A conversation on learning organizations with Daniel Kim. We are what we can learn. Interview by Joe Flower.
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Creativity↗
Biomedical subjects
D Kim
Publications and source records attributed to D Kim.
Psammaplin A, a natural phenolic compound, has inhibitory effect on human topoisomerase II and is cytotoxic to cancer cells.
We evaluated the topoisomerase II (Topo II) inhibitory activity of psammaplin A (PSA), a naturally occurring biphenolic compound, and its cytotoxicity to some human cancer cells including P-glycoprotein (Pgp)-overexpressing multidrug resistant (MDR) cell line. PSA completely inhibited the DNA relaxation activity of Topo II at 75.0 microM. It also completely inhibited the DNA decatenation activity of Topo II at 75.0 microM, and showed about 50% inhibitory activity at 18.8 microM. In the cytotoxicity assay, the effective concentrations that cause 50% inhibition of cell growth (EC50) were 0.48, 0.39, 1.83 and 3.76 microM to A549, SK-OV-3, HCT15 and HCT15/CL02 (MDR cell line established from HCT15 cells) cancer cells, respectively. In the presence of 8.0 microM of verapamil (VER), a well-known MDR modulator, the EC50 of PSA to HCT15/CL02 cells was reduced about 2.1 fold. Meanwhile, the EC50s of standard Topo II inhibitory drugs such as doxorubicin, etoposide and mitoxantrone to HCT15/CL02 cells were reduced about 8.5, 9.3 and 8.1 fold in the presence of 8.0 microM VER, respectively. From the results, we conclude that PSA has Topo II inhibitory activity, and its cytotoxicity to cancer cells is not so strongly affected by Pgp-associated MDR phenotype in comparison with some Topo II inhibitory anticancer drugs used in the clinic.
Adenosine Triphosphate↗
Piggy-back mesenteric arterial reconstruction.
Reimplantation of stenotic or occluded visceral arteries into the aorta is one solution to symptomatic chronic visceral ischemia. We report a patient in whom the associated problem of small bowel infarction precluded prosthetic reconstruction and saphenous vein was unavailable. Reimplantation of the celiac artery into the aorta was combined with piggy-back reimplantation of the superior mesenteric artery into the side of the celiac artery to provide successful revascularization of the small bowel. A 16-month angiographic and 5-year clinical follow-up is provided.
Aged↗
Malignant lymphoma of the central nervous system: difficult histologic diagnosis after glucocorticoid therapy prior to biopsy.
Four cases of central nervous system (CNS) lymphoma are reported which presented obstacles in diagnosis due to steroid treatment prior to biopsy. Reliable diagnoses were provided by molecular analysis. Malignant lymphoma of the CNS may be indistinguishable from other conditions, even in view of the gravity of the diagnosis. All patients had a previous history of glucocorticoid injection, for 2-18 days prior to stereotactic brain biopsy. The pathologic examination revealed in all cases axonal destruction and reactive gliosis with a variable infiltration of B- or T lymphocytes and macrophages. Characteristically, scattered degenerating small round cells with pyknotic or fragmented nuclei were also observed. However, the molecular assessment of paraffin-embedded tissues revealed the monoclonal IgH gene rearrangement, which allowed the confident diagnosis of B cell lymphoma. The histopathological findings of the present cases suggest that the tumor cells might be selectively destroyed by steroid treatment, which may render diagnosis impossible. Thus, molecular genetic investigation constitutes an important tool for establishing a diagnosis of CNS lymphoma obscured by steroid administration. This is especially true in cases where a paucity of tumor cells is observed or when monoclonality fails to be demonstrated by immunohistochemical tests.
Aged↗
Endovascular mechanical clot retrieval in a broad ischemic stroke cohort.
BACKGROUND AND PURPOSE: Our aim was to describe an expanded experience with endovascular mechanical embolectomy in a broad group of patients, including those not meeting entry criteria for the MERCI multicenter trials. METHODS: We performed an analysis of all patients with ischemic stroke treated with the Merci Clot Retrieval Device at a single academic center outside of the Mechanical Embolus Removal in Cerebral Ischemia (MERCI) trials. RESULTS: Twenty-four patients were treated with the device. Nine were MERCI trial ineligible: 4 received intravenous (IV) tissue plasminogen activator (tPA), 1 received IV tPA and was younger than 18 years of age, and 4 had time-to-treatment of longer than 8 hours. Mean age was 64 years (range, 14-89 years; 42% women). Median National Institutes of Health Stroke Scale (NIHSS) score was 21 (range, 11-30). Median symptoms-to-procedure-start time was 303 minutes (range, 85-2385 minutes). Recanalization (Thrombolysis in Myocardial Infarction, 2-3) was achieved in 15/24 (63%). In device-only patients, recanalization occurred in 10/16. In patients who failed IV tPA undergoing rescue embolectomy, recanalization was achieved in 4/5. Three patients unresponsive to device therapy received rescue intra-arterial tPA/abciximab; recanalization was achieved in 2/3. Recanalization was achieved in 3/4 patients in whom treatment was started longer than 8 hours after symptom onset. Asymptomatic hemorrhage occurred in 38%; symptomatic hemorrhage, in 8%. Three device fractures occurred; none worsened clinical outcome. In-hospital mortality was 17%; 90-day mortality, 29%. Good 90-day functional outcome (modified Rankin Scale, <or=2) was achieved by 25% (6/24). CONCLUSIONS: Endovascular mechanical embolectomy is an effective means of achieving revascularization in patients with acute ischemic stroke, including patients with late treatment start and intravenous tPA failure. Device-based therapy achieved recanalization in nearly two thirds of patients and good clinical outcomes in one fourth, with symptomatic hemorrhage in less than one tenth.
Adolescent↗
Traumatic pulmonary artery aneurysm: CT evaluation.
We present a patient with penetrating thoracic trauma who demonstrated an ill-defined, enlarging pulmonary opacity over several days. Computed tomography confirmed the clinical suspicion of a pulmonary artery aneurysm.
Adult↗
Studies on the calibration of enflurane vaporizers.
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Aerosols↗
Bilateral retinal venous caliber decrease following unilateral optic nerve sheath decompression.
We investigated retinal vascular changes in nine patients undergoing optic nerve sheath decompression for vision-threatening papilledema associated with pseudotumor cerebri. Two major (one superior and one inferior) retinal venous and arterial calibers were measured before and 1.1 +/- 0.1 months, 3.2 +/- 0.2 months, 5.0 +/- 0.2 months, 7.6 +/- 0.2 months, and 13.0 +/- 1.9 months after surgery. The retinal venous caliber decreased significantly, and the decrease progressed until 3.2 months after surgery. The venous caliber in the contralateral unoperated eyes also decreased significantly. The decrease in the venous caliber in the contralateral unoperated eye as well as in the operated eye following the surgery supports the hypothesis that slow filtration is the mechanism of successful optic nerve sheath decompression. Retinal venous caliber measurement, in either the operated eye or the unoperated fellow eye, can be used to quantitatively monitor the status of papilledema associated with pseudotumor cerebri.
Adult↗
Sialosis of unknown origin.
Sialosis (sialadenosis) is defined as an asymptomatic, non-inflammatory, non-neoplastic parenchymal salivary gland disease accompanied by a persistent painless bilateral swelling of the salivary glands, most commonly involving the parotid glands. There is no sex predilection, and the peak age incidence is between 30 and 70 years of age. Sialosis occurs in three different groups of patients: alcoholics, diabetics and the malnourished. An autonomic neuropathy, seen as a demyelinating polyneuropathy, seems to be the common underlying basis for this seemingly disparate group of patients with sialosis.
Biopsy, Needle↗