Holistic nursing in New Zealand

New Zealand nurses are active and dynamic emerging holistic practitioners. Despite an economic recession and dramatic changes in their health care delivery systems, the country's holistic nurses have mobilized to develop and begin a holistic nurses' association. Holistic nurses from both islands have begun independent practices using complementary therapies and modalities. Although New Zealand is distant from North America geographically, there have been increasing numbers of exchange visits and subsequent influence on international holistic nursing practice. New Zealand, being a lush, green, clean, semitropical country in the South Pacific, is a wonderful place for North American nurses to experience cross-cultural nursing while still being in an English-speaking country.

Nitric oxide and prostanoids protect the renal outer medulla from radiocontrast toxicity in the rat

Human radiocontrast nephrotoxicity is predicted by the presence of multiple risk factors, often associated with compromised renal circulation. To produce a simple model of radiocontrast nephropathy, rats were pretreated with indomethacin and N omega-nitro-L-arginine methyl ester (L-NAME, to inhibit nitric oxide synthesis) before the administration of iothalamate. Acute renal failure consistently developed, with a decline in creatinine clearance from 1.05 +/- 0.10 to 0.27 +/- 0.05 ml/min (P < 0.001) associated with selective necrosis of 49 +/- 9% of medullary thick ascending limbs. Hemodynamic studies using laser-Doppler probes revealed that when injected alone, iothalamate increased outer medullary blood flow to 196 +/- 25% of baseline (P < 0.001). Pretreatment by L-NAME or indomethacin both reduced basal medullary blood flow and transformed the medullary vasodilator response to radiocontrast into vasoconstriction, with a prolonged reduction of medullary blood flow to less then half of baseline. Combined administration of indomethacin, L-NAME, and iothalamate lowered medullary blood flow to 12 +/- 4% of baseline. We conclude that prostanoids and nitric oxide have an important protective role in the renal response to radiocontrast material. Reduced synthesis of these vasoactive substances in renal/vascular diseases may predispose patients to radiocontrast nephropathy.

Relationship of oral microflora with oral health status in Parkinson's disease

Parkinson's disease (PD) patients report an increased craving for sweets, which may have an effect on microflora. We compared patients of PD who crave sweets with PD patients who do not. Age- and sex-matched control subjects were used, with 14 subjects in each group. A plaque sample was taken from tooth #18 with a curette and placed into RTF, homogenized, and plated onto selective and non-selective media. Microflora were expressed as % CFU's of total anaerobes. Statistical analysis was performed by ANOVA and Newman-Keuls on log-transformed data. No statistical difference was observed among the three groups for lactobacilli, bacteroides, fusobacteria, veillonella, and actinomyces. S. mutans was lower in controls than in PD patients. Apparently, the craving for sweets in PD patients does not result in a significant increase in % of total anaerobes of certain microflora. PD patients showed a significant increase in mucositis compared with the control groups.

Intraocular pressure after neodymium:YAG laser treatments in the anterior segment

Intraocular pressure (IOP) increase soon after neodymium:YAG (Nd:YAG) treatments in the anterior segment has been reported. To evaluate this complication in a large sample of patients, we conducted a retrospective study of all Nd:YAG treatments during three years. Three hundred forty capsulotomies and 212 iridotomies were performed with the Q-switched Nd:YAG laser. An IOP elevation of 10 mm Hg or more within two hours of laser surgery was seen in 15 eyes (4.4%) that had a capsulotomy but in 45 eyes (21.2%) that had an iridotomy. In 13 of the 15 eyes in which the IOP increased after capsulotomy, additional risk factors (glaucoma, high myopia, aphakia) were found. Our results indicate that posterior capsulotomy with the Nd:YAG laser in otherwise healthy, pseudophakic eyes is usually not accompanied by immediate IOP elevation. Elevation can be predicted by risk factors and therefore anticipated in a small group of vulnerable patients.

The antimicrobial action of chlorhexidine-containing zinc-phosphate cement

In this study chlorhexidine dihydrochloride and diacetate salts were incorporated at a low level into a zinc-phosphate luting cement. Inhibition of three cariogenic organisms by cement specimens aged up to 8 weeks was significantly greater than the bacterial inhibition of unaltered zinc-phosphate cement. The addition of chlorhexidine caused no significant degradation in strength, film thickness, or solubility of the cement.

Loop diuretics reduce hypoxic damage to proximal tubules of the isolated perfused rat kidney

The straight portion (S3) of the proximal tubule lies in close proximity to the thick ascending limbs (TALs) at the cortico-medullary junction. Since a delicate balance exists between oxygen demand and the limited oxygen supply in this region, we hypothesized that reduction of thick limb metabolic activity might augment oxygen availability to S3 segments, which depend heavily upon aerobic metabolism, and prevent hypoxic damage. The degree of functional deterioration and morphological damage to S3 was assessed in isolated rat kidneys perfused with an erythrocyte-free medium. Bumetanide (10(-5) M) and furosemide (10(-4) M) reduced S3 fragmentation from 9.8 +/- 3.9% of tubules in controls to 0 and 1.4 +/- 0.9%, respectively (P < 0.0005). Tubular glucose reabsorption was better preserved in kidneys exposed to loop diuretics than in control kidneys (P < 0.01), and urinary alkaline phosphatase (P < 0.05) and the total amount of LDH released into the perfusate and urine (P < 0.01) were lower in the treatment groups. Morphological damage to S3 was closely correlated with medullary TAL necrosis (r = 0.66, P < 0.001), urinary alkaline phosphatase excretion (r = 0.89, P < 0.001) and glycosuria (r = 0.83, P < 0.001). We conclude that under hypoxic conditions TALs and S3 segments may compete with each other for a limited oxygen supply. Reduction of active transport in the mTAL might augment oxygen availability to S3 segments and improve their survival.

Activation of bovine factor IX by the reaction product of bovine factor VII and human tissue factor

A study was carried out on the alternate activation of factor IX (FIX) by bovine FVII and human tissue factor (TF) rather than by activated factor XI (FXIa). The reaction product of bovine FVII and human TF functioned as a FIX activator in the assay system used. Published studies suggest that in the presence of Ca2+ ions, the complex of human FVII-TF readily activates both human FIX and human FX, and at low TF concentrations, FIX appears to be the preferred substrate for the reaction product of FVII and TF. This may explain the discrepancy between the mild bleeding of hereditary FXI deficiency and the severe bleeding of hereditary FIX deficiency. The results obtained with bovine FVII and a crude human TF preparation confirm that at low TF concentrations, bovine FIX is the preferred substrate rather than FX. At higher TF concentrations, bovine FX was rapidly activated.

Experimental nephrotoxicity, hepatotoxicity and pharmacokinetics of cyclosporin G versus cyclosporin A

Cyclosporin G (CsG) is an analogue of cyclosporin A (CsA) with strong immunosuppressive activity. We compared these two drugs in a rat model in which salt depletion promotes irreversible renal interstitial fibrosis with renal dysfunction in animals given CsA for three weeks. When both drugs were given in the same dosage on a weight basis (15 mg/kg/day, subcutaneously), CsA blood levels were higher than CsG (3305 vs. 1824 ng/ml, P < 0.001). This could be explained by a higher CsG clearance (6.4 vs. 4.3 ml/min/kg in CsA, P < 0.0001) resulting in smaller CsG area under the curve. There was also lower renal and hepatic CsG tissue concentrations. CsA induced a dramatic decrease in GFR, 0.14 in CsA versus 0.67 ml/min/100 g in control, P < 0.001, and increased urinary excretion of N-acetyl beta-D-glucosaminidase (NAG), 21 in CsA versus 13 IU/gCr in control rats, P < 0.001. CsG-treated and control rats had similar GFR and urinary NAG. When CsA dosage was decreased to 7.5 mg/kg blood levels were similar to those found with CsG 15 mg/kg. CsA at this dose caused a reduced GFR (0.29 ml/min/100 g) and an increased urinary NAG (20 IU/gCr) (P < 0.01 vs. control for both). Both dosages of CsA induced considerable cortical and medullary injury (interstitial fibrosis and tubular atrophy), more severe than the histological damage found in CsG-treated rats. Neither drug promoted significant changes in liver function or histology.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterising auditory filter nonlinearity

An important aspect of auditory nonlinearity is that psychoacoustically measured auditory filters broaden as the level at which they are measured increases. However, it is not yet clear whether the change in filter shape is controlled primarily by the level of the probe or that of the masker. We have therefore developed a new method for fitting filter shapes to notched-noise data in which filter parameters depend explicitly on signal level (either probe or masker). By applying this technique to a set of notched-noise data in which both fixed-probe and fixed-masker paradigms have been used at a range of levels, we have been able to show that models in which filter parameters depend on probe level are considerably more successful than models in which filter parameters depend upon masker level. The results from this new procedure have enabled us to describe the nonlinear changes in auditory filter shape at 2 kHz with only five parameters. Also discussed are the implications of these findings for the generation of excitation patterns and for the computational implementation of simple, yet reasonably realistic nonlinear auditory filters whose shape depends on their output.

Effects of salt depletion on the kidney: changes in medullary oxygenation and thick ascending limb size

Previous studies have shown that salt depletion enhances the susceptibility of the kidney to nephrotoxins (amphotericin, cyclosporine, and contrast). To study the renal response to salt depletion, Sprague-Dawley rats were fed a sodium-deficient diet (N = 12) with pair-fed controls (N = 13) for 4 wk. In addition, rats from each group underwent 24-h water deprivation studies (N = 9; four salt deprived, five normal). Plastic 1-micron horizontal sections of mid-inner stripe were examined, and cross-sectional areas of the medullary thick ascending limb (mTAL) were analyzed. The mTAL of the salt-deprived rats were smaller (P = 0.04) and showed greater variance in size (P = 0.02) than control (618 +/- 106 versus 693 +/- 50 microns2). However, mean glomerular and collecting duct cross-sectional areas were unaffected by salt intake. Cross-sectional areas of long- and short-loop mTAL were significantly different, regardless of group (518 +/- 78 versus 732 +/- 92 microns2). Maximal urinary concentrating ability was found to correlate with mTAL cross-sectional area (r = 0.85; P = 0.004) and with long-loop mTAL size (r = 0.77; P = 0.016). However, it did not significantly correlate with short loop mTAL size (r = 0.53; P = 0.14).(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic reflexes in the measurement of auditory filters at high levels in normal listeners

The possible influence of the acoustic reflex in auditory filter shape measurements was investigated in 4 normal listeners by measuring contralateral acoustic reflexes to stimuli used in the notched-noise method. For probe/masker combinations centred at 125 and 250 Hz, the reflex was, at most, barely detectable even at masker levels of 80 dB SPL/Hz. On the other hand, all listeners had a measurable reflex at a masker level of 70 dB SPL/Hz for a probe/masker combination centred at 1 kHz. Some listeners also evidenced reflexes at a masker level of 60 kB SPL/Hz at this frequency and at 70 dB SPL/Hz at 500 Hz. As it is known that the acoustic reflex significantly attenuates frequency components of sounds below about 2 kHz as they pass through the middle ear, it appears that estimates of auditory filter bandwidths at high levels at 0.5 and 1 kHz can be influenced to some degree by the reflex.

Dissociation of glomerular filtration rate from tubulointerstitial fibrosis in experimental chronic cyclosporine nephropathy: role of sodium intake

In addition to its well-recognized ability to provoke acute renal dysfunction by promoting intense renal vasoconstriction, cyclosporine produces a chronic tubulointerstitial nephropathy characterized by striped interstitial fibrosis in humans. With a model of chronic cyclosporine nephropathy in which striped fibrosis develops in the uninephrectomized salt-depleted rat, the relationship between renal functional impairment and structural changes was studied during cyclosporine treatment and after its withdrawal in order to ascertain the natural history of this lesion. Groups of uninephrectomized rats maintained on a salt-depleted (-NaCl) or salt-replete (+NaCl) diet were treated with cyclosporine, 15 mg/kg per day, or vehicle by sc injection. GFR and morphology were assessed at 14 and 28 days of treatment and at intervals up to 28 days after drug withdrawal. Although GFR was similarly depressed in cyclosporine-treated animals on either diet (P < 0.001 versus vehicle), tubulointerstitial injury was largely confined to cyclosporine-treated rats on the -NaCl diet (P < 0.001 versus cyclosporine/+NaCl and vehicle). At 28 days after the withdrawal of cyclosporine, there was a marked discordance between renal structure and function in the cyclosporine/-NaCl group as GFR returned toward normal (P > 0.05 versus cyclosporine/+NaCl) but prominent tubulointerstitial injury persisted and, in some instances, even progressed (P < 0.001 versus cyclosporine/+NaCl and vehicle). Thus, sodium intake emerges as an important determinant of structural tubulointerstitial changes, whereas reductions in GFR during cyclosporine therapy are equivalent in sodium-depleted or sodium-replete animals.

Lip-reading the BKB sentence lists: corrections for list and practice effects

Two groups of 21 adult subjects with normal hearing viewed the video recordings of the Bamford-Kowal-Bench standard sentence lists issued by the EPI Group in 1986. Each subject viewed all of the 21 lists and attempted to write down the words contained in each sentence. One group lip-read the lists with no sound (the LR:alone condition). The other group also heard a sequence of acoustic pulses which were synchronized to the moments when the talker's vocal folds closed (the LR&Lx condition). Performance was assessed both by loose (KW(L)) and by tight (KW(T)) keyword scoring methods. Both scoring methods produced the same pattern of results: performance was better in the LR&Lx condition; performance in both conditions improved linearly with the logarithm of the list presentation order number; subjects who produced higher overall scores also improved more with experience of the lists. The data were described well by a logistic regression model which provided a formula which can be used to compensate for practice effects and for differences in difficulty between lists. Two simpler, but less accurate, methods for compensating for variation in inter-list difficulty are also described. A figure is provided which can be used to assess the significance of the difference between a pair of scores obtained from a single subject in any pair of presentation conditions.

Chronic amphotericin nephropathy: morphometric, electron microscopic, and functional studies

The two major hypotheses for the pathogenesis of amphotericin nephrotoxicity are direct interaction with epithelial cell membranes and vasoconstriction. Studies indicating the special vulnerability of the medullary ray and medulla to hypoxia led to a reexamination of amphotericin nephrotoxicity. Twenty-four rats were divided into four groups: amphotericin injection (5 mg/kg daily for 3 wk), amphotericin plus salt depletion, vehicle, and salt depletion and vehicle. The amphotericin group had polyuria (P < 0.01) but normal serum creatinine. In contrast, amphotericin plus salt depletion rats exhibited renal failure (creatinine of 1.49 +/- 0.05 versus amphotericin alone 0.98 +/- 0.01; P < 0.01). Semiquantitative histologic analysis of cortical and medullary injury correlated with functional impairment. Cortical changes in the amphotericin group were largely restricted to the medullary ray, where focal rupture and calcification of thick ascending limbs were noted. The S2/S3 tubules in the medullary rays showed focally diminished cell complexity with histiocytic/lymphocytic infiltration. However, calcification was also seen in the area of the macula densa. Morphometry revealed that the thick ascending limbs in the medulla were hypertrophied (1,420 +/- 63 versus 1,195 +/- 48 microns 2 for vehicle; P < 0.05). In contrast, in the amphotericin and salt depletion group, the changes in the medullary ray extended to the labyrinth and the thick ascending limbs in the inner stripe showed atrophic changes (772 +/- 23 microns 2; P < 0.01 versus vehicle). Thus, changes as a result of amphotericin toxicity take place both in areas known to be most vulnerable to hypoxia (medullary ray and medulla), and in areas rich in oxygen (adjacent to glomerulus). Salt depletion potentiates the cortical changes and converts medullary hypertrophy to atrophy. These findings support a dual pathogenesis for amphotericin nephropathy (direct toxicity and vasoconstriction).

Uncomodulated glimpsing in "checkerboard" noise

The ability of listeners to "glimpse" acoustic cues during the quieter sections of an interrupted noise has primarily been studied using maskers with interruptions occurring simultaneously across the entire frequency range of the masker--broadband comodulated interruptions. Here, the possibility of uncomodulated glimpsing (the glimpsing of acoustic cues separated both in time and frequency) was investigated. To achieve this, speech reception thresholds for a set of intervocalic consonants were adaptively measured in 100-Hz to 10-kHz pink noise divided into a varying number of frequency bands of equal energy. In uncomodulated noise conditions, the odd and even numbered bands were switched on and off alternately at a rate of 10 Hz. The spectrograms of such noises (on log frequency scales), resemble portions of a checkerboard. Glimpsing in "checkerboard" noise was found with maskers divided into two and four bands, but not into eight bands or more. Further investigations showed that, in the two-band case, this release from masking was indeed due to uncomodulated glimpsing, and not simply attributable to glimpsing in one of the modulated bands. In the four-band case, the release from masking in checkerboard noise can be accounted for without recourse to uncomodulated glimpsing. Interestingly, conditions which allowed glimpsing resulted in greater intersubject variability. The implications of these results for quantitative analyses of masker fluctuations are discussed.

Production of less chronic nephrotoxicity by cyclosporine G than cyclosporine A in a low-salt rat model

Chronic tubulointerstitial nephropathy during long-term cyclosporine A (CsA) use has led to a search for equally effective but safer analogues. In this study we evaluated one of these analogues, cyclosporine G (CsG), in a rat model of chronic cyclosporine nephrotoxicity. CsG has immunosuppressive effects equivalent to CsA when dosed on a weight basis. Pair-fed Sprague-Dawley rats kept on a low-salt rice diet were given CsA 15 mg/kg, CsG 15 mg/kg, CsG 25 mg/kg, or vehicle subcutaneously. After 21 days, CsA animals had a lower glomerular filtration rate, measured by inulin clearance (0.16 +/- 0.04 ml/min/100 g) and higher serum creatinine (0.94 +/- 0.06 mg/dl) than CsG 15 mg/kg (GFR: 0.41 +/- 0.10 ml/min/100 g and serum creatinine: 0.68 +/- 0.09 mg/dl), CsG 25 mg/kg (GFR: 0.39 +/- 0.16 ml/min/100 g) or control rats (GFR: 0.62 +/- 0.06 ml/min/100 g; serum creatinine: 0.56 +/- 0.03 mg/dl), respectively (P < 0.05). The CsA group had considerable cortical and medullary injury (interstitial fibrosis and tubular atrophy), whereas both groups of CsG animals had more limited changes. Despite the same or larger doses of CsG on a weight basis, cyclosporine blood levels were significantly lower in CsG than CsA rats. We conclude that CsG, an analogue of cyclosporine with immunosuppressive activity equivalent to that of CsA, produced less nephrotoxicity in a model of chronic renal injury in rats, using both functional and structural parameters.

Effects of ioversol versus iothalamate on endothelin release and radiocontrast nephropathy

RATIONALE AND OBJECTIVES

Certain radiocontrast agents, including iothalamate, iohexol, and ioxaglate, release the renal vasoconstrictor peptide endothelin from vascular endothelium in a way that might contribute to radiocontrast nephropathy. The effects of the nonionic, low osmolar agent, ioversol, on endothelin release and renal function are investigated.

METHODS

Effects of ioversol were compared with equi-iodine doses of iothalamate when applied to cultured bovine aortic endothelial cells or injected into normal rats and rats preconditioned by uninephrectomy, salt depletion, and indomethacin (USIC) to develop radiocontrast nephropathy.

RESULTS

In comparison with iothalamate, ioversol had a greatly reduced propensity to stimulate the release of endothelin, from cultured cells and when injected into anesthetized rats. Ioversol produced less renal vasoconstriction than did iothalamate, in control and in USIC rats, and the development of radiocontrast nephropathy, assessed by creatinine clearance and morphologic damage to the renal medulla, was largely avoided.

CONCLUSIONS

These results strengthen the hypothesis that endothelin release induced by radiocontrast agents is correlated with their renal toxicity and therefore, may play a role in radiocontrast nephropathy.