Subarachnoid Hemorrhage Confirmed by Magnetic Resonance Imaging in a Patient with Brain Death owing to Hypoxic Encephalopathy Following Suicide by Hanging

Although true subarachnoid hemorrhage (SAH) is an atypical complication owing to suicide by hanging, pseudo-SAH can often develop because of hypoxic encephalopathy. Therefore, differentiating pseudo-SAH from true SAH using brain computed tomography (CT) is often challenging. In Japan, an individual's cause of brain death must be determined to be eligible for organ donation, regardless of whether true SAH is involved or not. Herein, we report a case of SAH confirmed by magnetic resonance imaging (MRI) in a patient with brain death owing to hypoxic encephalopathy following suicide by hanging. A 48-year-old man attempted suicide by hanging. Upon arrival at the hospital, he developed pulseless electrical activity with apnea. Although spontaneous circulation returned within a few minutes of his arrival, spontaneous breathing did not recover. The patient was in deep comatose state without response to pain stimulation, brainstem reflexes, or electrical activities on an electroencephalogram. Consequently, the patient met diagnostic criteria for clinical brain death based on the Japanese organ transplantation law. Brain CT revealed global hypoxic injury and high density in the basal cisterns and subarachnoid space. Brain MR T2*-weighted imaging revealed low intensity at the left Sylvian fissure underlying the hematoma. These findings indicated brain death owing to hypoxic encephalopathy following hanging, and incidental true SAH was confirmed by MRI. Donor surgery and organ transplantation were performed. Spontaneous SAH can often develop secondary to hanging, and brain MRI can effectively determine whether the cause of brain death involves true SAH.

Feasibility of Diffusion-weighted Imaging (DWI) for Assessing Cerebrospinal Fluid Dynamics: DWI-fluidography in the Brains of Healthy Subjects

PURPOSE

The present study aimed to investigate whether diffusion-weighted imaging (DWI) can qualify and quantify cerebrospinal fluid (CSF) dynamics in the brains of healthy subjects. For this purpose, we developed new DWI-based fluidography and compared the CSF dynamics seen on the fluidography with two apparent diffusion coefficients obtained with different DWI signal models at anatomical spaces filled by CSF.

METHODS

DWI with multiple b values was performed for 10 subjects using a 7T MRI scanner. DWI-fluidography based on the DWI signal variations in different motion probing gradient directions was developed for visualizing the CSF dynamics voxel-by-voxel. DWI signals were measured using an ROI in the representative CSF-filled anatomical spaces in the brain. For the multiple DWI signals, the mono-exponential and kurtosis models were fitted and two kinds of apparent diffusion coefficients (ADCC and ADCK) were estimated in each space using the Gaussian and non-Gaussian diffusion models, respectively.

RESULTS

DWI-fluidography could qualitatively represent the features of CSF dynamics in each anatomical space. ADCs indicated that the motions at the foramen of Monro, the cistern of the velum interpositum, the quadrigeminal cistern, the Sylvian cisterns, and the fourth ventricle were more drastic than those at the subarachnoid space and anterior horns of the lateral ventricle. Those results seen in ADCs were identical to the findings on DWI-fluidography.

CONCLUSION

DWI-fluidography based on the features of DWI signals could show differences of CSF dynamics among anatomical spaces.

Symptomatic subdural hemorrhage following heart valve surgery: a retrospective cohort study

OBJECTIVE

Subdural hemorrhage (SDH) has been reported to be the most frequent intracranial hemorrhagic complication following open heart surgery; however, its clinical features and pathophysiology remain unclear. The aim of this retrospective study was to elucidate the incidence, clinical course, and factors associated with the development of symptomatic SDH following heart valve surgery.

METHODS

A retrospective review of medical records on the development of symptomatic SDH after heart valve surgery involving cardiopulmonary bypass (CPB) from April 2011 to March 2016 was performed. Patients who had undergone preoperative cranial computed tomography (CT) or brain magnetic resonance imaging (MRI) were included in this study, and factors associated with SDH following heart valve surgery were analyzed. When neurological symptoms developed after heart valve surgery, cranial CT or brain MRI was performed.

RESULTS

A total of 556 patients who had undergone heart valve surgery were analyzed. Among these patients, symptomatic SDH occurred in 11 (2.0%). The mean duration of symptomatic onset was 10.1 days (range 2-37 days). Ten of 11 patients (90.9%) developed SDH in the posterior fossa or occipital convexity. Logistic regression analysis revealed longer aortic clamp time (95% CI 1.00-1.10, p = 0.04), higher dose of heparin after surgery (95% CI 1.00-1.02, p = 0.001), and higher pulmonary artery pressure (PAP) just before disconnection of the CPB (95% CI 1.01-1.37, p = 0.04) as significantly associated with the development of SDH.

CONCLUSIONS

The incidence of symptomatic SDH following heart valve surgery was 2.0%. Symptoms due to SDH usually developed a few days to 1 month after surgery. Surprisingly, most SDHs developed in the posterior fossa or occipital convexity following heart valve surgery. A longer aortic clamp time, higher dose of heparin after surgery, and higher PAP just before disconnection of the CPB were related to the development of symptomatic SDH following heart valve surgery.

Delayed blink R1 latency in a patient with trigeminal neuralgia due to a contralateral vestibular schwannoma: An illustrative case

Background

Although the blink reflex (BR) is effective in objectively evaluating trigeminal neuropathy, few studies have demonstrated its effect on trigeminal neuralgia (TN). The authors report a patient with TN due to contralateral vestibular schwannoma (VS) functionally diagnosed by delayed R1 latency of the BR.

Case Description

A 36-year-old man presented with left-sided deafness and paroxysmal facial pain in the right V1-3 area. Magnetic resonance imaging (MRI) showed a solid cystic mass compressing the right pons and left brainstem at the left cerebellopontine angle. Although preoperative BR evoked by right supraorbital nerve stimulation-induced delayed ipsilateral R1 latency and normal ipsilateral and contralateral R2 responses, the BR latency evoked by left supraorbital nerve stimulation was normal, indicating deficits in the principal nucleus of the trigeminal nerve in the right pons. The symptoms of TN disappeared after the removal of the VS. Postoperative MRI showed subtotal removal of the tumor and sufficient decompression of the pons and cerebellopontine cistern. The R1 latency returned to normal 50 days after surgery.

Conclusion

The perioperative BR test was not only useful for objective evaluation of the localization of trigeminal neuropathy but also correlated with the symptoms of TN.

Intracranial aneurysm rupture within three days after receiving mRNA anti-COVID-19 vaccination: Three case reports

Background:

Although neurological adverse events have been reported after receiving coronavirus disease 2019 (COVID-19) vaccines, associations between COVID-19 vaccination and aneurysmal subarachnoid hemorrhage (SAH) have rarely been discussed. We report here the incidence and details of three patients who presented with intracranial aneurysm rupture shortly after receiving messenger ribonucleic acid (mRNA) COVID-19 vaccines.

Case Description:

We retrospectively reviewed the medical records of individuals who received a first and/ or second dose of mRNA COVID-19 vaccine between March 6, 2021, and June 14, 2021, in a rural district in Japan, and identified the occurrences of aneurysmal SAH within 3 days after mRNA vaccination. We assessed incidence rates (IRs) for aneurysmal SAH within 3 days after vaccination and spontaneous SAH for March 6–June 14, 2021, and for the March 6–June 14 intervals of a 5-year reference period of 2013–2017. We assessed the incidence rate ratio (IRR) of aneurysmal SAH within 3 days after vaccination and spontaneous SAH compared to the crude incidence in the reference period (2013–2017). Among 34,475 individuals vaccinated during the study period, three women presented with aneurysmal SAH (IR: 1058.7/100,000 person-years), compared with 83 SAHs during the reference period (IR: 20.7/100,000 persons-years). IRR was 0.026 (95% confidence interval [CI] 0.0087–0.12; P < 0.001). A total of 28 spontaneous SAHs were verified from the Iwate Stroke Registry database during the same period in 2021 (IR: 34.9/100,000 person-years), and comparison with the reference period showed an IRR of 0.78 (95%CI 0.53–1.18; P = 0.204). All three cases developed SAH within 3 days (range, 0–3 days) of the first or second dose of BNT162b2 mRNA COVID-19 vaccine by Pfizer/BioNTech. The median age at the time of SAH onset was 63.7 years (range, 44– 75 years). Observed locations of ruptured aneurysms in patients were the bifurcations of the middle cerebral artery, internal carotid-posterior communicating artery, and anterior communicating artery, respectively. Favorable outcomes (modified Rankin scale scores, 0–2) were obtained following microsurgical clipping or intra-aneurysm coiling.

Conclusion:

Although the advantages of COVID-19 vaccination appear to outweigh the risks, pharmacovigilance must be maintained to monitor potentially fatal adverse events and identify possible associations.

[Severe Traumatic Brain Injury due to Repeated Minor Head Injury while Snowboarding:A Report of Two Cases]

Second impact syndrome occurrs when a patient who has sustained an initial head injury, most often a concussion, sustains a second head injury before the symptoms associated with the first have fully resolved, leading to rapid brain swelling and herniation. However, the underlying pathophysiology remains unclear. We report two cases in which acute subdural hematoma with rapid malignant brain swelling developed after repeated head traumas while snowboarding. One patient did not undergo craniotomy and died 21h after symptom onset. The other underwent urgent decompressive craniotomy and experienced prolonged disturbance of consciousness. Axial susceptibility-weighted magnetic resonance imaging performed 1 month after surgery in the second patient revealed multiple microbleeds in the subcortical white matter and parasagittal white matter in the bilateral hemispheres. These findings indicate that axonal injuries from angular acceleration may contribute to the rapid malignant brain swelling and poor outcomes.

A case of paroxysmal homonymous hemianopsia: Uncommon presentation of nonconvulsive status epilepticus

Paroxysmal homonymous hemianopsia (HH) is uncommon presentation of epilepsy. We demonstrate a rare case of paroxysmal HH that was diagnosed by magnetic resonance (MR) arterial spin-labeling (ASL). A 82-year-old woman presented with abrupt onset of isolated visual field abnormality without convulsive epilepsy at 16 days after a traumatic head injury. Diffusion weighted and MR-ASL obtained on admission revealed hyperintensity and hyperperfusion in the right temporo-occipital cortex. Nonconvulsive status epilepticus was suspected. The patient was treated with oral levetiracetam and the symptoms resolved in 3 days. Paroxysmal HH should be considered in patients who present with simple partial epilepsy, and MR-ASL imaging may assist in the differential diagnosis of these patients.

Acetazolamide-Loaded Dynamic 7T MR Quantitative Susceptibility Mapping in Major Cerebral Artery Steno-Occlusive Disease: Comparison with PET

BACKGROUND AND PURPOSE

Dynamic changes in cerebrovascular reactivity after acetazolamide administration vary markedly among patients with major cerebral arterial steno-occlusive disease. MR quantitative susceptibility mapping can dynamically quantify the cerebral magnetic susceptibility. The purpose of this study was to determine whether dynamic changes in susceptibility after administration of acetazolamide on 7T quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in the cerebral hemispheres with major cerebral arterial steno-occlusive disease.

MATERIALS AND METHODS

Sixty-five patients underwent 7T MR imaging at baseline and at 5, 10, 15, and 20 minutes after acetazolamide administration. Differences between the susceptibility of venous structures and surrounding brain tissue were calculated in the quantitative susceptibility mapping images. Susceptibility differences at 5, 10, 15, and 20 minutes after acetazolamide administration relative to baseline were calculated in 97 cerebral hemispheres with major cerebral arterial steno-occlusive disease. CBV and the cerebral metabolic rate of oxygen were also calculated using ¹⁵O-gas PET in the resting state.

RESULTS

Dynamic changes of susceptibility after acetazolamide administration were classified into 3 patterns: abnormally increasing 5 or 10 minutes after acetazolamide administration; abnormally decreasing within 20 minutes after acetazolamide administration; and remaining unchanged after acetazolamide administration. CBV was significantly greater in the first pattern than in the latter 2. The cerebral metabolic rate of oxygen differed significantly in descending order from the first to middle to last pattern.

CONCLUSIONS

Dynamic changes of susceptibility after acetazolamide administration on 7T MR quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in major cerebral arterial steno-occlusive disease.

Wall Shear Stress and T1 Contrast Ratio Are Associated With Embolic Signals During Carotid Exposure in Endarterectomy

Supplemental Digital Content is available in the text.

Background and Purpose—

The frictional force because of blood flow may dislodge masses present on the surface of a plaque. Such frictional force is calculated as wall shear stress (WSS) using computational fluid dynamics. The aims of the present study were to determine whether, in addition to carotid plaque intensity on T1-weighted magnetic resonance (MR) imaging, WSS calculated using computational fluid dynamics analysis for carotid arteries is associated with development of an embolism during exposure of carotid arteries during carotid endarterectomy.

Methods—

One hundred patients with internal carotid artery stenosis (≥70%) underwent carotid plaque imaging with MR, and 54 patients with a vulnerable plaque (intraplaque hemorrhage or lipid/necrotic core) displayed as a high-intensity lesion underwent additional cervical 3-dimensional MR angiography. The maximum value of WSS within the most severe stenotic segment of the internal carotid artery was calculated using MR angiography. Transcranial Doppler monitoring of microembolic signals (MES) in the ipsilateral middle cerebral artery was performed during carotid endarterectomy.

Results—

Although none of the 46 patients with a nonvulnerable carotid plaque had MES during exposure of carotid arteries, 24 of the 54 patients with a vulnerable carotid plaque (44%) had MES. Logistic regression analysis showed that higher plaque intensity (P=0.0107) and higher WSS (P=0.0029) were significantly associated with the development of MES. When both cutoff points of plaque intensity and WSS in the receiver operating characteristic curves for predicting development of MES were combined, specificity (from 63% to 93%) and positive predictive value (from 66% to 90%) became greater than those for plaque intensity alone.

Conclusions—

In addition to carotid plaque intensity on T1-weighted MR imaging, WSS calculated using computational fluid dynamics analysis for carotid arteries is associated with development of an embolism during exposure of carotid arteries during carotid endarterectomy.

A Case of Cisternal Pilocytic Astrocytoma Diagnosed with the Balanced Steady-State Free Precession Sequence for Magnetic Resonance Imaging: A Rare Cause of Subarachnoid Hemorrhage

Objectives

In approximately 15% of cases of spontaneous subarachnoid hemorrhage (SAH), an obvious source of bleeding cannot be identified by angiography; these are considered cases of SAH of unknown etiology. A rare case of cisternal pilocytic astrocytoma (PA) presenting with SAH is reported. The usefulness of the balanced steady-state free precession (bSSFP) sequence for magnetic resonance imaging (MRI) to detect small cisternal lesions is discussed.

Case Description

The case of a 73-year-old woman who developed repeated SAHs owing to a cisternal PA is presented. She experienced sudden onset of headache and vomiting, and brain computed tomography showed diffuse SAH, whereas angiography demonstrated normal vasculature. Follow-up imaging, including T1-weighted, T2-weighted, T1-weighted contrast-enhanced, and diffusion-weighted MRI, did not show any parenchymal or cisternal lesions, although computed tomography and fluid-attenuated inversion recovery MRI showed SAH in the same region. In contrast, the bSSFP sequence, taken as a different sequence on the same day, showed mixed-intensity reticular lesions in the left basal cistern, while neither hematoma nor positive findings were identified with the other sequences. Based on the radiologic finding and the repeated history of SAH, the lesions were partially removed 2 weeks after onset. Histological examination showed a PA.

Conclusions

Despite being extremely rare, a small cisternal lesion should be considered as a cause of SAH of unknown etiology. The bSSFP sequence may be useful for detecting cisternal lesions that may be missed on the routine MRI sequences.

Cerebral Aneurysm Arising from Variant Posterior Communicating Artery Lying Lateral to Oculomotor Nerve

BACKGROUND

In most cases, the posterior communicating artery (PCoA) lies medial to the oculomotor nerve. In this report, a rare case of a ruptured cerebral aneurysm arising from a variant PCoA lying lateral to the oculomotor nerve is described.

CASE DESCRIPTION

A 41-year-old woman who had a history of surgical clipping of a right PCoA aneurysm 13 years earlier developed a subarachnoid hemorrhage due to a ruptured left true PCoA aneurysm. Three-dimensional computed tomography angiography showed a small saccular aneurysm arising from the PCoA itself. She underwent surgical clipping via a left frontotemporal craniotomy. Interestingly, the PCoA lay lateral to the oculomotor nerve, and the aneurysm dome projected medially and compressed the oculomotor nerve medially. A slightly angled fenestrated miniclip was applied across the PCoA, followed by reconstruction of the PCoA medial wall and simultaneous obliteration of the aneurysm. Complete aneurysm obliteration and good patency of both the PCoA and perforating arteries were confirmed intraoperatively by indocyanine green videoangiography. The patient's postoperative course was uneventful, and the patient was discharged with no neurologic deficits.

CONCLUSIONS

Recognizing this anatomic variant is helpful in minimizing the potential complications in microsurgical management around the PCoA and oculomotor nerve. Lateral localization of the P1-2 junction might affect this rare anatomic variant.

Impact of the Intracranial Course of Internal Carotid Artery on Optimal Surgical Approach for Posterior Communicating Artery Aneurysms

BACKGROUND

The anterior temporal approach (ATA) has been reported as suitable for surgical clipping of posteriorly projecting internal carotid artery (ICA) aneurysms. As the ICA follows a variable course, tortuosity of the ICA may affect visualization of the aneurysm. The aim of this study was to investigate the impact of the intracranial course of the ICA and aneurysm projection on surgical approach.

METHODS

Consecutive patients with posterior communicating artery aneurysms treated with clipping at our hospital between May 2015 and April 2018 were retrospectively reviewed. When the transsylvian approach (TSA) could not achieve adequate exposure of the aneurysm, the ATA was subsequently performed. Distance between the ICA and the anterior and posterior clinoid line, angle between the midline and the C1 segment of the ICA, and aneurysm projection were compared between ATA and TSA groups.

RESULTS

Of 52 patients (40 ruptured, 12 unruptured), 12 were in the ATA group, and 40 were in the TSA group. Mean ICA-anterior and posterior clinoid distance was significantly shorter in the ATA group than in the TSA group (P = 0.002), and mean midline-C1 angle was significantly larger in the ATA group than in the TSA group (P < 0.0001). The ATA group was associated with a greater frequency of posteriorly projecting aneurysms (12 of 12; 100%) than the TSA group (9 of 40; 22.5%) (P < 0.00001).

CONCLUSIONS

A low-lying, laterally projecting intracranial ICA and posteriorly projecting aneurysm are predictors of the necessity for the ATA in the surgical clipping of posterior communicating artery aneurysms.

Fenestrated Mini-Clip Application to Preserve a Tightly Adhering Branch Artery to a Middle Cerebral Artery Aneurysm: Technical Case Report

BACKGROUND

Fenestrated mini-clips have been reported as useful for treating dog ear-shaped remnant aneurysms, the small aneurysms to which the efferent artery adheres or is impeded by the surrounding neurovascular structure in the restricted operative corridor, because of the smaller clip head. Here, the alternative utility of fenestrated mini-clip was reported by mentioning the narrower clip blade.

METHODS

We report a case of middle cerebral artery aneurysm tightly adhered by the anterior temporal artery (ATA) as well as the efferent arteries and demonstrate the utility of fenestrated mini-clip.

RESULTS

During aneurysm dissection, the superior division of the M2 segment of the middle cerebral artery and the ATA adhered tightly to the aneurysm, thereby restricting meticulous aneurysm dissection. To preserve the efferent artery and the ATA, a fenestrated standard clip was applied, transmitting the efferent artery, and the clip blade was applied in the restricted space between the adhering ATA and the aneurysm neck. However, because kinking of the ATA was observed following first clip application, the fenestrated mini-clip was applied in similar fashion to avoid kinking of the ATA instead of a standard clip, thereby preserving the ATA without further aneurysm dissection. Finally, successful obliteration of the aneurysm and preservation of the ATA were achieved with the subsequent clip application.

CONCLUSIONS

In selected cases, application of a narrower bladed fenestrated mini-clip in the restricted space may be useful to preserve tightly adhering branch arteries, as well as efferent arteries.

[Preoperative Diagnosis of Spinal Immature Teratoma Associated with Cerebrospinal Fluid Leakage from the Congenital Dermal Sinus Tract in a 0-Day-Old Infant:A Case Report]

We report the case of a patient with spinal immature teratoma and cerebrospinal fluid leakage from the congenital dermal sinus tract. A 0-day-old female infant presented with a subcutaneous soft mass with a dimple in the lumbosacral region at birth. Magnetic resonance imaging revealed a mixed low-intensity mass located in the extraspinal and intraspinal canal with a sinus tract. The reconstructed three-dimensional spinal computed tomography image showed spina bifida and ectopic ossification at the dorsal aspect of the sacrum. Urgent removal of the tumor and dermal sinus tract was then performed under evoked electromyography monitoring. The resected tumor was histopathologically diagnosed as immature teratoma.

Accuracy of brain perfusion single-photon emission computed tomography for detecting misery perfusion in adult patients with symptomatic ischemic moyamoya disease

OBJECTIVE

The purpose of the present study was to determine how accurately relative cerebral blood flow (RCBF) and relative cerebrovascular reactivity (RCVR) to acetazolamide assessed using brain perfusion single-photon emission computed tomography (SPECT) detected misery perfusion identified on positron emission tomography (PET) in adult patients with ischemic moyamoya disease (MMD).

METHODS

Oxygen extraction fraction (OEF), RCBF, and RCVR were assessed using ¹⁵O gas PET and N-isopropyl-p-[¹²³I]-iodoamphetamine SPECT without and with acetazolamide challenge, respectively, in 45 patients. Regions of interest (ROIs) were automatically placed in the five middle cerebral artery (MCA) territories in the symptomatic cerebral hemisphere and in the ipsilateral cerebellar hemisphere using a three-dimensional stereotaxic ROI template. For RCBF and RCVR to acetazolamide, the ratio of the MCA ROI to cerebellar ROI was calculated. Of the five MCA ROIs in the symptomatic cerebral hemisphere in each patient, the ROI with the highest and lowest OEF value (two ROIs per patient) was selected for analyses.

RESULTS

A significant square or linear correlation was observed between the OEF and RCBF (correlation coefficient, 0.780) or RCVR (correlation coefficient, - 0.345), respectively. The area under the receiver operating characteristic curve for detecting misery perfusion (OEF > 51.3%) was significantly greater for the RCBF than for the RCVR (difference between areas, 0.221; p < 0.0001). Sensitivity, specificity, and positive- and negative-predictive values for the RCBF for detecting misery perfusion were 100, 91, 67, and 100%, respectively. The specificity and positive-predictive value did not differ between the combination of the RCBF and RCVR and the CBF ratio alone.

CONCLUSIONS

RCBF assessed using brain perfusion SPECT detects misery perfusion with high sensitivity, a high negative-predictive value, and a low positive-predictive value in adult patients with ischemic MMD. The accuracy of RCVR to acetazolamide assessed using brain perfusion SPECT is lower than that of RCBF.

Impact of external carotid artery occlusion at declamping of the external and common carotid arteries during carotid endarterectomy on development of new postoperative ischemic cerebral lesions

OBJECTIVE

The external carotid artery (ECA) is inadvertently occluded during carotid endarterectomy (CEA). The importance of ECA occlusion has been emphasized as a loss of extracranial to intracranial collaterals, a source of chronic embolization, or a site for extended thrombosis during wound closure. This study aimed to determine whether ECA occlusion that inadvertently developed during endarterectomy and that was eventually detected using blood flow measurement of the ECA after declamping of all carotid arteries is a risk factor for development of new postoperative ischemic lesions at declamping of the ECA and common carotid artery (CCA) while clamping the internal carotid artery (ICA). This study also aimed to determine whether intraoperative transcranial Doppler (TCD) monitoring predicts the risk for development of such lesions.

METHODS

This was a prospective observational study that included patients undergoing CEA for severe stenosis (≥70%) of the cervical ICA. When blood flow through the ECA measured using an electromagnetic flow meter decreased rapidly on clamping of only the ECA before carotid clamping for endarterectomy and was not changed by clamping of only the ECA after carotid declamping following endarterectomy, the patient was determined to have developed ECA occlusion. These patients underwent additional endarterectomy for the ECA. TCD monitoring in the ipsilateral middle cerebral artery was also performed throughout surgery to identify microembolic signals (MESs). Brain magnetic resonance diffusion-weighted imaging (DWI) was performed before and after surgery.

RESULTS

There were 104 patients enrolled in the study. Eight patients developed ECA occlusion during surgery. The incidence of intraoperative ECA occlusion was significantly higher in patients without MESs at the phase of ECA and CCA declamping (8/12 [67%]) than in those with MESs (0/92 [0%]; P < .0001). Six patients exhibited new postoperative ischemic lesions on DWI. The incidence of intraoperative ECA occlusion (P < .0001) and the absence of MESs at declamping of the ECA and CCA while clamping the ICA (P <. 0001) were significantly higher in patients with development of new postoperative ischemic lesions on DWI than in those without. Sensitivity and specificity for the absence of MESs at declamping of the ECA and CCA while clamping the ICA for predicting development of new postoperative ischemic lesions on DWI were 100% (6/6) and 94% (92/98), respectively.

CONCLUSIONS

ECA occlusion at declamping of the ECA and CCA while clamping the ICA during CEA is a risk factor for development of new postoperative ischemic lesions. Intraoperative TCD monitoring accurately predicts the risk for development of such lesions.

Straight Fenestrated Clips in Surgical Management of Internal Carotid Artery Aneurysms: Technical Note

BACKGROUND

Using angled fenestrated clips for posteromedially projecting internal carotid artery (ICA) aneurysms may allow the surgeon to simultaneously obliterate the aneurysmal neck and preserve the branching artery by applying the blade of the clip parallel to the ICA. However, using these clips when the aneurysm neck involves the branching artery may have a risk of branching artery stenosis, occlusion, or incomplete obliteration of the aneurysm.

CASE DESCRIPTION

A 52-year-old woman developed a subarachnoid hemorrhage. Three-dimensional computed tomography angiography showed a saccular aneurysm arising from the left ICA-posterior communicating artery (PCoA) bifurcation. The aneurysmal fundus projected posteromedially, and the PCoA was larger than the ipsilateral P1 segment, in which its origin involved the aneurysmal neck. Tandem straight fenestrated clips were applied across the ICA, followed by reconstruction of the ICA wall with preservation of the PCoA and obliteration of the aneurysm.

CONCLUSION

When using angled fenestrated clips is unsuitable because of a risk of branching artery stenosis, occlusion, or incomplete obliteration of the aneurysm, using multiple straight fenestrated clips may be a useful alternative.

Does preoperative measurement of cerebral blood flow with acetazolamide challenge in addition to preoperative measurement of cerebral blood flow at the resting state increase the predictive accuracy of development of cerebral hyperperfusion after carotid endarterectomy? Results from 500 cases with brain perfusion single-photon emission computed tomography study

The purpose of the present study was to determine whether preoperative measurement of cerebral blood flow (CBF) with acetazolamide in addition to preoperative measurement of CBF at the resting state increases the predictive accuracy of development of cerebral hyperperfusion after carotid endarterectomy (CEA). CBF at the resting state and cerebrovascular reactivity (CVR) to acetazolamide were quantitatively assessed using N-isopropyl-p-[¹²³I]-iodoamphetamine (IMP)-autoradiography method with single-photon emission computed tomography (SPECT) before CEA in 500 patients with ipsilateral internal carotid artery stenosis (≥ 70%). CBF measurement using ¹²³I-IMP SPECT was also performed immediately and 3 days after CEA. A region of interest (ROI) was automatically placed in the middle cerebral artery territory in the affected cerebral hemisphere using a three-dimensional stereotactic ROI template. Preoperative decreases in CBF at the resting state [95% confidence intervals (CIs), 0.855 to 0.967; P = 0.0023] and preoperative decreases in CVR to acetazolamide (95% CIs, 0.844 to 0.912; P < 0.0001) were significant independent predictors of post-CEA hyperperfusion. The area under the receiver operating characteristic curve for prediction of the development of post-CEA hyperperfusion was significantly greater for CVR to acetazolamide than for CBF at the resting state (difference between areas, 0.173; P < 0.0001). Sensitivity, specificity, and positive- and negative-predictive values for the prediction of the development of post-CEA hyperperfusion were significantly greater for CVR to acetazolamide than for CBF at the resting state (P < 0.05, respectively). The present study demonstrated that preoperative measurement of CBF with acetazolamide in addition to preoperative measurement of CBF at the resting state increases the predictive accuracy of the development of post-CEA hyperperfusion.

Application of ultrasonography to postmortem examination. Diagnosis of pericardial tamponade

In postmortem examination, it is difficult to diagnose pericardial tamponade in a dead body from the findings of conventional external examination alone. However, ultrasonography is a common diagnostic tool for pericardial tamponade in clinical practice. We studied the postmortem diagnosis of pericardial tamponade at external examination level by applying an ultrasonographic device. The ultrasonographic findings were compared with the conventional autopsy findings. Among 455 cases of forensic autopsy in Hamburg and Tokyo conducted within 5 days after death, we successfully diagnosed 11 cases of pericardial tamponade by ultrasound imaging prior to autopsy, and failed to diagnose pericardial tamponade in only two cases. In addition, 79 cases of external examination conducted at the Tokyo Medicinal Examiner's Office were also examined with ultrasonography, and we diagnosed three cases of pericardial tamponade and five cases of pericardial effusion. The differences in ultrasonographic findings between tamponade and effusion were relatively clear. Although autopsy provides definitive evidence for the cause of death, sometimes autopsy cannot be performed due to some social factors. In such cases, conventional external examination alone cannot establish a cause of death by pericardial tamponade, and application of diagnostic imaging technique will be helpful. While CT and/or MRI may provide more detailed information than ultrasound imaging, these techniques require special equipment, room and specialist, and most of all involves high cost, which is perhaps the most important consideration in the present atmosphere of medical cost containment. On the other hand, the ultrasonographic devices we use are compact, and can be used directly at the scene of death. Postmortem application of ultrasonography may be a valuable adjunct in the work of medical examiners and forensic pathologists.

Application of compact ultrasound imaging device to postmortem diagnosis

In regions with low autopsy rates, forensic examiners often have to rely on external findings. Imaging techniques can assist the external examination and provide a more objective diagnosis. The SonoSite 180, a portable ultrasound device, was used for the examination of dead bodies. The influence of different degrees of decomposition was estimated. Even in cases with intestinal gas formation images of internal organs could be obtained with special techniques. Various pathological findings were detected by ultrasound and verified by autopsy (e.g. pericardial tamponade, cardiac hypertrophy, fatty liver, aortic aneurysm, metastatic liver, etc.). The experiences with the SonoSite 180 are promising. The device can be carried to the death scene or to the morgue and therefore serve as a valuable tool for medicolegal applications.

[Changes of fatty acid composition of brain synaptosomal phospholipids in isoflurane exposure rat]

We examined effects of inhalational anesthetic drug, isoflurane, on phospholipid and fatty acid in brain synaptosome. Wistar strain male rat was treated by inhalation of isoflurane. Rats were divided into 3 groups each 6 rats, one was 1 minimum alveolar concentration (MAC) exposure group, 1MAC group, and another was 2 times of MAC exposure group, 2MAC group, and the other was non exposure group, control group. The animals were kept in to box (0.343 m3) and the gas flow rate was set in 4 L/min by anesthetic instrument. After 60 minutes of exposure, rats were decapitated. Immediately, cerebrums were removed and fraction of synaptosome was sampled. In 2MAC group, C14:0 of phosphatidylcholine (PC) increased significantly as compared to the control group, but C16:1, C18:0, C18:2 and C20:3 decreased significantly. And also, C18:2 and C20:3 decreased significantly in 1MAC group. In terms of phosphatidylethanolamine(PE), C18:1 in 1MAC group, C14:0 and C16:1 in 2MAC group increased, but C20:3, C20:4 and C22:5 in 2MAC group decreased significantly as compared to the control group. Regarding phosphatidylserine + phosphatidylinositol, C14:0 in 2MAC group increased, but C22:5 decreased. In lysophosphatidylcholine, C12:0 and C14:0 in 2MAC group and C18:0, C20:4 in 1MAC group increased significantly, but C18:1 in 2MAC decreased. The changes of phospholipids and fatty acid in synaptosome were due to the metabolism of phospholipids of basic matrix and this was caused by effects of isoflurane on neural cellular membrane. The results indicated the suppression of membrane activity. Isoflurane has physiological activity on metabolism of phospholipid of cellular membrane. Thus, it has effects on neural cellular functions in brain.

[Tracing of analysis and prophylaxis on medical malpractice in Japan]

The role of drugs, especially injectables, in medical treatment is extremely important. In Japan, accidents associated with injections were not uncommon. Post-injection neuroparalysis of the radial nerve and sciatic nerve was associated with problems in textbooks, which described injection sites at the regions of neural passage. Then, in the 1970s, quadriceps femoral muscle contracture and deltoid muscle contracture became a social problem. When the author examined the osmotic pressure of various injectables, some injectables were found to deviate from the physiological range. When 335 injectables were evaluated for the potential to cause hemolysis, many injectables marketed for intramuscular injection gave strong hemolytic reaction, which attracted attention. Next, 89 types of injectables were tested for the potential to cause muscle damage by injecting into the femoral muscle of rabbits, and severe muscular damages were observed with antipyretics, analgesics, and antibiotics. The group lawsuit of Yamanashi Prefecture was settled at the Tokyo High Court in 1989, with the pharmaceutical company agreeing to pay over 2.95 billion yen as settlement. Giving drugs to patients occupies an important place among medical act. Medical disputes concerning accidents of wrong drugs and wrong usage are common. Obviously health care workers should exercise great caution in their duties, but without measures taken against medical equipment and drugs, such as containers and seals, this type of accidents will not be reduced. Through giving numerous speeches and lectures on medical accidents throughout the years, the author had felt strongly the need for teaching materials such as video tapes that can be used for self-learning. In 1999, the video entitled "Medical Accident-Learning from Actual Cases-" was finally completed, which consists of 6 parts (1. General consideration, 2. Blood transfusion, 3. Drug administration, 4. Surgery, 5. Examinations, 6. Management). For each area, typical incidents are presented as reproduced video taping. Then the criminal responsibility, civil responsibility and administrative responsibility of the doctor or nurse concerned are questioned in the form of questionnaires. Subsequently, the author also published a commentary book for the video that provides commentaries of the cases.

Genetic polymorphisms of orosomucoid ORM1 and ORM2 in Egyptians, Sudanese, and Qataris: occurrence of two new alleles

Isoelectric focusing was used to investigate the genetic variants of the human plasma orosomucoid ORM1 and ORM2 gene loci in samples of Egyptians, Sudanese, and Qataris. The study populations were classified into 28 ORM phenotypes determined by 10 ORM1 and 9 ORM2 alleles that included 2 new alleles, designated ORM1*B13 and ORM2*H21. Family studies of these new alleles are in accordance with codominant autosomal inheritance. A new interpretation for two previously reported alleles, ORM1*C6 and ORM2*H17, is also presented.

An improved high resolution single method for orosomucoid ORM1 and ORM2 phenotyping

An improved high resolution single method for orosomucoid ORM1 and ORM2 phenotyping using isoelectric focusing (IEF) in wide-scales ultrathin layer polyacrylamide gels of pH range 4.2 to 4.9 is presented. The method is reliable, simple, and provides an alternative for the three currently required ones for typing this genetic system.

Paternity testing by the detection of D1S80 VNTR using fluorescence image analyzer (Dualcolour system)

An improved method for DNA polymorphism typing of D1S80 VNTR locus and its application to paternity testing are described. For accurate estimation of the length of polymorphic DNA fragments, the size marker was labeled with fluorescence different from that of PCR primers, and co-electrophoresed as an internal standard. The dualcolour system of fluorescence image analyzer was used to detect the fragments and determine their size. This internal marker method could successfully overcome the problems of band pattern distortion and tailing, besides it allows easy and accurate interpretation of the DNA types. Our results indicate that the internal marker method is much more accurate than the method of using size marker in gel, even with the presence of distortion or tailing of the band patterns. Family studies applying this method showed complete agreement between the observed and predicted types.

Effects of bezafibrate on erythrocyte membrane phospholipids in alcohol-treated rats

Male rats of the Wistar strain were divided 4 groups, and give a liquid diet of control feed, bezafibrate (150 mg/kg), ethanol, and ethanol plus bezafibrate for 5 week. The effect of bezafibrate supplementation on rats fed ethanol was examined in terms of the fatty acid composition of the phospholipids in the erythrocyte membrane. In the phospholipids profiles of erythrocyte membranes, PI was significantly decreased. The decrease in PI caused by bezafibrate appeared to substantially affect the membrane and consequently lead to changes in the membrane anchor. In the fatty acid composition of the PC, C20: 4 was significantly decreased in the group receiving alcohol (p < 0.05) but increased in the groups receiving bezafibrate (p < 0.05). In the fatty acid composition of the PE, C16: 0 was significantly increased in the three groups when compared with the control, and C20: 4 was decreased in the alcohol group (p < 0.05). In the fatty acid of SM and PI, C20: 4 was decreased and C18: 0 increased in the alcohol group. In the PS, C14: 0 was increased in the alcohol group, and decreased in the alcohol plus bezafibrate group (p < 0.01). The levels of arachidonic acid in the total fatty acids that constituted the membrane phospholipids were decreased in the rats given ethanol (p < 0.05). However, arachidonic acid in the group of bezafibrate supplementation on rats fed ethanol were elevated in comparison with the alcohol group (p < 0.05). With decreasing arachidonic acid as a marker of alcohol tissue injury following chronic alcohol intake, the effects of bezafibrate supplementation appear to contribute to membrane fluidity by altering the biochemical flexibility of the membrane.

Frequency of D1S80 and HLA DQ alpha alleles in a Chinese population

Allele frequency distributions for the D1S80 (MCT118) and HLA DQ alpha loci were determined in a Chinese population sample using the polymerase chain reaction (PCR). A total of 25 alleles and 100 phenotypes were observed for D1S80. The frequency of allele 18 was higher than allele 24 only in this Chinese population when compared to other reported populations. A total of 6 alleles and 21 possible phenotypes were observed for HLA DQ alpha. The power of discrimination was 0.97 and 0.93 for D1S80 and HLA DQ alpha, respectively.

[Arterial oxygen saturation monitoring of sleeping infants by pulse-oximeter--effect of sleeping position on arterial oxygen saturation in infants]

Monitoring of the arterial oxygen saturation (SaO2) in two sleeping infants was reported. They were a couple of female twins and had grown up normally after admission to NICU (Neonatal Intensive Care Unit) for a month. We investigated their SaO2 with the puls-oximeter at the terms between the 2nd and the 10th month. There was no significant difference between SaO2 in prone positions (n = 29) and that in supine positions (n = 30). In the infant with the sniffing conditions, however, SaO2 in prone positions seemed to be slightly lower than that in the healthy conditions. The slightly low SaO2 would give no effects on the healthy infants, but it may cause ALTE (Apparent Life Threatening Event) or death from SIDS (Sudden Infant Death Syndrome) to some infants who are not in good health and/or who are prone to get into ALTEA or SIDS. Especially, in the sniffing condition with hyperthermia, as the oxygen dissociation curve sifts to right and SaO2 degradation appears easily, sudden infant death may be possible to happen in prone position.

Simultaneous measurement of alcohols and hydrogen cyanide in biological specimens using headspace gas chromatography

We attempted to analyze biological specimens simultaneously for alcohols and hydrogen cyanide. A headspace gas chromatographic method with thick film wide bore column (PEG 20M) for the simultaneous determinations of methanol, ethanol, n-propanol and hydrogen cyanide in blood has been developed. This method was applied for the determinations of methanol, ethanol and hydrogen cyanide in a forensic autopsy case and animal experiments.

[Recommendations for preventing transmission of infection with biohazard in the practice of legal medicine (2). Equipment and practical applications. The Medico-Legal Society of Japan, Committee on Expert Opinions]

In May, 1993, our committee of the Medico-Legal society of Japan published an article entitled "Recommendations for Preventing Transmission of Infection with Biohazard in the Practice of Legal Medicine" in The Japanese Journal of Legal Medicine. Concerning this article, we received a lot of useful comments and opinions from many members of the society, for which we are very grateful. We also received a lot of requests for further information concerning details on the equipment and its practical applications. Since a lot of departments of Legal Medicine at several universities throughout Japan at present are remodelling their facilities in order to be able to perform autopsies, with respect to such circumstances, our committee felt the need to provide information on basic conditions concerning the prevention of transmission of infections with hazards.

[Concentrations of ethanol and ethanol metabolites and symptoms of acute alcohol-intoxicated patients]

Five patients who presented to an emergency room and did not have other injury and disease with acute alcohol intoxication were analyzed about blood and urine ethanol, acetaldehyde, acetate and acetone levels. The average concentrations of ethanol, acetaldehyde, acetate and acetone in blood were 37.0 mM (1.7 mg/ml), 18 microM, 1.00 mM and 18 microM, respectively and the concentrations in urine were 50.8 mM (2.3 mg/ml), 37 microM, 0.79 mM and 47 microM, respectively. Clinical symptoms were concerned with both ethanol concentration and concentrations of ethanol metabolites. Their symptoms of acute alcohol-intoxicated patients were caused by the ethanol concentrations which was less than the levels reported in early studies.

An analysis of low side molecular weight proteins in human seminal plasma by capillary electrophoresis

Semen was obtained from 45 healthy males, and its plasma proteins of low side molecular weight obtained by filtration with a Molcut II (Millipore) were analyzed by means of capillary electrophoresis (CE) for an application to forensic medicine, with a phosphoric acid of pH 4.5 and a column of 100 cm x 75 microns ID. There were noted 27 to 36 peaks on the chromatograms, two sections of which showed individual differences in the chromatographic patterns. The chromatographic patterns between 20.0 and 22.0 minutes were classified into 2 groups: I (66.7%) and II (33.3%). The main peak appearing at about 36 minutes was divided between two patterns: A (53.3%) and B (46.7%). The serum, saliva, and vaginal fluid were also analyzed for low-side-molecular-weight proteins by means of capillary electrophoresis, but their levels contained low and their chromatographic patterns different from those of seminal plasma. The patterns of the whole seminal plasma, saliva and serum with pH 7.0 phosphate buffer were different and appeared to be applicable for identifying such samples.

[Recommendations for preventing transmission of infection with biohazard in the practice of legal medicine. The Medico-Legal Society of Japan, Committee on Expert Opinions]

In Japan recently there arose a sudden need for special guidelines concerning medicolegal autopsy and the handling of medicolegal materials. In this respect, the Medico-legal Society of Japan, Committee on Expert Opinions has produced a guideline, entitled "Recommendations for Preventing Transmission of Infection with Biohazard in the Practice of Legal Medicine", which was then introduced to all members in Legal Medicine. This guideline contains First: Explanations about the most important types of Biohazard diseases, the dangers and ways of transmission. Second: Explanations concerning preventive measures in medicolegal autopsy, for handling of medicolegal materials and investigation samples, also concerning the equipment and tools within the autopsy room, as well as measures for correct disinfection. These guidelines, form the base on each department of the Medico-Legal Society of Japan, are asked to adjust their own practical manual in order to improve the safety of autopsy conditions.

[Metabolism and toxicity of n-pentane and isopentane]

n-Pentane and isopentane have a wide range of use, for example, for cleaning precision machinery, extracting essence and oil, and as liquid fuel for now very popular disposable lighters. They are contained in liquefied petroleum gas and natural gas as trace constituents. In our present experiments, we studied the metabolism and toxicity of these n-pentane and isopentane metabolites. Male mice of ICR strain were exposed to about 5% n-pentane for one hour while the oxygen in the environmental air was maintained at about 20%. Then their blood and liver tissue were collected and analyzed by means of GC and GC-MS. The metabolites thus obtained were 2-pentanol, 3-pentanol and 2-pentanone. The same procedure was repeated with isopentane; 3-methyl-2-butanol, 2-methyl-2-butanol and 3-methyl-2-butanone were detected as the resultant metabolites. In the presence of the NADPH-generating system liver microsomes were made to react to the substrate of saturated n-pentane or isopentane aqueous solution at 37 degrees C for one hour. As a result, the same metabolites were produced as obtained in the exposure experiment. It was therefore suggested that n-pentane and isopentane were metabolized chiefly by liver microsomes. Male mice of ICR strain were fed with 80 mg/kg b.w. of phenobarbital for consecutive four days and exposed to n-pentane or isopentane for one hour. This resulted in an increase in the amount of 2-pentanol and 2-pentanone in the n-pentane inhalation and 2-methyl-2-butanol in the isopentane inhalation experiment. The toxicity of each metabolite was studied on cultured cells. The metabolites were individually mixed with HeLa S3 cell suspension, incubated for three days, and their concentration which inhibited the growth of cells by 50% (IGC 50) were compared. It was demonstrated as a result that the IGC 50 for any of the metabolites was lower than that for methanol, ethanol or acetone used as control.

Production of carbon monoxide in cadavers

Carbon monoxide (CO), total hemoglobin (Hb) and carboxyhemoglobin (HbCO) in the blood and reddish discolored body cavity fluids of cadavers which had not been exposed to fire and CO were analyzed. In 13 cadavers found on land, the maximum saturation of HbCO in the blood was 3.6%, and was 10.1% in the body cavity fluids. There was only one case in which the HbCO saturations in the body cavity fluids were more than 10%. In seven drowned bodies found in fresh water, the highest HbCO saturation in the blood was 6.1%, and was 44.1% in the body cavity fluids. There were three cases in which the HbCO saturations in the body cavity fluids were more than 10%. In 12 drowned bodies found in sea water, the HbCO saturations in the blood were not more than 6.2%, and the maximum saturation of HbCO in the body cavity fluids was 83.7%. There were eight cases in which the HbCO saturations in the body cavity fluids were more than 10%. The results seem to indicate that the interpretation of HbCO saturation in the blood would not be affected significantly by the postmortem formation of CO, and that body cavity fluids should not be used for CO determination.

Estimation of postmortem interval from rectal temperature by use of computer (IV)--thermal diffusivity of the rabbit

The measurement of the postmortem rectal temperature fall is the most reliable procedure for estimation of the postmortem interval within one or two days. The thermal properties of a human corpse, however, are little known when applying the heat transmission theory to the temperature fall of the human corpse, which is assumed to be an infinite cylinder. Therefore, the thermal diffusivity of the whole body of a human corpse should be measured. The nonlinear least square method was thus proposed to measure the thermal diffusivity of the whole body of the human and animals. We needed to verify the reliability of the measurement method before measuring the human corpse. So, the thermal diffusivity of the rabbit was studied in this paper. The values in 5 specimens averaged 0.00036 m2/h, and the variation coefficient was 0.42. This method was considered to be applicable to the human corpse.

Estimation of postmortem interval from rectal temperature by use of computer (III)--thermal conductivity of the skin

The postmortem rectal temperature fall is the most reliable objective finding for estimation of the postmortem interval within one or two days. However, the thermal properties of human corpses are little known when applying the heat transmission theory to the temperature fall of a human corpse, which is assumed theoretically to be an infinite cylinder. Therefore, the thermal conductivity of excised human skin was measured by the transient hot-wire method. The values in 12 specimens averaged 0.30 Kcal/m.h.°C. The theoretical error due to the experimental conditions such as the size of specimen or heating probe was within about five per cent, and the deviation of three measurements for each material was slight. Accordingly, the deviation of thermal conductivity in 12 materials was considered to be due to the individual disparity in age, sex and postmortem changes.

Homicidal and camouflaged carbon monoxide poisoning in Japan

There were 1,985 fatal cases of CO poisoning in the Tohoku district of Japan in the period from 1969 to 1980. Among them, 1,322 cases were suicidal, 662 accidental, and one homicidal, in which a man killed his wife with the self-made CO gas to obtain by fraud a large amount of life insurance. Our nationwide survey revealed four other cases of homicidal CO poisoning and two cases of camouflaged CO poisoning. The police and police surgeons should be cautious enough in cases of CO poisoning.

Transferrin (Tf) polymorphism: an analysis by isoelectric focusing

The polymorphism of the transferrin (Tf) system was studied in a total of 300 unrelated Japanese individuals from Miyagi prefecture, the northern part of Japan using isoelectric focusing in thin-layer polyacrylamide gel. In our population samples three common phenotypes and nine variants were observed. The calculated allele frequencies were TfC1 = 0.773, TfC2 = 0.212, TfDchi (Chinese) = 0.008, and the combined frequencies for the TfBvar (variants) = 0.007. Family data (n = 44) were in accordance with an autosomal codominant fashion of inheritance. The use of isoelectric focusing procedure among Japanese will raise the probability of excluding a man falsely accused of paternity to 15.8% as compared with 1.5% when the conventional electrophoretic methods are used.

Estimation of postmortem interval from rectal temperature by use of computer--relationship between the rectal and skin cooling curves

The deep body temperatures at depths of 0.5 cm and of 1 cm and the skin and rectal temperatures of the living rabbit were monitored in order to clarify the initial condition. It was revealed that there is a temperature gradient similar to the logarithmic curve from the core to the surface. Taking this temperature gradient into consideration, the computer simulation model composed of the approximate equations was used to investigate the adaptability of the theoretical cooling curves to the experimental rectal and skin cooling curves. Our computer simulation model proved that the theoretical cooling curves reproduced well both the experimental rectal and skin cooling curves regardless of changes in the ambient temperature.

Estimation of postmortem interval from rectal temperature by use of computer

The simulation model of the approximate equations derived from the infinite cylinder was used to investigate the applicability of the theoretical curve to the actual one of rectal temperature. The rectum was found by the computer tomography to be near to the junction of the anterior three-quarters and the posterior quarter inside the body, and this result was employed in the simulation. The method of estimating the postmortem interval, in which two recordings of rectal temperature were used, was considered to be useful enough as it can be applied to any case in practice. As reported by Akaishi et al., fluctuation of less than 2 °C in the ambient temperature was shown by the simulation to have little effect on the rectal temperature curve.

Physico-chemical properties and local toxic effects of injectables

In Japan, many cases of muscle contracture as a sequela of injections have been reported. We studied the physico-chemical properties and muscle-damaging potential of many injectables which are commonly used in hospitals. Contrary to our expectations, the pH of the injectables was found to range widely from 1.4 to 12.8, and the osmotic ratio from 0.2 to 36. It was also found that their hemolytic potential was closely related to the severity of the muscle lesions in animal experiments and that there were many injectables with strong muscle-damaging potentials. Therefore, doctors should be informed of the physico-chemical properties and tissue-damaging potential of each injectable; pharmaceutical companies should exert all possible efforts to improve injectables; and doctors should keep the administration of intramuscular injections to a minimum and use them only in cases of actual need.