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Biomedical subjects

S Rakic

Publications and source records attributed to S Rakic.

At least 19 recordsLinked to original sources

Identification of Golli and myelin basic proteins in human brain during early development.

The myelin basic protein gene (Mbp) encodes for the major myelin structural proteins and it is included in the Golli-Mbp gene complex. Previously, we observed MBP-like proteins in the human central nervous system (CNS) at developmental stages preceding myelination. In an effort to distinguish between Golli (HOG5 and HOG7) and MBP mRNAs and to determine their spatiotemporal distribution, we performed in situ hybridization using two human Golli specific probes: one corresponding to exon 5a absent from all MBP transcripts, and the other corresponding to exon 5c specific for HOG5. HOG7 transcript was observed first, in 5 gestational week-old embryos, whereas both Golli transcripts were detected at 6-7 weeks gestation in the proliferative zones of the entire CNS. Golli proteins immunoreactivity was observed in microglia and early neurons of the developing telencephalon. During midgestation (17-22 weeks gestation), at the onset of myelination, MBP and Golli mRNAs were observed in the telencephalic subventricular zone and occasionally in the future cerebral cortex. Developmental expression of the human Golli-Mbp indicates that the two Golli proteins have different onset of expression, distribution and possibly function. These results support the hypothesis that at least one of them, HOG7, may be involved in the regulation of early neurogenesis, while both may have additional, still undefined function at the onset of myelination.

Brain↗

Expression of Golli proteins in adult human brain and multiple sclerosis lesions.

It has been suggested that Golli proteins, structurally related to myelin basic proteins (MBPs), have a role in autoimmune processes. We studied the expression of these proteins in multiple sclerosis (MS) and determined that the number of Golli-immunoreactive (ir) cells was significantly higher around lesions of chronic MS than in control white matter. Golli proteins were expressed in the adult oligodendrocyte precursor cells (OPCs), activated microglia/macrophages, and some demyelinated axons around MS lesions. Their expression in adult OPCs indicates remyelination attempts, whereas the expression in the subpopulation of microglia/macrophages suggests roles in the immune processes of MS. In addition, Golli proteins may be markers of axonal transection, which is characteristic for MS.

Acute Disease↗

Stapled laparoscopic gastropexy for paraesophageal hernia.

A minimally invasive correction of symptomatic paraesophageal hernia in high-risk elderly patients is described with an emphasis on a new method of laparoscopic gastropexy that is simple, reliable, and can be performed rapidly.

Digestive System Surgical Procedures↗

Incidence and onset of critical illness polyneuropathy in patients with septic shock.

BACKGROUND: To estimate the incidence and onset of critical illness polyneuropathy (CIP) in patients in septic shock. METHODS: Prospective, observational study, no interventions, in a general 9-bed ICU of a large teaching hospital. Twenty-five patients consecutively admitted to the ICU for treatment of septic shock were studied. Within 72 h of admission to the ICU a complete neurological examination and electromyografic studies were done. Studies were repeated weekly until discharge of ICU or death or CIP confirmed. RESULTS: Nineteen patients developed CIP (76%), with a majority (80%) within 72 h after onset of septic shock. All twenty-two patients with multi organ dysfunction syndrome (MODS) had CIP. The three patients without MODS did not have CIP (P<0.01). CONCLUSIONS: In a group of patients suffering from septic shock the incidence of CIP is high (76%). The onset is early, within 72 h after onset of septic shock. CIP is an early feature of MODS, developing after septic shock.

Adult↗

Programmed cell death in the developing human telencephalon.

Programmed cell death (PCD) in the form of apoptosis is recognized as one of the central events in the development of the central nervous system. To study the time of onset, extent and distribution of PCD in the human telencephalon, embryos and fetuses from 4.5 to 27 gestational weeks (g.w.) were examined using the TUNEL (TdT-mediated dUTP-biotin nick-end labelling) in situ method. At 4.5 g.w. sparse TUNEL(+) nuclei were observed in the ventricular zone of the neural tube. With the formation of the cortical plate at 7-8 g.w. , TUNEL(+) nuclei were seen in all developmental layers of the cortical anlage, as well as in the subcortical regions such as the ganglionic eminence and the internal capsule. The proliferative zones (the ventricular zone, the subventricular zone and the ganglionic eminence) contained the majority of all apoptotic nuclei observed in each specimen. However, the apoptotic index was highest in the subplate zone and in layer I. Double-labelling experiments suggested that neuronal precursors were the main population of cells undergoing PCD in the first trimester of gestation, whereas glial cells probably start dying around midgestation. The onset of labelling of microglial cells and apoptotic nuclei were synchronous, indicating the involvement of microglia in PCD. In conclusion, two distinct types of PCD were observed during human telencephalic development: embryonic apoptosis, which was synchronous with proliferation and migration of neuronal cells and probably not related to establishment of neuronal circuitry, and fetal apoptosis, which coincided with differentiation and synaptogenesis, and therefore may be related to the development of axonal-target connectivity.

Apoptosis↗

Perforation of gastric ulcer associated with paraesophageal hernia causing diffuse peritonitis.

BACKGROUND/AIMS: Free peritoneal perforation of a gastric ulcer associated with paraesophageal hernia causing diffuse peritonitis is an extremely rare event. METHODS: Two new cases of this rare condition and the specificities of management are described. RESULTS: One patient recovered well after surgery, while the other died with signs of persisting sepsis and multiple system organ failure. CONCLUSION: In the wide spectrum of complications related to paraesophageal hernia, free peritoneal perforation of an associated ulcer seems to be one of the gravest. Early elective repair of the paraesophageal hernia is justified.

Aged↗

Early development and composition of the human primordial plexiform layer: An immunohistochemical study.

The early expression of reelin, calcium-binding proteins (calretinin, calbindin, and parvalbumin), and neurofilament proteins have been explored in the developing central nervous system of human embryos and fetuses during the first trimester of gestation. Our objective has been to determine further the nature, developmental roles, and contributions of the early neurons and fibers of the original subpial neuropil, i.e., the primordial plexiform layer (PPL). In young embryos (4-5 weeks old), neurofilament protein-labeled fibers run through the subpial neuropil of the caudal portion of the neural tube, reaching the mesencephalon rostrally. At this age, calretinin-immunoreactive and calbindin-immunoreactive neurons are also found among cells already detached from the ventricular zone. The expression of neurofilament protein, calretinin, and calbindin follows an ascending caudorostral gradient, reaching the cerebral vesicles by the 6th-7th week of gestation. In the cerebral cortex, this timing coincides with the initial expression of reelin in the PPL. The reelin immunoreactivity throughout the most superficial cellular population of the cortical PPL supports the early genesis of Cajal-Retzius cells, around the 6th week of gestation. After the splitting of the PPL by the formation of the cortical plate (7-8 weeks of gestation), reelin-immunoreactive cells remain only in the newly established layer I. This study proposes that an initial PPL may be a universal feature of the developing central nervous system.

Calbindin 2↗

Role of esophageal body function in gastroesophageal reflux disease: implications for surgical management.

BACKGROUND: Effective esophageal peristalsis is a major determinant of esophageal clearance function. The relation of esophageal body function with a mechanically defective lower esophageal sphincter and the development of esophageal mucosal injury in patients with gastroesophageal reflux disease is unclear. STUDY DESIGN: We analyzed the relations among the manometrically determined esophageal clearance function, lower esophageal sphincter dysfunction, esophageal acid exposure, and the presence and severity of esophageal mucosal injury in patients with gastroesophageal reflux disease. Normal values for the manometric assessment of esophageal clearance function were established in 50 normal volunteers and subsequently applied to 160 symptomatic patients with increased esophageal exposure to gastric juice and various grades of esophageal mucosal injury (no minimal surgery, esophagitis, stricture, and Barrett's esophagus). RESULTS: Defective clearance function was present in 47.5% of the patients; a defective lower esophageal sphincter was documented in 63.1%. Compromised esophageal clearance function was significantly more common in patients with a defective lower esophageal sphincter than in those with normal sphincter function (55% versus 33.8%). Esophageal acid exposure time and the prevalence and severity of esophageal mucosal injury were highest in patients with a defective sphincter and compromised clearance function. CONCLUSIONS: These data show that esophageal motor function deteriorates with increasing severity of mucosal injury. This appears to be due to persistent reflux of gastric juice across a mechanically defective lower esophageal sphincter. This may influence the choice and outcome of antireflux surgery. Surgical correction of a mechanically defective sphincter before the loss of esophageal body function is advocated.

Esophagus↗

Prevalence and clinicopathologic features of multiple squamous cell carcinoma of the esophagus.

BACKGROUND: The occurrence of independent synchronous esophageal carcinoma in patients with grossly invasive esophageal cancer (GEC) is well known. Although multiple primary carcinoma of the esophagus is not uncommon, the exact prevalence is controversial, and its clinicopathologic features remain relatively unknown. METHODS: Fifty-four patients with squamous cell GEC who underwent transthoracic esophagectomy with systematic lymphadenectomy between 1987 and 1991 at the Institute for Digestive Diseases, Belgrade University Clinical Center, were included in the study. RESULTS: Detailed histopathologic examination of the esophagus resected for squamous cell carcinoma was performed in 54 patients and revealed 17 patients (31%) with associated cancer independent of the main tumor. The second lesion was significantly less invasive than the main tumor. There was no significant difference (P = 0.06) in sex, age, main tumor site, tumor differentiation, tumor diameter, lymph node involvement, or tumor stage between patients with multiple cancer and patients with solitary cancer, but there was a significant difference in the depth of invasion (P < 0.01). The tumor stage in patients with multiple cancer was determined by the main tumor stage and was not influenced by the associated lesion. The prevalence of multiple primary cancer of the esophagus is lower in other reports than in this series. CONCLUSIONS: The patients in this study had significantly more invasive main tumors. It seems likely that a higher prevalence of multiple cancer may be expected in patients with advanced main tumor penetration. These results support the concept that the entire esophagus may be considered as one entity of field cancerogenesis.

Carcinoma, Squamous Cell↗

Gastric foveolar hyperplasia in patients with cancer of the intact stomach.

The incidence of gastric foveolar hyperplasia, a reliable histological marker of bile reflux into the stomach, was evaluated in patients with cancer of the intact stomach. Lesions classified as foveolar hyperplasia were found in 17 of 32 gastric cancer patients and in seven of 30 controls. This difference was statistically significant (p < 0.02). Differences in the incidence of foveolar hyperplasia according to sex, tumor site, attendant chronic atrophic gastritis, and alcohol consumption were not significant, which lends support to the association of gastric cancer with duodenogastric reflux.

Alcohol Drinking↗

Atrophic chronic gastritis and esophagogastric anastomotic leak after resection and reconstruction for esophageal carcinoma.

The incidence of anastomotic leakage after esophagectomy for cancer and reconstruction with the stomach was analyzed with respect to the presence of coexistent atrophic chronic gastritis (ACG). Of a total of 28 operated esophageal cancer patients with ACG, 6 patients developed an anastomotic leak at the cervical esophagogastrostomy (21%). Of a total of 8 operated esophageal cancer patients none of the patients developed an anastomotic leak. The ACG positive and the ACG negative patients were found to be well matched for age, sex, type of operation, transplant route, level of the anastomoses, and suture technique, and all were operated on by the same surgeons. The difference in leakage rate did not reach statistical significance.

Aged↗