Excretion of Thiamine, Riboflavin, Niacin and Pantothenic Acid in Human Sweat

Abstract

needle of any obstruction. The plunger is withdrawn gently in order to make sure that the tip of the needle is not lying within the lumen of a blood vessel or within the subarachnoid space. Twenty-five cc. of the anes¬ thetic solution is injected slowly into the caudal canal. As soon as the initial dose has been injected the syringe is detached from the needle and a No. 5 French nylon ureteral catheter which has been sterilized in an autoclave is passed through the needle and is advanced until the tip of the catheter is approximately lj4 inches (3.8 cm.) above the sacral hiatus. The catheter is now supported in place while the needle is removed. The catheter is taped to the skin and the region is sealed with adhesive tape to prevent soiling from the perineum.The patient may now be turned on her back and made comfortable. It is important to refrain from advancing the tip of the catheter more than \y2 inches (3.8 cm.) into the caudal canal. If the catheter is placed high in the canal, unilateral anesthesia may result.Additional injections of 25 cc. of the anesthetic solu¬ tion are given whenever the patient begins complaining of discomfort. COMMENT We believe that the catheter method is much safer than the method of using an indwelling needle. If a needle breaks in the caudal canal, surgical intervention for its removal will be necessary. Indwelling needles also produce an unnecessary amount of trauma inside the caudal canal. The sacrococcygeal ligament acts as a fulcrum, holding the hub of the needle in a fixed position. Every motion of the patient will cause the tip of the needle to sweep the inside of the caudal canal, damaging the vascular plexus and traumatizing the periosteum. This cannot happen if the needle is replaced with a flexible ureteral catheter.The position of the patient during the initial injection is important. We do not believe we are justified in employing the knee-chest position. If the patient is placed in a modified right Sims position near the edge of the bed it is an easy matter to reach over her and place the needle and catheter in the caudal canal.We have kept our patients in a slight Fowler position during labor. This prevents the anesthesia from ascend¬ ing to an unnecessary height and also prevents the fall in blood pressure and nausea which frequently occur if the anesthetic solution ascends to envelop the thoracic nerves.Our first 25 or 30 patients were anesthetized with 1.5 per cent solution of procaine without epinephrine. In these cases we observed a few who had a sudden lower¬ ing of blood pressure followed by a feeble thready pulse, nausea and vomiting. Since that time we have included 2 minims of epinephrine with the initial injection for all patients except those with toxemia, We have not observed evidence of cardiovascular collapse since epinephrine was added to the anesthetic solution, nor have the patients become nauseated.We have used metycaine for a number of patients and have not been able to demonstrate results superior to those obtained with procaine. Procaine has ...

Studies of Thiamine Metabolism in Man. I. Thiamine Balance. The Normal Requirement of Vitamin B1 and the Rôle of Fecal Thiamine in Human Nutrition 1

“…Five to 15 per cent of the thiamine intake may thus be excreted and under the stimulus of heat as much as 0.15 mgm. per day may be lost (24). Since our observations were made during the winter season, the amount of thiamine lost in the sweat was probably less.…”

“…To assure maximum penetration of the enema, the subject alternately raised the legs and hips while lying on his back, turned on his left side, then to the right, and repeated this procedure several times for 10 minutes after the enema was instilled. The urge to defecate persisted for only a short time and the enema was retained for 24 hours. The urine excreted during these 24 hours and the stool passed at the end of this period were collected and analyzed.…”

“…The urge to defecate persisted for only a short time and the enema was retained for 24 hours. The urine excreted during these 24 hours and the stool passed at the end of this period were collected and analyzed.…”

Thiamine (vitamin B1) as an insect repellent: a scoping review

“…As the study is uncontrolled and the Mütings' intake of dietary thiamine and of thiamine-reducing substances such as coffee or alcohol is unreported during this time, the value of this self-experimentation is low: it could easily have been biased by a placebo effect, or ‘nocebo’ effect in the case of discharge, as well as daily variation in activity levels, bathing, clothing exposure, or location within Lapland that could affect exposure to mosquitoes. Müting also hypothesized that either thiamine or a breakdown product thereof excreted through the skin after 2–3 days is responsible for the repellency effect, although this was already known to be false at the time of his writing (Cornbleet et al ., 1943; Tennent and Silber, 1943).…”

“…Other foods or drugs that can reduce thiamine concentrations in the body due to the presence of thiamine antagonists and thiaminases include tea, coffee, betel nut, raw fish, and certain edible insects (Nishimune et al ., 2000; Ehigie et al ., 2013; Pacei et al ., 2020). While primarily excreted in the urine, free thiamine is also secreted in the sweat (Cornbleet et al ., 1943), with approximately 8% of ingested thiamine secreted through the skin (Alexander and Landwehr, 1946). The amount of thiamine in the sweat increases by an order of magnitude when subjects are given large oral doses, but the amount is still so small (<1 μ g per 1 ml sweat) as to be insignificantly different (Cornbleet et al ., 1943; Tennent and Silber, 1943), while thiamine excretion in urine greatly increases with such oral dosing.…”