Implementation of quantum search algorithm using classical Fourier optics

We report on an experiment on Grover's quantum search algorithm showing that classical waves can search a N-item database as efficiently as quantum mechanics can. The transverse beam profile of a short laser pulse is processed iteratively as the pulse bounces back and forth between two mirrors. We directly observe the sought item being found in approximately square root[N] iterations, in the form of a growing intensity peak on this profile. Although the lack of quantum entanglement limits the size of our database, our results show that entanglement is neither necessary for the algorithm itself, nor for its efficiency.

A unique experience with human pre-immune (12 weeks) and hypo-immune (16 weeks) fetal thymus transplant in a vascular subcutaneous axillary fold in patients with advanced cancer: a report of two cases

BACKGROUND

The successful development of fetal cell/tissue transplantation in adults has resulted in the possibility of eventual therapeutic solutions with a variety of intractable diseases. Umbilical cord whole blood transplantation appears to be safe in the adult system. In severe forms of DiGeorge Syndrome, cultured thymus transplant can help in the reconstitution of the immune condition of the host. Successful fetal tissue transplant in adults has raised the hope of future effective gene transplant and its manipulation prospects to combat many diseases including hemopathies, inborn errors of metabolism, immunodeficiencies and even cancer and AIDS.

MATERIALS AND METHOD

Two cases of advanced cancer were treated with fetal (pre-immune 12 weeks and hypo-immune 16 weeks) thymus transplants in subcutaneous vascular axillary folds, which were removed after one month. Thymuses were collected from consenting mothers undergoing hysterotomy and ligation.

RESULTS AND ANALYSIS

Patient I was suffering from non-Hodgkins lymphoma (Ann Arbor Stage IV) and was receiving cyclophosphomide, doxorubicin, vincristine and prednisolone after a course of radiotherapy; she developed leucopenia (2.400/cmm), which improved after receiving a 16-week human fetal thymic graft. The leucopenia was eventually over-corrected and the leucocyte count reached 44,000/cmm within a month, which was reversed after the thymus was taken out. Histology of the excised thymic graft showed growth and proliferation without any graft vs. host (GVH) reaction. Patient 2 was suffering from breast duct carcinoma (T4, N2, M0,) with estrogen, progesterone, and epidermal growth factor negative status, and was treated with modified radical mastectomy and axillary clearance followed by chemotherapy with cyclophosphomide, methotrexate and 5-fluorouracil for six cycles. She also received a 12-week-old human fetal thymus at the contra-lateral axilla which was removed after one month. In this case the peripheral leucocyte count did not show appreciable variation as in the first case. However, histology of the excised thymic graft showed growth and proliferation with an appearance of Hassel's corpuscles.

CONCLUSION

Pre-immune and hypo-immune human fetal thymic transplant is not rejected in patients suffering from advanced cancer within one month (observation period). Thymic lymphocyte shedding in the correction of leucopenia in the background of non-Hodgkin's lymphoma may have many therapeutic implications.

Pim-1: a serine/threonine kinase with a role in cell survival, proliferation, differentiation and tumorigenesis

Pim-1 belongs to a family of serine/threonine protein kinases that are highly conserved through evolution in multicellular organisms. Originally identified from moloney murine leukemia virus (MuLV)-induced T-cell lymphomas in mice, Pim-1 kinase is involved in the control of cell growth, differentiation and apoptosis. Expression of Pim-1 kinase can be stimulated by a variety of growth factors and regulated at four different levels: transcriptional, post-transcriptional, translational and post-translational. Several signal transduction pathways may be associated with the regulation of Pim-1's expression; accumulating data support that the expression of Pim-1 protein is mediated through activation of JAK/STATs. Recent studies of Pim family kinases indicate that Pim-1 kinase plays important roles outside of the hematopoietic system as well.

A case of atypical dengue haemorrhagic fever

A case of atypical dengue haemorrhagic fever is being described in a 30 years old male along with a short discussion on the subject.

A study report of 174 units of placental umbilical cord whole blood transfusion in 62 patients as a rich source of fetal hemoglobin supply in different indications of blood transfusion

BACKGROUND

In the animal kingdom, even herbivorous animals swallow the placenta after the birth of the baby (for example, the cow). In the human system, we do not know about the proper utilization of the placenta and membranes although there are suggestions regarding this on the basis of research on placental umbilical cord blood stem cells as an alternative to bone marrow transplantation. In this present series of placental umbilical cord whole blood transfusions, we wanted to examine the safety aspect of other components of cord blood transfusion, e.g., fetal RBC, growth factors and cytokine filled plasma, etc., in different indications of blood transfusion, from the pediatric to the geriatric age group, in malignant and non-malignant disorders affecting our patients.

METHODS

One hundred and seventy-four units of umbilical cord whole blood were collected aseptically from the umbilical vein after caesarean section in standard pediatric blood transfusion bags, after the removal of the baby from the operative field and after confirming the stable condition of the mother. The volume of cord blood varied from 50 ml to 140 ml with a mean of 86 ml+/-16 ml.

RESULTS AND ANALYSIS

The cord blood was transfused immediately (within three days of collection) to 62 patients from nine years to 78 years of age, of whom 32 were suffering from varying stages and grades of malignancy from 1 April 1999 till date i.e., 11 Aug 2000, after obtaining adequate consent and following the precautions of standard blood transfusion protocol. The remaining 30 patients included patients suffering from thalassemia major, aplastic anemia, systemic lupus erythematosus, chronic renal failure, rheumatoid arthritis, ankylosing spondylitis and a geriatric group of patients with benign prostatic hypertrophy. All have tolerated the procedure without any immunological or non-immunological reactions.

CONCLUSION

On the basis of our experience with 174 units of placental umbilical cord whole blood transfusion in malignant and non-malignant conditions (within three days of collection and preservation at 1-6 degrees C in a refrigerator), we are of the opinion that this is a safe transfusion protocol which takes advantage of the safety of nature's finest biological sieve, i.e., the placenta, as an alternative to adult whole blood transfusion. It also has the advantage of a higher oxygen carrying capacity of fetal hemoglobin in addition to many growth factors and other cytokine filled cord blood plasma along with its hypoantigenicity.

Pim-1 negatively regulates the activity of PTP-U2S phosphatase and influences terminal differentiation and apoptosis of monoblastoid leukemia cells

The levels of Pim-1, a serine/threonine kinase, increase during phorbol myristate acetate (PMA)-induced myeloid cell differentiation. The tyrosine phosphatase PTP-U2S is also associated with PMA-induced differentiation of myeloid cells and has been shown to enhance differentiation and the onset of apoptosis. PTP-U2S contains a Pim-1 phosphorylation consensus sequence, KKRKLTN, which is efficiently phosphorylated by Pim-1. Immunoprecipitated PTP-U2S from U937 cells was phosphorylated by recombinant Pim-1, resulting in a decrease in its phosphatase activity. During PMA-induced differentiation, U937 cells transfected with the dominant negative Pim-1 underwent rapid differentiation and accelerated apoptosis. The opposite effect was observed for wild-type Pim-1. Our results, therefore, provide compelling evidence that Pim-1 functions to negatively regulate PMA-induced differentiation in part through the phosphorylation of PTP-U2S. Together these data suggest that Pim-1 phosphorylates PTP-U2S in vivo to decrease the phosphatase activity that may be necessary to prevent the premature onset of apoptosis following differentiation.

Androgen-driven prostate epithelial cell proliferation and differentiation in vivo involve the regulation of p27

Androgens control both growth and differentiation of the normal prostate gland. However, the mechanisms by which androgens act upon the cell cycle machinery to regulate these two fundamental processes are largely unknown. The cyclin-dependent kinase (cdk) inhibitor p27 is a negative cell cycle regulator involved in differentiation-associated growth arrest. Here, we investigate the role and regulation of p27 in the testosterone proprionate (TP)-stimulated regeneration of the ventral prostate (VP) of castrated rats. Continuous TP administration to castrated rats triggered epithelial cell proliferation, which peaked at 72 h, and then declined despite further treatment. Castration-induced atrophy of the VP was associated with a significant increase in p27 expression as compared with the VP of intact animals. Twelve hours after the initiation of androgen treatment, total p27 levels as well as its fraction bound to cdk2, its main target, significantly dropped in the VP of castrated rats. Thereafter, concomitantly to the induction of epithelial cell proliferation, the glandular morphology of VP was progressively restored at 48-96 h of TP treatment. During this period of the regenerative process, whereas both proliferating basal and secretory epithelial cells did not express p27, the protein was selectively up-regulated in the nonproliferating secretory epithelial compartment. This up-regulation of p27 expression was coincident with an increase in its association with, and presumably inhibition of, cdk2. At each time point of TP treatment, p27 abundance in the VP was inversely correlated with the level of its proteasome-dependent degradation activity measured in vitro in VP lysates, whereas only slight changes in the amount of p27 transcripts were detected. In addition, the antiandrogen flutamide blocked maximal TP-induced p27 degradation completely. Finally, the expression of skp2, the ubiquitin ligase that targets p27 for degradation, was seen to increase with androgen administration, preceding maximal proliferation and concomitantly to augmented p27 degradation activity. Taken together, our data indicate that androgens mediate both proliferation and differentiation signals in normal prostate epithelial cells in vivo, through regulation of p27.

Electroencephalographic and perceptual asymmetry differences between responders and nonresponders to an SSRI antidepressant

BACKGROUND

Recent reports suggest the value of electroencephalographic and dichotic listening measures as predictors of response to antidepressants. This study examines the potential of electroencephalographic alpha asymmetry and dichotic measures of perceptual asymmetry as predictors of clinical response to 12 weeks of treatment with fluoxetine (Prozac).

METHODS

Resting electroencephalography (eyes open and eyes closed) and dichotic listening with word or complex tone stimuli were assessed in depressed outpatients during a pretreatment period.

RESULTS

Fluoxetine responders (n = 34) differed from nonresponders (n = 19) in favoring left over right hemisphere processing of dichotic stimuli. They also differed in their resting electroencephalographic alpha asymmetry, particularly in the eyes open condition. Nonresponders showed an alpha asymmetry indicative of overall greater activation of the right hemisphere than the left, whereas responders did not. The relationship between hemispheric asymmetry and treatment response interacted with gender, being evident among depressed women but not men.

CONCLUSIONS

The results are consistent with the hypothesis that a characteristic tendency toward greater left than right hemisphere activation is associated with favorable response to fluoxetine, whereas the opposite hemispheric asymmetry predicts poor response.

Reduction of Cdc25A contributes to cyclin E1-Cdk2 inhibition at senescence in human mammary epithelial cells

Replicative senescence may be an important tumor suppressive mechanism for human cells. We investigated the mechanism of cell cycle arrest at senescence in human mammary epithelial cells (HMECs) that have undergone a period of 'self-selection', and as a consequence exhibit diminished p16INK4A levels. As HMECs approached senescence, the proportion of cells with a 2N DNA content increased and that in S phase decreased progressively. Cyclin D1-cdk4, cyclin E-cdk2 and cyclin A-cdk2 activities were not abruptly inhibited, but rather diminished steadily with increasing population age. In contrast to observations in fibroblast, p21Cip1 was not increased at senescence in HMECs. There was no increase in p27Kip1 levels nor in KIP association with targets cdks. While p15INK4B and its binding to both cdk4 and cdk6 increased with increasing passage, some cyclin D1-bound cdk4 and cdk6 persisted in senescent cells, whose inhibition could not be attributed to p15INK4B. The inhibition of cyclin E-cdk2 in senescent HMECs was accompanied by increased inhibitory phosphorylation of cdk2, in association with a progressive loss of Cdc25A. Recombinant Cdc25A strongly reactivated cyclin E-cdk2 from senescent HMECs suggesting that reduction of Cdc25A contributes to cyclin E-cdk2 inhibition and G1 arrest at senescence. Although ectopic expression of Cdc25A failed to extend the lifespan of HMECs, the exogenous Cdc25A appeared to lack activity in these cells, since it neither shortened the G1-to-S phase interval nor activated cyclin E-cdk2. In contrast, in the breast cancer-derived MCF-7 line, Cdc25A overexpression increased both cyclin E-cdk2 activity and the S phase fraction. Thus, mechanisms leading to HMEC immortalization may involve not only the re-induction of Cdc25A expression, but also activation of this phosphatase.

Down-regulation of p21WAF1/CIP1 or p27Kip1 abrogates antiestrogen-mediated cell cycle arrest in human breast cancer cells

Estrogens and antiestrogens influence the G(1) phase of the cell cycle. In MCF-7 breast cancer cells, estrogen stimulated cell cycle progression through loss of the kinase inhibitor proteins (KIPs) p27 and p21 and through G(1) cyclin-dependent kinase (cdk) activation. Treatment with antiestrogen drugs, Tamoxifen or ICI 182780, caused cell cycle arrest, with up-regulation of both p21 and p27 levels, an increase in their binding to cyclin E-cdk2, and kinase inhibition. The requirement for these KIPs in the arrests induced by estradiol depletion or by antiestrogens was investigated with antisense. Antisense inhibition of p21 or p27 expression in estradiol-depleted or antiestrogenarrested MCF-7 led to abrogation of cell cycle arrest, with loss of cyclin E-associated KIPs, activation of cyclin E-cdk2, and S phase entrance. These data demonstrate that depletion of either p21 or p27 can mimic estrogen-stimulated cell cycle activation and indicate that both of these KIPs are critical mediators of the therapeutic effects of antiestrogens in breast cancer.

Involvement of p27Kip1 in G1 arrest by high dose 5 alpha-dihydrotestosterone in LNCaP human prostate cancer cells

The cell cycle is governed by cyclin dependent kinases (cdks), which are activated by binding of cyclins, inhibited by cdk inhibitors and regulated by phosphorylation and dephosphorylation. Exposure to high dose dihydrotestosterone (DHT) inhibits population growth of the human prostate carcinoma cell line, LNCaP. To determine the mechanism of growth arrest by high dose DHT, we assayed the changes in cell cycle profile and the cell cycle regulators that mediate these effects. Treatment of asynchronously growing LNCaP cells with 100 nM DHT caused a G1 arrest. The proportion of cells in S phase fell from 22 to 2%, while the G1 fraction rose from 74 to 92% by 24 h. Loss of phosphorylation of the retinoblastoma protein was noted and cdk4 and cyclin E/ cdk2 activities fell. Inhibition of these G1 cyclin dependent kinases was not due to loss of either cyclin or cdk proteins nor to increases in the cdk inhibitors p16INK4A and p21CiP1. p21Cip1 protein levels remained constant, and cyclin E-associated p21CiP1 fell, suggesting that p21CiP1 is not relevant to this form of cyclin E/cdk2 inhibition. Of note, total p27KiP1 levels and cyclin E-associated p27Kip1 increased as cells arrested and the amount of the CAK activated cdk2 bound to cyclin E decreased. p27KiP1 immunodepletion experiments demonstrated that the DHT-mediated increase in p27Kip1 was sufficient to fully saturate and inhibit target cyclin E/ cdk2. The inhibition of cyclin E/cdk2 by p27Kip1 contributes to G1 arrest of LNCaP following high dose DHT. p27KiP1 may be a key effector of androgen dependent growth modulation in prostate cancer cells.

Reduced expression of the cell cycle inhibitor p27Kip1 in non-small cell lung carcinoma: a prognostic factor independent of Ras

Levels of p27 have been found to have independent prognostic significance in a variety of tumors including breast, colon, prostate, ovary, and gastric carcinomas. We investigated p27 levels and determined ras mutational status in 136 non-small cell lung cancers. We found reduced levels of p27 in 86% of cases and showed a statistically significant inverse correlation between p27 levels and tumor grade. ras mutations were found exclusively in adenocarcinomas and showed no relationship to p27 levels. Clinical data on a subset of the patients studied indicated that all 16 patients who died of disease and 21 of 22 patients who relapsed had low p27 levels, whereas all patients with high p27 levels were alive at last follow up. These findings suggest that alteration in p27 levels plays an important role in lung tumor progression and that p27 levels may have independent prognostic significance in non-small cell lung cancer.

Interleukin-6 dependent induction of the cyclin dependent kinase inhibitor p21WAF1/CIP1 is lost during progression of human malignant melanoma

Human melanoma cell lines derived from early stage primary tumors are particularly sensitive to growth arrest induced by interleukin-6 (IL-6). This response is lost in cell lines derived from advanced lesions, a phenomenon which may contribute to tumor aggressiveness. We sought to determine whether resistance to growth inhibition by IL-6 can be explained by oncogenic alterations in cell cycle regulators or relevant components of intracellular signaling. Our results show that IL-6 treatment of early stage melanoma cell lines caused G1 arrest, which could not be explained by changes in levels of G1 cyclins (D1, E), cdks (cdk4, cdk2) or by loss of cyclin/cdk complex formation. Instead, IL-6 caused a marked induction of the cdk inhibitor p21WAF1/CIP1 in three different IL-6 sensitive cell lines, two of which also showed a marked accumulation of the cdk inhibitor p27Kip1. In contrast, IL-6 failed to induce p21WAF1/CIP1 transcript and did not increase p21WAF1/CIP1 or p27kip1 proteins in any of the resistant lines. In fact, of five IL-6 resistant cell lines, only two expressed detectable levels of p21WAF1/CIP1 mRNA and protein, while in three other lines, p21WAF1/CIP1 was undetectable. IL-6 dependent upregulation of p21WAF1/CIP1 was associated with binding of both STAT3 and STAT1 to the p21WAF1/CIP1 promoter. Surprisingly, however, IL-6 stimulated STAT binding to this promoter in both sensitive and resistant cell lines (with one exception), suggesting that gross deregulation of this event is not the unifying cause of the defect in p21WAF1/CIP1 induction in IL-6 resistant cells. In somatic cell hybrids of IL-6 sensitive and resistant cell lines, the resistant phenotype was dominant and IL-6 failed to induce p21WAF1/CIP1. Thus, our results suggest that in early stage human melanoma cells, IL-6 induced growth inhibition involves induction of p21WAF1/CIP1 which is lost in the course of tumor progression presumably as a result of a dominant oncogenic event.

Detection of HIV seropositivity during an outbreak of Japanese encephalitis in Manipur

An epidemic outbreak of Japanese encephalitis (JE) occurred during mid 1995. Sixteen serum samples from patients with history of febrile headache, convulsions, mental confusion, neck rigidity etc. were sent to the Department of Virology, School of Tropical Medicine, Calcutta, in August, 1995. Twelve (75%) showed HIV antibody against JEV. Out of these 12 sera showing HIV antibody titre between 1:40 and 1:160, eight (66.6%) showed IgM antibody, giving the presumptive diagnosis of recent JEV infection. Five of these 16 sera showed HIV seropositivity (31.25%). Concomitant JEV and HIV infection could be detected in 3 cases. However, in 2 sera HIV titre were less than 1:20. This is probably the first documentation of concomitant JEV and HIV infection in the eastern India.

Loss of cyclin-dependent kinase inhibitor p27Kip1 is a novel prognostic factor in localized human prostate adenocarcinoma

p27Kip1 is a cyclin-dependent kinase inhibitor that negatively regulates cell proliferation by mediating cell cycle arrest in G1. This study was undertaken to assess the prognostic value of p27Kip1 in localized human prostate cancer. Archival material from 113 radical prostatectomy specimens obtained between 1985 and 1993 was stained immunohistochemically for p27Kip1 protein using a commercially available antibody. Patient charts were reviewed for preoperative serum prostate-specific antigen, clinical and pathological staging, Gleason tumor grade, time to biochemical and clinical recurrence, and survival. Strong p27Kip1 staining was uniformly seen in benign prostatic epithelial components in all tumor sections. p27Kip1 staining was reduced in most prostate cancers and was variable in prostatic intraepithelial neoplasia. Decreased p27Kip1 staining (<25% of nuclei stained positive for p27Kip1) correlated with seminal vesicle involvement (P = 0.0032) and with higher Gleason grade (P = 0.0114). On univariate analysis, low p27Kip1 predicted an increased risk of treatment failure in the node-negative cohort (P = 0.0037) and in the subset who did not receive neoadjuvant hormonal therapy (P = 0.049). Low p27Kip1 expression was an independent predictor of treatment failure on multivariate analysis of lymph node negative prostate cancers following radical retropubic prostatectomy (n = 102; P = 0.047). Seminal vesicle involvement (P = 0.034) and positive surgical margins (P = 0.047) were also independent prognostic factors for disease recurrence. In patients who received preoperative neoadjuvant hormonal therapy, low p27Kip1 in the pathological specimen was an even stronger predictor of outcome than it was in the entire group (n = 23, P = 0.015).

Transforming growth factor beta stabilizes p15INK4B protein, increases p15INK4B-cdk4 complexes, and inhibits cyclin D1-cdk4 association in human mammary epithelial cells

The effects of transforming growth factor beta (TGF-beta) were studied in closely related human mammary epithelial cells (HMEC), both finite-life-span 184 cells and immortal derivatives, 184A1S, and 184A1L5R, which differ in their cell cycle responses to TGF-beta but express type I and type II TGF-beta receptors and retain TGF-beta induction of extracellular matrix. The arrest-resistant phenotype was not due to loss of cyclin-dependent kinase (cdk) inhibitors. TGF-beta was shown to regulate p15INK4B expression at at least two levels: mRNA accumulation and protein stability. In TGF-beta-arrested HMEC, there was not only an increase in p15 mRNA but also a major increase in p5INK4B protein stability. As cdk4- and cdk6-associated p15INK4B increased during TGF-beta arrest of sensitive cells, there was a loss of cyclin D1, p21Cip1, and p27Kip1 from these kinase complexes, and cyclin E-cdk2-associated p27Kip1 increased. In HMEC, p15INK4B complexes did not contain detectable cyclin. p15INK4B from both sensitive and resistant cells could displace in vitro cyclin D1, p21Cip1, and p27Kip1 from cdk4 isolated from sensitive cells. Cyclin D1 could not be displaced from cdk4 in the resistant 184A1L5R cell lysates. Thus, in TGF-beta arrest, p15INK4B may displace already associated cyclin D1 from cdks and prevent new cyclin D1-cdk complexes from forming. Furthermore, p27Kip1 binding shifts from cdk4 to cyclin E-cdk2 during TGF-beta-mediated arrest. The importance of posttranslational regulation of p15INK4B by TGF-beta is underlined by the observation that in TGF-beta-resistant 184A1L5R, although the p15 transcript increased, p15INK4B protein was not stabilized and did not accumulate, and cyclin D1-cdk association and kinase activation were not inhibited.

HCV activity in Calcutta--a serological study

HCV infection, a global public health problem is quite prevalent in India. In the present study conducted during February-July 1996 a total of 153 samples of different age groups and of both sexes were tested by ELISA for detection of Anti-HCV antibody. Anti-HCV was found in 13% of multi-transfused cases and in 8.8% cases with multiple needle-stick injury. Maximum seropositivity (20%) could be observed amongst males between 31-40 yrs. age group. HCV activity was noted more in males (13%) than in females (8.2%) and more relatively in subjects without a history of jaundice (11.5%) than those having the features of jaundice (10.5%). An increasing trend has also been observed amongst the multi-transfused cases in Calcutta.

Decreased levels of the cell-cycle inhibitor p27Kip1 protein: prognostic implications in primary breast cancer

Breast cancer is the second leading cause of cancer death in North American women. There is considerable need for reliable prognostic markers to assist clinicians in making management decisions. Although a variety of factors have been tested, only tumor stage, grade, size, hormone receptor status, and S-phase fraction are used on a routine basis. The cell cycle is governed by a family of cyclin-dependent kinases (cdks), which are regulated by associated cyclins and by phosphorylation. p27Kip1, a cyclin-dependent kinase inhibitor, regulates progression from G1 into S phase by binding and inhibiting cyclin/cdks. p27Kip1 protein levels and/or activity are upregulated by growth inhibitory cytokines including transforming growth factor-beta (TGF-beta) and, thus, provide an important link between extracellular regulators and the cell cycle. Loss of p27Kip1, a negative cell-cycle regulator, may contribute to oncogenesis and tumor progression. However, p27Kip1 mutations in human tumors are extremely rare. We have demonstrated by immunohistochemistry that p27Kip1 protein levels are reduced in primary breast cancers and that this is associated with tumor progression in both in situ and invasive lesions. This was confirmed by western analysis, reflected in increased G1/S-phase cyclin-dependent kinase activities and shown to be regulated posttranscriptionally by in situ hybridization. Furthermore, on multivariate analysis, low p27Kip1 is a predictor of reduced disease-free survival. This simple and reliable immunohistochemical assay may become a routine part of breast cancer evaluation and may influence patient management.

TGF-beta mediated G1 arrest in a human melanoma cell line lacking p15INK4B: evidence for cooperation between p21Cip1/WAF1 and p27Kip1

We have studied TGF-beta mediated G1 arrest in WM35, an early stage human melanoma cell line. These cells have lost p15INK4B expression through loss of one chromosome 9 and rearrangement of the other. In asynchronously growing WM35, TGF-beta caused reductions in cyclin D1, cyclin A and cdk4 proteins and their associated kinase activities and an increase in both p21Cip1/WAF1 and p27Kip1. These findings were confirmed in cells released from quiescence in the presence of TGF-beta, in which TGF-beta inhibited or delayed the reduction in the cdk inhibitors that normally occurs in late G1. In contrast to observations in other cell types, there was an increased association of both p21Cip1/WAF1 and p27Kip1 with cyclin D1/cdk4 and with cyclin E/cdk2 during TGF-beta mediated arrest of asynchronously growing cells. Upregulation of p21Cip1/WAF1 preceded that of p27Kip1. Furthermore, p21Cip1/WAF1 and p27Kip1 were not present in the same cdk complexes but bound distinct populations of target cdk molecules. Both p21Cip1/WAF1 and p27Kip1 immunoprecipitates from asynchronously growing cells contained active kinase complexes. These KIP-associated kinase activities were reduced in TGF-beta arrested cells. It has been proposed that in TGF-beta arrested epithelial cells, up-regulation of p15INK4B and of p15INK4B binding to cdk4 serves to destabilize the association of p27Kip1 with cyclin D1/cdk4, promoting p27Kip1 binding and inhibition of cyclin E/cdk2. Our findings demonstrate that this is not a universal mechanism of G1 arrest by TGF-beta. In TGF-beta arrested WM35, which lack p15INK4B, the increased p21Cip1/WAF1 may serve a similar function to that of p15INK4B: initiating kinase inhibition and providing an additional mechanism to supplement the effect of p27Kip1 on G1 cyclin/cdks.

Impact of the cyclin-dependent kinase inhibitor p27Kip1 on resistance of tumor cells to anticancer agents

A low proliferating fraction in solid tumors limits the effectiveness of cell cycle-dependent chemotherapeutic agents. To understand the molecular basis of such "kinetic" resistance we cultured tumor cells as multicellular spheroids and examined levels of p27Kip1, a cyclin-dependent kinase inhibitor known to be upregulated by intercellular contact in normal cells. When transferred from monolayer to three-dimensional culture, a consistent upregulation (up to 15-fold) of p27 protein was observed in a panel of mouse and human carcinoma cell lines. Antisense-oligonucleotide-mediated downregulation of p27 in EMT-6 mammary tumor cell spheroids reduced intercellular adhesion, increased cell proliferation, sensitized tumor cells to 4-hydroperoxycyclophosphamide, and restored drug- or radiation-induced cell-cycle perturbations repressed in spheroid culture. Our results implicate p27 as a regulator of drug resistance in solid tumors and suggest that tumor-targeted p27 antagonists may be useful chemosensitizers in conjunction with conventional anticancer therapy.

An institutional outbreak of hepatitis E--reported first time from Calcutta city

A sudden outbreak of hepatitis occurred in a micro-epidemic form, amongst the staff members of the School of Tropical Medicine, Calcutta, during May-June, 1995. A total of 21 persons developed jaundice, out of whom 11 members who attended the Virology Department and were tested for detection of different serological markers of hepatitis by ELISA. All the sera (N = 11) showed evidence of non-A, non-B infection by process of exclusion and 9 of the above sera showed evidence of anti-HEV when tested specifically. This is the first documented outbreak of viral hepatitis in respect of Calcutta.

Effect of acute haemodilution on right atrial type-B receptor activity in anaesthetized cats

In order to investigate whether the sensitivity of atrial type-B receptors to its natural stimulus is altered during acute haemodilution, experiments were conducted in nine anaesthetized, artificially ventilated and thoracotomized cats. Haemodilution was achieved by replacement of blood by the same volume of dextran (MW 150000). Atrial receptor activity, arterial blood pressure, right atrial pressure and ECG were recorded. Heart rate was calculated from ECG records. Arterial blood hematocrit was measured. Mean arterial blood pressure and heart rate were not altered by haemodilution even at a hematocrit level of 12.17 +/- 0.93 percent. Average activity of type-B atrial receptors, mean right atrial pressure, right atrial peak 'v' pressure, right atrial initial 'v' pressure and right atrial 'v' wave amplitude were changed significantly (r < 0.05) during acute haemodilution when the hematocrit was 12.17 +/- 0.93 percent but the atrial type-B receptor activity per cycle did not show any significant change. Average activity of type-B receptors increased from 8.56 +/- 1.02 spikes/sec to 9.56 +/- 1.11 spikes/sec. Mean right atrial pressure, right atrial 'v' wave amplitude, right atrial peak 'v' pressure increased significantly (P < 0.05) from respective control values. Right atrial initial 'v' wave pressure decreased significantly. Heart rate changed from 168.11 +/- 5.42 beats/min to 170.89 +/- 5.65 beats/min. Mean arterial pressure changed from 134.33 +/- 0.89 mmHg to 135.67 +/- 1.46 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)

Serosurvey of chikungunya antibody in Calcutta metropolis

Since its first isolation in Calcutta, in 1963, there have been many reports about epidemis of chikungunya virus infection in different parts of India. Calcutta experienced a concurrent epidemic of dengue and chikungunya between 1963 and 1965. But after that there is no report about any chikungunya infection in Calcutta. During routine investigations it is found that chikungunya antibody is on the wane. The present survey for chikungunya antibody showed only 4.37% (n = 17) seropositivity out of 389 sera tested. The highest (12.5%) seropositivity was observed in the age group of 51-55 years and no chikungunya antibody was detected in young and young adults. The findings suggest that chikungunya virus is disappearing from the Calcutta population.

Incidence of malignancy in Bankura (a retrospective study)

A retrospective study on pattern of malignant lesions in a rural district of West Bengal from 1981-1990 was conducted in the department of pathology, BS Medical College, Bankura, West Bengal. A total number of 17,130 cases were received out of which 1976 were malignant lesions (11.53%). The peak incidence of cancer in both sexes was found between the 4th, 5th and 6th decades, ie, 31-60 years of age. Sex-wise distribution showed more incidence in female (1246-62.17%) than in male (730-37.83%). Cancer of the cervix (35.62%) showed the highest incidence in this series. Cancer of the larynx (11.94%) was the commonest cancer in males. Malignancy of the lymph node was observed in 11.43% cases. Malignancy of the lungs and vagina (< 0.5%) showed very low incidence.

(-)-Deprenyl alters the survival of adult murine facial motoneurons after axotomy: increases in vulnerable C57BL strain but decreases in motor neuron degeneration mutants

The effect of (-)-deprenyl on the survival of axotomized adult murine facial motoneurons was investigated. Previously, (-)-deprenyl was shown to increase the number of rat facial motoneurons (FMns) surviving after axotomy at postnatal day 14, apparently by compensating for the loss of muscle-derived trophic factor. In the present study, three different strains of adult mice--A/J, C57BL/6J, and a congenic substrain of the C57BL/6J mice, the C57BL/Mnd mutants--underwent unilateral facial nerve transection. FMns were counted from serial sections taken through the entire length of the facial nuclei ipsilateral and contralateral to the facial nerve transections in animals sacrificed 21 days after axotomy. Subgroups of C57BL/6J and Mnd mutants were treated with either saline or 1.0 mg/kg (-)-deprenyl for 21 days. Another subgroup of Mnd mutants were treated with the metabolites of (-)-deprenyl, a mixture of (-)-amphetamine and (-)-methamphetamine, at a dosage equimolar to 1.0 mg/kg (-)-deprenyl. The number of surviving facial motoneurons in the A/J strain was 90% of unlesioned, control values which supports previous findings that adult FMns receive adequate trophic support and thus can survive loss of muscle-derived trophic support. In the C57BL/6J strain, the facial motoneuron survival was 35% and (-)-deprenyl increased the survival to 50.5%. Mnd mutants showed 62.4% survival; however, (-)-deprenyl decreased the number of motoneurons to 54.9% and amphetamine and methamphetamine treatment further decreased the motoneuron survival to 41.1%. These findings show that FMns in the Mnd mutants and their parental strain, C57BL/6J mice, show greater vulnerability to axotomy as compared to other adult strains of mice. The vulnerability is similar to that found in early postnatal life. (-)-Deprenyl increases the survival of the axotomized C57BL/6J FMns but its major metabolites, (-)-methamphetamine and (-)-amphetamine, further decrease FMn survival in the C57BL/Mnd mutants, possibly due to the induction of neurotoxic proteins causing programmed neuronal death. The efficacy of (-)-deprenyl in increasing the survival of damaged neurons would be expected to decrease as dosage increased above the dosage sufficient to induce maximum neuronal rescue (approximately 0.01 mg/kg) but would decrease as the dosage exceeded that necessary to produce toxic concentrations of the metabolites of (-)-deprenyl (1.0 mg/kg in this study).

Synthetic images by subspace transforms. I. Principal components images and related filters

The principal component (PC) approach offers compressions of an image sequence into fewer images and noise suppressing filters. Multiple MR images of the same tomographic slice obtained with different acquisition parameters (i.e., with different TR, TE, and flip angles), time sequences of images in nuclear medicine, and cardiac ultrasound image sequences are examples of such input image sets. In this paper noise relationships of original and linearly transformed image sequences in general, and specifically of original, PC, and PC-filtered images are discussed. As the spinoff, it introduces locally weighted PC transforms and filters, nonlinear PC's, and a single-image based filter for suppression of noise. Examples illustrate increased perceptibility of anatomical/functional structures in PC images and PC-filtered images, including extraction of physiological functional information by PC loading curves. Generally, the more correlated the original images are, the more effective is the PC approach.

Urinary bladder serosal chemoreceptor induced cardio-respiratory responses: possible pathway

There is limited experimental information about pain originating from the urinary bladder. In the present study application of 3-5 ml of 1% ammonium oxalate, 1% potassium chloride, 100m M citric acid, IM ammonium chloride, 1% oxalic acid, 0.5% sodium hydroxide, or 2 micrograms/ml bradykinin, to the serosal surface of the urinary bladder in anaesthetized dogs, resulted in an increase in heart rate, rise of both systolic and diastolic blood pressures and increase in respiratory rate and depth. These facilitatory cardio-respiratory responses were coupled with powerful contractions of the urinary bladder wall. By contrast, mucosal application of the chemicals did not bring about any significant change. The cardio-respiratory responses obtained were completely abolished on serosal application of procaine (1%), section of the hypogastric nerves or by spinalectomy at T8. Bilateral cervical vagotomy and pelvic nerve section did not modify the responses. However, the blood pressure responses were abolished by the administration of tolazoline hydrochloride, indicating a major role of sympathetics in this nociceptive reflex.

Morphine-induced modulation of sciatic nerve stimulation evoked blood pressure responses

Effect of i.v. morphine (1-2 mg/kg) on blood pressure changes evoked by sciatic nerve stimulation (SNS) were studied in chloralose anaesthetised cats. SNS gave a depressor, pressor or a biphasic BP response generally linked to the parameters of stimulation. Morphine produced marked attenuation of depressor and some facilitation of pressor response, suggesting a possible reciprocal relationship between depressor and pressor responses. Depressor response has been correlated with deep tissue or visceral pain mediated through A delta fibres and pressor response to cutaneous nociception involving C fibres or non nociceptive input via group II fibres. Involvement of medullary regions in differential modulation of these depressor and pressor response has been suggested.

Sensitivity of the different tests of enterotoxigenicity of Escherichia coli and their correlation

Enterotoxigenicity of E. coli isolates was tested in 136 cases of acute gastroenteritis. Heat labile toxin (LT) produced in-vitro was tested in rabbit ileal loop (RIL); vero cell line and Biktn plate. The results of live cultures were evaluated in RIL. The overall data of these four models were not statistically different. Elaboration of LT in these four models ranged from 14-21.4%. Out of the 20 LT producing strains 14 (70%) also revealed ST. Of the 6 positive reactors on vero cell line, appeared to produce vero toxin (VT) only. Out of 29 LT positive E. coli, 1 (3.45%) and 2 (6.89%) strains respectively revealed colonising factor antigen (CFA) I and II. The high incidence of ETEC showing both LT and ST has been highlighted in the age group 0-4 years, and its impact on nutritional status is discussed.