What a low result means when intake has halved
Reduced intake is a plausible mechanism for deficiency. Reduced absorption is not, and the two are conflated in most of the advice.
Perpetua Nwachukwu
Page 2 of 4 of this archive, newest first.
Archive — page 2
73 piecesTandem mass spectrometry, and the difference between weighing and reading
The Journal’s standing position: a mass that matches is necessary evidence of identity and nowhere near sufficient.
Leucine, isoleucine, and a difference no balance can measure
Deamidation adds 0.98 daltons. On a low-resolution instrument at incretin molecular weights, that is inside the noise.
EGFR, cystatin C, and the check on the check
The reference interval for alanine aminotransferase in most laboratories is derived from a population that included people with undiagnosed fatty liver.
Fat mass fell more than lean mass. That is the finding, and it is not the headline.
What was pre-specified, what was exploratory, and what was calculated afterwards by people who did not run the trial.
Continued treatment against continued placebo: the comparison that settled it
The evidence on stopping is better than the evidence on almost anything else in this field, because somebody deliberately randomised it.
Priming a pen is not optional
Aseptic technique here is four steps and none of them are difficult. They are, however, routinely compressed to two.
The out-of-range flag is a statistical convention with a printer attached
Two sources of noise sit under every number: how reproducible the assay is, and how much the analyte varies within the same person on the same day.
What VendorInvestigate would need in order to certify sterility, and why it does not
We asked all four services what they can determine, on what timescale, at what price, and under what accreditation. The answers are printed in full.
Priming a pen is not optional
For licensed products the in-use period is established by stability data. For a peptide reconstituted at home there is no such data, and the honest answer is that nobody…
Bone density during rapid weight loss: what is known, which is less than you would hope
What the Journal would want measured before treating this as settled in either direction.
The dose that got you here and the dose that keeps you here
Every withdrawal trial compared full dose against nothing. The clinically interesting comparison — full dose against a reduced one — has not been randomised.
Which results should be repeated before they are investigated
What the pivotal programmes measured and how often, which is a more defensible template than most published monitoring schedules.
The intramuscular injection nobody intended
A 4 mm needle at ninety degrees without a skin pinch is adequate for essentially all adults. The persistence of 12.7 mm needles in this market is habit, not reasoning.
The instrument was calibrated on Tuesday. Your sample ran on Friday.
Parts per million sound impressive until they are converted into daltons at the molecular weight of the thing being measured.
How much water: the question with no single right answer
The diluent choice affects preservation and in-use period rather than the arithmetic — but the wrong choice for a multi-dose vial is a sterility decision, not a convenience…
The cake is a record of the cycle that made it
Lyophilisation does not stop degradation. It slows every pathway by removing the solvent that most of them require, and the residue of solvent that remains sets the rate.
Five lines that would change what a certificate is worth
The Journal wrote to twenty companies asking five specific questions about sterility assurance. We report the response rate, the substance and the refusals.
Gauge, pain and flow rate
The insulin injection-technique literature is large, well conducted and directly transferable on questions of depth and tissue. We say where it stops transferring.
The intramuscular injection nobody intended
Skin thickness at the standard injection sites is approximately two millimetres in adults and varies remarkably little with body mass. That single finding is why short…