Sperm DNA damage: Role of Antioxidants

It is now known that male fertility is compromised as a result of sperm DNA fragmentation. Many studies have suggested the implication of oxidative stress in the cause of Sperm DNA fragmentation.

Greco, et al. (2005) conducted a study to find out whether pathologically increased incidence of DNA fragmentation in ejaculated spermatozoa can be reduced by oral treatment with two antioxidants namely vitamins C and E.

The study followed sixty-four men with unexplained infertility having an elevated  percentage of DNA-fragmented spermatozoa (> or = 15%)  in the ejaculate. They were randomly separated into two groups. One group (antioxidant treatment group) received 1 g vitamin C and 1 g vitamin E daily for 2 months while the other (placebo group) received placebo.

Results revealed that the percentage of DNA-fragmented spermatozoa was markedly reduced in the antioxidant treatment group after the treatment as compared with the pretreatment values. However, no differences were found in the basic sperm parameters between the antioxidant treatment and the placebo group before or after treatment. Also, no difference in the incidence of sperm DNA fragmentation was observed in the placebo group pre and post-treatment.

These findings show that incidence of sperm DNA fragmentation can be efficiently treated by oral antioxidants in a relatively short period of about 2 month.

Reference:

Greco, E., Iacobelli, M., Rienzi, L., Ubaldi, F., Ferrero, S., Tesarik, J. 2005. Reduction of the incidence of sperm DNA fragmentation by oral antioxidant treatment. J Androl; 26 (3):349-353.

Congenital hypothyroidism ( Cretinism)

Hypothyroidism usually appears as either congenital/from birth or acquired in children.  Acquired hypothyroidism is an under activity of thyroid gland in later childhood. It occurs from a condition in which the body attacks its own tissues. When the thyroid gland gradually stops working eventually it may cause acquired hypothyroidism. This first sign of acquired hypothyroidism is growth deceleration. Children may develop constipation, cold intolerance and decreased energy. Puberty may be very slow, late or absent. There are gradual changes in facial appearance, face appears pale and puffy. Other changes include a slow heart rate, some hair loss and slow reflexes.

On the contrary, congenital hypothyroidism also aka cretinism is an under activity of the thyroid gland at birth. When the thyroid gland is poorly developed or absent it causes thyroid hormone deficiency. As a result, thyroxine the main hormone produced by thyroid gland is not produced and a condition develops called as congenital hypothyroidism. Cretinism causes growth retardation, developmental delay and other abnormal features. Congenital hypothyroidism is twice as common in females. This condition is present from birth therefore it is likely to pass in families.

Cretinism is also caused due to dietary iodine deficiency in mothers during pregnancy. In areas of severe iodine deficiency, low concentration of thyroxine in the blood (hypothyroxinemia) can cause cretinism in both mother and fetus. The iodine deficient diets affect the developing fetus, newborn and the young children. In low iodine areas cretinism is a major cause of preventable intellectual impairment in children. Thus, to prevent irreversible damage iodine should be given before conception or early in pregnancy.

The symptoms of congenital hypothyroidism appear gradually. The clinical features depend upon thyroid hormone deficiency and age of the patient. The clinical features are not characteristic at birth. During the neonatal period the earliest sign may be prolonged physiological jaundice.  The other features present are poor/difficult feeding, noisy breathing, little cry and much sleep. The abdomen is large with an umbilical hernia.

The full clinical presentation develops by 3-6 months. The appearance becomes apathetic, infantile and unconcerned with the surrounding. The milestone of development is delayed resulting in short stature. The ratio of upper segment to lower segment is large due to short legs. The forehead appears wrinkled, while the tongue is broad and protruded keeping the mouth open. The neck appears short and thick, while the hands and legs are broad and stumpy. The muscle tone is decreased, slow relaxation of ankle jerk is observed.

The laboratory investigation consists of checking serum T4 level, TSH level. Most case of congenital hypothyroidism is detected by newborn screening tests. The radiograph detects any retardation of osseous development. Thyroid scans or radio labeled iodine detect absence of thyroid tissue. The thyroid hormone replacement treatment will be for lifetime. The thyroxine used for therapy however, should not be mixed with iron or any formula containing iron or soy.

References: Davidson's principles and practice of medicine, 18th edition

Bronchiolitis in Children

Bronchiolitis is a lower respiratory tract infection in infants. It is caused by virus and results in inflammatory obstruction of the small airways of the lower respiratory tract. Bronchiolitis develops in children younger than 2 years old. The peak incidence is approximately 6 months of age. A virus, usually respiratory syncytial virus invades the bronchioles causing obstruction from mucus, cellular debris, and edema. Other viruses that   may cause bronchiolitis in infants include para influenza type 3 virus, mycoplasma and adeno virus. 

Respiratory syncytial virus (RSV) is transmitted through droplets that contain viral particles when coughing, sneezing or breathing. Adults infected with RSV can easily transmit the virus to the child. If an RSV infected person uses hands to touch a child's eye, nose, or mouth the virus spreads and infect the child. A child with bronchiolitis should be kept away from other infants and individuals susceptible to severe respiratory infection until the wheezing and fever subsides.  Infants with mothers who smoke cigarettes are at risk for contracting bronchiolitis. The symptoms include upper respiratory tract infections, runny nose (rhinorrhea), sneezing, wheezy cough and difficulty breathing.

The fever develops and gradually respiratory distress is evidenced by rapid breathing (usually 60-80breaths/min), wheezing (a whistling sound heard when the children breaths out) and cough. The rate of breathing makes it difficult to feed the children. The child seems restless and irritable because of less air. In more severe cases rapid breathing, wheezing, crackles, chest retractions and cyanosis are seen. Usually the mild cases resolve in 1-3 days while severe the course lengthens.

Virus may be detected in nasopharyngeal secretion. Treatment is based on the level of severity. In case of uncomplicated cases treatment is symptomatic. Treatment includes the use of fluids, antipyretic and humidified air or oxygen. A bronchodilator may be administered to relieve wheezing, this might be continued if a response is obtained. Antibiotics are not helpful unless there is a secondary bacterial infection. Corticosteriods are harmful for infants thus, is not indicated.

Facts on UTIs in Children

There are three basic forms of Urinary tract Infection (UTI). Pyelonephritis (upper UTI) is an infection involving the upper urinary tract. Cystitis (lower UTI) is an infection of the urinary bladder. While, asymptomatic bacteriuria shows no associated clinical findings but have positive urine culture.

The fecal flora, especially coliform bacteria i:e E.coli, klebsiella, and Proteus ascends  up from the urethra to the urinary bladder and causes the Urinary tract infection. Cystitis is also caused by viral infections such as adenovirus. In both male and females Staphylococcus saprophyticus may also cause UTIs.  Urinary tract infections are more common in boys as infants, however after the age of 2-3 UTIs is more common in girls. The risk for UTI is high among girls when they first begin toilet training, because after going to bathroom when they wipe from back (near the anus) to front this can carry bacteria to the opening from where the urine flows. On the other hand, the risk for UTI among boys is slightly higher among uncircumcised infants.

The symptoms of cystitis (bladder infection) in children includes presence of blood in urine, cloudy urine, foul or strong urine odor, urgency to urinate, malaise, painful or burning urination and wetting problems in already toilet trained children. However, classic symptoms of cystitis – painful urination, urgency, increased frequency - are often absent in children therefore, it is difficult to identify infection. UTIs may also present with unexpected fever, failure to thrive, weight loss, and vomiting and diarrhea in other infants. An infant or child with pyelonephritis (upper UTI) may not have the classic symptoms of flank pain or shaking chills. Asymptomatic bacteriuria which is more persistent in girls shows no symptoms but has positive urine culture.

The diagnosis of UTI in children is done by urinalysis and urine culture. The urine sample is collected and sent to the laboratory for investigation.

The neonates are hospitalized and treated with intravenous antibiotics. Older children who need hospitalization are also treated with intravenous antibiotics. Children with dehydration, emesis, or possible sepsis should also be admitted to the hospital for re-hydration and intravenous antibiotics. Urinalysis should be repeated one week after completion of therapy of any UTIs. Most children are cured with proper treatment. The treatment may continue over a long period of time. Some children who get repeated UTIs may be recommended with long-term use of prophylactic antibiotics. Repeated UTIs in children can be serious and has a higher risk for developing renal diseases. Therefore, follow-up urine cultures may be needed to make sure that bacteria are no longer in the bladder with UTI. The work up should include renal ultrasound.

UTIs in children can usually be prevented. Children’s health solely depends on the hands of their caretakers. Children’s should wear loose-fitting underpants and clothing, refrained from bubble bath and taught to go to the bathroom several times a day. Children’s are to be encouraged to increase their fluid intake. The caretaker needs to teach children’s to keep their genital area clean and wipe the genital area from front to back to reduce the chance of spreading of bacteria from anus to the urethra.