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OBJECTIVE: The study objective was to determine the relationship of magnetic resonance imaging (MRI)-detected features of patellofemoral joint osteoarthritis to pain and functional outcomes.METHODS: We sampled 1,099 participants from the 60-month visit of the Multicenter Osteoarthritis Study (mean ± SD age: 66.8 ± 7.5 years; body mass index: 29.6 ± 4.8; 65% female). We determined the prevalence of MRI-detected features of patellofemoral joint osteoarthritis (eg, cartilage damage, bone marrow lesions, and osteophytes) and assessed the relationship between these features and knee pain severity, knee pain on stairs, chair stand time, and walking less than 6,000 steps per day. We evaluated the relationship of MRI features to each outcome using logistic and linear regression, adjusting for potential covariates.RESULTS: Participants with cartilage damage in 3-4 subregions had the highest mean pain severity (22.0/100; 95% confidence interval [CI]: 17.6-26.4 mm). They also showed higher odds of having at least mild pain on stairs (odds ratio [OR]: 3.3; 95% CI: 1.7-6.5) and of walking less than 6,000 steps per day (OR: 2.3; 95% CI: 1.1-4.4) compared with those without cartilage damage. Participants with bone marrow lesions in 3-4 subregions had higher odds of at least mild pain on stairs than those without (OR: 3.3; 95% CI: 2.2-5.2). Participants with osteophytes in 3-4 subregions also had higher odds of walking less than 6,000 steps/day (OR 2.1, 95% CI: 1.3-3.5, respectively).CONCLUSION: MRI-detected features of osteoarthritis of the patellofemoral joint are related to pain and functional performance. This knowledge highlights the need to develop treatments for those with patellofemoral joint osteoarthritis to improve pain and maximize function.

[Editor’s Note.—On the 19th of July, 1870, Mr. Maxwell left London for Syria, under instructions from Mr. Telford Macneill, to make a survey of a proposed line of railway through the valley of the Euphrates for the promoters of that scheme. Mr. Maxwell’s letters to his friends at home describe his journey from London and Paris, whence he travelled through France by the most direct route to Brindisi, crossing over Mont Cenis by Mr. Fell’s wonderful mountain railroad. The Letters contain little worth putting in print up to this point, as in these days everybody goes to Paris, and most people are familiar with a still wider radius from home; but Mr. Maxwell’s experience of the journey over the Cenis on the locomotive seems worthy of being printed, as that triumph of engineering adventure—so soon superseded by the more laborious work of tunnelling right through the mountain—is already forgotten. This will account for the abrupt commencement of the Letters. Writing from Brindisi, where an enforced delay took place, Mr. Maxwell gave a more detailed account of his experiences en route and his surroundings than he might otherwise have done. The real interest of the Letters lies in the description of Eastern places, people, and customs, and of the writer’s experience in regions but little known to Europeans; but it has been thought well to print the narrative as connectedly as possible from the point where it is taken up.]

HALF-DUPLEX multistation teletypewriter lines efficiently meet the needs of several points that require record communication with each other. In such cases it is important to be able to send messages to selected stations only. This ability is necessary to save paper, to provide privacy, and to avoid the need to scan all messages at each station to find those addressed to it. Direct interstation communication avoids sending all messages to a relay center for retransmission to other stations. This saves line and attendant time. To facilitate sending messages to addressee stations only, manually operated selective calling devices have been used. By present standards these are relatively slow. In addition, until recently it was necessary for attendants to initiate transmission of messages only when the line was idle. On a busy line this frequently required waiting for the line to become idle as shown by a line lamp. The attendant could then seize the line, operate the selecting equipment, and send the message. Sometimes attendants at two or more stations attempted to seize the line simultaneously. Unsuccessful attendants, unfortunately, had to resume waiting. On a busy line this procedure required appreciable amounts of nonproductive line and attendant time. Furthermore, there was no way to give an urgent message priority over other messages.

Residualizing labels for protein, such as dilactitol-125I-tyramine (125I-DLT) and cellobiitol-125I-tyramine, have been used to identify the tissue and cellular sites of catabolism of long-lived plasma proteins, such as albumin, immunoglobulins, and lipoproteins. The radioactive degradation products formed from labeled proteins are relatively large, hydrophilic, resistant to lysosomal hydrolases, and accumulate in lysosomes in the cells involved in degradation of the carrier protein. However, the gradual loss of the catabolites from cells (t1/2 approximately 2 days) has limited the usefulness of residualizing labels in studies on longer lived proteins. We describe here a higher molecular weight (Mr approximately 5000), more efficient residualizing glycoconjugate label, inulin-125I-tyramine (125I-InTn). Attachment of 125I-InTn had no effect on the plasma half-life or tissue sites of catabolism of asialofetuin, fetuin, or rat serum albumin in the rat. The half-life for hepatic retention of degradation products from 125I-InTn-labeled asialofetuin was 5 days, compared to 2.3 days for 125I-DLT-labeled asialofetuin. The whole body half-lives for radioactivity from 125I-InTn-, 125I-DLT-, and 125I-labeled rat serum albumin were 7.5, 4.3, and 2.2 days, respectively. The tissue distribution of degradation products from 125I-InTn-labeled proteins agreed with results of previous studies using 125I-DLT, except that a greater fraction of total degradation products was recovered in tissues. Kinetic analyses indicated that the average half-life for retention of 125I-InTn degradation products in tissues is approximately 5 days and suggested that in vivo there are both slow and rapid routes for release of degradation products from cells. Overall, these experiments indicate that 125I-InTn should provide greater sensitivity and more accurate quantitative information on the sites of catabolism of long-lived circulating proteins in vivo.

AUTOMATION recently has been extended to teletypewriter services used for exchanging messages among stations connected by half-duplex (nonsimultaneous 2-way) multistation telegraph lines. The automatic dispatch system to be described virtually eliminates all station-attendant operations except one. Typing of the message is required to perforate a tape with the teletypewriter codes corresponding to the characters in the message. The attendant then inserts the tape in an automatic transmitter and the dispatch system does the rest.