Qualitative and quantitative analysis of human cytotoxic T-lymphocyte responses to HIV-1 proteins.

To study the degree of immunogenicity of each HIV-1 protein. In most viral systems, antiviral cytotoxic T-lymphocytes (CTL) from a given donor preferentially recognize only one or a small number of viral proteins. Anti-HIV CTL were generated by in vitro stimulation of peripheral blood mononuclear cells from seropositive donors and tested against multiple HIV-1 proteins or groups of proteins encoded by seven genes (env, gag, pol, nef, rev, tat and vif). Using autologous target cells infected with recombinant vaccinia viruses expressing one of the HIV-1LAI proteins, we compared the cytolytic activities obtained from bulk culture with those found in limiting dilution analysis (LDA). Our results were noteworthy for the following reasons. (1) Each responding donor reacted simultaneously to multiple proteins; this is very unusual in other viral systems. Anti-Gag CTL were detected in most, and anti-Pol in approximately three-quarters, of the patients, together with very high amounts of the corresponding CTL precursors in LDA. CTL against Env and Nef were found in two-thirds of the patients, while Vif- and Rev-specific CTL were less frequent. Finally, Tat was seldom recognized by CTL, but its antigenicity was revealed in LDA. (2) All responding cells revealed in bulk cultures as well as in LDA were CD8+ T-cells, and their in vitro differentiation did not require the help of CD4+ T-cells. (3) Proteins from the HIV-1LAI isolate were recognized with high frequency by CTL from seropositive donors, most certainly being infected by other isolates, which suggests that relatively conserved epitopes are predominant targets of CTL. Taken together, these results are encouraging for vaccine purposes, since anti-HIV-1 CTL stimulation is thought to be a requirement for such a vaccine.


Tumor necrosis factor-alpha in pediatric HIV-1 infection.

To evaluate the diagnostic and prognostic value of serum tumor necrosis factor-alpha (TNF-alpha) levels in HIV-1-infected children. Serum levels of TNF-alpha were evaluated in 57 HIV-1-infected symptomatic children aged between 7 months and 8 years. TNF-alpha levels were determined by enzyme immunoassay. The sensitivity of the assay was 10 pg/ml. TNF-alpha levels (mean +/- s.d.) were significantly elevated in HIV-1-infected patients (285 +/- 390 pg/ml), compared with HIV-1-uninfected age-matched controls (22.7 +/- 4.9 pg/ml). Among HIV-1-infected children the highest levels of TNF-alpha were noted in those with Mycobacterium avium intracellulare (MAI) infection and those with interstitial lymphoid pneumonitis (LIP). In contrast, patients with Pneumocystis carinii pneumonia, progressive encephalopathy or cachexia did not have markedly elevated TNF-alpha levels. Serum TNF-alpha is increased in symptomatic HIV-1-infected children, with higher levels in children with LIP or MAI. Serum TNF-alpha levels are not diagnostic for cachexia or progressive encephalopathy.


Serological responses to mycoplasmas in HIV-infected and non-infected individuals.

To assess the frequency of mycoplasma infections in HIV-antibody-positive and -negative individuals by studying the serological responses against mycoplasmas, especially Mycoplasma fermentans and M. pirum. An enzyme-linked immunosorbent assay (ELISA) was used to measure immunoglobulin G (IgG) class antibody concentrations against six mycoplasma species in sera of HIV-positive and HIV-negative individuals. Serum samples were obtained from 30 HIV-positive individuals (10 asymptomatics, 10 with lymphadenopathy syndrome and 10 with AIDS), 10 HIV-negative partners of HIV-positive individuals and 40 HIV-negative blood donors. Antibodies to M. fermentans strains incognitus and PG18, M. pirum, M. genitalium, M. pneumoniae and M. hominis were assessed by immunoblot or ELISA. Absorbance values were taken as a semiquantitative measurement for antibody concentration and an arbitrary cut-off value (0.8) was set to establish seroprevalence. There was no significant difference in the mean IgG concentrations of any of the six mycoplasmas between HIV-positive and HIV-negative groups. Antibody concentrations were also similar in different clinical phases of HIV infection. Antibody concentrations to different mycoplasma strains were compared with each other to reveal eventual cross-reactions caused by shared antigens; the strongest correlation (r = 0.836) was found between M. fermentans strains incognitus and M. pirum antibody concentrations. The correlation between M. fermentans strains incognitus and PG18 was also significant but weaker (r = 0.522). No shared antigens between M. fermentans strain incognitus and M. pirum were demonstrated by immunoblot. Antibodies against M. fermentans type strain PG18, strain incognitus and against M. pirum are detected infrequently and their presence does not correlate with HIV infection per se or with the clinical stage of HIV infection.


Zidovudine-induced restoration of cell-mediated immunity to mycobacteria in immunodeficient HIV-infected patients.

To describe a localized form of Mycobacterium avium intracellulare (MAI) infection occurring concurrently with the restoration of cutaneous delayed-type hypersensitivity (DTH) responses to mycobacterial antigens after commencement of zidovudine therapy in immunodeficient HIV-infected patients. The first 108 Western Australian patients with a CD4+ T-cell count of < 200 x 10(6)/l and/or symptomatic disease to be given zidovudine (ZDV), of whom 72 had adequate DTH data. DTH responses to seven antigens were measured by the 'Multitest' method before and on at least two occasions during the 6 months after commencing ZDV. All patients were reviewed at regular intervals and clinical events recorded. Of the 64 patients who were anergic to tuberculin before commencing ZDV, 27 (42%) developed a DTH response to tuberculin after ZDV. Four of the nine patients with a 'Multitest' tuberculin response of > or = 8 mm and one patient who developed a positive Mantoux test to M. avium purified protein derivative developed an illness characterized by localized MAI infection, lymphadenopathy and/or severe fevers after 1-2 weeks. The development of localized MAI infection and/or fevers shortly after commencing ZDV in immunodeficient HIV-infected patients may reflect restoration of cellular immunity to mycobacterial antigens in some patients rather than early failure of therapy or hypersensitivity to ZDV.


Relationship of cerebrospinal fluid immune activation associated factors to HIV encephalitis.

Because macrophages are the predominant immune cell and the predominant infected cell in the brains of patients with HIV encephalitis, we studied macrophage and immune activation-associated factors in the cerebrospinal fluid (CSF) from 39 autopsied AIDS cases for whom complete neuropathologic evaluation of the brain was available. CSF HIV p24 antigen was present in less than one-third of cases (11 out of 39). Less than half of the autopsies with moderate to severe parenchymal infection by HIV had high levels of CSF p24, although all autopsies with elevated levels of HIV p24 had moderate to severe HIV encephalitis. Elevated levels of cytokines, beta 2-microglobulin, neopterin, and quinolinic acid were observed. Although many of the CSF findings showed a strong correlation with each other, none showed a strong correlation with the severity of HIV infection of the brain itself. The absence of a close association between CSF abnormalities and HIV encephalitis could reflect the abundance of complicating opportunistic infections in these terminally ill patients or the inadequacy of CSF as a marker of basal ganglia involvement in HIV encephalitis. These findings complicate interpretation of clinical studies of CSF in patients with AIDS where neuropathologic evaluation is unavailable.


Prevalence of measles antibodies in adults with HIV infection: possible risk factors of measles seronegativity.

To determine the prevalence of measles (rubeola) immunity in a group of HIV-1-infected adults and to examine predictors of measles seronegativity in this population. County hospital outpatient clinic and public-health department early HIV intervention clinic. A total of 262 HIV-infected adults presenting to outpatient clinics between September 1990 and January 1991. Patients were screened for the presence of measles immunoglobulin G antibody, as measured by an enzyme-linked immunosorbent assay (ELISA). Pertinent clinical and immunologic information was recorded. Univariate and multivariate analyses were performed to identify possible risk factors for measles seronegativity. Measles seronegativity, as defined by a lack of detectable antibody (ELISA predicted index value < 1.0). Thirteen (5%) patients lacked serologic evidence of immunity. Risk factors for measles seronegativity included year of birth in 1957 or later, Caucasian (non-Hispanic) race and oral hairy leukoplakia. Factors associated with progressive HIV disease (other than hairy leukoplakia) were not associated with a lack of existing immunity. A high prevalence (95%) of measles antibody was found in this large group of HIV-infected adults. Young, white individuals born in 1957 or later were at the greatest risk for measles seronegativity, but declining immunity due to progressive HIV infection did not appear to be associated with a lack of antibody. Self-reported histories of measles infection or immunization were not reliable predictors of measles immunity.


Bronchial responsiveness in AIDS patients with Pneumocystis carinii pneumonia.

To study bronchial responsiveness to inhaled histamine among HIV-infected patients. A prospective study in a regional infectious diseases unit. Three groups of patients were studied. Group A consisted of AIDS patients (n = 7) who had had Pneumocystis carinii pneumonia (PCP), group B of AIDS patients (n = 7) not known to have had PCP, and group C of asymptomatic HIV-positive patients (n = 7). Inhalational histamine challenge in cumulative doses (0.03-3.91 mumol) was administered by a nebulizer. It was stopped when the forced expiratory volume in 1 sec (FEV1) had fallen by more than 20% of the baseline value or when the cumulative dose administered exceeded 3.91 mumol. Response was measured as percentage change in FEV1 from the baseline value, and plotted on a linear scale against log dose histamine to enable the dose of histamine causing a 20% fall in FEV1 (PD20-FEV1) to be determined. Statistical analysis was performed by analysis of variance. AIDS patients previously infected with PCP (group A) had a significantly lower PD20-FEV1 [(mean, 0.31 mumol; range, 0.07-0.95; s.d., 0.31; s.e., 0.12; 95% confidence interval (CI), 0.03-0.60)] than AIDS patients without PCP (group B; mean, 1.01 mumol; range, 0.20-2.00; s.d., 0.67; s.e., 0.25; 95% CI, 0.39-1.64) or asymptomatic HIV-positive patients (group C; mean, 1.28 mumol; range, 0.49-1.80; s.d., 0.51; s.e., 0.19; 95% CI, 0.81-1.76) (P < 0.05). There was no significant difference between groups B and C. All patients recorded PD20-FEV1 within the asthmatic range of bronchial hyper-responsiveness. These results suggest that development of PCP in a small group of HIV-infected patients induces a significantly greater degree of bronchial hyper-responsiveness.


Prevention of blood-borne HIV transmission using a decentralized approach in Shaba, Zaire.

To prevent blood transfusion-acquired HIV infection with a decentralized approach to HIV screening of blood donors, using an instrument-free rapid test. Shaba province, Zaire (496,877 km2). The programme consisted of training health-care workers, distribution of a rapid HIV-antibody test (DuPont's HIVCHEK) for screening of all blood donations, and quality control of testing by a regional reference centre. Over a 2-year period, 11,940 rapid tests were distributed to 37 hospitals, covering 75% of all hospital beds outside the copper mine's health system in Shaba. Eighty-five per cent of the tests were used to screen blood donors (5.4% positive test rate) and 13% to test patients (39.7% positive test rate). At least 265 cases of HIV-positive blood donation were prevented, at an estimated cost of 137-279 ECU per case. Only 26% of initially positive specimens reached the central laboratory for supplemental testing, and sterile transfusion equipment and blood-grouping reagents were frequently unavailable. The lack of transport and communications and a deteriorating health system were major constraints. District hospitals in Africa are often long distances from major cities, difficult to reach for most of the year, and perform a small number of transfusions. In this context a classical centralized regional blood bank may not be a feasible option to ensure safe blood transfusions. However, safe blood transfusion can be achieved with a decentralized approach using a rapid test, provided that minimum standards of health-care services are available.


AIDS education for hospital workers in Manila: effects on knowledge, attitudes, and infection control practices.

To evaluate an AIDS education intervention for health workers in Metro Manila hospitals. A randomized controlled education program consisting of lectures, role-plays, posters and pamphlets was delivered to physicians, nurses, laboratory technologists and orderlies in Manila hospitals. Knowledge, attitudes and infection control practices were measured before, immediately after, and 2 months after the intervention. Baseline survey among 641 hospital workers revealed poor knowledge, negative attitudes towards AIDS patients, and inappropriate infection control practices. Immediately after the intervention, there was significant improvement in (1) knowledge scores (8.7-11.2 in the intervention group versus 8.5-9.5 in the control group; range, 0-14), (2) attitude scores (54.4-60.6 versus 54.6-56.8; range, 22-88), and (3) needle-recapping practices (14-43% versus 39-43%) (all P values < 0.001). After 2 months, attitude scores in the experimental group fell to the same level as those of the control group, while improvements in knowledge and needle recapping were largely maintained. Role-playing was considered by the participants to be the most effective component of the intervention. These results suggest that AIDS training for hospital workers in the Philippines and in similar countries is necessary and can be effective. Ideally, such training should include role-playing and should be ongoing in order to sustain the effect.


HIV-1 infection among non-intravenous drug user female prostitutes in Spain. No evidence of evolution to pattern II.

To assess the prevalence of HIV-1 infection among non-intravenous drug user (IVDU) female prostitutes in Spain and to determine risk factors for HIV-1 infection in this population. Cross-sectional seroepidemiological study of 519 non-IVDU prostitutes. Four university hospitals. All participants completed a questionnaire and provided a serum sample. Serum samples were tested for antibodies against HIV-1, hepatitis C virus (HCV) and Treponema pallidum. Twelve out of the 519 (2.31%) participants were HIV-1-seropositive. HIV-1 infection was associated with the presence of both HCV and T. pallidum antibodies, multiple sex partners, longer history of prostitution, history of genital ulcers and anal intercourse. Condom use was associated with HIV-1 seronegativity. The prevalence of HIV-1 infection in non-IVDU prostitutes in Spain remains relatively low. Risk increases with a higher rate of sexual exposure and practices such as anal intercourse and unprotected coitus.


Estimates of HIV infection among injecting drug users in Glasgow, 1985-1990.

To use research and surveillance studies in Glasgow (Scotland, UK) to estimate the number of current injectors infected with HIV, the total number of injectors infected up to the end of 1990 and the recent incidence of infection. (A) Prevalence of injecting drug use was estimated using log-linear modelling. (B) Prevalence of HIV infection was determined from voluntary testing of a community-wide sample of injectors. (C) The number of infected current injectors was predicted by combining the distributions generated by (A) and (B). (D) Data on known HIV-positive injectors were used in conjunction with (C) to forecast the cumulative number of infected injectors. The number of current injectors was estimated to be 9400; the prevalence of HIV infection among 447 injectors recruited to the HIV prevalence study during 1990 was 1.1%. From these data, the number of HIV-positive current injectors in 1990 was estimated to be between 52 and 138. Between 1985 and 1990, 110 known HIV-positive injectors were registered or received treatment in Glasgow for HIV-related diseases; the total number of cases estimated to have occurred during this period was between 110 and 300. The incidence of infection in Glasgow during 1990 was likely to have been low in light of the finding that only one case in the prevalence study had not previously been diagnosed HIV-positive. Linkage of datasets from a variety of sources and studies has enabled the substantial refinement of estimates of the number of injectors and the proportion infected with HIV in Glasgow up to 1990.


An economic evaluation of home-care assistance for AIDS patients: a pilot study in a town in northern Italy.

To evaluate the costs and cost-effectiveness of home-care assistance (HCA) as an alternative to hospital-based care only for patients with AIDS (PWA). A 6-month prospective study. Use of resources by a control group of PWA receiving ordinary hospital-based care (OC group) was compared with that by a random group of PWA who, in addition to hospital care, were also receiving home care (HC group). Home- and hospital-based care for PWA in Vicenza, Italy. HC group selection was based on eligibility criteria for severity of illness, home location and economic and family support. Ten of the PWA satisfying all eligibility criteria were randomly allocated to the HC group. The control group consisted of 32 PWA lacking one or more of the eligibility criteria. HCA involved the provision of palliative care for PWA by a multidisciplinary team of caregivers. Hospital-based services covered inpatient and outpatient services. The health benefits for HC and OC groups using a quantitative quality of life measure (the Quality of Well-Being Scale). Overall health-care cost savings of 6-7%, relative to the OC group, were predicted for the HC group. Costs per well week were estimated at US$482 for the HC group and US$791 for the OC group. Home-care assistance appears to be a cost-effective strategy for the treatment and care of PWA if strict eligibility criteria are adhered to.


Completeness of AIDS reporting in Switzerland: a study based on deaths between December 1987 and June 1990.

To assess completeness and determinants of reporting to the AIDS registry of the Swiss Federal Office of Public Health. Death certificates indicative of AIDS or HIV for deaths occurring between December 1987 and June 1990 were reviewed and compared with reports to the AIDS registry. The completeness of the AIDS registry was 68%. However, almost all cases have now been ascertained, because more than 90% of unreported AIDS cases are detected when death certificates are reviewed. Thus, the ongoing review of death certificates adds to the total case ascertainment. The most important determinant of reporting was the reporting source: specialized AIDS clinics reported 85% of their cases, while all other sources reported only 48%. The investigation of the heterogeneity of reporting is important. It can wrongly suggest regional and national differences in the epidemic and lead to a decrease in completeness of reporting over time without actual changes in reporting behavior.


A counseling dilemma involving anencephaly, acrania and amniotic bands.

A suggested fetal anencephaly on routine office ultrasound examination resulted in a diagnosis of fetal acrania when targeted ultrasonography was performed by a consultant. Following pregnancy termination, examination of the abortus revealed partial cranial destruction secondary to an amniotic band. It is often difficult to distinguish between anencephaly, acrania, and amniotic band sequence prenatally, but postnatal differentiation is imperative for accurate risk assessment in genetic counseling.


Fryns syndrome: another example of non-lethal outcome with severe mental handicap.

In this report we present clinical data of a patient with Fryns syndrome who survived the neonatal period. Two sibs died intra-uterine. The syndrome is characterized by craniofacial dysmorphism, diaphragmatic hernia and distal limb hypoplasia. Lethality in most cases is caused by the diaphragmatic hernia with concomitant lung hypoplasia. In patients with Fryns syndrome presenting without the diaphragmatic defect and lung-hypoplasia, survival beyond the neonatal period is possible; mental retardation is present in all four patients described so far. This report illustrates, once more, the great intrafamilial variation of the syndrome and emphasises its important consequences for genetic counseling and prenatal diagnosis.


Phenotypic variability of mannosidosis type II: report of two Greek siblings.

Two patients, a 13-year-old boy and his 24-year-old sister, were diagnosed as mannosidosis type II cases, on the basis of both presenting extremely reduced plasma and white blood cell acid-alpha-mannosidase are reported. With the exception of mental retardation and neurosensory deafness the two siblings manifested a wide phenotypic variability. The boy had several facial features indicating a lysosomal storage disorder, as well as spondylolisthesis. His sister, apart from heavy eyebrows and lower jaw prognathism appeared normal.


Translocation/duplication of 9p onto a duplicated 4q.

A 5-month-old girl with the classical dysmorphism of the 9p trisomy syndrome and a severe heart defect was found to have an unbalanced translocation of 9pter-->p22 onto q35 of a chromosome 4 with an inverted duplication of q32-->q35. This concurrence of two de novo rearrangements suggests that the breakpoint at 4q35 not only participated in the translocation but also predisposed to the segmental duplication of 4q.


Opitz-C syndrome: on the nosology of mental retardation and trigonocephaly.

We report on two patients with a complicated form of trigonocephaly. The first patient has the Opitz-"C"-trigonocephaly syndrome. The second patient had initially a delayed motor development, but finally attained normal intelligence. A review of 22 patients with Opitz-C syndrome from the literature is presented. Most of the typical facial dysmorphism can be regarded as part of a trigonocephaly "sequence" rather than presenting characteristic features of a syndrome. More specific are the intra-oral anomalies, abnormally modelled ears, cardiac anomalies and neonatal hypotonia. All surviving patients are severely retarded. Since almost all patients are sporadic cases we suggest that the "C"-syndrome is a cytogenetically yet undetectable microdeletion syndrome.


Pfeiffer acrocephalosyndactyly syndrome in mother and son with cloverleaf skull anomaly in the child.

A boy is reported with the cloverleaf skull anomaly as part of the Pfeiffer syndrome. So far, this combination has only been observed in sporadic cases. However, the mother of this patient had also the syndrome of Pfeiffer, indicating that the cloverleaf skull abnormality may occur in familial cases. Development of the child after birth and therapeutic approaches are reported.


Dysmorphology report: on the association of microcephaly and preaxial polydactyly. Another example of Howard-Young syndrome.

We present a 5-year-old boy with developmental delay, severe microcephaly and preaxial polydactyly. These features are very similar to those previously described by Howard and Young (1) in their princeps report.


The use of post-embedding immunoelectron microscopy in the diagnosis of glomerular diseases. Comparison of immunoelectron microscopic and immunofluorescence studies.

Fifty renal biopsies were studied by immunoelectron microscopy after embedding in a partly hydrophilic polyacrylic resin (LR White). Immunofluorescence studies were carried out on frozen sections of parallel tissue samples. Polyacrylic embedding gave good preservation of the renal ultrastructure and precise localization of immunoglobulin and C3c antibodies within glomerular electron-dense deposits. Non-specific staining of plasma proteins within vascular lumina could easily be detected. There was good correlation between immunoelectron and immunofluorescence microscopy. Immunoelectron microscopy is a very sensitive method, which can detect small amounts of antigen. More cases were, however, positive by immunofluorescence than by immunoelectron microscopy. This discrepancy may be explained by difference in sample size, and by difference in resolution of morphological details (electron microscopy versus fluorescence microscopy).


Nationwide spread of Klebsiella oxytoca K55 in Swedish neonatal special care wards.

In a nationwide survey of invasive bacterial infections in Swedish neonates, 36% of Klebsiella spp. were Klebsiella oxytoca serotype K55. This unexpectedly high proportion of K55 infections was due to clusters of infection in neonatal special care wards, and at first seemed attributable to nosocomial spread of a K. oxytoca strain of high virulence. Factors predisposing infants to infection were, however, found irrespective of whether the infecting strain was of serotype K55 or not. Additionally, the prevalence rates of a potential virulence factor, siderophore production, were similar among the two groups of strains. During the same period of time a K. oxytoca K55 with similar biochemical phenotype and drug resistance pattern was found to be spread among the neonates in 12 of 22 neonatal wards in Sweden. The increased proportion of invasive neonatal K. oxytoca K55 infections thus seemed to reflect a high rate of colonization rather than an increased virulence of the K55 strain.


Mucosal immunoreactivity in experimental pneumococcal otitis media.

A rat model was used to investigate immunological events in the middle ear mucosa during pneumococcal acute otitis media (AOM). Twelve healthy male Sprague-Dawley rats were challenged in the right middle ear with Streptococcus pneumoniae type 3, the presence of AOM being confirmed by otomicroscopy. Randomly selected rats, four at a time, were sacrificed on days 7, 14 and 56 after bacterial challenge. Immunohistochemical staining for IgG, secretory IgA (SIgA), and IgM was performed on tissue specimens from four separate locations in the middle ear and tubal mucosa. Immunoglobulins, especially IgG, were found around blood vessels in the middle ear mucosa. Immunoreactive lymphoid cells of all three Ig classes investigated, undetectable before bacterial challenge, appeared within 7-14 days after middle ear challenge, and the location of these cells in the middle ear mucosa suggests the presence of IgG, SIgA, and IgM, respectively. On the other hand, reactivity with anti-SIgA (but not with anti-IgG or anti-IgM) in Eustachian epithelial cells, and also in the subepithelial glands of tubal mucosa was present both before and after challenge. The results suggest that the middle ear mucosa is an immunoreactive site only after it has been activated with pathogens. In contrast, the tubal mucosa exhibits immunological activity also prior to the antigenic stimulation of present interest.


Neuronal uptake of plasma proteins in cryogenic brain lesions. An immunoelectron microscopic study.

A previous light microscopic study on cryogenic brain lesions in rats demonstrated uptake of plasma proteins into damaged neurons within a few minutes after the lesion. The protein concentration was much higher inside the nerve cell bodies than in the surrounding neuropil. This is puzzling since the neuropil to a large extent consists of damaged neuronal processes. The present investigation describes the intracellular localization of albumin in this model using a post-embedding immunoelectron microscopic technique. The distribution of albumin in the lesions was studied after 1, 6 and 12 h survival periods. The intraneuronal albumin was mainly bound to the particulate elements of the cytoplasm and nuclei, while the watery parts of the cells showed no immunoreactivity. The intracellular organelles contained very little albumin, indicating that their membranes may be more resistant to freezing than those of the cells. Most of the neuronal and glial processes in the neuropil were swollen and contained almost no albumin. This explains the contrast between the strong immunoreactivity of the neurons and the vague reactivity of the neuropil in light microscopy.


Experimental studies of survival of anaerobic bacteria at 4 degrees C and 22 degrees C in two different transport systems.

The survival of anaerobic bacteria on swabs in two different transport systems at 4 degrees C and 22 degrees C was evaluated. The transport systems were a charcoal-impregnated cotton swab in modified Stuart transport medium (MST), and a viscose swab in modified SIFF transport medium (BTM) (Bionor). The following eight clinical strains of anaerobic bacteria were tested for quantitative recovery at 24 h, 48 h, 72 h, and 96 h; Fusobacterium necrophorum, Bacteroides melaninogenicus, Bacteroides intermedius, Peptostreptococcus anaerobius, Peptococcus magnus, Clostridium perfringens, Clostridium tetani, and Actinomyces israelii. Additionally, a mixture of Staphylococcus aureus and Escherichia coli was tested together with Bacteroides fragilis, Fusobacterium necrophorum and Clostridium perfringens. Both transport systems preserved the bacteria, but the BTM medium gave a better quantitative recovery of the bacteria than the MST in 29/64 (45%) of the experiments, whereas the opposite was the case in 15/64 (23%) of the experiments (p < 0.05). There was no significant strain-related difference between the recovery of 10 different B. fragilis strains. There was no major difference in the recovery of the anaerobes in the two systems at 4 degrees C compared to 22 degrees C, except for Fusobacterium necrophorum, which survived best at 4 degrees C in the Bionor transport system.


Effects of the prostaglandin E2 analogue enprostil on the carbon tetrachloride-induced necrosis of liver cells in mice.

Female mice, eight weeks old, were injected with carbon tetrachloride (CCl4) (10 mg subcutaneously). Groups of mice (n = 10-30) were then injected with enprostil (E) 2, 20 or 50 micrograms/kg body weight (bw) intraperitoneally 15 min and two h after, or E 100 micrograms/kg bw two h after the CCl4 injection. The mice were killed after 24, 48 or 72 h. Plasma activity concentrations of alanine aminotransferase (ALAT) were determined in blood specimens from the iliac veins. The extent of liver cell necrosis in histological sections was recorded on a 100 mm Visual Analogue Scale (VAS) and measured using the electronic Mini Mop method. In the group given the highest single dose of E (100 micrograms/kg) a significant lowering of the CCl4-induced liver cell necrosis was found after 24 h. No significant differences were found after 48 and 72 h. In the other groups injected with lower doses of E after CCl4, no significant differences were found compared to groups injected with CCl4 alone.


Influence of muramyl dipeptide on renal candidiasis in genetically distinct mice.

Susceptible (DBA/2) and resistant (C57BL/6) mice were inoculated intravenously with Candida albicans to evaluate the effect of a four-day prophylaxis with muramyl dipeptide (MDP) on the renal burden of organisms during the first week after infection. In sham-treated DBA/2 mice injected with 8 x 10(4) candida cells, renal CFU (LOG10 +/- SEM) on days 1, 4 and 7 after infection were found to average 5.050 +/- 0.109, 4.882 +/- 0.133 and 5.482 +/- 0.245. In sham-treated C57BL/6 mice injected with 2 x 10(5) candida cells, renal CFU on days 1, 4 and 7 reached only 3.610 +/- 0.118, 3.404 +/- 0.107 and 4.176 +/- 0.580. MDP-treated DBA/2 mice achieved significant reduction in CFU of C. albicans on day 1 (1.3 log units) and day 4 (0.6 log unit), while MDP-treated C57BL/6 mice had significant reduction in CFU of C. albicans only on day 1 (0.6 log unit) after infection. Sham-treated mice of both strains had a 28.6 to 30% increase in kidney weights on day 4 only, a transient change not seen in MDP-treated mice. Histopathological examination on days 8, 15 and 21 after infection revealed a higher incidence of renal papillary necrosis in DBA/2 mice than C57BL/6 mice (approximately 70% vs 10%). The incidence of granulomas and of chronic interstitial inflammation was much higher in MDP-treated mice. We conclude that the genetic makeup of the host influences the potential effectiveness of MDP as a biological response modifier.


Growth of xenografted squamous cell carcinoma of the head and neck--possible correlation with patient survival.

Tumor biopsies from 100 cases of squamous cell carcinoma of the head and neck (HNSCC) were xenografted to athymic nude mice. To ascertain whether xenograft take might be a factor of clinical significance, it was compared with patient survival, the patients being divided into two groups (take and non-take) according to the results of transplantation. The tumor take rate was 29%. Median survival time with respect to cancer death was 18 months in the take group, as compared with over 74 months in the non-take group (p = 0.06). No significant differences were observed between the two groups with respect to age, tumor size, nodal status, clinical stage or histological differentiation. The findings suggest that take of HNSCC xenografts in nude mice may reflect the malignant potential of the original tumor. Moreover, the possibility cannot be excluded of a selection bias favoring the use of such malignant xenografts in therapeutic studies in nude mice.


Detection and quantitation of antibodies against Rhizopus by enzyme-linked immunosorbent assay.

In sawmills high concentrations of spores from the mould Rhizopus microsporus may occur, causing allergic alveolitis in exposed workers. Both symptomatic and asymptomatic exposed workers may develop antibodies. An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Rhizopus has been developed in order to study the relationship between antibody levels and exposure levels. The precision of the measurements of Rhizopus antibodies by ELISA carried out on the same microtiter plate was estimated to be 11%. It is therefore possible to detect changes in antibody levels of approximately 25% or more. Antibodies were studied longitudinally by ELISA in 60 wood trimmers. The observed changes in antibody levels exceeded the precision of the ELISA method substantially, indicating significant variability in antibody levels in wood trimmers. The ELISA test was compared with the double immunodiffusion test (DID). Sera from 67 wood trimmers were analyzed by both methods. Antibodies were detected by ELISA in 70% and by DID in 28% of the workers in this group, clearly demonstrating that the ELISA test is the most sensitive method for the detection of antibodies to Rhizopus.


Rat Sertoli and spermatogenic cells express a similar gene, and its product is antigenically related to an outer dense fiber-associated protein.

We have previously reported that a heterodimeric protein secreted by rat Sertoli cells is antigenically related to a protein associated with outer dense fibers of the sperm tail. Therefore, we have explored the possibility that Sertoli and spermatogenic cells express a similar gene encoding a homologous protein. A Sertoli cell heterodimeric protein cDNA probe recognizes specific mRNA in pachytene and round spermatids fractionated by centrifugal elutriation; however, this specific mRNA was less prominent than in cultured Sertoli cells. In agreement with these observations, in situ hybridization experiments show that Sertoli cells are predominantly engaged in active heterodimeric protein mRNA synthesis, while meiotic prophase spermatocytes and spermatids also show significant but less abundant specific mRNA. Immunoblotting experiments demonstrate that, while Sertoli cells synthesize a heterodimeric protein consisting of two disulfide-linked components with molecular masses of 45 and 35 kD, both primary spermatocytes and round spermatids synthesize single 30 kD monomers not associated by disulfide linkage but recognized by antisera to Sertoli cell heterodimeric protein. Immunoblotting and immunogold electron microscopic studies show that antisera to Sertoli cell heterodimeric protein recognize a protein associated with outer dense fibers. This immunoreactivity was abolished by a 5-min pronase treatment, without affecting the integrity of outer dense fibers. Results of this study and previous studies demonstrate that both Sertoli and spermatogenic cells express a similar gene and that an antigenically related product encoded by this gene becomes associated with outer dense fibers during their assembly at spermiogenesis.


Developmental expression of the S35-S45/SGP-2/TRPM-2 gene in rat testis and epididymis.

Testosterone-repressed prostate message-2 (TRPM-2) was originally isolated and cloned from the regressing ventral prostate of the rat. In this tissue, and in other hormone-dependent tissues such as the mammary gland, this gene is induced in the absence of the appropriate trophic hormone. Sequence analysis of the cDNA and genomic clones of TRPM-2 have demonstrated that the coding sequence of this gene is identical to S35-S45 (also known as SGP-2 and clusterin), which is constitutively expressed by the Sertoli cells of the adult testis. Using Northern, slot blot, S1-nuclease analysis, and in situ hybridization, we have investigated the regulation of TRPM-2 expression in the testis and epididymis during development. Slot blot analysis of RNA extracted from the testis and epididymis of 7-, 14-, 28-, 35-, and 91-day-old rats demonstrates that the gene is induced to detectable levels between days 7 and 14 and that the relative level of expression does not change significantly after day 14. In situ hybridization using frozen sections of testis from day 2-, 7-, 14-, 28-, 35-, and 91-day-old rats confirms that there is little expression of TPRM-2 in the seminiferous epithelium of 7-day-old rats, but this increases considerably after 14 days, primarily in Sertoli cells but also in association with meiotic developing spermatogenic cells. However, TRPM-2 mRNA is expressed in the rete testis at 2 days of age, reaches a peak at 35 days of age, and continues to be expressed in the adult. Slot blot analysis demonstrates that TRPM-2 is also induced in the epididymis between 7 and 14 days of age, although, as has been demonstrated by in situ hybridization, TRPM-2 mRNA is detectable in the epithelial cells in the head of the epididymis but is barely detectable in the midportion or tail regions. Northern analysis suggests that the size of the TRPM-2 transcript in the testis also changes during development. In the early stages of testicular development, the TRPM-2 transcript appears to be a broad band of approximately 1.5 kb, while the transcript in the adult appears to be approximately 1.8 kb in length. S1-nuclease protection assays suggest that this increase in size is not due to differential splicing of the first exon of TRPM-2/SGP-2 and most probably reflects a difference in the polyadenylation of the mRNA in the testis at different times during development.


Stage-specific expression of rat transition protein 2 mRNA and possible localization to the chromatoid body of step 7 spermatids by in situ hybridization using a nonradioactive riboprobe.

The present study has used methoxyacetic acid (MAA)-induced depletion of specific germ cell types in the rat and in situ hybridization with nonradioactive riboprobes to determine the stages of the spermatogenic cycle at which there is expression of the mRNA for the basic chromosomal protein transition protein 2 (TP2). On Northern blots, an abundant mRNA was detectable in samples from control adult rats, but the amount of message was markedly reduced when RNA was extracted from the testes of rats treated 14 and 21 days previously with methoxyacetic acid. These testes were depleted specifically of step 7-12 spermatids, suggesting that these cells contain TP2 mRNA. When tissue sections were subjected to in situ hybridization, the TP2 mRNA was localized at the cellular and subcellular levels. Messenger RNA for TP2 was first detectable in spermatids at step 7. In these spermatids, at high magnification, in addition to some positive reaction in the cytoplasm, intense staining was located to a perinuclear structure consistent with localization of mRNA within the chromatoid body. The amount of TP2 mRNA in the cytoplasm increased as remodelling of the early spermatid nucleus progressed and was highest in step 10 and 11 spermatids at stages X and XI. Thereafter, the mRNA decreased until it was undetectable in step 14 spermatids at stage XIV. The localization of TP2 mRNA to the chromatoid body of step 7 spermatids would be consistent with this organelle being a storage site for long-lived mRNAs utilized later in spermiogenesis.


Analysis of the DNA binding proteins interacting with specific upstream sequences of the S. purpuratus CyI actin gene.

The CyI actin gene of the sea urchin, Strongylocentrotus purpuratus, is regulated temporally and spatially within the cells of the early embryo. In an effort to understand the molecular basis for the CyI actin pattern of expression, we have begun analyzing the protein-DNA interactions within regions previously shown to be of potential functional importance (Katula et al., 1987). Using DNase I footprinting, 10 protected regions were identified containing both conserved and apparently novel protein binding sites. Gel mobility shift competition assays confirmed the presence of multiple protein factors which specifically recognize CyI actin upstream sequences. Determination of a relative affinity constant value (Kr) indicated that most of the protein factors preferred their respective oligonucleotide sequences vs. a synthetic competitor DNA in a range of 10(4). The highest affinity binding was observed for proteins binding to the oligonucleotide probe containing the octamer element (Kr approximately 10(6)). Heterologous gel shift competition assays were carried out to investigate the interrelatedness of the protein factors. These studies, combined with other data, indicate there are both unique and redundant protein-DNA interactions in the region being examined. Possible alterations in CyI actin DNA binding proteins were investigated during the period of CyI transcriptional activation by gel mobility shift analysis. An increase in binding activity was observed for most of the factors, indicating that early transcriptional activity of CyI actin may involve a general increase in the amount or activity of specific transcription factors. In addition, qualitative changes, as seen by alterations in the shift patterns, were observed for some of the oligonucleotide probes.


Expression of estrogen receptor gene in mouse oocyte and during embryogenesis.

Estrogen is required for oocyte maturation and embryonic development in vivo; however, the mechanism involved is not clear. Since the effect of estrogen is mediated through the estrogen receptor (ER), we examined the ontogeny and expression of the ER gene in mouse oocytes and embryos of various gestational stages using the highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) technique. Total RNA, extracted from 40 ovulated oocytes, 2-cell embryos, morulae, and blastocysts, was reverse transcribed into cDNA. A pair of primers flanking the 453-bp region encoding the hormone-binding domain of ER was used for 30 cycles of PCR. The identity of the amplified product was confirmed by sizing and Southern blot hybridization. The results indicated that ER gene is expressed in unfertilized oocytes and cumulus-oocyte complexes. The amount of ER mRNA decreases in 2-cell embryos, coincident with degradation of maternal mRNA. No ER transcript can be detected in the morulae or blastocyst stage when the embryonic genome has been activated. Postimplantation embryos do not contain detectable ER mRNA until gestation day 8. The levels of ER mRNA increase from day 10 to day 18 of gestation. These data suggest that estrogen, secreted by granulosa cells, may directly influence oocyte growth and maturation in vivo. Since estrogen is known to stimulate the production of growth factors in mouse uteri, the absence of ER mRNA in periimplantation embryos suggests that the effects of estrogen on early embryogenesis may be indirect, i.e., through estrogen-regulated growth-promoting factors produced by the reproductive tract. In mid- and late-post-implantation embryos which contain ER mRNA, estrogen may affect embryonic development through the receptor-mediated mechanisms.


Transforming growth factor beta and basic fibroblast growth factor synergistically promote early bovine embryo development during the fourth cell cycle.

Developmentally competent bovine blastocysts were produced by adding transforming growth factor beta (TGF beta) and basic fibroblast growth factor (bFGF) to serum-free cultures of in vitro produced, 2-cell bovine embryos. The effects of TGF beta were evaluated because this growth factor signals synthesis and secretion of the extracellular matrix component fibronectin and its receptor. Previous investigations have demonstrated that fibronectin promotes early bovine embryo development in vitro. The effects of TGF beta can be potentiated by bFGF; bFGF itself is an effector of protein synthesis and a potent mitogen. A positive interaction between the 2 growth factors resulted in 38.8% of fertilized oocytes maturing beyond the 16-cell stage; of these, 24.6% formed blastocysts. Transfer of early blastocysts produced using serum-free medium supplemented with growth factors resulted in pregnancy in 3 of 9 recipients. These results support the hypothesis that TGF beta and bFGF act synergistically to promote development of bovine embryos beyond the "8-cell block" observed in vitro.


Fate of microinjected genes in preimplantation mouse embryos.

The state of genes microinjected into mouse embryos was followed from the one-cell to the blastocyst stage using the polymerase chain reaction (PCR). Microinjected DNA was detected in all one-, two-, and four-cell injected embryos and in 44% of morula and 26% of blastocysts. Head-to-tail ligation of microinjected genes, a common feature of stably integrated transgene arrays, was detected in all embryos after injection of microinjected genes and occurred irrespective of the structure at the ends of the injected genes. Sensitivity of microinjected DNA to a methylation-dependent restriction endonuclease Dpn I was lost in all embryos by the two-cell stage (24 hr), indicating a change in DNA methylation, independent of transgene integration. Dissociation of blastomeres prior to compaction revealed a mosaic distribution of the microinjected DNA within the embryo and supports the notion that injected genes form a limited number of arrays, which segregate independently until they integrate into the genome or are degraded.


Characterization of fibronectin as a marker for human epididymal sperm maturation.

Fertilization involves adhesive interactions between gametes similar to those mediated by fibronectin (FN) in other cellular systems. Fibronectin has been found on the equatorial segment of ejaculated human serum. As sperm capacity to interact with the oocyte is acquired during epididymal transit, the possible participation of FN in human sperm maturation was studied. The presence of FN in both epididymal sperm and fluid was demonstrated by the detection of a major component of 220 kD in immunoblot studies using anti-FN antisera. The concentration of FN in soluble tissue extracts of epididymis was determined by enzyme-linked immunosorbent assay (ELISA). A gradual increase along the length of the organ, averaging 12-fold from proximal caput to distal corpus, was detected. Immunocytochemistry assays indicated that the number of spermatozoa with immunoreactive FN over the equatorial segment increased from 18% in caput to 64% in distal corpus epididymis. Immunoprecipitation of medium from epididymal explants culture with anti-FN antiserum demonstrated the de novo synthesis of FN in vitro. The greater number of FN-positive sperm coincident with FN accumulation in distal regions of the epididymis supports the role of FN in sperm maturation.


Fertilization envelope in diapause eggs of Pontella mediterranea (Crustacea, Copepoda).

The sequence and timing of morphological changes during envelope formation was followed in diapause eggs of Pontella mediterranea (Crustacea, Copepoda). The multilayer coat enveloping these eggs resulted from the exocytosis of 4 types of cortical vesicles that sequentially released their contents in the perivitelline space. These included small high-density vesicles (hDV) with electron-dense material, vesicles (V) with dense ring granules and a uniform matrix contained within the same compartment, large high-density (HDV) vesicles, and large moderately dense (MDV) vesicles. All of these cortical vesicles were present in newly spawned, fertilized eggs. Their exocytosis resulted from egg activation. One of these cortical vesicles (V) was similar in morphology to the intracisternal granules precursors of endogenous yolk. Intracisternal granules, characteristic of previtellogenic oocytes of many crustaceans, were present in previtellogenic oocytes of P. mediterranea but disappeared in later stages of oocyte development once yolk formation was completed. We discuss the role of cortical vesicles in the formation of the complex extracellular coat enveloping copepod diapause eggs.


Human sperm proteins from testicular and epididymal origin that participate in fertilization: modulation of sperm binding to zona-free hamster oocytes, using monoclonal antibodies.

In order to identify human sperm surface proteins involved in the gamete recognition process, mouse monoclonal antibodies were directed against human spermatozoa and screened with live spermatozoa by enzyme-linked immunosorbent assay (ELISA). Immunoperoxidase staining of human testis showed the early presence of four corresponding proteins on germinal cells, while six were detected primarily in testis fluid. The presence of 17 proteins was evidenced in the epididymis. Eight were detected with a decreasing gradient from the beginning to the end of the organ, including vasa efferentia for three of them. The other nine were observed in only one defined segment, usually the caput epididymis, which was found to be the most active region. Comparison of spermatozoa patterns from testis, vasa efferentia, and the three regions of epididymis pointed out a progressive coating. By contrast, three antibodies displayed a migration of spermatozoa surface domains in the course of epididymal transit. Six antibodies were found to inhibit human spermatozoa adherence to zona-free hamster oocytes, while nine promoted it. Molecular weights of antigens corresponding to nine of the antibodies ranged from 11 to 215 kDa. No correlation could be established with previously described human proteins. These observations emphasize the role of epididymis in human sperm maturation.


Immunological evidence for a P2 protamine precursor in mature rat sperm.

High molecular weight proteins in Rattus norvegicus that are immunoreactive with an anti-protamine 2 specific antibody but not with an anti-protamine 1 specific antibody are described. These proteins were detected by coupling high-performance liquid chromatography (HPLC) with an enzyme-linked immunosorbent assay (ELISA). Briefly, following HPLC separation of rat sperm nuclear proteins, the HPLC fractions were probed with the antibodies. We estimate that the antibody probes are 100-1000 times more sensitive than UV absorbance measurements. Immunoblot analysis following acid-urea electrophoretic separation of rat sperm nuclear proteins, and of the HPLC fractions, also detected putative protamine 2 precursor proteins. The proteins reactive with the anti-protamine 2 antibody are most likely not mature protamine 2, since they were detected in a region of the chromatogram where we would not expect protamine 2 to migrate based on the chromatographic locations of human and mouse protamine 2. Likewise, the immunoblotting experiments demonstrated that the anti-protamine 2 antibody recognized proteins with slower electrophoretic mobilities than would be expected for a mature protamine 2. An anti-protamine 1 monoclonal antibody, Hup1N, that binds rat protamine 1 is also described. Hup1N allowed for identification of the HPLC fractions that contained rat protamine 1. Finally, we demonstrated that Hup1N binds protamine 1 from a large number of species, suggesting a conserved epitope for Hup1N.


A comparison between in vitro fertilization and microinjection of immobilized spermatozoa from bulls producing spermatozoa with defects.

The objectives of this study were to compare the fertilization rate of bovine in vitro matured oocytes by in vitro fertilization (IVF) and by microinjection of a single spermatozoon (MI) and to relate these rates with fertility reported for these bulls in artificial breeding. Bull A (Holstein) had a nonreturn rate of 75%. Semen from this bull is routinely used in our standard IVF procedure. Bull B (Ayrshire), used regularly in artificial breeding and related to bull D, had a nonreturn rate of 69.2%. Bull C (Brown Swiss), with a chromosomal translocation and trisomy, achieved a nonreturn rate of 42%. Bull D (Ayrshire) produced nonmotile spermatozoa (SPZ) and had an abnormality described as "tail stump defect." No pregnancies sired by bull D have been reported. Oocytes were either fertilized in vitro by capacitated SPZ or by microinjection of a single immobilized SPZ into the ooplasm. SPZ were treated with 0.1 microM A23187 and used for IVF. For microinjection SPZ were cocultured for 5 h with bovine oviduct epithelial cells (BOEC) and then immobilized by freezing and thawing twice without cryoprotectant. A single batch of killed SPZ (stored at -25 degrees C) was used for all microinjections. All oocytes were cultured in Medium 199 for 22 h at 39 degrees C and subsequently fixed, stained, and examined for evidence of fertilization (i.e., female and male pronucleus formation, SPZ decondensation). Fertilization rates following IVF with semen from bulls A, B, C, and D were 80%, 54%, 1%, and 2%, and following microinjection were 39%, 22%, 21%, and 34%, respectively.


Making sense from antisense: a review of experimental data and developing ideas on sense--antisense peptide recognition.

Peptides encoded in the antisense strand of DNA have been predicted and found experimentally to bind to sense peptides and proteins with significant selectivity and affinity. Such sense--antisense peptide recognition has been observed in many systems, most often by detecting binding between immobilized and soluble interaction partners. Data obtained so far on sequence and solvent dependence of interaction support a hydrophobic-hydrophilic (amphipathic) model of peptide recognition. Nonetheless, the mechanistic understanding of this type of molecular recognition remains incomplete. Improving this understanding likely will require expanding the types of characteristics measured for sense--antisense peptide complexes and hence the types of analytical methods applied to such interactions. Understanding the mechanism of sense--antisense peptide recognition also may provide insights into mechanisms of native (sense) peptide and protein interactions and protein folding. Such insight may be helpful to learn how to design macromolecular recognition agents in technology for separation, diagnostics and therapeutics.


Design of novel affinity adsorbents for the purification of trypsin-like proteases.

A number of ligands for the selective purification by affinity chromatography of the trypsin-like protease, porcine pancreatic kallikrein, were designed de novo by computer-aided molecular design. The ligands were designed to mimic the side-chains of a number of arginyl dipeptides and included a benzamidine moiety substituted on a triazine ring. The ligands displayed inhibitory activities against pancreatic kallikrein which mirrored the specificity constants of the dipeptides they were designed to mimic. The ligand with the highest affinity for the enzyme, an analogue of a Phe-Arg dipeptide, when immobilized to Sepharose CL-4B via a hexamethylene spacer arm, purified pancreatic kallikrein 110-fold in one step from a crude pancreatic acetone extract.


Complex carbohydrate-lectin interaction at the interface: a model for cellular adhesion. II. Reactivity of both the oligosaccharide chain and sugar-binding domain of a glycoprotein lectin.

We describe studies of a new model cell adhesion system involving liposomes bearing lectins and the glycosphingolipid, asialomonosialoganglioside (asialoGM1). The model provides a simple analysis of experimental data to elucidate the mechanism of heterophilic cell-cell adhesion mediated by multiple protein-carbohydrate interactions. Phospholipid vesicles bearing the fatty acid conjugate of a glycoprotein lectin from Ricinus communis (RCAI vesicle) are shown to react with vesicles bearing the fatty acid conjugate of Concanavalin A (Con A) and asialoGM1 (Con A vesicle). The kinetics of aggregation and monosaccharide-induced disaggregation of the two types of vesicles were followed by monitoring the time-dependent change in turbidity. Depending on the surface density of the asialoGM1, 40-60% of the resulting precipitin complex was dissociable only in the presence of both RCAI-specific galactose and Con A-specific alpha-methyl-D-mannoside. Results indicate simultaneous participation of both the saccharide-binding domain and carbohydrate sequence of RCAI, a model cell adhesion molecule, to stabilize the encounter complex by two types of interactions. These findings support the possibility of stable cell-cell adhesion in vivo occurring via interactions between cell adhesion molecules on apposing cell-surface membranes.


A simple method for randomly mutating cloned DNA fragments by using chemical mutagens and the polymerase chain reaction.

Random mutagenesis of cloned DNA fragments can be an important tool for understanding genes and/or gene products. I report here a simple procedure for generating random mutations in any cloned DNA fragment in vitro. This method utilizes the polymerase chain reaction (PCR) to amplify chemically damaged single-stranded DNA containing the DNA fragment of interest. A mutagenized pool of plasmid DNA is produced by cloning the PCR product (containing chemically induced sequence heterogeneity) into a new vector. Therefore, extreme chemical treatments can be used that biologically inactivate the original vector. In this report, 10% of the plasmids contained a mutation in a 97-nucleotide DNA insert, giving a mutagenesis frequency of 10(-3)/base pair. Of 3000 yeast transformants screened, seven intron mutations were isolated that activate a cryptic 3' splice site, suggesting that 2% of the mutations could give rise to the desired phenotype. The seven mutations included transitions, transversions and single nucleotide deletions, demonstrating the well-balanced repertoire of nucleotide changes derived from this procedure.


Detection of specific alleles by using allele-specific primer extension followed by capture on solid support.

This article describes a method for determining whether a particular nucleic acid sequence is present in a sample and for discriminating between any two nucleic acid sequences if such sequences differ only by a single nucleotide. The method entails extension of a novel two-component primer on templates that may or may not include a target nucleic acid sequence. The 3' portion of the primer is complementary to a portion of the template adjacent to the target sequence (for example, the polymorphic nucleotide). The 5' portion of the primer is complementary to a different preselected nucleic acid sequence. Extension of the 3' portion of the primer with a labeled deoxynucleoside triphosphate yields a labeled extension product, but only if the template includes the target sequence. The presence of such a labeled primer-extension product is detected by hybridization of the 5' portion to the preselected sequence. The preselected sequence is immobilized on a solid support. The method has been applied to genotyping individuals for the two-allele polymorphism of the human tyrosinase gene.


PCR-based quantitation of low levels of HIV-1 DNA by using an external standard.

Beginning with 10(3)-10(5) molecules of a purified HIV-1 target sequence as a starting template, we have examined the effects of starting template concentration and cycle number on the amplification efficiency of the polymerase chain reaction. An external standard DNA sequence has been designed that when added to a DNA sample enables a determination of the starting concentration of HIV-1 target sequence in that sample of DNA. Varying ratios of external standard and target DNA sequences were amplified for 22 cycles. When the starting concentration of the external standard was within 50-fold of the starting concentration of the target, the amplifications of both sequences were proportional. These same results were obtained when the two templates were amplified in the presence of an excess of heterogeneous genomic DNA. Using this quantitative method, the number of starting target molecules in a DNA sample can be calculated to within a two-fold range of accuracy.


Factors which influence the decision whether or not to prescribe: the dilemma facing general practitioners.

In this study of the influences affecting general practitioners' decisions whether or not to prescribe, 69 principals and five trainees in general practice were asked about the factors that made these decisions difficult for them and the circumstances in which the decision caused them to feel uncomfortable. Discomfort was reported most frequently in prescribing for respiratory disease, psychiatric conditions and skin problems, though the range of problems mentioned was wide. The range of drugs for which the decision of whether or not to prescribe was difficult was also wide but psychotropic drugs, antibiotics, drugs acting on the cardiovascular system and non-steroidal anti-inflammatory drugs were most often mentioned. Patient factors said to be important included age, ethnicity, social class and education, the doctor's prior knowledge of the patient, the doctor's feeling towards the patient, communication problems, and the doctor's desire to try to preserve the doctor-patient relationship. Doctor specific factors included concerns about drugs, factors relating to doctors' role perception and expectations of themselves, uncertainty, peer influences, logistic factors, and the experience of medical or therapeutic misadventures. The results of this study support earlier work on the influence of social factors on prescribing decisions and show that this influence affects the entire range of clinical problems. The results also reveal the importance of logistic factors. The overriding concern of doctors to preserve the doctor-patient relationship and the range of attitudes, perceptions and experiences of doctors that have a bearing on the decision to prescribe begin to explain the apparent irrationality of some general practitioner prescribing.(ABSTRACT TRUNCATED AT 250 WORDS)


Reasons for consultation in irritable bowel syndrome: symptoms and patient characteristics.

This study compared the characteristics of patients with symptoms of irritable bowel syndrome who had either consulted or not consulted a general practitioner in the preceding two years. The subjects were identified by questionnaire in a community survey of irritable bowel syndrome symptoms and samples of 24 consulting and 24 non-consulting patients were interviewed. The groups were well matched for demographic characteristics, although those who consulted for irritable bowel syndrome also consulted more frequently for other problems. The only significant differences in the pattern, frequency and severity of a range of symptoms, which included the Manning criteria, were that more of the consulting patients experienced visible abdominal distension and had a higher mean score for severity of pain than the non-consulters. Mean negative life event scores and anxiety and depression scores were higher in the group who consulted and more of these patients were concerned about the possible serious nature of their symptoms, including fear of cancer, emphasizing the importance of eliciting patients' beliefs and anxieties about the meaning of their symptoms.


The evolution of chronic pain among patients with musculoskeletal problems: a pilot study in primary care.

Little is known about the evolution of chronic pain in primary care. Forty five patients with a four week history of musculoskeletal pain were assessed and followed up over 26 weeks by a research nurse using a structured interview and formal assessment instruments. Patients aged 18 to 65 years were recruited on presentation at two semirural Cheshire general practices and subsequently interviewed on a domiciliary visit. Twenty patients (44%) continued to have pain at 26 weeks and these patients were considered to have chronic pain. Nineteen patients had no pain after 12 weeks and a further six had no pain after 26 weeks; these patients together formed the group with acute pain. Comparing the two groups at entry into the study (pain of four weeks' duration) demonstrated significantly higher visual analogue scale scores for intensity of pain (P < 0.01) and a higher incidence of depression (P < 0.01) in the group which subsequently developed chronic pain. In this group, the presence of depression at 12 weeks was associated with higher visual analogue scale scores (P < 0.05) but at 26 weeks scores were similar in depressed and non-depressed patients. The correlation between visual analogue scale score for intensity of pain and the use of passive coping strategies to cope with pain appeared more strongly positive with duration of pain (P < 0.05 at 26 weeks). It is suggested that high pain intensity scores, the presence of depression, and the increasing use of passive coping strategies may be identifiable associations with the development of chronic pain. Areas for further research are identified.


Use of general practice by intravenous heroin users on a methadone programme.

Users of intravenous heroin represent a major challenge for general practice. A study was undertaken in a general practice in central London in 1990 to investigate the use of general practice made by intravenous heroin users who were on a methadone programme. Using information recorded in the patients' notes, 29 intravenous heroin users on a methadone programme were identified; 58 non-drug users (two controls per case) were matched for age, sex and general practitioner. A study of the number of routine consultations, missed appointments, emergency appointments and prescribed items showed that during the study period, those on a methadone programme made a larger number of routine consultations than the control subjects (median number of consultations 14 versus 0). When consultations at which only a prescription was issued were excluded this difference disappeared. Appointments were missed by 14 drug abusers (48%) but by none of the control group (P < 0.001). Emergency appointments were made by seven drug abusers (24%) compared with only two controls (3%) (P < 0.01). Even after prescriptions for methadone hydrochloride had been excluded from the analysis, patients on the methadone programme were prescribed significantly more items than patients in the control group (P < 0.001). This research has shown that intravenous heroin users on a methadone programme used general practice to a greater extent than non-drug users, according to the criteria used in the study. The implications that this may have in discouraging budget holding practices from running such schemes are discussed.


Motivational effect of cholesterol measurement in general practice health checks.

A randomized trial was conducted in five general practices in and around Aylesbury, Buckinghamshire to assess the motivational effect of cholesterol measurement on compliance with advice to reduce dietary fat intake and to stop smoking. The advice was given by practice nurses during health checks for cardiovascular risk factors. A total of 578 patients were recruited to the study and randomized into two groups. Both groups were given the same advice and were followed up after a median of three months, but the intervention group was also given immediate feedback on their cholesterol concentration. Follow up was completed for 88.2% of subjects, and those who were not followed up were assumed not to have changed their behaviour. The mean fall in total cholesterol at follow up was 0.11 mmol l-1 (95% confidence interval 0.03 to 0.18) in the intervention group who were told their cholesterol result and 0.02 mmol l-1 (95% CI -0.06 to 0.10) in the control group who were not. The proportion of smokers who were not smoking at follow up was 10.7% and 10.1% in the two groups, respectively. Patients in the intervention group with an initial total cholesterol level of 6.50 mmol l-1 or greater showed a mean fall of 6.2% in cholesterol level whereas those with an initial cholesterol level of less than 5.20 mmol l-1 experienced a mean increase of 3.6%, but as differences of this magnitude were also seen in the control group they probably reflect regression to the mean rather than an effect of knowledge of cholesterol level.(ABSTRACT TRUNCATED AT 250 WORDS)


General practice and the provision of information and services for physically disabled people aged 16 to 65 years.

The study reported here was part of a larger survey investigating the nature and extent of disability in the Grampian region. Interviews with 212 people aged between 16 and 65 years who had a wide range of physical disabilities elicited perceptions of current and past service provision. Respondents expressed a strong need for information on disability services and reported difficulty in knowing whom to approach for this. General practitioners were the most commonly reported source of such information and low usage of the Department of Social Security, social work departments and voluntary organizations was identified. No significant relationship was found between degree of disability and frequency of consultation with a general practitioner. However, the more severe the disability the more likely it was that the general practitioner initiated contact rather than the patient. Although in general those interviewed were satisfied with medical information given regarding their diagnosis, they were more critical of information provided in relation to coping with the disorder, including that concerning benefits and services. The study confirmed the pivotal role of the general practitioner in the care of physically disabled people in the community aged between 16 and 65 years. The need to re-evaluate the role of the general practitioner in the provision of information and services is discussed.


Residents of private nursing homes and their care.

A study was undertaken to examine the characteristics of residents in private nursing homes, to measure residents' dependency levels, to determine the adequacy of procedures for admitting new residents and to explore general practitioners' work with residents. Details were obtained of 61 nursing homes registered by Nottingham district health authority and of a selection of residents. Information about residents provided by the nurses in charge included aspects of self care, orientation and social integration, these items contributing to a dependency score for each resident. General practitioners completed postal questionnaires. Information was sought on the numbers of residents on the general practitioners' lists, visiting patterns, and opinions on their work with residents. It was found that almost half of the reports accompanying residents on admission were considered inadequate by the nurses in charge. The 357 residents varied widely in dependency level, need for nursing care and medication; 31% had low dependency scores. Most of the residents (57%), had been admitted from hospital, 26% from their own home and 15% from other nursing or residential homes. Higher overall dependency levels, problems with mobility and continence and need for care of wounds, catheters or colostomies were more frequent in residents admitted from hospital or nursing or residential homes than in those admitted from their own home. The 70 responding general practitioners varied widely in the numbers of residents on their lists and in their visiting patterns. The 16 general practitioners providing medical care for entire nursing homes were significantly more likely than the other general practitioners to visit routinely.(ABSTRACT TRUNCATED AT 250 WORDS)


Suicidal behaviour: a continuing cause for concern.

There is an increase in suicidal behaviour in the western world providing a major challenge to health care providers. There is an increase in the number of suicides among elderly people in Europe. The problem of suicides among elderly people is in itself a social problem, not solely a medical one. The general practitioner may be the only source of social contact for the elderly. Elderly individuals often present their problems to doctors as somatic complaints; these complaints must not be taken at face value but understood as expressions of psychosocial and social distress. The rise in suicide rates among young people is also alarming. The warning signs of escalating distress in adolescents are known and a treatment programme coordinating medical initiatives, such that recidivism of suicidal behaviour in adolescents is reduced, is necessary. The general practitioner is urged to sense when the problem presented by the individual stems from a source which is predominantly social, and to suggest an appropriate solution which may entail a family intervention. The general practitioner is in the front line of treatment and he or she may be better advised to treat both the social situation and the individual person in cases of attempted suicide. Medical initiatives must incorporate aspects of social medicine whereby community solutions are found for the management of individual distress. Social disruption, isolation, conflict and neglect are the doors to the house of despair. While medicine must respond to those who enter that house, it is the social level at which we must be the architects of change. People will die.(ABSTRACT TRUNCATED AT 250 WORDS)


Ethical aspects of medical certification by general practitioners.

As well as acting as personal physicians, general practitioners are often asked to provide medical certificates, enabling patients to obtain benefits. In these cases doctors may act for the state, for other institutions or individuals, or as an advocate on the patient's behalf in a dispute. The ethical basis of this activity differs from the therapeutic doctor-patient relationship. Difficulties are particularly likely to arise when doctors are called on to combine the roles of therapist and certifier. Although this is often convenient and saves money, the damage to confidentiality and to the primary therapeutic relationship which may result must be weighted against this. The limitations of such certificates should also be borne in mind. Fairness and the preservation of the therapeutic doctor-patient relationship are best served by restricting the role of the personal doctor to the provision of clearly defined factual information on which others, who may be medical or non-medical, can make the final judgement.


Hypothyroidism: a comprehensive review.

Hypothyroidism is a common clinical entity encountered frequently in most adult primary care settings. The reported prevalence in the general population is approximately 3% in men, but as high as 10% in women (Sawin, Geller, Hershman, Castelli, & Bacharach, 1989). The disease process affects every major organ system, contributing to a broad range of symptoms. Clinicians need to be familiar with the signs, the symptoms, and the appropriate laboratory studies, so that timely and accurate diagnoses can be made. This article reviews normal thyroid physiology and thyroid pathophysiology, as well as the diagnosis and treatment of several important clinical entities resulting in hypothyroidism. Research findings are included insofar as they relate to current clinical practice.


Primary health care of elderly women.

Traditional health care of the expanding elderly population has focused on illness diagnosis and management. However, because more individuals, women especially, are living longer and living better, the emphasis should be shifted and modified to include primary health care for elderly people. Primary health care includes active health promotion and health maintenance, prevention of illness or disability, and attention to the quality as much as to the quantity of life. Unfortunately, the health concerns of elderly women, especially the oldest-old groups who live more or less independently, have been addressed inadequately in medical and nursing literature. Routine approaches to health care for women aged 70 and older must consider women's apparent hardiness, potential social isolation, and unique worries about safety and independence. Nurse practitioners in adult health, family practice, and gerontology must expand their repertoire of health promotion and health maintenance strategies to meet the needs of this special population. This article outlines the role of the nurse practitioner in the care of the well elderly woman.


Children's response to acute pain: a developmental approach.

Pain in children is a major concern of health care providers. To adequately relieve children's pain, nurses and other health care providers must be able to determine when children of all developmental stages are experiencing pain. The purpose of this article is to review what is known about children's response to acute pain.


AIDS and Austrian physicians.

Physicians have key roles both in treating disease and educating their patients about health and disease-related issues. To assess which factors correlate with Austrian physician's willingness to treat and educate patients about HIV-related risk behaviors and deal with AIDS issues, we conducted a survey of general practitioners, internists, and dermatologists in Graz, Austria. We report on some aspects of the knowledge, attitudes, and practices of these physicians. Factor analysis revealed two attitudinal components significantly associated with HIV-related practices of the respondents. We labeled these components Reluctance and Infection. "Reluctance" reflected discomfort with sex-related matters and was associated with less HIV counseling and less interest in HIV-related continuing medical education. "Infection" reflected a fear of contracting HIV disease and was positively associated with an increased assessment of different risk factors and a tendency to refer HIV-infected patients for all further treatment. Results suggest that physicians need further training in their ability to deal with HIV issues. Fortunately they seem willing to improve and take further training to do so. Patients, physicians, and the public would all benefit from acknowledging and dealing with the attitudes and needs of physicians toward HIV-related issues.


Effect of Magic Johnson's HIV status on HIV-related attitudes and behaviors of an STD clinic population.

This paper reports data on the effects that Earvin "Magic" Johnson's announced HIV infection had on the clients of an Philadelphia sexually-transmitted-disease (STD) clinic. Interviews conducted after Johnson's announcement (N = 148) included questions about whether respondents had heard his announcement and how this news had influenced their sexual attitudes and behaviors. The findings include comparisons of matched samples (N = 138) of respondents interviewed before and after the news. The comparisons focused on 3 areas related to the human immunodeficiency virus (HIV): 1) passive concern; 2) sense of personal risk; and 3) resolve to be tested for HIV in the next 6 months. A significantly greater percent (92%) of the postannouncement respondents reported planning HIV tests than did the preannouncement respondents (52%). Although the differences in perceived risk were not statistically significant, 25% of the preannouncement and 34% of the postannouncement respondents indicated high perceived risk for HIV. Forty-four percent of the postannouncement sample indicated that, as a result of the news, they were now using condoms; 32% reported no effect; and 54% reported a variety of behavior changes that included monogamy (21%), greater selectivity (10.6%), fewer sexual partners (9.2%), and abstinence (3.5%). Overall, the announcement by Magic Johnson that he had been infected with HIV was associated with increased concern about HIV and with attitude and behavior changes that would lead to reduced risk. This was especially true for those in the sample at relatively higher risk.


Battered women: understanding, identification, and assessment. A psychosociocultural perspective, Part 1.

The clinical implications of research with battered women and their families are discussed using the holistic framework of nursing and anthropology. Moving beyond superficial answers to "Why do battered women stay?," barriers to leaving that stem from the sociocultural roots of violence are examined. Understanding these obstacles and the characteristics of violent men is fundamental to sensitive interaction with abused women who frequently enter and leave health care systems with no direct attention given to their primary problem of abuse. Assessment techniques are suggested, and triage and comprehensive assessment protocols are presented to aid nurse practitioners and nurses in their response to this urgent public health problem.


Controlling the spread of varicella zoster in the hospitalized patient.

In the health care setting, knowledge of communicable diseases is critical in the prevention of transmission. Communicable diseases transmitted by the respiratory route pose several difficult problems for control. One such disease, frequently overlooked in adults, because it is considered a childhood disease, is varicella zoster (chickenpox). Recognition of the disease and knowledge about its epidemiology, control, treatment, and follow-up care are necessary for the health care provider to prevent the spread of disease.


The stigmatization of AIDS in infants and children in the United States.

Many studies examining AIDS issues have detailed the policy implications of negative attitudes toward homosexuals, intravenous (IV) drug users, and the inner-city poor; however, none have specifically examined whether existing biases and prejudicial fears expressed toward HIV-infected adults also affect political responses to infants and children with AIDS. In this research, a survey was conducted among lobbyists to determine whether such prejudicial attitudes exist in the national policymaking arena when pediatric AIDS issues are considered. The data supports the hypothesis that policymakers legislate based on a prevailing moral code when considering AIDS treatment and education policies for children. Conversely, the moral codes appear to be absent from legislative considerations of other children's issues.


The Division of Nursing and its relationship to nurse practitioner education.

Nurses provide a large part of health care in the United States. Increasingly, among rural and underserved populations, urban and rural NPs and NMWs are taking the place of physicians who choose to specialize and to practice in metropolitan areas. Nurse practitioners and NMWs are well qualified to provide primary care for those with acute and chronic medical conditions, and to provide maternity care to the 95% of women whose pregnancies are normal and do not require specialist care by obstetricians. Since 1965, the DN, through its grant programs, has contributed to increasing the accessibility of health care in this country by helping to increase the supply of nurses in all specialties and improving the quality of graduates and undergraduates in nursing education. In the past 25 years, NPs and NMWs have proven their capability and worth. Federal support has helped to make these invaluable contributions possible.


Child care providers and AIDS: a study of knowledge versus acceptance.

A survey of child care providers' knowledge of human immunodeficiency virus (HIV) transmission and attitudes toward recommended child care policies regarding AIDS was conducted in a Southeastern state. Significant knowledge differences regarding HIV transmission were found between certain comparison groups, although all groups agreed more than disagreed with current information about HIV transmission. In contrast, the child care providers were uniformly more cautious than accepting of recommended child care policies regarding AIDS. Suggestions for follow-up research and educational strategies to promote providers' acceptance of children with AIDS are discussed.


AIDS outreach workers: an exploratory study of job satisfactions/dissatisfactions.

AIDS outreach workers operate at the frontlines of the AIDS epidemic to provide information and education to high-risk individuals. Recent reports indicate that these workers have been effective in helping to reduce high-risk behaviors. However, a review of retention data for 62 outreach workers employed from 1986 to 1988 at a private nonprofit research institute indicated a high rate of turnover, especially among males. The literature provides little information regarding the demographic characteristics of outreach workers and their sources of job satisfaction and dissatisfaction. This exploratory investigation was undertaken to address these topics. Structured interviews were conducted with 20 currently active outreach workers. Results indicate that altruistic motives were most frequently cited as reasons why people became outreach workers and also provided the primary source of satisfaction. Stress was most frequently mentioned as a source of dissatisfaction and also as a reason previous workers had left outreach work. Conclusions focus on the outreach workers' suggestions for job improvements. These included: improvement in the terms of employment (e.g., salary, benefits); more education and training opportunities; and more support groups or help with recovery.


Reliability of AIDS knowledge scales: conceptual issues.

A common approach to evaluating the reliability of AIDS knowledge scales has relied on the demonstration of internal consistency through the use of Kuder-Richardson formula 20 (KR-20) or coefficient alpha. In this study, the argument was made that, in a knowledge-based scale with diverse content (exemplified by AIDS knowledge scales), internal consistency does not make sense conceptually and underestimates the scale's true reliability. It was therefore hypothesized that a split-half approach, in which items in each half were matched for content, would provide superior estimates of reliability when compared to either KR-20 or an odd-even split-half approach. Reliability analyses performed on a knowledge scale developed by the author supported this hypothesis.


The Ohio AIDS Prevention Survey: a study of psychometric properties.

The reliability of a measuring instrument is a major criterion for assessing its quality and adequacy. This article describes reliability pilot testing done with the Ohio AIDS Prevention Survey (Fellner & Thomas, 1989-90) in a sample of sexually active women of childbearing age. Previous alpha reliabilities of the knowledge scale of the survey have ranged from .71-.81, while the reliabilities of the attitudes and beliefs scale have ranged from .33-.45. In this sample, reliability measures for the knowledge and attitudes and beliefs scales were .65 and .45, respectively. The results of this study indicate that the Ohio AIDS Prevention Survey is clearly in its developmental stages and that further development of the survey is necessary prior to continued use in public health settings.


AIDS in sub-Saharan Africa: implications for health education.

This paper reviews the current epidemiologic status of AIDS in sub-Saharan Africa, focusing on what is currently understood about the distinctive features of heterosexual transmission in young men, women, and children. Epidemiologic data show that AIDS is transmitted primarily through heterosexual vaginal intercourse. Heterosexual transmission is highlighted both as the principal mode of spread of AIDS in east, central, and southern Africa and as the primary focus for AIDS education and control of the epidemic. The transmission of AIDS, like that of other sexually transmissible diseases, results from sexual behaviors that are rooted in social and cultural values that are not easily changed. The primary risk factors--including multiple sex partners, prostitution, and unprotected intercourse--are examined. The perceived obstacles to control of the epidemic include unfavorable government reactions to the epidemic, poor public knowledge, prevailing sexual attitudes, and reluctance to use condoms. These and other immediate and competing risk factors like unemployment and poverty combine to complicate the task of AIDS education.


A review of pressure reduction device studies.

When considering patient morbidity, mortality and costs, pressure sore formation is a major health care concern. An adjunct to the nursing care plan for prevention and treatment is the selection of a pressure reduction/relief device. This review of four pressure reduction device studies is intended to increase the vascular nurse's knowledge base concerning pressure reduction device efficacy. Each study is reviewed and graphed to identify like patterns within each study. Foam is judged to be least effective. Air cell and air mattress overlays are found to be intermediate devices and the low air loss beds appear to be the most effective. Few of the tested devices reduced pressure below 32mmHg at the heel site, leaving the heel at risk for breakdown.


Arteriovenous malformation of the hand: a case study.

Arteriovenous malformations (AVMs) are complex congenital vascular anomalies resulting from faulty embryonic development of arterial and venous structures. The present discussion will specifically address AVMs of the extremities. Complications of these lesions can include tissue damage, functional impairment and amputation. The article reviews current diagnostic procedures and treatment options. A case study is presented with a discussion of nursing care focusing on pain, anxiety, and alteration in peripheral tissue perfusion.


Temporal and extended temporal resections for the treatment of intractable seizures in early childhood.

In our series of 33 children who underwent temporal and extended temporal lobe resections because of seizures, the average age at surgery was 7 years, 11 months. Sixteen cases (48%) were diagnosed as having tumors: low-grade astrocytoma (6), hamartoma (5), and ganglioglioma/neuroma (5). Other pathologic diagnoses included one or more cytoarchitectural abnormalities and/or reactive changes. Due to a more aggressive and early radiologic and electrophysiologic investigation of children with seizures, a resectable focus, e.g. neoplasm or structural abnormality, was found in a much younger age group of patients than previously reported. In children who had intractable seizures but normal radiologic studies, positron emission tomography was of great value in localizing the seizure focus. In a group of children with infantile spasms, seizures were controlled following the identification and resection of a focal lesion. Prompt detection and precise localization of lesions in the temporal lobe in the pediatric population may lead to surgical management and seizure control.


Diagnosis and management of the Dandy-Walker malformation: 30 years of experience.

Thirty-seven patients with Dandy-Walker malformation were treated between 1959 and 1989. Eighty percent of patients became symptomatic by 3 years of age, with 70% presenting within the 1st year of life. Hydrocephalus was present in 91% of patients at the time of diagnosis. Clinical presentation was most often heralded by symptoms and signs of hydrocephalus with focal neurological findings being a less prominent feature. One third of children demonstrated developmental delay. Associated congenital anomalies were present in 48% of children. Contemporary neuroimaging including computed tomography and magnetic resonance imaging facilitated diagnosis obviating the need for invasive studies such as pneumoencephalography and ventriculography. Patients were initially managed by posterior fossa craniectomy with membrane excision (8), lateral ventricle shunt alone (13), shunting of the cyst alone (4), or combined shunting of the cyst and lateral ventricles (12). Combined shunting proved superior to the other methods, being successful in alleviating hydrocephalus and posterior fossa symptoms in 92% cases. The overall mortality was 24%, the majority occurring before 1970. Of the 28 survivors, 27 (96%) are shunt-dependent, with 19 having a combined shunt system in place. Therefore, we currently favor combined shunting of the cyst and lateral ventricles as the initial procedure for patients with Dandy-Walker malformation.


Is intracerebral schwannoma a developmental tumor of children and young adults? Case report and review.

A case of intracerebral schwannoma in an 11-year-old girl is presented. Of the small number of intracerebral schwannomas reported without association to a cranial nerve, the majority have occurred in children or young adults. Several possible etiologies for this tumor type are discussed. Based upon the distribution of ages at presentation and theories of the pathological origin of this tumor, the possibility that intracerebral schwannoma represents a developmental tumor is suggested.


Split-thickness bone grafts in complex craniofacial reconstructions.

We have operated on 20 patients with various forms of complex skull defects due either to trauma, tumor, or craniofacial problems. These cases have required complex reconstruction of defects involving the calvarium and anterior skull base. We review here our techniques of using locally harvested split-thickness calvarium bone grafts in the reconstruction of complex face and anterior fossa defects, secondary to tumor, trauma and craniofacial problems. With these harvesting techniques sufficient bone becomes available for large reconstructions, with minimum morbidity to the patient. The aesthetic results are excellent allowing for good facial and forehead contouring with minimal risk to the patient. In the case of traumatic injuries the surgery can also be performed early with the risk of infection being markedly reduced. Long-term results with split-thickness calvarial grafts have shown less bone resorption when compared with rib grafts.


Chronic tonsillar herniation and Crouzon's syndrome.

Patients born with craniofacial syndromes such as Crouzon's syndrome will often develop hydrocephalus after their initial craniofacial reconstructive procedures. We have treated 10 patients with Crouzon's syndrome; 5 patients required a shunting procedure after cranial remodeling. Each of these 5 shunted patients later demonstrated chronic tonsillar herniation on magnetic resonance imaging studies. One of these patients exhibited signs of pseudotumor cerebri and 1 had a spastic quadriparesis. Of the 5 patients who did not require a shunt, none displayed chronic tonsillar herniation. Our evidence suggests that jugular foramen stenosis produces an increased cerebral venous turgor that leads to a cerebrospinal fluid absorption defect and hydrocephalus. After the hydrocephalus is treated the increased venous turgor remains and provides the driving force for the development of chronic tonsillar herniation.


Short- and long-term complications of radiation therapy for pediatric brain tumors.

Brain tumors are the second most common malignancy of childhood after acute lymphocytic leukemia. Improvements in therapy have led to increased survival. It is estimated that by the year 2000 there will be approximately 200,000 survivors of childhood cancer. A proportion of these will have survived a central nervous system malignancy. As more children survive, complications of treatment are increasingly recognized. This paper reviews the spectrum of radiation-induced complications, both short- and long-term. Their frequency and characteristics will be reviewed as well as suggestions made to decrease their incidence.


The history of ventriculoscopy: where do we go from here?

With the availability of better endoscopes, improved lighting and increased instrumentation, the use of ventriculoscopy and ventriculostomy in the management of hydrocephalus is becoming increasingly more common. Neurosurgeons recognized the potential for endoscopic surgery early in this century, but were frustrated in many of their attempts at treatment due to the poor quality of the instruments available. Nevertheless, much progress has been made, and the stage was set for better results with modern instrument design. This paper reviews the history of endoscopes in neurosurgery and ponders the direction these instruments will take us in the near future.