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PubMed2006

Altered plasma matrix metalloproteinase-9/tissue inhibitor of matrix [corrected] metalloproteinase-1 concentration during the early postoperative period in patients with colorectal cancer.

BACKGROUND: The authors have previously demonstrated that insulin-like growth factor binding protein-3 (IGFBP-3) is depleted in plasma for 1 to 3 days after major open surgery (OS), but not after laparoscopic surgery (LS). After surgery, IGFP-3 cleavage occurs rapidly and is likely attributable to altered plasma proteolytic activity. This study aimed to assess plasma proteolysis after both open and closed colorectal resection and, if possible, to identify a protease/protease inhibitor system affected by surgery. METHODS: Plasma from 88 patients with colorectal cancer (stages I-III) who underwent resection was obtained preoperatively (pre-OP) and on postoperative days (POD) 1 to 3. Plasma proteolytic activity was assessed via zymography. On the basis of the results, specific protease and protease inhibitor concentrations were next measured via enzyme-linked immunoassay (ELISA). Statistical analysis was performed using Wilcoxon's test. RESULTS: Early after surgery, zymography showed a predominant band representing a 92-kDa gelatinase corresponding to a proform of matrix metalloproteinase-9 (MMP-9), a protease known to cleave IGFBP-3. In OS patients, the mean concentration of plasma MMP-9 was significantly higher on POD 1 than at pre-OP (p < 0.003). On POD 2 and 3, no differences were noted. In the LS group, the mean levels of MMP-9 before and after surgery were comparable. The levels of a natural MMP-9 inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), also were measured. In the OS group, the level of TIMP-1 was significantly higher on POD 1 (p < 0.0003) and POD 2 (p < 0.01) and 3 (p < 0.01) than at pre-OP. In the LS group, a smaller but significant increase in TIMP-1 levels was found between the pre-OP sample and the POD 1 (p < 0.01) and POD 2 (p < 0.01) samples. No difference was noted on POD 3 (p = 0.1). CONCLUSIONS: Open surgery, but not laparoscopic surgery, is accompanied by a short-lived significant increase in MMP-9 levels, which likely accounts for the decrease in IGFBP-3 levels observed after OS. The transitory nature of MMP-9 imbalance may be attributable to the increase in TIMP-1 levels postoperatively.

Adenocarcinoma↗

PubMed2000

Time course of differences in lymphocyte proliferation rates after laparotomy vs CO(2) insufflation.

BACKGROUND: Our laboratory has previously demonstrated that cell-mediated immune function is significantly more suppressed after both laparotomy and laparoscopic-assisted bowel resection than after peritoneal insufflation or open bowel resection, as assessed by delayed-type hypersensitivity (DTH) response. The purpose of this study was to further evaluate cell-mediated immunity by examining lymphocyte proliferation rates after laparotomy vs CO(2) insufflation. METHODS: Female Balb/C mice (n = 75) were randomly divided into the following three groups: (a) anesthesia control (A/C), (b) CO(2) insufflation (INS), and (c) sham laparotomy (OPEN). The A/C group mice underwent no procedure. The INS group underwent insufflation with CO(2) gas at 4-6 mmHg for 20 min. The OPEN group underwent a midline incision from xiphoid to pubic symphysis, which was clipped closed after 20 min. Splenocytes were obtained via splenic harvest and lymphocyte isolation on postoperative days (POD) 1, 2, 3, 4, and 8. Lymphocyte proliferation was determined by a nonradioactive colorimetric MTS/PMS assay 72 h after concanavalin A stimulation. RESULTS: The laparotomy group's lymphocyte proliferation rates were significantly lower than both the control and the insufflation groups on POD 2, POD 3, and POD 4. On POD 1 and POD 8, there were no significant differences in lymphocyte proliferation among the three groups. No differences were found between the control and insufflation groups at any point. CONCLUSIONS: After stimulation, lymphocytes proliferate at a lower rate after laparotomy than after CO(2) insufflation. Significant differences in lymphocyte proliferation rates between groups persist at least through POD 4. By POD 8, the mean lymphocyte proliferation rate in the laparotomy group was back to the baseline level. Our results suggest greater immunosuppression after sham laparotomy than after CO(2) insufflation.

Animals↗

PubMed2001

Comparison of short-term versus long-term epidural analgesia after limited thoracotomy with special reference to pain score, pulmonary function, and respiratory muscle strength.

To determine the optimal duration of epidural analgesia (EA) after lung cancer surgery, a retrospective analysis was conducted to compare chest pain, pulmonary function, and respiratory muscle strength between patients given EA until postoperative day (POD) 3 and those given EA until POD 8. Each group comprised 25 lung cancer patients who underwent a lobectomy under anterior limited thoracotomy and given continuous thoracic EA using morphine until POD 3 (POD3-EA group) or POD 8 (POD8-EA group). The two groups were matched by sex and age. Postoperative pain from PODs 1 to 12 was evaluated by the pain score and analgesic requirements. The pulmonary function and respiratory muscle strength were measured on POD 7. The POD3-EA group did not experience any increase in pain after withdrawal, but the POD8-EA group did show a significant increase in pain the day after withdrawal (P < 0.05). The pain scores on PODs 8 and 9 in the POD8-EA group were significantly higher than those in the POD3-EA group (P < 0.05). There was no significant difference in pulmonary function and respiratory muscle strength on POD 7 between the two groups. Although the postoperative thoracic EA did not affect pulmonary function and respiratory muscle strength, prolonged thoracic EA after a limited thoracotomy significantly increased the pain after withdrawal, thus negatively affecting postoperative pain control.

Aged↗

PubMed1984

A comparative study of skin blood flow in musculocutaneous and random pattern flaps.

The present study in dogs was performed to evaluate the development of blood flow in cranial-based, rectus abdominis musculocutaneous (MCF) and random pattern (RPF) flaps and in adjacent intact skin before and after operation. Prior to raising of the flaps the intact skin area had the same blood flow in all the test injections. Following flap elevation blood flow in the MCF increased and on the second postoperative day (POD) it was 2.6 times the preoperative value. From POD 2 through POD 15 only minor changes were found for blood flow in MCF. Blood flow in the RPF immediately after surgery was only 31% of the preoperative value and 24% of the MCF value. After POD 2-3 blood flow in RPF, however, increased and reached the preoperative level and continued to increase through POD 15. Intact adjacent skin showed changes similar to those of MCF through POD 6, however, by POD 15 blood flow had decreased and was lower than that in MCF and RPF. Blood flow rates at remote sites in the groin and shoulder were identical and showed only a slight increase during the first two postoperative days. It is concluded that MCF have an early and continuous increase in blood flow after raising, while RPF have an early decrease. RPF, however, develop a subsequent increase in flow lasting through POD 15. Intact adjacent skin also showed increased blood flow which could not be attributed to a generalized increase in skin blood flow.

Animals↗

PubMed2006

Decrease of type IV collagen and TIMP-1 serum levels after splenectomy in patients with schistosomiasis mansoni.

The role of the spleen in the process of liver fibrosis in schistosomiasis still needs clarification. The aim of this study was to assess the effect of splenectomy on serum levels of two markers of fibrosis, type IV collagen and TIMP-1, in patients with schistosomiasis mansoni. Twenty-four patients with hepatosplenic schistosomiasis mansoni participated in the study. Type IV collagen and TIMP-1 serum levels were measured preoperatively, and after 2 (POD-1) and 60 days (POD-2) of spleen removal. Before splenectomy, both type IV collagen and TIMP-1 serum levels were elevated in the majority of patients. After splenectomy, the levels of type IV collagen showed a significant decrease in relation to the preoperative values both in POD-1 (median pre-splenectomy: 143.7 ng/ml versus 77.01 ng/ml; p=0.04) and POD-2 (103.3 ng/ml; p=0.015). Serum levels of TIMP-1 also showed a significant decrease in relation to the preoperative values both in POD-1 (pre-splenectomy: 585.9 ng/ml versus 196.4 ng/ml; p=0.008) and POD-2 (97.4 ng/ml; p<0.001). There was no difference between POD-1 and POD-2 values for each serum marker. In conclusion, splenectomy in schistosomotic patients was associated with a decrease in serum markers of fibrosis levels, which persisted for at least 60 days. These results suggest that the spleen may play a role in the extra cellular matrix production, and therefore may contribute to liver fibrosis in schistosomiasis mansoni.

Adult↗

PubMed2001

Laboratory evaluation of the entomopathogenic fungus, Metarhizium anisopliae for the control of the groundnut bruchid, Caryedon serratus on groundnut.

The pathogenicity of five isolates of Metarhizium anisopliae to adult Caryedon serratus was evaluated in the laboratory. All the isolates tested were virulent to the beetle but pathogenicity varied among the isolates. One isolate, CPD 4 was consistently superior to all other isolates in terms of mortality of the beetle, protection of groundnut pods from damage, reduction in progeny production and repellency to the beetle. At 10 days post-treatment, adult mortality treated with 0.1, 0.5 and 1.0g of dry conidia equivalent to 3.6x10(8), 1.8x10(9) and 3.6x10(9) conidia of isolate CPD 4 per 50g of groundnut pods was 100% which did not differ significantly from pirimiphos-methyl-treated pods at 10ppm. At the lowest dosage of 0.1g of conidia per 50g of pods, damage in pods protected with isolate CPD 4 was 5% which did not differ significantly from the 2% damage in pods protected by pirimiphos-methyl at 10ppm but significantly differed from damage in untreated pods which was 26%. Isolate CPD 4 caused complete reduction in progeny emergence at all dosages tested. It also exhibited some degree of repellency to the beetle with percentage repellency values of between 40-79% at concentrations of 0.1-1.0g of conidia per 50g of groundnut pods. These combined virulence and repellency characteristics of this isolate may increase its protectant potential against C. serratus.

Journal Article↗

PubMed2001

Abscisic acid induced changes in cell wall peroxidase activity and hydrogen peroxide level in roots of rice seedlings.

The changes in the activity of peroxidase (POD) extracted from the cell wall and the level of H(2)O(2) of rice seedling roots treated with abscisic acid (ABA) and their correlation with root growth were investigated. Increasing concentrations of ABA from 3 to 18 µM progressively reduce root growth and increase POD activities (using guaiacol or ferulic acid as a substrate) extracted from the cell wall of rice roots. The reduction of root growth by ABA is also correlated with an increase in H(2)O(2) level. Both diamine oxidase (DAO) and NADH peroxidase (NADH-POD) are known to be responsible for the generation of H(2)O(2). ABA treatment increased NADH-POD and DAO activities in roots of rice seedlings, suggesting that NADH-POD and DAO contribute to the generation of H(2)O(2) in the cell wall of ABA-treated roots. An increase in the level of H(2)O(2) and the activity of POD extracted from the cell wall of rice roots preceded root growth reduction caused by ABA. An increase in DAO and NADH-POD activities coincided with an increase in H(2)O(2) in roots caused by ABA. Since DAO catalyzes the oxidation of putrescine, the results that ABA increases the activity of DAO in roots is consistent with those that ABA decreases the level of putrescine. In conclusion, cell wall stiffening catalyzed by POD is possibly involved in the regulation of root growth reduction caused by ABA.

Journal Article↗

PubMed2003

Effect of hormone replacement therapy on lacrimal fluid peroxidase activity in woman.

OBJECTIVE: Lacrimal fluid peroxidase (POD) is an antioxidant and antimicrobial enzyme involved in the protection of the ocular surface. Our recent findings showed the existence of significant cyclic variations in POD activity that were positively correlated with those of 17beta-estradiol plasma levels throughout the menstrual cycle of fertile women. During the menopause, women lacrimal fluid POD activity significantly (P<0.05) decreased according to the natural oestrogen reduction. Since a possible influence of oestrogen on human POD activity was suggested, aim of the present investigation is to evaluate whether hormone replacement therapy (HRT) might influence this enzyme activity. METHODS: Lacrimal fluid POD activities of 10 healthy postmenopausal women (mean age: 52.0) and eight healthy postmenopausal women (mean age: 53.0) treated by oral or transdermal routes containing oestrogen or oestrogen plus progestin were determined. Enzyme activity of each tear sample (5 microl) was spectrophotometrically determined by the 5,5'-dithiobis, 2-nitrobenzoic acid thiocyanate (NBS-SCN) assay; total protein content of tears was determined too. 17beta-Estradiol plasma levels were assayed by ELISA test. RESULTS: HRT significantly (P<0.05) increased tear POD low postmenopausal levels. The significant (P<0.05) rise of 17beta-estradiol plasma levels of treated women was not strictly correlated to the enzyme activity increase in tears. CONCLUSIONS: The suggested estrogen regulation of lacrimal fluid POD activity could be one possible cause for the female gender predilection in some ocular diseases. HRT is able to increase tear POD activity levels of postmenopausal women, probably contributing to the effective relieve of ocular surface complications occurring during menopause.

Estradiol↗

PubMed2004

Allergenic properties of roasted peanut allergens may be reduced by peroxidase.

Peanut allergy is a public health issue. The culprits are the peanut allergens. Reducing the allergenic properties of these allergens or proteins will be beneficial to allergic individuals. In this study, the objective was to determine if peroxidase (POD), which catalyzes protein cross-linking, reduces the allergenic properties of peanut allergens. In the experiments, protein extracts from raw and roasted defatted peanut meals at pH 8 were incubated with and without POD in the presence of hydrogen peroxide at 37 degrees C for 60 min. The POD-treated and untreated samples were then analyzed by SDS-PAGE, western blots, and competitive inhibition ELISA. IgE binding or allergenicity was determined in blots and ELISA. Results showed that POD treatment had no effect on raw peanuts with respect to protein cross-linking. However, a significant decrease was seen in the levels of the major allergens, Ara h 1 and Ara h 2, in roasted peanuts after POD treatment. Also, polymers were formed. Despite this, a reduction in IgE binding was observed. It was concluded that POD induced the cross-linking of mainly Ara h 1 and Ara h 2 from roasted peanuts and that, due to POD treatment, IgE binding was reduced. The finding indicates that POD can help reduce the allergenic properties of roasted peanut allergens.

Allergens↗

PubMed2005

Purification and partial characterization of broccoli (Brassica oleracea Var. Italica) peroxidases.

Three peroxidase (POD) isoenzymes were purified from a soluble extract of broccoli stems. The acidic and neutral PODs were purified to homogeneity by using ion exchange and hydrophobic chromatography. The basic POD was purified by cation exchange and gel filtration chromatography. The neutral and basic PODs had molecular masses of approximately 43 kDa, and the acidic POD had a molecular mass of 48 kDa by SDS-PAGE. pI was approximately 4, 5, and 8 for acidic, neutral, and basic PODs, respectively. Optimum activity using guaiacol as the H donor was obtained at pH approximately 6 for both neutral and basic PODs and at pH approximately 4 for acidic POD. All three of the purified isoenzymes are glycosylated. Reaction rates with various substrates including guaiacol, guaiacol/MBTH, DMAB/MBTH, and ferulic acid/MBTH were different among the isoenzymes. K(m) and amino acid composition were also determined.

Amino Acids↗

PubMed2002

Perioperative changes in carbonylhemoglobin and methemoglobin during abdominal surgery: alteration in endogenous generation of carbon monoxide.

BACKGROUND: Carbon monoxide (CO), which is homologous to nitric oxide (NO) as a monoxide, has been recently studied as a novel gaseous mediator for the maintenance of circulatory homeostasis and as a regulator of organ functions. Abdominal surgery is supposed to modulate the gaseous mediator by the reduction of heme oxygenase (HO) activity or transcriptional regulation of inducible HO. Therefore, we investigated perioperative changes in CO generation during abdominal surgery. METHODS: A total of 397 patients who received abdominal surgery under intubation anesthesia were studied retrospectively by spectrophotometric analysis of carbonylhemoglobin (COHb) and methemoglobin (metHb) in arterial blood obtained at three points: before operation; several hours after return from operation room (0 POD); and next morning (1 POD). Thirty-three splenectomies, 36 hepatectomies and 42 drainages with control of infection focus for peritonitis were compared with 286 controls. The influences of smoking and blood transfusion were disregarded in the analysis, because smoking and blood transfusion were shown to increase exogenous and endogenous CO, respectively. RESULTS: In the non-smoker control group without blood transfusion, COHb did not change during the perioperative period, while metHb increased from the preoperative value of 0.52 +/- 0.03 to 0.72 +/- 0.02 at 0 POD and returned to 0.45 +/- 0.03 mg/dL at 1 POD. In the splenectomy group, COHb decreased from the preoperative value of 1.63 +/- 0.36 to 1.19 +/- 0.20 and 1.13 +/- 0.26 mg/dL at 0 and 1 POD, respectively, as a result of the removal of the organ with high HO activity. In the splenectomy group MetHb remained low: 0.47 +/- 0.09 mg/dL at 0 POD as compared with the control value. In the peritonitis and hepatectomy groups, COHb did not change during the perioperative period, while metHb increased to 0.64 +/- 0.06 and 0.73 +/- 0.10 mg/dL at 1 POD, respectively, as compared with the control value. In the hepatectomy group with or without blood transfusion, however, COHb and metHb were higher at 1 POD than the corresponding control value. CONCLUSION: Changes in COHb and metHb concentrations in arterial blood occur during abdominal surgery, although these amplitudes are small when compared with CO intoxication and methemoglobulinemia. It is likely that organ perfusion and functions are affected by these monoxide gas mediators during abdominal surgery.

Abdomen↗

PubMed2005

Disability and breathlessness in asthmatic patients--a scoring method by repetitive inspiratory effort.

Measurement of disability and breathlessness in asthma is important to guide treatment. Using an incentive spirometer, Triflo II (Tyco Healthcare, Mansfield, MA, USA), we developed a three-minute respiratory exercise test (3-MRET) to score the maximal breathing capacity (MBC) and perception of dyspnea (POD) index by means of repetitive inspiratory efforts achieved within 3 minutes. POD index was calculated based on the ratio of breathlessness on visual analogue scale over MBC score. In 175 normal healthy subjects and 158 asthmatic patients of mild (n = 26), moderate (n = 78), and severe (n = 54), severity, the mean (95% CI) MBC scores in mild, moderate, and severe asthma patients were 168 (145-192), 153 (136-169), and 125 (109-142) respectively, and 202 (191-214) in normal subjects (p < 0.001). The mean POD index in mild, moderate, and severe asthma patients was 16 (9-23), 25 (14-37), and 57 (14-100), respectively, and 6 (4-7) in normal subjects (p < 0.001). Intraclass correlation coefficients for MBC score and POD index in 17 asthmatic and 20 normal subjects were high. In 14 asthmatic patients randomized to receiving nebulized beta2-agonist or saline in a cross-over, double-blind study, % forced expiratory volume in one second (FEV1) change correlated with % change in MBC score [r(s) = 0.49, p < 0.01] and POD index [r(s)-0.46, p = 0.012]. In 21 asthmatic and 26 normal subjects, the MBC score and POD index correlated with the walking distance and walking POD index of the six-minute walking test (6MWT). We conclude that 3MRET is discriminative between asthmatic patients of varying severity and normal subjects, is reproducible, is responsive to bronchodilator effect, and is comparable with 6MWT. Taken together, it has the potential to score disability and POD in asthma simply and effectively.

Adrenergic beta-Agonists↗

PubMed1999

Ineffectiveness of burst suppression therapy in mitigating perioperative cerebrovascular dysfunction. Multicenter Study of Perioperative Ischemia (McSPI) Research Group.

BACKGROUND: Cerebral injury is among the most common and disabling complications of open heart surgery. Attempts to provide neuroprotection have yielded conflicting results. We assessed the potential of propofol-induced burst suppression during open heart surgery to provide cerebral protection as determined by postoperative neuropsychologic function. METHODS: Two hundred twenty-five patients undergoing valve surgery were randomized to receive either sufentanil or sufentanil plus propofol titrated to electroencephalographic burst suppression. Blinded investigators performed neurologic and neuropsychologic testing at baseline, postoperative day (POD) 1 (neurologic testing only), PODs 5-7, and PODs 50-70. Neuropsychologic tests were compared with the results of 40 nonsurgical patients matched for age and education. RESULTS: Electroencephalographic burst suppression was successfully achieved in all 109 propofol patients. However, these patients sustained at least as many adverse neurologic outcomes as the 116 controls: POD 1, 40% versus 25%, P = 0.06; PODs 5-7, -18% versus 8%, P = 0.07; PODs 50-70, -6% versus 6%, P = 0.80. No differences in the incidence of neuropsychologic deficits were detected, with 91% of the propofol patients versus 92% of the control patients being impaired at PODs 5-7, decreasing to 52 and 47%, respectively, by PODs 50-70. No significant differences in the severity of neuropsychologic dysfunction, depression, or anxiety were noted. CONCLUSIONS: Electroencephalographic burst suppression surgery with propofol during cardiac valve replacement did not significantly reduce the incidence or severity of neurologic or neuropsychologic dysfunction. The authors' results suggest that neither cerebral metabolic suppression nor reduction in cerebral blood flow reliably provide neuroprotection during open heart surgery. Other therapeutic approaches must be evaluated to address this important medical problem.

Adult↗

PubMed1998

The extracellular matrix: an early target of preservation/reperfusion injury and acute rejection after small bowel transplantation.

BACKGROUND: Endothelial cells are known to be an early target of preservation/reperfusion injury and acute rejection, whereas the extracellular matrix (ECM) may also play an equally important role in the sequelae of both events. METHODS: Syngeneic and allogeneic rat small bowel transplantations (SBTX) were performed after 6 hr of preservation. Animals were subsequently killed at defined time points for determination of ECM parameters within the graft and in plasma. RESULTS: Laminin levels were significantly increased 20 min after reperfusion (syngeneic SBTX: 357+/-65.9 ng/ml; allogeneic SBTX: 361+/-79.6 ng/ml; P< or =0.01). After syngeneic transplantation, laminin levels normalized by postoperative day (POD) 7, whereas there was a rejection-induced increase after allogeneic SBTX (POD 7: 179+/-60.1 ng/ml; POD 9: 333+/-13.6 ng/ml; P< or =0.01 vs. syngeneic SBTX). This increase was accompanied by an increase in tumor necrosis factor-alpha levels at POD 9. Hyaluronic acid levels were significantly elevated after 24 hr (syngeneic SBTX: 1086+/-176 microg/L; allogeneic SBTX: 918+/-108 microg/L; P< or =0.01). After syngeneic SBTX, hyaluronic acid levels normalized by POD 7, whereas persistently higher levels were observed after allogeneic SBTX. Immunohistochemistry confirmed early changes (20 min after reperfusion) at the ECM. Anti-laminin and anti-CD44 staining normalized at POD 5 after syngeneic SBTX. After allogeneic SBTX, rejection-specific changes were evident with anti-laminin staining commencing on POD 5 and progressing until POD 9. At similar time points, increased expression of fibronectin- and interferon-gamma-positive material was evident. CONCLUSIONS: The ECM can be considered to be an early target of preservation/reperfusion injury and acute rejection. Plasma parameters reliably reflected the changes observed within the graft. Laminin and hyaluronic acid levels may be used as indicators of initial graft function. Furthermore, the increase in laminin levels was an early indicator of acute rejection. Determination of these parameters may significantly improve monitoring after SBTX.

Animals↗

PubMedDate not supplied

A model "go-kit" for use at Strategic National Stockpile Points of Dispensing.

The Strategic National Stockpile (SNS) is a national repository of pharmaceuticals and other medical supplies forseeably needed during a medical disaster. In the event of SNS deployment, state and local public health authorities must be prepared to receive, distribute, and dispense the materials. We propose a cache of supplies, termed the "POD go-kit," prepared in advance and locally available prior to the establishment of Points of Dispensing (POD) for SNS material. Characteristics of the preassembled go-kit are its multiplicity of use, ease of storage and transportation, minimal redundancy with SNS material, and packaging in a manner consistent with POD function. The POD go-kit is assembled into 4 separate "subkits": administrative supplies, patient routing supplies, dispensing supplies, and POD staff protection supplies. Incorporating existing practices from the SNS Listserv, this article itemizes the contents of the POD go-kit and its subkits and provides a rationale for its packaging. The Division of Strategic National Stockpile (DSNS) has not certified the proposed "POD go-kit" as a standardized POD go-kit.

Disasters↗

PubMed1978

Enzymology of Glutamine Metabolism Related to Senescence and Seed Development in the Pea (Pisum sativum L.).

The metabolism of glutamine in the leaf and subtended fruit of the aging pea (Pisum sativum L. cv. Burpeeana) has been studied in relation to changes in the protein, chlorophyll, and free amino acid content of each organ during ontogenesis. Glutamine synthetase [EC 6.3.1.2] activity was measured during development and senescence in each organ. Glutamate synthetase [EC 2.6.1.53] activity was followed in the pod and cotyledon during development and maturation. Maximal glutamine synthetase activity and free amino acid accumulation occurred together in the young leaf. Glutamine synthetase (in vitro) in leaf extracts greatly exceeded the requirement (in vivo) for reduced N in the organ. Glutamine synthetase activity, although declining in the senescing leaf, was sufficient (in vitro) to produce glutamine from all of the N released during protein hydrolysis (in vivo). Maximal glutamine synthetase activity in the pod was recorded 6 days after the peak accumulation of the free amino acids in this organ.In the young pod, free amino acids accumulated as glutamate synthetase activity increased. Maximal pod glutamate synthetase activity occurred simultaneously with maximal leaf glutamine synthetase activity, but 6 days prior to the corresponding maximum of glutamine synthetase in the pod. Cotyledonary glutamate synthetase activity increased during the assimilatory phase of embryo growth which coincided with the loss of protein and free amino acids from the leaf and pod; maximal activity was recorded simultaneously with maximal pod glutamine synthetase.We suggest that the activity of glutamine synthetase in the supply organs (leaf, pod) furnishes the translocated amide necessary for the N nutrition of the cotyledon. The subsequent activity of glutamate synthetase could provide a mechanism for the transfer of imported amide N to alpha amino N subsequently used in protein synthesis. In vitro measurements of enzyme activity indicate there was sufficient catalytic potential in vivo to accomplish these proposed roles.

Journal Article↗

PubMed1983

Light and Shade Effects on Abscission and C-Photoassimilate Partitioning among Reproductive Structures in Soybean.

Field experiments were conducted in 1981 and 1982 to study the effects of low-irradiance supplemental light on soybean (Glycine max [L.] Merr. cv Evans) flower and pod abscission. Cool-white and red fluorescent lights illuminated the lower part of the soybean canopy during daylight hours for 3 weeks late in flowering. At the same time, flowers and young pods on half the plants were shaded with aluminum foil. Flowers were tagged at anthesis and monitored through abscission or pod maturity.Responses to red and white lights were similar. Supplemental light tended to reduce abscission and increase seed weight per node compared to natural light. Shading flowers and pods increased abscission and reduced seed weight per node. Number of flowers produced per node, individual seed weight, and seeds per pod were not affected by light or shade treatments.Further studies examined the effects of shading reproductive structures on their capacity to accumulate (14)C-photoassimilates. Individual leaves were pulse labeled with (14)CO(2) 1, 2, and 4 weeks post anthesis. Flowers and pods in the axil of the labeled leaf were covered with aluminum foil 0, 24, 72, and 120 hours before pulsing.Shading flowers and pods resulted in a 30% reduction in the relative amount of radiolabel accumulated from the source leaf. The reduction in (14)C accumulation due to shading was evident regardless of the length of the shading period and was most pronounced when the shades were applied early in reproductive development. We conclude that light perceived by soybean flowers and young pods has a role in regulating both their abscission and their capacity to accumulate photoassimilates.

Journal Article↗

PubMed2001

Genetic basis of variation of yield, and yield components in mungbean (Vigna radiata (L.) Wilczek).

Additive, dominance, and epistasis genetic basis of seed yield per plant, number of pods per plant, number of seeds per pod, and 1000 seed weight in mungbean (Vigna radiata (L.) Wilczek) have been examined, using Triple Test Cross (TTC) analysis. The material for TTC test was evaluated in two seasons i.e., kharif (July-October) and spring/summer (March-June), at the research station of the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan. Epistasis was present significantly for number of pods per plant and number of seeds per pod when grown in the spring/summer season (March to June). Partition of epistasis showed that additive x additive ('i' type) interaction was an important component of number of pods per plant, and number of seeds per pod was found to be of both types 'i' type, and additive x dominance, and dominance x dominance ('j' and 'l' type) interactions. This indicated that epistasis might be a non-trivial factor in the inheritance of pods per plant, and seeds per pod in mungbean. The expression of epistasis was influenced differentially by particular genotypes, indicating that a limited number of genotypes may not be sufficient to detect non-allelic interactions for a trait in mungbean. Additive and dominance genetic components were significant for all four traits in kharif season (July to October) but only for seed yield and 1000 seed weight in spring/summer season. This suggests that the genes controlling seed yield per plant, and 1000 seed weight are equally sensitive to the environment. The predominance additive gene action in those traits is not significantly influenced by epistasis, suggesting that improvement of the traits can be achieved through standard selection procedures.

Biometry↗