Detection and heterogeneity of herpesviruses causing Pacheco's disease in parrots

Pacheco's disease (PD) is a common, often fatal, disease of parrots. We cloned a virus isolate from a parrot that had characteristic lesions of PD. Three viral clones were partially sequenced, demonstrating that this virus was an alphaherpesvirus most closely related to the gallid herpesvirus 1. Five primer sets were developed from these sequences. The primer sets were used with PCR to screen tissues or tissue culture media suspected to contain viruses from 54 outbreaks of PD. The primer sets amplified DNA from all but one sample. Ten amplification patterns were detected, indicating that PD is caused by a genetically heterogeneous population of viruses. A single genetic variant (psittacid herpesvirus variant 1) amplified with all primer sets and was the most common virus variant (62.7%). A single primer set (23F) amplified DNA from all of the positive samples, suggesting that PCR could be used as a rapid postmortem assay for these viruses. PCR was found to be significantly more sensitive than tissue culture for the detection of psittacid herpesviruses.     

乳腺管状小叶癌

乳腺管状小叶癌（Tubulolobular carcinoma，TLC）最初是被作为小叶癌的管状变型。作者总结了27例TLC的组织学、免疫表型和临床特征，并与纯小管癌和经典型小叶癌进行了比较。此组患者年龄43-79岁（中位年龄60岁）。1例双侧乳腺受累，5例病变为多灶性。肿瘤直径0．5-2．5cm，色灰褐，质硬。组织学观察：TLC的肿瘤细胞形成管状和条索状两种结构模式并相互混杂，且两者比例相当（统称为管状小叶模式）。     

Germline mutations of the CDKN2 gene in UK melanoma families

Germline mutations in CDKN2 on chromosome 9p21, which codes for the cyclin D kinase inhibitor p16, and more rarely, mutations in the gene coding for CDK4, the protein to which p16 binds, underlie susceptibility in some melanoma families. We have sequenced all exons of CDKN2 and analysed the CDK4 gene for mutations in 27 UK families showing evidence of predisposition to melanoma. Five different germline mutations in CDKN2 were found in six families. Three of the mutations (Met53Ile, Arg24Pro and 23ins24) have been reported previously. We have identified two novel CDKN2 mutations (88delG and Ala118Thr) which are likely to be associated with the development of melanoma, because of their co-segregation with the disease and their likely functional effect on the CDKN2 protein. In binding assays the protein expressed from the previously described mutation, Met53Ile, did not bind to CDK4/CDK6, confirming its role as a causal mutation in the development of melanoma. Ala118Thr appeared to be functional in this assay. Arg24Pro appeared to bind to CDK6, but not to CDK4. No mutations were detected in exon 2 of CDK4, suggesting that causal mutations in this gene are uncommon. The penetrance of these mutant CDKN2 genes is not yet established, nor is the risk of non-melanoma cancer to gene carriers.      

Multigenic control of skin tumor susceptibility in SENCARA/Pt mice

Skin tumors induced in mice by initiation-promotion (2 microg DMBA-2 microg TPA) protocols were found to be under multigenic control. Eighty- one N2 mice from the cross (BALB/cAnPt x SENCARA/Pt)F1 x SENCARA/Pt that were either solidly resistant (no papillomas) or highly susceptible (> or = 7 papillomas/mouse) were subjected to a 'genome scan' using 89 microsatellite markers to check for associations with susceptible and resistant phenotypes. A locus on Chr 5 (Skts4) was found to control the susceptibility of SENCARA/Pt mice and the resistance of BALB/cAnPt mice to papilloma formation. In addition, higher than expected linkage scores were seen for the markers D9Mit271, D11Mit268 and D12Mit56. Further work is required to establish whether genes determining papilloma formation are located in these regions of the genome. In general, no evidence was seen for loss of heterozygosity in microsatellite markers on Chrs 5, 9 and 11 in 17 microdissected papillomas from (BALB/c x SENCARA)F1 hybrid mice.      

Mitral regurgitation in hypertrophic obstructive cardiomyopathy: relationship to obstruction and relief with myectomy

OBJECTIVES

This study examined: 1) the impact of myectomy on postoperative mitral regurgitation (MR) and 2) the association between the severity of MR and the left ventricular outflow tract (LVOT) gradient.

BACKGROUND

For patients with hypertrophic obstructive cardiomyopathy (HOCM) and MR, controversy exists as to whether myectomy alone is sufficient in eliminating MR. Furthermore, the relationship between the degree of MR and the LVOT peak gradient has not been well defined.

METHODS

We performed pre- and postoperative transthoracic as well as intraoperative transesophageal studies in 104 consecutive patients with HOCM undergoing septal myectomy. Left ventricular outflow tract gradient and the nature of MR were assessed.

RESULTS

In the 93 patients without independent mitral valve disease, a relationship was observed between MR severity and the LVOT gradient. Left ventricular outflow tract gradient (mean ± standard deviation) for trivial, mild, moderate and severe MR were: 23.2 ± 19.1, 43.8 ± 25.4, 70.1 ± 21.0 and 104 ± 21.0 mm Hg (p < 0.001). Early postoperative, MR was absent or trivial in 80%, mild in 19% and moderate in 1%. None of these patients required additional mitral valve surgery. For patients with independent mitral valve disease (n = 11), five required mitral valve surgery as well as myectomy. The remainder had significant reductions in the degree of MR with myectomy alone.

CONCLUSIONS

For patients with HOCM and MR not due to independent mitral valve disease, myectomy significantly reduced the degree of MR, without requirement for additional mitral valve surgery. In these patients the severity of MR was directly related to the magnitude of the LVOT gradient.     

Apical hypertrophic cardiomyopathy: clinical follow-up and diagnostic correlates

To determine the clinical course of apical hypertrophic cardiomyopathy, 26 patients (mean age 45 years) with asymmetric apical hypertrophy diagnosed by echocardiography or angiography were followed up for an average of 7.3 years (range 1 to 22). Presenting symptoms included atypical chest pain (n = 10), typical angina (n = 6), dyspnea (n = 5) and palpitation (n = 8). Ten patients were asymptomatic. At follow-up all patients had inverted precordial T waves, and 14 had the syndrome of "giant T wave negativity" (greater than or equal to 10 mm). In six patients with electrocardiographic follow-up of greater than 10 years (mean 13.4), precordial T wave inversion had progressed from -0.8 +/- 3.9 to -11.2 +/- 8.0 mm in lead V4 in association with increased QRS amplitude. Episodic atrial fibrillation occurred in 4 of 10 patients with echocardiographic left atrial enlargement. Although left ventricular systolic function was normal, diastolic relaxation was impaired in comparison with values in 10 healthy control subjects: in all 18 patients studied peak filling rate was decreased (4.44 +/- 0.44 versus 6.13 +/- 1.54 stroke volumes/s); time to peak filling was increased (174 +/- 40 versus 147 +/- 32 ms); and atrial systolic contribution to ventricular end-diastolic volume was increased (21.5 +/- 6.8 versus 11.5 +/- 4.6 stroke volume %). During follow-up, 21 of the 26 patients remained in stable condition or were asymptomatic. One patient with normal coronary arteries had an apical myocardial infarction with development of a discrete apical aneurysm and loss of "giant T wave negativity." This patient was the only one to have documented life-threatening ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)