#embryological

[markscherz]

now accepting guesses as to what this embryo becomes when it matures

[jcrmhscasereports]

COMPLETE PENOSCROTAL TRANSPOSITION WITH MULTIPLE CONGENITAL MALFORMATIONS by Jafari B. Lutavi in Journal of Clinical Case Reports Medical Images and Health Sciences  

SUMMARY

Penoscrotal transposition (PST) is an extremely rare congenital anomaly of the external genitalia, characterized by malposition of the penis in relation to the scrotum. PST can be either complete or incomplete according to the positional exchanges between the penis and scrotum and both forms of PST are generally linked with hypospadias. Incomplete transposition is the common form of this entity and the penis lies in the middle of the scrotum, but complete transposition, the scrotum almost entirely covers the penis, which emerges from the perineum. Both forms are most often associated with a wide variety of other anomalies. We describe a case of a newborn with complete PST, with other associated malformations.

BACKGROUND

Penoscrotal transposition (PST) is a rare anomaly of the external genitalia, characterized by malposition of the penis in relation to the scrotum1,2,3. PST can be defined as either complete or incomplete according to the positional exchanges between the penis and scrotum and both forms of PST are generally linked with hypospadias. Incomplete transposition is the common form of this entity and the penis lies in the middle of the scrotum, but in complete transposition, the scrotum almost entirely covers the penis, which emerges from the perineum1. PST was first reported by Appleby in 1923. Patients with PST often have accompanying urological abnormalities, such as chordee, hypospadias, and vesicoureteric reflux4.

The etiology and embryological sequence abnormalities that occur in PST is still unclear. The genital tubercle and the labioscrotal swellings are the embryological origins of the penis and scrotum, respectively. During normal embryonic development, in the 9th–11th week, the scrotal swellings migrate infero-medially and fuse in the midline caudal to the genital tubercle that forms the penis by the 12th week of gestation. This is usually achieved under the influence of androgens and poor response or absence of androgens results in abnormal migration  of the scrotal swellings3. Somoza et al suggested that an abnormal positioning of the genital tubercle at the 6th gestation week (GA) concerning the scrotal swellings or a defective gubernaculum leads to PST2.

Complete penoscrotal transposition (CPST) is frequently characterized by major and often life-threatening anomalies involving the urogenital, cardiovascular, gastrointestinal, and skeletal systems2. Common genital anomalies include hypospadias and chordee, and 100% of cases have a renal defect.

CASE PRESENTATION

A gravida 5, para 1, living 1 with 3 abortions woman aged 27 years was referred from Mwananyamara Referral Regional Hospital and admitted to Obstetrics and Gynecology department at Muhimbili National Hospital- Mloganzila. She has a referral diagnosis of antepartum hemorrhage and severe oligohydramnious at GA of 30 weeks 2 days. She had three previous pregnancy loses: 1st and 2nd loses both at 12 weeks GA with 6 months between the loses; her 3rd loss was 2 years after she had a term healthy baby by normal delivery.

She had no histories of phenotypic genetic abnormalities in their families, illicit drug use, cigarette or alcohol consumption, no chemical, radiation exposure, or any chronic illness. She is married, and is a university graduate, working as a transportation officer. She attended antenatal clinic (ANC) five times and all her laboratory work-up such as blood count indices, blood grouping, urinalysis, stool examination, and microscopy, and fasting blood sugar were normal. She was HIV negative and blood film for malaria parasites came back negative. Record of the ultrasound scan taken at 6th -week gestation indicates early multiple pregnancy (two gestational sacs seen) and the next scan performed at 27th weeks GA show a normal single fetus with no anomaly. She was given iron and folic acid supplements, received Tetanus Toxoid vaccine twice, sulfadoxine-pyrimethamine (SP) tables twice as part of intermittent preventive therapy for malaria and she was dewormed using Mebendazole. With her history of pregnancy loss and complaints of abdominal cramps, she had been kept on bed rest at home from 16th week of gestation as recommended by her obstetrician at Mwananyamala Hospital.

After she was brought to our hospital she had active vagina bleeding. A bed side ultrasound revealed placenta previa grade 3 and she was planned for emergency hysterotomy. She delivered a male baby, 1750 gm, who did not initiate spontaneous breathing after birth. The baby was initially resuscitated with a bag and mask before intubation at age 5 minutes. He was assigned an Apgar score of 3, 1, 4 at 1st, 5th and 10th minute respectively. On examination, baby had severe pallor, occipital-frontal circumference – 29cm, communicating anterior and posterior fontanelle, low set ears, short neck, wide-spaced nipples, undescended testes (empty scrotum), inverted genitals (CPST) with hypospadias (Figure 1), rectal atresia, prominent heel, and bilateral talipes equinovarus.

https://jmedcasereportsimages.org/wp-content/uploads/2022/10/fig-1-2.jpg

Figure 1: (a) shows a horizontal view of complete penoscrotal transposition and (b) shows an oblique view of complete penoscrotal transposition.

DISCUSSION

Penoscrotal transposition (PST) is a congenital urogenital anomaly described first in 1923 by Appleby. The embryological sequence responsible for this malformation remains unclear; however, it has been suggested that an abnormal positioning of the genital tubercle in relation to the scrotal swellings during the critical fourth to the fifth week of gestation could affect the migration of the scrotal swellings2. In this case report, there is a complete exchange of position with the scrotum located superior to the penis, which is inferior to scrotum. (Figures 1(a) and 1(b)). Also, there presents a spiral and hypoplastic penis crooked toward the anal position. Ayamba et al reported the same findings whereby noticed complete transposition of the external genitalia with cryptorchidism, hypoplastic penis from the perineum just above the blind anal position, and caudal to the scrotum3. Somoza et al also noted at birth a newborn has a complete transposition of the external genitalia, a 3.5-cm-long, hypospadic, and hypoplasic penis arose from the perineum, just above the anus and beneath a normal scrotum1–3,5.

CPST is often characterized by major associated malformations. Our baby had also other multiple physical abnormalities such as short neck, low set ears and talipes equinovarus. Unfortunately, due to our limited resources, we could not complete imaging of internal organs. Previous reports of CPST have also noted presence of other malformation with 100% occurrence of renal anomalies. For example, Parida et al had noted major renal anomalies in the form of agenesis, horseshoe kidney, ectopic and dysplastic kidney, obstructive uropathy, and hydronephrosis. Other systemic abnormalities are mental retardation, anorectal malformations, central nervous system, skeletal and cardiological defects5.  In our case, we did not perform imaging to detect renal anomalies, but literature suggests most likely there were there. The detection of CPST should warrant careful clinical evaluation to rule out other anomalies.

Although some reported a family history and genetic basis for the incidence of PST6, we did not find any evidence of positive family history of phenotypic abnormalities. When associated with severe hypospadias, penoscrotal transposition necessitates a staged surgical repair for physiological and psychological reasons.

Our newborn required advanced resuscitation at birth, likely due to hypoxia in utero as a result of significant blood loss (placenta previa grade 3). This is supported by the findings that baby was very pale at birth. However, we cannot rule out the possibility of other anomalies such as fatal cardiac anomalies which are incompatible with life1,5.

OUTCOME

The newborn was transferred to the neonatal intensive care unit for further treatment and passed on after 4 hours. No any radiological or laboratory investigation were completed within this time.

LEARNING POINTS/TAKE HOME MESSAGES

Strengthening of antenatal care services in a primary health facility is a key for positive outcome of pregnancy. This is by early detection of abnormal development of fetus in utero by early ultrasound

Referring hospitals in low-income settings should be strengthened with well knowledgeable personnel (radiographers) and modern equipment. As we have notice in this case even a placenta praevia was detected after being received in a tertiary hospital despite the woman being scanned in late 2nd

There is a need of strengthening neonatal ICU by ensuring bedside radiological equipment’s is available also other ICU equipment’s are enough. As we have seen no any radiological investigation done to the baby due to the fact that the baby was in critical condition but based on critical care knowledge and experience this could possible by bedside equipment.

Learning culture must be strengthened in our institute; if we had good learning culture radiological investigations would have been done to the dead baby for learning purpose to detect if there is any other internal congenital anomaly and other cause of death to this newborn

PATIENT’S PERSPECTIVE

Am so thankful for the services I receive from all hospitals and I declare to have no any experience of having an abnormal baby in my family and even my husband’s family. This is my first time to give birth a newborn with congenital malformation and i wondered the way it was not even discovered early during the antenatal period. Also, I promise to attend the clinic early for the next pregnancy and follow all instructions that i will be given by health care providers for the sake of the good health of herself and next baby.  Am so happy about this publication because it will help other doctors to identify the condition and treat it accordingly also for those who are in learning schools will learn more about this condition.

Competing interests: None.

Patient consent: Obtained

For more information: https://jmedcasereportsimages.org/about-us/

For more submission : https://jmedcasereportsimages.org/

[bloodbruise]

attending!james bringing med student!reg coffee each time he's been at the books for hours. he just wordlessly puts it down, slips his arms around regulus' waist and kisses the tension out of his jaw. hums along while regulus rants about germ layers, embryology, the whole unintuitive mess of it. has to stifle his smile in the back of reg's neck because, yeah he's been there too.

[secularprolifeconspectus]

My friend is 9 weeks pregnant! Her embryo is 7 weeks gestation. We call them Frijole and in this video they roll over, suck their thumb and wiggle their toes. You can also see their heart thumping!

[nemfrog]

"Development of body form in pig embryo." Comparative embryology of the vertebrates. 1953.

Internet Archive

[o-craven-canto]

Embryophylogeny

(original picture here)

A map showing the derivation of various structures and tissues of the human body from the parts of the early embryo.

Human figure partly traced from this Wiki Commons image (public domain). Main source is TW Sadler, Langman's medical embryology (12th ed.), 2012.

[nochd]

This came across my dash via the #lgbt tag yesterday. I don't want to engage with the OP because that would get me into fights on radfem tumblr and I don't have the energy for that. But the post itself I think is worth answering, just because it's so neatly and exactly wrong.

(Not that my answer is going to spread very far, because I have 37 non-bot followers, of whom I think roughly 35.5 are just here for the nude photos. But anyway.)

Even if I agree just for argument's sake that the existence of intersex people proves that some people can have "nonbinary" sexes, or "third" sexes, and that "sex is a spectrum," how does that have any relevance to people who are not intersex? Like okay, let's "agree" for the moment that intersex people are something other than male or female. How does that make YOU, as a person who is not intersex, something other than male or female? Saying that intersex people's existence somehow makes sex "complicated" for you specifically is like saying that the issue of whether or not you can hear is "complicated" because some other people who are not you suffer from hearing loss or deafness. Like sorry but for 99% of the human population it is not "more complicated" than born with perfectly normal male genitalia = male and born with perfectly normal female genitalia = female, and chances are you fall into that 99%. Sex is not a social construct or a nebulous enigma of a concept. It is not debatable and made up in the manner that gender is. You cannot philosophize about whether there are two sexes any more than you can philosophize about whether humans have two kidneys. Someone having a missing or malformed kidney or accessory kidneys does not change the fact that humans as a species have two kidneys. Humans are gonochoric just like nearly all other animal species on Earth.

Let's start with the arithmetic. If 99% people are of binary sex, that leaves 1% of people who aren't. There are approximately 8 billion humans on Earth. 1% of 8 billion is 80 million -- about sixteen times the population of my entire country. Even just the number of intersex Americans is something like two-thirds the population of my country. This is not a negligible number of people.

There's a deeper error here, one that goes to the root not just of this misunderstanding but of many. Biology is always complicated, at every scale and at every level of explanation. It's messy, it's fuzzy, and it's always bottom-up, never top-down. Everything biological is the way it is because it grew that way. Biology never does the same thing twice.

Why does it seem like it does? Because, of all the ways you can arrange the parts of a living body, only an astonishingly tiny fraction of them actually make a living body. Any genetic mutation that nudges an organism outside of that fraction dies out and doesn't get passed on. Embryonic development is a gruelling tight-rope walk over a vast pit of non-existence.

Now for most of the body's systems, evolution has only had to produce one arrangement that works and survives. There's not an alternative plumbing plan where the oesophagus goes to the lungs and the trachea to the stomach. But for the reproductive system, evolution has to allow for two arrangements that work and survive, and it has to grow them both from the same starter kit.

What it does, therefore, is grow a body plan that works with a continuum of possible arrangements that includes both of those two. Various other points on the continuum may or may not be capable of producing viable gametes, but they're all survivable.

What biology doesn't do -- what biology never ever does -- is run new products on a conveyor belt stamping them into shape with cookie-cutters. The only things made that way are artificial constructs.

[bat-snake]

In all seriousness though, I love that how, even though Leola has one horn, it has two branches, which just makes me Think Things about elf embryology (if she even developed from an embryo to begin with???)

Like...they probably START with a single horn that's supposed to split and move to the top of the skull as cell division goes along, but that never happened with Leola. Yet the genes for two horns kept going anyway...so we get the single horn with a small branch coming off it, in the middle of her forehead.

Single horns could also be regarded as one of the first signs that a baby might be neurodivergent. (Obviously not EVERY "unique and quirky" elf has had a single horn, but all single horned elves have been "unique and quirky")

[cheerfullycatholic]

[biologist4ever]

𝐈𝐧𝐭𝐚𝐜𝐲𝐭𝐨𝐩𝐥𝐚𝐬𝐦𝐢𝐜 𝐒𝐩𝐞𝐫𝐦 𝐈𝐧𝐣𝐞𝐜𝐭𝐢𝐨𝐧

 𝐓𝐡𝐞 d𝐫𝐞𝐚𝐦 𝐨𝐟 s𝐭𝐚𝐫𝐭𝐢𝐧𝐠 𝐚 f𝐚𝐦𝐢𝐥𝐲 𝐰𝐢𝐭𝐡 d𝐢𝐫𝐞𝐜𝐭 f𝐞𝐫𝐭𝐢𝐥𝐢𝐳𝐚𝐭𝐢𝐨𝐧

[bpod-bpod]

Signals for Embryos

A stem cell-derived mouse embryo model reveals the molecular signals that orchestrate early embryo tissue patterning [getting the cells and layers in the right place]

Read the published research article here

Video from work by Sina Schumacher and colleagues

Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany

Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Nature Communications, June 2024

You can also follow BPoD on Instagram, Twitter and Facebook

[strikeslip]

One of the things about the Commonweal books is they will differentiate the various named species by metabolism before they tell you what anyone looks like. We get thorough descriptions for Creeks, Graul, and not much else. I know Elegants drink ethanol instead of water and are 'pretty', which is not a helpful description without an idea of what's socially constructed as pretty. I know Typicals gesture a noticeable amount and will argue about egalité till they drop, but I have no idea what lets people visually differentiate them from Regulars. I know some kind of difference exists because the differentiation happens, you've got Crane as a 'possible typical antecedent' and more than one comment on how the various types of Regulars are hard to tell apart, even for Regulars. But what that looks like? Hahahaha, no.

I say this because on my uncountable Nth reread of Under One Banner, I finally noticed a reference to rope sandals and was shocked and delighted. There aren't no visual notes, there's lots of heights for comparison to Creeks, there's enough skin color descriptions to know various shades of brown are expected, there's references to seasonal wear like hats and mud shoes, there's a few wraps and tabard-like things, there's almost enough military uniform descriptions to give me confidence the army wears plate, individually sized via magic, and there's sorcerer formalwear and Halt's knitting. But still, rope sandals! Exciting!

Now please, please, please, give me some visual hints on how to make a dozen different humanoid species distinct without going to the classic elf ears and animal-parts. Because there's absolutely no justification for either of those default fantasy tropes in this book and I want to know if Wake has a different skull shape or what. How do you expect me to draw the height chart. Please. I just want to make art that can be recognized.

[savemygrades]

Brunch + study sesh <3

[noncompliantcyborg]

Let's Talk Sea Slugs: Rostanga pulchara

Rostanga pulchara is a small species of dorid nudibranch commonly found grazing on the red sponges that give it its color.

The adult below was 16mm long and 8mm wide, but they can grow to as large as 33mm long (Jensen et al 2018).

Above - Adult Rostanga pulchara collected from Cattle Point Intertidal, San Juan Island by Babonis Lab, Summer 2022.

Above - Closeups of Rostanga pulchara. Left - mantle showing the texture and shape of the tubercles. Center - gills. Right - rhinophore.

Along with size and color, a defining characteristic of the nudibranch is its uniquely shaped rhinophores (Jensen et al 2018). One is pictured above on the right.

A good way to find them in the wild is to look for the sponges that they eat. Two of these species are the velvety Clathria pennata and the "volcano-shaped" Acarnus erithacus (Jensen et al 2018). Both sponges are encrusting and highly pigmented.

The pigments from the sponge not only color the adult nudibranchs, but also their eggs (Jensen et al 2018). This can be seen in the early embryos below.

Above - Rostanga pulchara embryos, 2-cell and 4-cell stages. Viewed on 6/21/2022 under 40x magnification. The center 2-cell embryo was 111 microns across.

A week and a half later, these embryos had developed close to the point of hatching.

Unhatched veliger larvae, with visible shell anViewed on 7/1/2022 under 40X magnification. The center embryo measured at 125 microns across.

These nudibranchs, like many others, have a larval form called veligers. These veligers have shells and big ciliated lobes.

Hatched veliger larvae. Viewed on 7/7/2022 under 40X magnification.

Hatched veliger larvae from the same clutch of original eggs. Viewed on 7/13/2022 under 20X magnification. The larvae on the right was measured as 194 microns across the veler lobes and 178 micros from the top of the shell down to where the veler lobes exit the shell.

Sources:

Personal lab notes and obervations.

Jensen et al. Beneath Pacific Tides. MolaMarine, 2018.

All photographs by JA Fields, do not repost without express written permission.

*If you appreciate the work I do, you can support me through sharing my work, tipping me, or buying my art prints or embroidery.*

[nemfrog]

Chicken embryo at 20 hours. Comparative embryology of the vertebrates. 1953.

Internet Archive

[quark-nova]

Spec evo folks: Six limbed vertebrates can't exist, it wouldn't work physically

Six limbed vertebrates: