Enhanced intracortical inhibition in cerebellar patients

OBJECTIVE: The aim of the study was to examine intracortical excitability in cerebellar patients. METHODS: Short-latency intracortical inhibition (SICI), long-latency intracortical inhibition (LICI) and intracortical facilitation (ICF) to paired transcranial magnetic stimulation (TMS) were investigated in 8 patients with 'pure' cerebellar syndromes and in 14 age-matched normal controls. The conditioning stimulus for short-latency intracortical inhibition and intracortical facilitation was set at 70% of the resting motor threshold (RMT) and preceded the test stimulus (110-120% of the resting motor threshold) by interstimulus intervals (ISIs) of 1-30 ms. For the long-latency intracortical inhibition determinations, the conditioning stimulus was set at 120% of the resting motor threshold and preceded the test stimulus (also 120% of the resting motor threshold) by interstimulus intervals of 30-500 ms. RESULTS: No statistically significant differences were found between patients and controls as regards either short-latency intracortical inhibition or intracortical facilitation. A significant prevalence of long-latency intracortical inhibition was present in cerebellar patients at interstimulus intervals of 200-500 ms (conditioned MEP amplitude=29-41% of test MEP) as compared to controls (71-96% of test MEP). The amplitude of conditioned MEPs was persistently less than 45% of the test MEP in six patients, who were studied at interstimulus intervals up to 1000 ms. CONCLUSIONS: Long-latency intracortical inhibition was prevalent and abnormally longer-lasting in patients. Tonic hyperactivation of a subpopulation of GABAergic interneurons in the motor cortex of patients may be the mechanism responsible for this abnormality. Our findings seem to be specific to cerebellar diseases and are the opposite of those found in movement disorders such as dystonia and Parkinson's disease. These data suggest that the cerebellum and the basal ganglia may have opposite influences in tuning the excitability of the motor cortex.     

Serum Fructosamine and Colorectal Adenomas

The relationship of glucose in the blood with colorectal adenoma or cancer is not clear. Fructosamine, equivalent to total serum glycated proteins, is a marker of blood glucose levels in the previous 3 weeks. We evaluated in a case-control study the association between fructosamine and colorectal adenoma, a precursor of colorectal cancer. Cases were subjects with the first occurrence of one or more histologically confirmed colorectal adenomatous polyps removed after a complete colonoscopy (153 cases), and controls were subjects with normal colonoscopy performed in the same endoscopy units during the same period (84 controls). Serum fructosamine was measured by a colorimetric method. Unconditional multiple logistic regression was used for statistical analysis. We found that in non-diabetic subjects the risk of colorectal adenoma increased with the level of fructosamine, and the odds ratio of colorectal adenoma in subjects with fructosamine levels higher than the median (270 microg/100 ml), in comparison with subjects with fructosamine lower than the median, was 2.3 (95% CI: 1.1-4.8). The risk of colorectal adenoma increased also with increasing levels of serum triglycerides and cholesterol, and decreased with increasing levels of fasting serum insulin. The results of this study show that the risk of colorectal adenoma increases with the level of fructosamine, an indicator of the level of glucose in the blood more sensitive to foods with a high glycemic index.     

Marfan syndrome: orthopedic and genetic review

Marfan syndrome is an autosomal dominant disorder of connective tissue that affects the cardiac, eye, and skeletal systems. More than 135 mutations have been identified in the fibrillin-1 gene, localized on chromosome 15q21.1 [corrected] and responsible for the clinical manifestations of Marfan syndrome. The major orthopedic manifestations of Marfan syndrome include scoliosis, chest wall deformity, dural ectasia, joint hypermobility, and acetabular protrusion. In addition, decreased bone mineral density has been reported in patients with Marfan syndrome. This review summarizes recent developments in the genetic and orthopedic aspects of Marfan syndrome. Increased practitioner awareness of the clinical features associated with Marfan syndrome may facilitate earlier diagnosis and optimize patient treatment.     

Photosensitization of DNA strand breaks by three phenothiazine derivatives

The interaction and the photosensitizing activity of three phenothiazine derivatives, fluphenazine hydrochloride (FP), thioridazine hydrochloride (TR), and perphenazine (PP), toward DNA were studied. Evidences obtained from various spectroscopic studies such as fluorimetric and linear dichroism measurements indicate that these derivatives bind to the DNA at least in two ways: intercalation and external stacking on the DNA helix, depending on their relative concentrations. Irradiation of supercoiled plasmid DNA in the presence of these phenothiazines leads to single strand breaks. The DNA photocleavage appears to be due to externally bound molecules rather than to those intercalated. The highest photocleavage activity was observed with PP and TR whereas FP was less efficient. The efficiency of the photocleavage in aerated and deaerated solutions does not change thus indicating that an involvement of singlet oxygen can be excluded. Primer extension analysis of plasmid DNA irradiated in the presence of phenothiazines indicates that photocleavage of DNA occurs predominantly at Gua and Cyt residues. Laser flash experiments carried out in the presence of 2'-deoxyguanosine 5'-monophosphate reveal an efficient electron transfer between the nucleotide and the radical cations produced by photoionization of the phenothiazines. In the presence of DNA, an electron transfer process takes place within the laser pulse from the lowest singlet state of phenothiazines to the DNA bases; the time-resolved measurements showed that the back-electron transfer is a negligible decay pathway for the charged species.     

The combination of gemcitabine and vinorelbine is an active regimen as second-line therapy in patients with metastatic breast cancer pretreated with taxanes and/or anthracyclines: a phase I-II study

Purpose. To evaluate the activity and toxicity of gemcitabine and vinorelbine (GemVin), in patients with advanced breast cancer, previously treated with anthracyclines alone or with taxanes. Patients and methods. Nine patients were entered into the phase I and 50 patients were entered into the phase II study. Gemcitabine was administered beginning with the dose of 800 mg/m² and vinorelbine was given at the fixed dose of 25 mg/m², both on days 1 and 8, every 21 days. Escalated dose levels of gemcitabine were planned by increments of 200 mg/m² per level. The median age of the 50 assessable patients for the phase II study was 56.5 years (range 30–70) and median performance status (PS, ECOG score), 1 (range 0–2). The dominant sites of metastases were viscera in 40, bone in five and soft tissue in five patients. First-line chemotherapy for metastatic disease with taxanes and anthracyclines or with anthracyclines alone was administered in 36 and 14 patients, respectively. Results. The optimal schedule for the combination was gemcitabine 800 mg/m² and vinorelbine 25 mg/m². The maximum tolerated dose of gemcitabine was 1000 mg/m², with grade 4 neutropenia occurring in two cases at this dose level. Overall, 267 cycles were given to the 50 patients enrolled into the phase II (mean 5.3; range 3–9). The schedule was well tolerated: three patients experienced grade 4 neutropenia and another four patients experienced grade 3 anemia. Non-hematological toxicities were moderate. A major objective response was observed in 42% of patients (95% confidence interval (CI), 28–57%), with complete remission in four (8%) and partial response in 17 (34%) patients. The median time to progression was 6 months. Activity as well as toxicity were similar in the subgroups of the patients pretreated either with combinations of taxanes and anthracyclines or anthracyclines alone. Conclusions. The optimal GemVin schedule is an effective and well tolerated second-line therapy in patients with metastatic breast cancer pre-treated with anthracycline – based schedules or with combinations of anthracyclines and taxanes.     

Comparing the efficacy and safety of fixed versus weight-based dosing of epoetin alpha in anemic cancer patients receiving platinum-based chemotherapy

Fixed dosing is potentially more convenient than weight-based dosing for both patients and physicians. Therefore, this open-label, randomized (1:1), multicenter study was conducted to compare the effectiveness, safety, and quality-of-life benefits of fixed vs. weight-based dosing of epoetin alpha in anemic cancer patients undergoing chemotherapy. Five hundred forty-six anemic patients undergoing platinum-based chemotherapy for solid malignancies were enrolled. Patients received epoetin alpha, either a fixed dose of 10,000 IU or a weight-based dose of 150 IU/kg, administered subcutaneously 3 times weekly for up to 12 weeks. Endpoints were transfusion requirements over days 29-84, change in hemoglobin (Hb) level from baseline, and change in quality-of-life (QOL) scores from baseline as measured using the Cancer Linear Analog Scale (CLAS). Five hundred and thirty-two patients received at least 1 dose of epoetin alpha, and 510 of these (255 in each treatment group) were considered evaluable for efficacy. At day 84, rates for freedom from transfusion were similar between the fixed-dose and the weight-based dose group (84% vs. 87%, respectively, p=0.32), as calculated by the lifetable method. These rates were also similar between patients in the 45-63 kg weight group receiving the fixed 10,000 IU dose or 7,000-9,000 IU on a per-weight basis (83% vs. 87%, respectively), and those in the 70-100 kg weight group receiving the fixed 10,000 IU dose or 11,000-15,000 IU on a per-weight basis (85% vs. 83%, respectively). Mean Hb increases from baseline to last observation were 2.10 g/dl [95% confidence intervals (CI95) 1.85-2.35] in the 10,000 IU group (from 9.64-11.74 g/dl) and 2.06 g/dl (CI95 1.82-2.30) in the 150 IU/kg group (from 9.70-11.76 g/dl). QOL results were similar for both groups and cumulative data have been reported. For 275 patients (in both groups combined) with CLAS QOL scores both at baseline and 29-98 days thereafter, the QOL index (average of scores for the 3 QOL parameters: energy level, ability to do daily activities and overall QOL) increased by 10.4 mm (CI95 7.5-13.2), from 46.2 mm at baseline to 56.6 mm at the final observation. QOL improvements were directly associated with Hb increases (p<0.001, multiple linear regression analysis) within all chemotherapy response classes. Epoetin alpha was well tolerated in both groups. Fixed (10,000 IU) and weight-based (150 IU/kg) dosing regimens of epoetin alpha demonstrated similar efficacy in maintaining freedom from transfusion, increasing Hb levels, and improving QOL in anemic cancer patients undergoing platinum-based chemotherapy. QOL improvements were directly associated with Hb increases. These findings support the use of a fixed-dose regimen of epoetin alpha, which may offer greater convenience for physicians and patients than weight-based dosing with this agent.     

Apomorphine infusion and the long-duration response to levodopa in advanced Parkinson's disease

The authors investigated the long-duration response to levodopa in advanced Parkinson's disease. Eight patients with advanced Parkinson's disease disabled by severe ON/OFF fluctuations treated by chronic daytime subcutaneous apomorphine infusion with supplemental oral levodopa were studied. On day 1, oral levodopa was withdrawn at 4:00 pm and on the following morning subcutaneous apomorphine infusion was continued at the same rate without levodopa therapy. While receiving apomorphine alone, seven of the eight patients turned ON, and their usual dyskinesias returned. The ON phase persisted for 60 to 100 minutes (mean, 185.7 minutes) but then, despite continued, constant-rate apomorphine infusion to stabilize plasma levels, switched to an OFF phase. The authors conclude that the clinical effect of apomorphine is sustained by levodopa long-duration response. This effect is probably the result of postsynaptic mechanisms. In patients with advanced Parkinson's disease, the long-duration response to levodopa is present although slightly diminished.     

High incidence of head and neck squamous cell carcinoma in patients with Fanconi anemia

BACKGROUND: Fanconi anemia (FA) is a rare autosomal recessive disorder characterized by a high degree of genomic instability and predisposition to cancer development. Recent evidence suggests that the incidence of head and neck squamous cell carcinoma (HNSCC) may be increased in patients with FA. OBJECTIVE: To determine the cumulative incidence, tumor distribution, and outcome of HNSCC in patients with FA. DESIGN AND SETTING: We analyzed data from 754 subjects from the International Fanconi Anemia Registry, a prospectively collected database of patients with FA. MAIN OUTCOME MEASURES: Cumulative incidence of HNSCC and 2-year overall, relapse-free and disease-specific survival. RESULTS: Of the 754 patients in the International Fanconi Anemia Registry, 19 (3%) had HNSCC. This is a significantly higher incidence of HNSCC compared with that observed in the general population (standardized incidence ratio, 500; 95% confidence interval, 300-781) (P<.001). The patients' age ranged from 15 to 49 years (median, 31 years), and there was a 2:1 female predominance. Surgical treatment was well tolerated (n = 17); however, radiation therapy and chemotherapy were associated with significant morbidity and mortality. Of the 19 patients, 10 (53%) developed locoregional recurrences within a median of 16 months from diagnosis. The median follow-up was 29 months. The 2-year disease-specific, overall, and relapse-free survival rates were 49%, 49%, and 42%, respectively. The cumulative incidence of relapse by the age of 40 years was 50%. CONCLUSIONS: In patients with FA, there is a high incidence of aggressive HNSCC at a young age. Surgery remains the mainstay of treatment because patients with FA tolerate radiation therapy and chemotherapy poorly, with significant morbidity. An increased understanding of FA-associated malignancies is not only important in the clinical management of patients with FA but can also elucidate the role of chromosomal instability in the development of HNSCC in general.     

Synthesis and antimicrobial properties of new cepham and penam derivatives with the carboxylic group in the “wrong” β-configuration

The cepham (9) and the penam (10) derivatives, with their carboxylic group in the “wrong” β-configuration, which is opposite to that exhibited by the common penicillins, were synthesized and assayed in vitro for antimicrobial properties. Compounds 9 and 10, tested on Gram-positive and Gram-negative bacteria, both sensitive and resistant to β-lactamase inactivation, exhibited a very poor activity, directed only against non-β-lactamase-producing Gram-positive bacteria. One of the possible explanations for these results may be found in unfavourable steric and electronic effects deriving from the α-oriented methoxy group which is adjacent to the pharmacophoric carboxylic function.