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Biomedical subjects

A Waldman

Publications and source records attributed to A Waldman.

16 recordsLinked to original sources
PubMed2003

MRI of the brain with ultra-short echo-time pulse sequences.

As well as the long-T2 relaxation components normally detected with conventional imaging techniques, the brain has short-T2 components. We wished to use ultra-short (0.08 ms) echo time (UTE) pulse sequences to assess the feasibility of imaging these in normal subjects and patients. UTE sequences were employed, with or without fat suppression, 90 degree long-T2 suppression pulses, and selective nulling of long-T2 components using an inversion pulse. Subtraction of later echoes from the first was also used to reduce the signal from long-T2 components. We studied dive normal subjects and 15 patients with various diseases. Short-T2 components were demonstrated in grey and white matter. Increased signal from these components was seen in meningeal disease, probable calcification, presumed cavernomas, melanoma metastases and probable gliosis. Reduced signal was seen in some tumours, infarcts, mild multifocal vascular disease and vasogenic oedema. Further development and evaluation of these pulse sequences is warranted.

Adult↗
PubMed2003

[Clinical significance of macroscopic 5-aminolevulinic acid (ALA)-inducer fluorescence in transurethral resection of non-invasive bladder cancer].

Macroscopic fluorescence which is induced with aminolevulinic acid (ALA) allows visualizing of small flat tumors, carcinoma in situ, true neoplasm margins and dysplasias of the bladder. Following ALA instillation, cystoscopy was performed under both standard and blue light illumination. In a prospective randomized multicenter study, 102 patients underwent TUR of bladder tumor(s) either with white light or ALA-fluorescence. Significant reduction in the number of residual tumours was detected in 59% (p = 0.005) after 8 weeks, 3 months--in 58% (p = 0.002) and 6 months in 38% (p = 0.01) respectively.

Aminolevulinic Acid↗
PubMed2002

B Cell lymphoma of the brain stem masquerading as myasthenia.

A 54 year old man is described with signs compatible with ocular myasthenia gravis and an apparent excellent response to pyridostigmine. Subsequent clinical progression and further investigation suggested the presence of an inflammatory brain stem lesion, which responded to corticosteroid therapy. Clinical relapse, including the development of central neurogenic hyperventilation, led to a brain stem biopsy, confirming a diagnosis of B cell lymphoma. This case illustrates the propensity of primary CNS lymphoma (PCNSL) to mimic other conditions. Brain MRI is mandatory in presumed "test negative" ocular myasthenia with atypical clinical findings. Spontaneous regression of PCNSL or response to corticosteroids is common and should not mitigate against the diagnosis. Histopathological confirmation should ideally be made before starting therapy, as this may obscure or delay the correct diagnosis. Although PCNSL is rare, it must be considered in all patients with brain stem syndromes, and in all patients 50 years or older with contrast enhancing focal lesions.

Biopsy↗
PubMed2002

Ataxia in the setting of complicated enteropathy: double jeopardy.

The differential diagnosis of subacute onset ataxia in the setting of enteropathy is wide. A 54 year old patient with a pancerebellar syndrome and known ulcerative jejunoileitis is described. Small bowel biopsy showed evidence of enteropathy associated T cell lymphoma and subsequent neuropathological analysis and immunophenotyping confirmed metastasis of this tumour to the cerebellum. The presence of anti-gliadin antibodies and MRI evidence of a more longstanding process suggested additional immunologically mediated cerebellar dysfunction. Lymphomatous involvement of the CNS is rare in patients with complicated enteropathies, and has not been previously reported to involve the cerebellar parenchyma. This diagnostic possibility should be borne in mind before attributing cerebellar dysfunction in patients with the coeliac related enteropathies to nutritional compromise or immunological dysfunction (gluten ataxia) alone.

Ataxia↗
PubMed2002

Familial adult onset of Krabbe's disease resembling hereditary spastic paraplegia with normal neuroimaging.

Krabbe's disease (globoid cell leucodystrophy) is a disorder involving the white matter of the peripheral and central nervous systems. Mutations in the gene for the lysosomal enzyme galactocerebrosidase (GALC) result in low enzymatic activity and decreased ability to degrade galactolipids found in myelin. The disease is classically of infantile onset, but adult onset cases have been reported. Magnetic resonance imaging (MRI) of the brain shows characteristic abnormalities. A unique family with Krabbe's disease is described, with proven GALC deficiency but normal MRI. A neurological phenotype is present in heterozygotes and the family shows the extent of homozygotic phenotypic diversity that can be seen in this disorder.

Adult↗
PubMed2001

Incidence of Candida in psoriasis--a study on the fungal flora of psoriatic patients.

The presence of Candida albicans and other Candida species in saliva and faeces of 50 psoriatic patients compared with a control group of 50 healthy donors was examined quantitatively. The quantity of Candida in saliva and faeces of the psoriatics proved to be significantly higher than in the controls. Candida was detected in 78% of the saliva samples of the psoriatics but in only 50% of the controls, and in the faeces samples in 72% of the psoriatics, but in only 46% of the controls. Qualitative analysis revealed a predominance of Candida albicans (saliva, 77%; faeces, 64%) and Candida rugosa (saliva, 28%; faeces, 28%). We did not find a correlation between the severity of the psoriasis according to the Psoriasis Area and Severity Index and the amount of Candida in the saliva or in the faeces. Our results reinforce the hypothesis that C. albicans is one of the triggers to both exacerbation and persistence of psoriasis. We propose that in psoriatics with a significant quantity of Candida in faeces, an antifungal treatment should be considered as an adjuvant treatment of psoriasis.

Adolescent↗
PubMed1999

The role of laser and intense light sources in photo-epilation: a comparative evaluation.

The method for laser and light assisted hair removal is based on the theory of selective photothermolysis. Selective absorption of hair chromophores from lasers and broad band light sources results in destruction of hair follicles while leaving the skin undamaged. A discussion of the basic principles of selective photothermolysis as it applies to hair removal by lasers and light sources is presented, followed by a comparative review of three melanin target based systems: Ruby laser, Alexandrite laser, and a broad band intense pulsed light. These systems are efficient and safe with proper patient selection. Multiple treatments are necessary due to the nature of the hair growth cycle.

Hair↗
PubMed1997

Pulsed alexandrite laser technology for noninvasive hair removal.

OBJECTIVE: Determination of the efficacy of pulsed Alexandrite Laser technology for rapid noninvasive hair removal. SUMMARY BACKGROUND DATA: Although previous studies have already shown that Ruby lasers are capable of noninvasive hair removal, a technology for the substantial increase of treatment speed is of great interest. METHODS: We have used a 2 msec free running pulsed Alexandrite (lambda = 755 nm) laser operated at a repetition rate of up to 5 pps at energy fluences of 25-40 J/cm2 to treat a wide range of body sites on 126 patients in conjunction with a fiber delivery system and a transparent target ruler. A transparent gel was used as epidermal heat sink. The study lasted 15 months. Pretreatment as well as follow-up hair count per cm2 was performed to determine the level of success. Treatments were repeated when 1-2 mm growth was observed. RESULTS: The average hair count before the second treatment was found to be close to 65% of the pretreatment count. The average hair count 3 months after the last treatment, was found to be lower than 12%. The interval between treatments ranged from 4 weeks to 3 1/2 months. CONCLUSIONS: The 2 msec pulsed Alexandrite laser technology is effective for the removal of unwanted hairs, ranging from fair to dark, except when hairs are absent in the shaft depending on the stage of their growth cycle. This results in the necessity of a few treatments or touchups. Adverse effects are minimal and transient.

Female↗
PubMed1997

Laser-assisted hair removal by selective photothermolysis. Preliminary results.

BACKGROUND: Laser-assisted hair removal with the long pulsed ruby laser is a promising new technique based on selectively targeting melanin in hair follicles. OBJECTIVE: The purpose of this study was to evaluate the efficacy and safety of the long pulsed ruby laser (EpiTouch) for hair removal. METHODS: The Epitouch laser was used for hair removal of the arms of 20 patients. The areas were evaluated immediately post-treatment, and at 1, 4, 8, and 12 weeks, for efficacy and complications. RESULTS: Postoperative results showed 40-80% regrowth after 12 weeks. CONCLUSION: Selective melanin-based photothermolysis with a free running pulsed ruby laser seems to be a promising, noninvasive technique for long-term hair removal. More than one treatment is necessary since only anagen hair will be affected.

Hair Removal↗
PubMedDate not supplied

Measures to decrease the risk of acquired immunodeficiency syndrome transmission by blood transfusion. Evidence of volunteer blood donor cooperation.

We studied whether volunteers giving blood to the Greater New York Blood Program (GNYBP) cooperated with procedures implementing public health recommendations intended to decrease the risk of acquired immunodeficiency syndrome (AIDS) transmission by blood transfusion. Predonation medical screening was expanded to exclude donors who might be ill with AIDS. To exclude possible asymptomatic carriers of the disease, members of groups at increased risk of AIDS were asked either not to give blood or to give it for laboratory studies. A confidential questionnaire, administered to all donors after medical screening, provided the vehicle for donors to advise the GNYBP whether their donation was for laboratory studies or for patient transfusion. We found that the number of male donors decreased; AIDS-related questions in medical history led to a 2 percent increase in donor rejections; 97 percent of donors said their blood could be used for transfusions; 1.4 percent said their blood could be used for laboratory studies only; and 1.6 percent did not respond. Only units designated for transfusion were released to hospitals. People who indicated that their donation was for laboratory studies had a higher prevalence of markers for hepatitis B virus and of antibodies to cytomegalovirus. White cell counts and helper/suppressor T lymphocyte ratios were not significantly different in the two groups. We conclude that volunteer donors have cooperated with the established procedures. None of the laboratory assays identified blood units donated by individuals who, based on information about AIDS high-risk groups, designated their donation for laboratory studies.

Acquired Immunodeficiency Syndrome↗