Answer to Case 254

Answer:  Hirudo medicinalis, the European medicinal leech. 

Today, leeches are not used for 'balancing humors' but instead to to reduce venous pooling of blood in delicate surgeries such as reconstructive and reattachment surgeries.  Medicinal leeches secrete a number of anticoagulants in addition to hirudin which facilitate blood flow and therefore promote wound healing. 

Note that leeches are annelids and not trematodes, despite their superficial resemblence.  You can appreciated their segmented nature in this photograph:

Medicinal leeches carry Aeromonas hydrophila in their gut. Therefore, it is important to give the patient antimicrobial prophylaxis when prescribing medicinal leech therapy. 

Case of the Week 254

This week's case is just a fun identification.  (Hint, these objects were obtained at the local hospital pharmacy...)

 

Questions:

1.  What are they used for in the health care setting?

2.  Which bacteria is associated with them?

Answer to Case 344

Answer:  Earthworm, a segmented worm in the Annelida phylum.  As Hans pointed out, it has rings around its body and a "saddle" (clitellum) which is a sac in which eggs are deposited.

Thank you to Florida Fan for sharing your earthworm story. Another reader also wrote in with a comment on how often earthworms are submitted to the laboratory.  It's true! We get an earthworm submitted to our laboratory about once per week in the spring and summer months; (granted, we are a large reference lab and smaller labs probably don't see as many).

We've had several examples of annelids on this blog before:

Case 234 shows what an earthworm looks like on histologic sections (although sending intact worms to the microbiology lab is always preferred to sectioning them!)

and Case 254 is an example of medicinal leeches - another annelid.