Choline acetyltransferase activity in omental tissue

Acetylcholine and acetylcarnitine transport in peritoneum: Role of the SLC22A4 (OCTN1) transporter

A suitable experimental tool based on proteoliposomes for assaying Organic Cation Transporter Novel member 1 (OCTN1) of peritoneum was pointed out. OCTN1, recently acknowledged as acetylcholine transporter, was immunodetected in rat peritoneum. Transport was assayed following flux of radiolabelled TEA, acetylcholine or acetylcarnitine in proteoliposomes reconstituted with peritoneum extract. OCTN1 mediated, besides TEA, also acetylcholine and a slower acetylcarnitine transport. External sodium inhibited acetylcholine uptake but not its release from proteoliposomes. Differently, sodium did not affect acetylcarnitine uptake. These results suggested that physiologically, acetylcholine should be released while acetylcarnitine was taken up by peritoneum cells. Transport was impaired by OCTN1 inhibitors, butyrobetaine, spermine, and choline. Biotin was also found as acetylcholine transport inhibitor. Anti-OCTN1 antibody specifically inhibited acetylcholine transport confirming the involvement of OCTN1. The transporter was also immunodetected in human mesothelial primary cells. Extract from these cells was reconstituted in proteoliposomes. Transport features very similar to those found with rat peritoneum were observed. Validation of the proteoliposome model for peritoneal transport study was then achieved assaying transport in intact mesothelial cells. TEA, butyrobetaine and Na(+) inhibited acetylcholine transport in intact cells while efflux was Na(+) insensitive. Therefore transport features in intact cells overlapped those found in proteoliposomes.

Omental transpositionto the brain as a surgical method for treating Alzheimer's disease

The purpose of this study was to learn the effect of omental transposition to the brain of patients who exhibited the most serious effects of long-standing Alzheimer's disease. Ten patients who had extremely low Mini Mental-State Examination scores of 2-14 underwent placement of their elongated pedicled omentum onto their left parietal-temporal cerebral cortex. Patients underwent pre- and post-operative MRI and SPECT scans in addition to long-term neurological and neuropsychological testing. All were followed up to one year. In spite of the patients' severe cognitive and functional disability, several of the patients demonstrated subjective and objective improvement, especially in terms of their functional status.

The evolution of omentum transposition: from lymphedema to spinal cord, stroke and Alzheimer's disease

It is now well established that the omentum incorporates into its tissues a variety of biological factors that exert a favorable effect on the central nervous system. Physiological characteristics of the omentum include edema absorption, fibrotic inhibition, blood-brain barrier penetration and, of major importance, angiogenic activity. Over several decades, studies have shown increasing clinical uses of the omentum following its placement on various structures within the body. This paper details the evolution of omental transposition (OT) up to the present at which time OT is being applied to the brain of Alzheimer disease (AD) patients. Success in this area raises the possibility that the omentum may prove to be a present-day treatment for patients with AD until future pharmaceutical and/or genetic forms of treatment are developed.

Attenuation of pain perception after transposition of the greater omentum to the cauda equina region of rats--a preliminary observation

BACKGROUND

This paper addresses a specific experimental design to suggest the possible role of the greater omentum in the modulation of pain in rats.

METHODS

Fifteen male Sprague-Dawley rats weighing between 275 and 325 g were selected. The animals were randomized and then anesthetized with pentobarbital (35 mg/kg) and divided into three groups: (1) sham: laparotomy followed by laminectomy with exposure of the spinal epidural space (n=5); (2) transposition of pedicled omentum (n=5) to the cauda equina epidural space; and (3) transposition of pedicled omentum (n=5) to the cauda equina intradural space. The animals were operated upon and once more randomized by an independent investigator, so that the groups were thought to be similar during post-operative testing. The latency of paw withdrawal to noxious heat stimulation was tested and the values (seconds) plotted for 1, 3, 6, 11, 14 and 30 days after surgery. Randomization codes were open after the animals were euthanized. The analysis of variance (ANOVA) without replication was applied for each of the dataset and comparisons established among the different study groups involved. The omenta were removed and standard immunohistochemistry was performed for gamma-amino-butyric acid (GABA), serotonin, calcitonin-gene related protein (CGRP), vascular intestinal peptide (VIP) and Met-enkephalin.

RESULTS

The response to high heating rates of stimulation favored intradural versus sham and epidural omental transpositions. High and low noxious heat stimulation suggested an increased threshold to noxious stimulation after the 3 and 30 days of omental transposition. In the low heat stimulation series, responses were comparatively higher than in the sham animals.

CONCLUSIONS

The suggested increased threshold of response to noxious stimulation after transposition of the greater omentum onto the spinal cord of rats suggested a novel role of the omentum and a potential future application in the clinical arena.

Treatment of Alzheimer's disease by transposition of the omentum

There is increasing evidence that cerebral hypoperfusion plays a key role in the development of Alzheimer's disease (AD). As one ages, cerebral blood flow (CBF) decreases as a direct reflection of a normal aging process. Coupled with this expected drop in CBF are a host of other factors, such as hypertension, stress, smoking, diabetes, cholesterol buildup, etc., which further decrease blood flow to the brain. Maintaining a critical level of CBF is essential if adequate amounts of oxygen and glucose are to be presented to neurons to sustain their cellular energy production (ATP). If CBF drops below a critical flow level, insufficient ATP will be produced and, if this situation is not corrected, neurons will deteriorate and eventually die. When a critical mass of neurons die in areas of the brain involved with cognition and memory, AD will result. Omentum transposition to the brain is a surgical procedure by which a large volume of blood and other biological agents can be delivered to the brain over an indefinite period of time. The omentum gives metabolic support to deteriorating neurons and its presence on the brain has resulted in the reversal of AD symptoms. Additionally, omentum transposition to the brain can markedly reduce senile plaque accumulation, but has no apparent effect on reducing neurofibrillary tangles. Omental transposition may play an important role in the future treatment of AD, especially in early and moderate cases.

Role of the omentum in the treatment of Alzheimer's disease

Beneficial post-operative changes in Alzheimer patients have been observed following omentum transposition to the brain. It is believed that these changes are to a certain degree due to the omentum's ability to increase cerebral blood flow (CBF). Since the omentum is known to increase CBF and to have angiogenic, neurotransmitters and nerve growth substances in its tissues, it is theorized that these biological factors favorably affect still viable but deteriorating ischemic-sensitive neurons located within the Alzheimer brain. Being able to 'rescue' these neurons by increasing CBF and adding neurotrophic factors from the omentum are mechanisms which are believed to increase neuronal energy (ATP production) which leads to cognitive improvement.

Prospective study of omental transposition in patients with chronic spinal injury

OBJECTIVES

This prospective study was designed to assess the effects of omental transposition in patients with a chronic spinal injury.

METHODS

Neurological status was established to be stable and multiple baseline across patient studies were done preoperatively and repeated postoperatively. Assessments included activities of daily living (ADL), functional ability, degree of spasticity, motor power, sensation, pain perception, urodynamic studies, electromyography, sensory evoked potentials (SEPs), and infrared thermography to measure peripheral and general skin vascular responses. Each patient had MRI. Assessments were done at 3, 6, and 12 months after omental transposition in 17 patients.

RESULTS

The detailed assessments failed to show significant improvement, although some patients showed minor objective and subjective change in some categories. Neurological deterioration occurred in one patient. There were 20 surgical complications including urinary tract infection, deep vein thrombosis, wound infection, and incisional hernia.

CONCLUSIONS

Omental transposition has not been shown to improve neurological function in 17 patients with chronic spinal cord injury, and continued use of this operation in this situation is not supported by this study. Further advances in spinal cord repair may utilise the pedicled omental graft to provide an alternative vascular supply, but its current use should be limited to experimental models.

Omental transposition for cerebral infarction: a 13-year follow-up study

BACKGROUND

During the past decade there has been increasing use of omental transposition to the brain of patients who experienced neurologic sequelae after a cerebral infarction. This paper reports the long-term neurologic effects seen in a patient who underwent omental transposition 31 months after a stroke. Her postoperative follow-up period has been 13 years.

CASE DESCRIPTION

The patient had an expressive aphasia, a right hemiparesis and the inability to read which occurred immediately after her stroke. After surgery she demonstrated subjective and objective improvement in her speech and mobility. She also regained her ability to read shortly after surgery.

CONCLUSION

The patient demonstrated that omental transposition to the brain can improve neurologic function in the presence of a long-standing cerebral infarction and that the clinical improvement can be maintained over an extended period.

Omental transposition to the brain for Alzheimer's disease

Omental transposition (OT) to revascularize the brain was first performed in animals in the late 1960s, where it was shown that blood vessels originating from the omentum crossed through the omental-cerebral interface prior to developing into large-sized vessels that penetrated directly and deeply into the underlying brain. The additional cerebral blood flow coming from the omentum was of sufficient volume to protect an animal's brain from cerebral infarction even in the presence of middle cerebral artery ligation. It was also learned that the omentum was a rich source for neurotransmitters and omentum-derived nerve growth substance. OT to the brain is now being done for a variety of conditions which include strokes, TIAs, epilepsy, and Parkinson's disease. Of recent interest is the published information that OT may play some role in Alzheimer's disease (AD). The placement of the omentum on an AD brain has led to a profound decrease in senile plaque formation. The omentum may ultimately prove to be beneficial in reversing or at least stabilizing the dementia associated with the devastation of AD.

Experimental omento-myelo-synangiosis

In 18 cats the omentum was mobilized, transposed, and placed directly upon the pia mater of the spinal cord. Within 2 months, vascular anastomoses developed at the omento-spinal cord interface and, as demonstrated by India ink perfusion, communicated widely with the cord's intramedullary vessels. Light and scanning electron microscopy (SEM) of the interface revealed the development of a "fibrous coat" of Goldsmith in continuity with the edges of the dura mater. It consisted mainly of a matrix of collagen fiber and fibroblasts, well vascularized with sinusoids, capillaries, arterioles and venules. The sinusoids, as identified by SEM, were present in both the fibrous coat and adjacent omentum, were lined with attenuated endothelium, and had multiple communications. The possible significance of the sinusoidal formation is discussed in this report.

Omental transplantation in the management of chronic traumatic paraplegia. Case report

A 27 year old male patient with chronic traumatic paraplegia received an omental transplant to the spinal cord. During surgery we found 40 percent of the spinal cord hypotrophied, with vascular alterations and abundant scar tissue. Some neurological improvement already started a few days postoperatively. After 36 months of postoperative follow-up he presents with right crural monoparesis (grade 1-4), deep sensation and with sphincter control.

Regional cerebral blood flow after omental transposition to the ischaemic brain in man. A five year follow-up study

Regional cerebral blood flow, recorded by the 133Xenon inhalation method, was measured preoperatively and over a five years postoperative period in six patients with completed stroke and stabilized neurological deficits, who had undergone omental transposition for revascularization of the ischaemic brain. Comparisons of the preoperative blood flow values with those recorded following surgery demonstrate a postoperative increase of blood flow in five patients, with a high statistical degree of significance in four of them at the final examination. The flow increase was noted over the infarcted areas of the brain, upon which the omentum had been placed, as well as areas of the ischaemic hemisphere without omental placement and the contralateral hemisphere. Out of the five patients who demonstrated preoperative flow values below the expected norm for age, four showed final postoperative cerebral blood flow within the normal limits for their age. The results are consistent with the assumption that the transposed omentum played a role in postoperative blood flow increase, by adding collateral circulation to the ischaemic brain.