Association Between Serum Testosterone and Serum PSA Among Men With and Without Partial Androgen Deficiency.

Serum prostatic specific antigen (PSA) and serum testosterone levels share an undefined relationship with each other, with many conflicting studies showing both positive and negative correlation between them. Our aim was to assess association between serum PSA and serum testosterone in healthy men with normal testosterone levels and men with partial androgen deficiency (PADAM). A cross sectional study was conducted at a teaching hospital setting where serum testosterone and aging male symptom scale (AMS) scores along with PSA were studied in 255 men (> 50 years) with and without PADAM. Mean total testosterone and serum PSA was 9.35 ± 1.33 nmol/L, 1.96 ± 0.76 ng/mL in males with PADAM and 15.30 ± 1.95 nmol/L, 1.85 ± 0.73 ng/mL respectively in males without PADAM. No significant relationship was observed between serum PSA and serum testosterone levels among healthy males irrespective of PADAM in the study population. We suggest, there is no need to adjust PSA values for biopsy decisions according to testosterone levels.

TLC-bioautography identification and GC-MS analysis of antimicrobial and antioxidant active compounds in Musa × paradisiaca L. fruit pulp essential oil.

INTRODUCTION: The absence of microbial growth and resistance to oxidative deterioration in fruits of Musa × paradisiaca L. (bananas) is an indication of the presence of antimicrobial and antioxidant metabolites. OBJECTIVE: In order to investigate the secondary metabolomic spectrum as well as the active antimicrobial and antioxidants present in essential oils (EOs) from fruits of different geographical areas of M. × paradisiaca, gas chromatography-mass spectroscopy (GC-MS) principal component data correlation analysis is complemented with antimicrobial assays and phytochemical and bioautographic antioxidant fingerprints with thin layer chromatography (TLC). METHODOLOGY: An EO was obtained by steam distillation and subjected to GC-MS and TLC for metabolomic profiling from fruit pulp. The antimicrobial potential was tested in both Escherichia coli as a gram negative and Bacillus subtilis as a gram positive microbe. Potential antioxidant metabolites were identified through TLC-bioautography and GC-MS analysis of active zones. RESULTS: A maximum of 0.56% v/w EO was isolated from fruit pulps of M. × paradisiaca. Minimum inhibitory concentrations (MICs) against B. subtillis and E. coli were 0.25 and 0.35 µg/mL, respectively. Thus, 56 metabolites were identified through GC-MS. The major abundant antimicrobial metabolites found in EOs are α-thujene, γ-terpinene, α- and ß-pinene, sabinene, ß-myrcene, limonene, α-capaene, caryophyllene and (Z,E)-α farnesene. Aceteugenol, palmitic acid, stearic acid, palmitin, and stearin were identified as antioxidant metabolites. Principal component analysis of metabolite data reveals correlations and a clear separation based on metabolites obtained from various areas. CONCLUSION: The data generated using metabolic profiling and cluster analysis helped to identify antimicrobial and antioxidant compounds in M. × paradisiaca.

Comparison of two multifraction radiotherapy schedules in management of painful bone metastases: A single institution prospective study.

BACKGROUND: Metastatic disease of bone is a common complication of most of the advanced malignancies. The majority of patients with bone metastases (BM) experience pain during their disease course and pain control can significantly improve their quality of life. Radiotherapy (RT) is an important modality in the management of BM and different schedules are followed worldwide. AIM: The aim of this study was to compare two multi-fractionated RT regimens (30Gy in 10 fractions and 20Gy in 5 fractions) with respect to the patient's performance, response and pain score in palliative management of painful BM. METHODS: This prospective observational study was undertaken between October 2015 and September 2017 at a government medical college in central India. Two fractionation regimens (30 Gy/10 fractions and 20 Gy/5 fractions) were used to treat 50 patients with painful BM (n = 25 in each arm). Patients were treated on telecobalt machine and response assessment done in terms of complete/partial/intermediate response and pain progression. Assessment was performed at one, two and three months post treatment. Statistical analysis was done using Fisher's exact test, student t-test and Chi-square test. A value of P < 0.05 was considered significant. RESULTS: There were 9 males (36%) and 16 females (64%) in arm A, and 15 males (60%) and 10 females (40%) in arm B. The median age was 47.50 years (range 28-81 years) in arm A and 54 years (range 34-85 years) in arm B. There was no statistically significant difference between the two groups in terms of pain palliation at a 1 month (p = 0.73), 2 month (p = 0.75) or 3 month (p = 0.71) follow up. In addition, the mean performance scores at the end of 3rd month in the 2 arms did not show any statistically significant difference (p = 0.51). CONCLUSION: A shorter treatment schedule (5 fractions) was equally efficacious as the standard schedule (10 fractions) in our setting. With the advantage of shorter overall treatment time and avoidance of re-irradiation, this schedule may be favourable for high volume centres.

JAMI: a Java library for molecular interactions and data interoperability.

BACKGROUND: A number of different molecular interactions data download formats now exist, designed to allow access to these valuable data by diverse user groups. These formats include the PSI-XML and MITAB standard interchange formats developed by Molecular Interaction workgroup of the HUPO-PSI in addition to other, use-specific downloads produced by other resources. The onus is currently on the user to ensure that a piece of software is capable of read/writing all necessary versions of each format. This problem may increase, as data providers strive to meet ever more sophisticated user demands and data types. RESULTS: A collaboration between EMBL-EBI and the University of Cambridge has produced JAMI, a single library to unify standard molecular interaction data formats such as PSI-MI XML and PSI-MITAB. The JAMI free, open-source library enables the development of molecular interaction computational tools and pipelines without the need to produce different versions of software to read different versions of the data formats. CONCLUSION: Software and tools developed on top of the JAMI framework are able to integrate and support both PSI-MI XML and PSI-MITAB. The use of JAMI avoids the requirement to chain conversions between formats in order to reach a desired output format and prevents code and unit test duplication as the code becomes more modular. JAMI's model interfaces are abstracted from the underlying format, hiding the complexity and requirements of each data format from developers using JAMI as a library.

Encompassing new use cases - level 3.0 of the HUPO-PSI format for molecular interactions.

BACKGROUND: Systems biologists study interaction data to understand the behaviour of whole cell systems, and their environment, at a molecular level. In order to effectively achieve this goal, it is critical that researchers have high quality interaction datasets available to them, in a standard data format, and also a suite of tools with which to analyse such data and form experimentally testable hypotheses from them. The PSI-MI XML standard interchange format was initially published in 2004, and expanded in 2007 to enable the download and interchange of molecular interaction data. PSI-XML2.5 was designed to describe experimental data and to date has fulfilled this basic requirement. However, new use cases have arisen that the format cannot properly accommodate. These include data abstracted from more than one publication such as allosteric/cooperative interactions and protein complexes, dynamic interactions and the need to link kinetic and affinity data to specific mutational changes. RESULTS: The Molecular Interaction workgroup of the HUPO-PSI has extended the existing, well-used XML interchange format for molecular interaction data to meet new use cases and enable the capture of new data types, following extensive community consultation. PSI-MI XML3.0 expands the capabilities of the format beyond simple experimental data, with a concomitant update of the tool suite which serves this format. The format has been implemented by key data producers such as the International Molecular Exchange (IMEx) Consortium of protein interaction databases and the Complex Portal. CONCLUSIONS: PSI-MI XML3.0 has been developed by the data producers, data users, tool developers and database providers who constitute the PSI-MI workgroup. This group now actively supports PSI-MI XML2.5 as the main interchange format for experimental data, PSI-MI XML3.0 which additionally handles more complex data types, and the simpler, tab-delimited MITAB2.5, 2.6 and 2.7 for rapid parsing and download.

Retraction Note to: Environmental impact of plantations in and around the petroleum refinery: a case study.

This article [1] has been retracted at the request of the Editor-in-Chief. Significant sections of the article show a similarity with the author's own article published previously [2]. All the authors agree with the retraction.

Lineage shift of dengue virus in Eastern India: an increased implication for DHF/DSS.

Dengue fever, a mosquito-borne viral disease, has become a major public health problem with marked expansion in recent decades. Dengue has now become hyperendemic in India with co-circulation of all the four serotypes. Herein, we report an unprecedented outbreak which occurred during August to October 2011 in Odisha, eastern India. This is the first report of a large epidemic in Odisha. Detailed serological and molecular investigation was carried out to identify the aetiology. Almost half of the samples were found to be dengue antigen (NS1) positive. Further molecular assays revealed circulation of mixed dengue serotypes (DENV-2 and DENV-3). Cosmopolitan genotype of DENV-2 and -3 were identified as the aetiology by phylogenetic analysis. Interestingly, a new lineage of DENV-3 within cosmopolitan genotype was incriminated in this outbreak. The emergence of the unprecedented magnitude of the dengue outbreak with the involvement of a novel lineage of DENV in a newer state of India is a major cause for concern. There is an urgent need to monitor phylodynamics of dengue viruses in other endemic areas.

Inflammatory markers in patients with rheumatoid arthritis.

BACKGROUND: Autoimmune diseases such as rheumatoid arthritis (RA) are the consequence of a persistent imbalance between pro- and anti-inflammatory immune mechanisms, leading to chronic inflammation. The objective of this study was to determine whether the high sensitive C-reactive protein (hs-CRP) and cytokines are elevated in RA patients and to investigate the relationship between these markers and disease activity in RA, measured by disease activity score 28 (DAS28). METHODS: We studied 110 RA patients according to American College of Rheumatology revised criteria for RA, and 55 controls matched by age and sex. Serum levels of hs-CRP and cytokines interleukin (IL)-6, IL-10 and tumour necrosis factor-α (TNF-α) were estimated and correlated with the DAS28. Serum hs-CRP was assayed immunoturbidimetrically and cytokines were analysed by commercially available ELISA kit. RESULTS: We found that RA patients had significantly higher levels of serum hs-CRP (p<0.001), IL-6 (p<0.001), TNF-α (p<0.001), and IL-10 (p<0.01) as compared to healthy controls. hs-CRP, IL-6 and TNF-α correlated positively (p<0.001) and IL-10 correlated negatively (p<0.01) with DAS28. CONCLUSIONS: These results demonstrate that RA patients have high levels of inflammatory markers, and these levels are correlated with the DAS28. These findings suggest a possible role of these markers in the pathogenesis of RA. Moreover, these biomarkers can be used as markers of disease activity in the diagnosis and treatment of RA.

Arsenic and cadmium are inhibitors of cyanobacterial dinitrogenase reductase (nifH1) gene.

The enzyme nitrogenase complex is a key component conferring nitrogen fixation in all known diazotrophs. This study for the first time examines the impact of As, Na, Cd, Cu and butachlor on component II (dinitrogenase reductase, nifH1) of nitrogenase from diazotrophic cyanobacterium Anabaena sp. PCC7120 using in silico and wet lab approaches. The nifH1 of Anabaena is a glycine-rich stable protein having DNA-binding properties and shows close similarity with free living compared with symbiotic diazotrophs. Phylogenetic tree revealed an adverse effect of the selected stresses on close homologs across the diazotroph community. The protein interaction network demonstrated the presence of nirA, glnA, glnB, alr4255 and alr2485 proteins besides nif proteins, suggesting their involvement in nitrogen fixation along with nifH1. Homology modelling and docking under As, Na, Cd, Cu and butachlor revealed an interaction between stressors and nifH1 protein which was further validated by a transcript of the gene through quantitative real-time PCR (qRT-PCR). Presence of binding sites for As, Na, Cd and Cu on oxyR promoter attested their adverse affects on nifH1. Maximum down-regulation of nifH1 in Cd and As followed by salt, copper and butachlor revealed that arsenic and cadmium were most potential inhibitors of nitrogenase of diazotrophic community, which might negatively affect crop yield.

Uninostril endonasal trans-sphenoidal approach for pituitary macroadenoma-Operative nuances step by step.

The Uninostril Endonasal Transsphenoidal approach stands out for its ability to preserve nasal anatomy, ensuring normal postoperative breathing while reducing postoperative nasal complications. The Uninostril approach offers a simplified access, expedites both the nasal phase and closure, all while leaving the contralateral nostril untouched, allowing for a potential rescue flap if needed. This method is particularly suited for primary cases of sellar suprasellar Knosp 0/1 pituitary adenomas located medial to the carotid arteries and with T2 iso to hyperintense signals on the MRI. The objective of this article is to elucidate the operative step by step nuances of the uninostril endonasal trans-sphenoidal surgery. The patient positioning is key with a neutral head alignment positioned above the heart level and slightly tilted to the opposite side. This position is ergonomically better, reduces the venous bleeding, and enhances gravity-assisted tumor removal. Despite its advantages-such as improved postoperative nasal quality and a comparable rate of gross total tumor resection to the Bi-nostril approach-the Uninostril technique is not without limitations. Challenges include a restricted field of view, limited instrument maneuverability, and the potential need to convert to a Bi-nostril approach in cases of excessive bleeding or visualization difficulties. Overall, this approach provides a viable alternative for pituitary adenoma resection in selected subset of the patients, effectively balancing the oncologic resection and patient's related outcomes.

Fish-tail Plasty: A Secure Technique to Enhance Cosmesis at the Lateral End of Mastectomy Scar and Prevent Dog Ear.

Mastectomy is very common surgical procedure for breast cancer. The closure of transverse elliptical mastectomy incisions has been represented with numerous modifications since 1915. The technical challenge is to avoid a fold of skin dogging laterally ("dog-ear"). This might lead to off future discomfort and poor cosmetic result. However, various surgical techniques are reported to tackle this lateral dog ear, there is no standardized technique. We therefore conduct a systematic review of the surgical techniques with the aim of comparing the merits and limitations of every technique. The comparative study among 72 patients was performed in Bangabandhu Sheikh Mujib Medical University, Anower Khan Modern Medical College & Hospital and Care Medical College & Hospital, Bangladesh from July 2017 to January 2020. Patients were divided randomly into two groups: Group I underwent fishtail technique group (36 patients), Group II underwent modified suturing technique group (36 patients). The follow up periods were 1 month and 3 months post-operatively for determination of the presence of dog ear and patient's satisfaction regarding cosmetic outcome and comfortability. Incidence of dog ear in fish-tail plasty group patients was less than that for Group II yet the difference is not significant less (p value 0.001). In consideration of patient satisfaction, doctor satisfaction and patient comfortability were significantly higher in Group I than Group II (p value 0.476 and 0.001 respectively). Fish-tail plasty was significantly better in patient satisfaction, comfortability and doctor satisfaction than modified suturing techniques and it might be recommended following mastectomy in obese patients for improving cosmesis and avoiding discomfort due to redundant skin.

A new arsenate reductase involved in arsenic detoxification in Anabaena sp. PCC7120.

In silico analysis followed by experimental validation leads us to propose that the predicted protein All0195 of Anabaena sp. PCC7120 showing enhanced expression under sodium arsenate (Na2HAsO4) stress belongs to the thioredoxin superfamily with structural similarity to bacterial arsenate reductase. The All0195 protein demonstrated C-X-TC-X-K, NTSG-X2-YR, and D-X2-L-X-KRP as functional motifs that show similarity to seven known bacterial arsenate reductase family protein homologs with Cys, Arg, and Pro as conserved residues. In view of physicochemical properties, such as aliphatic index, ratio of Glu + Lys to Gln + His, and secondary structure, it was evident that All0195 was also a thermostable protein. The predicted three-dimensional structure on molecular docking with arsenate oxyanion ([Formula: see text]) revealed its interaction with conserved Cys residue as also known for other bacterial arsenate reductase. In silico derived properties were experimentally attested by cloning and heterologous expression of all0195. Furthermore, this protein functionally complemented the arsenate reductase-deficient sodium arsenate-hypersensitive phenotype of Escherichia coli strainWC3110 (ΔarsC) and depicted arsenate reductase activity on purification. In view of the above properties, All0195 appears to be a new arsenate reductase involved in arsenic detoxification in Anabaena sp. PCC7120.

Electromagnetic transition from the 4+ to 2+ resonance in 8Be measured via the radiative capture in 4He + 4He.

An earlier measurement on the 4+ to 2+ radiative transition in 8Be provided the first electromagnetic signature of its dumbbell-like shape. However, the large uncertainty in the measured cross section does not allow a stringent test of nuclear structure models. This Letter reports a more elaborate and precise measurement for this transition, via the radiative capture in the 4He + 4He reaction, improving the accuracy by about a factor of 3. Ab initio calculations of the radiative transition strength with improved three-nucleon forces are also presented. The experimental results are compared with the predictions of the alpha cluster model and ab initio calculations.

Limited asymmetry dependence of correlations from single nucleon transfer.

Single nucleon pickup reactions were performed with a 18.1 MeV/nucleon (14)O beam on a deuterium target. Within the coupled reaction channel framework, the measured cross sections were compared to theoretical predictions and analyzed using both phenomenological and microscopic overlap functions. The missing strength due to correlations does not show significant dependence on the nucleon separation energy asymmetry over a wide range of 37 MeV, in contrast with nucleon removal data analyzed within the sudden-eikonal formalism.

Prevalence of elevated blood lead levels and risk factors among children living in Patna, Bihar, India 2020.

Childhood lead exposure remains a key health concern for officials worldwide, contributing some 600,000 new cases of intellectually disabled children annually. Most children affected by high exposure to lead live in low- and middle-income countries. The leaded gasoline phase out in India was completed in 2000. Yet, in 2020, an estimated 275 million children aged 0 to 9 years had blood lead levels (BLLs) ≥ 5 µg/dL known to adversely affect intelligence and behavior. Lead sources reported in India include spices, cookware, paint, traditional medicines and cosmetics, and lead-acid battery recycling and repair. However, their relative contribution has not been characterized. More than 200 lead pollution sites related to battery recycling and repair activities were identified in Bihar and Jharkhand, India. Ninety percent of the recycling sites had soil lead concentrations exceeding the US Environmental Protection Agency's standards. We compared blood and environmental lead levels in two groups of children in Patna, Bihar. Households in proximity to battery recycling operations (Proximal n = 67) versus households distal to these operations (Distal n = 68). The average age of children was 40 months; 46% were female. Overall, the geometric mean (GM) BLL was 11.6 µg/dL. GM BLLs of children in Proximal and Distal households were not significantly different (10.2 µg/dL vs. 13.1 µg/dL respectively; p≤0.07). About 87% children, 56 Proximal and 62 Distal had BLLs ≥5 µg/dl. Lead concentrations in environmental samples were significantly higher in Proximal households (soil mean 9.8 vs. 1.6 µg/ft2; dust mean 52.9 vs. 29.9 µg/ft2 p<0.001; Proximal vs. Distal respectively) whereas concentrations in all spices were higher in Distal households (mean 46.8 vs 134.5 ppm p<0.001; Proximal vs. Distal respectively), and turmeric (mean 59.4 vs. 216.9 ppm Proximal vs. Distal respectively). In multivariate analyses for all children lead in spices and turmeric and number of rooms in the house were significant while for the Proximal group only lead in spices remained in the model. The predictive value of these models was poor. For the Distal group, a model with lead concentration in spices, turmeric and soil and number of rooms in the house was a much better fit. Of the 34 water samples collected, 7 were above the Indian standard of 10 ppb for lead in drinking water (2 in the Proximal area, 5 in the Distal area). Children in Patna, Bihar, India are exposed to multiple sources of lead, with lead levels in house dust and loose, locally sourced spices the most likely to increase blood lead levels. A holistic approach to blood lead testing and source identification and remediation are necessary to prevent lead exposure.

Growing Skull Fractures; Pathogenesis and Surgical Outcome.

BACKGROUND: We performed a retrospective study of 67 patients and their data for radiological investigations by serial Xrays, computed tomography, magnetic resonance imaging, uniform surgical procedure of craniotomy. The results were analyzed to determine the natural course of the disease, anatomical changes at various intervals following trauma, and outcome of surgical procedure in terms of cranial reconstruction, seizures, and progress in neurological deficit. RESULTS: Among 67 patients, 34 (50.74%) were male and 33 (49.26%) were female patients. About 86.67% of patients sustained the injury before the age of 3 years. Development of seizures in 28 patients (41.80%) is the most common symptom. In our study, 43.28% of patients (29 cases) had a combination of Type I and II of growing skull fracture. The dural defects confirmed in all cases were nearly twice (average 1.42) as large as the bone defects. All patients under the age of 3 years with diastatic skull fracture should be closely followed up and should be examined 2-3 months later to look for evidence of a growing skull fracture. Linear fractures and burst fractures in an infant with a scalp swelling must be corrected early to prevent a growing skull fracture. CONCLUSION: Early management can avoid difficult surgical dissection and progressive neurological sequelae seen with delayed intervention. Surgical correction results in the prevention of brain shift and increase in meningocerebral cicatrices. Meticulous surgery and vigilant postoperative care reduce the morbidity and mortality. In our opinion, the autologous material is the best choice because of its tissue compatibility, convenience, inexpensiveness, and rare rate of infection.

Reversal of hypermethylation and reactivation of the RARß2 gene by natural compounds in cervical cancer cell lines.

Reactivation of tumour suppressor genes that have been silenced by promoter methylation is a very attractive molecular target for cancer therapy. The treatment of a squamous cervical cancer cell line, SiHa, with 20 µM curcumin and genistein resulted in demethylation of promoter of the RARß2 gene and led to the reactivation of the gene. The degree of methylation as observed by MSP decreased as the time period of treatment was increased from 72 h to 6 days. In HeLa cells (an adenocarcinoma cervical cancer cell line) there was also reversal of hypermethylation of the RARß2 gene after six days of treatment with 20 µM curcumin. However, allyl sulphide treatment (20 µM) did not cause the reversal of hypermethylation until 72 h of treatment in the SiHa cell line. This is the first report to show the reversal of hypermethylation of the RARß2 gene by genistein and curcumin in cervical cancer cell lines. Furthermore, these compounds acted as doublepronged agents as they caused apoptosis in the treated cervical cancer cell lines in addition to reversal of promoter hypermethylation.

Environmental impact of plantations in and around the petroleum refinery: a case study.

Plantation or green belt (GB) grown around the factories and industrial premises improves the condition of land, mitigates air pollution (as the plants serve as a sink for pollutants and check the flow of dust, etc.), and reduces the level of noise pollution. The software developed by NEERI for the determination of the optimal width of GB in and around an industry is based on the pollution attenuation coefficient of selected plant species of deciduous trees existing in the region. The assessment of the impact of these plantations/green belts of 500-m width in and around a petroleum refinery in the west coast of India is evaluated for reducing/managing various waste generated, and it is observed that the overall efficiency is more than 60%.

Effectiveness of a training program about bio-medical waste management on the knowledge and practices of health-care professionals at a tertiary care teaching institute of North India.

BACKGROUND: Training of health-care providers about the various aspects of biomedical waste (BMW) management and handling (M and H) rules can improve the safe disposal of BMW and protect the patients and public from related hazards. OBJECTIVES: Our study objective was to evaluate the existing knowledge regarding BMW management rules among selected health-care professionals and to evaluate the impact of training program on BMW management on the knowledge and practices of health-care professionals. METHODOLOGY: The training program on BMW management rules was conducted in April 2018. A total of 250 participants were trained. A structured validated questionnaire was used. The data were analyzed, and the mean score of pre- and post-test was compared by the paired-t test. RESULTS: Majority of the participants were female (83%) aged 20-30 years (56%). The majority of the participants were married (74%) and were from urban areas (74%). The mean pretest and posttest score were 14.00 and 19.94 respectively (P < 0.000). CONCLUSION: The structured training on all aspects of BMW management led to statistically significant improvement in the knowledge among health-care professionals. RECOMMENDATIONS: Such training programs need to be regularly conducted.

Over-expression of Caj1, a plasma membrane associated J-domain protein in Saccharomyces cerevisiae, stabilizes amino acid permeases.

Hsp70: J-domain protein (JDP) machines, along with the cellular protein degradation systems play a central role in regulating cellular proteostasis. An equally robust surveillance system operates at the plasma membrane too that affects proper sorting, stability as well as the turnover of membrane proteins. Although plausible, a definitive role of the Hsp70: JDP machine in regulating the stability of plasma membrane proteins is not well understood in Saccharomyces cerevisiae. Here we show that a moderate over-expression of Caj1, one of the thirteen JDPs residing in the nucleo-cytosolic compartment of S. cerevisiae reduced the cold sensitivity of tryptophan auxotrophic yeast cells by stabilizing tryptophan permeases, Tat1 and Tat2 in a J-domain dependent manner. Concomitantly, higher Caj1 levels also caused slow growth and increased plasma membrane damage at elevated temperatures possibly due to the stabilization of thermolabile plasma membrane proteins. Finally, we show that although majorly cytosolic, Caj1 also co-localizes with the membrane dye FM4-64 at the cellular periphery suggesting that Caj1 might interact with the plasma membrane. Based on the results presented in this study, we implicate the Hsp70: Caj1 chaperone machine in regulating the stability or turnover of plasma membrane proteins in budding yeast.