches ranged in number from 2 to 9 (mean, 4.6) and in diameter between 90 microm and 600 microm (mean, 317 microm). The most proximal perforator arose 3.2 mm on average caudal to the AChA origin. The most distal (capsulothalamic) perforator varied in size from 200 microm to 610 microm (mean, 431 microm). One or more of the perforators always originated from the AChA (100%), but some of them also from the uncal (33.3%) or parahippocampal branch (10%) of the AChA, either as individual vessels only (70%) or from common trunks (30%). The perforators gave off the peduncular (20%), optic (23.3%), or uncal side branches (26.7%).

CONCLUSIONS

Our findings concerning the origin, position, number, size, branching, penetration site, and relationships of the AChA perforators gave the anatomic basis for safe operations in patients with AChA aneurysms or mediobasal limbic epilepsy.

[Rapid adaptation response after extensive resection of the small intestine: case report]

INTRODUCTION

Short-gut syndrome is defined as any of the malabsorptive conditions resulting from massive resection of small bowel. Clinically the syndrome is manifested by malnutrition, weight loss; steatorrhea, and diarrhea that occur because of decreased absorptive capacity. Intestinal failure is the end result of several complex interacting mechanisms relating in: reduced enterocyte mass, short small bowel length (8-15% of normal) with consequent reduced mucosal contact time for absorption, massive proximal loop dilatation with poor propulsion. Intraluminal stasis and bacterial overgrowth cause bacterial translocation to the liver and "liver injury" presents as intrahepatic cholestasis, with rapid onset and relentless in its progression to end stage hepatic failure. Patients with short bowel must be totally or partly supported with intravenous nutrition until enteral absorption can sustain survival and growth. Autologous bowel reconstruction attempts to reconfigure the residual bowel to eliminate negative factors of bowel dilatation and stasis, and to redistribute the absorptive mucosa to enhance the adaptation response.

CASE REPORT

A case of a newborn with extensive small bowel resection (about 80%) because of malrotation with volvulus and bowel gangrene is presented. The newborn had been six days on total parenteral nutrition and then enteral nutrition had been started. The adaptation response on twentieth day had been satisfactory so that parenteral nutrition was completely suspended. Full adaptation was achieved after two months when the child had one yellow colored bowel movement per day. Presently, the baby grows normally and gains weight.

CONCLUSION

What makes this case interesting is a really unusually rapid adaptation response towards complete enteral independence.

When to operate nonreducible ovary?

During the period from 1992, to 1996, ninety three girls with incarcerated inguinal hernias, mean age 6 weeks, underwent operation at the Clinic for Paediatric Surgery in Novi Sad. All infant girls had incarcerated ovaries or ovaries and fallopian tubes inside hernia sacs. The nonreducible ovaries were present at the time of operation in 35 (37%) girls and in 5 the ovary and tube were twisted. The ovary and tube, were twisted and ischemic at the time of operation, requiring oophorectomy in 2 out of 5 girls. The results of this review and recent experiences reveal that nonreducible ovary is not at risk of compression of its blood supply, but at significant risk of torsion. That is why asymptomatic nonreducible ovary should be treated as every incarcerated hernia--with urgent reduction, manual or operative.

[Short bowel syndrome--surgical aspects]

INTRODUCTION

Long-term survival after massive intestinal resection is now possible with parenteral nutritional support. The expense, morbidity, and inconvenience of this therapy, however, have led to continued interest in alternatives for the treatment of the short bowel syndrome. Patients with short bowel require a multi disciplinary approach over a prolonged period. HISTORICAL CONSIDERATIONS: The history of small bowel transplantation started in 1959 when Lillehei showed that autotransplantation of the small intestine in a dog was feasible. From 1964 to 1971, 7 attempts of small bowel allotransplantations in humans have been reported. All 7 patients died.

DEFINITION

Short gut syndrome is a malabsorptive condition occurring after significant loss of intestinal absorptive capacity. The clinical syndrome is manifested by malnutrition, steatorrhea, weight loss, and diarrhea due to decreased absorptive capacity.

ETIOLOGY

Etiologic factors leading to the short gut state include necrotizing enterocolitis, midgut volvulus, trauma, embolic phenomenon, and Crohn's disease.

PATHOPHYSIOLOGY

Intestinal failure is the end result of several complex interacting mechanisms related to: reduced enterocyte mass, short small bowel length with consequent reduced mucosal contact time for absorption, massive proximal loop dilatation with poor propulsion, and intraluminal stasis and bacterial overgrowth lead to bacterial translocation to the liver systemically.

MANAGEMENT

Patients with short bowel must be totally or partly supported with intravenous nutrition until enteral absorption can sustain survival and growth. Autologous bowel reconstruction attempts to reconfigure the residual bowel to eliminate negative factors of bowel dilatation and stasis, and redistribute the absorptive mucosa to enhance the adaptation response. Several procedures have been suggested to: prolong transmitting time and increase mucosal contact time, enhance absorption by bowel tailoring and bowel lengthening, and increasing the Enterocyte mass.

CONCLUSION

Autologous gastro-intestinal reconstruction is still in its infacny with prospect of new and different concepts for the future.

[Inguinal herniotomy in prematurely born infants]

INTRODUCTION

Inguinal hernia is the most common surgical condition in childhood; more than half of the cases occur during infancy (1, 2). As the number of surviving premature infants continues to grow, the pediatric surgeon has become more involved in the management of these hernias (3, 4). Several issues are contentious, such as the optimal time for herniotomy after diagnosis (5), the role of contralateral exploration, and the proper management for incarcerated inguinal hernia (6). Based on our experience, we attempted to study the above points in the infant population and we also examined the role of ventilator therapy in the etiology of inguinal hernia.

MATERIAL AND METHODS

We performed a retrospective review of records of all infants under 6 months of age who underwent a repair of inguinal hernia at the Clinic for Pediatric Surgery in Novi Sad between January 1994 and December 1996. After surgery, all infants were included in a 6-week follow-up examination.

RESULTS

During this period, 144 infants under 6 months of age underwent inguinal hernia repair. There were 114 males and 30 females. Fourteen patients had bilateral hernias at the time of presentation. Incarceration occurred in 32 infants (22%), that is in 27 of the 99 full-term cases (27%) and in 5 of the 45 preterm cases (11%). Only in three cases (8%) did it occur while the infant was awaiting repair. Over 90% of the full-term infants had their hernias repaired within 3 weeks from diagnosis. After reduction of incarceration, our policy is to operate within 24 to 48 hours. Four testicles appeared to be ischemic; one of these was excised. Patchy bowel ischemia was present in six cases, and bowel resection was required in one. The ovary and tube were twisted and ischemic at the time of operation, requiring oophorectomy in two female infants. Forty-five infants were premature. The mean age at the time of diagnosis was 8 weeks; at the time of herniotomy, it was 13 weeks. In the 24- to 28-week group, 44 of hernias were bilateral, and 7 of the 9 infants had been ventilated for an average of 6 weeks. The mean interval between diagnosis and surgery was 8 weeks for this group.

DISCUSSION

The management of an apparently simple condition such as pediatric inguinal hernia can prove difficult. Deaths have occurred after complications or surgery for inguinal hernia, and most are probably avoidable (9). Morbidity is common and primarily related to incarceration or to damage to vas or testicular vessels during a difficult herniotomy. Because of our policy to operate within 3 weeks from diagnosis, only 8% of incarcerations occurred in infants known to have inguinal hernia. It is surprising that 35% to 41% of incarcerations repeatedly occur in already diagnosed cases (10, 11). Our policy of operating within 24 to 48 hours of manual reduction of incarceration would avoid the 40% reincarceration rate still being reported (6, 10). Our recurrence rate of 2% (3 cases) in comparison to that of other reports (5.4%) (12) we consider acceptable. Because only 5% of cases developed a contralateral hernia, the contralateral exploration is unnecessary. Testicular atrophy has been reported in 1%, even after routine herniotomy (13). There was a large number of premature infants (31%) in our series; the typical range is 9% to 21% (1, 4). The incidence of bilaterality (44%) in this group is very high. The explanation could be that hernias may be caused by ventilation-induced positive intraabdominal pressure, which keeps the processus vaginalis open. Contrary to contemporary belief (1), we found that incarceration is less common in preterm (11%) than in full-term infants (27%).

CONCLUSION

The waiting period for premature infants is not hazardous, and herniotomy can be safely performed once the baby is mature (gestational age of 38 to 40 weeks), weighing more than 2200 grams, and is ready for discharge from the neonatal unit.

The blood supply of the hypoglossal nerve: the microsurgical anatomy of its cisternal segment

BACKGROUND

While the characteristics of the vasculature of the second (intracanalicular) segment of the hypoglossal nerve are well known, the vascularization of the first (cisternal) segment of this nerve has not been examined so far. Many pathologic processes and malformations can be located in the premedullary cistern, which may affect the vasculature of the cisternal segment. Consequently, we decided to examine the blood supply of the cisternal segment.

METHODS

The anatomic features of the cisternal segment and its vasculature were examined in 15 hypoglossal nerves after injection of india ink and gelatin into the vertebrobasilar arterial system.

RESULTS

The cisternal segment was noted to consist of 3-15 long roots, which usually formed two trunks of the hypoglossal nerve. The roots of each nerve received blood from the anterolateral and the lateral medullary arteries, which ranged from 3 to 5 in number and between 100 microns and 500 microns in caliber. These arteries may arise from the perforating branches or the pontomedullary branch of the basilar artery; the vertebral artery or its perforators; the anterior spinal artery or its vascular roots; the posterior spinal artery; and the posterior inferior cerebellar artery. The main hypoglossal arteries, which ranged in diameter from 20 microns to 80 microns, always coursed along the dorsal surface of the roots of the hypoglossal nerve.

CONCLUSIONS

The cisternal segment of the hypoglossal nerve was always vascularized by several vessels, which mainly originated from the vertebral artery and its branches. This observation was discussed from the neurosurgical point of view.

The surgical anatomy of the relationships between the perforating and the leptomeningeal arteries

OBJECTIVE

Despite detailed studies of the perforating arteries, their relationships with the leptomeningeal arteries are almost unknown. These relationships can be of great significance during neurosurgical operations.

METHODS

The arteries of the hemispheres, which ranged in number from 17 to 36, were injected with india ink or methylmethacrylate.

RESULTS

The perforating vessels were noted to arise from the following leptomeningeal arteries: the subcallosal branch of the anterior communicating artery (26.6%); the median artery of the corpus callosum (6.6%); the medial orbitofrontal (6.6%) and the olfactory branch (3.3%) of the anterior cerebral artery; the accessory middle cerebral artery (3.3%); the frontal and temporal branches of the middle cerebral artery (66.6%); the temporal branches of the internal carotid and the anterior choroidal arteries (25% each); the peduncular branch of the posterior communicating artery (4.8%); the peduncular, collicular and medial posterior choroidal branches of the posterior cerebral artery (40%); the cerebellar branches (100%); the long pontine branches (20-26.6%); the anterolateral branches (33.3%) of the basilar artery; and the anterolateral or the lateral medullary branches (35.3%) of the vertebral artery. From 19.4 to 100% of some leptomeningeal vessels originated in the large perforating arteries.

CONCLUSION

From 4.8 to 100% of certain groups of the perforating vessels originated in the leptomeningeal arteries. Occlusion of a leptomeningeal artery that gives rise to the perforating vessel(s) may lead to superficial and deep infarcts in the same patient.

Trigeminocerebellar artery--anatomy and possible clinical significance

The trigeminocerebellar artery was found on the left side in one of 22 brainstems, with the vasculature injected with India ink or methylmethacrylate. The trigeminocerebellar artery, which measured 910 microns in diameter, arose from the basilar artery. The artery was divided into the pontine, trigeminal, cerebellopontine, and cerebellar segments. The artery supplied the anterolateral and lateral part of the pons, the trigeminal nerve root, the middle cerebellar peduncle, and most of the petrosal surface of the cerebellar hemisphere. Although relatively rare, the trigeminocerebellar artery may cause trigeminal neuralgia. Occlusion of this artery would cause a syndrome similar to the lateral midpontine syndrome. The trigeminocerebellar artery could be misinterpreted on angiograms as the anterior inferior cerebellar artery with a high origin from the basilar artery.

The neurovascular relationships and the blood supply of the trochlear nerve: surgical anatomy of its cisternal segment

We examined in detail the cisternal segments of 15 trochlear nerves in brain stems injected with India ink and fixed in formalin. The nerves were found to emerge as singular trunks (33.3%), singular trunks with accessory rootlets (13.3%), or two or three roots with (26.7%) or without accessory rootlets (26.7%). The nerves were in close relationship or in contact with the superior cerebellar artery, that is, with the main trunk of the superior cerebellar artery, its medial and lateral terminal stems, the accessory superior cerebellar artery, and the vermian, paravermian, collicular, and lateral hemispheric arteries as well as their small branches. Some of these vessels were connected by anastomoses in 86.7% of the cases. The anastomotic channels varied from 40 to 530 microns in diameter. The cisternal segment of each trochlear nerve was usually supplied by a single long artery, which most often arose from the vermian artery (26.7%) or the collicular artery (26.7%). The feeding vessel ranged from 30 to 80 microns in caliber. We discuss the possible clinical significance of the anatomic data observed in the present study.

The anatomical basis for the cerebellar infarcts

BACKGROUND

Very little can be found in the literature concerning the variation of the irrigation area of the cerebellar arteries, as well as the characteristics of anastomoses among these vessels. The anatomical features may determine certain features of cerebellar infarcts. Consequently, we examined the irrigation area of and the anastomoses among the cerebellar arteries.

METHODS

The anatomical features of the posterior inferior cerebellar artery (PICA), the anterior inferior cerebellar artery (AICA), and the superior cerebellar artery (SCA) were studied in 26 cerebella injected with india ink, while their irrigation areas and anastomoses were examined in 8 of these cerebella.

RESULTS

The PICA, which most often (82%) arose from the vertebral artery, was found most commonly (81.3%) to supply the largest part of the occipital surface of the cerebellar hemisphere, the caudal or caudomedial part of the tentorial surface, and the inferior vermis. The AICA, which usually (92%) arose from the basilar artery, commonly (68.8%) supplied most of the petrosal surface of the hemisphere and the flocculus. The SCA, which divided into the medial and the lateral trunks, always irrigated most of the tentorial surface of the cerebellum, the superior vermis, and the dentate nucleus. The PICA, AICA, and SCA were always interconnected by anastomoses, which ranged from 40 microns to 420 microns in diameter.

CONCLUSIONS

Cerebellar infarcts were documented by computed tomography (CT) or magnetic resonance imaging (MRI) examinations in 10 patients. The infarcts were located in the PICA territory (60%) or the SCA region (40%). The authors compared the obtained anatomic data to the features of the cerebellar infarcts in these patients.

The neurovascular relationships and the blood supply of the oculomotor nerve: the microsurgical anatomy of its cisternal segment

The 27 oculomotor nerves were examined after injection of India ink or methylmethacrylate into the vertebral and the internal carotid arteries. The ventral surface of the cisternal segment of the nerve was noted to be in close relationship with the superior cerebellar artery (96.3%) and its pontine (37.0%), mesencephalic (25.9%) and perforating branches (81.5%); the posterolateral pontine artery (70.4%) and its branches; the anterolateral pontine branches (29.6%), and the perforating branches (85.2%) of the basilar artery; the mesencephalic perforating arteries (11.1%) and their peduncular branches (62.9%); the peduncular branches of the diencephalic perforators (11.1%) and the P1 segment (18.5%); and the accessory collicular artery (3.7%). The dorsal surface of the nerve was in close relationships to the P1 and P2A segments (100%) of the posterior cerebral artery and their peduncular branches (22.2%); the posterior communicating artery (100%); the collicular (100%) and the accessory collicular artery (33.3%), and their peduncular (51.8%) or the perforating branches (22.2%); the medial posterior choroidal artery (25.9%) and its branches (11.1%); and the mesencephalic and diencephalic perforating arteries (100%). Vascular penetration was noted in 51.8% of the third nerves. The most common penetrating vessel was the collicular artery (18.5%) and its branches (22.2%). The cisternal segment of the oculomotor nerve was most often supplied by the mesencephalic perforators (88.9%). The authors discuss the possible clinical significance of the obtained anatomic data.

[Respiratory complications during surgical treatment of patients in a paediatric intensive care unit]

Incidence of postoperative pulmonary complications (6-76%) depends on diagnostic criteria. Seventy four paediatric surgical patients were analysed during one-year period. In the first group (with complications) pneumonia was the most frequent complication (86.95%) in 65.21% of newborns. In contrast, atelectases, pneumothorax and intra-alveolar haemorhagia were rare. In the control group (group II, without complications) only 5.88% were newborn infants. Intubation and ventilatory support were necessary in 69.56% of patients in the first group, compared to 5.88% in the second group. Mortality rate was high in the first group, where more than a half of children were newborns. In conclusion, pulmonary complications had unfavourably influence on the mortality rate and morbidity, particularly in newborn infants. This was the reason for a prolonged hospitalisation in the paediatric intensive care unit.

Huge uncal branch of the anterior choroidal artery

A huge uncal branch of the anterior choroidal artery was found in one of 22 cerebral hemispheres. The uncal artery measured 0.7 mm in diameter. It gave off small branches to the uncus, as well as a large parahippocampal artery, the accessory anterior temporal artery, and the anterior hippocampal artery. This uncal artery supplied, in addition to the uncus, most of the ventromedial surface of the parahippocampal gyrus, part of its dorsal surface, the rostromedial portion of the lateral occipitotemporal gyrus, and the rostral part of the hippocampal formation. Such a huge uncal artery has implications for surgery in the uncohippocampal region.

RNA-directed RNA polymerase from tomato leaves. I. Purification and physical properties

An RNA-directed RNA polymerase (RdRP, EC 2.7.7.48) from tomato leaf tissue was purified to electrophoretic homogeneity. A terminal transferase activity that was found to cofractionate with RdRP from DEAE-Sepharose and DNA-cellulose columns was removed by chromatography on a Mono Q column. The highly purified RdRP exhibits a specific activity of 500 nmol x mg-1 x 30 min-1, which corresponds to a 100,000-fold enrichment of the enzyme. In buffer containing 50% glycerol, its activity decreased by about 15%/month. RdRP activity coincided with the silver staining intensity of a single 128-kDa polypeptide when the fractions eluted from the Mono Q column were analyzed by electrophoresis in a SDS-polyacrylamide gel. Its molecular mass and its sedimentation coefficient of 6.6 S indicate that RdRP is a nearly globular molecule. The catalytic activity of RdRP is resistant to alpha-amanitin and actinomycin D. In tomato leaves systemically infected with potato spindle tuber viroid, the activity of RdRP was found to be increased about 3-fold compared with RdRP isolated from healthy leaf tissue.

RNA-directed RNA polymerase from tomato leaves. II. Catalytic in vitro properties

The catalytic properties of electrophoretically homogeneous RNA-directed RNA polymerase (RdRP, EC 2.7.7.48) from tomato leaf tissue were studied with the aid of oligonucleotides of defined sequence. It was found that RdRP catalyzes in vitro the transcription of short single-stranded RNA and DNA molecules into precisely complementary RNA copies up to the full length of these templates. The transcription of RNA- and DNA-oligonucleotide templates was equally effective. Differences in transcription efficiency were found to depend on nucleotide sequence rather than on the RNA or DNA nature of the single-stranded nucleic acid. Double-stranded nucleic acids such as poly(A).poly(U) and a double-stranded DNA 14-mer were not transcribed. The RdRP-directed transcription could be primed because RNA and DNA dinucleotides and trinucleotides complementary to the 3'-terminal nucleotides of the template were extended by the enzyme. The unprimed transcription was shown to start preferentially at the 3'-terminal nucleotides of the template. RdRP is capable of adding a single noncomplementary nucleotide to the 3' terminus of about 50% of the runoff transcripts. AMP was preferred over GMP, whereas CMP and UMP were terminally added at very low frequency.

[Ultrasonographic verification of hypertrophic pyloric stenosis]

In a two-year study on 24 newborn infants, diagnosis of hypertrophic pyloric stenosis (HPS) was intraoperatively confirmed, following preoperative ultrasonography. By means of real time sonography three parameters of the pyloric muscle were measured; the mean length was 19.6 mm, diameter 13.4 mm and the muscle thickness was 5.1 mm.

Microvascular anatomy of the hippocampal formation

The hippocampal vessels were examined in 25 forebrain hemispheres injected with india ink or methylmethacrylate. There were two to seven hippocampal arteries, which measured 200-800 microns in diameter. The anterior hippocampal artery (AHA), which was present in 88.2% of the hemispheres, most often originated from the posterior cerebral and the anterior temporal arteries, that is, within the rostral hippocampo-parahippocampal arterial complex. It arose from the anterior choroidal artery in 29.4% of the hemispheres. The AHA extended between the uncus and the parahippocampal gyrus, and it supplied the head of the hippocampus. The middle hippocampal artery was constant. It most often arose from the posterior cerebral and the common temporal arteries. The middle hippocampal artery coursed just caudal to the uncus, in close relationship with the lateral posterior choroidal artery, and it usually supplied the middle part of the hippocampal formation. The posterior hippocampal artery, which existed in 94.1% of the hemispheres, most often arose from the posterior cerebral and the splenial arteries. It irrigated the caudal part of the hippocampal formation. The anastomoses connecting the posterior, middle, and the anterior hippocampal arteries were present in 29.4% of the hemispheres. The hippocampal arteries gave rise to the straight vessels, which divided into the large and the small intrahippocampal arteries. The highest density of the capillary network was noted in the pyramidal and molecular layers of the hippocampal formation. The clinical significance of the obtained microanatomical findings is discussed.

[Pain in patients with Parkinson disease]

The authors established the appearance of pain in 54 (68.3%) patients suffering from Parkinson's disease (PD) with levodopa treatment, and in 16 (76.2%) PD patients without treatment. Pain preceded the motor disorders in 39% of PD patients. Pain involved most often the upper (72.2%) and the lower limbs (68.1%), as well as the paravertebral (45.8%) and the neck regions (15.2%). It was located more frequently in joints (54.0%) than in muscles (28.1%). The frequency of pain was higher in PD patients with depression (20.17%) than in those without depression (11%). At the same time, the pain was noted in 61.9% of depressive patients without treatment, as compared to 35.4% depressive PD patients following treatment. The authors discussed the potential pathophysiological mechanism of pain in PD patients.

Distinct regulation of the interleukin-1 and interleukin-6 response elements of the rat haptoglobin gene in rat and human hepatoma cells

The transcription rate of the haptoglobin (Hp) gene is stimulated by interleukin-1 (IL-1), IL-6, and dexamethasone in rat hepatoma (H-35) cells. To identify the cis-acting regulatory elements responsive to these hormones, various lengths of 5' Hp gene-flanking regions, including the promoter, were inserted into chloramphenicol acetyltransferase gene expression vectors and transiently introduced into H-35 cells. The first 4 kb of 5' region mediated a severalfold increase in expression after treatment with IL-6 and dexamethasone. No response to IL-1 was detectable. When, however, upstream sequences were deleted to position -165 relative to the transcription start site, a significant stimulation by IL-1 was gained without appreciably affecting the IL-6 response. With the apparent removal of an inhibitory sequence, the promoter-proximal 165-bp region also displayed a severalfold enhanced response to the combination of dexamethasone, IL-1, and IL-6. The sequence from -165 to -147, termed the A-element, was found to be crucial for all hormone regulatory functions. Two copies of the A-element linked to a heterologous promoter responded to the three hormones, but to a lesser degree than in the Hp gene promoter context. The regulatory elements of the rat Hp gene were similarly active in human hepatoma cells. Optimal regulation by IL-6 in HepG2 cells was, however, independent of the A-element. The A-element functioned in these cells exclusively as an IL-1 response sequence. The results suggest that genomic sequences upstream of the rat Hp gene suppress the regulation by specific cytokines more prominently in transient expression assays than in the normal chromosomal context. Moreover, the functional comparison indicated that specific regulatory regions of the rat Hp gene do not function identically in different hepatic cell types.

Structure, hormonal regulation, and identification of the interleukin-6- and dexamethasone-responsive element of the rat haptoglobin gene

Hepatic expression of the haptoglobin (Hp) gene in mammalian species is stimulated severalfold during an acute-phase reaction. To identify the molecular mechanism responsible for this regulation, the single-copy rat Hp gene has been isolated. The genomic sequences showed a high degree of homology with the primate Hp gene. Activity of the rat Hp gene was increased in cultured liver cells by interleukin-1 (IL-1), IL-6, and glucocorticoids. The genomic Hp gene sequence spanning from -6500 to +6500, when transiently introduced into human hepatoma (HepG2) cells, directed IL-6- and dexamethasone-stimulated expression of rat Hp mRNA and protein. No response to IL-1 was detected, suggesting that the corresponding regulatory element(s) might lie outside of the tested gene sequences. An IL-6- and dexamethasone-responsive element has been localized to the promoter proximal region -146 to -55. Although the nucleotide sequences of this rat Hp gene region showed substantial divergence from that of the human gene, analysis of sequential 5' and 3' deletion constructs indicated an arrangement of functional IL-6 response elements in the rat Hp promoter sequence comparable to that of the human homolog. The magnitude of IL-6 regulation through the rat Hp gene promoter was severalfold lower than that of the human Hp gene. The reduced activity could be ascribed to a single-base difference in an otherwise conserved sequence corresponding to an active element in the human gene. The IL-6 response of the rat Hp element was improved severalfold by substituting that base with the human nucleotide.

Branches of the anterior communicating artery. Microsurgical anatomy

The anterior communicating artery (ACoA) and its branches were examined in 22 human brains after injecting Indian ink or methylmethacrylate. The ACoA branches were divided into the small and the large. Small branches were from 1 to 5 in number (mean 2), and from 70 to 270 microns in diameter (mean 151 microns). Seventy-six percent of the branches originated directly from the ACoA. They tended to arise closer to the left than to the right anterior cerebral artery. Fourteen percent of them arose from the junctional site of the ACoA with the anterior cerebral arteries, and 10% from the site of origin of the subcallosal artery. Large branches were identified as the median artery of the corpus callosum, and the subcallosal artery, respectively. The former vessel was present in 9% of the patients, and the latter in 91%. The subcallosal artery was from 320 to 640 microns in size (mean 486 microns). It tended to arise from the middle of the ACoA. In spite of the very frequent anastomoses involving the ACoA branches, care must be taken to avoid injury to these important vessels during operations of the ACoA aneurysms.

Soman intoxication-induced changes in serum acute phase protein levels, corticosterone concentration and immunosuppressive potency of the serum

We have studied the effect of soman intoxication on serum acute phase reactants (APR) levels, and the relationship of the APR and corticosterone concentrations and the immunosuppressive activity of the serum. One day after the injection of 1.8 LD50 soman the concentrations of alpha 2-macroglobulin (alpha 2-MG) and alpha 1-acid glycoprotein (AGP) in the serum of antidote protected rats increased 4- and 7-fold, respectively, whereas those of hemopexin (Hx), haptoglobin (Hp) and cysteine protease inhibitor (CPI) were two to three times higher than in the controls. A similar magnitude of increase of serum acute phase reactants levels was observed when 0.3 LD50 soman was administered at 24-h intervals over the 5-day period. The relationship of changes in the APR concentration, corticosterone level and immunosuppressive activity of the serum was also comparable to that observed in the acute phase response to tissue injury.

Regulation of acute phase protein genes by hepatocyte-stimulating factors, monokines and glucocorticoids

The synthesis of all the major acute phase plasma proteins is stimulated in rat hepatoma and primary cultures of hepatocytes by three, structurally and functionally distinct groups of hormones: 1) hepatocyte-stimulating factors (HSF) and interleukin-6 (IL-6); 2) interleukin-1 (IL-1) and tumor necrosis factor (TNF); and 3) glucocorticoids. Each plasma protein gene requires a specific combination of these 3 hormone types for maximal expression. One set of acute phase proteins, including alpha 2-macroglobulin, alpha 1-antichymotrypsin ( = contrapsin), cysteine protease inhibitor ( = thiostatin), alpha 1-antitrypsin, ceruloplasmin and fibrinogens are predominantly regulated by the keratinocyte-derived HSF-III/-II or IL-6, while a second set of proteins, including alpha 1-acid glycoprotein (AGP), haptoglobin and complement C3 are predominantly regulated by keratinocyte-derived HSF-I, IL-1 or TNF. In conjunction with the above peptide hormones, glucocorticoids synergistically enhance the stimulated expression of most, but not all, acute phase proteins. An exceptionally strong synergy between HSF (or IL-6), IL-1 and glucocorticoids is noted for the activation of the AGP gene. To elucidate the molecular mechanisms of regulation, we have identified the cis-acting genetic elements through which all these hormones control the transcriptional activity of the AGP gene. It appears that acute phase activates a specific nuclear binding protein in the rat liver that interacts with the peptide hormone responsive element located 5 kb upstream of the transcriptional start site.

Anatomic basis for surgical approach to the distal segment of the posterior cerebral artery

The distal segment of the posterior cerebral artery (PCA), which extends from the junction with the posterior communicating artery to its terminal division into the parieto-occipital and calcarine arteries, was examined in 37 brains. Three types of distal segment were distinguished. In the first type (42.9%), the terminal division was located either in the calcarine sulcus or in the quadrigeminal cistern. In the second type (41.4%), the terminal division had the same position, but the distal segment, in addition to its terminal stems, also gave off the common temporal artery. In the third type (15.7%), the terminal division was seen in the ambient cistern. The distal segment of the PCA gave rise to several collateral branches: the collicular artery (2.8%), the anterior (28.6%), middle (30.0%), and posterior (28.6%) hippocampal arteries, the proximal (82.9%) and distal (20.0%) lateral posterior choroidal arteries, the proximal (40.0%) and distal (41.4%) medial posterior choroidal arteries, the peduncular, thalamogeniculate and splenial branches, the lingual gyri artery and the temporal arteries. Several anatomic variants of the distal segment were observed in this study: fenestration of the distal segment (1.4%), location of the distal segment dorsal to the uncus (2.8%), origin of the collicular (2.8%) and anterior choroidal arteries (1.4%) from the distal segment, and protrusion of the parieto-occipital arterial loop into the lateral ventricle (2.8%). The authors discuss the clinical significance of these anatomic data.

Soman intoxication-induced increase in the levels of mRNAs coding for acute phase reactants

The effect of lethal and repetitive sublethal soman intoxication on the composition of rat liver mRNA was examined by cell-free translation and hybridization. It was found that lethal as well as sustained sublethal soman poisoning of rats elicited a typical acute phase response as judged by a several-fold increase in levels of mRNAs coding for the major acute phase proteins and the vast number of systemic and metabolic changes creating the acute phase response should be taken into account when the metabolic events during the recovery from organophosphate intoxication are under consideration.

Vertical ascending connections in the isocortex

Different fluorescent tracers were applied to the surface of the cortex of rats, marmosets and one hedgehog. Irrespective of the kind of tracer and the depth of penetration, some perikarya of layer VI were labelled in each specimen and in all cortical regions. In the rat almost all labelled neurons were packed in sublayer VIb, in the marmoset such cells were dispersed throughout layer VI, whereas in the hedgehog the degree of their segregation to sublayer VIb was intermediate. Additional experiments in the rat indicated that most of the medium-sized neurons in the VIb layer project to layer I, that most of the perikarya projecting to the thalamus are localized in sublayer VIa, that different neurons project to the thalamus and to the surface of the cortex, and that only very few perikarya in deep parts of layers III and V and of sublayer VIa send axons or axon collaterals to layers I and II.

Interpeduncular perforating branches of the posterior cerebral artery. Microsurgical anatomy of their extracerebral and intracerebral segments

Interpeduncular perforating branches were found in all 69 examined posterior cerebral arteries. They varied in number from 1 to 10, with an average of 2. They arose directly from the posterior cerebral artery (47.8%), from the collateral branches of the posterior cerebral artery (30.3%), or by their own common stems (88.4%). Their extracerebral segments varied from 100 to 750 microns in diameter (average, 321 microns). They gave off collateral branches to the cerebral peduncle, posterior perforated substance, oculomotor nerve, and mammillary bodies. Intracerebral segments had proximal and distal portions. The mean diameter of the former was 254 microns, and of the latter, 227 microns. The perforating arteries were divided into short interpeduncular and long mesencephalic and diencephalic vessels. Anastomoses among them were noticed in four-fifths of the cases. Despite this fact, the perforating arteries must be preserved during operations on aneurysms in the interpeduncular fossa.