A guide to initial management of minor head injury

We reviewed the records of 1,335 minor head injury patients with initial Glasgow Coma Scale (GCS) scores of 15 treated by our neurosurgery service between January 1998 and December 2000. Skull X-ray was performed in 945 patients (71%), and Computed tomography (CT) was performed in 590 patients (44%). Skull fracture was shown radiographically in 24 patients (2.5%), and abnormalities on the initial CT were seen in 29 patients (4.9%). The most frequent intracranial lesion on CT was acute epidural hematoma with skull fracture. Significantly more intracranial lesions were found in those with a fracture than in those without by chi2 analysis. Post-traumatic vomiting was significantly associated with radiographical abnormalities, but headache and nausea did not increase the risk of skull fracture and intracranial lesions on the CT. Patients required neurosurgical intervention in 4 cases, and all of those were acute epidural hematoma with skull fracture. In this study, the first thing we should do for asymptomatic minor head injury patients with a GCS score of 15 is to investigate the presence of a skull fracture by skull X-ray. Head trauma patients with a skull fracture and post-traumatic vomiting should undergo CT to facilitate detection of intracranial lesions, even when there are no abnormal neurological signs.     

CYP3A4*18: it is not rare allele in Japanese population

We sequenced all 13 exons of the CYP3A4 gene derived from 48 Japanese subjects. One subject possess the 20070 T>C mutation in the exon 10 (result in leu293Pro substitution, namely CYP3A4(*)18), as heterozygote. Thus, we investigated the frequency of CYP3A4(*)18 in 118 Japanese population using polymerase chain reaction-restriction fragment length polymorphism with Msp I and determined that the frequency of the CYP3A4(*)18 allele was 1.3%.     

The sympathomimetic actions of l-ephedrine and d-pseudoephedrine: direct receptor activation or norepinephrine release?

The basic mechanisms by which ephedrine is preferred over other vasopressors in obstetric anesthesia have not been clearly defined. We examined the sympathomimetic effects of l-ephedrine, currently used as a vasopressor, and d-pseudoephedrine, currently used as a decongestant. In anesthetized rats, l-ephedrine and d-pseudoephedrine caused dose-dependent increases in arterial blood pressure and heart rate, and these effects disappeared after destruction of the sympathetic nerve terminals with 6-hydroxydopamine (6-OHDA) pretreatment. The two ephedrine isomers produced concentration-dependent increases in tension of anococcygeal muscle and sinus rate of right atrium from rats. However, the anococcygeal and atrial responses to d-pseudoephedrine were abolished after 6-OHDA pretreatment, whereas approximately 50% of the responses to l-ephedrine were 6-OHDA-resistant. In human umbilical artery and vein, the two isomers failed to generate any contraction when given at the concentration that is capable of producing significant effects on anococcygeal and atrial tissues. Although direct adrenoceptor activation with l-ephedrine was detectable at tissue levels, the pressor response in vivo was entirely attributable to norepinephrine release from sympathetic nerves. This indirect mechanism could partly explain why l-ephedrine is better at increasing maternal arterial blood pressure while preserving the uteroplacental blood flow that is devoid of the involvement of the sympathetic innervation. IMPLICATIONS: The indirectly sympathomimetic property of l-ephedrine may be one of the mechanisms to explain why ephedrine is preferred over alpha-adrenergic agonists as a vasopressor for treatment of intraspinal anesthesia-induced hypotension in obstetrics.     

The development of new method for the assessment of perfusion reserve using split dose iodine-123-IMP SPECT: one-day protocol by modified ARG method

Evaluation of the regional cerebrovascular reactivity (rCVR) to a cerebral vasodilatory stimulus is important in the investigation of patients with ischemic cerebrovascular disease. We devised a simplified one-day protocol technique using [123I]N-isopropyl-p-iodoamphetamine (IMP) autoradiography (ARG) with SPECT. To validate the accuracy of IMP-ARG for quantifying rCVR to acetazolamide, we compared rCVR measured using IMP-ARG with rCVR calculated using IMP split dose method of microsphere model. Twenty patients with chronic steno-occlusive disease in a unilateral major cerebral artery underwent 123I-SPECT. On rCBF SPECT image above 3.5 cm from OM line, large cortical regions of interest (ROI) was bilaterally determined for bilateral middle cerebral artery and anterior cerebral artery. Based on rCBF values in each ROI, rCVR to acetazolamide was calculated. Significant correlation was observed between rCVR values obtained using IMP-ARG and microsphere model IMP methods in the 80 ROIs examined in the 20 patients (r = 0.72; p < 0.001). The result demonstrated that [123I]IMP-ARG split dose method can quantify rCVR non-invasively in a short time.     

Postnatal changes in the connective tissue in the region lateral to the eustachian tube: possible relationship to tube function

In order to delineate the possible role of connective tissue (CT) in the region lateral to the eustachian tube (ET) between the ET lumen and the tensor veli palatini muscle (TVPM), we studied the postnatal changes in the CT in histologic sections of human ET. In fetuses and neonates, the lateral region was filled with mesenchyme. Loose collagenous CT appeared first at 2 weeks of age, and in subjects older than 4 years of age, the collagen formed dense, meshlike structures attaching to both the subepithelial CT layer of the ET and the tendonlike membrane of the TVPM. Along the long axis of the ET, those attachments were distributed mainly in the region at the posterior part of the cartilaginous portion of the ET. Attachments to the subepithelial CT layer of the ET were distributed mainly in the upper half of the region. The dense, meshlike collagenous CT might help the ET to be opened by drawing the lateral wall of the ET lumen through inferolateral movement of the tendonlike membrane of the TVPM when the TVPM contracts. It may work to open mainly the parts that include the narrowest portion of the ET, and also the upper aspect of the ET lumen. Incomplete development of this structure in infants may be one of the factors associated with dysfunction in ET opening.     

Flow Cytometric Measurements of Somatic Cell Mutations in Thorotrast Patients

Exposure to ionizing radiation has long been well-recognized as a risk factor for cancer development. Since ionizing radiation can induce mutations, an accurate way of measuring somatic mutation frequencies could be a useful tool for evaluating cancer risks. In the present study, we have examined in vivo somatic mutation frequencies at the erythrocyte glycophorin A (GPA) and T-cell receptor (TCR) loci in 18 Thorotrast patients who have been continuously irradiated with alpha-particles emitted from the internal deposition of thorium dioxide and who thus have increased risks of certain malignant tumors. When compared with controls, the results showed a significantly higher frequency of mutants at the lymphocyte TCR loci but not at the erythrocyte GPA loci in the Thorotrast patients. The discrepancy between the results of the two assays is discussed.     

Dehydrothermal treatment of collagen influences on bone regeneration by octacalcium phosphate (OCP) collagen composites

We have engineered a scaffold constructed of synthetic octacalcium phosphate (OCP) and collagen composites (OCP-collagen) and report that OCP-collagen significantly enhanced bone regeneration more than the implantation of OCP. We hypothesized that the dehydrothermal treatment (DHT) during the fabrication of OCP-collagen might influence bone regeneration by OCP-collagen. To examine this hypothesis, bone regeneration by the implantation of OCP-collagen with DHT [OCP/Col(+)] was compared with that by OCP-collagen without DHT [OCP/Col(-)]. It was confirmed that both OCP/Col(+) and OCP/Col(-) contained the characteristics of OCP structure in X-ray diffraction. Before implantation, calcium deposition derived from OCP was observed within the collagen of both OCP/Col(+) and OCP/Col(-) by undecalcified histological sections. OCP/Col(+) or OCP/Col(-) was implanted into the critical-sized defects in rat crania. Radiographic and histological examination was performed and the percentage of newly formed bone (n-Bone%) in the defect was determined by a histomorphometrical analysis. N-Bone% treated with OCP/Col(+) was significantly higher than that with OCP/Col(-) at 4 and 12 weeks after implantation, because fast degradation of the implanted collagen of OCP/Col(-) elicited disappearance of the scaffold for bone regeneration. The stiffness of the calcified collagen in OCP-collagen would be more important than the existence of calcified collagen to enhance the bone regeneration by OCP-collagen composites. The present study suggests that the dehydrothermal treatment would influence effective bone regeneration by OCP-collagen.     

Severe <Emphasis Type="Italic">Chlamydophila psittaci</Emphasis> pneumonia rapidly diagnosed by detection of antigen in sputum with an immunochromatography assay

We report a case of severe Chlamydophila (Chlamydia) psittaci pneumonia rapidly diagnosed by detection of antigen in sputum with an immunochromatography assay. The patient was admitted to our hospital because of shock, disturbance of consciousness, accidental hypothermia, and multiple organ dysfunction syndrome, and he recovered after administration of intravenous erythromycin and high-dose methylpredonisolone therapy. Psittacosis was confirmed by detection of 16S rRNA gene of C.psittasi in sputum with multiplex-polymerase chain reaction analysis. Serological responses to C. psittasi, C. trachomatis, and C. pneumoniae were also evaluated, and serological cross-reactivity was observed between each species. We consider that the commercially available immunochromatography assay for Chlamydia species can be helpful for rapid diagnosis of Chlamydia infection of the respiratory tract. Hereafter, further examination will be necessary regarding pretreatment of specimens or detection sensitivity and specificity.     

Seeding of Gallbladder Carcinoma along the Tract after Percutaneous Transhepatic Choledochoscopy

An implant metastasis developed along the tract after percutaneous transhepatic cholecystoscopy 5 months after initial placement of the catheter into the gallbladder. Percutaneous transhepatic cholecystoscopy is conducted by insertion of choledochofiberscope into the gallbladder through the dilated sinus tract established around a catheter inserted into the gallbladder. The catheter had been placed for total of 15 days. Two days after the removal of the catheter, cholecystectomy supplemented by partial resection of the liver was carried out because of the extent of a gallbladder carcinoma. The choledochofiberscope used was Olympus CHF type 4B, with a thinner flexible part 5.0 mm in diameter. It is not surprising that carcinoma of the biliary tract or pancreas may seed along the tract of a biliary drainage catheter, but only few reports describing such incidence related to percutaneous transhepatic biliary drainage have previously been published. Physicians should be aware of this complication whenever a firm nodule develops at the site of previous entry of a biliary drainage catheter in a patient with malignant obstruction.