Echocardiographic evaluation of vagolytic effects of atropine sulfate during pediatric halothane anesthesia

The aims of this study were to define the antagonistic effects of atropine sulfate to halothane-induced cardiovascular depression in children, and to clarify whether or not a larger dose of atropine is more effective in attenuating the cardiovascular depression. Thirty-four children aged 1–12 years who had undergone minor surgery, free from cardiac or pulmonary disease, were assigned at random to two groups. M-mode echocardiographic evaluation of left ventricular function in each patient was performed at three points (before induction, point A; after induction, point B; and following administration of atropine, point C). Results were compared between points A and B, B and C and C and A, and between the two study groups with different doses of atropine (0.01 mg/kg vs 0.02 mg/kg). Heart rate (HR), mean blood pressure (MBP) and left ventricular shortening fraction (LVSF) decreased, and left ventricular end-diastolic dimension (LVEDD) were increased significantly by halothane induction. Although HR and MBP recovered following atropine, LVSF and LVEDD remained unchanged. There were no differences found between the values after vagolysis in both study groups, except for HR and mean velocity of circumferential fiber shortening (mVcf). Heart rate increased above that of pre-induction, even following the smaller dose of atropine. The myocardial depression cannot be necessarily attenuated by vagolysis regardless of the dosage of atropine. The smaller dose (i.e. 0.01 mg/kg) seems to be sufficient only to antagonize the bradycardia and hypotension during halothane anesthesia in children.     

Endoscopic Reduction of Acute Gastric Volvulus in a Child

Abstract: An 11-year-old girl with cerebral palsy was admitted with complaints of frequent vomiting and upper abdominal distension. After plain X-ray examination and upper gastrointestinal contrast study, she was diagnosed as having acute mesenterioaxial volvulus of the stomach. Endoscopic reduction was successfully performed. We describe herein the technical details of the endoscopic reduction in this rare case. In non-infant pediatric patients with primary gastric volvulus, we recommend that endoscopic reduction be considered prior to surgical intervention.     

Identifying Cerebral Large Vessel Occlusion in Acute Ischemic Stroke by MRI Positioning Scanning

Various approaches have been tried for acute ischemic stroke (AIS) treatment to shorten the time from onset to recanalization. MRI positioning scanning (PS), which must be taken before any MRI sequences, was examined whether it can detect cerebral large vessel occlusion. A total of 68 consecutive patients with AIS who underwent MRI and were treated with intravenous recombinant tissue plasminogen activator or mechanical thrombectomy at our hospital were retrospectively included in this study. Occluded vessels were identified on the axial or coronal views of PS images, and these images were compared with 3D time-of-flight MRA and digital subtraction angiogram. The sensitivities, positive predictive values (PPVs), and negative predictive values (NPVs) for internal carotid artery (ICA), the proximal M1, distal M1, and M2 segment of the middle cerebral artery occlusion were assessed, and the number of PS slices was assessed. The sensitivities of the axial slices for ICA, proximal M1, distal M1, and M2 occlusion were 62%, 21%, 35%, and 86%, respectively. The PPVs of the axial slices for ICA, proximal M1, distal M1, and M2 occlusion were 81%, 88%, 100%, and 97%, respectively, and the NPVs of the axial slices for ICA, proximal M1, distal M1, and M2 occlusion were 94%, 90%, 86%, and 100%, respectively. The detection rate for the ICA was significantly higher with three axial slices (91%) than with two slices (47%) (p <0.01). MRI PS is warranted to be referred to detect large cerebral vessel occlusion.     

Histochemical localisation of versican, aggrecan and hyaluronan in the developing condylar cartilage of the fetal rat mandible

We investigated the histochemical localisation of versican, aggrecan and hyaluronan in the developing condylar cartilage of the fetal rat mandible at d 15–17 of gestation. At d 15 of gestation, immunostaining for versican was detected in the anlage of the future condylar process (condylar anlage), although the staining intensity showed a considerable regional variation. At d 16 of gestation, a metachromatically stained matrix firstly appeared in the condylar anlage. Aggrecan, hyaluronan and versican were simultaneously detected in this newly formed condylar cartilage. At d 17 of gestation, immunostaining for versican became restricted to the perichondrium and was barely detected in the cartilage. Colocalisation of versican and aggrecan was also seen in the cranial base cartilage at d 14 of gestation. These results indicate that although versican is replaced by aggrecan during the transition from prechondrogenic tissue to cartilage, both molecules were temporally colocalised in the newly formed cartilage. A hyaluronan-rich, low-versican area was identified in the posterior end of the condylar anlage during d 15–17 of gestation. The existence of this area is a unique structural feature of the developing condylar cartilage.     

Potentiations of N-Methylcarbamate Toxicities by Organophosphorus Insecticides in Male Mice

Potentiations of N-Methylcarbamate Toxicities by OrganophosphorusInsecticides in Male Mice. TAKAHASHI, H., KATO, A., YAMASHITA,E., NAITO, Y., TSUDA, S., and SHIRASU, Y. (1987). Fundam. Appl.Toxicol. 8, 139–146. A N-methylcarbamate insecticide,2-sec-butylphe-nyl N-methylcarbamate (BPMC), is markedly potentiatedby low-dose treatments of P=S type organophosphorus insecticides.As a mechanism of this potentiation, the increase of plasmaBPMC concentrations due to the inhibited metabolic degradationhas been suggested. In this study, acute toxicities of fiveN-methylcarbamates structurally related to BPMC were studiedafter low-dose treatments of three P=S type organophosphorusinsecticides (cyanophos, feni-trothion, and malathion) and oneP=O type organophosphorus insecticide (dichlorvos), and therole of plasma concentrations of N-methylcarbamates in the potentiationswas examined. Acute toxicities of five N-methylcarbamates werepotentiated by the treatments of the P=S types, among whichthe potentiation of BPMC was strongest. BPMC toxicity was notpotentiated by the treatment of the P=O type. Plasma concentrationsof BPMC were increased by the treatments of the P=S types, butnot by the treatment of the P=O type. The acute toxicity andplasma concentrations of BPMC were increased by SKF 525-A (aninhibitor of mixed-function oxidase). These results suggestthat the increase of plasma BPMC concentrations may be relatedto the potentiation of BPMC toxicity. The treatment of fenitrothionincreased plasma concentrations of other N-methylcarbamatesmore than those of BPMC, although the potentiation of BPMC toxicitywas strongest. SKF 525-A and fenitrothion treatments increasedplasma BPMC concentrations to a similar degree, but the potentiationof BPMC toxicity by SKF 525-A was significantly less than thatby fenitrothion. Thus, some other mechanism(s) may be responsiblefor the potentiations of the N-methylcarbamate toxicities.     

A quantitative assessment of serum chylomicron by light scattering intensity: Application to the intestinal fat absorption test

A novel fat absorption test to clarify the malabsorption syndrome was developed using a micronephelometric technique and compared with the classic conventional technique using ¹³¹I-triolein. An integrity of time-sequential light scattered from chylomicron-related turbidity in serum was determined between 0 and 300 min after butter fat load, being expressed in terms of the light scattering intensity (LSI). A good correlation was obtained between LSI and the serum level of chylomicron-triglyceride determined by an ultracentrifugation technique (r=0.819, P < 0.001). The maximal LSI was consistently observed at 180 min after administration of a test meal in the normal group (n= 39), whereas the malabsorption syndrome group (n= 35) was distinctly different and could be further classified according to four patterns of LSI changes. In addition, an inverse correlation was found between this fat absorption test and the ¹³¹I-triolein absorption test. It was concluded that the micronephelometric technique which does not use a radionuclide is advantageous in its simple and safe evaluation of fat malabsorption syndrome.     

Histological findings in asymptomatic hepatitis C virus carriers

There is controversy about clinical management of individuals who persistently have hepatitis C virus antibodies (HCVAb) but who have no symptoms or signs of liver disease. Liver biopsy samples were taken from 15 individuals, all of whom had normal alanine aminotransferase (ALT) levels, to determine the prevalence of liver disease and whether HCVAb and HCV-RNA correlate with histological findings. Eleven patients with hepatitis C viremia had histological evidence of chronic hepatitis on biopsy. On the other hand, four HCV-RNA-negative individuals had almost normal liver histology. These findings indicate that serum HCV-RNA is a sensitive and specific marker of liver disease in HCVAb-positive subjects, independent of ALT levels. Furthermore, these results suggest that there are very few histologically healthy carriers of HCV among HCV-RNA-positive individuals.