Assessment of skull base involvement of nasopharyngeal carcinoma by bone SPECT using three detectors system]

SPECT of the skull was performed on twelve patients with histologically proven nasopharyngeal carcinoma using newly developed three detectors SPECT system (Toshiba GCA 9300A) mounted with fan-beam collimators, for the purpose of early detection of skull base involvement of the disease. This SPECT system has extremely improved resolution with FWHM of 8 mm in the center, and it provides clear tomographic images of the skull which has anatomically complex structure. SPECT image was taken 3 hours after injection of 740 MBq (20 mCi) of 99mTc-MDP following whole body skeletal survey. In twelve patients with confirmed nasopharyngeal carcinoma, 8 patients showed positive findings on SPECT. Three of SPECT positive patients also showed destructive findings on CT. Other five positive patients did not show destructive findings on CT at their initial examinations, but in three of them CT findings turned to positive later. SPECT was superior to CT in early detection of skull base involvement. We believe that SPECT of the skull is a diagnostic tool for early detection of skull base involvement of nasopharyngeal carcinoma.     

Postoperative infection with methicillin-resistant Staphylococcus aureus and its control measures in patients with esophageal cancer--prediction of high risk patients]

Whether or not compromised host defense prior to surgical treatment is related to development of infection with methicillin-resistant staphylococcus aureus (MRSA) following major surgery was examined. Of 22 patients undergoing esophagectomy for cancer between 1989 and 1990, 5 were free from MRSA colonization and infection (group I) while 8 had MRSA colonization without infection (group II) and 9 had MRSA infection (group III). Levels of neutrophil cytocidal functions, complements, immunoglobulins and cell-mediated immunity were not significantly different among these three groups. The mean of anti pneumococcal polysaccharide (PPS)-IgG was significantly lower in group III than in group I (p < 0.05) and tended to be lower than in group II (P = 0.08). All infected patients showed a titer < 600 EU while all but one non-infected patient did so > 600 EU. Serum IgG2 levels positively correlated with anti-PSS IgG levels. Thus, we concluded that a preoperative evaluation of antibody response against polysaccharides and serum IgG2 levels can serve to predict development of MRSA-related infection following esophageal surgery.     

Measurement of free and total hydroxyproline by automated flow injection of serum or urine samples from maintenance hemodialysis patients with renal osteodystrophy

An automated measurement of total and free hydroxyproline in serum or urine is presented that uses flow injection analysis. After exclusion of nonspecific substances, hydroxyproline was oxidized by chloramine- T and L-cysteine with Ehrlich's reagent. The linearity obtained was from 3.8μmole/ L to 1.22 mmole/L with good precision (CV <3%). Comparison of the proposed method with HPLC yielded r = 0.939 as the correlation coefficient. Reference intervals of free and total hydroxyproline are 1.4–9.7 μmole/L, 3.8–27.2 μmole/L for serum, and 10.0–72.5 μmole/L, 25.2–303.6 μmole/L for urine, respectively. Serum free and total hydroxyproline levels in renal osteodystrophy patients on maintenance hemodialysis (N = 71) were significantly higher than in controls (P<0.0001). This method is superior to the use of HPLC with regard to stability of the color reaction. The measurement of serum free and total hydroxyproline is a useful marker for therapeutic observation of renal osteodystrophy patients. © 1994 Wiley-Liss, Inc.     

Inhibition of inward rectifier K+ currents by angiotensin II in rat atrial myocytes: lack of effects in cells from spontaneously hypertensive rats.

We examined the effects of angiotensin II (Ang II) on inward rectifier K+ currents (IK1) in rat atrial myocytes. [125I]Ang II-binding assays revealed the presence of both Ang II type 1 (AT1) and type 2 (AT2) receptors in atrial membrane preparations. Ang II inhibited IK1 in isolated atrial myocytes with an IC50 of 46 nmol/l. This inhibition was abolished by the AT, antagonist RNH6270 but not at all by the AT2 antagonist PD123319. Treatment of cells with pertussis toxin or a synthetic decapeptide corresponding to the carboxyl-terminus of Gialpha-3 abolished the inhibition by Ang II, indicating the role of a Gi-dependent signaling pathway. Accordingly, Ang II failed to inhibit IK1 in the presence of forskolin, dibutyryl-cAMP or protein kinase A catalytic subunits. In spite of the increased binding capacities for [125I]Ang II, Ang II failed to affect IKI in cells from spontaneously hypertensive rats (SHR). AT, immunoprecipitation from atrial extracts revealed decreased amounts of Gialpha-2 and Gialpha-3 proteins associated with this receptor in SHR as compared with controls. The reduced coupling of AT, with Gialpha. proteins may underlie the unresponsiveness of atrial IK1 to Ang II in SHR cells.     

Pulmonary surfactant proteins and lipids as modulators of inflammation and innate immunity

Objectives: The pulmonary surfactant system of the human lung consists of unique lipids and proteins that contribute to the biophysical and innate immune properties of the organ. Surfactant protein A (SP‐A) is an oligomeric protein consisting of 18 protomers with collagen and lectin–like domains that recognizes glycoconjugates, lipids and protein determinants on both host cells and invading microorganisms. The authors examined the interaction of SP‐A with Mycoplasma pneumoniae and the influence of the protein upon the innate immune response to the bacteria. Methodology: The authors quantified SP‐A interaction with bacteria using ELISA, and identified the major surface ligand by thin layer chromatography, HPLC and mass spectrometry. The inflammatory response of human and rat macrophages was measured by quantifying tumour necrosis factor‐α secretion using ELISA, and nitric oxide production. Results: SP‐A bound the bacteria with high affinity and enhanced the inflammatory response of human and rat macrophages to the organism and its membranes. Analysis of the interaction of SP‐A with the bacteria revealed that the major ligand was a phospholipid. The lipid ligand was purified by a combination of thin layer and HPLC, and identified by mass spectrometry. The mass spectrometry demonstrated that the SP‐A reactive lipid consisted of several disaturated molecular species of phosphatidylglycerol (PtdGro). Additional experiments were performed to determine if disaturated PtdGro was capable of interfering with the action of SP‐A as an inhibitor of bacterial lipopolysaccharide‐induced inflammatory mediator production by macrophages. The disaturated PtdGro failed to alter the anti‐inflammatory action of SP‐A but unexpectedly these same studies revealed that unsaturated PtdGro can modify the host response to lipopolysaccharide. Conclusions: These findings reveal that both the lipids and proteins of pulmonary surfactant play a role in regulating the host response to invading microorganisms.     

Left anterior hemiblock studied by computer graphic electrocardiography

In order to find the three-dimensional distribution of ventricular depolarization potentials in left anterior hemiblock (LAHB) diagnosed by the conventional scalar ECG, 7 subjects with LAHB aged 9 to 62 years old who were otherwise healthy were studied by computer graphic electrocardiography (CGECG).Two modes of the initial ventricular depolarization (IVD) were noted. (1) The IVD appeared irregularly and separately on the mid- to lower central region of the anterior body surface. (2) The IVD appeared in a form rather like a parallelogram on the central region of the anterior body surface. Both (1) and (2) potentials propagated toward the left middle, lower, and lateral regions of the anterior body surface as normally observed; however, they were far lower in voltage than those observed in intact subjects.From the results, it has been concluded that LAHB may be, not a block, but rather a defective ventricular septal conduction.Presented at the 34th Annual Congress, International College of Angiology, Budapest, Hungary, July 1992.     

In vivo detection by microscopic chromocystoscopy of concurrent urothelial atypia in superficial bladder cancer.

Microendoscopic observation of methylene blue-stained urothelial surfaces, so-called microscopic chromocystoscopy (MCC), was undertaken in 65 patients with superficial bladder cancer (Ta and T1) and its effectiveness in detecting concurrent urothelial dysplasia or carcinoma in situ was studied. A total of 166 biopsy samples were taken from 75 stained and 91 non-stained portions. Of 75 methylene blue-stained areas, 21 were judged to be abnormal (MCC-positive) by microscopic observation. Fourteen of these 21 MCC-positive areas (67%) were proven to be abnormal histologically, while 7 of 54 MCC-negative portions (13%) were histologically abnormal. Only 4 of 91 biopsies (4%) from non-stained mucosa were proven to have urothelial atypia. In per patient figures, 1 or more concurrent field changes were detected in 15 of 65 cases (23%). MCC contributed to the diagnosis in 10 of these 15 patients.     

A brainstem variant of reversible posterior leukoencephalopathy syndrome (RPLS) presenting with visual disturbance]

A 40-year-old woman noticed blurred vision of the right eye. The optic disc edema of bilateral eyegrounds was noted, and brain MRI showed abnormal signals of the brainstem at a neurosurgical clinic. On her first visit, blood pressure was as remarkably high as 250/130 mmHg. Neurologically, only optic disc edema of bilateral eye-grounds was found. Both T2-weighted MRI and FLAIR showed hyperintense signal areas mainly from the ventral pons to medulla oblongata. These areas were not enhanced with gadolinium. About three weeks after the administration of an antihypertensive agent, brain MRI revealed no abnormal signal. About three months later, the blurred vision disappeared and ophthalmological abnormalities subsided. We diagnosed her with a brainstem variant of RPLS, presenting with visual disturbance caused by hypertensive retinopathy.     

Mild Hypercapnia Induces Vasodilation via Adenosine Triphosphate-sensitive K+ Channels in Parenchymal Microvessels of the Rat Cerebral Cortex

Background: Carbon dioxide is an important vasodilator of cerebral blood vessels. Cerebral vasodilation mediated by adenosine triphosphate (ATP)-sensitive K+ channels has not been demonstrated in precapillary microvessel levels. Therefore, the current study was designed to examine whether ATP-sensitive K+ channels play a role in vasodilation induced by mild hypercapnia in precapillary arterioles of the rat cerebral cortex.

Methods: Brain slices from rat cerebral cortex were prepared and superfused with artificial cerebrospinal fluid, including normal (Pco2 = 40 mmHg; pH = 7.4), hypercapnic (Pco2 = 50 mmHg; pH = 7.3), and hypercapnic normal pH (Pco2 = 50 mmHg; pH = 7.4) solutions. The ID of a cerebral parenchymal arteriole (5-9.5 [mu]m) was monitored using computerized videomicroscopy.

Results: During contraction to prostaglandin F2[alpha] (5 x 10-7 m), hypercapnia, but not hypercapnia under normal pH, induced marked vasodilation, which was completely abolished by the selective ATP-sensitive K+ channel antagonist glibenclamide (5 x 10-6 m). However, the selective Ca2+-dependent K+ channel antagonist iberiotoxin (10-7 m) as well as the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (10-4 m) did not alter vasodilation. A selective ATP-sensitive K+ channel opener, levcromakalim (3 x 10-8 to 3 x 10-7 m), induced vasodilation, whereas this vasodilation was abolished by glibenclamide.