PubMed Health⌕ Search

Biomedical subjects

P Allinson

Publications and source records attributed to P Allinson.

5 recordsLinked to original sources
PubMed2001

Transcutaneous oxygen measurements predict a beneficial response to hyperbaric oxygen therapy in patients with nonhealing wounds and critical limb ischemia.

Hyperbaric oxygen (HBO) therapy may be a useful adjunct in the treatment of patients with wounds associated with critical limb ischemia. These patients either cannot undergo a successful bypass or may not heal after vascular reconstruction alone. Identification of patients likely to benefit from HBO is essential before treatment, as this therapy is time-consuming, costly, and not without risk. Transcutaneous oxygen measurements (TCOM) can be used to evaluate the degree of hypoxia in ischemic tissue. In this study we evaluated whether TCOM could be used to identify those patients who would or would not benefit from HBO therapy. Our hypothesis is that a difference in transcutaneous oxygen tension readings measured near the ischemic lesion with the patient breathing room air and while breathing 100 per cent oxygen at ambient pressure may be predictive of wound healing with adjunctive hyperbaric oxygen therapy. Thirty-six patients with critical limb ischemia and nonhealing ulcers were referred for HBO therapy. They were deemed either nonreconstructible from a vascular surgical viewpoint, had failed prior revascularization attempts, or could not achieve complete wound healing even after a successful revascularization. Pretreatment assessment included a room air and post-100 per cent-O2 challenge TCOM reading obtained in the vicinity of the open wound. Hyperbaric oxygen treatments at 2.0 to 2.5 atm were then administered until healing occurred or failure was confirmed. All patients undergoing HBO had a baseline TCOM of <40 torr. Twenty-seven patients had an increase in TCOM of >10 torr with oxygen inhalation at initial evaluation. Of these patients, 19 (70%) healed their wounds with HBO therapy. Conversely the increase in TCOM was <10 torr in nine patients, and only one of these patients (11%) ultimately healed (P < 0.01). Patients with nonhealing ischemic extremity wounds may heal with adjunctive HBO therapy. We can predictably identify patients who are likely to benefit from this modality using TCOM at the time of initial evaluation. An increase of tissue O2 tension of > or =10 torr when breathing pure O2 suggests that the patient may benefit from HBO therapy. Those patients with an increase of <10 torr are unlikely to receive benefit from this treatment modality.

Aged↗
PubMed1999

Spinal muscular atrophy variant with congenital fractures.

A single report of brothers born to first-cousin parents with a form of acute spinal muscular atrophy (SMA) and congenital fractures suggested that this combination represented a distinct form of autosomal recessive SMA. We describe a boy with hypotonia and congenital fractures whose sural nerve and muscle biopsies were consistent with a form of spinal muscular atrophy. Molecular studies identified no abnormality of the SMN(T) gene on chromosome 5. This case serves to validate the suggestion of a distinct and rare form of spinal muscular atrophy while not excluding possible X-linked inheritance.

Adolescent↗
PubMed1999

Friedreich's ataxia: point mutations and clinical presentation of compound heterozygotes.

Friedreich's ataxia is the most common inherited ataxia. Ninety-six percent of patients are homozygous for GAA trinucleotide repeat expansions in the first intron of the frataxin gene. The remaining cases are compound heterozygotes for a GAA expansion and a frataxin point mutation. We report here the identification of 10 novel frataxin point mutations, and the detection of a previously described mutation (G130V) in two additional families. Most truncating mutations were in exon 1. All missense mutations were in the last three exons coding for the mature frataxin protein. The clinical features of 25 patients with identified frataxin point mutations were compared with those of 196 patients homozygous for the GAA expansion. A similar phenotype resulted from truncating mutations and from missense mutations in the carboxy-terminal half of mature frataxin, suggesting that they cause a comparable loss of function. In contrast, the only two missense mutations located in the amino-terminal half of mature frataxin (D122Y and G130V) cause an atypical and milder clinical presentation (early-onset spastic gait with slow disease progression, absence of dysarthria, retained or brisk tendon reflexes, and mild or no cerebellar ataxia), suggesting that they only partially affect frataxin function. The incidence of optic disk pallor was higher in compound heterozygotes than in expansion homozygotes, which might correlate with a very low residual level of normal frataxin produced from the expanded allele.

Adolescent↗