Postantibiotic effects and postantibiotic sub-MIC effects of benzylpenicillin on viridans streptococci isolated from patients with infective endocarditis

We investigated the postantibiotic effects (PAEs) and the postantibiotic sub-MIC effects of benzylpenicillin on three strains of viridans streptococci isolated from infective endocarditis patients. The PAEs of benzylpenicillin on penicillin tolerant Streptococcus sanguis TW-70 (0.4-3.9 h), penicillin tolerant S. sanguis TW-80 (0.3-6.3 h) and nontolerant Streptococcus oralis TW-186 (0.5-3.1 h) were dependent on exposure time. The PAEs were not concentration dependent for S. sanguis TW-70 and S. sanguis TW-80 above the MIC, and for S. oralis TW-186 above 16 x MIC. The antimicrobial effects of benzylpenicillin at sub-MIC concentrations were examined in bacteria pretreated with benzylpenicillin (8 x MIC) for 2 h and compared with untreated bacteria. At the sub-MICs tested, the regrowth of pretreated S. oralis TW-186 cells was more prolonged than that of untreated cells and bactericidal action was seen only in pretreated cells. These effects (so-called 'postantibiotic' sub-MIC effects') were not observed in penicillin tolerant S. sanguis TW-70. The presence of the postantibiotic sub-MIC effect may be an important factor in determining the dosing regimen for infective endocarditis.

Effect of D-Ala-D-beta Nal-Ala-Trp-D-Phe-Lys-NH2 (KP-102) on GH secretion in urethan-anesthetized rats

The effect of a newly developed growth hormone (GH)-releasing hexapeptide (KP-102) on GH secretion was studied in urethan-anesthetized adult male rats. Although KP-102 alone exerted a small influence on GH secretion, it produced a large plasma GH response in the presence of exogenous GH-releasing factor (GRF). During the continuous infusion of GRF, the somatotropes became refractory to a large bolus dose of GRF, but KP-102 induced a marked increase of plasma GH. The GH response to KP-102 alone or KP-102 with GRF was significantly augmented when antiserum to somatostatin (ASS) was previously administered. Although KP-102 and GRF acted synergistically on GH secretion in control animals, they acted additively in ASS-administered rats. The KP-102 effect on plasma GH was significantly attenuated in control animals and ASS-administered rats by prior i.v. injection of antiserum to GRF. Taken together, KP-102 stimulates GH secretion dependent on GRF and appears to act synergistically with GRF by antagonizing the SS effect.

Serum biochemical changes and chemiluminescent responses of whole blood in Holstein cattle with leukocyte adhesion deficiency

Serum biochemical profile and whole blood chemiluminescent (CL) responses in 8 Holstein cattle affected with leukocyte adhesion deficiency (LAD) were evaluated. Concentrations of sodium, chloride and calcium in serum from cattle affected with LAD were significantly (p < 0.05) decreased as compared with controls. The characteristic changes in serum proteins were hypoalbuminemia and hyperglobulinemia, and the concentrations of albumin and gammaglobulin in serum from normal cattle and cattle affected with LAD were significantly (p < 0.01) different. Significantly (p < 0.01) diminished CL indices and prolonged peak time of CL responses in whole blood were detected in cattle affected with LAD. These findings indicate that the CL response associated with iC3b receptor mediated phagocytic activity is impaired in cattle affected with LAD. The whole blood CL assay appeared to be practical and useful for routine evaluation of blood samples from cattle affected with LAD.

[Bone marrow transplantation from donors other than HLA matched siblings for hematological malignancies. Nagoya Bone Marrow Transplantation Group and Tokai Marrow Donor Bank]

One hundred and fourteen patients with hematological malignancies received bone marrow transplantation from donors other than HLA-identical siblings. Sixty-three patients received transplantations from related donors; 20 were phenotypically identical for HLA-A, B, D/DR (RM0). 32 differed at one locus (RM1) and 11 differed at more than one loci (RM2). Fifty-one transplantations were from unrelated donors; 37 were phenotypically identical and mixed lymphocyte culture (MLC) negative (UR0) and 14 were MLC positive (UR1). One hundred and four patients had durable engraftment. Four (RM1(1), RM2(2), UR0(1)) failed to achieve engraftment. In terms of the probability of > or = Grade II acute graft-versus-host disease (GVHD), there was no significant difference among the groups according to HLA disparity (RM0:25%, UR0:33%, UR1:39%, RM1:47%, and RM2:50%). The probability of chronic GVHD was significantly higher in UR0 and UR1 than RM0 (71%, 75% vs 28%, p < 0.05). The disease-free survival at 3 years was 45% (RM0), 50% (RM1) and 42% (UR0). More than 50% of patients other than RM0 died of fatal complications including GVHD within 60 days after grafting. In conclusion, unrelated donor and related donor mismatched at one locus could be selected for marrow graft in the case of the absence of an HLA-matched related donor. However, more advances in post-transplant management and in histocompatibility testing should be required.

[Secondary leukemia after etoposide treatment involved MLL gene rearrangement]

The 11q23 chromosomal abnormality is frequently observed in infantile leukemia and secondary leukemia, and the translocation associated gene in infantile leukemia is called mixed-lineage leukemia (MLL) gene. A 50-year-old man was admitted because of left axillary lymphadenopathy and IBL like T cell lymphoma was diagnosed by lymph node biopsy. The patient responded to the LSG-9 protocol with complete remission. After 10 months he was readmitted because of fever and was diagnosed acute myeloblastic leukemia by bone marrow aspiration. Chromosome analysis revealed 11q23 abnormality, suggesting that the leukemia was induced by etoposide treatment. Southern blot analysis demonstrated DNA rearrangement in the MLL gene at 11q23. It was suggested that the breakpoint region of the MLL gene in secondary leukemia is the same as that of infantile leukemia.

A double-blind controlled study of granulocyte colony-stimulating factor started two days before induction chemotherapy in refractory acute myeloid leukemia. Kohseisho Leukemia Study Group

We conducted a prospective, double-blind controlled study to determine the efficacy of a recombinant granulocyte colony-stimulating factor (G-CSF, 200 microgram/m2) starting daily from 2 days before an induction therapy until neutrophils recovered to above 1,500/microL or until 35 days after the therapy in 58 patients with relapsed or refractory acute myeloid leukemia (AML). Twenty-eight patients in the G-CSF group showed significantly faster recovery of neutrophils (P < .001) than 30 patients in the placebo group. The incidence of febrile episodes and of documented infections was almost the same in both groups. However, among 39 patients who did not show any infectious episodes during the 2-week period after the start of chemotherapy, the incidence of documented infections after the third week tended to be lower in the G-CSF group, but not statistically significantly. There was no evidence that G-CSF stimulated the growth of AML cells in the bone marrow during the 2-day period before the chemotherapy, nor that G-CSF accelerated the regrowth of AML cells during the 5-week period after the therapy. Fifty percent of patients in the G-CSF group and 37% in the placebo group had complete remission (CR). Although the rate was higher in the G-CSF group, the difference was not statistically significant (P = .306). There was no difference between the two groups in event-free survival of all patients and in disease-free survival of patients who had achieved CR.

Restoration of growth hormone secretion in prolonged food-deprived rats depends on the level of nutritional intake and dietary protein

Prolonged food deprivation inhibits GH secretion in rats. To learn more about the nutritional regulation of GH secretion, we observed whether the recovery of GH secretion from prolonged food deprivation depends on the level of nutritional intake or a specific macronutrient in the refeed meal. Adult male Wistar rats were deprived of food for 72 h. Serial blood specimens were withdrawn via an indwelling right atrial cannula every 10 min using an automatic blood-sampling device. In the 72-hour food-deprived rats, the amplitude of the GH pulse progressively decreased but the pulse frequency did not differ compared to that of the fed control rats. When adult male rats were fed 5, 10 or 40 kcal of mixed meal consisting of carbohydrate 60%, protein 25% and fat 15% after 72 h of food deprivation, both the pulse amplitude and the pulse frequency immediately increased compared to those of the fasted control rats. Following these changes, the pulsatility of GH secretion was restored to normal, while the pulse amplitude was recovered in a meal-size-dependent manner. The GH secretory pattern no longer differed from that of the fed control rats in the rats fed 40 kcal of mixed meal. In the second study, the 72-hour food-deprived rats were fed 10 or 40 kcal of a protein meal consisting only of casein powder or 40 kcal of a protein-deficient meal consisting of carbohydrate 85% and fat 15%. The GH secretory pattern was restored to normal among the food-deprived rats fed 40 kcal of a protein meal.(ABSTRACT TRUNCATED AT 250 WORDS)

[Antibacterial activity of tosufloxacin against fresh clinical isolates]

The antibacterial activity of tosufloxacin (TFLX) was compared with those of other new quinolones (ofloxacin, ciprofloxacin, sparfloxacin and fleroxacin) against clinical isolates. These isolates had been collected from May to June 1993 (22 species, 260 strains) and from June to July 1992 (Staphylococcus aureus and Pseudomonas aeruginosa, 87 strains) in Toyama municipal hospital. TFLX showed the most potent activities against methicillin-susceptible S. aureus, methicillin-susceptible Staphylococcus epidermidis, methicillin-resistant S. epidermidis, Enterococcus faecalis and Escherichia coli in 1993, at MIC50 levels. The MIC50's of TFLX for these species ranged from 0.025 to 0.39 microgram/ml. TFLX showed potent activities against Klebsiella pneumoniae and P. aeruginosa, and the MIC50's of TFLX were 0.05 and 0.39 microgram/ml, respectively. However, new quinolone resistant strains (MIC > or = 6.25 micrograms/ml) were found among some species. Especially, the number of methicillin-resistant S. aureus (MRSA) strains resistant to new quinolone exceeded 60% of all the S. aureus isolates in 1993. More MRSA strains resistant to new quinolones were isolated in 1993 than in 1992, and similar result was observed for P. aeruginosa. The coagulase typing was done, and all MRSA strains of resistant to new quinolones produced coagulase type II.

[Allogeneic cryopreserved marrow transplantation in a patient with chronic myelogenous leukemia]

A 45-year-old male with chronic myelogenous leukemia received cryopreserved allogeneic bone marrow from his HLA-identical sister. Bone marrow was harvested and cryopreserved prior to chemoradiotherapy since the donor had neurotic tendencies. The preconditioning regimen consisted of standard dosage of busulfan plus cyclophosphamide and total lymphoid irradiation (5Gy). A total of 3.1 x 10(7)/kg marrow mononuclear cells, containing 4.7 x 10(5) CD34+ cells/kg, and 8.0 x 10(6)/kg buffy coat cells collected from the donor at day 0 was infused. Marrow engraftment occurred by day 38 although hematological recovery was delayed and subsequent administration of GM-CSF, methylprednisolone and donor buffy coat cells were required. Mononuclear cells obtained from the patient's blood at day 28 had an inhibitory effect on CFU-GM formation of the donor's bone marrow mononuclear cells. We considered that this case suffered from a transient myelosuppression due to residual host cells after bone marrow transplantation.

Clinical significance of serum iron and ferritin in patients with colorectal cancer

To clarify the significance of serum iron and ferritin as indicators of iron loss caused by continuous bleeding, and, thus, to determine their value as markers of colorectal cancer, values for the two were compared in male patients with early and advanced colorectal cancer and age-matched male controls. The mean value of serum iron levels in patients with advanced colorectal cancer was significantly decreased compared with values in patients with early colorectal cancer and controls, 50.5 +/- 38.6 micrograms/dl vs 93.0 +/- 32.1 micrograms/dl and 107.1 +/- 32.9 micrograms/dl, respectively (p < 0.001). The mean value of serum ferritin levels in patients with early and advanced colorectal cancer was also significantly decreased compared with controls, 80.5 +/- 35.0 ng/ml (p < 0.01) and 48.8 +/- 72.8 ng/ml (p < 0.001), respectively, vs 117.1 +/- 46.8 ng/ml. However, there was no significant difference between mean serum iron levels in patients with early colorectal cancer and controls. Eighteen (78.3%) of the 23 patients with advanced colorectal cancer and 3 (16.7%) of the 18 patients with early colorectal cancer had serum iron levels below 85 micrograms/dl and serum ferritin levels below 60 ng/ml. Levels of both serum iron and ferritin, without clinically evident anemia, are useful indicators of advanced colorectal cancer.

[Analysis of chronic graft-versus-host disease in patients after bone marrow transplantation from HLA-identical siblings]

The incidence of chronic GVHD, involved organs, and outcome were evaluated in 59 patients aged 15 years or more who survived for 2 months or more after HLA-matched bone marrow transplantation. The incidence of chronic GVHD was 65.3%. The incidence was not correlated with the age at the time of transplantation, underlying disease, or the method to prevent GVHD (group treated with MTX alone and CSP-treated group). Concerning the degree of organ involvement, the CSP-treated group more frequently showed slight involvement and, especially a significantly lower incidence of dryness of the eyeballs. According to organs, the oral cavity was most frequently involved (87%), followed in order by the liver (74%), skin (52%), and the eyes (30%). The oral cavity alone was involved in 6 patients, and the outcome was generally good. The outcome of multi-organ involvement of chronic GVHD was poor, and the major causes of death were interstitial pneumonia and sepsis. Even of patients who did not develop chronic GVHD, 25% showed dryness of the eyeballs and oral cavity. Biopsy and careful observation of the clinical course are needed for diagnosing GVHD.

Expression of growth hormone receptor gene in rat hypothalamus

Growth hormone receptor (GHR) mRNA-expressing cells in the hypothalamus were observed using hybridization histochemistry in adult male rats. Digoxigenin-labeled cRNA corresponding to the extracellular part of rat GHR was used as a probe. Northern blotting analysis of hypothalamic total RNA from adult male rats revealed that the 4.5 kilobase (kb) transcript of the GHR gene corresponding to the GHR messenger RNA (mRNA) predominated over the 1.2 kb transcript corresponding to GH-binding protein mRNA. GHR mRNA-containing cells were observed in the arcuate nucleus (ARC), the periventricular nucleus (PeV), ventrolateral region of the ventromedial nucleus, the paraventricular nucleus and the supraoptic nucleus. To further understand the significance of the GHR gene expression in the hypothalamus, the effect of in vivo manipulation of GH on the somatostatin (SS) gene expression in the ARC and PeV, and the GRF gene expression in the ARC was observed among adult male rats using in situ hybridization histochemistry. Ten days after hypophysectomy, the SS mRNA level in the ARC as well as PeV was significantly lower than that in the respective nuclei of sham-operated control rats, while the GRF mRNA level in the ARC was significantly higher than that in the ARC of control animals. Subcutaneous injection of recombinant human GH (0.33 mg) to hypophysectomized rats every 12 h for 5 days restored the SS mRNA level in the ARC and PeV, and reduced the GRF mRNA level in the ARC to that of control animals. The data suggest that GH directly acts on the hypothalamic PeV and ARC, and alters the gene expression of SS and GRF.

Immunohistological study of LH-immunoreactive cells in the porcine anterior pituitary

Anterior pituitary glands were removed from 18 sows at different stages of their estrous cycle to immunohistologically study the relationship between the stage of the estrous cycle and state of the luteinizing hormone (LH)-immunoreactive cells. The LH-immunoreactive cells were grouped into three types according to the amount of LH-immunoreactive granules stored in the cytoplasm (types A, B, and C). The number of LH-immunoreactive cells fluctuated along with the stage of the estrous cycle. In the 1st and the 6th stages, numerous LH-immunoreactive cells were observed (398 +/- 39, 391 +/- 60 cells/10(-2)mm2, respectively). In the 2nd stage, only a few cells were observed (6 cells/10(-2)mm2) and from the 3rd to the 5th stages, their number gradually increased.

Application of polymeric N-acetyl-D-glucosamine (chitin) to veterinary practice

The sponge-, cotton-, and flake-type remedies made of chitin (chitin-sponge, chitin-cotton, and chitin-flake, respectively), and non-woven fabric of polyester (NWF) composited with chitin (chitin-NWF) were applied to various types of trauma, abscess, surgical tissue defect and herniorrhaphy in 147 clinical cases including 72 dogs, 38 cows, 33 cats, 2 rabbits, one monkey and one horse. Chitin-sponge was applied in 30 cases as filling agent of surgical tissue defect, and in 25 cases of trauma, 31 cases of abscess as wound dressing or tissue defect filling agent. In 77 out of 86 cases (89.5%), good healing developed. When chitin-sponge was buried in surgical tissue defects due to oncotomy in 20 cases, recurrence of the tumor developed in one case on one month post-operatively, but was not recognized for 3-24 months in 19 cases. Chitin-NWF was applied in 2 cases of trauma and 12 cases of abscess as wound dressing or tissue defect filling agent, 6 cases as filling agent of surgical tissue defect, and 12 cases of umbilical hernia as prosthesis of suture site of hernia ring. In 28 out of 32 cases (87.5%), good healing developed. Chitin-cotton was applied in 8 cases of trauma and 12 cases of abscess as wound dressing or tissue defect filling agent. In 18 out of 20 cases (90.0%), good healing developed. Chitin-flake was applied in 9 cases of trauma as wound dressing or tissue defect filling agent. In 8 out of 9 cases (88.9%), good healing developed. In all cases, no side effects were observed.

[A double-blind dose ranging study of weekly subcutaneous administration of rHuEPO (KRN5702) on post-phlebotomy anemia of patients scheduled for predeposit autologous blood transfusion (multicenter late PhII study)]

Preoperative blood reservation for autologous blood transfusion generally causes anemia. We performed a double blind controlled study to determine the optimal dose of subcutaneous rHuEPO (recombinant human erythropoietin, KRN5702) for preventing preoperative anemia due to blood reservation. Patients received KRN5702 subcutaneously once a week in a doses of 12000, 24000 or 36000 IU by a double blind technique. After storage of 1200 ml of their own blood right before surgery, their hemoglobin (Hb) averaged about 1 and was about 0.5 g/dl lower than the level before administration of KRN5702 in doses of 12000 and 24000 IU, respectively. This fall was significant. In patients receiving KRN5702 in a dose of 36000 IU, the level of Hb rose instead of a fall; Hb immediately before surgery was 1.1% higher than that before administration which, however, was not significant. This elevation indicates a possibility of abnormal elevation of Hb at this dose. The mean Hb value right before surgery was significantly lower in patients receiving 12000 IU KRN5702 than in patients of the other two groups. The recovery rate of Hb was an indicator to reflect improvement of anemic conditions, and increased as the dose increased after the blood reservation. The rate in the 12000 IU group was significantly lower than that in the other two groups; there was not much difference between the other two rates. We estimated that to reserve 1200 ml of autologous blood, 24000 IU of KRN5702 is adequate but not excessive. One patient receiving 24000 IU showed side effects including an elevation of body temperature, rash, and edema.

Polymeric N-acetyl-D-glucosamine (chitin) induces histionic activation in dogs

Analyses on the effects of polymeric N-acetyl-D-glucosamine (chitin), which was obtained from squid pen, on histiogenic activation in dogs were carried out with subcutaneous implants (5 x 5 cm2) of polyester non-woven fabric (NWF) supplemented with chitin (chitin group) and NWF (control group). These materials were implanted at 4 sites, on the lumbodorsal and lumbosacral subcutaneous tissues on both sides of the midline in each dog under general anesthesia. The implants and their surrounding tissues were isolated on post-implantation days (PIDs) 2, 4, 8, and 18 under general anesthesia. In the chitin group, the implant was organized gradually and its organization was completed on PID 18, when obvious angiogenesis toward the NWF was observed. On the other hand, in the control group, obvious angiogenesis toward the NWF was not observed macroscopically. Numbers of mononuclear (MN) and polymorphonuclear (PMN) cells concentrated around the implants on PID 2 were larger in the chitin than control group. In the chitin group, formation of granulating tissue around the implant was indicated on PID 4, whereas such a phenomenon was not observed in the control group. From these results, chitin accelerates the migration of MN and PMN cells to the NWF site with rapid follow-up organization of the NWF accompanied by angiogenesis.

Scoliosis associated with syringomyelia

From January 1986 to December 1991, 1,059 patients with scoliosis of 20 degrees or more were reviewed. By magnetic resonance imaging, 43 patients were found to have syringomyelia. Thirty-eight patients had Chiari type 1 malformation. Twenty-two of the patients were younger than 10 years. Scoliosis was the only presenting symptom in 32 patients. All patients had some neurologic abnormalities. Fifteen patients had left thoracic curves. The incidence of scoliosis with syringomyelia in our outpatient clinic was 4.0%; 18.4% in boys, and 2.6% in girls. Magnetic resonance imaging should be performed in patients who have abnormal neurologic findings.

Immunohistochemical localization of inhibin-activin subunits in hydatidiform mole and invasive mole

OBJECTIVE

To examine the cellular localization of each inhibin subunit in hydatidiform mole and invasive mole.

METHODS

Tissues were collected and fixed in Bouin's solution and studied with the immunohistochemical technique avidin-biotin-peroxidase complex.

RESULTS

In the villous trophoblasts of hydatidiform mole and invasive mole, distinct immunostaining for inhibin alpha-subunit was observed in proliferative syncytiotrophoblasts, but not in the cytotrophoblasts. Positive immunostaining for beta A- and beta B-subunits was observed in both syncytiotrophoblasts and cytotrophoblasts. In extravillous trophoblasts of the invasive mole, staining for beta A- and beta B-subunits was observed, whereas staining for alpha-subunit was not detected.

CONCLUSION

Inhibin-activin subunits may be produced in the trophoblasts of hydatidiform mole and invasive mole, and inhibin and activin may play a role in trophoblastic proliferation and invasion.

Immunohistochemical localization of inhibin subunits in polycystic ovary

The immunohistochemical localization of the alpha-, beta A-, and beta B-subunits of inhibin was examined in polycystic ovary (PCO). The granulosa cells in multicystic follicles in the PCO exhibited negative immunostaining for alpha-subunit and positive staining for beta A- and beta B-subunits. In contrast, the hyperplastic thecal cells exhibited distinct positive staining for alpha-, beta A-, and beta B-subunits. The luteinized stromal cells (stromal hyperthecosis) also exhibited positive staining for each inhibin subunit. The granulosa cells in the tertiary follicle exhibited negative staining for alpha-subunit and positive staining for beta A- and beta B-subunits. No staining for each inhibin subunit was observed in the thecal layer in the tertiary follicle. The present findings suggest that immunoreactive inhibin alpha-, beta A-, and beta B-subunits are present in hyperplastic thecal and stromal cells in PCO, and that granulosa cells in the follicular cyst of PCO might not produce inhibin, in contrast to the normal ovary.

Developmental expression of the growth hormone receptor gene in the rat hypothalamus

The ontogeny of growth hormone receptor (GHR) gene expression was studied in the rat hypothalamus. Total RNA from the hypothalamus of rats at different developmental stages (embryonic day 15-56 days of age) was characterized using a 32P-labeled RNA probe derived from the extracellular domain of the rat GHR cDNA. Two RNA species, 4.5 kilobases (kb) encoding for GHR and 1.2 kb encoding for GH-binding protein, were detected in hypothalamic tissue from embryonic day 15 to 56 days of age. Their levels were low at embryonic day 15 and increased toward 3 days of age. The level of 4.5-kb transcript preferentially increased from 7 days after birth, and it was maintained until 35 days of age. Thereafter, the level of 4.5-kb transcript declined. The ratio between the 4.5- and 1.2-kb transcripts was less than 2.0 from embryonic day 15 to 3 days after birth, while it was larger than 4 after 7 days of age. There was no sex difference in the levels or the ratios of the transcripts of the GHR gene from 7 to 56 days of age. The findings indicate that the 4.5-kb transcript preferentially processed postnatally in the rat hypothalamus.

[Treatment of aplastic anemia with antithymocyte globulin, Lymphoser Berna]

Twenty-four patients with aplastic anemia (19 severe: 5 moderate) were treated with combined immunosuppression consisting of antithymocyte globulin (ATG: Lymphoser Berna, Swiss Serum and Vaccine Institute Berne) and high-dose methylprednisolone. Danazol or meptiostane was administered concurrently for at least 3 months. Three batches of ATG were used, two were not absorbed with thrombocytes and one was absorbed with thrombocytes for the prevention of thrombocytopenia. Nine of 20 evaluable patient (45%) had sustained improvement in hematopoiesis within 3 months of treatment. Nine of 14 patients (64%) showed a response to ATG without thrombocyte absorption, on the other hand, none of 6 patients responded to ATG with thrombocyte absorption. By life table analysis, the 3 year probability of survival was 81 +/- 27% after the combined immunosuppressive therapy. These results indicated that ATG therapy was very effective in Japanese patients with aplastic anemia.

Impaired growth hormone secretion in VMH lesioned rats

To investigate impaired growth hormone (GH) secretion in ventromedial nuclei (VMH) lesioned rats, we examined spontaneous plasma GH secretion, and plasma GH responses to arginine, clonidine and growth hormone releasing factor (GRF) under unanaesthetized and unrestrained conditions. Spontaneous GH secretion was blunted with 75% decrease of peak value in VMH lesioned rats, while it clearly existed in control rats. When rats were pre-treated with chlorpromazine (1-2 mg/kg, i.v.) which eliminates pulsatile GH secretion, no difference was observed in the plasma GH response to arginine (1 g/kg, i.v.) or to clonidine (100 micrograms/kg, i.v.) between VMH lesioned and control rats, but response to GRF (10 micrograms/kg, i.v.) was enhanced in the former animals. Administration of antiserum against somatostatin (1 ml) plus chlorpromazine significantly elevated the basal plasma GH level and GH response to arginine in control rats, but did not elevate them in VMH lesioned rats. These results suggest that reduction of both hypothalamic GRF and somatostatin release contribute to the impaired GH secretion in VMH lesioned rats. Reduction of somatostatin caused enhanced GH response to GRF and no increase in basal GH level with pre-treatment of antiserum against somatostatin. Reduction of GRF resulted in a failure to restore GH response to arginine with pre-treatment of antiserum against somatostatin. Reduction of both GRF and somatostatin caused blunted spontaneous GH secretion and normal GH response to arginine and clonidine.

The renin-angiotensin-aldosterone system and hematologic changes during pulsatile and nonpulsatile cardiopulmonary bypass

The effects of pulsatile and nonpulsatile cardiopulmonary bypass using a roller pump on levels of vasoactive hormones and hematologic changes were studied in 32 patients subjected to elective primary coronary artery bypass graft surgery. Seventeen patients had nonpulsatile perfusion (nonpulsatile group) and 15 patients had pulsatile perfusion (pulsatile group) during the period of cardiac arrest. Vasoactive hormones (plasma renin, angiotensin II, aldosterone, epinephrine, and norepinephrine) were measured in these patients. In order to clarify hematologic changes, plasma free hemoglobin, number of platelets, platelet factor 4, and beta-thromboglobulin were measured. There were no significant differences between the pulsatile and nonpulsatile groups with regard to vasoactive hormones and damage of platelets. In the pulsatile group, however, the rise of plasma free hemoglobin levels was significantly higher than that in the nonpulsatile group during and after cardiopulmonary bypass. We did not see the benefit of pulsatile perfusion using a roller pump on vasoactive hormones. Evidence of increased hemolysis with pulsatile flow was demonstrated in our cases.

Effects of nitroglycerin on hemodynamics in dogs with experimentally inserted heartworms

Hemodynamic effects of nitroglycerin were investigated in dogs with right ventricular failure including engorgement of the pulmonary artery and ascites induced by insertion of adult live heartworms into the pulmonary artery. The mean pulmonary arterial pressure (21.5 +/- 6.6 mmHg) in heartworm-inserted dogs 4 or 5 weeks after heartworm insertion were higher than that of control (4.2-7.1 mmHg). Nitroglycerin administered intravenously at doses of 3 or 10 micrograms/kg decreased pulmonary arterial pressure in these heartworm inserted dogs. This drug also decreased pulmonary vascular resistance and total systemic resistance with no effect on cardiac index and heart rate.