Silver nanoparticles (AgNPs) induced impairment of in vitro pollen performance of Peltophorum pterocarpum (DC.) K. Heyne

Increasing use of silver nanoparticles (AgNPs) in myriad applications including electronics, medicines and agriculture has led to serious concerns regarding its release to plant ecosystems. Over the years, numerous studies have demonstrated the toxic impact of AgNPs in a variety of cell and tissue systems involved in vegetative growth across a wide range of plant species. However, assessing their impact on haploid phase of plant life cycle was restricted only to a study with Kiwifruit. In this study, in vitro pollen performance of Peltophorum pterocarpum at two endpoints i.e., germination and tube growth was assessed to evaluate the impact of nanoparticulate or ionic form of silver. Increasing concentrations of AgNO₃/AgNPs significantly reduced the pollen germination and retarded the tube growth. The EC 50 values indicated a more potent toxic effect of AgNPs than AgNO₃ on pollen germination as well as tube growth. Impairment of pollen performance was more pronounced at the stage of emergence of pollen tube. Extensive alterations in the muri and lumen of exine as revealed through SEM analysis and subsequent blockage of germpore might disrupt the emergence of pollen tube. The dynamics of pollen tube growth was analyzed with polynomial models of different degrees. A high degree of polynomial, the quintic model was able to approximate the real data points with highest coefficient of determination and smallest RMSE, compared to other models. An oscillating pattern of tube growth was portrayed with the passage of time in all the treatments that fits well with the established mechanistic oscillatory model of tube growth. It appears that exposure to AgNO₃/AgNPs inhibited pollen germination and retarded tube growth without affecting the oscillatory behavior of tip-growth.

Combining molecular docking and molecular dynamics studies for modelling Staphylococcus aureus MurD inhibitory activity

The ATP-dependent bacterial MurD enzyme catalyses the formation of the peptide bond between cytoplasmic intermediate UDP-N-acetylmuramoyl-L-alanine and D-glutamic acid. This is essential for bacterial cell wall peptidoglycan synthesis in both Gram-positive and Gram-negative bacteria. MurD is recognized as an important target for the development of new antibacterial agents. In the present study we prepared the 3D-stucture of the catalytic pocket of the Staphylococcus aureus MurD enzyme by homology modelling. Extra-precision docking, binding free energy calculation by the MM-GBSA approach and a 40 ns molecular dynamics (MD) simulation of 2-thioxothiazolidin-4-one based inhibitor $1 was carried out to elucidate its inhibition potential for the S. aureus MurD enzyme. Molecular docking results showed that Lys19, Gly147, Tyr148, Lys328, Thr330 and Phe431 residues are responsible for the inhibitor-protein complex stabilization. Binding free energy calculation revealed electrostatic solvation and van der Waals energy components as major contributors for the inhibitor binding. The inhibitor-modelled S. aureus protein complex had a stable conformation in response to the atomic flexibility and interaction, when subjected to MD simulation at 40 ns in aqueous solution. We designed some molecules as potent inhibitors of S. aureus MurD, and to validate the stability of the designed molecule D1-modelled protein complex we performed a 20 ns MD simulation. Results obtained from this study can be utilized for the design of potent S. aureus MurD inhibitors.

Intraguild Predation in Heteroptera: Effects of Density and Predator Identity on Dipteran Prey

In tropical freshwaters, different species of water bugs (Heteroptera) constitute a guild sharing similar prey resources including chironomid and mosquito larvae. Assuming possibilities of intraguild predation (IGP) among the constituent members, an attempt was made to evaluate the effects of prey and predator density on the mortality of mosquito and chironomid larvae (shared prey), using Laccotrephes griseus Guérin-Méneville (Hemiptera: Nepidae) and Ranatra filiformis Fabricius (Hemiptera: Nepidae) as IG predators and Anisops bouvieri Kirkaldy (Hemiptera: Notonectidae) as IG prey. The predation on mosquito and chironomid larvae varied with the density and combinations of the predators. When present as conspecific IG predators, L. griseus exhibited greater effect on the prey mortality than R. filiformis. The effects on shared prey suggest that the two predators are not substitutable in terms of the effect on the shared prey mortality. The mortality of A. bouvieri (IG prey) at low shared prey density was significantly different (p < 0.05) from high shared prey density. In view of predatory effect of the heteropteran predators on the dipteran larvae, the results suggest possible interference by the presence of A. bouvieri as an intermediate predator. It seems that the presence of heteropteran predators including A. bouvieri as IG prey may benefit the dipteran prey under situations when the density is low in tropical waters. The intensity of the predatory effect may differ based on the species composition at IG predator level. For mosquito biological control, the interactions between the predators may not be substitutable and are independent in their effects.

Prey preferences of aquatic insects: potential implications for the regulation of wetland mosquitoes

Wetlands are potential sites for mosquito breeding and are thus important in the context of public health. The use of chemical and microbial controls is constrained in wetlands in view of their potential impact on the diverse biota. Biological control using generalist aquatic insects can be effective, provided a preference for mosquito larvae is exhibited. The mosquito prey preferences of water bugs and larvae of odonate species were evaluated using chironomid larvae, fish fingerlings and tadpoles as alternative prey. Manly's selectivity (αi ) values with 95% confidence intervals (CIs) were estimated to judge prey preference patterns. Multivariate analysis of variance (manova) and standardized canonical coefficients were used to test the effects of density on prey selectivity. The αi values indicated a significant preference (P < 0.05) in all of the insect predators tested for mosquito larvae over the alternative prey as a density-dependent function. On a comparative scale, chironomid larvae had the highest impact as alternative prey. In a multiple-prey experiment, predators showed a similar pattern of preference for mosquito larvae over alternative prey, reflecting a significant (P < 0.05) niche overlap. The results suggest that, in a laboratory setting, these insect predators can effectively reduce mosquito density in the presence of multiple alternative prey.

Urinary tuberculosis presented as isolated bladder lesion - a case report

Extra-pulmonary Tuberculosis (EPTB) may affect all organs of the body with varied presentations. Genitourinary tuberculosis (GUTB) carries importance for its morbidity, though it is an uncommon form of TB. A widow of 45 years was admitted with several episodes of painless haematuria and recently developed urinary incontinence. Diagnosis of urinary bladder tuberculosis was made only by histopathology from bladder lesion with supportive evidence of few nonspecific constitutional symptoms and positive family history of pulmonary tuberculosis (PTB) and persistent sterile pyuria. Upper urinary tract involvement was not found. Category 1 anti-TB treatment was started. With this treatment recovery of the patient is satisfactory and symptoms are disappearing except for the incontinence. Urinary tuberculosis should be ruled out in a case of painless haematuria, repeated sterile pyuria.

Congenital stenosis in the descending colon causing intestinal obstruction in a one and half years male child

A one and half years male child presented with constipation with severe colicky abdominal pain, bilious vomiting & abdominal distension. He had history of recurrent bouts of constipation followed by gastroenteritis since birth for which he had taken symptomatic treatment & sometimes remained symptom free but he had no other significant history or associated condition. In laboratory investigations, barium enema study of large gut result simulates to Hirschsprung's disease but suction rectal biopsy revealed normal rectal tissue texture. So, consideration of diagnostic tools along with patient's general condition decision was taken for diagnostic laparotomy & peroperatively the child was diagnosed as a case of intestinal obstruction due to congenital colonic stenosis in the descending colon. After resection of stenotic segment and end to end anastomosis, histopathologycal examination of resected stenosed colon was done & it was finally proved as congenital stenosis in the descending colon. The post operative period of the patient was uneventful and he was discharged on 7th postoperative day & followed up upto 6 months. He had been found alright without any complain. Here we tried to high light that the congenital colonic stenosis as a rare, but might be a possible cause of partial/complete intestinal obstruction from newborn to older children in any part of the colon & that should kept in mind for avoiding diagnostic dilemma & proper management of patient.

Surgical outcome of laparoscopic and open surgery of pediatric inguinal hernia

Inguinal hernia repair is one of the most frequently performed surgical procedures in infants and young children. This prospective comparative study was conducted with initial experience in the department of pediatric surgery, Dhaka Shishu (children) hospital during the period of July 2007 to August 2008. We enrolled 62 children undergoing surgery for inguinal hernia, of which 30 underwent laparoscopic procedure (bilateral in 21, unilateral 9) and 32 open procedures (bilateral in 5, unilateral in 27). Mean±SD patient age was 5.92±2.11 months in laparoscopic group and 6.63±2.64 months in open group (p=0.264), 3 months to 5 years in both groups. Patients were studied under variables of operative time, duration of postoperative hospital stay & post operative complications. During laparoscopy a contralateral patent processus vaginalis of ≥2cm was noted and repaired peroperatively in 18 out of 27 children (66%), who were initially diagnosed as unilateral hernia. For unilateral repair mean±SD operative time was significantly longer in Group A (62.63±52.75) minutes compares to the Group B (29.37±9.40), p<0.001. On the contrary, for bilateral repair Mean±SD operative time was comparable between the two groups (64.65±49.70) minutes for laparoscopy & (35.65±11.53 minutes) for open herniotomy & P=0.01, that was not remarkably significant. The mean±SD post operative length of hospital stay (in hours) 36.00±32.7 hours in Group A compared to 29.97±11.82 hours in Group B which was not statically significant (p=0.342). The mean±SD follow up was 24.5±10.5 months in laparoscopic group (Group A) & 22.5±10.5 months in open group (Group B), p=0.251. Regarding post operative complication, in this study, contra lateral metachronous inguinal hernia (CMIH) manifested in none of the patient out of 27 (total unilateral repaired number) patients in laparoscopic group but contrary to this in open group 2 patients out of 27 had developed CMIH & p value was <0.05, which is statistically significant. There were 2 cases of scrotal hydrocele out of 30, observed in Group A whereas 1 case out of 32 in Group B, p=0.49, which was statistically insignificant. The scrotal hydrocele was lasted only for 2 days & resolved spontaneously. About recurrence after operation, our study noted that, 1 case (3.3%) out of 30 in laparoscopic group and 2 cases (6%) out of 32 in open surgery group had developed recurrent inguinal hernia in about one year follow up where p value was 0.459, & it was statistically insignificant. In this study, none of the patient had developed post operative testicular atrophy (due to any vas or vascular injury) or testicular ascend. So, overall this study result implies that, Laparoscopic herniotomy might be a safe and effective option as open herniotomy for the treatment of inguinal hernia in children but which one would be superior or best option it requires a large series of randomized trial.

Congenital duodenal web (wind-soak variety) in the fourth part of the duodenum causing obstruction in a female child

Delayed presentation of Duodenal Obstruction is a great diagnostic dilemma due to non-specific, varied & wide spectrum presentation. In this study, a 6 years female child presented with recurrent, intermittent, colicky abdominal pain with bilious vomiting, and occasional constipation from 9 months of her age, without having any significant family history or associated condition. She was initially diagnosed as a case of recurrent small bowel obstruction due to atypical variant of malrotation. But, after laparotomy, she was finally diagnosed as a case of recurrent duodenal obstruction due to Congenital Duodenal Web (Wind-Soak Variety) with a central hole in the fourth part of the duodenum. After uneventful recovery of post operative period the patient was discharged at 7th postoperative day & followed up upto 3 months. She had been found alright without any complication.

Congenital urogenital sinus anomaly without Adrenal Hyperplasia

Urogenital sinus anomaly is a mal-development of female urogenital system, usually associated with Congenital Adrenal Hyperplasia and may varied in presentation according to embryologic separation and length of sharing of common channel between vagina and urethra. We report a case of pure urogenital sinus anomaly of 2.5 years female child without any feature of Congenital Adrenal Hyperplasia or any other associated anomalies which is quite uncommon. The patient was diagnosed with thorough physical, biochemical, radiological and endoscopic evaluation. She had clitiromegaly, very poorly developed fused Labia minoras with a central hole, the length of common channel was about 2.5 cm and the level of vaginal confluence was at the mid portion of common channel. After in general counseling to parents, according to their desire she was operated. We performed Labialo-clitoro-vagino-urothroplasty and from post operative period to till now (after 3 months of operation) she is uneventful. Both functionally and cosmetically she is sound and her parents are also happy.

Laparoscopic versus open pyloromyotomy for infantile hypertropic pyloric stenosis: an early experience

This prospective comparative study was conducted with an initial experience in the Department of Pediatric Surgery, Dhaka Shishu (Children) Hospital during the period of December 2007 to January 2009, with the infants of 2-12 weeks age, diagnosed as Hypertrophic pyloric stenosis. Patients selection was done by simple random technique by means of lottery. For open pyloromyotomy conventional method & for laparoscopic pyloromyotomy three trocher techniques was applied. In this study, among 60 cases with infantile hypertrophic pyloric stenosis, 30 cases were finally selected for analysis irrespectively both in laparoscopic (Group A) & in open pyloromyotomy (Group B) group. Patients were studied under variables of operative time, required time of full feeds after operation, post operative hospital stay & both per and post operative complications. Regarding operative time, in Group A, mean±SD operating time (in minutes) was 61.59±51.73 whereas in Group B it was 28.33±8.40 & P value was 0.001. The result was statistically significant. The mean±SD time (in hours) of full feeds (ad libitum) was 35.00±31.70 hours in Group A compared to 28.95±10.99 hours in Group B and P value was found 0.342ns which was not statistically significant. On study of total length (in days) of post operative hospital stay, mean±SD was 3.09±2.25 & 2.58±1.15days in laparoscopic group & open pyloromyotomy group respectively. The p value was 0.355ns, which was statistically insignificant. Again, on study of complications, per operatively 6(19.5%) patients had developed haemorrage, 1(3.33%) had mucosal perforation & 4(13.36%) had developed duodenal serosal injury in laparoscopic group whereas only 1(3.33%) patient in open pyloromyotomy group had nothing else except simple hemorrhage. The p value (0.051ns) was also statistically insignificant. In regard to post operative complications, 2(6.6%) patients had developed wound hematoma, 2(6.6%) had wound infection, 1(3.33 %) had developed wound dehiscence and incisional hernia respectively in Group A. But in group B there was no subject with any complication. This result was also statistically insignificant. So, the overall study results denote that, laparoscopic pyloromyotomy would not be considered as a superior procedure or as safe as that of traditional open pyloromyotomy for the beginners.

Non-Hodgkin's lymphoma is a pathological lead point causing large gut (colo-colic varity) intussusception

Intussusception secondary to Primary Non-Hodgkin lymphoma presenting colo-colic variety is a very rare clinical entity and sometimes causing diagnostic dilemma due to non-specific, varied & wide spectrum presentation. In this study, a 9 years female child presented with recurrent, intermittent, colicky abdominal pain with occasional bilious vomiting, along with a left illiac fossa swelling & occasional per rectal bleeding and constipation for 3 months was clinically diagnosed as a case of recurrent obstructing intussusception. At laparotomy, a colo-colic intussusception with prolapsed intussusception was marked & finally on histopathology, she was diagnosed as a case of colo-colic variety of intussusception due to primary Non-Hodgkin lymphoma- a pathological lead point in mid transverse colon. After uneventful recovery of post operative period she was treated with combination chemotherapy accordingly & follow up was given up to 5 years. She had been found alright without any recurrence or organ involvement. The study focused on the avoidance of unusual delay in diagnosis as well as in proper management of rare variants of intussusception.

Comparison of post operative morbidity between laparoscopic and open appendectomy in children

This prospective comparative study was conducted in the department of Pediatric Surgery, Dhaka Shishu (children) Hospital during the period of June 2007 to September 2008 with the children of <12 years, diagnosed as acute Appendicitis. Patient selection was done by simple random technique by means of lottery. For open Appendectomy (OA) conventional method & for Laparoscopic Appendectomy (LA) 3 trocher technique was applied. Data was analyzed with the help of SPSS version 10. In this study 60 cases with acute Appendicitis including both gender were studied by two groups, group-A include 30 cases for laparoscopic and group-B include 30 cases for open appendectomy. Postoperative pain was assessed in both groups by using FLACC scale and compared at 1st 6-hours, 24 hours, 72 hours, 96 hours & at day 7. At 1st 6-hours, most of the children 24(80%) of group A had moderate pain whereas 17(56.7%) children of group B had severe pain (p<0.001). At 24 hours most of the patient 17(56.7%) of group A had mild pain compared to 27 (90%) patients of group B had moderate pain (p<0.0001). At 48 hours in group A most of the children 23(76.7%) had mild pain compared to moderate pain in 18(60%) children of group B (p<0.0001). Subsequently at 72 hours and at 96 hours most of the patients of LA group were free of pain compared to OA group. At final follow-up on day 7, 29(96.7%) children of group A had no pain compared to 26(86.7%) of group B. Regarding analgesics requirement both qualitative & quantitative requirements of analgesics were less in LA group than OA group. About post operative wound infection in group A only 1(3.3%) case had developed post operative wound infection whereas in group B 7(23.3 %) cases had. The mean (+/-SD) of post operative length of hospital stay was 52.00+/-11.62 (range 48-96) hours for group A and 76.00+/-12.74 (range 48-96) hours for group B children (p<0.001). Laparoscopic Appendectomy is more effective, preferable & superior procedure than that of open Appendectomy to reduce the post operative morbidity in children undergone appendectomy for acute appendicitis.

Blood protein polymorphism in the one-humped camel (Camelus dromedarius) in the Sudan

The blood protein polymorphism of serum albumin, haptoglobin, transferrin, ceruloplasmin and haemoglobin have been studied in 135 samples from one-humped Arabian camel (Camelus dromedarius) of the Sudan by starch gel electrophoresis. Only the serum albumin and haptoglobin systems exhibited polymorphism with the estimated frequencies of 0.0222, 0.2227 and 0.7773 for Albv, Hp1 and Hp2 respectively. The frequency of Hp0 was 0.0325. No electrophoretic variant was observed at transferrin, ceruloplasmin and haemoglobin loci in the camel. The activity of the ceruloplasmin of the camel sera was weak.

Influence of apolipoprotein B signal peptide insertion/deletion polymorphism on serum lipids and apolipoproteins in a Chinese population

Insertion/deletion polymorphism of the apo B gene encoding signal peptide and its influence on serum lipids and apolipoproteins was studied in 269 Chinese of both sexes in Singapore. The frequency of the Del allele was found to be 0.20, which is significantly lower than that in Caucasians (France) (0.34). The distribution of genotypes of ins/del polymorphism was at Hardy-Weinberg equilibrium in this population. There was an excess of individuals with the deletion allele in hypercholesterolemic subjects compared to those with normal cholesterol levels (P less than 0.05). All the lipid and apolipoprotein values were regressed for age, sex and BMI by multiple regression analysis. Individuals with one or two del alleles had significantly higher levels of serum total cholesterol (248.8 +/- 13.0 and 255.4 +/- 20.4 mg/dl, respectively) compared to those in individuals with only the Ins allele (218.4 +/- 7.8 mg/dl) (P less than 0.05). Serum LDL cholesterol level was also significantly higher in individuals with del allele (173.4 +/- 11.7 mg/dl) compared to that in those without the del allele (141.1 +/- 7.4 mg/dl) (P = 0.02). The percentages of sample variance of different lipid traits explained by apo B signal peptide polymorphism were estimated by analysis of variance (ANOVA) with sex, age and BMI as covariates. 2.3% of variability of serum total cholesterol (F = 3.27, P = 0.040) and 2.8% of LDL cholesterol (F = 3.87, P = 0.023) could be explained by the ins/del polymorphism of the apo B signal peptide gene.

Comparative bioavailability of metoprolol tartrate after oral and transdermal administration in healthy male volunteers

BACKGROUND AND OBJECTIVE

Transdermal drug delivery systems (TDDSs) of metoprolol tartrate have been previously prepared and evaluated in vitro and in vivo in an animal model. This study compares the bioavailability of metoprolol tartrate from a TDDS with that from a conventional marketed tablet in healthy human volunteers.

METHODS

This was an open-label, balanced randomised, two-treatment, two-period crossover study with a washout period of 1 week. Volunteers were randomised (by means of a SAS software-generated randomisation schedule) to have a TDDS applied to their chest for 48 hours or to receive a 100 mg conventional marketed tablet of metoprolol tartrate in period I. In period II, the volunteers received the other dosage form. Blood samples were collected through an indwelling cannula placed in the forearm vein of each subject. Metoprolol tartrate concentrations were quantified in plasma samples by a validated high-performance liquid chromatography method.

RESULTS

A 3-fold improvement in bioavailability was observed with the TDDS form over oral therapy as shown by the extent of absorption indicated by the mean area under the concentration-time curve from time zero to time t values for tablets (451.98 ng x h/mL) and TDDS (1552.66 ng x h/mL). Although the maximum plasma concentration was higher for the tablet form than the TDDS (77.67 +/- 23.33 vs 51.16 +/- 16.61 ng/mL), the variable absorption profile, which is a characteristic feature of oral therapy, was quite evident. Plasma metoprolol tartrate concentrations plummeted to therapeutically ineffective concentrations as early as 8 hours following oral administration.

CONCLUSION

The TDDS developed in our laboratory produced therapeutically effective plasma concentrations for up to 48 hours, with a minimum of 26.09 ng/mL and a maximum of 76.70 ng/mL, which is in good agreement with the therapeutic range (20-100 ng/mL) of metoprolol tartrate. It could be concluded that the TDDS meets the intended goal of 2-day management of hypertension with application of a single patch, obviating the inconvenience of frequent administration and thus improving patient compliance.

Genistein from Flemingia vestita (Fabaceae) enhances NO and its mediator (cGMP) production in a cestode parasite, Raillietina echinobothrida

Cyclic GMP (cGMP) is responsible for various cellular functions including signal pathways and it acts as a mediator for nitric oxide (NO). In order to evaluate the anthelmintic efficacy of the plant-derived isoflavones, the crude peel extract of Flemingia vestita and pure genistein were tested with respect to the activity of nitric oxide synthase (NOS), NO efflux and the cGMP concentration in Rallietina echinobothrida, the cestode parasite of domestic fowl. For comparison, the parasites were also treated with genistein (the major isoflavone present in the crude peel extract), sodium nitroprusside (SNP), a known NO donor, and praziquantel (PZQ), the reference drug. At the time of onset of paralysis in the parasite, the activity of NOS showed a significant increase (35-46%) and a 2-fold increase of NO efflux into the incubation medium in the treated worms in comparison to the respective controls. The cGMP concentration in the parasite tissue increased by 46-84% in the treated test worms in comparison to the controls. The results show that the isoflavones, genistein in particular, from the crude peel extract of F. vestita influence the cGMP concentration in the parasite tissue, which plays a major role in the downstream signal pathways.

The Effects of Three Factor VII Polymorphisms on Factor VII Coagulant Levels in Healthy Singaporean Chinese, Malay and Indian Newborns

Factor VII (FVII) is an independent risk factor for coronary artery disease. Three polymorphisms of the factor VII gene (F7) were studied in a group of healthy newborns comprising 561 Chinese, 398 Malays and 226 Asian Indians from Singapore. The allele frequencies of 3 polymorphisms (R353Q, Promoter 0/10bp Del/Ins and Intron 7) in the FVII gene were ascertained through genotyping by polymerase chain reaction and restriction digestion of amplified fragments. In Chinese the minor allele frequencies are Q: 0.04, Ins: 0.03, R7: 0.44; Malays, Q: 0.06, Ins: 0.10, R7: 0.41; and Indians, Q: 0.25, Ins: 0.23, R7: 0.43. Strong linkage disequilibrium (Delta > 0.7) is observed between the 0/10 bp and the R353Q sites in all ethnic groups. We conclude that: (i) the prevalence of the minor Q and Ins alleles of the R353Q and 0/10 bp polymorphisms are significantly higher in the Indian newborns than the Chinese and Malays; (ii) the Q allele is significantly associated (p = 0.01) with a lower plasma FVII coagulant level in the Indian and Malay neonates; and this polymorphism explains up to 3.8% of the variance in FVII coagulant levels; (iii) there is no significant difference in allele frequencies of the three polymorphisms between neonates with and without family histories of CAD.

Coexistent partial anodontia and supernumerary tooth in the mandibular arch: a rare case

Coexistent partial anodontia and supernumerary tooth in the lower jaw is a very uncommon condition. Very few cases have been reported in the literature of this condition, etiology of which is still obscure. Presented here is a rare case of simultaneous presence of single supernumerary tooth together with missing permanent central incisor teeth in the lower jaw without any associated systemic condition or syndrome.

Apolipoprotein B-gene DNA polymorphisms (Xbal andEcoRI), serum lipids, and apolipoproteins in healthy Chinese

The frequency of restriction fragment length polymorphisms (RFLPs) of the apolipoprotein B (apo B) gene, detected by XbaI and EcoRI, and their influence on serum lipids and apolipoproteins were studied in healthy Chinese of both sexes in Singapore. A total of 221 subjects (150 males, 71 females) were investigated for the XbaI and 159 subjects for the EcoRI polymorphisms, while serum lipids and apolipoprotein levels were available for 196 subjects. The frequency of the X2 allele was found to be significantly lower in the Chinese than that reported in Caucasians from the United Kingdom (0.09 vs. 0.51, P less than 0.001). The haplotype frequencies were also significantly different between the Chinese and Caucasians with a higher frequency of X1R1 in the former compared to the latter (0.85 vs. 0.34, P less than 0.0001). The distribution of RFLP genotypes at both of the restriction sites was at Hardy-Weinberg equilibrium in all groups. The influence of the apo B RFLPs on serum lipids and apolipoprotein levels (apo AI, AII, and B) was studied by both residual and multiple regression analyses considering age, sex, body mass index (BMI), and genotypes as independent variables in all possible combinations. No association was observed between the apo B genotypes and serum lipids or apolipoprotein levels except for high density lipoprotein cholesterol (HDLC), apo AI and AII, with the X2 being associated with significantly lower levels of HDLC as well as apo AI and AII, the effect being stronger in males. These data raise the possibility that the mechanism of reported association between apo B polymorphism and coronary artery disease may be through effects on HDLC.

Food reduces the bioavailability of lamotrigine

BACKGROUND AND OBJECTIVE

Lamotrigine is a relatively newer antiepileptic drug used in the treatment of partial seizures. It has a narrow therapeutic index and hence the achieved blood level of the drug is closely related to the therapeutic efficacy and toxicity. The bioavailability of lamotrigine is affected by food, hence the present study was done to investigate the effect of two types of food on the bioavailability of lamotrigine.

METHODS

A randomized, open-label, three treatment, three period, single dose and cross-over study was done in nine healthy male volunteers. A single dose of lamotrigine (100 mg) was administered at three occasions: after a north Indian diet (high calorie, high fat), after a south Indian diet (low calorie, low fat), and after an overnight fasting. Serial blood samples were collected up to 24 h post dose. Plasma lamotrigine concentrations were determined and pharmacokinetic parameters studied.

RESULTS

A statistically significant decrease in rate and extent of absorption was observed with north Indian diet and south Indian diet when compared with fasting group. Presence of both types of food causes decrease in mean values of C(max), AUC((0-t)), and AUC((0-alpha)) thus reducing the bioavailability of lamotrigine at significant level (P<0.05).

INTERPRETATION AND CONCLUSION

Lamotrigine should be taken preferably in fasting condition, as presence of food (low fat, low calorie or high fat, high calorie) decreases the bioavailability to a significant extent.

National Biometry Audit II

PURPOSE

To determine the change in compliance with the Royal College of Ophthalmologists biometry guidelines since the last National Audit 2 years ago and in particular to quantify the adoption of modern methods of axial length measurement and customization of A constants.

METHOD

A structured telephone questionnaire of individuals who perform biometry in all eye departments in the United Kingdom.

RESULTS

A biometrist was interviewed in 94 of the 178 United Kingdom Ophthalmology departments. Compared with 2 years ago, nurses alone perform biometry more frequently (67 vs 51%) and junior doctors less frequently (9 vs 15%). More biometrists now attend external training courses (45 vs 37%). The Royal College of Ophthalmologists recommended intraocular lens calculation formulae (SRK-T, Hoffer Q, and Holladay) are used more commonly (30 and 15%) and audit of prediction error is being performed more frequently (78 vs 71%). The routine use of a partial coherence laser interferometry has increased from 35 to 61% in United Kingdom Ophthalmology departments. Currently, only one United Kingdom department is routinely using immersion ultrasound biometry. 'A' constants are customized in 47% of departments.

CONCLUSION

Over the last 2 years, there has been improved implementation of the Royal College of Ophthalmologists guidelines on biometry. It is essential that the Royal College of Ophthalmologists guidelines are updated to include current best practice of routine use of partial coherence laser interferometry or immersion biometry and customization of A constants. A benchmark standard of 85-90% of patients achieving a final postoperative refraction within 1 dioptre of the predicted should be established.

Comparative effect of different types of food on the bioavailability of cefaclor extended release tablet

This randomized, six-treatment, six-period, six sequence, single dose, crossover pharmacokinetic study assessed the effect of different types of food on the bioavailability of 500-mg cefaclor extended release tablet in 23 healthy male volunteers. A single dose of cefaclor extended release 500-mg tablet was administered at six occasions: after overnight fasting, after two vegetarian (high-fat and low-fat), two non-vegetarian (high-fat and low-fat) and rice diets. Serial blood samples were collected up to 12 h after dose. Serum cefaclor concentrations were determined by a validated HPLC method. An almost equivalent increase in both Cmax and AUC was observed with both high-fat non-vegetarian and low-fat vegetarian breakfasts. However, when MIC90 values, a pharmacodynamic end-point were compared, the low-fat vegetarian diet fared better than the high-fat non-vegetarian diet. The results obtained favor low-fat vegetarian diet (breakfast) to be taken with cefaclor extended release tablet to achieve maximum benefit in terms of clinical efficacy.

Anthelmintic efficacy of Flemingia vestita (Fabaceae): alteration in the activities of some glycolytic enzymes in the cestode, Raillietina echinobothrida

The crude root-peel extract of Flemingia vestita, genistein and praziquantel were tested against some selected glycolytic enzymes--hexokinase (HK), phosphofructokinase (PFK), phosphoenolpyruvate carboxykinase (PEPCK), pyruvate kinase (PK), lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and malic enzyme (ME)--of the fowl tape worm, Raillietina echinobothrida. Following exposure to the various treatments, the activities of HK, PFK, PEPCK and LDH increased by 33-39%, 41-125%, 44-49% and 55-67%, respectively, and that of PK decreased by 14-26% in the parasite at the time of paralysis. The MDH and ME activities of the tissue homogenate were also found to be higher by 22-43% and 28-59%, respectively, in the treatments. However, whereas the activity of both cytosolic and mitochondrial MDH increased by 33-58% and 43-73%, respectively, the cytosolic ME activity showed an increase of 33-39%, and there was no significant enhancement in the mitochondrial ME activity. Histochemically, the enhancement in the activities of HK, LDH and MDH was clearly discernible. The enhanced glycolytic activity seems to be a function of anthelmintic stress caused by the phytochemicals.

The effect of four different types of food on the bioavailability of cefaclor

This randomized, open-label, balanced, five-treatment, five-period, five-sequence, single-dose and crossover pharmacokinetic study assessed the effect of different types of food on the bioavailability of cefaclor in 18 healthy male volunteers. A single dose of cefaclor, 250-mg capsule was administered at five occasions: after overnight fasting, after two vegetarian (high-fat and low-fat) diets and two non-vegetarian (high-fat and low-fat) diets. Serial blood samples were collected upto 8 h post dose. Serum cefaclor concentrations were determined by a validated HPLC method. AUC values were not significantly affected by food intake, but the T(max) was prolonged and C(max) was decreased, depending on the type of meal. The non-vegetarian diets affected the rate of absorption of cefaclor more than the vegetarian diets. The least decrease in C(max) was produced by low-fat vegetarian diet, while the maximum decrease was produced by high-fat non-vegetarian diet. The results of this study indicate that while the rate of absorption of cefaclor is significantly decreased, the extent of absorption and the rate of elimination are not significantly decreased in the presence of food. As compared to high-fat non-vegetarian diet, the time above MIC50 concentration was significantly increased by low-fat vegetarian diet. The implications of these findings for the large vegetarian Indian population are considerable.

National Biometry Audit

PURPOSE

To determine compliance with the Royal College of Ophthalmologists' (RCOphth) biometry guidelines.

METHOD

A structured telephone questionnaire of individuals who perform biometry in all eye departments in the United Kingdom (UK).

RESULTS

A biometrist was interviewed in 107 of the UK's 178 eye departments. Nurses alone run the biometry service in 58% of departments, orthoptists alone in 13%, junior doctors alone in 6%, optometrists alone in 3%, and a combination of staff in 20%. Of the staff interviewed, 37% had been on external biometry training courses. One intraocular lens (IOL) calculation formula was used for all eyes in 61% of departments with 17% using the obsolete SRK II formula, 36% of departments used two or more formulae and only 4% adhered to the RCOphth guidelines to use Hoffer Q in eyes with axial lengths <22.0 mm, an average of all three formulae in eyes between 22.0 and 24.5 mm, Holladay in eyes between 24.6 and 26.0 mm, and SRK/T in eyes >26.0 mm. Audit of refractive results was claimed by 71% of units but in only 17 (16%) did the biometrist know the percentage of eyes with a prediction error <or=1 D.

CONCLUSION

This study demonstrates poor awareness and/or implementation of the RCOphth biometry guidelines and indicates that audits are either not highlighting poor results or are not resulting in a change in practice. The guidelines should be updated to emphasise the importance of customising A constants and to set benchmark standards for prediction error.

STM imaging of flux line arrangements in the peak effect regime

We present the results of a study of vortex arrangements in the peak-effect regime of 2H-NbSe2 by scanning tunneling microscopy. By slowly increasing the temperature in a constant magnetic field, we observed a sharp transition from collective vortex motion to positional fluctuations of individual vortices at the temperature which coincides with the onset of the peak effect in ac susceptibility. We conclude that the peak effect is a disorder driven transition, with the pinning energy winning against the elastic energy.

Genotype associations of factor VII gene with plasma factor VII coagulant activity and antigen levels in healthy Chinese

A raised plasma factor VII (FVII) level is one of the risk factors for coronary artery disease. The R353Q polymorphism at codon 353 and the 10 base pair (bp) insertion (0/10 bp) polymorphism of the FVII gene have been reported to be associated with plasma FVII levels in several populations. We investigated these two polymorphisms in 209 male and 214 female healthy Chinese. The allele frequencies of 10 bp and Q were 0.036 and 0.045, respectively. Strong linkage disequilibrium was observed between these two sites (Delta = 0.85, P < 0.001). There were significant genotype associations of these two loci with FVII coagulant activity (FVIIc) and antigen (FVIIAg) levels. Heterozygous individuals had lower FVIIc and FVIIAg levels than those homozygous for the common alleles. When analyzed separately by gender, the 0/10 bp polymorphism was strongly associated with FVIIAg levels in males and females. However, both polymorphisms were significantly associated with FVIIc levels only in the females. The effect of 0/10 bp polymorphism predominated over that of the R353Q polymorphism in a two-way analysis of variance procedure. In the Chinese, the 10 bp insertion may reduce transcription of the FVII gene, leading to the decreased synthesis of FVII protein and thus FVIIc.