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Biomedical subjects

M Falcon

Publications and source records attributed to M Falcon.

8 recordsLinked to original sources
PubMed1999

Prevention of graft-versus-host disease in high risk patients by depletion of CD4+ and reduction of CD8+ lymphocytes in the marrow graft.

From March 1994 to September 1997, 30 patients with hematological malignancies (12 ANLL, 10 CML, four ALL and four multiple myeloma) received HLA-identical allogeneic bone marrow transplants with the marrow graft selectively depleted of CD4+ lymphocytes and the CD8+ cell content adjusted to 1x10(6)/kg. Total depletion of CD4+ and partial depletion of CD8+ lymphocytes was carried out by an immunomagnetical method. All patients were considered as having high risk for developing GVHD by at least one of the following criteria: patient age >35 years; donor age >35 years; donor multiparity or marrow from an unrelated donor. Twenty-four cases received marrow from an identical sibling and six from an unrelated donor. In order to assess the role of methotrexate (MTX) in addition to cyclosporin A (CsA) after transplant, patients were randomly assigned to received either CsA alone (n = 15) or CsA plus a short course of MTX (n = 15). No case of primary graft failure was observed, but two patients developed late graft failure. Six patients presented grade II acute GVHD and no case of severe III-IV GVHD was seen. The actuarial probability of developing grade II-IV acute GVHD was 25.9+/-9.6% for the entire population. Patients receiving post-transplant CsA + MTX had significantly less probability of acute GVHD than those receiving CsA exclusively (6.7+/-6.4% vs. 50.5+/-17.8%, P = 0.03) and the schedule of post-transplant immunosuppression was the only factor associated with the incidence of acute GVHD in a multivariate analysis. The actuarial incidence of chronic GVHD for the entire population was 31.8+/-12.5, and there was no significant difference between both groups with additional prophylaxis. Four patients with CML and three with ANLL relapsed: the actuarial probability of remaining in complete remission for all patients was 53.6+/-17.3%. For patients with acute leukemia, the probability of remaining in complete remission did not differ significantly between those transplanted in first complete remission and those receiving a transplant in more advanced phases of the disease (87.5+/-11.6% vs. 72.9+/-16.5%; P = 0.44). The incidence of mixed chimerism assessed by PCR was 34%. Nineteen patients are alive between 2 and 43 months post-transplant, the probability of overall survival being 57.8+/-10.4%. Our data indicate that this method of selective T cell depletion is very effective in preventing acute GVHD in high risk patients, particularly when used in combination with post-transplant CsA + MTX.

Adolescent↗
PubMed1993

A prospective randomised study of local versus general anaesthesia for cataract surgery.

One hundred and sixty-nine patients (aged 65-98 years) were randomised to receive either local or general anaesthesia for cataract surgery. Cognitive function was assessed using a battery of psychometric tests performed pre-operatively, and at 24 h, 2 weeks and 3 months postoperatively. Oxygen saturation, blood pressure and heart rate were monitored and the results recorded throughout the anaesthetic and immediate recovery period. In the general anaesthetic group, 19% of patients experienced at least one episode of oxygen desaturation during the procedure compared with none in the local anaesthetic group. Pulse rate and blood pressure were stable in the local anaesthetic group compared with the general anaesthetic group where marked fluctuations were noted; 61% of patients in the general anaesthetic group experienced falls in systolic blood pressure greater than 30% of the pre-induction value. No evidence of long-term postoperative cognitive dysfunction was detected and there was no significant difference between the performances of the two groups.

Aged↗
PubMed1993

The development of analgesic, pro- and anti-convulsant opiate effects in the rat.

Evidence indicates that the neonate is capable, if not perceiving nociception, then at least reacting to nociceptive stimuli. These responses can be inhibited by opiates such as morphine. The analgesic potency of morphine in rat pups increases with maturation, due to (a) the proliferation of opiate receptors and (b), the maturation of supraspinal descending inhibition which becomes functional at 3 weeks post-natally. Tolerance to repeated injections of morphine in pups is less pronounced than in adults since it is masked by several processes, it has been demonstrated to occur within the first two weeks of life. Toxic effects of morphine in the neonate, as can be demonstrated both in behavior and EEG, differ from those in adults. Thus, convulsions induced by morphine which have been reported to occur in adults, were absent in pups. Excitatory effects of morphine in behavior develop in 3 different stages. During the first week morphine caused behavioral activation which is not mediated by specific opiate receptors. In the second week morphine produces EEG spikes in a dose-dependent fashion, but at this age these spikes were not reversible by opiate antagonists. Opiate specific EEG spikes and other opiate specific excitatory effects start to predominate during the third week of life.

Age Factors↗
PubMed1991

Medical manpower requirements following penetrating keratoplasty for herpes simplex keratitis.

We have compared the post-operative course of patients requiring penetrating keratoplasty for herpes simplex virus keratitis, keratoconus, and Fuchs' endothelial dystrophy with a minimum of two years follow-up. Although some expected differences (age, sex) were found between these three groups, the number of post-operative clinic visits was not different between the three groups. This is contrary to the common belief that patients requiring penetrating keratoplasty for herpes simplex keratitis are high risk, and will make greater demands on medical resources in the post-operative period. The management of our patients with herpes simplex keratitis is not statistically different from a similar group managed at another centre.

Adult↗
PubMed1990

Penetrating keratoplasty in south east London 1981-1986: epidemiological aspects and demands on medical resources.

We have compared penetrating keratoplasty at a teaching hospital and a district general hospital (DGH). At the teaching hospital, the pathology was similar to previous reports, but at the DGH the patients were older (P less than 0.01) and had a worse prognosis. The vision in the unoperated eye was also frequently poor. The number of postoperative outpatient visits within a hospital was unrelated to the original disease, and there was no statistically significant difference between the two centres. At the DGH, a corneal transplant patient requires the outpatient resources equivalent to three matched cataract patients. The implications for medical manpower requirements are discussed.

Adult↗
PubMedDate not supplied

Chimerism analysis in long-term survivor patients after bone marrow transplantation for severe aplastic anemia.

BACKGROUND AND OBJECTIVE: Allogeneic bone marrow transplantation (BMT) is the most common treatment for young patients with severe aplastic anemia (SAA). Late graft failure represents one of the possible unfavorable outcomes in this setting. Mixed chimerism might represent a risk factor for late graft failure. We examined this relationship by studying chimerism in long-term survivor SAA patients after allogeneic BMT. METHODS: We analyzed long-term hematopoietic chimerism in 15 patients who received BMTs for SAA: 9 with an irradiation-based conditioning regimen and 6 with ATG. We used a PCR method targeting VNTR loci. Sensitivity of the technique ranged between 0.5 and 1.5%. RESULTS: All patients conditioned with radiation-based schemes showed complete donor chimerism. Conversely, out of six patients who received cyclophosphamide and ATG as a conditioning regimen, only one of them had late graft failure (day +168). In this patient, durable mixed chimera status was first detected two months after BMT. INTERPRETATION AND CONCLUSIONS: Our results suggest that in long-term survivors of SAA after BMT there is almost always complete donor chimerism in both irradiated and ATG-conditioned recipients. Mixed chimerism might predict graft failure in these patients.

Adolescent↗