Renal transplant function after ten years of cyclosporine

Although the nephrotoxic side effects of cyclosporine are well known, the impact of long-term CsA on renal transplant function is uncertain. We studied 5-10-year renal function in 347 CsA-treated patients, and in 64 randomly selected non-CsA-treated patients who had a minimum of 55 months of graft function. Non-CsA patients had a lower creatinine (Cr) level at one year than CsA patients (P = .001), with no change in renal function over time (P = .6). In CsA-treated patients there was also no suggestion of progressive renal damage, as evidenced by no change in Cr or 1/Cr. Simple linear regression models of 1/Cr vs. time for the first 10 years posttransplant were fit to the data for each patient. Analysis of the Y-intercept estimates from these regressions showed that age (P = .001), sex (P = .001), cyclosporine toxicity (P = .024), and initial cyclosporine dosage (P = .016) significantly affected the one-year serum Cr. Variables not affecting one-year Cr included donor source, early rejection episodes, late rejection episodes, ATN, diabetes, transplant number, HLA ABDR mismatch (for cadaver transplants), maximum PRA, and PRA at transplant. Analysis of the slope estimates from the regressions revealed that only age (P = .001) and late rejection episodes (P = .001) significantly affected the rate of change in 1/Cr over time. We conclude that, in long-term renal transplant patients, there is no evidence of progressive deterioration in renal function due to CsA nephrotoxicity.

Pediatric renal transplants--results with sequential immunosuppression

Cyclosporine has improved the results of renal transplantation. In 1984, we began using it as part of a sequential immunosuppression protocol (MALG, AZA, P, and delayed administration of CsA) in our pediatric renal transplant recipients. We studied the outcome of the 131 pediatric renal transplants (less than or equal to 18 years of age at transplant) performed at our institution between June 1984 and March 1991. We compared these results with the 144 similar transplants performed since January 1980 that did not involve CsA immunosuppression. In the sequential immunosuppression group, there were 97 primary (74%) (26 [27%] cadaver, 71 [73%] living donor [LD]) and 34 (26%) retransplant (23 [68%] CAD, 11 [32%]) recipients. Age at transplant (mean +/- SD) was 7.4 +/- 5.5. Overall, 1-year actuarial graft survival was 93%; 1-year patient survival was 100%. The mean number of hospital readmissions was 3.0 +/- 3.5; 26 (20%) were readmission-free. The mean number of rejection episodes was .87 +/- 1.3 per patient; 73 (56%) were rejection-free. Importantly, LD (vs. CAD) recipients had fewer rejection episodes (P = 0.06). In the first post-transplant year, the serum creatinine level was significantly lower in primary (vs. retransplant) recipients and in LD (vs. CAD) recipients (P less than 0.05). In the 144 patients not receiving CsA, there were 129 (90%) primary (27 CAD, 102 LD) and 15 (10%) retransplant (7 CAD, 8 LD) recipients. Age at transplant was 6.9 +/- 5.3 years. The 1-year actuarial graft survival rate was 82%; the 1-year patient survival rate was 94%. The mean number of hospital readmissions was 3.3 +/- 2.3; 5 (8%) were readmission-free. The mean number of rejection episodes was 1.2 +/- 1.5; 27 (45%) were rejection-free. There was no difference in the serum creatinine level based on donor source or transplant number. Sequential immunosuppression has significantly improved patient (P = 0.003) and graft survival (P = 0.004) rates. Comparing sequential vs. non-CsA immunosuppression, there was no difference in the number of readmissions (P = 0.47), number of rejection episodes (P = 0.17), or serum creatinine level. The number of rejection-free patients was significantly lower in LD (vs. CAD) recipients (P less than 0.05). There was no evidence of progressive deterioration in renal function in the sequential (vs. non-CsA) recipients.

Progression to AIDS in HIV-infected homosexual and bisexual men with hairy leukoplakia and oral candidiasis

OBJECTIVE

This study was designed to assess the significance of HIV-related oral lesions in predicting the rate of progression to AIDS.

DESIGN

Cohorts were investigated prospectively, and oral examinations were performed by clinicians trained in the diagnosis of oral lesions.

SETTING

We studied three existing cohorts of homosexual and bisexual men in San Francisco, California, USA.

PARTICIPANTS

Of the HIV-infected men who received standardized oral examinations (n = 791), 603 were eligible for analysis of baseline examinations and 448 for analysis of follow-up examinations.

MAIN OUTCOME MEASURES

We determined time from presence of oral lesion at baseline or follow-up examination, or from participant self-reported history of the lesion, to diagnosis of AIDS.

RESULTS

Using proportional hazard regression and stratifying by CD4 lymphocyte count at the time of baseline oral examination, we found that the rate of development of AIDS was increased among men with hairy leukoplakia [relative hazard, 1.8; 95% confidence interval (CI), 1.2-2.7], oral candidiasis (relative hazard, 7.3; 95% CI, 3.1-17.3), and both lesions (relative hazard, 3.1; 95% CI, 1.6-6.1) compared with men with normal findings. On follow-up examination, stratifying for CD4 count, the rate of progression to AIDS was similar for those with hairy leukoplakia compared with those with oral candidiasis. The progression rate from oral candidiasis to AIDS was faster from presence on baseline examination than from presence on follow-up examination or from self-reported history of the lesion.

CONCLUSION

The presence of oral candidiasis and/or hairy leukoplakia on baseline examination confers independent prognostic information and should be incorporated into HIV-staging schemes.

Mizoribine pharmacokinetics and pharmacodynamics in a canine renal allograft model of local immunosuppression

We utilized a canine renal transplant model to estimate the first-pass extraction of mizoribine (MZB) during renal artery infusion and to compare the efficacy and toxicity of continuous intraarterial (i.a.) versus intravenous (i.v.) MZB delivery, with and without a background of oral cyclosporine. Five autotransplanted mongrel dogs with programmable, implantable pump/catheter systems were given MZB by both i.v. bolus (5 mg/kg) and i.a. infusion (5.0 mg/kg/day). Mean +/- SD elimination half-life was 3.02 +/- 0.81 hr, and the transplanted kidney removed as much as 47-59% (mean 56%) of locally infused MZB. With increasing local and systemic MZB delivery in a single autografted dog undergoing both i.a. and i.v. pump/catheter placement, renal extraction decreased from at least 47% (5.0 mg/kg/day) to 33% (7.5 mg/kg/day), finally to 18% (10.0 mg/kg/day). A dose of 3.0 mg/kg/day MZB did not significantly prolong survival of renal allograft recipients over that of untreated controls (median survival time [MST] = 8 days) when administered either locally (MST = 9 days) or systemically (MST = 12 days). All dogs receiving 4.0 mg/kg/day MZB i.a. died from rejection, and a survival advantage was still not realized (MST = 7 days). In contrast, 4.0 mg/kg/day i.v. prolonged survival over controls (MST = 14 days; P = 0.03) but not when directly compared with the i.a. group (P = 0.30), and produced death from severe debility in five of seven animals with significantly higher mean systemic MZB levels (P = 0.02). Four of six dogs receiving 5.0 mg/kg/day MZB i.a. (MST = 14 days) and two of four dogs receiving 5.0 mg/kg/day i.v. (MST = 14 days) died from severe debility, though survival in both groups was prolonged over control values (P = 0.01 and P = 0.05, respectively). Coadministration of a subtherapeutic dose of oral CsA (5 mg/kg/day) significantly prolonged the overall survival of dogs receiving MZB 4.0 mg/kg/day i.a. (MST = 23; P = 0.01) but not i.v. (MST = 11; P = 1.00), so that a significant difference in overall survival between the combined MZB i.a. + CSA and MZB i.v. + CSA groups was now realized in favor of the former (P = 0.04). We conclude that at local doses required to achieve immunosuppression, the transplanted kidney was not able to extract enough MZB to prevent death from systemic toxicity, presumably as a result of saturation of renal elimination mechanisms, so that an overall survival benefit was not realized.(ABSTRACT TRUNCATED AT 400 WORDS)

Lack of evidence of occult human immunodeficiency virus in seronegative individuals at very high risk of infection

Reports of human immunodeficiency virus (HIV) infection in seronegative individuals prompted the authors to investigate subjects who are at very high risk of acquisition of HIV in San Francisco. Nine HIV seronegative subjects were evaluated extensively, eight of whom were drawn from a well-characterized cohort of seropositive and seronegative homosexual men who have been followed prospectively since 1983-1984. These men have calculated probabilities of infection based on a fitted model of between 0.22 and 0.94. One additional subject is an intravenous drug user who has shared needles with HIV-infected individuals extensively. Peripheral blood lymphocytes and monocytes were separately cultured from each subject and evidence of HIV infection was sought by a reverse transcriptase assay, enzyme immunoassay, and immunocytofluorographic analysis for HIV antigens, in situ hybridization, RNA slot blot analysis, and polymerase chain reaction amplification of HIV cDNA. Uncultured monocytes and lymphocytes from each donor were also examined by these techniques. Evidence of HIV infection was not found in the peripheral blood mononuclear cells of these high risk individuals.

Human T cell lymphotropic virus types I and II in intravenous drug users in San Francisco: risk factors associated with seropositivity

Serologic assays for human T cell lymphotropic virus types I and II (HTLV I/II) infection were done in 676 intravenous drug users (IVDUs) in San Francisco between 1985 and 1987: 150 in 1985, 44 in 1986, and 482 in 1987. All sera were tested by Western blot, ELISA, and p24 RIA. A total of 111 participants were seropositive in a minimum of two assays. Duration of intravenous heroin use was strongly associated with the risk of HTLV I/II seropositivity: greater than or equal to 21 years odds ratio, 6.1 (95% confidence interval [CI], 2.2-17.5), compared with less than 10 years of heroin use. Additional independent risk factors included black or Hispanic race, female sex, and the use of drugs in a shooting gallery. Coinfection of HTLV I/II and human immunodeficiency virus was less frequent than expected by chance (P less than .02). Longitudinal specimens were available in 154 participants. The age- and race-adjusted seroconversion rate was 3.4% (95% CI, 1.3-8.9) per person per year. Of the 349 homosexual men tested, none were HTLV I/II-seropositive.

Dissociable face processing impairments after brain injury

Matched populations of head-injured patients and normal control subjects completed three "forced-choice" face processing tasks designed to test facial expression recognition, familiar face recognition, and unfamiliar face matching. We hypothesised a significant difference in the performance of the patients and controls on the three tasks, and hoped to observe individual differences in the patients' performance across tasks. As predicted the head-injured patients made significantly more errors than the controls on the forced-choice tasks. Four cases of dissociable impairments affecting only one of the face processing tasks are reported; patient JP impaired only on facial expression recognition, patients AB and HI impaired only on familiar face recognition, and patient VS impaired only on unfamiliar face matching. These dissociable impairments provide further evidence for independent cognitive processing of specific face properties.

Acute effects of insulin-like growth factor I and insulin on glucose metabolism in vivo

We have compared the actions of insulin-like growth factor (IGF-I) and insulin on glucose metabolism in vivo, using the glucose clamp technique in rats. Both hormones caused dose-dependent inhibition of hepatic glucose production, stimulation of whole body glucose disposal, and an increase in the glucose metabolic rate of specific muscles. Infusion of IGF-I also decreased the plasma concentration of insulin. An an infusion rate of 0.57 nmol.kg-1.min-1, IGF-I led to stimulation of whole body glucose uptake that was similar to the glucose uptake produced by infusion of 0.01 nmol.kg-1.min-1 insulin. The glucose metabolic rate, as measured by 2-deoxy-D-glucose uptake, was comparable in quadriceps femoris, soleus, and diaphragm muscles during the infusion of 0.57 nmol.kg-1.min-1 IGF-I and 0.01 nmol.kg-1.min-1 insulin. However, at these rates of infusion, IGF-I caused only a 38 +/- 6% inhibition of hepatic glucose output compared with 66 +/- 12% inhibition by insulin (P less than 0.05). Thus, under these conditions, muscle is more responsive than liver to IGF-I, which agrees with the complement of IGF-I receptors in the two tissues.

Serum beta 2-microglobulin decreases in patients with AIDS or ARC treated with azidothymidine

Abnormally elevated serum beta 2-microglobulin has been associated with progression of human immunodeficiency virus (HIV) disease and could reflect in vivo HIV activity. We prospectively studied the effect of azidothymidine therapy on serum beta 2-microglobulin concentration in 41 patients with AIDS or AIDS-related complex. Median beta 2-microglobulin concentration decreased from 4.02 mg/L before therapy to 3.73 mg/L at week 24 of therapy (P = .016). Individual changes in beta 2-microglobulin during azidothymidine therapy correlated with changes in serum HIV p24 antigen (Spearman, r = .42, P = .007). Also, in a randomized placebo-controlled study, median beta 2-microglobulin concentration decreased after 16 w of therapy in 5 azidothymidine-treated patients compared with levels in 7 placebo-treated controls (P = .05). Serum beta 2-microglobulin appears to be a sensitive marker for in vivo antiretroviral drug activity and may be a better marker than serum p24 antigen for early intervention trials involving antiretroviral agents.

Distribution of insulin receptor-like immunoreactivity in the rat forebrain

Previous studies have suggested that insulin may play a role in the hormonal regulation of neurotransmitter metabolisms within the central nervous system. In order to provide additional information to support this hypothesis, we examined the distribution of insulin receptors within the forebrain of adult male rats. Insulin receptors were localized by immunocytochemistry, using an antibody directed against the carboxy-terminus of the beta-subunit of the insulin receptor. The antibody specificity was tested by immunoprecipitation of brain insulin receptors with antiserum and the purity of the receptor-antibody preparation was determined using hormone binding-assays with radiolabeled insulin and insulin-like growth factor-l. Insulin receptor-like immunoreactivity was found in a widespread, but selective, distribution on neurons throughout the rat forebrain. Double-labeling with glial fibrillary acidic protein did not demonstrate any detectable insulin receptor-like immunoreactivity on glial cells. Areas with the highest density of insulin receptor-like immunoreactivity were found in the olfactory bulbs, hypothalamus and median eminence, medial habenula, subthalamic nucleus, subfornical organ, CA 1/2 pyramidal cell layer of the hippocampus and piriform cortex. Double-staining of hypothalamic sections with somatostatin and vasopressin antisera revealed insulin receptor-like immunoreactivity on a subpopulation of somatostatin neurons in the periventricular region and on vasopressin neurons in the supraoptic nucleus. A moderately dense insulin receptor-like immunoreactivity was observed in layers II-IV of cerebral cortex, medial amygdala, reticular thalamic nucleus, zona incerta, and preoptic and septal regions, whereas a low density of insulin receptor-like immunoreactive neurons was found in basolateral amygdala and most thalamic regions. The basal ganglia and most parts of the thalamus were almost devoid of insulin receptor-like immunoreactivity. Our findings provide morphological support for a direct action of insulin on selected regions of the rat forebrain and suggest that the insulin receptor may modulate synaptic transmission or the release of neurotransmitters and peptide hormones in the CNS.

Prospective study of catheter-related infection during prolonged arterial catheterization

Ninety-six arterial catheters from 75 different anatomical sites in 56 surgical ICU patients were studied prospectively to determine the rate of catheter-related infection associated with prolonged arterial catheterization (defined as greater than 96 h). Every 96 h, all catheters were semiquantitatively (SQ) cultured and the percutaneous entry site was swab cultured. Sites were used indefinitely by exchanging the catheters over a guide-wire every 96 h as long as arterial monitoring was necessary and SQ cultures remained negative (less than or equal to 15 colonies). No sites used less than 96 h developed skin colonization, while 14/51 (27%) sites used greater than 96 h developed positive swab cultures. No SQ cultures were positive in sites with negative swab cultures (p less than .001). Catheter-related infection (a positive SQ culture) developed in 4/42 (9.5%) radial or femoral sites compared to 4/9 (44%) axillary sites used greater than 96 h (p less than .01). It is concluded that arterial catheter-related infection develops in less than 10% of radial or femoral sites used greater than 96 h, and 90% of radial and femoral sites may be used safely for prolonged periods if skin colonization at the percutaneous sites is controlled and SQ catheter cultures remain negative. Skin site swab cultures may be useful for determining when arterial catheters should be removed and SQ cultured.

Automated measurement of strabismic deviations using a remote haploscope and an infrared television-based eye tracker

Images

CT body stereotaxic system for placement of needle arrays

A new CT body stereotaxic system that is particularly suited to multiple placements of needles precisely in parallel is described. By scanning through a right triangle placed on the patient's skin, the stereotaxic method defines an entry point for the first needle placement. An articulating arm is then used to aim the needle at the entry point and hold the needle at the correct angle. The arm can be angled so that the complex approaches from one scan plane to another can be made to place needle arrays through inaccessible lesions, for instance, beneath the diaphragm. Animal and phantom studies have shown that placement of multiple needle arrays in parallel from CT scan data is possible.

Risk of seroconversion for acquired immunodeficiency syndrome (AIDS) in San Francisco health workers

The occupational risk of acquiring acquired immunodeficiency syndrome (AIDS) virus infection in health workers exposed to AIDS patients and specimens was assessed by a serologic study at San Francisco General Hospital and collaborating research laboratories. A total of 101 medical workers without risk factors for AIDS were examined for antibodies to two isolates of the AIDS retrovirus (AIDS-associated retrovirus 2[ARV-2] and human T cell lymphotropic virus III). Most had heavy, long-term exposure to AIDS patients and 29 had been exposed by needlestick or mucocutaneous accident. None of the 101 had antibodies to ARV-2 by immunofluorescence or to HTLV-III by enzyme-linked immunosorbent assay and Western Blot.

Ultrasound and the intestinal wall: experimental methods

High-frequency, high-resolution ultrasound provides a new approach to imaging structures in the wall of the gastrointestinal tract. Questions about internal ultrasound include: is the ultrasound image specific for disease states, in which diseases will this technology add new and useful information not available from existing diagnostic studies, and what are the necessary characteristics for a system to accomplish these diagnoses? Answering these questions requires that precise correlations be made between the ultrasound image and pathology. We have developed a method to image a resected gastrointestinal tissue with ultrasound and to remove and examine the corresponding piece of tissue histologically. Changes in wall thickness, obliteration of layers, and changes in the characteristics of the tissue can be studied. We have shown that ultrasound can resolve the layers of the gut wall. This system should enable us to answer questions about which intestinal wall diseases are suitable for internal ultrasound imaging and characterize the engineering features of an optimal ultrasound system for clinical application.

CT body stereotaxis: an aid for CT-guided biopsies

A new body stereotaxic system used to facilitate CT-guided biopsies is described. By scanning through a triangle placed on the patient's skin, the method defines an entry point for the biopsy. An articulating arm is then used to aim the needle at the entry point and hold the needle at the correct angle. The arm can be angled so that complex approaches from one scan plane to another can be made in order to take biopsies of lesions beneath the diaphragm. Using the system, 23 of 25 lesions were hit on the first needle manipulation; two manipulations were needed for each of the other two lesions. In comparison with previous experience, procedure time was decreased and the numbers of needle manipulations and localization scans were decreased 75% and 90%, respectively.

Early evaluation of coronary artery bypass grafts: CT or selective angiography

A prospective study was performed in 27 patients to compare the value of computed tomography and selective angiography in assessing coronary artery graft patency in the early post-operative period. The sensitivity of CT to graft patency was 85% with no falsely patent determinations. Dynamic CT was not found useful in predicting graft stenosis. There were no complications associated with CT studies, and two related to selective angiography. It is concluded that CT is the procedure of choice for graft evaluation in the early post-operative period; but that angiography is mandatory for the assessment of late symptom recurrence. A review is made of the results described in previous series.

Resection of gastrinomas

Exploratory laparotomy and a search for gastrinomas was performed in 52 patients with the Zollinger-Ellison syndrome (ZES). Gastrinoma tissue was resected in 11 patients (21%), 6 (12%) of whom appear to have been cured. After surgery, serum gastrin levels in these six patients have remained normal from 10 months to 10 years. In the 46 other patients, tumor was unresectable because of metastases or multiple primary tumors (21 patients; 40%) or inability to find the tumor at laparotomy (21 patients; 40%). Multiple pancreatic islet cell adenomata were found in six of seven patients with multiple endocrine neoplasia (MEN), indicating that patients with this condition usually have diffuse involvement of the pancreas. The results of CT scans correlated with findings at laparotomy in 13 of 16 patients. The smallest tumor detected by CT scans was 1 cm in diameter. CT technology is more accurate in finding gastrinomas now than in the past and has a useful role in preoperative evaluation. The possibility of resection should be seriously considered in every patient with Zollinger-Ellison syndrome. Abdominal CT scans, transhepatic portal venous sampling, and laparotomy should be used to find the tumor and to determine whether it is resectable. Using presently available methods, it should be possible to cure about 25% of patients with gastrinomas who do not have MEN and over 70% of those without MEN who appear to have a solitary tumor. Total pancreatectomy may be necessary to cure some patients with MEN, but that operation is rarely justified. The morbidity and mortality of surgical attempts at curing this disease have become minimal; we have had no deaths or serious complications following such operations in over 10 yrs. Total gastrectomy and indefinite use of H2-receptor blocking agents are the therapeutic options for patients with unresectable gastrinomas. Because H2-receptor blocking agents fail to control acid secretion in many patients after several yrs of therapy, total gastrectomy is indicated in a large proportion of patients whose tumors cannot be resected. Total gastrectomy in patients with ZES is also safe using current techniques; our last death following this operation for ZES occurred 15 yrs ago.

CT of the thoracic duct

The ability of computed tomography to demonstrate the normal anatomy of the thoracic duct was investigated after lymphangiography in 20 patients without evidence of chest diseases on the plain films. The entire opacified thoracic duct can be easily imaged from its origin at the thoraco-abdominal level, up to its arch, which enters the venous blood stream, usually at the left subclavian-jugular confluent. Variations of the arch of the duct have been observed in our series. The ability to detect the non-opacified duct with CT was also assessed in 80 patients. Imaging of part or totality of the lower, mid and upper segments of the thoracic duct is possible respectively in 81, 54 and 69 per cent of subjects. The arch of the duct was displayed in 57 per cent. Knowledge of the normal anatomy of the thoracic duct is important since it can be involved in many diseases of the posterior mediastinum and of the thoracic outlet.

Localization of parathyroid adenoma by computed tomography

Sixteen consecutive patients with the clinical diagnosis of hyperparathyroidism, nine with and seven without previous surgery, had computed tomography (CT) examinations preoperatively to evaluate the use of CT in localizing parathyroid adenomas. The patients were scanned at 5 mm intervals from the level of the hyoid bone to the lung apex. Scanning of the mediastinum was performed at 10 mm intervals from apex to lung base. Computed tomography correctly identified prospectively the site of the adenoma in 10 of 13 patients (77%), with surgically proven adenomas. In retrospect, all 13 adenomas could be identified. One false positive diagnosis of adenoma was made. Our study suggests that CT may be beneficial in the preoperative localization of parathyroid tumors, particularly in ectopic locations.

Clinical study of pheochromocytoma

Seventeen patients underwent 22 operations for pheochromocytoma over a 26 year period. The patients included 11 in three kindreds of familial pheochromocytoma and 6 with sporadic tumors. The diagnosis was usually suggested by the patient's history. Confirmation of the diagnosis frequently required repeated testing for urinary or plasma catecholamines. Arteriography was the most effective method of preoperative tumor localization. Two tumors were proven nonfunctional. Others secreted either norepinephrine or epinephrine and norepinephrine. The familial patients showed a high incidence of multiple, bilateral and extraadrenal lesions. In contrast to previous reports, the familial tumors were found more often in the right than in the left adrenal gland. HL-A genotyping analysis of the sporadic and familial patients failed to demonstrate any HL-A antigen association or interdependent segregation of tumor and HL-A antigens within kindreds.

Objective performance measurements versus perceived image quality in intensified fluoroscopic or photospot images

The relationship between perceived image quality and measurable performance parameters of an intensified fluoroscopic image, viewed via a TV monitor or recorded on 105mm film, was investigated. Four specially manufactured image tubes, differing significantly in x-ray absorption efficiency, spatial resolution, and/or contrast resolution, were studied. Quantitative measurements of tube performance included the conversion factor, the quantum detection efficiency, the limiting resolution, the contrast ratio, and the contrast-detail characteristics. An assessment of the quality of clinical images was made by two radiologist-observers, working independently and without knowledge of any quantitative results. The observers were asked to rate the noise, lag, resolution, and contrast of the images during a variety of fluoroscopic procedures on each tube. While general agreement was found between the quantitative measurements and the radiologists' perceptions of image quality, the noise and contrast performance of an intensifier had greater influence on the radiologists' judgment of image quality than did resolution.

Computerized tomography in the quantitative assessment of tumour response

While Computerized Tomographic (CT) scans have been a valuable asset to radiotherapy treatment planning, their role in the critical assessment of tumour response has been less well defined. Recent refinements in radiotherapy treatment techniques have intensified the need for non-invasive methods to evaluate the local control of inaccessible neoplasms. In this study, 20 cases in which both pre- and post-treatment CT scans were available up to 27 months post-therapy were reviewed. The majority of the patients had pancreatic carcinoma. In both pre- and post-therapy scans, the tumour volume was calculated from contours outlined on sequential CT slices. These interpretations were compared with surgical findings, clinical course and patient survival. The rate of the primary tumour regression had little bearing on the clinical outcome. However, there was CT scan evidence of initial local tumour stabilization or regression in > 80% of the cases. In addition, CT scan evidence of tumour progression was correlated with clinical progression in > 90% of the patients. This suggests that a growth delay analysis might be possible with the use of CT scans, at least for the evaluation of pancreatic carcinoma.

Abnormalities of central contrast sensitivity in glaucoma

The detectability of foveally presented low-contrast flickering stimuli was determined for glaucoma patients, ocular hypertensives, and normal control subjects. Two types of stimuli, a homogeneous flickering field, and a counterphase flickering grating of low spatial frequency, were presented on a screen subtending 4 degrees of visual angle. The average of the contrast sensitivities to these two simuli (defined as the dynamic response coefficient) was consistently lower in glaucomatous than in normotensive eyes. The dynamic response coefficient was also below normal in half the ocular hypertensive eyes.

Argyria: clinical implications of exposure to silver nitrate and silver oxide

This article reports the clinical findings in a work force of 30 individuals who were exposed to silver nitrate and silver oxide. Six individuals had argyria and 20 had argyrosis (deposition of silver in the eye). Measurements of blood silver levels were included as part of the examination. The results of this examination generally support the benign nature of argyria, although the question of silver causing a decrement in kidney function and night vision is not settled. Periodic slit lamp examinations as well as monitoring of silver air concentrations are necessary to assure that engineering controls are actually limiting worker exposure to silver.

Lack of association of histocompatibility antigens with primary open-angle glaucoma

Eighty-seven patients (35 with primary open-angle glaucoma, 20 with angle-closure glaucoma, and 32 controls) underwent HLA typing of peripheral lymphocytes. Sixteen specificities were detected at the A locus, 19 at the B locus, and four at the C locus. No significant differences were found between patients with either type of glaucoma and control patients.

The effect of supervised tooth cleansing every second week on dental caries in Danish school children

The purpose of the present study was to determine the effect of a program of regular plaque control carried out by a group of school children, supervised and assisted by dental personnel. Approximately 200 children 5--13 years of age were randomly assigned to two groups. Children in the experimental group performed supervised toothbrushing every second week during the school year, using a disclosing solution. Following this, a disclosing solution was reapplied and the remaining plaque removed by dental personnel. Both groups participated in fortnightly fluoride rinses, regular toothbrushing instruction and various educational activities. Mean dental caries increment at the precavitation level during the 2-year experimental period was 19 per cent lower in the experimental group than in the control group. At the cavitation level the difference was 17 per cent. None of these differences were statistically significant. The conclusion of the present study was that only limited effect of regular removal of dental plaque as performed by school children could be demonstrated.

CT scanning and ultrasound in the evaluation of pancreatic pseudocysts: a preliminary comparison

A retrospective review of 12 surgically proved cases of pancreatic pseudocyst was performed. CT correctly demonstrated 6/8 uncomplicated pseudocysts and 4/4 infected pseudocysts. Ultrasound identified 7/8 uncomplicated and 2/4 infected pseudocysts. Errors by one modality are due to limitations not shared by the other method. This suggests a basis for the complementary use of CT scanning and ultrasound in the evaluation of suspected pancreatic pseudocysts.

An improved method of fitting resultant prism in treatment of two-axis strabismus

A new chart determines resultant prism power and angle when correction of combined horizontal and vertical deviation with a single prism, set at an angle intermediate between horizontal and vertical, is desired. The chart is based on a derivation so weighted as never to permit a vertical error greater than one tenth as large as the associated horizontal error, with use of commercially available sizes of plastic Fresnel-type prisms. This weighting takes into account differences in horizontal and vertical fusional reserves. A compass rose facilitates proper alignment of the prisms.

Pathologic axons and synapses in human neuropsychiatric disorders

Ultrastructural studies of cerebral biopsy specimens from patients with various forms of psychomotor retardation and dementia have disclosed pathologic changes in axons and presynaptic or postsynaptic processes. The clinical disorders with lesions in axons and presynaptic terminals are reviewed. Three basic abnormalities have been detected: proliferation of tubulovesicular structures which probably originate from the smooth endoplasmic reticulum, "abnormal" mitochondria, and proliferation of 80 to 100 A filaments. Understanding of the pathogenesis of human disorders associated with axonic or "synaptic" lesions will probably depend on progress in areas of basic biomedical research concerned with the synthesis and turnover of biological membranes and the packaging and secretion of neurotransmitters, elucidation of mechanisms of cytoplasmic streaming and axoplasmic flow, and biophysical and biochemical characteristics and functions of "fibrous" proteins (neurotubules, neurofilaments, pathologic fibrous proteins). In several cases of mental retardation of unknown etiology, abnormal dendritic spines of cortical neurons have been observed with the use of the Golgi method. These dendritic (postsynaptic) disorders have been attributed to defective development ("dysgenesis"). The knowledge provided by ultrastructural analysis of brain tissue from the human disorders of mental retardation or dementia is "still formless, incomplete, lacking the essential threads of connection," and only future developments in lacking neurobiology will make possible the dissection of the primary phenomena from the secretory and probably irrelevant findings.