Advanced glycation end products stimulate plasminogen activator activity via GM-CSF in RAW 264.7 cells

The effects of advanced glycation end products (AGE) on the plasminogen activator (PA) activity were investigated with murine macrophage cell line RAW 264.7 cells. AGE-bovine serum albumin (BSA) showed a dose-dependent induction for the urokinase-type PA (uPA) activity. The uPA induction by AGE-BSA was effectively suppressed by the antibody against granulocyte-macrophage colony-stimulating factor (GM-CSF). The uPA activity of these cells was also induced by ligands for the macrophage scavenger receptor (MSR). These data provide evidence that AGE-BSA stimulates the uPA activity via GM-CSF through MSR in RAW cells. These findings, taken together with a recent demonstration of endocytic uptake of AGE-proteins by MSR in vitro and the presence of AGE-proteins in atherosclerotic lesions, strongly suggest that the uPA induction by AGE-proteins via MSR plays an important role in human atherogenesis.

Plasma levels of type II phospholipase A2 and cytokines in patients with sepsis

Plasma levels of type II phospholipase A2 (type II PLA2), cytokines and endotoxin were determined in patients with sepsis to investigate their interrelations and their role in the patient's prognosis. Type II PLA2 was measured by radioimmunoassay, tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and IL-8 were each measured by enzyme-linked immunosorbent assay (ELISA). Endotoxin was determined by a method based on an endotoxin-specific synthetic substrate. Plasma levels of type II PLA2 were significantly higher in the patients who died of sepsis than in those who survived the illness. There was a significant correlation between type II PLA2 and TNF-alpha and IL-6. Type II PLA2, TNF-alpha, IL-6, and IL-8 may be useful as indices of disease severity. The results suggest that TNF-alpha and IL-6 stimulate the production of type II PLA2 in the plasma of patients with sepsis.

Biological and physicochemical properties of fenitrothion microcapsules as a residual spraying formulation for mosquito control

Insecticidal properties of fenitrothion microcapsules (MC3) as a new residual spraying formulation for mosquito control were studied. Adult female Anopheles albimanus were confined so as to contact several surfaces treated with fenitrothion MC or wettable powder (WP) for 10 and 30 min. Residual efficacy of MC at the rate of 1 g/m2 was almost equivalent to that of WP at the rate of 2 g/m2 on a plywood surface and was superior to that on an unglazed pottery surface. Greater than 50% mortality was maintained for more than 28 wk after treatment by fenitrothion MC on a mud surface with 10 min of contact at the rate of 2 g/m2. The effective duration on a mud surface treated with WP was less than 44 wk with 30 min of contact and was less than 12 wk with 10 min of contact at the rate of 2 g/m2. Microcapsule particles were observed to be mechanically broken (trampled) by mosquito contact, and the amount of fenitrothion released from MC increased as contact time increased. Comparison of MC with WP and emulsifiable concentrate formulations in this study indicates that the increased residual activity results from protection from evaporation and decomposition afforded by capsule walls of the MC formulation.

Immunohistochemical examination of intraspinal serotonin neurons and fibers in the chicken lumbar spinal cord and coexistence with Leu-enkephalin

Intraspinal serotonin-positive cells and fibers were examined in the chicken lumbar spinal cord following removal of descending serotonin fibers by spinal transection. Co-localization of Leu-enkephalin immunoreactivity in intraspinal serotonin cells was also examined using a double immunofluorescence labeling technique. By one or two weeks after spinal transection, virtually all supraspinal serotonin fibers were eliminated. Intraspinal serotonin cells were located ventral or ventrolateral to the central canal corresponding to laminae VII, VIII, and IX, and the anterior funiculus. Intraspinal serotonin cells sent fibers to (1) the pia mater on the ventral or ventrolateral surface of the spinal cord; (2) vessels in the spinal cord; (3) sympathetic preganglionic column of Terni; (4) other intraspinal serotonin neurons; (5) the central canal. Some 30%-50% of the intraspinal serotonin cells co-localized with Leu-enkephalin. Intraspinal serotonin fibers co-containing Leu-enkephalin were observed in the pia mater located on the most lateral surface of the spinal cord.

Characterization of c-kit expression by primitive hematopoietic progenitors in umbilical cord blood

Human umbilical cord blood (CB) appears to be an exciting new source of transplantable stem cells for a variety of clinical conditions. In this study, we have attempted to further characterize the primitive progenitors in CB. First we analyzed the effects of early-acting growth factors on blast cell colony formation from CD34+ progenitors. Addition of Steel factor (SF), interleukin-6 (IL-6), or granulocyte colony-stimulating factor (G-CSF) to cultures containing interleukin-3 enhanced blast cell colony formation. These results indicated that cell cycle-dormant progenitors are present in CB. Next, based on results obtained in the murine system, we tested whether c-kit expression could separate the CB progenitors into cycle-dormant vs. cycle-active progenitors. Cells were separated into CD34+ c-kit-, c-kitlow, and c-kithigh. The results suggested that the c-kitlow population contains the majority of cycle-dormant progenitors and the c-kithigh population contains most of the forming cells were in the c-kitlow population, while the opposite is true for other colony-forming cells. Expression of c-kit may be useful in identifying CB progenitors with long-term engraftment capability.

Suppression of in vivo tumor growth by the transfection of the interleukin-5 gene into colon tumor cells

To investigate the influence of tumor producing interleukin-5 (IL-5) on growth kinetics of tumors, we transduced the murine IL-5 gene into murine colon C26 tumor cells. Two IL-5-secreting clones, low-level IL-5 producer C26-8B and high-level IL-5 producer C26-6F, were established. Both tumors, C26-6F and C26-8B, grew more slowly than the mock C26 tumor, although the in vitro growth rate of these IL-5 transfectants was much the same as that of the mock C26 cells. There was a significantly decreased number of colonies in the lung of mice given C26-6F or C26-8B tumors i.v. than in mice given mock C26 tumors i.v. Moreover, in mice given C26-6F cells i.v., a smaller number of tumor colonies in the lung was observed, as compared to the case with C26-6B cells. While the growth rate of C26-8B tumors in mice treated with anti-IL-5 mAb was more rapid than that seen in control mAb-treated mice, growth of C26-6F tumors in anti-IL-5-mAb-treated mice was slightly more rapid compared to findings in control mAb-treated mice. The isotype-matched mAb did not alter the in vitro growth of mock-C26 cells or of the IL-5-gene-modified C26 cells. Growth of IL-5-secreting C26 tumors transplanted in nude mice was also inhibited. These results suggest that tumor-producing IL-5 inhibits growth of colon tumors mediated through T-cell-independent protective mechanisms of the host.

[Comparison of CAF plus MPA with CAF plus TAM for advanced or recurrent breast cancer--Kyushu CAFT Study Group of Advanced or Recurrent Breast Cancer]

A multi-center randomized comparison study of CAF + TAM therapy (Arm A) and CAF + MPA therapy (Arm B) in advanced or recurrent breast cancer was conducted at 37 institutions in Kyushu. Out of 119 registered cases, 114 were eligible and 76 were evaluable. The response rate was 42% (15/36) in Arm A and 58% (23/40) in Arm B. In the comparison of side effects, nausea/vomiting and anorexia were significantly less and moon face and body weight gain were significantly more in Arm B. Leucocytopenia was significantly inhibited in Arm B compared with Arm A, which indicated the myeloprotective effect of MPA. These results indicated that CAF + MPA therapy (Arm B) may be more advantageous than CAF + TAM therapy (Arm A) in advanced or recurrent breast cancer.

[Anesthesia for hepatectomy in a patient with glycogen storage disease]

We successfully anesthetized a 19-year-old female with type I glycogen storage disease for hepatectomy. She had hypoglycemia and severe metabolic acidosis before surgery. General anesthesia was performed with epidural anesthesia. We used acetated Ringer solution mainly as intraoperative fluids instead of lactated Ringer solution and controlled administration of glucose determining blood glucose. The patient's plasma lactate levels, pyruvate and base excess during and after operation, were unchanged compared with those before operation. Administration of sodium bicarbonate was not necessary. In the case of metabolic acidosis due to accumulation of lactate as in glycogen storage diseases, it was useful to use acetated Ringer solution for fluid therapy.

Pharmacokinetic model of oral levodopa and role of carbidopa in parkinsonian patients

A pharmacokinetic model of oral levodopa is proposed to elucidate the effects of carbidopa on the pharmacokinetics of levodopa. The propriety of the model was evaluated by simultaneous computer Multi-Line fitting for the plasma concentration-time data of levodopa and dopamine-3-O-sulfate (DA-S), a major metabolite of levodopa, after oral administration of three different levodopa doses to parkinsonian patients. Plasma profiles of levodopa and DA-S were also determined in 12 parkinsonian patients during daily oral administration of Neodopaston, a levodopa preparation containing carbidopa in tablet form. We investigated the role of carbidopa by comparing the populational mean parameters calculated in the levodopa alone model with those obtained in patients coadministered levodopa and carbidopa. The results indicated that the pharmacokinetics of levodopa coadministered with carbidopa were dose-independent and that carbidopa reduces the first-pass metabolism of levodopa in the gut wall to less than 10% of the dose absorbed, and decreases the systemic clearance of levodopa by 35-39%. The proposed pharmacokinetic model and the evaluation of carbidopa in this study will provide useful information for the development of drug delivery systems for levodopa or catechol-O-methyltransferase inhibitors, for further stabilization of plasma concentrations of levodopa in parkinsonian patients.

Angiotropic B-cell lymphoma presenting with progressive dementia: an autopsy case and review of the literature in Japan

We report an autopsy case of angiotropic lymphoma and review the literature in Japan. A 68-year-old female presented with transient right facial nerve palsy, right hemiplegia and progressive dementia. Laboratory studies showed raised erythrocyte sedimentation rate, C-reactive protein and serum lactate dehydrogenase. Computed tomography of the brain did not show any abnormal density areas but on T2-weighted magnetic resonance imaging high signal areas were recognized at the basal ganglia. She was diagnosed as having dementia caused by cerebrovascular insufficiency. She soon developed a febrile state and died of respiratory failure within three months of presentation. Postmortem examination showed widespread angiotropic B-cell lymphoma.

Experimental infection with Yersinia enterocolitica serovar 0:8 in beagle dogs

Dogs were challenged orally with Yersinia enterocolitica serovar 0:8 biovar 1 for assessment of the infectivity of 0:8 bacteria. The bacteria were shed in the feces for 7-21 days following oral challenge. They were also recovered from intestinal contents and small intestinal Peyer's patches, but not from deeper organs of dogs euthanized 3 and 7 days after oral challenge. Dogs challenged subsequently with 10(10) bacteria showed protection from establishment of the bacteria in the intestinal tract. High titers of serum O-agglutinins developed in the dogs challenged with the bacteria. No clinical or hematological abnormalities were observed. The possibility that dogs may be a source of infection of 0:8 bacteria to human is discussed.

Identification of the control regions for mouse c-kit gene transcription induced by retinoic acid

The c-kit gene encodes a receptor tyrosine kinase that reveals the pleiotropic effects both in the developing embryo and in the adult animal. In this study, we characterized transcriptional control of the c-kit gene. F9 teratocarcinoma cells differentiated and expressed the c-kit gene upon exposure to retinoic acid (RA). We isolated c-kit genomic DNA from approximately 20 kb upstream to approximately 10 kb downstream of the transcribed region. We identified two control regions for c-kit gene transcription by fusing genomic sequences to bacterial chloramphenicol acetyl transferase reporter genes and introducing the resultant constructs into differentiated F9 cells. The fragments, Sac I-Apa I in the 9th intron and Xho I-Kpn I in the 13th intron induced reporter gene activities. Nucleotide sequencing of the regions showed in that there were no consensus sequences of the RA receptor or cyclic AMP-responsive elements. Cyclic AMP augmented the expression of the c-kit gene induced by RA; when combined with RA, it was less effective on the reporter gene activity. In contrast to other reports, continuous exposure to the reagents was not required for c-kit expression. These findings suggested that transcription of the c-kit gene is regulated by complex controls and that there are different control regions responsive to RA and cyclic AMP.

[A retroperitoneal cyst with elevated level of CA19-9 in its content]

A 52-year-old man, who had been treated for left mega-hydronephrosis (5.6L) 25 years ago in our hospital, recently complained of left lumbago and fever. An abdominal CT scan revealed a cystic mass partially surrounded by calcification in the retroperitoneal space, which appeared to be a hydronephrosis. Percutaneous puncture of the cystic mass was performed and 670 ml, brownish-yellow purulent fluid containing a high level of CA19-9 (over 10,000 U/ml) was obtained. Cytologic diagnosis of the fluid revealed class II cells. Within 7 months after the puncture, recurrence developed twice. Percutaneous instillation of 95% ethanol or Minocycline hydrochloride was instilled, but neither of them prevented recurrence. Ultimately, excision of the cystic mass was performed. Histopathological findings of the cystic mass showed no evidence of malignancy. The patient is follow-up with periodic CT scan showed no evidence of recurrence for more than 3 years.

Neutrophil elastase inhibitor (ONO-5046) prevents lung hemorrhage induced by lipopolysaccharide in rat model of cerulein pancreatitis

The protective effects of a neutrophil elastase inhibitor (ONO-5046) on cerulein-induced pancreatitis followed by a septic challenge with intraperitoneal lipopolysaccharide (LPS) were studied in a rat model. Pancreatitis was induced by four intramuscular injections of cerulein (50 micrograms/kg at 1-hr intervals). ONO-5046 was administered by continuous intravenous infusion via the right jugular vein (50 mg/kg/hr, 30 min prior to the first cerulein injection to 20 hr following the last cerulein injection). Significant differences in serum amylase and pancreatic wet weight ratio were not observed between the animals with pancreatitis treated with or without ONO-5046. There was no significant difference in the in vitro tumor necrosis factor-alpha (TNF-alpha) production by peritoneal macrophages from rats with pancreatitis treated with or without ONO-5046. In a second experiment, LPS (10 mg/kg) was administered intraperitoneally as the septic challenge 6 hr following the first cerulein injection. Lung hemorrhage was seen in the animals with pancreatitis untreated with ONO-5046 24 hr following the first cerulein injection. No significant lung hemorrhage was observed in the animals with pancreatitis treated with ONO-5046 administering 30 min prior to the first cerulein injection. These results suggest that lung hemorrhage in cerulein-induced pancreatitis that follows a septic challenge with LPS can be prevented by the intravenous administration of ONO-5046. Thus there is a significant role for neutrophil elastase in pancreatitis-associated lung injury.

Recombinant human thrombopoietin (Mpl ligand) enhances proliferation of erythroid progenitors

We have studied the effects of recombinant human thrombopoietin (TPO, Mpl ligand) on human hematopoiesis in vitro. TPO alone did not support erythroid burst formation but, in the presence of erythropoietin, it enhanced erythroid burst formation from CD34+ bone marrow and cord blood cells. The burst-promoting activity (BPA) was stronger under 5% serum than 30% serum conditions. The direct nature of BPA effects was documented by replating studies of early erythroid bursts. The BPA of TPO was less than that of interleukin-3 but was comparable with that of granulocyte/macrophage colony-stimulating factor and steel factor. The soluble form of Mpl receptor inhibited burst enhancing effects of TPO, suggesting that the BPA effects of TPO are mediated through the Mpl receptor. These results further delineate the physiologic roles of TPO and may aid in the determination of the clinical usages of TPO.

Plasma endothelin-1 as a marker for doxorubicin cardiotoxicity

The use of doxorubicin is often limited by cardiotoxicity that can lead to congestive heart failure (CHF). Although various techniques have been used to predict its cardiotoxicity, none has proven useful. We reported 2 patients in whom the level of plasma endothelin (ET)-1 rose progressively during doxorubicin treatment of breast cancer, and who subsequently developed CHF. Accordingly, we conducted a prospective study of 30 consecutive patients, 23 with breast cancer and 7 with small-cell lung cancer, who were treated with doxorubicin. Serial changes in plasma ET-1 during doxorubicin treatment were measured by a specific radioimmunoassay, and plasma levels of atrial natriuretic peptide (ANP) were determined by a sensitive immunoradiometric assay. M-mode echocardiography was performed serially to monitor the fractional shortening (FS) and the left ventricular ejection fraction (LVEF). The plasma concentrations of ET-1 rose progressively in 5 of the 30 patients during doxorubicin treatment. Two of the 5 patients developed clinically overt CHF after developing cumulative doses of doxorubicin of 500 and 480 mg/m2. Serial measurement of plasma levels of ANP, FS and LVEF showed no abnormalities until the development of CHF. Another 25 patients who had received doxorubicin (cumulative doses ranging from 400 to 660 mg/m2) and had not developed CHF showed no appreciable change in plasma ET-1 or other markers. This prospective study suggests that plasma ET-1 may be useful for predicting the risk of doxorubicin-induced cardiotoxicity.

Temperature effects on Legionella pneumophila killing by and multiplication in phagocytes of guinea pigs

We examined the effects of temperature on the interaction between Legionella pneumophila and phagocytes of guinea pigs. The body temperatures of guinea pigs infected with a sublethal dose (1.2 x 10(4) CFU) or a lethal dose (1.0 x 10(5) CFU) of L. pneumophila elevated from 38.4 +/- 0.15 C to 40.2 +/- 0.42 C or 40.3 +/- 0.62 C, respectively. The intracellular bacterial killing by and bacterial proliferation in the phagocytes were examined at 33, 37, 40, and 42 C, using in vitro culture systems of peritoneal macrophages or polymorphonuclear leukocytes (PMN) of guinea pigs. In all the macrophages incubated at different temperatures, significant intracellular bacterial killings were observed at 4 hr after in vitro phagocytosis. After 24 hr of incubation, there was about a 100-fold increase of CFU and the number reached a maximum after 48 hr of incubation in the macrophages incubated at 42 C as well as 37 and 40 C, suggesting that macrophages support the intracellular bacterial growth in hyperthermia. In the PMN, L. pneumophila CFU 4 hr or 12 hr after the infection were significantly lower at 42 C than those at 37 C (P < 0.05), indicating that the bactericidal capacity of PMN was enhanced at 42 C compared to 37 C. However, in all the PMN incubated at different temperatures, there were about 10-fold increases of CFU 24 hr after the infection, suggesting that PMN as well as macrophages support intracellular bacterial growth in hyperthermia. The extracellular bacterial growth was examined at 33, 37, 40, and 42 C in buffered yeast extract (BYE) broth or RPMI 1640 medium containing 50% guinea pig serum as a permissive or non-permissive liquid medium for the bacterial growth, respectively. Inhibition of bacterial growth in BYE broth at 42 C, and a decrease of CFU in RPMI 1640 medium containing 50% guinea pig serum at 42 C were observed. In conclusion, hyperthermia may be beneficial by restricting extracellular bacterial survival, but it exerts no beneficial effect on the restriction of intracellular bacterial growth in phagocytes, though PMN showed enhanced initial killing at 42 C. These results suggest that fever, or hyperthermia itself, may not largely contribute as a nonspecific host defense early in the course of legionellosis.

[Long-term survival in two cases of multiple liver metastasis successfully treated with intraoperative ultrasound-guided microwave tumor coagulation (MTC)]

Since April 1990, multiple metastatic liver tumors have been treated with intraoperative ultrasound-guided microwave tumor coagulation (MTC) in combination with postoperative intraarterial chemotherapy. Twenty-four patients have been enrolled in this therapeutic modality and two of five patients treated in 1990 achieved long-term survival. In case 1, a 67-year-old woman was diagnosed as bearing gastric leiomyosarcoma with multiple liver metastasis. Total gastrectomy was performed, and six hepatic lesions were treated by MTC along with implantation of an intraarterial reservoir. Postoperative intraarterial chemotherapy was administered in a selective or subselective manner. Her survival time was 4 years and 6 months. In case 2, a 47-year-old man was diagnosed as having liver metastasis from descending colon cancer 1 year and 5 months after left hemicolectomy. When he was laparotomized for the treatment of adhesive ileus, three metastatic liver tumors were treated with MTC. Afterward, he underwent hepatic resection, intraarterial and intraportal chemotherapy. He survived for 5 years and 5 months after being diagnosed with liver metastasis. MTC is one of the useful modalities for the treatment of multiple liver metastasis.

Plasma concentrations of type II phospholipase A2, cytokines and eicosanoids in patients with burns

The plasma concentrations of type II phospholipase A2 (type II PLA2) and eicosanoids, such as leukotriene B4 (LTB4), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), and thromboxane B2 (TXB2), were determined by radioimmunoassay in 23 patients with burns covering at least 20 per cent of their body surface. Cytokines such as tumour necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6) and interleukin 8 (IL-8) were determined by enzyme-immunosorbent assay. There was no increase in type II PLA2 concentration in the early stage of burns, but an increase in type II PLA2 concentration was triggered by infection (P < 0.0001). The level of type II PLA2 was significantly higher in the non-surviving group than in the surviving group (P = 0.0006), suggesting that it reflects the severity of the disease. There was a significant correlation between the maximum level of type II PLA2 and TNF-alpha (r = 0.6346, P = 0.0011). There was a significant correlation between the maximum level of type II PLA2 and the accompanying plasma concentrations of LTB4, 6-keto-PGF1 alpha, and TXB2 throughout the observation period (r = 0.4814, P = 0.0200; r = 0.5943, P = 0.0028; r = 0.4368, P = 0.0372 respectively). Plasma levels of LTB4, and TXB2 were significantly higher in the burn patients who died than in those who survived (P = 0.0493; P = 0.0493 respectively).

[Effects of azithromycin on fecal flora of healthy adult volunteers]

New macrolide antibiotic, azithromycin (AZM), was administered to six healthy male volunteers and its effects on their intestinal microflora were investigated. Each volunteer was given 500 mg of AZM orally, once a day for 3 consecutive days. Stool samples were obtained from them prior to the medication and 1, 7, 14 and 28 days after the third day the medication. A slight decrease in the total aerobic bacterial count was observed. Also, several species of anaerobic bacteria showed slight decreases through the 14th day post medication. Individual variances were observed, however. A marked decrease in the number of Bifidobacterium was found for each of the volunteers. Clostridium difficile was detected from one of the volunteers on the 28th day post medication without diarrhea related symptoms.

Isolation of Coxiella burnetii from dairy cattle and ticks, and some characteristics of the isolates in Japan

Coxiella burnetii was isolated from raw milk (36/214, 16.8%) and uterus swab samples (13/61, 21.3%) originating from dairy cattle with reproductive disorders, aborted bovine fetus samples (2/4, 50%), mammary gland samples (4/50, 8%) originating from healthy dairy cattle, and tick samples (4/15, 26.7%) originating from 2 pastures. Fifty-nine strains had various degrees of pathogenicity, high (8; 13.6%), moderate (28; 47.5%) and low (23; 39%), for guinea pigs. The results of isolation suggested a high prevalence of Coxiella infection in dairy cattle with reproductive problems in Japan. Twelve strains (7, 2 and 3 strains from cattle, ticks and humans, respectively) and the reference Nine Mile strain of phases I and II were propagated in both yolk sacs of embryonated hen eggs and Buffalo green monkey (BGM) cell cultures. Protein profiles of these strains were similar to those of the reference strain of phase I. Lipopolysaccharide (LPS) profiles of 12 strains were similar to those of the reference strain of phase I and different from those of the reference strain of phase II. The LPS profiles of 12 strains suggested that these strains are associated with an acute form of Q fever.

[Myocardial infarction caused by spontaneous coronary artery dissection associated with significant mitral regurgitation--a successful surgical case]

We experienced a case of 34-year-old male with old myocardial infarction, which seemed to be caused by spontaneous dissection of the left circumflex coronary artery, and associated papillary muscle disfunction with resultant significant mitral regurgitation. He was treated surgically by coronary artery bypass grafting and mitral valvuloplasty. Ungraftable circumflex was abandoned; instead, pediculated graft of the right gastroepiploic artery was anastomosed to the mid-portion of the right coronary artery, which also had been spontaneously dissected. Mitral regurgitation was treated with Reed's plasty of the posterior commissure and the ring annuloplasty using Carpentier-Edwards Ring. His postoperative course has been smooth and uneventful. According to the English literature of the Western hemisphere, spontaneous coronary arterial dissection usually occurs in relatively young people with a striking predilection for women, and nearly all report deal only with the coronary abnormality. To our knowledge, this is the first report of a surgical case of the spontaneous coronary dissection associated with significant mitral regurgitation.

Development of intestinal lactobacilli in normal piglets

The development of intestinal Lactobacillus spp. in 18 normal piglets from six litters was investigated from 1 to 45 d after birth. Faecal Lactobacillus strains isolated from piglets and their dams were identified at species and biovar levels on the basis of carbohydrate fermentation. A definite pattern was observed in the changes of four species and 20 biovars of lactobacilli appearing in faeces, with growth of the piglets. Lactobacillus reuteri colonized the animals on the first day of birth. The Lact. acidophilus group appeared 1 week after birth and maintained high levels in the intestine. Biovars B, C and E of Lact. reuteri were recovered as major biovars on the first to fourteenth days after birth. In the third and fourth weeks after birth, however, biovars F and G of Lact. reuteri were mainly recovered from piglet faeces. By the seventh week, biovars B, C and E predominated again in the intestine. No change in the composition of species and biovars of the genus Lactobacillus in the dams was detected.

Increased experimental pulmonary metastasis in pregnant mice

The effect of pregnancy on experimental pulmonary metastasis was studied. Compared to the incidence of pulmonary metastasis induced by G6 cells in non-pregnant mice, the incidence of such metastasis was found to be greatly enhanced when the cells were injected i.v. in the latter half of pregnancy. The maximum enhancement was seen on the 15th day of pregnancy. The incidence of pulmonary metastasis returned to the level observed in non-pregnant mice when the cells were injected 4 days after parturition. Pregnancy also significantly increased the incidence of pulmonary metastasis of 2 other cell lines (3LL and Colon 26). Injection of G6 cells after hysterectomy performed on the 15th day of pregnancy resulted in decreased lung colonization, similar to that seen after parturition. Quantificative analysis of the arrest of G6 cells labeled with [125I]-5-iodo-2'-deoxyuridine in the lungs showed that the tumor-cell clearance from the lungs during the 24-72 hr after tumor-cell injection was much slower in pregnant than in non-pregnant mice. The continuous administration of beta-estradiol and/or progesterone, which maintained serum levels of the hormones equivalent to those prevailing on the 15th day of pregnancy, did not affect the lung colonization of G6 cells. Tumor-cell-platelet aggregation was more extensive with platelets obtained from mice at the 15th day of pregnancy than with those from non-pregnant mice. When platelets isolated from pregnant mice were injected into normal mice 5 min before G6 injection, lung metastasis was also enhanced. These findings suggest that a pregnant host is handicapped with regard to pulmonary metastasis, this being partly due to increased platelet-aggregating activity in response to tumor cells.