Serum zinc and copper levels in the maternal blood and cord blood of neonates

Estimation of serum zinc and copper in the maternal blood and cord blood of neonates was carried out to correlate the trace metals in the neonates and their mothers in relation to gestational age and birth weight. Sixty-five healthy neonates, both term and preterm and their mothers were selected. This cross sectional study was done at Azimpur Maternity Centre, Dhaka Medical College Hospital and Chemistry Division, Atomic Energy Centre, Dhaka, Bangladesh from July 1997 to June 1998. The estimation of trace metals was carried out by Atomic Absorption Spectrophotometry (AAS). The mean serum zinc levels in the maternal blood and cord blood were 0.47 +/- 0.24 microgram/ml and 0.85 +/- 0.33 microgram/ml respectively and the mean copper levels in the maternal blood and cord blood were 1.37 +/- 0.62 micrograms/ml and 0.31 +/- 0.32 microgram/ml respectively. Cord blood zinc level was significantly higher and cord blood copper level was significantly lower than the corresponding maternal blood levels. There was no significant correlation between gestational age and serum zinc levels in the cord or maternal blood. But significant inverse correlation was found between gestational age and serum levels of copper in the maternal and cord blood.

The initial attachment of cemental fibrils to the root dentin surface in acellular and cellular cementogenesis in rat molars

To elucidate the initial attachment mechanism of cemental fibrils to the root dentin surface in acellular and cellular cementogenesis, developing rat molars were observed by light microscopy and scanning electron microscopy combined with NaOH maceration. The NaOH maceration was used to observe details of the positional association of cemental and dentinal fibrils during cementogenesis. An initial hematoxylin stained, cementum layer began to form on the root dentin surface with the first dentin mineralization in both acellular and cellular cementogenesis. The initial attachment of cemental fibrils to the dentin surface also began at this point. At the initial attachment the intermingling of cemental and dentinal fibrils occurred only in places. With advanced cementogenesis the initial cementum layer became the fibril-poor cemento-dentinal junction. This suggests that cemental fibrils attach on the initial cementum layer, and not directly on dentinal fibrils, so that the layer results in the fibril-poor cemento-dentinal junction. The present study suggests that an intervening adhesive is necessary for the cemento-dentinal attachment at any stage of cementogenesis in rat molars.

Seroprevalence of rubella antibodies among antenatal population attending a tertiary level hospital in Dhaka City

This study was performed to identify the seroprevalence of rubella IgG among the antenatal population attending a tertiary level hospital in Bangladesh. Sera from 609 pregnant women were tested for rubella IgG antibody using enzyme linked immunosorbent assay (ELISA) technique. Of the 609 pregnant women, 85.9% were seropositive and 14.1% were seronegative. The prevalence of the antibody was 80% between 15 and 20 years of age. This figure gradually increased with age until it peaked at 90.2% in the age group of 31-36 years. Then the seropositivity decreased to 81.3% in the age group of >36 years. No statistically significant difference of seroprevalence was found among housewives vs service-holders. This small preliminary study indicates that, like many other countries rubella is endemic in Bangladesh. The results of this study indicate the need for more detailed epidemiological studies to be used as the basis for a national immunization programme.

Effects of different intensities of cold stress on certain physiological phenomena related to skeletal health in a hypogonadal rat model

Intestinal transference pattern of calcium and associated changes in the activities of intestinal mucosal enzymes, rate of bone turnover and bone metabolism were evaluated in ovariectomized rats exposed to cold stress of various intensities i.e., mild (15 degrees C) or stronger (8 degrees C and 4 degrees C) for 5 min everyday for 7 consecutive days. Except mild cold stress-induced group (15 degrees C), rats of other two groups (8 degrees C and 4 degrees C) showed considerable decrease in the rate of in situ intestinal transference of calcium. Likewise, in these groups, the activities of intestinal mucosal enzymes, alkaline phosphatase (AP) and calcium ATPase (Ca2+-ATPase) were decreased significantly in all the segments of small intestine in a descending gradient. Also significant changes in bone turnover and bone resorption were confirmed in these animals by marked alterations in plasma AP activity, urinary calcium and phosphate excretion and urinary calcium to creatinine ratio (Ca: Cr). The skeletal changes were further ascertained by examining other physical and biochemical parameters of bone metabolism viz., body mass, bone density, ratio of mineral to matrix and mineral content of bone ash (calcium and phosphate) in the ovariectomized rat model. All these results suggest that stronger cold stress (8 degrees C and 4 degrees C) may be an important ecological factor in the development of earlier bone loss in hypogonadal rats.

Prevalence and risk factors of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infections among drug addicts in Bangladesh

This cross-sectional study investigated the prevalence and risk factors of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections among 266 drug users attending a drug-addiction treatment centre in Dhaka, Bangladesh, from November 1996 to April 1997. Of the 266 addicts, 129 were injectable drug users (IDUs), and 137 were non-injectable drug users (non-IDUs). The seroprevalences of hepatitis B virus surface antigen (HBsAg), anti-HBc, anti-HBs, and anti-HCV antibodies among the IDUs were 8 (6.2%), 41 (31.8%), 15 (11.6%), and 32 (24.8%), and among the non-IDUs were 6 (4.4%), 33 (24.1%), 9 (6.6%), and 8 (5.8%) respectively. None of the drug users were positive for anti-HIV antibody. Although the prevalence of HBV infection did not significantly differ between the IDUs and the non-IDUs, the prevalence of HCV infection was significantly higher among the IDUs. Among the IDUs, the prevalence of both HBV and HCV infections was associated with sharing of needles and longer duration of injectable drugs used. The seroprevalence of HBV infection in both IDUs and non-IDUs was significantly higher among those who had a history of extramarital and premarital sex. The prevalence of HCV infection was not associated with sexual promiscuity. There was no association between the seroprevalence of HBV and HCV infections and age. Active preventive programmes focusing on educational campaigns among the youths against substance abuse should be undertaken.

Light and electron microscopic study of the initial attachment of principal fibers to the alveolar bone surface in rat molars

This study was designed to observe the principal fibers and alveolar bone in various developmental stages in rat molars using light and transmission electron microscopy and to elucidate the mechanism of initial principal fiber attachment to the alveolar bone surface. Maxillary alveolar bone between the 2nd and 3rd molars of 20- and 25-day-old rats was used. A proteoglycan-rich, fiber-poor, and electron dense layer formed on the alveolar bone surface before the principal fiber organization. This layer was not seen before principal fibers had started to develop. Principal fibers first contacted and then became embedded in this layer. With further development, new bone deposited on this layer and around already attached principal fibers. These findings suggest that this electron dense, proteoglycan-rich layer may act as an adhesive factor to mediate the initial attachment of principal fibers to the alveolar bone surface.

The fibrillar structure of cementum and dentin at the cemento-dentinal junction in rat molars

The cemento-dentinal junction was examined in demineralized rat molars with complete roots by scanning electron microscopy combined with NaOH maceration. It is established that the NaOH maceration removes interfibrillar substances and cells from connective tissues selectively without structural damage to collagen fibrils. The cementum was detached from the dentin by the maceration. The inner cementum surface facing the dentin and the outer dentin surface facing the cementum were observed. In acellular cementum, both the outer dentin surface and the inner cementum surface had a smooth appearance. There was little indication of fibrils intermingling between dentin and cementum. In contrast, both the inner cementum surface and outer dentin surface in cellular cementum had an uneven appearance due to the irregular arrangement of collagen fibrils. Point-like protrusions of fibril bundles were observed on both surfaces. Some (not all) of these point-like protrusions appeared to correspond to places of fibrillar intermingling between dentin and cementum.

All-optical 100-Gbit/s word packet time-division-multiplexed access node in a looped-back configuration: enabling technologies for sequential add-drop functionality

We experimentally demonstrate the adding, dropping, and passing through of 100-Gbit/s word packets in a looped-back all-optical time-division-multiplexed (TDM) access node. Packets are routed with a 17-dB contrast ratio and demultiplexed with a 20-dB contrast ratio. This node uses short 100-Gbit/s words to demonstrate its potential to process data packets from multiple sources and to perform packet switching in a multinode ring network configuration. The ability to tolerate timing jitter as well as varying input signal characteristics is essential to an all-optical access node in a multinode network. For 2-ps input pulses, the header processor has a timing window of approximately 5 ps, and the demultiplexer has a timing window of approximately 5.5 ps. This allows for tolerance to bit-to-bit timing jitters or to an increase in the pulse width of as much as 3 ps. Packet-to-packet timing jitter is detected and compensated by the technique used to synchronize the local source to each packet. The key enabling technologies of an all-optical TDM packet add-drop multiplexer are discussed, including an erbium-doped fiber laser, a nonlinear optical loop mirror logic gate, self-synchronization to incoming packets with a fast-saturation/slow-recovery gain element followed by an intensity discriminator, a two-wavelength nonlinear optical loop mirror demultiplexer, and synchronization of new packets to the network packet rate with a phase-locked loop. The local source is automatically synchronized to the incoming packet, because it uses an extracted pulse from the packet, which has a contrast ratio of >20 dB to the rest of the packet. Finally, new packets are added by use of a local laser and a synchronization method, which gives a timing jitter of approximately 1 ps. Using a statistical method of measuring Q value with picosecond resolution, we show that a header processor with two cascaded logic gates has a Q value of 7.1 with a 95% confidence level.

Genetic analysis of the STR system D20S161 in Japanese and Bangladeshi

The allele distributions of the STR locus D20S161 have been investigated in Japanese and Bangladeshi people. No deviation from the Hardy-Weinberg equilibrium was observed in either population. D20S161 was found to be a polymorphic STR with seven alleles in Japanese and with six alleles in Bangladeshi. The distribution of allele frequencies in Japanese was very similar to that in Bangladeshi. The D20S161 system can be a potential marker for medicolegal individualization and paternity testing.

Two distinct Alu-mediated deletions of the human ABO-secretor (FUT2) locus in Samoan and Bangladeshi populations

The human secretor alpha(1,2) fucosyltransferase encoded by the FUT2 determines the production of ABO(H) antigens in secretions. Recent studies demonstrated the presence of several nonfunctional alleles in the FUT2. During the analysis for inactivating mutations at the FUT2 locus from 24 Samoan and 47 Bangladeshi individuals, we found two distinct Alu-mediated deletions of FUT2. The FUT2 deletion in a Bangladeshi population was identical with that found in Indian individuals with the Bombay phenotype (se(del)), but not associated with the null allele (T725G) of the H gene (FUT1). The FUT2 deletion in Samoans is a novel null allele (se(del2)). The junction region of se(del2) was successfully amplified using the same primers for the se(del) amplification. DNA sequencing of the junction region of the se(del2) indicated that there was a 32-bp sequence identity between DNA sequences surrounding the 5' and 3' breakpoints. The size of the deletion of the se(del2) was 9.3 kb, including the full coding region of FUT2. The frequency of the se(del) in a Bangladeshi population was 0.074, and that of the se(del2) in a Samoan population was 0.104. Hum Mutat 16:274, 2000.

Medicolegal practice in Samoa: an inside view

Samoa, considered the heart of Polynesia, has a medicolegal system with some limitations. There is a need to build a well-organized medicolegal service. The authors briefly outline the medicolegal system in Samoa from its beginning to the present and discuss future improvements.

The fibrillar structure of cement lines on resorbed root surfaces of human teeth

The cement lines between reparative cementum and resorbed dentin or cementum in human teeth were observed by light microscopy and scanning electron microscopy combined with NaOH maceration. The NaOH maceration was used to remove interfibrillar substances and to observe the fibrillar architecture of the cement lines directly. Light microscopy showed that the cement lines were rich in proteoglycans with mucopolysaccharides, but deficient in collagen fibrils. The cement lines were artificially broken after treatment with hyaluronidase, which digests some of the mucopolysaccharides, but digests no collagen fibrils. Scanning electron microscopy showed that fibril intermingling occurred only in some places between reparative cementum and resorbed tissue. These findings suggested that the proteoglycans in cement lines mediate the attachment between new and old mineralized tissue.

Efficacy of sulphasalazine plus methotrexate in rheumatoid arthritis

Early intervention with slow acting anti-rheumatic drugs (SAARDs) has led to improvement in substantial proportion of rheumatoid arthritis (RA) patients. The present open, controlled study was designed to assess whether a combination of SAARDs offer any added benefit. Fifty-four adult RA patients were randomly allocated to methotrexate (MTX) (n = 27) and MTX plus sulphasalazine (SSZ) (n = 27) groups. The subjects were followed-up fortnightly for four weeks then monthly for six months. The disease activity was assessed with the help of 10 clinical and four laboratory indices. The improvement was graded as: minor, mild decreases in indices, non-steroidal anti-inflammatory drugs (NSAIDs) continued, physician's global assessment (PGA) decreased by one; marked, acceptable decreases in indices, NSAIDs being taken sparingly, PGA decreased by at least 2, and complete, all indices normalised and patients discontinued NSAIDs completely. The improvement was considered clinically important when marked or complete improvement occurred. Adverse drug reactions resulted in withdrawal of 4 subjects from the MTX + SSZ group and 1 from the control groups. Four and three subjects in the combined and MTX groups respectively were lost to follow-up. Subjects in both groups showed significant decline in all indices except hemoglobin and neutrophil count. The differences between the two groups in the pre-treatment and post-treatment values were insignificant. Complete, marked, minor and no improvement occurred in 4 (21%), 12 (63%), 3 (16%) & 0 in the MTX and in 11 (48%), 7 (30%), 4 (17%) & 1 (4%) in MTX + SSZ groups respectively. The differences in the rates of complete and clinically important improvement between the two groups were insignificant (P 0.1398 and 0.7092). The incidence of side effects was insignificantly higher in the MTX + SSZ group. Most of them were mild and transient. The combination of SAARDs offered little added advantage in RA. However, the higher rate of complete improvement in the combination group justifies trials including larger samples.

The fibrous structure of the cemento-dentinal junction in human molars shown by scanning electron microscopy combined with NaOH-maceration

The cemento dentinal junction was studied in acellular and cellular cementum of human mandibular third molars by scanning electron microscopy combined with NaOH-maceration. Scanning electron microscopy with NaOH-maceration was applied to observe the fibrous structure in detail through long sections of the cemento-dentinal junction. In macerated specimens, the cemento dentinal junction was a fibril-poor groove. Some cemental fibrils or fibril bundles penetrated the groove and appeared to intermingle with dentinal fibrils. Prolonged maceration caused detachment of the cemento-dentinal junction irrespective of fibril intermingling allowing observation of the inner cementum surface facing the root dentin. Observations suggested that the fibril intermingling was point-like and present only in places at the cemento-dentinal junction. It was established that NaOH-maceration removes interfibrillar substances effectively in connective tissues and does no damage to the collagen fibril structure and architecture. This study showed the 3-dimensional fibrous structure of the cemento-dentinal junction in human mandibular third molars, and suggested that interfibrillar adhesive substances are more important than the fibril intermingling for the cemento-dentinal attachment.

Stable supercontinuum generation in short lengths of conventional dispersion-shifted fiber

By propagating 500-fs pulses through 2.5 m of standard fiber followed by 2 m of dispersion-shifted fiber, we generated >200 nm of spectral continuum between 1430 and 1630 nm, which is flat to less than ?0.5 dB over more than 60 nm. Pulses obtained by filtering the continuum show no increase in timing jitter over the source laser and are pedestal free to >28 dB, indicating excellent stability and coherence. We show that the second- and third-order dispersions of the continuum fiber and self-phase modulation are primarily responsible for the continuum generation and spectral shaping and found close agreement between simulations and experiments.

Polarization-insensitive nonlinear optical loop mirror demultiplexer with twisted fiber

We experimentally demonstrate reduction of the polarization sensitivity of a nonlinear optical loop mirror (NOLM) from 5 to 0.5 dB by use of 550 m of twisted dispersion-shifted fiber with a twist rate of 8 turns/m (24 turns/beat length). The twisting of the fiber induces circular birefringence and equates the parallel-and the orthogonal-polarization nonlinear phase-shift terms. Experimental results show that the polarization sensitivity monotonically decreases from 5 dB for nontwisted fiber to 0.5 dB for fiber that is twisted at a rate of 8 turns/m, and the twist rate should be more than 4 turns/m (>10 turns/beat length) for emulation of circularly polarized fiber. The minimum polarization sensitivity occurs when the control-pulse polarization is aligned with one of the eigenmodes of the twisted fiber. With the fiber twisted at a rate of 8 turns/m in the NOLM, the nonlinear transmission is 23% at a switching energy of 4 pJ/pulse. Simulations confirm the observed behavior and show that the remaining polarization sensitivity results from energy transfer between orthogonal modes of the signal pulse.

Unguided percutaneous transthoracic fine needle aspiration cytology in the diagnosis of the peripheral lung lesions

Percutaneous transthoracic fine needle aspiration cytology (PTFNAC) of lung was done in 614 cases at the department of Pathology of Institute of Diseases of Chest and Hospital (IDCH), Dhaka, during the period from July 1994 to July 1996. A definite diagnosis was possible in 417 cases (78.83%). More than half (57.65%) of the cases were proved to have malignant diseases. PTFNAC detected malignant lesion in these patients for the first time as because no other investigation was able to establish the diagnosis. Diagnostic accuracy was 74%. Only 12 (1.95%) patients developed pneumothorax and mild haemoptysis occurred in 23 (3.74%) patients. So unguided PTFNAC is a simple, time saving, safe and inexpensive method of diagnosis of peripheral lung lesions.

Two-Element Refracting System for Annular Gaussian-to-Bessel Beam Transformation

A refracting system consisting of two lenses is designed to transform an annular Gaussian laser beam into a circular Bessel beam. The slopes of the input and output surfaces fit well with a sixth-order polynomial. A smooth variation of the radii of curvature of the resulting aspheric surfaces is very attractive for easy machining of the surfaces. The diffraction-free length for the designed system is 59.4735 m at 633 nm.

Low-power high-efficiency wavelength conversion based on modulational instability in high-nonlinearity fiber

Bandwidth and peak efficiency are enhanced for wavelength conversion based on induced modulation instability by use of dispersion-shifted fiber in which the nonlinearity (n(2)/A(eff)) is enhanced by a factor of ~4.5 over that of conventional dispersion-shifted fiber. We experimentally obtain a peak conversion efficiency as high as 28 dB over a 40-nm bandwidth with 600 mW of peak pump power. Considerations for further enhancement of fiber-based wavelength conversion are also discussed.

Age at first marriage and its determinants in Bangladesh

The authors investigate marriage patterns and their determinants in Bangladesh, using data from the 1989 Bangladesh Fertility Survey. "It is believed that, whatever is the impact of the differentials that could be discerned from the analysis, a lower age at marriage (a) among rural women, (b) among those who are Muslims and (c) among those without pre-marital exposure to work is associated with a low level of education."

Seroprevalence of toxoplasma antibodies among the antenatal population in Bangladesh

OBJECTIVE

To determine the seroprevalence of toxoplasma antibodies toxoplasma IgG and toxoplasma IgM) among an antenatal population in a hospital of Bangladesh.

METHODS

Sera from 286 pregnant women were tested for toxoplasma IgG antibody by applying enzyme linked immunosorbent assay (ELISA) technique. Among the 286 sera, 88 sera were randomly selected and tested for toxoplasma IgM applying ELISA.

RESULTS

Among 286 patients 110 (38.5%) were positive for toxoplasma IgG antibody and among 88 patients only one (1.1%) was positive for toxoplasma IgM. The seroprevalence gradually increased with age and parity. The seroprevalence of antibody was higher among the women in poor (53.0%) than the upper socio-economic class (22.0%) and among the women with jobs (55.0%) than the housewife group (35.0%).

CONCLUSION

This study shows that toxoplasmosis is endemic in Bangladesh and also affecting pregnant women. There is need for further detailed studies on toxoplasmosis and its influence on perinatal morbidity and mortality.

Refracting System for Annular Gaussian-to-Bessel Beam Transformation

A refracting system is designed for transforming an annular Gaussian laser beam into a circular Bessel beam. The slope of the input and output surfaces fitted well with a sixth-order polynomial. The radii of curvature of the resulting aspheric surfaces are found to vary smoothly over the surface. The diffraction-free length for this system is found to be 59.4735 m at 633 nm.

[An autopsy case of carbon dioxide intoxication]

A 44-year-old male, engaged in the transportation of dry ice, was found dead on the floor of the freezer of his refrigerator car which was parked in front of the place where he was scheduled to make a delivery. Autopsy was performed to investigate the cause of death. Apart from the signs of acute death, no other significant findings were obtained, either macro or microscopically; carbon dioxide poisoning was thus strongly suspected. We created a simulation experiment by using the refrigerator car to reproduce the events of the accident. The oxygen concentration in the freezer was 21.0% as indicated by oxygen sensors, but decreased to 17.1-17.4% when the engine was stopped. This decrease in oxygen concentration supposedly results from the production of carbon dioxide by the vaporization of dry ice. Carbon dioxide concentration in the air could be calculated from the change in the oxygen concentration in the closed space of the freezer. The concentration was assessed at 17.1-18.6%. An oxygen concentration of 17.1-17.4% does not of itself cause serious hypoxia, but a carbon dioxide concentration of 17.1-18.6% probably causes serious intoxication, because this value is beyond that of intoxication levels published in references. Therefore, we concluded that the cause of death in this case was carbon dioxide intoxication.