Effect of polymorphonuclear leukocyte-derived oxygen free radicals and hypochlorous acid on cardiac function and some biochemical parameters

Polymorphonuclear (PMN) leukocyte activation is known to result in the production and release of oxygen free radicals and hypochlorous acid. Various clinical conditions are associated with PMN leukocyte stimulation. The present investigation deals with the effects of stimulated PMN leukocytes in the absence and in the presence of scavengers of oxygen free radicals (superoxide dismutase, catalase), hypochlorous acid quencher (methionine), and myeloperoxidase inhibitor (azide) on cardiac function and contractility; blood lactate, gases, and pH levels, blood and cardiac tissue malondialdehyde; and PMN leukocyte chemiluminescence activity in anesthetized dogs. Opsonised zymosan was used for stimulation of PMN leukocytes, and the effects were observed for 2 hours. The dogs were divided into four groups: group I, zymosan; group II, superoxide dismutase + catalase + zymosan; group III, methionine + zymosan; group IV, azide + methionine + zymosan. Zymosan produced a decrease in cardiac function and in indices of myocardial contractility and an increase in systemic and pulmonary vascular resistance. There was a decrease in blood pH and in PMN leukocyte chemiluminescense and an increase in the blood lactate and malondialdehyde. Superoxide dismutase plus catalase and methionine reduced the effect of zymosan on cardiac function and contractility and on blood malondialdehyde, lactate, and pH. The combination of azide and methionine did not prevent the deleterious effects of zymosan on cardiac function and contractility. Cardiac tissue malondialdehyde levels were lower in groups III and IV than in groups I and II which had values similar to each other. Methionine was superior to superoxide dismutase plus catalase in the prevention of the deleterious effects of PMN leukocyte stimulation on the various measured parameters. These results suggest that oxygen free radicals and hypochlorous acid are cardiac depressants and increase systemic and pulmonary vascular resistance in addition to causing tissue damage. Clinical situations with PMN stimulation may result in cardiac depression. The oxygen free radical scavenger and hypochlorous acid quencher may be beneficial in the counteraction of the deleterious effects of PMN leukocyte stimulation on the hemodynamic parameters and cellular integrity.

Study of quinalphos (an environmental oestrogenic insecticide) formulation (Ekalux 25 E.C.)-induced damage of the testicular tissues and antioxidant defence systems in Sprague-Dawley albino rats

The effect of quinalphos (O-O-diethyl-O-[quinoxalinyl-(2)-thionophosphate]), an environmental oestrogenic organophosphorus insecticide pollutant, was studied on Sprague-Dawley albino rats at doses of 250 and 500 microgram kg(-1) body wt. i.p. for 3, 8 and 15 days, respectively. After the treatment with quinalphos there was an increase in the lipid peroxides (as measured by manoldialdehyde production) and a decrease in the total lipid content for the testicular membrane. The effects were more pronounced at the low doses than at the higher doses, indicating that some physiological defence mechanisms were in operation at higher doses. The free-radical-scavenging enzymes (superoxide dismutase, catalase and glutathione peroxidase) showed significantly higher activity at high dose in comparison to their activities at low-dose treatment. Glutathione content was gradually reduced after quinalphos treatment, both in low and high doses. Histomorphohological studies showed that after the low-dose treatment shrinkage of the tubular diameter and testicular atrophy leading to degenerative changes in the germinal epithelium were observed. But at high dose, gradual recovery of various germ cell layers and significant expansion of seminiferous tubules of Sprague-Dawley rat testes were found; the latter is generally believed to be a useful index of testicular activity through the hypothalamo-hypophyseal-gonadal axis. The present study indicates that quinalphos caused damage and degeneration of the testicular tissues due to free-radical-mediated lipid peroxidation at low doses. We have also demonstrated that, in response to the damage, an endogenous antioxidant enzyme defence system became operative at the higher dose of treatment.

Digestive enzymes and metabolic profile of Labeo rohita fingerlings fed diets with different crude protein levels

Labeo rohita, commonly called rohu is one of the most important fish species for aquaculture in India. Digestive enzyme response and metabolic profile of fingerling L. rohita to different dietary crude protein (CP) levels (viz. 25, 30, 35 and 40%) were studied in an attempt to optimize a practical diet formulation for this species. After 45 days of feeding, activity of digestive enzymes and metabolite concentrations were assayed. Amylase, lipase and alkaline phosphatase (ALP) activities were not influenced by the dietary protein, but proteolytic and acid phosphatase (ACP) activities varied (P<0.05) between the treatments. Proteolytic activity showed a second order polynomial relationship with dietary crude protein (CP) as Y = 0.0734X(2) + 4.937X - 68.37, r(2)=0.97. A positive correlation was observed between dietary CP and amylase (r(2)=0.78). All the metabolites except muscle glucose showed significant change corresponding to the dietary protein levels. Glucose and glycogen levels corresponded to the dietary carbohydrate levels. Muscle and plasma pyruvic acid increased as the crude protein in the diet increased, whereas liver pyruvic acid showed the opposite trend. Muscle protein content was not affected by dietary CP. Protein fractions in plasma (total protein, albumin and globulin) showed maximum values in 30% CP fed group. It is concluded that proteolytic activity and ACP are the major digestive enzymes responsive to dietary CP in L. rohita fingerlings. Considering the cost effectiveness of the diet, and based on liver and plasma free amino acid levels and plasma protein fractions, 30% crude protein is recommended as the optimal dietary protein for L. rohita fingerlings.

Interactions of berberine with poly(A) and tRNA

The interaction of berberine chloride with poly(A) and tRNA has been studied by various spectroscopic techniques. Binding parameters determined from spectrophotometric and spectrofluorimetric measurements by Scatchard analysis indicate a very high effective binding capacity of berberine to poly(A) as compared to DNA or tRNA. The circular dichroism studies show that binding of berberine to poly(A) causes a significant change in the circular dichroic spectrum of poly(A) itself, as manifested by (i) a decrease of both positive and negative bands and (ii) appearance of a conservative type of extrinsic circular dichroic spectrum in the wavelength range of 300-400 nm, while it does not cause any significant alteration to the A form structure of tRNA. It is concluded that berberine interacts stronger with poly(A) than DNA or tRNA. The results are interpreted in terms of its reported biological activities.

Guidelines, compliance, and effectiveness: a 12 months' audit in an acute district general healthcare trust on the two week rule for suspected colorectal cancer

OBJECTIVES

The Department of Health had recently introduced guidelines so that all suspected colorectal cancer patients could be seen by a specialist within two weeks of referral by their general practitioners. The usefulness and practicality of such a decision had been questioned. The aims of this study were to measure the compliance to the guidelines and evaluate the effectiveness of such referrals.

METHODS

All patients who were referred to the rapid access colorectal clinic between August 2000 and July 2001 were included.

SETTINGS

Darlington Memorial Hospital and Bishop Auckland General Hospital, both under South Durham Health Care Trust, were considered for the study.

MEASURES

Date of referral, referring practitioner, time of appointment, reasons for referral, and diagnosis.

RESULTS

A total of 239 referrals were made; 96.2% of patients were given appointments within two weeks. Rectal bleed was the commonest (32%) cause for referral. Diverticular disease was the most frequent (29%) condition diagnosed. Altogether 97.4% of referrals were incomplete and 37.6% did not comply with the guidelines. Twenty one colorectal cancers (8.9%) were diagnosed. The early cancer detection rate was 4.6%.

CONCLUSIONS

This audit showed that compliance to the guidelines was associated with a higher cancer detection rate. The majority of patients received appointments within two weeks. Contrary to some speculations, the number of referrals was not limitless. However a high number of referrals failed to adhere to the guidelines. The cancer (particularly early cancer) detection rate was disappointingly low. This does not reflect an efficient system of referral and potential benefits to patients remain questionable.

Circular dichroism studies of the structure of DNA complex with berberine

The binding of the benzodioxolo-benzoquinolizine alkaloid, berberine chloride to natural and synthetic DNAs has been studied by intrinsic and extrinsic circular dichroic measurements. Binding of berberine causes changes in the circular dichroism spectrum of DNA as shown by the increase of molar ellipticity of the 270nm band, but with very little change of the 240nm band. The molar ellipticity at the saturation depends strongly on the base composition of DNA and also on salt concentration, but always larger for the AT rich DNA than the GC rich DNA. The features in the circular dichroic spectral changes of berberine-synthetic DNA complexes were similar to that of native DNA, but depends on the sequence of base pairs. On binding to DNA and polynucleotides, the alkaloid becomes optically active. The extrinsic circular dichroism developed in the visible absorption region (300-500nm) for the berberine-DNA complexes shows two broad spectral bands in the regions 425-440nm and 340-360nm with the maximum varying depending on base composition and sequence of DNA. While the 425nm band shows less variation on the binding ratio, the 360nm band is remarkably dependent on the DNA/alkaloid ratio. The generation of the alkaloid associated extrinsic circular dichroic bands is not dependent on the base composition or sequence of base pairs, but the nature and magnitude of the bands are very much dependent on these two factors and also on the salt concentration. The interpretation of the results with respect to the modes of the alkaloid binding to DNA are presented.

Thermodynamics of the interaction of berberine with DNA

The interaction of berberine [7,8,13,13a-tetrahydro-9-10-dimethoxy-2,3-(methylene dioxy)-berberinium] with calf thymus DNA has been studied by spectrophotometry in buffers of various salt concentrations and temperatures. Binding parameters obtained are best fit by the neighbour exclusion model. The salt and temperature dependence of the binding constants are used to estimate thermodynamic parameters involved in the complex formation of berberine with DNA. The binding process is exothermic over the entire range and the values of enthalpy and entropy change are strongly dependent on the salt concentration. The negative enthalpy and positive entropy changes compensate one another to produce a relatively small Gibbs' free energy change. Possible molecular contribution to the enthalpy and entropy changes is discussed.

Structural changes of horseradish peroxidase in presence of low concentrations of urea

The presence of very low concentrations of the widely used denaturant urea induces structural changes in the monomeric heme-containing enzyme, horseradish peroxidase (HRP). Structural alterations in the protein were reflected in quenching studies of tryptophan fluorescence using the widely used quencher acrylamide. Stern-Volmer quenching constants measured in presence of urea, even in concentrations below 100 mm, were higher than those measured in absence of the denaturant. The fluorescence emission maximum of 1, 8-ANS, used as a probe for monitoring conformational changes in the enzyme, was blue-shifted from 530 nm in aqueous buffer to 518 nm when incorporated in native HRP. This blue shift increased further by 3 nm in presence of HRP preincubated with 100 mm urea, whereupon it steadily decreased with increasing urea concentration to become zero at 8 m urea. The mean fluorescence lifetime of 1,8-ANS incorporated in HRP was much higher than that of ANS in aqueous buffer, and showed continuous variation with the concentration of urea in which the enzyme was incubated. Systematic changes in the microenvironment of the heme moiety in HRP were also reflected in the visible CD spectra of the enzyme incubated with low concentrations of urea. These results are consistent with those of our earlier studies performed with the denaturant guanidinium chloride and indicate structural relaxation of HRP, with retention of enzymatic activity and native-like secondary structure, in presence of millimolar concentrations of urea.

Use of antibiotic prophylaxis in elective inguinal hernia repair in adults in London and south-east England: a cross-sectional survey

Purpose

Evidence regarding whether or not antibiotic prophylaxis is beneficial in preventing post-operative surgical site infection in adult inguinal hernia repair is conflicting. A recent Cochrane review based on 17 randomised trials did not reach a conclusion on this subject. This study aimed to describe the current practice and determine whether clinical equipoise is prevalent.

Methods

Surgeons in training were recruited to administer the Survey of Hernia Antibiotic Prophylaxis usE survey to consultant-level general surgeons in London and the south-east of England on their practices and beliefs regarding antibiotic prophylaxis in adult elective inguinal hernia repair. Local prophylaxis guidelines for the participating hospital sites were also determined.

Results

The study was conducted at 34 different sites and received completed surveys from 229 out of a possible 245 surgeons, a 93 % response rate. Overall, a large majority of hospital guidelines (22/28) and surgeons’ personal beliefs (192/229, 84 %) supported the use of single-dose pre-operative intravenous antibiotic prophylaxis in inguinal hernia repair, although there was considerable variation in the regimens in use. The most widely used regimen was intravenous co-amoxiclav (1.2 g). Less than half of surgeons were adherent to their own hospital antibiotic guidelines for this procedure, although many incorrectly believed that they were following these.

Conclusion

In the south-east of England, there is a strong majority of surgical opinion in favour of the use of antibiotic prophylaxis in this procedure. It is therefore likely to be extremely difficult to conduct further randomised studies in the UK to support or refute the effectiveness of prophylaxis in this commonly performed procedure.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Are we missing diagnostic opportunities in cases of carcinoid tumours of the appendix?

OBJECTIVE

Carcinoid tumour of appendix is an uncommon condition that can potentially give rise to a variation in management. We aimed to assess the occurrence and mode of presentation of carcinoid tumour of appendix, and any variation of its management.

METHODS

All appendicectomies that took place at North Middlesex University Hospital, London between 1995 and 2005 were considered for study.

RESULTS

A total of 1941 appendicectomies took place. Sixteen (0.82%) patients had carcinoid tumours. The mean age of patients with carcinoid tumour (41.8 years) was significantly higher than those with non-carcinoid pathology (27.7 years) (p = 0.001). The incidence of female patients was higher than the male amongst the carcinoid tumour group (female/male ratio 2.2). None of the carcinoid tumours were identified at operation. Eight patients as well as their general practitioners (53.3%) were unaware of the diagnosis. Multidisciplinary team involvement or specialty referral took place in three cases (20%). One patient (6.6%) required right hemicolectomy. Three patients (20%) were followed-up in inconsistent manner.

CONCLUSIONS

Carcinoid tumour of the appendix remains an incidental diagnosis. Patients with carcinoids were significantly older than non-carcinoid conditions. There was a trend of increased occurrence of carcinoids amongst the females. Re-operation rate was low. There was a wide variation in involving the multidisciplinary team, conveying the diagnosis to patients as well as their general practitioners, and follow-ups. This can be perceived as a missed opportunity of selective screening of synchronous and metachronous lesions, raises clinical governance issues and has medicolegal implications.

Activity analysis of telemedicine in the UK

BACKGROUND

Telemedicine is a new way of delivering health care to people, particularly in remote areas. The UK has experienced a surge of telematic projects in recent years. However, there is little information available in the literature regarding the past and present of telemedicine in the UK.

OBJECTIVES

To evaluate the state of telemedicine in the UK.

METHODS

All the projects that took place in UK since 1991 were considered for the study and evaluated according to the population and area served.

RESULTS

A total of 216 projects were identified. The number of projects was highest in England (172). Emergency medicine, medical specialties, and educational projects received most consideration (9.7% each). With the exception of Wales, the number of projects increased steadily with time. The projects, when correlated in accordance with the area (per 10 000 sq km) and population (per million), were found to be highest in England (49.5%) and Northern Ireland (36.2%) respectively. No dedicated educational project took place in Scotland, Northern Ireland, and Wales.

CONCLUSIONS

The UK embraced telemedicine in the early 1990s and the overall growth had been steady. Scotland, in spite of being the most likely beneficiary in UK, has lagged behind in telemedicine schemes and merits more projects. The issue of tele-education needs urgent review. Multisite trials and a combined approach involving the government, health professionals, technologists, and patients' representatives would facilitate such developments and help widen the application of telemedicine.

Improving reporting of sharp injuries

There is considerable under-reporting of contaminated needlestick and other sharp object injuries among health-care workers. Some general and psychological factors contribute to such low reporting. Continued training of staff, a sympathetic attitude and clarification of some general issues might improve reporting of such incidents.

A novel RNA polymerase binding site upstream of the galactose promoter in Escherichia coli exhibits promoter-like activity

RNA polymerase is known to bind and utilize the overlapping promoters P1 and P2 in Escherichia coli galactose operon. We have identified an additional specific site upstream of P2, where RNA polymerase binds in a heparin-resistant manner. Binding of polymerase to this site, termed P3, occurs simultaneous to its binding at P1/P2. We have located this P3 site by DNase I footprinting. A 63 base pair region centered around position - 100 with respect to galP1 is protected by polymerase. Interestingly, a Pribnow box TATAAT is present within this protected region (-103 to -108). We have shown that transcription occurs from P3 in vitro. Primer extension analysis provides direct evidence that P3 is transcribed in vivo. The start site of transcription has been mapped at -96 position relative to galP1. beta-galactosidase assays with different gal promoter constructs reveal that while P3 alone functions as a weak in vivo promoter, it has a synergistic effect on transcription from the gal operon, since deletion of P3 or specifically mutating its -10 region result in a substantial reduction in the gal promoter activity.

Impact of postoperative acute kidney injury in patients undergoing major gastrointestinal surgery on 1-year survival and renal outcomes: a national multicentre cohort study

BACKGROUND

The intermediate-term impact of acute kidney injury (AKI) in patients after major gastrointestinal and liver surgery has not been well characterized. This study aimed to evaluate the 1-year mortality rate and renal outcomes associated with postoperative AKI in a national prospective cohort.

METHODS

This prospective multicentre, observational cohort with 1-year postoperative follow-up included adults undergoing major gastrointestinal and liver surgery across the UK and Ireland between 23 September and 18 November 2015. AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The primary outcome was death at 1-year after surgery, and the secondary outcome was Major Adverse Kidney Events (MAKE-365). Cox proportionate and multilevel logistic regression were used to account for case mix.

RESULTS

Of 5745 patients across 173 centres, 1-year follow-up data was completed for 3504 patients (62.2 per cent, 126 centres), with attrition largely explained by centre non-participation (63.1 per cent). Some 13.6 per cent (475 of 3504) patients developed AKI by 7 days after surgery (stage 1: 9.2 per cent; stage 2/3: 4.3 per cent). At 1 year, 10.8 per cent (378 patients) experienced a MAKE-365 endpoint (303 patients had died, 61 had renal replacement therapy and 78 had renal dysfunction). Patients who experienced AKI by 7 days after surgery had a higher hazard of death at 1 year for KDIGO stage 1 (hazard ratio 1.50 (95 per cent c.i. 1.08 to 2.08), P = 0.016) and KDIGO stage 2/3 (hazard ratio 2.96 (95 per cent c.i. 2.02 to 4.33), P < 0.001). Both KDIGO stage 1 (odds ratio 2.09 (95 per cent c.i. 1.50 to 2.92), P < 0.001) and stage 2/3 (odds ratio 9.26 (95 per cent c.i. 6.31 to 13.59), P < 0.001) AKI were independently associated with MAKE-365.

CONCLUSION

AKI events within 7 days after gastrointestinal or liver surgery are associated with significantly worse survival and renal outcomes at 1 year.

Haemato-biochemical responses and induction of HSP70 to dietary phosphorus in Catla catla (Hamilton) fingerlings

A feeding trial of 120 days was conducted to study the effect of graded levels of dietary phosphorus on haematology, serum protein concentrations and HSP70 expression in fingerlings of the Indian major carp, Catla (Catla catla). Eight isonitrogenous and isoenergetic purified diets were formulated to contain graded levels of dietary phosphorus (dP), i.e., T(1), 0.1%; T(2), 0.3%; T(3), 0.5%; T(4), 0.7%; T(5), 0.9%; T(6), 1.1%; T(7), 1.3%; or T(8), 1.5%. Four hundred and eighty fish (average weight 4.23 +/- 0.016 g) were equally distributed into 24 tanks forming eight treatments with three replicates each. The fish were fed daily at the rate of 3.5% body weight in two instalments. At the end of feeding trial fish were sampled to study total RBC and WBC count, haemoglobin, serum lysozyme activity, serum total protein, albumin (A), globulin (G) concentration and HSP70 expression. Total RBC count, haemoglobin concentration and serum lysozyme activity did not vary significantly in response to different dietary phosphorus concentrations. Total WBC count was found to be significantly (P < 0.05) higher in T(1 )relative to all other treatments. Serum albumin and A/G ratio was found to be significantly lower in fish of T(1) and T(2) in relation to T(7) group (P < 0.05). Serum globulin and total protein levels remained unaffected by variations in dietary phosphorus. HSP70 expression was observed in T(1) group (0.1% dP) in gills and brain tissue, but not in liver and muscle tissues. No HSP70 expression was observed in fish of T(4) (0.7% dP) and T(8) (1.5% dP) treatments. These prima facie results suggest that dietary phosphorus had only minor influence on the haemato-biochemical parameters studied; however dietary phosphorus deficiency caused organ specific induction of HSP70 in catla fingerlings.

Lesson learnt: don't prescribe heparin for hemoperitoneum!

This paper describes a case of spontaneous rupture of the spleen that was misdiagnosed as pulmonary embolism. Because of a lack of history of trauma, rarity of occurrence, and confusing clinical presentations, an unwary clinician may fail to diagnose this condition in time. It may result in erroneous treatment of a condition, which is potentially curable.