Markers of clonality and malignant transformation in the large intestine.
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Biomedical subjects
Publications and source records attributed to D Williams.
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A male weanling rabbit of the New Zealand White strain, born and living at an altitude of 3800 m in La Paz, Bolivia, developed right ventricular hypertrophy. This was found to be associated with growth of vascular smooth muscle cells in the intima of pulmonary arterioles, and contrasted with muscularization of the walls of pulmonary arterioles, without extension into the intima, found in a healthy, high-altitude control rabbit of the same strain. A low-altitude control showed no such muscularization. It is concluded that alveolar hypoxia, acting directly or through an intermediate agent, is a growth factor for vascular smooth muscle cells in pulmonary arterioles. This is the first report of pulmonary vascular disease due to high altitude in rabbits.
A genomic library of Bacteroides gingivalis W83 chromosomal DNA was constructed in the Escherichia coli lambda (lambda) vector EMBL 4. Three recombinant lambda phages expressing a cloned protease were identified in the library. All three lambda phages contained cloned overlapping DNA fragments from the same region of the chromosome and encoded the same cloned protease. The cloned protease was expressed poorly using its own promoter in E. coli.
In this report we present three cases of ruptured aneurysm of sinus of Valsalva which were detected by colour Doppler echocardiography. The diagnosis was confirmed by cardiac catheterization and at operation.
Re-186 and Re-188 have been suggested for radioimmunotherapy because of their energetic beta particles, imageable gamma photons, and chemical properties similar to technetium. Because of this potential, these isotopes were evaluated before in vivo imaging was attempted. It was found that low-abundance, high-energy gamma photons present in these rhenium isotopes require a medium-energy collimator to yield optimal image resolution and count rate, which are critical factors in the performance of preliminary imaging studies on patients for antibody imaging and therapy.
A study was made of the qualitative histological features of the small pulmonary arterial vessels of 25 adult citizens of La Paz, Bolivia (altitude 3600 m) coming to necropsy. Abnormalities found included muscularization of pulmonary arterioles, the development of longitudinal muscle in the intima of pulmonary arteries and arterioles, and the formation of muscular tubes lining the longitudinal muscle which extended through arterioles into the precapillaries of the lung. Arteriolar muscularization was found in three of the 13 Aymaras and in two of the 12 Mestizos studied. Intimal longitudinal muscle was present in four Aymaras and five Mestizos. Muscular tubes were found in only one case, a young Aymara. The features were very similar to those found in chronic obstructive airways disease. The appearances are consistent with a growth of new vascular smooth muscle in response to alveolar hypoxia as opposed to hypoxic vasoconstriction.
Thirty children aged 2-16 years with malignant tumours who were receiving chemotherapy were treated with the 5-HT3 antagonist ondansetron. Each received a single intravenous dose (5 mg/m2) followed by oral doses (2-4 mg depending on surface area) every eight hours for five days. Chemotherapy regimens comprised: carboplatin alone, carboplatin plus etoposide, cisplatin plus etoposide; adriamycin (doxorubicin) plus cyclophosphamide, or ifosfamide. Twelve patients received ondansetron with their first course of chemotherapy and the other patients were poor responders to previous antiemetic treatment. Efficacy was assessed by a questionnaire documenting the incidence of vomiting and severity of nausea. In a 24 hour period after starting chemotherapy a complete or major response (less than two vomiting episodes) was achieved in 87% of children. Although ondansetron was effective for early antiemesis after cisplatin or ifosfamide, delayed vomiting, retching, or nausea reduced responses to 50% and 20%, respectively. We conclude that in children ondansetron is an effective, well tolerated, oral antiemetic enabling simple administration in the outpatient setting. In the present schedule it was of limited efficacy against cisplatin or ifosfamide induced emesis.
Reports of close associations between recurring chromosomal abnormalities and the clinical behavior of acute nonlymphocytic leukemia (ANLL) have stimulated efforts to define this disease in cytogenetic terms. Here we report on the leukemic cell karyotypes of 155 children with ANLL who were treated from 1980 to 1987 in consecutive programs of chemotherapy at this institution. Of 121 cases with adequate banding, 20% were normal, 30% had miscellaneous clonal abnormalities, and 50% were classified into known cytogenetic subgroups: inv(16)/del(16q) (n = 15), t(8; 21) (n = 14), t(15;17) (n = 9), t(9;11) (n = 9), t(11;V)/del(11q) (n = 7) and -7/del(7q) (n = 6). The inv(16)/del(16q) cases showed a nearly equal distribution of myelocytic and monocytic French-American-British (FAB) subtypes; only four of these patients presented with M4Eo morphology. Despite a 100% remission induction rate, patients with inv(16)/del(16q)-positive ANLL fared no better overall than the entire group; only 40% of this subgroup were event-free survivors at 2 years from diagnosis (P = .23). Patients with inv(16)/del(16q) frequently had CNS involvement at diagnosis (eight of 15) or initially relapsed in this site (three of eight). Event-free survival (EFS) was clearly superior for young patients with FAB M5 leukemia and the t(9;11) (P = .041). These patients were clinically indistinguishable from others with the FAB disease subtype, yet their responses to etoposide-containing therapies were noteworthy. By contrast, children with structural abnormalities involving 11q23, other than t(9;11), were infants (median age, 6 months) with FAB M4 or M5 leukemia, hyperleukocytosis, and frequent coagulation abnormalities. Patients with such changes [t(11;V) or del(11q)] relapsed early during postremission therapy: none remained disease-free more than 16 months from diagnosis. Because of resistant leukemia, patients with monosomy 7/del(7q) had a poor remission induction rate (17%; P = .0015); patients with the t(15;17) were also poor responders to induction therapy (44%; P = 0.02) because of hemorrhagic deaths. These results identify several cytogenetic subtypes of pediatric ANLL that may represent unique disease processes for which more effective early cytoreduction [-7/del(7q), t(11;V)], better supportive care measures [t(15;17)], or more effective CNS prophylaxis [inv(16)/del(16q)] would be warranted.
Host immunosuppression after trauma contributes to septic morbidity. The macrophage is a key element in the host immune response. This study evaluated glucan, a macrophage stimulant, in a prospective, randomized, double-blind study of 38 trauma patients undergoing surgery. Glucan (21 patients), 50 mg/m2, or placebo (17 patients) was given intravenously daily for 7 days. Delayed hypersensitivity skin testing was performed on days 1 and 7 after trauma. Serum interleukin-1 (IL-1) and tumor necrosis factor (TNF) were assayed after trauma. While the total mortality rate was significantly less in the glucan group (0% versus 29%) (p less than 0.05), the mortality rate from sepsis was not statistically different (0% versus 17.6%). Glucan therapy significantly decreased septic morbidity (9.5% versus 49%; p less than 0.05). Serum IL-1 had a greater increase in glucan patients on day 3 after trauma (143.4 +/- 19.3% versus 78.6 +/- 11.7%; p less than 0.05), but there was no difference thereafter. Serum TNF did not vary between groups. Early increase in IL-1 correlated with subsequent skin test conversion to positive. Neither serum IL-1 nor TNF was a reliable indicator of future sepsis. Further clinical trials are indicated to evaluate biologic response modifiers that activate macrophages in the trauma patient.
The numbers, morphology and distribution of pulmonary endocrine cells in goats, sheep, and the yak and its interbreeds were demonstrated by means of the peroxidase-antiperoxidase technique using a polyclonal antiserum to neuron-specific enolase. The animals came from two different locations and altitudes, Srinagar, Kashmir at 1250 m and Sakti in Ladakh, 4500 m. The presence of immuno-reactive cells was demonstrated in all animals but was related to species and not to the altitude of residence.
Endotoxin release may amplify the neutrophil (PMN) responses to bacterial infection through the release of monocyte-derived tumour necrosis factor (TNF). The present study was designed to assess the effect of recombinant human TNF-alpha (rhTNF-alpha) on the in vitro response of human PMN to two defined strains of pathogenic Escherichia coli. In the absence of rhTNF-alpha, a P-fimbriate strain caused significant release of the PMN secondary granule marker vitamin B12-binding protein (B12 BP), and a low level of release of leukotriene B4 (LTB4). Type 1-fimbriate strain 504, however, stimulated the release of the primary granule marker myeloperoxidase (MPO) and PMN chemiluminescence (CL), in addition to B12 BP and LTB4 release. Following rhTNF-alpha (10(-9) M) pretreatment, the release of LTB4 by PMN stimulated with the P-fimbriate strain was synergistically augmented, while B12 BP and MPO release were additively increased. In contrast, rhTNF-alpha did not significantly affect any of the responses by the type 1-fimbriate strain. These results suggest selectivity in the priming of PMN by rhTNF-alpha and confirm the independence of PMN responses to phagocytic stimuli.
The antibody responses of 100 previously untreated multibacillary (MB) leprosy patients to one protein and two carbohydrate antigens were examined: 94% of the patients had Mycobacterium leprae-specific antibodies; 89% directed to the species-specific epitope on phenolic glycolipid (PGL-I), 89% against the specific epitope on the 35-kDa protein, and 94% against one or both of the two. By contrast, 67% of the patients had anti-lipoarabinomannan (LAM) antibodies. There were trends for the seropositivity rate and the antibody level to rise with the increasing extent of the disease and as patients moved to the polar lepromatous end of the spectrum. The bacillary load, as measured by the bacterial index, was moderately correlated with the IgM anti-PGL-I and the anti-35-kDa antibody levels and, to a lesser extent, with the IgG antibodies directed at the common mycobacterial carbohydrate LAM. The sensitivity of the IgM anti-PGL-I antibodies for detecting smear-positive MB disease was 91%; that for the anti-35-kDa antibodies was 92%.
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Research directed towards discovering agents that enhance PKCa channel activity has followed two courses. One has been defining properties of the channel, as well as making use of toxins that are specific probes for characterizing channel binding sites and for isolating and purifying the channel. The second has been a study of the regulation of PKCa channels by guanine nucleotides. The following list summarizes the major findings and conclusions that have been drawn to date. (1) The high conductance (266 +/- 11.5 pS) PKCa channel of bovine aortic smooth muscle, which is the most abundant of the 3 kinds of PKCa channels observed, has properties very similar to high conductance PKCa channels found in other cell types. (2) Charybdotoxin (ChTX), a rather specific probe for PKCa channels, has been purified to homogeneity, characterized in terms of primary sequence, labeled with 125I, and used to study binding of ChTX to the receptor/channel complex. (3) A second high affinity toxin probe, with distinct biological activity, IbTX-I, has been purified to homogeneity, and its amino acid sequence determined. One of its distinct actions is to enhance channel activity at low nM levels, and to block the channel at concentrations above approximately 5 nM. (4) A number of vasodilators having the common action of increasing cytosolic cGMP levels, have been found to enhance PKCa channel activity in on-cell patches. (5) While all of the guanine nucleotides have been noted to enhance channel activity in excised patches at high concentrations (500 uM), only GMP is effective in the 10-100 uM range. (6) These data have led us to conclude that GMP is a physiological modulator of PKCa channels, and that it is most likely the second messenger for mediating the vasodilator-induced potentiation of channel activity.
A case-control comparison of adequate and inadequate cervical smears (adequacy being defined as the successful detection of cervical intraepithelial neoplasia and inadequacy as the failure to do so when disease was almost certainly present) was undertaken to determine whether indicators of effective cytological sampling could be identified. The association between inadequate smears and the absence of two types of normal epithelial cells (columnar cells of endocervical origin and immature metaplastic cells) was measured. A significant and substantial association was found between inadequate cervical smears and immature metaplastic cells and between inadequate smears and both types of cell. Endocervical cells alone were less likely to be found in inadequate than in adequate smears, but this association was not statistically significant.
The compatibility of etoposide (VP-16-213) and cisplatin (CDDP) in an admixture solution was established by High Pressure Liquid Chromatography (HPLC) studies in vitro at room temperature. A Phase I dual-dose escalation study of the admixture was subsequently carried out utilizing a 24-hour continuous infusion schedule administered for 3 consecutive days and repeated at 3 to 4 week intervals. Twenty-seven patients received a total of 42 treatment courses. The daily dose rates for VP-16-213 were 50, 75, and 100 mg/m2/day. Cisplatin was delivered at 20, 30, and 40 mg/m2/day for each dose level of VP-16-213. Dose-rate limiting toxicity was observed first at the VP-16 dose of 50 mg/m2/day and CDDP at 30 mg/m2/day. At 100 mg/m2/day for VP-16-213, six of 17 courses were associated with life-threatening leukopenia and four of six patients died with sepsis. All but one of the patients developing severe or life-threatening leukopenia had associated acute renal failure with serum creatinine levels greater than 2 mg/dl. The optimal dose rate of delivery for VP-16 and CDDP administered as a 72-hour infusion admixture is 75 mg/m2/day and 30 mg/m2/day, respectively.
The compatibility and stability at room temperature for up to 7 days of a three-drug admixture of cyclophosphamide, methotrexate, and 5-fluorouracil (5-FU) (CMF) was established permitting the practical delivery of the combination as an infusion in an ambulatory setting. Fourteen patients received 20 courses of CMF administered on a continuous infusion schedule for 14 days of a 28-day cycle. The dose rates were fixed for 5-FU (300 mg/M2/day) and methotrexate (0.75 mg/M2/day). The cyclophosphamide dose was escalated from 25 to 50, 75, and 100 mg/M2/d. Leukopenia and thrombocytopenia were observed in two of five patients receiving the maximal dose of cyclophosphamide. No other toxicities were observed including alopecia, stomatitis or liver function abnormalities. This Phase I trial suggests that the cumulative doses of cyclophosphamide, methotrexate, and 5-FU are comparable to the maximum doses delivered as single agent infusions. Furthermore, when the infusion CMF is compared to the "standard" bolus schedule for CMF, the infusion schedule delivers 116%, 8%, and 350% of the respective three component drugs (cyclophosphamide, methotrexate, and 5-FU).
5-Fluorouracil (5-FU) and floxuridine (FUdR) were admixed in a single solution and administered via a central venous catheter on a continuous infusion schedule for 14 days. The Phase I trial design developed for admixture combinations was employed with starting doses for 5-FU at 250 mg/m2/day and for FUdR at 0.075 mg/kg/day. Twenty patients and 28 courses were studied. Dose rate limiting toxicity was pseudoregional enteritis with or without stomatitis experienced by five of ten of the courses administered at the highest dose rates of the admixture components. The simultaneous delivery of the two agents results in a modest compromise of the cumulative dose delivered for FUdR. Previous Phase I studies of single agent 5-FU and FUdR had demonstrated that the optimal dose rates for the individual agents in a 14-day continuous 24-hour infusion schedule is 350 mg/m2/d and 0.125 mg/Kg/day, respectively. The maximum dose rate of 5-FU at 350 mg/m2/day for 14 days is not restricted even with the addition of FUdR at up to 0.1 mg/kg/day. The optimal dose rates for Phase II trails should be as follows: 5-FU, 350 mg/m2/day; and FUdR, 0.1 mg/kg/day.