Microwave-assisted synthesis of sec/tert-butyl 2-arylbenzimidazoles and their unexpected antiproliferative activity towards ER negative breast cancer cells.

A new series of N-sec/tert-butyl 2-arylbenzimidazole derivatives was synthesised in 85-96% yields within 2-3.5 min by condensing ethyl 3-amino-4-butylamino benzoate with various substituted metabisulfite adducts of benzaldehyde under focused microwave irradiation. The benzimidazole analogues were characterised using (1)H NMR, (13)C NMR, high resolution MS and melting points. Evaluation of antiproliferative activity of the benzimidazole analogues against MCF-7 and MDA-MB-231 revealed several compounds with unexpected selective inhibitions of MDA-MB-231 in micromolar range. All analogues were found inactive towards MCF-7. The most potent inhibition against MDA-MB-231 human breast cancer cell line came from the unsubstituted 2-phenylbenzimidazole 10a.

Assessment of adjacent-segment mobility after cervical disc replacement versus fusion: RCT with 1 year's results.

Disc prostheses have been designed to restore and maintain cervical segmental motion and reduce the accelerated degeneration of the adjacent level. There is no knowledge about the reaction of the neighboured asymptomatic segments after implantation of prostheses or fusion. The effects of these procedures to segmental movement of the uninvolved vertebrae have not been subjected to studies so far. The objective of this study was to compare the segmental motion following cervical disc replacement versus fusion and the correlation to the clinical outcome. Another aim was to compare the segmental motion of the asymptomatic segments above the treated ones and to compare both with Roentgen stereometric analysis (RSA) including the asymptomatic segments. 20 patients with one-level cervical radiculopathy scheduled for surgery were randomized to arthroplasty (10 patients, study group) or anterior cervical discectomy and fusion (10 patients, control group). Clinical results were evaluated using Visual Analogue Scale and Neck Disability Index. RSA was performed immediately postoperative, after 6 and 12 months. The adjacent segment showed a significantly higher segmental motion in all three-dimensional axes in comparison to the segment treated with prostheses (P < 0.05). In the fusion group the segmental motion of the adjacent segment was significantly higher in all three-dimensional axes (P < 0.05) at each examination time. When the adjacent level of both groups is compared, the fusion group could show a higher segmental motion in all three-dimensional axes, but without significant difference (P > 0.05) 1 year after surgery. Regarding the clinical results, there was no significant difference in pain relief between both groups (P > 0.05). In conclusion, the adjacent segment could show a higher segmental motion, when compared with the segment either treated with prostheses or fusion. There was no significant difference in segmental motion adjacent to prosthesis or fusion. Clinical results did also show no significant difference in pain relief between both groups.

Analysis of spinal kinematics following implantation of lumbar spine disc prostheses versus fusion: radiological study.

STUDY DESIGN: This is a prospective controlled study comparing lumbar spine disc replacement versus fusion for monosegmental degenerative disc disease (DDD). SUMMARY OF BACKGROUND DATA AND OBJECTIVE: Fusion has been reported to be the standard therapy by DDD of the lumbar spine. Due to unsatisfactory long-term results of fusion by progressive adjacent level degeneration, disc replacement was developed and thought to reduce pain while restoring disc height and motion at the affected level. The expected long-term advantage of disc replacement over fusion is the preservation of motion. This again is very difficult to judge; therefore the aim of the current study was to analyze segmental motion following disc replacement versus fusion. METHODS: Patients meeting inclusion criteria were consented for the study. This analysis includes data up to 12 months from the first included patients. There were 13 patients who underwent disc replacement, and 11 patients had fusion procedures. Radiostereometric analysis was done 1 and 6 weeks and 3, 6, and 12 months after surgery. RESULTS: The mobility provocation RSA showed a significant segmental motion in the disc replacement group in comparison to fusion. CONCLUSIONS: Disc replacement using Active L prostheses preserves segmental motion during the period examination time of 12 months.

Segmental kinematics and adjacent level degeneration following disc replacement versus fusion: RCT with three years of follow-up.

STUDY DESIGN: Prospective, randomized and controlled clinical and radiological study. OBJECTIVE: The aim of this study was to assess the segmental kinematics and clinical outcome of disc replacement with ProDisc C versus anterior cervical discectomy and fusion (ACDF) for monosegmental disease 3 years after surgery. SUMMARY OF BACKGROUND DATA: Anterior cervical discectomy and fusion (ACDF), including plate fixation, is an accepted technique for treatment of symptomatic degenerative disc disease (DDD). However, various studies could show that fusion of a relative mobile spinal segment leads to heightens of stresses on the discs below and above fusion, which is manifested as adjacent level degeneration. Intervertebral disc replacement has been attempted to restore intervertebral disc height and to maintain segmental motion, which may be thought to avoid the accelerated degeneration to the adjacent level. In earlier studies, we could show that ProDisc C could maintain segmental motion for 1 year after surgery. METHODS: 49 patients with cervical disc herniation underwent arthroplasty of a single level using ProDisc C disc prosthesis or received fusion using a cage and anterior titanium plate fixation. Clinical outcome was assessed using the visual analogue scale (VAS) and the neck disability index (NDI). Radiostereometry was performed immediately postoperative and then after 1, 2, and 3 years after surgery to quantify the segmental kinematics. RESULTS: The range of motion of the treated segment with prosthesis remained unchanged 3 years after surgery in comparison to the 1-year result. The prosthesis shows a significant segmental motion in contrast to the fusion group at each RSA examination time (p < 0.05). After both procedures, a significant pain reduction in neck and arm was observed, without significant differences between both groups. During the course of the 3 years follow-up, no patients of the prosthesis group required further surgical intervention.

Poliovirus neutralising antibody in infants and cord blood.

Singapore participated in the WHO EPI protocol for rapid assessment of serological response to three doses of standard oral poliovirus vaccine. The 100% seropositive finding of thirty infants below one year old is no proof of seroconversion rate to the Trivalent Oral Poliovirus Vaccine (TOPV) administered. Investigation of 100 cord blood samples showed that passively transferred maternal poliovirus neutralising antibody cannot be relied upon for protection of infants against poliomyelitis. This paper emphasises the importance of vaccine potency testing and serves as a timely reminder that although the last case of indigenous poliomyelitis was recorded in 1974, non Sabin-like (wild) polioviruses are being isolated from imported cases and foreigners hospitalised in Singapore, and unexpectedly, from the conjunctiva and pharynx of Singaporeans treated for conjunctivitis. It discusses the WHO (World Health Organization) Plan of Action for Eradication of Polio in the Western Pacific Region which includes Singapore.

Chromosomal rearrangements and speciation of sportive lemurs (Lepilemur species).

Theoretical configurations of meiotic chromosomes of potential hybrids between the different Lepilemur species were examined, and the classification of this genus was reviewed in the light of this information. Among the chromosomal rearrangements that occurred during the chromosomal evolution of the sportive lemurs, only those which would generate a pronounced reproductive barrier were considered in relation to the geographic distribution of this genus. The analysis showed that the pattern of geographic distribution is compatible with the inferred chronological occurrence of these chromosomal rearrangements in the phylogenetic tree of the genus Lepilemur.

Chromosomal evolution in Malagasy lemurs: X. chromosomal banding studies of Propithecus diadema edwardsi and Indri indri and phylogenic relationships between all the species of the Indriidae.

The R-banded karyotypes of two Indriidae, Propithecus diadema and Indri indri, are described and compared with each other and with those of the other species of this family, previously reported, Avahi laniger and Propithecus verreauxi. These comparisons show that 30 chromosomal rearrangements, including 21 Robertsonian translocations and eight pericentric inversions, differentiate these karyotypes. A phylogenic diagram is proposed, showing the early separation of Avahi and the relatively late divergence of the three other species. A populational evolution has occurred between the three other species, but Indri is clearly separated from the two other species by at least five complex rearrangements, although it shares four Robertsonian translocations with P. verreauxi but not P. diadema.

Phylogenetic relation between Lepilemuridae and other lemuriform families.

A comparative study between the ancestral karyotype of the Lepilemuridae and that of the other lemuriforms showed that there are strong arguments supporting the hypothesis that the lepilemurs derive directly from the latter, essentially through end-to-end translocations. These results support a monophyletic origin of the lemurs of Madagascar and the classification of the Lepilemuridae as a separate family.

Enterovirus and enterovirus infections.

An account of the nature of enterovirus and enterovirus infections with special reference to experiences encountered in Singapore is presented. The most common of enterovirus epidemic diseases since 1970 is Acute Haemorrhagic Conjunctivitis caused by Coxsackievirus A24 variant and Enterovirus type 70. Enterovirus of various serotypes were isolated from a wide range of illnesses varying in severity throughout the year.

Successful artificial insemination in Lemur fulvus mayottensis.

A method is reported for collection of sperm by electrostimulation or prostatic massage in order to carry out artificial in utero insemination in Lemur fulvus mayottensis. Using fresh sperm, one success out of 7 attempts was obtained, although it was achieved with a vesiculectomized male.

Chromosomal evolution in Malagasy lemurs. IX. Chromosomal banding studies of Lepilemur mustelinus, L. dorsalis, and L. edwardsi.

The karyotypes of three Lepilemuridae species, Lepilemur mustelinus, L. edwardsi, and L. dorsalis, are described and compared to those of three Lepilemur species previously reported. The phylogenetic relationships between the six species and their presumed last common ancestor are given. The results obtained, and the comparison with other groups, strongly suggest a monophyletic origin for all Malagasy lemurs.

Chromosomal evolution in Malagasy lemurs. VIII. Chromosome banding studies of Lepilemur ruficaudatus, L leucopus, and L septentrionalis.

The karyotypes of three Lepilemuridae species, Lepilemur ruficaudatus, L leucopus, and L septentrionalis, are described and compared. An almost complete analogy of chromosome banding is exhibited. Several complex chromosomal rearrangements, especially end-to-end translocations, have occurred in the evolution of these species. The chromosomal data indicate that the species studied are well separated. In addition, their common chromosomal characters show that they constitute a clearly distinct family among the lemurs.

Cytogenetic study of complex hybrids in the genus Lemur (Primates Prosimians).

A cytogenetic study was carried out of several Lemur hybrids and their progeny. The effects of Robertsonian translocations in the heterozygous state on fertility and the possibility of a preferential transmission of metacentric trivalents are debated.

Intraoperative autonomic dysfunction associated with Arnold-Chiari malformation.

This is a report of 2 infants with Arnold-Chiari malformation who showed various degrees of cardiovascular instability prior to and during surgical decompression of the posterior fossa which was abruptly terminated with successful decompression.

Intestinal bacterial flora of the household lizard, Gecko gecko.

A total of 114 isolates was recovered from the intestines of 43 househould lizards, Gecko gecko. Among the important ones were Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa, Proteus mirabilis and Edwardsiella tarda.

Ecology of mycoplasmas in clinically healthy cats.

Mycoplasmas were isolated from various sites and organs of a series of 319 clinically healthy cats. They include M. felis, M. gateae, M. Arginini, A. laidlawii, feline ureaplasmas, M. pulmonis, M. arthritidis, and M. gallisepticum. In addition, there were 10 strains of mycoplasmas which could not be identified with the specific antiserums by growth inhibition tests. Antibody against M. felis was demonstrated by haemagglutination-inhibition and complement-fixation tests in cats which were over 6 months of age. However, no such antibody against M. felis was detected in animals which were less than 6 months old. No antibody against A. laidlawii, M. gateae, M. arginini and feline ureaplasmas was demonstrated by the same serological methods. The significance of these mycoplasmas in cats is described.

Significance and pathogenic role of Mycoplasma arginini in cat diseases.

Eighty-one strans of Mycoplasma arginini were isolated from swabs and tissues cultured from a series of 555 cats. The majority of these strains (84%) were recovered from the oropharyngeal regions. M. arginini was experimentally inoculated into young kittens. No clinical disease was produced. However, there was rapid colonization in the inoculated sites.

Torulopsis glabrata--urinary tract infections in diabetic patients in Singapore.

Urinary tract infections result mostly from ascending infection by micro-organisms introduced by way of the urethra. Bacteria are the usual causative agents. Occasionally, yeasts notably Candida albicans, are involved. Females are more prone to acute infections than males because of shorter urethra and the higher risks of contamination in the females.