Bradykinin improves postischaemic recovery in the rat heart: role of high energy phosphates, nitric oxide, and prostacyclin

OBJECTIVE

The aim was to define: (1) whether bradykinin administration during reperfusion improves postischaemic myocardial recovery; (2) whether high energy phosphate compounds are involved in the protective effects of bradykinin; and (3) whether bradykinin-induced release of prostacyclin and nitric oxide mediate the protective effects of bradykinin.

METHODS

In the Langendorff rat heart preparation, coronary flow, left ventricular developed pressure, and, using 31P magnetic resonance spectroscopy, the high energy phosphate compounds phosphocreatine and beta-ATP were assessed during 15 min of global ischaemia and 30 min of reperfusion. Administration of 10(-7) M bradykinin was started before ischaemia and maintained throughout the experiment (BK-pre). This was compared to 10(-7) M bradykinin given exclusively with reperfusion (BK-post). Then 10(-7) M bradykinin was given simultaneously with 10(-4) M N omega-nitro-L-arginine-methyl ester (BK-LNAME) or 10(-5) M indomethacin (BK-indo).

RESULTS

In comparison to control hearts, BK-pre exerted a significant protective effect on the postischaemic recovery of coronary flow [71(5)% v 43(4)%, P < 0.05], left ventricular pressure [81(8)% v 42(5)%, P < 0.05], phosphocreatine [105(4)% v 67(8)%, P < 0.05], and beta-ATP [78(9)% v 48(7)%, P < 0.05]. With BK-post, recovery of coronary flow [71(4)% v 43(4)%, P < 0.05] and left ventricular pressure [78(4)% v 42(5)%, P < 0.05] significantly improved; however the recovery of phosphocreatine [70(4)% v 67(8)%, NS] and beta-ATP [58(2)% v 48(7)%, NS] was not different from control. When bradykinin and L-NAME or indomethacin was given the beneficial effects of bradykinin on ischaemic hearts were abolished.

CONCLUSIONS

(1) Bradykinin improved postischaemic myocardial recovery when given before ischaemia or starting exclusively with reperfusion; (2) this was only partially related to a protective action on the high energy phosphate compounds during ischaemia; (3) the beneficial effects of bradykinin on ischaemic hearts are dependent from an unrestrained action of prostacyclin and nitric oxide.

Color holography using the angular selectivity of volume recording media

A display hologram of an object can be recorded and reconstructed in three primary colors if the angular selectivity of volume recording media is exploited. Three holograms are recorded in the same medium, each at a different primary color. These three holograms are reconstructed by simultaneous illumination of the hologram with the original reference beams. By proper choice of the angles that the reference beams make to the hologram, it is possible to suppress strongly cross talk between the different reconstructions (e.g., the red object reconstruction in green light). The technique exhibits high resolution, high diffraction efficiency, and vivid colors. Through the addition of three holographically recorded volume gratings it is possible to reconstruct the hologram with a beam of white light. The saturation and brightness of each primary color in the reconstruction can be adjusted by selection of an appropriate thickness for the corresponding grating.

Typing Neisseria meningitidis by analysis of restriction fragment length polymorphisms in the gene encoding the class 1 outer membrane protein: application to assessment of epidemics throughout the last 4 decades in China

A typing method was developed for Neisseria meningitidis serogroup A by analysis of restriction fragment length polymorphisms (RFLP) of the class 1 outer membrane protein gene (porA). By using appropriate primers, an approximately 1,116-bp fragment of the porA gene was amplified by PCR and then was digested with the restriction endonuclease MspI. The digestion products were separated on 10% polyacrylamide gels and were stained with silver. One hundred three clinical isolates of group A N. meningitidis from 17 provinces of China collected over a 26-year period were analyzed. Results of MspI-generated RFLP profiles of PCR-amplified porA genes were compared with those obtained by conventional serosubtyping. There was a band of about 400 bp common to all strains examined, and the 103 strains of serogroup A resulted in 22 unique RFLP patterns. The differences in bands could be observed mainly in the range of 120 to 280 bp. The smaller fragments were useful in distinguishing meningococci with the same serosubtype. Three epidemic periods were characterized by the presence of three distinct genotypes (a1, a2, and a3), accounting for 74.5% of the strains examined (3.88, 26.21, and 44.66%, respectively). Three predominant RFLP patterns were correlated epidemiologically with cycles of epidemic meningococcal meningitis and were well-matched to the predominant serosubtypes (P1.9, P1.7, 10, and P1.9) that presented at the same prevalence cycles. The genotyping yielded information that allowed strains from one epidemic to be distinguished from those from another that would have been indistinguishable if only serotyping and serosubtyping were available. Therefore, the PCR-RFLP typing method was very useful in the epidemiologic investigation of group A meningococcal meningitis.

Ultrastructural study of the hemopoietic microenvironment in human fetal spleen

Reciprocal interactions between hemopoietic stromal cells and immature hemopoietic cells in human spleens obtained from 20 fetuses of 10-28 weeks gestation were observed by transmission electron microscopy and scanning electron microscopy. The close association of stromal cells with immature hemopoietic cells was confirmed under the electron microscope and a presumptive HIM (Hemopoietic inductive microenvironment) was visualized. In regions of immature hemopoietic cell-reticular cell, endothelial cell, macrophage and interdigitating cell contact, some communicating structures were found between the plasma membranes of adjacent cells; moreover, the cytoplasm of these four stromal cells were full of various kinds of organelles. These results suggest that reticular cells, endothelial cells, macrophages and interdigitating cells are component parts of the HIM of human fetal spleen and that these cells have a nurturing function in relation to hemopoietic cells.

[Changes of PTH, 1,25(OH)2D3 and biochemistry in renal osteodystrophy]

The changes of plasma PTH, 1,25(OH)2D3, serum calcium, phosphorus and AKP were observed in 55 uremic patients with renal osteodystrophy. The results showed that: In all types of renal osteodystrophy, plasma PTH were markedly higher than normal (P < 0.001), while plasma 1,25(OH)2D3 and serum calcium were lower than normal (P < 0.001). In low bone-turnover uremic osteodystrophy (LTO), plasma phosphorus was markedly lower than that of high bone-turnover uremic osteodystrophy (HTO) and mixed uremic osteodystrophy (MO) (P < 0.05), and plasma 1,25(OH)2D3 was significantly lower than that of HTO (P < 0.05). In HTO and MO, serum phosphorus was much higher than normal (P < 0.001). Plasma PTH had a negative linear correlation with plasma 1,25(OH)2D3 (P < 0.05), a positive linear correlation with serum AKP (P < 0.05), but no linear correlation with the duration of hemodialysis, serum calcium, serum aluminum and bone aluminum content. Plasma 1,25(OH)2D3 had no linear correlation with the duration of hemodialysis, serum phosphorus, serum aluminum and bone aluminum content. There was no significant difference in the plasma PTH, 1,25(OH)2D3 and serum AKP between the bone aluminum stain positive and negative groups.

[A study on cellular differentiation and antigen receptor gene rearrangement in lymphoid malignancies]

Cellular differentiation origin and genotype of IgH and TCR gamma, delta gene rearrangement in 42 cases of lymphoid malignancies were studied by using immunoenzymatic method with monoclonal antibodies (McAbs) and polymerase chain reaction (PCR) technique respectively. The results suggested that among the 23 cases, in which malignant cells expressed B-lineage cell surface markers, 20 showed IgH gene rearrangement and 11 had TCR gamma gene rearrangement and/or TCR delta gene deletion. All the 11 cases expressed T-lineage cell differentiation antigens were found to have TCR gamma and TCR delta gene rearrangement or deletion and only one had IgH gene rearrangement. Double rearrangement of IgH and TCR gamma genes were detected in all the 3 cases of T.B double-phenotype ALL. In the cases, in which malignant cells did not express any lineage specific antigens, 4/5 had TCR gamma gene rearrangement, but all failed in IgH gene rearrangement. The relation of cellular differentiation origin and rearrangement of antigen receptor genes with clinical manifestations was also discussed.

The presence of mast cells in the human endometrium pre- and post-insertion of intrauterine devices

A study of the density of mast cells in the human endometrium was carried out on biopsy specimens prepared for light microscopy in 87 cases with three types of IUDs (stainless steel ring SS-type, copper Cu-T 220 and LNG-IUD levonorgestrel-releasing device) pre- and post-insertion. The results revealed that, in general, there was an increase of mast cells after 3 to 24 months' use of IUD, independent of type (p < 0.01 when compared with the pre-insertion value). The increase in number of mast cells was most prominent in women having used the Cu-T220 IUD for 24 months (p < 0.05 when compared with the SS-IUD and p < 0.01 when compared with the LNG-IUD). The difference between the SS-IUD and the LNG-IUD as to the number of mast cells was not significant. No significant difference was found between the "bleeders" and "non-bleeders" in any of the three types of IUDs. It is noteworthy that patients using the Cu-T220-IUD had the highest percentage of patients with abnormal bleeding (> 50%) and that this group also had the highest density of mast cells per mm2 after 24 months' use. Although no significant difference with regard to the density of mast cells could be found between the "bleeders" and the "non-bleeders" in the present study, the number of "bleeders" of the three study groups is usually small and sometimes this number does not allow an adequate statistical analysis for comparison. Further investigations, involving larger number of IUD users, may yield a better understanding with regard to the potential relationship between the number of bleeding episodes and the density of mast cells in the human endometrium.

[A pathological analysis of 51 cases of renal osteodystrophy]

Renal osteodystrophy is a metabolic bone disease of chronic renal failure. The long-standing alterations in mineral metabolism generated by renal failure have a profound effect on the skeleton and induce severe systemic metabolic bone disease. Iliac crest biopsy was performed in 51 patients of chronic renal failure and examined with microscopy. The histological bone changes are characterized by ostitis fibrosa, increased resorption of bone and number of osteoclasts, increased osteoid volume (osteoblastic osteoid and acellular osteoid), active remodelling of bone and aluminum deposition in bone. According to the histological appearance, advanced renal bone disease can be subdivided into three major histological groups: secondly hyperparathyroid bone disease (high turnover uremic osteodystrophy), osteomalacia (low turnover uremic osteodystrophy) and mixed uremic osteodystrophy consisting of mild to moderate hyperparathyroid bone disease and defective mineralization. Aluminum-related bone changes can be seen in varying degrees in all these groups. Even though these groups do not fully represent separate entities and transformation from one form to another can occur, it is essential to distinguish them since therapy can be tailored according to the predominant histologic findings.

[Aluminum in renal osteodystrophy]

To evaluate the relationship between aluminum and renal osteodystrophy, iliac bone biopsies and bone aluminum staining were studied in 51 patients with end-stage renal failure. In 27 of 51 cases were measured PTH, 1.25 (OH)2D3 levels and bone aluminum contents. We found that the incidence of renal osteodystrophy was 100%. The positive rate of bone aluminum staining was 12%. The rate was highest in low-turnover osteomalacia. Serum aluminum and bone aluminum contents were significantly higher than controls in three types of renal osteodystrophy on hemodialysis. Bone aluminum correlated with the duration of hemodialysis (r = 0.704), also with the serum calcium (r = 0.341). The duration of hemodialysis and bone aluminum contents were markedly longer and higher in positive group of bone aluminum staining than that of negative group (P < 0.001, respectively). Our data suggested that: (1) aluminum accumulation in bone was related to duration of hemodialysis, (2) aluminum may play important roles in the intervention of bone mineralization.

Differential effects of endothelin-1 on normal and postischemic reperfused myocardium

Using an isolated rat heart preparation and 31P magnetic resonance spectroscopy, we studied the effects of endothelin-1 (ET-1) and U-46619, a thromboxane-A2 analogue, on coronary flow (CF), left ventricular developed pressure (LVP), and high-energy phosphate metabolism under control conditions (normal myocardium) and during postischemic reperfusion (reperfused myocardium). The selected doses of ET-1 and U-46619 reduced CF in the normal myocardium to a similar extent (47.8 +/- 1.5% and 48.7 +/- 4.6%, respectively). In contrast to ET-1, U-46619 induced a depression of LVP (20.2 +/- 6.9% versus 6.8 +/- 4.7%; p < 0.05) which was accompanied by an intracellular acidosis, indicating that a low-flow ischemia occurred. In reperfused hearts, the ET-1-induced decrease in CF was more pronounced compared to U-46619 (79.5 +/- 1.6% versus 59.0 +/- 5.9%; p < 0.05) and to ET-1-induced decrease in CF in the normal myocardium (74.0 +/- 7.9% versus 32.4 +/- 6.3%; p < 0.05). This was accompanied by a large decrease in LVP and in levels of high-energy phosphate compounds. Therefore, the effects of ET-1 but not of U-46619 are enhanced in reperfused hearts. This may contribute to the delayed recovery of the postischemic reperfused myocardium.

Influence of reducing luxury calories in the treatment of experimental mammary carcinoma

The aim of this study was to investigate the influence of dietary calorie intake at three different fat levels on (a) the growth of established methylnitrosourea (MNU)-induced mammary carcinoma, (b) the reappearance of mammary carcinomas after surgical removal, and (c) the growth of manifest lesions in animals treated with the cytostatic agent hexadecylphosphocholine (HPC). A reduction of calories by 30% significantly inhibited tumour growth of manifest mammary carcinomas in rats, without having a negative influence on body weight gain. After chemotherapeutic treatment no significant dietary influence was observed besides the high antineoplastic efficacy of HPC, but when feeding calorically restricted diets to surgically treated animals the number of reappearing tumours was considerably smaller (P = 0.06) than after feeding the diets ad libitum. The fat content of the diets did not influence the growth of manifest mammary carcinomas. No significant dietary effects were exerted on oestradiol or testosterone levels in untreated tumour bearing animals. An elevation of oestradiol levels was observed when animals were subjected to HPC and fed a high calorie diet. An elevation of testosterone levels was assessed after surgical treatment of the rats, irrespective of fat content and calorie level. Our results suggest that a reduction of calories can inhibit growth of manifest mammary carcinomas and has impeding effects on tumour development after surgical removal. After effective chemotherapeutic treatment the additional influence of dietary changes was of less relevance. Furthermore, our data do not establish any association between growth inhibition of mammary tumours, caused by the mild caloric restriction, and altered oestradiol or testosterone production.

Effects of Hantaan virus on human endothelial cells and their significance in pathogenesis of hemorrhagic fever with renal syndrome

The effects of Hantaan virus (HTNV) on human endothelial cells (HECs) were investigated both in vivo and in vitro. The 76-118 strain or SR-11 strain of HTNV were inoculated into HECs monolayers respectively, and the virus antigens could be detected on the seventh day of the first passage after inoculation by immunofluorescent technique. The HTNV could also be isolated through cultures of Vero E-6 cells. HTNV particles and inclusion bodies together with various changes in the organelles were observed in the infected cells by transmission electronic microscopy (TEM), and the immunoenzyme positive virus particles were seen by immunoelectronic microscopy. Samples of skin biopsy were individually obtained from 14 cases of hemorrhagic fever with renal syndrome on the second to the fifth day after the onset of the illness. It was found that HTNV antigens were widely distributed in the cytoplasm of endothelial cells of the samples from 5 out of 14 cases by avidin-biotin-peroxidase complex staining, and morphologic changes of the endothelial cells similar to those observed in vitro, were also seen by TEM. The results indicated that HEC is one of the target cells susceptible to HTNV. The virus could invade and propagate in HECs, and could induce damage to the latter.

Effect of dietary calorie and fat restriction on mammary tumor growth and hepatic as well as tumor glutathione in rats

Effect of dietary calorie restriction and fat reduction on growth of established mammary carcinoma in rats and on glutathione levels in liver and tumor tissue was investigated. Reduced (GSH) and oxidized (GSSG) glutathione were determined enzymatically. Female Sprague-Dawley rats were injected with 25 mg/kg methylnitrosourea (MNU) on day 50 of life for tumor induction, and subsequently fed a diet containing 50 kcal/day with 45% (energy %) fat. When tumors reached approximately 1 cm3, the diet was changed for 10 +/- 2 weeks. Four dietary groups were formed: two high calorie groups (50 kcal/day) with 45% or 25% fat and two calorie restricted groups (35 kcal/day) with 45% or 25% fat, respectively. Tumor growth was significantly inhibited by the 30% calorie restriction, and the inhibition was most effective in the calorie restricted group with low fat level. However, reduction of fat, alone, had no significant inhibitory effect. GSSG levels in both liver and tumor showed no differences among the groups. Hepatic GSH levels tended to be lower in the calorie-restricted groups, and showed no difference between isocaloric groups with different fat levels. In contrast, GSH in tumor tissue tended to be lower in the low fat groups, independently of calorie levels.

Design and implementation of full-frame, bit-allocation image-compression hardware module. Work in progress

A hardware module was designed and built to implement the full-frame, bit-allocation image-compression algorithm in a clinical setting. The algorithm transforms an entire image without prepartitioning into small subimages. This adaptation eliminates block artifacts at subimage borders that can mimic relevant pathologic conditions. The quality of 1,024- and 2,048-pixel images compressed at a rate up to 10:1 with a custom-designed processor board (which contains four digital signal processors that transform and quantize separate rows and columns of an image independently with a two-pass cosine transform) and a 16-Mbyte frame buffer was found to be diagnostically acceptable in preliminary receiver operating characteristic studies. The module can compress a 1,024-pixel image in 4 seconds in a general-purpose computer system; images can be compressed in 1 second with the addition of a custom-designed data transporter. Copies of the compression module are being installed in the authors' department and in collaborating hospitals for laboratory and clinical evaluation.

Vertical frontal subtotal laryngectomy and immediate reconstruction of larynx with cervical skin flap

Vertical frontal subtotal laryngectomy, a procedure that can remove as much as 90% of the larynx, was used to produce a functionally acceptable neolarynx with adjacent cervical skin flaps. Thirty-four patients with laryngeal carcinoma underwent this operation. All patients were staged according to their physical findings before operation. Of these patients, 1 was lost to follow-up and 2 died from other causes 6 months and 4 years after operation respectively. The remainder are living and well without recurrence. The longest follow-up was 8 years and the shortest 14 months. Laryngeal functions were restored completely in 27 patients and partially in 7. We conclude that the procedure is best suited for the removal of anterior commissure tumor extending from both vocal cords to the anterior 1/3 or the entire length of the true cords and that if the tumor extends to the supraglottis or subglottis, this procedure is adequate as long as the posterior part of the larynx is not involved, leaving a sufficient safety margin.

[Experimental study on myocardial protection with verapamil and salvia miltiorrhiza Bunge cardioplegia]

Myocardial 45Ca sequestration was studied in dogs during 60 minutes of global ischemia and 30 minutes of reperfusion using cardiopulmonary bypass (CPB) and myocardial function was studied before and after CPB. Group A (n = 5), as a control, received cold hyperkalemic cardioplegic solution, Group B (n = 5) received the same solution plus verapamil (150 micrograms/kg/L) and Group C plus specific activity (TSA = DPM x 10(4)/g) and plasma specific activity (PSA = DPM x 10(4)/ml) were determined by biopsy before and after release of the cross-clamp The results showed that myocardial function in Group B and C were better than that in Group A (P less than 0.01). It is suggested that verapamil and Salvia miltiorrhiza Bunge effectively control myocardial calcium sequestration during early reperfusion and reduce myocardial reperfusion injury As to myocardial protection, cardioplegia with verapamil and Salvia miltiorrhiza Bunge were superior to hyperkalemic alone. Verapamil cardioplegia was still better than Salvia miltiorrhiza Bunge.