Structural Insight of KSIII (ß-Ketoacyl-ACP Synthase)-like Acyltransferase ChlB3 in the Biosynthesis of Chlorothricin.

Chlorothricin (CHL) belongs to a spirotetronate antibiotic family produced by Streptomyces antibioticus that inhibits pyruvate carboxylase and malate dehydrogenase. For the biosynthesis of CHL, ChlB3 plays a crucial role by introducing the 6-methylsalicylic acid (6MSA) moiety to ChlB2, an acyl carrier protein (ACP). However, the structural insight and catalytic mechanism of ChlB3 was unclear. In the current study, the crystal structure of ChlB3 was solved at 3.1 Å-resolution and a catalytic mechanism was proposed on the basis of conserved residues of structurally related enzymes. ChlB3 is a dimer having the same active sites as CerJ (a structural homologous enzyme) and uses a KSIII-like fold to work as an acyltransferase. The relaxed substrate specificity of ChlB3 was defined by its catalytic efficiencies (kcat/Km) for non-ACP tethered synthetic substrates such as 6MSA-SNAC, acetyl-SNAC, and cyclohexonyl-SNAC. ChlB3 successfully detached the 6MSA moiety from 6MSA-SNAC substrate and this hydrolytic activity demonstrated that ChlB3 has the potential to catalyze non-ACP tethered substrates. Structural comparison indicated that ChlB3 belongs to FabH family and showed 0.6-2.5 Å root mean square deviation (RMSD) with structural homologous enzymes. Molecular docking and dynamics simulations were implemented to understand substrate active site and structural behavior such as the open and closed conformation of the ChlB3 protein. The resultant catalytic and substrate recognition mechanism suggested that ChlB3 has the potential to use non-native substrates and minimize the labor of expressing ACP protein. This versatile acyltransferase activity may pave the way for manufacturing CHL variants and may help to hydrolyze several thioester-based compounds.

Co-amplification of microbial DNA: A novel observation of a misconstrued second peak at locus D7S820.

DNA fingerprinting, a gold standard, is one of the most powerful tool in applied sciences especially helpful in criminal investigation. Entering in advanced era of forensic DNA, profile reading is much trickier than ever. An unusual DNA profile was observed from a nail swab of female brutally murdered in a domestic violence case. At first, DNA profile was misconstrued as heterozygote at locus D7S820 but later, it was confirmed as homozygous from other evidence items submitted in the same case. Subsequent reprocessing of the same sample, from the extraction stage through to DNA profiling and DNA profile form victim's blood, conclusively established that the unusual peak is from a non-specific microbial presence at that locus.

An updated landscape on nanopharmaceutical delivery for mitigation of colon cancer.

Globally, colorectal cancer (CRC) continues to rank among the leading causes of cancer-related death. Systemic toxicity, multidrug resistance, and nonspecific targeting often pose challenges to conventional therapy for CRC. Because it is a complex disease with a complex genetic and environmental pathophysiology, advanced therapeutic strategies are needed. Nanotechnology presents a potential solution that may maximize therapeutic efficacy while minimizing negative effects by enabling personalized delivery of anticancer drugs. This review focuses on recent developments in colorectal drug delivery systems based on nanotechnology. Numerous nanomaterials, including liposomes, dendrimers, micelles, exosomes, and gold nanoparticles, are developed and used. Distinctive characteristics of mentioned nanocarriers are discussed along with strategies that can be employed for enhancing the delivery of drugs to colorectal cancer cells. The review also quotes the most relevant preclinical and clinical studies that show how these nanomaterials improve drug solubility, stability, and targeted delivery while overcoming the shortcomings of conventional therapies. Nanotechnology has made CRC treatment very efficient and advanced, which has opened up new possibilities for targeted drug delivery. Preclinical and clinical studies have also proved that the use of nano-formulations in colon-specific delivery systems have significant results, indicating potential for better patient outcomes. Future research can be done in order to overcome the hurdles regarding biocompatibility, expansion, and regulatory challenges. Large-scale clinical trials and nanomaterial formulation optimization should be the main goals of future research to confirm the efficacy and safety of these novel treatments.

Neutrophil-to-Lymphocyte Ratio and Absolute Lymphocyte Count as Early Diagnostic Tools for Corona Virus Disease 2019.

Background and objectives In comparison to real-time polymerase chain reaction (RT-PCR) testing, blood-related parameters including absolute lymphocyte count (ALC) and neutrophil-to-lymphocyte ratio (NLR) carry an indeterminate potential in the assessment of corona virus disease 2019 (COVID-19). Our main objective was to assess their efficacy in timely identification of COVID-19 patients and to determine whether these biomarkers can be employed as an early diagnostic tool in patients presenting with symptoms suggestive of COVID-19. Methodology This cross-sectional study was conducted at the Emergency Department of a Tertiary Care Hospital in Rawalpindi, Pakistan from November 2020 to March 2021. Patients suspected to have COVID-19 on a clinical basis (fever, cough or shortness of breath) were selected by using convenience non-probability sampling. RT-PCR was used to diagnose COVID-19 after evaluating NLR and ALC of the sample population. An NLR = 3.5 and ALC < 1 x 103 cells/mm3 was considered as the cut-off value. Statistical analysis was conducted via SPSS 23.0 (IBM Corp., Armonk, NY). Chi-square and independent t-tests were used to correlate various data variables, while p-value <0.05 was considered significant. Results Out of the 172 subjects included in the study, the mean age was 40.6 ± 10.0 years, while 51% of individuals were males. Fever was found to be the most prevalent complaint (94%). Double RT-PCR testing showed that 51.2% of the population was RT-PCR positive, having a mean ALC of 1.4 ± 0.9 x 103/mm3, significantly lower than RT-PCR negative cases (p < 0.001). In addition, NLR was drastically elevated for RT-PCR-positive individuals (p < 0.001) while it also had a distinctly high specificity of 91.7% among COVID-19 patients. Additionally, NLR did not correlate with any of the baseline patient-related parameters (presenting complaint, age, and gender). Conclusion NLR and ALC are potentially efficacious measures for an early diagnosis of COVID-19, and can be possibly utilized for an early diagnosis of COVID-19 suspects.

The metabolic response of subjects with type 2 diabetes to a high-protein, weight-maintenance diet.

In a randomized, crossover 5-wk study design, we recently reported that a weight-maintaining diet in which the percentage of total food energy as protein was increased from 15-30% resulted in a decrease in postprandial glucose and glycohemoglobin in people with untreated type 2 diabetes without a significant change in insulin. Protein was substituted for carbohydrate in the diet. The fat content remained unchanged. In this publication, we present data on other hormones and metabolites that were considered to potentially be affected by substitution of protein for carbohydrate in the diet. The mean fasting plasma GH and total IGF-I concentrations were elevated on the 30% protein diet. The urinary free cortisol also was increased. However, the urinary aldosterone was unchanged. Although urinary pH was decreased, calcium excretion was not significantly increased. The plasma postprandial alpha-amino nitrogen concentrations were increased, but the 24-h integrated concentration was unchanged, indicating an accelerated amino acid removal rate. The plasma urea nitrogen was increased as expected. The urea production rate also was increased such that a new steady-state fasting value was present. The calculated urea production rate accounted for 97% of the protein ingested on the 15% protein diet, but only 80% on the 30% protein diet, suggesting net nitrogen retention on the high-protein diet. In conclusion, an increase in dietary protein results in a number of metabolic adaptations in addition to reducing the circulating glucose concentration. Serum TSH, total T(3), free T(4), B(12), folate, homocysteine, uric acid, and creatinine concentrations were unchanged.

An increase in dietary protein improves the blood glucose response in persons with type 2 diabetes.

BACKGROUND: In single-meal studies, dietary protein does not result in an increase in glucose concentrations in persons with or without type 2 diabetes, even though the resulting amino acids can be used for gluconeogenesis. OBJECTIVE: The metabolic effects of a high-protein diet were compared with those of the prototypical healthy (control) diet, which is currently recommended by several scientific organizations. DESIGN: The metabolic effects of both diets, consumed for 5 wk each (separated by a 2-5-wk washout period), were studied in 12 subjects with untreated type 2 diabetes. The ratio of protein to carbohydrate to fat was 30:40:30 in the high-protein diet and 15:55:30 in the control diet. The subjects remained weight-stable during the study. RESULTS: With the fasting glucose concentration used as a baseline from which to determine the area under the curve, the high-protein diet resulted in a 40% decrease in the mean 24-h integrated glucose area response. Glycated hemoglobin decreased 0.8% and 0.3% after 5 wk of the high-protein and control diets, respectively; the difference was significant (P < 0.05). The rate of change over time was also significantly greater after the high-protein diet than after the control diet (P < 0.001). Fasting triacylglycerol was significantly lower after the high-protein diet than after the control diet. Insulin, C-peptide, and free fatty acid concentrations were not significantly different after the 2 diets. CONCLUSION: A high-protein diet lowers blood glucose postprandially in persons with type 2 diabetes and improves overall glucose control. However, longer-term studies are necessary to determine the total magnitude of response, possible adverse effects, and the long-term acceptability of the diet.

A fasting-induced decrease in plasma glucose concentration does not affect the insulin response to ingested protein in people with type 2 diabetes.

We previously have reported that protein, on a weight basis, is just as potent as glucose in increasing the insulin concentration in people with type 2 diabetes. In people without diabetes, protein is only approximately 30% as potent as glucose in this regard. In the present study, we tested the hypothesis that the increased insulin responsiveness to protein in people with type 2 diabetes is due to the elevated plasma glucose concentration in these individuals. Seven male subjects with untreated type 2 diabetes were given 50 g protein in the form of very lean beef at 8 AM after an overnight fast. On another occasion, the same individuals were fasted for an additional 24 hours to lower their plasma glucose concentration to near the normal reference range. They were then given 50 g protein. The 8 AM glucose concentration was lower after 24 hours of additional fasting, as expected. After ingestion of the protein meal, there was an unexpected, modest increase in glucose concentration after an additional 24 hours of fasting that was not observed with only an overnight fast. Despite the approximately 15% lower plasma glucose concentration at the time of the protein meal, the insulin responses were nearly identical. Thus, the greater insulin response to ingested protein is not likely to be due merely to a higher initial glucose concentration.

Chromium infusion in hospitalized patients with severe insulin resistance: a retrospective analysis.

OBJECTIVE: To investigate the effects of intravenous chromium on serum glucose and insulin infusion rates in hospitalized patients with severe insulin resistance. METHODS: In this retrospective study, we reviewed hospital records from January 1, 2008, to December 1, 2008, to identify patients for whom intravenous chromium was ordered at our academic medical center. To be included, patients were required to demonstrate profound insulin resistance and uncontrolled hyperglycemia (defined as the inability to achieve a blood glucose value less than 200 mg/dL during the 12 hours before chromium was given despite administration of continuous insulin infusion at a rate of 20 or more units/h) and to have received a continuous infusion of chromium chloride at 20 mcg/h for 10 to 15 hours for a total dose of 200 to 240 mcg. RESULTS: Fourteen patients met our inclusion criteria. Over the hour preceding intravenous chromium infusion, the mean ± standard deviation rate of insulin infusion was 31 ± 15 units/h, and blood glucose was 326 ± 86 mg/dL. Twelve hours after the initiation of chromium, these values were 16 ± 16 units/h and 162 ± 76 mg/dL, respectively (P = .011 for difference in mean insulin rate from baseline, P<.001 for difference in mean blood glucose from baseline) and 24 hours after, these values were 12 ± 15 units/h and 144 ± 48 mg/dL, respectively (P<.001 for both). CONCLUSIONS: Intravenous chromium decreases insulin needs and improves glucose control at 12 and 24 hours compared with baseline values. Chromium appears to improve hyperglycemia and insulin resistance in acutely ill patients and represents a potential new therapy. Future prospective randomized controlled trials are needed to confirm these results.

Cystic fibrosis-related diabetes: current trends in prevalence, incidence, and mortality.

OBJECTIVE: Cystic fibrosis (CF)-related diabetes (CFRD) diagnosis and management have considerably changed since diabetes was first shown to be associated with a poor prognosis in subjects with CF. Current trends in CFRD prevalence, incidence, and mortality were determined from a comprehensive clinical database. RESEARCH DESIGN AND METHODS: Data were reviewed from 872 CF patients followed at the University of Minnesota during three consecutive intervals: 1992-1997, 1998-2002, and 2003-2008. RESULTS: CFRD is currently present in 2% of children, 19% of adolescents, and 40-50% of adults. Incidence and prevalence are higher in female subjects aged 30-39 years; otherwise, there are no sex differences. In younger individuals, CFRD without fasting hyperglycemia predominates, but fasting hyperglycemia prevalence rises with age. CFRD mortality has significantly decreased over time. From 1992-1997 to 2003-2008, mortality rate in female subjects dropped by >50% from 6.9 to 3.2 deaths per 100 patient-years and in male subjects from 6.5 to 3.8 deaths per 100 patient-years. There is no longer a sex difference in mortality. Diabetes was previously diagnosed as a perimorbid event in nearly 20% of patients, but of 61 patients diagnosed with diabetes during 2003-2008, only 2 died. Lung function but not nutritional status is still worse in CF patients with diabetes compared with those without diabetes. Nutritional status and pulmonary status are similar between patients without fasting hyperglycemia and those with fasting hyperglycemia. CONCLUSIONS: Previously noted sex differences in mortality have disappeared, and the gap in mortality between CF patients with and without diabetes has considerably narrowed. We believe that early diagnosis and aggressive treatment have played a major role in improving survival in these patients.