Spectrum of K ras mutations in Pakistani colorectal cancer patients.

The incidence of colorectal cancer (CRC) is increasing daily worldwide. Although different aspects of CRC have been studied in other parts of the world, relatively little or almost no information is available in Pakistan about different aspects of this disease at the molecular level. The present study was aimed at determining the frequency and prevalence of K ras gene mutations in Pakistani CRC patients. Tissue and blood samples of 150 CRC patients (64% male and 36% female) were used for PCR amplification of K ras and detection of mutations by denaturing gradient gel electrophoresis, restriction fragment length polymorphism analysis, and nucleotide sequencing. The K ras mutation frequency was found to be 13%, and the most prevalent mutations were found at codons 12 and 13. A novel mutation was also found at codon 31. The dominant mutation observed was a G to A transition. Female patients were more susceptible to K ras mutations, and these mutations were predominant in patients with a nonmetastatic stage of CRC. No significant differences in the prevalence of K ras mutations were observed for patient age, gender, or tumor type. It can be inferred from this study that Pakistani CRC patients have a lower frequency of K ras mutations compared to those observed in other parts of the world, and that K ras mutations seemed to be significantly associated with female patients.

Spectrum of K ras mutations in Pakistani colorectal cancer patients

The incidence of colorectal cancer (CRC) is increasing daily worldwide. Although different aspects of CRC have been studied in other parts of the world, relatively little or almost no information is available in Pakistan about different aspects of this disease at the molecular level. The present study was aimed at determining the frequency and prevalence of K ras gene mutations in Pakistani CRC patients. Tissue and blood samples of 150 CRC patients (64% male and 36% female) were used for PCR amplification of K ras and detection of mutations by denaturing gradient gel electrophoresis, restriction fragment length polymorphism analysis, and nucleotide sequencing. The K ras mutation frequency was found to be 13%, and the most prevalent mutations were found at codons 12 and 13. A novel mutation was also found at codon 31. The dominant mutation observed was a G to A transition. Female patients were more susceptible to K ras mutations, and these mutations were predominant in patients with a nonmetastatic stage of CRC. No significant differences in the prevalence of K ras mutations were observed for patient age, gender, or tumor type. It can be inferred from this study that Pakistani CRC patients have a lower frequency of K ras mutations compared to those observed in other parts of the world, and that K ras mutations seemed to be significantly associated with female patients.

Effect of mercuric chloride on the activities of some hepatic enzymes of regenerating rabbit liver following partial hepatectomy.

Mercuric chloride (HgCl2) administered at a dose of 1mg/kg body wt/day for 5 days decreased hepatic lactate dehydrogenase (LDH) activity (63%) and increased isocitrate dehydrogenase (ICDH) activity (127%). After withdrawal of HgCl2 treatment for 10 days, the LDH and glutamate pyruvate transaminase (GPT) activities showed 56% and 40% decrease, respectively, while alkaline phosphatase (AkP) activity increased 4.12 fold. The ICDH activity got normalized. Glutamate oxaloacetate transaminase (GDT) was not affected at all. The hepatic LDH, ICDH and GPT activities decreased 58%, 72% and 82%, respectively, five days after partial hepatectomy (PH), while AkP activity increased 90%. At the end of 15 days after PH, the hepatic ICDH activity increased 4.27 fold, while GPT and GOT activities decreased 67% and 91%, respectively. The hepatic ICDH activity of PH-rabbit increased 53%, after 5 days of HgCl2 treatment post-PH, while GPT and AkP activities decreased 89% and 97%, respectively, during this period. The ICDH activity increased 416%, 10 days after the last dose, while all other enzymes showed normal values. The total body growth rate and relative liver weight decreased under all experimental conditions.

Effect of mercuric chloride on the activities of some hepatic enzymes of regenerating rabbit liver following partial hepatectomy.

Mercuric chloride (HgCl2) administered at a dose of 1mg/kg body wt/day for 5 days decreased hepatic lactate dehydrogenase (LDH) activity (63

) and increased isocitrate dehydrogenase (ICDH) activity (127

). After withdrawal of HgCl2 treatment for 10 days, the LDH and glutamate pyruvate transaminase (GPT) activities showed 56

and 40

decrease, respectively, while alkaline phosphatase (AkP) activity increased 4.12 fold. The ICDH activity got normalized. Glutamate oxaloacetate transaminase (GDT) was not affected at all. The hepatic LDH, ICDH and GPT activities decreased 58

, 72

and 82

, respectively, five days after partial hepatectomy (PH), while AkP activity increased 90

. At the end of 15 days after PH, the hepatic ICDH activity increased 4.27 fold, while GPT and GOT activities decreased 67

and 91

, respectively. The hepatic ICDH activity of PH-rabbit increased 53

, after 5 days of HgCl2 treatment post-PH, while GPT and AkP activities decreased 89

and 97

, respectively, during this period. The ICDH activity increased 416

, 10 days after the last dose, while all other enzymes showed normal values. The total body growth rate and relative liver weight decreased under all experimental conditions.

Effect of mercuric chloride on the activities of some hepatic enzymes of regenerating rabbit liver following partial hepatectomy

Mercuric chloride (HgCl2) administered at a dose of 1mg/kg body wt/day for 5 days decreased hepatic lactate dehydrogenase (LDH) activity (63

) and increased isocitrate dehydrogenase (ICDH) activity (127

). After withdrawal of HgCl2 treatment for 10 days, the LDH and glutamate pyruvate transaminase (GPT) activities showed 56

decrease, respectively, while alkaline phosphatase (AkP) activity increased 4.12 fold. The ICDH activity got normalized. Glutamate oxaloacetate transaminase (GDT) was not affected at all. The hepatic LDH, ICDH and GPT activities decreased 58

. At the end of 15 days after PH, the hepatic ICDH activity increased 4.27 fold, while GPT and GOT activities decreased 67

, respectively. The hepatic ICDH activity of PH-rabbit increased 53

, after 5 days of HgCl2 treatment post-PH, while GPT and AkP activities decreased 89

, 10 days after the last dose, while all other enzymes showed normal values. The total body growth rate and relative liver weight decreased under all experimental conditions.

Evaluation of liver function after thioacetamide treatment of partially hepatectomized rabbits.

A group of male rabbits was partially hepatectomized, while another group was administered intraperitoneally with aqueous thioacetamide (TAA) solution (2 mg/kg body weight/alternate day) after partial hepatectomy (PH). The blood samples of animals of both groups were collected on day 10, 15, 20, 30, 60 and 90 following PH and used for various haematological and biochemical analyses. The haemoglobin content decreased significantly within 10 days of PH and gained significant increase 3 months after. An abrupt increase was, however, recorded after TAA treatment. All the enzymatic activities remained unchanged except for that of lactate dehydrogenase (LDH), which was elevated 87% during the first 10 days of PH. The serum glutamate pyruvate transaminase (SGPT) activity was raised 2.8 times. It was only two months after the operation that the alkaline phosphatase (AP) and LDH activities showed signs of inhibition. The only enzyme affected by TAA treatment after the PH was AP activity, which was inhibited drastically within 15 days after operation. It was concluded that, except for the AP activity and bilirubin and urea content, that essentially decreased in the presence of TAA during the first 15-20 days of experimental period, all the other haematological and biochemical parameters got normalized more quickly in the presence of TAA.

Evaluation of liver function after thioacetamide treatment of partially hepatectomized rabbits.

A group of male rabbits was partially hepatectomized, while another group was administered intraperitoneally with aqueous thioacetamide (TAA) solution (2 mg/kg body weight/alternate day) after partial hepatectomy (PH). The blood samples of animals of both groups were collected on day 10, 15, 20, 30, 60 and 90 following PH and used for various haematological and biochemical analyses. The haemoglobin content decreased significantly within 10 days of PH and gained significant increase 3 months after. An abrupt increase was, however, recorded after TAA treatment. All the enzymatic activities remained unchanged except for that of lactate dehydrogenase (LDH), which was elevated 87

during the first 10 days of PH. The serum glutamate pyruvate transaminase (SGPT) activity was raised 2.8 times. It was only two months after the operation that the alkaline phosphatase (AP) and LDH activities showed signs of inhibition. The only enzyme affected by TAA treatment after the PH was AP activity, which was inhibited drastically within 15 days after operation. It was concluded that, except for the AP activity and bilirubin and urea content, that essentially decreased in the presence of TAA during the first 15-20 days of experimental period, all the other haematological and biochemical parameters got normalized more quickly in the presence of TAA.

Effect of starvation and refeeding on the blood and liver of domesticated rabbits.

A group of male rabbits was starved for 7 days. Their blood samples were collected, before and after the starvation period. Six rabbits were slaughtered for the recovery of livers, while the rest were refed for the next 7 days, at the end of which their blood samples were collected and livers taken out for various analyses. After 7 days of starvation, the total leukocytic count, haemoglobin, bilirubin, proteins and glucose contents, and activities of alkaline phosphatase and glutamate pyruvate transaminase of blood serum decreased significantly, while its lactate dehydrogenase activity and cholesterol, total lipids and urea contents showed a significant increase. In liver, except for the bilirubin and glucose contents, all the biochemical components--RNA, DNA and total proteins included--showed highly elevated values. Refeeding of the starved rabbits tended to normalize most within 7 days. Although RNA, DNA, total proteins, cholesterol and urea contents did not reach the normal level in liver during this period, they were definitely less than those of the starved condition. The hepatic transaminases activities and lipid content in starved + refed livers were considerably decreased during the refeeding period. The histological parameters were slow to recover.

Effect of starvation and refeeding on the blood and liver of domesticated rabbits.

A group of male rabbits was starved for 7 days. Their blood samples were collected, before and after the starvation period. Six rabbits were slaughtered for the recovery of livers, while the rest were refed for the next 7 days, at the end of which their blood samples were collected and livers taken out for various analyses. After 7 days of starvation, the total leukocytic count, haemoglobin, bilirubin, proteins and glucose contents, and activities of alkaline phosphatase and glutamate pyruvate transaminase of blood serum decreased significantly, while its lactate dehydrogenase activity and cholesterol, total lipids and urea contents showed a significant increase. In liver, except for the bilirubin and glucose contents, all the biochemical components--RNA, DNA and total proteins included--showed highly elevated values. Refeeding of the starved rabbits tended to normalize most within 7 days. Although RNA, DNA, total proteins, cholesterol and urea contents did not reach the normal level in liver during this period, they were definitely less than those of the starved condition. The hepatic transaminases activities and lipid content in starved + refed livers were considerably decreased during the refeeding period. The histological parameters were slow to recover.