Ultrasound-guided foam sclerotherapy as a therapeutic modality in venous ulceration.

OBJECTIVES: The objective of this systematic review and meta-analysis was to evaluate rates of ulcer healing following ultrasound-guided foam sclerotherapy (UGFS). METHODS: The MEDLINE, CENTRAL and Embase databases were used to search for relevant studies using the terms ' (sclerotherapy AND ulcer) OR (vein AND ulcer) OR (sclerotherapy AND vein)'. Heterogeneity between studies was quantified using the I2 statistic. A random effects model was used to calculate risk ratios where substantial heterogeneity was found. RESULTS: The initial search yielded 8266 articles. 8 studies were included in the qualitative synthesis and 3 in the meta-analysis. Superior complete ulcer healing rates were noted in patients treated with foam sclerotherapy versus compression therapy alone (pooled OR 6.41, 95% CI = 0.3-148.2, p = 0.246, random effects method). A marked degree of heterogeneity was observed between studies (I2 = 81%). CONCLUSION: A prospective, trial is warranted in order to determine the true merits of UGFS in the setting of venous ulceration.

The Barts Health NHS Trust COVID-19 cohort: characteristics, outcomes and risk scoring of patients in East London.

BACKGROUND: Barts Health National Health Service Trust (BHNHST) serves a diverse population of 2.5 million people in London, UK. We undertook a health services assessment of factors used to evaluate the risk of severe acute respiratory coronavirus 2 (SARS-CoV-2) infection.METHODS: Patients with confirmed polymerase chain reaction (PCR) test results admitted between 1 March and 1 August 2020 were included, alongwith clinician-diagnosed suspected cases. Prognostic factors from the 4C Mortality score and 4C Deterioration scores were extracted from electronic health records and logistic regression was used to quantify the strength of association with 28-day mortality and clinical deterioration using national death registry linkage.RESULTS: Of 2783 patients, 1621 had a confirmed diagnosis, of whom 61% were male and 54% were from Black and Minority Ethnic groups; 26% died within 28 days of admission. Mortality was strongly associated with older age. The 4C mortality score had good stratification of risk with a calibration slope of 1.14 (95% CI 1.01-1.27). It may have under-estimated mortality risk in those with a high respiratory rate or requiring oxygen.CONCLUSION: Patients in this diverse patient cohort had similar mortality associated with prognostic factors to the 4C score derivation sample, but survival might be poorer in those with respiratory failure.

The Effect of Multiple Assessments on Delirium Detection: a Pilot Study.

BACKGROUND: Delirium is characterized by fluctuating attention or arousal, with high prevalence in the orthopaedic ward. Our aim was to: 1) establish the prevalence of delirium on an orthopaedic ward, and 2) compare delirium prevalence using a single geriatrician assessment vs. multiple 3D-CAM (3-Minute Diagnostic Interview for Confusion Assessment Method) assessments during the day. We hypothesized that multiple assessments would increase the detection rate due to the fluctuating nature of delirium. METHODS: Comparative study conducted at an academic hospital in Hamilton, Ontario. Participants included patients 65 years and older admitted to the orthopaedic ward (n=55). After a geriatrician made the first assessment of delirium by 3D-CAM on each patient, teams with specialized geriatrics training re-assessed participants up to four times. Delirium rates based on first assessment were compared to cumulative end-of-day rates to determine if detection increased with multiple assessments. RESULTS: The prevalence of delirium was 30.9% (17 participants) using multiple assessments. Of these cases, 13 (76.4%) were detected in the initial geriatrician assessment. In patients with hip fractures, 70.6% (12 of 17) were identified as delirious by multiple assessments. CONCLUSION: As symptoms fluctuate, multiple daily CAM assessments may increase the identification of delirium in orthopaedic inpatients.

Prospective longitudinal comparison study of surgical therapies for peri-implantitis: 3-year follow-up.

BACKGROUND: The aim of this study was to compare different surgical therapies to treat peri-implantitis. METHODS: Twenty-three patients presenting one implant affected by peri-implantitis were divided into three groups: (i) open flap debridement (OFD) and citric acid decontamination (CAD); (ii) OFD, CAD and subepithelial connective tissue graft (SCTG); (iii) OFD, CAD and implantoplasty. Modified plaque index (MPI), gingival bleeding index (GBI), keratinized mucosa (KM) width, probing depth (PD), bleeding or suppuration on probing (B/SOP), and radiographic crestal bone level were registered 1(T1), 2(T2) and 3(T3) years after treatment. RESULTS: In Group 1 there was a significant improvement in MPI from baseline to T1, and a significant reduction in PD over time. In Group 2, none of the assessed clinical parameters showed any statistically significant variation over time. In Group 3, there was a significant decrease in PD and B/SOP over time. When comparing the 3 Groups, KM was significanlty greater in Group 2 vs. Group 1 and Group 3 at T1 and T2, and in Group 2 vs. Group 3 at T3. CONCLUSION: All therapies were successful in the management of peri-implantitis; however, SCTG maintained the greatest KM width. Surgical therapies combined with mechanical and chemical decontamination contributed to peri-implant tissue health.

Manganese exposure and association with hormone imbalance in children living near a ferro-manganese alloy plant.

It has been suggested that manganese (Mn) plays a fundamental role in the reproductive system through interference with the regulation of the secretion of hormones related to puberty. The objective of this study was to evaluate the environmental exposure to Mn and its effects on the endocrine regulation of hormones related to puberty in school-aged children living near a ferro-manganese alloy plant. Toenails, occipital hair, and blood samples were collected from 225 children, between 7 and 12 years of age, in four elementary schools in Simões Filho, Bahia, Brazil, who were exposed to different Mn levels owing to different Mn dust deposition rates. The Mn content was determined in the toenails (MnTn), hair (MnH), and blood (MnB), in addition to blood lead levels (PbB), by using graphite furnace atomic absorption spectrometry. Luteinizing hormone (LH), prolactin (PRL), estradiol (E2), testosterone (T), and thyroid stimulating hormone (TSH) levels were determined by using a chemiluminescence method. Of the total participants, 50.2% were boys, with an average age of 9 years. PRL values were higher in children attending the school with a higher Mn deposition rate (p < 0.004). We observed that MnTn was positively correlated with PRL levels and exhibited a non-linear association with LH levels. None of the tested Mn biomarkers were associated with E2, T, or TSH levels. To date, despite several animal studies that have focused on the correlation between Mn exposure and the endocrine regulation of hormones and pubertal development, very few studies have reported a similar relationship between environmental Mn effects and the human endocrine system. Our findings support the hypothesis that elevated exposure to Mn in children may be associated with hormonal imbalances that might trigger the early onset of puberty.

Space-based observations of crustal deflections for drought characterization in Brazil.

Widespread environmental impacts of frequent drought episodes in Brazil have resulted in several drought-related diagnostics studies. However, the potential of many "opportunistic sensors", such as the Global Positioning System (GPS), has not yet been considered in hydrological hazard monitoring in Brazil. In this study, the response of the Earth's crust to Brazil's 2012-2015 drought event in different structural provinces is analyzed by comparing GPS-observed vertical crustal deformations (VCDs) with the terrestrial water storage (TWS) derived from the Gravity Recovery and Climate Experiment (GRACE). The results indicate that there is no spatial correlation between annual amplitudes of the TWS and VCDs in different structural provinces apart from the purely elastic response of the crust to TWS dynamics, at almost all the 39 GPS stations that were analyzed. However, approximately 15% of the monitoring stations show that VCD leads TWS with a phase lag of 2-4 months. Errors associated with VCD and TWS are within the accepted range for space geodetic techniques (i.e., GPS and GRACE) and despite the need for further investigation, the phase lead seems to be associated with rainfall, which impacts the TWS through the hydrographs. Overall, the GPS-based drought index (DIVCD) reflects the water depletion in many regions of Brazil, which agrees with the GRACE-based DITWS in terms of the Spearman correlation coefficient (ranging from 0.4 to 0.9) in the Amazon, Tocantins, La Plata, and São Francisco river basins. This agreement confirms the drought persistence during the study period and that DIVCD can be used to monitor hydrological droughts. In regions in which DITWS sufficiently agrees with DIVCD (48% of the sites), near real-time drought monitoring is feasible. This could be useful in the optimization of models for the forward prediction of drought events in other regions worldwide, where GPS vertical displacements strongly correlate with hydrological GRACE signals.

Efficacy of a single session protocol for endodontic treatment in primary teeth: in vivo study.

AIMS: To determine the efficacy of a single session protocol (SSP) in the reduction of septic content of primary teeth root canals and identify the persistence of bacterial species associated with unsuccessful treatment. METHODS: Primary teeth root canals (16) with pulp necrosis and peri-radicular lesions were treated. Samples were collected at baseline (T1), and after chemo-mechanical preparation, before filling (T2). Identification of the microorganisms was determined using checkerboard DNA-DNA hybridisation. STATISTICAL ANALYSIS: Wilcoxon test was applied for comparison of mean number of species, proportion and mean count of each species between the evaluation times. RESULTS: Significant reductions were found in the mean number of bacteria species between T1 and T2 (p < 0.05), but not for the reduction in proportion (p > 0.05). There was a reduction (6.0-4.6) of the mean number of species associated with failure, without statistical significance. CONCLUSION: The SSP was capable of significantly reducing the septic content, even though, many of the bacteria associated with failure persisted at the time of root canal filling.

A Bowman-Birk inhibitor induces apoptosis in human breast adenocarcinoma through mitochondrial impairment and oxidative damage following proteasome 20S inhibition.

Proteasome inhibitors are emerging as a new class of chemopreventive agents and have gained huge importance as potential pharmacological tools in breast cancer treatment. Improved understanding of the role played by proteases and their specific inhibitors in humans offers novel and challenging opportunities for preventive and therapeutic intervention. In this study, we demonstrated that the Bowman-Birk protease inhibitor from Vigna unguiculata seeds, named black-eyed pea trypsin/chymotrypsin Inhibitor (BTCI), potently suppresses human breast adenocarcinoma cell viability by inhibiting the activity of proteasome 20S. BTCI induced a negative growth effect against a panel of breast cancer cells, with a concomitant cytostatic effect at the G2/M phase of the cell cycle and an increase in apoptosis, as observed by an augmented number of cells at the sub-G1 phase and annexin V-fluorescin isothiocyanate (FITC)/propidium iodide (PI) staining. In contrast, BTCI exhibited no cytotoxic effect on normal mammary epithelial cells. Moreover, the increased levels of intracellular reactive oxygen species (ROS) and changes in the mitochondrial membrane potential in cells treated with BTCI indicated mitochondrial damage as a crucial cellular event responsible for the apoptotic process. The higher activity of caspase in tumoral cells treated with BTCI in comparison with untreated cells suggests that BTCI induces apoptosis in a caspase-dependent manner. BTCI affected NF-kB target gene expression in both non invasive and invasive breast cancer cell lines, with the effect highly pronounced in the invasive cells. An increased expression of interleukin-8 (IL-8) in both cell lines was also observed. Taken together, these results suggest that BTCI promotes apoptosis through ROS-induced mitochondrial damage following proteasome inhibition. These findings highlight the pharmacological potential and benefit of BTCI in breast cancer treatment.

A Heart for Travel: Travel Health Considerations for Patients with Heart Disease and Cardiac Devices.

Cardiovascular disease is the leading cause of death in adult international travellers. Patients living with heart disease should receive specific, individualised pre-travel health advice. The purpose of this article is to provide evidence-based advice to physicians who are consulted by travellers with cardiovascular disease. Fitness-to-travel evaluation will often be conducted by the general practitioner but other medical specialists may also be consulted for advice. Patients with chronic medical conditions should purchase travel health insurance. The general pre-travel health consultation addresses food and water safety, insect and animal bite avoidance, malaria chemoprophylaxis, and travel vaccinations. Patients with devices such as cardiac pacemakers should be familiar with how these may be affected by travel. Cardiac medications may cause adverse effects in cold or hot environments, and specific precautions must be followed by anticoagulated travellers. The physician should be aware of how to access medical care abroad, and of the potential for imported tropical diseases in returned travellers.

The INTERPRET-DD study of diabetes and depression: a protocol.

AIM: People with diabetes are at an increased risk of developing depression and other psychological disorders. However, little is known about the prevalence, correlates or care pathways in countries other than the UK and the USA. A new study, the International Prevalence and Treatment of Diabetes and Depression Study (INTERPRET-DD) aims to address this dearth of knowledge and identify optimal pathways to care across the globe. METHOD: INTERPRET-DD is a 2-year longitudinal study, taking place in 16 countries' diabetes outpatients' facilities, investigating the recognition and management of depressive disorders in people with Type 2 diabetes. Clinical interviews are used to diagnose depression, with clinical and other data obtained from medical records and through patient interviews. Pathways to care and the impact of treatment for previously unrecognized (undocumented) depression on clinical outcomes and emotional well-being are being investigated. RESULTS: Initial evidence indicates that a range of pathways to care exist, with few of them based on available recommendations for treatment. Pilot data indicates that the instruments we are using to measure both the symptoms and clinical diagnosis of depression are acceptable in our study population and easy to use. CONCLUSIONS: Our study will increase the understanding of the impact of comorbid diabetes and depression and identify the most appropriate (country-specific) pathways via which patients receive their care. It addresses an important public health problem and leads to recommendations for best practice relevant to the different participating centres with regard to the identification and treatment of people with comorbid diabetes and depression.

Increasing leptin level in abstaining alcohol-dependent women.

INTRODUCTION: Leptin, hormone secreted by the fat tissue, changes the signaling of dopamine in the nucleus accumbens, which directly affects the sensitivity of reward and modulation of abstinence. AIMS: To evaluate the level of serum leptin and its relation to nutritional status among alcoholic abstainers and non-abstinent. METHODS: Patients of both sexes, over 18 years old and who used alcohol as their primary drug were included in the study. Abstaining patients were separated according to the time without the use of the drug as A2 (1-3 month-abstainers) and A3 (4 month and over-abstainers). Waist circumference (WC), body fat percentage (%BF) and weight and height were measured to calculate Body Mass Index (BMI). Blood samples were collected for leptin measurement. RESULTS: Mean levels of leptin, leptin/BMI, leptin/%BF were higher in all women categories. Abstaining women (A2) also showed higher leptin, leptin/BMI and leptin/ %BF than non-abstinent (p = 0.039; p = 0.023; p = 0.023). Statistical differences were also shown among abstaining women A2 and A3 as well a significant positive association between leptin levels and BMI and leptin and WC in active female drinkers (leptin × BMI: r = 0.91; p < 0.01; leptin × WC: r = 0.87; p = 0.001). However, a significant association was not shown among these results in abstaining women (leptin × BMI: r = 0.28; p = 0.37/ leptin × WC: r = -0.32, p = 0.92). CONCLUSION: Our results suggest that leptin levels seem to increase only in abstaining women. This result can be related to the length of abstinence.

[Effect of neuromuscular electrical stimulation and isotonic exercises in flexor and extensor muscles of knee of hemiplegic patients]. / Efecto de la estimulación eléctrica neuromuscular y de los ejercicios isotónicos en los músculos flexores y extensores de la rodilla en pacientes hémiplejicos.

AIM: To verify the muscular force and resistance to the movement of the flexor and extensor muscles of the knee of patients with spasticity after treatment with neuromuscular electrical stimulation (NMES) and isotonic exercises. PATIENTS AND METHODS: The patients this study were divided into group 1 (NMES) and group 2 (isotonic exercises). Their muscular torque and resistance to the movement of the flexor and extensor knee muscles were measured by the isokinetic dynamometer and the degree of spasticity by the modified Ashworth scale before and after ten sessions. RESULTS: Alterations in the scores of the modified Ashworth scale were not observed. An increase in the flexor torque in group 1 (p = 0.041) and in group 2 (p = 0.001) was verified. In the passive mode, group 1 presented a reduction of resistance to the flexion movement (p = 0.026), while in group 2, a reduction of resistance to both the flexion (p = 0,029) and extension movements (p = 0.019) was verified. CONCLUSIONS: The two therapeutical resources had their efficiency proven only for the increase of the force of the flexor muscles. The resistance to movement, the isotonic exercises were more effective because they promoted a reduction in the resistance of the flexor and extensor knee muscles.

Efecto de la estimulación eléctrica neuromuscular y de los ejercicios isotónicos en los músculos flexores y extensores de la rodilla en pacientes hemipléjicos / Effect of neuromuscular electrical stimulation and isotonic exercises in flexor and extensor muscles of knee of hemiplegic patients

Comprobar la fuerza muscular y la resistencia al movimiento de los músculos flexores y extensores de larodilla de los pacientes con espasticidad después del tratamiento con estimulación eléctrica neuromuscular (EENM) y ejercicios isotónicos. Pacientes y métodos. Los pacientes se dividieron en grupo 1 (EENM) y grupo 2 (ejercicios isotónicos). Su momentode fuerza muscular y la resistencia al movimiento de los músculos flexores y extensores de la rodilla se midieron mediante el dinamómetro isocinético, y el grado de espasticidad se midió mediante la escala modificada de Ashworth antes y después de diez sesiones. Resultados. No se observaron variaciones en las puntuaciones de la escala modificada de Ashworth.Se verificó un aumento del momento de fuerza de flexión en el grupo 1 (p = 0,041) y en el grupo 2 (p = 0,001). En el modo pasivo, el grupo 1 presentó una disminución de la resistencia al movimiento de flexión (p = 0,026), mientras que en el grupo 2 se verificó una disminución de la resistencia tanto al movimiento de flexión (p = 0,029) como al movimiento de extensión(p = 0,019). Conclusiones. Los dos recursos terapéuticos demostraron su eficacia sólo para el aumento de la fuerza de los músculos flexores. En la resistencia al movimiento, los ejercicios isotónicos fueron más eficaces porque fomentaron una disminuciónde la resistencia de los músculos flexores y extensores de la rodilla

To verify the muscular force and resistance to the movement of the flexor and extensor muscles of the knee of patients with spasticity after treatment with neuromuscular electrical stimulation (NMES) and isotonic exercises. Patients and methods. The patients this study were divided into group 1 (NMES) and group 2 (isotonic exercises). Their muscular torque and resistance to the movement of the flexor and extensor knee muscles were measured by the isokinetic dynamometer and thedegree of spasticity by the modified Ashworth scale before and after ten sessions. Results. Alterations in the scores of the modified Ashworth scale were not observed. An increase in the flexor torque in group 1 (p = 0.041) and in group 2 (p = 0.001)was verified. In the passive mode, group 1 presented a reduction of resistance to the flexion movement (p = 0.026), while in group 2, a reduction of resistance to both the flexion (p = 0,029) and extension movements (p = 0.019) was verified.Conclusions. The two therapeutical resources had their efficiency proven only for the increase of the force of the flexor muscles. The resistance to movement, the isotonic exercises were more effective because they promoted a reduction in the resistance of the flexor and extensor knee muscles

Purification and characterization of a novel pectinase from Acrophialophora nainiana with emphasis on its physicochemical properties.

An extracellular pectinase (PECI) was purified to apparent homogeneity from liquid state cultures of the thermophilic fungus Acrophialophora nainiana by ultrafiltration and a combination of gel filtration and ion-exchange chromatographic procedures. The molecular masses of PECI were 35,500 and 30,749 Da, as determined by SDS-PAGE and mass spectrometry, respectively. It was more active at 60 degrees C and pH 8.0 and showed high stability at 50 degrees C with half-life of 7 days. However at 60 and 70 degrees C, PECI was much less stable with half lives of approximately 20 and 3 min, respectively. The thermostability of purified PECI was also investigated by fluorescence and circular dichroism spectroscopy. Fluorescence revealed that the unfolding transition region was observed between 45 and 70 degrees C. A major decrease in the stability was found at 70 degrees C. Circular dichroism measurements at pH between 5.0 and 9.0 showed a transition temperature (T(m)) range of 50-55 degrees . The thermodynamic analysis of these results showed that EPGI is thermal stable protein exhibiting maximum stability (DeltaG(25)) of 22.65 and 19.19 kcal/mol at pH 8.0 and 9.0, respectively. The apparent K(m) value on pectin from citrus fruits was 4.22 mgml(-1). PECI exhibited no detectable activity of pectin methylesterase, endo-polygalacturonase, mannanase, xylanase and cellulase. However, it showed exo-polygalacturonase and pectin lyase activities. The presence of carbohydrate was detected in the pure PECI. It was activated by l-tryptophan, DEPC, DTT, DTNB, DTP, l-cystein and beta-mercaptoethanol and inhibited by NBS, Fe(2+), Cu(2+), Zn(2+), Mn(2+), Al(3+) and Ca(2+). The enzyme showed homology with a pectin lyases from Xanthomonas campestris and Bacillus licheniformis.

[Allocation of health care resources in the state of Santa Catarina, Brazil: a contribution to a discussion on health financing]. / Distribuição de recursos de saúde no Estado de Santa Catarina, Brasil: um subsídio para discussões sobre o financiamento em saúde.

OBJECTIVE: To describe the health situation in municipalities in the state of Santa Catarina, Brazil, in 1996, and to investigate how that correlated with federal health spending in 1997. METHODS: Multiple regression analysis was used to investigate the association between federal health care funding and proportional mortality, supply of health services (hospitals and outpatient clinics), and the municipality's population (number of inhabitants). Also investigated was the association between mortality from broad groups of causes and socioeconomic structure, supply of health services, and the municipality's population. RESULTS: The multiple regression analysis showed an association between proportional mortality due to: 1) infectious diseases and: infant mortality, number of non-doctor medical professionals per 10,000 inhabitants, and number of physicians per 10,000 inhabitants (negative association); 2) chronic degenerative diseases and: percentage of individuals 60 years and older, infant mortality (negative association), and number of non-doctor medical professionals per 10,000 inhabitants (negative association); and 3) external causes of death and: the municipality's population, number of hospitals per 10,000 inhabitants (negative association), and percentage of children younger than 1 year. Health spending per inhabitant in 1997 was mainly associated with the municipality's population, number of outpatient clinics per 10,000 inhabitants, Swaroop and Uemura mortality rate, and deaths due to chronic degenerative diseases in 1996. CONCLUSIONS: Municipalities with a better morbidity and mortality profile and a better health services structure received more federal health care resources. To improve this situation, special strategies should be considered in order to ensure additional resources for municipalities that have poorer health indicators.

Lateral esophagostomy: an alternative in the initial management of long gap esophageal atresia without fistula.

The authors report an alternative method of cervical esophagostomy that was used in a child with type A esophageal atresia. This method involved performing a lateral esophagostomy in the proximal pouch, preserving its distal end, allowing the child to swallow normally, without choking, while stimulating the spontaneous growth of the proximal esophagus. As a result, the infant could be discharged home on G-tube feedings while waiting for spontaneous growth of the proximal pouch to occur. There were no episodes of aspiration during this period, and definitive reconstruction through end-to-end esophageal anastomosis was accomplished successfully at the age of 18 months. The authors consider that this alternative might increase the possibility of a definitive correction through delayed primary anastomosis of the infant's own esophagus in children with this type of malformation.

Parallel synthesis of a library of 1,4-naphthoquinones and automated screening of potential inhibitors of trypanothione reductase from Trypanosoma cruzi.

Solid- and solution-phase parallel syntheses of 1,4-naphthoquinones (1,4-NQ) are described. A library of 1360 amides was constructed from the combination of 12 newly synthesised 1,4-NQ carboxylic acid and 120 amines, and was screened for inhibition of trypanothione reductase (TR) from Trypanosoma cruzi. The most active hits from a primary screening were re-synthesised and confirmed. This approach proves that it is possible to design potent and highly specific TcTR inhibitors deriving from menadione, juglone and plumbagin.

[Breast-feeding habits in Ouro Preto, MG, Brazil]. / Práticas de amamentação no município de Ouro Preto, MG, Brasil.

OBJECTIVE: To identify the frequency and median duration of breast-feeding in children aged 0-24 months in the city of Ouro Preto, Brazil. METHODS: A cross-sectional study was carried out to identify the median duration of breastfeeding in children aged 0-24 months. A sample of 229 children from 1800 households was drawn by clusters at three different occasions and stratified according to the area (urban or rural). The frequency and median duration of breast-feeding were calculated using the life table technique. RESULTS: A median duration of 198 days was found for breast-feeding as a whole: 71 days for the group of exclusive plus mainly breastfeeding and 17 days for exclusive breastfeeding. CONCLUSION: The current pattern of breast-feeding is of a short-term practice. This evidence suggests the need for intervention programs to promote breast-feeding for longer periods and delay the introduction of food supplementation, preventing the early weaning.

Effects of denaturing and stabilizing agents on the inhibitory activity and conformational stability of Schizolobium parahyba chymotrypsin inhibitor.

The conformational stability of the Schizolobium parahyba chymotrypsin inhibitor (SPCI) was investigated based on conformational changes and inhibitory activity in the presence of chaotropic and stabilizing agents. At 90 degrees C, the half-lifetime of SPCI was 154 min, while in the presence of 1 M KCl and 20% PEG 20,000, it was drastically reduced to 6 and 3 min, respectively. In contrast, at 90 degrees C, the SPCI structure remained unaltered with the addition of 1 mM DTT and 56% glycerol. The reduction of the two disulfide bonds caused conformational changes in the SPCI without altering the inhibitory activity, suggesting that disulfide bonds are irrelevant to the maintenance of SPCI conformation. Unfolded structures were formed in the presence of 6 M GdnHCl, while in the presence of 8 M urea, destabilization was due to peptide bond rupture. These results suggest that the thermal inactivation of SPCI involves conformational changes and that hydrophobic and electrostatic interactions play a significant role, while the disulfide bonds are of secondary importance in maintaining the high thermal stability of SPCI.