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Biomedical subjects

P Philip

Publications and source records attributed to P Philip.

At least 19 recordsLinked to original sources
PubMed1998

Cytogenetically unrelated clones in therapy-related myelodysplasia and acute myeloid leukemia: experience from the Copenhagen series updated to 180 consecutive cases.

During the period from 1995 to 1997, we studied 19 new cases of therapy-related myelodysplasia (t-MDS) and acute myeloid leukemia (t-AML), extending our series to 180 consecutive cases: 123 patients with t-MDS and 57 patients with t-AML. Cytogenetically unrelated clones were observed in 13 patients: 11 patients with two unrelated clones, one patient with three unrelated clones, and one patient with four unrelated clones. Twelve cases of unrelated clones presented as t-MDS, whereas only one case presented as overt t-AML. Partial or complete deletions of the long arms or monosomy for chromosome 5 or chromosome 7, which are characteristic of t-MDS and t-AML, were observed in both unrelated clones in four patients and in one unrelated clone only in six patients, whereas three patients showed aberrations in both clones that were uncharacteristic of t-MDS or t-AML. Three different interpretations of the origin and significance of cytogenetically unrelated clones in t-MDS and t-AML are presented, although the disease is still considered to be monoclonal. First, patients with different defects of the long arm of chromosome 5 or chromosome 7 in two unrelated clones often seem to have acquired these aberrations as independent events. For this reason, it is possible that they may play an important role in leukemic transformation, for instance, by activating or potentiating the effect of a genetic change that is present in all cells but not disclosed as a visible chromosome abnormality. In cases with involvement of other chromosomes, unrelated clones sometimes develop by cytogenetic change in only a subclone of cells, indicating that they play a role only in tumor progression. Finally, unrelated clones in t-MDS and t-AML may represent two different monoclonal diseases: the primary tumor and t-MDS. This view is supported by the significant excess of unrelated clones observed in t-MDS following multiple myeloma (4 in 13 cases) compared with other diseases (9 in 167 cases; P = 0.02), and by results from a case with a balanced translocation that is highly characteristic of non-Hodgkin's lymphoma in one clone and a t-MDS-associated deletion of the long arm of chromosome 5 in another.

Adult↗
PubMed1998

Sleep and neuromuscular disease: bilevel positive airway pressure by nasal mask as a treatment for sleep disordered breathing in patients with neuromuscular disease.

OBJECTIVE: Investigation of the therapeutic effects of bilevel positive airway pressure delivered by nasal mask in patients with neuromuscular disease. METHODS: 20 patients with neuromuscular disease were evaluated for symptoms of nocturnal sleep disruption. These symptoms included daytime tiredness, fatigue, sleepiness, and complaints of insomnia. The patients were studied with nocturnal polysomnograms and daytime multiple sleep latency tests (MSLT). Their immediate and long term responses to bilevel positive airway pressure were also investigated. The study took place at the Stanford University Sleep Disorders Clinic. Some of the polygraphic evaluations were performed with portable equipment in the patients' homes. The reported population comprised 20 patients, all of whom had progressive neuromuscular disease. Five of the patients were women. Four patients had muscular dystrophy, six had myotonic dystrophy, and two patients each had mitochondrial myopathy and glycogen storage disease. Two patients had post-traumatic lesions, one bulbar and the other phrenic. The remaining patients had vascular myopathy, unclassified myopathy, syringomyelia, and slow evolving spinocerebellar degeneration. RESULTS: 19 of the 20 patients accepted some form of non-invasive ventilation. All but one of these were initially maintained on bilevel positive airway pressure spontaneous (S) mode, although one patient required a switch to the timed (T) mode within a year. The mean expiratory positive airway pressure (EPAP) used was 4.5 with a range of 4 to 5 cm H2O. The mean inspiratory positive airway pressure (IPAP) was 11.5, range 9 to 14 cm H2O. Before treatment the MSLTs were < or = 8 minutes in 11 of the patients. The overall mean score was 8.2 (SD) 1.3 minutes. After long term treatment the mean MSLT was 12.5 (SD 2) minutes and the mean ESS score was 7 (SD 3). During the mean 3.5 years of follow up, three patients needed supplemental oxygen at a flow of 0.5 to 1.0 l/min bled into their masks. Three patients with myotonic dystrophy presented continued daytime somnolence despite apparent adequate treatment of their sleep disordered breathing. This required the addition of stimulant medication to their regimen. During this time three additional subjects had to be switched to nasal mask intermittent positive pressure ventilation delivered by traditional volume cycled home ventilator (volume controlled NIPPV). CONCLUSIONS: Bilevel positive airway pressure delivered by nasal mask may be used successfully to treat sleep disordered breathing associated with neuromuscular disease. This device can be employed to assist nocturnal ventilation by either the spontaneous or timed mode. In the United States it is less expensive and easier to institute than volume controlled NIPPV and may be as efficacious as this mode if close surveillance and regular reevaluation of the patient's status is maintained.

Adolescent↗
PubMed1998

Nocturnal wandering and violence: review of a sleep clinic population.

Sleep consists of two complex states--NREM and REM sleep--and disturbances of the boundaries between the states of sleep and wakefulness may result in violence. We investigated our population for reports of violence associated with sleep. REM behavior disorder is rarely associated with injury to the sufferer or others. NREM sleep related nocturnal wandering associated with self-inflicted injuries has variable etiologies. In the elderly, it is associated with dementia. In young individuals, it may be associated with mesio-temporal or mesio-frontal foci and an indication of a complex partial seizure. It also may be related to abnormal alertness and is associated with excessive daytime sleepiness, micro-sleeps, and hypnagogic hallucinations in sleep disorders such as narcolepsy or sleep disordered breathing.

Adult↗
PubMed1997

Fusion of TEL, the ETS-variant gene 6 (ETV6), to the receptor-associated kinase JAK2 as a result of t(9;12) in a lymphoid and t(9;15;12) in a myeloid leukemia.

Translocations in hematologic disease of myeloid or lymphoid origin with breakpoints at chromosome band 12p13 frequently result in rearrangements of the Ets variant gene 6 (ETV6). As a consequence either the ETS DNA-binding domain or the Helix-Loop-Helix (HLH) oligomerization domain of ETV6 is fused to different partner genes. We show here that a t(9;12)(p24;p13) in a case of early pre-B acute lymphoid leukemia and a t(9;15;12)(p24;q15;p13) in atypical chronic myelogenous leukemia in transformation involve the ETV6 gene at 12p13 and the JAK2 gene at 9p24. In each case different fusion mRNAs were found, with only one resulting in an open reading frame for a chimeric protein consisting of the HLH oligomerization domain of ETV6 and the protein tyrosine kinase (PTK) domain of JAK2. The cloning of the complete human JAK2 coding and genomic sequences and of the genomic junction fragments of the translocations allowed a characterization of the different splice events leading to the various mRNAs. JAK2 plays a central role in non-protein tyrosine kinase receptor signaling pathways, which could explain its involvement in malignancies of different hematologic lineages. Besides hop in Drosophila no member of the JAK family has yet been implicated in tumorigenesis.

Amino Acid Sequence↗
PubMed1997

Objective measurement of sleepiness in summer vacation long-distance drivers.

The study investigated whether sleepiness at the wheel is a problem in non-commercial drivers going on summer vacation. All drivers, who stopped at a rest area on a large European freeway while one of the interviewers was available, were systematically approached and asked to respond to a questionnaire. All subjects who had driven at least 400 km (240 miles), whose age was between 20 and 46 years of age, and who agreed to participate were asked to undergo a longer investigation that included a short sleep/wake diary describing overall sleep habits during the year, a sleep/wake log covering the days just prior to departure, an analog visual scale indicating sleepiness at time of interview, and a polygraphically monitored two nap sleep test (TNST). A control group was recruited that consisted of subjects of the same age range, normal sleep habits, and normal nocturnal sleep time before administration of the TNST. One hundred and four drivers (2 women) participated between 08:00 and 20:00 h. The total group was subdivided into 6 subgroups based upon the time of day of their investigation (08:00-10:00 h, 10:01-12:00 h, etc.). The control group included 50 men with 50-55% of control subjects, relative to the total number of index-cases, in each subgroup. Eighty-eight percent (n = 92) of studied drivers had experienced acute sleep deprivation within one day prior to departure due to the planned long driving. The TNST demonstrated that, overall, drivers had a significantly shorter sleep latency in nap 1 and nap 2 than controls, had a significantly longer sleep duration in nap 1 and nap 2, and there was a significant correlation between the sleep debt prior to departure and the sleep stage reached during the TNST. It is concluded that the TNST is a test which allows the objective study of sleepiness in drivers without the burden of the multiple sleep latency test. Many drivers are excessively sleepy when making long summer vacation journeys.

Adult↗
PubMed1997

Prevalence and correlates of nocturnal desaturations in a sample of elderly people.

We designed an epidemiological study to estimate the prevalence and correlates of nocturnal desaturations in a sample of elderly subjects from the general population. Sleep-related respiratory disturbances were assessed by questionnaire and MESAM IV (MADAUS electronic sleep apnoea monitor) ambulatory monitoring. An oxygen desaturation index (ODI), oxygen desaturation being defined as a decrease in SaO2 of or exceeding 4%, was then computed from these data. An oxygen desaturation index > or = 10 was observed in 27.0% of the 293 subjects studied (mean age 76.6+/-5.7 y, median=75 y, min.=69, max.=99), an oxygen desaturation index > or = 30in 4.4%. Multivariate analysis identified as correlates to an oxygen desaturation index > or = 10: male gender (OR=1.80; P=0.04), a high body mass index (BMI) in men (OR=1.20 per kg m2; P=0.0009), and advanced age in women (OR=1.09 per y; P=0.02). A positive association was found between loud snoring (OR=1.75; P=0.06) and an oxygen desaturation index > or = 10. However, there was no statistically significant relationship between an oxygen desaturation index > or = 10 and either daytime somnolence (OR=1.50; P=0.19) or trouble getting to sleep (OR=0.59; P=0.09). We found no significant relationship in our sample between oxygen desaturation index and arterial hypertension or cardiac dysrhythmia. Previous studies on younger populations have reported different results. It may well be the advanced age of our sample that explains these inconsistencies. For the elderly persons we studied our results underline the relatively high prevalence of sleep-related respiratory disturbances. However, these may be of less consequence than in younger populations.

Aged↗
PubMed1996

Determinants of sleepiness in automobile drivers.

Governmental agencies do not systematically investigate the presence of daytime sleepiness as a determinant of driving accidents. We surveyed automobile drivers traveling on summer vacations and driving long distances on a European highway. We evaluated their subjective daytime sleepiness while driving and any sleep deprivation just prior to departure. Five-hundred sixty-seven automobile drivers (mean age 37.7 +/- 11 years) were interviewed at a roadside rest-stop. Questions covered the sleep/wake schedule during the year, sleep habits, and the presence of symptoms frequently associated with sleep-disordered breathing. Sleep behavior just prior to departure was compared to the usual sleep schedule during the year. Fifty percent of the responders had a sleep restriction just prior to departure (mean -203 minutes) compared to usual total sleep time during the year; 10% had no nocturnal sleep prior to departure. Drivers younger than 30 years were significantly more acutely sleep deprived than other drivers. Economic migrants (subjects with low economic status) also experienced significant acute sleep restriction.

Accidents, Traffic↗
PubMed1996

Chronic neutrophil leukaemia in adolescence and young adulthood.

Chronic neutrophil leukaemia (CNL) is a rare myeloproliferative disorder predominantly reported in elderly patients. We present a 15-year-old girl and a 25-year-old male with CNL. Clonal cytogenetic abnormalities were detected in both patients. One showed trisomy 21 evolving into tetrasomy 21. The second patient showed a unique chromosome aberration during blast crisis: t(2;2)(q32;p24). Both patients were successfully treated with allogeneic bone marrow transplantation (BMT). CNL should also be considered as a differential diagnosis in adolescence and young adulthood. BMT represents a potentially curative treatment option in such patients.

Adolescent↗
PubMed1996

Tiredness and somnolence despite initial treatment of obstructive sleep apnea syndrome (what to do when an OSAS patient stays hypersomnolent despite treatment).

From a database of 4,129 patients with sleep-disordered breathing (SDB), we found 207 subjects (43 women) that still complained of daytime tiredness, fatigue, and/or sleepiness despite treatment. In 25 subjects the sleepiness developed 1 to 36 months following treatment and was related to noncompliance (8 subjects), significant weight increase and/or inappropriate treatment (10 subjects), or development of new medical problems (7 subjects). In the remaining 182 subjects, sleepiness was noted within 1 month after what was judged appropriate treatment for SDB. In this group, the reason for persistent complaint was divided into four categories: 1) inappropriate treatment as a result of not using the measurement of esophageal pressure (Pes) in the initial diagnosis (41 subjects), 2) nonfunctional treatment (3 subjects), 3) associated narcolepsy-like syndrome (2 subjects), and 4) emergence of obesity and/or periodic leg movements as significant factors (135 subjects). The 135 subjects in this last category could be subdivided into three subgroups: 1) younger subjects, severely overweight with lower mean nocturnal saturated arterial oxygen (SaO2) values; 2) older subjects, of normal weight, with high numbers of periodic leg movements (PLM); and 3) moderately overweight subjects, with a combination of PLM and lower mean SaO2 values than expected. Treatments were aimed at eliminating the identified problems; they included standard medications for PLM and nasal bilevel positive airway pressure (BiPAP) for low SaO2 measurements. These treatments were not effective in specific cases, and stimulant medications had to be prescribed.

Adult↗
PubMed1996

Clonal chromosome aberrations in myeloid leukemia after styrene exposure.

OBJECTIVES: The purpose of the study was to determine the risk of myeloid leukemia subclassified according to clonal chromosome aberrations in styrene-exposed workers. METHODS: A nested case-referent study was carried out on 19 myeloid leukemia patients, of which 12 showed clonal chromosome aberrations, and 57 referents ascertained within the Danish reinforced plastics industry and similar industries with no styrene exposure. RESULTS: A 2.5-fold increased risk for myeloid leukemia with clonal chromosome aberrations (95% confidence interval 0.2-25.0) was found among workers of companies with styrene exposure. CONCLUSIONS: The results suggest that styrene may cause leukemia through a clastogenic effect. But similar findings could also have been found if the exposure was associated with a specific subtype of leukemia prone to develop the chromosome aberrations in question. Due to the few observations and the lack of detailed exposure data, additional studies are needed to corroborate or refute the present suggestive findings.

Adult↗
PubMed1996

Adult psychophysiologic insomnia and positive history of childhood insomnia.

Sixty-five adults diagnosed with "psychophysiologic chronic insomnia" following the criteria of the Association of Sleep Disorders Centers were investigated. They were subdivided into two groups based on whether onset of the insomnia had occurred in childhood or adulthood. Fifty similar-aged patients with obstructive sleep apnea syndrome (OSAS) were also investigated and served as a contrast group. All subjects were given polygraphic recordings and structured interviews, and all completed sleep questionnaires after reviewing the questions with an investigator. On many indices evaluating subjective daytime alertness and well-being, the psychophysiologic insomnia patients had scores similar to the OSAS patients. There were no significant differences between the childhood-onset and adult-onset psychophysiologic insomnia patients on most of the investigated items. However, the childhood-onset psychophysiologic insomniinacs had moderately but significantly higher reports of nightmares. This group also reported having had longer sleep latencies, significantly more "fear of the dark" and more frequent nightmares during childhood than the adult-onset group. These statistically significant findings reflected only a moderate increase in subjective scores, however, and in general the childhood-onset and adult-onset psychophysiologic insomnia patients were very similar.

Adult↗
PubMed1995

Different genetic pathways in leukemogenesis for patients presenting with therapy-related myelodysplasia and therapy-related acute myeloid leukemia.

Development of myelodysplasia (MDS) with subsequent progression to acute myeloid leukemia (AML) is an example of the multistep process of malignant transformation in which each step often relates to genetic abnormalities that can be directly seen as chromosomal aberrations. Therapy-related MDS and AML (t-MDS and t-AML) may serve as an ideal model for a study of the genetic evolution of MDS and AML because chromosomal abnormalities are observed in most cases and because the disease is often diagnosed early due to a close patient follow-up. The cytogenetic characteristics at diagnosis were studied in 137 consecutive cases of t-MDS and t-AML, including 22 new cases, and correlated with the clinical characteristics and the course of the disease. Balanced translocations to chromosome bands 11q23 and 21q22 represent primary steps in pathways leading directly to overt t-AML. Specific chromosomal deletions or losses, on the other hand, represent primary or secondary events in alternative pathways leading to t-MDS with potential for subsequent transformation to overt t-AML. Loss of a whole chromosome 7 (-7) or deletion of its long arm (7q-) and deletion of the long arm of a chromosome 5 (5q-) were the most frequent primary abnormalities significantly related to t-MDS. Loss of a whole chromosome 5 (-5) was also a primary event, but surprisingly, was observed equally in t-MDS and in t-AML. Deletion of chromosome 13, including bands q13q14, was another less common primary aberration of t-MDS. Except for -7 and del(13q), these primary aberrations were most often observed together with secondary abnormalities. These included balanced aberrations involving band 3q26 and various deletions of chromosome 3, a gain of a whole chromosome 8, deletions of the short arm or loss of chromosomes 12 and 17, loss of a whole chromosome 18, and deletions of the short arm of chromosome 21. Deletions or loss or chromosomes 5 and 7 were significantly associated with previous therapy with alkylating agents (P = .002), and balanced translocations to chromosome bands 3q26, 11q23, and 21q22 were significantly associated with previous therapy with drugs targeting DNA-topoisomerase II (P < .00005). Other characteristic aberrations were not related to any specific type of therapy. The molecular changes believed to contribute to the development of t-MDS and t-AML have been identified for many of these chromosomal abnormalities.

Acute Disease↗
PubMed1994

Translocation (3;21)(q26;q22) in therapy-related myelodysplasia following drugs targeting DNA-topoisomerase II combined with alkylating agents, and in myeloproliferative disorders undergoing spontaneous leukemic transformation.

Translocation (3;21)(q26;q22) has been observed only rarely in de novo myelodysplasia (MDS) and de novo acute myeloid leukemia (AML), but, including the two new cases in the present study, the aberration has now been identified in at least 10 cases of t-MDS or t-AML. All these 10 patients had previously received alkylating agents, in nine patients combined with a drug targeting at DNA-topoisomerase II (doxorubicin in eight cases). Eight of the ten patients presented with t-MDS. A further 20 patients with various myeloproliferative disorders and an identical t(3;21) have been reported. In these cases, t(3;21) was not related to any specific type of previous therapy but was associated with transformation from chronic stage disease to overt AML.

Alkylating Agents↗
PubMed1994

Standardized multicentric quantimetry of differentiation antigens expression. The GEIL's approach in acute lymphoblastic leukemia. Groupe d'Etude Immunologique des Leucémies.

The use of flow cytometry as a common tool has opened the field of quantimetric immunophenotyping. This could help refine the definition of leukemic proliferations, and perhaps provide new prognostic criteria. We investigated whether this approach could be applied to multicentric immunophenotyping. The reproducibility of quantitative measurements on different types of flow cytometers was tested using a single batch of calibrating and "blind" fluorescent beads. Less than 7% CV was obtained between 20 different laboratories. We then explored the variations noted with control or normal lymphocytes, using various CD4 monoclonal antibodies, which were found to be lower than 10%. We finally applied this strategy to acute lymphoblastic leukemias (ALL), performing quantitative measurements of CD10 using one single aliquoted batch of FITC-CD10 in comparison with locally used reagents. PreB-ALL could indeed be further stratified depending on the density of CD10 expression. Use of the same monoclonal antibody is however recommended, since PreB-ALL also seem to display epitopic variations of the CD10 molecule.

CD4 Antigens↗
PubMed1994

Sleep fragmentation in normals: a model for sleepiness associated with upper airway resistance syndrome.

Eight young adults underwent 1 night of auditory sleep fragmentation followed by four naps of the multiple sleep latency test and performance testing the next day. A latin-square design was used to compare results with baseline. Efforts were made to eliminate effects of learning on repeated performance tests. A mean of 303 arousals, lasting a mean of 11 seconds, disrupted nocturnal sleep. This sleep fragmentation was induced to mimic as closely as possible the nocturnal sleep disruption seen in subjects with upper airway resistance syndrome. There was a significant disruption of nocturnal sleep architecture with a significant overall decrease in slow-wave sleep (SWS) and a significant but more moderate decrease in rapid eye movement (REM) sleep during the fragmented night. The most interesting finding related to analysis by thirds of the night, which indicated an important increase over time in arousal threshold during SWS followed by REM sleep. This threshold increase was associated with a parallel increase in dB(A) levels needed to induce an arousal. Stages 1 and 2 nonrapid eye movement (NREM) sleep were less affected by the stimulation, but the amount of stage 1 NREM sleep decreased from the beginning to the end of the night, again indicating an increase in pressure to sleep. Following 1 night of sleep fragmentation, subjects had significantly shorter sleep latencies on the multiple sleep latency test for naps 2, 3 and 4. There was a significant relationship between percent nocturnal SWS and mean sleep latencies. The selected performance tests were not affected by 1 night of sleep fragmentation, despite the obvious sleepiness.

Adult↗
PubMed1993

Rearrangements of the MLL gene in therapy-related acute myeloid leukemia in patients previously treated with agents targeting DNA-topoisomerase II.

Chromosome band 11q23 is frequently involved in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) de novo, as well as in myelodysplastic syndromes (MDS) and lymphoma. Five percent to 15% of patients treated with chemotherapy for a primary neoplasm develop therapy-related AML (t-AML) that may show rearrangements, usually translocations involving band 11q23 or, less often, 21q22. These leukemias develop after a relatively short latent period and often follow the use of drugs that inhibit the activity of DNA-topoisomerase II (topo II). We previously identified a gene, MLL (myeloid-lymphoid leukemia or mixed-lineage leukemia), at 11q23 that is involved in the de novo leukemias. We have studied 17 patients with t-MDS/t-AML, 12 of whom had cytogenetically detectable 11q23 rearrangements. Ten of the 12 t-AML patients had received topo II inhibitors and 9 of these, all with balanced translocations of 11q23, had MLL rearrangements on Southern blot analysis. None of the patients who had not received topo II inhibitors showed an MLL rearrangement. Of the 5 patients lacking 11q23 rearrangements, some of whom had monoblastic features, none had an MLL rearrangement, although 4 had received topo II inhibitors. Our study indicates that the MLL gene rearrangements are similar both in AML that develops de novo and in t-AML. The association of exposure to topo II-reactive chemotherapy with 11q23 rearrangements involving the MLL gene in t-AML suggests that topo II may play a role in the aberrant recombination events that occur in this region both in AML de novo and in t-AML.

Adult↗