Growth hormone and insulin-like growth factor I augment Escherichia coli-killing activity of murine peritoneal exudative cells

Effects of growth hormone (GH) and insulin-like growth factor (IGF)-I on Escherichia coli-killing activity of murine peritoneal exudative cells (PECs) were investigated. Plasma from the mice, injected subcutaneously with saline, GH (4.8 mg/kg/day), or IGF-I(24 mg/kg/day) for 6 days, was mixed with E. coli and pooled murine PECs. Plasma from GH- and IGF-I-treated mice modestly but significantly augmented the E. coli-killing activity of PECs, as compared with that from saline controls. Plasma from IGF-I-treated mice also enhanced PEC interleukin 1 production. In the next experiment, PECs preincubated with medium, GH (10-1000 ng/mL), or IGF-I (50-5000 ng/mL) for 3 h were investigated for E. coli-killing activity. Preincubation of PECs with all concentrations of GH and IGF-I significantly enhanced the E. coli-killing activity of PECs, as compared with the medium control. These results indicate that GH and IGF-I enhance phagocytosis and the E. coli-killing activity of PECs, via a modestly increased plasma capacity to support these activities, as well as by a strong direct action.

In vivo biological activity of antioxidative aminothiazole derivatives

For the development of novel antioxidants having therapeutic utility, a new series of condensed 4- and 5-aminothiazole derivatives has been synthesized using simple methods. Condensed 4-aminothiazoles were prepared by the reaction of alpha-bromolactams with thioamides in ethanol and 5-aminothiazole derivatives were obtained by the treatment of 3-(acylamino)lactams with a thiating agent such as phosphorous pentasulfide and Lawesson's reagent in pyridine. In vitro assay of the condensed 5-aminothiazole derivatives showed them to be potent inhibitors of lipid peroxidation. In order to evaluate these compounds in an in vivo system, we devised a simple and reproducible method in which the inhibition of characteristic behaviors induced by spinal injection of FeCl2 was expressed numerically. Compounds having strong in vitro activity protected the central nervous system form injury caused by iron-dependent lipid peroxidation. The results suggest that the in vivo assay developed in this study should be useful as a screening method for antioxidants and also that condensed 5-aminothiazole derivatives are promising candidates for the treatment of traumatic and ischemic injury of the central nervous system.

The greater omentum is the primary site of neutrophil exudation in peritonitis

BACKGROUND

Peritonitis remains a major infectious problem. Neutrophil influx into the peritoneal cavity is one of the most important host defense mechanisms. However, no studies have focused on the site of neutrophil exudation. This study examined the primary anatomic site of neutrophil exudation in bacterial peritonitis.

STUDY DESIGN

Fifty-five rats were injected intraperitoneally with saline solution (control group) or 10(7) Escherichia coli (peritonitis group). In experiment 1, 1 x 10(6) fluorescein-labeled neutrophils were infused 3 hours after the challenge. Then, peritoneal-lavaged fluids and peritoneal tissues (the greater omentum, mesentery, parietal peritoneum, colon, and ileum) were obtained. Subpopulations of peritoneal exudative cells and numbers of labeled neutrophils in tissues were counted. In experiment 2, labeled neutrophils were infused at 10 minutes and at 1 and 5 hours after the challenge. Peritoneal tissues were also harvested. The number of labeled neutrophils in each tissue was determined.

RESULTS

In experiment 1, numbers of labeled peritoneal neutrophils and exudative neutrophils were higher in the peritonitis group than in the control group. Numbers of exudative neutrophils showed a positive correlation with numbers of labeled peritoneal neutrophil. In experiment 2, at 1 and 5 hours after the challenge, the number of labeled neutrophils was higher in the peritonitis group than in the control group. The number of neutrophils in the omentum was higher than the number in other peritoneal tissues.

CONCLUSIONS

Our fluorescence microscopic method is useful for detecting neutrophil adhesion. Neutrophil exudation into the peritoneal cavity was most marked in the omentum. The greater omentum may play an important role in host defense as a source of exudative neutrophils.

Effects of growth hormone and insulin-like growth factor 1 (IGF-1) treatments on the nitrogen metabolism and hepatic IGF-1-messenger RNA expression in postoperative parenterally fed rats

BACKGROUND

Few studies have made direct comparisons of the metabolic effects of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). We have assessed the dose-dependent effects of GH and IGF-1 treatments on nitrogen metabolism, intestinal structure, and hepatic IGF-1-messenger RNA (mRNA) expression in postoperative parenterally fed rats.

METHODS

Rats were maintained on total parenteral nutrition (TPN) for 3 days after gastrectomy. GH (0.4 or 0.8 IU/kg/d) or IGF-1 (1,2, or 4 mg/kg/d) was infused throughout the experimental period. Anabolic effects of GH and IGF-1 were assessed by body weight change, nitrogen excretion, and whole-body protein turnover. Organ weights, intestinal structure, plasma IGF-1 levels and hepatic IGF-1-mRNA contents were also determined.

RESULTS

Both GH and IGF-1 attenuated body weight loss and nitrogen excretion and increased whole-body protein synthesis and spleen weight. These observations suggest that the anabolic effects of 1 mg/kg/d of IGF-1 were equivalent to those of 0.66 IU/kg/d of GH. IGF-1, but not GH, reduced atrophy of the intestinal mucosa. GH treatment increased hepatic IGF-1-mRNA and the plasma IGF-1 level, whereas IGF-1 treatment increased the plasma IGF-1 level with no change in the hepatic IGF-1-mRNA content.

CONCLUSIONS

Administration of GH or IGF-1 attenuates catabolism after surgery. The anabolic effects of 1 mg/kg/d of IGF-1 are equivalent to those of 0.66 IU/kg/d of GH. IGF-1 reduces intestinal mucosal atrophy. GH increases hepatic IGF-1-mRNA and the plasma IGF-1 level.

Effects of three inhibitors of nitric oxide synthase on host resistance to bacterial infection

OBJECTIVE

To examine the effects of three nitric oxide synthase inhibitors on survival in a murine sepsis model.

DESIGN

Prospective randomized experimental trials.

SETTING

Laboratory.

SUBJECTS

Female Balb/c mice.

INTERVENTIONS

Escherichia coli (10(8) colony-forming-units/body) were injected into the peritoneal cavities of Balb/c mice. NG-nitro-L-arginine-methyl-ester, NG-monomethyl-L-arginine, or N-iminoethyl-L-ornithine was given at various concentrations, intraperitoneally, one hour before bacterial challenge.

MEASUREMENTS

One hundred and fifteen animals were observed for survival.

RESULTS

These inhibitors provided the mice no protection from the bacterial challenge. Notably, pretreatment with NG-nitro-L-arginine-methyl-ester (100 mg/kg i.p.) actually reduced survival time after E. coli challenge.

CONCLUSIONS

Inhibition of nitric oxide production improved neither the survival time nor rate in this murine sepsis model.

Route of nutritional supply influences local, systemic, and remote organ responses to intraperitoneal bacterial challenge

OBJECTIVE

The authors' aim was to investigate whether antecedent nutritional routes influence immune responses after surgical insult.

SUMMARY BACKGROUND DATA

Total parenteral nutrition (TPN) may influence host responses to infection. To the best of the authors' knowledge, however, no study has focused on the mechanisms underlying the influence of nutritional route on local, systemic, and remote organ (lung) responses after surgical insult.

METHODS

Sixty-eight rats were divided into TPN and total enteral nutrition (TEN) groups. The two groups received identical nutrients for 7 days and were then challenged intraperitoneally with 3 x 10(8) Escherichia coli. In the first experiment, the rats were observed for survival. In the second experiment, the rats were killed before (0 hours) challenge or 2 or 6 hours after challenge. Peritoneal exudative cells (PEC) and bronchoalveolar cells (BALC) were harvested and cultured in vitro. Colony-forming units of bacteria in the peritoneal lavage fluid (PLF) were determined. Tumor necrosis factor (TNF), interleukin-1 alpha (IL-1 alpha), interferon-gamma (IFN-gamma) levels in serum, PLF, bronchoalveolar lavage fluid (BALF), and cell culture supernatants were measured.

RESULTS

The 48-hour survival rate was higher in TEN than in TPN rats. Local immunity was depressed in the TPN group. Bacterial colony counts in PLF were significantly higher in the TPN group than in the TEN group after challenge. The number of PECs was significantly lower, and at 2 hours, local cytokine (TNF and IL-1 alpha) responses were diminished in the TPN group compared with the TEN group at 2 hours. The number of PECs showed a significant positive correlation with levels of local cytokines in the TEN group but not in the TPN group. Elevation of local IFN-gamma was significant from 0 to 6 hours in the TEN group but not in the TPN group. In vitro production of TNF by PEC was impaired in the TPN rats before challenge. Remote organ (lung) responses were suppressed in the TPN group. The number of BALCs and the TNF levels in BALF declined significantly between 0 and 2 hours in the TEN group but not in the TPN group. Interferon-gamma levels in BALF were higher in the TEN group than in the TPN group at 2 hours. Systemic cytokine responses were disturbed in the TPN group. Production of systemic TNF was greater, but the IFN-gamma response was diminished in the TPN group compared with the TEN group after intraperitoneal bacterial challenge.

CONCLUSION

Local, systemic, and remote organ (lung) immune responses to intraperitoneal bacterial challenge are suppressed in TPN-treated animals, leading to poor survival after challenge. Enteral nutrition before surgical insult may enhance host immune responses after the insult as compared to parenteral nutrition.

Growth hormone and the immune response to bacterial infection

Growth hormone (GH) and insulin-like growth factor 1 (IGF-1), especially the former, have immunoregulatory effects in addition to anabolic effects. The hormones may act to protect the host from lethal bacterial infection by promoting the maturation of myeloid cells, stimulating phagocyte migration, priming phagocytes for the production of superoxide anions and cytokines, and enhancing opsonic activity. GH administration may be beneficial for the prevention, as well as treatment, of severe sepsis in critical illness.

Growth hormone and insulinlike growth factor I enhance host defense in a murine sepsis model

OBJECTIVE

To investigate the effects of exogenous growth hormone (GH) and insulinlike growth factor I (IGF-I) on host defense and survival in a murine model of Escherichia coli sepsis.

DESIGN

Prospective randomized experimental trials.

SETTING

Laboratory.

MATERIALS

Nine-week-old female BALB/c mice.

INTERVENTIONS

Mice were injected subcutaneously with 4.8 or 0.48 mg/kg of body weight per day of GH, 24 or 2.4 mg/kg of body weight per day of IGF-I or, as a control, normal saline solution, for 6 days. Mice were then challenged intraperitoneally with 1 x 10(8) colony-forming units per body of E coli.

MAIN OUTCOME MEASURES

Fifty mice were observed for survival. In the next experiments, samples from the high-dose GH, high-dose IGF-I, and saline control groups were harvested before or at 4 or 6 hours after challenge. Numbers of peritoneal exudative cells and tissue-viable bacterial counts were determined. Peritoneal exudative cells were cultured with lipopolysaccharide (10 micrograms/mL) for 24 hours. Levels of tumor necrosis factor, interleukin-1, and interleukin-6 in the peritoneal lavage fluid, plasma and supernatants of peritoneal exudative cell culture were measured.

RESULTS

Both high and low doses of GH and high-dose IGF-I significantly prolonged survival. Growth hormone and IGF-I significantly increased peritoneal exudative cell numbers and reduced viable bacterial counts in the peritoneal lavage fluid and the liver. These hormones significantly suppressed excessive systemic cytokine production, while enhancing in vitro cytokine production and preserving local cytokine responses.

CONCLUSION

The immunomodulation produced by administration of GH or IGF-I leads to improved host defense in this murine model of E coli sepsis.

Detrimental effects of a nitric oxide synthase inhibitor (N-omega-nitro-L-arginine-methyl-ester) in a murine sepsis model

OBJECTIVE

To examine the effects of a nitric oxide synthase inhibitor on host elimination of bacteria, tumor necrosis factor (TNF) production, and survival in a murine sepsis model.

DESIGN

Prospective randomized experimental trials.

SETTING

Laboratory.

MATERIALS

Female Balb/c mice.

INTERVENTIONS

Balb/c mice were injected with Escherichia coli (10(8) colony-forming units per body) into the peritoneal cavity. N-omega-Nitro-L-arginine-methyl-ester (L-NAME), an inhibitor of nitric oxide synthase, was given intraperitoneally at 10 mg/kg (N10 group) or 100 mg/kg (N100 group) 1 hour before bacterial challenge.

MAIN OUTCOME MEASURES

Thirty animals were observed for survival. Samples of peritoneal lavaged fluid (PLF), blood, liver, and lungs were obtained at 4 and 6 hours after bacterial challenge (n = 60). The peritoneal exudative cells were counted. Viable bacterial counts were determined in PLF, blood, and organs. The TNF levels also were determined in plasma, PLF, and supernatant samples of cultured peritoneal exudative cells.

RESULTS

Survival times after E coli challenge were significantly reduced by pretreatment with L-NAME (100 mg/kg intraperitoneally). Numbers of viable bacteria in the peritoneal cavity and plasma TNF level 4 hours after E coli challenge were higher in both L-NAME-treated groups than in the control group. The number of bacteria in the blood and the plasma TNF level 6 hours after E coli challenge were higher in the L-NAME-treated group (N100 group) than in the control group. Conversely, the number of hepatic bacteria in the control group was significantly higher than in the L-NAME-treated groups. Plasma TNF level showed significant positive correlations with numbers of bacteria in the PLF and in the blood 4 hours after challenge. No significant differences were noted in TNF levels in PLF and peritoneal exudative cell cultured supernatants.

CONCLUSION

Inhibition of nitric oxide production is detrimental in this gram-negative sepsis model.

[Spontaneous subcapsular hemorrhage: a rare clinical presentation of renal cell carcinoma]

We present a case of renal subcapsular hemorrhage caused by a small renal cell carcinoma. The patient was a 52-year-old housewife, presenting abdominal pain and vomiting, of abrupt onset. Modern imaging modalities clearly visualized a perirenal or subcapsular hematoma in her left kidney, but no underlying pathology, was found even on the arteriogram. Relying on the statistics based on more than 100 reported cases with the spontaneous renal rupture, nephrectomy was carried out. The renal carcinoma was of granular cell type (G2), and classified as pT2, pN0 and pM0. Difficulties in making a correct diagnosis as to the pathology and therefore a rational decision for nephrectomy were also stressed.

[A case of recurrent mediastinal goiter (oxyphilic cell carcinoma)]

A case of recurrent mediastinal goiter (oxyphilic cell carcinoma) in a 66-year-old female was reported. 19 years ago, the patient submitted to a right-hemithyroidectomy for the oxyphilic cell adenoma. Since two months, her dyspnea gradually aggravated. On admission, abnormal mass of right upper mediastinum was shown by chest X-ray. CT scan and MRI showed a 8 cm sized right upper mediastinal tumor with tracheal compression.