When Does it Happen
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When does it happen?

I will be updating  the information/research in a separate page as I gain further information. One of the advantages of going back to school has been gaining access to journal material through the university library. This includes a great deal of on line material not available to the public with out subscription. I Love It  
 

 What is Gender? and What is  Sex?

 Sex Referring to the biological classification of an individual into either "male" or "female" based on chromosomes, genitalia, secondary sexual characteristics, etc.

Gender Referring to a psychological identification that a person has of himself as either "man" or "woman".   

When does it begin?

 It all starts at the very moment of conception. Advanced studies are continually shedding more light on how an embryo becomes male or female and how this process sometimes goes awry.

There is increasing evidence that there is both a genetic and or an endocrine disruption that determines the gender and sex of a fetus.

the sperm approaching the ovum     the unborn child at 8 weeks    an unborn child at 5 months, bottom view

  two weeks                                      eight weeks                           five months

All embryos are identical in external appearance for the first eight weeks of gestation, and then several factors nudge the infant toward male or female development. In the seventh week, the embryo has both male and female primordial ducts. In the normal female fetus, the millerian duct system then develops into oviducts and a uterus. In the normal male fetus, the wolferian duct system on each side develops into the epididymis and vas deferens. The external genitalia are similarly bipotential until the eighth week (The reproductive organs and genitals associated with "female" or "male" arise from the same initial (fetal) tissue). Thereafter, the urogenital slit disappears and male genitalia form or alternatively, it remains open, and female genitalia form.

 If the egg was fertilized with the x chromosome then the female structures continue to mature, the default system.

However if the y chromosome fertilized the egg then a hormonal switch happens,,, two genes are activated and the female structures are completely dissolved and destroyed and the male organs take their place. But some embryos step off track.

 If everything goes right!

  If the fetus is a male? It is normally under the influence of the mother’s female hormone (her estrogen) for nine months the first trimester being the most critical in brain development.

 In a pregnant woman, the binding action between special blood proteins and estrogens ties up most of the hormone circulating and thus acts to protect fetuses from excessive estrogen exposure in the womb. …

 What factors can disrupt this?

Two studies with male and female rats

The experiments conducted describe the interaction of sex hormones on the developing brain, particularly the region known as the hypothalamus.

For instance, when female rats are administered male hormones prenatally, they exhibit male sexual behavior during adulthood. Similarly, when male rats are prenatally administered a steroid drug to counteract the self-produced male hormone, the animals exhibit female sexual behavior.

In a second study rat mothers placed in stress during the equivalent of the first trimester, ended up with ratty sons with female (Lordic) behavior. in my case Mom was a nurse and dad was an intern, and they played doctor once too often, can you imagine the stress from that? I am adopted by the way.

 Toxicology

Endocrine Disrupting Chemicals

 Exposure to a wide variety of endocrine disrupting chemicals ever-present in the environment produces disruptions to the fetal endocrine system which can produce numerous developmental anomalies, including varying degrees of gender dysphoria

 Communication between the central nervous system and cells of the body are, in part, controlled by hormones which act as chemical messengers to direct the activity of cells.

Endocrine disrupting chemicals behave much like natural hormones, but interfering signals result in erroneous decisions at the cellular level because the cell's receptors accept both endocrine disruptors and natural hormones as valid signals, albeit with different strength.

Hormone disruptors appear to interfere with sexual development by affecting normal communications between the hypothalamus, pituitary, and gonadal glands.

Chemicals modulate (up or down) the reception or secretion of hormones in any of these glands change the concentrations of hormones which have been programmed by genetics produced by the fetus during development.

Endocrine disruptors in the fetus change this "correct" value to some value which is not programmed by genetics.

Hormones from an external source, and many commonly used chemicals and materials have properties which are estrogenic, anti-estrogenic, androgenic, and anti-androgenic. These chemicals can also affect enzymes which amplify the effect of hormones, and they occur in nature.

 Factors of Toxicity Involved

Multiple chemical exposures in humans are today the rule!

Combinations of the 100,000 chemicals manufactured by man can multiply the effects of a single hormone disruptor by up to 1,600 times

Synergism occurs when the effect or response of a combined exposure of two or more chemicals is greater than when they are added.

Bioaccumulation is the inability of the body to excrete certain chemical.

In the field of toxicology, developments in the last decade have highlighted the reproductive, behavioral, and anatomical effects of endocrine disruptors on animals exposed to these chemicals.

Effects due to endocrine disrupting chemicals are observed at concentrations as low as parts per trillion for animals in the laboratory, indicating that the fetal endocrine system is more sensitive to disruption than any other known body system.

Some researchers have suspected that humans acquired some defense against plant estrogens through their long evolutionary experience with such substances in food.

"A new study from researchers at Tulane University and the University of Florida provides added evidence that some natural and synthetic estrogens differ in another extremely critical respect – their ability to circumvent the body’s natural defense system.

as for the disparity between the number of M to F’s compared to F to M’s , the default is female and any disruption will disproportionately affect the male fetus plus many chemicals which are ubiquitous around the world, such as DDT, have estrogenic potential, whereas there are fewer chemicals which have androgenic potential.

 This disparity has been seen in wildlife as well. Scientific American recently reported on a study published in Environmental Health Perspectives, which showed that 84% of genetically male Chinook salmon appeared to be female in the Columbia river in the Northwest US, but they do not report sex reversed female salmon.

 "Chemicals known to disrupt the endocrine system include: DDT and its degradation products, DEHP (di(2-ethylhexyl)phthalate), dicofol, HCB (hexachlorobenzene), kelthane, kepone, lindane, and other hexachlorocyclohexane congeners, methoxyclor, octachlorostyrene, synthetic pyrethroids, triazine herbicides, EBDC fungicides, certain PCB congeners, 2,3,7,8-TCDD and other dioxins, 2,3,7,8-TCDF and other furans, cadmium, lead, mercury, tributyltin, and other organo-tin compounds, alkyl phenols (non-biodegradable detergents and anti-oxidants present in modified polystyrene and PVCs), styrene dimers and trimers, soy products, and laboratory animal and pet food products."

 In 1991, after years of reviewing research that examined a variety of problems with the wildlife of the Great Lakes region of the United States, Theo Colborn and a team of scientists pieced together troubling data from several fields of science which indicated that man-made chemicals introduced into the environment are having a variety of effects on animals and humans which were summarized in a set of statements which is now known as the Wingspread Statement. The full statement was included in the book "Our Stolen Future (1)," by Colborn, Dumanoski, and Myers, which discussed some of the consequences of endocrine disrupting chemicals upon wildlife and humans.

A large number of man-made chemicals that have been released into the environment, as well as a few natural ones, have the potential to disrupt the endocrine system of animals, including humans. Among those are the persistent, bioaccumulative, organohalogen compounds that include some pesticides (fungicides, herbicides, and some insecticides) and industrial chemicals, and other synthetic products, and some metals.

Many wildlife populations are already affected by these compounds. The impacts include thyroid dysfunction in birds and fish; decreased fertility in birds, fish, shellfish, and mammals; decreased hatching success in birds, fish, and turtles; metabolic abnormalities in birds, fish, and mammals; behavioral abnormalities in birds; demasculinization and feminization of male fish, birds, and mammals; defeminization and masculinization of female fish and birds; and compromised immune systems in birds and mammals.

The pattern of effects vary among species and among compounds. Four general points can nonetheless be made: (1) the chemical of concern may have entirely different effects on the embryo, fetus, or perinatal organism than on the adult; (2) the effects are most often manifested in the offspring, not in the exposed parent; (3) the timing of the exposure is crucial in determining its character and future potential; and (4) although critical exposure occurs during embryonic development, obvious manifestations may not occur until maturity. Laboratory studies corroborate the abnormal sexual development observed in the field and provide biological mechanisms to explain the observations in wildlife.

Humans have been affected by compounds of this nature, too. The effect of DES (diethylstilbestrol), a synthetic therapeutic agent,  like many of the compounds mentioned above, are estrogenic. Daughters born to mothers who took DES now suffer increased rates of vaginal clear cell adenocarcinoma, various genital tract abnormalities, abnormal pregnancies, and some changes in immune responses. Both sons and daughters exposed in utero experience congenital abnormalities of their reproductive system and reduced fertility. The effects seen in in utero DES-exposed humans parallel those found in contaminated wildlife and laboratory animals, suggesting that humans may be at risk for the same environmental hazards as animals."

They also state: "Chemicals known to disrupt the endocrine system include: DDT and its degradation products, DEHP (di(2-ethylhexyl)phthalate), dicofol, HCB (hexachlorobenzene), kelthane, kepone, lindane, and other hexachlorocyclohexane congeners, methoxyclor, octachlorostyrene, synthetic pyrethroids, triazine herbicides, EBDC fungicides, certain PCB congeners, 2,3,7,8-TCDD and other dioxins, 2,3,7,8-TCDF and other furans, cadmium, lead, mercury, tributyltin, and other organo-tin compounds, alkyl phenols (non-biodegradable detergents and anti-oxidants present in modified polystyrene and PVCs), styrene dimers and trimers, soy products, and laboratory animal and pet food products."

A more complete listing of Endocrine Disrupting Chemicals can be found at www.ourstolenfuture.org  

 Intersexuality

Intersexuality, in a variety of forms, occurs in about one of every 200 births. For most this will never be discovered.For some this will only be discovered when attending a fertility treatment clinic later on in life…

 Sex, in reality, is more than the simple blueprint learned in high-school biology--XX for female, XY for male. The cause can be chromosomal or hormonal.

 Infants with androgen insensitivity syndrome, for example, have XY cells but cannot process testosterone, and they look like females.

 An inherited condition called 5-alpha-reductase deficiency triggers an apparent female-to-male sex change at puberty.

Congenital adrenal hyperplasia--the most common intersexual condition--results from hormonal imbalances that masculinize the genitals of XX children.

 Scientists speculate that such an imbalances may masculinize or feminize the brain, establishing gender and sexual orientation.

There are Over 70 different variations of intersex syndromes recognized.

Diagnosis at time of birth is virtually non existence, because gender identification usually consists of nothing more then a casual glance of the genital sex by the nurse or doctor.    

It kind of makes you think, doesn’t it that sex and gender are not as cut and dry as we have been taught …..two examples of these different syndromes are

 Androgen Insensitivity Syndrome (old name Testicular Feminization Syndrome)  AIS causes an interruption of the fetal development of the reproductive system. Typical male (XY) sex chromosomes. Embryonic testes develop inside the body and start to produce androgens. These male hormones cannot complete the male genital development due to an insensitivity in the fetus to accept androgens. So the external genital development continues along female lines (the ‘backup’ route) but the development of female internal organs has already been suppressed by a hormone from   the male testes. So what often ends up happening is a child who appears physically female and but has the chromosomes of a male.

  Klinefelter's syndrome is a genetic disorder that affects only males. Normally a person, has a total of 46 chromosomes. Sometimes male sperm fuses with the female egg, the fetal at least one extra X chromosome. Total number of chromosomes 47 or more. With 47 being the most common , making him a XXY or XXXY male.

KS is not Hereditary it only occurs by accident. At puberty blood testosterone levels are normal may fail to rise into the normal adult range from age 14 onwards.  A boy's hips may develop fatty deposits so that the boys assume more of a female pear shape.  may develop breast enlargement as well. If testosterone is low, muscle development and beard growth may be reduced, and sexual interest lowered. 

In one study at the Netherlands Institute for Brain Research in Amsterdam 1995,  detectable difference in transsexual brains, as viewed at autopsy. The region is the hypothalamus responsible for sexual behavior.

 The genetically male transsexuals had a female brain structure,  the volume of the BST (bed nucleus of the stria terminals) of the hypothalamus was similar in male-to-female transsexuals and genetic females.

 Brain Dimorphism

Brain dimorphism is defined as a structural or other observable difference between the brains of males and females. In a 1995 article entitled "A Sex Difference in the Human Brain and its Relation to Transsexuality" published in Nature, J.-N. Zhou, et al. demonstrated an observable difference in certain structures in the hypothalamus of transsexuals males compared to males, females, and homosexual males. (6) They report:

"The possible psychogenic or biological etiology of transsexuality has been the subject of debate for many years. Here we show that the volume of the central subdivision of the bed nucleus of the stria terminalis (BSTc), a brain area that is essential for sexual behaviour, is larger in men than in women. A female-sized BSTc was found in male-to-female transsexuals. The size of the BSTc was not influenced by sex hormones in adulthood and was independent of sexual orientation. Our study is the first to show a female brain structure in genetically male transsexuals and supports the hypothesis that gender identity develops as a result of an interaction between the developing brain and sex hormones."

D.F. Swaab, one of the authors of the study, commented in the January 1996 issue of Discover magazine that this research "shows that transsexuals are right. Their sex was judged in the wrong way at the moment of birth because people look only to the sex organs and not to the brain." (7)

The authors of this study reiterate a common theme in the study of transsexualism: that brain changes can arise due to an alteration in sex hormone levels - precisely the consequence of exposure to endocrine disrupting chemicals.  

The conclusions from all of these studies on the brain to date in regards to gender have not given any final proof. There is still much to learn in this arena and there is still much criticism from those who are very conservative.

A case in point can be best illustrated in a real life experiment that was practically forced upon a naive young couple who gave birth to healthy twin boys. During circumcision a year after birth, the  penis was burned by an electro-cautery needle, (Blackened fell off)!

 John underwent sex reassignment surgery ( 22months and was placed on hormones and raised as a little girl as if nothing ever happened (by direction of the doctor).

Linda and Frank did their best to do just that.  When Joan's brother, Kevin, at age 4, was watching Frank shave and asked to shave, too, Frank gave him an empty razor and some shaving cream to play with.  But when Joan also clamored for a razor, Frank refused.  "I told her that girls don't shave," Frank recalls.  "I told her girls don't have to."  Linda offered to put makeup on her.  But Joan didn't want to wear makeup.

"I remember saying, 'Oh, can I shave, too?' " John says of this incident, which forms his earliest childhood memory.  "My dad said, 'No, no.  You go with your mother.' I started crying, 'Why can't I shave, too? " Kevin says that the incident was typical of the way their parents tried to steer them into opposite sexes – and how such efforts were, inevitably, doomed to failure.

"I recognized Joan as my sister," Kevin says, "but she never, ever acted the part.  She'd get a skipping rope for a gift, and the only thing we'd use that for was to tie people up, whip people with it.  Never used it for what it was bought for.  She played with my toys: Tinker toys, dump trucks.  Toys like this sewing machine she got just sat."

Dr. Milton Diamond, University of Hawaii. And Dr John Money had a dispute nature vs Nurture.

The parents finally told their Daughter about the whole ordeal. Her life changed, things started to make sense.

At 25 John married. 

 Diamond wrote that John's case is evidence that gender identity and sexual orientation are largely inborn, and that while rearing may play a role in helping to shape a person's sexual identity, nature is by far the stronger of the two forces so much so that even the concerted 12-year efforts of parents, psychologists, psychiatrists, surgeons and hormone specialists could not override it.

In the four decades since the first sex reassignments were performed, no comprehensive, long-term follow-up study of the patients who have been surgically reassigned as a result of ambiguous genitalia had ever been conducted. 

Such a study was, finally, launched at the Johns Hopkins medical center in June 1995.  Child psychiatrist (and former pediatric urologist) Bill Reiner has been following the lives of 16 reassigned people,  focusing on six genetic males who were born without penises, castrated in infancy and raised as girls. 

Two years into his study, Reiner says that all six are closer to males than to females in attitudes and behavior. 

 Two have spontaneously (without being told of their XY male chromosome status) switched back to being boys. 

 "These are children who did not have penises," Reiner points out, "who had been reared as girls and yet knew they were boys.  They don't say, 'I wish I was a boy,' or 'I'd really rather be a boy,' or 'I think I'm a boy.' They say, 'I am a boy.' "

This is a case where I have recently found some new and recent material  on the Genetic and endocrine disruption, thesee are from peer reviewed journals and are in the form of PDF's if you would like copies you have but to e-mail me.  

 

Last modified: 12/24/13