Intracisternal infusion of magnesium sulfate solution improved reduced cerebral blood flow induced by experimental subarachnoid hemorrhage in the rat

Magnesium has neuroprotective and antivasospastic properties in the presence of subarachnoid hemorrhage (SAH). The present study investigated the effect of intracisternal administration of magnesium on cerebral vasospasm in the experimental SAH rat model. The rat double-SAH model (0.2 mL autologous blood injected twice into the cisterna magna) was used. Normal saline (SAH group, N = 8) or 10 mmol/L magnesium sulfate in normal saline (SAH + MG group, N = 8) was infused into the cisterna magna at 1.5 μL/min for 30 min on day 5. Control rats without SAH also received intracisternal infusion of normal saline (control group, N = 6). Local cerebral blood flow (CBF) at 24 locations and the weighted average were quantitatively measured by the autoradiographic technique using [¹⁴C]iodoantipyrine during infusion. The weighted average CBF was significantly reduced (P < 0.01, Student’s t-test) in the SAH group (0.78 ± 0.16 mL g⁻¹ min⁻¹) compared to the control group (1.0 ± 0.15 mL g⁻¹ min⁻¹) and was significantly improved (P < 0.01, Student’s t-test) in the SAH + MG group (0.98 ± 0.18 mL g⁻¹ min⁻¹). Local CBF was significantly reduced (P < 0.05, unpaired t test) in 16 locations in the SAH group and significantly improved (P < 0.05, unpaired t test) in 12 locations in the SAH + MG group. Intracisternal infusion of magnesium sulfate significantly improved reduced CBF induced by experimental SAH in the rat.     

Influence of output energy and pulse repetition rate of the Er:YAG laser on dentin ablation

OBJECTIVE: We sought to improve the efficiency of dentin ablation with the Er:YAG laser by investigating the effects of output energy and pulse repetition rate on ablation. Background Data: The Er:YAG laser is superior to other lasers in ablating dental hard tissues. However, the factors affecting the efficiency of ablation with an Er:YAG laser remain unclear. METHODS: Fifty bovine root dentin plates were irradiated with an Er:YAG laser at an output power of 1.0 W, 1.5 W, or 2.0 W under a water spray while moving the plate at 1 mm/sec. After irradiation, the depth and volume of each ablated site were measured by laser microscopy and the ablated surfaces were examined by scanning electron microscopy. RESULTS: The output power showed a strong positive correlation with the depth and volume of ablation. The output energy had much more pronounced effects on the depth and volume of ablation compared to the pulse repetition rate. The shape of the ablated site varied with the output power, and no cracking or vitrification was observed under the irradiated dentin. The most effective parameters for dentin ablation were an output power of 2.0 W, with an output energy of 80 mJ/pulse at 25 pulses per second (pps) or 100 mJ/pulse at 20 pps. CONCLUSION: These findings suggest that the output energy is the main factor affecting the efficiency of dentin ablation with an Er:YAG laser. We propose that the efficiency of dentin ablation can be improved by choosing an optimal combination of output energy and repetition rate.     

Association of cavernous malformation within vestibular schwannoma: immunohistochemical analysis of matrix metalloproteinase-2 and -9

A 65-year-old man presented with a rare case of cavernous malformation with hemorrhage located within vestibular schwannoma. He had suffered hearing impairment for 20 years, and was admitted to our hospital with vertigo and ataxic gait. Neurological examination revealed hearing loss, facial nerve paresis, and left cerebellar ataxia. Magnetic resonance imaging demonstrated a left vestibular schwannoma 35 mm in diameter, as well as a heterogeneous area associated with hypointense rim within the tumor, indicating intratumoral hemorrhage. Subtotal removal of the tumor together with the fibrously encapsulated hematoma was performed through a left retrosigmoid craniotomy. Histological examination of the surgical specimen revealed cavernous malformation within vestibular schwannoma. Immunohistochemistry for matrix metalloproteinase (MMP)-2 and -9, and tissue inhibitors of metalloproteinase-2 showed strong expression in the endothelial cells of the cavernous malformation, but not in the interstitial structures. His symptoms significantly improved after surgery and he underwent gamma-knife therapy for the residual tumor. Cavernous malformations may show dynamic characteristics such as repeated hemorrhage and de novo formation. MMP-2 and -9, which are implicated in angiogenesis and hemorrhage, may be upregulated in such tumors.     

Idiopathic Granulomatous Appendicitis Treated Surgically with Long-Term Follow-Up: Report of a Case

Isolated granulomatous inflammation of the appendix is extremely rare, and its etiology is still unknown. Thus, differentiating between idiopathic granulomatous appendicitis and isolated appendiceal Crohn's disease is difficult. We report a case of idiopathic granulomatous appendicitis with long-term follow-up after surgery. A 26-year-old woman was referred to our hospital for investigation of persistent right lower abdominal pain. Abdominal computed tomography showed a mass, suggesting an inflammatory tumor around the appendix; thus, we suspected subacute appendicitis and performed laparoscopically assisted ileocecal resection. Histological examination of the resected specimen revealed several noncaseous epithelioid granulomas in the wall of the appendix, but no foreign bodies, obstructing lesions, or parasites. Stains for acid-fast bacillus and fungi, and serology for yersinia were all negative. The patient has been followed up for 9 years and remains asymptomatic. This clinical course suggests that her isolated granulomatous appendicitis was idiopathic granulomatous appendicitis unrelated to Crohn's disease.     

Temporary neurologic deterioration due to cerebral hyperperfusion after superficial temporal artery-middle cerebral artery anastomosis in patients with adult-onset moyamoya disease

BACKGROUND: Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving CBF, but little is known about the change in CBF and its effect on neurologic status during the acute stage after revascularization. METHODS: 123I-IMP-SPECT was performed 1 and 7 days after STA-MCA anastomosis on 34 sides of 27 consecutive patients with adult-onset moyamoya disease (6 men, 21 women; 22-62 years old). The follow-up period ranged from 5 to 28 months (mean, 17.6 months). RESULTS: Thirteen patients (13 sides, 38.2%) suffered temporary neurologic deterioration due to hyperperfusion several days after surgery, which was sustained for several days (7.4 days in average). Postoperative magnetic resonance imaging/angiography showed the STA as a higher intensity signal than the preoperative finding without ischemic changes in all 13 patients. Postoperative SPECT revealed focal intense increase in CBF at the sites of anastomosis in all 13 patients. Eleven patients (32.4%) had transient focal neurologic deficit mimicking ischemic attack. Two patients (5.9%) had cerebral hyperperfusion syndrome associated with subarachnoid hemorrhage extending to the ipsilateral sylvian cistern. Symptoms were relieved by intensive blood pressure control, and no patients had permanent neurologic deficit or delayed neurologic deterioration during the follow-up period. CONCLUSIONS: Surgical revascularization including STA-MCA anastomosis is a safe and effective treatment for moyamoya disease, although temporary neurologic deterioration due to hyperperfusion could occur at a substantial rate. Routine CBF measurement is recommended for accurate diagnosis of postoperative hyperperfusion in moyamoya disease because its treatment is contradictory to that for ischemia.     

Seizure following superficial temporal-middle cerebral artery anastomosis in patients with moyamoya disease: possible contribution of postoperative cerebral hyperperfusion

Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving cerebral blood flow (CBF). Seizure is known as a rare complication after revascularization for moyamoya disease, although its underlying mechanism is undetermined. We investigated the relationship between seizure attack and postoperative alteration in CBF in patients with moyamoya disease. CBF was routinely measured by N-isopropyl-p-[123I] iodpamphetamine (123I-IMP-SPECT) 1 and 7 days after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis on 64 sides of the 44 consecutive patients (male:female = 13:31, 2-62 years old) with moyamoya disease. Three patients (male:female = 1:2, 40-55 years old) suffered from seizure attack at 1 to 10 days after surgery. Two of the three patients manifested as seizures at 8-10 days after surgery and presented transient neurologic deteriolation before seizure. Postoperative SPECT revealed significant increase in CBF at the sites of the anastomosis in all three patients. Postoperative magnetic resonance imaging showed no ischemic changes, and magnetic resonance angiography showed the apparently patent STA-MCA anastomosis as thick high signal intensity sign in all three patients. The anatomical location and the temporal profile of hyperperfusion were completely in accordance with the focus of seizure attack. Intensive blood pressure control and the use of antiepileptic agents were instituted. The neurologic deficits were resolved and no seizure attack recurred in three patients. Seizure following STA-MCA anastomosis can be caused by hyperperfusion in patients with moyamoya disease. When seizure attacks occur, routine CBF measurement is recommended to differentiate hyperperfusion and ischemia, since the treatments for these conditions are contradictory.     

Preoperative and intraoperative evaluation of diameter-reflux relationship of calf perforating veins in patients with primary varicose vein

OBJECTIVE: Interruption of incompetent perforating veins (PVs) is important for varicose vein surgery. The purpose of this study was to evaluate the preoperative and intraoperative diameter-reflux relationship of PVs and to evaluate the accuracy of preoperative duplex scanning in patients with varicose vein. METHODS: Patients with primary varicose veins were retrospectively investigated. Diameters and reflux of PVs were evaluated before surgery with color flow duplex ultrasound scan (US). During operation, the incompetent PVs were defined as those that showed an outward spurt of blood flow from the stump of the PVs. The sensitivity and specificity of US in the detection of reflux of PVs were calculated. Competent versus incompetent vein diameters were compared with the Student t test and one-way analysis of variance. RESULTS: Three hundred twenty-four calf PVs were detected in 304 legs of 175 patients with varicose vein. Diameters of competent and incompetent PVs confirmed with intraoperative finding averaged 2.67 +/- 1.10 mm (n = 28) and 3.28 +/- 1.01 mm (n = 58), respectively, at the upper calf (P =.012), 2.85 +/- 0.85 mm (n = 53) and 3.68 +/- 0.94 mm (n = 137), respectively, at the lower calf (p <.001), and 2.67 +/- 0.99 mm (n = 14) and 3.27 +/- 0.66 mm (n = 22), respectively, at the posterior calf (P =.036). The overall sensitivity of detection of reflux with US was 87.7%, and the specificity was 75.3%. Diameters of true-incompetent PVs and false-incompetent PVs were 3.59 +/- 0.94 mm (n = 199) and 3.31 +/- 0.84 mm (n = 24), respectively (P =.157). Diameters of true-competent PVs and false-competent PVs were 2.61 +/- 0.91 mm (n = 73) and 2.89 +/- 0.82 mm (n = 28), respectively (P =.158). CONCLUSION: Although the diameter of incompetent PVs was larger than that of competent PVs in both US and intraoperative findings, diameter measurement alone can not completely distinguish competent and incompetent PVs. The sensitivity and specificity of reflux obtained with US showed that the accuracy of preoperative duplex scanning to evaluate PV competency was not sufficient.     

Efficacy and safety of immunization for pre- and post- liver transplant children

BACKGROUND: Infection is a serious complication after liver transplantation. Immunization is one means of controlling infections. The objective of this study was to investigate the efficacy and safety of simultaneous administration of several vaccines before transplantation and the efficacy and safety of administration under immunosuppressive conditions after transplantation. METHODS: Fifty-eight patients who underwent living-related liver transplantation between April 1994 and March 2000 were included in this study. Simultaneous administration of a maximum of six vaccines was performed in a short period of time before transplantation. We also readministered vaccines to 15 patients with waning antibody titers after transplantation from June 1999. We investigated whether patients could seroconvert for measles, rubella, mumps, and varicella after immunization and how long antibody titers could be retained by measuring them several times throughout the period before and after transplantation. We also examined side effects caused by immunization. RESULTS: The rates of seroconversion against measles, rubella, mumps, and varicella after the pretransplantation vaccination were 82%, 100%, 90%, and 95%, respectively. The rates of reseroconversion against measles, rubella, mumps, and varicella after the posttransplantation revaccination were 85%, 100%, 100%, and 71%, respectively. Although antibody titers against these viruses generally waned with time, no patient exhibited any serious illness or side effects. CONCLUSION: Although 12 of 58 patients (21%) had an infection, pretransplantation immunization was effective to prevent serious illness, especially for the 6 months after transplantation. Posttransplantation live-vaccine administration under immunosuppressive conditions is effective and safe.     

Penetration of linezolid into rabbit intervertebral discs and surrounding tissues

Linezolid belongs to a new class of synthetic antimicrobial agent that is effective for a variety of methicillin-resistant Staphylococcus aureus (MRSA) infections including bone and joint MRSA infections, but the effectiveness of linezolid for the treatment of MRSA spine infection remains controversial. In this study, we investigated the diffusion of linezolid or vancomycin into normal rabbit spinal tissues to determine the adequacy of linezolid for the treatment of spinal infection. The penetration efficacy of linezolid into the annulus fibrosus, nucleus pulposus, and vertebral bone (10, 8, and 10%, respectively) was lower than that of vancomycin (27, 11, and 14%, respectively). The penetration efficacy of linezolid into the bone marrow and iliopsoas muscle (88 and 84%, respectively), however, was higher than that of vancomycin (67 and 9%, respectively). These results suggest that linezolid is inadequate for the treatment of spine infection limited to the intervertebral disc, but may be effective for the treatment of infection extending into the muscle and bone marrow, such as in vertebral osteomyelitis, iliopsoas abscess, and postsurgical infection.