SPECT gallium scanning for lymphoma and infection

Thirty gallium scans, using currently acceptable dosage levels (5-6 mCi) and a conventional rotating gamma camera, were performed on 20 patients with lymphoma or infection. Compared to planar scans, SPECT increased sensitivity and lesion detection from 48% to 89% in lymphoma, and from 50% to 80% in infection. The predictive value of a negative site was 81% in lymphoma and 67% in infection. Gallium utility is markedly increased by SPECT imaging. A normal gallium SPECT scan is highly accurate in ruling out disease.     

Progress toward re‐engineering non‐ribosomal peptide synthetase proteins: a potential new source of pharmacological agents

Many important pharmaceutical agents, including vancomycin, bleomycin, cyclosporin, and several antibiotics, are produced by non‐ribosomal peptide synthetase (NRPS) enzymes in microorganisms. The NRPS pathway produces an extensive library of products using multienzyme complexes acting in an assembly‐line fashion. Engineering an NRPS system to produce an even greater variety of products, some of which may also have beneficial therapeutic value, would be an enormous advantage. Several approaches have been successful in generating novel NRPS products: mutational biosynthesis during which nonnatural substrates are fed to an organism; domain and module swapping between different species to generate hybrid enzymes; and rational site‐directed mutagenesis, based either on phylogeny or computational prediction, intended to switch substrate specificity and produce altered products. This review will highlight the progress in these areas and describe research in the future that will extend the capacity for re‐engineering NRPS systems. Drug Dev. Res. 66:9–18, 2006. © 2006 Wiley‐Liss, Inc.     

A comparison of the effects of climbing fiber deafferentation in adult and weanling rats

The climbing fiber input to the cerebellar cortex was destroyed using both electrolytic and chemical (3-acetylpyridine) lesions. The long-term effects of climbing fiber deafferentation on the ansiform lobule of weanling and adult rats were examined at both the light and electron microscopic levels. Image analysis of Golgi-impregnated Purkinje cells indicated a significantly lower number of smooth branches and spiny branchlets following climbing fiber deafferentation of both adult and weanling rats. The results suggest that the lower number of smooth branches and spiny branchlets following climbing fiber deafferentation of the weanling rat is the result of a loss of postnatal growth rather than transneuronal degeneration. Ultrastructural evidence is provided in confirmation of these quantitative findings. Formation of ectopic dendritic spines was found following climbing fiber deafferentation of the weanling rat, but not the adult. It is shown that ectopic spines and the denervated dendritic thorns of these animals were synaptically innervated by the parallel fiber system and basket axons. The formation of ectopic spines on climbing fiber deafferentated Purkinje cells may represent a form of dendritic plasticity. Ultrastructurally, the dendritic arborizations of weanling deafferentated Purkinje cells showed no signs of transneuronal degeneration. However, the primary response to climbing fiber deafferentation in the adult rat was marked transneuronal degeneration of the Purkinje cell dendrites. It is suggested that the inability of the adult Purkinje cell to form ectopic spines and to replace the excitatory postsynaptic potential of the climbing fiber varicosity is directly related to the Purkinje cell's subsequent transneuronal degeneration.     

Thiazide diuretics and the risk of hip fracture. Results from the Framingham Study

Thiazide diuretics may preserve bone mass and prevent elderly women's osteopenic fractures, but studies have not distinguished between thiazide preparations or examined former users. We performed a case-control study looking at thiazide use and subsequent hip fracture in postmenopausal female members of the Framingham Study cohort. Cases who had experienced a first hip fracture (n = 176) were compared with age-matched controls (n = 672). Results showed a modest protective effect of any recent thiazide use (not significant). However, recent pure thiazide users experienced significant protection against fracture (adjusted odds ratio, 0.31; 95% confidence interval, 0.11 to 0.88), whereas recent users of combination drugs containing thiazides experienced no protection (adjusted odds ratio, 1.16; 95% confidence interval, 0.44 to 3.05). Combination drugs generally contained only 25 mg of hydrochlorothiazide, suggesting that the small amount of thiazide was insufficient to preserve bone mass. Former thiazide users were not protected against fracture. In sum, recent pure thiazide use in women protects against hip fracture.     

The impact of percutaneous transluminal angioplasty on the management of peripheral vascular disease

Percutaneous transluminal angioplasty is a well established technique with wide application, but its place in the overall management of peripheral vascular disease is not well defined. This study compares similar groups of patients with peripheral vascular disease in 1981 and 1984, before and after the introduction of the technique to a district general hospital. More patients are now being investigated and treated and this is almost entirely due to the availability of angioplasty. The rates for surgery have not changed. Percutaneous transluminal angioplasty should therefore be seen as a new and separate form of treatment for peripheral vascular disease, not necessarily influencing or replacing surgery, and requiring its own allocation of resources in accordance with the increase in the level of care afforded by the technique.     

A review of lacrimal drainage surgery

The advent of improved silicone intubation sets, increased understanding of lacrimal and nasal anatomy and physiology, and refinements in surgical instrumentation and technique have led to higher success rates in lacrimal surgery. Recent clinical studies, combined with new techniques in canalicular reconstruction, have helped identify which patients will benefit from surgical intervention and which techniques are indicated. Fortunately, this has greatly reduced the number of CDCRs necessary.     

Distribution and prevalence of Octomyomermis troglodytis (Nematoda: Mermithidae), a parasite of the western tree hole mosquito, Aedes sierrensis

Octomyomermis troglodytis was found infecting Aedes sierrensis larvae in 14.5% of 165 tree holes sampled between 1982 and 1986. Mermithid infections were detected in tree hole waters that ranged in pH from 6.5 to 9.3 and electrical conductivities between 0.10 and 5.11 mmhos/cm. Third and fourth instar larvae were most frequently infected, and most immatures that succumbed to infections died while in the fourth instar. Most hosts contained only one nematode. Infected adults were obtained from emergence traps over tree holes, from field-collected immatures reared in the laboratory, and from mosquito collections from sentinel humans. Octomyomermis troglodytis escaped from adults into water vials in the laboratory, suggesting that infected adult mosquitoes serve as dispersal agents for this parasite.