Medical evaluation and management of calcium nephrolithiasis

Stone disease is a common medical problem, frequently recurs, and is associated with significant morbidity. Because appropriate medical therapy significantly decreases stone recurrence, this disorder must not be ignored by nonurologists. Even the single stone-former should be offered a metabolic evaluation.

An evaluation of the one-day NBT-PABA/14C-PABA in the assessment of pancreatic exocrine insufficiency

The one-day NBT-PABA/14C-PABA has been performed on 58 consecutive subjects with suspected or established pancreatic disease. 23 of these were normal subjects, 12 were subsequently shown to have other gastrointestinal disease and 23 had proven pancreatic disease. A PABA excretion index (PEI) has been calculated and, using our lower limit of normality (0.61), the test has shown an overall sensitivity of 83% and specificity of 89%. False positives were a particular problem in the other gastrointestinal disease group (25%). There was a close correlation between PEI and Lundh mean tryptic activity (r = 0.89). These results indicate that this test is a satisfactory screening test for pancreatic exocrine disease and is easier to perform with less likelihood of error than many other non-invasive tests of pancreatic function.

Climate and the evolution of brachycephalization

Significant associations of cranial shape for 82 ethnic groups and seven climate variables are described. Variation among current populations is partially attributed to cold adaptation throughout the Pleistocene. Application of data files tabulated by the authors is described for a number of problems. Temporal distribution of 115 specimens indicates a geometric trend (CI = 76.7-1.96 log time X 10(3) ). Cranial indices are summarized within alternative taxonomic models and between climatic ecotypes. Evidence supports the hypothesis of cold adaptation among "Classic" Neandertals. Limitations of the thermodynamic model are discussed. It is probable that a decrease of the cranial index occurs from the Middle to Upper Paleolithic. During the Holocene, the index increases under all climatic conditions.

Adaptive doses of MNNG efficiently induce a recA-trp gene fusion

The recA gene product plays a critical role in the Escherichia coli SOS system. To facilitate studies of the regulation of the recA operon, we constructed a gene fusion between the recA operon and the Salmonella trp operon. This gene fusion closely mimics the behavior of the authentic recA operon in vivo. Using the gene fusion, we looked at the effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on recA expression. In contrast to the expectations from previous work, we found that low (0.5 microgram/ml) adaptive doses of MNNG induce the recA-trp gene fusion as efficiently as other SOS inducers without inducing either lambda or phi 80 prophages. These results are a clear example of the ability of some agents to induce a subset of the SOS-dependent operons. They force a reevaluation of many of the arguments that have led to the conclusion that the SOS and adaptive responses are completely independent.

The development and postnatal organization of primary afferent projections to the rat thoracic spinal cord

Primary afferent projections to the thoracic spinal cord in fetal and postnatal rats were labelled by applying horseradish peroxidase (HRP) to the central stumps of cut peripheral nerves. Diaminobenzidine (DAB) and tetramethyl benzidine (TMB) histochemical processing procedures were used to reveal the HRP reaction product. In postnatal rats, individual muscle nerves were labelled to reveal the organization of muscle afferent projections to the motor nuclei. The terminals of muscle afferents were distributed widely across the dendritic arbors of motoneurons supplying the same muscles. No spatial segregation of the terminations of different populations of muscle afferents was discernable. Afferents supplying different regions of the skin were labelled by applying HRP to the dorsal and ventral primary rami of the spinal nerves. Afferents in the dorsal rami projected to lateral portions of both the ipsilateral and contralateral dorsal horns while afferents in the ventral rami projected to the medial portions of both dorsal horns. The projections of the dorsal rami were shifted caudally relative to those of the ventral rami. This relationship reflects the fact that the regions of skin innervated by the dorsal rami are displaced caudally relative to those innervated by the corresponding ventral rami. In fetuses, dorsal rami were labelled alone or in combination with ventral rami. These experiments disclosed the time course of development of the projections to different laminae of the spinal gray matter and revealed that afferents in the two primary rami project to appropriate regions in the ipsilateral and contralateral dorsal horns from the very outset.

The development and postnatal organization of motor nuclei in the rat thoracic spinal cord

The topographic organization of the motor nuclei supplying individual thoracic muscles in postnatal rats was investigated by horseradish peroxidase (HRP) labelling from the periphery. To determine whether aspects of the same organization are apparent at early developmental stages, we used HRP to label neurons contributing axons to the two primary rami of thoracic nerves in rat fetuses ranging in age from the 13th day of gestation to birth. This developmental period includes stages during which peripheral nerves and muscles are forming. The results show that motoneurons in the appropriate positions in the ventral horn have axons in each primary ramus even at stages prior to the innervation of muscle. However, in fetuses at certain developmental stages, there are also neurons located outside the motor nuclei which send axons into the peripheral nerves.

Surgical treatment of renal hyperparathyroidism

Renal hyperparathyroidism can be a major clinical problem in those receiving dialysis treatment and in those having renal transplants. This review of 66 patients during a five year period has led us to believe that laboratory data are useful for confirming the clinical diagnosis or for following the outcome of medical or surgical therapy. The screening for renal hyperparathyroidism should be on clinical grounds and not on isolated biochemical tests. All patients with renal failure, whether receiving dialysis therapy or renal transplantation, are at risk for having renal hyperparathyroidism develop. A careful assessment of the clinical and biochemical data is required to ensure proper patient selection for operation. Bone disease and persistent pruritus unresponsive to medical management remain the principle clinical indications for operation. Our preferred procedure is the standard subtotal parathyroidectomy.

Failure to demonstrate altered gastric emptying in irritable bowel syndrome

In irritable bowel syndrome (IBS), abnormalities of motility have been observed in the esophagus and small bowel, as well as in the colon. In order to investigate gastric function, gastric emptying has been measured in 25 patients with strictly defined IBS and compared with 25 age- and sex-matched controls. A standard radioisotope method for measuring gastric emptying has been employed. There was no significant difference between the two groups (T1/2 gastric emptying, IBS subjects 99.3 +/- 9.4 min, control subjects 104.0 +/- 11.9 min, mean +/- SEM), nor was there any major correlation between different symptom patterns and altered gastric emptying times. The results of the present investigation suggest that future studies on abnormalities in IBS should investigate other aspects of gastric motor function.

The misdiagnosis of common bile duct stones with ultrasound

Ultrasound is now widely used to demonstrate the presence of gall-stones in the gall bladder and common bile duct in jaundiced patients. The ultrasound appearance of gall-stones is characteristic and consists of strong, bright reflections with shadowing distally, though stones smaller than 3 or 4 mm may not always show shadowing. We report our experience with large common bile duct stones which do not show the characteristic features of gall-stones and so may be misdiagnosed as tumour masses. The possible reasons for these appearances are discussed.

The absorption and conjugation of methyldopa in patients with coeliac and Crohn's diseases during treatment

The absorption and elimination of a single 500 mg dose of methyldopa has been studied after oral administration to 10 normal volunteers, 10 patients with coeliac disease, who were on a gluten-free diet, and to five patients with Crohn's disease. In patients with Crohn's disease the percentage of the dose recovered in urine (24%) was about one-half of normal (50%). This decreased absorption was associated with reduced plasma concentrations of both free and conjugated methyldopa and a decreased pharmacological response. In patients with coeliac disease the percentage of dose recovered in urine (43%) was similar to normals, indicating a normal absorption of the drug. However, the plasma concentrations of both free and conjugated methyldopa were significantly higher than normal, although there was no increase in drug-related effects. These findings confirm the importance of using indices other than drug plasma concentrations in the assessment of bioavailability in disease states.

recF-dependent induction of recA synthesis by coumermycin, a specific inhibitor of the B subunit of DNA gyrase

Genetic and biochemical studies on enzymes known to be involved in regulating DNA supercoiling yield a complex spectrum of effects on the Escherichia coli SOS system. Previous studies indicated that only inhibition of DNA gyrase by antibiotics that act on the DNA gyrase A subunit results in turning on the E. coli SOS system. Here we show that coumermycin, an antibiotic that acts on the DNA gyrase B subunit, can also induce. Like nalidixic acid induction, coumermycin induction is dependent on the recBC DNase. In both cases induction apparently results from a response of the cell to the DNA gyrase-inhibitor complex rather than just the loss of DNA gyrase activity. However, unlike induction by the DNA gyrase A-specific antibiotics, coumermycin induction also requires the recF gene product. This demonstrates a functional relationship between DNA gyrase and the recF gene product.

Genotoxicity of N-acetylarylamines in the salmonella/hepatocyte system

Coincubation of isolated, intact rat hepatocytes with Salmonella typhimurium tester strain TA 98 (Salmonella/hepatocyte system) has been employed to determine both bacterial mutagenicity and DNA damage in the hepatocytes following treatment with 2-acetylaminofluorene (AAF) and other AAF derivatives. In vivo pretreatment of rats with either 2,3,7,8,-tetrachlorodibenzo-p-dioxin (TCDD) or 3-methylcholanthrene (MC) markedly increased both DNA damage and bacterial mutation frequency upon incubation of AAF or 2-aminofluorene (AF), in this system. The increase in damage to the hepatocyte-DNA was more pronounced after AAF treatment than by that for AF, while the increase in bacterial mutation frequency was greater after AF treatment. Hepatocytes treated with paraoxon prior to exposure to N-hydroxy-2-acetylaminofluorene (N-OH-AAF) or N-acetoxy-2-acetylaminofluorene (N-OAc-AAF) partially inhibited the DNA damage caused by these agents, as well as inhibiting the bacterial mutagenicity of N-OAc-AAF (50% inhibition) and N-OH-AAF (80% inhibition). These data indicate that metabolic processes other than those involved in activating AAF and its derivatives into a bacterial mutagen(s) may contribute to the genotoxic effects of these compounds. Thus, the Salmonella/hepatocyte system may provide a useful model in which to study the relative role of the various metabolic processes associated with the carcinogenic effects of N-acetylarylamines.

Mutagenicity and DNA damage induced by arylamines in the Salmonella/hepatocyte system

Coincubation of isolated, intact rat hepatocytes with Salmonella typhimurium tester strain TA 98 (Salmonella/hepatocyte system) has been employed to determine both bacterial mutagenicity and DNA damage in rat hepatocytes following treatment with 2-acetylaminofluorene (AAF) and its derivatives. In vivo pretreatment of rats with either 2,3,7,8-tetrachlorodibenzodioxin or 3-methylcholanthrene markedly increased both DNA damage and bacterial mutation frequency upon incubation of AAF or 2-aminofluorene (AF) in this system. The increase in damage to the hepatocyte DNA was more pronounced after AAF treatment than following AF exposure, while the increase in bacterial mutation frequency was greater after AF treatment. Treatment of hepatocytes with paraoxon prior to exposure to N-hydroxy-2-acetylaminofluorene (N-OH-AAF) or N-acetoxy-2-acetylaminofluorene (N-OAc-AAF) partially inhibited both DNA damage and the bacterial mutagenicity caused by these agents. Treatment of primary rat hepatocytes with 2-hydroxy-2-aminofluorene (N-OH-AF) causes a low level of DNA breaks. Substitution of primary rat hepatocytes with highly differentiated rat hepatoma cells (Reuber H4-II-E) revealed a low level of DNA breakage after exposure to N-OH-AAF whereas treatment with either N-OAc-AAF or N-OH-AF induced a dose dependent increase in DNA breaks. Pretreatment of the Reuber cells with paraoxon inhibited the DNA damage caused by N-OAc-AAF whereas the DNA damage induced by N-OH-AF was increased after paraoxon treatment. Employing host cells with differing metabolic capacity, such as Reuber vs. primary hepatocytes, in the Salmonella/hepatocyte system, may allow a determination of the relative importance of different metabolic pathways in mutagenicity and/or genotoxicity of arylamines.

Characterization of an antigenic determinant of the glycoprotein that correlates with pathogenicity of rabies virus

The pathogenicity of fixed rabies virus strains for adult mice depends on the presence of an antigenic determinant on the viral glycoprotein. Two virus-neutralizing monoclonal antibodies have been used to identify this determinant. All pathogenic strains of fixed rabies virus bind to these antibodies and are neutralized by them, whereas nonpathogenic strains fail to react with these monoclonal antibodies and are not neutralized by them. Antigenic variants of the rabies virus with altered glycoprotein were selected by growing virus in the presence of one monoclonal antibody, 194-2. All variants that lost their ability to react with this antibody and an additional antibody, 248-8, were found to be nonpathogenic for adult mice. Analysis of tryptic peptides of the glycoproteins of pathogenic parent virus and nonpathogenic variants and the amino acid sequence of a specific variant tryptic peptide revealed that the change in pathogenicity corresponded to an amino acid substitution at position 333 of the glycoprotein molecule. The nucleotide sequence of the nonpathogenic variant glycoprotein gene contained a base change that confirmed the single amino acid substitution in the tryptic peptide replacing arginine-333 in the parental glycoprotein. We conclude that arginine-333 is essential for the integrity of an antigenic determinant and for the ability of rabies viruses to produce lethal infection in adult mice.

Delay in diagnosis of adult coeliac disease

The delay in diagnosis of 106 patients with adult coeliac disease, diagnosed between 1976 and 1980, was studied. Overall, delay in diagnosis was 11 +/- 10.6 years, being considerably greater in females (12.8 +/- 7.8 years) than in males (3.5 +/- 9.8 years). Most of this delay occurred prior to hospital referral, although that following referral to hospital clinics was still significant (1.8 +/- 4.8 years). The most common presenting complaints were lassitude (75%) anaemia (65%) and flatulence (50%). Typical gastro-intestinal symptoms were relatively uncommon and mild, but when present led to a more speedy diagnosis. It is concluded that, despite advances in modern diagnostic procedures, little progress has been made in hastening the diagnosis of coeliac disease.

Is purified poly(ethylene glycol) able to induce cell fusion?

Preparations of poly(ethylene glycol) 6000 (PEG) from five different commercial sources have been purified, and their ability to fuse hen erythrocytes has been investigated. Quantitative assessments of cell fusion showed that before purification one of the preparations (PEG Wako), was able to induce limited fusion (5-6%) of erythrocytes with conditions (1 min incubation with 50% w/w PEG) under which the other four unpurified preparations of PEG were inactive. On purification, PEG (Wako) became inactive. By contrast, when erythrocytes were incubated with 45% w/w PEG for 15 min, extensive fusion (23-27%) occurred with all five unpurified preparations of PEG. Under these conditions, the fusogenic properties of four of the preparations of PEG were unaffected by purification: fusion induced by PEG (Wako) was, however, decreased on purification from 27% to 19%. It appears that polymeric poly(ethylene glycol) is itself able to fuse cells, but that some commercial preparations, e.g. PEG (Wako), have enhanced fusogenic properties resulting from the presence of contaminating substances. No relationship between the absorbance at 290 nm of PEG and its fusogenic properties was found in this study. The addition of small quantities of fusogenic lipid-soluble compounds to PEG was, however, observed to enhance cell fusion by up to 50%.

Autoimmune neutropenia in early infancy: a review

Fourteen infants with autoimmune neutropenia reported in the literature have been reviewed. Autoantibodies directed against their own neutrophils were demonstrated in the sera of these infants by agglutination, complement-dependent cytotoxicity, and immunofluorescence techniques. These antibodies were highly specific and were directed against antigens present on neutrophils. Among the currently known neutrophil antigens (NA1, NA2, NB1, NC1, NE1, ND1, 9A), antibodies reacting with either NA1 or NA2 have been identified frequently in the sera of infants with autoimmune neutropenia. Good correlation was demonstrated between the presence or absence of autoantibodies and the episodes of neutropenia in many cases. Antibodies from the patients also reacted with neutrophils from their parents and from normal unrelated volunteers when they shared the neutrophil-specific antigen against which the antibody was directed. Antibodies demonstrable by complement-dependent cytotoxicity appeared to detect different antigens which may also cause autoimmune neutropenia. Infants with this disorder were healthy at birth and for a few months afterwards, then became chronically ill with such symptoms as intermittent fever, diarrhea, and infections. Their hemoglobin levels, lymphocyte and platelet counts, and other immunological studies were normal except for severe to moderate neutropenia.

Ulcerative colitis: effect of sulphasalazine, its metabolites and indomethacin on the ability of human colonic mucosa to metabolize prostaglandins in vitro

1 Homogenates of mucosa from human colon metabolize [3H]-prostaglandin E1 in the presence of nicotinamide adenine dinucleotide to 15-oxo prostaglandin E1 or 15-oxo, 13,14 dihydro prostaglandin E1. 2 Metabolic capacity of tissue from patients with active ulcerative colitis under treatment with sulphasalazine (0.021 +/- 0.004 nmol/Mg protein +/- s.e. mean) did not differ from mucosa of normal patients (0.02 +/- 0.004 nmol/mg protein) during 1 h incubation. 3 Sulphasalazine inhibits prostaglandin E1 metabolism by mucosal homogenates in a dose-dependent manner with an ID50 of 125 microM. Its therapeutically active metabolite, 5-aminosalicylic acid (2.6 mM) was without significant inhibitory activity. 4 Indomethacin inhibits prostaglandin E1 metabolism by colonic mucosa with an ID50 of 388 microM. 5 At present we cannot clearly relate the therapeutic benefit of sulphasalazine and its therapeutically active metabolite, 5-aminosalicylic acid, in ulcerative colitis to their effects on prostaglandin E synthesis or metabolism in vitro.

Effects of thymosin and evidence of monocyte suppression of both T- and B-cell functions in two cases of 'common variable immunodeficiency'

We have studied two patients with common variable immunodeficiency (CVID), impaired cell-mediated immunity, and high percentages of monocytes in their peripheral blood. Removal of monocytes from cultures of peripheral blood mononuclear cells from both patients increased the in vitro responses to phytohaemagglutinin (PHA) and concanavalin A (Con A) but not to purified protein derivative (PPD), as measured by [3H]thymidine uptake. Similarly, supernatants of monocyte cultures from both patients, unlike supernatants of normal monocytes, suppressed the in vitro responses to PHA and Con A but enhanced the response to PPD by cultured mononuclear cells from the patients and from normal donors. Addition of unfractionated mononuclear cells from both patients to normal mononuclear cells suppressed both pokeweed mitogen (PWM) stimulation and IgG production; this effect was abrogated by removal of monocytes from the patients' mononuclear cell populations. This effect of thymosin on both patients' mononuclear cells was assayed in vitro. Thymosin was ineffective in vitro with cells from the first patient; for the other patient, [3H]thymidine uptake by mononuclear cells stimulated with PPD increased, whereas uptake by Con A-stimulated cells decreased, as did the percentage of E rosette-forming cells, providing further evidence of heterogeneity of the CVID syndrome. The effects of thymosin were also dependent on monocytes.

The metabolic effects of moderately severe upper gastrointestinal haemorrhage in man

The metabolic effects of moderately severe gastrointestinal haemorrhage were investigated in man. Before resuscitation, patients had raised circulating concentrations of glucose, lactate, alanine, glycerol and cortisol. After urgent operation for haemorrhage, metabolite concentrations were similar to those of control patients having elective abdominal surgery, but insulin concentrations were higher and cortisol lower in haemorrhage patients. There were no significant differences in nitrogen excretion between haemorrhage patients and their controls, but urinary 3-methyl-histidine excretion by haemorrhage patients was lower indicating decreased muscle protein breakdown. Decreased amino acid release from muscle might account for previously reported imparied wound healing after haemorrhage.

A double-blind controlled trial of the effect of sodium cromoglycate in preventing relapse in ulcerative colitis

A double-blind controlled trial of the effect of sodium cromoglycate (SCG) in preventing relapse in ulcerative colitis has been completed in 100 subjects. In patients already taking sulphasalazine, SCG did not prove to be of any additional benefit. However, in patients not on any other maintenance therapy, the relapse rate was 40% for SCG as compared with 75% for placebo. A large study of the effect of SCG in patients intolerant of sulphasalazine is indicated.