Strategies for single base gene editing in an immortalized human cell line by CRISPR/Cas9 technology

The use of CRISPR/Cas9 system has rapidly grown in the last years. Here, the optimization of gene editing of a single-nucleotide polymorphism in a human non-malignant somatic cell line of thyrocytes (Nthy-Ori) was described highlighting strategies for overcoming the problems concerning the delivery and off-targets. We employed both lentivirus and chemical lipids as delivery agents and two strategies for creating the double-strand breaks (DSB). The former induced a DSB by a classical Cas9 nuclease (standard strategy), while the second one employed a modified Cas9 creating a single-strand break (SSB). The knock-in was carried out using a single-stranded donor oligonucleotide or the HR410-PA donor vector (HR). The desired cells could be obtained by combining the double nickase system with the HR vector transfected chemically. This result could be due to the type of DSB, likely processed mainly by non-homologous end joining when blunt (standard strategy) and by HR when overhanging (double nickase). Our results showed that the double nickase is suitable for knocking-in the immortalized Nthy-Ori cell line, while the standard CRISPR/Cas9 system is suitable for gene knock-out creating in/del mutations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03878-4.

Alpha-1 Adrenergic Antagonists Sensitize Neuroblastoma to Therapeutic Differentiation

Neuroblastoma (NB) is an aggressive childhood tumor, with high-risk cases having a 5-year overall survival probability of approximately 50%. The multimodal therapeutic approach for NB includes treatment with the retinoid isotretinoin (13-cis retinoic acid; 13cRA), which is used in the post-consolidation phase as an antiproliferation and prodifferentiation agent to minimize residual disease and prevent relapse. Through small-molecule screening, we identified isorhamnetin (ISR) as a synergistic compound with 13cRA in inhibiting up to 80% of NB cell viability. The synergistic effect was accompanied by a marked increase in the expression of the adrenergic receptor α1B (ADRA1B) gene. Genetic knockout of ADRA1B or its specific blockade using α1/α1B adrenergic antagonists led to selective sensitization of MYCN-amplified NB cells to cell viability reduction and neural differentiation induced by 13cRA, thus mimicking ISR activity. Administration of doxazosin, a safe α1-antagonist used in pediatric patients, in combination with 13cRA in NB xenografted mice exerted marked control of tumor growth, whereas each drug alone was ineffective. Overall, this study identified the α1B adrenergic receptor as a pharmacologic target in NB, supporting the evaluation of adding α1-antagonists to the post-consolidation therapy of NB to more efficiently control residual disease.

SIGNIFICANCE

Targeting α-adrenergic receptors synergizes with isotretinoin to suppress growth and to promote differentiation of neuroblastoma, revealing a combinatorial approach for more effective management of the disease and prevention of relapse.

Digenic inheritance of STUB1 variants and TBP polyglutamine expansions explains the incomplete penetrance of SCA17 and SCA48

PURPOSE

This study aimed to unravel the genetic factors underlying missing heritability in spinocerebellar ataxia type 17 (SCA17) caused by polyglutamine-encoding CAG/CAA repeat expansions in the TBP gene. Alleles with >49 CAG/CAA repeats are fully penetrant. Most patients, however, carry intermediate TBP_41-49 alleles that show incomplete penetrance.

METHODS

Using next-generation sequencing approaches, we investigated 40 SCA17/TBP_41-54 index patients, their affected (n = 55) and unaffected (n = 51) relatives, and a cohort of patients with ataxia (n = 292).

RESULTS

All except 1 (30/31) of the index cases with TBP_41-46 alleles carried a heterozygous pathogenic variant in the STUB1 gene associated with spinocerebellar ataxias SCAR16 (autosomal recessive) and SCA48 (autosomal dominant). No STUB1 variant was found in patients carrying TBP_47-54 alleles. TBP_41-46 expansions and STUB1 variants cosegregate in all affected family members, whereas the presence of either TBP_41-46 expansions or STUB1 variants individually was never associated with the disease.

CONCLUSION

Our data reveal an unexpected genetic interaction between STUB1 and TBP in the pathogenesis of SCA17 and raise questions on the existence of SCA48 as a monogenic disease with crucial implications for diagnosis and counseling. They provide a convincing explanation for the incomplete penetrance of intermediate TBP alleles and demonstrate a dual inheritance pattern for SCA17, which is a monogenic dominant disorder for TBP_≥47 alleles and a digenic TBP/STUB1 disease (SCA17-DI) for intermediate expansions.

Pro64His (rs4644) Polymorphism Within Galectin-3 Is a Risk Factor of Differentiated Thyroid Carcinoma and Affects the Transcriptome of Thyrocytes Engineered via CRISPR/Cas9 System

Background: Galectin-3 (LGALS3) is an important glycoprotein involved in the malignant transformation of thyrocytes acting in the extracellular matrix, cytoplasm, and nucleus where it regulates TTF-1 and TCF4 transcription factors. Within LGALS3 gene, a common single-nucleotide polymorphism (SNP) (c.191C>A, p.Pro64His; rs4644) encoding for the variant Proline to Histidine at codon 64 has been extensively studied. However, data on rs4644 in the context of thyroid cancer are lacking. Thus, the aim of the present work was to evaluate the role of the rs4644 SNP as risk factor for differentiated thyroid cancer (DTC) and to determine the effect on the transcriptome in thyrocytes. Methods: A case/control association study in 1223 controls and 1142 unrelated consecutive DTC patients was carried out to evaluate the association between rs4644-P64H and the risk of DTC. We used the nonmalignant cell line Nthy-Ori (rs4644-C/A) and the CRISPR/Cas9 technique to generate isogenic cells carrying either the rs4644-A/A or rs4644-C/C homozygosis. Then, the transcriptome of the derivative and unmodified parental cells was analyzed by RNA-seq. Genes differentially expressed were validated by quantitative reverse transcription PCR and further tested in the parental Nthy-Ori cells after LGALS3 gene silencing, to investigate whether the expression of target genes was dependent on galectin-3 levels. Results: rs4644 AA genotype was associated with a reduced risk of DTC (compared with CC, OR_adj = 0.66; 95% confidence interval = 0.46-0.93; P_ass = 0.02). We found that rs4644 affects galectin-3 as a transcriptional coregulator. Among 34 genes affected by rs4644, HES1, HSPA6, SPC24, and NHS were of particular interest since their expression was rs4644-dependent (CC>AA for the first and AA>CC for the others), also in 574 thyroid tissues of Genotype-Tissue Expression (GTEx) biobank. Moreover, the expression of these genes was regulated by LGALS3-silencing. Using the proximity ligation assay in Nthy-Ori cells, we found that the TTF-1 interaction was genotype dependent. Conclusions: Our data show that in thyroid, rs4644 is a trans-expression quantitative trait locus that can modify the transcriptional expression of downstream genes, through the modulation of TTF-1.

Local pesticide use intensity conditions landscape effects on biological pest control

Complex landscapes including semi-natural habitats are expected to favour natural enemies thereby enhancing natural pest biocontrol in crops. However, when considering a large number of situations, the response of natural biocontrol to landscape properties is globally inconsistent, a possible explanation being that local agricultural practices counteract landscape effects. In this study, along a crossed gradient of pesticide use intensity and landscape simplification, we analysed the interactive effects of landscape characteristics and local pesticide use intensity on natural biocontrol. During 3 years, using a set of sentinel prey (weed seeds, aphids and Lepidoptera eggs), biocontrol was estimated in 80 commercial fields located in four contrasted regions in France. For all types of prey excepted weed seeds, the predation rate was influenced by interactions between landscape characteristics and local pesticide use intensity. Proportion of meadow and length of interface between woods and crops had a positive effect on biocontrol of aphids where local pesticide use intensity was low but had a negative effect elsewhere. Moreover, the landscape proportion of suitable habitats for crop pests decreased the predation of sentinel prey, irrespectively of the local pesticide use intensity for weed seeds, but only in fields with low pesticide use for Lepidoptera eggs. These results show that high local pesticide use can counteract the positive expected effects of semi-natural habitats, but also that the necessary pesticide use reduction should be associated with semi-natural habitat enhancement to guarantee an effective natural biocontrol.

PARP inhibitors enhance replication stress and cause mitotic catastrophe in MYCN-dependent neuroblastoma

High-risk and MYCN-amplified neuroblastomas are among the most aggressive pediatric tumors. Despite intense multimodality therapies, about 50% of these patients succumb to their disease, making the search for effective therapies an absolute priority. Due to the important functions of poly (ADP-ribose) polymerases, PARP inhibitors have entered the clinical settings for cancer treatment and are being exploited in a variety of preclinical studies and clinical trials. PARP inhibitors based combination schemes have also been tested in neuroblastoma preclinical models with encouraging results. However, the expression of PARP enzymes in human neuroblastoma and the biological consequences of their inhibition remained largely unexplored. Here, we show that high PARP1 and PARP2 expression is significantly associated with high-risk neuroblastoma cases and poor survival, highlighting its previously unrecognized prognostic value for human neuroblastoma. In vitro, PARP1 and 2 are abundant in MYCN amplified and MYCN-overexpressing cells. In this context, PARP inhibitors with high 'PARP trapping' potency, such as olaparib or talazoparib, yield DNA damage and cell death preceded by intense signs of replication stress. Notwithstanding the activation of a CHK1-CDC25A replication stress response, PARP-inhibited MYCN amplified and overexpressing cells fail to sustain a prolonged checkpoint and progress through mitosis in the presence of damaged DNA, eventually undergoing mitotic catastrophe. CHK1-targeted inhibition of the replication stress checkpoint exacerbated this phenotype. These data highlight a novel route for cell death induction by PARP inhibitors and support their introduction, together with CHK1 inhibitors, in therapeutic approaches for neuroblastomas with high MYC(N) activity.

The MRN complex is transcriptionally regulated by MYCN during neural cell proliferation to control replication stress

The MRE11/RAD50/NBS1 (MRN) complex is a major sensor of DNA double strand breaks, whose role in controlling faithful DNA replication and preventing replication stress is also emerging. Inactivation of the MRN complex invariably leads to developmental and/or degenerative neuronal defects, the pathogenesis of which still remains poorly understood. In particular, NBS1 gene mutations are associated with microcephaly and strongly impaired cerebellar development, both in humans and in the mouse model. These phenotypes strikingly overlap those induced by inactivation of MYCN, an essential promoter of the expansion of neuronal stem and progenitor cells, suggesting that MYCN and the MRN complex might be connected on a unique pathway essential for the safe expansion of neuronal cells. Here, we show that MYCN transcriptionally controls the expression of each component of the MRN complex. By genetic and pharmacological inhibition of the MRN complex in a MYCN overexpression model and in the more physiological context of the Hedgehog-dependent expansion of primary cerebellar granule progenitor cells, we also show that the MRN complex is required for MYCN-dependent proliferation. Indeed, its inhibition resulted in DNA damage, activation of a DNA damage response, and cell death in a MYCN- and replication-dependent manner. Our data indicate the MRN complex is essential to restrain MYCN-induced replication stress during neural cell proliferation and support the hypothesis that replication-born DNA damage is responsible for the neuronal defects associated with MRN dysfunctions.

SUMO1 in human sperm: new targets, role in motility and morphology and relationship with DNA damage

In studies carried out previously, we demonstrated that small ubiquitin-like modifier 1 (SUMO1) is associated with poor sperm motility when evaluated with a protocol that reveals mostly SUMO1-ylated live sperm. Recently, with another protocol, it has been demonstrated that SUMO is expressed in most sperm and is related to poor morphology and motility, suggesting that sumoylation may have multiple roles depending on its localisation and targets. We show herein, by confocal microscopy and co-immunoprecipitation, that dynamin-related protein 1 (DRP1), Ran GTPase-activating protein 1 (RanGAP1) and Topoisomerase IIα, SUMO1 targets in somatic and/or germ cells, are SUMO1-ylated in mature human spermatozoa. DRP1 co-localises with SUMO1 in the mid-piece, whereas RanGAP1 and Topoisomerase IIα in the post-acrosomal region of the head. Both SUMO1 expression and co-localisation with the three proteins were significantly higher in morphologically abnormal sperm, suggesting that sumoylation represents a marker of defective sperm. DRP1 sumoylation at the mid-piece level was higher in the sperm of asthenospermic men. As in somatic cells, DRP1 sumoylation is associated with mitochondrial alterations, this protein may represent the link between SUMO and poor motility. As SUMO pathways are involved in responses to DNA damage, another aim of our study was to investigate the relationship between sumoylation and sperm DNA fragmentation (SDF). By flow cytometry, we demonstrated that SUMO1-ylation and SDF are correlated (r=0.4, P<0.02, n=37) and most sumoylated sperm shows DNA damage in co-localisation analysis. When SDF was induced by stressful conditions (freezing and thawing and oxidative stress), SUMO1-ylation increased. Following freezing and thawing, SUMO1-Topoisomerase IIα co-localisation and co-immunoprecipitation increased, suggesting an involvement in the formation/repair of DNA breakage.

Surgical treatment of congenital nasolacrimal duct obstructions in Italy

AIM

The aim of this study to present the surgical treatments performed in Italy for congenital nasolacrimal duct obstruction.

METHODS

This was a retrospective review of the Ministry of Health database for groups aged 0-1 and 1-4 years from 1999 through 2005.

RESULTS

During the study period, a total of 9081 surgical procedures was performed on children 0-4 years of age, 2739 of which on infants under 1 year of age and 6342 on children 1-4 year-old; 8067 (88.8%) of these interventions were represented by nasolacrimal duct probing, 2556 of which in infants under one year of age and 5511 in the 1-4 year age group. Total number of the other surgical techniques was 984, 183 of which among infants younger than one year of age and 801 among children aged 1-4 years. The seven-year mean number of surgical treatments corresponds to a rate of 7.3/10000 live births for infants <1 year old and 4.3/10000 for children aged 1-4 years.

CONCLUSION

When congenital nasolacrimal duct obstructions do not improve spontaneously, probing resulted the more common surgical treatment performed. Our data are related exclusively to infantile inpatients and cases managed on an office basis are not included. Consequently, our figures cannot be considered indicative of the incidence of this pathology in Italy. However, the mean number per 10000 of surgical procedures may represent, in our opinion, a useful indicator for the more severe forms of congenital lacrimal drainage system pathologies.

Penetrating keratoplasty in a newborn: case report and analysis of current surgical trends in Italy

PURPOSE

The aims of this study were to describe bilateral penetrating keratoplasty (PK) in a newborn and to analyze the data of PKs performed in Italy during the 5-year period 1999-2003 in children under 4 years of age.

METHODS

A male newborn had PK at age 3 months and 5 months for near-blindness secondary to severe congenital corneal clouding in both eyes. The infant''s explanted corneas were subjected to histochemical and ultrastructural analyses. Data regarding the number of PKs performed in Italy on 0-4-year-olds were obtained from the Web site of the Italian Ministry of Health.

RESULTS

The postoperative courses were uncomplicated, and 42 months of follow-up data show bilateral graft transparency and substantial improvement in visual acuity despite high-grade myopia and nystagmus. At the ultrastructural level, the main alterations involved the endothelial cells and Descemet membrane. A total of 45 PKs were performed in Italy on patients 0-4 years old from 1999 through 2003; only nine involved babies under 1 year of age.

CONCLUSIONS

In babies with congenital corneal opacities, early PK can reduce severe amblyopia. However, the risk of intra- and postoperative complications in PK is high. Based on the 42-month follow-up, the anatomic and functional results achieved in the current patient are satisfactory despite the presence of nystagmus and postoperative high-grade myopia. This study shows that PKs are rarely performed, in Italy, in children aged 0-4 years, and very few are done during the first year of life.

Analgesic effect of watching TV during venipuncture

AIMS

To assess the analgesic effect of passive or active distraction during venipuncture in children.

METHODS

We studied 69 children aged 7-12 years undergoing venipuncture. The children were randomly divided into three groups: a control group (C) without any distraction procedure, a group (M) in which mothers performed active distraction, and a TV group (TV) in which passive distraction (a TV cartoon) was used. Both mothers and children scored pain after the procedure.

RESULTS

Main pain levels rated by the children were 23.04 (standard deviation (SD) 24.57), 17.39 (SD 21.36), and 8.91 (SD 8.65) for the C, M, and TV groups, respectively. Main pain levels rated by mothers were 21.30 (SD 19.9), 23.04 (SD 18.39), and 12.17 (SD 12.14) for the C, M, and TV groups, respectively. Scores assigned by mothers and children indicated that procedures performed during TV watching were less painful (p<0.05) than control or procedures performed during active distraction.

CONCLUSION

TV watching was more effective than active distraction. This was due either to the emotional participation of the mothers in the active procedure or to the distracting power of television.

[Excision of a schwannoma of the neck: surgical technique]

We present a case of schwannoma of the neck in 49 year old man, symptomatic (paresthesia, cervical mass and dysphagia). After ultrasonography and magnetic resonance of the neck, the patient was operated and excision of the lesion was completely performed. The operation was performed through a cervical approach: the nerves and the vascular and muscular structures were carefully isolated and preserved. The tumour arised from the cervical sympathetic chain. The diagnosis of schwannoma was possible only by histopathologic examen. After 48 months no local recurrence or postoperative complication related to intervention were found. These lesions are uncommon. The identification of the nerve is often difficult until the operation, which is the treatment of choice for the schwannoma.

[Carcinoid tumors of the appendix: when right colectomy?]

Three cases of carcinoid tumour of the appendix (about 0,3 % of all performed appendectomies) has induced the Authors to a review of the literature with the aim to underline the most important biological and pathological findings and the current clinic and therapeutic knowledges. The diagnosis before surgery is rarely made; it is formulated incidentally in most patients by the histological exam during the operation for an appendicitis or during other surgical procedures. The kind of surgical intervention, that is the entity of the surgical demolition, for the treatment of the carcinoid tumours of the appendix is still controversial: appendectomy or right colectomy? It is possible identify, also during the operation for an appendicitis or for other abdominal lesions, criteria that can orient toward a major surgery (size of the neoplasia, subserosal lymphatic invasion, infiltration of the serosa, diffusion in the meso-appendix, location in closeness of the base of the appendix, invasion of the the locoregional lymph nodes, presence of metastases, section ?margins, number of mitoses, cellular pleiomorfism).

[Abdominal emergency surgery in the geriatric patients. Our experience]

The ageing process of general population implies new socio-sanitary problems. Indications for surgical intervention have been modified and enhanced. As far as elective surgery is concerned, the results in elderly subjects do not seem alarming, whereas less satisfactory results have been registered in the patients who underwent an emergency surgical intervention, where nowadays morbidity and mortality still turn out to be high. The Authors have reported their experience of emergency surgery in the geriatric patient. From 1982 to 2002, 718 pts (361 males, 50.3% and 357 females, 49.7%; average age 50 yrs, range 5-92) underwent emergency surgical interventions for abdominal lesions. The pts were subdivided in two groups: group A (> 65 years; 190 pts, 87 males and 103 females; average age 72 yrs, range 66-92); control group B (<65 years; 528 pts, 274 males and 254 females; average age 43 yrs, range 5-65). The results were assessed in terms of morbidity and of the operative and post-operative mortality. Postoperative morbidity proved to be equal to 25.7% (36.3% in the group A, 21.9% in the group B), while intraoperative mortality equal to 0.27%. Postoperative mortality resulted equal to 12.1% (significantly higher in group A pts -- 16.8%- than in group B pts --10.4%). The mortality of the 190 pts belonging to group A was higher in the pts which were presenting respectively 1, 2, 3 or more concomitant diseases. The progressive percentage increase in the number of interventions on elderly pts not only can be due to the demographic increase of old people, but it can also be linked to a change in the surgeon's attitude. At the present time, while elective geriatric surgery implies an acceptable mortality rate (5-8 %), emergency geriatric surgery has not notably modified the prognosis in the last decades and mortality has turned out to be still high (20-30%). We think that it will be possible to obtain better results through geriatric surgery only by reducing emergency interventions as much as possible. In order to do so, it will be important to insist on intervening before the illness, during its natural evolution, requires actions which cannot be postponed. This would lead to positive results not only in terms of mortality and morbidity, which are still considered as the main targets, but also as far as the period of the stay in hospital and costs are concerned.

[Surgical treatment of Crohn's disease complications. Our experience]

Thirty-five patients with Crohn's Disease (CD) were observed: 18 have been treated with medical therapy and 17 (48.6%) underwent to surgical treatment : 1) intolerance to the medical treatment in 5.9% (1 case); 2) local complications in 94.1% (16 cases: 6 stenosis, 2 occlusions, 3 abscesses, 3 fistulas, 1 perforation with peritonitis, 1 case toxic megacolon). The operations have been 19: resective interventions 14 (bowel and/or colon resections), conservative interventions 5. The mortality was 0, the morbidity 35,29%. The incidence of the recurrences in a follow up of 5 year was 42,9%. The Authors conclude that the surgery, indicated for the treatment of complications, can be resective surgery (perforating Crohn disease: fistulas, abscess) or conservative surgery (stenosing Crohn disease: stenosis). Recently the conservative intervention are proposed in the treatment of fistulas and abscesses too, but when the inflammation is mild and in patients that underwent to extensive intestinal resection with risk of short bowel syndrome.

Environmental enrichment promotes improved spatial abilities and enhanced dendritic growth in the rat

An enriched environment consists of a combination of enhanced social relations, physical exercise and interactions with non-social stimuli that leads to behavioral and neuronal modifications. In the present study, we analyzed the behavioral effects of environmental complexity on different facets of spatial function, and we assessed dendritic arborisation and spine density in a cortical area mainly involved in the spatial learning, as the parietal cortex. Wistar rat pups (21 days old) were housed in enriched conditions (10 animals in a large cage with toys and a running wheel), or standard condition (two animals in a standard cage, without objects). At the age of 3 months, both groups were tested in the radial maze task and Morris water maze (MWM). Morphological analyses on layer-III pyramidal neurons of parietal cortex were performed in selected animals belonging to both experimental groups. In the radial maze task, enriched animals exhibited high performance levels, by exploiting procedural competencies and working memory abilities. Furthermore, when the requirements of the context changed, they promptly reorganized their strategies by shifting from prevalently using spatial procedures to applying mnesic competencies. In the Morris water maze, enriched animals more quickly acquired tuned navigational strategies. Environmental enrichment provoked increased dendritic arborisation as well as increased density of dendritic spines in layer-III parietal pyramidal neurons.

[Role of aortofemoral bypass in the management of unilateral iliac occlusive disease. A follow-up study of 95 patients over a 25-year period]

BACKGROUND

To evaluate the results in a series of patients submitted to aortofemoral bypass due to an unilateral iliac occlusion.

METHODS

Retrospective follow-up study. A total of 95 patients underwent, between 1975 and 2000, aortofemoral bypass because of unilateral iliac occlusion. Most of them (71 patients) were claudicants, Fontaine stage II b, while 12 complained rest pain and 12 suffered ischemic ulcers. Mean follow-up was 128 months (min 2.5 - max 292).

RESULTS

Immediate success was obtained in 88 cases (92.6%), 7 patients were submitted to early redo with restored patency in 6 cases. One month global patency was gained in 98.9% (94 cases). The mean Ankle-brachial index (ABI) improvement was 0.35. At a mean follow-up of 128 months the cumulative patency was 90.8%. During the follow-up, 15 graft occlusions were observed, followed by 9 successful reoperations achieving a 5-year secondary patency of 92.1%. The contralateral iliac artery evolved toward an occlusion in 10 patients (10.5%) during a long time observation (104 months average).

CONCLUSIONS

The unilateral aortofemoral bypass confirmed an excellent long term outcome regarding effectiveness and graft related complications. The low contralateral occlusion rate, in our series, does not justify a more aggressive approach as first surgical option.

Octyl 2-cyanoacrylate tissue adhesive in experimental scleral buckling

PURPOSE

In this experimental study, a sutureless scleral buckling was performed by using a tissue adhesive glue to fixate a silicone band to the sclera. In fact, one of the major risks of traditional scleral buckling is accidental perforation of the bulb, which is more frequent when the sclera is extremely thin as it is in newborns or in eyes with high myopia or scleromalacia.

METHODS

An encircling band of silicone, which is generally anchored to the sclera itself, was sutured in 36 rabbit eyes to three small silastic patches that had been glued to the sclera, at the level of the equator, using octyl 2-cyanoacrylate tissue adhesive. In this manner the anchoring sutures passed through silicone and silicone. The band was tightened to produce buckling of the sclera and its ends were glued together using the same adhesive.

RESULTS

Examination of the eyes from 15 days to 6 months after surgery revealed that the buckle was stable, with no signs of slippage, in 33 eyes. In the remaining 3 (one examined after 15 days, 2 examined after 45 days), one of the three support patches had become detached but there was still no evidence of slippage.

CONCLUSIONS

The stability of the buckle up to six months after surgery suggests that this new adhesive might be used for sutureless surgery in certain types of retinal detachment, such as that associated with stage 4 ROP in which the encircling band has to be removed after several months.

Iris vascular changes in newborns of diabetic mothers

Routine ophthalmic examinations of 600 full-term neonates, including 54 born to mothers with insulin-dependent diabetes mellitus and 12 whose mothers had developed gestational diabetes, revealed significant tortuosity and dilatation of the iris vessels in over half of the infants born to diabetic mothers. Ninety percent of the newborns in the diabetic group presented hypoplasia of the iris stroma and pupil dynamics were altered in 85%. The vessel changes resolved spontaneously within 2 weeks after birth. These changes, which have also been observed in cocaine-intoxicated newborns, should raise the suspicion of adverse vascular effects in the fetus caused by maternal diabetes.

An ultrasonographic study of stage-5 retinopathy of prematurity

BACKGROUND

In preterm infants with severe retinopathy of prematurity, there is often a discrepancy between ophthalmic ultrasound findings and the ophthalmoscopic and/or intraoperative aspect of the eye.

METHODS

Six preterm infants (8 eyes) with stage-5 retinopathy of prematurity were examined with standardized ophthalmic echography (A and B scans) shortly before undergoing open-sky vitrectomies. Sonographic findings were evaluated according to four A-scan and four B-scan criteria used to diagnose retinal detachment in adults and compared to intraoperative findings.

RESULTS

Although the retinal detachments and vitreal proliferation found in all 8 eyes at surgery were almost identical, the sonographic aspects varied widely: 3/8 satisfied most of the criteria used in adults, 3/8 presented two criteria only and the remaining 2 were negative for all criteria used.

CONCLUSION

The variability in the ultrasonographic aspects of these preterm eyes may depend on the degree of maturity of the preterm retina at the time of examination, with more mature retinas presenting greater reflectivity and therefore greater visibility in the sonographic exam.

Oxygen-induced retinopathy in the newborn rat: morphological and immunohistological findings in animals treated with topical timolol maleate

Oxygen-induced retinopathy (OIR) similar to that seen in premature infants can be produced in newborn rats by exposure to 80% oxygen for the first 5 days of life, with subsequent recovery for 7 days in a room air environment. Previous studies have shown that the latter phase is associated with degeneration of retinal astrocytes. In the absence of astrocytes, the vascular endothelial growth factor (VEGF) is produced by the neurons of the inner retina. In this study, immunohistochemical methods were used to assess retinal expression of VEGF protein in ratlings exposed to the above protocol, with and without simultaneous treatment with topical timolol maleate. Intraocular pressure (IOP) and arterial pressure were measured. The severity of OIR was also evaluated in retinal flat mounts after India ink perfusion. The mean IOP was 8.25 +/- 0.32 mm Hg in untreated ratlings and 5.15 +/- 0.24 mm Hg in timolol-treated animals. OIR in retinas from the timolol group was less severe than that seen in untreated ratlings. VEGF protein expression was almost completely absent in the latter group. Retinas from timolol-treated animals expressed VEGF protein, though the level was inferior to that found in controls raised under room air conditions. In conclusion, these data seem to indicate that experimental OIR can be attenuated by a reduction of the IOP during and after oxygen supplementation. It is possible that these effects are due to improved ocular perfusion pressure, which would mitigate the hypoxic insult to the retina during the room air recovery period.

Octyl 2-cyanoacrylate in sutureless surgery of extraocular muscles: an experimental study in the rabbit model

BACKGROUND

Sutureless surgery for strabismus eliminates the risk of perforating the ocular bulb in patients with extremely thin sclerae. Thus far, however, the results obtained with tissue adhesives such as the cyanoacrylates instead of sutures have been less than satisfactory.

METHODS

A new adhesive, octyl 2-cyanoacrylate, was tested in 36 rabbit eyes in which the superior rectus was recessed 5 mm. In 36 other eyes the same operation was performed using 5/0 Vicryl sutures. Animals were killed 1, 3, 5, 15, 30 and 45 days after surgery. One eye from each animal was used for histopathological examination of the reinserted muscle and sclera, while the other was used in a tensiometric test to measure how many grams of weight were needed to detach the muscle from its new insertion site.

RESULTS

The tensile strength of the bond achieved with the cyanoacrylate adhesive was 94+/-12 g 1 day after surgery (vs 238+/-19 g in the suture group) and 520+/-24 g after 45 days (vs 576+/-27 g with sutures). No cases of slippage, muscle detachment, or local tissue reactions were observed in either group. There were no differences in histological findings between the eyes of the two groups.

CONCLUSIONS

Although further study will be necessary before this technique can be used in humans, our findings indicate that octyl 2-cyanoacrylate is superior to the cyanoacrylate adhesives used in the past in terms of adhesion and holding power; given its favorable toxicity profile, this product may offer interesting applications in the future.

Refractive errors and ocular motility disorders in preterm babies with and without retinopathy of prematurity

Ocular motility, refraction and visual acuity (VA) were evaluated at the age of 4 years in 136 preterm infants with gestational ages (GAs) at birth of less than 32 weeks. Group 1 (non-retinopathy of prematurity, ROP) included 87 children that had never developed ROP. Group 2 contained 19 children whose ROP had regressed spontaneously. Group 3 (cryo-ROP) was composed of 30 patients who had undergone cryotherapy for severe ROP. Strabismus was found in 13.9% of the total population. chi(2) analysis revealed that strabismus was significantly (p < 0.01) associated with prematurity (i.e. GA <29 weeks), ROP and cryotherapy. Myopia of more than 3 dpt was significantly (p < 0.001) more common in the cryo-ROP infants than in the regressed-ROP and non-ROP groups. The distribution of hypermetropia was similar in all three groups. VA was measured with the E chart. Of the 272 eyes examined, 251 (92.3%) displayed VA of more than 20/25. The majority of these eyes were from the non-ROP group (65.4%), 15.3% had regressed ROP and 21.1% belonged to the cryo-ROP group. Fifteen eyes (8 non-ROP, 3 regressed ROP and 4 cryo-ROP) presented VAs between 20/25 and 20/60. VA of less then 20/60 was found in 6 eyes (2 non-ROP, 1 regressed ROP, 3 cryo-ROP). Cryotherapy did not appear to preclude the development of good VA.

Intraocular pressure in premature babies in the first month of life

PURPOSE

The purpose of this work was to study the values of intraocular pressure (IOP) in premature babies during the first month of life.

METHODS

Using a hand-held applanation tonometer, IOP was measured in 40 eyes of 20 preterm infants (gestational age ranging from 26 to 32 weeks) shortly after birth and at weekly intervals for the first month of life.

RESULTS

IOP values in preterm infants ranged from 7.6 to 18.3 mm Hg. The mean IOP decreased during the study period from 13.25+/-2.86 mm Hg to 10.96+/-2.01 mm Hg (P< .001).

CONCLUSIONS

Although the values of IOP found in this study are by no means within the range that is considered to be pathologic for newborns, the possible lack of the decreasing tendency of IOP observed during the first month of life could have, in a given case, some clinical implications. Because systemic blood pressure in preterm infants is already quite low, even a moderately elevated IOP during the first weeks of life might in some cases result in a significant reduction of the ocular perfusion pressure. The latter might play a contributory role in the development of retinopathy of prematurity by decreasing the blood supply to the peripheral retinal tissues.

An MTP inhibitor that normalizes atherogenic lipoprotein levels in WHHL rabbits

Patients with abetalipoproteinemia, a disease caused by defects in the microsomal triglyceride transfer protein (MTP), do not produce apolipoprotein B-containing lipoproteins. It was hypothesized that small molecule inhibitors of MTP would prevent the assembly and secretion of these atherogenic lipoproteins. To test this hypothesis, two compounds identified in a high-throughput screen for MTP inhibitors were used to direct the synthesis of a highly potent MTP inhibitor. This molecule (compound 9) inhibited the production of lipoprotein particles in rodent models and normalized plasma lipoprotein levels in Watanabe-heritable hyperlipidemic (WHHL) rabbits, which are a model for human homozygous familial hypercholesterolemia. These results suggest that compound 9, or derivatives thereof, has potential applications for the therapeutic lowering of atherogenic lipoprotein levels in humans.

Vulvar hemangiopericytoma. Case report

A rare case of a hemangiopericytoma of the vulva, observed in a 55-year old woman, is presented. So far, only six cases of this uncommon disease--which continues to be a source of uncertainty from both a prognostic and therapeutic point of view--have been reported. The case is described along with a review of international literature.

[Extension and features of parks and gardens around spas in Italy: explorative census; possible therapeutic usefulness II]

There are described the results of a census about parks and gardens own to 27 italian Spas. The considerable areas of green around Spas, the correct ratio whith the number of subjects in thermal treatment and other arguments represent favourable elements for italian medical Hydrology. In our census the found plants generally are in conformity with their correct geographical placing. Moreover they are in order to cause favourable effects for environmental Psychology and Therapeutics. The species of recommended plants for the increase and for improvement of green around italian Spas are mentioned. The importance of green around Spas in thermal Medicine and in Ecology is stressed.

[Characteristics of Italian thermal parks and gardens: explorative study; therapeutic possibilities. I]

There are reported the results of a research about thermal parks and thermal gardens own to 27 italian Spas. The considerable areas of green around Spas, the correct ratio with the number of subjects in thermal treatment and others arguments represent favourable elements for italian Medical Hydrology. The importance of green around Spas in Thermal Medicine and in Ecology il stressed.

An inhibitor of the microsomal triglyceride transfer protein inhibits apoB secretion from HepG2 cells

The microsomal triglyceride (TG) transfer protein (MTP) is a heterodimeric lipid transfer protein that catalyzes the transport of triglyceride, cholesteryl ester, and phosphatidylcholine between membranes. Previous studies showing that the proximal cause of abetalipoproteinemia is an absence of MTP indicate that MTP function is required for the assembly of the apolipoprotein B (apoB) containing plasma lipoproteins, i.e., very low density lipoproteins and chylomicrons. However, the precise role of MTP in lipoprotein assembly is not known. In this study, the role of MTP in lipoprotein assembly is investigated using an inhibitor of MTP-mediated lipid transport, 2-[1-(3, 3-diphenylpropyl)-4-piperidinyl]-2,3-dihydro-1H-isoindol-1-o ne (BMS-200150). The similarity of the IC50 for inhibition of bovine MTP-mediated TG transfer (0.6 microM) to the Kd for binding of BMS-200150 to bovine MTP (1.3 microM) strongly supports that the inhibition of TG transfer is the result of a direct effect of the compound on MTP. BMS-200150 also inhibits the transfer of phosphatidylcholine, however to a lesser extent (30% at a concentration that almost completely inhibits TG and cholesteryl ester transfer). When BMS-200150 is added to cultured HepG2 cells, a human liver-derived cell line that secretes apoB containing lipoproteins, it inhibits apoB secretion in a concentration dependent manner. These results support the hypothesis that transport of lipid, and in particular, the transport of neutral lipid by MTP, plays a critical role in the assembly of apoB containing lipoproteins.

Scleral buckling surgery in stage 4 retinopathy of prematurity

BACKGROUND

Technical advances in neonatal intensive care have significantly increased the number of very low birth-weight babies that survive the perinatal period. Some of these infants develop severe retinopathy of prematurity that may lead to retinal detachment.

METHODS

Between November 1988 and January 1994, 28 eyes from 15 preterm babies underwent scleral buckling for stage 4 retinopathy of prematurity at a mean age of 4.2 months. Cryotherapy was performed preoperatively on 12 eyes and intraoperatively in the remaining 16 eyes. The mean follow-up period was 35 months.

RESULTS

Scleral buckling produced retinal reattachment in 13 eyes (46.4%). Severe myopia (-5 D to -15 D) was found in all 13 of these eyes, 12 also presented convergent strabismus. Mean visual acuity, measured in 6 eyes from children over the age of 3 years was 20/40. In 7/28 eyes of the younger children of this group we found a fix and follow the light capability. No light perception was detected in 11/28 eyes; in the remaining 4/28 eyes there was only light perception. Scleral buckling failed to prevent the progression to stage 5 in 15 eyes (53.6%). Additional surgery was excluded for 9 of these eyes based on ultrasonography findings; the other 6 eyes underwent vitrectomy, which led to macular reattachment in 4 cases.

CONCLUSIONS

Clinical experience shows that scleral buckling is not always capable of preventing progression of the disease to stage 5. Furthermore, even when the anatomic results of this procedure are good, the functional outcome is often complicated by severe visual impairment.

[Thermal-spring parks within the ambit of protected areas: general trends in morphology and botany]

It is remembered that, in contemporary era, the thermal parks arose in U.S.A. and in Canada: they represent the first example of national parks in the world. Are described legislation, classifications and various types of protected areas. The species of recommended plants for the formation, increase and/or improvement of italian thermal are mentioned.

A 30-amino acid truncation of the microsomal triglyceride transfer protein large subunit disrupts its interaction with protein disulfide-isomerase and causes abetalipoproteinemia

The microsomal triglyceride transfer protein (MTP) is a heterodimer composed of the multifunctional enzyme, protein disulfide-isomerase, and a unique large, 97 kDa, subunit. It is found as a soluble protein within the lumen of the endoplasmic reticulum of liver and intestine and is required for the assembly of very low density lipoproteins and chylomicrons. Mutations in MTP which result in an absence of MTP function have been shown to cause abetalipoproteinemia. Here, the gene encoding the MTP 97-kDa subunit of an abetalipoproteinemic subject, which we have previously demonstrated lacks MTP activity and protein (Wetterau, J. R., Aggerbeck, L. P., Bouma, M.-E., Eisenberg, C., Munck, A., Hermier, M., Schmitz, J., Gay, G., Rader, D. J., and Gregg, R. E. (1992) Science 258, 999-1001), was isolated and sequenced. A nonsense mutation, which predicts the truncation of the protein by 30 amino acids, was identified. To investigate if this apparently subtle change in MTP could explain the observed absence of MTP, protein disulfide-isomerase was co-expressed with either the normal or mutant MTP 97-kDa subunit in Sf9 insect cells using a baculovirus expression system. Although there were high levels of expression of both the normal and mutant forms of the MTP 97-kDa subunit, only the normal subunit was able to form a stable, soluble complex with protein disulfide-isomerase. These results indicate that the carboxyl-terminal 30 amino acids of the MTP 97-kDa subunit plays an important role in its interaction with protein disulfide-isomerase.

Oxygen-induced retinopathy in the newborn rat: effects of hyperbarism and topical administration of timolol maleate

BACKGROUND

Lesions resembling those of human retinopathy of prematurity can be provoked in newborn Wistar rats by exposure to an FiO2 of 80% for the first 5 days of life followed by 5 days recovery under room-air conditions.

METHODS

We evaluated the effects of moderate hyperbarism (+60.75 kPa, i.e. 455 mmHg or 0.6 atm) and topical administration of 0.25% timolol maleate on oxygen-induced retinopathy (OIR) in this experimental model.

RESULTS

OIR (including neovascularization in most cases) was observed in 100% of the retinas of normobaric oxygen-reared ratlings that did not receive timolol. OIR was less frequent in oxygen-reared ratlings treated with hyperbarism (60%) or timolol (65%). Hyperbaric oxygen supplementation combined with timolol treatment during both the hyperoxic and room-air phases reduced the incidence of OIR to 30%. There was no sign of vasoproliferation in any of the retinas from the latter three groups.

CONCLUSIONS

The highly significant protective effects of hyperbarism and timolol observed in this study are not fully understood. We speculate that vasoconstriction induced by the hyperbarism reduces the amount of oxygen that reaches the retina from the choroid during O2 supplementation, while an increased ocular perfusion pressure caused by timolol-induced reduction of the intraocular pressure might decrease the stimulus to vasoproliferation that normally occurs with room-air recovery.