From traditional medicine to personalized medicine

From prehistory, where medicine started began with plants, minerals and parts of animals; until today, medicine has evolved very quickly. Much of the “fault” of his fact is due to genetics, which allows us to talk about personalized medicine. In the following article we discuss this.

THE EVOLUTION OF DISEASES

To talk about medicine, we have first to know diseases. We cannot think that all diseases are genetic, but there are diseases related to anatomical changes, fruit of our evolution.

Chimpanzees are the closest animal to us, humans, with which we share 99% of our genome. Despite this, humans have very particular phenotypic characteristics as the brain most develop, both in size and expansion of the cerebral cortex; hairless sweaty skin, bipedal posture and prolonged dependence on offspring, allowing the transmission of knowledge for longer; among other.

Possibly, the bipedal position was key to the early development of the divergence between the chimpanzee lineage and that of humans; and is also the reason for the appearance of some diseases related to anatomical factors. Among them are hernias, haemorrhoids, varices, disorders of the spine, such as herniated intervertebral discs; osteoarthritis in the knee joint, uterine prolapse and difficulties in childbirth.

The fact that the pelvis was remodelled (Figure 1) and narrower resulted in obstetric problems millions of years later, when the brain expanded. Consequently, the skull as well. The heads of the foetuses were longer and larger, making birth difficult. This explains why the deliveries of humans are longer and longer compared to those of chimpanzees and other animals.

Figure 1. Comparison between human pelvis and chimpanzee pelvis in bipedal position (Source: Libros maravillosos – La especie elegida (capítulo 5))

The evolution towards modern life has behaved many changes in every way. In comparison to our hunter-gatherer ancestors (Figure 2), our diet has changed a lot and has nothing to do with what other primates eat. For the latter, the fruit represents most of the intake, but for us it is red meat. In addition, we are the only animals that continue to feed us milk after the lactation period.

Figure 2. Picture of hunter-gatherer humans (Source: Río Verde en la historia

If we add to the sedentary lifestyle and the limited physical activity of modern humans, it can help explain the seriousness and frequency of some modern human diseases.

Lifestyle can also affect us. For example, myopia, which rate is higher in western individuals who read a lot or do activities of near vision, compared to individuals of Aboriginal’s towns.

Another clear example is the alteration in the female reproductive stage. Currently, women have children more and more later. This is also linked to a decrease in the duration of breastfeeding. These changes, which can be considered socially positive, have negative effects on the health of the reproductive organs. It has been shown that the combination of early menarche, limited or no breastfeeding and later menopause are the main risk factors for breast and ovarian cancer.

Humans increasingly live more years and we want the best quality of life. It is easy for more longevity to appear more diseases, by the deterioration of the organism and its cells.

THE EVOLUTION OF MEDICINE

The history of medicine is the history of the struggle of men against disease and since the beginning of this century, is also the history of human effort to maintain health.

We have acquired the scientific knowledge of medicine based on observation and experience, but it has not always been so. Our ancestors experienced sickness and the fear of death before a rational picture could be made of them, and the medicine of that time was immersed in a system of beliefs, myths and rites.

However, in the last years it has been born personalized genomics, which tells you your risk factors. This opens a door to personalized medicine, which adjusts treatments to patients depending on their genome (Figure 3). It uses information from a person’s genes and proteins to prevent, diagnose and treat a disease, all thanks to the sequencing of the human genome.

Figure 3. Personalized medicine that treats people individually, according to their genome (Source: Indiana Institute of Personalized Medicine)

Molecular methods that make precision medicine possible include tests of gene variation, proteins, and new treatments targeting molecular mechanisms. With the results of these tests and treatments can determine the state of the disease, predict the future state of the disease, the response to the drug and treatment or even the role of the food we eat at certain times, which results of great help to the doctors to individualize the treatment of each patient.

To do this, we have within our reach the nutrigenetics and the nutrigenomics, that like the pharmacogenetics and the pharmacogenomics, they help the advance of a medicine is more and more directed. Therefore, these disciplines are today one of the pillars of personalized medicine since it involves treating each patient individually and tailor-made.

The evolution towards precision medicine is personalized, preventive, predictive and participatory. There is increasing access to information and the patient is more proactive, getting ahead of problems, preventing them or being prepared to deal with them efficiently.

REFERENCES

• Varki, A. Nothing in medicine makes sense, except in the light of evolution. J Mol Med (2012) 90:481–494
• Nesse, R. and Williams, C. Evolution and the origins of disease. Sci Am. (1998) 279(5):86-93
• Mackenbach, J. The origins of human disease: a short story on “where diseases come from”. J Epidemiol Community Health. (2006) 60(1): 81–86
• Main picture: Todos Somos Uno

Danger, poisonous mammals!

We usually associate snakes, spiders, jellyfish, etc. as venomous animals par excellence, but did you know that there are poisonous mammals? In this article we will discover who are they and the nature and use of their poisons.

THE PLATYPUS

The platypus (Ornithorhynchus anatinus) is the most famous among the poisonous mammals, and not just for this feature. With a peak like a duck and oviparous (laying eggs), when it was discovered some scientists thought it was a fraud.

Platypus (Ornithorhynchus anatinus). Photo by Jonathan Munro

They belong to the order monotremes, which means “one hole” in reference to the cloaca, the end of the digestive and reproductive systems. Some evolutionary biologists refer to them as the “missing link” between reptiles and mammals, as they have characteristics of both groups. Monotremes are the only mammals that lay eggs, but his body is covered with hair and the young are fed with breast milk. They are distributed by Australia, Tasmania and New Guinea.

Platypuses have a spur on the hind legs, which only in the case of males, release poison produced by femoral glands (located in the leg). The male uses it mainly to defend their territory and establish their dominance during the mating season, although if it is bothered also uses it as a defense. This poison can kill small animals, including dogs, and cause severe pain and swelling in humans. This pain can last days or months.

Spur on the hind leg of a platypus. Photo by E. Lonnon

Toxins are four proteins, three of which are unique to the platypus. They are like the defensins (DLP, defensin-like proteins). These are globular proteins, small and compacted, involved in the activation of pain receptors. Understanding how these toxins act it has special interest because they cause a lasting and severe pain; it may open new chances in the synthesis of analgesic drugs.

Short-beake echidna (Tachyglossus aculeatus). Photo de Tony Britt-Lewis

Echidnas (family Tachyglossidae) complete the order of monotremes with the platypus; consequently they are also oviparous. The family consists of four species, with the common characteristic of having the body covered with dense hair and spines. They are mainly insectivores specializing in ants and termites.

Like the platypus, they also have spurs behind the knees, but their secretions are not poisonous. The substances are used to mark their territory, according to the recent studies.

SLOW LORIS

As we saw in a previous post, lorises are primates in the prosimians suborder. They are nocturnal, arboreal and feed primarily on insects, vegetables and fruits. The slow lorises (Nycticebus) living in Southeast Asia, are the only poisonous primate. They possess poison glands on the elbows (brachial gland), and poison their body with arms and tongue, which can also join saliva and be transmitted by bitting.

Pygmy slow loris (Nycticebus pigmaeus). Photo by Ch’ien C. Lee

In this case the poison is used as a defense against predators, causing them pain, inflammation, necrosis (cell death) in the area of the bite, hematuria (blood in urine) or in some cases anaphylactic shock (allergic reaction) which can lead to death, even in humans (some are threatened by the illegal pet trade and traditional Chinese medicine). The poison also serves as protection for the young, they are licked by their parents and the poisonous secretion is distributed throughout the coat. Being poisonous, unusual among primates, can help counteract the disadvantages of its slow movements. Exudate from glands, as in echidnas, can also give olfactory information of range and territory between individuals of loris (Hagey et al., 2007).

Kayan loris (Nycticebus kayan). Photo by Ch’ien C. Lee

Toxins are polypeptides (generated when glandular secretion is mixed with saliva) and an unidentified steroid. Secretion is similar to the allergen Fel d 1 which is in the domestic cat and cause allergies in humans (Hagey et al., 2006; Krane et al., 2003).

It is believed that slow lorises even have converged evolutionarily with cobras, for his defensive behavior when threatened, whistling and raising his arms around his head. (Nekaris et. al, 2003).

Mimicry between loris and cobras. 1. Javan slow loris, 2 y 3. Spectacled cobra, 4. Bengal slow loris. Photo by Nekaris et. al.

In the following video a lazy lori is disturbed and hisses like a snake while trying to bite:

SOLENODON OR ALMIQUI

They are small and nocturnal mammals, basically insectivores, that live in the West Indies. The Hispaniolan solenodon (Solenodon paradoxus), also known as the Dominican solenodon, Haitian solenodon or agouta, lives on the island de La Española (Dominican Republic and Haiti) while The Cuban solenodon or almiqui (Solenodon cubanus) is distributed throughout Cuba. They are considered living fossils because they have similar characteristics to primitive mammals of the end of the Mesozoic Era (kingdom of the dinosaurs).

Hispaniolan solenodon (Solenodon paradoxus). Photo by Eladio M. Fernández.

Unlike other poisonous mammals, toxic saliva is produced under the jaw (submandibular glands), which is transported by pipes to the front of the mouth. The second incisor teeth have a groove where toxic saliva accumulates to promote their entry into the wounds. They are the only mammals that inject venom through its teeth, similar to the way snakes do.

Paradoxus Solenodon lower jaw incisor showing the groove. Photo by Phil Myers

The main function of this venom is to immobilize prey, as well as insects they can hunt small vertebrates such as reptiles, amphibians and birds.

Cuban solenodon (Solenodon cubanus). Photo by Julio Genaro.

This poison may have been developed to keep alive but immobilized prey during times of shortage, to aid in digestion, minimize energy expenditure in the struggle for hunting and face prey even twice as big as them. This venom is not deadly to humans.

SHREWS

The northern short-tailed shrew (Blarina brevicauda), the Eurasian water shrew (Neomys fodiens) and the Mediterranean water shrew (Neomys anomalus) also have submandibular glands similar to solenodons. They are distributed by North America (northern short-tailed shrew) and Europe and Asia (water shrews), including the Iberian Peninsula.

The northern short-tailed shrew (Blarina brevicauda). Photo by Gilles Gonthier.

The short-tailed shrew can consume up to three times its weight in food per day. Their saliva is the most poisonous and uses it to paralyze their prey, to eat them or keep them alive in times of shortage. The water shrews also store its immobilized prey under rocks.

Mediterranean water shrew (Neomys anomalus). Photo by Rollin Verlinde.

These animals attack from behind and bite the neck of its prey so that the poison acts more quickly, affecting the central nervous system (neurotoxins). The respiratory and vascular system is also affected and causes seizures, incoordination, paralysis and even death of small vertebrates.

Eurasian water shrew (Neomys fodiens). Photo by R. Altenkamp.

Its teeth don’t have grooves as the solenodons do, but a concave surface to store the toxic saliva.

Lower jaw of Neomys anomalus. Photo by António Pena.

It is suspected that other mammals also produce toxic saliva similarly, as the European mole (Talpa europaea) and other species of shrew, but there are no conclusive studies.

MANED RAT

The maned rat or crested rat (Lophiomys imhausi), lives in Africa and  uses his poisoned hair to protect themself from predators.

Maned rat (Lophiomys imhausi). Photo by Kevin Deacon

Unlike other mammals that produce their own poison, the crested rat gets toxin (called ouabain) from the bark and roots of a tree (Acokanthera schimperi). Chews the bark and the mixture of saliva and toxins are distributed on the body. Their hairs are cylindrical whith a perforated microscopic structure, which favors the absorption of venom. In case of danger, it bristles and shows his brown coat with white stripes, warning of its potential danger. This strategy of persuasion based on brightly colored warning is known as aposematism present in many animals, such as bees.

In this BBC video you can see a crested rat and a hair under the microscope absorbing ink, showing its porous structure:

It is unknown how it is immune to the toxin, since it is the same substance used by some African tribes for hunting such large animals like elephants.

Ouabain is a glycoside which controls the heartbeat, causing infarcts if absorbed in large quantities. The study of the mechanisms that protect the crested rat of a substance that regulates the heartbeat, can help develop treatments for heart problems.

European hedgehogs (Erinaceus europaeus) have similar behavior (smearing the body with foreign poison), but it is not established whether the objective is defensive because it does not scare away predators.

In conclusion, strategies, practices and nature of the poison in mammals are varied and their study may have important medical implications for drug development and increase awareness of the evolutionary relationships between different groups of living animals (reptiles-mammals) and their ancestors.

REFERENCIAS

• Platypus poison
• Scientists discover the function of the echidna’s spur
• Los primates venenosos existen
• El único primate venenoso del mundo ya no está solo
• “Venom” of the slow loris: sequence similarity
  of prosimian skin gland protein and Fel d 1 cat allergen
• Venomous Slow Loris May Have Evolved To Mimic Cobras
• La rata que se unta con veneno para defenderse
• ¿Es cierto que los erizos se embadurnan de veneno?
• Pequeños pero feroces: mamíferos venenosos
• Are slow lorises really venomous?
• Encuentro con un “fósil viviente” en R. Dominicana
• Imagen de portada de Dave Watts

Pangolin: poaching is condemning it to extinction

Neither the tiger or elephant or rhino: the most hunted mammals by humans are pangolins, to the point of critically threaten their survival as a species. Discover the only mammal with scales, its current condition and what can we do to prevent the extinction of all species of pangolin in the world.

WHAT IS A PANGOLIN?

Tree pangolin (Phataginus tricuspis). (Photo by Bart Wursten).

The name pangolin (also known as scaly anteater or trenggiling) includes 8 different species distributed by a variety of habitats (tropical rainforests, dry forests, savanna areas, cultivated fields…) in Africa and Asia. They measure between 90 cm and 1.65 m. They are the only family in the order Pholidota: although physically similar, armadillos, sloths and anteaters are not its relatives (order Xenarthra). Most are nocturnal, solitary and shy, so there are still many questions about their biology and behavior in the wild (they don’t usually survive captivity).

MORPHOLOGY

Pangolins are the only mammals with scales: they are made of keratin (like our nails) and give them a look like a pineapple or artichoke. Scales are very sharp and they can move them voluntarily. If pangolins feel threatened hiss and puff, curl into a ball leaving the scales exposed and secrete pestilential acids to ward off predators (tigers, lions, panthers … and humans).

An impenetrable defense even to a lioness. (Photo by Holly Cheese)

The claws allow them both climb as digging: terrestrial pangolins hide and breed in underground galleries and arboreal pangolins do the same in hollows on trees. The tail of the tree pangolin is prehensile to attach to the branches. In addition, pangolins are excellent swimmers.
They are mainly bipedal animals: forepaws are so large that force them to walk on its hind legs, with a maximum speed of 5 km/h. Watch a pangolin walking and feeding:

NUTRITION

Pangolin has no teeth and is unable to chew. It feeds on ants and termites, which locates with its powerful sense of smell (the view is underdeveloped) and catch them with its sticky and long tongue (may be longer than the body itself, up to 40 cm). The stones swallowed involuntarily and corneal structures of their stomach help them to crush the exoskeletons of insects. With its powerful claws destroy their nests to access them and avoid their attack plugging his ears and nostrils, besides having an armored eyelid. It is estimated that a pangolin can consume about 70 million insects per year, which makes them important regulators of the population of ants and termites.

The tongue of the pangolin. (Photo by Wim Vorster).

REPRODUCTION

Pangolins can reproduce at any time of the year. After pregnancy (two to five months, depending on species) only one young is born (African species) or up to three (Asian species).

Female pangolin. (Photo by Scott Hurd)

The pangolin is born with soft scales, which begin to harden after two days. When after a month come out of the burrow, they travel on the tail of her mother and become independent at 3-4 months. Their lifespan is unknown, although in captivity an individual lived until 20 years old.

Female with her baby in the tail. Bali zoo. (Photo by Firdia Lisnawati)

THREATS AND CONSERVATION

In addition to habitat destruction, the main threat that pangolins face is direct hunting for human consumption. Although there are international laws to protect them, it is estimated that about 100 000 pangolins are hunted annually. Given the defense strategy of this animal, poachers only have to catch them of the ground. Like other species, like sharks, the food market and traditional medicine are the main causes of directing the pangolin towards extinction.

Illegal trade in pangolin. (Photo by Soggydan Benenovitch).

WHY PANGOLINS ARE POACHED?

• Bushmeat is considered a delicacy and an indicator of high social status in Vietnam and China. The pangolin fetus soup is sold as an elixir to increase virility and improve breast milk production. The price of bushmeat on the black market can reach $ 300 per kilo. The price of an individual can reach $ 1,000.

Pangolin fetus soup. (Photo by TRAFFIC).

• Blood is sold as a tonic to improve health and as an aphrodisiac.
• Scales can reach $ 3000 per kilo and are used for almost anything: to cure from acne to cancer. This belief is curious, considering that the scales have the same structure as our fingernails.

Products of traditional Chinese medicine made of pangolin. (Photo by TRAFFIC).

All these purported medicinal and magical effects have no scientific basis, making yet more nonsense pangolin smuggling.

CONSERVATION

The population trend of all species of pangolin is declining in some cases to an alarming extent. The IUCN (International Union for the Conservation of Nature) Red List of Threatened Species classifies them as it follows:

IUCN Red List categories. (Image from iucn.org)

• Vulnerable: all species of african pangolins: black-bellied/long-tailed pangolin (Phataginus tetradactyla), white-bellied/tree pangolin (Phataginus tricuspis), giant pangolin (Smutsia gigantea) and Temminck’s ground pangolin (Smutsia temminckii).
• Endangered: philippine pangolin (Manis culionensis) and indian pangolin (Manis crassicaudata).
• Critically endangered: sunda/malayan pangolin (Manis javanica) and chinese pangolin (Manis pentadactyla).

Because of their status, IUCN restored in 2012 a group of specialists within the Species Survival Commission (SSC) dedicated to pangolins (Pangolin Specialist Group -PangolinSG-). Its main objective are do research to increase knowledge of pangolins, the threats they face and how they can be mitigated to facilitate preservation.

The conservation projects that are being carried out include campaigns to reduce the demand of bushmeat and pangolin scales and the tightening of laws. Still, the total ignorance of populations’ state and low survival in captivity for breeding makes it difficult to design strategies for their conservation.

WHAT CAN YOU DO FOR PANGOLIN?

• Reject any product derived from this animal, either bushmeat, scales or “miracle” products for the cure of diseases. Read the labels of any traditional remedies, especially if they are from the Asian market, and recall that its hypothetical benefits have no scientific basis, so that you can rethink their use.
• Share information. If you own new data on pangolins, photos or videos contact with PangolinSG to cooperate with the investigation. Talk about them in your immediate environment to raise awareness and publicize this fantastic single animal.
• Do a PhD about pangolins. Lot of research on these species is still needed, so if you are a student and you are planning to do a PhD, you can collaborate with PangolinSG with your future research.
• Become a PangolinSG volunteer. Get involved in the development and implementation of projects and conservation programs.
• Make a financial donation so PangolinSG can continue its work.

In conclusion, more scientific research, a change of mind and protection policies are needed to prevent the pangolin become an example of extinct species at the hands of ours, as it is about to happen to white rhino.

REFERENCES

• IUCN SSC Pangolin Specialist Group website
• I fucking love science
• The most trafficked mammal you’ve heard of (CNN)
• National Geographic
• Save Pangolins
• Havocscope. Global Black Market Information
• Traffic
• WWF
• Cover photo by Nigel J. Dennis.

If the nymphs were plants, they would be water lilies

This week, I’m going to introduce water lilies, some flowers very nice and known for being important in the ornamentation.

INTRODUCTION

The Nymphaeaceae family has few species and most of them are freshwater aquatic plants in quiet places and commonly are known as water lilies. Because they are aquatic plants, the family’s name is derived from the Latin word nympha, as they have some similarity with nymphs, mythological beings with a predilection for the waters.

Water nymphs, water lilies can be seen around (Painting by Henrietta Rae, 1909).

The water lilies were originated in warm regions, but they are now subcosmopolitan and can be found in several parts of the world, living in ponds, lakes and freshwater streams.

MORPHOLOGICAL CHARACTERS

The water lilies are perennial aquatic plants, they live several years, and are rhizomatous, that is, they have a thickened stem below the soil at the bottom of the water. In some species, we see that some leaves are immersed and others are floating on the water surface, being sometimes even membranous (they have raised edges perpendicularly upward to avoid the ingress of too much water). When this morphological difference happens, we talk about heteromorphous leaves.

Water lily's membranous leaves (Victoria amazonica) (Photo taken by Dirk van der Made).

Their flowers grown out of water and are constituted by a variable number of sepals, petals and stamens, which are helically born. Therefore, flowers are acyclic, that is, are asymmetrical or irregular because they have no symmetric plane. These flowers are solitary, not born grouped, and hermaphrodites, that is, both male (stamens) and female (ovary) sex organs occur in the same flower.

Pygmy waterlily (Nymphaea tetragona)(Photo taken by Miguel303xm).

These perianth parts (petals and sepals) and stamens are free among them, therefore, they are not united or fused among them, and normally appear in large numbers. The stamens are different to several of other flowers, because they are laminar stamens, similar to the petals. Therefore, they are not filamentous, are thicker and wider.

DIVERSITY

Currently, the genera of water lilies which have more relevance are Nuphar, Nymphaea and Victoria, but there are also some others. Below I present some cases of very interesting species.

The tiger lotus or Egyptian white water-lily (Nymphaea lotus) is native of the Nile Valley and eastern Africa. It is prized as an ornamental and ancient Egyptians believed that the flower could give strength and power.

Egyptian white water-lily (Nymphaea lotus) (Photo taken by Meneerke bloem).

The yellow water-lily (Nuphar lutea) is typical of Europe, North Africa and the Middle East and, as the previous one, is also very ornamental. Furthermore, it has been long used in traditional medicine. Its roots were applied on the skin and seeds and roots were eaten to treat different diseases.

Yellow water-lily (Nuphar lutea) (Photo taken by Oksana Golovko).

Finally, I’d want to introduce the genus of Victoria, whose pollinitation is very curious. It has two American species: V. cruziana in Argentina and V. amazonica in the Amazon and Brazil. Plants of this genus are very big, with floating leaves reaching to 2 meters in diameter and with showy flowers which can reach up to 30 centimeters and are opened at evening.When these flowers are opened, strong scents and a little heat are released and with the whitish and beige colours of the petals, they result very attractive to the beetles (Coleoptera) that are feed of starch extensions on the flowers (starch bodies). The next morning, flowers are closed and the beetles are captured within, causing them to be permeated of pollen. At afternoon, flowers are reopened and allow beetles to escape. Then, as the flowers have been pollinated, their colour varies to pink and they also lose scent. Therefore, the beetles feel more attracted to white flowers that have not been pollinated yet. Finally, the pink flowers are dipped.

On the left, V. cruziana (Photo taken by Greenlamplady); On the right, V. amazonica (Photo taken by frank wouters).

IMPORTANCE

Currently, several species are used as ornamentals, decorative. Furthermore, the water lilies can also be used to get food; the seeds and rhizomes of the genera Nymphaea and Victoria are edible. On the other hand, a very curious thing is that the nerves of the leaves of some species have been used to extract a liquid, which has been applied to treat snake bites.

I hope you liked the way the water lilies behave and all their tales and uses that are associated to them, although only for its beauty are charming. If you enjoyed, do not forget to share in different social networks. Thanks for your interest.

REFERENCES

• Bolòs, J. Vigo, R. M. Masalles & J. M. Ninot. 2005. Flora manual dels Països catalans. 3ed. Pòrtic Natura, Barcelona: pp. 1310.
• Notes of Botany and Phanerogamae, Degree of Environmental Biology, UAB.
• http://www.biologia.edu.ar/diversidadv/fascIII/11.%20Nymphaeaceae.pdf
• http://www.thecompositaehut.com/www_tch/webcurso_spv/familias_pv/nymphaeaceae.html
• http://web.ing.puc.cl/~ing1004/Homeworks/SeresVivos_E3/g63_Sof%C3%ADaGjuranovic_VictoriaAmaz%C3%B3nica.pdf

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