Metabolic studies of [18F-alpha-methyl]tyrosine in mice bearing colorectal carcinoma LS-180

Brain and tumor uptake of [18F-alpha-methyl]tyrosine (18F-AMT) and the incorporation into each of four fractions (lipid, RNA, DNA and protein) were investigated in mice bearing LS180 colorectal carcinoma. Homogenized tissues were analyzed by the fractionation method into an acid-soluble fraction (ASF) and an acid-precipitable fraction (APF). The APF was further investigated to assess the incorporation of 18F-AMT into each fraction. Incorporation into four fractions of brain and tumor at 60 min post-injection was 20 and 12%, respectively; 10% of the activity was incorporated to lipid in brain and 5% in tumor. There was 5, 2 and 2% incorporation with RNA, DNA and protein, respectively. Metabolites in ASF were analyzed by high-performance liquid chromatography and thin-layer chromatography. There was only one radioactive peak, which corresponded to 18F-AMT. The incorporation of 18F-AMT into lipid was twice that of 18F-AMT in tumor. The uptake of 18F-AMT in tissues was rapid and accomplished before 30 min, and then slowly diffused in blood. These results implied that 18F-AMT was metabolized to protein to only a small extent and trapped as intact 18F-AMT in cells up to 60 min. We conclude that 18F-AMT is a promising tracer for tumor imaging and quantification of the transport rate using two-compartment models.

Antimicrobial resistance and serotype distribution of Streptococcus pneumoniae strains causing childhood infections in Bangladesh, 1993 to 1997

Three hundred sixty-two Streptococcus pneumoniae strains were isolated from children under 5 years of age at Dhaka Shishu (Children) Hospital from 1993 to 1997. The strains were isolated from blood (n = 105), CSF (n = 164), ear swab (n = 61), eye swab (n = 20), and pus (n = 12). Of the 362 isolates, 42 (11.6%) showed intermediate resistance (MIC, <0.1 microgram/ml) and only 4 (1.1%) showed complete resistance (MIC, >2.0 microgram/ml) to penicillin. Penicillin resistance exhibited a strong relationship with serotype 14; 47.8% of the penicillin-resistant strains belonged to this type. A remarkably high (64.1%) resistance to co-trimoxazole was observed, along with a significant increase during the time period studied; there was no relationship to capsular type. By way of contrast, penicillin resistance did not show any significant change during the study period. Resistance to chloramphenicol (2.2%) and erythromycin (1.1%) was rare. The high resistance to co-trimoxazole and its increasing trend demand elucidation of the clinical impact of pneumonia treatment by this antimicrobial and reconsideration of the World Health Organization recommendation for co-trimoxazole administration to children with community-acquired pneumonia at the health care worker level in Bangladesh.

Day-to-day variability of fasting plasma glucose in newly diagnosed type 2 diabetic subjects

OBJECTIVE

To determine the day-to-day intraindividual variability of fasting plasma glucose (FPG) in newly diagnosed Caucasian type 2 diabetic subjects.

RESEARCH DESIGN AND METHODS

A total of 193 newly diagnosed, previously untreated, Caucasian type 2 diabetic subjects (135 men, 58 women) had FPG measured on two consecutive days (FPG1, FPG2). Ethical approval and subjects' full informed consent were obtained. Subjects fasted for 12 h before each study day and rested for at least 30 min before blood was taken. Plasma glucose was analyzed by a glucose oxidase method with intra- and interassay coefficients of variation (CVs) < 2%. Variability of FPG was assessed by comparison of percentage differences (PDs): PD = 100 (FPG2 - FPG1)/FPG1, with averaged FPG (FPGaver = [FPG1 + FPG2]/2). Biological and analytical variability were determined by use of SD2total = SD2biological + SD2analytical, where SD2analytical approximately equal to 2 x (CVglucose measurement)2. Given normally distributed data with zero mean, 95% of daily percentage differences will be expected to fall within a range of +/- 2 SDtotal.

RESULTS

Subjects were age 54 +/- 10 years (mean +/- SD) and had BMI of 29.3 +/- 5.3 kg/m2. FPG values for both days were 12.2 +/- 3.4 mmol/l (FPG1) and 12.1 +/- 3.3 mmol/l (FPG2), with a mean paired difference (95% CI) of 0.1 (0.0 to 0.3) mmol/l. The variance of these differences increased with increasing FPGaver. The PDs did not exhibit this effect and were normally distributed (mean -0.6% [-1.7 to 0.4]; SD 7.4% [6.8 to 8.3]), giving a 95% variability (2 SD) of 14.8%. Biological variability (2 SDbiological) was 13.7%. No significant difference in PD was found between men and women (mean difference 1.3% [-1.0 to 3.6]; SDmale 7.4%, SDfemale 7.3%; P = 0.62).

CONCLUSIONS

A total of 95% of the FPG values for this group of newly diagnosed type 2 diabetic subjects varied within approximately +/- 15% on a daily basis, with approximately 14% caused by biological variability. As these results are expressed in percentage terms, subjects in the group with higher FPG values are likely to experience larger changes in FPG values measured from day to day. This variability should be considered when using FPG for the diagnosis and/or monitoring of response to treatment in patients with type 2 diabetes.

Intrauterine growth restriction: a perspective for Pakistan

BACKGROUND

Intrauterine growth restriction (IUGR) is the second leading contributor to the prevailing perinatal mortality and morbidity. It affects 23.8% of newborns around the world and 75% of these affected infants are born in Asia. In Pakistan the incidence of IUGR is around 25%, more than the WHO criteria for triggering a public health action.

INTRODUCTION

IUGR is implicated with profound long-term impacts in adult life; like coronary heart disease, NIDDM and abnormal cortisol levels. The effects of the short and long term sequelae are reviewed.

ETIOLOGY

IUGR is associated with a wide variety of etiological factors. But the factor unique in its importance to Pakistan is maternal malnutrition. The fetal gene expression is under the influence of nutrition. Growth projection curves showing the interaction between the genetic and environmental factors are discussed.

SURVEILLANCE

Identification of IUGR baby in a primary care setting and the options in diagnosis in secondary and tertiary care settings are overviewed.

CONCLUSION

The roots of this problem, with multi factorial causes are in the socioeconomic infrastructure. This calls for a synergistic approach of reducing this public health issue. Women empowerment can help us to get out of this intergenerational cycle of growth failure. Availability of resources aside, it is also a matter of political will to change things for the better.

Modulation of nuclear matrix protein phosphorylation by histones: possible involvement of NM-associated protein kinase CK2 activity

Nuclear matrix (NM), a proteinaceous network of filaments, dictates nuclear morphology and the structure/function of DNA. Phosphorylation of NM proteins is a potential signal for regulating matrix functions. Histones also are intimately involved in DNA structure and transcription. Here, we report that various histones enhanced 32P incorporation into certain NM proteins. Modulation of NM protein phosphorylation by histones is mediated through regulation of protein kinase CK2, a messenger-independent serine/threonine kinase, which is significantly associated with the NM. The stimulatory effect of histones was mitigated by prior incubation of histones with DNA in the reaction. Phosphorylation of NM proteins was extensively reduced when an excess of the CK2-specific peptide substrate was included in the phosphorylation reaction as a competitor. Also, enhancement in the NM-associated CK2 activity by histones was blocked by inhibitors of CK2. Histone H1 effect appeared to be mediated mainly by charge effect since a stretch of polylysine induced a similar effect. Various histones also differentially affected the autophosphorylation of NM-associated CK2 subunits. This may contribute to the observed effects of histones on the NM, resulting in an enhancement and differential pattern of NM protein phosphorylation. Such a regional modification of NM protein phosphorylation might influence the nuclear functions that require histone displacement, namely, replication and transcription.

Role of protein kinase CK2 in phosphorylation nucleosomal proteins in relation to transcriptional activity

Protein kinase CK2 undergoes rapid translocation to nuclear matrix and nucleosomes on androgenic stimulation of growth in prostatic epithelial cells. Further, CK2 appears to be regulated differentially in the transcriptionally active and inactive nucleosomes. We have investigated the role of CK2 in phosphorylation of nucleosome-associated proteins in the transcriptionally active and inactive nucleosomes that were isolated from ventral prostate subjected to different androgenic status in vivo. Proteins associated with these nucleosomes were phosphorylated via the intrinsic protein kinase activity, using [gamma-32P]ATP in the absence and presence of GTP. Several proteins appear to be potential substrates for CK2 associated with the nucleosomes. Among them are proteins that are differentially associated with the transcriptionally active and inactive nucleosomes. Phosphorylation of several of these proteins is modulated depending not only on their sites of association (i.e., active vs. inactive nucleosomes) but also on the state of transcriptional activity. Differential phosphorylation of specific proteins by CK2 associated with the active and inactive nucleosomes may be pertinent to the process of transcription regulation.

Attachment of Burkholderia pseudomallei to pharyngeal epithelial cells: a highly pathogenic bacteria with low attachment ability

Respiratory infections are initiated by the attachment of bacteria to pharyngeal epithelial cells. We studied the attachment of Burkholderia pseudomallei to pharyngeal epithelial cells. After one, two, three, and four washes, there were 22.6+/-8.9, 15.7+/-7.0, 6.8+/-3.1, and 4.6+/-1.1 (mean+/-SD) attached bacteria/cell, respectively. If the bacterial concentration was maintained at 1 X 10(8) colony-forming units (cfu)/ml and three washes were done, at concentrations of 2.5 x 10(4), 5 X 10(4), and 1 x 10(5) cells/ml there were 9.9+/-3.6, 3.3+/-0.8, and 2.5+/-1.1 attached bacteria/cell, respectively. If the cell concentration was kept at 2.5 x 10(4) cells/ml and three washes were done, at bacterial concentrations of 1 x 10(5), 1 X 10(6), 1 X 10(7), 1 x 10(8), and 1 x 10(9) cfu/ml, there were 0.3+/-0.3, 0.6+/-0.6, 1.0+/-0.2, 5.1+/-2.3, and 9.6+/-1.9 attached bacteria/cell, respectively. There were 4.8+/-1.9, 5.5+/-2.5, 5.6+/-1.9, and 6.4+/-2.6 attached bacteria/cell at 0, 30, 120, and 240 min of incubation, respectively. Pharyngeal cells from 10 persons (seven men and three women, mean+/-SD age = 30.7+/-8.1 years, 12 experiments with a single isolate) showed that there were 7.8+/-4.3 attached bacteria/cell. It was found that the efficiency of attachment of this bacteria was very low (7.0+/-3.3 bacteria/cell). Electron microscopy revealed that there were no fimbriae but a thin capsular polysaccharide layer on the surface of B. pseudomallei. Attachment to pharyngeal epithelial cells appeared to be mediated by this structure.

Attachment of nontypable Haemophilus influenzae to human pharyngeal epithelial cells mediated by a ganglioside receptor

Nontypable Haemophilus influenzae (NTHI) is one of the major pathogens of human respiratory infections and has the ability to attach to pharyngeal epithelial cells. We characterized the epithelial cell receptor to which NTHI bind. Neuraminidase pretreatment of pharyngeal epithelial cells resulted in a significant decrease in NTHI attachment, suggesting sialic acid as an important component of the receptor. The attachment was not decreased in NTHI pretreated with 1,000 microg/ml of fucose, N-acetyl-neuraminic acid, N-acetyl-glucosamine, N-acetyl-galactosamine, acetyl-salicylic acid and colominic acid. Only treatment with gangliosides D1a, D1b and D2 at a concentration of 12.5 microg/ml significantly decreased the attachment. On the other hand, treatment with gangliosides M1, M2, M3, D3, T1b and asialoganglioside M1 did not decrease the attachment of NTHI. Only ganglioside D2 inhibited the attachment significantly at a concentration of 12.5 ng/ml. Other isolates of NTHI showed a decrease in attachment after treatment with ganglioside D2. Treatment of cells with anti-human GD2 monoclonal antibody also decreased the attachment of NTHI in a dose-dependent manner. This study indicates that sialic acid glycoconjugate, GD2, is one of the receptors of NTHI on human pharyngeal epithelial cells.

Isolation of pathogenic bacteria from induced sputum from hospitalized children with pneumonia in Bangladesh

A prospective study was carried out on 157 patients admitted to a paediatric hospital in Dhaka, Bangladesh to determine the bacteria present in the induced sputum of paediatric patients with X-ray proven pneumonia. Their ages ranged from 21 days to 11 years; 65 per cent of them were male and 35 per cent were female. The most affected age group was between 6 months and 2 years old. Respiratory secretions produced by induced cough were taken by swab from the oropharynx for culture and smear. The predominant bacteria were Haemophilus influenzae, Streptococcus pneumoniae, Branhamella catarrhalis and Gram-negative bacilli. Serotyping of H. influenzae revealed that 76 per cent were non-typable and 18 per cent were of type b; 23.5 per cent of isolates of H. influenzae were beta-lactamase producing. MIC90 of penicillin against S. pneumoniae and H. influenzae were 0.025 and 3.13 micrograms/ml respectively. Ampicillin, penicillin G (benzylpenicillin), amoxycillin, and gentamicin were administered for the treatment of these patients. All cases were apparently improved, on the basis of clinical evaluation, and discharged from the hospital.

Protein kinase CK2 activities in human prostatic and seminal-vesicle secretions and seminal plasma

Human prostatic secretion and seminal plasma contain certain protein kinase activities. Protein kinases play important roles in regulating a vast variety of cellular functions. The objective of this study was to determine whether one of these protein kinase activities in human prostatic secretion and seminal plasma is due to CK2, a messenger-independent, serine/threonine protein kinase that has considerable potential as a regulatory enzyme. By employing an anti-CK2 antibody and a CK2-specific peptide substrate, we have established that CK2 is present in these secretions. Approximately 70% of the CK2 activity present in seminal plasma of normozoospermic men (n = 49) is correlated to the number of sperm originally present in the semen. Further, both the prostate gland and the seminal vesicles are sources of CK2 activity in the seminal plasma of vasectomized men (n = 38). Although there was considerable variation between individuals in CK2 activity, the variation in repeat semen samples of the same vasectomized men (n = 6) was within 21%. There was no correlation of CK2 activity in seminal plasma with age for vasectomized (27-48 years, n = 38), oligozoospermic (28-43 years, n = 24), or normozoospermic men (26-48 years, n = 49). These data suggest that the majority of CK2 activity in the seminal plasma of normozoospermic men originates from sperm but that the prostate and seminal vesicles are accessory sex-gland sources of this enzyme.

Prostate specific origin of dipeptidylpeptidase IV (CD-26) in human seminal plasma

PURPOSE

A number of peptidases which can metabolize certain bioactive peptides and growth factors have been identified in seminal plasma. Our goal in this study was to determine molecular properties and the tissue source(s) for one of these peptidases, dipeptidylpeptidase IV (DPP IV), in human seminal plasma.

MATERIALS AND METHODS

We measured the activities of DPP IV with the dipeptide glycylprolyl-p-nitroanalide and its molecular forms using immunoblotting of seminal plasmas of men who were vasectomized or with different sperm concentrations, and in prostatic and seminal vesicle secretions of men undergoing prostatic surgery.

RESULTS

DPP IV in seminal plasma of vasectomized men was a membrane associated dimer comprised of subunits of approximately 110 kDa. Its activity did not differ in seminal plasmas of vasectomized, azoospermic, oligozoospermic and normozoospermic men indicating no correlation with the concentration of sperm originally present in the semen. The DPP IV antigen (CD -26) and enzymic activity were present in prostatic secretion, but absent from that of the seminal vesicles. These data indicate that the prostate gland is the primary source of DPP IV activity in seminal plasma. There was little variation in its activities in repeat seminal plasma samples from the same individual, and there was no change in its activity with age to 50 years.

CONCLUSIONS

DPP IV in seminal plasma was derived from the prostate gland and it may be useful as a bioindicator of prostate function and/or disease with age in men.

Comparative study of positron emission tomography and quantitative digital radiography (QDR) in detecting effects of aging and diet on bone metabolism of guinea pig

The purpose of this study was to compare positron emission tomography and quantitative digital radiography (QDR) in detecting the effects of aging and diet on bone metabolism. Bone imaging of guinea pigs was performed with fluorine-18 fluoride ions using a high-resolution animal PET system to analyze bone metabolism quantitatively in different age groups of guinea pigs, young (8 weeks), adult (36 weeks), and aged groups (96 weeks), and also in a dietary manipulation group (low calcium and low vitamin D3 diet for 1, 2, and 3 weeks). A three-compartment kinetic model was applied for the analysis of bone metabolism to evaluate the rate constant (K, K1-K4). There was a significant difference in K-constant between the young and other groups. The K-constant was higher (0.100+/-0.005 ml/min/ml) in the young group than in adults (0.028+/-0.001 ml/min/ml) (p < 0.001) and the aged group (0.047+/-0.020 ml/min/ml). This high value of the K-constant in the young group indicates high turnover in bone metabolism, but there was no significant difference between the adult and aged groups. Bone mineral density (BMD) was lower in the young group (0.15+/-0.026 g/cm2) than in the adult (0.230+/-0.021 g/cm2) (p < 0.001) and aged groups (0.26+/-0.03 g/cm2). There was no significant difference in BMD between the adult and aged groups. Although there was no difference in BMD between the control and dietary manipulation groups, PET study revealed a significant difference in K-constant between them (0.028+/-0.001 vs. 0.090+/-0.009 ml/min/ ml) (p < 0.001). The quantitative skeletal dynamic PET study with 18F fluoride ions was more sensitive and superior in the early detection of metabolic disorders in bone disease than QDR.

Dynamics of protein kinase CK2 association with nucleosomes in relation to transcriptional activity

Protein kinase CK2 has been implicated in control of cell growth and proliferation. Since growth stimuli evoke its preferential association with chromatin and nuclear matrix, we examined the dynamics of CK2 in nucleosomes fractionated on the basis of their transcriptional activity in the rat prostate. In this model, androgens induce expression of androgen-dependent genes but inhibit the androgen-repressed genes, whereas absence of androgens has the reverse effect. The level of CK2 was higher in the active than in inactive nucleosomes from normal prostate. Differential alterations in the levels of CK2 activity in the transcriptionally active versus inactive nucleosomes were evoked by androgen deprivation or administration. Comparison of the distribution of CK2 in active and inactive nucleosomes under varying androgenic conditions showed that the relative CK2 activity intrinsic to the transcriptionally active nucleosomes remained fairly stable, concordant with gene activity specific to the androgenic status. However, CK2 associated with inactive nucleosomes declined to a minimal level on androgen deprivation but increased rapidly on androgen administration (reflecting expression of multiple androgen-dependent genes). We suggest a role for CK2 in promoting the conformational transition of inactive nucleosomes to the active form and in the function of transcriptionally active nucleosomes.

Mechanism of protein kinase CK2 association with nuclear matrix: role of disulfide bond formation

Nuclear matrix (NM) appears to be an intranuclear locale for significant and dynamic association of the ubiquitous multifunctional messenger-independent serine/threonine protein kinase CK2 that has been implicated in growth control [Tawfic et al. (1996): J Cell Biochem 61:165-171]. We have examined the nature of the association of CK2 with the NM. Nuclei prepared in the presence of a sulfhydryl-blocking reagent such as iodoacetamide demonstrate a reduction in the amount of CK2 associated with the NM to less than 5% of the control. On the other hand, when nuclei are treated with the sulfhydryl crosslinking reagent sodium tetrathionate, NM-associated CK2 increases severalfold. Treatment of nuclei with sodium tetrathionate followed by 2-mercaptoethanol blocks this increase. Nuclei isolated from rat liver and prostate behaved similarly, suggesting an identical mode of association of CK2 with the NM regardless of the organ. These results indicate a role of sulfhydryl interactions such that NM anchoring of CK2 occurs via its beta subunit, which contains several vicinal cysteine residues. Further, various sulfhydryl-blocking reagents inhibited CK2 activity in a concentration-dependent manner, and the inhibitory effect was reversed by agents such as dithiothreitol, implying that cysteine residues in the CK2 play a role in its catalytic activity.

Biodistribution studies on L-3-[fluorine-18]fluoro-alpha-methyl tyrosine: a potential tumor-detecting agent

Iodine-123-alpha-methyl tyrosine has proven to be a promising SPECT agent for imaging amino acid uptake in tumors. We developed L-[3-(18)F]-alpha-methyl tyrosine (FMT) for PET studies. The aim of this study was to investigate its potential use as a tumor-detecting agent by using tumor-bearing mice.

METHODS

We investigated the biodistribution in normal BALB/C mice and BALB/cA nude mice bearing human rectal cancer cell line (LS180) until 120 min postinjection. FMT tumor uptake at 60 min postinjection in mice with LS180 rectal cancer, RPM11788 B-cell lymphoma and MCF7 mammary cell carcinoma was assessed, and the results were compared with 18F-fluoro-2-deoxy-D-glucose (FDG) tumor uptake. The effect of competitive inhibition of large neutral amino acid transport system using unlabeled L-alanine was also investigated.

RESULTS

The amount of FMT in blood fell to 1.05%ID/20 g at 60 min postinjection, whereas that in the pancreas was 15.2%ID/20 g, resulting in a high pancreas-to-blood ratio of 14.5. In other organs, initial uptake peaked at 5 min postinjection and then declined with time. In LS180 tumor-bearing mice, peak FMT uptake in tumor was observed at 60 min postinjection. Tumor-to-blood and tumor-to-muscle ratios ranged from 1.60 to 2.94 and from 2.79 to 3.25 over the 120-min observation period. Tumor uptake of FMT was clearly reduced by inhibition of the amino acid transport system. In mice with LS180 and MCF7 tumors, FMT tumor uptake at 60 min postinjection was significantly higher than FDG tumor uptake, whereas in RPM11788 lymphoma, uptake of FDG was significantly higher than FMT tumor uptake. Tumor-to-blood ratios of FMT in mice with LS180, RPMI1788 and MCF7 tumor at 60 min postinjection were 1.82, 5.88 and 3.56, respectively.

CONCLUSION

FMT, like other fluorinated amino acids, may become a promising tumor-detecting agent for PET, assuming that efficient methods of radiosynthesis are developed.

[Comparison of combined treatment for venous ulcers in postphlebitic syndrome and use of PGE-1--introductory remarks]

We have included PGE-1 to the clinical management of varicose ulcers of the leg. We found the results very interesting and promising. The literature on using PGE-1 for this disease entity is rather poor and the biomechanics is still unclear.

Effects of isradipine on renal hemodynamics in renal transplant patients treated with cyclosporine

Cyclosporine A is the mainstay of modern immunosuppressant therapy in human organ transplants. However, its use has been associated with nephrotoxicity and hypertension that may be hemodynamically mediated. This study was undertaken to see if the calcium channel blocker, isradipine, could improve renal hemodynamics by decreasing renal vascular resistance and to determine its effects on cyclosporine pharmacokinetics. Eighteen hypertensive renal transplant recipients (3 to 60 months post transplant) were enrolled. Antihypertensive medications were stopped. Patients were placed on isradipine and followed for 8 weeks. Blood pressure, creatinine clearance, cyclosporine trough levels, and renal plasma flow using p-aminohippurate clearance, were measured pre- and at 8 weeks of therapy. Only one patient did not complete renal plasma flow measurement. Systolic and diastolic blood pressures dropped significantly (p < 0.001) from baseline to 8 weeks with isradipine. Sbp decreased from 166 +/- 18 to 142 +/- 14 mmHg and Dbp decreased from 97 +/- 8 to 82 +/- 10 mmHg (mean +/- 1 SD). Renal vascular resistance, calculated from mean arterial pressure and renal blood flow, decreased significantly (p < 0.002) from 0.57 +/- 0.21 to 0.41 +/- 0.12 mmHg/ml/min (mean +/- 1 SD). Isradipine appeared to have no significant effect on cyclosporine trough levels, creatinine clearance, or renal plasma flow. This study shows a role for isradipine use in renal transplant recipients on cyclosporine. Renal vasoconstriction caused by cyclosporine may be partially prevented with isradipine therapy. Furthermore, isradipine is effective in the treatment of hypertension in renal transplant recipients without affecting cyclosporine levels.

Nuclear matrix proteins as malignant markers in squamous cell carcinoma of the head and neck

OBJECTIVE

To test the hypothesis that transformation of normal upper aerodigestive mucosa to squamous cell carcinoma of the head and neck (SCCHN) is associated with specific changes in nuclear matrix (NM) proteins.

DESIGN

Retrospective, nonrandomized investigation using a cellular fractionation sequence followed by 2-dimensional gel electrophoresis analysis of NM proteins.

SUBJECTS

Nuclear matrix proteins were extracted from a cohort of 12 pathologic SCCHN specimens and 5 normal specimens of oropharyngeal mucosa.

RESULTS

All SCCHN specimens examined expressed 11 NM proteins that were not detected in normal mucosa. Conversely, at least 4 NM proteins that were expressed by all specimens of normal mucosa were absent from all SCCHN tumors. Seven NM proteins were common to carcinomas and normal specimens. Spindle cell histological variants of squamous cell carcinoma had distinct NM patterns.

CONCLUSIONS

Malignant transformation of normal upper aerodigestive mucosa to SCCHN is associated with specific changes in NM composition. These data suggest that different NM proteins might serve as specific tumor markers.

Serotypes of Streptococcus pneumoniae causing invasive childhood infections in Bangladesh, 1992 to 1995

One hundred sixty-five invasive Streptococcus pneumoniae strains were isolated from children under five at Dhaka Shishu (Children's) Hospital during the period 1992 to 1995. Ninety-four strains were from cerebrospinal fluid, and 71 were from blood. More than 91% of the strains were isolated from patients aged 24 months or less. Predominant serotypes were, in descending order 7F, 12F, 14, 15B, 18, 5, and 22A. These comprised 70% of all isolates. The marked differences in serotype distribution in different countries indicate the need for a sentinel surveillance study for the countries of South Asia, particularly Bangladesh, China, India, and Pakistan.

The increasing burden of disease in Bangladeshi children due to Haemophilus influenzae type b meningitis

A laboratory-based study of diagnosed bacterial meningitis in the national paediatric hospital identified 852 cases of meningitis in the 8-year period 1987-1994. There were 587 culture-positive cases, of which Haemophilus influenzae (47%) and Streptococcus pneumoniae (32%) accounted for 80%. H. influenzae showed a remarkable increase of 700% during the study period. Most of the H. influenzae cases (90%) occurred in the 1st 2 years of life. Analysis of culture-negative specimens by antigen detection in the last 2 years also revealed the predominance of H. influenzae (71.4%) and S. pneumoniae (22.4%). Typing of H. influenzae isolates during this time showed that 98% of the strains were type b. This retrospective hospital-based study indicated a pronounced increase in the incidence of H. influenzae meningitis and strongly supports the need for large-scale Hib vaccination for young children. However, such nationwide intervention will probably need to be based on a prospective on a prospective and population-based surveillance of H. influenzae infections.

Association of protein kinase CK2 with nuclear matrix: influence of method of preparation of nuclear matrix

Nuclear matrix (NM) plays a role of fundamental structural and functional significance as the site of replication, transcription, and RNA processing and transport, acting as an anchor or attachment site for a variety of enzymes and other proteins involved in these activities. We have previously documented that protein kinase CK2 translocates from the cytosol to the nucleus, where it associates preferentially with chromatin and NM, in response to certain growth stimuli. Considering that characteristics of the isolated NM can depend on the procedural employed for its isolation, we compared three standard methods for NM preparation to confirm the association of intrinsic CK2 with this structure. Our data suggest that the method used for isolating the NM can qualitatively influence the measurable NM-associated CK2. However, all three methods employed yielded qualitatively similar results with respect to the stimulus-mediated modulation of NM-associated CK2, thus further supporting the notion that NM is an important site for physiologically relevant functions of CK2. In addition, core filaments and cytoskeleton that were isolated by two of the preparative methods had a small but significant level of associated CK2 activity.

Moraxella (Branhamella) catarrhalis adherence to human bronchial and oropharyngeal cells: the role of adherence in lower respiratory tract infections

To study the role of Moraxella (subgenus Branhamella) catarrhalis (B. catarrhalis) adherence to airway cells in lower respiratory tract infections, the in vitro attachments of B. catarrhalis to upper airway (oropharyngeal) and lower airway (bronchial) epithelial cells were compared. The adherence of 4 strains (1 nonfimbriated and 3 fimbriated) of B. catarrhalis to respiratory tract epithelial cells collected from 11 patients with chronic pulmonary disease (CPD) and 11 healthy individuals was evaluated. Both the fimbriated and nonfimbriated strains showed increased attachment to oropharyngeal cells in the CPD patients (mean +/- SEM; 25.0 +/- 3.2/cell; P < 0.01) when compared to the control subjects (12.1 +/- 1.1/cell). On the average, the attachment to bronchial cells was 6.1 to 13.6 times greater per surface area (bacteria/micron2) than the attachment to oropharyngeal cells. The fimbriated strains tended to adhere in higher numbers to bronchial cells (19.0 +/- 1.8/cell) than the nonfimbriated strain (8.7 +/- 1.2/cell), although there was no difference between the CPD and control groups. In conclusion, the attachment of B. catarrhalis to oropharyngeal cells may be an enhancing factor for colonization in the upper respiratory tract in patients with CPD, and elevated adherence of the bacteria to bronchial cells may suggest pathogenic importance when mucociliary function is impaired.