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PubMed1979

[Improvement of male fertility through ligation of varicocele? A study of 100 subfertile varicocele patients three months after ligation (author's transl)].

With 100 subfertile varicocele patients, three months after ligation (high ligation of the left internal spermatic vein in accordance with Bernardi) had control spermiograms made. An improvement of sperm count (upgrade in a higher class according to MacLeod's partition) was found in 28% of the cases, whereas an improvement of progressive motility was found only in 13%. The percentage of patients reaching the normal value in sperm count of over 40 mill./ml increased from 23% to 39%. The increase in these patients came primarily from the class of 20--40 mill./ml. In progressive motility, there was an increase of patients reaching the standard value of over 40%, from 6 to 11. However, if sperm count and progressive motility together were evaluated in the individual patients after ligation, only 6 patients presented a normospermia, i.e. a sperm count of more than 40 mill./ml with normal progressive motility. Thus 94 of the 100 patients must be considered as subfertile three months after ligation. A significant fertility improvement through ligation of varicocele has not yet taken place.

Adult↗
PubMed1995

[Clinical evaluation of endoscopic variceal ligation (EVL) using an intensive ligation method].

Endoscopic variceal ligation using an intensive ligation method, or intensive EVL, as we call it, was performed in 17 cases of esophageal varices, from August 1993 to November 1994. Intensive EVL involves making as many ligations as possible from just above the esophago-gastric junction at every session for the complete eradication of varices (F0 and negative Red color sign). Our success rate for the complete eradication of varices was 82.4% (14 out of 17 cases) with the mean number of sessions at 2.2 +/- 0.5 times. The total number of rubber bands used was 20.2 +/- 8.4, with 14.1 +/- 6.0 being used in the initial session alone. The rate of recurrence in complete eradicated cases was 50% (7 out of 14 cases) and the period to recurrence was 6.3 +/- 0.7 months. Although EVL using the intensive ligation method is useful for complete eradication of varices, a high incidence of recurrence in the short term is a concern. We conclude therefore that it is difficult to achieve long term complete eradication of varices with EVL alone, and that additional therapy is needed for long term control.

Adult↗
PubMed1991

HMG 14 and protamine enhance ligation of linear DNA to form linear multimers: phosphorylation of HMG 14 at Ser 20 specifically inhibits intermolecular DNA ligation.

HMG 14 and protamine can be used to enhance intermolecular ligation of low concentrations of linear DNA. Adding HMG 14 (50 moles per mole DNA) caused 50% of blunt-ended DNA to form predominantly dimers, and all cohesive-ended DNA to form multimers (greater than 6-mer) in response to T4 ligase. Protamine was maximally effective at 40:1, producing mostly dimers and trimers. Adding higher concentrations of HMG 14 did not affect the ligation pattern of cohesive-ended DNA, while higher concentrations of protamine inhibit the formation of multimers. Phosphorylation of HMG 14 at Ser 20 by Ca(++)-phospholipid dependent protein kinase abolished the ability of HMG 14 to stimulate intermolecular ligation, but did not substantially interfere with intramolecular ligation, or the binding of HMG 14 to linear or circular DNA as assessed by gel mobility. Thus Ser 20, which is located in the amino terminal DNA-binding domain of HMG 14, appears to modulate DNA-DNA interactions.

Animals↗
PubMed1989

Tubal ligation at cesarean delivery in five Asian centers: a comparison with tubal ligation soon after vaginal delivery.

Increasingly more tubal sterilizations are being performed at the time of cesarean section in the United States and probably also in developing countries. This descriptive study provides us with hitherto unavailable information on the impact of this combined procedure on the women undergoing it. Five Asian centers were included for study. In these centers, 618 women had concurrent tubal ligation at cesarean section in 1973 and 1974. During this period, 3399 women had tubal ligation soon after term vaginal deliveries. The much higher morbidity and mortality in the former group were judged to be attributable to the indications leading to, or the complications of, cesarean section and not to the concurrent tubal ligation. Women undergoing the combined procedure of tubal ligation and cesarean section were more likely to have characteristics associated with later regretting the sterilization.

Adult↗
PubMed1994

A comparative study of conventional ligation and self-ligation bracket systems.

The increased use of self-ligating bracket systems frequently raises the question of how they compare with conventional ligation systems. An in vitro and clinical investigation was undertaken to evaluate and compare these distinctly different groups, by using five different brackets. The Activa ("A" Company, Johnson & Johnson, San Diego, Calif.), Edgelok (Ormco, Glendora, Calif.), and SPEED (Strite Industries Ltd., Cambridge, Ontario) self-ligating bracket systems displayed a significantly lower level of frictional resistance, dramatically less chairtime for arch wire removal and insertion, and promoted improved infection control, when compared with polyurethane elastomeric and stainless steel tie wire ligation for ceramic and metal twin brackets.

Ceramics↗
PubMed2006

Sugar-assisted ligation of N-linked glycopeptides with broad sequence tolerance at the ligation junction.

A novel method for the synthesis of N-linked glycopeptides using the sugar-assisted ligation strategy from cysteine free peptides is presented. The ligation junction tolerates a variety of amino acids, favoring less hindered amino acids and those with side chains that could serve as a general base in the ligation pathway. Since our approach allows the ligation of difficult junctions, the method could be applied to the synthesis of large peptides by enzymatic removal of the sugar moiety. Alternatively, more complex glycopeptides can be synthesized using glycosyltransferases. Together, this sequence of reactions should be amenable to the synthesis of glycopeptides and glycoproteins and their deglycosylated products.

Carbohydrates↗
PubMed1983

Polymer-stimulated ligation: enhanced blunt- or cohesive-end ligation of DNA or deoxyribooligonucleotides by T4 DNA ligase in polymer solutions.

The rates of blunt-end and cohesive-end ligation of DNA by T4 DNA ligase are increased by orders of magnitude in the presence of high concentrations of a variety of nonspecific polymers such as polyethylene glycol, Ficoll, bovine plasma albumin, or glycogen. Blunt-end ligation of small self-complementary oligodeoxyribonucleotides is also stimulated. The use of polyethylene glycol 6000 in such systems is characterized in some detail. Conditions are suggested which either greatly increase the rate of formation of and size of linear ligation products or which allow smaller but significant improvements in the amounts of circular ligation products.

DNA↗
PubMed2003

Evaluation of low ligation and high ligation procedures of varicocele.

OBJECTIVE: To describe the mode of presentation of varicocele and to compare the low ligation (Inguinal approach/Ivanissevich's procedure) and high ligation (Retroperitoneal approach/modified Palomo's procedure) of varicocele repair regarding efficacy and postoperative complications. DESIGN: Institutional-based randomized comparative clinical trial. PLACE AND DURATION OF STUDY: This study was conducted at the Urology Department, Bolan Medical College and Sandeman Provincial Teaching Hospital, Quetta from December 1996 to November 2001 (5 years). SUBJECTS AND METHODS: A total of 213 patients of varicocele who underwent treatment in the department and completed 6 months follow-up were included in the study. The mode of presentation of varicocele was recorded for all patients. For treatment purpose patients were randomly divided into two groups: in group I (n: 115) varicocele was ligated by inguinal approach (Ivanissevich's procedure) while in group II (n: 98) by retroperitoneal approach (modified Palomo's procedure). The efficacy and postoperative complications of the two procedures were carefully recorded and compared between the two groups. RESULTS: The mean age of the patients of group-I and group-II was 27.2 and 27.5 years respectively. More than 50% patients of both groups presented with feeling of heaviness/dragging sensation on ipsilateral side. Presentation with infertility/sub fertility in group-I and group-II was 16.5% and 15.3% respectively. Majority of patients of both groups had grade III varicocele with visible deformity. The rate of postoperative complications was very low in both groups of patients. Recurrence of varicocele and postoperative hydrocele formation were slightly more common in group-II as compared to group-I but the difference was statistically not significant (p>0.05). An extremely significant improvement occurred postoperatively in both sperms density and motility in infertile/sub fertile patients of both groups. CONCLUSION: Both procedures of varicocele repair are equally effective and have a low rate of complications. There is no significant difference in postoperative complications. An extremely significant improvement occurs in semen parameters of infertile/sub fertile patients postoperatively, irrespective of method/technique of varicocelectomy

Adolescent↗
PubMed2000

Hemorrhoid banding using videoendoscopic anoscopy and a single-handed ligator: an effective, inexpensive alternative to endoscopic band ligation.

OBJECTIVE: We evaluated a technique of hemorrhoid banding using videoscopic anoscopy and a single-handed ligator that offers substantial cost savings over endoscope-mounted devices. METHODS: Patients with rectal bleeding from grade II/III hemorrhoids had videoscopic anoscopy, which provided a magnified view, allowing accurate localization of the hemorrhoids and the dentate line before banding, and a photographic record, if required. Banding was performed using a suction ligator that could be operated by one hand, allowing the other to control the anoscope. RESULTS: Of 39 patients with second- and third-degree hemorrhoids, 34 (87%) had no further bleeding after a single banding session and a further three had no recurrence after a second session. The only complications were pain (one patient) and infection (one patient). CONCLUSIONS: This method is convenient and effective, costing per procedure less than one-tenth of endoscope-mounted band ligators. We recommend its use in preference if magnified views and a photographic record are required. However, its cost and complexity, compared with traditional hemorrhoid banding, may mean that the latter is preferred in the office setting.

Adult↗
PubMed2000

To ligate or not to ligate the hernial sac in adults?

OBJECTIVE: Prospective evaluation of the long term effect of leaving the hernial sac open without ligation on the recurrence rate of indirect inguinal hernia repair. METHODS: During the period from July 1987 to July 1990, a total of 60 consecutive patients with 64 indirect inguinal hernia were entered into this prospective study. The indirect inguinal hernia was repaired using Maloney technique with excision of the hernial sac proximally as deep as possible without any attempt to ligate or transfix the sac. All patients were followed up at regular intervals. RESULTS: During the 3-year period, a total of 64 indirect inguinal hernia in 60 consecutive patients were repaired. Their ages ranged between 15-85 years (mean of 50 years). The follow up ranged from 9-12 years (a mean of 10 years and 5 months). Four patients died of unrelated causes. There was no clinically documented case of recurrence in the remaining 56 patients. CONCLUSION: This study, although not controlled, confirmed that non-ligation of the proximal sac during indirect hernia repair was not associated with an increase rate of recurrence.

Adolescent↗
PubMed2001

[Laparoscopic varicocele ligation. The comparative assessment of artery-ligating and artery-preserving varicocelectomy].

For over ten years more and more significant role in the diagnostics and clinical treatment of marital infertility have been ascribed to the male factor, which accounts for 30-40% of infertility cases. One of the most common reasons of male infertility is varicocele. Between the years 1994-2000 transperitoneal laparoscopic varicocelectomy was performed in 166 men with unilateral varicoceles. Two methods of surgical correction were administered. In I group--88 men (53%)--testicular artery and vein were ligated, in II group--78 men (47%) only testicular vein was ligated. The success of the treatment was evaluated in two age groups; A--19-30 and B--31-41 years of age. Before the operation in group I and II the sperm count was respectively 18.19?10.51 and 19.05 +/- 10.62 x 10(6)/ml. The percentage of the progressive motility was 18.95 +/- 9.46% in I group and 20.12 +/- 9.08% in II group. The percentage of normal forms was 22.04 +/- 8.42% in I group and 23.02 +/- 9.81% in II group. After 12 months of surgical observation the sperm count was 35.21 +/- 13.46 in I and 31.82 +/- 12.14 x 10(6)/ml, in II group. The percentage of progressive motility increased to 36.48 +/- 15.76% in I group and to 31.26 +/- 10.78% in II group. In both groups the percentage of normal forms was comparable, in I group was 49.11 +/- 26.72% and in II group was 47.15 +/- 17.18%. In both age groups sperm count before operation was respectively: 20.42 +/- 10.20 in A, and 16.42 +/- 9.16 x 106/ml in B. The percentage of progressive motility was in A and B respectively 22.98 +/- 9.91% and 15.38 +/- 9.66%. At percentage of normal forms was respectively 25.62 +/- 8.92 and 18.81 +/- 7.93%. In the end of observation period the improvement of sperm count was observed in A--42.69 +/- 22.36, in B--22.86 +/- 11.76 x 10(6)/ml. The improvement of progressive motility was ia A--43.27 +/- 23.96% and in B--23.09 +/- 17.01%. The improvement of normal forms were in A--55.39 +/- 24.31% and 39.69 +/- 22.29 in group B. The pregnancy rate was; in I group +/- 30.6% in II group--23.1%, in A group--33.3%, in B--group--19.7%. The laparoscopic ligation of the testicular vein and artery produced better improvement of semen characteristics and percentage of pregnancies in comparison with artery sparing technique. The laparoscopic varicocelectomy regardless of the technique allows a significant improvement of semen characteristics and pregnancy rate among the couples, where men were less than 30 years of age.

Adult↗
PubMed1978

Influence of fasting period, ligation time, sex, age and bodyweight on the gastric secretory response of pylorus-ligated Wistar rats.

A study on variables influencing the gastric secretory response of pylorus-ligated Wistar rat, shows that: 1. 24 h is a sufficient fasting period for satisfactory emptying of the stomach, periods of up to 48 h yielding no advantage; 2. between 2 and 4 h is the most appropriate pyloric ligation time because in this range there are no variations in volume of gastric secretion, concentration and output of acid per unit of ligation time; 3. sex has no influence on any of the parameters; 4. animals should be age-selected because only above a given age threshold the gastric secretory response per unit of bodyweight is constant.

Aging↗
PubMed1993

Foot volumetry can predict recurrent ulceration after subfascial ligation of perforators and saphenous ligation.

PURPOSE: The purpose of this study was to determine whether foot volumetry is of value in predicting the outcome after superficial venous surgery for chronic venous ulceration. METHODS: Fifty-three patients who underwent subfascial ligation of perforating veins with or without saphenous vein ligation for recurrent venous ulceration had foot volumetry performed before operation, immediately after operation (1 month), and at regular intervals during follow-up (median 60, range 3 to 144 months). RESULTS: Fourteen patients (26%) had recurrent ulceration (median time to recurrence 48, range 10 to 72 months) and 39 patients remained ulcer free. Before operation expulsion fraction (EF) and half refilling time (HRT) were significantly higher in the no recurrence group. Both groups gained improvement in EF and HRT from their surgery; however, although this was sustained in the no recurrence group, by the time of first recurrence in the recurrence group, EF and HRT had returned to preoperative levels. CONCLUSIONS: Preoperative foot volumetry can therefore predict failure after subfascial perforator and saphenous vein ligation, probably by identifying patients with deep venous incompetence. After operation deterioration in foot volumetry and can also be used to predict the onset of recurrent ulceration.

Adult↗
PubMed1990

Crystal structures of phosphonoacetamide ligated T and phosphonoacetamide and malonate ligated R states of aspartate carbamoyltransferase at 2.8-A resolution and neutral pH.

The T----R transition of the cooperative enzyme aspartate carbamoyltransferase occurs at pH 7 in single crystals without visibly cracking many of the crystals and leaving those uncracked suitable for single-crystal X-ray analysis. To promote the T----R transition, we employ the competitive inhibitors of carbamoyl phosphate and aspartate, which are phosphonoacetamide (PAM) and malonate, respectively. In response to PAM binding to the T-state crystals, residues Thr 53-Thr 55 and Pro 266-Pro 268 move to their R-state positions to bind to the phosphonate and amino group of PAM. These changes induce a conformation that can bind tightly the aspartate analogue malonate, which thereby effects the allosteric transition. We prove this by showing that PAM-ligated T-state crystals (Tpam), space group P321 (a = 122.2 A, c = 142.2 A), when transferred to a solution containing 20 mM PAM and 8 mM malonate at pH 7, isomerize to R-state crystals (Rpam,mal,soak), space group also P321 (a = 122.2 A, c = 156.4 A). The R-state structure in which the T----R transition occurs within the crystal at pH 7 compares very well (rms = 0.19 A for all atoms) with an R-state structure determined at pH 7 in which the crystals were initially grown in a solution of PAM and malonate at pH 5.9 and subsequently transferred to a buffer containing the ligands at pH 7 (Rpam,mal,crys). In fact, both of the PAM and malonate ligated R-state structures are very similar to both the carbamoyl phosphate and succinate or the N-(phosphonoacetyl)-L-aspartate ligated structures, even though the R-state structures reported here were determined at pH 7. Crystallographic residuals refined to 0.16-0.18 at 2.8-A resolution for the three structures.

Amino Acid Sequence↗
PubMed1998

Y-ligation: an efficient method for ligating single-stranded DNAs and RNAs with T4 RNA ligase.

Very efficient ligation of oligodeoxyribonucleotides was attained through a simple molecular construct, which is composed of one stem and two branches (Y-shape), with use of T4 RNA ligase. Single-stranded DNAs (naturally, RNAs also) of more than 100 nucleotides (even 800 nts) were considerably ligated, approximately as theoretically expected. Owing to the molecular construct adopted, such a tiny amount of ligation products could be amplified to a sufficient amount by PCR and then recovered as single-stranded DNAs. This advantage of being amplifiable is shown to be useful for both combinatorial chemistry and evolutionary molecular engineering, which deal with a pool of diversity molecules.

Biomedical Engineering↗
PubMed1996

Domain-specific interactions between entactin and neutrophil integrins. G2 domain ligation of integrin alpha3beta1 and E domain ligation of the leukocyte response integrin signal for different responses.

Extracellular matrix proteins activate neutrophils to up-regulate many physiologic functions that are necessary at sites of tissue injury. To elucidate the ligand-receptor interactions that mediate these functions, we examined neutrophil activation by the basement membrane protein, entactin. Entactin is structurally and functionally organized into distinct domains; therefore, we utilized glutathione S-transferase -fusion proteins encompassing its four major domains, G1, G2, E, and G3, to assess interactions between entactin and neutrophil integrin receptors. We show that the E domain, which contains the single RGD sequence of entactin, is sufficient for ligation of the beta3-like integrin, leukocyte response integrin, and signaling for chemotaxis. Moreover, the G2 domain signals for stimulation of Fc receptor-mediated phagocytosis via ligation of alpha3beta1. This receptor-ligand interaction was revealed only after stimulation of neutrophil by immune complexes or phorbol esters. Interestingly, the E domain does not enhance phagocytosis, and the G2 domain is not chemotactic. Furthermore, cleavage of entactin with the matrix metalloproteinase, matrilysin, liberates peptides that retain E domain-mediated chemotaxis and G2 domain-mediated enhancement of phagocytosis. These studies indicate that multiple domains of entactin have the ability to ligate individual integrins expressed by neutrophils and to activate distinct functions.

Antigen-Antibody Complex↗
PubMed2005

Combination endoscopic band ligation and sclerotherapy compared with endoscopic band ligation alone for the secondary prophylaxis of esophageal variceal hemorrhage: a meta-analysis.

Endoscopic band ligation (EBL) is the community-accepted standard therapy for the secondary prophylaxis of esophageal variceal hemorrhage. Recent data indicate that combination EBL and sclerotherapy may be a more effective therapy than EBL alone. Yet existing data are conflicting. We therefore performed a meta-analysis to compare the efficacy and safety of EBL and sclerotherapy versus EBL alone for the secondary prophylaxis of esophageal variceal hemorrhage. We performed a systematic review of two computerized databases (MEDLINE and EMBASE) along with manual-searching of published abstracts to identify relevant citations without language restrictions from 1990 to 2002. Eight studies met explicit inclusion criteria. We performed meta-analysis of these studies to pool the relative risk for the following outcomes: esophageal variceal rebleeding, death, number of endoscopic sessions to achieve variceal obliteration, and therapeutic complications. There were no significant differences between EBL and sclerotherapy versus EBL alone in the risk of esophageal variceal rebleeding (RR = 1.05; 95% CI = 0.67-1.64; P = 0.83), death (RR = 0.99; 95% CI = 0.68-1.44; P = 0.96), or number of endoscopic sessions to variceal obliteration (RR = 0.23; 95% CI = 0.055-0.51; P = 0.11). However, the incidence of esophageal stricture formation was significantly higher in the EBL group than in the sclerotherapy group. There is no evidence that the addition of sclerotherapy to endoscopic band ligation changes clinically relevant outcomes (variceal rebleeding, death, time to variceal obliteration) in the secondary prophylaxis of esophageal variceal hemorrhage. Moreover, combination EBL and sclerotherapy had more esophageal stricture formation than EBL alone.

Esophageal and Gastric Varices↗
PubMed2006

Administration of r-VEGF-A prevents hepatic artery ligation-induced bile duct damage in bile duct ligated rats.

The hepatic artery, through the peribiliary plexus, nourishes the intrahepatic biliary tree. During obstructive cholestasis, the nutritional demands of intrahepatic bile ducts are increased as a consequence of enhanced proliferation; in fact, the peribiliary plexus (PBP) displays adaptive expansion. The effects of hepatic artery ligation (HAL) on cholangiocyte functions during cholestasis are unknown, although ischemic lesions of the biliary tree complicate the course of transplanted livers and are encountered in cholangiopathies. We evaluated the effects of HAL on cholangiocyte functions in experimental cholestasis induced by bile duct ligation (BDL). By using BDL and BDL + HAL rats or BDL + HAL rats treated with recombinant-vascular endothelial growth factor-A (r-VEGF-A) for 1 wk, we evaluated liver morphology, the degree of portal inflammation and periductular fibrosis, microcirculation, cholangiocyte apoptosis, proliferation, and secretion. Microcirculation was evaluated using a scanning electron microscopy vascular corrosion cast technique. HAL induced in BDL rats 1) the disappearance of the PBP, 2) increased apoptosis and impaired cholangiocyte proliferation and secretin-stimulated ductal secretion, and 3) decreased cholangiocyte VEGF secretion. The effects of HAL on the PBP and cholangiocyte functions were prevented by r-VEGF-A, which, by maintaining the integrity of the PBP and cholangiocyte proliferation, prevents damage of bile ducts following ischemic injury.

Animals↗