Plasma activity of contact coagulation factors in patients with IgA nephritis

Intraglomerular coagulation, initiated by the local activation of contact coagulation factors, has been suggested as one possible factor causing glomerular injury in IgA nephritis. The plasma activity of factor XII, prekallikrein and high molecular weight (HMW) kininogen were measured in 24 patients with biopsy-proven IgA nephritis and in 123 normal controls, using an activated partial thromboplastin time assay with the appropriate factor-deficient plasma as substrate. IgA patients had significantly lower plasma activity of factor XII (45.5% +/- 28.3% against 80.7% +/- 31.8%; mean +/- standard deviation, P < 0.001), prekallikrein (37.7% +/- 24.5% against 119.8% +/- 37.7%; P < 0.001) and HMW kininogen (72.8% +/- 37.8% against 119.1% +/- 42.8%; P < 0.001) when compared with controls. In the IgA patients, there was no significant correlation between factor XII, prekallikrein and HMW kininogen activity and 24-hour total urinary protein excretion, suggesting that the reduced plasma activity was not due to increased urinary loss of the coagulation factors. One possible explanation for these results is that the intrinsic coagulation pathway is activated in patients with IgA nephritis.

Mesangial cell culture: its role in the understanding of the pathogenesis of glomerular disease

Many forms of renal disease that progress to renal failure are characterised histologically by mesangial cell proliferation and accumulation of mesangial matrix. These diseases include IgA nephropathy, lupus nephritis and diabetic nephropathy. In recent years the introduction of mesangial cell culture techniques has allowed investigators to characterise the mesangial cell and its functions and examine the role of the mesangial cell in the pathogenesis of glomerular disease. The properties of the mesangial cell include the ability to contract, certain macrophage functions, and the ability to synthesize matrix and produce growth factors and cytokines. Factors that control mesangial cell function include cytokines and growth mediators, matrix components including integrins, and interactions with other cells such as the endothelial and epithelial cells. When exposed to an injurious stimulus, the mesangial cell responds by cellular proliferation and matrix synthesis leading to an increase in mesangial cells and matrix accumulation that ultimately progresses to the development of glomerulosclerosis. A better understanding of this disease process will allow future investigators the opportunity to formulate therapeutic interventions.

Radionuclide detection of dialysate leakage in patients on continuous ambulatory peritoneal dialysis

While continuous ambulatory peritoneal dialysis (CAPD) offers several advantages over haemodialysis in patients with end-stage renal disease, several complications have been recognised. The intraperitoneal instillation of dialysate increases intra-abdominal pressure and consequently predisposes to leaks and herniations through defects in the abdominal wall. This can lead to disruption of CAPD therapy. Peritoneal scintigraphy with Tc99m colloid has been used to identify such leaks of dialysate. This report analyses the clinical role of peritoneal scintigraphy in patients on the CAPD programme in the Singapore General Hospital. The results of 25 scans performed over a two-and-a-half year period were correlated with clinical and surgical findings. The clinical presentations of suspected dialysate leakage were varied, but can be broadly classified into three subsets for this analysis: (A) swellings confined to the inguinal and genital region, (B) peri-catheter, umbilical and incisional swellings, and (C) diffuse pattern of swellings in the abdominal wall, pelvic and genital region. In group A, the scan proved to be clearly helpful, correctly identifying 10/10 inguinal hernias, all of which resolved after herniorrhaphy. In group B, the scan correctly identified 7/9 leaks and hernias in the ventral abdominal wall. There was one false negative scan in a patient with a peri-catheter leak, and an equivocal result in another with fluid leakage in the lower anterior abdominal wall. In group C, which presented the greatest difficulty in clinical diagnosis, 2/3 cases were correctly diagnosed by scintigraphy. An equivocal result was seen in a patient who had had multiple operations for recurrent incisional hernias.(ABSTRACT TRUNCATED AT 250 WORDS)

Isoelectric focusing and selectivity index in IgA nephrotic syndrome

Proteinuria in 13 patients with IgA nephritis with nephrotic syndrome (IgANS) was analysed by isoelectric focusing (IEF) and compared with 12 patients with minimal change nephrotic syndrome (MCNS) (n = 8) or focal global sclerosis nephrotic syndrome (FGS) (n = 4) to determine the pattern of proteinuria on IEF and to assess the value of IEF and protein selectivity index (SI) as predictors of response to therapy with predisolone or cyclophosphamide. Steroid/cyclophosphamide responsive patients with IgANS had SC:UA (cationic serum albumin with anionic urine albumin) or SA:UC (anionic serum albumin with cationic urine albumin) IEF patterns and steroid/cyclophosphamide unresponsive patients with IgANS had an SC:UC (cationic serum albumin with cationic urine albumin) IEF pattern. The majority of patients with MCNS or FGS who had an SA:UC IEF pattern were steroid responsive. SI was a better predictor of steroid/cyclophosphamide responsiveness in patients with IgANS (r = 0.78, p < 0.002 compared to IEF, r = 0.64, p < 0.02).

The mutator mut7-1 of Saccharomyces cerevisiae

The mut7-1 mutant of Saccharomyces cerevisiae is a cell-division-cycle mutant, exhibiting temperature-sensitive lethality and enhancement of mutator activity with increases in temperature. The base-sequence alterations in mutants arising in a mut7-1 background differed from the control by there being a higher transversion/transition ratio and by the much increased production of multi-base deletions. The deletions were, in every instance, associated with repeated oligonucleotide sequences (3-8 bases in length), where one of the two sequences was removed during the deletion process. The mutant mut7-1 failed to complement with cdc2, the temperature-sensitive mutant of the locus which encodes DNA polymerase III (delta).

Continuous ambulatory peritoneal dialysis in type II diabetics

Forty-two Type II diabetic patients with end stage renal failure who had never previously received dialysis treatment were treated with continuous ambulatory peritoneal dialysis (CAPD) for a period of two to 48 months (average 16.8 months) with a total experience of 640 patient-months. Of the 42 patients, 29 (69%) were male and 13 (31%) were female. The mean duration of diabetes before dialysis was 12 years. Eleven patients (40%) were on dietary control alone, seven patients (24%) on oral hypoglycaemic control and ten patients (36%) on insulin treatment. Blood glucose control between these groups did not differ significantly. There was a significant gain in dry weight from a mean of 60.3 kg prior to dialysis to 74 kg two years after dialysis. There was no significant improvement in the haemoglobin level. Blood triglyceride levels increased from 214 +/- 63 mgm/dl to 283 mgm +/- 156 mgm/dl with an insignificant reduction in the cholesterol level. Serum calcium levels increased significantly from 8.0 +/- 1.3 to 9.1 +/- 1.0 mgm/dl in 12 months (p < 0.05). Serum alkaline phosphatase level remained stable. Blood pressure was stable throughout the dialysis period. Adequacy of dialysis clearance was shown by the mean value of serum urea 115 +/- 40 mgm/dl, serum creatinine 10.6 +/- 2.7 mgm/dl and serum phosphate 4.65 +/- 1.6 mgm/dl after two years on CAPD. No peritoneal membrane failure was reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Human sperm hyperactivation and acrosome reaction and their relationships to human in vitro fertilization

OBJECTIVE

To determine the relationships between human sperm hyperactivation (HA) and acrosome reaction with fertilization of human oocytes in vitro.

DESIGN

Prospective analysis of infertile patients undergoing IVF.

SETTING

Tertiary center for infertility and assisted reproductive technology.

PATIENTS

Fifty-two couples who underwent IVF or GIFT were studied. The male partners had normal semen parameters on routine analyses.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Sperm HA in seminal fluid and after 1 and 6 hours incubation in capacitation media; sperm acrosome reaction after 0, 6, and 24 hours' incubation in capacitation media; and fertilization rate of human oocytes.

RESULTS

The percent spermatozoa with transitional HA after 6 hours of incubation correlated significantly with the fertilization rate of human oocytes. Multivariate discriminant analyses selected six sperm HA and acrosome reaction variables of predictive value in classifying semen samples that achieved fertilization rates above and below 70% threshold. Combination of the selected sperm HA and acrosome reaction variables in seminal fluid and after different times of incubation in capacitation medium classified the samples achieving good or poor fertilization rate with > 80% accuracy.

CONCLUSIONS

Assessment of sperm HA and acrosome reaction may be of prognostic value in prediction of human oocyte fertilization rates.

Cytomegalovirus infection in renal transplant patients with hepatitis B--case report

Cytomegalovirus (CMV) infection in Hepatitis B carrier renal transplant patients who are immunosuppressed can be easily overlooked especially in those presenting with jaundice and liver failure. Recognising hepatitis due to CMV in renal transplant patients who are also hepatitis B carriers is important therapeutically as measures for the treatment and prevention of CMV infection are already available. This is especially so as Hepatitis B has a moderately high prevalence in this part of the world. We describe our clinical experience of cytomegalovirus infection in two renal transplant patients who are also asymptomatic hepatitis B carriers.

Early activation of splenic macrophages by tumor necrosis factor alpha is important in determining the outcome of experimental histoplasmosis in mice

Experimental infection of animals with Histoplasma capsulatum caused a massive macrophage infiltration into the spleen and induced the production of tumor necrosis factor alpha (TNF-alpha) locally. The cytokine was also produced in vitro by peritoneal exudate macrophages exposed to a large inoculum of yeast cells. Depletion of the cytokine by injection of polyclonal sheep anti-TNF-alpha antibody was detrimental to sublethally infected mice. Fungous burdens in the spleens of TNF-alpha-depleted mice were higher than they were in the infected control mice at days 2, 7, and 9 after infection, and the antibody-treated animals succumbed to the infection. Histopathological study of spleen sections revealed that splenic macrophages were not able to control proliferation of intracellular yeasts as a result of TNF-alpha depletion. It seems that TNF-alpha plays a role in early activation of splenic macrophages which is important in controlling the outcome of an infection.

Infection in continuous ambulatory peritoneal dialysis (CAPD): aetiology, complications and risk factors

Continuous ambulatory peritoneal dialysis (CAPD) was started in the Singapore General Hospital in 1980. Peritonitis and exit site infections have been the major cause of morbidity and catheter loss in CAPD. In 1990, 130 patients were on CAPD and the peritonitis rate was one episode in 20.4 patient months. Gram positive organisms accounted for 54% of the infections of which Staphylococcus epidermidis was the commonest (24%). Catheter removal was required in 14% of the cases and 9% of the patients discontinued CAPD as a result of peritonitis. The exit site infection rate was one episode in 27.5 patient months and the commonest organism was Staphylococcus aureus (54%). Twenty-three (47%) of the cases of exit site infection required catheter removal and 83% of the cases were the result of S. aureus infections. Patients with preexisting exit site infections experienced more episodes of peritonitis. Patients above the age of 50 years experienced more episodes of peritonitis and exit site infection. Sex, diabetes and the duration on CAPD did not influence the frequency of infections. Patients using the UV Germicidal Exchange Device had fewer episodes of peritonitis than those using the conventional spike system.

Early increased renal procollagen alpha 1(IV) mRNA levels in streptozotocin induced diabetes

Changes in renal procollagen mRNA levels were measured shortly after the induction of streptozotocin induced diabetes in the rat. "Medullary" procollagen alpha 1(IV) levels seven days after diabetes induction was significantly higher in untreated diabetic rats (DM, N = 12; 244 +/- 57% of the mean control value), than in diabetic rats receiving small doses of insulin insufficient to achieve euglycemia (NPH, N = 10; 87 +/- 12%) and in diluent injected nondiabetic control rats (C, N = 15; 100 +/- 12%; P less than 0.01, DM vs. C and DM vs. NPH). "Medullary" procollagen alpha 1(I) mRNA levels were numerically increased in DM to a lesser degree (141 +/- 5%, ANOVA not significant) compared to C (100 +/- 13%), and this small increment was further normalized by insulin treatment (NPH, 120 +/- 11%). A trend for increased beta-actin mRNA levels in DM did not reach significance (P greater than 0.05). Increases in "medullary" procollagen mRNA levels did not correlate with kidney weight, glomerular tuft volume, creatinine clearance, food intake, or body weight gain, and occurred when renal morphology was normal by light microscopy. Statistically significant but weak correlations were noted between the serum glucose levels and "medullary" procollagen alpha 1(IV) mRNA levels (r = 0.43, P less than 0.05). In addition, weak correlations were noted between glycosuria and "medullary" procollagen alpha 1(I) levels (r = 0.38, P less than 0.05). In situ hybridization studies localized the increased procollagen alpha 1(IV) mRNA levels predominantly in the DM group primarily in the deep cortex and medullary outer stripe of proximal tubules. Glomerular procollagen alpha 1(IV), alpha 1(I), alpha 1(III) and beta-actin mRNA levels were not increased in untreated diabetic rats 7 or 28 days after diabetes induction. Thus, tubular procollagen alpha 1(IV) mRNA levels increased prior to any measurable change in glomerular levels and were ameliorated by insulin administration.

Base alterations in yeast induced by alkylating agents with differing Swain-Scott substrate constants

The base alterations induced by four alkylating agents, methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), N-nitroso-N-methylurea (MNU), and N-nitroso-N-ethylurea (ENU), have been determined at the URA3 locus in the yeast Saccharomyces cerevisiae. The mutagen treatment was carried out on yeast cells in the logarithmic phase of growth. The mutants were selected by their resistance to 7.3 mM-5-fluoroorotic acid at pH 3.8. DNA sequence analysis was carried out by the dideoxy chain termination method. The alkylating agents were selected for their widely differing Swain-Scott substrate constants (s values), which are as follows: MMS, s = 0.83; EMS, s = 0.67; MNU, s = 0.42; ENU, s = 0.26. A higher s value is correlated with a higher ratio of 7-alkylguanine to O6-alkylguanine in native DNA in vitro. 125 forward mutations from URA3----ura3 were sequenced with marked differences in the mutational spectra being observed as the s value changed. Five hotspots were recorded for the four alkylating agents. They were all G.C----A.T transition mutations. There was one common hotspot for all of them; there were two additional ones for the two ethylating agents (ENU and EMS) and two different ones for MNU. Four of the five hotspots have the 5'-GG-3' sequence with the 3'-guanine mutated. It was seen that MMS, which has the highest Swain-Scott substrate constant, yielded the widest array of mutational types. As the substrate constants decreased, the types of mutations became more and more restricted to the G.C----A.T transitions and the A.T----T.A transversions. The transitions are consistent with the concept that mutations arise from O6-alkylation of guanine and alkylation of thymine. The transversions are consistent with the notion of N1-alkylation of adenosine or adenylic acid.

The effect of thyroxine on small intestinal motility in the elderly

OBJECTIVE

To study the effects of thyroxine on orocaecal transit time in a group of elderly hypothyroid patients on long-term thyroxine replacement therapy.

DESIGN

Measurement of the effect of withdrawal and subsequent replacement of thyroxine replacement therapy on orocaecal transit time.

PATIENTS

Fifteen elderly, previously hypothyroid patients on full replacement therapy with oral thyroxine were studied. There were 11 females and four males, aged 60-94 years (median 78 years) receiving initially 50-200 micrograms of oral thyroxine daily (median 100 micrograms).

MEASUREMENTS

Serum TSH and FT4 were measured by radioimmunoassay and orocaecal transit time assessed using a lactulose hydrogen breath test. These tests were repeated 7 days after withdrawal of thyroxine replacement and again 7 days after subsequent reinstatement of therapy.

RESULTS

On withdrawal of therapy, the median transit time increased from 75.0 to 135 minutes (P less than 0.01), the median TSH increased from 1.8 to 2.3 mU/l (P = NS) and the median FT4 decreased from 13.7 to 10.6 pmol/l (P less than 0.01). On reinstatement of therapy, the median transit time decreased to 95 minutes (P = NS), the median TSH decreased to 1.1 mU/l (P = NS) and the median FT4 increased to 14.1 pmol/l (P less than 0.01).

CONCLUSIONS

These findings demonstrate the sensitivity of the small bowel to changes in thyroid hormone status and suggest that constipation arising as a result of this hypomotility may well be an early physical manifestation of hypothyroidism.

Effects of triple therapy in IgA nephritis: a follow-up study 5 years later

This study is a 5-year post trial assessment of patients with IgA nephritis who entered a 3-year prospective controlled trial of cyclophosphamide, dipyridamole (D) and low-dose warfarin (W). Patients entered the trial from 1979 to 1981 and the trial ended in 1984 with those in the treatment group having more stable renal function and less proteinuria compared to the control group. Present reassessment of the patients in 1989 showed no difference in the renal function between those in the treatment group (n = 27) and the control group (n = 21). 6 patients in the treatment group and 7 in the control group were in ESRF. At the conclusion of the trial in 1984, among the 27 patients in the original treatment group, 13 patients elected to continue with D + W while the other 14 patients chose to cease therapy and therefore served as the new control group. 5 years later, renal function in the new treatment group (n = 13) was significantly stable compared to the new control group (n = 14), (serum creatinine 1.4 +/- 0.7 versus 4.4 +/- 3.2 mg/dl, p less than 0.01). Furthermore, all the 6 patients with ESRF in the original treatment group of 27 patients were from the new control group (n = 14) where treatment with D + W had been ceased. None of the patients still on D + W are in ESRF.

Medical problems in dialysis patients awaiting renal transplantation

While awaiting renal transplantation, patients with end-stage renal failure frequently have to spend a period of time on dialysis. Although dialysis controls uraemia, the patient undergoing dialysis still faces problems related to the continuing uraemic state such as anaemia, renal bone disease, malnutrition and cardiovascular complications. Apart from the problems related to uraemia, patients on dialysis are also exposed to problems that are peculiar to the mode of dialysis. In haemodialysis, patients face complications related to the use of heparin and dialyser related problems such as air embolism and haemolysis. Patients on continuous ambulatory peritoneal dialysis (CAPD) are exposed to complications such as infection, hernias and hypertriglyceridaemia. The introduction of hormone therapy with erythropoietin and vitamin D and recent advances in dialysate solutions and biocompatibility of membranes in haemodialysis and in control of infection and a better understanding of peritoneal kinetics in CAPD have helped to overcome some of the problems in dialysis patients.

Pattern of proteinuria in IgA nephritis by SDS-PAGE: clinical significance

Of sixty patients with IgA nephritis, none had CRF at first examination, 13 developed CRF with creatinine above 1.6 mg/dl within 6 years. Among these patients who had analysis of proteinuria by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), 31 patients had middle molecular weight (MMW) proteinuria alone (pattern 1), 10 had MMW and Low MW (LMW) or tubular proteinuria (pattern 2), 10 had high MW (HMW) and MMW proteinuria (Pattern 3) and 9 had HMW, MMW and LMW proteinuria (Pattern 4). At the end of a follow up period of 6 years (1983-1989) patients with mixed proteinuria had a higher incidence of chronic renal failure (CRF), 11/29 (38%) compared to those with pattern 1 proteinuria, 2/31 (6%) (chi 2 = 8.7, p less than 0.005). Based on the glomerular selectivity index (GSI), 19 patients had nonselective proteinuria but they did not have a higher incidence of CRF. By the selectivity index (SI), 18 patients had nonselective proteinuria and they showed a significantly higher incidence of CRF. Compared to the 41 patients who did not have LMW proteinuria, 19 patients with LMW proteinuria had more severe proteinuria. After a follow-up period of 6 years, patients with LMW proteinuria had a higher incidence of CRF (10% versus 47%, p less than 0.001). The presence of LMW proteinuria indicates a less favourable outcome and the pattern of proteinuria as assessed by the SDS-PAGE appears to be a better prognostic index in IgA nephritis than the SI and the GSI.

Acute renal failure prognostic indices in hospital inpatients referred for haemodialysis

Forty-eight patients with acute renal failure (ARF) who were referred to the Department of Renal Medicine, Singapore General Hospital for acute dialysis between August 1985 and August 1989 were studied retrospectively to identify risk factors associated with ARF that serve as prognostic indicators. There was no difference in the mean age of survivors and non-survivors (49.5 +/- 17.5 years vs 53.5 +/- 18 years, p greater than 0.05). The overall mortality rate was 52%. ARF as a result of surgical complication had a higher mortality rate in comparison to ARF from medical complications (66% vs 50%, p greater than 0.05). Septicaemia was the most common cause of ARF requiring dialysis. Hepatobiliary sepsis was the most frequent cause of septicaemia. Pre-dialysis serum urea and creatinine levels, and the number of dialysis treatments did not affect the outcome. Poor prognostic indicators included oliguria or anuria, fluid overload and coma. Patients tended to have a worse outcome if they had more than three risk factors taken from the following list:-decreased renal perfusion, assisted ventilation, coma, gastrointestinal dysfunction, recent surgery, sepsis, congestive heart failure, hepatobiliary dysfunction, malignancy, diabetes mellitus, chronic renal insufficiency and poor nutritional status. Early referral of patients with septicaemia due in particular to hepatobiliary infection may improve the prognosis.

Duodenal mucosal morphometry of elderly patients with small intestinal bacterial overgrowth: response to antibiotic treatment

Microscopic changes in duodenal biopsy specimens from 16 elderly patients with small-bowel bacterial overgrowth were studied before and after cyclical courses of antibiotic treatment, using computer-aided morphometry measurements as well as visual assessment. Twenty-three subjects in the same age group with no evidence of intestinal disorder were studied as controls. Mean villus height was significantly reduced in the pre-treatment study compared to the post-treatment measurements and those in controls. Similar significant differences were found in mean crypt depth and total mucosal thickness. The mean intra-epithelial lymphocyte count was raised before treatment and fell after treatment to a level similar to that of the controls. The mean lymphocyte count in the peripheral blood rose significantly after treatment. This study provides objective evidence of microscopic structural changes in the bacterial overgrowth syndrome in old age. The return to normality after antibiotic treatment suggests that these changes are directly attributable to the presence of bacteria in the gut lumen.

Acanthamoeba keratitis: report of a case

Acanthamoeba keratitis, rarely seen in Taiwan, has aroused much attention in western countries in recent years because of the increasing number of reported cases and its usually disastrous outcome. Most of the reported cases were closely associated with contact lens wearing. Others were related to a minor trauma or contacting contaminated water. We report a case of recalcitrant corneal ulcer following trauma, which is the first reported case of Acanthamoeba polyphaga keratitis proven by a special culture method and pathological examination in Taiwan. We reviewed the nature and characteristics of Acanthamoeba keratitis, and discussed the laboratory examinations such as staining techniques, culture methods, light and electron microscopic findings, and treatment for such cases.

Isolation and in vitro susceptibility of Acanthamoeba from a patient with keratitis

The acanthamoebae are facultative parasites of man, and may infect the brain, skin, bone, respiratory passages and eyes. Over the past several years, Acanthamoeba keratitis has become a growing problem. This is the first case isolating Acanthamoeba polyphaga from a corneal biopsy of an ophthalmic patient in Taiwan. Direct impression smear by trichrome stain gave positive result. To provide effective clinical treatment, chemotherapeutic agents available for ophthalmic use were tested for its susceptibility with a microtiter plate method. Reading at 24- and 48-hour intervals, only amphotericin B, clotrimazole and neomycin-polymyxin B had an MIC (minimal inhibition concentration) lower than 1,000 micrograms/ml. If reading interval was prolonged to one week, neomycin, 5-flucytosine and gentamicin also showed appreciable activity. Amoebicidal concentrations (AC) and cysticidal concentrations (CC) were much higher than MIC. Only neomycin-polymyxin B, neomycin, and amphotericin B of high concentration were proved to be cysticidal.

Protein selectivity: a prognostic index in IgA nephritis

Among 98 patients with IgA nephritis who had protein selectivity studies performed, 54% had nonselective proteinuria and the remaining 46% had selective proteinuria. Patients with nonselective proteinuria had a higher incidence of glomerulosclerosis. At the end of a 4-year follow-up period, patients with nonselective proteinuria had lower creatinine clearance, higher incidence of hypertension and chronic renal failure when compared to patients with selective proteinuria. Six out of eleven patients (55%) in the study who had the nephrotic syndrome had selective proteinuria. Among these 6 patients, 1 had spontaneous remission and 5 responded to steroid or cyclophosphamide therapy. The remaining 5 patients with nonselective proteinuria did not respond to therapy. In the patients who had selectivity studies repeated, the data showed that the selectivity index (SI) can fluctuate depending on the clinical course of the patients. SI can therefore be used to monitor the progress of patients on long-term follow-up. Protein selectivity appears to be a useful prognostic index in IgA nephritis. For patients with the nephrotic syndrome it may serve as a guide to therapy.

Small bowel bacterial overgrowth: a cause of malnutrition in the elderly?

A study was conducted to examine the effect of small bowel contamination on the nutritional status in the elderly. Dietary assessment and anthropometric measurements were used to assess malnutrition. Sixteen elderly patients were studied before and after regular treatment with antibiotics. A significant gain in body weight, triceps skinfold thickness, mid-arm circumference and arm muscle circumference was noticed after eliminating bacterial overgrowth of the small bowel. Occult malabsorption due to bacterial overgrowth should therefore be considered as a cause of malnutrition in the elderly.

The base-alteration spectrum of spontaneous and ultraviolet radiation-induced forward mutations in the URA3 locus of Saccharomyces cerevisiae

A forward mutation system has been developed to obtain rapidly clonable mutants at the URA3 locus in yeast by means of selection for 5-fluoroorotic acid resistance. We have used this system to determine base changes in 35 spontaneous and 34 ultraviolet radiation-induced ura3 base substitution mutants. Other mutants (frameshift, deletion, duplication, replacement) were detected as well. Evidence is reported which suggests cyclobutane dimers are the principal mutagenic lesions induced by UV radiation in stationary phase cells of the yeast Saccharomyces cerevisiae. Since most of the induced lesions are at 5'-TT-3' sites, the results suggest that the "A-rule", preferential insertion of adenine residues opposite poorly pairing sites in DNA, does not apply for yeast cells irradiated in stationary phase, whereas the spontaneous mutation data indicate that the A-rule applies for cells in logarithmic phase. Most of the spontaneous mutations are transversions. UV-induced transitions and transversions occur at approximately equal frequencies.

Underdiagnosis of asthma in the elderly

One hundred and ninety-nine elderly men and women were assessed for their pulmonary function and their mental ability. One hundred and twenty-one patients had a PEFR less than 70% of the predicted for their age and height. Reversibility tests showed that 82 patients had 15% or more improvement in their PEFR following 200 micrograms salbutamol. However, only 6% of the patients were receiving respiratory-related medication. Further analysis showed that there was no correlation between the patients' age, sex, amounts of sputum production, wheeze, breathlessness, smoking habits, chest expansion, hospitalization, mental function and airway reversibility. 'Reversible' patients did, however, have a high incidence of cough and a low pre-test PEFR value. The predominant symptom of 'reversible' and 'non-reversible' patients was cough. The study emphasizes the importance of routinely performing lung function tests in elderly patients and the use of reversibility tests to identify reversible airways obstruction. These results suggest that in old age potentially reversible airways obstruction is often overlooked or misdiagnosed.

Androgen-induced changes in rat ovarian granulosa cells in vitro

Ovarian granulosa cells collected from small antral follicles from immature rats were cultured in McCoy's 5A medium, for 1-6 days in the presence of delta 4-androstenedione, testosterone, dihydrotestosterone, and dehydroepiandrosterone (10(-5) M and 10(-7) M). Granulosa cells examined by electron microscopy demonstrated many lipid droplets, mitochondria with tubular cristae and profiles of smooth endoplasmic reticulum, all suggestive of active metabolism in the cell. Cells cultured in androstenedione, testosterone, dihydrotestosterone and dehydroepiandrosterone produced estrogen and progesterone as measured by radioimmunoassay. By day 4, cells cultured in androgen had almost completely degenerated. The control cells acquired none of the aforementioned characteristics and survived up to beyond 6 days, at which time the experiments were terminated. This study supports the hypothesis that high concentrations of androgens in cultured granulosa cells contribute to their degeneration through altered structure, which is associated with functional change.

Serial thyroid iodine content in hyperthyroid patients treated with radioiodine

X-ray fluorescent scanning was used to measure initial thyroidal iodine content in 64 patients diagnosed as being hyperthyroid and selected for I-131 therapy, and serially in 48 of these patients after therapy in an attempt to determine those patients that were at high risk of becoming hypothyroid. Iodine content fell rapidly after therapy, reaching a nadir at about three months. Based on the population studied, the chance of early hypothyroidism (within 12 months) is about 80% if the iodine content measured at three months is less than 2 mg. If the iodine content is greater than 2 mg, the chance is only about 14%. The serial measurement of thyroidal iodine content (with x-ray fluorescent scanning) may allow early identification of those patients at high risk of developing permanent hypothyroidism following a therapeutic dose of I-131.

The relationship of semen parameters to fertilization in patients participating in a program of in vitro fertilization

Approximately 80% of the patients in a program of in vitro fertilization (IVF) will fertilize an oocyte. The purpose of this study was to determine which parameters of the semen analysis influence fertilization in vitro. Of 120 patients participating in an in vitro fertilization program, 98 achieved fertilization of at least one mature oocyte and 22 did not. Ovulation induction was standardized and patients whose sperm was exposed to at least one mature oocyte (by light microscopy) were included in the study. Semen washing was accomplished using a "swim-up" technique. Semen parameters were assessed both before (raw) and after washing. Following insemination with 100,000 motile sperm, fertilization was determined by the presence of pronuclei or cleavage. Mean sperm count and motility were higher in patients who fertilized. However, morphology was similar. Fertilization was more likely to occur with a raw density greater than 104 million/ml and a motility greater than 64%, as well as with a density greater than 18 million/ml and a motility greater than 86% following washing. Furthermore, washing lowered sperm counts by 75% and increased motility by 25% but had no effect on morphology. This study demonstrates that sperm count and motility, but not morphology, influence fertilization in a program of in vitro fertilization and that patients with higher counts and motility have a greater probability of fertilization.

The metabolism of an exogenous lipid source during septic shock in the puppy

Septic shock induces physiologic and hemodynamic responses that may alter the host's ability to metabolize an exogenous source of lipids. The present study examined the metabolic changes occurring during septic shock in the young animal receiving an intravenous fat emulsion. Five 8-wk-old male Beagle puppies were studied. Each animal served as his own control twice, during which time 14C-palmitic acid alone or with a 10% fat emulsion (Liposyn) was administered. Septic shock (cardiac output less than 50% of control) was induced with an intravenous bolus of live Escherichia coli. During shock the puppies received intravenous 14C-palmitic acid and Liposyn. The mean respiratory quotient for the shock dogs (0.96 +/- 0.01) was significantly (p less than 0.05) higher than that of the controls (0.83 +/- 0.06). The amount of expired 14CO2 was 25.0 +/- 15.9% for the shock animals, 53.9 +/- 28.1% for the Liposyn controls, and 75.7 +/- 30.5% for the controls receiving only 14C-palmitic acid (these differences are all significant, p less than 0.05). After the onset of shock, serum triglyceride levels peaked within 2 min at 851 +/- 540 mg/100 ml and remained elevated at 333 +/- 213 mg/100 ml. Triglyceride levels in the Liposyn control animals returned to baseline values (54 +/- 13 mg/100 ml) at the end of the 4-hr experimental period. Free fatty acids in the shock dogs reached a maximal level of 1.44 +/- 0.09 mEq/liter at 1 hr and remained at this elevated value for a significantly longer period of time than in the Liposyn control puppies. Glycerol value followed a similar pattern and cholesterol remain unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of promoter mutations in the histidine transport operon of Salmonella typhimurium: use of hybrid M13 bacteriophages for cloning, transformation, and sequencing

Mutations that cause an increased level of expression of the histidine transport operon were isolated and characterized genetically. Five independently isolated promoter-up mutations were transferred to an M13 hybrid phage that carries the histidine transport operon, and their nucleotide sequences were determined. For all five mutations, the change was the same as the one previously determined for promoter-up mutation dhuA1: a C-to-T change in the Pribnow box rendered this region more homologous to the consensus sequence. Methods for enabling Salmonella typhimurium to support growth of M13 phage effectively and for easy transfer of chromosomal mutations onto the hybrid phage are presented.

Diagnostic imaging in pediatric emergencies

Evaluation of pediatric emergencies by diagnostic imaging technics can involve both invasive and noninvasive procedures. Nuclear medicine, conventional radiography, ultrasound, computerized axial tomography, and xeroradiography are the major nonangiographic diagnostic technics available for patient evaluation. Appropriate decisions regarding choice of these imagining technics can be made only if the advantages and limitations of each are known. We will emphasize the use of computerized axial tomography, nuclear medicine, xeroradiography, and ultrsound in the evaluation of emergencies in the pediatric age group. Basic principles with specific reference to clinical disorders will be presented. Since the radiologist is the primary consultant with regard to diagnostic imaging, his knowledge of these modalities can greatly influence patient care and clinical results.

A comparison of cefaclor and ampicillin in the treatment of respiratory infection in elderly in-patients

Fifty patients admitted to a geriatric ward with respiratory tract infection were randomly allocated to treatment with 250 mg cefaclor 8-hourly or 250 mg ampicillin 6-hourly. Assessment of response was performed by nursing and medical staff independently and it was found that the nurses tended to record changes in overall condition earlier than did the doctors. The failure rate was 15%, with no difference between the two treatments. The significance of this in relation to the different pharmacokinetic properties of these antibiotics is discussed.

T3 toxicosis and its relation to the iodide status in Singapore

Baseline thyroid function tests (including total serum thyroxine iodide-T4I, total serum tri-iodothyronine T3 as well as T3 Sephadex Uptake Studies (T3U)) were determined in 82 normal Asian subjects. In addition, another group of normal volunteers (39) were assessed as regard serum and 24-hour urinary iodide levels to gauge the iodide status of the community; the results were comparable to that of goitre-free regions of the world. Having established the range of values of normal thyroid function tests, 103 consecutive clinically thyrotoxic patients (both new and relapsed cases) were similarly studied in an attempt to elucidate the magnitude of the problem of T3 toxicosis, and its relation to the iodide status in Singapore. Only three clinically hyperthyroid patients were foudn to have normal PBI T3 levels. A detailed analysis and discussion of the data is presented. It is concluded that T3 toxicosis is a rarity in Singapore.

Differentiation between malignant and benign solitary thyroid nodules by fluorescent scanning

A quantitative fluorescent technique has been developed for making in vivo iodine content determinations of the total thyroid gland or of selected parts. In solitary thyroid nodules "cold" to radionuclide studies, the ratio of iodine content in the nodule to that in a corresponding area of the contralateral lobe has proven to be a good indicator of malignancy. In a preliminary study of 42 surgical patients, an iodine content ratio (ICR) below 0.60 (chosen a posteriori) proved to be an excellent indication of malignancy with a sensitivity of 100%, a specificity (predictive value) of 79%, and an overall accuracy of 90%. Further definitive studies are needed to verify these preliminary observations.

The sick sinus syndrome. A study of 15 cases

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