Biomedical subjects
Publications and source records attributed to T K Lin.
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Hypotension is one of the most important predictors of mortality in sodium monofluoroacetate (SMFA) intoxication. This paper reports the hemodynamic response in one fatal and another survival case of SMFA intoxication. Despite correction of hypovolemia and with inotropic support, the patients remained in shock. Hemodynamic observations have provided evidence that shock after SMFA intoxication is due to diminished systemic vascular resistance and increased cardiac output. This is the first report in which such an invasive hemodynamic investigation has been recorded in a clinical case of SMFA intoxication.
Virchow-Robin spaces normally surround the perforating arteries that enter the brain. These spaces are a well-defined sites where immunological reactions take place and they may have implications in the pathogenesis of a number of neuropathological conditions. We present the case of a 52-year-old woman who had a history of complex partial seizures for 30 years. Her routine neurological examinations and mini-mental tests had normal results. Magnetic resonance images of this patient revealed unusual widening of the Virchow-Robin spaces up to 1.5 cm in diameter along the perforating medullary arteries in the white matter, more so in the left hemisphere. Although it has been concluded that these large spaces are a phenomenon of the normal aging brain and are unrelated to neurological diseases, our patient had had epileptic seizures for 30 years. The large Virchow-Robin spaces of our patient might have been an incidental radiologic finding. Their pathogenesis remains unclear, and their possible clinical relationship to epilepsy deserves further pathological studies.
Diagnosis of an intracranial dural arteriovenous fistula (DAVF) with spinal perimedullary venous drainage is challenging because the presenting symptoms are usually related to dysfunction of the spine, not of the brain. Repeated spinal angiograms are usually performed before the diagnosis is finally made by cerebral angiography. We report two cases of intracranial DAVFs with spinal perimedullary venous drainage. In both cases contrast-enhanced cervical MRI demonstrated dilated lower brainstem and upper spinal veins, which, we believe, is a good indicator of the existence of such drainage. We suggest that, in cases with perimedullary serpentine enhancement on thoracic or lumbar MR images, additional Gd-enhanced cervical spinal MR imaging should be performed. The simple process of tracing the veins upwards may avoid a lot of unnecessary examinations and delay in the diagnosis.
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OBJECTIVE: Previous studies have shown that exogenous growth hormone (GH) produces increases in sperm motility when given to subfertile men. Previous studies have also demonstrated the presence of IGFs and IGFBPs in seminal plasma. We have therefore investigated the effects of insulin-like growth factor-I (IGF-I), IGF-II, IGF-binding protein 2 (IGFBP-2) and intact IGFBP-3 on in vitro sperm motility. DESIGN AND METHODS: Using computer-aided sperm analysis, we investigated the effects of IGFs and IGFBPs on the in vitro sperm motility parameters: curvilinear velocity (CV), progressive velocity (PV), linearity (Ln), straightness (St), amplitude of lateral head movement (ALH), and beat frequency (BF). Washed motile sperm selected by the 'swim-up' method, from normozoospermic samples, were incubated at 37 degrees C in 5% CO2 in air with IGF-I, IGF-II, IGFBP-2, IGFBP-3, or control Earle's media, and were examined at time 0 and after 60 min incubation. Changes in motility parameters after 60 min incubation were compared with controls by analysis of variance (ANOVA). RESULTS: Compared to controls, statistically significant changes occurred at time 60 min after incubation: IGF-I decreased CV and ALH significantly (P < 0.05), but IGFBP-3 increased Ln, St, BF, and decreased ALH significantly (P < 0.05). In contrast, IGF-II, IGFBP-2, and a combination of IGF-I/IGFBP-3, had no significant effects. CONCLUSIONS: IGF-I and IGFBP-3 have differing and opposing effects on in vitro sperm motility parameters and thus may have a role in modulating in vivo sperm motility.
BACKGROUND: Replacement donors are more likely than volunteer donors to have positive or abnormal tests for transfusion-transmissible disease. In an effort to increase the donor pool, workers sought to identify a safer replacement-donor subgroup that may be acceptable for routine donations. STUDY DESIGN AND METHODS: In a retrospective review and cohort study, the replacement-donor effect was separated from the new-donor effect. The relative effect the replacement donor has on the risk of transfusion-transmissible diseases, donor retention, and frequency of returning donations was then quantified by comparison against the effect of repeat volunteer donors. RESULTS: The replacement donor had 3.1 times the risk and 0.72 times the donor retention rate and made 0.81 times as many returning donations as the repeat volunteer donor. The figures for the new-donor effect were similar. The two risks were additive, making a new replacement donor particularly hazardous. If replacement donations only from repeat replacement donors were considered, the donor risk and the number of donations per returning donor were made comparable to those for the general (combined) volunteer donor. CONCLUSION: The negative effect of the replacement donor is similar in magnitude to that of the new volunteer donor. A replacement-donation program targeting repeat replacement donors has an acceptable risk profile and may be a valuable adjunct to the collection of blood from general volunteer donors.
Osmotic demyelination syndrome (ODS) is characterized by regions of demyelination throughout the brain, which are most prominent in the pons. This demyelinating disease is associated with electrolyte disturbances and typically occurs in patients who are alcoholic or malnourished. Movement disorders are not frequently recognized in patients with ODS. This report describes a 22-year-old woman with ODS after correction of profound hyponatremia. The main neurologic symptom was two-phase movement disorder. First, she had acute onset dystonia, then the movement disorder transformed to generalized rigidity and tremors in the delayed second phase. Magnetic resonance imaging in the first phase revealed demyelinating lesions in the central pons, bilateral thalami and basal ganglia. In the second phase, the previous myelinolysis had been partially resolved. The clinical course of the two-phase movement disorder did not correlate with the resolving feature of neuroradiologic findings. During the second-phase movement disorder, the patient had a good response to propranolol and trihexyphenidyl.
We retrospectively compared the efficacy of preoperative superselective and subselective embolization for intracranial meningiomas. Between January and December 1996, 22 patients (7 men, 15 women, mean age 51 +/- 15.5 yr) underwent superselective embolization with 45 to 150 mm polyvinyl alcohol particles after superselective catheterization of the feeding vessels with a microcatheter system. Another 30 patients (12 men, 18 women, mean age 50 +/- 12.9 yr) underwent subselective embolization between January and December 1995 with 150 to 300 mm Gelfoam particles after catheterization of the terminal external carotid artery just proximal to the orifice of the maxillary artery with a 4- or 5-F angiocatheter. The mean intraoperative blood loss (918 versus 1450 mL, p < 0.05), amount of blood transfused (4.9 versus 7.5 units, p = 0.09), and surgical resection time (422 versus 529 min, p < 0.05) were all lower in the superselective group than in the subselective group, while the occurrence of fresh ischemic necrosis (59% versus 53%, p = 0.68), hemorrhage (77% versus 60%, p = 0.19), and embolic material (55% versus 13%, p < 0.05) on pathologic examination were higher in the superselective group. No procedure-related complications occurred in the superselective group, whereas two patients in the subselective group had postoperative scalp necrosis. Our findings show that superselective embolization is more effective than subselective embolization for preoperative endovascular devascularization of meningiomas, with significant reductions in intraoperative blood loss and surgery time. Preoperative embolization of meningiomas, if indicated, should be done with the superselective technique whenever feasible.
We report a case of Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum), an uncommon disorder of uncertain pathogenesis characterized by disarrangement of the normal cerebellar laminar cytoarchitecture. A 40-year-old man was admitted because of vomiting and syncope of a few days' duration, and a 2-month history of intermittent headaches and unsteady gait. A computed tomographic scan of the patient's head showed obstructive hydrocephalus due to displacement of the fourth ventricle by a large, nonenhancing cerebellar mass. The magnetic resonance images of the brain also revealed a space-occupying lesion within the right cerebellum with unusual septation. After surgery, the histologic examination confirmed the diagnosis of Lhermitte-Duclos disease. This is the first report of Lhermitte-Duclos disease in Taiwan.
BACKGROUND: Microvascular decompression (MVD) is an effective technique for those who have trigeminal neuralgia (TN) but cannot tolerate, or show no response to medicine. Though the initial success rate is high, some patients may develop severe recurrent neuralgia, especially after a longer period of follow-up. The efficacy of reoperation needs to be evaluated. To know the possible risk factors of recurrence after initial MVD is mandatory to the management of recurrent TN. METHODS: Among the 80 cases of TN treated with MVD, five cases showed severe recurrent symptoms within a follow-up period from 9 months-4 years. The symptoms recurred on the same side of the face, and were unresponsive to medical treatment. Brain computed tomography (CT) and magnetic resonance imaging (MRI) may reveal the etiology of recurrence. Repeat decompression of the trigeminal nerve was the main goal of reoperation, which was done via a suboccipital approach. RESULTS: Over the past 17 years, 80 MVDs for TN have been performed at Chang Gung Memorial Hospital. There were five cases of serious postoperative recurrence, which could not be relieved by medicine. Recurrence occurred 1 day-12 months after the initial surgery. Three cases were due to vascular compression, while two were caused by the local effect of Teflon felt. Reoperation produced complete remission in four patients, and partial remission in one. CONCLUSIONS: An increasing number of patients may experience severe recurrent TN after initial MVD during a long period of follow-up. Reoperation is safe and beneficial for these patients, but the results are dependent on the etiology of the recurrence. Further vascular compression of the trigeminal nerve can be relieved by MVD. Otherwise, in cases of severe adhesion caused by Teflon, complete microneural lysis can achieve satisfactory results.
Red cell heterogeneity, as represented by the red cell distribution width (RDW), can be used to distinguish thalassemia traits from iron deficiency. Two other indices of heterogeneity, the hemoglobin distribution width and the cell hemoglobin distribution width (CHDW), are also available. In addition, the CHDW may reflect the process of cell hemoglobinization more accurately than does the RDW. In this study, recursive partitioning methods were used to compare the ability of these three indices to discriminate between thalassemia traits and other nonthalassemic conditions among hospital patients who had microcytosis. The data indicate that the CHDW can segregate patients who have either iron replete or iron deficient nonthalassemic conditions from those who have thalassemia traits. A CHDW level of less than 3.05 correctly discriminated 78.4% of patients in a mixed hospital sample. A CHDW/RBC ratio of 0.57 improved the segregation further, with a sensitivity of 79.2% and a specificity of 88.5% for the identification of a thalassemia trait.
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A 44-year-old man with a St. Jude mitral valve was admitted because of progressive pulmonary edema. He was diagnosed with prosthetic heart valve thrombosis (PHVT) based on the findings of "muffled" prosthetic valve clicks. Doppler echocardiographic evidence of severe mitral stenosis and transesophageal echocardiographic evidence of limited mitral valve motility. Because the patient hesitated to undergo our recommended surgical treatment, he was immediately treated with intravenous recombinant tissue plasminogen activator (100 mg over 3 h) followed by heparinization. Two hours after the thrombolytic therapy, the prosthetic valve clicks became clearly audible and his congestive symptoms were dramatically improved. Follow-up echocardiography no longer-showed significant mitral valve obstruction. A transient cerebral ischemic attack occurred at the end of thrombolytic therapy but there were no neurologic sequalae. The patient, on warfarin therapy, was well at follow-up 8 months after discharge. Surgical intervention has long been the standard therapy for patients with PHVT. Our case experience suggests that thrombolytic therapy may be considered as an effective alternative to surgical intervention for selected patients with PHVT. In this report, we also review the current literature regarding the indications, effectiveness and safety of thrombolytic therapy in PHVT.
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Twenty-two patients, aged 16 to 67, who had malignant gliomas after surgical resection were treated with carmustine and cisplatin intravenous infusion before, during, and after radiotherapy. All patients had subtotal or total resection, or biopsy as the initial procedure. Twenty-one patients who had at least 2 cycles of chemotherapy and finished the whole course of radiotherapy were considered to be evaluable for responses. Among them, 5 had glioblastoma multiforme, 16 had anaplastic astrocytoma. The median time to tumor progression was 35 weeks (range 12-130 weeks) and median survival time was 66 weeks (range 10-156 weeks). Early progression occurred more frequently in patients with biopsy only and subtotal resection, and in patients with glioblastoma than in those with anaplastic astrocytoma. This combined modality treatment program was associated with reversible hematologic toxicity which was severe in 2 patients, and with ototoxicity in 1 patient, nephrotoxicity in 2 patients. Combination of carmustine and cisplatin with cranial irradiation for malignant gliomas is moderately toxic and appears to offer no obvious survival advantage compared with radiation therapy plus BCNU alone.