Regulatory roles for histone deacetylation in IL-1beta-induced nitric oxide release in pancreatic beta-cells.

Histone (de)acetylases control gene transcription via modification of the chromatin structure. Herein, we investigated potential roles for histone deacetylation (or hypoacetylation) in interleukin-1beta (IL-1beta)-mediated inducible nitric oxide synthase (iNOS) and nitric oxide (NO) release in insulin-secreting INS 832/13 (INS) cells. Western blot analysis suggested localization of members of Class 1 and Class 2 families of histone deacetylases (HDACs) in these cells. Trichostatin A (TSA), a known inhibitor of HDACs, markedly reduced IL-1beta-mediated iNOS expression and NO release from these cells in a concentration-dependent manner. TSA also promoted hyperacetylation of histone H4 under conditions in which it inhibited IL-1beta-mediated effects on isolated beta cells. Rottlerin, a known inhibitor of protein kinase Cdelta, also increased histone H4 acetylation, and inhibited IL-1beta-induced iNOS expression and NO release in these cells. It appears that the putative mechanism underlying the stimulatory effects of rottlerin on acetylation status of histone H4 are distinct from the HDAC inhibitory property of TSA, since rottlerin failed to inhibit HDAC activity in nuclear extracts isolated from INS cells. These data are suggestive of potential regulatory effects of rottlerin at the level of increasing the histone acetyltransferase activity in these cells. Together our studies present the first evidence to suggest a PKCdelta-mediated signalling step, which promotes hypoacetylation of candidate histones culminating in IL-1beta-induced metabolic dysfunction of the isolated beta cell.

Elements in the distal 5'-flanking sequence and the first intron function cooperatively to regulate glutamine synthetase transcription during adipocyte differentiation.

Glutamine synthetase (GS) expression increases dramatically during adipocyte differentiation of confluent 3T3-L1 cells. To identify differentiation-responsive cis-acting elements in the GS gene, several GSfusion genes were prepared and analyzed in stably transfected 3T3-L1 cells under conditions that trigger adipocyte differentiation. We find that the GS proximal 5'-flanking sequence lacks the regulatory elements required for differentiation-responsive expression. In contrast, a 2 kb intron 1 restriction fragment fused upstream of a heterologous promoter does drive reporter gene expression during hormone-triggered differentiation. The enhancer activity was localized to a 310 bp sequence near the middle of intron 1. Expression of fusion genes that include this 310 bp sequence does not temporally coincide with native gene expression. However, a composite gene that includes a far upstream GS sequence and the 2 kb intron 1 sequence yields a qualitatively different pattern of expression that closely resembles that of the native GS gene. The far upstream sequence alone exhibits no enhancer activity. Electrophoretic mobility shift analyses indicate that a 32 bp sequence within the 310 bp functional enhancer specifically binds differentiation-associated nuclear proteins. Although a C/EBP consensus sequence occurs in the 32 bp fragment, supershift analyses exclude C/EBP isoforms as the binding factor. In contrast, mutational analysis of the putative enhancer suggests that an HNF-3 isoform is involved. Thus our data indicate that elements in the distal 5'-flanking sequence and the first intron function cooperatively to regulate GS transcription and that HNF-3 may participate in that regulation.

An oligogene family encodes actins in the housefly, Musca domestica.

Southern hybridization analyses of genomic DNA and dot-blot reconstruction experiments indicated that 5-6 members comprise the actin gene family in the housefly, Musca domestica. Hybridization data failed to reveal conservation between housefly and fruitfly sequences flanking actin genes at their 3' ends, in marked contrast to the high degree of conservation observed in these regions of orthologous actin genes in vertebrates. Hybridization analysis of genomic DNA isolated from individual houseflies revealed polymorphism within actin-associated sequences. A representative genomic library was constructed in lambda EMBL3 and screened using a heterologous actin coding sequence probe. Of nearly 20 recombinants isolated, 6 represented overlapping clones and the remainder proved to be inviable.

The single burr hole technique for the evacuation of non-acute subdural hematomas.

A 4-year retrospective study was made of 111 consecutive surgically treated patients with chronic or subacute subdural hematomas. All underwent single burr hole evacuation with accompanying saline irrigation of the subdural space. Postoperative outcomes at 6 weeks were 90% excellent, 5.5% fair, and 4.5% poor. Postoperative re-evacuation was performed either by needle aspiration or reoperation via the burr hole on 12 patients; one required a craniectomy and neomembrane stripping. These results compare favorably with previous data and support the use of the single burr hole technique as a simple and effective treatment of subacute and chronic subdural hematomas. This addresses the decompression of the brain parenchyma, the removal of the residual semisolid subdural hematoma component, and the removal, dilution, and inactivation of endogenous fibrinolytic agents.

The treatment of hydrocephalus in preterm infants with intraventricular haemorrhage.

The hospital charts and clinical course of forty-one patients requiring one or more ventricular drainage procedures for hydrocephalic complications of neonatal intraventricular haemorrhage were evaluated retrospectively. All drainage procedures were performed on patients with intraventricular haemorrhage with ventricular dilatation (Grade III [25 patients]) and intraventricular and intraparenchymal haemorrhage (Grade IV [16 patients]) who were medical management failures. Twenty-six ventricular reservoirs (Rickham or McComb reservoirs) were placed in neonates weighing less than 1500 grams, allowing for a safe but intermittent ventricular access. Eighteen of these reservoirs were subsequently converted to ventriculoperitoneal shunts. Thirty-two percent of the patients incurred a shunt and/or reservoir infection and 59% required a shunt revision during the first year of life. There was no mortality related to the neurosurgical interventions. These results compare favorably with the published literature. No grade IV patients achieved a normal functional level, while 10 grade III patients did. The incidence of severe developmental delay (44% versus 28%) and death (38% versus 12%) was greater in the grade IV than the grade III patients. The placement of ventricular reservoirs is acceptable as an alternative to the early placement of ventriculo-peritoneal shunts. This approach may reduce the incidence of shunt infection as well as noninfectious shunt complications.

Slit ventricle syndrome in children: clinical presentation and treatment.

Symptomatic ventricular coaptation, or the slit ventricle syndrome, is frequently described and recognized as a clinical entity in the pediatric population. It is characterized by symptoms of shunt failure (i.e., ataxia, obtundation, nausea, vomiting, lethargy, irritability, and complaints of headache) and the CT findings of ventricular coaptation (slit-like ventricles). This study of twenty-two children with this syndrome reflects the variety of possible clinical presentations, and the variety of available treatment modalities. Multiple therapeutic approaches were required in seven of the patients. This illustrates not only an evolving treatment regimen, but also that a single treatment modality is not universally effective. Six patients needed only occasional symptomatic support. Blockage and/or removal of the shunt system was the definitive therapy in six patients, pressure augmentation in nine patients, and subtemporal craniectomy in one. This article outlines the theoretical pathophysiology, and a scheme for the management of patients with this syndrome.

Cervical laminectomy and dentate ligament section for cervical spondylotic myelopathy.

Seventy-five patients who underwent surgical treatment for cervical spondylotic myelopathy were evaluated with respect to the operative procedure performed and their outcome. Forty patients underwent a laminectomy plus dentate ligament section (DLS), 18 underwent laminectomy alone, and 17 underwent an anterior cervical decompression and fusion (ACDF). The patients were evaluated postoperatively for both stability and for neurologic outcome using a modification of the Japanese Orthopaedic Association Assessment Scale. Functional improvement occurred in all but one patient in the laminectomy plus DLS group. The average improvement was 3.1 +/- 1.5 points in this group; whereas the average improvement in the laminectomy and the ACDF groups was 2.7 +/- 2.0 and 3.0 +/- 2.0 points respectively. All of the patients who improved substantially (greater than or equal to 6 points) in the laminectomy plus DLS and the laminectomy alone groups had normal cervical spine contours (lordosis). The remainder had either a normal lordosis or no curve (no kyphosis or lordosis). All patients in the ACDF group had either a straight spine or a cervical kyphosis. These factors implicate spine curvature, in addition to choice of operation, as factors which are important in outcome determination. No problems with instability occurred in either the laminectomy or the laminectomy plus DLS group. Two patients incurred problems with stability in the ACDF group. Both required reoperation. In addition, four patients in this group who initially improved, subsequently deteriorated. Six patients in the laminectomy plus DLS group had a several day febrile episode related to an aseptic meningitis process. Laminectomy plus DLS is a safe and efficacious alternative to laminectomy for the treatment of cervical spondylotic myelopathy. The data presented here suggests that myelopathic patients with a cervical kyphosis are best treated with an ACDF and that patients with a normal cervical lordosis are best treated with a posterior approach. Although some selected patients may benefit from DLS, no criteria are available which differentiate this small subset of patients.

Civilian craniocerebral gunshot wounds.

Experience with 120 patients who incurred a gunshot wound to the head with dural penetration is presented. All of the patients were managed by a standard resuscitation protocol and assigned a clinical grade based on their level of consciousness both at the time of presentation and at 2 to 4 months after injury. Fifty patients (42%) underwent surgery. Twenty-eight patients (23%) had a good recovery, 19 (16%) were moderately disabled, 6 (5%) were severely disabled, and 67 (56%) died. All patients who were alert and awake with a normal or near normal neurological examination at the time of admission survived with a good outcome. All but 4 patients who were comatose at the time of admission died. Nine patients, however, who were not comatose at the time of admission died from potentially preventable causes. In 3 of these patients, a more aggressive diagnostic approach (including cerebral angiography) may have altered their ultimate outcome. An expeditious approach to the trauma victim with a comprehensive management scheme after injury may have altered the course in the remainder of these patients.

Evaluation of CSF shunt function: value of functional examination with contrast material.

Functional positive-contrast shuntography includes a patency check of both limbs of the shunt and the shunt valve by fluoroscopy following the injection of an iodinated contrast agent (anatomic shuntogram) and an assessment of the adequacy of ventricular fluid drainage under physiologic conditions by using serial CT scans to assess the rate of iodine dissipation from the ventricular system (physiologic shuntogram). To demonstrate its efficacy and utility, 82 functional shuntograms were obtained in 55 patients. Fifty-one of the 82 studies were abnormal. Of these, 22 demonstrated patency of both the proximal and distal limbs with an accompanying slow dissipation of contrast material after injection (21 of 22 patients were adults). Eighteen of these 22 patients improved following the reduction of shunt drainage pressure. In the case of frank shunt obstruction, the site of obstruction was delineated clearly in all 29 cases. Correlation of clinical outcome with test results confirmed the utility of this technique, especially when applied to the shunted adult hydrocephalic patient whose response to the shunt had been inadequate. The technique described here allows the clinician to differentiate between physiologic and anatomic shunt failure and between shunt failure and normal shunt function. It also allows for precise localization of the shunt obstruction in anatomic shunt failure and for demonstration of physiologic shunt failure when shunt patency is demonstrated in the presence of the slow dissipation of intraventricular contrast medium.

Neurologic manifestations of child abuse.

During a four-year period, we saw 23 cases of child abuse with central nervous system involvement. Of these, five died and four were left with a substantial neurologic deficit as a result of injury. Of the 18 survivors, eight (44%) were removed from their home along with their siblings, one was placed in a sheltered environment with its mother, and nine (50%) were kept under surveillance. Six of the 12 patients with CT evidence of intracranial damage had no or minimal evidence of external cranial trauma. Although shaking as the major etiologic factor in neurologic impairment from child abuse has recently been questioned, our results implicate it as a common mechanism of injury. Every patient had a parent or guardian whose account of the mechanism of injury either changed from moment to moment or was inconsistent with the child's injury. Nine patients (39%) were known to have been seen previously by other physicians because of similar problems or other injuries consistent with child abuse. Early recognition of child abuse is paramount to saving not only the life of the affected child, but possibly the lives of siblings. Neurosurgeons should maintain a high index of suspicion for the diagnosis of child abuse.

The apnea test for the determination of brain death.

By conventional criteria, an apneic patient's PaCO2 must be greater than 60 mm Hg before apnea can be attributed to brain death. The rate of a PaCO2 increase in the apneic patient traditionally has been thought to be in the range of 3 mm Hg/min. In order to assess the validity of these data and the validity of the "apnea test" for determination of brain death, the results of this test were reviewed in 20 patients. In all patients, arterial blood samples were drawn for blood gas measurements every 2 minutes following the cessation of volume ventilation (with an oxygen cannula at 6 liters O2/min passed into the tracheobronchial tree). The rate of PaCO2 increase was noted to be very erratic. The average rate of rise was 3.7 +/- 2.3 mm Hg/min (+/- standard deviation). This, however, varied from 0.5 to 10.5 mm Hg/min and was not predictable from the variables evaluated. The rate of PaCO2 increase was noted to decline throughout the duration of the test. This ranged from 3.9 +/- 1.2 mm Hg/min (for patients with baseline PaCO2 less than or equal to 30 mm Hg) and 4.5 +/- 1.9 mm Hg/min (for patients with baseline PaCO2 greater than or equal to 30 mm Hg) in the first 4 minutes of the test to an average of 0.92 mm Hg/min for patients with test lasted longer than 12 minutes. These unpredictable results might be related to CO2 washout, atelectasis, cardiac ventilations, or other yet-undefined parameters. The nonlinear relationship between rate of PaCO2 increase and time following onset of apnea resulted in the test being prolonged in several patients. In these patients, the PaCO2 approached 60 mm Hg in an asymptotic fashion. These lengthy tests could have been avoided by utilizing a standardized apnea test with a baseline PaCO2 of 40 mm Hg or greater. The observation that a high baseline PaCO2 greatly augments the efficiency and safety of the test allows criteria that have previously been based on conjecture to be documented and applied clinically. A standardized apnea test, utilizing these principles, may satisfy many of the criticisms regarding brain-death testing that have been raised by neurologists, neurosurgeons, and transplant surgeons.

Pulsatile dysesthesia and an axillary artery pseudoaneurysm associated with a penetrating axillary artery injury.

A patient is presented in whom an uncommon subjective complaint of pulsatile dysesthesia (periodic dysesthesias following a radicular pattern and occurring simultaneously with the transmitted pulse) occurred following a gunshot wound to the axilla. The patient's symptoms were relieved by the surgical obliteration of a pseudoaneurysm of the axillary artery.

A comparison of the Minerva and halo jackets for stabilization of the cervical spine.

The motion at each intervertebral level permitted by the halo jacket and the thermoplastic Minerva body jacket was compared in 10 ambulatory patients with an unstable cervical spine. The thermoplastic Minerva body jacket is a new lightweight modification of a Minerva jacket which is fabricated from Polyform (a splinting material made of a polyester polycaprolactone) and Polycushion (a closed-cell foam for padding). Each patient served as his/her own control. The average movement from flexion to extension at each intervertebral level was significantly less in the thermoplastic Minerva body jacket (2.3 degrees +/- 1.7 degrees) than in the halo jacket (3.7 degrees +/- 3.1 degrees) (p less than 0.0025). This difference is attributable to the "snaking phenomenon" encountered with halo jacket immobilization and should be taken into account when considering an external splint for an unstable cervical spine. The thermoplastic Minerva body jacket also offered a substantial improvement in comfort for the patient over that experienced in the halo jacket. The apparent advantage with respect to stability and comfort of the thermoplastic Minerva body jacket over the halo jacket suggests that the former device is the orthosis of choice for ambulatory stabilization of most patients with an unstable posttraumatic cervical spine injury.

Holocord astrocytoma: a two-staged operative approach.

Biopsy or subtotal resection followed by radiation for intramedullary astrocytomas of the spinal cord offer palliation but not cure. A treatment modality using an ultrasonic suction device has revolutionized the treatment of these tumors and has been extended to include the treatment of intramedullary tumors involving the entire length of the spinal cord (holocord tumors) with evident success. An alternative to this technique, a two-staged microsurgical approach, allows complete excision of the tumor and thus offers a chance for cure. Two patients have been treated in this manner, and more than 3 years after the operations, both patients were still improving neurologically without any evidence of tumor recurrence.

Management of a large skull defect utilizing a vascularized free omental transfer.

A patient who underwent prior cranial surgery and radiation therapy and had the loss of his bone and skin flaps is presented. Basal cell carcinoma of a skin graft, placed on the dura mater and osteomyelitis of the surrounding cranium subsequently occurred. This problem of infection, neoplasia, cerebral protection, coverage, and cosmesis was managed successfully with a complex repair. The repair utilized autogenous fascia lata for the replacement of dura mater, rib and iliac crest bone for an autogenous cranioplasty, a free vascularized omental transfer for soft tissue bulk overlying the cranioplasty, and an autogenous split thickness skin graft over the omentum for coverage. Subsequent partial resorption of the autogenous cranioplasty necessitated the placement of a methyl methacrylate cranioplasty.

Civilian gunshot wounds to the spinal cord and cauda equina.

We evaluated 42 patients with neurological deficits after civilian gunshot wounds to the spine. Thirty-five of these patients (the study population presented here) received their initial and follow-up care at Louisiana State University Medical Center in Shreveport over a 4-year period. Each patient had incurred a single gunshot wound to the spinal cord or cauda equina with an accompanying neurological deficit. The patient population was divided into three groups. Group 1 patients had incurred a complete motor and sensory loss below the injury (20 patients (57%]. Group 2 patients had incurred incomplete spinal cord injuries (9 patients (26%], whereas Group 3 patients had cauda equina injuries (6 patients (17%]. Myelography was performed for all Group 2 and 3 patients as well as Group 1 patients in whom the trajectory of the bullet did not explain a higher level of neurological injury (3 patients (15%]. A decompressive operation was performed in the patients whose myelography showed neural compression. Three patients in Group 1 (15%), 5 patients in Group 2 (56%), and 5 Group 3 patients (83%) underwent operation. All 3 Group 1 patients who underwent operation had some improvement of nerve root function postoperatively. All operated Group 2 and 3 patients had improvement of myelopathic or radicular function postoperatively. All began improving within several days of operation, implying a cause and effect relationship. None of the 17 nonoperated Group 1 patients improved neurologically, whereas 3 of the 4 nonoperated Group 2 patients improved. The single nonoperated Group 3 patient improved neurologically.(ABSTRACT TRUNCATED AT 250 WORDS)

Blastomycotic meningitis.

A difficult and tragic case of central nervous system blastomycosis is presented as the basis for a review of the diagnostic criteria required to establish this diagnosis and to present a scheme for the diagnosis and therapy of chronic meningitis. The diagnosis in our case was complicated by preexisting inadequately treated tuberculosis; a prepontine mass; and a cervical intradural, extramedullary, circumferential mass. This exceptional case of chronic basilar meningitis with cervical myelopathy was caused by Blastomyces dermatitidis.

Pulmonary fibrin microembolism with Echis carinatus venom in dogs: effects of a synthetic thrombin inhibitor.

We produced pulmonary fibrin microembolism using an infusion of a prothrombin activator (Echis carinatus venom, 30 min, 0.5 NIH thrombin equivalent units/kg) in open-chest mongrel dogs. To determine the nonclotting effects of this venom on edemagenesis we infused an irreversible thrombin inhibitor, D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone (PPACK, 57 nmol X kg-1 X min-1 for 120 min), alone (n = 5) or with venom (Echis + PPACK, n = 5). The control group (n = 5) was given 1 ml of 0.9% NaCl. A decline in left atrial pressure (means +/- SE, 5.3 +/- 0.4 to 4.0 +/- 0.5 mmHg, P less than 0.05) and cardiac index (149 +/- 10 to 82 +/- 13 ml X min-1 X kg-1, P less than 0.01) in association with a marked increase in pulmonary arterial pressure (14.5 +/- 0.6 to 26.6 +/- 2.5 mmHg, P less than 0.001) and pulmonary vascular resistance (64 +/- 5 to 304 +/- 42 mmHg X ml-1 X min-1 X kg-1, P less than 0.001) was observed after 20 min of venom infusion. During this interval, pulmonary artery wedge pressure increased (4 +/- 1 to 12 +/- 4 mmHg, P less than 0.01) in four of eight animals. Fibrinogen declined below measurable levels and fibrin microemboli were seen in many pulmonary arterioles. These changes were not observed in the Echis + PPACK, PPACK, or control groups. Leukopenia and thrombocytopenia were observed in the Echis and Echis + PPACK groups.(ABSTRACT TRUNCATED AT 250 WORDS)