Efficacy of ceftiofur hydrochloride for treatment of experimentally induced colibacillosis in neonatal swine

Ceftiofur hydrochloride was tested for effectiveness against induced colibacillosis in neonatal swine. In this model, pigs less than 12 hours old were inoculated via stomach tube with a virulent, K99+, nalidixic acid-resistant strain of Escherichia coli. Six hours after challenge exposure, 1 dose of ceftiofur was administered either IM or orally in experiment 1 and orally only in experiment 2. Mortality, shedding of bacteria, fecal consistency scores, and body weight changes were monitored for 10 days. In experiment 1 (n = 383 pigs), all treatments at dosage that ranged between 0.5 and 64.0 mg of ceftiofur/kg of body weight significantly (P less than 0.001) reduced mortality, bacterial shedding, and diarrhea and increased weight gain, compared with findings in untreated controls. There were no detectable differences between oral and IM routes, except that there was greater reduction in bacteria shedding associated with the oral route of administration. In experiment 2 (n = 505 pigs), ceftiofur was administered orally either once at 6 hours after challenge exposure or twice at 6 and at 48 hours after the first dose. Dosage of ceftiofur was 0, 5, 10, 20, 30, or 60 mg/kg administered once, or half the same dose was administered at each of 2 times. At the optimal dosage (10 mg/kg), a single dose was as effective as 2 doses. The single administration at all dosages reduced mortality, bacterial shedding, and diarrhea scores and increased body weight gain, compared with findings in untreated pigs (P less than 0.01). In this induced infection model, the optimal treatment dosage was determined to be 10 mg/kg administered once.

L-NG-nitro arginine (L-NOARG), a novel, L-arginine-reversible inhibitor of endothelium-dependent vasodilatation in vitro

1. The effect of L-NG-nitro arginine (L-NOARG) was compared with that of L-NG-monomethyl arginine (L-NMMA) on vasodilatation of the isolated aorta of the rabbit and perfused mesentery of the rat in response to acetylcholine (ACh) and sodium nitroprusside (NP). 2. L-NOARG (1.5-100 microM) and L-NMMA (3-100 microM) produced concentration-related contraction of the rabbit aorta precontracted with phenylephrine (700-900 nM). Similarly, L-NOARG (10-200 microM) and L-NMMA (30-100 microM) elevated perfusion pressure of the noradrenaline (NA, 0.6-2.5 mM)-preconstricted rat mesentery preparation. 3. L-NOARG (1.5-100 microM) and L-NMMA (3-100 microM) caused concentration-related inhibition of the vasodilator effect of ACh (0.01-1.0 microM) on the rabbit aorta without influencing responses to NP (0.03-0.5 microM). L-NOARG methyl ester (30 microM) also inhibited ACh-induced vasorelaxation with similar potency to NOARG. L-arginine (30-150 microM) but not D-arginine (100 microM) caused graded reversal of the inhibitory effect of both L-NOARG (15 microM) and L-NMMA (30 microM). Complete reversal of the effect of both inhibitors was achieved with 150 microM L-arginine. L-Alanine (50 microM), L-arginosuccinic acid (5 microM), L-citrulline (50 microM), L-methionine (50 microM) and L-ornithine (50 microM) failed to reverse the inhibitory effect of L-NOARG (15 microM). 4. L-NOARG (10-200 microM) and L-NMMA (30-100 microM) inhibited the vasodilator effect of ACh (0.006-18.0 nmol) in the rat mesentery without affecting vasodilatation due to NP (1.1-11.1 nmol). L-Arginine (100 microM) but not D-arginine (100 microM) produced partial reversal of the effect of L-NOARG (30 microM) and L-NMMA (30 microM). 5. L- and D-N'-butyloxycarbonyl No-nitro arginine (100 microM) produced modest (approximately 20%) inhibition of the effect of ACh on the rabbit aorta; this effect was not reversible with L-arginine (100 microM). L-Namonocarbobenzoxy arginine (L-NMCA, 5O microM), L-N-NG-dicarbobenzoxy arginine (L-NDCA, 5 microM) and L-NG-tosyl arginine (50 microM) were inactive. 6. These results identify L-NOARG as a potent, L-arginine reversible inhibitor of endothelium-dependent vasodilatation. The available data suggests that L-NOARG, like L-NMMA, inhibits endothelial nitric oxide (NO) biosynthesis.

Epistaxis: a study of the relationship with weather

Epistaxis is the commonest ENT emergency requiring hospital admission. A seasonal variation in the admission rate has been documented. The role of weather in accounting for this variation is uncertain. A retrospective review of 686 adult hospital admissions for idiopathic spontaneous epistaxis over a 2-year period in the Greater Glasgow area was carried out. The most significant weather parameter which correlated with monthly admissions was mean monthly temperature (Pearson's correlation coefficient -0.81, P less than 0.01). Admissions increased by over 100% from the warmest to the coldest months. This is the first report of the high correlation between hospital admissions for epistaxis and mean monthly temperature.

Preservation surgery for malignant disease: why it works

Local recurrence has been considered a grave prognostic sign after radical surgery for breast cancer. Controlled trials have recently discovered local recurrence to be an innocent event after limited surgery. Nine years ago I proposed a hypothesis to resolve this dilemma. The discovery of natural killer (NK) cells has added support to this hypothesis. Patients vary widely in their ability to kill metastasizing tumor cells. Patients who survive their initial tumor without subsequent distant disease may have an NK system sufficient to resist recurrence of a similar volume of tumor arising within the field of initial treatment. Both clinical and laboratory investigations suggest that this hypothesis may be applicable to a variety of solid tumors. Surgeons who support this perception of tumor-host balance may prudently limit the extent of their operations for those malignancies so affected.

Mastoid ache in acoustic neuroma

In a series of 100 patients with unilateral acoustic neuroma the incidence of mastoid aching was found to be 25 per cent, though none of the patients reported this as their principal symptom. Mastoid ache was not related to tumour size, hydrocephalus, or duration of symptoms. However, there was a significantly higher incidence of facial numbness and diminished facial sensation, but not facial weakness, compared with the whole series. Since motor fibres are more resistant to pressure than sensory fibres, mastoid ache may signify the pressure of an expanding cerebellopontine angle tumour.

Reliability of the House and Brackmann grading system for facial palsy

The House and Brackmann grading system has been recommended as a universal standard for assessing the degree of facial palsy. This study examined the inter-observer reliability of this system. Three observers assigned a grade to each patient, examined independently, on the same day. Forty patients with a unilateral facial palsy of varying aetiology and severity were assessed. Of the 120 judgements, eight were in dispute, by a maximum of one grade, giving an inter-observer reliability of 93 per cent. We conclude that the House and Brackmann grading system is a simple and robust method of assessing facial function.

Measurement of bone in the os calcis: a clinical evaluation

Bone mineral content (BMC) was measured in the os calcis of 232 normal subjects aged 17-82 years. The mean reproducibility (coefficient of variation) of the measurement was 1.8%. Substantial bone loss occurred between the ages of 20 and 50 years, and in females the menopause was associated with additional bone loss. There was no significant difference in the rate of bone loss in females and males, but the mean BMC was greater at all ages in males than in females. We also compared os calcis BMC with spinal bone mineral density (BMD), measured by quantitative computed tomographic (CT) scanning, in 85 subjects: 33 were normal controls, 19 had osteoporosis defined by the presence of one or more pathological fractures, and in the remainder the CT examination was performed at the patient's request. Os calcis BMC correlated with spinal BMD in both females (r = 0.69, p less than 0.001) and males (r = 0.84, p less than 0.001). However, the os calcis BMC did not reliably predict spine values around the CT "fracture threshold" of 90-100 mg/cm3 and did not correlate with osteoporotic fracture as well as did spinal BMD. It is concluded that measurement of the os calcis BMC is of limited clinical usefulness for the early diagnosis of osteoporosis.

Open-cavity mastoid surgery: its effect on the acoustics of the external ear canal

Temporal bone studies have demonstrated that a modified radical mastoidectomy changes the resonant characteristics of the external auditory canal, but the effect has not been reported in patients. In 12 patients, performing open-cavity mastoid surgery for cholesteatoma changed the mean peak resonant frequency of the external ear canal from 2.5 to 2.2 kHz (p less than 0.02). This is in comparison with creating a modified radical mastoid cavity in 6 temporal bones which changed the mean peak resonant frequency of the external ear canal from 3.9 to 1.9 kHz. It is concluded that open-cavity mastoid surgery in patients changes the acoustics of the external ear canal less than in temporal bone studies.

Breast cancer: the dilemma of local recurrence

Local recurrence following surgery for breast cancer has long been considered a grave sign. Recent controlled trials indicate that breast and axillary recurrences can behave in an innocent fashion and, in many cases, contribute no risk to patient survival. Thus far there is no biological explanation for the remarkable finding. It is suggested here that patients vary widely in their defense against metastasizing tumor cells, and that the level of resistance is quite stable throughout one's life. Natural killer (NK) cells may contribute significantly to this role of immune protection. From these two assumptions an hypothesis is fashioned which attempts to reconcile the different perceptions of locally recurrent breast cancer.

Disorders of calcium and bone metabolism

Calcium levels in blood are maintained within narrow limits by parathyroid hormone, acting on kidney, bone and gut. Our understanding of the mechanisms of these actions has increased greatly in recent years, for example by identification of new hormones (eg 1,25 dihydroxy vitamin D) and by the study of isolated bone cells. Though most clinical disorders of calcium metabolism are now readily diagnosed and many are effectively treated, some serious problems still remain. Foremost amongst these are the early diagnosis of osteoporosis and the treatment of osteoporosis after fractures have occurred. Most disorders of calcium metabolism have ophthalmologic manifestations, sometimes troublesome to the patient, and sometimes diagnostically helpful.

Bone histology in young adult osteoporosis

Bone histology was quantitated in 10 osteoporotic patients aged between 17 and 51 years and in six healthy subjects aged between 23 and 43 years. The osteoporosis was of varying aetiology and was clinically stable. All patients were given tetracycline before biopsy and double tetracycline labelling was used in seven patients. Bone forming and resorbing surfaces were defined by the presence of osteoblasts and osteoclasts, respectively, which were identified by histochemical techniques. The associations between bone forming and resorbing surfaces were similar in patients and controls, though the range of values was wider in the patients than in the controls. Mineral apposition rate was normal in the osteoporotic patients, but there was a reduction in mineralising (tetracycline) surface, whether related to osteoid surface or to osteoblast surface. This did not indicate osteomalacia as the directly and indirectly measured mineralisation lag times were normal. The osteoid seams were thinner in osteoporotic patients than in controls. The data suggest that osteoclast and osteoblast numbers were normal in this group of osteoporotic patients but that the metabolic activity of osteoblasts was impaired.

Candidiasis-endocrinopathy syndrome with progressive myopathy

A women suffering from the candidiasis-endocrinopathy syndrome, developed severe myopathy in her fourth decade and died from it at the age of 37 years. Associated conditions were hypoparathyroidism, vitiligo, chronic mucocutaneous candidiasis, short stature, intellectual disability, ovarian failure and alopecia totalis. Muscle biopsy findings were non-specific with focal atrophy of type 2 fibres. Serum immunoglobulin levels were normal. The only demonstrable abnormalities of her immune system were impaired T-cell function and antibody production by B-cells (detectable to smooth muscle, mitochondria and gastric parietal cells). The T-cell abnormality may have been part of a more generalized cell defect, resulting from an unidentified genetic abnormality, whilst the circulating antibodies could have been a response to tissue damage. There was no convincing evidence of primary autoimmune damage.

Bone mass is low in relatives of osteoporotic patients

STUDY OBJECTIVE

To determine whether the failure to attain normal bone mass in young adulthood contributes to the later development of osteoporotic fractures.

DESIGN

Case-control study.

SETTING

Referral-based bone clinic at a large teaching hospital.

PATIENTS

Sequential sample of 35 asymptomatic relatives, aged 19 to 59 years, of patients with osteoporotic fractures, and 24 patients with osteoporotic fractures.

MEASUREMENTS AND MAIN RESULTS

Bone mineral density in the spine was measured by quantitative computed tomographic scanning. Bone mineral content in the os calcis was measured in 19 of the relatives of osteoporotic patients by single-photon absorptiometry. The values for bone mineral density in the spine were corrected to age 50 years with the regression equation derived from the normal values in the controls. The values were lower in relatives of osteoporotic patients than in controls. In men, the mean values (+/- standard deviation [SD]) for relatives were 91 +/- 16 mg/cm3, and for controls, 129 +/- 21 mg/cm3 (P less than 0.001). In women, the mean values for relatives were 96 +/- 17 mg/cm3 and for controls, 126 +/- 19 mg/cm3 (P less than 0.001). In the osteoporotic patients, the corrected mean value for men was 53 +/- 12 mg/cm3, and for women, 77 +/- 20 mg/cm3. The os calcis values did not correlate with the spine values and were mostly well within the normal range.

CONCLUSIONS

Mean bone mass is lower in apparently healthy young and middle-aged adult relatives of osteoporotic patients than in normal persons with no family history of osteoporosis. Our findings suggest that the failure to attain an adequate peak bone mass may play an important role in the later development of osteoporotic fractures. Relatives of osteoporotic patients should be advised to have measurements of bone mass taken. This measurement should be taken at the spine, because peripheral sites do not appear to provide adequate information about early osteoporosis.

The effectiveness of a soluble calcium preparation as a gut phosphate binder

We determined the phosphate binding capacity of a soluble commercial calcium preparation by carrying out metabolic balances on four normal subjects and by administering it for 4 weeks to six patients treated by maintenance hemodialysis. Each tablet of Sandocal 1000 (Sandoz, Australia) contained 1 g of elemental calcium as calcium lactate-gluconate 5.23 g and calcium carbonate 0.8 g. The metabolic balance study was performed over two consecutive nine-day periods. A constant, normal diet was consumed throughout, but in the second period one Sandocal 1000 tablet was added to each of the three major daily meals. Each period consisted of four days of equilibrium, then five days of collection of urine and feces. Polyethylene glycol 4,000 was used as a continuous fecal marker and carmine red was used to indicate gut transit time. Calcium supplementation increased fecal phosphate excretion by 11.2 +/- 2.3 mmol/d (SD), and decreased urinary phosphate by 8.4 +/- 2.6 mmol/d. Plasma calcium levels were unchanged, while plasma phosphate levels rose slightly. The increase in fecal phosphate was similar to that previously reported when calcium carbonate 8 g/d or aluminum hydroxide 6.4 g/d were administered. In the patients treated by maintenance hemodialysis, the reduction in plasma phosphate induced by Sandocal 1000, three tablets daily, was similar to that obtained with aluminum hydroxide 1.8 +/- 1.2 g/d. Hence, this calcium preparation appears to have a phosphate binding capacity similar to that of standard doses of aluminum hydroxide.

Assessment of permanent hearing impairment following radical megavoltage radiotherapy

Twenty patients who had received unilateral radical megavoltage radiotherapy to the temporal bone had their hearing assessed by pure tone audiometry between 2 and 16 years after completion of treatment. Hearing loss was not detected in the irradiated ear when compared with the non-irradiated ear of each patient.

Recovery from steroid-induced osteoporosis

The reversibility of steroid-induced osteoporosis, a major complication of Cushing syndrome and long-term use of exogenous corticosteroids, is not well documented. We measured the bone mineral density of lumbar vertebras and the femoral neck by dual-photon absorptiometry and determined the biochemical variables of bone turnover in two patients successfully treated for Cushing syndrome who were followed for the next 24 months. Our data are the first to show marked increases in bone density (up to 20%) during the recovery period. The accompanying biochemical changes, particularly the marked increase in serum osteocalcin levels, confirm that enhanced bone formation occurred during the recovery phase. These findings suggest that steroid-induced osteoporosis can be reversed at least in young persons.

Response of the growth plates to tibial osteotomy in rats

The parameters of cellular proliferation and growth in the growth plates of immature rats were measured after unilateral tibial osteotomy and used to calculate growth rates. Distal osteotomy of one tibia was followed by a bilateral increase in the calculated growth rate of the distal growth plates. However, the ipsilateral distal growth plate grew faster than the contralateral between 12 and 18 days after operation, which appeared to be related to increased cell proliferation and height. Proximal osteotomy led to an increase in growth rates proximally which was more marked on the contralateral side. The lesser response of the ipsilateral growth plate may have been due to local impairment of blood supply, or to greater local release of metabolites after bony damage. Distal tibial osteotomy gave similar results to circumferential release of the distal tibial periosteum. Proximal osteotomy, however, produced a relative impairment of growth on the operated side. This may be of importance in the correction of childhood deformities associated with inequality of leg length.

The response of the rat tibial growth plates to distal periosteal division

The growth plate chondrocytes have been examined in the tibiae of normal immature rats and in similar rats after circumferential distal periosteal release. In control rats, calculation of the growth rate as the product of the rate of cell proliferation and the maximum hypertrophic cell height correlated with gross measurements. The labelling index also correlated with the calculated growth rate. During the period 28 to 46 days of age there was little change in the growth rate but a diminution in the height of the hypertrophic cells. Unilateral circumferential periosteal division produced bilateral increases in tibial growth rate and in the activity of both the proliferative and hypertrophic zones as part of the systemic response to the trauma. There was a 1% ipsilateral increase in tibial length, as compared to the contralateral side, which appeared to be related principally to an increase in the number of proliferative cells. This simple method of stimulating bone growth can usefully be undertaken at the same time as other operative procedures.

Aminohydroxypropylidene diphosphonate treatment of hypercalcemic crisis due to primary hyperparathyroidism

A 43 year old man was known to have had mild primary hyperparathyroidism for several years. Nine days following surgery for acute cholecystitis he developed a hypercalcemic crisis with a plasma calcium level of 4.23 mmol/l, despite intravenous and oral hydration. The hypercalcemia was corrected by a single intravenous dose of (3-amino-1-hydroxypropylidene)-1,1-diphosphonate (15 mg), allowing parathyroidectomy to be performed electively and on a well patient.

The pathogenesis of osteoarthritis of the hip. Evidence for primary osteocyte death

Osteocyte viability was investigated in femoral head bone removed from 38 patients with chronic hip disease, with the use of a histochemical stain to demonstrate lactate dehydrogenase (LDH) activity in osteocytes. Where the osteocyte cytoplasm did not show LDH activity, the cell was considered dead; when several adjacent osteocytes were dead, the bone in that area was regarded as nonviable. The preoperative diagnoses were idiopathic osteoarthritis in 25, chondrocalcinosis in six, rheumatoid arthritis in two, Paget's disease in two, avascular necrosis in two, and congenital dislocation of the hip in one patient. In 16 of the patients with idiopathic osteoarthritis and the two with avascular necrosis, nonviable osteocytes were present in the central regions of many trabeculae, these areas usually being separated by cement lines from viable bone. The pattern suggested previous necrosis of part of the femoral head, with later new bone formation. The pattern was not observed in either control subjects, or patients with known articular disease, such as chondrocalcinosis. Bone collapse of variable severity was apparent radiographically in nine patients with histologic bone death, but not in other patients. Bone death is commonly present in idiopathic osteoarthritis and could be a cause rather than a result of the arthritis.

The aetiology of Dupuytren's disease

Dupuytren's disease is a disorder frequently encountered in clinical practice. Knowledge of its aetiology has recently grown, but the precise cause remains unclear.

Immobilization hypercalcaemia due to low bone formation and responding to intravenous sodium sulphate

A young man developed acute renal failure and hypercalcaemia following severe burns. The hypercalcaemia was initially controlled by haemodialysis, but it persisted after return of renal function. Plasma PTH was inappropriately elevated, but the nephrogenous cyclic adenosine monophosphate level was low; thus the PTH was probably not biologically active, and may have been artefactually elevated by the moderate renal impairment. Bone histology, showed a normal resorbing surface, but a zero forming surface, implying that the bone dissolution leading to hypercalcaemia resulted from a failure of bone formation. Because of widespread infection and impaired renal function, the hypercalcaemia could not be treated by corticosteroid drugs, mithramycin or phosphate, and there was no response to salmon calcitonin. He was therefore treated with intravenous sodium sulphate, which increased urinary calcium excretion and reduced the plasma calcium. Sodium sulphate still has a role in the treatment of patients with hypercalcaemia.

Hypercalcaemia. What does it signify?

Hypercalcaemia can be caused by many disorders, but is most commonly due to primary hyperparathyroidism in outpatients, and to malignant disease in hospital inpatients. When mild (less than 3 mmol/L) it does not cause symptoms, but can have long term effects such as renal calculi. It is important that the aetiology of the hypercalcaemia be established, as it can reflect serious disease. In most patients the correct diagnosis can be suspected from clinical history and examination, and confirmed by laboratory tests and x-rays. The most difficult diagnostic problem is the patient with negative clinical findings, mild hypercalcaemia and mild renal impairment, when the parathyroid hormone level is normal or slightly elevated. When hypercalcaemia is severe (greater than 3.5 mmol/L), it can cause vomiting, polyuria, dehydration and renal impairment, and is then an important therapeutic problem. Therapy includes treatment of the cause, such as radiotherapy for malignant disease or surgery for primary hyperparathyroidism. In addition, it is usually necessary to treat the hypercalcaemia itself, and the initial step is always rehydration. If the plasma calcium concentration remains high, drug treatment must be added, the most effective and reliable agent being intravenous mithramycin. Aminohydroxypropylidene diphosphonate (APD), though less studied, may be equally useful in this situation. Glucocorticoids are not always effective, and phosphate may cause renal damage, particularly when given intravenously. For long term treatment of malignant hypercalcaemia, oral glucocorticoids and phosphate are often effective, and can be given in combination. When primary hyperparathyroidism cannot be corrected surgically, the hypercalcaemia (and hypercalciuria) are probably best treated with a low calcium diet and cellulose phosphate, a regimen also effective for the hypercalcaemia of sarcoidosis.

Differential ontogeny of putative M1 and M2 muscarinic receptor binding sites in the murine cerebral cortex and heart

Studies with [3H]pirenzepine [( 3H]PZ) suggest that this nonclassical muscarinic antagonist selectively identifies putative M1 muscarinic receptors. We now compare the ontogeny of these putative M1 sites, identified by high-affinity [3H]PZ binding, with sites identified by the classical antagonist (-)-[3H]quinuclidinyl benzilate ((-)-[3H]QNB) in murine cerebral cortical and cardiac homogenates. Dissociation constants (Kd) for [3H]PZ (2.1-6 nM in the cortex and 2.0-21 nM in the heart) and for (-)-[3H]QNB (10-28 pM in the cortex and 10-39 pM in the heart) are similar in adult and neonatal tissues, whereas receptor density (maximum binding, femtomoles per milligram of protein) varies significantly. Cerebral cortical [3H]PZ binding rises from 14% at birth, to 88% of adult levels by day 14, peaks at 128% at day 28 and falls to the mean adult level of 606 fmol/mg of protein. Cerebral cortical (-)-[3H]QNB binding parallels [3H]PZ binding. Conversely, parallel studies show cardiac (-)-[3H]QNB density is 3- to 17-fold greater than the comparable density of high-affinity [3H]PZ binding sites throughout ontogeny. We conclude that: 1) the high ratio of [3H]PZ binding to (-)-[3H]QNB binding identifies the murine cerebral cortex as a tissue which contains predominantly putative M1 muscarinic binding sites; 2) the relatively low ratio of [3H]PZ binding to (-)-[3H]QNB binding throughout ontogeny identifies the murine heart as a tissue which contains primarily the putative M2 muscarinic binding site; and 3) M1 and M2 receptor binding sites show distinct developmental curves in the cerebral cortex and heart.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of childhood renal osteodystrophy with calcitriol or ergocalciferol

Quantitative bone histology, biochemistry and height velocities were studied in 18 children suffering from chronic renal failure. Eight received calcitriol, 7 ergocalciferol and 3, though alloted to a treatment group, failed to comply with therapy. A histochemical stain for aluminum showed heavy deposition at the calcification front in 3 patients; 2, in the calcitriol group had severe osteomalacia which worsened during treatment, and 1 in the ergocalciferol group had osteomalacia which did not improve. One had never undergone hemodialysis. Bone histology improved markedly in the remaining 12 patients, whichever vitamin D preparation was used; it was unchanged in 3 non-compliant children. Plasma calcium levels rose while parathyroid hormone and alkaline phosphatase levels fell following both treatments, and were unchanged in non-compliant children. Hypercalcemia occurred more frequently following calcitriol therapy (11 episodes) than following ergocalciferol therapy (3 episodes). Height velocities, studied in 11 children, increased in 5 (3 on ergocalciferol and 2 on calcitriol) and were unchanged in 6 (1 on ergocalciferol, 5 on calcitriol). Improved bone histology did not correlate with increase in height velocity. As ergocalciferol and calcitriol had similar therapeutic effects and as side-effects were more common with calcitriol, it is concluded that calcitriol provides no advantage over ergocalciferol in the treatment of renal bone disease in children.

Investigation and treatment of renal calculi

We have investigated and treated 176 patients who were suffering from renal calculi. The stones contained calcium in 87% of patients, predominantly urate in 11%, and rarely contained magnesium ammonium phosphate or cystine. Of the patients with calcium stones, hypercalciuria was present in 75% and was identified in 57% by the measurement of the 24-hour urinary calcium excretion, and in a further 18% by a standardization calcium "fast-and-load" test. Nine patients were found to have primary hyperparathyroidism and were treated surgically. A further 21% were suspected to have normocalcaemic hyperparathyroidism, and metabolic studies are being developed to clarify this. The treatment of hypercalciuria included a low-calcium diet, and various combinations of a thiazide diuretic, phosphate supplements and sodium cellulose phosphate. Hypercalciuria was controlled in all compliant patients, and only two developed further stones. Hyperuricosuria was rarely the sole metabolic abnormality in patients with calcium stones, though this might reflect the referral pattern of the Unit. Uric acid stones were frequently, but not invariably, associated with hyperuricosuria and acid urine, and even large uric acid calculi dissolved with a combined therapy of high fluid intake, allopurinol and an alkalinizing agent. Surgical treatment was rarely required in these patients. A stone in the renal pelvis of one patient was removed percutaneously and did not require ultrasonic fragmentation. Modern methods of investigation and treatment have greatly improved the outlook for patients with recurrent renal calculi.

The effect of age on bone composition and viability in the femoral head

We studied the effect of age on bone composition and osteocyte viability in femoral heads from fifty-one subjects. The assessment included determination of: bone volume, ash weight, calcium, and phosphorus content; osteocyte viability in fresh sections stained for lactate dehydrogenase activity; microfractures in fresh sections after removal of marrow elements; bone area, the presence of metabolic bone disease, and the histology of microfractures in embedded calcified sections; and the extent of trabecular microfractures. Bone area and numbers of microfractures were also assessed in eight elderly hip-fracture patients. Bone volume decreased with age, but there was considerable variation in each age group, and no significant difference between men and women. Ash weight and the bone content of calcium and phosphorus also decreased with age, but were constant if corrected for bone volume. Almost all osteocytes were viable in subjects who were younger than twenty-five years, and thereafter viability progressively decreased to a mean of 74 per cent in the eighth decade of life. There was a significant negative correlation between osteocyte viability and age. There was no evidence of metabolic bone disease in any patient. The numbers of microfractures increased with age and correlated negatively with bone viability (r = -0.31, p less than 0.05); in simple linear correlation a relationship between bone area and microfractures could not be demonstrated but in multiple linear correlation, after the inclusion of bone viability, there was an additional negative correlation between numbers of microfractures and bone area (p less than 0.005). Bone area and numbers of microfractures in hip-fracture patients were similar to those in age-matched controls.

Effect of aluminum and parathyroid hormone on osteoblasts and bone mineralization in chronic renal failure

Bone aluminum, quantitative bone histology, and plasma parathyroid hormone (PTH) were compared in 29 patients undergoing chronic hemodialysis. Histologic techniques included double tetracycline labeling and histochemical identification of osteoclasts and osteoblasts. Bone aluminum was measured chemically by flameless atomic absorption spectrophotometry, and histochemically. When measured chemically, the bone aluminum was 67 +/- 46 (SD) mg/kg dry weight (normal 2.4 +/- 1.2 mg/kg); histochemically, aluminum was present at 2.9 +/- 4.4% of trabecular surface. The biochemical and histochemical results agreed well (r = 0.80, P less than 0.001). No double tetracycline labels were seen at the mineralization front where aluminum was deposited, indicating cessation of mineralization at these sites. The osteoblast surface correlated positively with plasma PTH (r = 0.67, P less than 0.001) and negatively with bone aluminum level (r = -0.42, P less than 0.05). Multiple linear regression showed a correlation of aluminum with osteoblasts additional to that of PTH, consistent with a direct effect of aluminum in depressing osteoblast numbers. Though a relationship between PTH and chemically determined bone aluminum level could not be demonstrated, there was a negative correlation between osteoclast count and aluminum, and the nine patients with severe hyperparathyroid bone disease had lower chemically determined aluminum levels than the other patients. These results suggest that aluminum (a) directly inhibits mineralization, (b) is associated with decreased PTH activity and hence osteoblast numbers, and (c) directly reduces osteoblast numbers. In addition to inducing severe, resistant osteomalacia, aluminum appears to contribute to the mild osteomalacia commonly seen in renal failure, characterized by extensive thin osteoid and low tetracycline and osteoblast surfaces.

Growth retardation and renal osteodystrophy in children with chronic renal failure

Height, expressed as standard deviation scores for chronological age and for bone age, was studied in relation to glomerular filtration rate, bone age delay, and bone histology in 47 children with chronic renal disease and GFR less than 80 ml/min/1.73 m2. In multiple regression in all 47 patients, only GFR and bone age delay significantly affected height; 40% of children were short (height standard deviation score less than -2) for chronological age, and 9% were short for bone age. Renal osteodystrophy, which only occurred at GFR less than 30 ml/min/1.73 m2, significantly affected height only in children with congenital renal disease and GFR less than 20 ml/min/1.73 m2. Although radiological and biochemical changes of renal osteodystrophy were seen more often in short children, histological bone disease occurred just as frequently in tall children as in short children. Thus much of the observed height retardation in chronic renal failure is associated with delayed skeletal maturation. In addition, although severe renal osteodystrophy may contribute to growth retardation in advanced renal failure, our data suggest that milder degrees of bone disease evident only on histological study cannot be implicated in the etiology of growth failure in chronic renal impairment.

Categorical list differentiation by mentally retarded adolescents as a function of transfer list composition and response mode

Likely sources of interference encountered in free-recall transfer word lists were investigated. Recall, but not recognition performance, was assumed to be sensitive to the relatively greater interference generated by old-categories transfer lists to those employing new categories. Eighty EMR subjects were assigned to the cells of a 2 (list novelty) X 2 (response mode) factorial arrangement. Since response mode was manipulated within subjects, a counterbalanced order of testing factor was also included. For the recognition task, one-half of the subjects received either same- or different-categories distractors. Results revealed that recognition performance was significantly influenced by the list novelty variation; performance was better on new- than on old-categories transfer lists. Additionally, the recognition task with same-categories distractors was associated with a greater response bias to call new items old than was the task with different-categories distractors. Results suggest that the recognition task may be more vulnerable to interference than has been previously supposed.

Pathologic fracture due to severe osteomalacia following low-dose diphosphonate treatment of Paget's disease of bone

Ethane-I-hydroxy-I,I-diphosphonate (EHDP) 5 mg/kg body weight/day was administered to a patient suffering from Paget's disease of bone. After 150 days of treatment, when the plasma alkaline phosphatase was 40% of initial, he suffered a pathologic fracture of his Pagetic right patella, which was found to have osteomalacia of extreme severity. An iliac crest bone biopsy, following double tetracycline labels, also showed severe osteomalacia of Pagetic bone. Osteoclast acid phosphatase activity was reduced, as occurs in diphosphonate-treated rats. The patient's history included two previous pathologic fractures of Pagetic bone and unusual sensitivity to EHDP. It might be prudent to perform needle bone biopsy in order to exclude osteomalacia in EHDP-treated patients with these clinical manifestations.

Effect of aluminum on normal and uremic rats: tissue distribution, vitamin D metabolites, and quantitative bone histology

The effects of intraperitoneal aluminum chloride (1.5 mg aluminum/kg/day for 9 weeks) were studied in normal and uremic rats. Parameters measured included tissue aluminum, serum vitamin D metabolites, and quantitative bone histology. Aluminum administration increased tissue concentrations of this metal in uremic and nonuremic animals. Bone aluminum concentrations were higher in uremic rats (121 +/- 27 mg/kg compared to 47 +/- 4), whereas liver values were higher in the nonuremic group (175 +/- 47 mg/kg compared to 100 +/- 36). Serum concentrations of 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D were reduced in uremia, but aluminum was without apparent effect on any vitamin D metabolite. Aluminum, in the doses administered, caused no skeletal changes in nonuremic animals. Some uremic, non-aluminum-treated rats developed osteomalacia and marrow fibrosis. However, osteomalacia was more severe and the osteoclast count was higher in the uremic, aluminum-treated rats. In this group of animals the mineral apposition rate was reduced at the metaphyseal endosteum but increased at the periosteum, indicating different control mechanisms at the two sites.

Diphosphonates and painful feet

Localised foot pain occurred in four patients with Paget's disease of bone or myositis ossificans who were treated with disodium etidronate (EHDP) in a dose of 10 to 20 mg/kg body weight/day for four to six months. There was localised tenderness and sometimes slight swelling at the painful areas. Bone x-rays were normal, but bone scans showed increased uptake of the isotope at these areas. The pain persisted for several weeks, causing considerable difficulty in walking. The symptoms were most likely due to diphosphonate-induced stress fractures. These cases emphasise the importance of administering EHDP in low dosage for short periods only.

Treatment of Paget's disease of bone

One hundred and four patients with Paget's disease of bone received treatment with a calcium/thiazide regimen, salmon calcitonin, or ethane-1-hydroxy-1, 1-diphosphonate (EHDP). Most patients commenced therapy with the calcium/thiazide regimen; in 67% of these, the disease was satisfactorily controlled for some years. When the response was unsatisfactory, calcitonin was given. This was frequently effective, but produced troublesome nausea in 28% of patients. When these side effects were unacceptable, or the response was not adequate, EHDP was given, unless the patient appeared to be at risk of fracture. It is suggested that the calcium/thiazide regimen has a place in the management of Paget's disease; that calcitonin is more frequently effective, but has a high incidence of unpleasant, though not serious, side effects; and that EHDP is a useful agent in the treatment of Paget's disease, but must be administered with care, and does carry a small risk of pathological fracture.

Adult osteosclerosis

Quantitative bone histology was carried out in five osteosclerotic adults. The bone was extremely hard in all patients, and open biopsy was usually required. One patient, aged 18 years, presented with hypoplastic anemia, and the most probable explanation for the osteosclerosis is a marrow stem cell defect leading to defective osteoclasts. Another had the dominant form of osteopetrosis. Her bone contained cartilage remnants, and there were many large, morphologically abnormal osteoclasts, which lacked normal cytoplasmic acid phosphatase activity. The third patient had chronic renal failure and osteomalacia; here the increased bone mass might have resulted from an inability of normal osteoclasts to resorb bone, due to the surface coating of osteoid, though an earlier increase of bone formation cannot be excluded. The fourth patient, who suffered from systemic mastocytosis, had high turnover bone, with greatly increased bone formation. The fifth patient, with fluorosis of bone, also had increased bone formation and resorption, the process being much more pronounced in the head of her pathologically fractured femur than it was in the iliac crest. In this patient some osteoclasts had reduced acid phosphatase activity and long cytoplasmic extensions, both changes similar to those observed in diphosphonate-treated animals. Very diverse processes can result in the increased cancellous bone mass producing the radiographic appearance of diffuse osteosclerosis.

Bone metabolism in idiopathic juvenile osteoporosis: a case report

A previously healthy 12-year-old boy developed pain on walking and x-rays showed osteoporosis. Over the next 2 years deterioration occurred, the condition became extremely severe, and he was confined to a wheelchair. After 5 years, marked kyphoscoliosis and pigeon chest deformity were present and little increase in height occurred. A wheelchair accident at the age of 17 resulted in several major long bone fractures. Iliac crest biopsies were taken at ages 15 and 17, and subjected to quantitative histology. A histochemical technique for osteoclast recognition by acid phosphatase activity showed resorption parameters to be normal. Double tetracycline labeling and histochemical identification of osteoblasts showed no abnormality of endosteal bone formation. Because of "coupling" of endosteal formation and resorption, these measurements might primarily reflect bone turnover. Failure of periosteal bone formation as shown by failure of radial growth of long bones and of epiphyseal growth was clearly evident. It is likely that osteoporosis developed in this patient due to a reduction in bone formation of unknown etiology rather than by increased bone resorption.

Long-term experience with a calcium-thiazide treatment for Paget's disease of bone

75 patients with Paget's disease of bone were treated with a drug combination intended to increase the production of endogenous calcitonin and decrease that of parathyroid hormone. The first regimen of oral calcium, thiazide diuretic, aluminum hydroxide and low-phosphorus diet was given to 41 patients for a mean of 800 days. A simpler regimen of oral calcium and thiazide diuretic was given to 34 patients for a mean of 750 days. There was a similar fall in mean plasma alkaline phosphatase to 71 +/- 24 (SD)% of initial with the first regimen and 72 +/- 17% with the second at 150 days, with a gradual rise after 500 days. Urinary hydroxyproline fell from 165 +/- 111 to 112 +/- 93 mg/day. Plasma calcium rose slightly with both regimens and plasma inorganic phosphorus fell with the first. Serum parathyroid hormone and calcitonin levels were unchanged. Urinary calcium was not changed by the first regimen and rose by 40 +/- 54 mg/24 h with the second. Clinical improvement approximately paralleled biochemical improvement. It is suggested that, in view of its low cost and convenience, this treatment has a place in the management of Paget's disease of bone.

Quantitative bone histology in the hypercalcemia of malignant disease

Quantitative bone histology was studied in 23 patients with malignant hypercalcemia (MH) due to carcinoma (16) or immunoproliferative disease (7). Plasma calcium was 3.37 +/- 0.47 (mean +/- SD) mmol/liter. Bone resorbing surface (RS) was measured using a sensitive histochemical stain to identify osteoclasts. In the MH patients with carcinoma, the RS was 3.1 +/- 2.6% compared to 1.0 +/- 0.3% in controls (P less than 0.02). In the myeloma patients it was 2.3 +/- 1.7%, and in normocalcemic patients with malignant disease 0.8 +/- 1.1%. RS did not correlate with serum PTH, and several high RS values were associated with undetectable PTH. RS correlated with forming surface (FS) in MH patients (r = 0.44, P less than 0.05) and controls (r = 0.68, P less than 0.005), but there was a greater RS relative to FS in MH patients than in controls (P less than 0.005). "Excess" RS in the MH patients was calculated by subtracting the RS accounted for by the measured FS, using the relationship defined by the controls. Bone loss, as reflected in urinary calcium excretion, correlated weakly with excess RS (r = 0.44, P less than 0.05) but was high even when excess RS was zero. Thus, the histological findings do not account for the bone loss, and additional resorption around bone metastases is likely; the results of this study are consistent with a humoral substance produced by the malignant tissue causing generalized bone resorption in addition to bone dissolution around metastases.