POST CAESAREAN VESICOUTERINE FISTULAE - YOUSSEF SYNDROME: OUR EXPERIENCE AND REVIEW OF PUBLISHED WORK

OBJECTIVE

To analyse the incidence, symptomatology, diagnosis and therapeutic aspects of Youssef syndrome (post caesarean vesicouterine fistula), and to review relevant published work.

METHODS

A retrospective study from the urosurgical unit of a tertiary care referral hospital was carried out. In a retrospective analysis of urogenital fistulae over 10 years, we identified 14 patients with uterovesical fistulae, resulting from caesarean section. All the patients were evaluated by history, physical examination, radiological tests and cystoscopy. All patients underwent transperitoneal repair of these fistulae with omental interposition. Results of surgery were evaluated by absence of cyclic haematuria, stoppage of urinary incontinence, and achievement of fertility.

RESULTS

A total of 12 patients who had minimum follow up was included in the present study. The results showed that 50% of the fistulae resulted from emergency caesarean operation with 58% of patients presenting after their second caesarean section. The mean age of the patients was 19 years (range 15-29) and mean duration of symptoms was 7 months (range 3-16). Menouria and amenorrhoea were predominant presenting symptoms. The results of surgical treatment were excellent with good continence and resolution of the cyclic haematuria. Three pregnancies (37.5%) which resulted in elective caesarean section were recorded.

CONCLUSION

Vesicouterine fistulae, despite being infrequent, are no longer a rare diagnosis and are most commonly secondary to lower segment caesarean section. With patient history and selected investigations diagnosis is relatively easy. The surgical repair of these fistulae is standard treatment, especially with delayed fistulae with achievement of total continence, and complete resolution of cyclic haematuria. Meticulous practice of obstetric and surgical principles during caesarean section can prevent the formation of these fistulae.

Hybridization of PNA to structured DNA targets: quadruplex invasion and the overhang effect

Peptide nucleic acid (PNA) probes have been synthesized and targeted to quadruplex DNA. UV-vis and CD spectroscopy reveal that the quadruplex structure of the thrombin binding aptamer (TBA) is disrupted at 37 degrees C by a short PNA probe. The corresponding DNA probe fails to bind to the stable secondary structure at this temperature. Thermal denaturation experiments indicate surprisingly high thermal and thermodynamic stabilities for the PNA-TBA hybrid. Our results point to the nonbonded nucleobase overhangs on the DNA as being responsible for this stability. This "overhang effect" is found for two different PNA-DNA sequences and a variety of different overhang lengths and sequences. The stabilization offered by the overhangs assists the PNA in overcoming the stable secondary structure of the DNA target, an effect which may be significant in the targeting of biological nucleic acids, which will always be much longer than the PNA probe. The ability of PNA to invade a structured DNA target expands its potential utility as an antigene agent or hybridization probe.

Protection of translation initiation factor eIF2 phosphorylation correlates with eIF2-associated glycoprotein p67 levels and requires the lysine-rich domain I of p67

The rate of protein synthesis in mammals is largely regulated by phosphorylation of the alpha-subunit of eukaryotic initiation factor 2 (eIF2) that is modulated by the cellular glycoprotein, p67, due to its protection of eIF2alpha phosphorylation (POEP) activity. At the N-terminus of p67, there are three unique domains, and at the C-terminus there is a conserved amino acid sequence. To analyze the importance of these domains, C-terminal deletion mutants of rat p67 were expressed constitutively in KRC-7 cells. In these cells, the phosphorylation level of the alpha-subunit of eIF2 was determined, and it was found that expression of the 1-97 amino acid segment of rat p67 increases POEP activity in vivo, and induces the endogenous levels of p67. These cells also show increased growth rate, and efficient translation of chloramphenicol acetyltransferase and beta-galactosidase reporter genes. At the N-terminus of p67, there are two unique domains: a lysine-rich domain I with the sequence (36)KKKRRKKKK(44), and an acidic residue-rich domain with the sequence (77)EEKEKDDDDEDGDGD(91). Substitution of lysine-rich domain I with (36)NMKSGNKTQ(44) in rat recombinant p67 resulted in the inhibition of its POEP activity, and substitution of the acidic residue-rich domain with (77)QNIQKALEPEAGDGA(91), resulted in no inhibition of POEP activity in KRC-7 cells. Taken together, our data suggest that protection of translation initiation factor eIF2 phosphorylation correlates with eIF2-associated glycoprotein p67 levels and requires the lysine-rich domain I of p67.

Efficacy of noninvasive nasal mechanical ventilation in acute respiratory failure: monitored by breathing patterns

OBJECTIVES

Till a decade back, the mainstay delivery of mechanical ventilation to patients with acute respiratory failure was through the endotracheal tube. To obviate the various complications of endotracheal intubation, noninvasive mechanical ventilation (NIMV) techniques were devised which could be used outside the confines of an ICU setting, and have been employed by several workers to achieve a high success rate.

METHODS

Twenty patients of acute respiratory failure (ARF) were treated with NIMV. The latter was delivered by assist control mode of ventilator and nasal CPAP mask. Improvement of the illness was monitored by serial ABG analysis and breathing pattern parameters over one week.

RESULTS

The application of NIMV was successful in reversing the illness in 17 patients (85%) and the other three patients had to be intubated. The pH rose from 7.267 +/- 0.087 at presentation to 7.411 +/- 0.032 (p < 0.00005), the PaCO2 dropped from 85.17 +/- 13.48 mmHg to 46.27 +/- 3.79 mmHg (p < 0.00005). The PaO2 improved from 52.36 +/- 11.14 mmHg to 63.60 +/- 7.55 mmHg (p < 0.005) on the seventh day. The respiratory rate (RR) decreased from 30.07 +/- 6.10 breaths/min to 22.05 +/- 4.05 breaths/min (p < 0.00005), the %RC (percent rib cage) also showed a significant reduction in rib cage contraction from 61.7 +/- 10.17 to 42.76 +/- 10.66 (p < 0.00005). A marked improvement during the initial four hours of application of NIMV was observed in all the 17 patients.

CONCLUSIONS

It was concluded that NIMV resulted in marked improvement in both the breathing pattern and blood gas parameters in patients of ARF; and PaCO2, pH, RR, %RC served as the best indicators of improvement. NIMV was observed to be most useful in those patients who had CO2 retention.

Advocacy for sexual and reproductive health: the challenge in India

Six years after the Indian government affirmed its commitment to the principles of the 1994 International Conference on Population and Development, there is still a limited understanding of the concept of reproductive and sexual health among policymakers, programme managers and the public in India. Despite some progressive changes, there is a continuing focus on stabilising population growth rates and lack of unity of goals among women's rights advocates, service providers and policymakers. Advocacy efforts need to begin focusing on turning progressive reproductive health policies into concrete programmes on the ground, and continue to push for progressive policies in uncharted areas such as domestic violence. Those who implement programmes need to work with potential allies such as women's groups, development groups, health workers' associations and the media, who all need to be brought on board. What continues to be missing are policies and programmes that promote not only health but also rights and the empowerment of women. Without a strong focus on the links between these, India's reproductive health policies and programmes may become like 'grass without roots'.

Conversion of Neutron Stars to Strange Stars as the Central Engine of Gamma-Ray Bursts

We study the conversion of a neutron star to a strange star as a possible energy source for gamma-ray bursts. We use different recent models for the equation of state of neutron star matter and strange quark matter. We show that the total amount of energy liberated in the conversion is in the range of &parl0;1-4&parr0;x1053 ergs (1 order of magnitude larger than previous estimates) and is in agreement with the energy required to power gamma-ray burst sources at cosmological distances.

MAPs and POEP of the roads from prokaryotic to eukaryotic kingdoms

Methionine aminopeptidases (MAPs) play important roles in protein processing. MAPs from various organisms, for example E. coli, S. typhimurium, P. furiosus, Saccharomyces cerevisiae, and porcine have been purified to homogeneity and their MAP activities have been tested in vitro and in vivo. The DNA sequence analyses of MAP genes from the above organisms reveal sequence homologies with other prokaryotic MAPs as well as with various eukaryotic homologues of rat p67. The cellular glycoprotein, p67 protects the alpha-subunit of eukaryotic initiation factor 2 (eIF2) from phosphorylation by its kinases. We call this POEP (protection of eIF2alpha phosphorylation) activity of p67. The POEP activity of p67 is observed in different stress-related situations such as during heme-deficiency of reticulocytes, serum starvation and heat-shock of mammalian cells, vaccinia virus infection of mammalian cells, baculovirus infection of insect cells, mitosis, apoptosis, and possibly during normal cell growth. The POEP activity of p67 is regulated by an enzyme, called p67-deglycosylase (p67-DG). When active, p67-DG inactivates p67 by removing its carbohydrate moieties. Remarkable amino acid sequence similarities at the C-terminus of rat p67 with its eukaryotic and prokaryotic homologues which have MAP activities, raise several important questions: i) does rat p67 have MAP activity?; and ii) if it does have MAP activity, how the two activities (POEP and MAP) of p67 are used by mammalian cells during their growth and differentiation. In this review, discussions have been made to evaluate both POEP and MAP activities of p67 and their possible involvement during normal growth and cancerous growth of mammalian cells.

Increased phosphorylation of eukaryotic initiation factor 2alpha at the G2/M boundary in human osteosarcoma cells correlates with deglycosylation of p67 and a decreased rate of protein synthesis

The rate of protein synthesis in higher eukaryotes is largely regulated at the level of eIF2alpha phosphorylation by its kinases. A cellular glycoprotein, p67, protects eIF2alpha from phosphorylation. An enzyme, p67-deglycosylase, when active, removes the carbohydrate moieties from p67 and inactivates it. Subsequently, protein synthesis is inhibited. During mitosis the overall rate of protein synthesis sharply declines. To understand the molecular mechanism underlying this inhibition of protein synthesis, we have examined the phosphorylation of eIF2alpha and the activity of p67. We find that the phosphorylation of eIF2alpha increases at the G2/M border of cycling U2-OS cells, and p67 is deglycosylated at the same period of the cell cycle. In addition, the level and the activity of p67-deglycosylase also increase at the G2/M boundary of cycling U2-OS cells. These results thus provide an important in vivo correlation between the increased phosphorylation of eIF2alpha and deglycosylation of p67 by p67-deglycosylase at the G2/M boundary of cycling U2-OS cells. This may explain in part the inhibition of protein synthesis in U2-OS cells approaching mitosis.

Induction of apoptosis due to lowering the level of eukaryotic initiation factor 2-associated protein, p67, from mammalian cells by antisense approach

p67, a cellular glycoprotein, protects eIF2alpha from phosphorylation by inhibitory kinases such as double-stranded RNA dependent eIF2 kinase, PKR, and heme-controlled repressor and thus promotes protein synthesis in mammalian cells. To investigate whether p67 is essential for the survival of mammalian cells, the basal level of p67 was lowered from rat tumor hepatoma cells using antisense approach. The antisense p67 RNA specifically lowered the levels of p67 message and the protein from these cells. As a result, the level of eIF2alpha phosphorylation increased significantly, the overall rate of protein synthesis decreased, and the rate of DNA synthesis also decreased in mammalian cells with low levels of p67 as compared to that seen in control cells. In addition, the majority of the cells with low levels of p67 are arrested at the G1 phase of the cell cycle and die with apoptosis. Taken together, these results suggest that appropriate levels of p67 is required for normal growth of mammalian cells.

Expression and activity of p67 are induced during heat shock

p67, a cellular glycoprotein, protects eIF2 alpha from phosphorylation by inhibitory kinases such as PKR and HCR. p67 promoter contains heat shock element (HSE). To investigate whether this HSE of p67 has any role during heat-shock, rat tumor hepatoma cells were transiently transfected with CAT reporters linked to p67 promoter with HSE and without HSE. Heat shock induced CAT activity when p67 promoter contained HSE and this induction was not observed when HSE was deleted from the p67 promoter. In response to heat-shock, the endogenous p67 mRNA was also induced to more than 36-fold, and much of it translated into protein which was modified by GlcNAc moieties. The time of induced glycosyl modification at the later stages of the heat-shock correlates with the reduced level of eIF2 alpha phosphorylation. During later stages of the heat shock of animal cells, there is a preferential translation of a small class of messages encoding heat shock proteins. Our results suggest that the expression and activity of p67 are induced at the later stages of the heat-shock, and may be involved in the preferential translation of the heat-shock messages.

Increase in p202 expression during skeletal muscle differentiation: inhibition of MyoD protein expression and activity by p202

p202 is a primarily nuclear, interferon-inducible murine protein that is encoded by the Ifi 202 gene. Overexpression of p202 in transfected cells retards cell proliferation. p202 modulates the pattern of gene expression by inhibiting the activity of various transcription factors including NF-kappaB, c-Fos, c-Jun, E2F-1, and p53. Here we report that p202 was constitutively expressed in mouse skeletal muscle and that the levels of 202 RNA and p202 greatly increased during the differentiation of cultured C2C12 myoblasts to myotubes. When overexpressed in transfected myoblasts, p202 inhibited the expression of one muscle protein (MyoD) without affecting the expression of a second one (myogenin). Thus, the decrease in the level of MyoD (but not of myogenin) during muscle differentiation may be the consequence of the increase in p202 level. Overexpressed p202 also inhibited the transcriptional activity of both MyoD and myogenin. This inhibition was correlated with an interaction of p202 with both proteins, as well as the inhibition by p202 of the sequence-specific binding of both proteins to DNA. This inhibition of the expression of MyoD and of the transcriptional activity of MyoD and myogenin may account for the inhibition of the induction of myoblast differentiation by premature overexpression of p202.