The malate shuttle detoxifies ammonia in exhausted T cells by producing 2-ketoglutarate

The malate shuttle is traditionally understood to maintain NAD+/NADH balance between the cytosol and mitochondria. Whether the malate shuttle has additional functions is unclear. Here we show that chronic viral infections induce CD8+ T cell expression of GOT1, a central enzyme in the malate shuttle. Got1 deficiency decreased the NAD+/NADH ratio and limited antiviral CD8+ T cell responses to chronic infection; however, increasing the NAD+/NADH ratio did not restore T cell responses. Got1 deficiency reduced the production of the ammonia scavenger 2-ketoglutarate (2-KG) from glutaminolysis and led to a toxic accumulation of ammonia in CD8+ T cells. Supplementation with 2-KG assimilated and detoxified ammonia in Got1-deficient T cells and restored antiviral responses. These data indicate that the major function of the malate shuttle in CD8+ T cells is not to maintain the NAD+/NADH balance but rather to detoxify ammonia and enable sustainable ammonia-neutral glutamine catabolism in CD8+ T cells during chronic infection.

A novel autosomal recessive TERT T1129P mutation in a dyskeratosis congenita family leads to cellular senescence and loss of CD34+ hematopoietic stem cells not reversible by mTOR-inhibition

The TERT gene encodes for the reverse transcriptase activity of the telomerase complex and mutations in TERT can lead to dysfunctional telomerase activity resulting in diseases such as dyskeratosis congenita (DKC). Here, we describe a novel TERT mutation at position T1129P leading to DKC with progressive bone marrow (BM) failure in homozygous members of a consanguineous family. BM hematopoietic stem cells (HSCs) of an affected family member were 300-fold reduced associated with a significantly impaired colony forming capacity in vitro and impaired repopulation activity in mouse xenografts. Recent data in yeast suggested improved cellular checkpoint controls by mTOR inhibition preventing cells with short telomeres or DNA damage from dividing. To evaluate a potential therapeutic option for the patient, we treated her primary skin fibroblasts and BM HSCs with the mTOR inhibitor rapamycin. This led to prolonged survival and decreased levels of senescence in T1129P mutant fibroblasts. In contrast, the impaired HSC function could not be improved by mTOR inhibition, as colony forming capacity and multilineage engraftment potential in xenotransplanted mice remained severely impaired. Thus, rapamycin treatment did not rescue the compromised stem cell function of TERT^T1129P mutant patient HSCs and outlines limitations of a potential DKC therapy based on rapamycin.

Highly selective infusions of supradose Cisplatin for cranial base malignancies

Treatment results for malignant skull base lesions may be improved with combined modality therapy. Using a novel drug infusion technique that capitalizes on the pharmacodynamic cisplatin-neutralizing properties of thiosulfate, 14 patients (6 untreated, 8 recurrent) received cisplatin (120 to 200 mg/m(2) for 1 to 4 weeks x 2-4 cycles) as part of a multimodality treatment program. Histology included squamous cell carcinoma, 11 patients (8 upper aerodigestive tract, 3 cutaneous); sarcoma, 2 patients (malignant fibrous histiocytoma, synovial cell sarcoma); and salivary gland cancer, 1 patient. The lesions involved the lateral skull base (12 patients) and the anterior (2 patients).Dose intensities for cisplatin were between 33.3 and 200 mg/m(2)/wk. Major responses occurred in 9/14 patients (64.3%), 3 of whom had complete responses. Drug toxicity, occurring in 11 patients, was mild and there were no significant complications as a result of the infusions. Eleven patients subsequently underwent surgical resections. The mean survival time is 23.3 months. Eight patients are alive without disease, 2 alive with disease, and 4 are dead of disease.The effectiveness of this highly selective supradose cisplatin infusion technique and its low morbidity support continued investigations of its application to patients with cranial base malignancies.

[Carney complex. Clinical, pathological and genetic features in two generations of a family]

Clinical symptoms of Carney complex occurred in two female members of one family (mother and daughter). In addition to the clinical symptoms, we describe the pathological findings in the adrenals (pigmented nodular hyperplasia of the adrenal cortex), heart (myxoma) and skin/soft tissues (superficial angiomyxomas). Genetic investigation revealed a mutation on the long arm of chromosome 17 in both patients; this mutation had previously been described only in Carney complex type 1. Unilateral adrenalectomy was performed in both these cases, 13 years ago and 7 months ago, respectively. Lifelong cardiac surveillance is mandatory to prevent death from embolism or arrhythmia.

Program requirements for residency/fellowship education in neuroendovascular surgery/interventional neuroradiology: a special report on graduate medical education

BACKGROUND AND PURPOSE

Neuroendovascular surgery/interventional neuroradiology is a relatively new subspecialty that has been evolving since the mid-1970s. During the past 2 decades, significant advances have been made in this field of minimally invasive therapy for the treatment of intracranial cerebral aneurysms; acute stroke therapy intervention; cerebral arteriovenous malformations; carotid cavernous sinus fistulas; head, neck, and spinal cord vascular lesions; and other complex cerebrovascular diseases. Advanced postresidency fellowship programs have now been established in North America, Europe, and Japan, specifically for training in this new subspecialty.

METHODS

From 1986 to the present, an ad hoc committee of senior executive committee members from the American Society of Interventional and Therapeutic Neuroradiology, the Joint Section of Cerebrovascular Neurosurgery, and the American Society of Neuroradiology met to establish, by consensus, general guidelines for training physicians in this field.

RESULTS

In April 1999, the Executive Committee of the Joint Section of Cerebrovascular Neurosurgery voted unanimously to endorse these training standard guidelines. In May 1999, the Executive Committee of the American Society of Interventional and Therapeutic Neuroradiology and the American Society of Neuroradiology also unanimously voted to endorse these guidelines. In June 1999, the Executive Council of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons unanimously voted to endorse these guidelines.

CONCLUSION

The following guidelines for residency/fellowship education have now been endorsed by the parent organization of both the interventional and diagnostic neuroradiology community, as well as both senior organizations representing neurosurgery in North America. These guidelines for training should be used as a reference and guide to any institution establishing a training program in neuroendovascular surgery/interventional neuroradiology.

Transcatheter snare removal of acute middle cerebral artery thromboembolism: technical case report

OBJECTIVE AND IMPORTANCE

We describe the case of a patient in whom a snare designed for the removal of foreign bodies was successfully used to retrieve a thromboembolism from the middle cerebral artery. This technique can be used to reestablish blood flow when maximal pharmacological therapies have failed.

CLINICAL PRESENTATION

A 38-year-old man with scrotal squamous cell carcinoma presented with the abrupt onset of left hemiparesis and numbness. Computed tomography of the head showed no hemorrhage or hypodensity, and right middle cerebral artery thrombosis was suspected.

INTERVENTION

Cerebral angiography demonstrated a near-total occlusion of the right middle cerebral artery at the M1-M2 junction. The administration of intra-arterial urokinase, systemic heparin, and systemic abciximab, and mechanical maceration failed to lyse the clot. A 4-mm goose-neck snare was guided through a microcatheter, and the clot was snared and withdrawn. Immediate postoperative angiography demonstrated the reconstitution of normal flow. Pathological examination of the snared material was consistent with clot. By postoperative Day 5, the patient had regained full strength, except for the fingers of the left hand, which remained moderately weak. Computed tomography demonstrated a right insular and extreme capsular infarct.

CONCLUSION

To our knowledge, this is the first reported use of a snare to remove clot in the setting of thromboembolic stroke. As the use of intra-arterial thrombolysis increases, transcatheter snare removal of pharmacologically resistant clot may be considered as a salvage strategy.

Phase I trial of retinoic acid and cis-platinum for advanced squamous cell cancer of the head and neck based on experimental evidence of drug synergism

OBJECTIVE

Cis-platinum and 13-cis-retinoic acid have received much attention in the treatment of head and neck squamous cell cancer. Even though they have different mechanisms of action, little information is available on their interaction. This paper reviews experimental evidence for retinoic acid-cis-platinum synergy and presents toxicity data from patients with stage IV head and neck squamous cell cancer participating in a phase I trial combining 13-cis-retinoic acid and cis-platinum.

METHODS

Patients were given 13-cis-retinoic acid orally daily for 7 days before and daily during high-dose (150 mg/m2 per week for 4 weeks) intraarterial cis-platinum treatment with concurrent radiation. Toxicity was scored with use of the cancer and leukemia group B scale.

RESULTS

In the phase I clinical trial, 15 patients were treated to determine a maximum tolerated dosage for 13-cis-retinoic acid of 20 mg/day. Grade 4 hematologic toxicity was dose limiting in 3 of 8 patients treated with 40 mg/day and in 1 patient treated with 60 mg/day. There were no deaths caused by toxicity; 12 of the 15 patients received all four weekly doses and the remaining 3 received three doses. Of 10 patients with fully evaluable data, all achieved a complete response at the primary site and 9 had a complete response in the neck. One patient had persistent neck disease after chemoradiation, and this tumor was removed with neck dissection.

CONCLUSIONS

13-Cis-retinoic acid and cis-platinum are strongly synergistic against head and neck squamous cell cancer in vitro. Pretreatment with retinoic acid results in stronger synergy than concurrent drug exposure alone. Preliminary clinical experience with combined retinoic acid and cis-platinum in a design that parallels the in vitro study indicates that toxicity is acceptable with 13-cis-retinoic acid dosages of 20 mg/day in a high-dose-intensity intraarterial chemoradiation regimen.

A novel organ preservation protocol for advanced carcinoma of the larynx and pharynx

OBJECTIVE

To pilot a targeted chemoradiation protocol for patients with advanced carcinoma of the larynx and pharynx that would circumvent upper aerodigestive tract dysfunction related to major oncologic surgery.

DESIGN

Weekly intra-arterial infusions of supradose cisplatin (150 mg/m2 per week x 4) rapidly delivered to the tumor bulk, simultaneous intravenous sodium thiosulfate for systemic drug neutralization, and conventional external-beam irradiation (1.80-2.00 Gy per fraction x 35) were used. Between February 1991 and April 1994, 42 patients were treated who would otherwise have required a major resection of the tongue base, pharyngeal wall, or larynx.

MAIN OUTCOME MEASURES

Tumor response, toxic effects, disease control above the clavicle, preservation of the larynx, maintenance of oral nutrition, and overall and disease-related 2-year survival.

RESULTS

Three complications were related to the weekly transfemoral superselective intra-arterial procedures performed 160 times. Grade 3 to 4 chemotoxic effects were infrequent, occurring in 9 (5.5%) of 160 cycles, and only 1 patient required a radiotherapy break because of severe mucositis. A complete response in the primary site was obtained in 36 (86%) of 42 patients, 2 of whom had residual disease in the neck. Median follow-up was 13 months (range, 3-46 months). To date, there have been 5 recurrences: 2 regional and 3 distant. The 2-year overall and disease-related survival was 64% and 76%, respectively. The rate of disease control above the clavicle at 2 years was 86%.

CONCLUSIONS

We believe this chemoradiation protocol represents an effective management scheme for patients with advanced head and neck cancer while minimizing dysfunction and possibly improving survival.

Case-finding instruments for depression in primary care settings

OBJECTIVE

To evaluate the usefulness of case-finding instruments for identifying patients with major depression in primary care settings.

DATA SOURCES

A MEDLINE search of the English-language medical literature; bibliographies of selected papers; and experts.

STUDY SELECTION

Studies that were done in primary care settings with unselected patients and that compared case-finding instruments with accepted diagnostic criterion standards for major depression were selected.

DATA SYNTHESIS

9 case-finding instruments were assessed in 18 studies. More than 15,000 patients received screening with a case-finding instrument; approximately 5300 of these received criterion standard assessment. Case-finding instruments ranged in length from 2 to 28 questions. Average administration times ranged from less than 2 minutes to 6 minutes. Sensitivities and specificities for detecting major depression ranged from 67% to 99% and from 40% to 95%, respectively. No significant differences between instruments were found. Overall sensitivity was 84% (95% CI, 79% to 89%); overall specificity was 72% (CI, 67% to 77%). If a case-finding instrument were administered to 100 primary care patients with a 5% prevalence of major depression, the clinician could expect that 31 patients would screen positive, that 4 of the 31 would have major depression, and that 1 patient with major depression would not be identified.

CONCLUSIONS

Several instruments with reasonable operating characteristics are available to help primary care clinicians identify patients with major depression. Because the operating characteristics of these instruments are similar, selection of a particular instrument should depend on issues such as feasibility, administration and scoring times, and the instruments' ability to serve additional purposes, such as monitoring severity or response to therapy.

A targeted supradose cisplatin chemoradiation protocol for advanced head and neck cancer

BACKGROUND

Hypothesizing that cisplatin (DDP) drug resistance is dose dependent and the radiosensitizing effect of DDP is clinically beneficial, we conducted a chemoradiation protocol using extremely high doses of DDP delivered intra-arterially (IA) to locally advanced head and neck tumors.

PATIENTS AND METHODS

Twenty-nine patients with untreated stage IV disease received 4 weekly infusions of 150 mg/m2, simultaneous systemic DDP neutralization with intravenous (IV) bolus sodium thiosulfate, and concomitant radiotherapy (180 to 200 cGy/day x 35 fractions).

RESULTS

The complete response rate of the 24 evaluable patients as determined with repeat biopsies was 23/24 (96%). Of the 29 patients evaluable for toxicity, central nervous system complications related to the infusion technique occurred with 2/110 infusions, both of which were reversible. The rate of grade III to IV chemotoxicity was 13%. The median length of follow-up was 22 months. There have been 6 recurrences: 1 local; 3 regional; and 2 at distant sites. The projected overall and disease-free 3-year survival was 88% and 53%, respectively.

CONCLUSION

We conclude that the combination of rapid selective delivery of supradose DDP/IV thiosulfate neutralization and concomitant radiotherapy can be safely and effectively applied to patients with advanced head and neck cancer. Preliminary survival analysis indicates that this approach may improve the prognosis for patients with an otherwise devastating disease.

Phase I study of highly selective supradose cisplatin infusions for advanced head and neck cancer

PURPOSE

To determine the maximum dose-intensity of cisplatin (DDP) that could be administered by selective intraarterial (IA) infusion in combination with systemic sodium thiosulfate neutralization to patients with head and neck carcinoma.

PATIENTS AND METHODS

Forty-two patients (23 untreated stage III/IV, 19 recurrent) received highly selective IA DDP, rapidly delivered through microcatheters placed angiographically, to a maximum dose-intensity of 200 mg/m2/wk. Concurrently, the systemic effects of DDP were neutralized by intravenous (IV) bolus sodium thiosulfate.

RESULTS

Problems related to the infusion technique occurred in eight of 140 courses, all of which were inconsequential. The rates of reversible grade I/II and grade III/IV toxicity were 14.8% and 1.1%, respectively. Dose-limiting toxicity, which consisted of severe electrolyte loss, occurred at a dose of 200 mg/m2/wk. The maximum-tolerated dose of DDP was 150 mg/m2 administered weekly for four doses. The overall and complete response rates in 38 assessable patients were 19 of 22 (86%) and nine of 22 (41%) for stage III/IV untreated tumors and 10 of 16 (62%) and four of 16 (25%) for patients with recurrent disease, respectively.

CONCLUSION

This pharmacologic strategy permits the selective and rapid delivery of extremely high doses of DDP to head and neck carcinomas with minimal procedural complications, low systemic toxicity, and high tumor response rates.

Rapid superselective high-dose cisplatin infusion for advanced head and neck malignancies

Advances in vascular radiology techniques for superselective arterial infusions and methods to overcome systemic toxicity from high-dose cisplatin chemotherapy encouraged us to reevaluate the effects of rapid regional cisplatin infusion for patients with head and neck malignancies. Twenty patients (17 carcinomas, three sarcomas) received high-dose cisplatin (100-200 mg/m2) by this method. Fifteen of the 17 patients with upper aerodigestive tract carcinoma are part of an ongoing phase I dose escalation of cisplatin with sodium thiosulfate neutralization. Three additional patients with sarcomas were treated with intra-arterial (IA) cisplatin and systemic Adriamycin. Fifty-three IA infusions were performed without any complications. Only minimal toxicity related to the chemotherapy was observed. The overall response rate for previously untreated patients was nine of 10 (90%) [complete response (CR) 67%; partial response (PR) 33%]. The response rate for patients with recurrent disease was five of eight (63%) (CR 20%, PR 80%). The average length of follow-up is 9.5 months and the actuarial survival rate is 56%. Superselective rapid infusion of high-dose cisplatin for patients with advanced head and neck malignancies is feasible, relatively nontoxic, and may have important applications in multimodality therapy, particularly for patients with bulky primary disease.

Comparison of high resolution real time ultrasonography and high resolution computed tomography in an infant with spinal dysraphism

An infant with a lumbosacral spinal subcutaneous and intraspinal lipoma involving the conus medullaris was studied with computed tomography and high resolution real time ultrasonography to determine the extent and location of the disease before operation. The high resolution ultrasonogram demonstrated the abnormality with good detail and the added advantage of real time display of the lack of pulsatile mobility of the neural elements, confirming spinal cord tethering. Spinal high resolution ultrasonography is a noninvasive diagnostic tool in infants with spinal abnormalities and should be an important part of a neurosurgeon's diagnostic support system.

Ventricular obstruction secondary to vascular malformations

Enlarged veins in two vascular malformations blocked the cerebrospinal fluid outflow pathways, causing hydrocephalus. Both patients presented not with the usual clinical picture (hemorrhage, seizure, etc.), but with signs of increased intracranial pressure. Computed tomography and angiography were necessary to understand the pathophysiology. An arteriovenous malformation was responsible for the first patient's headache, and a venous varix was the causative lesion in the second patient. Hydrocephalus caused by a venous varix has not been reported before.

External carotid-cavernous fistula in an infant

A 7-week-old infant developed a nontraumatic fistula of the external carotid artery and the cavernous sinus. Therapeutic embolization produced an uncomplicated clinical and angiographic cure. Treatment was prompted by the availability of new methods of treatment and our hope of preventing irreversible anatomic and visual sequelae.

External carotid-cavernous fistula in infancy: case report and review of the literature

A case of external carotid-cavernous fistula in a 7-week-old infant is presented. Unlike post-traumatic internal carotid-cavernous fistulas, most of these dural fistulas are low flow, low pressure shunts with a benign and chronic clinical course sometimes ending in spontaneous closure. In adults and older children, meticulous follow-up of visual symptoms and signs may be adequate management. The only indications for aggressive therapy is progressive visual failure, which occurs rarely. In infants and visually immature children, however, persistent proptosis and intraocular hypertension can lead to anisometropic amblyopia, the prevention of which deserves urgent therapeutic intervention. In our patient, therapeutic embolization led to an uncomplicated clinical and angiographic cure. The vascular anatomy, the pathophysiology of associated visual failure, and the treatment modalities are reviewed.

Spinal cord compression by extramedullary hematopoiesis in agnogenic myeloid metaplasia

Extramedullary hematopoiesis presented as a diffuse mass causing almost complete obliteration of the spinal subarachnoid space in a patient with known agnogenic myeloid metaplasia. Pre- and post-radiation therapy films correlate well with significant clinical improvement in his neurological status.

Asymptomatic angiographic occlusion of the internal carotid artery: an indication for emergency endarterectomy

A 56-year-old man had retinal artery embolization from a carotid artery atheroma. Complete occlusion of the internal carotid artery occurred during cerebral angiography, but the patient developed no acute symptoms of cerebral ischemia. The patient immediately underwent emergency carotid endarterectomy which he tolerated well, and follow-up angiography nine days later demonstrated continued patency. The patient has remained neurologically unchanged.

Trigeminal artery and microemboli to the brain stem. Report of two cases

The authors report two cases of transient ischemic attacks (TIA's) involving the brain stem. The TIA's were due to microemboli that originated from a carotid bifurcation atherosclerotic plaque and travelled through a persistent trigeminal artery.

Balloon catheter with a calibrated leak. A new system for superselective angiography and occlusive catheter therapy

Problems with the use of the diagnostic angiography catheter as a therapeutic tool relate to difficulty in placing the catheter precisely in the desired area and controlling the infusion of the occluding agent. The author describes a soft microcatheter which has been developed to overcome these problems. The catheter ends in a balloon tip and thus can be flow-directed. To overcome the traditional difficulties of flow-guided catheters and the need for a double lumen, a calibrated leak in the balloon allows distal fluid delivery while the balloon remains inflated.

Pediatric pneumoencephalography with nitrous oxide

The recent advances in neurodiagnostic procedures have changed pneumoencephalography. Now we must find the smallest lesions and demonstrate accurately their relationships to the ventricular system cisterns and surrounding structures. Complex blurring motion tomography gives this detail, but the pediatric patients are difficult to examine and immobilization during the long exposure needed for tomography frequently compromises the airway. Hypoventilation from sedation and from the radiographic positioning may lead to increased intracranial pressure. By performing pediatric pneumoencephalography under general anesthesia, with nitrous oxide as both an anesthetic agent and as the contrast material, we are able to control patient motion, preserve the child's airway, and prevent hypoventilation. The nitrous oxide, rapidly diffusible, is a good contrast agent, as large volumes can be used and the gas leaves the ventricular system quickly after the discontinuation of the anesthetic. This rapid reabsorption and elimination of the subarachnoid gas may decrease pneumoencephalographic morbidity.

Selective cerebral angiography through the axillary artery

The femoral artery approach to cerebral angiography has become well accepted. Some patients, however, are not candidates for femoral catheterization because of severe arteriosclerosis. One hundred cerebral angiograms were performed in 88 severely arteriosclerotic patients, using No. 5 French polyethylene catheters and the axillary approach. The technique, degree of success, patient population, and their complications are described. This approach allows selective vertebral and internal carotid artery injections. Only one serious complication occurred, thrombosis of the axillary artery. Because of the time saved, this technique is often preferable to the femoral approach in severely arteriosclerotic patients.

Presurgical embolization of neurogenic hamartoma in an infant. A case report

The vessels supplying a rare congenital tumor (neurogenic hamartoma) were deliberately occluded by emboli. This extensive tumor presented both in the oropharynx and in the left middle cranial fossa. Using a 3.7 French catheter, Gelfoam emboli suspended in contrast medium were injected into the vessels of the tumor under fluoroscopic visualization. The once vacular tumor was then removed in two stages with little blood loss.

Selective carotid angiography in the diagnosis of fibrous histiocytoma. A case report

Selective carotid angiography is of value in the diagnosis of an orbital fibrous histiocytoma, an uncommon tumor with a high local recurrence rate and frequent distant metastases. The angiogram shows the physical extent of the tumor and also suggests its general microscopic anatomy. Comparison is made with similar angiographic presentations seen in cerebellar hemangioblastomas, glomus tumors, meningiomas, and hemangiopericytomas.

Experimental arteriovenous fistula. Creation and percutaneous catherter obstruction with cyanoacrylate

Arteriovenous fistula models were created of plastic and in dogs, allowing exploration of the intraarterial use of tissue adhesive, isobutyl cyanoacrylate. A delivery system utilizing superselective coaxial catheterization was developed on the model. Carotid artery to external jugular vein shunts constructed in 19 dogs provided a suitable in vivo model. Using varied injection techniques, the shunts were occluded in 17 of 17 treated animals. Three dogs subsequently died because of embolization to the lungs and one carotid artery was occluded. Techniques to avoid these complications were devised. Refinement of the intraarterial use of these adhesives will offer us another mode of treatment of vascular abnormalities.

Total brain opacification in children during angiography

Total brain opacification is an angiographic method of neuroradiological examination in children which will often make examination with air unnecessary. The substance of the brain becomes temporarily opaque while the ventricles and avascular masses are radiolucent. The examinations in 6 children are presented to illustrate the method and to emphasize its value.