A compartmental model of water radon contamination in the human body

A multicompartmental model is developed to simulate the biokinetics in the human body following the ingestion of an inert gas. It was assumed that 100% of the radon ingested appears in the stomach, from which it is transported through the body to different organs via the blood stream. Each of these organs absorbs and releases radon differently, and, amongst all, the fat retains radon for the longest time. To test the model, the information on elimination rates of 222Rn in expired breath was obtained from other experiments done at the University of Maine. The data included male and female participants with a wide range of ages and physical activity levels. The radiation doses in the different organs and tissues were computed. As was expected, the stomach sustained the maximum dose. In this study, the highest stomach dose to any volunteer was evaluated as 115 mSv y(-1).

Sustained stress and fixed interval performance

The effects of sustained stress on response rate and temporal patterning (quarter-life) of rats performing either a previously learned fixed-interval schedule (FI 60) or learning an FI 60 simultaneously with stress onset were determined. Rats lived 24 h/day in operant cages, where they earned all of their food via lever-pressing. During the stress portion of each experiment, one group of rats was able to avoid or escape signalled intermittent footshock (Avoidance/ Escape Group), a second group (Yoked) did not have control over shock termination, a third group never received shock (Control). Shock trials were presented around the clock at approximately 5-min intervals and the stress portion of each study lasted 1-2 weeks. We have previously reported that rats tolerate this paradigm well and avoid/escape 99% of the shock trials. In rats previously trained on the FI task, both rate of responding and quarter-life values were significantly decreased on the first day of stress for both the Avoidance/Escape and Yoked Groups. Food intakes and quarter-life values were not significantly different from the controls by stress Days 3 and 2, respectively. In the acquisition study, controls learned the F1 task by Day 4 as judged by quarter-life of responding. FI task acquisition was significantly impaired in stressed rats compared to controls, not reaching asymptotic performance until Day 9 of stress. There were no major differences between the 2 stress groups in either study. These data demonstrate that stress may impair both the rate and patterning of behavior, and suggest that this rodent paradigm may usefully model some aspects of the effects of stress in humans.

Bcl-2 prevents CD95 (Fas/APO-1)-induced degradation of lamin B and poly(ADP-ribose) polymerase and restores the NF-kappaB signaling pathway

In the study presented here, we investigated the possible interactions between CD95 (Fas/APO-1) and Bcl-2 by studying the effects of Bcl-2 on the modulation of cellular pathways activated by CD95 using HeLa cells as a model system. We report that stable expression of Bcl-2 in HeLa cells is associated with multiple phenotypic changes. Treatment of HeLa cells with anti-CD95 monoclonal antibody (mAb) resulted in preferential degradation of lamin B compared with lamins A and C. Significant lamin B degradation was detected as early as 1 h after anti-CD95 mAb treatment. In contrast, lamins A and C as well as actin remained unchanged until 4 h after treatment with anti-CD95 mAb, a time point that correlated with the period of DNA fragmentation. These results indicate that selective degradation of lamin B is an early cellular event in response to activation of the CD95 pathway and that it precedes DNA fragmentation. Overexpression of Bcl-2 resulted in prevention of lamin B degradation and DNA fragmentation into oligonucleosome fragments in response to the apoptotic signal by anti-CD95 mAb. In addition, in Bcl-2-overexpressing cells that were protected against apoptosis, anti-CD95 mAb-induced cleavage of poly(ADP-ribose) polymerase was completely blocked. Overexpression of Bcl-2 also resulted in restoration of the CD95-mediated signaling pathway involving activation of the transcription factor NF-kappaB (p50/RelA). These findings suggest that Bcl-2 prevents apoptosis in part by preventing the degradation of major nuclear polypeptides such as lamin B and poly(ADP-ribose) polymerase. In addition, our results demonstrate that CD95-mediated signaling involves activation of NF-kappaB (p50/RelA).

Retinopathy after solar eclipse, 1995

BACKGROUND

Visual damage following direct sighting of the solar eclipse is a well established clinical entity. In spite of warnings in the media, a number of people attempted to observe the solar eclipse. Consequently, some developed visual damage.

METHODS

Twenty-one patients were referred to the Solar Eclipse Cell at our centre. Their demographic and clinical features were evaluated.

RESULTS

Foveal findings correlated with the duration of exposure and frequency of watching the eclipse. Six patients had used protective devices for viewing the eclipse. More than 47% eyes had discernible fundus lesions.

CONCLUSION

Lasting visual damage can follow a solar retinal burn with little or no protection from the viewing devices. Prevention remains the best treatment and there is a need to educate the public in this regard.

Health and nutritional status of boys aged 6 to 12 years in a children observation home

One hundred and ninety two boys in the age group 6 to 12 years, living in a Children Observation Home in Delhi were studied for their nutritional status and morbidity profile. Body Mass Index (BMI), an age-independent index was used to grade the nutritional status according to which, 36.7% of the boys were found to be malnourished. Signs of specific nutritional deficiencies were observed in 13.5% of the boys. Morbidity in some form or the other was present in 148 (60%) boys. Skin disease was the commonest morbidity (31.7%), followed by diseases of the oral cavity (16.1%), acute respiratory infections (8.6%) and diseases of the ear (9.9%). Need for health promotional activities is stressed to reduce the morbidity and improve the health status of these children.

Alteration of peripheral blood lymphocyte subsets in essential hypertension

OBJECTIVE

To assess lymphocytic subpopulation by labelled monoclonal antibody technique in a small group of patients with untreated essential hypertension (EH) and to detect any alteration with control of blood pressure.

DESIGN

Prospective study with phenotypic estimation of lymphocytes at presentation and a minimum of two weeks after the control of blood pressure.

SETTING

Referral, tertiary care hospital.

PATIENTS

Group 1, normotensive controls (n = 10); group 2, mild to moderate essential hypertension (n = 10); group 3, severe (accelerated/malignant) hypertension (n = 10). All the secondary causes of hypertension were ruled out by a thorough history, physical examination and appropriate radiological and biochemical investigations.

TESTS

Venous blood samples, taken at entry and a minimum of two weeks after control of blood pressure, were analyzed by alkaline phosphatase antialkaline phosphatase (APAAP) antibody technique for CD4, CD3, CD8 and CD22. Peripheral lymphocytes were separated and cocultured with phytohemagglutinin (PHA) for 72 h and assayed for CD25 by the APAAP technique.

MAIN RESULTS

In untreated patients with EH (groups 2 and 3), there was a significant down regulation of CD3, and CD4 lymphocytes whereas the proportion of mature CD22 cells increased. In group 3 there was a significant down regulation of CD25 with PHA stimulation. A negative correlation was observed between CD25 and diastolic pressure upon pooling the results of groups 2 and 3. No significant alteration in these parameters was observed following control of blood pressure with drugs for up to two weeks.

CONCLUSION

In this small group of patients with untreated EH, a significant alteration in the lymphocytic repertoire was observed. Whether this will be found in large groups of hypertensives remains to be seen.

Topical fluconazole therapy of Candida keratitis

A prospective clinical trial of topical fluconazole solution (2 mg/ml) was undertaken in six consecutive eyes of microbiologically proven Candida keratitis with abscess formation. All eyes responded well to the medical therapy. Average duration required for healing was 22.6 +/- 2.3 days. The findings of our study suggest that topical fluconazole is a safe and effective antifungal drug for the management of Candida keratitis with deep abscess.

Mapping of two genetic loci, Ten-1 and Ten-2, associated with thymus enlargement in BUF/Mna rats

The thymoma-prone BUF/Mna rat is a useful model for human thymoma. Thymoma develops spontaneously in these rats at an incidence of nearly 100%. At pre-thymoma age, BUF/Mna rats have extremely large thymuses when compared with those of rats of the other strains, suggesting the presence of genes that regulate the thymus enlargement. We performed linkage study to identify the genetic loci associated with thymus enlargement in {(WKY/NCrj x BUF/Mna) F1 x BUF/Mna} backcross rats. Linkage study showed the significant associations between thymus size and markers on Chromosomes (Chrs) 1 and 13, suggesting the presence of two genes, Ten-1 and Ten-2, which regulate the thymus enlargement. Ten-1 was located between myosin light chain, muscle 2 (MYL2) and D1Mgh11 loci on Chr 1, and Ten-2 was located between synaptotagmin II (SYT2) and D13N2 loci on Chr 13.

Cell cycle-dependent modulation of telomerase activity in tumor cells

Telomerase is a ribonucleoprotein complex that is thought to add telomeric repeats onto the ends of chromosomes during the replicative phase of the cell cycle. We tested this hypothesis by arresting human tumor cell lines at different stages of the cell cycle. Induction of quiescence by serum deprivation did not affect telomerase activity. Cells arrested at the G1/S phase of the cell cycle showed similar levels of telomerase to asynchronous cultures; progression through the S phase was associated with increased telomerase activity. The highest level of telomerase activity was detected in S-phase cells. In contrast, cells arrested at G2/M phase of the cell cycle were almost devoid of telomerase activity. Diverse cell cycle blockers, including transforming growth factor beta1 and cytotoxic agents, also caused inhibition of telomerase activity. These results establish a direct link between telomerase activity and progression through the cell cycle.

Low level nitrogen laser therapy in pulmonary tuberculosis

We report a technique for treatment of pulmonary tuberculosis that has become resistant to traditional antibiotics. We introduce a needle into the lung that carries the N2 laser to the affected chest cavity. It is irradiated for 10 min and usually only one sitting is required. Clinical improvement occurred in 90% of the patients; 60% of the patients showed improvement on their X-rays. This technique is recommended as an adjuvant to traditional tuberculosis therapy.

Postoperative spindle cell nodule of the bladder: a diagnostic problem

A case of postoperative spindle cell nodule of the bladder is reported. Initial pathological analysis was interpreted as leiomyosarcoma for which the patient underwent radical cystectomy, but subsequent reviews were consistent with a postoperative spindle cell nodule. Recognition of this benign, yet rare lesion is of significant importance to urologists, pathologists, and to the patient who may undergo extensive surgical procedure unnecessarily.

Oxygen-dependent and -independent mechanisms of renal injury in experimental ascending pyelonephritis

Pyelonephritis is the most common urinary tract infection affecting females of all age groups. Despite concerted efforts the mechanism of renal injury in pyelonephritis is not clearly understood. In the present study we have made an attempt to characterise the mediators of inflammatory insult in an experimental model of ascending pyelonephritis. Mice infected with Escherichia coli O6:K13:H1 were sacrificed at 2, 7 and 14 days post-infection. Luminol-dependent chemiluminescence response, NADPH oxidase, acid phosphatase, beta-glucuronidase and N-acetyl-beta-D-glucosaminidase activities were monitored in circulating as well as renal phagocytic cells in order to determine the role of reactive oxygen species and lysosomal enzymes in genesis of renal injury. We have demonstrated that reactive oxygen species are generated at the initiation of infection and the levels increase progressively during the course of infection. While intracellular release of lysosomal enzymes was seen in all groups, extracellular release was primarily observed at 7 and 14 days post-infection only. The results indicate that while reactive oxygen species play a significant role in tissue injury during all stages of infection, lysosomal enzyme release in extracellular milieu augments tissue destruction at later stages only.

Molecular characterization of the Azotobacter vinelandii recF gene

The recF gene from Azotobacter vinelandii (Av) has been cloned by complementation in an Escherichia coli (Ec) recF mutant. The sequence of 1568 bp has been determined and analyzed. It showed an open reading frame of 1092 nt coding for a 364-amino-acid (aa) polypeptide. The comparison of the deduced aa sequence of the recF of Av with those of other bacteria has elicited the presence of the four conserved domains thought to be essential for RecF function. A transcriptional fusion of a DNA fragment containing the promoter sequence of recF with the lacZ gene of Ec was constructed and 3-4-fold enhancement of promoter activity was observed upon UV induction.

Therapeutic penetrating keratoplasty in nonhealing corneal ulcer

Results of penetrating keratoplasty in 443 eyes of 439 patients of active infective corneal ulcers, from a period of 10 years, were analyzed. All these eyes were proven refractory to maximal medical therapy for extended periods of time, in some cases more than 6 weeks. As the surgery was performed during the active stage, the outcome was not favorable functionally. Clinical cure was obtained, however, by therapeutic penetrating keratoplasty in all but 27 of these eyes. Of unsuccessful cases, 16 could be saved with additional medical therapy, two led to phthisis bulbi, and nine required repeat therapeutic penetrating keratoplasty. Complications encountered included disturbances in intraocular dynamics such as extrusion of the lens and vitreous during surgery, secondary rise of intraocular pressure leading to damage of the optic nerve, loss of the eye due to above factors, and reinfection. The anatomical success achieved was 97% with graft clarity of 2+ or more in 39% of eyes. Useful vision, ie, better than or equal to 6/60, was possible in 33% of eyes. Thus, therapeutic keratoplasty in refractory corneal ulcer still has scope in a Third-World country.

Linkage of the athymic nude locus with the myeloperoxidase locus in the rat

In rats of the BUF/Mna strain epithelial thymoma development is regulated by a single autosomal susceptible gene, Tsr-1. In pre-thymoma stage, BUF/Mna rats have extremely large thymuses, when compared with those of other strains of rats. The large thymus size of this strain is contributed by a thymus-enlargement gene, Ten-1. On the other hand, reduced thymus size and suppression of thymoma development were found in heterozygous BUF/Mna-rnu/+ rats. Linkage studies between RNU and microsatellite and restriction fragment length polymorphism markers in ([BUF/Mna-rnu/rnu x WKY/NCrj] F1 x WKY/NCrj)- and (WKY/NCrj x [BUF/Mna-rnu/rnu x WKY/NCrj] F1)- backcross rats have led to the localization of RNU on chromosome 10. The rat homolog of mouse Mpo (myeloperoxidase) was also assigned to the chromosome 10. The gene order on the chromosome was MYHSE (myosin heavy chain of embryonic skeletal muscle)--(1.0 centimorgan [cM])--SHBG (sex hormone-binding globulin)--(4.0 cM)--RNU (Rowett rat nude)--(10.0 cM)--MPO--(13.0 cM)--AEP (anion exchange protein). Conserved linkage of homologous loci mapped to rat chromosome 10 and mouse chromosome 11 supports the hypothesis that the RNU and MPO loci are rat homologs of the mouse nu and Mpo loci.

Time-resolved immunofluorometric assay and specimen storage conditions for measuring urinary gonadotropins

We optimized storage conditions and validated a sensitive immunofluorometric assay (IFMA) for urinary gonadotropins. Assay linearity and parallelism for luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was observed to 0.04 IU/L. Urinary LH and FSH were unaffected by changes of osmolarity from 0.5 to 3.0 mOsm/kg, and from pH 4.5 to 10.5. Serum and urine measurements of the hormones correlated well over a wide range of values: for LH, R2 = 0.94, P < 0.01; for FSH, R2 = 0.71, P < 0.01 (n = 304). Preservation of urine with glycerol (70 mL/L) and storage at -20 degrees C yielded > 80% recovery of LH and FSH after 51 weeks; this was comparable with recovery for acetone extracts of urine. Untreated urine showed loss of activity by 4 weeks of storage. Preserving urine specimens with glycerol is a simple method of storage for longitudinal study and compares favorably with acetone extraction. IFMAs can measure urinary gonadotropins reproducibly over a wide range of pH and osmotic conditions.

Time-resolved immunofluorometric assay and specimen storage conditions for measuring urinary gonadotropins

We optimized storage conditions and validated a sensitive immunofluorometric assay (IFMA) for urinary gonadotropins. Assay linearity and parallelism for luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was observed to 0.04 IU/L. Urinary LH and FSH were unaffected by changes of osmolarity from 0.5 to 3.0 mOsm/kg, and from pH 4.5 to 10.5. Serum and urine measurements of the hormones correlated well over a wide range of values: for LH, R2 = 0.94, P &lt; 0.01; for FSH, R2 = 0.71, P &lt; 0.01 (n = 304). Preservation of urine with glycerol (70 mL/L) and storage at -20 degrees C yielded &gt; 80% recovery of LH and FSH after 51 weeks; this was comparable with recovery for acetone extracts of urine. Untreated urine showed loss of activity by 4 weeks of storage. Preserving urine specimens with glycerol is a simple method of storage for longitudinal study and compares favorably with acetone extraction. IFMAs can measure urinary gonadotropins reproducibly over a wide range of pH and osmotic conditions.

Application of papaya latex-induced rat paw inflammation: model for evaluation of slowly acting antiarthritic drugs

Papaya latex-induced rat paw inflammation model for evaluating antiinflammatory activity has been developed and reported earlier. A number of drugs viz. aspirin, indomethacin, piroxicam, ibuprofen, prednisolone, levamisole, chloroquine, and boswellic acids showed antiinflammatory activity in this model. As the last three drugs showing the activity belonged to the group of slowly acting antiarthritic drugs, this present study was undertaken to study in detail the sensitivity of this model for slowly acting, clinically effective, antiarthritic drugs viz. chloroquine, levamisole, penicillamine, aurothioglucose, cyclophosphamide, and boswellic acids. These drugs are known to show no appreciable activity in the known models of inflammation and arthritis. All these drugs tested in three graded doses showed dose-related significant antiinflammatory activity in this model, whereas those drugs in the carrageenan model tested in similar doses showed insignificant activity. Aspirin employed as a reference standard showed significant activity in both the models. Thus the slowly acting antiarthritic drugs will be identified as those displaying significant activity in the papaya latex model and insignificant activity in the carrageenan model and to be aspirin-like by their significant activity in both the above models of inflammation.

Tetanus in Auckland: a preventable disease

AIMS

To determine the clinical features, management and outcome for patients admitted to hospital with tetanus in Auckland.

METHODS

Medical records of all patients with tetanus admitted to hospitals in Auckland between January 1982 and December 1992 were retrospectively reviewed.

RESULTS

Fifteen patients were admitted to hospital during the study period. All patients were more than 40 years old and no patient had a history of more than one tetanus toxoid immunisation before the injury presumed responsible for tetanus. Failure to consider the diagnosis led to delay in starting appropriate treatment in most patients. Eleven patients required mechanical ventilation. The median duration of hospital stay was 44 days. All patients survived.

CONCLUSIONS

Tetanus is rare in Auckland and almost exclusively affects those born before 1960 when universal childhood immunisation against tetanus was started. The disease causes significant morbidity which could be avoided by increased efforts to ensure that all persons have completed a full course of immunisation. Universal vaccination against tetanus with regular boosters to maintain immunity would also circumvent the problems encountered with postexposure tetanus prophylaxis.

Patients' intentions in primary care: relationship to physical and psychological symptoms, and their perception by general practitioners

A series of three studies of consecutive primary care patients examined their intentions when visiting a general practitioner (GP). In study 1, a principal, components analysis of responses to a specially-devised symptom check-list was used to form component-based scales on which patients' physical symptoms were scored. Apart from a modest association of cold symptoms with seeking simple explanation, physical symptoms were unrelated to intentions. By contrast, the level of psychological symptoms correlated with the desire for support from the GP. In study 2 this result was replicated and shown to be unaffected by the amount of support which patients already experienced from family and friends. In study 3, GPs were found to be able to detect at better than chance level which patients desired support, but they were insensitive to other intentions. The results indicate that a technique for the quantification of patients' intentions permits the formal investigation of important questions concerning primary care consultations.

Fibular shortening in poliomyelitis

This study arose from observation that in children will leg shortening from paralysis, the relationship between the tibia and fibula is disturbed. This article analyses 76 patients of post polio residual paralysis involving only one lower limb. Sixteen patients had fibular shortening. Several factors that interfere with fibular growth, i.e. anatomical continuity, soleus strength, abnormal forces at distal fibular physis, result in fibular shortening. Early the age at onset of paralysis, more is the fibular shortening which is associated with lateral wedging of distal tibial epiphysis, valgus at ankle, external torsion of tibia and genu valgus.

Studies on processing and refrigerated storage of 'Rista'

Effects of mutton fat levels, hot-boned versus cold-boned meat and manual versus machine mincing were studied on the quality of 'Rista'-a popular emulsion type ground meat product of Kashmir (India). Incorporation of lamb fat at 20% level was found optimum for processing Rista. Both pre-rigor and chilled (post-rigor) meat were utilised for product manufacture. Addition of 0·5% sodium tripolyphosphate improved product binding, texture and yield. All these effects were more pronounced in machine minced Rista samples processed from cold-boned lamb meat, as compared with hot-processed and hand minced product. Cooked Rista was stored in low density polyethylene bags (0·25 μm thickness) at 4 ± 1°C in satifactory condition for 4 days.

Antisense MAP-2 oligonucleotides induce changes in microtubule assembly and neuritic elongation in pre-existing neurites of rat cortical neurons

Microtubule-associated protein 2 (MAP-2) is an abundant component of the cytoskeleton present in dendrites and cell bodies of neurons of the CNS. To examine the biological function of MAP-2, two MAP-2 antisense (AS) oligonucleotides complementary to the 5' region of the rat MAP-2 cDNA were added to rat primary embryonic day 17-18 (E17-18) cultured cortical neurons 24 h after plating and neurite outgrowth and morphology studied. The treatment of primary cortical cultures with either of the two MAP-2 AS oligonucleotides resulted in decreased MAP-2 and reduction in the number of neuritic processes relative to the control or MAP-2 sense-treated cultures. By immunostaining and light microscopy the AS-treated neurons appeared smaller, more rounded, and less intensely stained for MAP-2 than the untreated or the MAP-2 sense-treated cultures. By electron microscopy disorganized microtubules and a reduction in the number of microtubules within neurites of the AS-treated cultures were observed. We conclude that MAP-2 continues to be required for microtubule spacing and stability within neurites once they have formed.

Nerve growth factor regulates the abundance and distribution of K+ channels in PC12 cells

We examined the effect of nerve growth factor (NGF) treatment on expression of a neuronal delayed rectifler K+ channel subtype, Kv2.1 (drk1), in PC12 cells. Anti-Kv2.1 antibodies recognized a single polypeptide population of M(r) = 132 kD in PC12 cell membranes, distinct from the more heterogeneous population found in adult rat brain. In response to NGF treatment, levels of Kv2.1 polypeptide in PC12 membranes increased fourfold. This increase in polypeptide levels could be seen within 12 h, and elevated levels were maintained for at least 6 d of continuous NGF treatment. RNase protection assays indicate that this increase in Kv2.1 protein occurs without an increase in steady state levels of Kv2.1 mRNA following NGF treatment. Immunofluorescent localization of the Kv2.1 polypeptide revealed plasma membrane-associated staining of cell bodies in both untreated and NGF-treated PC12 cells. In undifferentiated cells, intense staining is seen at sites of cell-cell and cell-substratum contact. In differentiated cells the most intense Kv2.1 staining is observed in neuritic growth cones. These studies show that in PC12 cells both the abundance and distribution of the Kv2.1 k+ channel are regulated by NGF, and suggest that PC12 cells provide a model for the selective expression of Kv2.1 in neuritic endings.

Suppression of the hypothalamic-pituitary-ovarian axis in normal women by glucocorticoids

To determine whether cortisol has an effect on hypothalamic-pituitary-gonadal function, we studied 11 eumenorrheic women in the early follicular phase of consecutive menstrual cycles by performing daytime 10-min blood sampling, one before and one during hydrocortisone administration. Daily blood sampling for gonadotropins and sex steroids was also performed. LH pulsations were determined by modification of a widely used threshold method and compared by paired t-testing. The LH interpulse interval was significantly prolonged (95 +/- 5 to 119 +/- 14 min; p = 0.001), and the mean LH pulse amplitude remained unchanged (1.3 +/- 0.1 and 1.5 +/- 0.2 mIU/ml) with glucocorticoid exposure. Mean estradiol was not altered (46 +/- 5 and 43 +/- 3 pg/ml), but mean LH and FSH from pooled serum aliquots were slightly but significantly reduced (2.6 +/- 0.2 to 2.2 +/- 0.2, 5.5 +/- 0.4 to 4.5 +/- 0.3 mIU/ml; p = 0.004, 0.012, respectively). Mean progesterone levels were also decreased (0.8 +/- 0.3 to 0.5 +/- 0.2 ng/ml; p = 0.011) in the presence of exogenous glucocorticoid. Twenty-four-hour urinary free cortisol levels confirmed a substantial increase in free cortisol excretion (74 +/- 10 to 305 +/- 50 micrograms/day; p = 0.001). These results demonstrate that cortisol can slow LH pulse frequency and, by inference, hypothalamic GnRH secretion, in a manner that appears independent of corticotropin releasing factor. Excess cortisol alone may therefore play a role in the development of stress-associated menstrual disturbances.

Interactions between the Escherichia coli cyclic AMP receptor protein and RNA polymerase at class II promoters

The effects of a number of mutations in crp have been measured at different cyclic AMP receptor protein (CRP)-dependent Class II promoters, where the CRP-binding site is centred around 41 1/2 base pairs upstream from the transcription start point. The amino acid substitutions HL159 and TA158 result in reduced CRP-dependent activation, but the reduction varies from one Class II promoter to another. Deletions in the C-terminus of the RNA polymerase alpha subunit suppress the effects of HL159 and TA158. The role of the C-terminus of alpha at these promoters is assessed. Other changes at E58, K52 and E96 affect CRP activity specifically at Class II promoters and their role is discussed.

Magnitude of acute respiratory infections in under five

A community-based study was carried out in a rural area of Delhi to measure the prevalence and incidence of acute respiratory infections among children below the age of 5 years. The prevalence of 12.1%, was similar in boys and girls and was seen to decline with age. The incidence of acute respiratory infections was 2.5 episodes per child per year; it was not different in boys and girls. There was a statistically significant decline in the incidence with age. Upper respiratory tract infections comprised 87.5% of total acute respiratory infection morbidity while lower respiratory tract infections were 12.5%. Both upper and lower respiratory tract infections declined with increasing age; while the former was similar among boys and girls, the incidence of latter was significantly greater in boys (0.4 episodes per year) as compared to girls (0.2 episodes per year). A total of 87.5% episodes were mild, 10.4% moderate and only 2.1% were severe. The results suggest that acute respiratory infections are a major community health problem and an acute respiratory infection control programme needs to be implemented urgently.

Okadaic acid induces early changes in microtubule-associated protein 2 and tau phosphorylation prior to neurodegeneration in cultured cortical neurons

Microtubules and their associated proteins play a prominent role in many physiological and morphological aspects of brain function. Abnormal deposition of the microtubule-associated proteins (MAPs), MAP2 and tau, is a prominent aspect of Alzheimer's disease. MAP2 and tau are heat-stable phosphoproteins subject to high rates of phosphorylation/dephosphorylation. The phosphorylation state of these proteins modulates their affinity for tubulin and thereby affects the structure of the neuronal cytoskeleton. The dinoflagellate toxin okadaic acid is a potent and specific inhibitor of protein phosphatases 1 and 2A. In cultured rat cortical neurons and a human neuroblastoma cell line (MSN), okadaic acid induces increased phosphorylation of MAP2 and tau concomitant with early changes in the neuronal cytoskeleton and ultimately leads to cell death. These results suggest that the diminished rate of MAP2 and tau dephosphorylation affects the stability of the neuronal cytoskeleton. The effect of okadaic acid was not restricted to neurons. Astrocytes stained with antibodies to glial fibrillary acidic protein (GFAP) showed increased GFAP staining and changes in astrocyte morphology from a flat shape to a stellate appearance with long processes.

The effect of non-mutagenic stress on liquid holding recovery in Escherichia coli AB2463

Previous work has shown that exposure to many non-mutagenic stresses causes greater UV resistance in Escherichia coli K12 via an error-free, excision repair-dependent process. Induction of the latter should enhance liquid holding recovery in the bacteria. The results in this paper show that this is the case and that the increased UV-resistance is due entirely to an increase in the capacity of the cells for DNA excision repair. The latter arises wholly or in part from an increase in the intracellular level of the key enzyme of the pathway, UvrABC endonuclease.

CSF-1 expression is upregulated in astrocyte cultures by IL-1 and TNF and affects microglial proliferation and morphology in organotypic cultures

Astrocytes produce factors that control the growth and differentiation of many cell types within the CNS as well as play a role in the generation of the immune response. The extent to which these two functions interact has received less attention. We now report that astrocyte cultures established from rat brain endogenously express mRNA and low levels of secreted biologically active protein for the monocyte growth and differentiation factor colony stimulating factor-1 (CSF-1). Exposure of astrocytes to interleukin-1 (IL-1) and/or tumor necrosis factor (TNF) upregulated the expression of CSF-1 mRNA and protein. Following treatment with 100 U/ml of TNF, IL-1, or TNF+IL-1, maximum CSF-1 mRNA expression was observed at 3 hr. In the presence of IL-1 an increase in biologically active CSF-1 was detected in the astrocyte conditioned medium at 6 hr. These data indicate that the expression of CSF-1 by astrocytes can be modulated by exposure to the cytokines IL-1 and TNF. To determine whether CSF-1 provides a mitogenic signal for microglia during development, mouse spinal cord organotypic cultures were exposed to recombinant mouse CSF-1 (rmCSF-1), resulting in proliferation of microglia by 7 days and an increase in the number of ramified microglia over ameboid microglia by 14 days.

Differential regulation of S-adenosylmethionine synthetase isozymes by gibberellic acid in dwarf pea epicotyls

Dwarf pea epicotyls contained a single activity peak of S-adenosylmethionine (AdoMet) synthetase (isozyme I). Gibberellic acid (GA3, 1 microM) induced two additional isozymes (II and III). Cycloheximide (20 microgram/ml) blocked the appearance of GA3-induced isozymes, suggesting that it is dependent on de novo protein synthesis. Conclusive proof was obtained by labelling the isozymes II and III with [35S]SO2-(4) in vivo. The purified 35S-labelled AdoMet synthetase isozymes (II, III) showed a single protein band that coincided with the single radioactive peak on SDS-PAGE. Molecular-sieve chromatography of the isozyme I from control dwarf pea epicotyls and three isozymes of GA3-treated epicotyls on Sepharose CL-6B showed a single activity peak with an identical molecular mass of 174 kDa for each isozyme. Analysis of purified AdoMet synthetase isozymes (I, II, III) on SDS-PAGE showed a single silver-stained protein band with a molecular mass of 87 kDa. This proved the dimeric nature of all the isozymes of AdoMet synthetase which could be physically separated by ion-exchange chromatography on DE-52. In vitro molecular hybridization of physically separated isozymes by NaCl-freeze-thaw treatment method revealed that the three isozymes (I, II, III) in GA3-treated dwarf pea epicotyls are formed through the random dimerization of two different species of enzyme subunits that differ in their net charge. Thus, the two flanking activity peaks (isozymes I, III) represent homodimers, while the middle activity peak (isozyme II) is a heterodimer. Apparently, the single isozyme I in control epicotyls is a product of one gene of AdoMet synthetase (SAM 1), while three isozymes in GA3-treated epicotyls are the product of two genes of AdoMet synthetase. We speculate that the differential regulation of AdoMet synthetase in GA3-treated epicotyls is achieved by the expression of an alternate gene of AdoMet synthetase (SAM 2).

Esophageal ulcer due to ingestion of melted copper

We report a patient with esophageal stricture as a result of the accidental swallowing of melted copper by a 49-year-old male. As a result, esophagogastric ulcers developed and left a cicatrical stricture. The patient could only manage to swallow liquid food. Radiology of the upper gastrointestinal tract showed marked stricture of the esophagus from the middle thoracic portion to the esophagogastric junction and shortening of the lesser curvature of the stomach. The patient underwent a single-session total gastrectomy, and excision of the thoracic esophagus and construction of anterior thoracic esophagocolic and duodenocolic anastomoses were performed by right thoracotomy and laparotomy, respectively. Macroscopic findings of the surgical specimens showed extensive circular ulcers at the esophagus, and microscopic findings showed deep ulcers extending to the muscle layer with marked fibrosis. The postoperative course was uneventful.

A sensitive and relevant model for evaluating anti-inflammatory activity-papaya latex-induced rat paw inflammation

A new model employing latex of papaya as an inflammagen has been developed for testing anti-inflammatory activity. The latex (exudate) was harvested from the unripe papaya fruit, which had been dried under vacuum. The latex was then suspended in 0.05 M sodium acetate buffer. This suspension when injected in rat hind paw produced concentration-dependent inflammation. Of the 0.25% of this suspension, 0.1 ml was found ideal for evaluating anti-inflammatory activity of test drugs. This concentration produced 70%-100% inflammation lasting for about 5 hr with a maximum effect at h 3. The test drugs employed were prednisolone, aspirin, indomethacin, phenylbutazone, ibuprofen, piroxicam, chloroquine, levamisole, and a mixture of boswellic acids. For comparison, these drugs were also tested against carrageenan-induced inflammation. All the test drugs--steroidal, aspirin, and non-aspirin-like--showed anti-inflammatory activity against latex-induced inflammation. The activity of chloroquine, levamisole, and boswellic acids was significantly more against latex as compared with that of the carrageenan model. The inflammation caused by latex may be attributed to both its hydrolytic enzymes--papain and chymopapain--and glutathione, the activator of these enzymes. These enzymes seem to act like lysosomal enzymes that are released in inflammatory disease processes which mediate inflammation by stimulating the synthesis of prostaglandins. The papaya latex-induced inflammation model appears to be a sensitive, broad-based, and relevant one likely to prove useful for discovering new and effective drugs against inflammation and rheumatoid arthritis.

Giant parotid calculus--an unusual presentation

We describe a case of a giant sialolith of Stensen's duct in a 48-year-old woman. The patient was investigated and treated with a mistaken diagnosis of chronic inflammation until the clue to the diagnosis was provided by plain radiography. This is an unusual presentation of a salivary calculus and to our knowledge such a huge parotid calculus has not been reported so far in the literature.

Low-temperature storage of Rauvolfia serpentina Benth. ex Kurz.: An endangered, endemic medicinal plant

On a standard shoot culture medium, nodal cultures of Sarpagandha (Rauvolfia serpentina) could be maintained for nine months at 25° C by replacing cotton plugs with polypropylene caps as enclosures for culture tubes. Low temperature incubation of in vitro cultures appeared highly promising because cultures exhibited normal health even after 15 months of storage at 15° C; while 10°C and 5°C were found deleterious to growth of the cultures of R. serpentina.

Biochemical studies on mouse liver following Plasmodium berghei infection

The lipid composition of mouse liver following infection with P. berghei was investigated. The liver lipid contents of infected animals were greatly increased mainly due to the accumulation of triacylglycerides. There was enhanced lipid concentration (85.29%). Significantly (23.7%) depleted liver cholesterol was also found in the mice. Similarly, phospholipid contents of liver were also decreased by 19.90 per cent. The liver from P. berghei infected mouse produced more lipid peroxide, as compared to control animals (314%). Significant depletion was also observed in carbohydrate, glycogen and glucose (79.1, 86.26 and 78.6% respectively) contents of liver at high parasitaemia. The lower contents of nucleic acid in the infected hosts observed in the study may be partly due to the absorption of nucleic acids by the parasites from the host cells.

Insulin reverses haemodynamic changes and pulmonary oedema in children stung by the Indian red scorpion Mesobuthus tamulus concanesis, Pocock

The efficacy of insulin administration in reversing haemodynamic changes in pulmonary oedema in victims of poisonous scorpion sting is assessed by a study based on animal experiments in which insulin administration reversed metabolic and electrocardiographic changes induced by scorpion envenomation. Six previously healthy children aged 18 months to 11 years were admitted to hospital five to 17 hours after scorpion sting. Frusemide for raised central venous pressure and pulmonary oedema, crystalloid infusion for reduced central venous pressure, and hydrocortisone and dopamine for hypotension were used as standard therapy. Insulin (0.3 units g-1 of glucose) was administered when the standard therapy failed to produce an improvement, and at the earliest sign of haemodynamic instability. Reversal of pulmonary oedema and haemodynamic changes, and attainment or normal respiratory rate, blood pressure and central venous pressure, were observed. It is concluded that insulin administration may be useful in reversing haemodynamic changes and pulmonary oedema in victims of scorpion stings.