Selectively induced high MRP gene expression in multidrug-resistant human HL60 leukemia cells

A subclone HL60/DOX was selected from a human leukemic HL60 cell line for resistance to doxorubicin (DOX) by exposure to stepwise increasing concentrations of the drug and coexposure to a potential P-glycoprotein (P-gp) inhibitor, cepharanthine (a biscoclaurine alkaloid). Compared with the parent HL60 cells, the HL60/DOX cells were 13.0-fold more resistant to DOX and showed multidrug-resistant (MDR) phenotype characterized by 4.6-fold, 2.3-fold, and 5.7-fold cross-resistance to vincristine, pirarubicin, and etoposide, respectively, but no cross-resistance to alkylating agent, cisplatin. Immunocytochemical analyses using the specific monoclonal antibody, MRPr1, and quantitative analyses using a competitive reverse transcription-polymerase chain reaction (CRT-PCR) confirmed overexpression of MRP gene products (about 8-fold determined by CRT-PCR) in this resistant clone. The P-gp expression was not detectable by the monoclonal antibody, C219, in the HL60/DOX cells, and that was consistent with extremely low levels of mdr1 mRNA expression determined by CRT-PCR in this clone. Drug accumulation and efflux studies demonstrated the significantly increased efflux rate of DOX compared to the parent HL60 cells. This enhancement of DOX efflux was reversed by the addition of 10 microM verapamil. To investigate the additional underlying mechanisms contributing to MDR phenotype in the HL60/DOX cells, the levels of DNA topoisomerases (Topo) including Topo I, Topo IIalpha, and Topo IIbeta, and gamma-glutamylcystein synthetase (y-GCS) expression were determined using CRT-PCR techniques. Normal expression of each enzyme at the transcriptional level was demonstrated in this resistant clone. Southern blot analysis of the gene organization in the HL60/DOX cells revealed the amplification of MRP gene. These results indicate that alteration of the drug accumulation from enhanced efflux appears to be a major mechanism(s) of MDR phenotype and attributable to high levels of MRP expression in the HL60/DOX cells. Overexpression of MRP in this clone is regulated by the genomic amplification of DNA and increased levels of the MRP mRNA, independently with the normal expression of Topo I, Topo IIalpha, Topo IIbeta, or gamma-GCS.

Isolation and characterization of a cDNA clone encoding a novel peptide (OSF) that enhances osteoclast formation and bone resorption

Using an expression cloning approach, we identified and cloned a novel intracellular protein produced by osteoclasts that indirectly induces osteoclast formation and bone resorption, termed OSF. Conditioned media from 293 cells transiently transfected with the 0.9 kb OSF cDNA clone stimulated osteoclast-like cell formation in both human and murine marrow cultures in the presence or absence 10(-9) M 1,25-dihydroxyvitamin D3. In addition, conditioned media from 293 cells transfected with the OSF cDNA clone enhanced the stimulatory effects of 1,25-(OH)2D3 on bone resorption in the fetal rat long bone assay. In situ hybridization studies using antisense oligomers showed expression of OSF mRNA in highly purified osteoclast-like cells from human giant cell tumors of the bone. Northern blot analysis demonstrated ubiquitous expression of a 1.3 kb mRNA that encodes OSF in multiple human tissues. Sequence analysis showed the OSF cDNA encoded a 28 kD peptide that contains a c-Src homology 3 domain (SH3) and ankyrin repeats, suggesting that it was not a secreted protein, but that it was potentially involved in cell signaling. Consistent with these data, immunoblot analysis using rabbit antisera against recombinant OSF demonstrated OSF expression in cell lysates but not in the culture media. Furthermore, recombinant OSF had a high affinity for c-Src, an important regulator of osteoclast activity. Taken together, these data suggest that OSF is a novel intracellular protein that indirectly enhances osteoclast formation and osteoclastic bone resorption through the cellular signal transduction cascade, possibly through its interactions with c-Src or other Src-related proteins.

Extracellular calcium-sensing receptor in rat oligodendrocytes: expression and potential role in regulation of cellular proliferation and an outward K+ channel

A G protein-coupled, extracellular calcium (Ca(0)2+)-sensing receptor (CaR) cloned from parathyroid, kidney, and brain plays crucial roles in systemic calcium metabolism. In brain, the CaR is located in nerve terminals as well as in fiber tracts, where it may be expressed in glia. Moreover, there is Ca2+- and K+-dependent communication between axons and oligodendroglia. To investigate further the potential role of the CaR in oligodendroglia, we studied expression of CaR mRNA and protein as well as the effects of CaR agonists on cellular proliferation and Ca2+-activated K+ channel activity in immature rat oligodendrocytes in primary culture. Reverse transcriptase polymerase chain reaction and sequencing of CaR transcripts from oligodendrocytes revealed >99% sequence identity with the rat kidney CaR. Northern analysis demonstrated 7.5 and 4.1 kb transcripts in oligodendrocytes, similar to those in rat parathyroid and kidney, while Western analysis and immunocytochemistry with CaR-specific antisera showed the presence of CaR protein. Immunocytochemically, the CaR was colocalized with galactocerebroside in the cultured oligodendrocytes. Raising Ca(0)2+ from 1.8 to 4.8 mM or addition of the polycationic CaR agonist neomycin (300 microM) modestly but significantly increased [3H]-thymidine incorporation into oligodendrocytes. Elevating Ca(0)2+ from 0.75 to 3.0 mM or addition of 100 microM neomycin also produced 2-2.5-fold increases in the open state probability (Po) of an outward K+ channel with a unitary conductance of 88+/-5 pS. Taken together, our data show that the CaR is expressed in immature oligodendrocytes and may be functionally linked to cellular proliferation and an outward K+ channel potentially contributing to local ionic homeostasis in the vicinity of oligodendroglia.

The fibrotic focus in advanced colorectal carcinoma: a hitherto unrecognized histological predictor for liver metastasis

A fibrotic focus (FF) is a clearly defined area consisting of fibroblasts and/or collagen fibres arranged in irregular or storiform patterns within tumours. We looked to see whether FF in advanced colorectal carcinoma was associated with distant organ metastasis especially to the liver. The correlation between FF and the presence of synchronous or total (synchronous and/or metachronous) liver metastasis and tumour recurrence was assessed in 77 patients with Dukes B and C advanced colorectal carcinoma treated by resection. The median follow-up period was 21 months. In multivariate analysis, FF significantly increased the relative risk (RR) of synchronous liver metastasis (RR=4.9, P<0.05) and total liver metastasis (RR=4.6, P<0.05). FF also increased the RR of tumour recurrence (RR=2.4), but the increase was not statistically significant. FF is a newly recognized histological indicator of liver metastasis in advanced colorectal carcinoma.

A rare case of patent ductus arteriosus in a dog with glomerular mesangiolysis

Rare case of patent ductus arteriosus (PDA) was observed in a 2-year and 9 month-old Miniature Dachshund which had been diagnosed as severe cardiac failure. Pulmonary artery from the right ventricle connected to dilated ductus arteriosus, and pulmonary artery-ductus arteriosus-descending aorta formed a continuous duct, which seemed to be the main route of bloodstream. Ascending aorta from the left ventricle was hypoplastic, and connected to the dilated ductus arteriosus. Glomerular mesangiolysis due to heart failure was also observed in the kidney.

Puberty, IDDM, and death in Japan. Diabetes Epidemiology Research International Study Group

OBJECTIVE

To investigate the impact of age at onset on the prognosis of childhood IDDM in Japan.

RESEARCH DESIGN AND METHODS

The study population consisted of 987 prepubertal-onset and 345 pubertal-onset IDDM cases who were registered by two nationwide surveys and who were diagnosed between 1965 and 1979. The living status was identified as of 1 January 1990 with the ascertainment rate of 96.5%. Prognosis was evaluated by cause- and age-specific mortality rates and life-table analyses; in addition, an attained-age-matched case-control study was analyzed by conditional logistic regression.

RESULTS

The adjusted mortality rates per 100,000 person-years for the pubertal-onset cases were significantly higher than those of the prepubertal-onset cases (835 [95% CI 573-1,168] vs. 391 [283-526]). Life-table analyses revealed that the survival rate of the pubertal-onset cases was lower than that of the prepubertal-onset cases for each observation period. Life-table analyses after the age of 15 years indicated that the prognosis of pubertal cases was almost the same as that of the prepubertal cases despite having a shorter duration of diabetes. The attained-age-matched case-control study indicated that the pubertal onset was a potent determinant of death.

CONCLUSIONS

The prognosis of pubertal-onset IDDM was considerably poorer than that of prepubertal-onset IDDM.

[Two cases of spontaneous hemopeumothorax]

We experienced two cases of spontaneous hemopeumothorax. One case was a 17-year-old male with a complaint of back pain. A chest tube for rapid pleural evacuation disclosed hemorrhage as much as 3,000 ml, with drainage volume being gradually decreased. He needed about two month's admission because of complication of pyothorax. The other case was a 46-year-old male with a complaint of chest pain. Chest X-P gave the diagnosis of right hemopeumothorax. Thirty minutes later, he became shock, and five hours later, we performed an emergency intervention of video-assisted thoracoscopic surgery (VATS). Bleeding site of a funicular structure from the parietal pleura was stopped by clipping, with excellent postoperative results. Spontaneous hemopeumothorax is often indicated for early surgical intervention because of association with a high risk of hemorrhagic shock. In such a case, VATS is very helpful.

Evaluation of the Japanese health risks induced by global fallout tritium

Radioactive tritium (3H) generated by the atmospheric nuclear detonation tests has been circulated in the global environment to cause, through various pathways, low-level world-wide contamination of the environment and potential health risks to human beings. In this study, the dynamic performance of tritium in the global environment was modeled considering its transport with foods/feeds imported from all over the world. The mathematical model was examined by comparing the numerically simulated results with the fallout monitoring data. Main results obtained in this study were as follows: (1) The mathematical model developed in this study can reproduce well the global scale tritium circulation and its concentration in food; (2) The excess fatality rate of Japanese by the dietary intake of tritium is estimated to be on the order of 10(-8) y(-1) at present, which is about two orders of magnitude smaller than that by 90Sr; and (3) About 70% of the Japanese internal radiation dose by tritium is due to drinking water. Farm products, especially imported wheat, are secondly important in the Japanese health risk evaluation; its contribution, however, becomes small if the isotopic exchange effect of tritium is considered.

A case control study on risk factors involved in inflammatory breast recurrence after breast-conserving surgery

Recurrence that poses the biggest problem after breast-conserving surgery is local recurrence. Particularly, in the case of inflammatory breast recurrence which is rare but has a specific pathologic nature, it is important to elucidate the pathology and risk factors and to consider appropriate countermeasures. In the present study, we classified 133 cases of recurrence following breast-conserving surgery, collected from 18 key hospitals/institutes in Japan. Recurrence types were divided into three groups, namely, inflammatory breast recurrence, noninflammatory breast recurrence and distant metastasis only, and the risk factors involved in recurrence were investigated by the case control study allotting 2 controls to each case. The study population consisted of 9 cases of the inflammatory type, 64 cases of the noninflammatory type and 60 cases of distant metastasis. The significant risk factor for inflammatory breast recurrence was positive lymph node metastasis, which was significantly more frequent in lymphatic invasion-positive cases unlike in the distant metastasis group. The positive surgical margin and nonradiation therapy which have been shown to be significant risk factors for noninflammatory breast recurrence were entirely unrelated with inflammatory breast recurrence. In addition, the inflammatory-type recurrence time was as short as about 12 months irrespective of whether radiation therapy was performed or not. The inflammatory type was accompanied with local wide extension (cancerous embolus of the dermal lymphatic vessels), and distant metastasis (lymphangitis carcinomatosa) at the time of recurrence, and further surgery was impossible in most cases, with a significantly poorer prognosis than the other recurrence types. These findings suggest that this recurrence corresponds to the so-called 'occult' case of primary inflammatory breast carcinoma. We think it important to predict this recurrence by close pathological examination, particularly in patients with lymph node metastasis, and to consider appropriate measures.

First Report of A1 and A2 Mating Types of Phytophthora infestans on Potato and Tomato in Nepal

Late blight caused by Phytophthora infestans (Mont.) de Bary is an important disease of potato and tomato that occurs annually in the hills and occasionally in the terai (plain) of Nepal. In 1996 and 1997, each year, 50 samples of late blight-infected potato and tomato leaves were collected from the hill and terai areas. The pathogen was cultured on Rye A agar. Each isolate was paired on clear V8 agar with reference isolates DN111 (A1 mating type) and DN107 (A2 mating type) received from Hokkaido University, Japan, and examined for oospore formation after 10 to 15 days of incubation at 20°C. The proportion of A2 isolates was 6% in 1996 and 42% in 1997. The A2 isolates were mainly from the high hills (2,000 to 2,500 m) where local and Andean types of potatoes are grown. Analysis of genotypes of isolates at the glucosephosphate isomerase (GPI-1), malic enzyme (ME), and peptidase (PEP-1) (1,2) isozyme loci revealed genetic diversity between A1 and A2 isolates. A1 isolates from potato were either homozygous (100/100) or heterozygous (86/100) for GPI-1, whereas all A1 isolates from tomato were heterozygous (86/100). All A1 isolates were homozygous (100/100) at the ME locus and heterozygous (92/100) at the PEP-1 locus. A2 isolates were homozygous (100/100) at all isozyme loci. The results show that both A1 and A2 mating types of P. infestans are present in Nepal, and that they display different isozyme genotypes. It is speculated that the A1 type may have migrated with potatoes from Europe while the A2 type may have been introduced with Andean potatoes from Latin America more recently. The simultaneous occurrence of both mating types may allow the fungus to increase its pathogenic diversity and to survive by means of oospores. References: (1) A. A. Mosa et al. Plant Pathol. 42:26, 1993. (2) P. W. Tooley et al. J. Hered. 76:431, 1985.

Study of the measurement of defense style using Bond's Defense Style Questionnaire

Two hundred and seventy healthy university students were surveyed in December 1995 using Bond's Defense Style Questionnaire (DSQ) to measure the subjects' defense mechanisms. At the same time, a survey using Byrne's R-S Scale (Repression-Sensitization Scale) of the MMPI (Minnesota multiphasic personality inventory) and five psychiatric symptom indexes (anxiety, sense of inadequacy, sensitivity, depression and impulsive anger) selected from the CMI (Cornell Medical Index-Health Questionnaire) was conducted. Three factors were extracted from the DSQ through factor analysis: immature defenses, neurotic defenses, and mature defenses. The results of analysis of variance revealed the following: (i) for anxiety and anxiety related symptoms, both immature defenses and neurotic defenses indicated principal effect; (ii) for impulsive anger and depression, immature defenses presented principal effect; and (iii) for sensitivity and impulsive anger, interaction between a mature defense style and neurotic defense style was noted. The relationship between defense styles and psychiatric symptoms in healthy people is studied in this paper.

Optimal image resolution for digital storage of radiotherapy-planning images

PURPOSE

To evaluate the quality of digitized radiation-planning images at different resolution and to determine the optimal resolution for digital storage.

METHODS AND MATERIALS

Twenty-five planning films were scanned and digitized using a film scanner at a resolution of 72 dots per inch (dpi) with 8-bit depth. The resolution of scanned images was reduced to 48, 36, 24, and 18 dpi using computer software. Image qualities of these five images (72, 48, 36, 24, and 18 dpi) were evaluated and given scores (4 = excellent; 3 = good; 2 = fair; and 1 = poor) by three radiation oncologists. An image data compression algorithm by the Joint Photographic Experts Group (JPEG) (not reversible and some information will be lost) was also evaluated.

RESULTS

The scores of digitized images with 72, 48, 36, 24, and 17 dpi resolution were 3.8 +/- 0.3, 3.5 +/- 0.3, 3.3 +/- 0.5, 2.7 +/- 0.5, and 1.6 +/- 0.3, respectively. The quality of 36-dpi images were definitely worse compared to 72-dpi images, but were good enough as planning films. Digitized planning images with 72- and 36-dpi resolution requires about 800 and 200 KBytes, respectively. The JPEG compression algorithm produces little degradation in 36-dpi images at compression ratios of 5:1.

CONCLUSION

The quality of digitized images with 36-dpi resolution was good enough as radiation-planning images and required 200 KBytes/image.

Effects of halothane, enflurane, isoflurane, and sevoflurane on slowly adapting pulmonary stretch receptor activity in anesthetized dogs

The aim of this study was to evaluate the effects of halothane, enflurane, isoflurane, and sevoflurane on slowly adapting pulmonary stretch receptor (SAR) activity in dogs. Eight beagles were anesthetized with an intravenous injection of a mixture of urethane and alpha-chloralose as a basal anesthesia, then vagotomized, artificially ventilated, and chest opened. Single afferent activities from SARs were recorded from the peripheral nerve cut end of the left vagus. Changes in SAR activities with inhalation of halothane, enflurane, isoflurane, and sevoflurane at 1, 1.5, and 2 times the minimal alveolar anesthetic concentration (MAC) were measured, and differences in the discharges within and among four anesthetics were evaluated. As a result, two different types of SARs, low threshold SARs and high threshold SARs, were detected in this study. In all anesthetics, expiratory discharges of low threshold SARs decreased significantly in a dose-dependent manner, whereas inspiratory discharges did not change significantly at any anesthetic level. Discharges of high threshold SARs tended to decrease with increasing anesthetic level; however, no statistical significance was observed at any anesthetic level. Only one exception to these changes was observed at 1 MAC of halothane where no significant decrease in the expiratory discharge of low threshold SARs or significant increase in the discharge of high threshold SARs was induced against a control value. In conclusion, recent inhalation anesthetics, except for halothane at the light anesthetic level, tended to decrease SAR activities depending on the anesthetic level, suggesting attenuation of the Hering-Breuer inflation reflex.

Cadherin-6 mediates the heterotypic interactions between the hemopoietic osteoclast cell lineage and stromal cells in a murine model of osteoclast differentiation

Osteoclasts are multinucleated cells of hemopoietic origin that are responsible for bone resorption during physiological bone remodeling and in a variety of bone diseases. Osteoclast development requires direct heterotypic cell-cell interactions of the hemopoietic osteoclast precursors with the neighboring osteoblast/stromal cells. However, the molecular mechanisms underlying these heterotypic interactions are poorly understood. We isolated cadherin-6 isoform, denoted cadherin-6/2 from a cDNA library of human osteoclast-like cells. The isolated cadherin-6/2 is 3,423 bp in size consisting of an open reading frame of 2,115 bp, which encodes 705 amino acids. This isoform lacks 85 amino acids between positions 333 and 418 and contains 9 different amino acids in the extracellular domain compared with the previously described cadherin-6. The human osteoclast-like cells also expressed another isoform denoted cadherin-6/1 together with the cadherin-6. Introduction of cadherin-6/2 into L-cells that showed no cell-cell contact caused evident morphological changes accompanied with tight cell-cell association, indicating the cadherin-6/2 we isolated here is functional. Moreover, expression of dominant-negative or antisense cadherin-6/2 construct in bone marrow-derived mouse stromal ST2 cells, which express only cadherin-6/2, markedly impaired their ability to support osteoclast formation in a mouse coculture model of osteoclastogenesis. Our results suggest that cadherin-6 may be a contributory molecule to the heterotypic interactions between the hemopoietic osteoclast cell lineage and osteoblast/bone marrow stromal cells required for the osteoclast differentiation. Since both osteoclasts and osteoblasts/bone marrow stromal cells are the primary cells controlling physiological bone remodeling, expression of cadherin-6 isoforms in these two cell types of different origin suggests a critical role of these molecules in the relationship of osteoclast precursors and cells of osteoblastic lineage within the bone microenvironment.

Effects of volatile anesthetics on vagal C-fiber activities and their reflexes in anesthetized dogs

Effects of halothane, enflurane, isoflurane, and sevoflurane on vagal capsaicin (CAPS)-sensitive C-fibers were elucidated in anesthetized dogs. The CAPS-sensitive C-fibers were significantly stimulated by all volatile anesthetics with a significantly greater response to halothane than with sevoflurane. A significant increase in respiratory frequency (fR) and a significant decrease in tidal volume (VT) were observed with halothane and isoflurane, and a significant increase in fR was observed with sevoflurane. In contrast, a significant decrease in fR was induced by enflurane. The tachypnea induced by halothane, isoflurane, and sevoflurane was significantly reduced or no longer observed after perineural CAPS-treatment or bilateral vagotomy, whereas the slowing of respiration observed with enflurane was not affected by either of these treatments. These results suggest that vagal C-fibers play an important role in the reflex tachypnea that occurs with halothane, isoflurane, and sevoflurane.

Establishment and characterization of two cell lines derived from canine spontaneous osteosarcoma

Two new canine osteosarcoma cell lines were established. One (OOS) was established from a 10-year-old female maltese dog with mandibular osteosarcoma and the other (HOS) from a 7-year-old male mongrel dog with scapular osteosarcoma. Histopathological types of OOS and HOS were mixed and fibroblastic cell type, respectively. Transmission electron microscopic features of HOS revealed prominent rough endoplasmic reticulum, suggesting higher malignancy comparing to OOS. Doubling time of OOS and HOS were 45.0 +/- 0.5 hr and 42.0 +/- 0.1 hr, respectively. Alkaline phosphatase activities of OOS and HOS were quite low. Histological features of tumor tissues produced by transplantation of these cells into nude mice were identical to those of original osteosarcomas.

The influence of obsessive-compulsive neurosis patients' premorbid personality on obsessive-compulsive symptoms and efficacy of medication

We conducted a survey with the Lynfield obsessive-compulsive symptom questionnaire (revised version) on 48 obsessive-compulsive neurotic patients as the survey subjects. In the factor analysis five factors of obsessions, were identified: (i) the desire for perfection; (ii) compulsive checking; (iii) washing; (iv) feelings of uncleanliness; and (v) anthropophobia. High correlations were noted between these factors. We also investigated the premorbid personalities of obsessive-compulsive neurotic patients with a multidimensional personality scale and obtained an extroversion dimension and neuroticism dimension. The influence of these premorbid personality dimensions on obsessive-compulsive symptoms became clear; (i) neuroticism is related to the levels of obsession after onset, but not related to compulsive behaviors; and (ii) No differences in premorbid personality dimensions were noted between compulsive checking and compulsive washing behaviors. We also studied whether it was possible to predict the efficacy of pharmacotherapy upon obsessive-compulsive symptoms. It was elucidated that the obsessions of those whose premorbid personalities are emotionally stable and extroversive are susceptible to antidepressants. Based on these results, we discussed the usefulness of premorbid personalities in predicting diversity of obsessive-compulsive symptoms, as well as in prediction the efficacy of medication.

Ovarian mixed germ cell tumor composed of polyembryoma and immature teratoma

We report the case of a 41-year-old woman with ovarian mixed germ cell tumor which was composed of polyembryoma and immature teratoma and who had high serum levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). By immunohistochemical methods, AFP was found in yolk sac cells of the embryoid bodies and immature hepatoid tissues, and hCG was found in giant syncytiotrophoblastic cells. She was treated with surgery followed by cisplatin-based combination chemotherapy. She is well, and her serum levels of AFP and hCG have not been elevated for more than 4 years after the treatment.

Combination of interleukin-6 and soluble interleukin-6 receptors induces differentiation and activation of JAK-STAT and MAP kinase pathways in MG-63 human osteoblastic cells

Studies on the role of interleukin-6 (IL-6) in bone metabolism have been accumulating. However, its effects on osteoblasts are still unclear because the results are conflicting depending on the study models employed. We reasoned that these conflicting data are due to variable expression levels of membrane-bound IL-6 receptors (IL-6Rs). In the present study, we found that IL-6 in combination with soluble IL-6R (sIL-6R) consistently caused a marked elevation of alkaline phosphatase and a decrease in proliferation in the human osteoblastic cell line MG-63, which expressed no detectable membrane-bound IL-6R and failed to respond to IL-6. These effects of IL-6/sIL-6R were blocked by neutralizing antibodies to the IL-6 signal transducer gp130, suggesting an involvement of IL-6 signaling in the elicitation of the effects of IL-6/sIL-6R. Upon stimulation with IL-6/sIL-6R, the gp130, cytoplasmic Janus kinases JAK1 and JAK2 were tyrosine phosphorylated. Moreover, signal transducers and activators of transcription STAT1 and STAT3 were also tyrosine phosphorylated, translocated to the nucleus, and bound to the putative STAT-binding DNA elements. In addition, mitogen-activated protein (MAP) kinase was also activated in response to IL-6/sIL-6R These data demonstrate that sIL-6R may enhance the responsiveness of MG-63 cells to IL-6. Thus, IL-6 in collaboration with sIL-6R may modulate differentiation and proliferation of osteoblastic cells, presumably by activating two distinct signaling pathways of JAK-STAT and MAP kinase.

Dural carotid cavernous fistulas: role of conventional radiation therapy--long-term results with irradiation, embolization, or both

PURPOSE

To evaluate the long-term results of irradiation alone or of embolization with or without irradiation in patients with dural carotid cavernous fistulas (DCCFs).

MATERIALS AND METHODS

Between 1984 and 1996, symptomatic DCCFs in 26 patients were treated by using irradiation alone (protocol 1, n = 12) before April 1988 and by using embolization as an initial treatment (protocol 2, n = 14) during and after April 1988. When angiography showed no improvement after embolization, irradiation was added (n = 6). On the basis of drainage flow speed, DCCFs were classified as fast, medium, or slow.

RESULTS

With irradiation alone, all six patients with slow- to medium-type DCCFs had cure with a mean follow-up of 62 months. Four of six patients with fast-type DCCFs had cure or improvement, but the remaining two had no change. In the embolization group, irradiation was added in six patients with fast-type DCCFs. With a mean follow-up of 24 months, four of the six patients had cures, one had improvement, and one had no clinical change. Those who underwent protocol 2 had cures significantly earlier than those who underwent protocol 1 (P < .05).

CONCLUSION

Conventional radiation therapy resulted in cure of DCCFs in nine (75%) of the 12 patients and in improvement of signs and symptoms in one (8%). Fast-type DCCFs may not always be improved. Radiation therapy may be useful in DCCFs after embolization.