A Model for Empowering Rural Solutions for Cervical Cancer Prevention (He Tapu Te Whare Tangata): Protocol for a Cluster Randomized Crossover Trial

BACKGROUND

Māori are the Indigenous people of Aotearoa (New Zealand). Despite global acceptance that cervical cancer is almost entirely preventable through vaccination and screening, wāhine Māori (Māori women) are more likely to have cervical cancer and 2.5 times more likely to die from it than non-Māori women. Rural Māori residents diagnosed with cervical cancer have worse outcomes than urban residents. Living in rural Aotearoa means experiencing barriers to appropriate and timely health care, resulting from distance, the lack of community resourcing, and low prioritization of rural needs by the health system and government. These barriers are compounded by the current screening processes and referral pathways that create delays at each step. Screening for high-risk human papillomavirus (hrHPV) and point-of-care (POC) testing are scientific advances used globally to prevent cervical cancer.

OBJECTIVE

This study aims to compare acceptability, feasibility, timeliness, referral to, and attendance for colposcopy following hrHPV detection between a community-controlled pathway and standard care.

METHODS

This is a cluster randomized crossover trial, with 2 primary care practices (study sites) as clusters. Each site was randomized to implement either pathway 1 or 2, with crossover occurring at 15 months. Pathway 1 (community-controlled pathway) comprises HPV self-testing, 1-hour POC results, face-to-face information, support, and immediate referral to colposcopy for women with a positive test result. Pathway 2 (standard care) comprises HPV self-testing, laboratory analysis, usual results giving, information, support, and standard referral pathways for women with a positive test result. The primary outcome is the proportion of women with hrHPV-positive results having a colposcopy within 20 working days of the HPV test (national performance indicator). Qualitative research will analyze successes and challenges of both pathways from the perspectives of governance groups, clinical staff, women, and their family. This information will directly inform the new National Cervical Screening Program.

RESULTS

In the first 15-month period, 743 eligible HPV self-tests were performed: 370 in pathway 1 with POC testing and 373 in pathway 2 with laboratory testing. The positivity rate for hrHPV was 7.3% (54/743). Data collection for the second period, qualitative interviews, and analyses are ongoing.

CONCLUSIONS

This Māori-centered study combines quantitative and qualitative research to compare 2 clinical pathways from detection of hrHPV to colposcopy. This protocol draws on rural community practices strengths, successfully engaging Māori from a whānau ora (family wellness) approach including kanohi ki te kanohi (face-to-face), kaiāwhina (nonclinical community health workers), and multiple venues for interventions. It will inform the theory and practice of rural models of the use of innovative technology, addressing Māori cervical cancer inequities and facilitating Māori wellness. The findings are anticipated to be applicable to other Indigenous and rural people in high-income countries.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12621000553875; https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12621000553875.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51643.

He Tapu Te Whare Tangata (sacred house of humanity): Under-screened Māori women talk about HPV self-testing cervical screening clinical pathways

OBJECTIVE

To develop an in-depth understanding of HPV self-testing cervical screening clinical pathways for never-/under-screened Māori women.

METHODS

Based on a community-based cluster randomized controlled trial in Aotearoa (New Zealand), a Kaupapa Māori (by Māori, for Māori) qualitative study enrolled Māori women who met the eligibility criteria of the HPV trial intervention (aged 25-69 years, no screen in >4 years). In total, 28 were recruited (22 had a negative test, six had a positive test and colposcopy). They were asked about their clinical pathway.

RESULTS

The HPV self-test was seen as empowering and promoting bodily autonomy, although some women expressed fears or misconceptions about this new technology. While those with a negative test were relieved, for the six women who had a positive test, there were many fears, compounded by seeking out information on the Internet. When attending colposcopy, the importance of support and responsive care was emphasized.

CONCLUSION

HPV self-testing has the potential to improve access to cervical screening and reduce inequities for Māori. Care must be taken in the delivery of screening and colposcopy results. Primary care and colposcopy services need to take special care with never-/under-screened Māori women to provide sensitive, responsive care, and mitigate trauma.

Examining the potential preventability of adverse fetal/neonatal outcomes associated with severe maternal morbidity

BACKGROUND

Severe maternal morbidity (SMM) occurs in 1-2% of pregnancies. Despite the knowledge that a SMM event can contribute to poor fetal/neonatal outcomes, little is known about the preventability of these adverse outcomes.

AIMS

To examine adverse fetal/neonatal outcomes associated with SMM to determine if these outcomes were potentially preventable.

MATERIALS AND METHODS

A New Zealand national retrospective cohort study examining cases of SMM with an adverse fetal/neonatal outcome. Maternity and initial neonatal care were explored by multidisciplinary panels utilising a preventability tool to assess whether the fetal/neonatal harm was potentially preventable. Adverse fetal/neonatal outcomes were defined as fetal or early neonatal death, Apgar score <7 at five minutes, admission to neonatal intensive care unit or special care baby unit and neonatal encephalopathy.

RESULTS

Of 85 cases reviewed, adverse fetal/neonatal outcome was deemed potentially preventable in 55.3% of cases (n = 47/85). Preventability was related to maternal antenatal/peripartum care (in utero) in 39% (n = 33/85), to initial neonatal care (ex utero) in 36% (n = 29/80), and to both maternal and neonatal care in 20% (16/80) of cases. Main contributors to potential preventability were factors related to healthcare providers, particularly lack of recognition of high risk, delayed or failure to diagnose, and delayed or inappropriate treatment.

CONCLUSIONS

Multidisciplinary panels found that over half of adverse fetal/neonatal harm associated with SMM was potentially preventable. The novel approach of examining both maternal and neonatal care identifies opportunities to improve fetal/neonatal outcomes associated with SMM at multiple points on the perinatal continuum of care.

Reaching under-screened/never-screened indigenous peoples with human papilloma virus self-testing: A community-based cluster randomised controlled trial

BACKGROUND

Indigenous women in the high-income countries of Canada, Australia, New Zealand and USA, have a higher incidence and mortality from cervical cancer than non-Indigenous women. Increasing cervical screening coverage could ultimately decrease cervical cancer disparities.

AIMS

To increase cervical screening for under-screened/never-screened Māori women.

MATERIALS AND METHODS

This study was a cluster randomised controlled trial. Inclusion criteria were women aged 25-69, last screened ≥4 years ago, in Northland, New Zealand. The intervention arm was the offer of a human papilloma virus (HPV) self-test and the control arm was the usual offer of standard care - a cervical smear. The primary outcome was rate of cervical screening in the intervention group compared to control in Māori, the Indigenous peoples of New Zealand. Six primary care clinics were randomly allocated to intervention or control.

RESULTS

Of 500 eligible Māori women in the intervention arm, 295 (59.0%) were screened. Of 431 eligible Māori women in the control arm, 94 (21.8%) were screened. Adjusting for age, time since last screen, deprivation index, Māori women in the intervention arm were 2.8 times more likely to be screened than women in the control arm (95% CI: 2.4-3.1, P-value <0.0001).

CONCLUSIONS

Offer of HPV self-testing could potentially halve the number of under-screened/never-screened Māori women and decrease cervical morbidity and mortality. These results may be generalisable to benefit Indigenous peoples facing similar barriers in other high-income countries.

Examining adverse fetal/neonatal outcomes associated with severe maternal morbidity

BACKGROUND

While there is a global focus on severe maternal morbidity (SMM), less is known about the impact of SMM on fetal and neonatal outcomes.

AIMS

To examine fetal/neonatal outcomes associated with SMM.

MATERIALS AND METHODS

A national New Zealand (NZ) retrospective cohort study describing fetal/neonatal outcomes of all women with SMM admitted to a NZ Intensive Care Unit (ICU) or High Dependency Unit (HDU) in 2014. Adverse fetal/neonatal outcomes were defined as one or more of the following: fetal or early neonatal death, hypoxic ischaemic encephalopathy, Apgar score less than seven at five minutes, admission to Neonatal Intensive Care Unit or Special Care Baby Unit.

RESULTS

There were 400 women with SMM admitted to NZ ICU/HDU units in 2014, and 395 (98.8%) had complete birth/pregnancy outcome information. Of these, 49.4% (195/395) were associated with an adverse fetal/neonatal outcome. Indigenous Māori women had a 30% higher rate of adverse fetal/neonatal outcome compared to NZ European women (63.7% and 48.9% respectively; relative risk = 1.30, 95% CI 1.04-1.64). Pre-eclampsia was associated with an adverse fetal/neonatal outcome in 67% (81/120). Perinatal-related mortality rate was 53.1 per 1000 total births compared to NZ perinatal mortality of 11.2 per 1000 total births for 2014.

CONCLUSION

SMM events are associated with high rates of adverse fetal/neonatal outcomes with a higher burden of adverse events for Māori. Further research is needed to explore opportunities in maternal and neonatal care pathways to improve fetal/neonatal outcomes and address inequities.

Preventability of severe acute maternal morbidity

OBJECTIVE

We sought to assess potential preventability of severe acute maternal morbidity (SAMM) cases admitted to intensive-care units (ICUs) or high-dependency units (HDUs).

STUDY DESIGN

Inclusion criteria were admissions to ICUs or HDUs of women who were pregnant or within 42 days of delivery in 4 District Health Board areas (accounting for a third of annual births in New Zealand) during a 17-month period. Cases were reviewed by external multidisciplinary panels using a validated model for assessing preventability.

RESULTS

In all, 98 SAMM cases were assessed; 38 (38.8%) cases were deemed potentially preventable, 36 (36.7%) not preventable but improvement in care was needed, and 24 (24.5%) not preventable. The most frequent preventable factors were clinician related: delay or failure in diagnosis or recognition of high-risk status (51%); and delay or inappropriate treatment (70%). The most common causes of preventable severe morbidity were blood loss and septicemia.

CONCLUSION

The majority of SAMM cases were potentially preventable or required improvement in care. Themes around substandard care related to delay in diagnosis and treatment for postpartum hemorrhage and septicemia. These findings can inform clinical educational programs and policies to improve maternal outcomes. This study has now been expanded to a national New Zealand audit of all SAMM cases admitted to an ICU/HDU.

The effect of 6-hydroxydopamine on the oestrus cycle and fertility of rats

Increases in the numbers of foetuses resorbed and stillborn are reported in rats after treatment with 6-hydroxydopamine given before and during pregnancy. 6-Hydroxydopamine (100 mg kg−1 i.p.) given before mating had no effect on the oestrus cycle. Intrahypothalamic 6-hydroxydopamine (200 μg) produced a temporary loss of oestrus. However, after mating the injected rats had normal pregnancies despite substantially lower levels of brain noradrenaline.

Unlinked anonymous HIV prevalence among New Zealand sexual health clinic attenders: 2005-2006

This unlinked anonymous study aimed at determining the prevalence of HIV among sexual health clinic attenders having blood samples taken for syphilis and/or hepatitis B serology in six major New Zealand cities over a 12-month period in 2005-2006. Overall, seroprevalence was five per 1000 (47/9439). Among men who have sex with men (MSM), the overall prevalence and that of previously undiagnosed HIV were 44.1 and 20.1 per 1000, respectively. In heterosexual men, the overall prevalence was 1.2 per 1000 and in women 1.4 per 1000. HIV remains to be concentrated among homosexual and bisexual men. Comparison with a previous survey in 1996-1997 suggests an increase in the prevalence of undiagnosed HIV among MSM and also an increase in the number of MSM attending sexual health clinics. The low prevalence of HIV among heterosexuals suggests no extensive spread into the groups identified at risk of other sexually transmitted infections.

Effects of feedborne fusarium mycotoxins on brain regional neurochemistry of turkeys

An experiment was conducted to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins on brain regional neurochemistry of turkeys. The possible preventative effect of a poly-meric glucomannan mycotoxin adsorbent (GMA) was also determined. Forty-five 1-d-old male turkey poults were fed wheat-, corn-, and soybean meal-based diets up to wk 6, formulated with control grains, contaminated grains, or contaminated grains + 0.2% GMA. Deoxynivalenol was the major contaminant, and the concentrations were 2.2 and 3.3 mg/kg of feed during starter and grower phases, respectively. Concentrations of brain monoamine neurotransmitters and metabolites were measured in discrete regions of the brain including the pons, hypothalamus, and cortex by HPLC with electrochemical detection. Neurotransmitters and metabolites analyzed included norepinephrine, dopamine, 3,4-dihydroxyphenylacetic acid, serotonin (5-hydroxytryptamine, 5-HT), and 5-hydroxyindoleacetic acid (5-HIAA). The concentration of 5-HIAA and the 5-HIAA:5-HT-ratio were significantly decreased in pons after feeding contaminated grains. Dietary supplementation with GMA prevented these effects. In the pons, a significant positive correlation (r = 0.52, P < 0.05) was observed between the concentration of 5-HT and BW gain after feeding contaminated diets. The feeding of contaminated diet had no significant effects on the concentrations of neurotransmitters and metabolites in hypothalamus and cortex. It was concluded that consumption of grains naturally contaminated with Fusarium mycotoxins adversely altered the pons serotonergic system of turkeys. Supplementation with GMA partially inhibited these effects.

Effects of Feeding Grains Naturally Contaminated with Fusarium Mycotoxins on Brain Regional Neurochemistry of Laying Hens, Turkey Poults, and Broiler Breeder Hens

Three experiments were conducted to compare the effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on brain regional neurochemistry of laying hens, turkey poults, and broiler breeder hens. In Experiment 1, thirty-six 45-wk-old laying hens were fed diets including the following for 4 wk: 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% polymeric glucomannan mycotoxin adsorbent (GMA). Concentrations of brain neurotransmitters and metabolites were analyzed in pons, hypothalamus, and cortex by HPLC with electrochemical detection. Neurotransmitters and the metabolites measured included dopamine, 3,4-dihydroxylphenyacetic acid, homovanillic acid, serotonin [5-hydroxytryptamine (5-HT)], 5-hydroxyindolacetic acid, epinephrine, and norepinephrine. The feeding of contaminated grains significantly increased concentrations of 5-HT and decreased the 5-hydroxyindolacetic acid:5-HT in the pons region in the brain stem. Dietary supplementation with GMA prevented these effects. There was no effect of diet on concentrations of other neurotransmitters or metabolites in the pons, hypothalamus, or cortex. In Experiment 2, thirty-six 1-d-old turkey poults were fed diets including the following for 4 wk: 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% GMA. Hypothalamic, pons, and cortex neurotransmitter concentrations were not affected by diet. In Experiment 3, forty-two 26-wk-old broiler breeder hens were fed diets including the following for 15 wk: 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% GMA. There was no effect of diet on neurotransmitter concentrations in the pons, hypothalamus, or cortex. It was concluded that differences in intraspecies effects of these mycotoxins on brain neurotransmitter concentrations might explain the intraspecies differences in the severity of Fusarium mycotoxin-induced reductions in feed intake.

The use of an alternative light source to detect semen in clinical forensic medical practice

One of the primary aims of forensic examination in sexual offences is to detect and recover biological material that will link the offender with the complainant. One potentially valuable method by which trace biological evidence may be identified in other forensic settings is via the use of an Alternate Light Source (ALS). The aim of this study was to determine whether or not there was any potential benefit in using an ALS as an adjunct in sexual assault examinations to aid the detection of forensically relevant areas on the body which are not identifiable on visual inspection for sampling. We present two case reports, which illustrate the potential value of using an ALS in clinical forensic medical practice as an adjunct in sexual assault examinations to detect potentially forensically useful areas of skin to sample for semen. Prior to introducing the ALS into our clinical forensic medical practice, we undertook a number of simple laboratory studies to determine a protocol for its use. Semen is known to fluoresce using an ALS at a wavelength of 450 nm. Although we did not conduct a rigorous scientific evaluation of the technique, we evaluated the use of an ALS to detect semen on a range of inanimate surfaces as well as human skin. On all surfaces, visibility of fluorescence was increased by reduced distance of light source from the surface and increased concentration of semen on the surface, but was not noticeably affected by the angle at which the light source was held in relation to the surface.

Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on brain regional neurochemistry of starter pigs and broiler chickens1

Two experiments were conducted to compare the effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on brain regional neurochemistry of starter pigs and broiler chickens. A polymeric glucomannan mycotoxin adsorbent (GM polymer) was also tested for its efficacy in preventing Fusarium mycotoxicoses. In Exp. 1, a total of 150 starter pigs (initial weight = 9.3+/-1.1 kg) were fed five diets (six pens of five pigs per diet) for 21 d. Diets (as-fed basis) included control, 17% contaminated grains, 24.5% contaminated grains, 24.5% contaminated grains + 0.2% GM polymer, and a pair-fed control for comparison with pigs receiving 24.5% contaminated grains. In Exp. 2,360 1-d-old male broiler chicks were fed for 56 d one of four diets containing the same source of contaminated grains as was fed to pigs. The diets included control, 37% contaminated grains, 58% contaminated grains, and 58% contaminated grains + 0.2% GM polymer (as fed). Neurotransmitter concentrations in the cortex, hypothalamus, and pons were analyzed by HPLC. The following brain neurotransmitter alterations (P < or = 0.05) were observed. In pigs, inclusion of contaminated grains in the diet 1) linearly increased cortex 5-hydroxytryptamine (5HT, serotonin) concentrations, while linearly decreasing hypothalamic tryptophan concentrations; 2) quadratically increased hypothalamic and pons 5-hydroxyindoleacetic acid (5HIAA):5HT ratios, whereas the ratio decreased linearly in the cortex; and 3) linearly increased the ratio of hypothalamic 3,4-dihydroxyphenylacetic acid:dopamine (DA) concentrations, whereas hypothalamic norepinephrine (NRE) and pons DA and homovanillic acid (HVA) concentrations linearly decreased. In broiler chickens, inclusion of contaminated grains in the diet 1) linearly increased concentrations of 5HT and 5HIAA in the pons and 5HT concentrations in the cortex; 2) linearly decreased 5HIAA:5HT ratio; and 3) linearly increased pons NRE, 3-methoxy-4-hydroxyphenylethylene glycol, DA, and HVA concentrations. Supplementation of GM polymer to the contaminated diet decreased (P < 0.05) 5HT and 5HIAA concentrations in the cortex of pigs. It was concluded that the differences in alterations of brain neurochemistry might explain the species differences in the severity of Fusarium mycotoxin-induced feed refusal.

Effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on growth and immunological measurements of starter pigs, and the efficacy of a polymeric glucomannan mycotoxin adsorbent1

An experiment was conducted to investigate the effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on growth and immunological parameters of starter pigs. A polymeric glucomannan mycotoxin adsorbent (GM polymer, Alltech Inc., Nicholasville, KY) was also tested for its efficacy in preventing Fusarium mycotoxicoses. A total of 150 starter pigs (initial weight of 9.3 +/- 1.1 kg) were fed one of five treatment diets (six pens of five pigs per diet) for 21 d. Diets included control, low level of contaminated grains, high level of contaminated grains, high level of contaminated grains + 0.20% GM polymer, and pair-fed control for comparison with pigs receiving the high level of contaminated grains. Feed intake and cumulative weight gain of pigs decreased linearly with the inclusion of contaminated grains in the diet throughout the experiment (P < 0.0001). Weight gains recovered, however, during wk 3 (P > 0.05). There was no difference between the pair-fed group and the pigs fed the diet containing the high level of contaminated grains in terms of weight gain or feed efficiency (P > 0.05). Feeding contaminated grains linearly increased the serum albumin:globulin ratio (P = 0.01), whereas serum urea concentrations and gamma-glutamyltransferase activities responded in a quadratic fashion (P = 0.02). When compared with the pair-fed pigs, serum concentrations of total protein (P = 0.01) and globulin (P = 0.02) were decreased in pigs fed the diet containing the high level of contaminated grains. The feeding of contaminated diets did not significantly alter organ weights expressed as a percentage of BW, serum immunoglobulin concentrations, percentages of peripheral blood lymphocyte subsets, contact hypersensitivity to dinitrochlorobenzene, or primary antibody response to sheep red blood cells (P > 0.05). It was concluded that most of the adverse effects of feeding Fusarium mycotoxin-contaminated grains to starter pigs were caused by reduced feed intake. Although supplementation of GM polymer to the contaminated diet prevented some toxin-induced changes in metabolism, it did not prevent the mycotoxin-induced growth depression under the current experimental conditions.

Effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on swine performance, brain regional neurochemistry, and serum chemistry and the efficacy of a polymeric glucomannan mycotoxin adsorbent

The co-occurrence of Fusarium mycotoxins in contaminated swine diets has been shown to result in synergistic toxicity beyond that observed for individual toxins. An experiment was conducted, therefore, to investigate the effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on growth, brain regional neurochemistry, serum immunoglobulin (Ig) concentrations, serum chemistry, hematology, and organ weights of starter pigs. Three levels of glucomannan polymer (GM polymer, extract of yeast cell wall, Alltech Inc.) were also tested for its efficacy to overcome Fusarium mycotoxicoses. A total of 175 starter pigs (initial weight of 10 +/- 1.1 kg) were fed five diets (seven pens of five pigs per diet) for 21 d. Diets included (1) control, (2) blend of contaminated grains, (3) contaminated grains + 0.05% GM polymer (4) contaminated grains + 0.10% GM polymer and (5) contaminated grains + 0.20% GM polymer. Diets containing contaminated grains averaged 5.5 ppm deoxynivalenol, 0.5 ppm 15-acetyldeoxynivalenol, 26.8 ppm fuuric acid, and 0.4 ppm zearalenone. Feed intake and weight gain of all pigs fed contaminated grains was significantly reduced compared to controls throughout the experiment. The weights of liver and kidney, expressed as a percentage of body weight, were lower in pigs fed the contaminated diet than in those fed the control diet. The feeding of contaminated grains significantly reduced concentrations of dopamine in the hypothalamus and pons and concentrations of dihydroxyphenylacetic acid and norepinephrine in the pons. The ratios of 5-hydroxyindoleacetic acid to serotonin, however, were elevated in the hypothalamus and pons. The feeding of contaminated grains increased serum IgM and IgA concentrations, while serum IgG concentrations were not altered. The supplementation of GM polymer prevented some of the mycotoxin-induced alterations in brain neurotransmitter and serum Ig concentrations. In summary, the feeding of grains naturally contaminated with Fusarium mycotoxins reduced growth, altered brain neurochemistry, increased serum Ig concentrations, and decreased organ weights in starter pigs. Some of the Fusarium mycotoxin-induced changes in neurochemistry and serum Ig concentrations can be prevented by the feeding of yeast cell wall polymer at appropriate concentrations, although this was not reflected in increased growth rate under these experimental conditions.

Effect of fusaric acid on brain regional neurochemistry and vomiting behavior in swine

Fusaric (5-butylpicolinic) acid is a phytotoxin produced especially by Fusarium moniliforme, a mold commonly found in Canadian-grown corn. Experiments were conducted to determine the effects of acute doses of fusaric acid on brain neurochemistry and behavior in swine. A total of 40 crossbred barrows (initial weight 10 kg) were orally dosed with 0 or 200 mg of fusaric acid/kg of BW and five animals from each treatment were killed 4.5, 9, 18, or 36 h after dosing. All brains were dissected, and concentrations of indoleamine and catecholamine neurotransmitters and metabolites were determined. Animals in the group killed 36 h after dosing were observed for behavioral changes. Vomiting was noted in 60% of the pigs dosed with fusaric acid. These pigs also seemed more lethargic than controls and appeared sedated. The major neurochemical changes due to exposure to fusaric acid were seen in the hypothalamus 18 h after dosing. Brain tryptophan, serotonin, and 5-hydroxyindoleacetic acid all tended to be elevated by the action of fusaric acid. Brain catecholamine concentrations were largely refractory to treatment. It was concluded that exposure to acute doses of fusaric acid can cause vomiting and neurochemical changes in swine. Fusaric acid may, therefore, be acting synergistically with trichothecene mycotoxins to cause vomiting and feed refusal in pigs consuming trichothecene-contaminated feedstuffs.

Potential for dietary amino acid precursors of neurotransmitters to overcome neurochemical changes in acute T-2 toxicosis in rats

Experiments were conducted to determine the potential for overcoming T-2 toxin-induced changes in brain neurotransmitter concentrations through dietary manipulation. Rats were fed either a tryptophan-deficient, gelatin-based diet or the same diet supplemented with a mixture of large neutral amino acids for 4 d. Rats were then dosed with 0 or 2.0 mg T-2 toxin/kg body weight and killed 4, 8 or 12 h after dosing. The large neutral amino acid supplements successfully reduced brain concentrations of tryptophan and serotonin in control rats, but this was not enough to overcome the acute effects seen in T-2 toxin-treated rats. A further experiment was then conducted to monitor the effect of T-2 toxin on the ratio of free to protein-bound tryptophan in plasma. Total plasma tryptophan increased in T-2 toxin-treated rats, although there were no significant differences in the ratio of free to protein-bound tryptophan. A final experiment was conducted to determine the specificity of the T-2 toxin effect on concentrations of plasma amino acids. Concentrations of amino acids that use the large neutral amino acid transport system into the brain were higher in T-2 toxin-treated animals. The only other amino acid that had a higher concentration was arginine. It was concluded that acute doses of T-2 toxin may selectively alter membrane transport of amino acids.

Effect of acute oral doses of T-2 toxin on tissue concentrations of biogenic amines in the rat

T-2 toxin [3 alpha-hydroxy-4 beta, 15-diacetoxy-8 alpha-(3-methylbutyryloxy)-12,13-epoxytrichotec-9-ene] is an emetic Fusarium trichothecene mycotoxin known to cause lethargy, ataxia and feed refusal in economically important animals. Experiments were conducted to determine the effect of acute oral doses of T-2 toxin on tissue concentrations of neurotransmitters thought to play some role in regulation of feed consumption. Sixty-seven male weanling rats were intubated with a few grams of diet in a liquid slurry with or without 2.0 mg T-2 toxin per kilogram of body weight. At 1, 2, 4, 6, 8, 12, 24 and 48 h following dosing, rats were killed, and brains, spleens, hearts and adrenal glands were excised and analyzed for concentrations of neurotransmitters and metabolites using high-performance liquid chromatography with electrochemical detection. Administration of T-2 toxin caused increases in brain concentrations of tryptophan and serotonin at the early time intervals after dosing. Brain concentrations of dopamine increased, whereas concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC) decreased at the later time interals following dosing. Concentrations of dopamine were increased in adrenal glands, whereas epinephrine concentrations decreased. Epinephrine was detected in spleen and heart after administration of T-2 toxin. It was concluded that the increase in brain indoleamines induced by T-2 toxin could contribute to feed refusal in animals suffering from T-2 toxicosis.

Protective effect of tryptophan and 5-hydroxytryptophan on experimental phenylketonuria induced with phenylalanine+ p-cholorophenylalanine in rats

An experimental phenylketonuria-like syndrome was produced in rats by oral administration of 1-phenylalanine (Phe, 500 mg/kg) and dl-p-chloro-phenylalanine (pCPA, 100-125 mg/kg) daily from the 2nd-3rd day of life to the age of 42 days. The effects of added dl-5-hydroxytryptohan (5HTP, 5 mg/kg) or 1-tryptophan (Trp, 100-125 mg/kg) were also studied. The groups receiving Phe+pCPA gained less weight than normal and less than the Phe controls. When tested during the last week of treatment the Phe+pCPA rats made more errors in the swim maze without changes in swimming times, and they showed significantly poorer learning of conditioned shock avoidance. These effects were partly antagonized by 5HTP or Trp. One to three weeks after the end of the treatments similar differences still remained in conditioned shock avoidance (and Trp and 5HTP prevented the effect of pCPA), but no more in maze learning, motor activity, or exploration on open field. Brain 5HT and 5-hydroxyindoleacetic acid (5HIAA) were lowered in all the pCPA treated rats during the treatment but returned to normal after it. Trp and 5HTP in the doses used only partly corrected the decrease of 5HT and 5HIAA. Brain noradrenaline did not change much.