The Changing Pattern of Bone Quality Through Life - Research Paper Example

1. Describe the presentation and aetiology of osteoporosis, and discuss how the changing pattern of bone quality through life supports the disposablesoma view of ageing. Answer: Osteoporosis is a pathological condition in which there is a decrease seen in the bone density which leads to decreased strength of the bones and makes the bones more susceptible to fractures. After menopause due to decreased estrogen levels females develop osteoporosis. In old age decreased division of bone cells also leads to osteoporosis. Other causes include malnutrition, malabsorption, deficiency of vitamins, decreased activity and endocrine disorders like hyperparathyroidism. The disposable soma theory explains that the body works according to the amount of energy provided to it for repair and its normal functioning. The changing pattern of bone quality which has been provided with the advance of technology includes hormone replacement theory for females after menopause, physiotherapy and exercises for the old along with calcium supplements and medications available to overcome the other conditions which lead to osteoporosis. These methods employ the body with better resources for repair and it makes the body function in a proper way. This is how the changing pattern of bone quality through life supports the disposable soma view of ageing. 2. Review the causes of gonadal disease, and show how biochemical markers of gonadal function may be used to assess and monitor disease. Answer: Gonadal disease can be caused by sexually transmitted diseases which include gonorrhoea and syphilis. It can be caused by genetic abnormalities which include Turner’s syndrome and gonadal dysgenesis. Autoimmunity against the ovaries and the testes can also be a cause of gonadal disease. Endocrine disorders also result in gonadal disease. These include the androgen resistance syndrome, pituitary tumors, hypothalamic tumors and excess secretion of androgens. Blood tests for the levels of hormones serve to act as biochemical markers in gonadal disease. Low or high levels of sex hormones can be indicative of this. In the case of sexually transmitted diseases the levels of antigens and antibodies can also serve as markers. Chromosomal karyotyping can also lead to diagnosis. 3. Describe the mechanisms determining embryonic and fetal development of male and female phenotypes and discuss ways in which an individual with a normal XY phenotype might present as a female adult. Answer: During the embryonic and fetal development the Y chromosome in the male is responsible for the formation of testes whereas the XX genotype is responsible for the formation of the ovaries. The testes releases testosterone and the ovary release oestrogen. Testosterone causes the development of male sexual organs whereas oestrogen contributes to the formation of female sexual organs. In the case of androgen insensitivity syndrome the receptors for testosterone in a child with XY genotype do not respond to it. Hence an individual with XY will not develop the male characteristics due to irresponsiveness to testosterone and will have a female phenotype. 4. A 25-year-old woman reported with amenorrhea, saying she had a good appetite but had lost weight (10kg over the last year). She is a “resting” actress, divorced recently and has had no serious illnesses, doesn’t smoke, and only drinks moderately. On clinical examination she weighs 40kg (MBI = 13.84), is wasted, her BP is 90/60, pulse rate 55 bpm and she has excessively fine hair growth on her cheeks, neck and forearms. Plasma analysis indicates hypokalaemia, and hypochloraemic metabolic alkalosis indicated by raised bicarbonate. Plasma LH, FSH, and oestrogens are low, but thyroid function and cortisol were normal. Haematological and other plasma metabolic indices (Na, creatinine, glucose and albumin) were also normal. Answer: The female is suffering from secondary hypogonadotrophic hypogonadism. This condition can have a late onset. It results in low levels of the gonadotropins which include LH and FSH due to a defect in the gobadotrophic cells of the anterior pituitary. LH is responsible for the stimulation of estrogen hence low levels of estrogen are also observed. Low levels of LH, FSH and estrogen lead to amenorrhea. Estrogen plays a role in the reabsorption of potassium. Hence low levels of potassium ions are seen. Due to hypokalemia there is movement of potassium out of the cells and a subsequent movement of hydrogen ions inside. The amount of chloride ions in the blood also rises. This low hydrogen ion concentration with a proportional high bicarbonate level and high chloride ions in the blood lead to hyperchloremic metabolic alkalosis. 5. Kevin, a 32 year old photographer, comes in with girlfriend Regina to see local GP. Kevin and Regina have been together for about two years, and she wants to have a child. Kevin has been married twice before, but has never had children. Regina, a 27 year old teacher, has two children aged 5 and 3 from a previous relationship. The couple do not use contraceptives, and do not smoke or drink. Kevin has a history of maldescended testis, when a child. He is able to ejaculate, and carry out sexual relationships with women. Recently he has gained some body weight and also noticed a decrease in libido. On examination Kevin’s height is 181cm, body weight 89kg and his body mass index (BMI) is 27. His arm span is 181cm. Both testes are small and firm. Bilateral gynaecomastia is present. Cardiovascular and respiratory functions are normal. 1) What are the possible causes for the presenting problem? Answer: The other possible causes include obesity, an ectopic tumor of hCG or a testes tumor which releases estrogen. 2) What further questions might you ask to aid diagnosis? Answer: The patient can be asked about his diet, the medications that he is taking to determine any induced hormonal imbalance and about similar problems running in the family. Results of laboratory tests: KEVIN NORMAL RANGE Semen analysis azoospermia FSH (IU dm-3) 33.9 3-15 LH (IU dm-3) 18.7 3-13 Testosterone (nmol dm-3) 10.8 12-40 Free testosterone (pmol dm-3) 180 >250 SHBG (nmol dm-3) 80.5 11-71 Oestradiol (pmol dm-3) 82.5 73-184 Chromosome analysis 47, XXY 46, XY 3) In the light of the clinical presentation, how would you interpret the laboratory results? Answer: The levels of SHBG are high whereas the levels of free as well as bound testosterone are low. The levels of FSH and LH are above normal and there is presence of an extra X chromosome. 4) What is your diagnosis? Answer: It is Klinefelters Syndrome. 5) Summarise the observations that support this Answer: The patient presents with an abnormal chromosomal analysis which presents an extra X chromosome. Along with this azoospermia associated with increased levels of FSH, LH and low levels of free and bound testosterone are all suggestive of the diagnosis. 6. Describe the principal hormonal factors that regulate normal growth through infancy and puberty, and discuss abnormalities of growth resulting from disturbances in their actions. Answer: The principal hormonal factors that regulate growth through infancy include growth hormone and thyroid hormones whereas growth at puberty requires growth hormones and the sex hormones which include the adrenal androgens, leutinizg hormone, follicle stimulating hormone, testosterone, estrogen and progesterone. Decreased amount of thyroid and growth hormone results in stunted growth. The decrease in the sex hormones prevents the proper development of secondary sexual characteristics at puberty. 7. Examine the clinical data below from a two-month infant with an XX genotype. Identify the condition and discuss the expected symptoms, the aetiology of the condition, and therapeutic indications. Plasma concentration Infant Ref range Urea (mmoldm-3) 7.72. 5-7.0 Fasting glucose (mmoldm-3) 3.93. 5-5.5 Na+ (mmoldm-3) 122 134–147 K+(mmoldm-3) 7.1 3.5–5.0 17-hydroxyprogesterone(nmoldm-3) 670 Read More