Alpha-synuclein seeds of Parkinson's disease show high prion-exceeding resistance to steam sterilization.

BACKGROUND: Cerebral deposition of abnormally misfolded and aggregated alpha-synuclein (αSyn) is a neuropathological hallmark of Parkinson's disease (PD). Pathologically aggregated αSyn species of PD (αSynPD) can act, in a 'prion-like' manner, as proteinaceous nuclei ('seeds') which are capable of self-templated propagation. This has raised concerns that αSynPD seeds transmitted iatrogenically between humans may stimulate αSyn pathologies or clinically harmful effects in the recipients. Effective decontamination when reprocessing medical devices could significantly counteract such risks. Steam sterilization at 134°C is recommended as an essential pathogen inactivation step in many reprocessing guidelines for medical devices, and also shows effectiveness against prions, the self-propagating biological agents long thought to exhibit the highest resistance to steam sterilization. METHODS: This study examined the reduction in αSynPD seeding activity in brain tissue homogenates from patients with PD after steam sterilization at 134°C using a specifically adapted real-time quaking induced conversion assay. FINDINGS: Titres of approximately 1010 50% seeding doses per gram were detected in non-steam-sterilized caudate nucleus tissue of patients with PD by endpoint titration. Five minutes of steam sterilization reduced this titre by only 2.25 ± 0.15 decadic-logarithmic units, with an extension of the sterilization time to 90 min not causing additional inactivation. These findings reveal that αSynPD species are disease-associated biological agents with seeding activity that has higher resistance to steam sterilization than prions. CONCLUSION: The remarkable heat resistance of αSynPD seeds calls for thoroughly validated cleaning and disinfection methods that reliably remove or inactivate possible contaminations of seeding-active αSyn aggregates when reprocessing medical devices.

The use of round ended needles for high dose rate brachytherapy implants.

The use of Speiser needles for interstitial implants has resulted in malfunctioning of HDR afterloading equipment due to seepage of blood. We have successfully used rounded ended needles in the patient after removal of the trocar ended needles, preventing the seepage of blood. This technique also helps to prevent any possible cross contamination between patients.

Local shielding of high dose rate brachytherapy in an operating theatre.

A high-dose rate brachytherapy facility was installed into an established operating theatre by using local shielding in the form of mobile lead screens and by taking advantage of the ease with which staff movements can be controlled in an operating suite. This facility was inexpensive to develop, and has proved clinically efficient and entirely adequate from a radiation safety standpoint.

ZD2767, an improved system for antibody-directed enzyme prodrug therapy that results in tumor regressions in colorectal tumor xenografts.

ZD2767 represents an improved version of antibody-directed enzyme prodrug therapy. It consists of a conjugate of the F(ab')2 A5B7 antibody fragment and carboxypeptidase G2 (CPG2) and a prodrug, 4-[N,N-bis(2-iodoethyl)amino]phenoxycarbonyl L-glutamic acid. The IC50 of the prodrug against LoVo colorectal tumor cells was 47 microM, and cleavage by CPG2 released the potent bis-iodo phenol mustard drug (IC50 = 0.34 microM). The drug killed both proliferating and quiescent LoVo cells. Administration of the ZD2767 conjugate to nude mice bearing LoVo colorectal xenografts resulted in approximately 1% of injected ZD2767 conjugate localizing/g of tumor after 72 h, and blood and normal tissue levels of the conjugate were 10-50-fold lower. A single round of therapy involving the administration of the prodrug 72 h after the conjugate to athymic mice bearing established LoVo xenografts resulted in approximately 50% of the tumors undergoing complete regressions, tumor growth delays greater than 30 days, and little toxicity (as judged by body-weight loss). Similar studies using a control antibody-CPG2 conjugate that does not bind to LoVo tumor cells resulted in a growth delay of less than 5 days, confirming the tumor specificity of this approach. These studies demonstrate the potential of ZD2767 for the treatment of colorectal cancer.

Protocols constructed around the nursing process. 3: Autonomic dysreflexia.

Autonomic dysreflexia is a serious problem in patients with spinal cord lesions above the fifth thoracic level. This nursing protocol outlines assessment, diagnosis, and interventions for nurses and physicians and lists appropriate medications.

Protocols constructed around the nursing process. 2: Oral contraceptives.

The author offers detailed procedures for RNs and NPs who provide oral contraceptives to students through a college health service. She includes an outline of necessary subjective assessments, objective examinations, and laboratory work, and includes a list of absolute contraindications, strong relative contraindications, and other situations that may indicate that it would be unwise to provide oral contraceptives to students. Interventions for the registered nurse and nurse practitioner are described and schedules for follow-up visits are given.

PIP: A protocol is described which can be used by nurses and nurse practitioners who provide oral contraceptives (OCs) to college students. A list of relevant and necessary subjective, objective, and laboratory assessments is given; contraindications are defined and categorized as absolute, strong relative (which require refer to a physician) and possibly relative (which require consultation with a physician). The latter are further categorized as those which may contraindicate initiation of OCs and those which require careful observation of the women after initiation of OCs. The protocol includes a plan of appropriate activities for registered nurses, nurse practitioners, patient education, and follow-up visits.

A comparison of the accumulation of novobiocin into bacteria with its antibacterial properties.

The accumulation of novobiocin in bacteria has been compared with the MIC, inhibition of DNA biosynthesis and inhibition of the activity of isolated DNA gyrase for a range of species. There was a good correlation between MIC and the inhibition of DNA biosynthesis and DNA gyrase. Novobiocin accumulation did not correlate with any other parameter.

Protocols constructed around the nursing process. 1: Asthma.

The author provides a nursing process style protocol for dealing with acute attacks of bronchial asthma in adult patients. Diagnoses, laboratory work, tests, treatment plans, including interventions for nurses, nurse practitioners, and physicians, are outlined. In addition, possible complications of bronchial asthma are listed and suggestions for patient education are offered.

The accumulation of novobiocin by Escherichia coli and Staphylococcus aureus.

The accumulation of novobiocin by Escherichia coli was shown to be a nonsaturable process. Inhibitors or uncouplers of respiration had no effect on accumulation in cells grown in Isosensitest broth, whereas, bacteria grown in nutrient broth demonstrated an energy-dependent efflux mechanism. In contrast, accumulation of novobiocin by Staphylococcus aureus was found to have a Km of 74 microM and uncouplers and inhibitors of respiration reduced the accumulation suggesting that in S. aureus novobiocin is transported actively.

(6S)-6-fluoroshikimic acid, an antibacterial agent acting on the aromatic biosynthetic pathway.

(6S)-6-Fluoroshikimic acid inhibited the growth of Escherichia coli B on minimal medium (MIC, 0.25 micrograms ml-1), and it protected mice challenged intraperitoneally with the same organism (50% protective dose, 0.06 mg kg of body weight-1). We propose that inhibitors of bacterial aromatic biosynthesis have the potential for use in human medicine.

Comparison of the cellular internalization of antibodies used either as immunotoxins or in ADEPT.

The internalization into tumor cells of two antibodies (C242 and 454A12), which make potent immunotoxins when linked to ricin A-chain, and an antibody (A5B7), which does not make a potent immunotoxin but has proven useful in ADEPT, was evaluated. The 454A12 antibody was rapidly taken into the cells, 50% of the antibody being internalized after 2 h. The C242 antibody was internalized more slowly, approx 50% being taken up by the cells in 24 h. With A5B7, less than 10% of the antibody was internalized after 24 h. Internalization of the C242 antibody was accompanied by the appearance of antibody degradation products in the cell medium after 2 h, and this degradation could be inhibited by addition of a metabolic inhibitor that prevented cell internalization. In contrast, minimal degradation of the A5B7 antibody could be detected up to 24 h after binding to the cells. In conclusion, both 454A12 and C242 antibodies, which make potent immunotoxins, were internalized into tumor cells. The A5B7 antibody, which does not make a potent immunotoxin, was not internalized, and this property may be one reason why A5B7 has proved useful for delivery of enzymes in ADEPT.

Life events and breast cancer prognosis.

OBJECTIVE: To determine whether psychosocial stress, in the form of adverse life events and social difficulties, depressive illness, or lack of confiding relationships, shortens the postoperative disease free interval in breast cancer patients. DESIGN: Prospective follow up of a cohort of newly diagnosed breast cancer patients for 42 months after primary surgical treatment, using a life events and social difficulties schedule (LEDS) and assessment of depressive symptomatology (DSM-III). SETTING: Patients recruited from breast clinics in Southampton and Portsmouth were interviewed in their homes. PATIENTS: 204 women (83% of 246 consecutive cases) treated either by mastectomy or wide excision followed by radiotherapy interviewed four, 24, and 42 months after operation. MAIN OUTCOME MEASURES: Hazard ratios for relapse of breast cancer in relation to various measures of psychosocial stress. Relapse was defined as local recurrence or distant metastasis, or both, with histological or radiological confirmation and timed from the month when clinical symptoms began. RESULTS: After adjustment for age and axillary lymph node involvement, the hazard ratio associated with severe life events or social difficulties (excluding "own health" ones), or both, during the year before breast cancer surgery was 0.43 (95% confidence interval 0.20 to 0.93); for those during the follow up period it was 0.88 (0.48 to 1.64). For prolonged major depression before surgery and during the follow up period, hazard ratios were 1.26 (0.49 to 3.26) and 0.85 (0.41 to 1.79) respectively. For absence of a full confidant the figures were 0.93 (0.42 to 2.09) and 0.86 (0.38 to 1.93). CONCLUSION: These results give no support to the theory that psychosocial stress contributes to relapse of breast cancer.

Biochemical changes associated with the antifungal action of the triazole ICI 153,066 on Candida albicans and Trichophyton quinckeanum.

The triazole antifungal agent, ICI 153,066, acts on Candida albicans and Trichophyton quinckeanum by inhibiting demethylation of the sterol ring. In C. albicans this is at the level of lanosterol whereas in T. quinckeanum it is at the level of 24-methylene lanosterol. Inhibition of the demethylation system was shown to be non-competitive, the Vmax of the enzyme was reduced rather than affinity for the substrate lanosterol. The changes in the sterols of C. albicans lead to inhibition of the transport of amino acids into the yeasts which probably resulted from alterations in the membrane bound permeation systems. The reduction in uptake of amino acids was shown to reflect a change in the velocity of transport rather than the affinity of the amino acids for the transport systems.

In vitro stimulation of monocyte tissue factor activity by autologous platelets.

Washed human platelets were found to enhance phytohemagglutinin (PHA)-stimulated tissue factor (TF) synthesis when incubated with autologous mononuclear cell cultures. Furthermore, platelets increased TF synthesis even when no other stimulator was present during the incubation. Experiments utilizing similar cultures derived from blood of patients with Glanzmann's disease, von Willebrand's disease, and platelet storage pool disease indicated that platelets with each of these genetic defects possessed the capacity to enhance the synthesis of this initiator of coagulation by unstimulated cells as did normal platelets. The degree of platelet enhancement varied between individuals, but for any given donor, the extent of the effect depended on the concentration of platelets used. The effect was demonstrable at platelet/monocyte ratios ranging from a low of approximately 15 to the highest ratio used, about 300. For comparison the ratio of these two cellular elements in normal human blood is estimated to be approximately 1,000. These findings may reflect a relationship between these two cell types that can occur in vivo.