RESUMO
CD14 is involved in primary immune and inflammatory responses. The -159 C/T variation in the CD14 gene plays an important role in regulating CD14 expression and has been associated with the susceptibility to various diseases, including allergies. In this study, we examined the association between the C-159T polymorphism and atopic asthma susceptibility in children from Southeastern China. The study population included 746 unrelated children of Chinese Han nationality (362 patients with atopic asthma and 384 healthy controls). CD14 gene polymorphisms were identified by direct sequencing of polymerase chain reaction products. Total immunoglobulin E (IgE) levels in human serum samples were determined using an enzyme-linked immunosorbent assay. Individuals carrying the TT genotypes for rs2569190 were significantly associated with an increased risk of atopic asthma compared with those carrying the wild-type homozygous CC genotypes [adjusted odds ratio (OR) by gender and age, from 1.075-2.398, P = 0.025]. Total serum IgE levels in TT genotype carriers were significantly higher than those in CC genotype carriers in atopic asthma patients (286.3 ± 161.5 IU/mL vs 248.3 ± 147.8 IU/mL). Our data suggest that the CD14 TT genotype may be a genetic susceptibility marker for atopic asthma in Chinese Han children.
Assuntos
Asma/genética , Frequência do Gene/genética , Imunoglobulina E/sangue , Receptores de Lipopolissacarídeos/genética , Polimorfismo de Nucleotídeo Único/genética , Sequência de Bases , Estudos de Casos e Controles , Criança , Pré-Escolar , China , Ensaio de Imunoadsorção Enzimática , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Masculino , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
Objective: To describe the clinical characteristics of Mycoplasma pneumoniae infection and analyze the factors associated with co-infections with other pathogens in children, and provide evidence for improvement of community acquired pneumonia (CAP) prevention and control in children. Methods: Based on the surveillance of hospitalized acute respiratory infections cases conducted in Soochow University Affiliated Children's Hospital (SCH), the CAP cases aged <16 years hospitalized in SCH between 2018 and 2021 were screened. The pathogenic test results of the cases were obtained through the laboratory information system, and their basic information, underlying conditions, and clinical characteristics were collected using a standardized questionnaire. The differences in clinical characteristics between M. pneumoniae infection and bacterial or viral infection and the effect of the co-infection of M. pneumoniae with other pathogens on clinical severity in the cases were analyzed; logistic regression was used to analyze the factors associated with the co-infections with other pathogens. Results: A total of 8 274 hospitalized CAP cases met the inclusion criteria. Among them, 2 184 were positive for M. pneumoniae (26.4%). The M. pneumoniae positivity rate increased with age (P<0.001), and it was higher in girls (P<0.001) and in summer and autumn (P<0.001). There were statistically significant differences in the incidence of wheezing, shortness of breath, wheezing sounds and visible lamellar faint shadow on chest radiographs, as well as fever and hospitalization days among M. pneumoniae, bacterial, and viral infection cases (all P<0.05). In the cases aged <60 months years, co-infection cases had higher rates of wheezing, gurgling with sputum and stridor; and in the cases aged ≥60 months, co-infection cases had a higher rate of shortness of breath (all P<0.05). Multifactorial logistic regression analysis showed that being boys (aOR=1.38,95%CI:1.15-1.67), being aged <6 months (aOR=3.30,95%CI:2.25-4.89), 6-23 months (aOR=3.44,95%CI:2.63-4.51), 24-47 months (aOR=2.50,95%CI:1.90-3.30) and 48-71 months (aOR=1.77,95%CI:1.32-2.37), and history of respiratory infection within 3 months (aOR=1.28,95%CI:1.06-1.55) were factors associated with co-infections of M. pneumoniae with other pathogens. Conclusions: M. pneumoniae was the leading pathogen in children hospitalized due to CAP. M. pneumoniae infections could cause fever for longer days compared with bacterial or viral infections; M. pneumoniae was often co-detected with virus or bacteria. Being boys, being aged <72 months and history of respiratory infection within 3 months were associated factors for co-infections.
Assuntos
Coinfecção , Infecções Comunitárias Adquiridas , Pneumonia por Mycoplasma , Infecções Respiratórias , Viroses , Bactérias , Criança , Coinfecção/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Dispneia , Feminino , Humanos , Masculino , Mycoplasma pneumoniae , Pneumonia por Mycoplasma/epidemiologia , Pneumonia por Mycoplasma/microbiologia , Sons Respiratórios , Infecções Respiratórias/epidemiologiaRESUMO
Objective: To estimate the hospitalization rate of Haemophilus (H.) influenzae associated community-acquired pneumonia in children under 5 years in Suzhou. Methods: From 2010 to 2014, medical records and bacteriology results of children under 5 years hospitalized with community-acquired pneumonia in Children's Hospital of Soochow University were collected, retrospectively. Detection rate of H. influenzae was describe. The hospitalization rate of H. influenzae associated community-acquired pneumonia was estimated using the number of local children in urban area of Suzhou, which was obtained from the immunization platform of Suzhou Center for Disease Prevention and Control. Results: A total of 28 043 hospitalized pneumonia cases were included from 2010 to 2014, in which 19 526 (69.63%) had bacteriological examination. The overall detection rate of H. influenzae was 11.06% (2 160/19 526), and children aged 12-23 months had the highest positive rate (14.29%, 550/3 850), and the rate was higher during winter-spring than during summer-autumn (χ2=455.11,P<0.01). The average hospitalization rate of H. influenzae associated pneumonia in children under 5 years was 760.36/100 000 (95%CI: 733.70/100 000-787.01/100 000), which was higher in winter and spring (898.79/100 000 and 1 249.52/100 000) than in summer and autumn (514.35/100 000 and 359.04/100 000), and the hospitalization rate was higher in boys (942.12/100 000) than in girls (563.76/100 000), the differences were all significant (P<0.01). The highest hospitalization rate was observed in children aged 1-5 months (2 478.31/100 000) and the hospitalization rate decreased with age (χ2=2 129.80, P<0.01). Conclusion: There was a considerable burden of H. influenzae associated community-acquired pneumonia in children under 5 years in Suzhou, especially in children under 6 months.
Assuntos
Infecções Comunitárias Adquiridas , Pneumonia , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Feminino , Haemophilus influenzae , Hospitalização , Humanos , Lactente , Masculino , Pneumonia/epidemiologia , Estudos RetrospectivosRESUMO
Submandibular gland excision was performed on two patients using trans-oral robotic surgery (TORS). Complications such as the injury of marginal mandibular branch of facial nerve, ranula in the floor of the mouth, and postoperative hemorrhage were not observed. Visible cervical scar can be avoided and esthetic outcome can be expected by using this surgical modality.
Assuntos
Rânula , Procedimentos Cirúrgicos Robóticos , Glândula Submandibular , Estética Dentária , Humanos , Glândula Submandibular/cirurgiaRESUMO
Objective: To explore the feasibility of using da Vinci Surgical System to perform supraomohyoid neck dissection (SOND) to avoid visible scar and reduce trauma. Methods: Between September 2017 and December 2018, twenty patients (two females and 18 males, mean age, 54.8 years) with oral cancer treated in the Department of Stomatology, Hainan Hospital of General Hospital of Chinese PLA were enrolled in this study. Eight patients were assigned into robotic surgery group, and received robot-assisted SOND with retroauricular hairline incision. After the da Vinci Surgical System robotic platform was positioned, the neck dissection was performed in level â ¡b, â ¡a, â ¢, â b and â a orderly from the near region to far region. The other 12 patients were assigned into traditional surgery group, and received SOND with a traditional incision. The operation time, bleeding and amount of lymph node dissected were compared between two groups. Results: All the 8 cases of robot-assisted SOND were completed smoothly. Operation time [(4.5±1.0) h] was significantly longer in robotic surgery group than that [(2.5±1.0) h] in traditional surgery group (P<0.05). The amount of bleeding in robotic surgery group [30.0 (27.5) ml] was significantly lower than that in traditional surgery group [(100.0 (87.5) ml, P<0.05]. There's no difference in the number of lymph nodes dissected between robotic surgery group (23.6±5.2) and traditional surgery group (22.8±6.0)(P>0.05). No postoperative hemorrhage, symptoms of nerve injury, flap necrosis and secondary healing were observed in robotic surgery group. Conclusions: SOND through retroauricular hairline incision is feasible with the assistance of da Vinci Surgical System. The main advantage of this method is superior esthetic effects due to a hidden incision with minimal bleeding. There was no obvious differences in the amount of lymph nodes dissected and postoperative complications between two methods. However, robotic surgery costs a significantly longer operation time than traditional neck dissection.
Assuntos
Neoplasias Bucais , Esvaziamento Cervical , Procedimentos Cirúrgicos Robóticos , Robótica , Estética Dentária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/cirurgia , Esvaziamento Cervical/métodosRESUMO
This study was designed to examine the effects of angiogenesis inhibitors IFN-alpha and TIMP-1 on lymphangiogenesis. We cultured lymphatic endothelial (LE) cells from pig thoracic ducts and performed morphological observations using light microscopy, TEM, and confocal microscopy to confirm their lymphatic origin. We tested these cells for growth inhibition by angiogenesis inhibitors IFN-alpha and TIMP-1 using both the scraping line and MTT methods. In addition, we analyzed apoptosis using the Hoechst and Caspase staining methods. Finally, we tested IFN-alpha and TIMP-1 using in vivo inhibitory assays. By morphological observations, all LE cells in vivo and in vitro were found to be of very similar morphology. Both in vitro inhibitory assays of scraping line and MTT showed significant differences for the IFN-alpha treatment (p < 0.01) and no significant difference for TIMP-1. Hoechst and Caspase apoptosis assays demonstrated that IFN-alpha could induce apoptosis of LE cells, and TIMP-1 had little effect. IFN-alpha and TIMP-1 inhibitory in vivo assays showed a lack of healing following IFN-alpha treatment compared to control and TIMP-1 treatment. In summary, these different angiogenesis inhibitors have different effects on lymphangiogenesis. IFN-alpha inhibits proliferation and migration of LE cells in a dose-dependent fashion and induces apoptosis of LE cells while TIMP-1 has no significant inhibitory effects on proliferation, migration, or inducing apoptosis.
Assuntos
Inibidores da Angiogênese/farmacologia , Células Endoteliais/efeitos dos fármacos , Interferon-alfa/farmacologia , Linfangiogênese/efeitos dos fármacos , Inibidor Tecidual de Metaloproteinase-1/farmacologia , Animais , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/ultraestrutura , Imunofluorescência , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Suínos , Ducto Torácico/citologiaRESUMO
OBJECTIVE: In this study, we retrospectively evaluated the therapeutic efficacy of China Children Leukemia Group-ALL2008 (CCLG-ALL 2008) protocol in pediatric patients with mixed-lineage leukaemia (MLL) gene rearrangement of acute lymphoblastic leukemia (ALL) to identify the prognostic factors. PATIENTS AND METHODS: Six hundred and thirty-four patients with ALL were enrolled in this study between June 2008 and Dec 2014. High-risk group (HR) consisted of 217 cases, of which 28 cases were MLL related positive (first group), 22 cases were BCR/ABL positive (second group), and 167 cases were negative with MLL related or BCR/ABL (third group). The therapeutic efficacy was evaluated at the time points of day 8 (TP1), day 15 (TP2), day 33 (TP3) and 12th week (TP4) with the protocol, respectively. Overall-survival (OS) and relapse-free-survival (RFS) and treatment-related mortality (TRD) were analyzed as well. RESULTS: The first group accounted for 4.4% of all patients. Compared with the second and third group, the first group had more cases younger than 2 years, with initial leukocytes ≥50×109/L, and poor response on TP2. Moreover, patients older than 2 years old had a good 5 years OS (84% ± 9% vs. 37% ± 20%, p<0.05) and RFS (84% ± 9% vs. 29% ± 17%, p<0.05). There were no significant differences in the recurrence rate, TRD, 5 years OS and RFS among three groups. For the first group, compared with good response to prednisone, patients with poor response to prednisone had a poor 5 years RFS (41% ± 17% vs. 81% ± 10%, p<0.05). Multivariate Cox regression analysis identified that RFS and OS were influenced by such factors as age, MLL fusion partners, and prednisone response (p<0.05). CONCLUSIONS: Such factors as younger age than 2 years old, MLL/AF4 fusion gene, poor response to prednisone, or no complete remission (CR) on TP3 were poor prognostic parameters in predicting the outcome in childhood ALL with MLL gene rearrangement treated with CCLG-ALL 2008 protocol.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Proteína de Leucina Linfoide-Mieloide/genética , Proteínas de Fusão Oncogênica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Prednisona/administração & dosagem , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Pré-Escolar , China , Esquema de Medicação , Feminino , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Prednisona/uso terapêutico , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Resultado do TratamentoRESUMO
OBJECTIVE: Chemokine (C-C motif) ligand 2 (CCL2) is a member of the CC subfamily, which displays chemotactic activity for monocytes and basophils. This molecule plays a very important role in many solid tumors and shows changes in the bone marrow microenvironment. However, its role in acute myeloid leukaemia (AML) is still unclear. MATERIALS AND METHODS: In this study, we established a HL-60 cell line with CCL2 knockdown to explore its effect on leukemogenesis. Lentivirus with CCL2-knockdown was successfully constructed after screening effective CCL2 short hairpin RNA (shRNA) sequences and was transfected into HL-60 cells, which was further validated at the mRNA and protein levels by real-time polymerase chain reaction (PCR) and Western blotting, respectively. RESULTS: Low expression of CCL2 significantly decreased HL-60 cell growth by increasing the cell arrest at G1 phase by 12% more than controls. We applied RNA sequencing technology to discriminate the gene expression profiles between the cells with CCL2 knockdown and the controls, and Cyclin D1 was selected for further experiments as its expression level was significantly downregulated, which was validated at the mRNA and protein levels. Cyclin D1 knockdown experiments showed that the cell proliferation rate was evidently decelerated, and cell cycle analysis also indicated a similar pattern for CCL2. CONCLUSIONS: Our study revealed that Cyclin D1 is an effector that mediates CCL2's function in cell proliferation by blocking cells at G1 phase.
Assuntos
Quimiocina CCL2/fisiologia , Ciclina D1/fisiologia , Leucemia Mieloide Aguda/patologia , Linhagem Celular Tumoral , Proliferação de Células , Células HL-60 , HumanosRESUMO
Malignant cancers commonly invade locally followed by spread through venous or lymphatic channels or both to distant sites. Hemangiogenesis and its relation to tumor growth and metastasis have been extensively studied. However, the role played by lymphangiogenesis in growth and metastasis of cancer has been largely neglected until just recently. Inhibition of lymphangiogenesis, as compared to inhibition of hemangiogenesis, may provide new insights into the mechanisms of cancer metastasis. The current study was designed to examine the in vitro effect of two commonly used inhibitors of hemangiogenesis, angiostatin and thalidomide, on the growth and proliferation of lymphatic endothelial cells isolated from pig thoracic ducts. We first isolated and characterized the lymphatic endothelial (LE) cells using specific markers for VEGFR3 and LYVE-1. The experimental results showed that treatment of the LE cells with these two drugs resulted in a decrease in the rate of cell proliferation in a dose-dependent manner as assessed by MTT assays. Cell migration rate was assessed by the speed of cell migration from the scrape-wound margin, and the results showed that migration of LE cells was also significantly inhibited in a dose-dependent fashion compared to controls. Treatment with angiostatin and thalidomide both resulted in an increase in apoptosis of LE cells as assessed by Hoechst staining and flow cytometry. We conclude that both angiostatin and thalidomide are able to inhibit LE cell growth in a dose-dependent manner and that the inhibition may be through induction of apoptosis.
Assuntos
Inibidores da Angiogênese/farmacologia , Angiostatinas/farmacologia , Linfangiogênese/efeitos dos fármacos , Talidomida/farmacologia , Inibidores da Angiogênese/administração & dosagem , Angiostatinas/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Endotélio Linfático/citologia , Endotélio Linfático/efeitos dos fármacos , Citometria de Fluxo , Técnicas In Vitro , Coloração e Rotulagem , Suínos , Talidomida/administração & dosagemRESUMO
This study was designed to screen potential safe and effective inhibitors of lymphangiogenesis. Lymphatic endothelial cells from pig thoracic duct were isolated and cultured. The control group, 3 endostatin, and 3 PF-4 experimental groups were tested for effects on proliferation and distance of migration of the cultured cells by two methods (method of the scraping line and MTT assay), and observations by light, confocal, and electron microscopy were also made. Total cells migrating past the scrape line for the endostatin control group was 28.6 +/- 1.2 (mean +/- standard error) and the 3 endostatin experimental groups (50 ng/ml, 100 ng/ml, and 150 ng/ml), respectively, were 17.5 +/- 0.6, 10.5 +/- 0.5, and 4.8 +/- 0.3 (all p < 0.05 cf control). Migration distance for the endostatin control group was 381.7 +/- 9.67 microm, and the migration distance of the 3 endostatin experimental groups, respectively, were 252.9 +/- 5.58, 164.5 +/- 7.09, and 91.2 +/- 7.98 microm (all p < 0.05). Cell migration number for the PF-4 control group was 28.3 +/- 1.0 compared with doses of 40 ng/ml, 80 ng/ml, or 120 ng/ml of PF-4, respectively, were 13.6 +/- 0.7, 9.5 +/- 0.6, and 4.6 +/- 0.4 (all p < 0.05 cf control). Migration distance of cells in PF-4 control group was 419.9 +/- 5.87 microm, and the 3 PF-4 experimental groups, respectively, were 199.2 +/- 8.16, 152.5 +/- 7.28, and 104.2 +/- 6.70 microm (all p < 0.05 cf control). The MTT assay confirmed that as the concentrations of endostatin and PF-4 were increased, the inhibitory effect was increased. We conclude that endostatin and PF-4 are able to inhibit the migration and proliferation of lymphatic endothelial cells, and these effects are dose-dependent.
Assuntos
Inibidores da Angiogênese/farmacologia , Coagulantes/farmacologia , Endostatinas/metabolismo , Linfangiogênese/fisiologia , Fator Plaquetário 4/farmacologia , Animais , Técnicas de Cultura de Células , Movimento Celular , Proliferação de Células , Relação Dose-Resposta a Droga , Células Endoteliais , Suínos , Ducto TorácicoRESUMO
Regulatory actions of angiotensin II (AngII), which is involved in the pathophysiology of hypertension and also participates in cell proliferation and cell differentiation, are mainly mediated by AngII type 1 (AT1) receptor. Recently, activating mutations of receptors causing hyperfunctioning endocrine diseases have been described in the case of the TSH and LH receptors, implicating that such mutations might occur in other G-protein-coupled receptors. Furthermore it seems to be possible that genetic variations of AT1 receptor have an influence upon the action of AngII. Therefore, we searched by sequence analysis of the coding region of AT1 receptor gene for activating mutations and genetic polymorphisms in 56 human adrenal tumors (16 aldosterone-producing adenomas, 10 cortisol-producing adenomas, 1 aldosterone-producing carcinoma, and 29 incidentalomas). We were not able to identify any activating mutation in the coding region of AT1 receptor gene. We conclude that activating mutations of the AT1 receptor are not a major cause of the development of adrenal adenomas, if at all. In addition, polymorphic subtypes of AT1 receptor do not seem to play a major role in the pathogenesis of these tumors, even though a tendency towards a higher frequency of the polymorphic base substitution at position 573 (T573-->C) in cortisol-producing tumors needs to be further evaluated.
Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Mutação , Receptores de Angiotensina/genética , Adenoma/genética , Adenoma/metabolismo , Aldosterona/biossíntese , Carcinoma/genética , Carcinoma/metabolismo , Humanos , Hidrocortisona/biossíntese , Reação em Cadeia da Polimerase , Receptores de Angiotensina/metabolismo , Análise de Sequência de DNARESUMO
BACKGROUND: Mycoplasma Pneumoniae (M. pneumoniae) is a common cause of respiratory tract infections (RTIs), especially in children. Combined diagnostic techniques have provided more reliable information about the epidemiology of infections by this pathogen. The relationship between M. pneumoniae RTIs and climatic conditions is not well documented in the literature. AIMS: To study the epidemiology of M. pneumoniae infections in hospitalized children with RTIs and its association with meteorological factors. METHODS: Samples were obtained from children with RTIs and tested for M. pneumoniae by PCR and ELISA. Meanwhile, meteorological factors were recorded. RESULTS: M. pneumoniae was identified in 11.02% of the 8,157 specimens. There were significant differences among the annual distribution of infections (χ(2) =130.13, P<0.0001) and among different seasons (χ(2) =93.59, P<0.0001). Of the total number of patients with M. pneumoniae infections, 14.5% were infected with more than one pathogen. M. pneumoniae infection strongly correlated with mean temperature. Children with a single M. pneumoniae infection had significantly higher neutrophil percentages and CRP levels than children with co-infections. CONCLUSIONS: M. pneumoniae is one of the most commonly held pathogens, according to the 5-year surveillance. M. pneumoniae infection has its own epidemic season, especially in the summer. Mean temperature is the main meteorological factor affecting the epidemiology of M. pneumoniae infections.
Assuntos
Sistema Linfático/fisiologia , Massagem , Animais , Permeabilidade da Membrana Celular , Coelhos , TemperaturaRESUMO
The development of the lymphatic system in the rat diaphragm was studied from embryonic day 16 to 25 weeks after birth by histochemistry for 5'-nucleotidase, scanning electron microscopy of KOH-treated or intact tissues, and transmission electron microscopy of thin sections. On embryonic day 16, distinct lymphatics were noted in the subpleural space of the diaphragm periphery. The endothelial cells at this stage contained an abundance of rough endoplasmic reticulum, a developed Golgi apparatus and mitochondria, and fewer pinocytotic vesicles than those in adults. The subpleural lymphatics subsequently increased and formed a polygonal network. They possessed many valves, and by postnatal week 6, some thick collecting lymphatics became endowed with smooth muscle cells. On embryonic day 19, some lymphatics appeared in the subperitoneal space. They extended centripetally and had many lateral projections that subsequently became elongated and connected with those from adjacent lymphatics, thus forming a lattice-like network. During the early postnatal days, the subperitoneal lymphatics projected many bulges that subsequently became elongated, and came into contact with the pores among the mesothelial cells, thus forming lymphatic stomata connecting the lymphatic lacunae to the peritoneal cavity. The lymphatic stomata increased until postnatal week 10. The results show that lymphatics appear as early as embryonic day 16 in the subpleural space of the diaphragm periphery, and develop with age by sprouting to form networks in both the subpleural and the subperitoneal spaces, and that the direct connection of the lymphatic lacunae to the peritoneal cavity is formed after birth.
Assuntos
Diafragma/ultraestrutura , Sistema Linfático/ultraestrutura , Cavidade Peritoneal , Animais , Diafragma/embriologia , Feminino , Hidróxidos , Imuno-Histoquímica , Sistema Linfático/embriologia , Sistema Linfático/crescimento & desenvolvimento , Masculino , Microscopia Confocal , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Músculo Liso/ultraestrutura , Cavidade Peritoneal/embriologia , Pleura/embriologia , Compostos de Potássio , Ratos , Ratos WistarRESUMO
The distribution and ultrastructure of the lymphatics of the rat mammary gland in virgin, pregnant, lactating and post-weaning periods were examined by enzyme-histochemistry for 5'-nucleotidase (5'-Nase) and transmission electron microscopy. Enzyme-histochemistry for 5'-Nase stained lymphatics in dark brown. In the lactating period, lymphatics abounded in the interlobular connective tissues, but in other periods they were few. The interlobular lymphatics drained into collecting lymphatics running along the mammary ducts. Gaps between lymphatic endothelial cells were significantly wider in lactating period than in other periods, while both number and area of vesicles in the lymphatic endothelial cells were significantly larger in the virgin period than in other periods. In the pregnant and lactating period, the lymphatics contained many lymphocytes and lipid droplets. The results show that during lactating period, the interlobular lymphatics increase and that gaps between lymphatic endothelial cells serve as a major route through which tissue fluids and particulate matters enter the lymphatics, while vesicles seem to be main trans-endothelial transport route during the virgin period. The results will provide basic information for our next investigation on lymphangiogenesis in association with breast cancer.