Successful Implementation of Image-Guided Pencil-Beam Scanning Proton Therapy in Medulloblastomas.

Medulloblastoma is the most common malignant brain tumour in children, while much rarer in adults. Although the prognosis and outcomes have greatly improved in the era of modern multidisciplinary management, long-term treatment-induced toxicities are common. Craniospinal irradiation followed by a boost to the primary and metastatic tumour sites forms the backbone of treatment. Proton therapy has been endorsed over conventional photon-based radiotherapy due to its superior dosimetric advantages and subsequently lower incidence and severity of toxicities. We report here our experience from South-East Asia's first proton therapy centre of treating 40 patients with medulloblastoma (38 children and adolescents, 2 adults) who received image-guided, intensity-modulated proton therapy with pencil-beam scanning between 2019 and 2023, with a focus on dosimetry, acute toxicities, and early survival outcomes. All patients could complete the planned course of proton therapy, with mostly mild acute toxicities that were manageable on an outpatient basis. Haematological toxicity was not dose-limiting and did not prolong the overall treatment time. Preliminary data on early outcomes including overall survival and disease-free survival are encouraging, although a longer follow-up and data on long-term toxicities are needed.

Amide proton transfer imaging-arterial spin labeling mismatch: a new imaging biomarker for pilocytic astrocytoma.

We describe the potential utility of Amide Proton Transfer weighted (APTw) Magnetic Resonance Imaging and arterial spin labeling (ASL) in characterizing pilocytic astrocytoma (PA), a type of brain tumor that can be challenging to accurately diagnose and treat. The study included 50 patients with solid or predominantly solid intra-cranial and intra-axial tumors, with 25 patients diagnosed with PA and 25 patients diagnosed with other types of tumors. The study found that the APTw imaging-arterial spin labeling (ASL) mismatch is a new imaging biomarker that could be used to differentiate PA from other types of tumors with a high degree of sensitivity and specificity. The results suggest that APTw imaging and ASL may be useful in characterizing PA, potentially improving diagnosis and treatment planning for this type of brain tumor.

Role of dynamic and parametric whole-body FDG PET/CT imaging in molecular characterization of primary breast cancer: a single institution experience.

AIM: The aim of this pilot study was to assess the role of dynamic whole-body PET and parametric imaging in the biological characterization of primary breast cancer. MATERIALS AND METHOD: In total 24 histologically proven primary breast cancer lesions in 21 consecutive patients were retrospectively analyzed. Each patient underwent 18F-fluoro-deoxyglucose whole-body dynamic PET-CT before any treatment. Dynamic PET images were acquired in the list mode for a total duration of 70 min. The reconstructed parametric imaging generated Patlak plot-based 'Slope' and 'Intercept' images, from which parametric indices ki and DV were obtained. The standard uptake value (SUV) metric was also obtained by summing the last few frames of the dynamic study. ki, distribution volume (DV) and SUV were correlated with the histological tumor grade, biomarkers [hormone receptors and human epidermal growth factor receptor 2 (HER-2) neu expression] and molecular subtypes (A, B and C) as well as with tumor size, regional nodal metastases and distant metastases. RESULTS: The mean ki was found to be significantly higher in grade III than II lesions (P = 0.005), HER-2 neu positive status (P = 0.04) and molecular subtype B (P = 0.04) as well as in greater than T1 lesions(P = 0.0003 and P = 0.04, respectively) and node-positive lesions (P = 0.009). Though mean ki was not found to be significant for the hormone receptors status (P = 0.08), it showed the best correlation compared to the other parameters (P = 0.8 for DV and P = 0.1 for SUV). Spearman's correlation test, area under the curve (AUC) and mismatch percentage also revealed ki to predict tumor grade (AUC, 0.95; r = 0.7; P = 0.0001), HER-2 neu status and molecular subtypes (AUC, 0.81; r = 0.49 and P = 0.01) along with the hormone receptors status (AUC, 0.83; r = 0.32; P = 0.1). The mean DV failed to show any association with any of the biological or anatomical staging parameters. Though ki was found to be comparable to that of SUV in almost all the assessed parameters, it appeared to be better for predicting hormone receptors status even though both parameters were not statistically significant. CONCLUSION: Our initial observation in a small cohort of breast cancer patients suggests that ki is promising in stratifying primary breast cancer lesions according to the tumor grade and biological characteristics.

Spinal Drop Metastasis of Glioblastoma-Two Case Reports, Clinicopathologic Features, Current Modalities of Evaluation, and Treatment with a Review of the Literature.

BACKGROUND: Glioblastomas (World Health Organization grade IV) are aggressive primary neoplasms of the central nervous system. Spinal metastasis occurs supposedly in 2%-5% of patients. This percentage may be only the tip of iceberg because most succumb to the disease before clinical detection and few documented cases are reported. CASE DESCRIPTIONS: A 45-year-old man presented with history of diplopia and gait disturbance. Magnetic resonance imaging showed a left cerebellar space-occupying lesion. The histopathology was consistent with glioblastoma. The patient underwent adjuvant chemoradiation. A year later, he presented with seizures, worsening headache, neck stiffness, and low back pain. Imaging showed metastasis to the S1/S2 region of the spinal canal. A 29-year-old man presented with episodic headaches associated with nausea, vomiting, neck stiffness, and imbalance while walking. Computed tomography of the brain showed a hypodense lesion involving the left midbrain, pons, and left middle cerebellar peduncle, causing fourth ventricular pressure with obstructive hydrocephalus. A navigation-guided biopsy of the brainstem lesion confirmed the diagnosis of glioblastoma World Health Organization grade IV, isocitrate dehydrogenase 1 (R132 H) and H3K27M negative. Isocitrate dehydrogenase gene sequencing was suggested. The patient was referred for chemoradiation. During treatment, he worsened neurologically and developed axial neck and back pain. Neuraxis screening showed disseminated leptomeningeal spread, which was confirmed on dural biopsy. CONCLUSIONS: Spinal and dural metastasis should always be suspected in patients with glioblastoma with signs and symptoms not explained by primary lesion. A regular protocol with postcontrast magnetic resonance imaging before and after initial surgery is mandatory to detect spinal metastasis before it becomes clinically apparent, thereby improving the prognosis and quality of life in patients.

Multidimensional Studies of Pancratium parvum Dalzell Against Acetylcholinesterase: A Potential Enzyme for Alzheimer's Management.

Objective:Pancratium L. (Amaryllidaceae J.St. Hil.) is a monocot genus with bulbous habitat and about 20 species worldwide have significant medicinal properties. The present envision aims to investigate the potential ability of Pancratium species for acetylcholinesterase (AChE) inhibition as a remedy for Alzheimer disease (AD). Different Pancratium species were screened for the inhibition of AChE enzyme from various localities across India. Prominent species was further studied for anti-inflammatory, antioxidant, metal chelating and UHPLC-QTOF-MS analysis.Methods: Nine different species collected across India were examined for AChE inhibition and for binding affinity studies using Surface Plasmon Resonance (SPR). Highest inhibition species was subjected to Response Surface Methodology (RSM) to accomplish the effective conditions for maximum extraction of phytomolecules in accordance with the inhibition of the AChE. Further, extract under optimized conditions were used to study anti-inflammatory, antioxidant, metal chelating and UHPLC-QTOF-MS analysis for tentative identification of phytomolecules.Results: Amongst different species collected, P. parvum Dalzell exhibited maximum inhibition 93.30 ± 1.71% with promising IC50 20 ± 0.22 µg/ml value. In addition, binding affinity toward AChE and ß plaques using SPR technique showed a higher binding response toward the enzyme. RSM study resulted that water extracts at 50 °C and 5.46 hours heating executed maximum inhibition. Other studies showed prominent anti-inflammatory and metal chelating ability with low antioxidant property.Conclusion: By using UHPLC-QTOF-MS compounds were tentatively identified for the concerned activities mentioned above. This work reports for accounting the detailed study of P. parvum and which can be further entailed for the treatment of various neurological disorders.

The Binding Affinity of Small Molecules with Yam Tyrosinase (Catechol Oxidase): A Biophysical Study.

Yam tyrosinase has become an economically essential enzyme due to its ease of purification and abundant availability of yam tubers. However, an efficient biochemical and biophysical characterization of yam tyrosinase has not been reported. In the present study, the interaction of yam (Amorphophallus paeoniifolius) tyrosinase was studied with molecules such as crocin (Crocus sativus), hydroquinone, and kojic acid. Surface plasmon resonance (SPR), fluorescence spectroscopy, and circular dichroism techniques were employed to determine the binding affinities and the changes in secondary and tertiary structures of yam tyrosinase in the presence of four relevant small molecules. Hydroquinone and crocin exhibited very low binding affinities of 0.24 M and 0.0017 M. Due to their apparent weak interactions, competition experiments were used to determine more precisely the binding affinities. Structure-function interrelationships can be correlated in great detail by this study, and the results can be compared with other available tyrosinases.

Clinicopathological Analysis of HIF-1alpha and TERT on Survival Outcome in Glioblastoma Patients: A Prospective, Single Institution Study.

Glioblastoma multiforme is a highly malignant and aggressive primary brain tumor with a dismal prognosis. We studied the association of immunohistochemical expression of hypoxia inducible factor-1 alpha (HIF-1α), telomerase reverse transcriptase (TERT), isocitrate dehydrogenase 1 (IDH1) and tumor protein p53 with overall survival (OS) in glioblastoma patients uniformly treated by standard of care, with adequate follow-up. In 87 patient samples studied, 59 were male and 28 were female. The median age was 55 years. The median follow-up was 27.7 months and the median overall survival was 14.9 months. Nuclear staining of HIF-1α was expressed in all samples and scored as strong in 42 (48%) and weak in 45 (52%). Multivariable Cox regression revealed strong HIF-1α expression as an independent poor prognostic factor (Hazard Ratio 2.12, 95% CI 1.20 - 3.74, P = 0.01). There was a statistically significant difference in OS (9.8 months vs. 16.3 months) between the "HIF-1α - strong and TERT - strong" and the "HIF-1α - weak and TERT - weak" patient subgroups, as evaluated by Kaplan-Meier analysis (P = 0.005). In our study, HIF-1α expression was an independent predictor of OS. The subgroup of patients with strong expression of both HIF-1α and TERT had the poorest prognosis.

Intraosseous Hemangioma of Sella: Case Report and Review of Literature.

BACKGROUND: Primary intraosseous hemangioma (PIH) of the skull base, when localized in the sella, is a rare, benign lesion that can mimic other common sellar tumors. Such tumors may be asymptomatic incidental radiologic findings or present with nonspecific symptoms (e.g., headaches). CASE DESCRIPTION: :We present a case of a primary intraosseous hemangioma of the body of sphenoid bone extending into the sellar cavity, clinicoradiographically mimicking an atypical pituitary adenoma. CONCLUSIONS: PIH should be included as a rare differential diagnosis in cases of space-occupying sellar lesions with atypical features. Radiologic and intraoperative findings may be suited to entertain a probable diagnosis; however, a definite diagnosis can only be obtained via histopathologic analysis. Surgical excision may be chosen under the assumption of dealing with a primary pituitary lesion, but extent of resection depends on the accessibility, extent, involvement of surrounding structures (such as the internal carotid artery/cavernous sinus), and control of intraoperative bleeding. When facing inoperable or residual lesions, radiotherapy can be a viable option.

Comparative biophysical characterization: A screening tool for acetylcholinesterase inhibitors.

Among neurodegenerative diseases, Alzheimer's disease (AD) is one of the most grievous disease. The oldest cholinergic hypothesis is used to elevate the level of cognitive impairment and acetylcholinesterase (AChE) comprises the major targeted enzyme in AD. Thus, acetylcholinesterase inhibitors (AChEI) constitutes the essential remedy for the treatment of AD. The study aims to evaluate the interactions between natural molecules and AChE by Surface Plasmon Resonance (SPR). The molecules like alkaloids, polyphenols and substrates of AChE have been considered for the study with a major emphasis on affinity and kinetics. To better understand the activity of small molecules, the investigation is supported by both experimental and theoretical approach such as fluorescence, Circular Dichroism (CD) and molecular docking studies. Amongst the screened ones tannic acid showed promising results compared with others. The methodology followed here have highlighted many molecules with a higher affinity towards AChE and these findings may take lead molecules generated in preclinical studies to treat neurodegenerative diseases. Additionally, we suggest a unique signature for the heterogeneous analyte model using competitive experiments for analyzing simultanous interactions of both the analytes.

Statistical optimization of process parameters for inulinase production from Tithonia weed by Arthrobacter mysorens strain no.1.

Tithonia rotundifolia is an easily available and abundant inulin rich weed reported to be competitive and allelopathic. This weed inulin is hydrolyzed by inulinase into fructose. Response surface methodology was employed to optimize culture conditions for the inulinase production from Arthrobacter mysorens strain no.1 isolated from rhizospheric area of Tithonia weed. Initially, Plackett- Burman design was used for screening 11 nutritional parameters for inulinase production including inulin containing weeds as cost effective substrate. The experiment shows that amongst the 11 parameters studied, K2HPO4, Inulin, Agave sisalana extract and Tithonia rotundifolia were the most significant variables for inulinase production. Quantitative effects of these 4 factors were further investigated using Box Behnken design. The medium having 0.27% K2HPO4, 2.54% Inulin, 6.57% Agave sisalana extract and 7.27% Tithonia rotundifolia extract were found to be optimum for maximum inulinase production. The optimization strategies used showed 2.12 fold increase in inulinase yield (1669.45 EU/ml) compared to non-optimized medium (787 EU/ml). Fructose produced by the action of inulinase was further confirmed by spectrophotometer, osazone, HPTLC and FTIR methods. Thus Tithonia rotundifolia can be used as an eco-friendly, economically feasible and promising alternative substrate for commercial inulinase production yielding fructose from Arthrobacter mysorens strain no.1.

Frequency, distribution, and immunomorphologic characteristics of peripheral T-cell lymphoma, not otherwise specified in a tertiary care center in Southern India.

AIMS: In world literature, Peripheral T-cell lymphomas (PTCLs) constituted about 12% of non-Hodgkin's lymphomas (NHL) of which PTCL not otherwise specified (NOS) was the most common subtype. This study was undertaken to ascertain the frequency and to assess the morphologic and immunophenotypic characteristics of PTCL, NOS over a period of 5 years in a tertiary care referral center in Southern India. MATERIALS AND METHODS: Slides and blocks of all PTCL, NOS were retrieved, and a detailed morphologic and immunophenotypic study using a wide panel of antibodies was done. RESULTS: During this study, NHL constitutes 77.61% of all lymphomas. PTCL formed about 12.55% (251 cases) of all NHL. PTCL NOS was the most common subtype (30.68%). The most common site of involvement was lymph nodes (75%) followed by extranodal sites such as soft tissue (8.33%), gastrointestinal tract including oral cavity (6.67%), nasal cavity (5%), central nervous system (1.67%), lung (1.67%), and spleen (1.67%). PTCL, NOS showed a broad morphologic spectrum and had varied morphologic patterns with some mimicking reactive hyperplasia and some mimicking known type of T-cell lymphomas, B-cell lymphomas, and Hodgkin's lymphoma. CONCLUSIONS: PTCL, NOS constituted about 30.68% of all PTCLs in our institution during a 5-year period and was the second most common type of PTCL. Immunophenotyping using a wide panel of T-cell antibodies is necessary to distinguish PTCL, NOS from other lymphomas which they mimic, as they are known to carry a worse prognosis.

Exploration of surface plasmon resonance for yam tyrosinase characterization.

Tyrosinase is a ubiquitous enzyme in nature. It catalyzes the reaction in melanin formation. In this investigation, tyrosinase from a Yam tuber (Amorphophallus paeoniifolius) was extracted and purified by ultra-centrifugal filtration followed by ion exchange chromatography. The purified enzyme was obtained with purification fold of 12.65 and specific activity of 60.25 U/mg. The molecular weight of purified enzyme was confirmed to be 45 kDa by SDS-PAGE. The enzyme activity was optimal at pH 6 and 30 °C with Km 10 mM. Further the kinetic study of purified yam tyrosinase was carried out using Surface Plasmon Resonance method. In brief, enzyme was immobilized on chip surface by amine coupling method and different small molecules were analyzed for their binding affinities at different concentrations (mM). The affinity of each compound for yam tyrosinase was different with KD values as tannic acid (5.13 × 10-5), gallic acid (2.05 × 10-8), ascorbic acid (0.004544), caffeic acid (3.09 × 10-9), pyrogallol (2.13 × 10-4) and catechol (1.09 × 10-4). The kinetics data results were confirmed by inhibition assays and IC50 values were calculated. This data will help to study the role of tyrosinase in hyperpigmentation which will create an avenue for tyrosinase inhibitors. Tyrosinase inhibitors have wide range of applications in cosmetics, medical and food industries.

Interaction of small molecules with human tyrosinase: A surface plasmon resonance and molecular docking study.

Studies on tyrosinase have recently gained the attention of researchers due to the enzyme's biological functions and potential applications in food and cosmetic applications. In this present study, screening and kinetic evaluation of small molecules (>300Da) on human tyrosinase was carried out using surface plasmon resonance and molecular docking studies. Four molecules showed significant binding were further characterized. The binding constant KD (M) values obtained for crocin, curcumin, tannic acid, pyrogallol and hydroquinone are 5.60×10-5, 1.52×10-3, 6.45×10-5, 1.34×10-5 and 2.433×10-7M respectively. In silico docking studies using autodock indicated significant binding and revealed the binding pocket residues for all molecules. The study shows the Biacore/SPR sensor's ability for screening and detection of inhibitors for human tyrosinase. This study can be used to rapidly screen and optimize various lead compounds as binders/inhibitors/modulators of human tyrosinase enzyme activity.

Interaction of small molecules with fungal laccase: A Surface Plasmon Resonance based study.

Laccases have a great potential for use in industrial and biotechnological applications. It has affinity towards phenolics and finds major applications in the field of bioremediation. Here, Surface Plasmon Resonance (SPR) as a biosensor with immobilized laccase on chip surface has been studied. Laccase was immobilized by thiol coupling method and compounds containing increasing number of hydroxyl groups were analyzed for their binding affinity at various concentrations in millimolar range. The small molecules like phloroglucinol (1.532×10(-8) M), crocin (3.204×10(-3) M), ascorbic acid (8.331×10(-8) M), kojic acid (6.411×10(-7) M) and saffron (3.466×10(-7) M) were studied and respective KD values are obtained. The results were also confirmed by inhibition assay and IC50 values were calculated. All these molecules showed different affinity towards laccase in terms of KD values. This method may be useful for preliminary screening and characterization of small molecules as laccase substrates, inhibitors or modulators of activity. This method will be useful for rapid screening of phenolics in waste water because of high sensitivity.

Epithelioid Glioblastomas and Anaplastic Epithelioid Pleomorphic Xanthoastrocytomas--Same Entity or First Cousins?

Epithelioid glioblastoma (eGBM) and pleomorphic xanthoastrocytoma (PXA) with anaplastically transformed foci (ePXA) show overlapping features. Eleven eGBMs and 5 ePXAs were reviewed and studied immunohistochemically. Fluorescence in situ hybridization for EGFR amplification, PTEN deletion and ODZ3 deletion was also performed, with Ilumina 450 methylome analysis obtained in five cases. The average age for eGBM was 30.9 (range 2-79) years, including five pediatric cases and a M : F ratio of 4.5. The ePXA patients had a M : F ratio of 4 and averaged 21.2 (range 10-38) years in age, including two pediatric cases. Six eGBMs and two ePXAs recurred (median recurrence interval of 12 and 3.3 months, respectively). All tumors were composed of solid sheets of loosely cohesive, "melanoma-like" cells with only limited infiltration. ePXAs showed lower grade foci with classic features of PXA. Both tumor types showed focal expression of epithelial and glial markers, retained INI1 and BRG1 expression, occasional CD34 positivity, and lack of mutant IDH1 (R132H) immunoreactivity. BRAF V600E mutation was present in four eGBMs and four ePXAs. ODZ3 deletion was detected in seven eGBMs and two ePXAs. EGFR amplification was absent. Methylome analysis showed that one ePXA and one eGBM clustered with PXAs, one eGBM clustered with low-grade gliomas, and two eGBMs clustered with pediatric-type glioblastomas. Common histologic, immunohistochemical, molecular and clinical features found in eGBM and ePXA suggest that they are closely related or the same entity. If the latter is true, the nomenclature and WHO grading remains to be resolved.

Screening of inhibitors for mushroom tyrosinase using surface plasmon resonance.

Tyrosinase inhibitors have been used as whitening or antihyperpigment agents because of their ability to suppress dermal-melanin production. In the present study, screening and kinetic evaluation of various small molecules were performed on mushroom tyrosinase (MT) using surface plasmon resonance. The binding constant KD (M) values obtained for tannic acid, phloroglucinol, saffron, catechol, and pyrogallol are 1.213 × 10(-4), 7.136 × 10(-5), 3.111 × 10(-5), 1.557 × 10(-5), and 7.981 × 10(-6) M, respectively. Pyrogallol has been found to display high affinity for MT, whereas catechol, saffron, and phloroglucinol have been found to bind with low affinity. MT shows considerable changes in the secondary structure in the presence of inhibitors. The study reveals the Biacore/SPR sensor's ability in the rapid identification and characterization of inhibitors for MT. The methodology described here can be used to rapidly screen and optimize various lead compounds for other enzymes and elucidate structure function inter-relationships between various enzymes.

Evaluation of Various Factors Affecting Bioconversion of l-Tyrosine to l-DOPA by Yeast Yarrowia lipolytica-NCIM 3450 Using Response Surface Methodology.

ABSTRACT: 3,4-Dihydroxy l-phenylalanine (l-DOPA) is considered a potent drug for the treatment of Parkinson disease. Physical and nutritional parameters where optimized by using Yarrowia lipolytica-NCIM 3450 to accomplished the highest production of l-DOPA. Screenings of critical components were completed by using a Plackett-Burman design, while further optimization was carried out using the Box-Behnken design. The optimized factor levels predicted by the model were pH 6.1, 1.659 g L(-1) yeast extract, 1.491 g L(-1)l-tyrosine and 0.0290 g L(-1) CuSO4. The predicted yield of l-DOPA with these levels was 1.319 g L(-1), while actual yield obtained was 1.273 g L(-1). The statistical analysis revealed that model is significant with F value 19.55 and R(2) value 0.9514. This process resulted in a 3.594-fold increase in the yield of l-DOPA. l-DOPA was confirmed by HPTLC and HPLC analysis. Thus, Yarrowia lipolytica-NCIM 3450 has potential to be a new source for the production of l-DOPA.

Evaluation of crocin and curcumin affinity on mushroom tyrosinase using surface plasmon resonance.

Tyrosinase inhibitors have potential applications in the cosmetics and food industries for preventing browning reactions and also as therapeutic drugs for neurodegenerative diseases such as Parkinson's. In this article, crocin and curcumin were evaluated as mushroom tyrosinase inhibitors. Results showed that, both compounds strongly inhibited the diphenolase activity than monophenolase. The IC50 values for diphenolase activity were estimated to be 0.11 mM and 0.18 mM for crocin and curcumin respectively. The binding kinetics of crocin and curcumin was studied with mushroom tyrosinase using surface plasmon resonance (SPR). Tyrosinase was immobilized on the gold surface of a Biacore sensor chip through amine coupling. Binding of inhibitors was analyzed by SPR without the need to further modify the surface or the use of other reagents. The binding constant KD (M) for mushroom tyrosinase obtained was 1.21×10(-4) M for crocin and 1.64×10(-4) M for curcumin, while showing a higher affinity for L-DOPA 1.95×10(-8) M, a substrate for tyrosinase (positive control). The study reveals the SPR sensor's ability to detect binding of the inhibitors.

Febrile ulceronecrotic Mucha-Habermann disease with central nervous system vasculitis.

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD) is a severe variant of pityriasis lichenoides et varioliformis acuta (PLEVA). We report a case of FUMHD in an 11-year-old boy who subsequently developed neurologic symptoms and was found to have necrotizing vasculitis on brain biopsy. Over 5 years of follow-up, he had one biopsy-proven recurrence of his skin lesions and continued rehabilitation and treatment for residual neurologic complications. This case provides histological evidence of central nervous system vasculitis associated with FUMHD. Our patient's disease was eventually controlled with cyclophosphamide.

Optimization of Biotransformation of l-Tyrosine to l-DOPA by Yarrowia lipolytica-NCIM 3472 Using Response Surface Methodology.

l-DOPA (3,4-dihydroxyphenyl-l-alanine) is the most widely used drug for treatment of Parkinson's disease. In this study Yarrowia lipolytica-NCIM 3472 biomass was used for transformation of l-tyrosine to l-DOPA. The process parameters were optimized using response surface methodology (RSM). The optimum values of the tested variables for the production of l-DOPA were: pH 7.31, temperature 42.9 °C, 2.31 g l(-1) cell mass and 1.488 g l(-1)l-tyrosine. The highest yield obtained with these optimum parameters along with recycling of the cells was 4.091 g l(-1). This optimization of process parameters using RSM resulted in 4.609-fold increase in the l-DOPA production. The statistical analysis showed that the model was significant. Also coefficient of determination (R(2)) was 0.9758, indicating a good agreement between the experimental and predicted values of l-DOPA production. The highest tyrosinase activity observed was 7,028 U mg(-1) tyrosine. l-DOPA production was confirmed by HPTLC and HPLC analysis. Thus, RSM approach effectively enhanced the potential of Y. lipolytica-NCIM 3472 as an alternative source to produce l-DOPA.