Crystal deposition in hypophosphatasia: a reappraisal

Six subjects (three female, three male; age range 38-85 years) with adult onset hypophosphatasia are described. Three presented atypically with calcific periarthritis (due to apatite) in the absence of osteopenia; two had classical presentation with osteopenic fracture; and one was the asymptomatic father of one of the patients with calcific periarthritis. All three subjects over age 70 had isolated polyarticular chondrocalcinosis due to calcium pyrophosphate dihydrate crystal deposition; four of the six had spinal hyperostosis, extensive in two (Forestier's disease). The apparent paradoxical association of hypophosphatasia with calcific periarthritis and spinal hyperostosis is discussed in relation to the known effects of inorganic pyrophosphate on apatite crystal nucleation and growth.

Maternal age and primary cesarean section rates: a multivariate analysis

To study the effect of maternal age on primary cesarean section rates, 3458 consecutive deliveries were analyzed. The cesarean section rates in primiparous women less than 25, 25 to 34, and over 34 years of age were 13.1%, 18.5%, and 28.2%, respectively. A similarly dramatic rise with advancing maternal age was seen in multiparous women with rates of 3.4%, 4.7%, and 10.1%, respectively, in the three age groups. The strong association between cesarean section and maternal age persisted after multivariate adjustment for induction of labor, epidural anesthesia, meconium-stained amniotic fluid, and fetal distress, and thus these factors do not explain the relationship.

The organization of the araBAD operon of Escherichia coli

The nucleotide (nt) sequence of the araBAD operon of Escherichia coli B/r has been determined. The nt sequence predicts a transcript of about 4250 nt. The coding regions of araB, araA and araD genes were identified by partial amino acid (aa) sequences of the purified proteins and their cleavage products. We have deduced that the polypeptides encoded by the araBAD operon consist of 566 (araB), 500 (araA) and 231 (araD) aa residues. The operon contains a leader sequence of 27 nt. The intergenic region between araB and araA is 10 bp in length, while the araA and araD genes are separated by 283 bp consisting primarily of six REP sequences. Comparison of the E. coli sequence with that of Salmonella typhimurium [Lin et al., Gene 34 (1985) 111-122; 123-128; 129-134] shows that, while considerable divergence in nt sequence has occurred, the aa sequences are largely conserved. The most pronounced difference, found in the araD gene, is the deletion of a single nt in the S. typhimurium sequence.

Vascular abnormalities in a fetus with multiple pterygia

We describe a 16-week fetus with a lethal multiple pterygium syndrome and hydrops. No bony abnormalities were noted on radiographic or anatomical examination. A prominent meshwork of dilated, thin-walled vessels was present in the subcutis over the entire body. This abnormal vascularity may have caused pterygium formation and death of the fetus.

Prosthesis with electric elbow and hand for a three-year-old multiply handicapped child

The usefulness of wisely prescribed powered components in the rehabilitation of upper extremity amputees has long been recognized (Schmidl, 1973). Their value is especially evident in the prosthetic rehabilitation of high level adult and child amputees (Heger et al, 1985). In recent years, manufacturers of prosthetic hardware have provided practitioners with a wide selection of either myo-electrically or switch controlled electromechanical components and systems. As a rule, however, most commercially available components are designed to serve the adult amputee and do not lend themselves for use in the prosthetic rehabilitation of children. One current exception is the availability of child-size electric hands. The availability of the world's first child-size electric hand in 1970 at the Ontario Crippled Children's Centre later known as the Variety Village 105 hand, gave tremendous impetus to the fitting of younger children with externally powered components and myoelectric control systems. However, this trend served to benefit the young below-elbow patient only (Sorbye et al, 1972). The successful fitting of higher amputation levels in this age group stopped at the elbow level. Existing artificial elbows such as the Variety Village and Hosmer elbow with their necessary powerpacks are simply too bulky and too heavy for pre-school age children. The need for a lightweight compact electric elbow, suitable for 3-8 year old children, still has not been addressed. This single case report illustrates an innovative and successful conversion of a 6-3/4 Otto Bock hand into a small electric elbow. The idea was first proposed by Schmidl (1973).

Prevention of immune precipitation by purified components of the alternative pathway

The role of the alternative pathway in complement-mediated prevention of immune precipitation has been investigated by the use of BSA-anti-BSA immune complex (IC) purified components. For immune precipitation to be prevented all six alternative pathway components (C3, factors B D, P, H and I) were required. In the absence of one or both of the control proteins H and I, excessive fluid phase turnover of C3 occurred with precipitation of IC. Kinetic studies showed that in the presence of the control proteins, an initial phase of precipitation occurred, and was followed by a phase of resolubilization of IC. When the efficiency of classical and alternative pathways in the prevention of immune precipitation was compared it was found that the classical pathway proteins were more effective than the alternative pathway components. A reaction mixture containing the components of both pathways was no better than the classical pathway protein alone. 125I-C3 was bound to IC which had been rendered soluble in the presence of classical or alternative pathway components. A molar ratio of two molecules C3b:five molecules IgG was calculated. Other complement components which were bound to IC which had been formed in the presence of serum were C1q, C4, C2, C3, C5, P and H. Factors B and I were not detected. Our findings suggest that the alternative pathway is of secondary importance to the classical pathway in the prevention of immune precipitation.

The validity of the labelling index in tumour studies

The distribution of labelled cells through 5 different mouse tumours was measured after a single injection of [3H]-thymidine [( 3H]-TdR) or [3H]-deoxyuridine [( 3H]-UdR). All the tumours had areas where the percentage of labelled cells (the labelling index, LI) was high and areas where the LI was very low. The total area with a low LI was greater after [3H]-TdR than after [3H]-UdR injection in all 5 tumours. In one of the tumours, carcinoma NT, repeated injections of [3H]-UdR at 2 h intervals caused the areas of high LI to spread, eliminating all areas of low LI in many specimens. When 5-fluorodeoxyuridine (FUdR) was injected, to block de novo DNA synthesis in carcinoma NT, [3H]-TdR was incorporated by many more cells. The LI was increased throughout the tumour and no area had a LI below 20% after FUdR plus [3H]-TdR. After flash-labelling with [3H]-TdR alone, nearly half the tumour had a LI below 20%. We conclude that the labelling seen after FUdR plus [3H]-TdR represented the true distribution of S phase cells in carcinoma NT. Routine flash-labelling with [3H]-TdR or [3H]-UdR left nearly half the S phase cells unlabelled and gave an erroneously low value for the proportion of DNA synthesising cells in the tumour. The results suggest that many tumour cells have very large endogenous nucleotide pools which cannot be flooded by a single injection, even of [3H]-UdR.

Arterial pressure and hormone relationships in phaeochromocytoma

To investigate the regulation of arterial pressure and vasoactive hormones in phaeochromocytoma, we measured intra-arterial pressure and hourly venous hormones (renin, angiotensin II, aldosterone, catecholamines and cortisol) for 24 h in two patients before and three months after removal of a catecholamine-secreting tumour. Before surgery, plasma catecholamines, renin and angiotensin II levels showed a weak inverse correlation with arterial pressure, whereas after surgery norepinephrine-blood pressure correlations were close and positive. Heart rate and arterial pressure fluctuations were reciprocal during short-term recordings but were parallel after removal of the tumour. Renin, angiotensin II and aldosterone levels, initially elevated, fell into the normal range after surgery. Circulating norepinephrine correlated in a positive fashion with renin before and after operation. Slopes of log renin (or angiotensin II)/aldosterone, and log cortisol/ aldosterone regression lines were steeper in the initial study compared to the second. We conclude that arterial pressure fluctuations measured hourly are not determined by concurrent levels of catecholamines or angiotensin II in phaeochromocytoma, although we surmise that minute-by-minute changes in blood pressure are catecholamine-related. Renin release is, at least in part, controlled by circulating catecholamines. Aldosterone responsiveness to angiotensin II and to ACTH is enhanced in phaeochromocytoma.

The percentage labelled mitoses technique shows the mean cell cycle time to be half its true value in Carcinoma NT. I. [3H]thymidine and vincristine studies

Cell kinetic parameters measured by the percentage labelled mitoses (PLM) technique have been compared with those derived from continuous labelling and stathmokinetic data in the mouse tumour Carcinoma NT. In [3H]TdR labelled tumours, a PLM curve showed the length of DNA synthesis (TS) to be 9 hr. With continuous labelling, 2.5% of cells entered S phase per hour and TS was 16 hr. Six per cent of cells incorporated [3H]TdR between 1 and 3 hr after an injection of the label. The stathmokinetic technique showed that the rate of entry to mitosis was 2.0% hr. The turnover time (TT) of the population was found to be 16 hr with the PLM data and 35 and 37 hr with the continuous labelling and stathmokinetic data, respectively. The PLM technique therefore showed the mean cell cycle parameters to be about half the values obtained with other methods of measurement. We conclude that in Carcinoma NT there is a wide range of cell cycle times. The continuous labelling and stathmokinetic data represent the mean cell cycle parameters, while the PLM data give the minimum values. A cell loss factor calculated from the PLM data would, therefore, be too high by a factor of two.

The percentage labelled mitoses technique shows the mean cell cycle time to be half its true value in Carcinoma NT. II. [3H]deoxyuridine studies

Cell cycle parameters measured by the percentage labelled mitoses (PLM) technique have been compared with the results of grain counting and continuous labelling studies in the mouse tumour Carcinoma NT. In [3H]deoxyuridine( [3H]UdR)-labelled tumours a PLM curve showed that the mean length of DNA synthesis (TS) was 7 to 9 hr and the mean cell cycle time (TC) was 16 hr. The turnover time (TT) was between 13 and 17 hr. In contrast, the rate of grain count halving showed that mean TC was 40 hr and TS was at least 19 hr. Cells entered S phase at a rate of 2.3%/hr with continuous labelling, which gave values of 22 hr for TS and 39 to 44 hr for TT. The PLM data therefore gave mean kinetic parameters which were less than half the lengths shown by the other techniques. We conclude that in Carcinoma NT there is a wide range of cell cycle times. The grain count halving and continuous labelling data showed the true mean values of TS and TC or TT, while the PLM data showed only the fastest cycle times. Therefore in this tumour, calculating the cell loss factor from PLM data would give a value too high by at least a factor of two.

N-terminal peptide of pro-opiomelanocortin in human amniotic fluid

N-terminal peptide of pro-opiomelanocortin (N-POMC) was measured in the human amniotic fluid. At the gestational age of 16 to 20 weeks, the radioimmunoassay with three different antibodies demonstrated the respective values of 2.39 +/- 0.78, 4.69 +/- 2.27, and 5.92 +/- 2.66 ng/ml. These values are approximately 10 times higher than the measurements in the plasma of women at the corresponding gestational period. The amniotic fluid collected during the delivery had significantly lower concentrations of N-POMC than the amniotic fluid at 16 to 20 weeks' gestation. However, the plasma values of N-POMC had increased approximately three times when measured at delivery and compared with the plasma values at 16 to 20 weeks' gestation. Adrenocorticotropic hormone, measured simultaneously with N-POMC in some of the samples, showed changes similar to those in N-POMC. The N-POMC immunoreactivity from the amniotic fluid has the same retention time on reversed-phase high-performance liquid chromatographic separation as the peptide purified from the human pituitary gland, thus indicating the identity of both peptides.

Early and late morphological changes (including carcinoma of the urothelium) induced by irradiation of the rat urinary bladder

Effects of X-irradiating the urinary bladder of female F344 rats with a single dose of 20 Gy were studied by light and electron microscopy. The animals were killed 1 week-20 months post-irradiation, and all tissues of the bladder wall were found to be affected by the irradiation. In the urothelium, damage was initially restricted to the basal cells but slowly extended to intermediate cells, and by 6 months post-irradiation the urothelium was focally hyperplastic. Twenty months post-irradiation, transitional-cell carcinomas were found in 10 of the surviving 17 animals (59%). The blood vessels in the bladder wall showed damage to both the endothelial cells and the smooth muscle. The fibroblasts in the connective tissue of the bladder wall appeared to show increased secretion after irradiation, and there was abundant collagen deposition, resulting in severe fibrosis of the bladder wall. After a latent period of a few months, focal degeneration and extensive necrosis of the smooth muscle cells were seen, leading to severe destruction and disorganization of the muscular coats of the bladder wall. Thus, a single dose of irradiation of 20 Gy was sufficient to produce severe fibrosis of the bladder wall with smooth muscle degeneration and to induce carcinoma of the urothelium in most of the treated animals within 20 months.

[3H]thymidine labels less than half of the DNA-synthesizing cells in the mouse tumour, carcinoma NT

We have studied carcinoma NT, a transplantable mouse adenocarcinoma of spontaneous origin. Cells labeled with [3H]thymidine ([3H]TdR) were restricted to a narrow zone around the periphery of this tumour and were also found in rings up to 50 micrometers wide, around isolated blood vessels in the central necrotic area. Labelling with [3H]deoxyuridine ([3H]UdR), another DNA synthesis precursor, produced a very different pattern. The labelled zone around the periphery was much wider than with [3H]TdR, and [3H]UdR labelled cells were found up to 110 micrometers from isolated vessels. [3H]iododeoxyuridine ([3H]IUdR) gave the same pattern of labelling as [3H]UdR. In the heavily labelled zone, within 1 mm of the tumour periphery, the labelling index (LI) was 51% after [3H]UdR or [3H]IUdR injection, and only 36% with [3H]TdR. The data show that at least half of the DNA-synthesizing cells in this tumour did not incorporate [3H]TdR. Previous workers reported cell loss factors for carcinoma NT of 60% calculated from [3H]TdR labelling data and 30% from the rate of loss of [125I]UdR. The present work suggests that calculations based on [125I]UdR data are more likely to be accurate for carcinoma NT than those using [3H]TdR data.

Increased C1q binding and arthritis in primary biliary cirrhosis

Using the C1q binding assay, circulating immune complexes were detected in 31 of 50 (62%) patients with primary biliary cirrhosis and 17 of these had arthritis. This took the form of a seropositive inflammatory polyarthritis in 12 of 18 patients with C1q binding greater than or equal to 20%, whereas a milder seronegative arthritis associated with scleroderma and Raynaud's phenomenon was found in five of 13 patients with C1q binding < 20%. Only two of the 19 patients with normal binding had arthritis and this was of a mild and transient nature. There was a positive correlation between C1q binding and the serum concentrations of IgG and IgM. Results also supported the hypothesis that circulating immune complexes may be involved in the development of arthritis in patients with primary biliary cirrhosis.

Diurnal variation in proliferative compartments and their relation to cryptogenic cells in the mouse colon

The depth of the crypts in mouse descending colon varied diurnally, between twenty-six cells at 24.00 hours and thirty-eight cells at 12.00 hours. Cell loss from the colon was greatest immediately before the maximum faeces production, at the beginning of the dark period. The labelling index of the colon also changed, from 9% at 20.00 hours to 16% at 12.00 hours. The greatest variation in labelling index occurred at the top of the zone of proliferative cells, between the ninth and eighteenth cell position up the crypt. In this region a synchronized cohort of about forty cells apparently entered S phase once a day. Although the length of the proliferative zone doubled at 12.00 hours, that of the non-proliferative zone remained fairly constant all day. The number of cryptogenic cells per crypt was estimated by comparing single and split-dose X-ray survival curves. This gave a mean value of two cryptogenic cells per crypt. Crypts rarely regenerated from the base after irradiation. The cryptogenic cells probably lay between cell positions Nos 9 and 18 up the crypt and probably did not function as stem cells in the normal crypt.