Brain death

Summary Following the research of Giessen Neurosurgery on primary and secondary lesions of the hypothalamo-pituitary system and the brainstem over a period of more than 30 years, cerebral failure and death does not represent a uniform syndrome but consists of several, well characterized syndromes of irreversible hypothalamo-pituitary, mesencephalic and bulbar failure. The specific syndromes are described in detail. The diagnosis is based on establishing complete irreversible damage of specific vital basal functions such as hypothalamo-pituitary transmission, water-and electrolyte metabolism, temperature regulation, circulation and respiration. The common feature of all types is the irreversible break-down of the complex central neurogenous and/or neurohumoral regulatory system. The permanent and irreversible loss of central regulation and modulation means at the same time the complete cessation of the specific human cortical function, the death of the whole brain. Only in bulbar failure with primary irreversible cessation of respiration artificial respiration can maintain the autonomous functions of the heart for a limited time. It is indicated when organ explantation is to be considered. Complete and irreversible isolated loss of cortical function abolishes the normal human life, but does not mean death of the remaining vegetating human being.Presented at the meeting of the Working Group of the Pontificia Academia Scientiarum on The artificial prolongation of life and the exact determination of the moment of death, Vatican City, October 19–21, 1985.Dedicated to Prof. Dr. Jean Brihaye at the occasion of his 65th anniversary.     

Is the placement of jejunostomy tubes in patients with esophageal cancer undergoing esophagectomy associated with increased inpatient healthcare utilization? An analysis of the National Readmissions Database

BackgroundPatients undergoing esophagectomy often receive jejunostomy tubes (j-tubes) for nutritional supplementation. We hypothesized that j-tubes are associated with increased post-esophagectomy readmissions.Study designWe identified esophagectomies for malignancy with (EWJ) or without (EWOJ) j-tubes using the 2010–2015 Nationwide Readmissions Database. Outcomes include readmission, inpatient mortality, and complications. Outcomes were compared before and after propensity score matching (PSM).ResultsOf 22,429 patients undergoing esophagectomy, 16,829 (75.0%) received j-tubes. Patients were similar in age and gender but EWJ were more likely to receive chemotherapy (24.2% vs. 15.1%, p < 0.01). EWJ was associated with decreased 180-day inpatient mortality (HR 0.72 [0.52–0.99]) but not with higher readmissions at 30- (15.2% vs. 14.0%, p = 0.16; HR 0.9 [0.77–1.05]) or 180 days (25.2% vs. 24.3%, p = 0.37; HR 0.94 [0.79–1.10]) or increased complications (p = 0.37). These results were confirmed in the PSM cohort.ConclusionJ-tubes placed in the setting of esophagectomy do not increase inpatient readmissions or mortality.     

Experience sharing of conservative treatment after a 90-year-old male replacing the suprapubic bladder catheter enters the small intestine: A rare case report

IntroductionThe treatment of intestinal perforation caused by the SBC enters the small intestine in elderly patients is a challenge for urologists. The report is to share our experience of conservative treatment after a 90-year-old male with the suprapubic bladder catheter enters the small intestine.Presentation of caseBecause of the device was obstructed, a 90-year-old male went to our hospital with his family and requested to replace the SBC. When the fistula tube was replaced, it entered the intestine through the intestinal injury site instead of entering the bladder. During the hospitalization, the patient was given supportive treatments and the SBC was dynamically monitored daily and it was intermittently withdrawn out during this period. After the drainage volume was less than 10 mL for three consecutive days and the intestinal fistula was healing gradually, the catheter was taken out.DiscussionAccording to our experience, the common complications in the process include failure to pull out the SBC, abnormal position of the SBC, and poor drainage of the SBC. However, the drainage tube placing into the small intestine through the original hole of the suprapubic bladder fistula during the replacement process is quite rare. When elderly patients have traumatic small bowel perforation, the diagnosis and treatment of intestinal perforation in elderly patients was particularly important.ConclusionThe conservative treatment of intestinal perforation is suitable for elderly patients who are unsuitable or unwilling to undergo a surgical operation. Of course, it should be in accordance with the patient's condition to make the right choice of treatment.     

Central patterning of speech movements

Summary Previous speech kinematic studies have demonstrated systematic timing relations among the upper lip, lower lip, and jaw suggesting the operation of a central pattern generator (CPG). The present study evaluated the consistency of these timing relations following unanticipated perturbation of the lower lip. Using this approach, it was also possible to evaluate the influence of sensory information on the timing of motor output and subsequent coordination of the multiple speech movements. Perturbations were applied to the lower lip during the closing movement associated with the first p in sapapple. Muscle activity and movements of the upper lip, lower lip, and jaw were obtained. Changes in movement displacement, velocity and duration, the timing and sequencing of peak velocities, EMG area, and EMG rise time were analyzed for the control and load conditions. Similar to previous perturbation results, significant magnitude compensations from the muscles and movements of the upper lip, lower lip, and jaw were observed. In contrast, movement durations and the sequencing of peak velocities were relatively unaffected by the lower lip load. The timing of peak EMG amplitude and consequently the timing of peak closing velocity for all structures (UL, LL, and J) occurred earlier relative to the preceding opening movement. These results are consistent with the interaction of phasic sensory input with centrally-driven commands resulting in a phase-advanced motor output. Further, as the timing of one structure is modified so were all the functionally-linked components thereby maintaining the necessary coordination. As in other rhythmic motor behaviors such as locomotion and chewing, there appears to be a centrally patterned framework for speech movement coordination.     

Developmental transition in plasticity properties of differentiating astrocytes: age-related biochemical profile of plasminogen activators in astroglial cultures

Plasminogen activator (PA) is a key enzyme in control of the cascade of extracellular proteolytic activities, proteases that degrade the extracellular components. Mammalian cells produce two molecular forms of PA, the urokinase type (u-PA) and the tissue type (t-PA); the u-PA type enzyme regulates cell migration/invasion and related tissue plasticity events. Thus, these plasticity properties of cells are defined by their PAs' biochemical profiles. The capacity of the differentiating glial cells of the central nervous system (CNS) to express and regulate the two types of PA activities has been examined as a function of cell age in culture. Results of the study suggest that only the immature astrocyte is endowed with these plasticity properties. Differentiating heterogeneous rat glial cells in culture express PA activity. Astroglia were identified as the primary source for the glial PA activity, as no PA activity was detected in the purified oligodendroglia. Cellular PA activity levels of differentiating rat and mouse astroglia are developmentally regulated. The specific activity of PA reached its highest level in rat astroglia at a cell age corresponding to 20-32 postnatal days (P20-P32) and in mouse astroglia at P8-P14; thereafter, this declined (three- to fourfold decrease) within 2 weeks to a low value. At comparable ages (P0-P35), the magnitudes of the PA specific activities of the differentiating rat astroglia and of the developing cerebrum, the tissue from which these cells were purified, were similar. Differentiating rat astroglia produce u-PA and t-PA, the cellular content of both is developmentally regulated, and the u-PA form is only found in the immature cells. u-PA is the predominant form in the immature astrocyte until age P13. Both forms are found in cells at ages P14-P30, and at later stages u-PA disappears while the t-PA type persists as the sole form. After 3 more weeks neither of the PA types was detected. Astroglia express also PA inhibitory activity; the rat astroglial PA inhibitor (PAI) seemed to be identical to PAI-1, one of the known types of PAIs. Stimulation of astroglial proliferation by their subculturing in contrast to Schwann cells did not lead to an increase; rather, beyond a certain cell age (P13) it resulted in a threefold irreversible decline in the PA specific activity of the daughter cells. It has been established that various biochemical properties of CNS mature glia appear on schedule with cell age in culture, thus defining "mature"glia in vitro.(ABSTRACT TRUNCATED AT 400 WORDS)     

The inflammatory lesion of T cell line transferred experimental autoimmune encephalomyelitis of the Lewis rat: distinct nature of parenchymal and perivascular infiltrates

We have investigated the T cell receptor (TCR) repertoire in the inflammatory infiltrates of T line-transferred experimental autoimmune encephalomyelitis (EAE) of the Lewis rats. Using a panel of TCR V-specific monoclonal antibodies (mAbs) and immunocytochemistry, we studied the nature of the T cells entering the central nervous system (CNS) after transfer of either myelin basic protein (MBP)-reactive, or MBP-reactive but non-encephalitogenic T cell lines. All the MBP-specific T cell lines predominantely used the V8.2 TCR chain. T cell lines specific for the tuberculin purified protein derivative (PPD), using TCR V genes different from V8.2, served as controls. We first studied the time course of T cells entering the CNS. In all recipient rats, small, but significant numbers of -TCR-expressing infiltrate cells appeared in the CNS within the first 24 h after T cell transfer. In animals injected with either type of MBP-reactive T cells, the early infiltrate cells were preferentially located within the parenchyma of the spinal cord, while in PPD T lineinjected rats, the lymphocytes were mostly found in the meninges. TCR V gene usage was examined on the peak of clinical disease. Six days after T cell transfer, the TCR repertoire used by infiltrating lymphocytes in general seemed to be highly diverse. None of the V isotypes examined (i.e. V8.2, V8.5 or V10) was used by a major population of the -TCR-positive T cells. A more detailed, quantitative analysis of individual infiltrate compartments revealed, however, a preferential accumulation of V8.2-positive T cells within the parenchyma. In contrast, perivascular infiltrating cells used V genes randomly. Our results confirm first that activated T lymphocytes enter the brain rapidly irrespective of their antigen specificity. Second, the data show that most of the perivascular infiltrate T cells in the acute EAE lesion are host-derived, recruited presumably from the recirculating T cell pool, while the encephalitogenic, V8.2-positive T cells preferentially persist within the parenchyma.Abbreviations EAE experimental autoimmune encephalomyelitis - MBP myelin basic protein - TCL T cell line Supported by the Brazilian Research Council (CNPq)     

Acute airway obstruction following placement of a subclavian Hickman catheter

The purpose of this case report is to describe the events, intervention, and aetiology which led to acute airway obstruction in an adult patient after the placement of a Hickman catheter. Airway obstruction secondary to superior vena cava obstruction occurred after placement of a subclavian vein Hickman catheter. This was felt to occur, in part, to a narrowed superior vena cava as evident by subclavian venography. It resulted in emergency oral tracheal intubation to relieve airway obstruction. Shortly after removal of the Hickman catheter, the signs of superior vena cava obstruction syndrome resolved and the patient was extubated without incidence. It is concluded that, although rare, the serious complication of acute airway obstruction can occur after placement of a Hickman catheter.     

Release and actions of adenosine in the central nervous system

Adenosine is released from active neurons into the extracellular fluid at a concentration of about 1mol/l. Neither the precise cellular origin nor the biochemical form of release has been firmly established, though the nucleotide is probably released partly directly, as a result of raised intracellular levels, and partly as nucleotides, which are subsequently hydrolysed. Once in the extracellular medium, adenosine markedly inhibits the release of excitatory neurotransmitters and modulatory peptides and has direct inhibitory effects on postsynaptic excitability via A₁ receptors. A population of A₂ receptors may mediate depolarization and enhanced transmitter release. Adenosine also modulates neuronal sensitivity to acetylcholine and catecholarnines, all these effects probably contributing to the behavioural changes observed in conscious animals. As a result of their many actions, adenosine analogues are being intensively investigated for use as anticonvulsant, anxiolytic, and neuroprotective agents.