Critical Perspectives on Boys’ Circumcision

Circumcision is a procedure in which the foreskin is partially or completely removed from the penis. There are a number of ways in which this is performed, and it has been done for different reasons across history and culture. In the United States, for example, circumcision is generally performed in infancy for nonreligious reasons, while it is often performed ceremonially among Muslim and Jewish populations in keeping with religious tenets. In societies where routine circumcision is performed in infancy, parents tend to report that the decision was made because of cultural beliefs surrounding hygiene, cleanliness, aesthetics, and “fitting in” with other boys. In societies where circumcision is performed after infancy, it is often done as part of a rite of passage from childhood or adolescence into adulthood. All mammals are born with foreskin, which is a clitoral prepuce in females and a penile prepuce in males. For those individuals with indeterminate sex status, they also have a prepuce. In the United States, only the penile prepuce of male infants is routinely removed; it is illegal to modify the clitoral prepuce of female infants. On penises, the foreskin naturally adheres to the glans, or head, of the penis, and over time the foreskin will retract on its own. No special cleaning is required, and as the individual gets older and the foreskin retracts naturally, it can be cleaned like any other body part. The foreskin serves a number of important functions. It protects the glans from external trauma and allows it to remain moist. It also serves to allow for a natural “gliding” mechanism during penetrative intercourse or masturbation that allows for loose skin on the penis to slide along the shaft. One of the challenges of evaluating circumcision and scholarship is that oftentimes the studies and scholars have partisan views on circumcision. Some research is anti-circumcision and some is pro-circumcision. While these debates are not new, they are ongoing and important because they reflect the complexity of the subject matter and the realization that circumcision is never “just a snip,” but rather is imbricated in a long history and a significant debate among scholars, scientists, parents, and religious leaders. The study of circumcision is thus an interdisciplinary one that brings together knowledge from a range of fields, including, of course, the study of childhood. Scholarship on circumcision is incredibly diverse not just because of the fields from which it is studied, but also because of the diversity of opinions about circumcision. For some it is a “biomedical imperative” to prevent the spread of HIV/AIDS, while for others it is “a solution looking for a problem.” In circumcising cultures, the practice is often normalized and therefore invisible to critique; as a result, much of the research and commentary surrounding the practice serves to uphold social norms and the status quo. Thus, our explicit goal here is to refocus and make visible the counter-discourse that provides a more skeptical view of a procedure that is otherwise taken for granted. The focus of this bibliography is to address more of the cultural, religious, ethical, moral, and medical arguments against the routinized practice of circumcision in secular societies. Our aim is to provide scholarly and popularized sources that critique, question, problematize, or reframe the current cultural dialogues that already maintain and uphold routinized penile circumcision performed on boys during the neonatal period.

Directed Binding of Gliding Bacterium,Mycoplasma mobile, Shown by Detachment Force and Bond Lifetime

ABSTRACTMycoplasma mobile, a fish-pathogenic bacterium, features a protrusion that enables it to glide smoothly on solid surfaces at a velocity of up to 4.5 µm s−1in the direction of the protrusion.M. mobileglides by a repeated catch-pull-release of sialylated oligosaccharides fixed on a solid surface by hundreds of 50-nm flexible “legs” sticking out from the protrusion. This gliding mechanism may be explained by a possible directed binding of each leg with sialylated oligosaccharides, by which the leg can be detached more easily forward than backward. In the present study, we used a polystyrene bead held by optical tweezers to detach a starved cell at rest from a glass surface coated with sialylated oligosaccharides and concluded that the detachment force forward is 1.6- to 1.8-fold less than that backward, which may be linked to a catch bond-like behavior of the cell. These results suggest that this directed binding has a critical role in the gliding mechanism.IMPORTANCEMycoplasmaspecies are the smallest bacteria and are parasitic and occasionally commensal, as represented byMycoplasma pneumoniae, which causes so-called “walking pneumonia” in humans. Dozens of species glide on host tissues, always in the direction of the characteristic cellular protrusion, by novel mechanisms. The fastest species,Mycoplasma mobile, catches, pulls, and releases sialylated oligosaccharides (SOs), which are common targets among influenza viruses, by means of a specific receptor based on the energy of ATP hydrolysis. Here, force measurements made with optical tweezers revealed that the force required to detach a cell from SOs is smaller forward than backward along the gliding direction. The directed binding should be a clue to elucidate this novel motility mechanism.

Structural Study of MPN387, an Essential Protein for Gliding Motility of a Human-Pathogenic Bacterium, Mycoplasma pneumoniae

ABSTRACTMycoplasma pneumoniaeis a human pathogen that glides on host cell surfaces with repeated catch and release of sialylated oligosaccharides. At a pole, this organism forms a protrusion called the attachment organelle, which is composed of surface structures, including P1 adhesin and the internal core structure. The core structure can be divided into three parts, the terminal button, paired plates, and bowl complex, aligned in that order from the front end of the protrusion. To elucidate the gliding mechanism, we focused on MPN387, a component protein of the bowl complex which is essential for gliding but dispensable for cytadherence. The predicted amino acid sequence showed that the protein features a coiled-coil region spanning residue 72 to residue 290 of the total of 358 amino acids in the protein. Recombinant MPN387 proteins were isolated with and without an enhanced yellow fluorescent protein (EYFP) fusion tag and analyzed by gel filtration chromatography, circular dichroism spectroscopy, analytical ultracentrifugation, partial proteolysis, and rotary-shadowing electron microscopy. The results showed that MPN387 is a dumbbell-shaped homodimer that is about 42.7 nm in length and 9.1 nm in diameter and includes a 24.5-nm-long central parallel coiled-coil part. The molecular image was superimposed onto the electron micrograph based on the localizing position mapped by fluorescent protein tagging. A proposed role of this protein in the gliding mechanism is discussed.IMPORTANCEHuman mycoplasma pneumonia is caused by a pathogenic bacterium,Mycoplasma pneumoniae. This tiny, 2-μm-long bacterium is suggested to infect humans by gliding on the surface of the trachea through binding to sialylated oligosaccharides. The mechanism underlying mycoplasma “gliding motility” is not related to any other well-studied motility systems, such as bacterial flagella and eukaryotic motor proteins. Here, we isolated and analyzed the structure of a key protein which is directly involved in the gliding mechanism.

Periodicity in Attachment Organelle Revealed by Electron Cryotomography Suggests Conformational Changes in Gliding Mechanism ofMycoplasma pneumoniae

ABSTRACTMycoplasma pneumoniae, a pathogenic bacterium, glides on host surfaces using a unique mechanism. It forms an attachment organelle at a cell pole as a protrusion comprised of knoblike surface structures and an internal core. Here, we analyzed the three-dimensional structure of the organelle in detail by electron cryotomography. On the surface, knoblike particles formed a two-dimensional array, albeit with limited regularity. Analyses using a nonbinding mutant and an antibody showed that the knoblike particles correspond to a naplike structure that has been observed by negative-staining electron microscopy and is likely to be formed as a complex of P1 adhesin, the key protein for binding and gliding. The paired thin and thick plates feature a rigid hexagonal lattice and striations with highly variable repeat distances, respectively. The combination of variable and invariant structures in the internal core and the P1 adhesin array on the surface suggest a model in which axial extension and compression of the thick plate along a rigid thin plate is coupled with attachment to and detachment from the substrate during gliding.IMPORTANCEHuman mycoplasma pneumonia, epidemic all over the world in recent years, is caused by a pathogenic bacterium,Mycoplasma pneumoniae. This tiny bacterium, about 2 µm in cell body length, glides on the surface of the human trachea to infect the host by binding to sialylated oligosaccharides, which are also the binding targets of influenza viruses. The mechanism of mycoplasmal gliding motility is not related to any other well-studied motility systems, such as bacterial flagella and cytoplasmic motor proteins. Here, we visualized the attachment organelle, a cellular architecture for gliding, three dimensionally by using electron cryotomography and other conventional methods. A possible gliding mechanism has been suggested based on the architectural images.