Leishmaniasis

Leishmaniasis is an infectious disease caused by a parasite. This parasite is transmitted by a vector, namely sand flies. 

There are many types of Leishmania. Leishmania infantum is a species that grows around the Mediterranean Sea, where it is transferred from dogs or rats to humans by sand flies. Leishmaniasis is thus a zoonosis. Some Leishmania species are transferred from humans to humans by sand flies, for example in India. The parasites can also be transmitted through blood transfusions and, in dogs, through fighting wounds with blood-blood contact.

Fig 2. - Leishmania donovani. Motic B410E PlanApo 100X o.i. Moticam S12. 

Image credit: Willem Cramer

The symptoms in humans depend on the severity of the infection and the type of Leishmania. The syndromes that can occur are at the cutaneous (the skin), mucocutaneous (the skin and mucous membranes) or visceral (the intestines) level.

Fig 2. - Leishmania donovani. Motic B410E PlanApo 100X o.i. Moticam S12. 

Image credit: Willem Cramer

• With the cutaneous form, an ulcer develops where the infected sand fly stings. Several ulcers can develop at the same time, at the different stinging spots. The sores can disappear spontaneously over months or years, but can leave severe scars.

• With the mucocutaneous form, ulcers develop on the mucous membranes of the mouth or nose, for example, and can deform the entire face.

• In the visceral form, an enlargement of the spleen occurs first and later also of the liver. Anemia, a decrease in the number of white blood cells, bleeding in the mucous membranes and pigmentation of the skin can also occur. Patients suffer from weight loss, long-lasting fever with alternating fever peaks, general malaise, and sometimes diarrhea or cough. The visceral form can be lethal without treatment, but can also be latent or cause only mild phenomena, depending on the host's resistance. The incubation period can vary from 10 days to several years, on average it takes 2 to 6 months from the bite of the sand fly to the onset of symptoms. Often secondary infections occur.

There is no vaccine against Leishmaniasis, neither for animals nor for humans. That is why it is important to protect humans and animals against the sand flies that are mainly active around dusk. Protective clothing, insect repellent and mosquito nets can help keep the flies at bay. There are special collars with insecticides for dogs. The sand flies are less often present indoors and insecticides can also be used. Leishmaniasis is common in tropical regions, as well as in countries around the Mediterranean.

Fig 3. - Leishmania donovani. Motic B410E PlanApo 100X o.i. Moticam S12. 

Image credit: Willem Cramer

In the photos, amastigotes are indicated with an arrow. Amastigotes are the parasites forms that persist in the infected host; they infect cells recruited to lesions and disseminate the infection to secondary sites.

Sample: Leishmania donovani viewed through Motic B410E PlanApo 100X o.i. Recorded with Moticam S12.  With thanks to Cees Koopman veterinarian.

© willemsmicroscope.com

Printings techniques on World Design Day 2023

The 27th of April is World Design Day, an initiative that recognizes how design makes everyday life both beautiful and meaningful. 

Printing techniques are an imprescriptible area in the field of design, and thanks to microscopy we can discover old and new techniques from the smallest details.

The beginnings of World Design Day came from Kim Paulsen, V.P. of the International Council of Graphic Design Associations (ico-D), and the first edition was held in 1995, but it was named World Graphics Day then. 

Today we are going to show you how the history of graphic design and printing techniques can be discovered by looking under a microscope. There are two microscopically observed samples of graphic design products, such as an antique stamp and a brochure of a high-end product, both were printed with different techniques, which we can learn about today, thanks to microscopic observation.

Old stamp printing techniques from a century ago

Here we see a vintage Dutch jubilee stamp of Queen Wilhelmina, 7 1/2 cents 1923 carmine. This stamp was issued to commemorate the Queen’s 25th anniversary of her reign from 1898 till 1923. 

The basis for the image of her portrait on this stamp is a copper engraving. The stamps were printed with copper plates with the printing ink being rolled into the grooves of the engraving.

Fig 1. - Old stamp. Image credit: Willem Cramer

During pressing of the stamps, the paper absorbs the ink from the grooves of the engraving. In the resulting short video, it is easy to recognize how the printing ink is clearly on top of the paper. This stamp was printed on sheets of 100 pieces. 

Fig 2. - Old stamp. Image credit: Willem Cramer

Fig 3. - Old stamp. Image credit: Willem Cramer

Produced with Motic equipment:

Motic SMZ-171, stereomicroscope

Moticam ProS5 Lite camera

With thanks to Rijk Koster, stamp collector.

Mayfly larva or Cloeon dipterum

In our geographical area, especially in spring, nature is busy creating new life, such as these Mayfly larvas which will become adult insects in a few months.

Fig 1. - Mayfly adult. Mayfly, Leaf, Dew Image. Pixabay.com

Mayflies are aquatic insects belonging to the order Ephemeroptera. This order is part of an ancient group of insects termed the Palaeoptera, which also contains dragonflies and damselflies. Over 3,000 species of mayfly are known worldwide, grouped into over 400 genera in 42 families. 

In these images, you are seeing Mayfly larvae, which have a slender and soft-body like the adult insects. They do not have wings but have a series of leaf-like or feathery external gills attached along the sides or to the upper rear part of the abdomen. In the video, you can see them fluttering up and down. Their eyes are smaller than those of the adult insects.

Fig 2. - Mayfly larva or Cloeon dipterum. Motic SMZ-171

Moticam 1080. Image credit: Willem Cramer

As mentioned, adult mayflies are slender, soft-bodied, with four membranous, extensively veined wings held upright and together (like a butterfly). The forewings are much longer and often overlap the hindwings.

Mayflies play an important role in aquatic ecosystems, eating algae and other small objects and being eaten by larger animals. As winged adults, mayflies only live for a few days. The only function of the adult is reproduction. Their swarms often cause a feeding frenzy among fish.

Mayflies are the only insect to have two "mature" molts. They begin life as eggs that are laid on the surface of the water and sink to the bottom. The larvae of mayflies crawl around rocks and vegetation. After months or years of growth (depending on the species), they float to the surface and molt into a winged but sexually immature subadult. Often another molt occurs within hours and the final stage emerges - the reproductive adults who live for only days or hours.

Fig 3. - Mayfly larva or Cloeon dipterum. Motic SMZ-171

Moticam 1080. Image credit: Willem Cramer

In places where mayflies synchronize their maturation and mating cycles, appearing in swarms, they also usually cause fish to gather, and anglers create fly baits to resemble adult mayflies.

All life stages of mayflies are favorite foods for fish such as trout, perch and many others, as well as smaller aquatic predators in the food chain. Adult mayflies are also eaten by terrestrial predators such as spiders and birds.

Sample: Mayfly larva or Cloeon dipterum. Motic SMZ-171 Recorded with Moticam S12. 

Spinel Fluorescence

Vibrant colors of a Spinel stone from Cambodia.

With the aid of a Motic microscope with fluorescence attachment, using a DAPI lp filter set, the available Spinel stones fluoresced with a weak red light under UV light, at an excitation wavelength of 375 nm.

Fig 1. - Spinel from Cambodja. Motic AE31E Plan Fluar 5X.

Moticam S12. Image credit: Willem Cramer

The fluorescence of Spinel was studied as early as 1887 by De Boisbaudran who found a red glow in most specimens and some green fluorescence in a few. Crookes plotted in 1887 the red fluorescence spectra of Spinel and pointed out the particular sharp band at about 690 nm.

The general chemical formula of Spinel is MgAl2O4. It belongs to the oxides and hydroxides family. The most common fluorescence activators for Spinel are Cr3+ and Mn2+. Peaks in the spectrum are:

Cr3+ : lines at 676 (675), 686 (685), 698 (697), 708 (707), 712, 718 (717) nm

Mn2+ : broad band peaking at 550-612 nm

Due to the rough shape of the available small and rough Spinel stones, it was necessary to take a large series of photos and stack them in order to visualize the surface structure. The stones were too big in size to put them under an upright fluorescence microscope. However, the Motic inverted microscope AE31E came in handy here. Although fluorescence observed with the naked eye was very weak, the Moticam S12 coped well with the low light conditions.

Sample: Spinel from Cambodja viewed through Motic AE31E Plan Fluar 5X. Recorded with Moticam S12. 

© willemsmicroscope.com