Study of movement disorders and brain iron by MR.

Heavily T2-weighted high-field MR images provide a unique opportunity for the evaluation of the extrapyramidal motor system. The images are affected by the presence of small amounts of naturally occurring paramagnetic substances--principally iron--that delineate the neostriatum (caudate and putamen), globus pallidus, red nucleus, substantia nigra, and dentate nucleus, primarily by a decrease in signal secondary to the T2* effect. Movement disorders are associated with either increased or decreased signal or both in these structures, depending on the pathologic process.

Complicated cholesteatomas: CT findings in inner ear complications of middle ear cholesteatomas.

Patients with facial palsy and middle ear disease, which may be chronic but clinically occult, may have a cholesteatoma with extension medially along the facial canal. In two patients, axial computed tomographic (CT) scans demonstrated involvement of the medial petrous bone. Patients with vertigo and chronic middle ear disease may have a cholesteatoma with a "fistula" between the middle and inner ears.

The entrepreneurial revolution in health care delivery.

The rapid changes in the health marketplace have opened the door for entrepreneurs. The author shows how entrepreneurs seek previously unthought of solutions to problems and through a team effort increase corporate value. According to the author, there is a specific profile of the successful entrepreneur.

The opacified maxillary sinus: CT findings in chronic sinusitis and malignant tumors.

To distinguish opacification owing to inflammatory conditions (sinusitis) from that caused by nasomaxillary malignancy, computed tomography scans in 24 proved cases of sinusitis or tumor were reviewed for features related to sinus size, wall thickness, and character of bone erosion. An anatomic system was defined for classifying lesions according to the surface and type of bony involvement. In 12 cases of chronic maxillary sinusitis, the involved sinus was usually small and thick walled.

Mechanism of action of some bioreducible 2-nitroimidazoles: comparison of in vitro cytotoxicity and ability to induce DNA strand breakage.

The interaction of a series of nitroimidazole-aziridine radiosensitisers, as parent or radiation-reduced species, with plasmid DNA in aqueous solution at pH7 results in strand breakage. The efficiency of strand breakage substantially increases on reduction of the nitroimidazole analogues. The rate of production of strand breaks decreases on interaction with both parent and reduced nitroimidazole analogues as the aziridine moiety is deactivated through alkyl-substitution.

The age threshold for isoniazid chemoprophylaxis. A decision analysis for low-risk tuberculin reactors.

Isoniazid chemoprophylaxis recommendations include its use in persons who have positive tuberculin reactions, but neither recent conversion nor other activation risk factors, only if they are under age 35 years. Above this threshold, the isoniazid hepatitis risk is said to outweigh the benefit of preventing activation. Because this policy is controversial, we performed a decision analysis contrasting those who take with those who decline isoniazid therapy according to three outcome measures: life expectancy, likelihood of illness (isoniazid hepatitis and active tuberculosis), and likelihood of fatal illness.

Induction of DNA strand breaks by reduced nitroimidazoles. Implications for DNA base damage.

Radiation-reduced 2-nitroimidazoles (misonidazole, RSU-1137, Ro.03-8799 and Ro.03-8800) incubated in air with plasmid DNA (pH 7.

The phosphate-group of DNA as a potential target for RSU-1069, a nitroimidazole-aziridine radiosensitizer.

Strand breakage of plasmid DNA by parent and radiation-reduced RSU-1069 (2.0-8.0 mmol dm-3) has been measured in air over 4 hr at 310K.

Studies on the mechanisms of the radiosensitizing and cytotoxic properties of RSU-1069 and its analogues.

RSU 1069 is a substantially more efficient sensitizer than misonidazole when hypoxic Chinese hamster V79 cells are irradiated in vitro at room temperature; such that for 0.5 mmol dm-3 sensitizer an ER of 3.0 is obtained for RSU 1069 whereas an ER of only 1.

Immunoassays for low concentrations of albumin in urine.

We have developed and validated simple, rapid immunoassays to measure concentrations of albumin in urine ranging from 5 to 200 mg/L. We use antiserum to human albumin, raised in sheep, and we separate the antibody-bound and free fractions of albumin by using a second antiserum, produced in donkeys, against the Fc fragment of sheep IgG. These two antisera can be mixed and added to assay tubes as a single reagent without inhibiting antigen binding.

Interaction of the aziridine moiety of RSU-1069 with nucleotides and inorganic phosphate. Implications for alkylation of DNA.

The aziridine moiety of RSU-1069 (1-(2-nitro-1-imidazolyl)-3-(1-aziridino-2-propanol] alkylates inorganic phosphate and a range of nucleotides in aqueous solutions of pH 7.0. From the rate constants obtained and a study of the adducts formed it is demonstrated that phosphate is a major target on nucleotides at neutral pH, although additional sites may exist particularly on dGMP and dAMP.

Children with autistic behavior in a self-contained unit in the public schools.

The diagnosis of "autism" has been used to encompass a heterogeneous group of children who may differ in etiology, clinical manifestations, prognosis, and needed treatment. This paper presents the results of a comprehensive evaluation, using strict diagnostic criteria, of 33 children comprising the entire population of a self-contained unit for "autistic" children in the public school system of Hillsborough County, Florida. Only five of the children fit the criteria for early infantile autism.

The differential cytotoxicity of RSU 1069: cell survival studies indicating interaction with DNA as a possible mode of action.

The hypoxic cell radiosensitizer RSU 1069 (1-(2-nitro-1-imidazolyl)-3-(1-aziridinyl)-2-propanol) shows, on a concentration basis, a 100-fold greater toxicity towards hypoxic relative to aerobic cells. This toxicity is substantially greater than that of misonidazole, a compound of similar electron affinity. Reductive processes are important for hypoxic toxicity; this is demonstrated by the fact that misonidazole, in excess, can protect against the hypoxic but not aerobic toxicity of RSU 1069.

CT of pineal region tumors.

The computed tomographic (CT) features of pineal region tumors were analyzed in 60 histologically proven tumors. This is the largest reported series of histologically verified pineal region tumors studied with CT. The tumors were classified as germ-cell tumors, glial tumors, pineal parenchymal tumors, and meningiomas.

Induction of DNA strand breaks by RSU-1069, a nitroimidazole-aziridine radiosensitizer. Role of binding of both unreduced and radiation-reduced forms to DNA, in vitro.

[2-14C]-RSU-1069 [1-(2-nitro-1-imidazolyl)-3-(1-aziridino)-2-propanol], either as a parent (unreduced) or following radiation reduction, binds to calf thymus DNA in vitro. Radiation-reduced RSU-1069 binds to a greater extent and more rapidly than the parent compound. RSU-1137, a nonaziridino analogue of RSU-1069, binds following radiation reduction.

Lumbar puncture in asymptomatic late syphilis. An analysis of the benefits and risks.

We evaluated the treatment of asymptomatic patients with untreated syphilis of more than one year's duration (asymptomatic late syphilis) using a decision-analysis model. Two strategies were compared: treatment with 7.2 million units of penicillin G benzathine, or performing a lumbar puncture to test for asymptomatic neurosyphilis followed by penicillin and management based on cerebrospinal fluid analysis.