(a) (i) Enumerate the causes of radio-opacities on a plain abdominal radiograph. (ii) Enlist the causes of hydronephrosis in…

(a)(i) Causes of radio-opacities on a plain abdominal radiograph

Calcified or dense objects, grouped by site: Urinary tract: renal, ureteric and bladder calculi (about 90% are radio-opaque), nephrocalcinosis, and prostatic calcification. Biliary and pancreatic: gallstones (10 to 15% are opaque), porcelain gallbladder, and pancreatic calcification of chronic pancreatitis. Vascular: calcified aorta and aneurysm walls, splenic artery calcification, and pelvic phleboliths. Lymph nodes and soft tissue: calcified mesenteric nodes (tuberculosis), adrenal calcification, uterine fibroid ("popcorn"), dermoid cyst with teeth, and hydatid cyst wall. Gastrointestinal: appendicolith, faecolith, and enteroliths. Foreign bodies and drugs: swallowed coins and metal objects, iron, bismuth or barium residues, IUCD, surgical clips and swabs, and bullets.

(a)(ii) Causes of hydronephrosis in adults

Within the lumen: ureteric or renal calculus, blood clot, sloughed papilla and tumour of the urothelium. In the wall: pelvi-ureteric junction obstruction, ureteric stricture (tuberculous, schistosomal, post-radiation or after surgery), and ureterocele. Outside the ureter: pregnancy, pelvic malignancy (cervix, ovary, rectum, prostate), retroperitoneal fibrosis or lymph nodes, aortic aneurysm, a crossing renal vessel, and uterine prolapse. Lower urinary tract: benign prostatic enlargement, bladder cancer, urethral stricture and neurogenic bladder (these usually give bilateral disease). Non-obstructive: vesico-ureteric reflux, and persistent dilatation after relief of obstruction.

(a)(iii) Investigation of unilateral right-sided hydronephrosis

History and examination: colic, haematuria, fever, a palpable kidney, and pelvic and abdominal examination. Urine microscopy and culture, blood urea and creatinine. Ultrasound of kidney, ureter and bladder: confirms hydronephrosis, shows cortical thickness, the left kidney, stones and masses, and the level of dilatation. Plain X-ray KUB, and non-contrast CT (KUB) for stones; CT urography (or MR urography) shows the level and cause, including crossing vessels and tumours. Diuretic renography (MAG3 or DTPA with frusemide): separates true obstruction (prolonged washout, T½ over 20 minutes) from simple dilatation and gives the split function of each kidney. Cystoscopy with retrograde pyelography, or antegrade pyelography, if the level remains uncertain; DMSA scan for scarring and function. Pelvic examination and pregnancy test where relevant.

(a)(iv) Management of pelvi-ureteric junction obstruction

Asymptomatic, mild obstruction with split function above 40% and stable on follow-up: observation with serial ultrasound and renography. Indications for surgery: pain, infection or stones, split function below 40%, a fall of more than 10% on serial scans, and increasing hydronephrosis. Anderson-Hynes dismembered pyeloplasty (open, laparoscopic or robotic): excision of the narrow segment and redundant pelvis and a fresh anastomosis over a double-J stent; success is over 90%. A crossing vessel is transposed in the same operation. Endopyelotomy or balloon dilatation (antegrade or retrograde) is an alternative for secondary or recurrent obstruction, with lower success (60 to 70%). Percutaneous nephrostomy first, for infected or obstructed kidney or poor renal function. Nephrectomy for a non-functioning kidney (function below 10 to 15%) with symptoms, with a normal opposite kidney.

(b)(i) Essential amino acids

Essential amino acids are those that the body cannot synthesise, or cannot make in adequate amounts, and which must be supplied in the diet. Six: leucine, isoleucine, valine, lysine, methionine and phenylalanine. The others are threonine, tryptophan and histidine; arginine is semi-essential.

(b)(ii) Biologically complete protein and supplementary action of proteins

A protein is biologically complete (first-class, high biological value) when it provides all the essential amino acids in the proportion that the body requires, for example egg, milk and meat proteins; their biological value is high (egg 100, milk about 90). Plant proteins are usually incomplete, because one essential amino acid is the limiting amino acid: cereals (rice, wheat) are poor in lysine, and pulses (dal) are poor in methionine (and cysteine) but rich in lysine.

Supplementary action of proteins means that when two incomplete proteins with different limiting amino acids are eaten together in the same meal, each makes up for the deficiency of the other, so the mixture has a higher biological value and net protein utilisation than either protein alone. Example from daily life: rice or wheat with dal (khichdi, dal-roti, dal-chawal, idli with sambar). The lysine-rich dal makes up the lysine deficiency of the cereal, and the methionine-rich cereal makes up the deficiency of the pulse, giving a protein of quality close to milk or egg protein. Cereal and pulse in a ratio of about 3 or 4 to 1 serves best. This is the basis of low-cost protein mixtures given in mid-day meals and in supplementary nutrition for children, and it is of value to vegetarian diets.

(c)(i) Screening methods for cancer of the cervix

Visual inspection with acetic acid (VIA) and with Lugol's iodine (VILI): low-cost, immediate result, used in India's programme. Cytology: Papanicolaou (Pap) smear or liquid-based cytology. High-risk HPV DNA testing: the most sensitive and the WHO-preferred test, from 30 years of age, repeated every 5 to 10 years; self-collection is possible. Colposcopy with biopsy is the diagnostic step for a positive screen; screen-positive women are treated by ablation or excision.

(c)(ii) Risk factors for cervical cancer

Persistent infection with high-risk HPV (types 16 and 18 cause about 70%). Early age at first intercourse and early marriage or childbearing; multiple partners or a partner with many partners. High parity (three or more births). Smoking. Immunosuppression, especially HIV infection. Long-term use of oral contraceptives (over 5 years); other genital infections (chlamydia, HSV-2); poor genital hygiene, and low socioeconomic status with no screening.

(c)(iii) Preventive strategies for cancer of the cervix

Primary prevention: HPV vaccination of adolescent girls before sexual exposure (India started a national campaign in February 2026 with a single dose of the quadrivalent vaccine for 14-year-old girls); health education, delay of marriage and first pregnancy, condom use, avoiding tobacco and preventing HIV. Secondary prevention: organised screening of women aged 30 to 65 years (VIA or HPV test), with "screen and treat" by cryotherapy, thermal ablation or loop excision for pre-cancer. Tertiary prevention: early treatment of invasive cancer (radical hysterectomy, chemoradiation and brachytherapy) and palliative care. The WHO elimination targets are 90% of girls vaccinated by age 15, 70% of women screened by 35 and 45, and 90% of those with disease treated.