A Morphometric Study of Olecranon Fossa of Adult Human Humerus of Bangladeshi Population

Olecranon fossa is the largest fossa among the three fossae of the humerus. It is present in the lower end of the posterior surface just above the trochlea. Osteometry of olecranon fossa is important since their fractures occur in 10.0% of upper limb fractures. The aim of this study was to measure different parameters of olecranon fossa. This study was taken from 100 (right=43 and left=57) samples were selected through the purposive sampling technique for this cross-sectional descriptive study which was carried out in the Department of Anatomy, Mymensingh Medical College, Mymensingh, Bangladesh from July 2021 to June 2022. Any damaged, unossified bones or fractured bones were excluded. Data were tabulated and statistically analyzed using Microsoft Excel and SPSS software. The mean ±SD vertical diameter of the olecranon fossa of the right humeri was 16.858±2.623mm and the left humeri were 17.071±2.905mm. The mean ±SD width of the olecranon fossa of the right humeri was 24.239±2.520mm and the left humeri were 24.509±2.692mm. The mean ±SD maximum depth of the olecranon fossa of the right humeri was 13.442±1.688mm and the left humeri were 13.124±1.733mm. The anatomical knowledge of the olecranon fossa is beneficial for anthropologists, orthopedic surgeons and radiologists in cases of olecranon fractures of the humerus.

Anatomical Study of Number, Location and Position of Nutrient Foramina of Fully Ossified Dry Human Humerus

The nutrient foramen is the natural opening present in the shaft of the humerus. It passes the nutrient artery to the medullary cavity. The nutrient artery is the chief artery that enters the bone through a nutrient foramen to provide nutrition for its growth. It plays an important role in healing during fracture and trauma and is also important for bone grafting. This study aimed to determine the common location, position and number of nutrient foramina of fully ossified dry human humerus. One hundred samples (right- 43 and left- 57) were selected through the purposive sampling technique for this cross-sectional descriptive study carried out in the Department of Anatomy, Mymensingh Medical College, Bangladesh from July 2021 to June 2022. Any damaged, unossified bones or fractured bones were excluded. Data were tabulated and statistically analyzed using Microsoft Excel and SPSS software. Among 43 right humeri, 37(75.51%) have single-nutrient foramen and 06(24.49%) have double-nutrient foramina. Among 57 left humeri, 53(92.98%) have single nutrient foramen, 03(5.27%) have double nutrient foramina and 01(1.75%) has triple nutrient foramina. In case of location of nutrient foramina, among 49 right nutrient foramina, 45(91.84%) were found on the anteromedial surface, 02(4.08%) were found on the anterolateral surface and 02(4.08%) were on the posterior surface of the shaft of the humerus. In case of 62 left nutrient foramina, 57(91.94%) were found on the anteromedial surface and 05(8.06%) were found on the posterior surface of the shaft of the humerus. Among 49 right nutrient foramina, 01(2.04%) was found on the upper third, 46(93.88%) on the middle third and 02(4.08%) on the lower third of the shaft of the humerus. In case of 62 left nutrient foramina, 01(1.60%) was on the upper third, 57(91.95%) were on the middle third and 04(6.45%) were on the lower third of the shaft of the humerus.

1577 Using CTS5 Calculator to Predict The 5-10-Year Risk of Late Distant Recurrence for Women With ER-Positive Breast Cancer Who Are Recurrence-Free 5 Years After Endocrine Therapy and To Reduce the Number of Patients Needing Discussion for The Extended Endocrine Therapy in The Breast MDTs: A Quality Improvement Project

Introduction

The increasing number of patients has created a pressure on the services provided that aim to ensure the maximum level of care, particularly MDT meetings. Using the CTS5 calculator can readily reduce the number of patients needing discussion for EET. This is will prevent delays in decisions made for patients and more importantly, an evidence-based tool will be used for more accurate results.

Method

A retrospective data collection was undertaken from the Breast MDT records, initially dating from January to December 2018. Then when the optional use of CTS5 was established, data were retrieved from August to October 2019. As per guidance for the use of the CTS5 calculator; Women were deemed low risk if their 5–10-year risk is less than 5%, intermediate if between 5–10%, and high risk if their 5–10-year risk is more than 10%. Finally, a prospective data collected from January to March 2020 where an agreement was made for all involved Surgeons to use the CTS5 calculator.

Results

Before Introducing the CTS5 Calculator, in 2018, the number of patients was 1523 from which 66 were for EET 4.3%. When CTS5 Calculator was first introduced, 1st of August - 31st October 2019, the percentage reduced to 4.1% and from January to March 2020, a further reduction 3.9% was noticed.

Conclusions

The CTS5 calculator is an effective evidence-based tool used to predict the risk of 5-10 years recurrence in breast cancer patients. Implementing it will reduce the number of patients needing discussion in Breast MDTs, sparing meetings’ and patients’ time.

Socio-demographic Profile of COVID-19 Patients and Difficulties Faced by Them while Testing RT-PCR: A Multi-center Cross-sectional Study

This study was aimed to find out the socio-demographic profiles as well as difficulties of Reverse transcription polymerase chain reaction (RT-PCR) testing faced by Coronavirus Disease 2019 (COVID-19) patients. This cross-sectional study was conducted from 10th August to 7th September 2020. Data were collected by telephone interview using a pre-designed questionnaire after taking verbal consent from the participants. Out of 281 COVID-19 patients, 279 were diagnosed by RT-PCR; 10.3% were asymptomatic. Off them 67.6%were males, 24% were hospital staffs. Majority (66.2%) were from the non-city corporation area. History of recent contact with known COVID-19 patients was present in 56.9% cases. Fever (78.3%) and cough (58%) were the most common symptoms. One third of the patients faced difficulty to test RT-PCR for COVID-19. Sixteen percent patients complained of difficulty of getting serial for testing, the maximum waiting time was one week before giving samples. Thirty patients (10.8%) had to wait longer than usual time after reaching the center before giving sample. Hospital staffs were unable to co-operate in 2.5% of the patients while difficulty of managing transport to the hospital for suspected COVID-19 patient was an issue in 2.2% of the patients. Though testing was more difficult in city corporation areas (p=0.028), delay of getting test result was less (p<0.001). Maximum delay of getting test result was 10 days. Finding out the difficulties of COVID-19 testing will help to point out the issues behind these and will help to take necessary steps to tackle this matter. Testing rate can be increased to contain this highly contagious virus in this densely populated country.

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.

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.

Letter 1: Clinicoradiological score for predicting the risk of strangulated small bowel obstruction (Br J Surg 2010; 97; 1119–1125)

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.

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.

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.

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.

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.

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.

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.

Atraumatic rupture of the spleen in adults

Atraumatic rupture of the spleen is an uncommon but important clinical entity. Unfortunately, the diagnosis is often missed due to the absence of any history of trauma. Various aspects of atraumatic rupture of the spleen, including those of 'pathologic' and 'spontaneous' rupture of the spleen, have been reviewed. Increased awareness of this condition would enhance early diagnosis and effective treatment. Further research is required to identify the possible risk factors associated with spontaneous rupture of the spleen.

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.

Structural perturbation of proteins in low denaturant concentrations

The presence of very low concentrations of the widely used chemical denaturants, guanidinium chloride and urea, induce changes in the tertiary structure of proteins. We have presented results on such changes in four structurally unrelated proteins to show that such structural perturbations are common irrespective of their origin. Data representative of such structural changes are shown for the monomeric globular proteins such as horseradish peroxidase (HRP) from a plant, human serum albumin (HSA) and prothrombin from ovine blood serum, and for the membrane-associated, worm-like elongated protein, spectrin, from ovine erythrocytes. Structural alterations in these proteins were reflected in quenching studies of tryptophan fluorescence using the widely used quencher acrylamide. Stern-Volmer quenching constants measured in presence of the denaturants, even at concentrations below 100 mM, were higher than those measured in absence of the denaturants. Both steady-state and time-resolved fluorescence emission properties of tryptophan and of the extrinsic probe PRODAN were used for monitoring conformational changes in the proteins in presence of different low concentrations of the denaturants. These results are consistent with earlier studies from our laboratory indicating structural perturbations in proteins at the tertiary level, keeping their native-like secondary structure and their biological activity more or less intact.

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.

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.

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.

Interaction of the antitumour alkaloid coralyne with duplex deoxyribonucleic acid structures: spectroscopic and viscometric studies

The interaction of coralyne, an antitumour alkaloid with natural and synthetic duplex DNAs was investigated under conditions where the drug existed fully as a true monomer for the first time using spectrophotometric, spectrofluorimetric, circular dichroic and viscometric techniques. The absorption spectrum of coralyne monomer showed hypochromic and bathochromic effects on binding to duplex DNAs. This effect was used to determine the binding parameters of coralyne. The binding constants for four natural DNAs and four synthetic polynucleotides obtained from spectrophotometric titration, according to an excluded site model, using McGhee-von Hippel analysis, were all in the range of (0.38-9.8) x 10(5) M-1, and showed a relatively high specificity for the GC rich ML DNA and the alternating GC polynucleotide. The binding of coralyne decreased with increasing ionic strength, indicating that the binding affinity has a strong electrostatic component. Coralyne stabilized all the DNAs against thermal strand separation. The intense steady state fluorescence of coralyne was effectively quenched on binding to DNAs and the quantitative data on the Stern-Volmer quenching constant obtained was sequence dependent, being maximum with the GC rich DNA and alternating GC polymer. Circular dichriosm studies further evidenced for a strong perturbation of the B-conformation of DNAs consequent to coralyne binding with the concomitant development of extrinsic circular dichroic bands for the bound drug molecules suggesting their strong intercalated geometry in duplex DNAs. Further tests of intercalation using viscosity measurements on linear and covalently closed plasmid DNA conclusively proved the strong intercalation of coralyne in duplex DNA. Binding of the closely related natural alkaloid, berberine under these conditions showed considerably lower affinity to duplex DNAs in all experiments. Taken together, these results suggest that coralyne binds strongly to duplex DNAs by a mechanism of intercalation with specificity towards alternating GC duplex structure.

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.

Conformational aspects of poly(dI-dC).poly(dI-dC) and poly(dG-dC).poly(dG-dC) on binding of the alkaloid, berberine chloride

Interaction of berberine chloride with poly(dI-dC).poly(dI-dC) and poly(dG-dC).poly(dG-dC) has been studied by various spectroscopic methods. Comparative data on binding parameters, fluorescence enhancement and Tm measurements indicate a stronger binding of berberine to the IC polymer than to the GC one. Conformational changes as monitored by circular dichroic spectra indicate change of the unusual circular dichroism of poly(IC) to a conformation similar to A-conformation, while in poly(GC) only a B-conformational change is observed. Extrinsic CD bands developed in the visible absorption region of berberine on interaction with poly(IC) are of much higher intensity compared to poly(GC). It is concluded that berberine induces a conformational change similar to the A-conformation on binding to poly(IC).

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.

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.

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.

Interaction of berberine chloride with deoxyribonucleic acids: evidence for base and sequence specificity

The interaction of berberine chloride with natural and synthetic DNAs of differing base composition and sequences was followed by various spectroscopic and viscometric studies. The binding of berberine chloride was characterized by hypochromism and bathochromism in the absorption bands, enhancement of fluorescence intensity, stabilization against thermal denaturation, perturbations in the circular dichroic spectrum, increase in the contour length of sonicated rod-like DNA and induction of unwinding-rewinding process of covalently closed superhelical DNA, depending on the base composition and sequences of base pairs. Binding parameters determined from absorbance and fluorescence titration by Scatchard analysis, according to an excluded-site model, indicated a very high specificity of berberine to AT-rich DNAs and alternate AT polymer. Fluorescence quantum yield was maximum for the complexes with AT-rich DNAs and alternate AT polymer. Taken together, these results suggest that berberine chloride exhibits considerable specificity towards alternating AT polymer and binds to AT-rich DNAs by a mechanism of classical intercalation.

Effect of hydrocortisone on the hemodynamics and serum CK and MBCK enzymes in acute myocardial infarct in dogs

The effects of hydrocortisone on the hemodynamics and plasma creatine kinase (CK) in dogs with acute myocardial infarction were investigated. Acute myocardial infarction was produced by ligating the anterior descending branch of the left coronary artery and the effects on hemodynamics and plasma CK were observed for two hours. Complete coronary ligation produced a decrease in the cardiac index and left ventricular work index following two hours of coronary ligation. Other hemodynamic parameters (systemic and pulmonary arterial pressure, left ventricular pressure, right atrial pressure, pulmonary arterial wedge pressure, systemic and pulmonary vascular resistance, heart rate, cardiac effort) were essentially unaffected. There was a tendency for an increase in (dp/dt)/IIP but the increase was not significant. In hydrocortisone treated dogs, all the hemodynamic parameters were unaffected except the cardiac index which decreased significantly. Partial coronary ligation produced an increase in the systemic and pulmonary vascular resistance and a decrease in the cardiac index. The other hemodynamic parameters were unaffected. Plasma CK and MBCK increased significantly in dogs with partial or complete ligation of coronary artery. The serum CK was more in partially ligated than in complete coronary ligated dogs. Although hydrocortisone pretreatment decreased the rise of plasma CK it did not change the rise in MBCK observed in coronary ligated dogs without hydrocortisone treatment. These results indicate that hydrocortisone prevents, although not completely, the deleterious effects of ischemia on the plasma CK but has no effect on the increase in plasma MBCK and decrease in the cardiac index.