Carbon-dioxide-guided vascular interventions: technique and pitfalls

Purpose: To evaluate the usefulness of carbon dioxide (CO2) angiography to guide vascular interventions. Methods: A prospective study was carried out of 50 procedures (angioplasty, stenting, stent-grafting and embolization) using CO2 angiography. Indications for using CO2 were renal impairment, cardiac failure, previous reaction to conventional iodinated contrast, or likelihood of needing high doses of conventional contrast. CO2 was intended to be the sole contrast agent. The use of additional conventional contrast or gadolinium was recorded, as were procedural complications. Radiation dose was compared with similar procedures using conventional contrast. Results: Angiographic quality was satisfactory in 44 (88%) procedures and CO2 guidance was all that was required; in 6 (12%) cases adjunctive use of conventional contrast or gadolinium was necessary. Contrast doses were significantly reduced and there was a trend toward decreased radiation doses with CO2. There were two significant complications but only one related to the use of CO2. Conclusion: CO2 angiography is well tolerated and can be successfully used to guide even complex vascular interventions. High-risk patients can be spared the risks of conventional contrast agents.     

A critical appraisal of pinhole scintigraphy of the ankle and foot

BACKGROUND: Scintigraphy is an established imaging technique for injuries of the ankle and foot that are not apparent on plain radiographs. The scintigraphic technique has varied, with planar and pinhole images being used. MATERIALS AND METHODS: The incremental value of pinhole scintigraphy over planar imaging was studied in 16 patients with established diagnoses. Inter-reporter reproducibility was also measured. RESULTS: Pinhole scintigraphy improved the diagnostic specificity in nearly one half of the patients (48%). It did not contribute substantial information in 46% and led to confusion in the diagnosis of one patient. Inter-reporter agreement was good, with a kappa value of 0.78. Diagnoses varied from fractures of the talar dome to avulsion fractures of the malleoli and impingement syndromes. CONCLUSIONS: Pinhole images add a significant incremental value to planar scintigraphy of the foot and ankle. Although this had been perceived intuitively in the past, it has not been critically evaluated. The technique has good inter-reporter agreement.     

MRI findings of vestibulocochlear hemorrhage in a leukemic patient with sensorineural hearing loss

This case report presents a patient with M4 leukemia with signs and symptoms of acute sensorineural hearing loss. The patient's MRI demonstrated high signal on unenhanced T1-weighted images within the left vestibulocochlear complex that was consistent with subacute hemorrhage. Follow-up MRI showed clearing of the previously seen high T1-weighted signal from the left vestibulocochlear complex. This case report documents for the first time the MRI findings of vestibulocochlear complex hemorrhage in a leukemic patient.     

Role of serine/threonine kinase casein kinase-II in vascular smooth muscle cell proliferation and inhibition by heparin

The role of serine/threonine kinase casein kinase-II (CK-II) in vascular smooth muscle cell proliferation and inhibition by heparin was investigated. cDNAs for α and β subunits of CK-II form rabbit vascular smooth muscle cells were cloned and sequenced. A strong evolutionary conservation was found at amino acid and nucleotide levels in CK-II from rabbit and human. Treatment of smooth muscle cells with a specific antisense oligonucleotide to CK-II blocked stimulation of DNA synthesis in response to PDGF. Addition of a known inhibitor of CK-II to cultures of smooth muscle cells also blocked DNA synthesis. Mitogenic stimulation of growth arrested quiescent cultures of smooth muscle cells with PDGF produced a 2–3-fold increase in CK-II activity. Heparin was a potent inhibitor of smooth muscle cell derived CK-II in vitro and attenuated the stimulation of CK-II activity in response to PDGF in intact cells. Intracellular localization studies showed that heparin and CK-II were localized in the nucleus. These results suggest a potential role of CK-II in signal transduction mediating smooth muscle cell growth. Modulation of CK-II activity by heparin and its co-localization in the nucleus suggest that heparin may effect CK-II activity in intact cells. © 1993 Wiley-Liss, Inc.     

Identification of a novel selective peroxisome proliferator-activated receptor alpha agonist, 2-methyl-2-(4-{3-[1-(4-methylbenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl]propyl}phenoxy)propanoic acid (LY518674), that produces marked changes in serum lipids and apolipoprotein A-1 expression

Low high-density lipoprotein-cholesterol (HDL-c) is an important risk factor of coronary artery disease (CAD). Optimum therapy for raising HDL-c is still not available. Identification of novel HDL-raising agents would produce a major impact on CAD. In this study, we have identified a potent (IC50 approximately 24 nM) and selective peroxisome proliferator-activated receptor alpha (PPARalpha) agonist, 2-methyl-2-(4-{3-[1-(4-methylbenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl]propyl}phenoxy)propanoic acid (LY518674). In human apolipoprotein A-1 (apoA-1) transgenic mice, LY518674 produced a dose-dependent increase in serum HDL-c, resulting in 208 +/- 15% elevation at optimum dose. A new synthesis of apoA-1 contributed to the increase in HDL-c. LY518674 increased apoA-1 mRNA levels in liver. Moreover, liver slices from animals treated with LY518674 secreted 3- to 6-fold more apoA-1 than control liver slices. In cultured hepatocytes, LY518674 produced 50% higher apoA-1 secretion, which was associated with increase in radiolabeled methionine incorporation in apoA-1. Thus, LY518674 is a potent and selective PPARalpha agonist that produced a much greater increase in serum HDL-c than the known fibrate drugs. The increase in HDL-c was associated with de novo synthesis of apoA-1.     

Anorectal malignant melanoma. Report of three cases

The authors report three cases of primary anorectal malignant melanoma in order to discuss the various diagnostic problems, therapeutic modalities and to remind of the prognostic factors of this rare and unknown affliction. The diagnosis is unfortunately realized in the advanced stage. Mrs B.O, 55 years old, presented rectal hemorrhages and false meeds since a year, the clinical examination showed rectal tumor that bleeds with touch. The mass has been biopsed during the rectoscopy and the diagnosis of the malignant melamoma has been confirmed. Abdominoperitoneal amputation had been realized. Mr F.K, 35 years old, hospitalized because of constipation and rectal hemorrhages that evolve since 7 months with loss of weight and alteration of the general state. The rectal touch emphasizes a budy rectal polypoid tumor about 6 cm that the biopsies confirmed the diagnosis of invasive malignant. A Hartman's operation has been realized. A resection of the tumoral bud has been realized 3 months later, the patient died 4 months after that. Mrs F.K, 50 years old, presented since 50 days relapsing rectorrhages. The rectal touch showed a rectal tumor far about 6 cm from the amal margin, the biopsy during the rectoscopy confirmed the diagnosis of the pigmented and little invasive malignant melanoma. The abdominal exhography showed hepatic metastases and a resection by endo-mal way in order to reduce the tumor has been realized. The inclusion of the primary anorectal malignant melanoma in the diagnosis of the afflictins of the anorectal region would permit an improvement of this affliction prognosis, this is still unfortunate when the diagnosis is late. Its treatment is still surgical, the role of the other therapies still needs to be defined.     

Acute phosphate nephropathy following oral sodium phosphate bowel purgative: an underrecognized cause of chronic renal failure

The findings of diffuse tubular injury with abundant tubular calcium phosphate deposits on renal biopsy are referred to as nephrocalcinosis, a condition typically associated with hypercalcemia. During the period from 2000 to 2004, 31 cases of nephrocalcinosis were identified among the 7349 native renal biopsies processed at Columbia University. Among the 31 patients, 21 presented with acute renal failure (ARF), were normocalcemic, and had a history of recent colonoscopy preceded by bowel cleansing with oral sodium phosphate solution (OSPS) or Visicol. Because the precipitant was OSPS rather than hypercalcemia, these cases are best termed acute phosphate nephropathy. The cohort of 21 patients with APhN was predominantly female (81.0%) and white (81.0%), with a mean age of 64.0 yr. Sixteen of the 21 patients had a history of hypertension, 14 (87.5%) of whom were receiving an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. The mean baseline serum creatinine was 1.0 mg/dl, available within 4 mo of colonoscopy in 19 (90.5%) patients. Patients presented with ARF and a mean creatinine of 3.9 mg/dl at a median of 1 mo after colonoscopy. In a few patients, ARF was discovered within 3 d of colonoscopy, at which time hyperphosphatemia was documented. Patients had minimal proteinuria, normocalcemia, and bland urinary sediment. At follow-up (mean 16.7 mo), four patients had gone on to require permanent hemodialysis. The remaining 17 patients all have developed chronic renal insufficiency (mean serum creatinine, 2.4 mg/dl). Acute phosphate nephropathy is an underrecognized cause of acute and chronic renal failure. Potential etiologic factors include inadequate hydration (while receiving OSPS), increased patient age, a history of hypertension, and concurrent use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker.