Asynchronous telehealth visits for the treatment of overactive bladder

OBJECTIVE

Overactive bladder affects 17% of women, and adherence to treatment is notoriously low. The objective of this pilot study is to investigate the efficacy and feasibility of the use of asynchronous telehealth visits for the treatment of women with overactive bladder.

METHODS

This is a pilot study of women who participated in the asynchronous telehealth program with a new diagnosis of overactive bladder presenting to the Massachusetts General Hospital from January of 2020 to March of 2021. Pre-post differences in Urogenital Distress Inventory score-6, and Incontinence Severity Index Scores were compared with paired t tests as coprimary endpoints. To assess potential mechanisms of association between asynchronous visits and patient-reported outcomes, total fluid intake, caffeinated beverage consumption, urinary frequency, episodes of urinary leakage were also compared as secondary endpoints.

RESULTS

A total of 23 women participated, with 50 e-visits completed. The first asynchronous visit was completed after a median of 42days (IQR 36, 51.5) from the initial visit. There was a decrease in the Urogenital Distress Inventory-6 score between the first asynchronous visit and the last (29 points, IQR 16, 37 vs 12 points, IQR 12, 25), respectively (P = 0.014). Similar findings were seen with the Incontinence Severity Index questionnaire, from three (IQR 2, 4) to three (IQR 1, 3) after the asynchronous visit (P = 0.002).

CONCLUSION

We demonstrate the feasibility of asynchronous visits for the treatment of overactive bladder. Although our results suggest efficacy, given the prepost change in overactive bladder-related questionnaire scores following asynchronous visits, the comparative effectiveness of asynchronous visits versus regular care needs to be confirmed in a randomized trial.

Decision aids and shared decision making in urogynecology

OBJECTIVES

To examine the efficacy and acceptability of decision aids (DAs) in counseling urogynecology patients with prolapse, stress urinary incontinence, or refractory overactive bladder.

METHODS

This pilot study enrolled 33 patients into a control group that underwent usual care without a DA, followed by 33 patients into an intervention group where providers utilized a DA for counseling. Postvisit patient surveys assessed differences in treatment preference, knowledge, and in patient-physician collaboration using SURE, CollaboRATE, and Shared Decision Making (SDM) Process scales. Postvisit provider surveys assessed their perception of the usefulness and the difficulty of using a DA and visit length. Independent t tests were used for continuous variables (Knowledge and SDM Process scores) and Chi-Square for categorical variables (treatment preference, SURE, and CollaboRATE).

RESULTS

The majority of eligible patients 66/71 (93%) completed the survey. The intervention group trended toward higher knowledge scores (72% vs 60%, P  = 0.06), clearer treatment preferences (85% vs 67%, P  = 0.08), higher rates of top SURE scale scores (91% vs 73%, P  = 0.11), and top CollaboRATE scores (75% vs 52%, P  = 0.07). SDM process scores were similar across groups (3.2 vs 3.2, P  = 0.96). Providers used the DA in 73% of intervention group visits and rated the visit length as "normal" in both groups (70% vs 76%, P  = 0.78).

CONCLUSIONS

There were no statistically significant differences between the control group and the intervention group. The use of DAs was acceptable to providers and indicated a trend toward increased patient knowledge, treatment preference, and satisfaction. A larger study is warranted to examine the impact of DAs on decision making and patient experience.

Cohort study of impact on length of stay of individual enhanced recovery after surgery protocol components

Objective

The goal of this study was to explore which enhanced recovery after surgery (ERAS) bundle items were most associated with decreased length of stay after surgery, most likely associated with decreased length of stay after surgery.

Design

A cohort study.

Setting

Large tertiary academic medical centre.

Participants

The study included 1318 women undergoing hysterectomy as part of our ERAS pathway between 1 February 2018 and 30 January 2020 and a matched historical cohort of all hysterectomies performed at our institution between 3 October 2016 and 30 January 2018 (n=1063).

Intervention

The addition of ERAS to perioperative care.

This is a cohort study of all patients undergoing hysterectomy at an academic medical centre after ERAS implementation on 1 February 2018. Compliance and outcomes after ERAS roll out were monitored and managed by a centralised team. Descriptive statistics, multivariate regression, interrupted time series analysis were used as indicated.

Main outcome measures

Impact of ERAS process measure adherence on length of stay.

Results

After initiation of ERAS pathway, 1318 women underwent hysterectomy. There were more open surgeries after ERAS implementation, but cohorts were otherwise balanced. The impact of process measure adherence on length of stay varied based on surgical approach (minimally invasive vs open). For open surgery, compliance with intraoperative antiemetics (−30%, 95% CI −18% to 40%) and decreased postoperative fluid administration (−12%, 95% CI −1% to 21%) were significantly associated with reduced length of stay. For minimally invasive surgery, ambulation within 8 hours of surgery was associated with reduced length of stay (−53%, 95% CI −55% to 52%).

Conclusions

While adherence to overall ERAS protocols decreases length of stay, the specific components of the bundle most significantly impacting this outcome remain elusive. Our data identify early ambulation, use of antiemetics and decreasing postoperative fluid administration to be associated with decreased length of stay.

In patients with rectoceles and obstructed defecation syndrome, surgery should be the option of last resort

BACKGROUND

The indications for operation in patients with obstructed defecation syndrome (ODS) with rectocele are not well defined.

METHODS

A total of 90 female patients with ODS and rectocele were prospectively evaluated and treated with fiber supplements and biofeedback training. Univariate and multivariate regression was used to determine factors predictive of failing medical management.

RESULTS

Obstructive symptoms were the most prevalent presenting complaint (82.2%). Ultimately, 71.1% of patients responded to medical management and biofeedback. Multivariate regression analysis suggested that the presence of internal intussusception was associated with a lower chance of undergoing surgery to address ODS symptoms [odds ratio 0.18; P = .05], whereas inability to expel balloon, contrast retention on defecography, and splinting were not (P ≥ .15).

CONCLUSION

Rectoceles with concomitant intussusception in patients with ODS appear to portend a favorable response to biofeedback and medical management. We argue that all patients considered for surgery for rectoceles because of ODS should first undergo appropriate bowel retraining.

Are rectoceles the cause or the result of obstructed defaecation syndrome? A prospective anorectal physiology study

AIM

To determine the relationship between obstructed defaecation syndrome (ODS) and rectoceles.

METHOD

From December 2007 to November 2011, all female patients with ODS were prospectively evaluated with full interview, clinical examination and anorectal physiology testing. The characteristics of patients with and without rectoceles were compared, and logistic regression was utilized to identify factors predictive of patients having a rectocele beyond the introitus.

RESULTS

Of 239 patients with ODS, 90 (mean age: 52.3 ± 1.7 years) had a rectocele. Patients with rectoceles (R+) had a similar prevalence of incomplete emptying compared with patients with no rectocele (R-) (P ≥ 0.21), but only R+ patients reported splinting with defaecation (36.7% vs 0%; P < 0.0001). Anorectal manometry measurements, including mean resting pressure, maximum resting pressure and maximum squeeze pressure, were similar between groups (P ≥ 0.12). There were also no significant differences in rectal compliance (maximum tolerated volume) or rectal sensitivity (volume of first sensation) (P ≥ 0.65). R+ patients had greater difficulty expelling a 60 cm(3) balloon (70.1% R+ patients vs 57.5% R- patients; P = 0.05), but the prevalence of pelvic floor dyssynergia, as quantified by nonrelaxation on electromyography (EMG) testing, was similar to that of R- patients (P = 0.49). Logistic regression suggested that only difficulty with balloon expulsion was associated with higher odds of having a rectocele (OR = 3.00; P = 0.002), whereas mean resting pressure, EMG nonrelaxation and symptoms of incomplete emptying were not (P ≥ 0.12).

CONCLUSION

Rectoceles are not associated with an increased severity of ODS-type symptoms, anorectal abnormalities or pelvic floor dyssynergia in patients with ODS. This suggests that rectoceles may be the result, rather than the cause, of ODS.

Studies on the molecular mechanism of the interactions between the cyanobacterial transcription factor, SmtB, and its recognition DNA sequences

Tolerance to the heavy-metal ion stress in cyanobacterial cell is regulated by the transcriptional repressor SmtB that senses the Zn/Cd concentration in the cell. SmtB regulated the transcriptional level of class II metallothionein, SmtA. There are two recognition DNA sequences (Bbs1 and Bbs2) in the operator/promoter region of smtA gene. To clear the functional meaning of the presence of these two sequences, we have compared the affinities of native and point-mutated SmtBs to these two sites. We also have compared the sizes of the protein-DNA complexes being formed with these two sites. SmtB forms protein-DNA complex in an unique size with Bbs1, in three different sizes with Bbs2. We have further designed the modified Bbs1 and Bbs2 sequences, and the results obtained with these sequences indicate that the differences observed between the cases of Bbs1 and Bbs2 are caused by the presence of direct repeat sequence and the differences in the linker sequences.

2',5'-oligoadenylate synthetase gene in chicken: gene structure, distribution of alleles and their expression

We have cloned the gene for chicken 2',5'-oligoadenylate synthetase (ChOAS) by the method of polymerase chain reaction with use of ChOAS cDNA sequence. The ChOAS gene is composed of five introns and six exons containing all of the sequence of the ChOAS cDNA from the start to the stop codon. The first five exons of ChOAS gene which encode the OAS catalytic domain have a similar structure to HuOAS1 gene including the exon-intron boundaries. However, the length of introns of ChOAS gene is only 1/7 of those of HuOAS1 gene. The sixth exon of the ChOAS gene encodes the ubiquitin-like (UbL) domain of two consecutive sequence (UbL1 and UbL2) homologous to ubiquitin. ChOAS encoded in a single copy gene has at least two alleles, OAS(*)A and OAS(*)B. The differences between these two alleles are in the sixth exon of the gene; a 96-nucleotide sequence in the UbL1 portion of OAS(*)A is deleted from OAS(*)B. No OAS(*)B gene was detected in nine lines of chickens tested other than Leghorns. Almost the same levels of ChOAS-A and -B proteins induced physiologically in erythrocytes were detected in infant chickens (2-week-old), but in grown-up chickens (6-month-old) the level of erythrocyte OAS-B was markedly reduced in most of B/B chickens. Thus, the UbL domain of ChOAS is responsible for the maintenance of the OAS level in the tissue.

Hereditary persistent right oviduct in the chicken PNP/DO line

Hereditary, persistent, right oviduct manifested in an inbred line (PNP/DO line) from the Fayoumi breed of chickens was investigated for form of expression and mode of inheritance. Females in the PNP/DO line have varying lengths of elongated right oviducts, besides the normal left ovary, and oviducts that generally possess, irrespective of their total length, regions similar to those normally observed in a left oviduct. Observations of embryos indicated that the existence of right oviduct in this line could be attributed to the slow regression of right Müllerian duct during the embryonic stage, and left-right asymmetry in female genital system is intrinsic in this line. Intracrosses of the PNP/DO line produced 93% of female embryos with persistent right Müllerian ducts at the next generation, and reciprocal crosses of the PNP/DO line and control strains produced 5 and 30% of female embryos with persistent right Müllerian ducts in the F1 and N2 generations, respectively. Mating results suggested that this mutant trait is controlled by two pairs of autosomal recessive genes with major effects and numerous loci that have minor effects. Thus, expression of this trait is due to the interaction of major loci and the background genotype.

Required structure of cationic peptide for oligonucleotide-binding and -delivering into cells

Improvement of the methods for oligonucleotide delivery into cells is necessary for the development of antisense therapy. In the present work, a new strategy for oligonucleotide delivery into cells was tested using cationic peptides as a vector. At first, to understand what structure of the peptide is required for binding with an oligonucleotide, several kinds of alpha-helical and non-alpha-helical peptides containing cationic amino acids were employed. As a result, the amphiphilic alpha-helix peptides were best for binding with the oligonucleotide, and the long chain length and large hydrophobic region in the amphiphilic structure of the peptide were necessary for the binding and forming of aggregates with the oligonucleotide. In the case of non-alpha-helical peptides, no significant binding ability was observed even if their chain lengths and number of cationic amino acid residues were equal to those of the alpha-helical peptides. The remarkable ability of oligonucleotide delivery into COS-7 cells was observed in the alpha-helical peptides with a long chain length and large hydrophobic region in the amphiphilic structure, but was not observed in the non-alpha-helical peptides. It is considered that such alpha-helical peptides could form optimum aggregates with the ODN for uptake into cells. Based on these results, the alpha-helical peptide with a long chain length and large hydrophobic region is applicable as a vector for the delivery of oligonucleotides into cells.

[An autopsy case of thymic carcinoma producing various tumor markers and the examination of 222 autopsy cases of thymic malignant tumor in Japan]

The autopsy of a 76-year-old Japanese female patient, which revealed thymic carcinoma with various tumor markers such as NSE, CYFRA, and CA-125, is presented. The patient died from hepatic failure because the liver was overtaken by the tumors. At autopsy, the thymic carcinoma was found to have metastased only in the liver. From microscopical analyses and electron microscopical findings, we diagnosed poorly differenciated squamous cell carcinoma of thymic origin. In the histochemical analyses, the tumor cells were positively stained in CA 125, CA 19-9, EMA, NSE, AE 1, AE 3, CEA, S-100, glimerius and Bcl-2. These date suggest that the tumor cells produced various tumor markers. In 222 autopsy cases of thymic malignant tumor observed in Japan over a period of 4 years, the dominant pathohistological image was squamous cell carcinoma. It is interesting that the greatest number of combined malignant tumors with thymic malignancies were thyroid papillary carcinomas.

Expression of two Trichoderma reesei xylanases in the fission yeast Schizosaccharomyces pombe

Two xylanase genes (xyn1 and xyn2) were amplified by the polymerase chain reaction (PCR) technique from first-strand cDNA prepared from mRNA of Trichoderma reesei QM9414. The genes were located under the human cytomegalovirus gene promoter (CMVp) on copy-number-controlled plasmids (pTLxyn1 and pTLxyn2). When both plasmids were introduced into Schizosaccharomyces pombe, functional xylanases (XYN I and XYN II) were secreted by the recombinant yeasts. The secreted XYN I protein had a molecular mass of 21 kDa whereas XYN II was produced as two molecular forms with sizes of 21 and 28 kDa, the former being not glycosylated and the latter N-glycosylated. XYN I was secreted in the culture medium at a level of about 25 microg/ml and XYN II at about 170 microg/ml. The recombinant xylanases had the same characteristics with respect to the effects of temperature and pH on the enzyme activity as the native ones.

[Changes in intraoperative blood glucose and ketone body concentrations during the repair of lipomyelomeningocele in children]

Blood glucose and ketone body (3-hydroxy-butyrate) concentrations were measured in 8 children (4.2 +/- 2.8 years old) during the repair of lipomyelomeningocele (9.0 +/- 2.6 hours) to elucidate whether lipid mobilization can be prevented by glucose infusion at the rate of 0.2 +/- 0.05 g.kg-1.h-1. The operation was followed in about 4 hours by a significant increase in blood glucose and ketone body concentrations, with their maximum value of 195 +/- 75 mg.dl-1 and 656 +/- 75 mumol.l-1, respectively (P < 0.05), as compared with the preoperative level. The lipid mobilization soon returned to normal state by increasing the rate of glucose infusion, as indicated by ketone body level of 92 +/- 58 mumol.l-1 at the end of operation. These results show that glucose infusion rate should be adjusted based on serial analysis of both blood sugar and ketone body concentrations in the anesthetic management of children undergoing a long operation.

Mixed connective tissue disease complicated by pneumatosis cystoides intestinalis and malabsorption syndrome: case report and literature review

A case of mixed connective tissue disease (MCTD) in a female with positive ribonucleoprotein antibody and overlapped manifestations of systemic lupus erythematosus and dermatomyositis is presented. During the last 9 years of her 13 year clinical course, she repeatedly manifested abdominal distension, pneumoperitoneum and malabsorption syndrome. She died, aged 54 years, of respiratory failure secondary to pulmonary compression from marked abdominal distention. Autopsy revealed esophageal fibrosis with ulceration and the typical appearance of pneumatosis cystoides intestinalis (PCI), in association with atrophy and fibrosis of the inner circular muscle layer of the small bowel. The association of PCI with MCTD is reviewed briefly.

[Effects of prostaglandin E1 on temperature gradients between hand and foot during epidural anesthesia]

We studied the effects of prostaglandin E1 (PGE1) on hand-foot temperature gradients (foot temperature-hand temperature) induced by lumbar epidural anesthesia. Thirty-six ASA class 1 patients undergoing rotatory acetabular osteotomy were randomly assigned to receive 0 gamma (n = 13), 0.005 gamma (n = 10) and 0.02 gamma (n = 13) of PGE1. Thermometric probes were placed on the palm and sole of each patient. Bladder temperature was also monitored to evaluate the change of core temperature. Epidural catheter was indwelled at the level between L2 and L3 prior to induction and 2 % lidocaine was administered epidurally. All patients were warmed by water blanket at 37 degrees C and fluids for infusion warmed at 37 degrees C. Humidity and moisture exchanger was placed in breathing circuit. Hand-foot temperature gradients of patients given 0 and 0.005 gamma of PGE1 increased to 2.8 +/- 1.5 and 2.3 +/- 2.3 degrees C at extubation, respectively. In contrast, temperature gradient of patients given 0.02 gamma of PGE1 was 0.0 +/- 1.8 degrees C (P < 0.01). There was no difference among the values of bladder temperature in each group. The effects of PGE1 on mean arterial pressure, heart rate and central venous pressure were minimal. These data suggest that 0.02 gamma of PGE1 administration is effective to reduce hand-foot temperature gradient during epidural anesthesia.

[Anesthesia for a patient with red cell aldolase deficiency]

Aldolase deficiency of red blood cell is a rare cause of hereditary hemolytic anemia and now there exists only three patients in the world. We had a 24-year-old man operated on for gallbladder stone secondary to this uncommon disease. He underwent a cholecystectomy under general anesthesia combined with thoracic epidural block, using isoflurane, fentanyl, vecuronium, midazolam and lidocaine. During the surgery serum concentrations of bilirubin, free hemoglobin and LDH showed no change, suggesting a lower incidence of drug-induced hemolysis in the case of aldolase deficiency than in other enzyme deficiency. This fact also provides a useful guide to the choice of anesthetics and related agents. In the postoperative period, however, we found a hemolytic response to fever with a drop in hemoglobin level to 2.5 g.dl-1. Aldolase activity of his red cell is heat labile and an increase in body temperature may aggravate a disturbance in the glycolytic pathway leading to hemolytic crisis. It is thus important to prevent the body temperature from rising when a patient is suffering from hemolytic anemia due to red cell aldolase deficiency.

[Optimal glucose dose in the preoperative fluid infusion]

We have measured blood concentrations of glucose, 3-hydroxybutyrate (3-OHBA), non-esterified fatty acid (NEFA) and lactate before and after glucose administration in 105 patients to determine the optimal glucose dose during the period of preoperative fasting state. The patients, scheduled for laparotomy in the afternoon, received fluid infusion containing an arbitrary glucose dose for 4 hours prior to surgery. The glucose dose showed a negative correlation with the ratio of 3-OHBA or NEFA prior to and after glucose administration (r = 0.40, r = 0.41 respectively, P < 0.05). There was no correlation between lactate ratio and glucose dose (r = 0.06). Glucose administration more than 0.4 g.kg-1 significantly suppressed 3-OHBA production (P < 0.05). Hyperglycemia (> 200 mg.dl-1) developed more often in the groups given 0.5 g.kg-1 or more glucose (P < 0.05), while significant hypoglycemia (< 60 mg.dl-1) occurred in the groups given less than 0.2 g.kg-1 of glucose (P < 0.05). This study demonstrates that preoperative infusion of glucose 0.4-0.5 g.kg-1 is useful to maintain the energy metabolism during the fasting state in patients scheduled for operation in the afternoon.

[Effects of prostaglandin E1 on renal function during deliberate hypotension with epidural anesthesia]

We studied the effects of prostaglandin E1 (PGE1) on renal function during and after deliberate hypotension induced by epidural anesthesia. Twenty-seven ASA class 1 patients undergoing rotatory acetabular osteotomy were divided into three groups according to the dose of PGE1. Deliberate hypotension was induced and maintained during the surgery by epidural anesthesia combined with general anesthesia. PGE1 increased urine output and creatinine clearance (Ccr) during hypotension in dose dependent manner, and the changes were statistically significant compared with control at the dose of 0.02 micrograms.kg-1 x min-1 (gamma). PGE1 also tended to increase postoperative urine output and Ccr. Regardless of PGE1 administration, urine NAG/Cr ratio tended to increase during and after deliberate hypotension. Though total dose of local anesthetics was attenuated by PGE1, serum catecholamine levels of all patients were within normal ranges. In conclusion, PGE1 0.02 gamma is effective to maintain urine output during deliberate hypotension with epidural anesthesia. However, PGE1 is unlikely to prevent renal tubular damage at the dose less than 0.02 gamma.

[Effect of combined spinal and epidural anesthesia on blood loss during total hip replacement]

Ninety total hip replacements (THRs) performed by one surgeon were reviewed to compare the effects of different anesthetic techniques on the perioperative bleeding. Half of the THRs were performed under either combined spinal and epidural (CSE) anesthesia with lidocaine or general anesthesia with N2O/O2, vecuronium, enflurane or isoflurane. Deliberate hypotensive technique was not employed in any THR. All patients were female and had suffered from osteoarthritis of the hip joints. The patients in the two anesthesia groups were similar as to age, body weight, height, perioperative hemoglobin level, duration of anesthesia and operation, and blood transfusion requirement. A positive linear correlation existed between total operative blood loss and operation time in each group (P < 0.01). The rate of operative blood loss was significantly higher in the CSE anesthesia (6.2 +/- 3.0 ml.min-1) than in the general anesthesia (5.1 +/- 2.0 ml.min-1), while the amount of blood loss itself was without statistical difference. A significant increase in total volume of perioperative blood loss was also observed in the group with CSE anesthesia (1520 +/- 90 ml) compared with the general anesthesia group (1279 +/- 58 ml). These results show that spinal and/or epidural anesthesia can not always lead to reductions in operative blood loss during THR.

[Anesthetic problems in patients with Forestier's disease]

We have studied common problems associated with the anesthetic management of Forestier's disease in 8 patients undergoing neurosurgery. This disease is a systemic degenerative disorder and is characterized by osteo-spur formation at anterior spinal body. In two of eight patients the trachea was intubated with great difficulty even by well-trained anesthesiologist. Its cause could be found not only in limited cervical mobility but also in constrained epiglottic elevation, suggesting that Forestier's disease requires special anesthetic considerations. It is thus important to predict the possibility of difficult tracheal intubation on both physical examination and the preoperative X-ray photography.

[The catecholamine concentrations of collected autologous blood during adrenalectomy for pheochromocytoma]

We have studied the concentrations of catecholamines in collected autologous blood. The measured levels of the blood samples from Cell-stat collecting chamber were epinephrine 4.74 ng.ml-1 and norepinephrine 2.39 ng.ml-1. First wash of collected blood with 700 ml of saline diluted the catecholamine concentrations to epinephrine 3.13 ng.ml-1 and norepinephrine 1.6 ng.ml-1. The concentrations of catecholamines after second wash were epinephrine 2.19 ng.ml-1 and norepinephrine 1.11 ng.ml-1. These values were three to twenty folds of normal ranges even after the second wash, and still the same levels as intraoperative plasma catecholamine (the measured values; epinephrine 0.81-2.81 ng.ml-1 and norepinephrine 0.96-3.15 ng.ml-1). Since platelets actively concentrate catecholamines during their life span, the destruction of platelets by suction or centrifugation may probably play the most important role in the elevation of catecholamine concentrations in the collected autologous blood. We concluded that intraoperative autotransfusion in the resection of pheochromocytoma is likely to result in the elevation of systemic blood pressure by catecholamines of the transfused blood.

[Combined spinal and epidural anesthesia for orthopaedic surgery in the elderly]

The pros and cons as to which anesthesia is more beneficial, either spinal or epidural, prompted us to perform combined spinal and epidural block in the elderly undergoing lower limb surgery. The selected epidural space was entered with a 17-gauge Tuohy needle and a longer 26-gauge spinal needle was passed through it and into the subarachnoid space. Following the injection of required dose of 2% preservative-free lidocaine (isobaric), spinal needle was withdrawn and an epidural catheter was inserted. We could use this combined technique on 17 patients older than 80 yr (mean age; 84.5 +/- 3.9 years) with satisfactory results and without any serious cardiovascular change, as with 17 middle-aged patients (57.5 +/- 5.2 years). This combination of techniques provides a rapid onset and reliability of spinal block with high quality analgesia by supplementation through the epidural catheter during and after surgery. In the orthopaedic procedures on the lower limbs, combined spinal and epidural block is more useful even for the elderly over the age of 80 yr than spinal or epidural anesthesia alone.

[The effects of thromboxane receptor antagonist on hemodynamic responses after neutralization of heparin by protamine]

In a double blind test, the effects of ONO 3708, thromboxane A2 (TXA2) receptor antagonist, on hemodynamic responses after neutralization of heparin by protamine, were evaluated in 19 patients undergoing coronary artery bypass graft. Severe circulatory disturbances were not observed in all patients after intravenous administration of protamine (3 mg.kg-1) over 5 minutes, and in particular ONO 3708 (2.5 micrograms.kg-1.min-1 given with continuous infusion) group (n = 10) showed no deleterious hemodynamic responses to protamine. On the other hand, in placebo group (n = 9) the mean pulmonary artery pressure (mPAP) and the mean pulmonary/systemic artery pressure ratio (Pp/Ps) increased significantly, immediately following protamine administration, compared with the baseline values and ONO 3708 group. The results suggest that pulmonary hypertension after protamine is associated with TXA2 release and that ONO 3708 is useful to avoid this reaction.

Pulmonary hypertensive response to declamping of the aorta during abdominal aortic reconstructive surgery-role of metabolic derangement and anaphylatoxin in the reaction

Metabolic parameters and anaphylatoxin activities in mixed venous blood were measured in 16 patients undergoing abdominal aortic reconstructive surgery to study the mechanism of pulmonary hypertensive response after aortic declamping. This reaction was confirmed by a rise in ratio between mean pulmonary arterial pressure and mean systemic arterial pressure (Pp/Ps). Aortic declamping was followed by a significant increase in lactate level and lactate-pyruvate ratio (L/P ratio) as compared with pre-declamping level ( P << 0.01). Although anaphylatoxin C3a concentration rose significantly after declamping ( P << 0.01), C5a showed no change at any stage. When the patients were divided into two groups according to the degree of Pp/Ps change by declamping, significant elevation of L/P ratio and C3a level were observed in the group with higher increase (Post-/Pre-declamp value >/=1.25) of Pp/Ps compared to the lower (>>1.25) group. After declamping, in the higher Pp/Ps group, a positive correlation existed not only between Pp/Ps change and aortic clamp time, but also between L/P ratio and C3a level. The present results suggest that muscular metabolic derangement distal to the aortic clamp may play an important role in the development of post-declamping pulmonary hypertensive response through anaphylatoxin C3a.

Kinetic anomalies in chymotryptic hydrolyses of p-nitrophenyl acetate and N-benzoyl-L-alanine methyl ester

Kinetic and thermodynamic parameters were evaluated for the acylation and the deacylation steps in the hydrolysis of p-nitrophenyl acetate by alpha-chymotrypsin at pH 7.8 and at temperatures between 15 and 35 degrees C by the use of stopped-flow and ordinary ultraviolet spectrophotometers. In contrast to the temperature dependencies of k2 and Ks reported in the literature (P.A. Adams and E.R. Swart, Biochem. J., 161, 83 (1977], no kinetic anomaly was observed in either of the steps, but reasonable straight lines were obtained in both Arrhenius and van't Hoff plots. On the other hand, in the chymotryptic hydrolysis of N-benzoyl-L-alanine methyl ester a sharp kinetic anomaly was found. The discrepancy in the case of p-nitrophenyl acetate is discussed in connection with a possible conformational change of the enzyme, an alteration of the rate-limiting step or differences in the experimental procedures. The cause of the anomaly observed in the case of N-benzoyl-L-alanine methyl ester is also discussed in detail.

Effects of anesthetic and related agents on calcium-induced calcium release from sarcoplasmic reticulum isolated from rabbit skeletal muscle

We have investigated the effects of anesthetic and related agents on Ca(2+)-induced Ca2+ release (CICR) in heavy sarcoplasmic reticulum isolated from rabbit skeletal muscle. The purpose of this study is to elucidate their possible role as triggering agents in malignant hyperthermia (MH). None of the agents (ketamine, procaine, lidocaine, succinylcholine, pancuronium and fentanyl) affected CICR at clinical concentrations. At higher concentrations, procaine, pancuronium and succinylcholine inhibited CICR, but ketamine rather potentiated it. It is unlikely that lidocaine is a potent facilitator of CICR at any concentrations. We conclude that procaine, lidocaine, non-depolarizing muscle relaxants and opiate can be used safely for MH susceptible patients and that ketamine and succinylcholine are not recommended.

Combined effects of succinylcholine and calcium on membrane-bound acetylcholinesterase activity

The effects of succinylcholine and calcium (Ca2+), alone and together, on membrane-bound acetylcholinesterase ("true-type" cholinesterase) were examined using human erythrocyte ghosts to elucidate the combined pharmacological activity of succinylcholine and calcium in in vivo system. Succinylcholine inhibited the acetylcholinesterase by a mixed style. Calcium alone exhibited an inhibitory effect on the enzyme, but a biphasic effect together with succinylcholine: marked restoration of the enzyme activity at calcium concentrations lower than 6 mM and depression at its higher concentrations. It is suggested that calcium induces a conformational change of the enzyme protein leading to the altered binding capacity of succinylcholine. In anesthetic practice, therefore, the use of calcium may not be indicated for the treatment of SCh phase II block.