Lowering PCO2 With Noninvasive Ventilation Is Associated With Improved Survival in Chronic Hypercapnic Respiratory Failure

BACKGROUND

Chronic hypercapnic respiratory failure is associated with high mortality. Although previous work has demonstrated a mortality improvement with high-intensity noninvasive ventilation in COPD, it is unclear whether a PCO2 reduction strategy is associated with improved outcomes in other populations of chronic hypercapnia.

METHODS

The objective of this study was to investigate the association between PCO2 reduction (by using transcutaneous PCO2 as an estimate for PaCO2 and survival in a broad population of individuals treated with noninvasive ventilation for chronic hypercapnia. We hypothesized that reductions in PCO2 would be associated with improved survival. Therefore, we performed a cohort study of all the subjects evaluated from February 2012 to January 2021 for noninvasive ventilation initiation and/or optimization due to chronic hypercapnia at a home ventilation clinic in an academic center. We used multivariable Cox proportional hazard models with time-varying coefficients and PCO2 as a time-varying covariate to test the association between PCO2 and all-cause mortality and when adjusting for known cofounders.

RESULTS

The mean ± SD age of 337 subjects was 57 ± 16 years, 37% women, and 85% white. In a univariate analysis, survival probability increased with reductions in PCO2 to < 50 mm Hg after 90 d, and these remained significant after adjusting for age, sex, race, body mass index, diagnosis, Charlson comorbidity index, and baseline PCO2 . In the multivariable analysis, the subjects who had a PaCO2 < 50 mm Hg had a reduced mortality risk of 94% between 90 and 179 d (hazard ratio [HR] 0.06, 95% CI 0.01-0.50), 69% between 180 and 364 d (HR 0.31, 95% CI 0.12-0.79), and 73% for 365-730 d (HR 0.27, 95% CI 0.13-0.56).

CONCLUSIONS

Reduction in PCO2 from baseline for subjects with chronic hypercapnia treated with noninvasive ventilation was associated with improved survival. Management strategies should target the greatest attainable reductions in PCO2 .

Recombinase polymerase amplification for fast, selective, DNA-based detection of faecal indicator Escherichia coli

The bacterium Escherichia coli is commonly associated with the presence of faecal contamination in environmental samples, and is therefore subject to statutory surveillance. This is normally done using a culture-based methodology, which can be slow and laborious. Nucleic acid amplification for the detection of E. coli DNA sequences is a significantly more rapid approach, suited for applications in the field such as a point of sample analysis, and to provide an early warning of contamination. An existing, high integrity qPCR method to detect the E. coli ybbW gene, which requires almost an hour to detect low quantities of the target, was compared with a novel, isothermal RPA method, targeting the same sequence but achieving the result within a few minutes. The RPA technique demonstrated equivalent inclusivity and selectivity, and was able to detect DNA extracted from 100% of 99 E. coli strains, and exclude 100% of 30 non-target bacterial species. The limit of detection of the RPA assay was at least 100 target sequence copies. The high speed and simple, isothermal amplification chemistry may indicate that RPA is a more suitable methodology for on-site E. coli monitoring than an existing qPCR technique.

Comparison of MRI, MRA, and DSA for Detection of Cerebral Arteriovenous Malformations in Hereditary Hemorrhagic Telangiectasia

BACKGROUND AND PURPOSE

Patients with hereditary hemorrhagic telangiectasia (HHT) have a high prevalence of brain vascular malformations, putting them at risk for brain hemorrhage and other complications. Our aim was to evaluate the relative utility of MR imaging and MRA compared with DSA in detecting cerebral AVMs in the HHT population.

MATERIALS AND METHODS

Of 343 consecutive patients evaluated at the University of California, San Francisco HTT Center of Excellence, 63 met the study inclusion criteria: definite or probable hereditary hemorrhagic telangiectasia defined by meeting at least 2 Curacao criteria or positive genetic testing, as well as having at least 1 brain MR imaging and 1 DSA. MRIs were retrospectively reviewed, and the number of AVMs identified was compared with the number of AVMs identified on DSA.

RESULTS

Of 63 patients, 45 (71%) had AVMs on DSA with a total of 92 AVMs identified. Of those, 24 (26%) were seen only on DSA; 68 (74%), on both DSA and MR imaging; and 5 additional lesions were seen only on MR imaging. Of the 92 lesions confirmed on DSA, 49 (53.3%) were seen on the 3D-T1 postgadolinium sequence, 52 (56.5%) were seen on the 2D-T1 postgadolinium sequence, 35 (38.0%) were seen on the SWI sequence, 24 (26.1%) were seen on T2 sequence, and 25 (27.2%) were seen on MRA. The sensitivity and specificity of MR imaging as a whole in detecting AVMs then confirmed on DSA were 80.0% and 94.4%, respectively, and the positive and negative predictive values were 97.3% and 65.4%, respectively.

CONCLUSIONS

This study reinforces the use of MR imaging as a primary screening tool for cerebral AVMs in patients with hereditary hemorrhagic telangiectasia and suggests that 3D-T1 postgadolinium and 2D-T1 postgadolinium performed at 3T are the highest yield sequences.

Patients with retinoblastoma and chromosome 13q deletions have increased chemotherapy-related toxicities

BACKGROUND

A total of 5-10% of patients with retinoblastoma (RB) harbor deletion of the long arm (q) chromosome 13 (13q-). The treatment-related toxicities in this population have not been described.

METHODS

Sixty-eight RB patients on a single institutional protocol (RET5) from 2005 to 2010 were reviewed. Genetic screening identified 11 patients (seven female) with 13q-. Patients with early (Reese-Ellsworth [R-E] group I-III) disease (6/23 with 13q-) received eight courses of vincristine/carboplatin (VC). Patients with advanced (R-E group IV-V) bilateral disease (2/27 with 13q-) received two courses of vincristine/topotecan (VT) followed by nine courses of alternating VT/VC. Patients undergoing upfront enucleation received histopathology-based chemotherapy: intermediate risk (2/8 with 13q-) or high risk (1/10 with 13q-). Dose reductions were mandated for >7 day delay in two consecutive courses following hematologic toxicity. Grades 3 and 4 hematologic, infectious, and gastrointestinal toxicities were compared between RET5 patients with and without 13q-.

RESULTS

Demographics were similar between groups. When present, prolonged neutropenia (median 7 days, range 0-14 days) delayed chemotherapy and resulted in more frequent dose reductions among 13q- patients (5/11) than non-13q- patients (4/57) (P < 0.01). GI toxicity was similar between groups (5/11 13q- vs. 13/57 non-13q-; P = 0.14), but halted chemotherapy in one 13q- patient. Infectious complications and disease outcomes were similar between groups. At follow-up, all patients are alive (median 6.1 years, range 7.6 months-9.5 years).

CONCLUSIONS

13q- RB patients had a higher incidence of neutropenia requiring chemotherapy dose reductions, but did not have increased treatment failure.

Endovascular catheter for magnetic navigation under MR imaging guidance: evaluation of safety in vivo at 1.5T

BACKGROUND AND PURPOSE

Endovascular navigation under MR imaging guidance can be facilitated by a catheter with steerable microcoils on the tip. Not only do microcoils create visible artifacts allowing catheter tracking, but also they create a small magnetic moment permitting remote-controlled catheter tip deflection. A side product of catheter tip electrical currents, however, is the heat that might damage blood vessels. We sought to determine the upper boundary of electrical currents safely usable at 1.5T in a coil-tipped microcatheter system.

MATERIALS AND METHODS

Alumina tubes with solenoid copper coils were attached to neurovascular microcatheters with heat shrink-wrap. Catheters were tested in carotid arteries of 8 pigs. The catheters were advanced under x-ray fluoroscopy and MR imaging. Currents from 0 mA to 700 mA were applied to test heating and potential vascular damage. Postmortem histologic analysis was the primary endpoint.

RESULTS

Several heat-mitigation strategies demonstrated negligible vascular damage compared with control arteries. Coil currents ≤300 mA resulted in no damage (0/58 samples) compared with 9 (25%) of 36 samples for > 300-mA activations (P = .0001). Tip coil activation ≤1 minute and a proximal carotid guide catheter saline drip > 2 mL/minute also had a nonsignificantly lower likelihood of vascular damage. For catheter tip coil activations ≤300 mA for ≤1 minute in normal carotid flow, 0 of 43 samples had tissue damage.

CONCLUSIONS

Activations of copper coils at the tip of microcatheters at low currents in 1.5T MR scanners can be achieved without significant damage to blood vessel walls in a controlled experimental setting. Further optimization of catheter design and procedure protocols is necessary for safe remote control magnetic catheter guidance.

Delayed transcutaneous extrusion of embolic coils after embolization of facial artery pseudoaneurysm

External carotid artery (ECA) pseudoaneurysm is a known complication of treatment for head and neck cancer. We report a case of facial artery pseudoaneurysm arising after irradiation and salvage surgery for advanced tonsillar cancer, that was treated with endovascular embolization. The case was complicated by delayed transcutaneous extrusion of embolization coils through the skin of the anterior neck. We review the literature for related cases of coil extrusion in the head and neck, and discuss the implications for pseudoaneurysm surveillance.

Retinoblastoma: one world, one vision

Retinoblastoma is curable when diagnosed early and treated appropriately; however, the prognosis is dismal when the basic elements of diagnosis and treatment are lacking. In developing countries, poor education, lower socioeconomic conditions, and inefficient health care systems result in delayed diagnosis and suboptimal care. Furthermore, the complexity of multidisciplinary care required is seldom possible. Whereas ocular salvage is a priority in the Western world, death from retinoblastoma is still a major problem in developing countries. To bring the 2 ends of this spectrum together and provide a forum for discussion, the "One World, One Vision" symposium was organized, at which clinicians and researchers from various cultural, geographic, and socioeconomic backgrounds converged to discuss their experiences. Strategies for early diagnosis in developing countries were discussed. Elements of the development of retinoblastoma centers in developing countries were discussed, and examples of successful programs were highlighted. An important component in this process is twinning between centers in developing countries and mentor institutions in high-income countries. Global initiatives by nongovernmental organizations such as the International Network for Cancer Treatment and Research, Orbis International, and the International Agency for Prevention of Blindness were presented. Treatment of retinoblastoma in developing countries remains a challenge; however, it is possible to coordinate efforts at multiple levels, including public administrations and nonprofit organizations, to improve the diagnosis and treatment of retinoblastoma and to improve the outcome for these children.

Secondary acute myelogenous leukemia in patients with retinoblastoma: is chemotherapy a factor?

PURPOSE

To describe a series of patients with secondary acute myelogenous leukemia (sAML) and retinoblastoma (RB).

DESIGN

Retrospective observational cases series.

PARTICIPANTS

Ocular and pediatric oncologists at referral centers in Europe and the Americas and the RB databases at the National Institutes of Health and the Ophthalmic Oncology Service at Memorial Sloan-Kettering Cancer Center.

METHODS

Physician survey, retrospective database review, and literature search.

MAIN OUTCOME MEASURES

History of RB and development of sAML, management of RB (surgery, radiotherapy, chemotherapy), age at diagnosis of RB and leukemia, French-American-British (FAB) subtype, and current status of patient (alive or dead).

RESULTS

Fifteen patients with sAML were identified; 13 occurred in childhood. Mean latent period from RB to AML diagnosis was 9.8 years (median, 42 months). Nine cases were of the M2 or M5 FAB subtypes. Twelve patients (79 %) had received chemotherapy with a topoisomerase II inhibitor, 8 (43%) had received chemotherapy with an epipodophyllotoxin. Ten children died of their leukemia.

CONCLUSIONS

Acute myelogenous leukemia is a rare secondary malignancy among retinoblastoma patients, many of whom were treated with primary or adjuvant chemotherapy. Additional studies are needed to assess potential risk factors contributing to sAML development in this cohort.

The spectrum of orbital Rosai-Dorfman disease

PURPOSE

To describe the spectrum and treatment of orbital Rosai-Dorfman disease and to review previously documented cases.

METHODS

Retrospective, interventional case series of seven patients and literature review.

RESULTS

Each patient with Rosai-Dorfman disease had unique disease expression requiring aggressive therapy, such as chemotherapy, radiation, and/or surgical excision. One systemically aggressive case presented with intraocular and choroidal invasion, a previously unreported finding. Response to therapy was variable and unpredictable.

CONCLUSIONS

Rosai-Dorfman disease, although historically described as benign and self-limiting, may cause significant morbidity and mortality involving multiple organ systems. Available treatment options may not control the disease. Further research and long-term clinical correlation is necessary.

Antilisterial activity of grape juice and grape extracts derived from Vitis vinifera variety Ribier

Grape juice and skin and seed extracts of Vitis vinifera var. Ribier black table grapes were found to be highly inhibitory towards Listeria monocytogenes. This grape juice was also active against all other Listeria species tested but not against Bacillus cereus, Salmonella Menston, Escherichia coli, Staphylococcus aureus or Yersinia enterocolitica. Fractionation of the extracts showed that the antilisterial activity was strongest in the polymeric phenolic fractions. Two different types of active compounds were identified: the red-pigmented polymeric phenolics from juice and skin showed pH-dependent antilisterial activity, while the unpigmented polymeric phenolics from the seed showed antilisterial activity which was independent of pH.

Incidence of important hemobilia following transhepatic biliary drainage: left-sided versus right-sided approaches

Our purpose here is to describe our experience with important hemobilia following PTBD and to determine whether left-sided percutaneous transhepatic biliary drainage (PTBD) is associated with an increased incidence of important hemobilia compared to right-sided drainages. We reviewed 346 transhepatic biliary drainages over a four-year period and identified eight patients (2.3%) with important hemobilia requiring transcatheter embolization. The charts and radiographic files of these patients were reviewed. The side of the PTBD (left versus right), and the order of the biliary ductal branch entered (first, second, or third) were recorded. Of the 346 PTBDs, 269 were right-sided and 77 were left-sided. Of the eight cases of important hemobilia requiring transcatheter embolization, four followed right-sided and four followed left-sided PTBD, corresponding to a bleeding incidence of 1.5% (4/269) for right PTBD and 5.2% (4/77) for left PTBD. The higher incidence of hemobilia associated with left-sided PTBD approached, but did not reach the threshold of statistical significance (p = 0.077). In six of the eight patients requiring transcatheter embolization, first or second order biliary branches were accessed by catheter for PTBD. All patients with left-sided bleeding had first or proximal second order branches accessed by biliary drainage catheters. In conclusion, a higher incidence of hemobilia followed left-versus right-sided PTBD in this study, but the increased incidence did not reach statistical significance.

Multiagent chemotherapy as neoadjuvant treatment for multifocal intraocular retinoblastoma

PURPOSE

To evaluate the efficacy of multiagent chemotherapy in the neoadjuvant treatment of retinoblastoma.

DESIGN

Noncomparative, prospective case series.

PARTICIPANTS

Twenty consecutive patients with multifocal intraocular retinoblastoma (4 unilateral, 16 bilateral [36 eyes]).

INTERVENTION

Eight cycles of chemotherapy with carboplatin and vincristine were administered at 3-week intervals over a 6-month period. Supplemental therapy was withheld until disease progression was documented.

MAIN OUTCOME MEASURES

Disease progression (defined as tumor growth, vitreous or subretinal seed progression, and new tumor formation), delay of external beam radiotherapy, and ocular survival.

RESULTS

Thirty-six eyes were treated. Eighteen eyes had Reese-Ellsworth group I-III tumors, and 16 eyes had Reese-Ellsworth group IV-V tumors at diagnosis. Two patients, who had unilateral disease at diagnosis, subsequently had tumors develop in the contralateral eye. Nineteen of 20 patients (95%) completed eight cycles of chemotherapy without disease progression. Three eyes of three different patients were successfully treated with chemotherapy alone. Thirty-three of 36 eyes (92%) progressed after completion of chemotherapy: 15 of the 18 eyes (83.3%) with Reese-Ellsworth group I-III and 16 of 16 eyes (100%) with Reese-Ellsworth group IV-V tumors. Seventeen eyes (52%) had growth of a tumor, whereas 14 eyes (42%) had progressive vitreous seeding, and 2 eyes (6%) had new tumors develop. Fifteen eyes (42%) required external beam radiotherapy. Twenty-nine of 36 (80.5%) eyes were salvaged. The median follow-up after chemotherapy was 19 months (range, 3-42 months).

CONCLUSIONS

Multiagent chemotherapy alone does not ensure a cure for multifocal intraocular retinoblastoma. Supplemental focal therapy is needed to control disease progression.

Intracranial paraganglioma (glomus tumor) with orbital extension

PURPOSE

To describe the clinical features of an intracranial glomus tumor with orbital extension.

METHODS

Case report.

RESULTS

A 15-year-old girl was examined for a large, vascular intracranial mass extending into the orbit. Attempted orbital biopsy was aborted for fear of uncontrollable hemorrhage. Tumor embolization and partial resection was performed. Histology was consistent with paraganglioma (glomus tumor).

CONCLUSION

The orbital surgeon should include glomus tumor in the differential diagnosis of vascular orbital lesions. Their vascularity and hemorrhagic potential should be considered when approaching these lesions surgically.

Sentinel node biopsy for orbital and ocular adnexal tumors

PURPOSE

To describe a technique for sentinel node mapping and biopsy in patients with orbital or adnexal tumors.

METHODS

Five patients with orbital and adnexal tumors were studied. Two patients had malignant eyelid melanomas (one of the skin and one of the conjunctiva), one with orbital invasion. Two patients had sebaceous gland carcinoma, and one patient had a mucoepidermoid carcinoma of the conjunctiva; 500 microCi of Technetium-99m sulfur nanocolloid (Nycomed Amersham, Princeton, NJ) diluted to 1.0 mL was injected intradermally at the lateral canthus. The patients were positioned as they would be during surgery. Lymphoscintigraphy was performed by means of anterior, lateral, and oblique views. The tracer was followed to the first lymphatic basin, and the sentinel node was identified. Cutaneous markers were placed to denote the site. During surgery, lymphoscintigraphy scans and a hand-held gamma probe were used to locate the sentinel node. Once excised, the sentinel node was sent for histopathology. Frozen sectioning confirmed the presence of lymphoid tissue. Permanent sections with immunohistochemical markers were performed to examine for metastatic disease.

RESULTS

The sentinel node biopsy technique was applied to 5 patients with orbital and adnexal tumors. All lymph nodes were free of tumor on histopathologic examination.

CONCLUSIONS

Sentinel node mapping and biopsy are possible for orbital and adnexal tumors. The morbidity of elective lymph node dissection and adjuvant radiotherapy can be avoided. Our results are preliminary, and further work must be done to identify the lymphatic basins of the orbit and ocular adnexa.

Analysis of initial CT findings after endovascular repair of abdominal aortic aneurysm

PURPOSE

To determine the spectrum and frequency of specific computed tomographic (CT) findings in the acute period after endovascular repair of abdominal aortic aneurysm (AAA).

MATERIALS AND METHODS

CT images obtained 1--3 days after endograft placement were evaluated in 88 patients. The images were analyzed for stent position, appearance of endograft components, perigraft leak, and postoperative findings including air and acute thrombus within the aneurysm and air surrounding the femoral-femoral bypass graft. Findings that could be misinterpreted as perigraft leak were evaluated.

RESULTS

Fifteen (17%) of 88 patients had perigraft leak in the acute postoperative period. The bare segment of the proximal self-expanding stent covered one or both renal arteries in 54 (61%) patients. One patient had CT evidence of renovascular compromise. Postoperative air was within the aneurysmal sac in 51 (58%) patients and surrounded the femoral-femoral bypass graft in 67 (94%) of 71 patients in whom the grafts were evaluated with CT. Mottled attenuation within the aneurysmal sac was seen in 50 (57%) patients. Forty-six (52%) patients had calcifications within longstanding thrombus. In 31 (35%) patients, findings that could have been misinterpreted as perigraft leak were identified.

CONCLUSION

Accurate analysis of CT findings after endovascular AAA repair requires careful review of all available CT images (preprocedural and pre- and postcontrast) and clear understanding of specific stent-graft components and placement.

Endoleak after endovascular repair of abdominal aortic aneurysm

PURPOSE

We sought to assess the role of endovascular techniques in the management of perigraft flow (endoleak) after endovascular repair of an abdominal aortic aneurysm.

METHOD

We performed endovascular repair of abdominal aortic aneurysm in 114 patients, using a variety of Gianturco Z-stent-based prostheses. Results were evaluated with contrast-enhanced computed tomography (CT) at 3 days, 3 months, 6 months, 12 months, and every year after the operation. An endoleak that occurred 3 days after operation led to repeat CT scanning at 2 weeks, followed by angiography and attempted endovascular treatment.

RESULTS

Endoleak was seen on the first postoperative CT scan in 21 (18%) patients and was still present at 2 weeks in 14 (12%). On the basis of angiographic localization of the inflow, the endoleak was pure type I in 3 cases, pure type II in 9, and mixed-pattern in 2. Of the 5 type I endoleaks, 3 were proximal and 2 were distal. All five resolved after endovascular implantation of additional stent-grafts, stents, and embolization coils. Although inferior mesenteric artery embolization was successful in 6 of 7 cases and lumbar embolization was successful in 4 of 7, only 1 of 11 primary type II endoleaks was shown to be resolved on CT scanning. There were no type III or type IV endoleaks (through the stent-graft). Endoleak was associated with aneurysm dilation two cases. In both cases, the aneurysm diameter stabilized after coil embolization of the inferior mesenteric artery. There were two secondary (delayed) endoleaks; one type I and one type II. The secondary type I endoleak and the associated aneurysm rupture were treated by use of an additional stent-graft. The secondary type II endoleak was not treated.

CONCLUSIONS

Type I endoleaks represent a persistent risk of aneurysm rupture and should be treated promptly by endovascular means. Type II leaks are less dangerous and more difficult to treat, but coil embolization of feeding arteries may be warranted when leakage is associated with aneurysm enlargement.

Immunohistochemical localization of NAD(P)H:quinone oxidoreductase in conjunctival melanomas and primary acquired melanosis

PURPOSE

Mitomycin C has been used in the treatment of primary acquired melanosis and melanomas of the conjunctiva. Because there is increasing evidence that NAD(P)H:quinone oxidoreductase (EC 1.6.99.2, NQO1) or DT-diaphorase plays an important role in the bioactivation of mitomycin C, we examined pathologic specimens of these tumors for NQO1 by immunohistochemistry.

METHODS

Formalin-fixed, paraffin-embedded sections with histologic diagnoses of primary acquired melanosis or conjunctival melanomas were obtained from the Eye Pathology Laboratory, University of Colorado Health Sciences Center. Detection of NQO1 in tissues was performed using standard immunohistochemical techniques with monoclonal antibodies against NQO1 and immunoperoxidase staining. Samples were examined by two independent reviewers and NQO1 staining was graded from 0 (no staining) to 3+ (intense staining).

RESULTS

Eleven of 11 melanomas (95% confidence interval, 72% to 100%) and three of three lesions with primary acquired melanosis with atypia stained positively for NQO1. In the melanomas, staining was relatively uniform, while in primary acquired melanosis there was cell-to-cell variability in the staining.

CONCLUSIONS

NQO1 was detected by immunohistochemistry in every examined section of primary acquired melanosis and melanoma of the conjunctiva, suggesting that NQO1 may play a role in the bioactivation of mitomycin C in these tumors.

Chemotherapy for eye cancer

Chemotherapy has been used to treat a multitude of eye cancers. We attempted to review the role of chemotherapy in the treatment of ocular, adnexal, and orbital malignancies by conducting an extensive search of the medical literature. Unfortunately, the published reports typically contain few patients with limited follow-up, precluding definitive recommendations. For most eye cancers, multicenter trials will offer the potential to gather the numbers of patients required to determine the clinical utility of chemotherapy.

Giant tumors of the chest: preoperative embolization and resection

Giant tumors of the chest are rare. These tumors comprise a spectrum of disease from benign lesions to highly aggressive malignant tumors with cells of origin in the pleura, pulmonary parenchyma, blood vessels, thymus, and connective tissues. We report four cases of giant tumors of the thorax treated with preoperative arterial embolization followed by complete surgical resection. Their diagnostic and treatment courses, imaging, and pathology are described.

Secondary fractures of Le Fort I osteotomy

PURPOSE

To report the ophthalmic complications of Le Fort I osteotomy for the correction of dentofacial deformities and to determine the maximal compressive loads applied during pterygomaxillary separation in a cadaver model.

METHODS

Two cases of ophthalmic complications arising after Le Fort I osteotomy are reported. Le Fort I osteotomy was performed on five cadavers. The maximal compressive load applied during pterygomaxillary separation was recorded with a 10 kN (3,000 lbf) load cell of a MTS Mini-Bionix servo-hydraulic machine (MTS, Eden Prairie, MN, U.S.A.). A paired t test was used to compare forces applied to the right and left sides. Computed tomography scans of each specimen were obtained after Le Fort I osteotomy to document secondary fractures. The skulls were subsequently stained with 1% fuschin red to highlight secondary fractures.

RESULTS

Maximum compressive loads during pterygomaxillary separation ranged from 22 N (5.0 lbf) to 162 N (36.5 lbf), with an average of 106 N (23.8 lbf) (SD 47.6 N [10.7 lbf]). Forces applied on the first operative side were significantly greater than forces applied on the second operative side (p = 0.0034). Secondary fractures were found in three specimens by computed tomography and in two specimens by 1% fuschin red. All secondary fractures occurred on the second operative side.

CONCLUSION

Secondary fractures in the Le Fort I osteotomy procedures occurred on the side opposite the greater maximal compressive load and on the second operative side.

Immunohistochemical localization of NQO1 in epithelial dysplasia and neoplasia and in donor eyes

PURPOSE

To examine the expression of NAD(P)H:quinone oxidoreductase 1 (NQO1, DT-diaphorase), a potential bioactivating enzyme for mitomycin C in corneal and conjunctival epithelial dysplasia and neoplasia and in normal tissues from human donor eyes, by immunohistochemistry.

METHODS

Formalin-fixed, paraffin-embedded sections of human donor eyes and tissue sections with histologic diagnoses of corneal and conjunctival epithelial dysplasia and neoplasia from the Eye Pathology Laboratory, University of Colorado Health Sciences Center were analyzed. Detection of NQO1 in tissues was performed using standard immunohistochemical techniques with monoclonal antibodies against NQO1 and immunoperoxidase staining.

RESULTS

All 20 tumors stained positive for NQO1. In seven eyes from four donors, positive staining for NQO1 was detected in all epithelial and endothelial layers, in fibroblasts, in all retinal layers except the photoreceptor outer segments, and in the fascicles and arachnoid of the optic nerve. Only minimal staining was detected in the photoreceptor outer segments and the optic nerve pia and dura. Immunostaining was markedly reduced in all tissues in both eyes from donor 5. Genetic analysis confirmed that this individual was homozygous for a polymorphism in NQO1 (NQO1*2).

CONCLUSIONS

NQO1 was detected by immunohistochemistry in every examined section of corneal and conjunctival epithelial dysplasia and neoplasia, suggesting that NQO1 may play a role in the bioactivation of mitomycin C in these tumors. However, the presence of NQO1 in the corneal, conjunctival, and ciliary epithelium; the retinas; and the optic nerves of donor eyes may indicate the potential for mitomycin C toxicity, particularly at higher doses.

Tesio catheter: radiologically guided placement, mechanical performance, and adequacy of delivered dialysis

PURPOSE

Tunneled catheters are an alternative means of vascular access for patients in need of hemodialysis who cannot undergo dialysis through a surgical shunt. This study was undertaken to evaluate the performance of the Tesio dialysis catheter.

MATERIALS AND METHODS

A prospective study of the Tesio catheter was performed. Follow-up data regarding catheter function and adequacy of dialysis were obtained from nine hemodialysis facilities.

RESULTS

Seventy-nine Tesio catheters were placed in 71 patients. Immediate technical success was 99% (78 of 79 catheters). The procedure complication rate was 9% (seven catheters). Only two complications required intervention: one fatal air embolism and one chest wall hematoma. Sixty-seven catheters in 60 patients were followed up for a total of 4,367 catheter days. Overall, catheter-related infection occurred in 9% (six of 67 catheters). Primary catheter patency was 87% at 1 week, 82% at 1 month, 72% at 3 months, and 66% at 6 months. Mean blood flow was 286 mL/min immediately after insertion, 301 mL/min at 3 months, and 306 mL/min at 6 months. Adequate dialysis dose as reflected by a urea reduction ratio of 60 or more or a urea kinetic modeling, or Kt/V, value of 1.2 or more was observed on at least one occasion for 74% and 76% of catheters, respectively.

CONCLUSION

The Tesio catheter is a reasonable means of vascular access for patients who undergo dialysis but are not candidates for surgical shunt placement.

Arteriographic detection of renovascular disease in potential renal donors: incidence and effect on donor surgery

PURPOSE

To determine the arteriographic incidence and severity of renal arterial disease in potential renal donors and to evaluate the effect of identifying vascular abnormalities on subsequent donor surgery.

MATERIALS AND METHODS

The records of 716 potential living renal donors who underwent conventional arteriography were reviewed. Abnormal arteriograms were reexamined to characterize vascular disease, and the effect of identifying renovascular disease on subsequent donor surgery was ascertained with chart review.

RESULTS

Renovascular abnormalities were noted in the dictated reports in 78 patients (10.9%). The most common causes were fibromuscular dysplasia and atherosclerosis. The arteriograms of 64 patients were available for retrospective review. Abnormalities were characterized as minimal stenosis (<30% narrowing) in 42 patients and mild stenosis (30%-50% narrowing) in 19 of 61 patients with arteriographic abnormalities at retrospective review. In three patients, no significant abnormality was seen at retrospective review. The effect of detecting renovascular disease on donor selection was determined in 74 of the 78 patients. In 73 of these 74 patients (99%), detection of an abnormality directly affected donor surgery.

CONCLUSION

In this population of potential renal donors, the arteriographic incidence of renovascular disease (10.9%) was higher than previously reported. Although renovascular abnormalities were mild, their detection influenced the plan for donor surgery in almost all patients.

Endovascular aneurysm repair in high-risk patients

PURPOSE

The purpose of this study was to evaluate the role of endovascular aneurysm repair in high-risk patients.

METHODS

The elective endovascular repair of infrarenal aortic aneurysm was performed in 116 high-risk patients with either custom-made or commercial stent grafts. The routine follow-up examination included contrast-enhanced computed tomography (CT) before discharge, at 3, 6, and 12 months, and annually thereafter. Patients with endoleak on the initial CT underwent re-evaluation at 2 weeks. Those patients with positive CT results at 2 weeks underwent endovascular treatment.

RESULTS

Endovascular repair was considered feasible in 67% of the patients. The mean age was 75 years, and the mean aneurysm diameter was 6.3 cm. The American Society of Anesthesiologists grade was II in 3.4%, III in 65.5%, IV in 30.1%, and V in 0.9%. There were no conversions to open repair. Custom-made aortomonoiliac stent grafts were implanted in 77.6% of the cases, custom-made aortoaotic stent grafts in 11.2%, and commercial bifurcated stent grafts in 11.2%. The 30-day rates of mortality, major morbidity, and minor morbidity were 3.4%, 20.7%, and 12%, respectively, in the first 58 patients and 0%, 3.4%, and 3.4%, respectively, in the last 58. The late complications included five cases of stent graft kinking, two cases of femorofemoral graft occlusion, and three cases of proximal stent migration, one of which led to aneurysm rupture. At 2 weeks after repair, endoleak was present in 10.3% of the cases. All the type I (direct perigraft) endoleaks underwent successful endovascular treatment, whereas only one type II (collateral) endoleak responded to treatment. The technical success rate at 2 weeks was 86.2%, and the clinical success rate was 96.6%. The continuing success rate was 87.9%. Seventeen patients died late, unrelated deaths.

CONCLUSION

Endovascular aneurysm repair is safe and effective in patients at high risk, for whom it may be the preferred method of treatment.

Talc pleurodesis through small-bore percutaneous tubes

Pleurodesis using talc as the sclerosing agent is an effective procedure for preventing reaccumulation of malignant pleural effusions. Because of its thickness, the talc slurry is usually instilled through large bore (20-28 Fr), surgically placed thorocostomy tubes. However, these tubes often cause considerable patient discomfort. Herein we report a series of eight patients in whom the talc slurry was inserted through 10 and 12 Fr percutaneous chest tubes. Six of the eight patients (75%) had a successful pleurodesis without a reaccumulation of fluid. We conclude that this is an acceptable method for treating patients with malignant pleural effusions.

Comparison of episcleral plaque and proton beam radiation therapy for the treatment of choroidal melanoma

PURPOSE

To compare the efficacy of iodine-125 (125I) and ruthenium-106 (106Ru) episcleral plaque radiation therapy and proton beam radiation therapy (PBRT) in the treatment of choroidal melanoma.

DESIGN

A retrospective, nonrandomized comparative study.

METHODS

Charts of patients treated with 125I, 106Ru, and PBRT for choroidal melanoma between January 1988 and June 1996 at St. Bartholomew's Hospital and Moorfields Eye Hospitals were reviewed.

MAIN OUTCOME MEASURE

Local control of choroidal melanomas after 125I, 106Ru, or PBRT.

RESULTS

A total of 597 patients were identified (125I = 190, 106Ru = 140, PBRT = 267). Patients treated with 106Ru had a significantly greater risk of local tumor recurrence than did patients treated with either 125I (P = 0.0133; confidence interval [CI], 1.26-7.02; risk ratio, 2.97) or PBRT (P = 0.0097; CI, 1.30-6.66; risk ratio, 2.94). A stepwise Cox proportional hazard model found maximal basal diameter to be a significant covariate (P = 0.0033).

CONCLUSION

Patients treated with 106Ru had a significantly greater risk of local tumor recurrence than did those patients treated with either 125I or PBRT.

Transcatheter embolization for the treatment of misperfusion after hepatic artery chemoinfusion pump implantation

BACKGROUND

The use of surgically implanted chemoinfusion pumps for the treatment of hepatic metastases from colorectal carcinoma can be complicated by intra- or extrahepatic misperfusion. This may result in suboptimal tumor exposure to the chemotherapeutic agent and injury to other gastrointestinal organs. Misperfusion can be managed by selective arterial transcatheter embolization.

METHODS

Between 1989 and 1996, 16 patients with liver metastases from colorectal carcinoma and with hepatic artery chemoinfusion pump misperfusion were treated using transcatheter coil embolization. Six female and 10 male patients (age range, 34-84 years; median, 51.5 years) were identified by retrospective review of the records of the Department of Interventional Radiology. After pump placement, abnormal liver perfusion scan or methylene blue endoscopy study results prompted angiography with coil embolization. After embolization, the imaging studies were repeated and patients were monitored in the Oncology Clinic.

RESULTS

Eight patients exhibited intrahepatic misperfusion (group 1) and eight extrahepatic misperfusion (group 2). Coil embolization was immediately successful in 100% of patients in group 1, with restoration of normal hepatic perfusion, and in 75% in group 2. There were no immediate procedure-related complications. Follow-up periods ranged from 1 to 23 months (median, 13.5 months). Embolization was unsuccessful for two patients (in group 2), who tolerated a modified chemotherapeutic regimen, with follow-up periods of 18.5 and 22 months.

CONCLUSIONS

Transcatheter coil embolization is the therapy of choice for the management of hepatic artery chemoinfusion pump misperfusion. It is rapid, effective, and well tolerated by patients and obviates the need for additional surgical intervention.

Generation of a library of 4-thiazolidinones utilizing polymer supported quench (PSQ) reagent methodology

A one-pot, three-component, solution-phase synthesis of 2, 3-disubstituted and 2,3,5-trisubstituted 4-thiazolidinones is described. Poly(styrene-co-divinylbenzene)-supports functionalized with tris(2-aminoethyl)amine and 2-amino-ethanethiol are used to remove excess reagents from the desired product upon completion of the reaction. Simple filtration followed by concentration provides products of sufficient purity for biological evaluation. This approach has been used for a parallel combinatorial generation of a library of multi-substituted 4-thiazolidinones. Copyright 1998 John Wiley & Sons, Inc.

Percutaneous biopsy of a posterior mediastinal mass through an extrapleural window created with dilute contrast

Extrapleural administration of dilute contrast was used to facilitate biopsy of a posterior mediastinal mass.

Severe ocular and orbital toxicity after intracarotid etoposide phosphate and carboplatin therapy

PURPOSE

To report severe ocular and orbital toxicity after administration of intracarotid etoposide phosphate and carboplatin.

METHOD

Case report.

RESULTS

A 52-year-old man with glioblastoma multiforme underwent left intracarotid administration of eto poside phosphate and carboplatin inferior to the ophthalmic artery. Within 7 hours, a nonpupillary block angle-closure glaucoma developed secondary to uveal effusion in the ipsilateral eye, which was relieved by cycloplegia. Four days later, severe orbital inflammation resulted in a visual acuity of counting fingers, proptosis, optic neuropathy, and total external ophthalmoplegia in the eye. The patient's condition improved after a lateral cantholysis and administration of high-dose intravenous corticosteroids. Two weeks later, an anterior uveitis occurred in the left eye, which responded to topical corticosteroids. During a 2-month period, the patient recovered to a visual acuity of 20/70, near normal motility, and normal intraocular pressure, and the ocular and orbital inflammation resolved. Preexisting ipsilateral chemotherapy-induced maculopathy became more pronounced.

CONCLUSION

Ocular and orbital toxicity after intracarotid etoposide phosphate and carboplatin therapy is infrequently reported.

Percutaneous management of abscess and fistula following pancreaticoduodenectomy

PURPOSE

To evaluate the efficacy of percutaneous drainage of fluid collections following pancreaticoduodenectomy (Whipple's procedure).

METHODS

We performed a retrospective review of 19 patients referred to our service with fluid collections following pancreaticoduodenectomy. The presence of associated enteric or biliary fistulas, the route(s) of access for image-guided drainage, the incidence of positive bacterial cultures, and the duration and success of percutaneous management were recorded.

RESULTS

Fistulous communication to the jejunum in the region of the pancreatico-jejunal anastomosis was demonstrable in all 19 patients by gentle contrast injection into drainage tubes. Three patients had concurrent biliary fistulas. In 18 of 19 patients, fluid samples yielded positive bacterial cultures. Successful percutaneous evacuation of fluid was achieved in 17 of 19 patients (89%). The mean duration of drainage was 31 days.

CONCLUSION

Percutaneous drainage of abscess following pancreaticoduodenectomy is effective in virtually all patients despite the coexistence of enteric and biliary fistulas.

Infection of a porous polyethylene orbital implant with Capnocytophaga

A 68-year-old woman experienced an infection of a porous polyethylene orbital implant caused by Capnocytophaga after a dental procedure. The infection was unresponsive to both topical and oral antibiotics and required removal of the porous polyethylene orbital implant. Capnocytophaga is a capnophilic, gram-negative bacillus. Capnocytophaga is a normal commensal of the mouth and is responsible for both gingivitis and periodontal disease. Capnocytophaga is a rare cause of ocular infections. This is the first reported patient with an infection of a porous polyethylene orbital implant caused by Capnocytophaga. The authors believe infected integrated orbital implants must be removed because neither topical or systemic therapy provide effective treatment.

Transcatheter embolization of biopsy-related vascular injury in the transplant kidney: immediate and long-term outcome

PURPOSE

To assess the effect of transcatheter embolization for treatment of biopsy-related vascular injury in renal allografts, specifically evaluating technical success, clinical benefit, and long-term effect on renal function.

MATERIALS AND METHODS

A retrospective review was performed of all postbiopsy renal allograft vascular injuries referred for embolization during a 113-month period. The likelihood of a prolonged detrimental effect on allograft function was estimated from observed variation in serum creatinine levels before and after the procedure.

RESULTS

Embolic therapy with use of metallic coils and superselective technique was performed in 21 renal transplant patients. Technical success was achieved in 95% of cases. There were no serious complications. Eradication of the clinical sign or symptom prompting referral was seen in 15 of 17 (88%) patients. Eleven of 19 (58%) patients analyzed demonstrated no evidence of a long-term detrimental effect on allograft function. A detrimental effect was possibly present in six of 19 (32%) patients, and probable in only two of 19 (10%) patients.

CONCLUSIONS

Transcatheter embolization can be an appropriate and effective therapeutic choice for biopsy-related renal allograft vascular injury.

Ureteral obstructions and leaks after renal transplantation: outcome of percutaneous antegrade ureteral stent placement in 44 patients

PURPOSE

To analyze the outcome of percutaneous antegrade ureteral stent placement for treatment of ureteral stenoses and leaks after renal transplantation.

MATERIALS AND METHODS

Antegrade pyelography and percutaneous ureteral stent placement were performed in 45 patients with ureteral obstruction (n = 40), leak (n = 3), or both (n = 2). Obstructions were graded as mild, moderate, or complete, and as early (< or = 3 months after transplantation) or late (> 3 months).

RESULTS

The outcome of stent placement was successful in 25 (57%) patients (average follow-up, 30 months). The ureteroneocystostomy (UNC) was the most common site of obstructions (22 of 41), leaks (four of five), and successful outcomes (16 of 22). Moderate obstructions were most common (29 of 41) and responded best to treatment (17 of 29). Eighteen (69%) of 26 early obstructions and five (33%) of 15 late obstructions were successfully managed percutaneously. All complications (12 of 45 patients) were minor, with infections the most common (n = 7). No mortality or allograft loss was attributable to stent placement.

CONCLUSION

Ureteral stents are safe and effective for the treatment of obstructions and leaks and are particularly effective for early and UNC obstructions. These stents may also be useful for temporary drainage.

Gadolinium-enhanced magnetic resonance venography of the portal venous system prior to transjugular intrahepatic portosystemic shunts and liver transplantation. Original investigation

RATIONALE AND OBJECTIVES

The accuracy of gadolinium-enhanced magnetic resonance venography (GdMRV) in identifying visceral venous abnormalities was assessed in patients before they underwent transjugular intrahepatic portosystemic shunt (TIPS) or orthotopic liver transplantation (OLT).

METHODS

Twenty-seven patients with portal hypertension underwent GdMRV and transcatheter venography prior to OLT or TIPS. The gadolinium dose was 0.5 mL/kg (0.25 mmol/kg), administered by rapid hand injection. Coronal 3D spoiled gradient-echo GdMRV was performed in a single breath-hold. Four blinded reviewers retrospectively evaluated coronal maximum intensity projection (MIP) images, while two reviewers evaluated the MIPs and multiplanar reconstructions. Abnormalities that could affect transjugular intrahepatic portosystemic shunt or transplantation were noted and compared with the results of corresponding catheter venograms read by a separate blinded reviewer.

RESULTS

Abnormalities were identified by GdMRV with a sensitivity and specificity of 83% and 97% for the right hepatic vein, 86% and 100% for the main portal vein (MPV), 42% and 99% for the right portal vein, 54% and 94% for the left portal vein, 61% and 96% for the superior mesenteric vein, and 74% and 91% for the splenic vein. Varices and shunts were correctly identified with a sensitivity of 96%. Multiplanar reconstruction increased MPV sensitivity to 100%.

CONCLUSION

Vascular abnormalities that affect TIPS and OLT can be identified by GdMRV. Multiplanar reconstruction increased the accuracy to 100% for the MPV.

Solid-supported syntheses of 3-thio-1,2,4-triazoles

Two solid-supported synthesis strategies for the preparation of 3-thio-1,2,4-triazoles are described. In the first, Rink amide resin is combined with Fmoc-protected omega-amino acids, acid hydrazides, and alkyl halides to provide diverse sets of starting materials from which numerous triazoles may be prepared. The second employs t-alkylcarbamate resin (Boc resin) which permits the use of additional pools of starting materials, including isothiocyanates and alpha- and omega-amino esters, resulting in triazoles with patterns of functional groups that are not possible from the initial route. The combination of multiple resins and resin attachment sites allows the preparation of a diverse library based upon the 3-thio-1,2,4-triazole scaffold and avoids the pitfall of having a single linker functionality present at the same position in all library members. General synthetic procedures and representative products from each route are presented. A similarity analysis of representative sublibraries from each synthesis strategy concludes that variation of the solid-phase linker chemistry and attachment site can enhance molecular diversity of the combined triazole library.

Expandable metallic stents in benign tracheobronchial obstruction

Expandable metallic stents offer advantages over previously available techniques for treating benign tracheobronchial stenosis or obstruction. Endoluminal stent placement offers a rapid and effective means of opening up narrowed airways, and results in excellent relief of symptoms and improvement in pulmonary function. Because they are delivered in a nonexpanded state using flexible over-wire systems, they can be placed using a flexible bronchoscope and can be located in second-order bronchial branches. Metallic stents have been used to treat benign airway obstruction caused by anastomotic narrowing after lung transplantation, infection, congenital lesions, tracheobronchial malacia, inflammatory conditions including relapsing polychondritis, Wegener granulomatosis, and acquired immunodeficiency syndrome, and external compression from benign mediastinal masses or fibrosis. The stents become epithelialized, which prevents migration and permits ciliary activity to continue. Significant complications can occur, including airway inflammation, stent migration, airway erosion, and stent fracture and collapse, but more serious complications are uncommon. Computed tomography is essential in imaging patients being considered for stent placement, as it allows 1) accurate representation of airway anatomy in three dimensions. 2) measurement of airway diameter, 3) evaluation of airway anatomy distal to a narrowed segment and invisible to bronchoscopy, 4) demonstration of dynamic changes in airway morphologic features during forced exhalation in patients with airway malacia, and 5) demonstration of focal or diffuse air trapping in lung peripheral to the abnormal airway. In patients who have had stent placement, computed tomography is valuable in assessing airway morphologic features and dynamics distal to the stent, and can be valuable in assessing stent dysfunction.

Myoepithelioma of the lacrimal gland

A right orbital tumor was excised from a 76-year-old woman. Pathological examination showed that the tumor was composed of spindle to cuboidal cells arranged in a solid to trabecular pattern. Immunohistochemical stains were positive for S-100 protein, muscle-specific actin, cytokeratins MAK6 and AE1,3, and glial fibrillary acid protein and negative for CD34 in tumor cells. Ultrastructural features of tumor cells included microvillous processes, intercellular junctions, and intracytoplasmic filaments with electron densities. To our knowledge, this is the first non-spindle cell myoepithelioma noted to arise in the lacrimal gland. This tumor likely has a similar biological behavior to pleomorphic adenoma (benign mixed tumor).

Topical mitomycin C for the treatment of conjunctival and corneal epithelial dysplasia and neoplasia

PURPOSE

To evaluate the efficacy of topical mitomycin C in treating conjunctival and corneal epithelial dysplasia and neoplasia.

METHODS

Seven eyes of seven patients with conjunctival and corneal epithelial dysplasia and neoplasia were treated with one drop of topical mitomycin C 0.04% four times a day for 7 days in alternate weeks. The patients' charts were reviewed retrospectively. Patients with either multiple recurrences or extensive ocular surface involvement were treated. In all eyes, the diagnosis of epithelial dysplasia or neoplasia was confirmed by histopathology before the onset of therapy. Patients were examined at least every 14 days during treatment and examined at intervals after completion of treatment.

RESULTS

With topical mitomycin C, six eyes of seven patients had complete clinical regression of their conjunctival and corneal epithelial dysplasia and neoplasia. One eye of one patient had partial clinical regression of conjunctival and corneal epithelial dysplasia. Follow-up after completion of topical mitomycin C therapy and excision of residual disease ranged from 2 to 16 months (mean, 9 months; SD, 4.3 months) and was without clinical sign of recurrence. Topical mitomycin C therapy was associated with transitory ocular discomfort, conjunctival injection, tearing, photophobia, and punctate epithelial keratopathy.

CONCLUSION

In this small series of eyes, topical mitomycin C was effective as a treatment for conjunctival and corneal epithelial dysplasia and neoplasia.

Selective arterial embolization for the control of lower gastrointestinal bleeding

BACKGROUND

Transcatheter embolization is accepted as a safe method for treating acute bleeding from the upper gastrointestinal (GI) tract. Hesitancy persists using this technique below the ligament of Treitz, based on the belief that the risk of intestinal infarction is unacceptably high, despite mounting clinical evidence to the contrary.

METHODS

A series of 17 consecutive patients with angiographically demonstrated small intestinal or colonic bleeding was retrospectively reviewed. The success and complication rate of subselective embolization was assessed.

RESULTS

Bleeding was stopped in 13 of 14 patients (93%) in whom embolization was possible, and in 13 of 17 patients (76%) where there was an intention to treat. Sufficiently selective catheterization to permit embolization could not be achieved in 3 patients. No clinically apparent bowel infarctions were caused.

CONCLUSION

Subselective embolization is a safe treatment option for lower GI bleeding, suitable for many patients and effective in most. Careful technique and a readiness to abandon embolization when a suitable catheter position cannot be achieved are important.

Heterocyclic ureas: inhibitors of acyl-CoA:cholesterol O-acyltransferase as hypocholesterolemic agents

A series of diaryl-substituted heterocyclic ureas was prepared, and their ability to inhibit acyl-CoA: cholesterol O-acyltransferase (ACAT) in vitro and to lower plasma total cholesterol in cholesterol-fed animal models in vivo was examined. N-(2,6-Diisopropylphenyl)-N'-tetrazole or isoxazole-substituted heterocyclic ureas proved optimal. A carbon chain of 11-14 carbons substituted 1,3 with respect to the amine provided the optimal side chain. Substitution of the alkyl chain generally lowered activity. Tetrazole urea 2i dosed at 3 mg/kg lowered plasma total cholesterol (TC) 67% in an acute, cholesterol-fed (C-fed) rat model of hypercholesterolemia and 47% in C-fed dogs. Tetrazole 2i, dosed at 10 mg/kg, also lowered TC 52% and raised HDL cholesterol 113% in rats with pre-established hypercholesterolemia.