Environmental and Biological Monitoring in a Lead Acid Battery Manufacturing Unit in India

An environmental and biological monitoring of a lead acid battery manufacturing unit was carried out to measure the respirable particulate matter, lead content in working atmosphere and blood lead levels of workers employed in different sections. The results showed high mean air lead concentration in buffing (1444.45 microg/m(3)), plate cutting (430.14 microg/m(3)) and pasting (277.48 microg/m(3)) sections. The mean blood lead levels of employees in these sections were also higher than the values prescribed by ACGIH.

Hepatocellular carcinoma in glycogen storage disease type Ia: a case series

We present a series of 8 patients (6 males, 2 females) with hepatocellular carcinoma (HCC) and glycogen storage disease type Ia (GSD Ia). In this group, the age at which treatment was initiated ranged from birth to 39 years (mean 9.9 years). All patients but one were noncompliant with treatment. Hepatic masses were first detected at an age range of 13-45 years (mean 28.1 years). Age at diagnosis of HCC ranged from 19 to 49 years (mean 36.9 years). Duration between the diagnosis of liver adenomas and the diagnosis of HCC ranged from 0 to 28 years (mean 8.8 years, SD = 11.5). Two patients had positive hepatitis serologies (one hepatitis B, one hepatitis C). Alpha-fetoprotein (AFP) was normal in 6 of the 8 patients. Carcinoembryonic antigen (CEA) was normal in the 5 patients in which it was measured. Current guidelines recommend abdominal ultrasonography with AFP and CEA levels every 3 months once patients develop hepatic lesions. Abdominal CT or MRI is advised when the lesions are large or poorly defined or are growing larger. We question the reliability of AFP and CEA as markers for HCC in GSD Ia. Aggressive interventional management of masses with rapid growth or poorly defined margins may be necessary to prevent the development of HCC in this patient population.

Behavioural and chemical confirmation of the preovulatory pheromone, (Z)-7-dodecenyl acetate, in wild Asian elephants: its relationship to musth

Mammalian breeding strategies vary depending on particular social contexts and sensory systems emphasized in various species. Among sexually dimorphic non-territorial Asian elephants, Elephas maximus, a multiplex olfactory chemical signaling system has been implicated in ensuring effective reproduction. This study explores how, using chemosensory mechanisms, widely roaming, wild male elephants locate periovulatory females in matriarchal-led female family units and precisely assess their ovulatory status. In this species, the dual obstacles of separately living sexes and infrequent oestrus are overcome by lengthy female cycles. During an extended preovulatory period captive females release increasing concentrations of the urinary pheromone (Z)-7-dodecenyl acetate, timed to reach a maximum just before ovulation. The current field studies combined chemical identification and quantification of female urinary (Z)-7-dodecenyl acetate with behavioural observations, monitoring the frequencies of chemosensory responses and premating behaviours by various categories of males. The results suggest the temporal extension of the preovulatory period effectively provides a synchrony between sexes for successful reproduction. Male elephants undergo a two-decade-long maturation process that involves physical, sexual, social, and physiological maturation. Males older than 30 years are generally large, sexually active, socially adept and capable of sustaining long periods of musth, during which they release secretions distinctive of adult musth. These older adult males in musth demonstrated significantly more chemosensory responses and premating behaviours than their younger or nonmusth counterparts; they apparently are more skilled at detecting the precise ovulatory status of females. Male–male interactions are affected by size, age, and musth; the winners gain greater access to females, as indicated by the high incidence of mate guarding. The Asian elephant shares some breeding tactics common to other mammals including some primates (e.g. orangutans) and whales, while the musth parameter adds a unique feature. Fusion–fission events are influenced by elephant reproductive strategies, as roving males join female groups while tracking preovulatory pheromone concentrations.

Mammalian breeding strategies vary depending on particular social contexts and sensory systems emphasized in various species. Among sexually dimorphic non-territorial Asian elephants,

Elephas maximus

, a multiplex olfactory chemical signaling system has been implicated in ensuring effective reproduction. This study explores how, using chemosensory mechanisms, widely roaming, wild male elephants locate periovulatory females in matriarchal-led female family units and precisely assess their ovulatory status. In this species, the dual obstacles of separately living sexes and infrequent oestrus are overcome by lengthy female cycles. During an extended preovulatory period captive females release increasing concentrations of the urinary pheromone (

Z

)-7-dodecenyl acetate, timed to reach a maximum just before ovulation. The current field studies combined chemical identification and quantification of female urinary (

Z

)-7-dodecenyl acetate with behavioural observations, monitoring the frequencies of chemosensory responses and premating behaviours by various categories of males. The results suggest the temporal extension of the preovulatory period effectively provides a synchrony between sexes for successful reproduction. Male elephants undergo a two-decade-long maturation process that involves physical, sexual, social, and physiological maturation. Males older than 30 years are generally large, sexually active, socially adept and capable of sustaining long periods of musth, during which they release secretions distinctive of adult musth. These older adult males in musth demonstrated significantly more chemosensory responses and premating behaviours than their younger or nonmusth counterparts; they apparently are more skilled at detecting the precise ovulatory status of females. Male–male interactions are affected by size, age, and musth; the winners gain greater access to females, as indicated by the high incidence of mate guarding. The Asian elephant shares some breeding tactics common to other mammals including some primates (e.g. orangutans) and whales, while the musth parameter adds a unique feature. Fusion–fission events are influenced by elephant reproductive strategies, as roving males join female groups while tracking preovulatory pheromone concentrations.

Diagnostic and treatment challenges of neuronopathic Gaucher disease: two cases with an intermediate phenotype

Gaucher disease (GD) is a lysosomal storage disorder with a broad, overlapping clinical spectrum. The presented two case reports highlight the clinical evaluation required in neuronopathic GD to assist with medical management and genetic counselling.

Mellifluous matures to malodorous in musth

Male Asian elephants in musth--an annual period of heightened sexual activity and intensified aggression--broadcast odoriferous, behaviourally influential messages from secretions of the temporal gland. From our observations in the wild, together with instantaneous chemical sampling and captive-elephant playback experiments, we have discovered that young, socially immature males in musth signal their naivety by releasing honey-like odours to avoid conflict with adult males, whereas older musth males broadcast malodorous combinations to deter young males, facilitating the smooth functioning of male society. As elephant--human conflicts can upset this equilibrium, chemically modulating male behaviour may be one way to help the conservation of wild elephants.

S-adenosyl-L-methionine is required for DNA cleavage by type III restriction enzymes

The requirement of S-adenosyl-L-methionine (AdoMet) in the cleavage reaction carried out by type III restriction-modification enzymes has been investigated. We show that DNA restriction by EcoPI restriction enzyme does not take place in the absence of exogenously added AdoMet. Interestingly, the closely related EcoP15I enzyme has endogenously bound AdoMet and therefore does not require the addition of the cofactor for DNA cleavage. By employing a variety of AdoMet analogs, which differ structurally from AdoMet, this study demonstrates that the carboxyl group and any substitution at the epsilon carbon of methionine is absolutely essential for DNA cleavage. Such analogs could bring about the necessary conformational change(s) in the enzyme, which make the enzyme proficient in DNA cleavage. Our studies, which include native polyacrylamide gel electrophoresis, molecular size exclusion chromatography, UV, fluorescence and circular dichroism spectroscopy, clearly demonstrate that the holoenzyme and apoenzyme forms of EcoP15I restriction enzyme have different conformations. Furthermore, the Res and Mod subunits of the EcoP15I restriction enzyme can be separated by gel filtration chromatography in the presence of 2 M NaCl. Reconstitution experiments, which involve mixing of the isolated subunits, result in an apoenzyme form, which is restriction proficient in the presence of AdoMet. However, mixing the Res subunit with Mod subunit deficient in AdoMet binding does not result in a functional restriction enzyme. These observations are consistent with the fact that AdoMet is required for DNA cleavage. In vivo complementation of the defective mod allele with a wild-type mod allele showed that an active restriction enzyme could be formed. Furthermore, we show that while the purified c2-134 mutant restriction enzyme is unable to cleave DNA, the c2-440 mutant enzyme is able to cleave DNA albeit poorly. Taken together, these results suggest that AdoMet binding causes conformational changes in the restriction enzyme and is necessary to bring about DNA cleavage.

ATP-dependent restriction enzymes

The phenomenon of restriction and modification (R-M) was first observed in the course of studies on bacteriophages in the early 1950s. It was only in the 1960s that work of Arber and colleagues provided a molecular explanation for the host specificity. DNA restriction and modification enzymes are responsible for the host-specific barriers to interstrain and interspecies transfer of genetic information that have been observed in a variety of bacterial cell types. R-M systems comprise an endonuclease and a methyltransferase activity. They serve to protect bacterial cells against bacteriophage infection, because incoming foreign DNA is specifically cleaved by the restriction enzyme if it contains the recognition sequence of the endonuclease. The DNA is protected from cleavage by a specific methylation within the recognition sequence, which is introduced by the methyltransferase. Classic R-M systems are now divided into three types on the basis of enzyme complexity, cofactor requirements, and position of DNA cleavage, although new systems are being discovered that do not fit readily into this classification. This review concentrates on multisubunit, multifunctional ATP-dependent restriction enzymes. A growing number of these enzymes are being subjected to biochemical and genetic studies that, when combined with ongoing structural analyses, promise to provide detailed models for mechanisms of DNA recognition and catalysis. It is now clear that DNA cleavage by these enzymes involves highly unusual modes of interaction between the enzymes and their substrates. These unique features of mechanism pose exciting questions and in addition have led to the suggestion that these enzymes may have biological functions beyond that of restriction and modification. The purpose of this review is to describe the exciting developments in our understanding of how the ATP-dependent restriction enzymes recognize specific DNA sequences and cleave or modify DNA.

Rule-based programming paradigm: a formal basis for biological, chemical and physical computation

A rule-based programming paradigm is described as a formal basis for biological, chemical and physical computations. In this paradigm, the computations are interpreted as the outcome arising out of interaction of elements in an object space. The interactions can create new elements (or same elements with modified attributes) or annihilate old elements according to specific rules. Since the interaction rules are inherently parallel, any number of actions can be performed cooperatively or competitively among the subsets of elements, so that the elements evolve toward an equilibrium or unstable or chaotic state. Such an evolution may retain certain invariant properties of the attributes of the elements. The object space resembles Gibbsian ensemble that corresponds to a distribution of points in the space of positions and momenta (called phase space). It permits the introduction of probabilities in rule applications. As each element of the ensemble changes over time, its phase point is carried into a new phase point. The evolution of this probability cloud in phase space corresponds to a distributed probabilistic computation. Thus, this paradigm can handle tor deterministic exact computation when the initial conditions are exactly specified and the trajectory of evolution is deterministic. Also, it can handle probabilistic mode of computation if we want to derive macroscopic or bulk properties of matter. We also explain how to support this rule-based paradigm using relational-database like query processing and transactions.

Functional analysis of conserved motifs in type III restriction-modification enzymes

EcoP1I and EcoP15I are members of type III restriction-modification enzymes. EcoPI and EcoP15I DNA methyltransferases transfer a methyl group from S-adenosyl-L-methionine (AdoMet) to the N6 position of the second adenine residues in their recognition sequences, 5'-AGACC-3' and 5'-CAGCAG-3' respectively. We have altered various residues in two highly conserved sequences, FxGxG (motif I) and DPPY (motif IV) in these proteins by site-directed mutagenesis. Using a mixture of in vivo and in vitro assays, our results on the mutational analysis of these methyltransferases demonstrate the universal role of motif I in AdoMet binding and a role for motif IV in catalysis. All six cysteine residues in EcoP15I DNA methyltransferase have been substituted with serine and the role of cysteine residues in EcoP15I DNA methyltransferase catalysed reaction assessed. The Res subunits of type III restriction enzymes share a distant sequence similarity with and contain the motifs characteristic of the DEAD box proteins. We have carried out site-directed mutagenesis of the conserved residues in two of the helicase motifs of the EcoP1I restriction enzyme in order to investigate the role of motifs in DNA cleavage by this enzyme. Our findings indicate that certain conserved residues in these motifs are involved in ATP hydrolysis while the other residues are involved in coupling restriction of DNA to ATP hydrolysis. Taken collectively, these results form the basis for a detailed structure-function analysis of EcoP1I and EcoP15I restriction enzymes.

Essential thrombocythemia and epidural analgesia in the parturient. Does thromboelastography help?

BACKGROUND AND OBJECTIVES

It is often considered that essential thrombocythemia contraindicates placement of an epidural catheter because of the danger of epidural hematoma. Thromboelastography offers a possible means of determining the appropriateness of epidural analgesia in a patient with this disorder.

METHODS

A pregnant woman with essential thrombocythemia and a history of spontaneous abortions was evaluated by thromboelastography at 38 weeks of gestation to determine the safety of using epidural analgesia for labor pain management. On the basis of the thermoelastography findings, the patient was given epidural analgesia with bupivacaine and fentanyl during her labor.

RESULTS

The patient experienced good pain relief, delivered a healthy infant vaginally, and suffered no complications.

CONCLUSIONS

Thromboelastography may be a useful diagnostic test in determining the suitability of regional techniques for labor analgesia in parturients with essential thrombocythemia. However, success in one patient does not prove the general safety of this approach.

DNA recognition by the EcoP15I and EcoPI modification methyltransferases

The DNA-binding properties of the EcoP15I DNA methyltransferase (M.EcoP15I; MTase) were studied using electrophoretic mobility shift assays. We show by molecular size-exclusion chromatography and dimethyl suberimidate cross-linking that M.EcoP15I is a dimer in solution. While M.EcoP15I binds approx. threefold more tightly to its recognition sequence, 5'-CAGCAG-3', than to non-specific sequences in the presence of AdoMet or its analogs, the discrimination between specific and non-specific sequences significantly increases in presence of ATP. These results suggest for the first time a role for ATP in DNA recognition by type-III restriction-modification enzymes. Furthermore, we show that although c2 EcoPI mutant MTases are defective in AdoMet binding, they are still able to bind DNA in a sequence-specific manner.

Interaction of EcoP1 modification methylase with S-adenosyl-L-methionine: a UV-crosslinking study

EcoP1 modification methylase was radioactively labeled when incubated with S-adenosyl-L-[methyl-3H]methionine in the presence of ultraviolet light. Crosslinking of the enzyme as detected by electrophoresis on sodium dodecyl sulfate-polyacrylamide gel followed by fluorography and autoradiography, was shown to be specific by a number of criteria. More importantly, EcoP1 modification methylase was also radioactively labeled with S-adenosyl-L-[carboxyl-14C]methionine demonstrating that labeling involved binding of the entire AdoMet molecule rather than methylation of the protein. Further, c2 EcoP1 mutant DNA modification methylases which show negligible or very little methylation activity, correspondingly formed a weak or no adduct upon crosslinking. These results suggest that photolabeling of EcoP1 DNA modification methylase occurs at the AdoMet binding site.

Wave digital matched filter for electrocardiogram preprocessing

Digital filters play an important role in electrocardiography. Digital filter algorithms having low sensitivity to finite word-length errors are generally desirable. Wave digital filters (WDFs) are a class of filters having excellent sensitivity properties. A wave digital matched filter (WDMF) for ECG preprocessing is presented here.

Adaptive processing techniques based on hidden Markov models for characterizing very small channel currents buried in noise and deterministic interferences

Techniques for characterizing very small single-channel currents buried in background noise are described and tested on simulated data to give confidence when applied to real data. Single channel currents are represented as a discrete-time, finite-state, homogeneous, Markov process, and the noise that obscures the signal is assumed to be white and Gaussian. The various signal model parameters, such as the Markov state levels and transition probabilities, are unknown. In addition to white Gaussian noise, the signal can be corrupted by deterministic interferences of known form but unknown parameters, such as the sinusoidal disturbance stemming from AC interference and a drift of the base line owing to a slow development of liquid-junction potentials. To characterize the signal buried in such stochastic and deterministic interferences, the problem is first formulated in the framework of a Hidden Markov Model and then the Expectation Maximization algorithm is applied to obtain the maximum likelihood estimates of the model parameters (state levels, transition probabilities), signals, and the parameters of the deterministic disturbances. Using fictitious channel currents embedded in the idealized noise, we first show that the signal processing technique is capable of characterizing the signal characteristics quite accurately even when the amplitude of currents is as small as 5-10 fA. The statistics of the signal estimated from the processing technique include the amplitude, mean open and closed duration, open-time and closed-time histograms, probability of dwell-time and the transition probability matrix. With a periodic interference composed, for example, of 50 Hz and 100 Hz components, or a linear drift of the baseline added to the segment containing channel currents and white noise, the parameters of the deterministic interference, such as the amplitude and phase of the sinusoidal wave, or the rate of linear drift, as well as all the relevant statistics of the signal, are accurately estimated with the algorithm we propose. Also, if the frequencies of the periodic interference are unknown, they can be accurately estimated. Finally, we provide a technique by which channel currents originating from the sum of two or more independent single channels are decomposed so that each process can be separately characterized. This process is also formulated as a Hidden Markov Model problem and solved by applying the Expectation Maximization algorithm. The scheme relies on the fact that the transition matrix of the summed Markov process can be construed as a tensor product of the transition matrices of individual processes.

Double blind, placebo controlled trial on the cytoprotective effect of misoprostol in subjects with rheumatoid arthritis, osteoarthritis and seronegative spondarthropathy on NSAIDs

Ninety arthritic patients were randomly allotted to receive misoprostol 200 micrograms thrice daily or placebo, for 4 weeks, while they were started on various NSAIDs. While upper gastrointestinal symptoms occurred equally in both groups, patients on placebo had significantly more post-therapy abnormal endoscopy findings. Misoprostol was well tolerated without any adverse side effects; it did not interfere with the therapeutic efficacy of the NSAIDs. Arthritic patients requiring long term NSAID therapy appear to benefit from misoprostol because of its cytoprotective effect on the gastrointestinal mucosa.

Progressive systemic sclerosis in south India

Seventy eight patients with progressive systemic sclerosis (PSS) were seen over a period of 14 years. They were analysed after clinical, haematological, biochemical, immunological and radiological investigations for comparison with other Indian and Western studies. Nine of the 78 were cases of childhood PSS. There was a female preponderance (3.9:1) and the peak age of occurrence was the 4th decade (32.1%). Arthralgia (53.8%) and skin thickening (70.5%) were the common presenting symptoms. Raynaud's phenomenon (28.2%) was less common. Involvement of the skin was present in all the patients and skin biopsy was positive in 96% of the cases. Joints were affected in 66.7%; internal organs were involved in 52.6%. Antinuclear antibody was positive in 56.8%. Abnormal echocardiography (37.6%) and barium studies (20.4%) were seen. Restrictive airway pattern by pulmonary function test was present in 55%. Death occurred in 5 patients, of whom 3 died of severe pulmonary hypertension.