Composition and Drug Resistance of Pathogenic Isolates from CSF Culture of Pediatric Patients in Guangzhou / 现代检验医学杂志

Objective To explore the composition and drug resistance characteristics of pathogenic isolates from cerebrospinal fluid (CSF) cultures to facilitate empirical therapy of pediatric patients with meningitis in Guangzhou district.Methods During 2011 Jan 1st to 2015 Dec 31st,cerebrospinal fluids were collected from pediatric patients with suspected meningitis for regular culture,identification and drug susceptibility test of pathogenic isolates according to the national clinical laborato ry standard operation procedure,followed by analysis of their composition and drug resistance characteristics.Results There were 132 pathogenic isolates from CSF cultures,including Gram-positive strains (39.40％,52/132),Gram-negative strains (757.58％,6/132),fungi (3.03 ％,4/132),respectively.The main isolates were Escherichia coli (E.coli) (23.48％,31/132),Streptococcus pneumonia (S.pneumonia) (22.73％,30/132),Staphylococcus aureus (S.aureus) (12.12％,16/132)and Streptococcus agalactiae (S.agalactiae) (9.85％,13/132),respectively.E.coli had no resistance to piperacillin/tazobactam,furantoin,cefepime,amikacin,tobramycin,imipenem,ertapenem and meropenem.3.22 ％ resistance rate to cefotetan,9.38％ to ceftazidime,12.90 ％ to aztreonam,approximately 30 ％ to ampicillin/sulbactam,ofloxacin,ciprofloxacin,ceftriaxone,gentamycin,cefazolin,over 60 ％ to both sulfamethoxazole and ampicillin,31.25 ％ strains were ESBL positive.S.pneumonia had no re sis tance to ertapenem,5.88 ％ resistance rate to telithromycin,14.71％ to chloromycetin,17.76 ％ to ceftriaxone,23.53 ％ to amoxicillin,32.30 ％ to meropenem,35.29 ％ to cefotaxime,over 70 ％ to tetracycline,erythromycin,penicillin,and sulfamethoxazole.S.a ureus had no resistance to rifampicin,tigecycline,quinuprin/dupletin,linezolid and vancomycin,6.25％ resistance to ciprofloxacin,6.25％ to gentamicin,12.50％ to sulfamethoxazole,18.75％ resistance to clindamycin,31.25 ％ to tetracycline,62.50 ％ to erythromycin,over 90 ％ to cephalosporins and nearly 100 ％ to penicillin,the rate of MRSA strain was 56.25 ％.S.agalactiae had no resistance to penicillin,23.08 ％ resistance rate to ofloxacin,7.69 ％ to ciprofloxacin,over 60％ to tetracycline,erythromycin and clindamycin.Conclusion The main pathogenic isolates from CSF cultures were E.coli,S.pneumonia,S.aureus,S.agalactiae,different species of isolates have different drug resistance characteristics.This will provide instructions for the prevention,pathogenic diagnosis and treatment of meningitis in pediatric patients.

Standard protocol of ALK fusion gene assessment by fluorescent in situ hybridization in non-small cell lung cancer / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the standard protocol for anaplastic lymphoma kinase (ALK) fusion gene assessment by fluorescent in situ hybridization (FISH) in non-small cell lung cancer (NSCLC).</p><p><b>METHODS</b>Tissue specimens of NSCLC cases were retrospectively collected from Jan. 2011 to July 2012. ALK fusion gene was examined by FISH using break-apart ALK gene probes (Vysis company). The identification of ALK fusion gene was determined by fluorescent signals under a fluorescence microscope.</p><p><b>RESULTS</b>One hundred and forty-six eligible NSCLC tumor specimens were tested for ALK fusion gene by FISH. The specimens included 110 cases (75.4%) of surgically-removed tissues, 11 cases (7.5%) of biopsy, 19 cases (13.0%) of lymph node and 6 cases (4.1%) of other metastatic tissues. The positivity of ALK fusion gene was 8.9% (13/146).</p><p><b>CONCLUSIONS</b>The assessment of ALK fusing gene by FISH using standard protocol for formalin-fixed, paraffin-embedded (FFPE) tissue is feasible. The protocol can used to test in surgically-removed tissues, biopsies, metastatic lymph nodes and other metastastic specimens.</p>

Analysis of HER2 status in breast carcinoma using fully automated HER2 staining and fluorescence in-situ hybridization technology / 中华病理学杂志

<p><b>OBJECTIVE</b>To determine human epidermal growth factor receptor 2 (HER2) status in breast carcinoma by the techniques of a fully automated immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), to compare the concordance of protein expression with gene amplification and to explore the optimization in process quality control.</p><p><b>METHODS</b>A prospective study of invasive breast cancer specimens excised between May 2009 and April 2011 at the Cancer Hospital, Chinese Academy of Medical Sciences was conducted by automated IHC staining with the new 4B5 rabbit monoclonal antibody and FISH. An evaluation was performed according to the ASCO/CAP guidelines (2007) and Chinese guidelines (2009). The gene amplification status of 740 cases were detected by FISH.</p><p><b>RESULTS</b>A total of 2420 cases of breast invasive ductal carcinoma without pre-operation therapy were tested by automated IHC. 551 cases (22.8%) were scored as positive (3+), 664 cases (27.4%) as equivocal (2+), and 1205 cases (49.8%) as negative (1+/0). Gene amplification was detected in 98.0% (242/247) HER2 protein expression positive (3+) cases and in 13.6% (53/389) equivocal (2+) cases. One of 247 (0.4%) HER2 expression 3+ cases and 5 of 389 (1.3%) HER2 expression 2+ cases were equivocal for gene amplification. No gene amplification was detected in expression negative (1+/0) cases by FISH (0/104). The overall concordance between IHC and FISH was 98.6% [(242 + 104)/(247 + 104)].</p><p><b>CONCLUSIONS</b>There is a high concordance rate between automated IHC with 4B5 rabbit monoclonal antibody and FISH results for assessing the HER2 gene amplification status in surgically-excised breast cancer specimens, suggesting that automated IHC with 4B5 antibody can provide a reliable method to detect HER2 overexpression for eligibility of HER2 targeted therapy.</p>

Expression of fascin and CK14 in different histological types of cancer and its differential diagnostic significance / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate and analyze the expression of fascin and CK14 in multiple histological types of cancer and to explore the potential value of the two proteins as markers in diagnosis and differential diagnosis of various cancer types.</p><p><b>METHODS</b>Tissue microarray containing esophageal squamous cell carcinoma (SCC), lung SCC, larynx SCC, uterine cervical SCC, SCC of external genital organs, lung adenocarcinoma, gastric adenocarcinoma, colorectal adenocarcinoma, heptocellular carcinoma, pancreatic ductal adenocarcinoma, breast infiltrating ductal carcinoma, thyroid papillary carcinoma, uterine endometrioid adenocarcinoma, ovarian serous adenocarcinoma and renal clear cell carcinoma, 30 cases each, as well as corresponding normal controls was constructed. The expression of fascin and CK14 among different types of carcinoma and corresponding normal controls was detected by immunohistochemistry.</p><p><b>RESULTS</b>In normal esophagus, bronchus, larynx, uterine cervix and skin, fascin was mainly expressed in the basal cells or reserve cells, but the expression was diffuse in esophageal SCC, lung SCC, larynx SCC, uterine cervical SCC and SCC of external genital organs, with a positive rate of 90.0%, 90.0%, 96.7%, 78.6% and 89.7%, respectively. In the normal tissue of other organs, except breast and uterine endometrium, fascin was negative. In lung adenocarcinoma, gastric adenocarcinoma, colorectal adenocarcinoma, hepatocellular carcinoma, pancreatic ductal adenocarcinoma, breast infiltrating dutal adenocarcinoma, thyroid papillary carcinoma, uterine endometrioid adenocarcinoma, ovarian serous adenocarcinoma and renal clear cell carcinoma, the positive rates were 38.0%, 23.3%, 14.3%, 10.3%, 73.3%, 13.3%, 6.7%, 60.0%, 66.7% and 10.0%, respectively. The difference between fascin expression in SCC and in other histological types was statistically significant (P < 0.001). CK14 was mainly expressed in the basal cells, reserve cells or myoepithelia of normal tissues. The positive rates of CK14 were 76.7%, 36.7%, 83.3%, 60.7% and 96.3% in esophageal SCC, lung SCC, larynx SCC, uterine cervical SCC and SCC of external genital organs, respectively. It was weak and focal in lung adenocarcinoma, gastric adenocarcinoma, colorectal adenocarcinoma, hepatocellular carcinoma, pancreatic ductal adenocarcinoma, breast infiltrating dutal adenocarcinoma, thyroid papillary carcinoma, uterine endometrioid adenocarcinoma, ovarian serous adenocarcinoma, and renal clear cell carcinoma, with a positive rate of 13.3%, 13.3%, 20.7%, 41.4%, 46.7%, 6.7%, 40.0%, 13.3%, 20.0% and 6.7%, respectively. The difference between CK14 expression in SCC and in other histological types was statistically significant (P < 0.001). The difference between co-expression of fascin/CK14 in SCC and in other histological types was also statistically significant (P < 0.001).</p><p><b>CONCLUSION</b>Fascin and CK14 are highly expressed in SCC, compared with other histological types of carcinoma. Combination of fascin and CK14 should be a valuable marker in diagnosis and differential diagnosis of carcinoma.</p>

Distribution and antibiotic resistance of pathogens isolated from children with infectious diarrhea in Guangzhou / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the distribution and antibiotic resistance of the isolated pathogens from children with infectious diarrhea in Guangzhou.</p><p><b>METHODS</b>The fecal samples of 2 409 children with infectious diarrhea between January 2006 and December 2007 were collected and cultured. Pathogenic bacterium were isolated and identified by biochemical and serological methods. The antibiotic susceptibilities were tested by the Kirby-Bauer method.</p><p><b>RESULTS</b>A total of 448 isolates of pathogenic bacterium (18.6%) were obtained, including Shigella (n=159), enteropathogenic Escherichia coli (n=141), Salmonella (n=76), Vibrion (n=11), fungus (n=41), and C jejuni (n=20). All of isolates of the three major pathogenic bacterium, Shigella, enteropathogenic Escherichia coli and Salmonella, were susceptible to imipenem and less than 10% of the isolates were resistant to the third generation cephalosporins and beta-lactamase inhibitors. However, the isolates showed a high resistance to ampicillin and sulfamethoxazole/trimethoprim (>75%).</p><p><b>CONCLUSIONS</b>Shigella, enteropathogenic Escherichia coli and Salmonella were major pathogenic bacterium of diarrhea in children from Guangzhou. The major isolates were susceptible to imipenem, the third generation cephalosporins and beta -lactamase inhibitors, but were resistant to ampicillin and sulfamethoxazole/trimethoprim.</p>

Cloning and sequence analysis of UreB of Helicobacter pylori isolated from children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To clone UreB gene of Helicobacter pylori (H. pylori) isolated from children to pGEX-4T-1 expression plasmid, and do sequence analysis.</p><p><b>METHODS</b>A pair of specific primer was designed according to H. pylori UreB gene in the GenBank. Using H. pylori strains isolated from children as a template, a UreB gene was obtained by PCR. After EcoR I and Not I digestion, the PCR production was linked with pGEX-4T-1 which was digested with the same enzymes. The recombinant plasmid was transformed into E.coli BL21 and identified by double enzyme digestion and sequence analysis. The sequence results were compared with the gene sequence in the GenBank.</p><p><b>RESULTS</b>A UreB gene was successfully amplified from children's H. pylori strain GZCH1. It was 1710 bp in size. The objective band was identified by double enzyme digestion. DNA sequence showed that UreB was in the correct open reading frame. The sequence comparison analysis showed that DNA and amino acid sequence identities of UreB gene with other strains were 98%. The sequence of UreB of H. pylori strain GZCH1 was submitted to GenBank (accession number:FJ455126).</p><p><b>CONCLUSIONS</b>UreB of H. pylori strain GZCH1 is successfully cloned to pGEX-4T-1, which provides a basis for research of oral H. pylori vaccine.</p>

Investigation of campylobacter jejuni infection in children with diarrhea in Guangzhou / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the incidence of campylobacter jejuni (CJ) infection and the drug resistance of CJ in children with diarrhea in Guangzhou.</p><p><b>METHODS</b>The fecal samples of 3,351 children with diarrhea between July 2005 and June 2008 were collected for CJ culture. The species of CJ strains were identified by Lior methods. The drug susceptibility tests were performed by the Kirby-Bauer method.</p><p><b>RESULTS</b>Two hundred and sixty-seven CJ strains (8.0%) were isolated from 3,351 samples. The children at age of 1 month to 1 year were susceptible to CJ, accounting for 91.0%. A higher incidence of CJ infection (76.8%) was found in summer and autumn. The CJ strains were susceptible to imipenem, amikacin, cefoperazone/sulbactam, chloramphenicol, macrolides and lincomycins. Parts of CJ strains (20%-40%) were resistant to ampicillin, quinolones and ambramycin. All CJ strains were resistant to sulfamethoxazole/trimethoprim and cefditoren. Two hundred and one strains (75.3%) were CJ biotype I.</p><p><b>CONCLUSIONS</b>CJ is an important pathogen of diarrhea in children from Guangzhou. CJ is resistant to some antibiotics used often in clinical practice, and so it is thus important to use antibiotics based on the results of drug susceptibility tests in children with CJ infection.</p>

Clinicopathological features of uterine neoplasms with perivascular epithelioid cell differentiation / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the neoplasm with perivascular epithelioid cell differentiation (PEComa) with respect to their morphologic, immunohistochemical and clinical phenotypes.</p><p><b>METHODS</b>Three PEComas were included in this study, one located at the left uterine horn, and two presented as a mass in the uterine corpus. The tumors were examined by histopathology and immunohistochemistry.</p><p><b>RESULTS</b>The lesions were composed of spindle, blunt epithelioid cells, with foci of, or scattered, cells showing adipose differentiation in two cases. The myomelanocytic differentiation was demonstrated, proving the diagnosis as PEComa. Mild nuclear atypia and focal necrosis was observed in one lesion, and the rest two showed malignant morphologic phenotypes including moderate nuclear atypia and coagulative necrosis. The mitotic and Ki67-labelling indices ranged from 0.5/10 HPF to 14/10 HPF and 0.6% to 7.0%, respectively. All of the three patients remain alive. Malignant nature of the two lesions with worrisome morphology was confirmed by occurrence of metastases after hysterectomy.</p><p><b>CONCLUSION</b>PEComa is a rare tumor, occurring preferentially in the uterus. It is regarded as a tumor with uncertain malignant potential, but a minority of them shows malignant clinical behaviors. Some pathologic parameters including large tumor size, sheet-like necrosis, marked nuclear atypia, elevated mitotic index (> or = 10/10 HPF), aberrant mitotic figure and vascular invasion may help to establish a diagnosis of malignant PEComa.</p>

Diagnosis and long-term results of surgical resection of early cardiac adenocarcinoma / 中华外科杂志

<p><b>OBJECTIVE</b>To summarize therapeutic experience and the long-term results of early cardiac adenocarcinoma with surgical resection.</p><p><b>METHODS</b>Ninety cases were diagnosed with early cardiac adenocarcinoma during endoscopic screening in high incidence rate area of esophageal cancer from 1972 to 1997. All of the patients accepted surgical treatment. Cardiectomy included partial stomach and esophagus was performed through left thoracotomy in all patients. Esophagogastrostomy was carried out in the infra-aortic region and thoracoabdominal lymphatic dissection was performed in all cases.</p><p><b>RESULTS</b>The resection rate was 100%. One patient died in one month after the operation. Postoperative complications occurred in 4 cases (4.4%). Pathological examination of cancer specimens showed that 46 cases (51.1%) were intramucosal carcinoma without lymphatic metastasis and 44 cases (48.9%) were submucous infiltrating carcinoma with lymphatic metastasis in 5 (11.4%). The patients were followed-up to 2002, and the overall 5, 10, 15, 20 and 25 year survival rates were 91.9%, 83.6%, 69.6%, 49.8% and 16.6%, respectively.</p><p><b>CONCLUSIONS</b>Early diagnosis and early treatment may be the best approach for promoting the survival of the cardiac cancer. Surgical resection of early cardiac carcinoma provides excellent long-term survival.</p>

Surveillance of antimicrobial susceptibility of Streptococcus pneumoniae and Hemophilus influenzae isolated from children in Guangzhou area between 2003 and 2004 / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the situation of antibiotic resistance of Streptococcus pneumoniae (Sp) and Hemophilus influenzae (Hi) clinical isolates from children in Guangzhou area.</p><p><b>METHODS</b>The authors cultured, isolated and identified the Sp and Hi strains from nasopharyngeal secretion of patients who visited Guangzhou Children's Hospital for upper respiratory tract infection between 2003 and 2004. K-B disc diffusion and E-test for antibiotic susceptibility were performed for these clinical isolates.</p><p><b>RESULTS</b>Totally 172 and 484 strains of Sp and Hi were respectively isolated from nasopharyngeal secretions in the hospital. For Sp strains, the rates of resistance to penicillin, amoxicillin/clavulanic acid, ceftriaxone, cefuroxime, cefaclor, erythromycin, tetracycline, chloramphenicol, sulfamethoxazole/trimethoprim (SMZ/TMP), clindamycin and ofloxacin were 32.0%, 11.1%, 32.6%, 18.1%, 39.5%, 82.6%, 78.5%, 24.4%, 87.2%, 69.2% and 3.1%, respectively. The penicillin non-susceptible Sp (PNSSP) isolates showed higher rates of resistance to other antimicrobial agents such as other beta-lactam antimicrobial agents, erythromycin, and SMZ/TMP than those of penicillin susceptible Sp (PSSP) isolates. More than 90% of PNSSP were multidrug resistant strains. The average rate of beta-lactamase production among 484 strains of Hi was 29.5% (143/484). For Hi isolates, the rates of resistance to ampicillin, amoxicillin/clavulanic acid, ceftriaxone, cefuroxime, cefaclor, SMZ/TMP, tetracycline, chloramphenicol, azithromycin, and ofloxacin were 40.1%, 3.4%, 4.1%, 1.9%, 5.6%, 56.2%, 52.1%, 17.4%, 2.1%, and 0.6%, respectively.</p><p><b>CONCLUSION</b>The antimicrobials resistant Sp and Hi isolated from children with respiratory tract infection in the area have become a severe problem. The rate of resistance to penicillin of Sp had been decreased compared with the last three years, but the rate of resistance to ceftriaxone of Sp increased, and the multidrug resistance rates of PNSSP was rather high. PNSSP was characterized by a multidrug-resistance to erythromycin, tetracycline and SMZ/TMP. beta-lactamase production and ampicillin resistance among the Hi isolates from children in the area had increased generally during the period 2003 - 2004. The Hi isolates were more susceptible to the second and the third generation cephalosporins, amoxicillin/clavulanic acid and azithromycin.</p>

A clinicopathological analysis of gastric lymphoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To discuss the clinicopathological features and prognostic factors of gastric lymphoma.</p><p><b>METHODS</b>83 gastric lymphoma cases were analyzed retrospectively in accordance to the criteria of the new World Health Organization classification for neoplastic diseases of the hematopoietic and lymphoid tissues. The correlations between clinicopathological features, therapeutic measures and survival were discussed.</p><p><b>RESULTS</b>The age of patients ranged from 25 to 77, with a median of 52. The number of males were similar to that of females. There were no specific symptoms. The most common symptoms were stomach ache (60 cases, 72%) or discomfort. The duration of symptoms was often long and with a history of chronic gastric diseases (21 cases, 25%). 13 cases had multiple lesions in the gastrointestinal mucosa. 51 cases (61%) were accompanied by lymph node involvement. According to the new World Health Organization classification for neoplastic diseases of the hematopoietic and lymphoid tissues, 57 cases were extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT)-type (MALT lymphoma), 23 were diffuse large B cell lymphoma accompanying MALT lymphoma, 2 were diffuse large B cell lymphoma and 1 was follicular lymphoma. Of all the cases, 31 were stage I E, 38 stage II E, 8 stage III E and 6 stage IV by the Ann Arbor staging system (1972). The total 5-year and 10-year survival rates were 77.8% and 70.1% respectively, with the mean survival time of 146 months. The 5-year and 10-year survival rates of MALT lymphoma were 77.4% and 72.3%, the 5-year and 10-year survival rates of diffuse large B cell lymphoma accompanying MALT lymphoma were 81.8% and 68.2%, the 5-year survival rate of diffuse large B cell lymphoma was 50.0%.</p><p><b>CONCLUSIONS</b>There are no specific symptoms in gastric lymphoma patients. Extranodal marginal zone lymphoma of MALT-type is the main histopathological type of gastric lymphoma, often accompanied by multiple mucosa involvement and also often accompanied by a history of chronic gastric disease. The lesion is usually localized for a long time, with a very good prognosis. Survival rate has a significant correlation with lymph node involvement and clinical stage. No correlations were found between the survival rates with age, gender, B symptoms, invasive depth of the wall of stomach, the size and range of the tumors or different therapeutic measures.</p>

Lung pathology of severe acute respiratory syndrome / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the morphological features of the lungs obtained from autopsies of severe acute respiratory syndrome (SARS) patients.</p><p><b>METHODS</b>Bilateral lungs from 7 patients died from SARS were carefully studied grossly and microscopically. All tissues from these cases were routinely processed and carefully studied.</p><p><b>RESULTS</b>All lungs from these cases were extremely expanded and became solid. Microscopically, the edema and fibrin exudates in the alveoli was the most common findings, especially in the early phase of the disease. The hyaline membrane was almost always present in the lungs of these cases. The organization of intra-alveolar fibrin exudates along with the interstitial fibrosis led to obliteration of alveoli and consolidation of lungs. The desquamation and hyperplasia of alveolar lining cells was also apparent. Foci of haemorrhage and lobular pneumonia, even diffuse fungal infection were frequently seen in these specimens. Micro-thrombus were easily found in these lungs.</p><p><b>CONCLUSIONS</b>The lung of SARS from autopsy is characterized by edema, intra-alveolar fibrin exudates, hyaline membrane formation, organization of intra-alveolar exudates and fibrosis, which lead to the obliteration of alveoli and consolidation of lungs.</p>

Immunohistochemical investigation of lungs with severe acute respiratory syndrome / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the roles of different cells in the pulmonary lesions in the severe acute respiratory syndrome (SARS) patients.</p><p><b>METHODS</b>The monoclonal antibodies of CD8, CD20, CD34, LCA, CD56, CD68, and AE1/AE3 are used to demonstrate the different cells in the lung specimens of SARS patients in order to study the patterns of cell responses in this new disease. Meanwhile the HE stained slides were also carefully studied to compare with the results of immunohistochemical staining.</p><p><b>RESULTS</b>The number of capillaries increased and the capillaries clearly outlined the contour of alveolar wall from beginning to early stage of organization, the number of lymphocytes decreased sharply while the number of macrophage remarkably increased, together with proliferation of type II pneumocytes. The numbers of blood vessels decreased in the fibrotic and consolidated lung tissue, and the vessel cavities enlarged, losing the normal contour of alveolar septa.</p><p><b>CONCLUSIONS</b>The lesions in the lung from SARS patients are consisted of the tissue reaction to the inflammatory injury, including extensive exudation, capillary proliferation, fibrosis, and obvious infiltration of macrophages which may play a key role in the pathogenesis of pulmonary lesions of SARS.</p>

Morphological study of severe acute respiratory syndrome (SARS) / 中华病理学杂志

<p><b>OBJECTIVE</b>Seven cases of autopsy from SARS patients are studied to investigate the pathogenesis and the pathologic changes of the major organs.</p><p><b>METHODS</b>Detailed gross and microscopic examination of the autopsy specimen is performed, including lung, heart, liver, kidney, spleen and lymph nodes.</p><p><b>RESULTS</b>All of the lungs are markedly enlarged and consolidated. Microscopically, pulmonary edema is a prominent finding, especially at the early stage of the disease (5 days after the onset). The alveolar spaces are filled with fibrinous exudates and lined with hyaline membrane. In 5 cases that undergo over 3 weeks of the course, the main pattern is organization of intra-alveolar deposit, along with fibroblastic proliferation in the alveolar septa, which leads to obliteration of alveolar space and pulmonary fibrosis. All of the lungs show bronchopneumonia, scattered hemorrhage, and proliferation of alveolar epithelial cells with desquamation. Microthrombi are seen in 6 cases. Fungal infection is noted in 2 cases. One of them is disseminative, involving bilateral lungs, heart, and kidney; the other one is diagnosed in hilar lymph nodes. In immune system, hilar and abdominal lymph nodes are usually congested and hemorrhagic, with depletion of lymphocytes, and accompanied with subcapsular sinus histiocytosis. One of the cases shows enlargement of abdominal lymph nodes, which have reduced number of germinal centers. Spleen exhibits atrophy of white pulps, and even lost of white pulps in some areas. The red pulp is markedly congested and hemorrhagic. In 5 cases, cardiomegale is prominent. Thrombosis (2 cases), focal myocarditis (1 case), and fungal myocarditis (1 case) are observed. In addition, liver shows massive necrosis (1 case) and nodular cirrhosis (1 case).</p><p><b>CONCLUSIONS</b>Lung is the major organ affected by SARS, demonstrated as diffuse alveolar damage. It is postulated that viral infection induces severe damage of alveolar epithelial and capillary endothelial cells, leads to pulmonary edema, intra-alveolar fibrin deposit, and hyaline membrane formation. Consequently, intra-alveolar organization and alveolar septal fibrosis causes loss of alveolar spaces, eventually, pulmonary fibrosis and atelectasis. The immune system is often affected, and presented as depletion of lymphoid tissue in lymph nodes and spleen. Secondary infection is a common complication, which should be paid close attention in the management of SARS patients.</p>