Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
Diagnosis of oculocerebrorenal syndrome can be done via genetic testing Among the different investigations that can de done are:
- Urinalysis
- MRI
- Blood test
A doctor normally can diagnose renal glycosuria when a routine urine test (Urinalysis) detects glucose in the urine, while a blood test indicates that the blood glucose level is normal.
It is possible to analyze urine samples in determining albumin, hemoglobin and myoglobin with an optimized MEKC method.
Conventionally, proteinuria is diagnosed by a simple dipstick test, although it is possible for the test to give a false negative reading, even with nephrotic range proteinuria if the urine is dilute. False negatives may also occur if the protein in the urine is composed mainly of globulins or Bence Jones proteins because the reagent on the test strips, bromophenol blue, is highly specific for albumin. Traditionally, dipstick protein tests would be quantified by measuring the total quantity of protein in a 24-hour urine collection test, and abnormal globulins by specific requests for protein electrophoresis. Trace results may be produced in response to excretion of Tamm–Horsfall mucoprotein.
More recently developed technology detects human serum albumin (HSA) through the use of liquid crystals (LCs). The presence of HSA molecules disrupts the LCs supported on the AHSA-decorated slides thereby producing bright optical signals which are easily distinguishable. Using this assay, concentrations of HSA as low as 15 µg/mL can be detected.
Alternatively, the concentration of protein in the urine may be compared to the creatinine level in a spot urine sample. This is termed the protein/creatinine ratio. The 2005 UK Chronic Kidney Disease guidelines states protein/creatinine ratio is a better test than 24-hour urinary protein measurement. Proteinuria is defined as a protein/creatinine ratio greater than 45 mg/mmol (which is equivalent to albumin/creatinine ratio of greater than 30 mg/mmol or approximately 300 mg/g) with very high levels of proteinuria having a ratio greater than 100 mg/mmol.
Protein dipstick measurements should not be confused with the amount of protein detected on a test for microalbuminuria which denotes values for protein for urine in mg/day versus urine protein dipstick values which denote values for protein in mg/dL. That is, there is a basal level of proteinuria that can occur below 30 mg/day which is considered non-pathology. Values between 30–300 mg/day are termed microalbuminuria which is considered pathologic. Urine protein lab values for microalbumin of >30 mg/day correspond to a detection level within the "trace" to "1+" range of a urine dipstick protein assay. Therefore, positive indication of any protein detected on a urine dipstick assay obviates any need to perform a urine microalbumin test as the upper limit for microalbuminuria has already been exceeded.
As of today, no agreed-upon treatment of Dent's disease is known and no therapy has been formally accepted. Most treatment measures are supportive in nature:
- Thiazide diuretics (i.e. hydrochlorothiazide) have been used with success in reducing the calcium output in urine, but they are also known to cause hypokalemia.
- In rats with diabetes insipidus, thiazide diuretics inhibit the NaCl cotransporter in the renal distal convoluted tubule, leading indirectly to less water and solutes being delivered to the distal tubule. The impairment of Na transport in the distal convoluted tubule induces natriuresis and water loss, while increasing the reabsorption of calcium in this segment in a manner unrelated to sodium transport.
- Amiloride also increases distal tubular calcium reabsorption and has been used as a therapy for idiopathic hypercalciuria.
- A combination of 25 mg of chlorthalidone plus 5 mg of amiloride daily led to a substantial reduction in urine calcium in Dent's patients, but urine pH was "significantly higher in patients with Dent’s disease than in those with idiopathic hypercalciuria (P < 0.03), and supersaturation for uric acid was consequently lower (P < 0.03)."
- For patients with osteomalacia, vitamin D or derivatives have been employed, apparently with success.
- Some lab tests on mice with CLC-5-related tubular damage showed a high-citrate diet preserved kidney function and delayed progress of kidney disease.
Regular X-rays often fail to show the cystine stones, however they can be visualized in the diagnostic procedure that is called intravenous pyelogram (or IVP for short). Stones may show up on XR with a fuzzy gray appearance. They are radioopaque due to sulfur content, though more difficult to visualize than calcium oxalate stones.
In people with a history of stones, those who are less than 50 years of age and are presenting with the symptoms of stones without any concerning signs do not require helical CT scan imaging. A CT scan is also not typically recommended in children.
Otherwise a noncontrast helical CT scan with sections is the diagnostic modality of choice in the radiographic evaluation of suspected nephrolithiasis. All stones are detectable on CT scans except very rare stones composed of certain drug residues in the urine, such as from indinavir. Calcium-containing stones are relatively radiodense, and they can often be detected by a traditional radiograph of the abdomen that includes the kidneys, ureters, and bladder (KUB film). Some 60% of all renal stones are radiopaque. In general, calcium phosphate stones have the greatest density, followed by calcium oxalate and magnesium ammonium phosphate stones. Cystine calculi are only faintly radiodense, while uric acid stones are usually entirely radiolucent.
Where a CT scan is unavailable, an intravenous pyelogram may be performed to help confirm the diagnosis of urolithiasis. This involves intravenous injection of a contrast agent followed by a KUB film. Uroliths present in the kidneys, ureters or bladder may be better defined by the use of this contrast agent. Stones can also be detected by a retrograde pyelogram, where a similar contrast agent is injected directly into the distal ostium of the ureter (where the ureter terminates as it enters the bladder).
Renal ultrasonography can sometimes be useful, as it gives details about the presence of hydronephrosis, suggesting the stone is blocking the outflow of urine. Radiolucent stones, which do not appear on KUB, may show up on ultrasound imaging studies. Other advantages of renal ultrasonography include its low cost and absence of radiation exposure. Ultrasound imaging is useful for detecting stones in situations where X-rays or CT scans are discouraged, such as in children or pregnant women. Despite these advantages, renal ultrasonography in 2009 was not considered a substitute for noncontrast helical CT scan in the initial diagnostic evaluation of urolithiasis. The main reason for this is that compared with CT, renal ultrasonography more often fails to detect small stones (especially ureteral stones), as well as other serious disorders that could be causing the symptoms. A 2014 study confirmed that ultrasonography rather than CT as an initial diagnostic test results in less radiation exposure and did not find any significant complications.
Laboratory investigations typically carried out include:
- microscopic examination of the urine, which may show red blood cells, bacteria, leukocytes, urinary casts and crystals;
- urine culture to identify any infecting organisms present in the urinary tract and sensitivity to determine the susceptibility of these organisms to specific antibiotics;
- complete blood count, looking for neutrophilia (increased neutrophil granulocyte count) suggestive of bacterial infection, as seen in the setting of struvite stones;
- renal function tests to look for abnormally high blood calcium blood levels (hypercalcemia);
- 24 hour urine collection to measure total daily urinary volume, magnesium, sodium, uric acid, calcium, citrate, oxalate and phosphate;
- collection of stones (by urinating through a StoneScreen kidney stone collection cup or a simple tea strainer) is useful. Chemical analysis of collected stones can establish their composition, which in turn can help to guide future preventive and therapeutic management.
Treatment consists of oral bicarbonate supplementation. However, this will increase urinary bicarbonate wasting and may well promote a bicarbonate . The amount of bicarbonate given may have to be very large to stay ahead of the urinary losses. Correction with oral bicarbonate may exacerbate urinary potassium losses and precipitate hypokalemia. As with dRTA, reversal of the chronic acidosis should reverse bone demineralization.
Thiazide diuretics can also be used as treatment by making use of contraction alkalosis caused by them.
Treatment of children with Fanconi syndrome mainly consists of replacement of substances lost in the urine (mainly fluid and bicarbonate).
Another approach would
In most affected individuals, the condition causes no apparent symptoms (asymptomatic) or serious effects. When renal glycosuria occurs as an isolated finding with otherwise normal kidney function, the condition is thought to be inherited as an autosomal recessive trait.
In terms of treatment of oculocerebrorenal syndrome for those individuals who are affected by this condition includes the following:
- Glaucoma control (via medication)
- Nasogastric tube feeding
- Physical therapy
- Clomipramine
- Potassium citrate
Type 4 RTA is not actually a tubular disorder at all nor does it have a clinical syndrome similar to the other types of RTA described above. It was included in the classification of renal tubular acidoses as it is associated with a mild (normal anion gap) metabolic acidosis due to a "physiological" reduction in proximal tubular ammonium excretion (impaired ammoniagenesis), which is secondary to hypoaldosteronism, and results in a decrease in urine buffering capacity. Its cardinal feature is hyperkalemia, and measured urinary acidification is normal, hence it is often called hyperkalemic RTA or tubular hyperkalemia.
Causes include:
- Aldosterone deficiency (hypoaldosteronism): Primary vs. hyporeninemic (including diabetic nephropathy)
- Aldosterone resistance
1. Drugs: NSAIDs, ACE inhibitors and ARBs, Eplerenone, Spironolactone, Trimethoprim, Pentamidine
2. Pseudohypoaldosteronism
In some patients, RTA shares features of both dRTA and pRTA. This rare pattern was observed in the 1960s and 1970s as a transient phenomenon in infants and children with dRTA (possibly in relation with some exogenous factor such as high salt intake) and is no longer observed. This form of RTA has also been referred to as juvenile RTA.
Combined dRTA and pRTA is also observed as the result of inherited carbonic anhydrase II deficiency. Mutations in the gene encoding this enzyme give rise to an autosomal recessive syndrome of osteopetrosis, renal tubular acidosis, cerebral calcification, and mental retardation. It is very rare and cases from all over the world have been reported, of which about 70% are from the Magreb region of North Africa, possibly due to the high prevalence of consanguinity there.
The kidney problems are treated as described above. There is no treatment for the osteopetrosis or cerebral calcification.
Type 3 is rarely discussed. Most comparisons of RTA are limited to a comparison of types 1, 2, and 4.
Dent disease 2 (nephrolithiasis type 2) is associated with the "OCRL" gene. Both Lowe syndrome (oculocerebrorenal syndrome) and Dent disease can be caused by truncating or missense mutations in "OCRL".
Individuals with renal papillary necrosis due to excess use of analgesic have an elevated risk of epithelial tumors, hence a urine cytology exam is useful. In terms of imaging this condition can be identified by retrograde pyelography (RGP). The diagnosis of renal papillary necrosis is therefore done via:
Familial disorders
- Cystinosis
- Galactosemia
- Glycogen storage disease (type I)
- Hereditary fructose intolerance
- Lowe syndrome
- Tyrosinemia
- Wilson's disease
Acquired disorders
- Amyloidosis
- Multiple myeloma
- Paroxysmal nocturnal hemoglobinuria
- Toxins, such as HAART, ifosfamide, lead, and cadmium
Inborn errors of renal tubular transport are metabolic disorders which lead to impairment in the ability of solutes, such as salts or amino acids, to be transported across the brush border of the renal tubule. This results in disruptions of renal reabsorption.
Examples of these disorders include Iminoglycinuria, renal tubular acidosis and Gitelman syndrome.
The primary treatment for type 1 tyrosinemia is nitisinone (Orfadin) and restriction of tyrosine in the diet. Nitisinone inhibits the conversion of 4-OH phenylpyruvate to homogentisic acid by 4-Hydroxyphenylpyruvate dioxygenase, the second step in tyrosine degradation. By inhibiting this enzyme, the accumulation of the fumarylacetoacetate is prevented. Previously, liver transplantation was the primary treatment option and is still used in patients in whom nitisinone fails.
It is named after Guido Fanconi, a Swiss pediatrician, although various other scientists, including George Lignac, contributed to its study. It should not be confused with Fanconi anemia, a separate disease.
Treatment of renal papillary necrosis is supportive, any obstruction (urethral) can be dealt with via stenting. This condition is not linked to a higher possibility of renal failure. Control of infection is important, thus antimicrobial treatment is begun, so as to avert surgery (should the infection not respond).
Initial treatment is with adequate hydration, alkalization of the urine with citrate supplementation or acetazolamide, and dietary modification to reduce salt and protein intake (especially methionine). If this fails then patients are usually started on chelation therapy with an agent such as penicillamine. Tiopronin is another agent.
Once renal stones have formed, however, the first-line treatment is ESWL (Extracorporeal shock wave lithotripsy). If ESWL do not work efficiently surgery can be necessary. Both endoscopic surgery and conventional open-abdominal surgery have proven to be effective treatment modalities for patients with more advanced disease. Adequate hydration is the foremost aim of treatment to prevent cysteine stones. The goal is to increase the urine volume because the concentration of cystine in the urine is reduced which prevents cystine from precipitating from the urine and forming stones. People with cystine stones should consume 5 to 7 liters a day. The rationale behind alkalizing the urine is that cystine tends to stay in solution and causes no harm. In order to alkalize the urine, sodium biocarbonate has been used. One must be careful in alkalizing their urine because it could lead to other forms of stones in process of preventing cystine stones. Penicillamine is a drug that acts to form a complex with cystine that is 50 times more soluble than cystine itself. Percutaneous nephrolithotripsy (PNL) is performed via a port created by puncturing the kidney through the skin and enlarging the access port to 1 cm in diameter. Most of the time, cystine stones are too dense to be broken up by shock (ESWL) so PNL is needed.
Videos of surgery are available on various websites that show stone removal by percutaneous nephrolithotomy.
In February 2017, an article was published in Nature Medicine entitled 'Alpha lipoic acid treatment prevents cystine urolithiasis in a mouse model of cystinuria', suggesting that a high dose of the readily available antioxidant, alpha-lipoic acid at 2,700 mg/67 kg body weight daily reduced the incidence of stones. The effects were dose dependent. The results are unprecedented for cystinuria. A clinical trial is underway based on this mouse model.
Below is an example of how glutamate is used to synthesize alanine via alanine transaminase.
Another example is the conversion of aspartate to glutamate via the enzyme aspartate transaminase.
Metabolic disorder screening can be done in newborns via the following methods:
- Blood test
- Skin test
- Hearing test
The diagnosis is based on the biochemical findings (increased concentrations of lysine, arginine and ornithine in urine and low concentrations of these amino acids in plasma, elevation of urinary orotic acid excretion after protein-rich meals, and inappropriately high concentrations of serum ferritin and lactate dehydrogenase isoenzymes) and the screening of known mutations of the causative gene from a DNA sample.