Previous studies have indicated that women are more likely than men to form CaP stones. 11, 18 However, like Parks and colleagues 11 we noted that when CaP stones were divided into individual subtypes brushite stone composition was strongly associated with male gender. These findings lead us to question what role hormones and/or genetics play in the conversion of brushite to hydroxyapatite. Urolithiasis is a common condition in the United States with an estimated prevalence of 11.7% by age 70 and is associated with considerable patient morbidity and occasional mortality. 1 The epidemiology of stone disease appears to be changing with an increase in the number of women and children diagnosed. Over the past 25 years the male to female ratio for the prevalence of renal calculi has decreased from 3:1 to currently less than 2:1. 2, 3 Some have speculated this increase in affected females is due to changes in life-style factors, such as increasing obesity among women. 4 The increased diagnosis of urolithiasis in children has likewise been, in part, attributed to a rise in childhood obesity. 5, 6 On May 3rd, 2017, Facebook account funnylookingdog posted an image of Otis. The post received more than 100 likes and 80 shares. [5] That day, they published a four-panel meme [4] featuring the image and the caption "Perhaps." The post received more than 745 shares and 100 reactions (shown below). There is evidence to support that brushite stone formers are increasing in incidence and are more commonly encountered by urologists. Parks and colleagues found that the calcium phosphate fraction in stones had increased over the last 3 decades, along with an increase in urinary pH and brushite saturation. 11 Mandel and colleagues studied 33,198 stones from the National Veterans Administration Crystal Identification Center in 2002. 12 Compared to a 1989 survey of crystal study, the percentage occurrence of hydroxyapatite stones had increased 1% (26.9% to 27.9%) and brushite stones had increased 3% (1.7% to 4.14%). The authors further noted that some patients who once produced calcium oxalate stones had converted to CaP stone producers over time.

Although Pak and colleagues have previously reported an association between the amount of CaP composition in a stone and metabolic abnormalities, such as renal tubular acidosis and primary hyperparathyroidism, 20 we found no such association in our brushite cohort. No patient in this cohort had a systemic acidosis and, therefore, none had complete RTA. Many of these patients had low citrate and elevated urine pH and could be viewed as having a form of incomplete RTA. In fact, in our cohort nearly all the patients were found to have hypercalciuria, and most had elevated urinary pH leading us to conclude that brushite stone disease should be considered a harbinger for hypercalciuria. Based on the metabolic study results and high stone recurrence rate observed in our cohort, we recommend that all patients with brushite renal or ureteral calculi undergo a metabolic stone evaluation and have close long-term urologic follow-up. Since brushite stone disease appears to be increasing we conclude that these patients will become a more common patient seen by urologists. Biscuits are not crunchy by definition, at least not in the wide meaning, and apart from cantuccini they are not normally baked twice. After institutional review board approval, patients with brushite renal or ureteral calculi were enrolled in our prospectively collected database. From January 23, 1996 to February 11, 2008 we identified 82 brushite stone patients. To be considered for the database a patient must have a documented stone containing any amount of brushite on stone analysis. The percentage of brushite and secondary components for each retrieved stone was recorded. Demographic and surgical data for each patient was collected. Post surgical stone-free status was determined by non-contrast computed tomography CT scan for PCNL, and noncontrast CT or plain abdominal x-ray (KUB) for patients treated with ureteroscopy or SWL. Twenty-four hour urine metabolic studies were performed either preoperatively, or 4 to 6 weeks postoperatively with patients on an unrestricted diet.

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On June 5th, 2017, Redditor [3] DaddyFarquar posted another meme based on the macro to /r/MemeEconomy subreddit. The post gained over 7,800 upvotes in six months. And that’s even before we go over to America and inspect what they call ‘a biscuit’ there. Crunchy it isn’t. But I don’t make the impression that I belittle crunchiness in general. There's time and place for crunchy, as much as soft in the biscuit world. Dunk it in your tea or not, everyone likes a biscuit with a crunch, when it melts into sweet and buttery tenderness in your mouth, plain, simple and sublime.

The cause for the observed increase in brushite stone disease is not yet understood; however speculations of possible mechanisms have been made. Evan and colleagues studied papillary biopsy taken from brushite stone formers undergoing PCNL. 15 They noted hydroxyapatite plugs filling the lumens of the terminal collecting ducts with surrounding epithelial damage and destruction. Furthermore the interstitium around the affected tubules were scarred and inflamed. The authors noted that brushite stone formers in their cohort had received a greater number of prior SWL treatments compared to calcium oxalate stone formers. Evan et al theorize that SWL could produce the renal damage and subsequent brushite stone formation in some patients. They further suggest that the current liberal use of citrate therapy without attention to urinary pH may result in the rising prevalence of CaP stones over the last 3 decades by increasing CaP supersaturation. In our study nearly all of the patients had received a prior SWL similar to that observed by Evan et al.; however, it is uncertain if the high number of prior SWL in our brushite patients is just a result of our practice being a tertiary referral center or an underlying cause of the brushite stones. Furthermore, unlike Evan and colleagues we could find no obvious associate between citrate usage and brushite stone disease. Plus, as I was happy to discover, some seriously talented bakers share my view that you must sample raw cake batter: if it’s tasty raw, it will bake well. I’m all for a good biscuit (although I don’t dunk), crunchy or not, but let’s not make sweeping generalisations. It’s as if someone said that all steaks must be made with fillet beef. Crunchy is good Crunchy should not mean hard and tooth-breaking though. Crunchy is perfect when it melts in your mouth and tastes of butter and sugar - which is basically all a crunchy biscuit should be made of.Stone composition was available for all patients in the cohort. Pure brushite stones were present in 64 (78.4%) patients. Brushite mixed with hydroxyapatite was noted in 6 (7.3%) and mixed with calcium oxalate in 5 (6.1%). There were 7 (8.5%) patients who presented with non-brushite stones (all calcium oxalate mixed with apatite), but had a documented history of brushite stones. Of the entire cohort, 16 (19.5%) patients had a history of a prior non-brushite stone, but subsequently converted to brushite calculi at time of enrollment in the database.