Prediction of Response to Immune Checkpoint Blockade in Patients with Metastatic Colorectal Cancer with Microsatellite Instability

BACKGROUND

Mismatch repair deficient (dMMR) tumors displaying microsatellite instability (MSI) represent a paradigm for the success of immune checkpoint inhibitor (ICI)-based immunotherapy, particularly in patients with metastatic colorectal cancer (mCRC). However, a proportion of patients with dMMR/MSI mCRC exhibit resistance to ICI. Identification of tools predicting MSI mCRC patient response to ICI are required for the design of future strategies further improving this therapy.

PATIENTS AND METHODS

We combined high-throughput DNA and RNA sequencing of tumors from 116 patients with MSI mCRC treated with anti-PD-1 +/- anti-CTLA-4 of the NIPICOL phase II trial (C1, NCT03350126, discovery set) and the IMMUNOMSI prospective cohort (C2, validation set). The DNA/RNA predictors whose status was significantly associated with ICI status of response in C1 were subsequently validated in C2. Primary endpoint was iPFS (progression-free survival by iRECIST).

RESULTS

Analyses showed no impact of previously suggested DNA/RNA indicators of resistance to ICI, e.g., MSISensor score, tumor mutational burden, or specific cellular and molecular tumoral contingents. By contrast, iPFS under ICI was shown in C1 and C2 to depend both on a multiplex MSI signature involving the mutations of 19 microsatellites (HR_C2 = 3.63; 95% CI [1.65-7.99] ; p = 1.4x10^-3) and the expression of a set of 182 RNA markers with a non-epithelial TGFB-related desmoplastic orientation (HR_C2 = 1.75 ; 95% CI [1.03-2.98] ; p = 0.035). Both DNA and RNA signatures were independently predictive of iPFS.

CONCLUSIONS

iPFS in patients with MSI mCRC can be predicted by simply analyzing the mutational status of DNA microsatellite-containing genes in epithelial tumor cells together with nonepithelial TGFB-related desmoplastic RNA markers.

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

BACKGROUND

Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV-HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV-HCV co-infected cannabis users and to characterize persons who reduced their use.

METHODS

We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not.

RESULTS

Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one's dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction).

CONCLUSIONS

Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment.

Discordance between immunochemistry of mismatch repair proteins and molecular testing of microsatellite instability in colorectal cancer

Background

DNA mismatch repair system deficiency (dMMR) is found in 15% of colorectal cancers (CRCs). Two methods are used to determine dMMR, immunohistochemistry (IHC) of MMR proteins and molecular testing of microsatellite instability (MSI). Only studies with a low number of patients have reported rates of discordance between these two methods, ranging from 1% to 10%.

Materials and methods

Overall, 3228 consecutive patients with CRCs from two centers were included. Molecular testing was carried out using the Pentaplex panel and IHC evaluated four (MLH1, MSH2, MSH6, and PMS2; cohort 1; n = 1085) or two MMR proteins (MLH1 and MSH2; cohort 2; n = 2143). The primary endpoint was the rate of discordance between MSI and MMR IHC tests.

Results

Fifty-one discordant cases (1.6%) were initially observed. Twenty-nine out of 51 discordant cases were related to IHC misclassifications. In cohort 1, after re-reading IHC and/or carrying out new IHC, 16 discordant cases were reclassified as nondiscordant. In cohort 2, after the addition of MSH6/PMS2 IHC and re-examination, 13 were reclassified as nondiscordant. In addition, 10 misclassifications of molecular tests were identified. Finally, only 12 discordant cases (0.4%) remained: 5 were proficient MMR/MSI and 7 were dMMR/microsatellite stable.

Conclusions

Our study confirmed the high degree of concordance between MSI and MMR IHC tests. Discordant cases must be reviewed, and if needed, tests must be repeated and analyzed by an expert team.

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Concordance between MMR IHC (four proteins) and MSI molecular testing (Pentaplex) is superior to 98% in CRC cases

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Most discordant cases are related to misinterpretation of the tests, which may lead to clinical management errors.

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Discordant cases must be reviewed and tests must be repeated because most cases will be reclassified as nondiscordant.

Clinical and molecular characterisation of hereditary and sporadic metastatic colorectal cancers harbouring microsatellite instability/DNA mismatch repair deficiency

BACKGROUND

Patients treated with chemotherapy for microsatellite unstable (MSI) and/or mismatch repair deficient (dMMR) cancer metastatic colorectal cancer (mCRC) exhibit poor prognosis. We aimed to evaluate the relevance of distinguishing sporadic from Lynch syndrome (LS)-like mCRCs.

PATIENTS AND METHODS

MSI/dMMR mCRC patients were retrospectively identified in six French hospitals. Tumour samples were screened for MSI, dMMR, RAS/RAF mutations and MLH1 methylation. Sporadic cases were molecularly defined as those displaying MLH1/PMS2 loss of expression with BRAFV600E and/or MLH1 hypermethylation and no MMR germline mutation.

RESULTS

Among 129 MSI/dMMR mCRC patients, 81 (63%) were LS-like and 48 (37%) had sporadic tumours; 22% of MLH1/PMS2-negative mCRCs would have been misclassified using an algorithm based on local medical records (age, Amsterdam II criteria, BRAF and MMR statuses when locally tested), compared to a systematical assessment of MMR, BRAF and MLH1 methylation statuses. In univariate analysis, parameters associated with better overall survival were age (P < 0.0001), metastatic resection (P = 0.001) and LS-like mCRC (P = 0.01), but not BRAFV600E. In multivariate analysis, age (hazard ratio (HR) = 3.19, P = 0.01) and metastatic resection (HR = 4.2, P = 0.001) were associated with overall survival, but not LS. LS-like patients were associated with more frequent liver involvement, metastatic resection and better disease-free survival after metastasectomy (HR = 0.28, P = 0.01). Median progression-free survival of first-line chemotherapy was similar between the two groups (4.2 and 4.2 months; P = 0.44).

CONCLUSIONS

LS-like and sporadic MSI/dMMR mCRCs display distinct natural histories. MMR, BRAF mutation and MLH1 methylation testing should be mandatory to differentiate LS-like and sporadic MSI/dMMR mCRC, to determine in particular whether immune checkpoint inhibitors efficacy differs in these two populations.

Combined HER2 analysis of biopsies and surgical specimens to optimize detection of trastuzumab-eligible patients in eso-gastric adenocarcinoma: a GERCOR study

BACKGROUND

HER2 is overexpressed in 10 to 20% of gastro-esophageal adenocarcinoma (GE-ADK), and is a target for trastuzumab in metastatic patients. We conducted a study to compare HER2 expression between diagnostic biopsies (DBs) and surgical specimens (SSs) of GE-ADK, and to determine the influence of non-trastuzumab containing neoadjuvant chemotherapy (NAC) on this expression.

PATIENTS AND METHODS

Pathological specimens from biopsies of 228 patients operated on between 2004 and 2011 were collected. Two cohorts treated (n = 141) or not (n = 87) with a NAC were constituted. Two blind independent pathological HER2 analyses on DB and on SS were carried out using immunohistochemistry (IHC) and colorimetric in situ hybridization (CISH). HER-2 overexpression (HER2+) was defined by a score 3+ in IHC, or 2+ with a positive CISH test, according to the specific HER2 scoring guidelines for GE-ADK.

RESULTS

Paired HER2 status could be determined for 218 out of the 228 patients (95.6%). HER2+ rates were 13.3% on DB (29/218) and 14.7% on SS (32/218). HER2+ tumors were mainly cardial or esophageal adenocarcinomas, with a well-differentiated, intestinal histological type. HER2 status differed between DB and SS in 6% of cases. When DB analyses were added to SS analyses, the relative increase in HER2+ cases was 13.5% (17.1% for patients with NAC and 23.5% for patients with histological response to NAC, versus 7.1% for patients without NAC, P = 0.4, NS). Differences between DB and SS HER2 expression could be explained by intratumoral heterogeneity and by a HER2 expression decrease in SS after NAC in responding patients possibly due to a higher chemosensitivity of HER2-positive clones.

CONCLUSION

The determination of HER2 status on DB provides results that complete those obtained with SS. Combining the analysis of DB and of SS enables to optimize the selection of trastuzumab-eligible patients in case of metastatic relapse, and particularly in previously NAC-responding patients.

[Pathology: on the way to molecular analysis]

For a long time, pathology has been playing an important role in digestive diseases, especially in digestive cancers. This contribution was based and is still based on classical morphological techniques: staining of cells and tissues and recognition of diagnostic morphological patterns characteristic for a disease. Pathology is changing, and accompanies major improvements in endoscopy and imaging of gastrointestinal diseases, and new high throughput biological techniques. Recent examples show that molecular pathology (including immunohistochemistry), often included in wider "biopathology" processes, participates to pathophysiological research (for example recognition of the serrated pathway in colorectal carcinogenesis and its relation with microsatellite instability and methylation of promoters), and to diagnostic and therapeutic procedures (for example targeted therapies of gastrointestinal stromal tumours). However, the current example of the recognition of predictive factors of response to anti-EGFR treatments in colorectal cancer shows that morphological and non morphological techniques have to find their respective role in this kind of process.

Comparison of somatostatin receptor expression in human gliomas and medulloblastomas

The expression of the five somatostatin receptor subtypes, sst1-5 was compared on tissue containing glial tumours (glioblastomas or oligodendrogliomas), medulloblastomas, and on normal human cortex. By semiquantitative reverse transcription coupled to polymerase chain reaction, the receptor expression profiles were high in cortex and in tissue containing oligodendrogliomas. It was moderate in medulloblastomas. Tissue containing glioblastomas displayed lower expression of somatostatin receptor subtypes, sst1 and sst3 being mostly expressed. By 125I-Tyr0DTrp8 somatostatin-14 or 125I-Leu8DTrp22 Tyr25 somatostatin-28 autoradiography combined with synaptophysin immunohistochemistry, it was possible to differentiate between isolated tumoral cell component infiltrating the cerebral parenchyma (cortex or white matter) and tumoral tissue (without residual parenchyma) in glioblastomas or oligodendrogliomas. Glial tumoral tissue per se presented few somatostatin receptors. By contrast, medulloblastoma tumoral cells exhibited numerous octreotide sensitive somatostatin receptors. sst2 immunocytochemistry demonstrated immunostaining of neuronal cells and neuropile; sst2 and sst3 immunostaining was identified on glioblastoma proliferating vessels endothelial cells and on medulloblastomas tumoral cells. Faint sst2 immunostaining among glial tumoral cells was due to microglia, while glioma cells did not significantly stain. In summary, medulloblastoma tumoral cells express sst2/sst3 receptors at a high level while glioma cells do not. In gliomas, sst expression is restricted to endothelial cells on proliferating vessels (displaying both sst2 and sst3 receptors), including parenchyma and reactive microglia (only sst2). The differential expression of sst2/sst3 receptors on gliomas and medulloblastomas has implications for the therapy of these tumours.

Assessment of dietary adequacy for an elderly population based on a Mediterranean model

This study analysed whether at different energy levels, a varied diet based on Mediterranean Diet patterns would meet the RDIs for specific nutrients in a population > 65 y. Based on RDIs for elderly persons > 65 y for PRO, FAT CHO, phosphorus, calcium, magnesium, iron, zinc, vitamin C, B6, folate and fibre, menu models based on Mediterranean diet food patterns were calculated for the following calorie levels: 1400, 1500, 1600, 1700 and 1800 kcals. 15 menu variations for each calorie level were then created based on the previously calculated models. Utilising the Program for Alimentation and Nutrition (PAN) database, nutritional analysis was carried out for all menus and the mean nutrient values for a 2 week period were calculated for each calorie level. Intakes at all calorie levels provided adequate amounts of folate, phosphorus, iron and Vitamin B6. Intakes were low in all groups for Calcium, Zinc, Magnesium and Vitamin E, with the exception of the 1800 kcal level for Vitamin E. Results show that at low energy levels, meeting nutrient needs was difficult and that even at higher calorie intakes, contrary to what was expected, certain nutrients were found to be inadequate.

Dietary guidelines for the breast-feeding woman

Sociodemographic and economic changes in Spain have played a role in the choice of infant feeding as more and more women enter the workforce. Nevertheless, the prevalence of breast-fed-only infants at 6 weeks remains fairly high, at 65.5% in 1999, although there is a sharp decline by 3 and 6 months postpartum. Achieving adequate nutritional status for lactation principally begins during pregnancy, as this constitutes the biological stage for accumulating nutrient stores. The benefits of breast-feeding for the mother and infant are presented, along with nutrition and dietary guidelines for the nursing woman. Apart from dietary considerations, special attention should be paid to encouraging a positive attitude and environment for breast-feeding success.

[Obstetric trauma. A current problem?]

Advances in obstetric practice have decreased birth traumas in the last years, although they are still an important chapter in neonatal age. Between 1993-1998 a total of 21,375 stillborns were registered with a total of 309 birth injuries in 303 neonates (1.44%). The diagnoses were: 2 liver subcapsular hematomas, 105 cephalohematomas, 16 parietal fractures, 11 subdural hemorrhages, 107 clavicular fractures, 10 miscellaneous fractures, 8 soft tissue injuries, 25 facial nerve injuries and 25 braquial palsy. About relation between type of labor and birth trauma was found that clavicular fracture and cephalic vaginal delivery were associated in 50% of the cases, cephalohematoma and forceps in 51%, braquial palsy and vaginal delivery in 44% and forceps in 36%. High weight at birth was another risk factor for entities such as clavicular fracture and braquial palsy. We conclude that birth trauma is a pathology with a relevant incidence and their epidemiology factor had to be known.

Characterization and distribution of Hxt1, a Na(+)/Cl(-)-dependent orphan transporter, in the human brain

Rxt1, a transporter-like protein structurally related to the large family of Na(+)/Cl(-)-dependent carriers, was isolated from the rat brain. In the present study, Hxt1, the homologue of Rxt1, was isolated from human cortex cDNA. Comparison of their respective nucleotidic sequences revealed a 96% conservation between Hxt1 and Rxt1. Genetic mapping with human genome radiation hybrids allowed the location of the gene coding for Hxt1 between 323ya5 and 084xb3 AFM markers, on a portion of chromosome 1p which spans over 7 cM or 118 cRay. Northern blot analyses demonstrated that Hxt1 mRNA ( approximately 7.5 Kb) is expressed in the human brain but not in peripheral tissues. The immunodistribution of Hxt1 was determined with antibodies raised against the C-terminus of Rxt1. Hxt1 is concentrated in the cerebral cortex, caudate-putamen, substantia nigra, hippocampus, and cerebellum, appearing as a diffuse or a punctate labeling at the light microscope level. This regional and cellular distribution suggests that Hxt1, as its rat homologue, could be present in axon terminals of glutamatergic neurons. The high pressure of selection exerted upon this protein, its strategic anatomical and subcellular distributions suggest that this orphan transporter could be involved in critical functions in the central nervous system.

Edg-2 in myelin-forming cells: isoforms, genomic mapping, and exclusion in Charcot-Marie-Tooth disease

Edg-2 is an heptahelical receptor whose spatio-temporal distribution during rat brain development is consistent with a role in the control of myelination. We have now identified two splice variants of Edg-2 mRNA in rat brain that encode two receptor isoforms differing by a stretch of 18 amino acids in the NH2-terminal extracellular tail of the receptor. Prenatally (i.e., before oligodendrocyte myelination), the two variants detected by selective in situ hybridization are equally abundant, vary in parallel, and remain restricted to proliferative zones in the brain. Postnatally, the long isoform becomes predominant in myelinating structures, where its abundance increases sharply during the period of myelination. In the adult human brain, only the long variant was detected, while in situ hybridization showed it selectively expressed in the white matter and in clusters of cells showing features of oligodendrocytes of the temporal cerebral cortex. Consequently, the human Edg-2 gene was studied to assess its possible contribution in inherited neuropathies. The coding sequence was found to be contained in three exons and to map to chromosome 9q31.3-32 by using radiation hybrid panel and Yeast-Artificial Chromosomes. Two intragenic bi-allelic polymorphisms and a rare mutation were identified. As a first application to molecular genetic studies, they were used to exclude the Edg-2 gene in six families with phenotype of demyelinating Charcot-Marie-Tooth disease of unknown origin.

Oligodendrogliomas. Part I: Patterns of growth, histological diagnosis, clinical and imaging correlations: a study of 153 cases

The present study has attempted to demonstrate that the morphological spectrum of oligodendrogliomas includes tumors which are traditionally misinterpreted as 'diffuse fibrillary astrocytoma'. We have shown that these tumors are in fact made of isolated neoplastic oligodendrocytes which are entrapped in a fibrillary background composed of axons and fibrillary reactive gliosis. Analysis in a series of 153 'pure' supratentorial oligodendrogliomas composed of 'classical' or pseudo 'diffuse fibrillary oligodendrogliomas' diagnosed by imaging-based serial stereotactic biopsies showed that 2/3 of the tumors were exclusively made of isolated tumor cells (ITCs) (structure type III) and that only 1/3 of them exhibited both ITCs and solid tumor tissue components (structure type II). The tumor tissue destroys the brain parenchyma and contains new formed microblood vessels whereas ITCs do not destroy the parenchyma and are not associated with microangiogenesis. These fundamentally opposite morphological characteristics were reflected by the following findings: 1) contrast enhancement was observed in 64% of structure type II but was never seen in structure type III oligodendrogliomas. 2) a neurological deficit occurred in 57% of structure type II but in only 8% of structure type III oligodendrogliomas. 3) using the new grading system described in the companion paper to this study, we found that the biological behavior of oligodendrogliomas was also closely related to the patterns of tumor growth. From a synthesis of data gathered in this study it is suggested that emergence of microangiogenesis within a tumor which at first grows slowly with a structure type III pattern is a crucial event toward more aggressive behavior.

Oligodendrogliomas. Part II: A new grading system based on morphological and imaging criteria

This second part of our study of 'pure' oligodendrogliomas focuses on survival data analysis. In order to identify potentially useful prognostic factors and to assess the effectiveness of a new grading system, the 79 patients in the previously analyzed series for whom adequate follow-up could be obtained (52%) were entered in the present analysis. Statistical analysis demonstrated that contrast enhancement and endothelial hyperplasia had powerful and similar influence on survival. Median survival with and without contrast enhancement were: 3 versus 11 years, and with or without endothelial hyperplasia were: 3.5 versus 11 years. Conversely, the degree of nuclear atypia and presence or absence of mitosis or necrosis were not correlated with survival. These findings allowed us to devise a simple grading system which discriminates two malignancy grades as follows: absence of endothelial hyperplasia and of contrast enhancement = Grade A, presence of endothelial hyperplasia and/or of contrast enhancement = Grade B. Of the 79 oligodendrogliomas in this study, 59 tumors were categorized as grade A and 20 as grade B. Median survival were: 11 years in grade A and 3.5 years in grade B. Five-year and 8-year survival rates were: 89% and 60% in grade A and: 33% and 15% in grade B. Double blind grading between two independent observers was concordant in 96% of the cases. Application of this simple efficient and reproducible grading scheme should permit reliable comparison of retrospective or prospective therapeutic data emanating from various institutions.

[Low-grade papillary adenocarcinoma of the endolymphatic sac. Report of three cases with immunohistochemical study]

Glandular tumors involving the mastoid and the middle ear are rare, and distinguishing between adenoma and adenocarcinoma remains difficult. Among these latter lesions, two distinct patterns are accepted. One of them, the papillary form takes a more aggressive course with wider regional spread and must be separated from the other type, the middle ear carcinoma. Its microscopic appearance and clinical course have been extensively described by Heffner who considered it as "low-grade adenocarcinoma of probable endolymphatic sac origin". A few cases have been associated with von Hippel-Lindau disease. Three cases of papillary adenocarcinoma of endolymphatic sac origin are reported. One concerned an isolated tumor, the two others were associated with von Hippel-Lindau disease. Their clinical, pathological and immunohistochemical data are presented.

Mechanisms of lysis by activated cytotoxic cells expressing perforin and granzyme-B genes and the protein TIA-1 in muscle biopsies of myositis

OBJECTIVE

Polymyositis (PM) and cermatomyositis (DM) are inflammatory muscle diseases of autoimmune origin. A chronic mononuclear cell infiltrate is always present around PM and DM muscle damage. In PM, the predominant cells are activated cytotoxic cells, natural killer, and CD8+ T lymphocytes. Cytotoxic cells can kill the target cells via 2 mechanisms. Both pathways induce target cell death by releasing the molecules (granule exocytosis) perforin (PF), which attacks the target cell membrane and causes cell death by necrosis, and TIA-1 protein and granzyme-B (GZB), possibly responsible for apoptosis. We studied the mechanisms of lysis in muscle biopsies of myositis.

METHODS

We used a panel of monoclonal antibodies to determine the phenotypes of reactive lymphocyte subsets, in situ hybridization to study the expression of PF and GZB genes, and immunohistochemistry to evaluate TIA-1 protein production in muscle biopsies from 14 patients with myositis (11 PM/3 DM). Results were compared to those obtained from muscle biopsies of 12 control patients with muscle weakness, including patients with muscle dystrophy and vasculitis, but without myositis.

RESULTS

Abundant CD8+ cells, especially in endomysial sites in PM, formed the predominant phenotype. The predominant mononuclear cells observed in DM were CD4+ T cells and CD22+ B lymphocytes, in perivascular sites. The GZB and PF genes and the TIA-1 protein were expressed simultaneously in muscle samples from patients with myositis. GZB, PF, and TIA-1 positive cells were predominantly located in endomysial sites of PM, in the nonnecrotic muscle fibers. In DM, these positive cells were rare.

CONCLUSION

In myositis, especially PM, cytotoxic cells may cause muscle damage and muscle cell necrosis and/or apoptosis by releasing several proteins (PF, GZB, and TIA-1 proteins) responsible for the lysis of these stimulating target cells. Some drugs (prednisone and cyclosporine) inhibit the release of GZB and PF. Their efficacy may be due in part to this inhibitory effect.

Short- and long-term effects of calcitonin and calcium administration on blood calcium, magnesium and inorganic phosphorus in post menopausal osteoporosis

This paper studies the effects of the administration of calcitonin (CT) and Ca on post menopausal osteoporosis, immediately (short-term) and after three months (long-term) of treatment, on total and ionic calcium (Ca), magnesium (Mg), inorganic phosphorus (Pi), calcitonin (CT) and parathyroid hormone (PTH) in plasma. The short-term results show a decrease in total and ionic Ca and Pi four hours after the beginning of the treatment; at seven hours, only Pi varies. A decrease in the total and ionic Ca was observed after three months of CT treatment (long-term effects). No hormonal (PTH and CT) variations were found either in the short or the long-term. However, the PTH/CT ratio decreased significantly during the experiment and this may be an important factor in explaining the long-term Ca variations.

Role of pontine nuclei damage in smooth pursuit impairment of progressive supranuclear palsy: a clinical-pathologic study

We performed a quantitative study of the pontine nuclei in the basis pontis and a semiquantitative study of extrapontine structures involved in smooth pursuit in four patients with severe impairment of horizontal smooth pursuit and histopathologically confirmed diagnosis of progressive supranuclear palsy (PSP). There were only slight changes in the extrapontine structures involved in smooth pursuit, but there was a significant neuronal loss--massive in three patients and mild in one patient--in all nuclei of the basis pontis. Our results suggest that degenerative lesions affecting the pontine nuclei are largely responsible for the horizontal smooth pursuit impairment in PSP.

Cerebral palsy in twins

Eighty-six children with cerebral palsy (CP) born as a product of twin pregnancies were studied. Data regarding their co-twins were also gathered. The authors' findings suggest that (1) monozygotic twins have a higher risk of CP than dizygotic twins, (2) twin order at birth does not seem to be a relevant factor in the etiology of CP, (3) mothers less than 24 or more than 34 years of age had the highest incidence of children with CP as a product of a twin pregnancy, and (4) the data do not support a genetic basis for the disease.

Alzheimer's disease: is the decrease of the cholinergic innervation of the hippocampus related to intrinsic hippocampal pathology?

Consistent findings in the hippocampi of patients with Alzheimer's disease are the presence of neurofibrillary tangles in pyramidal neurons and the loss of choline acetyltransferase activity due to degeneration of hippocampal cholinergic terminals. The present study sought to clarify, in the brains of five patients with Alzheimer's disease and four controls, whether the loss of cholinergic terminals in the hippocampal stratum pyramidale in Alzheimer's disease is related to degenerative changes in hippocampal pyramidal cells. A polyclonal antibody to human choline acetyltransferase was employed to visualize immunohistochemically cholinergic terminals. Hippocampal neurons were stained with Cresyl Violet, neurofibrillary tangles with thioflavin S and a monoclonal antibody against phosphorylated neurofilament (RT97). Quantification of the stained structures was performed in CA4, CA1 and the subiculum, on five sections selected from the entire anteroposterior extent of each hippocampus. In the group of Alzheimer patients, the densities of cholinergic terminals were homogeneously diminished in the three hippocampal subregions in comparison with the controls (32-33%). In contrast, a significant loss of pyramidal neurons was found only in CA1, and the density of neurofibrillary tangles was markedly increased only in CA1 and the subiculum in Alzheimer's disease. These findings suggest that there is no relationship between the loss of cholinergic terminals and the degeneration of pyramidal cells in the hippocampus of patients with Alzheimer's disease.

Progressive supranuclear palsy: loss of choline-acetyltransferase-like immunoreactive neurons in the pontine reticular formation

We performed a quantitative immunocytochemical study using a polyclonal antibody directed against choline acetyltransferase (ChAT) in the lower pontine reticular formation in four control subjects and three patients with progressive supranuclear palsy (PSP). In the normal brains, there was detectable ChAT-like immunoreactivity in the nucleus papillioformis, a precerebellar reticular nucleus, and in the nucleus pontis centralis caudalis. In PSP patients, the mean estimated total number of ChAT-like immunoreactive cells was 54% of controls in nucleus papillioformis and 40% of controls in nucleus pontis centralis caudalis. The demonstration of ChAT-like immunoreactivity in nucleus papillioformis is consistent with studies suggesting an extrinsic cholinergic innervation of the cerebellar cortex. Loss of cholinergic cells in nucleus pontis centralis caudalis that corresponds largely to the paramedian pontine reticular formation may be related to disturbances of horizontal saccades in PSP patients.

Differential vulnerability of cholinergic projections to the mediodorsal nucleus of the thalamus in senile dementia of Alzheimer type and progressive supranuclear palsy

The cholinergic innervation of the mediodorsal nucleus of the thalamus, which is thought to originate primarily in the laterodorsal tegmental nucleus and the substantia innominata, was studied by acetylcholinesterase histochemistry and immunohistochemistry with a polyclonal antiserum against human choline acetyltransferase on autopsy tissue from eight control subjects, five patients with progressive supranuclear palsy and four patients with senile dementia of Alzheimer type. In controls, cholinergic innervation of the mediodorsal nucleus of the thalamus was distributed heterogeneously in densely labelled patches surrounded by less heavily stained matrix. In patients with progressive supranuclear palsy, the density of choline acetyltransferase-positive varicosities decreased by 75% in the matrix and 60% in the patches. The number of choline acetyltransferase-positive cell bodies decreased by 84% in the laterodorsal tegmental nucleus, but more moderately (-33%) in the substantia innominata. In patients with senile dementia of Alzheimer type, choline acetyltransferase-positive varicosities decreased by 34% in the matrix, but 46% in the patches. Choline acetyltransferase-labelled cell bodies were spared in the laterodorsal tegmental nucleus, whereas severe loss (-80%) was observed in the substantia innominata. These results suggest that cholinergic innervation of mediodorsal nucleus matrix derives mainly from the laterodorsal tegmental nucleus and mediodorsal nucleus patches from the substantia innominata. Differential loss of innervation to the matrix and patches in progressive supranuclear palsy and senile dementia of Alzheimer type may in turn differentially affect mediodorsal nucleus innervation of the frontal cortex, resulting in dissimilar symptomatologies.

Constant neurofibrillary changes in the neocortex in progressive supranuclear palsy. Basic differences with Alzheimer's disease and aging

Neocortical neurofibrillary tangles (NFT) revealed by Bodian technique and anti-tau immunolabelling were seen in 5/5 cases of progressive supranuclear palsy (PSP) aged 58-76 years. These lesions differed from Alzheimer's disease or age-related changes: (1) they were most frequent in the precentral gyrus (Brodmann's area 4) whereas associative areas are predominantly lesioned in Alzheimer's disease; (2) they affected mainly large pyramidal neurons and small cells, relatively sparing the cell population selectively involved in Alzheimer's disease; (3) they predominated in layers V and VI of area 4, whereas NFT are most dense in layers III and V in Alzheimer's disease; (4) mature senile plaques (1/5 cases) and beta-amyloid diffuse deposits (3/5 cases), which usually precede or go together with NFT in Alzheimer's disease were rare or absent (2/5) in PSP. Neuropil threads and tufts of abnormal fibres were also seen. In addition, NFT and neuropil threads were found in the hippocampus. PSP is thus another example of abnormal storage of tau developing in the neocortex in the absence of beta-amyloid deposits. It might prove a useful model for the understanding of the mechanisms of localization and spreading of tau storage in the brain.

Catecholaminergic systems in the medulla oblongata in parkinsonian syndromes: a quantitative immunohistochemical study in Parkinson's disease, progressive supranuclear palsy, and striatonigral degeneration

We investigated tyrosine-hydroxylase (TH)-immunoreactive neurons in the medulla oblongata corresponding to the A1 and A2 cell groups in autopsy tissue of patients with Parkinson's disease (PD) (n = 3), progressive supranuclear palsy (PSP) (n = 3), striatonigral degeneration (SND) (n = 2), and in controls (n = 4). The estimated total number of TH-positive neurons in the A1 and the A2 regions was normal in PD and PSP patients. The sparing of medullary catecholaminergic cells in PD and PSP may be related to their minor degree of melanization and the possibility that intermediate compounds associated with the oxidative catabolism of norepinephrine and epinephrine may be less cytotoxic than those generated by degradation of dopamine. Patients with SND showed a marked loss of TH-immunoreactive cells in the A1 and the A2 groups, which may contribute to the impairment of vasomotor control characteristic of the disease.

Piroxicam-induced photosensitivity and contact sensitivity to thiosalicylic acid

A photocontact dermatitis developed in three patients after the application of gel containing 0.5% piroxicam. Patch tests were positive to thiomersal and thiosalicylic acid. Photopatch tests with piroxicam at several concentrations were positive in the three patients but negative in 62 normal volunteer subjects. Patch tests performed on 14 patients with proved systemic photosensitivity to piroxicam were positive for thiomersal and thiosalicylic acid. Nine of 12 patients previously sensitized to thiosalicylic acid and with no history of exposure to piroxicam showed positive photopatch test reactions to this chemical. These results support a relation between piroxicam-induced photosensitivity and contact sensitivity to thiosalicylic acid. Contact allergic sensitivity to the latter is a marker for patients with a high risk of developing photosensitivity reactions to piroxicam. These reactions may be due to photoproducts of the drug rather than metabolites.

Tyrosine hydroxylase-like immunoreactivity in senile plaques is not related to the density of tyrosine hydroxylase-positive fibers in patients with Alzheimer's disease

The numbers of silver-stained senile plaques and plaques containing tyrosine hydroxylase (TH)-like immunoreactivity were counted in the neocortex, amygdala and hippocampus of control subjects and patients with Alzheimer's disease, and compared with the density of TH-positive nerve fibers. The number of silver-stained senile plaques was lowest in the hippocampus and highest in the amygdala, and increased in all three structures in relation to the degree of dementia in the patients. A small proportion of plaques in the hippocampus of the most demented subjects and a large proportion of plaques in the amygdala were TH-positive. No TH-like immunoreactivity was found in plaques in the neocortex, although this structure contained almost as many silver-stained senile plaques and was as densely innervated by TH-positive fibers as the amygdala. The number of plaques containing TH-like immunoreactivity was, therefore, not proportional to the innervation of the structures by TH-positive fibers, nor to the total number of plaques in the structure, suggesting that the dissociation between the proportion of TH-positive plaques in the amygdala and neocortex may be due to differences in the populations of TH-positive fibers innervating the structures.

Selective loss of cholinergic neurons in the ventral striatum of patients with Alzheimer disease

Cholinergic neurons were studied by immunohistochemistry with an antiserum against human choline acetyltransferase in the caudate nucleus, putamen, and ventral striatum (including the nucleus accumbens) of three patients with Alzheimer disease and three control subjects. Immunoreactive cell bodies were mapped and counted. In the ventral striatum of patients with Alzheimer disease, a 60% decrease in the number of cholinergic neurons was observed, whereas in the caudate nucleus and putamen values for control subjects and patients were similar. To determine whether all neurons in the ventral striatum were affected, neuropeptide Y-containing neurons were also immunostained, mapped, and counted. The number of these neurons was the same in control subjects and patients with Alzheimer disease, indicating that neuronal loss is not generalized in the ventral striatum and may be specific to the cholinergic population.

[A parametric description of the parenteral nutrition protocols of 19 American hospitals]

In the preparation of a centralized parenteral nutrition unit project in our hospital, following the creation of a multi-disciplinary commission entrusted with the study of this project, we proceeded to evaluate parenteral nutrition protocols of national and foreign hospitals, as a first approach to the subject. This study evaluates and extracts the data we consider most relevant in a sample of 19 American hospitals. With regard to the types of parenteral diet, we observed that most of them (63%) had "standard diets", mainly formulated with 25% glucose and 4.25% crystalline amino acids. None of the protocols studied contained alternatives to glucose as a calorie-contributor, nor were there special formulae for amino acids, although many of them included it in their therapies for use if considered necessary. In all protocols, the contribution of fats was reduced to concrete situations and administered in a different way to the rest of the food in 73% of cases. With regard to additives, despite the existence of standard formulations of electrolytes and vitamins and oligoelements, in 100% of the hospitals studied, there was the possibility of formulating each element separately. Administration was done in several doses per day in 42% of cases and in 100%, using perfusion pumps. The data obtained from this review was of great value in preparing our own parenteral nutrition protocols.

Distribution of monoaminergic, cholinergic, and GABAergic markers in the human cerebral cortex

Mapping of a number of biochemical markers for noradrenergic, dopaminergic, serotoninergic, cholinergic and GABAergic systems was undertaken in 93 samples removed from the human cerebral cortex. The right hemisphere of brains from two subjects with no known history of neurological and psychiatric diseases was examined. Neurotransmitter markers were present in all cortical samples analysed, suggesting a widespread distribution of the corresponding neurons throughout the cerebral cortex. Each marker distributed heterogeneously in a distinct pattern. Noradrenaline concentrations were highest in the frontoparietal region and lowest in prefrontal and occipital areas. Markers for dopaminergic neurons (dopamine levels, dopamine/noradrenaline ratio and homovanillic acid levels) seemed denser in the prefrontal and temporal regions. 5-Hydroxyindolacetic acid levels were particularly high in the occipital area and decreased along the caudorostral axis. Choline acetyltransferase activity was highest in temporal and frontal lobes, at variance with muscarinic receptor distribution, which was highest in occipital cortex. Glutamate decarboxylase activity, an index of GABAergic innervation, did not vary markedly among the different areas of the cerebral cortex. The different biochemical markers investigated were detected in all cerebral cortical regions; their distribution was not homogeneous. A mismatch was observed between the distribution of cholinergic neuronal systems and receptors.

Choline acetyltransferase-like immunoreactivity in the hippocampal formation of control subjects and patients with Alzheimer's disease

A qualitative and quantitative immunohistochemical study of cholinergic systems in the human hippocampal formation was performed with an antibody against choline acetyltransferase. Four control subjects and six patients with Alzheimer's disease, matched for age and post-mortem delay, were examined. Immunoreactive nerve fibres and terminals were visualized, but no cholinergic cell bodies were seen. The distribution of the fibres and terminals suggests that a major afferent cholinergic pathway enters the hippocampus dorsally via the fimbria-fornix, a minor input entering from the temporal lobe along the alvear path. The cholinergic innervation suffers some degenerative change in normal aged subjects, but decreases considerably in density in patients with Alzheimer's disease. The extent of the decrease differs somewhat among the subregions of the hippocampus, but is homogeneously distributed within each subregion, and throughout the rostrocaudal extent of the structure. Compensatory sprouting in reaction to denervation was not detected.