Treatment of stable and recalcitrant vitiligo by autologous miniature punch grafting: a prospective study of 1,000 patients

BACKGROUND

Stable and refractory vitiligo may be unresponsive to medical therapy. Melanocyte transplantation by punch grafting (PG) can restore the normal pigmentation.

OBJECTIVE

To evaluate the efficacy of PG on repigmentation of vitiligo patches.

METHODS

Autologous miniature PG was undertaken in 1,000 patients with stable and recalcitrant vitiligo. Test grafting (TG) was done in all the patients. Those who showed negative TG results were excluded from the study.

RESULTS

Of the 1,000 patients, 880 (88%) showed positive TG results. In 656 (74.55%) patients, 90-100% repigmentation was achieved. In 93 (10.57%) patients, there was no spread of pigment, while in 21 (2.39%) patients depigmentation of the graft(s) was notices. Of various complications, polka dot appearance (43.98%) and colour mismatch (34.32%) were most frequent.

CONCLUSION

Partial to near-total repigmentation of a vitiligo patch can be achieved by PG.

Influence of ATM function on interactions between telomeres and nuclear matrix

The ATM (ataxia telangiectasia mutated) gene product has been implicated in mitogenic signal transduction, chromosome condensation, meiotic recombination, and cell cycle control. The human ATM protein shows similarity to several yeast and mammalian proteins involved in meiotic recombination and cell cycle progression. Because of the homology of the human ATM gene to the TEL1 and rad3 genes of yeast, it has been suggested that mutations in ATM could lead to defective telomere maintenance. Recently, we have shown that the ATM gene product, which is defective in the cancer-prone disorder ataxia telangiectasia (AT), influences chromosome end associations and telomere length. A possible hypothesis explaining these results is that the defective telomere metabolism in AT cells is due to altered interactions between the telomeres and the nuclear matrix. These interactions were examined in nuclear matrix halos prior to and after irradiation. A difference was observed in the ratio of soluble and matrix-associated telomeric DNA between cells derived from AT and normal individuals. Treatment with ionizing radiation affected the ratio of soluble and matrix-associated telomeric DNA only in the AT cells. To test the hypothesis that the ATM gene product is involved in interactions between telomeres and the nuclear matrix, such interactions were examined in human cells expressing either a dominant-negative effect or complementation of the ATM gene. The phenotype of RKO colorectal tumor cells expressing ATM fragments containing a leucine zipper motif mimics the altered interactions of telomere and nuclear matrix seen in AT cells. Fibroblasts from AT individuals transfected with a wild-type ATM gene had corrected telomere-nuclear matrix interactions. In experiments designed to determine whether there is a link between the altered telomere-nuclear matrix interactions and defective telomere movement and clustering, a significant difference was observed in the ratio of soluble compared to matrix-associated telomeric DNA sequences in meiocytes of Atm(-/-) and control mice. These results suggest that the ATM gene influences the interactions between telomeres and the nuclear matrix and that alterations in telomere chromatin could be at least partly responsible for the pleiotropic phenotypes of the ATM gene. This paper summarizes our recent publications on the influence of inactivation of ATM on the interaction of telomeres with nuclear matrix in somatic and germ cells.

An analysis of quasi-frequency-modulated noise and random-sideband noise as comparisons for amplitude-modulated noise

Experiments were performed to determine under what conditions quasi-frequency-modulated (QFM) noise and random-sideband noise are suitable comparisons for AM noise in measuring a temporal modulation transfer function (TMTF). Thresholds were measured for discrimination of QFM from random-sideband noise and AM from QFM noise as a function of sideband separation. In the first experiment, the upper spectral edge of the noise stimuli was at 2400 Hz and the bandwidth was 1600 Hz. For sideband separations up to 256 Hz, at threshold sideband levels for discriminating AM from QFM noise, QFM was indiscriminable from random-sideband noise. For the largest sideband separation used (512 Hz), listeners may have used within-stimulus envelope correlation in the QFM noise to discriminate it from the random-sideband noise. Results when stimulus bandwidth was varied suggest that listeners were able to use this cue when the carrier was wider than a critical band, and the sideband separation approached the carrier bandwidth. Within-stimulus envelope correlation was also present in AM noise, and thus QFM noise was a suitable comparison because it made this cue unusable and forced listeners to use across-stimulus envelope differences. When the carrier bandwidth was less than a critical band or was wideband, QFM noise and random-sideband noise were equally suitable comparisons for AM noise. When discrimination thresholds for QFM and random-sideband noise were converted to modulation depth and modulation frequency, they were nearly identical to those for discrimination of AM from QFM noise, suggesting that listeners were using amplitude modulation cues in both cases.

Performance status of health care facilities changes with risk adjustment of HbA1c

OBJECTIVE

To develop a risk adjustment method for HbA1c, based solely on administrative data and to determine the extent to which risk-adjusted HbA1c changes the identification of high- or low-performing medical facilities.

RESEARCH DESIGN AND METHODS

Through use of pharmacy records, 204,472 diabetic patients were identified for federal fiscal year 1996 (FY96). Complete information (HbA1c levels, demographic data, inpatient records, outpatient pharmacy utilization records) was available on 38,173 predominantly male patients from 48 Veterans Health Administration (VHA) medical facilities. Hierarchical mixed-effects models were used to estimate risk-adjusted unique facility-level HbA1c.

RESULTS

Predicted HbA1c demonstrated expected patterns for major factors known to influence glycemic control. Poorer glycemic control was seen in minorities and patients with greater disease severity, longer duration of disease (using treatment type or presence of amputation as surrogates), and more extensive comorbidity (measured by an adapted Charlson index). Better glycemic control was seen in Caucasians, older diabetic patients, and patients with higher outpatient utilization. The number of performance outliers was reduced as a result of risk adjustment. For mean HbA1c levels, 7 facilities that were initially identified as statistically significant outliers were no longer outliers after risk adjustment. For high-risk HbA1c (>9.5%) rates, 12 facilities that were initially identified as statistically significant outliers were no longer outliers after risk adjustment.

CONCLUSIONS

Risk adjustment using only administrative data resulted in substantial changes in identification of high or low performers compared with non-risk-adjusted HbA1c. Although our findings are exploratory, risk adjustment using administrative data may be a necessary and achievable step in quality assessment of diabetes care measured by rates of high-risk HbA1c (>9.5%).

Receptor subtypes mediating depressor responses to microinjections of nicotine into medial NTS of the rat

Microinjections (50 nl) of nicotine (0.01-10 microM) into the nucleus of the solitary tract (NTS) of adult, urethan-anesthetized, artificially ventilated, male Wistar rats, elicited decreases in blood pressure and heart rate. Prior microinjections of alpha-bungarotoxin (alpha-BT) and alpha-conotoxin ImI (specific toxins for nicotinic receptors containing alpha7 subunits) elicited a 20-38% reduction in nicotine responses. Similarly, prior microinjections of hexamethonium, mecamylamine, and alpha-conotoxin AuIB (specific blockers or toxin for nicotinic receptors containing alpha3beta4 subunits) elicited a 47-79% reduction in nicotine responses. Nicotine responses were completely blocked by prior sequential microinjections of alpha-BT and mecamylamine into the NTS. Complete blockade of excitatory amino acid receptors (EAARs) in the NTS did not attenuate the responses to nicotine. It was concluded that 1) the predominant type of nicotinic receptor in the NTS contains alpha3beta4 subunits, 2) a smaller proportion contains alpha7 subunits, 3) the presynaptic nicotinic receptors in the NTS do not contribute to nicotine-induced responses, and 4) EAARs in the NTS are not involved in mediating responses to nicotine.

Regulation of the hTERT telomerase catalytic subunit by the c-Abl tyrosine kinase

BACKGROUND

Telomeres consist of repetitive (TTAGGG) DNA sequences that are maintained by the multisubunit telomerase ribonucleoprotein. Telomerase consists of an RNA, which serves as template for the sequence tracts, and a catalytic subunit that functions in reverse transcription of the RNA template. Cloning and characterization of the human catalytic subunit of telomerase (hTERT) has supported a role in cell transformation. How telomerase activity is regulated, however, is largely unknown.

RESULTS

We show here that hTERT associates directly with the c-Abl protein tyrosine kinase. We also found that c-Abl phosphorylates hTERT and inhibits hTERT activity. Moreover, our findings demonstrate that exposure of cells to ionizing radiation induces tyrosine phosphorylation of hTERT by a c-Abl-dependent mechanism. The functional significance of the c-Abl-hTERT interaction is supported by the demonstration that cells deficient in c-Abl show telomere lengthening.

CONCLUSIONS

The ubiquitously expressed c-Abl tyrosine kinase is activated by DNA double-strand breaks. Our finding of telomere lengthening in c-Abl-deficient cells and the functional interactions between c-Abl and hTERT support a role for c-Abl in the regulation of telomerase function.

Metastatic pancreatic adenocarcinoma to the heart diagnosed antemortem

Pancreatic tumors frequently metastasize widely, though it is rare to diagnose pancreatic cardiac metastases in the antemortem state. We report an unusual case of metastatic pancreatic adenocarcinoma to the right atrium. Transesophageal echocardiography showed that the tumor was attached to the superior aspect of the right atrium, prolapsing through and obstructing the tricuspid valve in diastole and retracting back into the right atrium during systole. The tumor was excised, and histologic examination confirmed the presence of moderately differentiated adenocarcinoma with a papillary architectural pattern and with desmoplastic stroma, features comparable to the original primary pancreatic neoplasm.

Herpes simplex virus 1 late gene expression is preferentially inhibited during infection of the TAF250 mutant ts13 cell line

A key component of the polymerase II transcription machinery is the transcription factor TFIID, a complex that contains the TATA-box binding protein and several (10-12) associated factors designated as TAFs (TBP-associated factors). ts13 cells, which contain a temperature-sensitive mutant in TAF250, the largest subunit of TFIID, exhibit promoter-specific defects in gene expression at the nonpermissive temperature, suggesting that individual TAFs are required for transcription of specific subsets of eukaryotic genes. Herpes simplex virus 1 (HSV-1) does not replicate in ts13 cells at the nonpermissive temperature, but the point at which the replicative process is blocked is not known. We used the TAF250 defect in ts13 cells to investigate the role of TAF250 in the expression of HSV-1 genes of each temporal class. At a low m.o.i., expression of most immediate-early mRNAs is reduced at the nonpermissive temperature, and consequently, there is little expression of early genes and no viral DNA replication. In contrast, at high m.o.i., expression of immediate-early genes is unaffected by the TAF250 defect and is not dependent on de novo viral protein synthesis. Early genes and early proteins are produced under these conditions, and viral DNA replication ensues, albeit at somewhat reduced levels. In contrast, late gene expression and late protein synthesis are severely restricted, even in the presence of appreciable viral DNA replication. Thus the lack of late protein synthesis is responsible for the inability of HSV-1 to replicate in ts13 cells at the nonpermissive temperature. Further, it appears that late viral gene expression may be preferentially inhibited by the TAF250 mutation in ts13 cells.

Antitumour activity of suramin analogues in human tumour cell lines and primary cultures of tumour cells from patients

Suramin has shown promising antitumour activity against several tumour types, both in vitro and in vivo, but the clinical utility of this compound is hampered by its unfavourable toxicity profile. In the present study, the semi-automated fluorometric microculture cytotoxicity assay (FMCA) was employed for evaluation of the cytotoxicity of seven suramin analogues in vitro in a panel of human tumour cell lines and in primary cultures of tumour cells from patients. Like suramin, the analogues showed little sensitivity to resistance mechanisms involving P-glycoprotein, topoisomerase II, multidrug resistance associated protein and glutathione-mediated drug resistance. In the cell line panel, NF067 and FCE 26644 showed activity comparable with suramin. All analogues were less potent than suramin in patient cells except for FCE 26644. Correlation to suramin activity patterns in the cell line panel was highest for NF037 and low to moderate for the remaining analogues. In patient cells, high correlation coefficients were obtained for FCE 26644, NF110, NF031 and NF037. The results indicate that the cytotoxic activity of suramin on patient tumour cells is shared by the analogues with FCE 26644 being the most active. The pharmacophore for cytotoxicity in patient cells may be different from that observed in the cell lines.

Ionizing radiation activates the ATM kinase throughout the cell cycle

The ATM protein kinase is a critical intermediate in a number of cellular responses to ionizing irradiation (IR) and possibly other stresses. ATM dysfunction results in abnormal checkpoint responses in multiple phases of the cell cycle, including G1, S and G2. Though downstream targets of the ATM kinase are still being elucidated, it has been demonstrated that ATM acts upstream of p53 in a signal transduction pathway initiated by IR and can phosphorylate p53 at serine 15. The cell cycle stage-specificity of ATM activation and p53Ser15 phosphorylation was investigated in normal lymphoblastoid cell line (GM536). Ionizing radiation was found to enhance the kinase activity of ATM in all phases of the cell cycle. This enhanced activity was apparent immediately after treatment of cells with IR, but was not accompanied by a change in the abundance of the ATM protein. Since IR activates the ATM kinase in all phases of the cell cycle, DNA replication-dependent strand breaks are not required for this activation. Further, since p53 protein is not directly required for IR-induced S and G2-phase checkpoints, the ATM kinase likely has different functional targets in different phases of the cell cycle. These observations indicate that the ATM kinase is necessary primarily for the immediate response to DNA damage incurred in all phases of the cell cycle.

The catalytic subunit of telomerase is expressed in developing brain neurons and serves a cell survival-promoting function

Telomerase, a specialized reverse transcriptase (RT) linked to cell immortalization and cancer, has been thought not to be expressed in postmitotic cells. We now report that telomerase activity and its essential catalytic subunit, telomerase reverse transcriptase (TERT), are expressed in neurons in the brains of rodents during embryonic and early postnatal development, and are subsequently downregulated. Suppression of TERT expression in cultured embryonic hippocampal neurons increases their vulnerability to apoptosis and excitotoxicity. Overexpression of TERT in PC12 cells suppresses apoptosis induced by trophic factor withdrawal. TERT exerts its anti-apoptotic action at an early stage of the cell death process prior to mitochondrial dysfunction and caspase activation. TERT may serve a neuron survival-promoting function in the developing brain, and downregulation of TERT in the adult brain may contribute to increased neuronal vulnerability in various age-related neurodegenerative disorders.

CHS 828, a novel pyridyl cyanoguanidine with potent antitumor activity in vitro and in vivo

A new class of recently discovered antineoplastic agents, the pyridyl cyanoguanidines, exert a potent antitumor activity in rodents after oral administration. Optimization in vitro and in vivo has resulted in the selection of the lead candidate CHS 828 (N-(6-chlorophenoxyhexyl)-N'cyano-N"-4-pyridylguanidine). CHS 828 was found to exert potent cytotoxic effects in human breast and lung cancer cell lines, with lesser effects on normal fibroblasts and endothelial cells. In a study using a panel of cell lines with different resistance patterns, the effects of CHS 828 showed a low correlation with the activity patterns of known anticancer agents, and no sensitivity to known mechanisms of multidrug resistance was observed. In nude mice bearing human tumor xenografts, CHS 828, at doses from 20 to 50 mg/kg/day p.o., inhibited the growth of MCF-7 breast cancer tumors and caused regression of NYH small cell lung cancer tumors. Oral administration of CHS 828 once weekly improved efficacy without increasing toxicity. CHS 828 was found to compare favorably with established chemotherapeutic agents such as cyclophosphamide, etoposide, methotrexate, and paclitaxel. In mice with NYH tumors, long-term survival (>6 months) was observed after treatment with CHS 828 was stopped. In conclusion, CHS 828 is an effective new antitumor agent, with a potentially new mechanism of action. CHS 828 is presently being tested in Phase I clinical trials in collaboration with the European Organization for Research and Treatment of Cancer.

Fibrolamellar carcinoma: an unusual clinico-radiological presentation

We report a case of fibrolamellar carcinoma presenting in a 26-year old female. The patient had gross ascites at presentation. Imaging studies (ultrasonography and computed tomography) strongly suggested extensive intraperitoneal drop metastases.

Liver transplantation in patients with chronic hepatitis C and alcoholism

We evaluated the contribution of alcohol abuse to liver failure among patients undergoing liver transplantation by reviewing their records for alcohol consumption, hepatitis serology, and outcome. Anti-HCV was present in the serum of 42 patients (39%), while 35 had consumed more than 80 g/day of alcohol for at least 10 years, allowing patients to be divided into four groups: group I, hepatitis C alone (N = 31); group II, alcoholic liver disease alone (N = 24); group III, both hepatitis C and alcoholism (N = 11); and group IV, liver failure due to other causes (N = 41). Patients were followed for a mean of 29 months after transplantation (range 0-66). Twenty-eight (26%) died during follow up, while 11 (10%) required retransplantation. There were no other significant differences in patient or graft survival among patients in the four groups. Patients with both alcoholism and chronic hepatitis C comprise a large proportion of those undergoing liver transplantation and appear to do as well as those with other causes of liver failure, at least in the short term.

Altered telomere nuclear matrix interactions and nucleosomal periodicity in ataxia telangiectasia cells before and after ionizing radiation treatment

Cells derived from ataxia telangiectasia (A-T) patients show a prominent defect at chromosome ends in the form of chromosome end-to-end associations, also known as telomeric associations, seen at G(1), G(2), and metaphase. Recently, we have shown that the ATM gene product, which is defective in the cancer-prone disorder A-T, influences chromosome end associations and telomere length. A possible hypothesis explaining these results is that the defective telomere metabolism in A-T cells are due to altered interactions between the telomeres and the nuclear matrix. We examined these interactions in nuclear matrix halos before and after radiation treatment. A difference was observed in the ratio of soluble versus matrix-associated telomeric DNA between cells derived from A-T and normal individuals. Ionizing radiation treatment affected the ratio of soluble versus matrix-associated telomeric DNA only in the A-T cells. To test the hypothesis that the ATM gene product is involved in interactions between telomeres and the nuclear matrix, we examined such interactions in human cells expressing either a dominant-negative effect or complementation of the ATM gene. The phenotype of RKO colorectal tumor cells expressing ATM fragments containing a leucine zipper motif mimics the altered interactions of telomere and nuclear matrix similar to that of A-T cells. A-T fibroblasts transfected with wild-type ATM gene had corrected telomere-nuclear matrix interactions. Further, we found that A-T cells had different micrococcal nuclease digestion patterns compared to normal cells before and after irradiation, indicating differences in nucleosomal periodicity in telomeres. These results suggest that the ATM gene influences the interactions between telomeres and the nuclear matrix, and alterations in telomere chromatin could be at least partly responsible for the pleiotropic phenotypes of the ATM gene.

Erythrocyte associated haemato-biochemical changes in Babesia equi infection experimentally produced in donkeys

Equine babesiosis, caused by Babesia equi and transmitted by ticks is of major economic importance in India. The adverse effects which B. equi organism and its metabolites inflict on red blood cells have not been reported. Erythrocytes were analysed for red cell membrane phospholipids, proteins and haemoglobin (Hb) concentration and plasma for malondialdehyde (MDA) in B. equi carrier donkeys before splenectomy (< 1% parasitaemia) and after splenectomy at 1-5, 5-15, 15-50 and >50% parasitaemia. Before splenectomy the mean values of membrane protein, phospholipids, plasma MDA and Hb were found to be 1.63 +/- 0.12 mg/ml PCV, 2.28 +/- 0.9 mg/ml PCV, 3.63 +/- 0.33 nmoles/ml plasma and 11.52 +/- 0.45 g/dl blood respectively. Erythrocyte membrane protein showed a significant increase at and beyond 5-15% parasitaemia, whereas a significant increase in total phospholipids and MDA level was observed at and beyond 50% parasitaemia. Though, a gradual decrease in Hb value was observed at various stages of parasitaemia and there was a sharp fall when parasitaemia reached more than 50%. Examination of blood smears showed phagocytosis of both healthy and infected erythrocytes.