1.Biopharmaceutical Analysis by HPLC: Practices and Challenges
Golshan MAHDI ; Ashkan ALAMDARY ; Hooman KAGHAZIAN ; Nayebali AHMADI ; Rajab MARDANI ; Alireza GHOLAMI
Chonnam Medical Journal 2025;61(1):19-31
High-Performance Liquid Chromatography (HPLC) is an essential analytical technique in the biopharmaceutical industry, crucial for the separation, identification, and quantification of complex biological molecules such as monoclonal antibodies and recombinant proteins. It plays a vital role in assessing the purity, potency, and stability of biopharmaceutical products, which are critical for regulatory approval. HPLC offers high resolution and sensitivity, allowing for the detection of small quantities of compounds in complex samples. Its versatility is evident in various modes, including reversed-phase, ion-exchange, size-exclusion, and affinity chromatography. However, challenges remain, such as selecting the appropriate stationary phase, addressing peak overlapping and matrix interference, and optimizing operational parameters like flow rate and mobile phase composition. Standardization and method validation are essential for ensuring reproducibility, accuracy, and regulatory compliance in HPLC analyses. The need for reliable reference materials and calibration methods is also a significant challenge. Recent advancements in HPLC technology, including ultra-high-performance liquid chromatography (UHPLC) and hybrid systems that integrate HPLC with mass spectrometry, are helping to overcome these challenges by enhancing sensitivity, resolution, and analysis speed. In summary, as biopharmaceutical products grow more complex, HPLC’s role will continue to evolve, highlighting the need for ongoing research and development to refine this critical analytical tool.
2.Biopharmaceutical Analysis by HPLC: Practices and Challenges
Golshan MAHDI ; Ashkan ALAMDARY ; Hooman KAGHAZIAN ; Nayebali AHMADI ; Rajab MARDANI ; Alireza GHOLAMI
Chonnam Medical Journal 2025;61(1):19-31
High-Performance Liquid Chromatography (HPLC) is an essential analytical technique in the biopharmaceutical industry, crucial for the separation, identification, and quantification of complex biological molecules such as monoclonal antibodies and recombinant proteins. It plays a vital role in assessing the purity, potency, and stability of biopharmaceutical products, which are critical for regulatory approval. HPLC offers high resolution and sensitivity, allowing for the detection of small quantities of compounds in complex samples. Its versatility is evident in various modes, including reversed-phase, ion-exchange, size-exclusion, and affinity chromatography. However, challenges remain, such as selecting the appropriate stationary phase, addressing peak overlapping and matrix interference, and optimizing operational parameters like flow rate and mobile phase composition. Standardization and method validation are essential for ensuring reproducibility, accuracy, and regulatory compliance in HPLC analyses. The need for reliable reference materials and calibration methods is also a significant challenge. Recent advancements in HPLC technology, including ultra-high-performance liquid chromatography (UHPLC) and hybrid systems that integrate HPLC with mass spectrometry, are helping to overcome these challenges by enhancing sensitivity, resolution, and analysis speed. In summary, as biopharmaceutical products grow more complex, HPLC’s role will continue to evolve, highlighting the need for ongoing research and development to refine this critical analytical tool.
3.Biopharmaceutical Analysis by HPLC: Practices and Challenges
Golshan MAHDI ; Ashkan ALAMDARY ; Hooman KAGHAZIAN ; Nayebali AHMADI ; Rajab MARDANI ; Alireza GHOLAMI
Chonnam Medical Journal 2025;61(1):19-31
High-Performance Liquid Chromatography (HPLC) is an essential analytical technique in the biopharmaceutical industry, crucial for the separation, identification, and quantification of complex biological molecules such as monoclonal antibodies and recombinant proteins. It plays a vital role in assessing the purity, potency, and stability of biopharmaceutical products, which are critical for regulatory approval. HPLC offers high resolution and sensitivity, allowing for the detection of small quantities of compounds in complex samples. Its versatility is evident in various modes, including reversed-phase, ion-exchange, size-exclusion, and affinity chromatography. However, challenges remain, such as selecting the appropriate stationary phase, addressing peak overlapping and matrix interference, and optimizing operational parameters like flow rate and mobile phase composition. Standardization and method validation are essential for ensuring reproducibility, accuracy, and regulatory compliance in HPLC analyses. The need for reliable reference materials and calibration methods is also a significant challenge. Recent advancements in HPLC technology, including ultra-high-performance liquid chromatography (UHPLC) and hybrid systems that integrate HPLC with mass spectrometry, are helping to overcome these challenges by enhancing sensitivity, resolution, and analysis speed. In summary, as biopharmaceutical products grow more complex, HPLC’s role will continue to evolve, highlighting the need for ongoing research and development to refine this critical analytical tool.
4.Analysis of hard tissue facial symmetry after unilateral mandibular reconstruction
Mohamad Saleh KHAGHANINEJAD ; Leila KHOJASTEPOUR ; Hanie AHMADI ; Saeid TAVANAFAR ; Alireza EBRAHIMI ; Mohammad MAHJOORI-GHASRODASHTI
Maxillofacial Plastic and Reconstructive Surgery 2021;43(1):15-
Background:
This study aimed to determine how successful reconstruction of the mandible can recover the symmetry.
Materials and methods:
All patients who underwent surgical treatment for unilateral mandibular reconstruction in 4 years were retrospectively examined. Bilateral differences of gonion (GO) positions were measured in 3 dimensions based on immediate postoperative computed tomography. The data collected was analyzed in 3 ways: First, the comparison of bilateral differences of GO in 3 dimensions. Second, the mean Asymmetry Index in control subjects was used to divide all cases into three groups: “Symmetry,” “Asymmetry,” and “Marked asymmetry.” Third, “maximum normal asymmetry” was calculated, and all cases were categorized as below and above maximum normal asymmetry. The difference between two gonial angles was used to determine the amount of asymmetry.
Results:
Forty-seven patients and 47 normal adults were enrolled. The mean bilateral GO difference in the control group was higher than in the study group patients, but it was not statistically significant. The mean Asymmetry Index for the control group was not also significantly higher than the study cases. The study group was “Symmetric” in 78.7% of the cases whereas the control group in 91.4%, 19.1% of the study group and 8.5% of controls were “Asymmetric,” and 2.1% of study cases and 0% of controls were “Markedly Asymmetric.” Maximum normal asymmetry was 82.9% in the study group and 97.8% in the control group. The mean differences between the right and left gonial angles were higher in the study group, but it was not significant (P = 0.1).
Conclusions
Our study’s results showed that bilateral symmetry in mandibular reconstruction patients was satisfactory and similar to the normal individuals.
5.The Effect of Flaxseed Enriched Yogurt on the Glycemic Status and Cardiovascular Risk Factors in Patients with Type 2 Diabetes Mellitus: Randomized, Open-labeled, Controlled Study
Nazila HASANIANI ; Mehran RAHIMLOU ; Amirhossein RAMEZANI AHMADI ; Alireza MEHDIZADEH KHALIFANI ; Mohammad ALIZADEH
Clinical Nutrition Research 2019;8(4):284-295
Flaxseed is one of the rich sources of α-linolenic acid and lignan. Flaxseed and its components have antioxidant, hypolipidemic and hypoglycemic effects. The study aimed to investigate the effect of flaxseed enriched yogurt on glycemic control, lipid profiles and blood pressure in patients with type 2 diabetes. A randomized, open-labeled, controlled clinical trial was conducted on 57 patients with type 2 diabetes. Participants were assigned to receive 200 g 2.5% fat yogurt containing 30-g flaxseed or plain yogurt daily for 8 weeks. Anthropometrics and biochemical parameters were evaluated at the beginning and end of the study. After 8 weeks of supplementation, Hemoglobin A1c was significantly decreased in the intervention group compared to control (p = 0.007). Also, at the end of the study, significant differences were seen between the flaxseed enriched yogurt and control groups in triglycerides and total cholesterol concentrations (p = 0.04 and p = 0.01), systolic blood pressure and diastolic blood pressure (p = 0.02 and p = 0.002, respectively). However, we did not find any difference between 2 groups in low-density lipoprotein, high-density lipoprotein, body weight and waist circumference (p > 0.05). Our results showed that the addition of flaxseed to yogurt can be effective in the management of type 2 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02436369
Blood Pressure
;
Body Weight
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Cholesterol
;
Diabetes Mellitus, Type 2
;
Flax
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Humans
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Hypoglycemic Agents
;
Lipoproteins
;
Risk Factors
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Triglycerides
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Waist Circumference
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Yogurt
6.Effect of face mask on pulmonary artery pressure during echocardiography in children and adolescents
Alireza AHMADI ; Mohammad Reza SABRI ; Zohreh Sadat NAVABI
Clinical and Experimental Pediatrics 2024;67(3):161-167
Background:
Face masks have become an important tool for preventing the spread of respiratory diseases. However, we hypothesized that face masks with reduced nasal airflow may alter pulmonary artery systolic pressure (PASP).Purpose: This study aimed to evaluate the effect of face masks on PASP in children and adolescents.
Methods:
This case-control study was conducted between March 2021 and April 2022 at the Pediatric Cardiovascular Research Center in Isfahan, Iran. Using a convenience sampling method, a total of 120 children and adolescents, boys and girls aged 3–18 years, were allocated into 2 groups of 60 each (case group with congenital heart disease (CHD), control group of healthy subjects). For each patient in the case and control groups, echocardiography (ECHO), heart rate (HR), and blood oxygen saturation (SpO2) were performed and measured twice—once with a surgical mask and once without a surgical mask—by a pediatric cardiologist at 10-min intervals.
Results:
A total of 110 participants were analyzed. The mean patient age was 9.58±3.40 years versus 10.20±4.15 years in the case (n=50) and control (n=60) groups, respectively. Approximately 76.0% (n=38) of the participants in the case group versus 60.0% of those in the control group were male. In the case and control groups, there was a statistically significant reduction in the mean changes in tricuspid regurgitation (P=0.001), pulmonary regurgitation (P=0.002), and PASP (P=0.001) after face mask removal. Although this study showed a reduction in pulmonary arterial pressure after face mask removal in patients with CHD and healthy subjects, no significant changes in HR (P=0.535) or SpO2 (P=0.741) were observed in either group.
Conclusion
Wearing a face mask increased PASP in healthy children and adolescents with CHD; however, the SPO2 and HR remained unchanged. Therefore, mask removal during ECHO is recommended.
7.Effect of face mask on pulmonary artery pressure during echocardiography in children and adolescents
Alireza AHMADI ; Mohammad Reza SABRI ; Zohreh Sadat NAVABI
Clinical and Experimental Pediatrics 2024;67(3):161-167
Background:
Face masks have become an important tool for preventing the spread of respiratory diseases. However, we hypothesized that face masks with reduced nasal airflow may alter pulmonary artery systolic pressure (PASP).Purpose: This study aimed to evaluate the effect of face masks on PASP in children and adolescents.
Methods:
This case-control study was conducted between March 2021 and April 2022 at the Pediatric Cardiovascular Research Center in Isfahan, Iran. Using a convenience sampling method, a total of 120 children and adolescents, boys and girls aged 3–18 years, were allocated into 2 groups of 60 each (case group with congenital heart disease (CHD), control group of healthy subjects). For each patient in the case and control groups, echocardiography (ECHO), heart rate (HR), and blood oxygen saturation (SpO2) were performed and measured twice—once with a surgical mask and once without a surgical mask—by a pediatric cardiologist at 10-min intervals.
Results:
A total of 110 participants were analyzed. The mean patient age was 9.58±3.40 years versus 10.20±4.15 years in the case (n=50) and control (n=60) groups, respectively. Approximately 76.0% (n=38) of the participants in the case group versus 60.0% of those in the control group were male. In the case and control groups, there was a statistically significant reduction in the mean changes in tricuspid regurgitation (P=0.001), pulmonary regurgitation (P=0.002), and PASP (P=0.001) after face mask removal. Although this study showed a reduction in pulmonary arterial pressure after face mask removal in patients with CHD and healthy subjects, no significant changes in HR (P=0.535) or SpO2 (P=0.741) were observed in either group.
Conclusion
Wearing a face mask increased PASP in healthy children and adolescents with CHD; however, the SPO2 and HR remained unchanged. Therefore, mask removal during ECHO is recommended.
8.Effect of face mask on pulmonary artery pressure during echocardiography in children and adolescents
Alireza AHMADI ; Mohammad Reza SABRI ; Zohreh Sadat NAVABI
Clinical and Experimental Pediatrics 2024;67(3):161-167
Background:
Face masks have become an important tool for preventing the spread of respiratory diseases. However, we hypothesized that face masks with reduced nasal airflow may alter pulmonary artery systolic pressure (PASP).Purpose: This study aimed to evaluate the effect of face masks on PASP in children and adolescents.
Methods:
This case-control study was conducted between March 2021 and April 2022 at the Pediatric Cardiovascular Research Center in Isfahan, Iran. Using a convenience sampling method, a total of 120 children and adolescents, boys and girls aged 3–18 years, were allocated into 2 groups of 60 each (case group with congenital heart disease (CHD), control group of healthy subjects). For each patient in the case and control groups, echocardiography (ECHO), heart rate (HR), and blood oxygen saturation (SpO2) were performed and measured twice—once with a surgical mask and once without a surgical mask—by a pediatric cardiologist at 10-min intervals.
Results:
A total of 110 participants were analyzed. The mean patient age was 9.58±3.40 years versus 10.20±4.15 years in the case (n=50) and control (n=60) groups, respectively. Approximately 76.0% (n=38) of the participants in the case group versus 60.0% of those in the control group were male. In the case and control groups, there was a statistically significant reduction in the mean changes in tricuspid regurgitation (P=0.001), pulmonary regurgitation (P=0.002), and PASP (P=0.001) after face mask removal. Although this study showed a reduction in pulmonary arterial pressure after face mask removal in patients with CHD and healthy subjects, no significant changes in HR (P=0.535) or SpO2 (P=0.741) were observed in either group.
Conclusion
Wearing a face mask increased PASP in healthy children and adolescents with CHD; however, the SPO2 and HR remained unchanged. Therefore, mask removal during ECHO is recommended.
9.Effect of face mask on pulmonary artery pressure during echocardiography in children and adolescents
Alireza AHMADI ; Mohammad Reza SABRI ; Zohreh Sadat NAVABI
Clinical and Experimental Pediatrics 2024;67(3):161-167
Background:
Face masks have become an important tool for preventing the spread of respiratory diseases. However, we hypothesized that face masks with reduced nasal airflow may alter pulmonary artery systolic pressure (PASP).Purpose: This study aimed to evaluate the effect of face masks on PASP in children and adolescents.
Methods:
This case-control study was conducted between March 2021 and April 2022 at the Pediatric Cardiovascular Research Center in Isfahan, Iran. Using a convenience sampling method, a total of 120 children and adolescents, boys and girls aged 3–18 years, were allocated into 2 groups of 60 each (case group with congenital heart disease (CHD), control group of healthy subjects). For each patient in the case and control groups, echocardiography (ECHO), heart rate (HR), and blood oxygen saturation (SpO2) were performed and measured twice—once with a surgical mask and once without a surgical mask—by a pediatric cardiologist at 10-min intervals.
Results:
A total of 110 participants were analyzed. The mean patient age was 9.58±3.40 years versus 10.20±4.15 years in the case (n=50) and control (n=60) groups, respectively. Approximately 76.0% (n=38) of the participants in the case group versus 60.0% of those in the control group were male. In the case and control groups, there was a statistically significant reduction in the mean changes in tricuspid regurgitation (P=0.001), pulmonary regurgitation (P=0.002), and PASP (P=0.001) after face mask removal. Although this study showed a reduction in pulmonary arterial pressure after face mask removal in patients with CHD and healthy subjects, no significant changes in HR (P=0.535) or SpO2 (P=0.741) were observed in either group.
Conclusion
Wearing a face mask increased PASP in healthy children and adolescents with CHD; however, the SPO2 and HR remained unchanged. Therefore, mask removal during ECHO is recommended.
10.Introduction of a handmade vacuum-assisted sponge drain for the treatment of anastomotic leakage after low anterior rectal resection
Amir KESHVARI ; Abolfazl BADRIPOUR ; Mohammad Reza KERAMATI ; Alireza KAZEMEINI ; Behnam BEHBOUDI ; Mohammad Sadegh FAZELI ; Ehsan RAHIMPOUR ; Parisa GHAFFARI ; Seyed Mohsen Ahmadi TAFTI
Annals of Coloproctology 2022;38(3):230-234
Purpose:
Anastomotic leakage, a known major postoperative complication, potentially leads to readmission, reoperation, and increased mortality rates in patients, such as rectal cancer patients following a low anterior resection (LAR). Currently, vacuum-assisted closure, as featured by B-Braun (B-Braun Medical B.V.), is already being used for the treatment of gastrointestinal leakages and fistulas. The main aim of this study was to introduce a novel method for creating a vacuum-assisted drain for the treatment of anastomotic leakage after LAR.
Methods:
All 10 patients, who underwent LAR surgery from 2018 to 2019, were diagnosed with anastomotic leakage and had received neoadjuvant chemotherapy prior to surgery. Therefore, patients were treated with a handmade vacuum-assisted drain and were revisited every 5 to 7 days for further evaluations and drain replacement until leakage resolution. Physical features of cavity, time of diagnose, and duration of treatment were analyzed correspondingly. The handmade vacuum-assisted sponge drain was prepared for each patient in each session of follow-up.
Results:
Eight out of 10 patients experienced complete closure of the defect. The mean delay time from the day of operation to the diagnosis of anastomotic leakage was 61.0±80.4 days while the mean time for leakage closure was 117.6±68.3 days. Eventually, 7 cases underwent ileostomy reversal with no complications during a 3-month follow-up.
Conclusion
In this study, we evaluated the healing process of anastomotic leakage after the usage of a handmade vacuum-assisted sponge drain in a case series method. In our trial, we provided an innovative cost-benefit method easily applicable in the operating room.