Are we teaching the health impacts of climate change in a clinically relevant way? A systematic narrative review of biomechanism-focused climate change learning outcomes in medical curricula

PURPOSE

Introducing biomedical approaches to the health impacts of climate change can improve medical student engagement with relevant climate-related issues, improve the development of medical schemas, and minimise displacement into crowded medical curricula. This paper aims to systematically review the medical education curricula related to climate change, with a particular focus on systems-based biomechanisms for the health impacts of climate change. We do this to provide a clear agenda for further development of learning outcomes (LOs) in this area to maximize the clinical applicability of this knowledge.

MATERIAL AND METHODS

A systematic review was undertaken following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA; Liberati et al. 2009) guidelines for both the published and grey literature. Five databases (PubMed, SCOPUS, ERIC, Open Access Thesis and Dissertation, and Proquest Global Dissertation and Theses) were searched for works published between 2011 and June 2023. Full texts that contained LOs were the main inclusion criteria for the final review. Descriptive and content extraction guided the final narrative synthesis.

RESULTS

Analysis indicated that biomechanism-related LOs represented about 25% of each published LO set, on average. These outcomes were primarily at the "understand" level of Bloom's taxonomy and were spread across a range of body systems and climate-change aspects. Infectious diseases and extreme heat were strong focuses. Authorship analysis indicated that the majority of these sets of published LOs are from Western contexts and authored by researchers and educators with medical and population health qualifications.

CONCLUSIONS

Biomechanism-focused teaching about the health impacts of climate change is relatively rare in published curricula. Of the available sets of LOs, the majority are sourced from Western authors and are focused on a fairly circumscribed set of biomedical topics. There is scope to both broaden and deepen curriculum in this area, and we would recommend the field prioritise collaboration with medical educators from the Global South, where the effects of climate change are already the most acutely felt.

Climate change, environmental extremes, and human health in Australia: challenges, adaptation strategies, and policy gaps

Climate change presents a major public health concern in Australia, marked by unprecedented wildfires, heatwaves, floods, droughts, and the spread of climate-sensitive infectious diseases. Despite these challenges, Australia's response to the climate crisis has been inadequate and subject to change by politics, public sentiment, and global developments. This study illustrates the spatiotemporal patterns of selected climate-related environmental extremes (heatwaves, wildfires, floods, and droughts) across Australia during the past two decades, and summarizes climate adaptation measures and actions that have been taken by the national, state/territory, and local governments. Our findings reveal significant impacts of climate-related environmental extremes on the health and well-being of Australians. While governments have implemented various adaptation strategies, these plans must be further developed to yield concrete actions. Moreover, Indigenous Australians should not be left out in these adaptation efforts. A collaborative, comprehensive approach involving all levels of government is urgently needed to prevent, mitigate, and adapt to the health impacts of climate change.

Forest buffer-strips mitigate the negative impact of oil palm plantations on stream communities

The global area cultivated with oil palm has doubled in the past two decades, causing deforestation, land-use change, freshwater pollution, and species loss in tropical ecosystems worldwide. Despite the palm-oil industry been linked to severe deterioration of freshwater ecosystems, most studies have focused on terrestrial environments, while freshwaters have been significantly less studied. We evaluated these impacts by contrasting freshwater macroinvertebrate communities and habitat conditions in 19 streams from primary forests (7), grazing lands (6), and oil palm plantations (6). In each stream, we measured environmental characteristics, e.g., habitat composition, canopy cover, substrate, water temperature, and water quality; and we identified and quantified the assemblage of macroinvertebrates. Streams in oil palm plantations lacking riparian forest strips showed warmer and more variable temperatures, higher turbidity, lower silica content, and poorer macroinvertebrate taxon richness than primary forests. Grazing lands showed higher conductivity and temperature, and lower dissolved oxygen and macroinvertebrate taxon richness than primary forests. In contrast, streams in oil palm plantations that conserved a riparian forest, showed a substrate composition, temperature, and canopy cover more similar to the ones in primary forests. These habitat improvements by riparian forests in the plantations increased macroinvertebrate taxon richness and maintained a community resembling more the one in primary forests. Therefore, the conversion of grazing lands (instead of primary forests) to oil palm plantations can increase freshwater taxon richness only if riparian native forests are safeguarded.

Vascular Parameters for Ambulatory Monitoring of Congestive Heart Failure Patients: Proof of Concept

PURPOSE

Prompt detection of congestion is an essential target in order to prevent heart failure (HF) related hospitalization, being ambulatory monitoring a promising strategy to do so. A successful non-invasive ambulatory monitoring system requires automatic devices for physiological data recording; these data must give information about HF deterioration early enough to predict HF-related adverse events. This work aims to evaluate seven vascular parameters for the ambulatory monitoring of congestive heart failure patients.

METHODS

Seven vascular parameters are proposed as indicators of HF deterioration. These parameters are obtained using venous occlusion plethysmography; a technique that uses hardware able of being miniaturized and easily integrated into wearables for ambulatory monitoring. The ability of the proposed vascular parameters to detect congestion is evaluated in eight healthy volunteers and ten congestive heart failure patients with different congestion levels-mild, moderate and severe.

RESULTS

Most parameters distinguish between healthy volunteers and heart failure patients, and some of them present significant differences between volunteers and low levels of congestion-mild or moderate.

CONCLUSION

Home monitoring of some of the proposed parameters could detect HF deterioration on its onset and alert to health personnel.

Neuroinflammation, cortical activity, and fatiguing behaviour during self-paced exercise

The present study aimed to identify whether or not the release of interleukin (IL)-6 and soluble (s) IL-6 receptor (R) is associated with fatiguing behaviour and changes in cortical activity during self-paced exercise. Relationships between the IL-6 and its soluble receptors, total work, reductions in power output, and changes in slow, alpha (α) and fast, beta (β) brain waves during self-paced exercise were evaluated. Different intensities and environments were used to manipulate the release of IL-6, whereby seven active males cycled for 60 min in heat stress (HS) or thermoneutral (TN) environments at a clamped rating of perceived exertion (RPE) equating to low intensity (RPE = 12) or high intensity (RPE = 16). IL-6 and sIL-6R were positively associated with total work, but not with reductions in power output. There was greater α activity in high-intensity conditions, which was associated with the reduction in power output. Both high-intensity conditions appeared to have greater β activity, and there was a positive correlation between β activity and total work and β activity and sIL-6R. We conclude that IL-6 and sIL-6R may contribute to perturbations in cortical activity and are associated with total work output, but reductions in power output are likely influenced greater by other internal and external factors.

Heat stress, gastrointestinal permeability and interleukin-6 signaling - Implications for exercise performance and fatigue

Exercise in heat stress exacerbates performance decrements compared to normothermic environments. It has been documented that the performance decrements are associated with reduced efferent drive from the central nervous system (CNS), however, specific factors that contribute to the decrements are not completely understood. During exertional heat stress, blood flow is preferentially distributed away from the intestinal area to supply the muscles and brain with oxygen. Consequently, the gastrointestinal barrier becomes increasingly permeable, resulting in the release of lipopolysaccharides (LPS, endotoxin) into the circulation. LPS leakage stimulates an acute-phase inflammatory response, including the release of interleukin (IL)-6 in response to an increasingly endotoxic environment. If LPS translocation is too great, heat shock, neurological dysfunction, or death may ensue. IL-6 acts initially in a pro-inflammatory manner during endotoxemia, but can attenuate the response through signaling the hypothalamic pituitary adrenal (HPA)-axis. Likewise, IL-6 is believed to be a thermoregulatory sensor in the gut during the febrile response, hence highlighting its role in periphery – to – brain communication. Recently, IL-6 has been implicated in signaling the CNS and influencing perceptions of fatigue and performance during exercise. Therefore, due to the cascade of events that occur during exertional heat stress, it is possible that the release of LPS and exacerbated response of IL-6 contributes to CNS modulation during exertional heat stress. The purpose of this review is to evaluate previous literature and discuss the potential role for IL-6 during exertional heat stress to modulate performance in favor of whole body preservation.

Amatoxin and phallotoxin composition in species of the genus Amanita in Colombia: a taxonomic perspective

Some species in the genus Amanita have a great variety of toxic secondary metabolites. They are characterized macroscopically by having a white spore print and free gills, and microscopically by the presence of a divergent hymenophoral trama. Some species of Amanita present in Colombia were chemically characterized by analyzing their toxin composition using HPLC. Samples were collected in oak (Quercus humboldtii) and pine (Pinus radiata) forests. Twelve species were recovered, Amanita fuligineodisca, Amanita xylinivolva, Amanita flavoconia, Amanita rubescens, Amanita bisporigera, Amanita muscaria, Amanita humboldtii, Amanita sororcula, Amanita brunneolocularis, Amanita colombiana, Amanita citrina, Amanita porphyria as well as two unreported species. Results showed that most of the analyzed species have α -amanitin in concentrations ranging from 50 ppm to 6000 ppm. Concentrations of α-amanitin in the pileus were significantly greater than in the stipe. Phalloidin and phallacidin were only present in A. bisporigera. Chromatographic profiles are proposed as an additional taxonomic tool since specific peaks with similar retention times were conserved at the species level.

[A case of sepsis caused by BCG (Bacillus Calmette Guerin) after its bladder instillation in a 71-year-old patient affected by bladder carcinoma]

Sometimes the Calmette-Guerin bacillus can be used with success as local immunotherapy for superficial bladder carcinoma. BCG is a living attenuated strain of Mycobacterium bovis and therefore its biadder instillation may give rise, in some particular cases, to serious systemic effects, caused either by hypersensitivity reaction or by systemic dissemination in case with low efficiency of cellular immunity. We describe a case of sepsis in a 71-year-old patient after bladder instillation of BCG with a rare complication of granulomatous hepatitis. The etiological diagnosis of granulomatous hepatitis with PCR on liver biopsy is very important for the specific therapy before the patient can undergo a steroid regime.

Two main clusters within Trypanosoma cruzi zymodeme 3 are defined by distinct regions of the ribosomal RNA cistron

Trypanosoma cruzi is currently classified into 2 major phylogenetic lineages, T. cruzi I and II, that correlate with the formerly described zymodeme 1 and 2, respectively. Another isoenzymic group (zymodeme 3-Z3) was also described. In this study, we analysed the genetic diversity among Z3 isolates of the Brazilian Amazon by restriction fragment length polymorphism of the intergenic transcribed spacers (ITSs) of the ribosomal RNA cistron and the size of the divergent domain D7 of the 24Salpha rRNA gene. DNAs from 12 T. cruzi Z3 isolates obtained from humans (2), Panstrongylus geniculatus (1), and Rhodnius brethesi (9) were submitted to PCR amplification of the ITSs plus the 5.8S rDNA. The PCR products were digested with 4 distinct endonucleases and the profiles analysed by a numerical methodology. The phenetic dendrogram revealed a clear dichotomy in the Z3 group, defining 2 groups that were named Z3-A and Z3-B. Dimorphism was also found in the band sizes of the amplified D7 divergent domain of the 24Salpha rDNA, which showed a perfect correlation with the ITSs clustering. The organization of the ribosomal cistron was investigated by Southern blotting and shown to be conserved in the genome of the 2 Z3 groups. This study shows that the rDNA cistron allows the definition of 2 distinct subclusters in Z3 isolates.

Amplification of a specific repetitive DNA sequence for Trypanosoma rangeli identification and its potential application in epidemiological investigations

Trypanosoma rangeli can infect humans as well as the same domestic and wild animals and triatomine vectors infected by Trypanosoma cruzi in Central and South America. This overlapping distribution complicates the epidemiology of American trypanosomiasis due to the cross-reactivity between T. rangeli and T. cruzi antigens and the presence of conserved DNA sequences in these parasites. We have isolated a T. rangeli-specific DNA repetitive element which is represented in approximately 103 copies per parasite genome and is distributed in several chromosomal bands. The 542-bp nucleotide sequence of this element, named P542, was determined and a PCR assay was standardized for its amplification. The sensitivity of the assay is high, allowing the detection of one tenth of the DNA content of a single parasite. The presence of the P542 element was confirmed in 11 T. rangeli isolates from mammalian hosts and insect vectors originating from several countries in Latin America. Negative amplification was observed with different T. cruzi strains and other trypanosomatids. The potential field application of the P542 PCR assay was investigated in simulated samples containing T. rangeli and/or T. cruzi and intestinal tract and feces of Rhodnius prolixus. Epidemiological studies were conducted in DNA preparations obtained from the digestive tracts of 12 Rhodnius colombiensis insects collected in a sylvatic area in Colombia. Positive amplification of the P542 element was obtained in 9/12 insects. We have also compared in the same samples the diagnostic performance of two PCR assays for the amplification of the variable domain of minicircle kinetoplast DNA (kDNA) and of the large subunit (LSU) of the ribosomal RNA gene of T. cruzi and T. rangeli. Data indicate that the kDNA PCR assay does not allow diagnosis of mixed infections in most insects. On the other hand, the PCR assay of the LSU RNA gene showed lower sensitivity in the detection of T. rangeli than the PCR assay of the P542 element. It is predicted that the use of sensitive detection techniques will indicate that the actual distribution of T. rangeli in America is wider than presumed.

Trypanosoma rangeli: discrimination from Trypanosoma cruzi based on a variable domain from the large subunit ribosomal RNA gene

306-314. Three synthetic oligonucleotides corresponding to sequences within the D7a divergent domain of the large subunit ribosomal RNA gene have been used to amplify the total DNA of Trypanosoma rangeli and Trypanosoma cruzi, two morphologically similar protozoa with overlapping geographical distribution and hosts. The two organisms may be distinguished by the electrophoretic mobilities of their respective amplification products. For T. rangeli a 210-bp product was obtained. The presence of this fragment was confirmed in 14 T. rangeli strains. For T. cruzi two possible amplification products were originated: a 265-bp DNA fragment for strains typed as lineage 1 and a 250-bp fragment for lineage 2 strains. Eleven unidentified trypanosome stocks, recently isolated from Amazonian vectors, could be discriminated using the proposed assay. The potential field application of multiplex PCR was further demonstrated by identification of the two parasite species in samples containing intestinal tract and feces of triatomines. In the present study we have also amplified the D7a domain of several trypanosomatids employing primers complementary to the conserved flanking regions. Size and sequence polymorphisms were observed, indicating that this region could also be explored as a target for specific detection of other members of the Trypanosomatidae family.

The insulin-like growth factor axis and plasma lipid levels in the elderly

The activity of the hypothalamic-GH-insulin-like growth factor (IGF) network declines with age. It has recently been shown that increased cardiovascular mortality occurs in adults with GH deficiency. As hypercholesterolemia is common in GH-deficient adults, and because there is experimental evidence that GH may play a role in regulating plasma cholesterol, we decided to investigate the activity of the GH-IGF axis in an elderly population by measuring serum IGF-I, IGF-II, and IGF-binding protein-3 (IGFBP-3) levels and to study their relationship with blood lipid levels. One hundred and thirty-two elderly subjects, 52 men and 80 women, were studied (age range, 60-91 yr). Men had significantly lower levels of IGFBP-3, high density lipoprotein cholesterol (HDL-C) and apoprotein A1 (ApoA1) compared to the women, whereas IGF-I and IGF-II were only slightly lower. Using linear regression analysis, we observed an inverse relationship of age with IGF-I (r = -0.35; P < 0.001), IGF-II (r = 0.40; P < 0.001), IGFBP-3 (r = 0.52; P < 0.001), body mass index, and lipid levels. Univariate regression analysis showed a strong and positive correlation of both IGF-I and IGFBP-3 with HDL-C and ApoA1. Partial correlation analysis, after adjustment for age and body mass index, showed that IGFBP-3 and IGF-II were still significantly and positively related to HDL-C and ApoA1. Furthermore, a strong association was documented among IGF-I, IGF-II, and IGFBP-3. These data demonstrate that even in an elderly population, further aging is accompanied by a progressive decline in circulating IGF-I, IGF-II, and IGFBP-3, suggesting a continuing diminution of the GH-IGF axis throughout aging. Moreover, the strong correlation between HDL-C and an index of GH secretion, such as IGFBP-3, suggests that GH might play an important role in lipid metabolism in healthy elderly subjects.

Trypanosoma cruzi genome project: biological characteristics and molecular typing of clone CL Brener

Clone CL Brener is the reference organism used in the Trypanosoma cruzi Genome Project. CL Brener was obtained by cloning procedures from bloodstream trypomastigotes isolated from mice infected with the CL strain. The doubling time of CL Brener epimastigotes cultured at 28 degrees C in liver infusion-tryptose (LIT) medium is 58 +/- 13 h. Differentiation to metacyclic forms is induced by incubation of epimastigotes in LIT-20% Grace's medium. Metacyclics give very low parasitemia in mice, contrary to what is observed for blood forms which promote 100% mortality of the animals with inocula of 5 x 10(3) parasites. CL Brener blood forms are highly susceptible to nifurtimox, benznidazole and ketoconazole. Allopurinol is inefficient in the treatment of mice experimental infection. The clone infects mammalian cultured cells and performs the complete intracellular cycle at 33 and 37 degrees C. The molecular typing of CL Brener has been done by isoenzymatic profiles; sequencing of a 24S alpha ribosomal RNA gene domain and by schizodeme, randomly amplified polymorphic DNA and DNA fingerprinting analyses. For each typing approach the patterns obtained do not change after prolonged parasite subcultivation in LIT medium (up to 100 generations). The stability of the molecular karyotype of the clone was also confirmed.

[Reproductive history of Chilean puerperal women hospitalized in a public hospital of the metropolitan region]

BACKGROUND

Maternal and infantile morbidity is closely related to the features of women's reproductive history.

AIM

To study the reproductive behavior of women hospitalized due to labor or abortion in a public maternity of Metropolitan Santiago.

SUBJECTS AND METHODS

One thousand women were interviewed about their reproductive behavior, 24 to 72 hours after pregnancy resolution.

RESULTS

Ages of interviewed women ranged from 13 to 47 years old. Eighty seven percent had three children or less. The proportion of single women with a first pregnancy was 62% and decreased to 9.3% in those with a second pregnancy. At the first pregnancy, 1.3% of women were using contraceptives, notwithstanding that 27% did not want to become pregnant. Most women had a birth spacing of 24 to 59 months. There was a low number of stillbirths in this sample.

CONCLUSIONS

This work shows that studied women have pregnancies at low risk ages and an adequate parity.

Apparatus for home monitoring of pregnant hypertensive patients

A simple, convenient to use apparatus suitable for patient self-monitoring is described and illustrated with graphs of mean arterial pressure determinants which provide clinically useful hemodynamic details unobtainable with cuff blood pressure measurements. A bathroom scale and a forearm cuff blood pressure system completes the home monitoring apparatus.

[Trends and fluctuations in morbidity and mortality by selected causes, and economic activity: Costa Rica, Chile, and Guatemala, 1960-1986]

"The paper examines the relationship between medium and short-term changes in aggregate economic activity, and national morbidity and mortality rates by certain causes. Although overall mortality conditions have continued to improve during the economic crisis of the nineteen-eighties in the three countries studied, mortality by some causes...[has] discontinued [its] decline and [has] even increased [its] rates in some recent years.... The short-term changes in mortality in Costa Rica and Chile are generally lower than in Guatemala, but tend to be more systematic in their inverse relationship with economic fluctuations in the former. Many of the causes studied affect young and older adults, which are groups that have so far received little attention in evaluations of the health effects of economic crises in the region." (SUMMARY IN ENG)

[Incidence of insulin-dependent diabetes mellitus in the metropolitan region]

We used a retrospective search and confirmation method to establish the number of new cases of insulin dependent diabetes mellitus diagnosed between Jan 1, 1986 and Dec 31, 1989 in subjects under 15 years of age in the Metropolitan region of Chile. All hospitals and outpatient facilities of the National Health Service, other hospitals and private offices of endocrinologists and specialists in diabetes were surveyed, as well as the registry from the Juvenile Diabetes Foundation. A total of 115 cases, 52 in males and 63 in females were found, for an annual incidence of 1.69 and 2.15 per 100,000, respectively. Overall, the annual incidence rates were 2.22 in 1986, 1.22 in 1987 (p < 0.001), 2.13 in 1988 and 2.09 in 1989. A greater number of cases was diagnosed at age 4 in males and at age 12 in females (p < 0.001). The greater number of cases were diagnosed from June to August (winter) and the lowest in October (p < 0.001).

[Newborn infants of diabetic mothers]

Some features as well as pathological findings in 63 infants born to diabetic mothers (IDM) under control in a diabetes unit of a general hospital at metropolitan Santiago, Chile, from 1985 through 1988 are presented. Out of 63 newborns, 22 came from mothers with pregestational diabetes mellitus (PGDM) and 41 were born to mothers with gestational diabetes mellitus (GDM). Significant differences were detected among PGDM and GDM groups of newborns in the following features: mean gestational age (GE) premature (54.5% vs. 26.8% 37 weeks GE or less), jaundice (40.9% vs. 17.1%) and congenital malformations (18.2% vs. 0%). No significant differences were found in fetal distress, hypoglycemia, respiratory distress syndrome and birth trauma although as a whole these last were more frequently recorded among infant born to insulin dependent diabetic mothers. It is concluded that in spite of an appropriate control, morbidity remains higher in IDM, particularly in IDM PGDM.

[Treatment of acute leukemia: usefulness of an immunodepressed unit]

A special unit for immune-depressed patients was used in the treatment of acute leukemia in 33 patients. Results of therapy were compared to those in 30 historical controls treated in a general ward. Both groups were comparable regarding age, sex, type of leukemia and severity of bone marrow depression. The incidence of fever and the percentage of complete remission were higher in patients treated in the unit, including patients with acute lymphoblastic leukemia. The remission rate in the subgroup of patients with acute myeloid leukemia was not improved. Mortality rates were also not different. We recommend the use of this unit for treatment of patients with acute leukemia, given the lower infection rate and the higher probability of remission.

[Prevalence of insulin dependent diabetes mellitus in school children of the metropolitan area]

The prevalence of insulin dependent diabetes mellitus was determined in 1,078,109 students of 2,150 schools between 5 and 19 years of age. 147 diabetic females and 107 diabetic males were found, for a prevalence of 25/100,000 in females and 20/100,000 in males (p less than 0.01). Prevalence of diabetes among 3 age groups, 5-9, 10-14 and 15-19 years, was 17, 22 and 19 per 100,000 in males and 22, 32 and 28 per 100,000 in females, respectively. The higher prevalence in females was significant at all age levels. Overall prevalence according to age was 19, 27 and 24 per 100,000 in the corresponding age groups (significantly higher in the 10-14 year old age group, p less than 0.01).

[Unwanted children: incidence and characteristics among puerperal women in a hospital of Santiago]

A scoring instrument to detect unwanted newborns was applied to 556 living-in women at a Santiago urban hospital in december 1987. Based upon previous research a scoring instrument including 10 items was designed and applied within 24 hours following delivery. According to the total score each newborn was classified as wanted (W), unwanted (U) or doubtful situation: 37.6% of children were born to unwed mothers. In a total of 556 children 4.5% (n = 25) were classified as U, 91.4% as W (n = 508) and 4.1% as doubtful (n = 23). Comparing U and W children the former had mothers with poorer education, higher frequency of bad relationships with their partners as well as higher proportion of three or more previous deliveries and late beginning of prenatal care (significant). On the other hand no significant differences were detected in age distribution of the mothers or their socio-economic level. The applicability of this scoring system and the magnitude and importance of the problem are analyzed and discussed. The need for further research on the natural history of the sequence unwanted pregnancy-unwanted child is stressed.

Air pollution impact on phagocytic capacity of peripheral blood macrophages and antioxidant activity of plasma among school children

Peripheral blood macrophages of school children from downtown Santiago, Chile--a highly polluted city--exhibited a lower phagocytic index with higher percentage of killing than those of the rural village of María Pinto. These findings were observed concomitantly with a lower antioxidant activity of plasma in Santiago students. No differences were observed in serum immunoglobulins (IgA, IgG, and IgM), secretory IgA in saliva, and complement component C3. White blood cell count was higher in María Pinto residents than in Santiago students, including those cells with phagocytic capacity. It is suggested that particulate air pollution may enhance macrophage activity with impairment of the antioxidant capacity of plasma.