Some developments in brain ageing and dementia

The aetiology of the common dementias of old age remains incompletely understood. Here we describe some of the biological, neurophysiological and psychological changes associated with ageing of the human brain, in terms of those that occur throughout life and those that are characteristic of senescence. Age-dependent diseases, such as Alzheimer's disease (AD), idiopathic Parkinson's disease (IPD) and dementia with Lewy bodies (DLB), are considered from these viewpoints, and risk factors described. Vascular dementia (VaD) is related to hypertension and atherosclerosis and detailed description of its pathogenesis is outside the scope of this review. The importance of age as the main risk factor raises basic questions about the relationship of these diseases to the ageing process itself. Similarities and differences between ageing and disease may be important for a rational approach to prevention and treatment of cognitive decline and dementia in later life.

Peer resource consulting: redesigning a new future

The current case describes a young woman with diabetes mellitus who developed end-stage renal disease (ESRD) and many other devastating complications related to her primary illness. Her experience illustrates many ways in which complicated illness can interrupt life's plans, dashing any dreams that she or her family might have for the future. Yet her story also illustrates the important role that a trained Peer Resource Consultant (PRC) can play in helping to better understand chronic illness, face and grieve losses, and even design new plans and create new dreams for the future. The discussion that follows includes several perspectives that offer poignant insight into the difficult situations characterized by the young diabetic with ESRD.

Autologous bone marrow versus non-mobilized peripheral blood stem cell transplantation for lymphoid malignancies: a prospective, comparative trial

Autologous transplantation using bone marrow stem cells (BMSC) or peripheral blood stem cells (PBSC) is widely used for non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). We report a randomized, comparative trial comparing BMSC vs. non-mobilized PBSC for responsive NHL or HD. Patients randomized to BMSC (n = 13) vs. PBSC (n = 15) had more rapid neutrophil recovery (median 23 vs. 30 days), RBC independence (25 vs. 62 days), platelet independence (24 vs. 54 days), and shorter hospital stay. However, neither relapse, overall survival, nor relapse-free survival were different receiving BMSC vs. PBSC (all P > .7). Concurrently, 54 others (34 BMSC, 20 PBSC) were assigned non-randomly because of resistant disease or marrow unsuitable for harvest and similar patterns of engraftment favoring BMSC over PBSC were observed. In the entire group, BMSC transplantation (n = 47) led to quicker neutrophil recovery (P = .02), RBC (P = .06), and platelet independence (P =.04) and earlier hospital discharge (P = .02) vs. PBSC (n = 35). No difference in relapse, overall, or relapse-free survival were observed using BMSC vs. PBSC. These data suggest that non-mobilized PBSC are a satisfactory alternative to BMSC in patients with unsuitable marrow; however, transplantation with non-mobilized PBSC was associated with slower hematologic recovery, and longer hospital stay. No difference in tumor recurrence rates was observed between the PBSC or BMSC recipients. Unprimed PBSC transplantation offered no clinical advantage to BMSC.

Why is it difficult for staff to discuss advance directives with chronic dialysis patients?

General experience and reported data show that a substantial number of patients, at least 10% in many surveys, eventually choose to withdraw from chronic dialysis. There are additional studies suggesting that discussing and completing advance directives (AD) can promote more acceptance and less acrimony for patients, families, and staff when patients die. Even so, surprisingly few AD are completed, and dialysis staff often shun discussion of AD with patients. Thus, in this study, a survey of approximately 400 dialysis staff from 12 representative Michigan dialysis facilities was undertaken both to determine the beliefs, attitudes, and life experiences that might influence such discussions, as well as to guide future strategies aimed at encouraging the discussion and meaningful execution of AD. More than 50% (210) of the distributed questionnaires were completed. Overall results show that respondents report having discussed AD with only 30% of patients on average and that as many as 40% of respondents report never having done so. Among the professional disciplines responding to this survey, social workers report the largest percentage of patients with whom they discussed AD (60%), physicians a smaller percentage (38%), licensed practical (30%) and registered (25%) nurses even fewer patients, and dialysis technicians (20%) and dietitians (4%) the least. Across all disciplines, staff reported discussing AD with a larger percentage of patients when staff had experienced significant losses within their own personal lives, discussed such issues with friends or family, or had prepared their own AD. In rating specific barriers that correlated strongly with reported discussion of AD, each professional discipline had characteristic responses reflecting the approach of the discipline to addressing AD. The survey results suggest that the interdisciplinary variations observed are attributable to: (1) important differences not only in training, but also in the customary roles taken by each discipline; (2) inherent cultural differences, suggested by the findings among nonwhite staff of a lower reported frequency of having discussed AD with patients and of more concern over the barriers to doing so; and (3) a lack of support from supervisory and physician staff within the dialysis team. In conclusion, this survey shows, not surprisingly, that personal experiences and intrinsic cultural differences influence the attitudes of dialysis staff toward discussing AD with patients. The results of this survey underscore important differences between individual professional disciplines that affect both the perceived barriers to, as well as the likelihood of, discussing AD with patients. It seems that emotional issues such as death and dying stress interdisciplinary team interaction and amplify discomfort. However, it may be possible to increase the level of comfort in talking to patients about AD for each professional discipline by addressing the findings from this study (role differences and barriers) through focused interventions and by facilitating mutual support among the distinct members of the dialysis staff.

Dialysis staff influence patients in formulating their advance directives

Patients on chronic dialysis were surveyed to determine the degree to which completion of advance directives (ADs) was influenced by personal factors that patients bring to their dialysis situation (eg, demographic characteristics or personal preferences) and by environmental factors that are not under their control (eg, interaction with dialysis staff or hospital system). Of the 113 questionnaires distributed to the population of 40 hemodialysis and 73 peritoneal dialysis patients, 90 (80%) were completed. Although only 17% of the respondents had actually completed written ADs previously, respondents seemed to have a good general understanding of ADs, as evidenced by the 80% overall accuracy on a 19-question portion of the survey that tested knowledge regarding ADs. While a few personal factors, such as gender, dialysis, modality, perceived quality of life, and attitude toward death, were associated with completion of ADs, most other demographic variables, including age, marital status, religion, work status, number of years of education, disability status, locus of control, renal diagnosis, and number of years on dialysis, were not correlated. More prominently correlated with completion of ADs were environmental factors, such as having dialysis staff discuss ADs with patients, patients being asked to complete ADs at the time of hospitalization, and perception of staff as being comfortable discussing ADs with patients. The overall results of the survey suggest that discussing ADs as an ongoing activity may have been positively influenced by the Federal Patient Self-Determination Act of 1991.(ABSTRACT TRUNCATED AT 250 WORDS)

The option to withdraw from chronic dialysis treatment

This multidisciplinary discussion focuses on the case of a young diabetic woman who chose to stop chronic hemodialysis during a long and complicated illness. The perspective presented here include an academic lawyer's view of such medical decisions; a hospital chaplain's view of the religious framework for end-of-life situations; a clinical psychiatrist's considerations when consulted to evaluate patients in such straits; a transplant nurse's view of the opportunities for personal interaction that such clinical situations present; and a renal social worker's approach to chronic illness, advance directives, and death in the dialysis patient population. The discussion is intended to address objectively some important issues associated with death in this population, aimed at increasing our willingness to discuss these issues more openly with patients and with our colleagues.

Distribution of nicotinic receptors in the human hippocampus and thalamus

Neuronal nicotinic acetylcholine receptors consist of different subunits, alpha and beta, with different subtype arrangement corresponding to distinct pharmacological and functional properties. The expression of alpha 3, alpha 7 and beta 2 mRNA in the human brain was studied by in situ hybridization and compared to [3H]nicotine, [3H]cytisine and [125I]alpha-bungarotoxin binding in contiguous sections. The beta 2 probe showed a strong hybridization signal in the granular layer of the dentate gyrus and in the CA2/CA3 region of the hippocampus and in the insular cortex, and a signal of lower intensity in the subicular complex and entorhinal cortex. The alpha 3 probe showed strong hybridization in the dorsomedial, lateral posterior, ventroposteromedial and reticular nuclei of the thalamus, and a weak signal in the hippocampal region and in the entorhinal, insular and cingular cortex. The amount of alpha 7 mRNA was high at the level of the dentate granular layer and the CA2/CA3 region of the hippocampus, in the caudate nucleus and in the pulvinar and ventroposterolateral nuclei of the thalamus. [3H]Nicotine and [3H]cytisine binding appeared to be identical in anatomical distribution and relative intensity. It was high in the thalamic nuclei, the putamen and in the hippocampal formation in the subicular complex and the stratum lacunosum moleculare. The level of [125I]alpha-bungarotoxin binding was particularly high in the hippocampus and in the pyramidal cells of the CA1 region, but was relatively low in the subicular complex. Our data indicate that in the human brain nicotinic receptor subtypes have discrete distributions, which are in part different from those of other species.

Dichloroacetic acid and related compounds: induction of prophage in E. coli and mutagenicity and mutation spectra in Salmonella TA100

We performed three types of studies to evaluate the genotoxicity of the chlorinated organic solvent perchloroethylene (PERC or tetrachloroethylene) and its volatile metabolites, trichloroacetyl chloride (TCAC) and trichloroacetic acid (TCA), as well as the volatile metabolites of trichloroethylene, i.e. dichloroacetyl chloride (DCAC), dichloroacetic acid (DCA), and 2,2,2-trichloroethanol (TCE). In the first set of studies, which involved the evaluation of these chemicals in the Microscreen prophage-induction assay, only DCA (+S9) was genotoxic, producing 6.6-7.2 plaque-forming units/mM. This places DCA among the weakest of the > 100 chemicals that have been identified previously as inducers of prophage in this assay. In the second set of studies, which involved the evaluation of these chemicals in the vapor state in Salmonella TA100 using a Tedlar bag vaporization technique, DCA (+/-S9), DCAC (-S9), and TCAC (+/-S9) were mutagenic, producing 3-5x increases in revertants/plate relative to the background. S9 enhanced the mutagenic potency of DCA but had no effect on the mutagenic potency of TCAC. The potencies ranged from 0.7 to 3.9 rev/p.p.m., resulting in a potency ranking of DCA > DCAC approximately TCAC. The lowest effective concentrations were 50-300 p.p.m., which are similar to those for ethylene oxide and epichlorohydrin in this assay. In the third set of studies, the mutation spectra of DCA, DCAC, and TCAC were determined at the base-substitution allele hisG46 of Salmonella TA100. DCA and DCAC induced primarily G.C-->A.T transitions, whereas TCAC induced primarily G.C-->T.A transversions, which was also the predominant mutation among the background revertants.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of neuronal nicotinic receptor subunits in human brain

Neuronal nicotinic acetylcholine receptors (nAchRs) are multimeric proteins constituted of two different subunits, alpha and beta, with different subtypes arrangement and different pharmacological and functional properties. nAchRs mediate neurotransmission in many central and peripheral synapses and appear to be affected in human degenerative disorders. We have studied the distribution of nAchR in human brain, particularly in the hippocampus and thalamus, by binding of 3H-nicotine and 3H-cytisine and by in situ hybridization with human alpha 3 and beta 2 nAchR subunits of mRNA. An alpha 3 probe shows a strong hybridization signal in the thalamus, while a beta 2 probe has a good signal at the level of the enthorinal cortex, hippocampus and in caudate and putamen. The alpha 3 and beta 2 mRNA localization is different from that described in other species. 3H-nicotine and 3H-cytisine binding were very similar in terms of anatomical distribution and comparable to the binding described in other animal species. The binding of the two ligands was distributed over the areas labeled by the alpha 3 and beta 2 probes and did not completely overlap with either of the subunits.

Advance directives are associated with "good deaths" in chronic dialysis patients

The effect of prior advance directives (AD) on the outcome when chronic dialysis patients died was evaluated in a retrospective review of consecutive deaths over a period of more than 6 yr in a large academic dialysis center. Among 182 patients who died during the period under review, 74 (41%) had previously stated their AD verbally or in writing and the prevalence of AD was highest among patients with age-related or chronically debilitating diseases. Previous statement of AD was significantly more prevalent (P < 0.001) among patients who withdrew from treatment in reconciled fashion than among patients who died suddenly and unexpectedly or who died without a reconciled decision to forego life-sustaining intervention (e.g., dialysis, intubation, emergency surgery). Further analysis shows that patients stating prior AD and patients withdrawing from treatment were most often those who made their own medical decisions ("internal" locus of decision making), rather than relying on relatives or other agents ("external" locus), and tended to be those with a definite spouse or spouse-equivalent relationship. Finally, retrospective assessment suggests that cases in which patients stated prior AD and cases in which patients withdrew from treatment were associated more frequently with a favorable outcome. It was concluded that addressing AD before a medical crisis ensues may increase the likelihood of a "good death" when complications bring the course of chronic dialysis to termination.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroleptic sensitivity in patients with senile dementia of Lewy body type

OBJECTIVE

To determine the outcome of administration of neuroleptics to patients with senile dementia of Lewy body type confirmed at necropsy.

DESIGN

Retrospective analysis of clinical notes blind to neuropathological diagnosis.

SETTING

Specialist psychogeriatric assessment units referring cases for necropsy to a teaching hospital neuropathology service.

PATIENTS

41 elderly patients with diagnosis of either Alzheimer type dementia (n = 21) or Lewy body type dementia (n = 20) confirmed at necropsy.

MAIN OUTCOME MEASURES

Clinical state including extrapyramidal features before and after neuroleptic treatment and survival analysis of patients showing severe neuroleptic sensitivity compared with the remainder in the group.

RESULTS

16 (80%) patients with Lewy body type dementia received neuroleptics, 13 (81%) of whom reacted adversely; in seven (54%) the reactions were severe. Survival analysis showed an increased mortality in the year after presentation to psychiatric services compared with patients with mild or no neuroleptic sensitivity (hazard ratio 2.70 (95% confidence interval 2.50-8.99); (chi 2 = 2.68, p = 0.05). By contrast, only one (7%) of 14 patients with Alzheimer type dementia given neuroleptics showed severe neuroleptic sensitivity.

CONCLUSIONS

Severe, and often fatal, neuroleptic sensitivity may occur in elderly patients with confusion, dementia, or behavioural disturbance. Its occurrence may indicate senile dementia of Lewy body type and this feature has been included in clinical diagnostic criteria for this type of dementia.

Cardiac xenografting in the pig-to-rhesus monkey model: manipulation of antiendothelial antibody prolongs survival

Transplantation of immediately vascularized grafts across species barriers in which preformed cytotoxic antibodies exist, otherwise known as discordant combinations, has uniformly resulted in hyperacute rejection. We studied how well plasma exchange and perfusion through organs removes preformed immunoglobulin M cytotoxic antibodies and prolongs survival of a porcine heart heterotopically transplanted into a rhesus monkey. With the use of plasma exchange or absorption of antibodies by porcine kidney perfusion with or without immunosuppression, graft survival was prolonged, although antibody-mediated rejection ultimately occurred. In one case in which plasma exchange, kidney perfusion, and immunosuppression were combined, a functioning pig heart survived in a rhesus monkey for 8 days without evidence of rejection. The animal was killed on day 8 according to protocol because of a wound dehiscence. With this animal we were able to demonstrate that circulating antibodies against graft endothelium had bound to the graft endothelium without inducing rejection, a process referred to as accommodation. In this case, despite the presence of antiendothelial antibodies, complement did not appear to be activated, and fibrin thrombi did not form. Although we have achieved this rejection-free survival only in one animal, this case suggests that it may be possible to maintain xenotransplants in discordant species without rejection if preformed antibodies are appropriately lowered or altered during the initial period of graft implantation.

Safe and effective plasma exchange to remove antibodies prior to xenogeneic heart transplantation in small primates

The ability of an on-line, rapid plasma exchange (PE) system to remove circulating antibodies in preparation for xenogeneic heart transplantation was studied. Plasma exchanges were performed 27 times on 13 rhesus monkeys weighing from 6.5 to 12.0 kg, using systemic heparinization, without untoward effects. Blood flow rates of 22-72 ml/min resulted in plasma collection rates of 7-22.5 ml/min. Serum immunoglobulin levels were decreased by more than 90%, and specific antiendothelial xenoreactive IgM was completely removed after two plasma exchanges. Transferrin levels were decreased 85-95%, and complement levels fell by greater than 80%. Platelets were partially conserved, with removal rates of 18-60%. All factors returned to normal ranges within 48 hours and no bleeding complications were encountered. When antiendothelial antibodies were removed in this manner, survival of a pig heart transplanted into a rhesus monkey was extended to 12 hours, from a baseline of 2 hours, without treatment.

Distribution of nerve growth factor receptor immunoreactivity in the human hippocampus

Nerve growth factor (NGF) receptor-like immunoreactivity has been demonstrated in the normal adult human hippocampus, using minimally fixed cryostat sections obtained from snap-frozen tissue and incubated with the mouse monoclonal antibody, ME 20.4. The majority of the reactivity was associated with nerve fibre processes and their terminals. Numerous fibres were apparent in the alveus, originating from the fornix, and extending into the stratum oriens and pyramidal layer of the hippocampal formation. A more diffuse particulate reactivity, presumed to be nerve terminal, was observed around the pyramidal neurons and in the stratum radiatum, stratum lacunosum moleculare and also in the dentate fascia. The pattern of hippocampal NGF receptor immunoreactivity was broadly similar to acetylcholinesterase histochemical localization, indicating a principal localization on cholinergic axons innervating this area. Preliminary observations indicate an overall reduction in NGF receptor-immunoreactive axons and terminals in old age and Alzheimer's disease.

Current advances in research in Alzheimer's disease

The pace of research into Alzheimer's disease has quickened remarkably in the last few years as it has entered the realms of genetics and molecular biology. The nature of the protein giving rise to the amyloid deposits in senile plaques has been identified together with its location on chrosome 21, which is also the chromosome (although at a different locus) on which the abnormality in the familial form of the disease is found. Together with previous neuropathological and neurochemical data implicating specific neuronal populations - particularly the basal forebrain cholinergic system projecting to the cortex - in cardinal clinical features of the disease such as memory loss, it would seem that scientists are on the verge of understanding the foundamental nature of the disease process. However, in the absence of any clues regarding the cause of the disease in the predominantly "sporadic" cases and of any effective clinical treatment, new insights are clearly urgently needed. The present review highlights currently active areas of research and attempts to outline unexplored areas where novel approaches are now required.

Chemical and biological characterization of products of incomplete combustion from the simulated field burning of agricultural plastic

Chemical and biological analyses were performed to characterize products of incomplete combustion emitted during the simulated open field burning of agricultural plastic. A small utility shed equipped with an air delivery system was used to simulate pile burning and forced-air-curtain incineration of a nonhalogenated agricultural plastic that reportedly consisted of polyethylene and carbon black. Emissions were analyzed for combustion gases; volatile, semi-volatile, and particulate organics; and toxic and mutagenic properties. Emission samples, as well as samples of the used (possibly pesticide-contaminated) plastic, were analyzed for the presence of several pesticides to which the plastic may have been exposed. Although a variety of alkanes, alkenes, and aromatic and polycyclic aromatic hydrocarbon (PAH) compounds were identified in the volatile, semi-volatile, and particulate fractions of these emissions, a substantial fraction of higher molecular weight organic material was not identified. No pesticides were identified in either combustion emission samples or dichloromethane washes of the used plastic. When mutagenicity was evaluated by exposing Salmonella bacteria (Ames assay) to whole vapor and vapor/particulate emissions, no toxic or mutagenic effects were observed. However, organic extracts of the particulate samples were moderately mutagenic. This mutagenicity compares approximately to that measured from residential wood heating on a revertant per unit heat release basis. Compared to pile burning, forced air slightly decreased the time necessary to burn a charge of plastic. There was not a substantial difference, however, in the variety or concentrations of organic compounds identified in samples from these two burn conditions. This study highlights the benefits of a combined chemical/biological approach to the characterization of complex, multi-component combustion emissions. These results may not reflect those of other types of plastic that may be used for agricultural purposes, especially those containing halogens.

Fatty acid profiles of Chlamydia using capillary gas chromatography

Fatty acid profiles of purified elementary bodies of Chlamydia trachomatis (CT) serotypes D, G and L3 were investigated by gas liquid chromatography (GLC) utilizing three fused silica capillary columns of different polarities. CT serotype C and C. psittaci (CP) strain DD34 were investigated using one column only due to the lack of adequate quantities of purified material. Significantly similar fatty acid profiles were observed in the serotypes examined. However, based on the percentage ratio of 13-methyl tetradecanoate (i-15:0) to 12-methyl tetradecanoate (a-15:0), serotypes D and L3, with ratios of 0.18 and 0.19, respectively, could be differentiated from serotypes C and G with ratios of 1.3 and 1.5, respectively. CP demonstrated a ratio of 0.4, thus differentiating it from the CT serotypes examined. Fatty acids i-15:0 and a-15:0 were absent in uninfected McCoy cells. Results were significantly comparable in all three capillary columns. This study suggests that GLC could be used for identification and differentiation of Chlamydia serotypes.

Acetylcholine and Alzheimer's disease

The hypothesis that cognitive impairment in Alzheimer's disease is related to cholinergic degeneration in the brain is still, a decade after its formulation, subject to critical evaluation. In marked contrast to the monoamine hypotheses of affective disorders or schizophrenia--based primarily on the mechanisms of action of therapeutic drugs, and yet lacking convincing pathological data on the human brain itself--the cholinergic hypothesis of Alzheimer's disease currently rests largely on evidence of neurochemical pathology in affected tissue, but still depends on effective therapy for its ultimate validation. The urgent need for a means of countering cognitive impairment in degenerative dementias such as Alzheimer's disease (probably the most important cause of intellectual decline in old age) hardly needs emphasising. In this annotation, a number of key questions specifically relating to the cholinergic involvement in Alzheimer's disease are considered. These questions are already being answered both within and, as so often in the history of biological psychiatry, outside the immediate area of investigation.

Assessing the effect of colony counting methods and genetic drift on Ames bioassay results

Accuracy of automatic colony counters and variation among subcultures of the Salmonella tester strains are two factors that cause variation within the Ames bioassay. This paper examines these potential sources of variation. In contrast to results seen by other researchers, this genetic drift study demonstrated that except for TA100 the subcultures of tester strains from four research laboratories are very stable in biochemical characteristics measured using Analytical Profile Index (API) strips. This study also documented the levels of accuracy for hand- and automatic-counting techniques, and provides a simple method for generating acetate calibration transparencies for use with most colony counters.

Comparison of five methods of cytomegalovirus antibody screening of blood donors

A group of 120 sera from blood donors was screened by complement fixation and commercially available immunofluorescence, solid-phase fluorescence immunoassay, enzyme-linked immunosorbent assay, and indirect hemagglutination tests. Twenty-four of the sera were positive by three or more of the five tests and judged to be true positives; 89 were negative by three or more of the tests and considered to be true negatives. The tests were ranked for accuracy, sensitivity, specificity, false-positive rate, and false-negative rate. The indirect hemagglutination test scored best, followed by enzyme-linked immunosorbent assay, solid-phase fluorescence immunoassay, complement fixation, and immunofluorescence, in that order. When the tests were ranked on the basis of technical demands, turnaround time, requirement for special equipment, and subjectivity in reading, the indirect hemagglutination test again scored best, followed by solid-phase fluorescence immunoassay, enzyme-linked immunosorbent assay, immunofluorescence, and complement fixation in that order. Our findings suggest that the indirect hemagglutination test is the most reliable and effective commercially available test for the identification of those donors who are very unlikely to transmit cytomegalovirus to recipients.

A flexible sealed tube transverse radio frequency excited carbon dioxide laser for dermatologic surgery

A new CO2 laser system, of special characteristics, has been found to be effective for CO2 laser dermatological surgery. The unit is compact, freely movable, and suitable for office practice. A highly flexible operating probe makes for precision surgery. The initial investigative clinical series included resistant warts in many areas including extensive plantar warts, oral lesions, and condylomata. There were also excisions of broad base granuloma pyogenicum, large seborrheic warty lesions, thermal photocoagulation of rhinophyma, and laser dermabrasion of tattoos. Flaps were done in animals.

Surgery with the argon laser: recent advances in instrumentation and techniques

There have been several recent advances in the instrumentation and techniques of use of the argon laser in dermatologic surgery. Dispersion lenses that enlarge the areas of impact, operation through a microscope that permits precise microsurgery, templates that delimit areas of treatment, special eyeshields, nerve block anesthesia, and intermittent, light general anesthesia feasible in an out-patient setting are discussed.

Prevalence of hepatitis B infection among residents of an institution for the mentally retarded

Data on prevalence of antibody to hepatitis B surface antigen (anti-HBs) and of hepatitis B surface antigen (HBsAg) among 95 matched pairs of Down's syndrome (DS) and other mentally retarded (OMR) patients in an institution were analyzed by age on admission and by length of residence. Passive hemagglutination test were used to determine anti-HBs. Anti-HBs prevalence increased with admission age among DS patients (26%, 42% and 56% for age groups less than or equal to 5, 6-15 and greater than 15 years, respectively) but decreased among OMR patients (85%, 71% and 78%), giving overall rates of 38% for DS and 77% for OMR which are significantly different (p less than .001). Anti-HBs prevalence increased with length of residence for OMR patients but was unchanged for DS patients. For both groups, the prevalence of hepatitis B (HB) infection (both anti-HBs and HBsAg) increased with length of residence and, overall, was nearly the same for DS and OMR patients. These observations are consistent with the hypothesis that, with respect to response to HB virus, younger DS patients are immunologically immature.

Treatment of portwine marks by an argon laser

Although the treatment of the ordinarily incurable portwine birthmark by lasers has been practiced for more than 10 years, recent therapeutic investigations have been carried out particularly with the argon laser. Argon lasers now available for medical purposes produce treatment spots that are small. For certain practical reasons, at present, only relatively small portwine marks can be treated effectively. With trained personnel and proper safety measures, the treatment is safe for the patient and the operator. The treatment as yet is not proved to be better with the argon laser because the ruby laser and even an incoherent infrared thermal coagulator can produce similar and often larger cleared areas. It is recommended for the present that treatment of portwine marks by argon lasers be restricted to investigation in medical centers where critical evaluations, control studies, and more powerful laser systems can be developed.

Hepatitis B surface antigen and its subtypes in an institution for the mentally retarded

The prevalence of hepatitis B surface antigen (HBsAg) in 155 patients with Down's syndrome (DS) and 209 with other types of mental retardation (OMR) at Huronia Regional Centre, Orillia, Ontario was 34.8 and 5.3%, respectively. There was no significant difference in prevalence between males and females in either group of patients. In 75 matched pairs (DS-OMR) the HBsAg prevalence was 45% in DS and 8.3% in OMR males; in females 40% of those with DS were HBsAg-positive, whereas all the OMR residents were negative. The prevalence of HBsAg in both DS and OMR groups was higher in those admitted in early childhood and in those who had resided in the institution for more than 10 years. In all 54 HBsAg-positive DS patients the antigen subtype was ad. Among the 11 HBsAg-positive OMR patients the subtype was ad in 10 cases and ay in 1.

Hepatitis B antigen: distribution of ad and ay subtypes in blood donors and hepatitis patients

Hepatitis B antigen (HBAg) from blood donors and patients with hepatitis was tested for ad and ay subspecificity by immunodiffusion in agarose. A total of 59 sera from blood donors and 81 sera from hepatitis patients were subtyped.Subtyping of HBAg from blood donors showed ad and ay subspecificity in 64.4 and 35.6% of cases respectively. Patients' sera on the other hand showed HBAg with ad and ay subspecificity in 6 and 94% of cases respectively. Therefore, ad subtype was more frequently associated with blood donors whereas ay subtype was predominant among hepatitis patients. The relationship between clinical findings and HBAg subtype is also discussed.

Studies on cell fusion and the rescue of SV40 from cell cultures of successive generations of C1 2 TSV 5 - and RHaT-produced hamster tumors

Five successive generations of tumors have been produced in inbred Syrian hamsters after initial inoculation of SV40-transformed Cl2TSV5 and RHaT cell lines.SV40 could be rescued by cell fusion with inactivated Sendai virus from cell cultures of all five tumor generations. T-antigen was detected in all cultures by fluorescent antibody staining.An increased capacity for fusion of SV40-transformed cells after successive passages in hamsters has been observed.In addition to monkey kidney cells, bovine and lapine kidney cells have been successfully used for SV40 rescue by cell fusion.