RESUMO
ABSTRACT: In the putrefied brain, the cortex and basal ganglia show dark-grayish to green discoloration due to sulfhemoglobin formed from hydrogen sulfide (H 2 S) produced by endogenous bacteria and hemoglobin. In this study, we propose and demonstrate another mechanism of green discoloration in the brain. The formalin-fixed brain of a cadaver donated for medical education with no putrefaction was used. Half of the brain was immersed in sodium hydrosulfide solution, to imitate the H 2 S produced by bacteria. This half showed greenish discoloration, mainly in the basal ganglia and cortex. The other half showed positive Perls' Prussian blue staining, mainly in the basal ganglia and cortex. The area of greenish discoloration due to H 2 S and the region positive for Perls' Prussian blue staining coincided. Tissue treatment with strong oxidizing agents is required to liberate heme iron. The positive Perls' Prussian blue staining in this study thus does not reflect heme iron. In conclusion, we considered that non-heme iron compounds physiologically present in the brain and H 2 S represent sources of putrefactive greenish discoloration in the brain.
Assuntos
Sulfeto de Hidrogênio , Ferro , Humanos , Encéfalo , Coloração e Rotulagem , Mudanças Depois da MorteRESUMO
ABSTRACT: We report a rare case of fatal exsanguination by a wakizashi , a Japanese short sword ( shinken ). A man in his 60s was found lying on his back on his bed. He was in cardiopulmonary arrest when the ambulance crew arrived and was pronounced dead on arrival at the hospital. A wakizashi with blood stains on the blade was found on the floor, and blood was present on the bed sheets on which the man was found. Autopsy revealed an incised wound extending diagonally from superolaterally to inferomedially on the anterior left thigh as the only injury. The wound appeared mostly straight, approximately 44 cm long and 9 cm deep, with smooth walls. The left femoral artery and vein had been cleanly severed, and the cause of death was determined to be blood loss from the severed blood vessels. The wakizashi (blade length, 45 cm) was large enough to have caused the wound, and the left thigh was presumed to have been incised by a downward slash from the sword.
Assuntos
Exsanguinação , Armas , Autopsia , Exsanguinação/etiologia , Humanos , Japão , MasculinoRESUMO
PURPOSE: The evaluation of all ribs on thin-slice CT images is time consuming and it can be difficult to accurately assess the location and type of rib fracture in an emergency. The aim of our study was to develop and validate a convolutional neural network (CNN) algorithm for the detection of acute rib fractures on thoracic CT images and to investigate the effect of the CNN algorithm on radiologists' performance. METHODS: The dataset for development of a CNN consisted of 539 thoracic CT scans with 4906 acute rib fractures. A three-dimensional faster region-based CNN was trained and evaluated by using tenfold cross-validation. For an observer performance study to investigate the effect of CNN outputs on radiologists' performance, 30 thoracic CT scans (28 scans with 90 acute rib fractures and 2 without rib fractures) which were not included in the development dataset were used. Observer performance study involved eight radiologists who evaluated CT images first without and second with CNN outputs. The diagnostic performance was assessed by using figure of merit (FOM) values obtained from the jackknife free-response receiver operating characteristic (JAFROC) analysis. RESULTS: When radiologists used the CNN output for detection of rib fractures, the mean FOM value significantly increased for all readers (0.759 to 0.819, P = 0.0004) and for displaced (0.925 to 0.995, P = 0.0028) and non-displaced fractures (0.678 to 0.732, P = 0.0116). At all rib levels except for the 1st and 12th ribs, the radiologists' true-positive fraction of the detection became significantly increased by using the CNN outputs. CONCLUSION: The CNN specialized for the detection of acute rib fractures on CT images can improve the radiologists' diagnostic performance regardless of the type of fractures and reader's experience. Further studies are needed to clarify the usefulness of the CNN for the detection of acute rib fractures on CT images in actual clinical practice.
Assuntos
Fraturas das Costelas , Humanos , Redes Neurais de Computação , Radiologistas , Fraturas das Costelas/diagnóstico por imagem , Costelas , Tomografia Computadorizada por Raios X/métodosRESUMO
ABSTRACT: A case involving an adult dismembered body with myositis ossificans (MO) is described. A woman in her 20s was found dead in her cohabitants' room. The body had dismembered into 15 pieces. Computed tomography showed ectopic mineralization in the bilateral upper arms and thighs. On autopsy, the skin and soft tissue were in the process of adipocere formation. Darkened areas that appeared to be subcutaneous hemorrhage were distributed on the face, left chest, and back. Bilateral upper arms and thighs showed organized granulations adherent to underlying bone. Microscopically, these organized lesions represented mature bone tissue in the periphery, cartilage tissue in the middle layer, and fibrotic tissue in the central part. These were typical findings of MO. Myositis ossificans and subcutaneous hemorrhage seemed to be evidence of antemortem repetitive physical abuse. In cases of dismemberment, the absence of organs and parts of the body provide limitations to determining cause of death. In forensic fields, adult autopsy cases involving MO are rare. This is an unusual case in which MO revealed antemortem physical abuse despite dismemberment of the body.
Assuntos
Desmembramento de Cadáver , Miosite Ossificante/patologia , Abuso Físico , Adulto , Feminino , Humanos , Úmero/diagnóstico por imagem , Úmero/patologia , Tomografia Computadorizada por Raios XRESUMO
PURPOSE: To investigate whether head CT should be included in whole-body CT in road traffic accident victims. METHODS: A review of electronic medical records identified 124 patients (81 males, 43 females; age 4 to 92 years, mean 47.7 years) involved in a road traffic accident in a 12-month period. All had undergone whole-body CT and physical and neurologic examinations. We recorded their age, sex, Glasgow Coma Scale (GCS), systolic blood pressure (SBP), the type of traffic accident, and the presence/absence of visible trauma above the clavicles (VTCs) and of acute traumatic brain injury (TBI) on CT. Statistical analyses were performed to evaluate predictors of acute TBI. RESULTS: Of 124 patients, 34 (27%) manifested acute TBI on CT. Univariate analysis identified their age, GCS, SBP, VTCs, and the accident type as statistically significant factors for acute TBI (p < 0.05). Multivariate analysis demonstrated VTCs, GCS score < 15, and SBP ≤ 90 mmHg were significant independent predictors of acute TBI (p = 0.001, p = 0.001, and p = 0.004, respectively); the odds ratio was 16.07 for VTCs, 14.85 for GCS score < 15, and 13.78 for SBP ≤ 90 mmHg. No patients without both decrease in GCS score and VTCs manifested acute TBI. CONCLUSION: Our pilot study showed that visible trauma above the clavicles and decrease in GCS score were highly associated with the presence of acute TBI in road traffic accident victims. In whole-body CT, a head CT may not be indicated in patients without these factors.
Assuntos
Acidentes de Trânsito , Traumatismos Craniocerebrais/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Imagem Corporal Total , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Retrospectivos , Procedimentos DesnecessáriosRESUMO
A case of clinically unsuspected fatal interrupted aortic arch (IAA) is described. A 17-day-old Japanese girl unexpectedly entered respiratory arrest at home. On autopsy, the heart was hypertrophic, with no apparent connection between the ascending and descending aortas. The ascending aorta branched into common carotid and right subclavian arteries, whereas the left subclavian artery arose from the descending aorta, which was supplied by the ductus arteriosus, indicating type B IAA. In addition, ventricular septal defect, bicuspid aortic valve, patent foramen ovale, and thymic aplasia were identified. The immediate cause of death was assumed to be "ductal shock." Because of the known strong association between type B and 22q11.2 deletion, her parents received genetic counseling and requested chromosomal analysis of the child. Fluorescence in situ hybridization worked well on a frozen blood sample, identifying the suspected deletion. This case was thus diagnosed as 22q11.2 deletion syndrome exhibiting IAA and thymic defect.
Assuntos
Aorta Torácica/anormalidades , Deleção Cromossômica , Cromossomos Humanos Par 22 , Evolução Fatal , Feminino , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/patologia , Humanos , Recém-Nascido , Timo/anormalidadesRESUMO
BACKGROUND: Simultaneous acquisition of magnetic resonance angiography (MRA) and diagnostic images is challenging in contrast-enhanced upper abdominal MRI. PURPOSE: To evaluate the image quality of MRA of the abdomen acquired simultaneously with diagnostic MR images, and to compare the contrast effect, conspicuity of aortic branches, and pancreatic lesions in MRA between gadobutrol and gadoterate meglumine. STUDY TYPE: Prospective. POPULATION: Eighty-eight patients with known and suspected upper abdominal disease. FIELD STRENGTH/SEQUENCES: 3T/4D-eTHRIVE (T1 -weighted fat-suppressed 3D fast gradient echo) for multiarterial phase imaging. ASSESSMENT: The artery-to-muscle signal intensity ratio (SIR), conspicuity of aortic branches on the axial, maximum intensity projection (MIP), and volume-rendered (VR) images, and conspicuity of focal pancreatic lesions were compared between gadobutrol and gadoterate meglumine. The diameters of aortic branches were measured on axial MRA and computed tomography angiography (CTA) images and then compared. STATISTICAL TESTS: Quantitative and qualitative data were assessed with the Mann-Whitney U-test. The diameters of aortic branches between MRA and CTA were compared with a Spearman rank correlation test. RESULTS: View-sharing multiarterial phase imaging was successfully performed in all patients. The SIRs of common hepatic artery (P = 0.0051) and left renal artery (RA) (P = 0.045), vascular conspicuities of right and left hepatic arteries (P = 0.010 and 0.030) and right and left RAs on axial (P = 0.0065 and 0.036), and that of gastroduodenal artery on MIP (P = 0.039) with gadobutrol were significantly higher than those with gadoterate meglumine. The conspicuity of focal pancreatic lesions were comparable between the gadobutrol and gadoterate meglumine (P = 0.73). The vascular diameters on MRA and CTA were strongly correlated in all aortic branches (r = 0.842-0.942, P < 0.0001). DATA CONCLUSION: High-quality MRA of the abdomen was obtained simultaneously with the diagnostic MR images using view-sharing multiarterial phase imaging that also demonstrated comparable image quality between gadobutrol and gadoterate meglumine. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage 1 J. Magn. Reson. Imaging 2017.
Assuntos
Abdome/diagnóstico por imagem , Aorta/diagnóstico por imagem , Meios de Contraste/química , Angiografia por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Meglumina/química , Pessoa de Meia-Idade , Compostos Organometálicos/química , Pâncreas/diagnóstico por imagem , Estudos ProspectivosRESUMO
We describe herein the findings from postmortem computed tomography (PMCT) of barium peritonitis due to descending colon perforation. The patient was a woman in her 60s who underwent upper gastrointestinal series with barium swallow for the purpose of physical examination. The patient developed abdominal pain the next day and visited a clinic, but was sent home for later follow-up. She was found dead at home 8 days after upper gastrointestinal series. Based on the corpse phenomena and police investigations of the scene of death, the patient was estimated to have died 6 days after the upper gastrointestinal series. PMCT revealed free gas within the peritoneal cavity. Barium and fat stranding were also observed around a diverticulum in the descending colon. A large amount of residual barium was seen in the ascending colon and was considered to represent antemortem constipation and delayed barium excretion. No gas was detected in the abdominal wall, cardiac chambers or hepatic vasculature. The pancreas and adrenal glands had a normal appearance. We diagnosed barium peritonitis due to descending colon perforation as the cause of death. Diverticular perforation was suspected because barium retention and fat stranding were particularly noticeable around the descending colon diverticulum. In conclusion, we have presented a rare case of postmortem diagnosis of barium peritonitis. In PMCT interpretation, distinguishing between ante- and postmortem intestinal perforations is important.
RESUMO
In forensic cases for which the time of death is unknown, several methods are used to estimate the postmortem interval. The quotient (Q) defined as the difference between the rectal and ambient temperature (Tr - Ta) divided by the initial difference (T0 - Ta) represents the progress of postmortem cooling: Q = (Tr - Ta)/(T0 - Ta), (1 ≥ Q ≥ 0). Henssge was able to show that with the body weight and its empirical corrective factor, Q can be reasonably predicted as a double exponential decay function of time (Qp(t)). On the other hand, actual Q is determined as Qd by measuring Tr and Ta under an assumption of T0 = 37.2 °C. Then, the t value at which Qp(t) is equal to Qd (Qd=Qp(t)) would be a good estimate of the postmortem interval (the Henssge equation). Since the equation cannot be solved analytically, it has been solved using a pair of nomograms devised by Henssge. With greater access to computers and spreadsheet software, computational methods based on the input of actual parameters of the case can be more easily utilized. In this technical note, we describe two types of Excel spreadsheets to solve the equation numerically. In one type, a fairly accurate solution was obtained by iteration using an add-in program Solver. In the other type (forward calculation), a series of Qp(t) was generated at a time interval of 0.05 h and the t value at which Qp(t) was nearest to Qd was selected as an approximate solution using a built-in function, XLOOKUP. Alternatively, a series of absolute values of the difference between Qd and Qp(t) (|Dq(t)| = |Qd - Qp(t)|) was generated with time interval 0.1 h and the t value that produces the minimum |Dq(t)| was selected. These Excel spreadsheets are available as Supplementary Files.
Assuntos
Morte , Medicina Legal , Humanos , Medicina Legal/métodos , Mudanças Depois da Morte , Fatores de Tempo , Autopsia , Temperatura CorporalRESUMO
We describe herein an autopsy case involving fatal hemorrhagic shock due to idiopathic sigmoid colonic intramural hematoma rupturing into the abdominal cavity. Antemortem computed tomography revealed a mass lesion in the sigmoid colon and a large amount of hemoperitoneum. On forensic autopsy, intramural hematoma of the sigmoid colon with ruptured serosa was identified, while the mucosa remained intact. Microscopically, hematomas were apparent, mainly in the muscularis propria. We diagnosed the cause of death as hemorrhagic shock due to idiopathic intramural hematoma of the sigmoid colon rupturing into the abdominal cavity. Although the patient had been receiving peritoneal dialysis, no relationship was identified between dialysis catheters and sigmoid colon intramural hematoma rupture. On computed tomography, the mass lesion was initially considered a submucosal neoplastic lesion or endometriotic lesion. Intramural hematoma should be considered as a differential diagnosis.
RESUMO
The Acetaminophen Detection Kit® (Kanto Chemical Company Co. Inc., Tokyo, Japan) is a colorimetric test based on an indophenol reaction. The test involves three reactions: deproteination of the sample, hydrolysis of acetaminophen to yield p-aminophenol, and coupling p-aminophenol with a derivative of phenol in alkali conditions to form a blue-colored indophenol dye. The kit was devised to accomplish these three reactions with only two reagents, allowing the prompt diagnosis of acetaminophen overdose in emergency medicine. In the user instructions included with the kit and in reports introducing the kit, the chemical composition of the two reagents was not disclosed. Details about the composition can be found in the Safety Data Sheet from the manufacturer; however, there is little explanation about the principle (mechanism) of the coupling reaction. This lack of information appears to have hampered the use of this kit in forensic medicine. In this report, we conducted the coupling reaction by successively adding the two reagents to a p-aminophenol (intermediate molecule) solution with the reaction vessel open to the air and under an anaerobic condition. Development of the blue color was inhibited in the absence of air but gradually developed when the reaction vessel was opened to air. Thus, the coupling reaction is an oxidation-reduction (redox) reaction that requires molecular oxygen (O2) dissolved from the air to act as an oxidant. This finding corroborates statements in previous reports and will hopefully facilitate the use of the kit for forensic purposes.
Assuntos
Acetaminofen , Indofenol , Humanos , Aminofenóis , OxigênioRESUMO
Intracranial hypostasis is a common postmortem change evident on postmortem CT (PMCT), but can be readily misinterpreted as subdural hematoma by inexperienced physicians. Although PMCT is necessarily lacking contrast enhancement, we reconstructed hypostatic sinuses into three-dimensional images resembling the results of in vivo venography. This simple methodology facilitates easy recognition of intracranial hypostasis.
Assuntos
Hematoma Subdural , Trombose Intracraniana , Mudanças Depois da Morte , Imageamento Tridimensional , Hematoma Subdural/diagnóstico por imagem , Flebografia , Humanos , Trombose Intracraniana/diagnóstico por imagem , Medicina Legal , Tomografia Computadorizada por Raios X , Diagnóstico DiferencialRESUMO
An autopsy case involving a child showing various shapes of tramline bruises caused by a single weapon is described. On autopsy, multiple tramline bruises in different orientations were found, mainly on the back. Shapes of the tramline bruises were variable, including linear, arcuate, nodular, hook-like, and hook-like with a knot at the end. Due to the presence of severe subcutaneous hemorrhages and the absence of other potentially fatal injuries or diseases, we determined the cause of death to be traumatic shock. Microscopically, of the many tramline bruises, characteristic hemorrhages were observed on the right abdominal and left lumbar regions. Those hemorrhages were observed in the dermis, corresponding to macroscopic tramline bruises. Hemorrhage was also observed in the subcutis, corresponding to the pallor of the outer surface. The mechanisms by which tramline bruises occurred in the dermis and subcutis in this case are discussed with reference to the literature. We also propose subcutaneous and intradermal hemorrhagic types of tramline bruising.
Assuntos
Contusões , Criança , Humanos , Autopsia , Contusões/patologia , Hemorragia/patologia , Tela Subcutânea/patologia , Gordura Subcutânea/patologiaRESUMO
Low rates of diatom positivity in the closed organs of drowning victims present challenges for diatom testing. High positivity rates in closed organs of non-drowning victims also raise an important issue. These contradictory findings were common in diatom testing studies undertaken during the 1960-80 s, but the reasons remained unclear. In the present study, we identified one of the most important factors associated with false-positive results in diatom testing using strong acid. One to 290 false-positive diatoms were found in reused Kjeldahl flasks that were thoroughly washed after the first diatom testing and kept free of tissue before the second testing. False-positive results occurred in 11 of 20 cases when more than approximately 10,000 diatoms were present in digested tissue or water samples. Reused flasks were found to contain many common diatoms (<30 µm), including Cocconeis, Cymbella, Diatoma, Gomphonema, Navicula, and Nitzschia, in agreement with reports of diatoms identified in closed organs. Surprisingly, such false-positive results occurred even at the sixth diatom testing using the same flasks kept free of tissues in each analysis. In contrast, no diatoms were detected in any reagent or associated with other glassware. Thus, reuse of Kjeldahl flasks can readily cause false-positive results that cannot be completely prevented by cleaning the flasks using alkali detergents, as evidenced by detection of diatoms even after six tests. We assume that diatoms causing false-positive results are partially melted by heating and fixed onto the flask's inner surface glass, as the diatom frustule consists primarily of SiO2, similar to glass. Adherent diatoms are then released from the glass by re-heating at the next diatom testing. These results also suggest that the number of diatoms remaining in a flask can increase steadily as a result of repeated reuse for analysis of lung or water samples. In contrast, in analyses using only new flasks, only one or two diatoms were found in 4 of 20 kidney, 2 of 12 liver, and 2 of 8 blood samples from 20 drowning victims. It is difficult to determine whether such diatoms are actually carried via the blood circulation, as contamination with a few diatoms can occur during autopsy procedures and diatom testing. In conclusion, only new (unused) Kjeldahl flasks should be used for diatom testing with strong acid digestion. Moreover, these data suggest that the number and frequency of diatoms present in closed organs of drowning victims may be much lower than previously thought.
Assuntos
Diatomáceas , Afogamento , Monitoramento Ambiental , Afogamento/diagnóstico , Patologia Legal , Humanos , Pulmão , Dióxido de Silício , ÁguaRESUMO
The number of diatoms detected in the kidneys and liver varies considerably when comparing various reports, but the reason remains unclear. We previously showed that the reuse of Kjeldahl flasks is susceptible to generating false positives; false-positive results were observed in 17 of 60 tested flasks, and a maximum of 290 diatoms were detected. Furthermore, these data suggested that the number of diatoms in kidney and liver tissue may be much lower than previously thought. Therefore, only new Kjeldahl flasks were used to perform diatom tests on 80 autopsy cases (drowning and non-drowning victims) in this study. When combined with the 20 cases in a previous study, a total of 100 cases were analyzed. Four grams of lung, 10-30 g each of kidney and liver, 10 mL of blood, and 50-100 mL of water (discovery site) were examined. A large number of diatoms (n = 400) were found in organs other than the lungs in only 1 of 56 cases of suspected drowning (excluding cases of suspected drowning in baths). Together with the previous 20 cases, this single case represented only 1 of 76 cases (1.3 %). In closed organs and blood samples, 3 diatoms were found in 2 of 56 victims (3.6 %), and 1 or 2 diatoms were found in 8 victims (14 %). However, 5 diatoms were found in 1 of 10 bathtub drowning victims and 12 non-drowning victims (4.5 %), and 1 or 2 diatoms were found in 6 victims (27 %). Moreover, 1 or 2 diatoms were found in negative control flasks in 3 of 80 victims (3.8 %). The results showed that distinguishing false-positive results is difficult when a small number of diatoms are found in the kidneys and liver. Thus, the presence of diatoms in closed organs and blood seems to be unreliable as evidence of death by drowning, at least in the water environments in our region (freshwater areas: 23-26,000 diatoms/mL, median 200 diatoms; brackish water areas: 26-1200 diatoms/mL, median 210 diatoms; seawater area: 2-1000 diatoms/mL, median 24 diatoms). These results also reconfirmed that the reuse of flasks is the most important cause of false positives. Conversely, the presence of a large number of diatoms in lung samples (1-850,000 diatoms/g lung tissue; median (right lung): 440 diatoms, (left lung): 320 diatoms) is very informative and is an effective diagnostic aid in many cases.
Assuntos
Diatomáceas , Afogamento , Humanos , Autopsia , Afogamento/diagnóstico , Água , PulmãoRESUMO
We describe the case of a 40s woman with a carbohydrate antigen (CA)19-9-producing splenic cyst. The lesion was detected incidentally at the splenic hilum, and resected after 5 years of follow-up. Size of the lesion was enlarged from 1.6 cm to 5.3 cm, and serum CA19-9 was elevated from the normal range to 1766 U/ml. Microscopically, CA19-9-producing splenic cyst was diagnosed. It was mimicked pancreatic malignancy due to its location at the splenic hilum. Benign lesions with elevated serum CA19-9 also to be differential diagnosis.
RESUMO
OBJECTIVES: To compare "black ring-shaped burn" (BRSB) and charring using spectral computed tomography (CT). METHODS: Spectral CT was performed using chicken pectoralis minor muscle, processed in three ways and unprocessed as a control: a) BRSB generated by bringing the negative pole surface of a 3 V button battery (BB) into contact with the muscle; b) BRSB caused by a 1.5 V BB; c) charring caused by broiling; and d) control. Attenuation values were compared between BRSB and charring. Muscles were formalin-fixed and stained with Perls' Prussian blue. RESULTS: Attenuation values from polychromatic 120-kVp images were significantly higher for BRSBs than for charring. In the spectral Hounsfield unit curve, attenuation values for BRSBs were higher for lower energy. Histopathologically, BRSBs stained positively with Perls' Prussian blue. CONCLUSIONS: This study using spectral CT revealed that BRSB contains metal and confirmed the presence of Fe3+ histopathologically. BRSB differs from charring due to burns. ADVANCES IN KNOWLEDGE: The exact composition of BRSB remains unclear, but this report is the first to show that BRSB differs from charring using spectral CT. Clarification of the composition of BRSB is expected to facilitate the development of more effective BRSB removal therapy.
Assuntos
Queimaduras/diagnóstico por imagem , Corpos Estranhos/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Animais , Galinhas , Modelos Animais de Doenças , Músculo Esquelético/diagnóstico por imagemRESUMO
Diatom analysis is very effective for positive diagnosis of water inhalation in drowning. However, conventional strong acid diatom testing is laborious and potentially dangerous. We propose a simple, fast, and safe protocol using inexpensive reagents such as papain, SDS, and 5 N HCl for extracting diatoms from lung, kidney, and liver tissues. First, we determined optimal conditions for papain digestion using porcine tissues. Papain digestion was clearly superior to Proteinase K digestion. Next, for assessing the assay effectiveness in practical cases, the papain digestion protocol was applied to 80 tissue samples from 20 suspected drowning victims. Left and right lung tissues (1 g each) were digested in 15-mL conical centrifuge tubes. Kidney and liver tissues (10 g each) were extracted in 175-mL conical centrifuge bottles. Papain dissolved all organs sufficiently and permitted clear visualization of diatoms, although papain's solubilization activity was still inferior to strong acid digestion. The proposed enzymatic method requires only a low-speed centrifuge and water bath. Diatoms typically can be extracted from tissue samples within 3-5 h. The cost of protease is reduced some 6-fold by using papain in place of Proteinase K. Thus, the proposed method can be useful as a less-laborious, less-hazardous, and less-costly minimal test when the conventional strong acid digestion method is not performed due to personnel, equipment, budgetary limitation, or environmental and safety considerations.
Assuntos
Diatomáceas/isolamento & purificação , Afogamento/diagnóstico , Patologia Legal/métodos , Indicadores e Reagentes , Papaína , Animais , Cadáver , Centrifugação/instrumentação , Endopeptidase K , Humanos , Incubadoras , Rim/patologia , Fígado/patologia , Pulmão/patologia , Manejo de Espécimes/métodos , SuínosRESUMO
The first quantitative study on the effect of visible light irradiation on the luminol reaction, used forensically, was conducted using whole human blood aqueous solutions (hemolytic state) and an LED lamp. Whole human blood aqueous solutions under an air atmosphere were irradiated with visible light, resulting in the maximum chemiluminescence (CL) intensity (@ 440 nm) increasing about 1.7-fold due to acceleration of the luminol reaction rate. No acceleration effect was observed under an argon (Ar) atmosphere, or under an air atmosphere in the presence of sodium azide (NaN3; a scavenger of singlet oxygen (1O2)). Furthermore, no conversion from Fe(II) hemoglobin to Fe(III) hemoglobin (methemoglobin) was observed in the absorption spectrum following irradiation. We suggest that these effects are due to easier approach of the luminol reagents to heme following damage of the globin protein around the heme, or damage to the red blood cell membrane, induced by 1O2 generated by an excited state of heme.