Laser structuring of materials for biomedical applications

Laser processing methods have become very appealing for the fabrication of micro/nano structures. To fabricate 3D structures with high resolution andarbitrary complexity, several material deposition processes are in use. By using appropriate moulding techniques, these structures can be fabricated out of a variety of materials such as polymers, ceramics and composites. In this work different lasers have been investigated regarding their suitability for additive and subtractive patterning of small features for biomedical applications. The main focus is on a technique based on two-photon polymerisation of photosensitive materials; this is a nonlinear optical stereo lithography which allows direct-writing of high-resolution three dimensional structures. During the two-photon absorption process, temporal and spatial overlap of photons leads to nonlinear absorption in a highly localized volume. Absorbed photons induce chemical reactions which cause a polymer to form. Due to the quadratic intensity dependence of the process, resolutions of less than 100nm in polymerized structures can potentially be achieved because of the well-defined polymerization threshold. Here, we have emphasised another regime whereby deep structures (~300µm) can be generated in a single pass. This allows rapid fabrication of structures suitable for cell scaffolds where the length scales are small (~10µm) and are required over long ranges (~cm). A Ti: sapphire femtosecond laser at 800nm wavelength with 150fs pulse duration and 1kHz repetition rate was used to determine the two-photon absorption cross section of photoinitiators. This approach was used to initiate two-photon polymerization of resin allowing the fabrication of cell scaffolds suitable for biomedical applications. Diffraction calculations for the imaging optics employed, show that spherical aberration plays a significant role in determining the feature sizes achieved.For subtractive patterning of materials, a femtosecond laser system and an ArF excimer laser have been used. Using ablative techniques keratin films were processed to investigate physical realisation of the commonly used theoretical bricks-and-mortar description of skin. This structure was successfully fabricated and is being used for skin cream research. Also the threshold fluence for ablation of Polyimide Kapton (HN) foils has been measured at oblique angles as an analogue for corneal sculpturing based on beam scanning

Comparison of Letrozole and Clomiphene citrate on ovulation in achievement of successful Pregnancy

Objective: to compare the efficacy of letrozole and clomiphene citrate in terms of pregnancy achievement and in anovulatory infertile women. Study Design: A randomized controlled trial. Place and Duration: study conducted at the department of obstetrics and gynaecology DG Khan Teaching Hospital. DG Khan from March 2017 to March 2018. Methodology: Two hundred and ten patients were included in this study. The patients were equally divided into two Groups as Group A and Group B by random number method. Study was started after permission from hospital ethical committee. Study variables were age and duration of infertility. SPSS version 24 was used to analyze data. T test and chi square test were applied and p≤0.05 was taken as significant.  Results: the mean age and duration of infertility of Group B was 25.66±3.39 years and 3.72±2.01 years, respectively. There were 73.3% patients between 18-30 years and 26.7% in 31-40 years of age. There were 79% patients had <5 years of duration of infertility and 21% had >5 years of duration of infertility. The difference was statistically significant (p=0.000) for age. The efficacy of Group A and B was observed as 16.2% and 45.7%, respectively. The difference was statistically significant, (p=0.000). Conclusion: use of Letrzole is safe and more effective for achieving pregnancy in anovulatory infertile women as compared to clomiphene citrate. Keywords: Letrozole, Clomiphene Citrate, Ovulation, pregnancy rate, Infertility

Relation of Striae Gravidarum with Cesarean Scar and Peritoneal Adhesions

Objective: to find out the relation between striae gravidarum and, cesarean scar and peritoneal adhesions. Study Design: Cross sectional Study. Place and Study Duration: Department of Gynecology and Obstetrics, DG Khan Teaching Hospital Multan, from January 2018 to June 2018. Material and methods: A total number of 150 patients presenting to the department of gynecology and obstetrics for cesarean section were included in the study. Severity of striae gravidarum was assessed using Davey scoring system. Modified Blauer classification was used to define the intraperitoneal adhesions in five categories. Three groups were designed group 1, 2 and 3. In group 1 those women were involved that had no striae gravidarum, in group 2 were those women who had mild to moderate number of striae gravidarum and in group 3 women with severe amount of striae gravidarum were included. Students T test and Mann-Whitney test was applied to compare the two groups. Frequency and percentages were calculated for categorical variables and mean and standard deviation was calculated for continuous variables. P value of less than or equal to 0.05 was considered as statistically significant. Results: Grade 2-4 intraperitoneal adhesions, keloids and pigmentations were more in Group 2 and Group 3 but no statistically significant difference was present (p-value 0.517, 0.427 and 0.372, respectively). The appearance of scar was also not different among the three groups (p=0.541). Scar length was more in Group-3 (p=0.289) but the width was more in Group-1 (p=0.248) with no statistically significant difference. Conclusion: The results of this study show that striae gravidarum was associated with scar characteristics but no correlation between striae gravidarum and intraperitoneal adhesions could be observed as such. Keywords: Striae Gravidarum, Cesarean Section, Abdominal Adhesion

Isolation frequency and susceptibility patterns of Nocardia species at a tertiary hospital laboratory in Karachi, Pakistan

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Therapeutic potential of Pegnum harmela against Schistosoma bovis in buffaloes

Background: Peganum harmala have many biological and pharmacological activities such as antifungal, antibacterial, analgesic and antiinflammatory. The present study was carried out to evaluate the  antischistosomal activities of Peganum harmala with special reference to bovine schistosomiasis in naturally infected buffaloes.Methods and Materials: A total of 54 naturally infected buffaloes with “Schistosomiasis” of ages around five years were used for anthelmintic studies. All of the buffaloes were properly marked so as to make a distinction from one other. A doctor of veterinary was available for daily checkup. Samples prepared according to the available methods in literature.Results: In the present study, naturally infected buffaloes with Schistosoma bovis were treated with  Peganum harmala (Harmal, seed), with dose 75 mg/kg, 150 mg/kg and 225 mg/kg body weight  respectively, and their impact on various parameters like eggs reduction, milk production, weight gain and feed intake was noted. Furthermore, their efficiency (%) was evaluated with “Praziquantel”  (allopathic drug) at “10mg/Kg body weight” dose level. After first dose of “Praziquantel” hundred percent effectiveness was noted, while the same result obtained for herbal drug after giving second dose of  “225mg/kg body weight”. To evaluate the effect of herbal medicines on protein portions, sera of treated and control buffaloes were also investigated.Conclusion: From present findings, it is concluded that the herb Peganum harmala can easily replace  Praziquantal (PZQ) with almost same efficiency (%). Furthermore, the herb is easily available at cheap price at local market and it will be good for the economy of Pakistan Key words: Pegnum harmela, Schistosoma, infectio

High prevalence of typhoidal Salmonella enterica serovars excreting food handlers in Karachi-Pakistan: a probable factor for regional typhoid endemicity

Background: Typhoid fever is the persistent cause of morbidity worldwide. Salmonella enterica serovar\u2019s carriers among food handlers have the potential to disseminate this infection on large scale in the community. The purpose of this study was to determine the prevalence of typhoidal S. enterica serovars among food handlers of Karachi. Methods: This cross-sectional study was conducted in Karachi metropolis. A total of 220 food handlers were recruited on the basis of inclusion criteria from famous food streets of randomly selected five towns of Karachi. Three consecutive stool samples were collected from each food handler in Carry Blair transport media. Culture, biochemical identification, serotyping, and antimicrobial susceptibility tests for S. enterica serovars were done. Results: Out of 220 food handlers, 209 consented to participate, and among them, 19 (9.1 %) were positive for S. enterica serovars. Serotyping of these isolates showed that 9 (4.3 %) were typhoidal S. serovars while 10 (4.7 %) were non-typhoidal S. serovars. Of the typhoidal S. serovars, 7 were S. enterica serovar Typhi and 1 each of S. enterica serovar Paratyphi A and B. The resistance pattern of these isolates showed that 77.7 % were resistant to ampicillin and 11.1 % to cotrimoxazole. All typhoidal S. enterica serovars isolates were sensitive to chloramphenicol, ceftriaxone, cefixime, nalidixic acid, and ofloxacin. Conclusions: Carrier rate of typhoidal S. enterica serovars in food handlers working in different food streets of Karachi is very high. These food handlers might be contributing to the high endemicity of typhoid fever in Karachi, Pakistan

THERAPEUTIC POTENTIAL OF PEGNUM HARMELA AGAINST SCHISTOSOMA BOVIS IN BUFFALOES

Background: Peganum harmala have many biological and pharmacological activities such as antifungal, antibacterial, analgesic and antiinflammatory. The present study was carried out to evaluate the antischistosomal activities of Peganum harmala with special reference to bovine schistosomiasis in naturally infected buffaloes. Methods and Materials: A total of 54 naturally infected buffaloes with “Schistosomiasis” of ages around five years were used for anthelmintic studies. All of the buffaloes were properly marked so as to make a distinction from one other. A doctor of veterinary was available for daily checkup. Samples prepared according to the available methods in literature. Results: In the present study, naturally infected buffaloes with Schistosoma bovis were treated with Peganum harmala (Harmal, seed), with dose 75 mg/kg, 150 mg/kg and 225 mg/kg body weight respectively, and their impact on various parameters like eggs reduction, milk production, weight gain and feed intake was noted. Furthermore, their efficiency (%) was evaluated with “Praziquantel” (allopathic drug) at “10mg/Kg body weight” dose level. After first dose of “Praziquantel” hundred percent effectiveness was noted, while the same result obtained for herbal drug after giving second dose of “225mg/kg body weight”. To evaluate the effect of herbal medicines on protein portions, sera of treated and control buffaloes were also investigated. Conclusion: From present findings, it is concluded that the herb Peganum harmala can easily replace Praziquantal (PZQ) with almost same efficiency (%). Furthermore, the herb is easily available at cheap price at local market and it will be good for the economy of Pakista

TREATMENT OF BOVINE SCHISTOSOMIASIS WITH MEDICINAL PLANT VERONIA ANTHELMINTICA (KALIZIRI), AN ALTERNATIVE APPROACH

Background: Veronia anthelmintica (Kaliziri) is a medicinally very important plant as being reported for remarkable therapeutic potential. The present research evaluates its antischistosomal activity. Methods and Materials: 54 buffaloes naturally infected with Schistosomiasis were used for anthelmintic trails. All animals for the study were tagged so as to distinguish from others. The animals were checked up on routine basis by a veterinary doctor. Preparation of samples of herbal drug and experiment was design according to available literature. Results: During present studies, buffalos naturally infected with Schistosomiasis were treated with Veronia anthelmintica (Kaliziri), with dose 75 mg/kg, 150 mg/kg and 225 mg/kg body weight respectively, and their impact on various parameters like eggs reduction, milk production, weight gain and feed intake was noted. Furthermore, their efficiency (%) was compared with standard drug “Praziquantel” (allopathic drug) at “10mg/Kg” body weight dose level. The effectiveness (%) of “Praziquantel” was noted as hundred after first dose, while the effectiveness for the herbal drug get to this level after injecting of second dose of “225mg/kg body weight”. Statistically significant (